Information overload and data overload in lexicography

DEFF Research Database (Denmark)

Gouws, Rufus H.; Tarp, Sven

2017-01-01

the often uncritical inclusion of too much data. This paper discusses the general term information overload and its lexicographical counterpart data overload. Different types of data overload are identified and the problems users have when retrieving the necessary information from dictionary articles...

The ideal tensile strength and deformation behavior of a tungsten single crystal

International Nuclear Information System (INIS)

Liu Yuelin; Zhou Hongbo; Zhang Ying; Jin Shuo; Lu Guanghong

2009-01-01

We employ first-principles total energy method based on the density functional theory with the generalized gradient approximation to investigate the ideal tensile strengths of a bcc tungsten (W) single crystal systemically. The ideal tensile strengths are shown to be 29.1, 49.2 and 37.6 GPa for bcc W in the [0 0 1], [1 1 0] and [1 1 1] directions, respectively. The [0 0 1] direction is shown to be the weakest direction due to the occurrence of structure transition at the lower strain and the [1 1 0] direction is strongest. The results can provide a useful reference for W as a PFM in the nuclear fusion Tokamak.

Fatigue crack retardation of high strength steel in saltwater

International Nuclear Information System (INIS)

Tokaji, K.; Ando, Z.; Imai, T.; Kojima, T.

1983-01-01

A high strength steel was studied in 3 percent saltwater to investigate the effects of a corrosive environment and sheer thickness on fatigue crack propagation behavior following the application of a single tensile overload. Experiments were carried out under sinusoidally varying loads at a load ratio of 0 and frequency of 10 H /SUB z/ . A single tensile overload was found to cause delayed retardation, and the crack propagation rate at first increased, followed by fairly rapid decrease to a minimum value and then increased gradually to its steady-state value, just as it did in air. The overload affected zone size and the retardation cycles increased with decreasing sheet thickness, just as they did in air. However, the zone size and the cycles were larger in 3 percent saltwater than in air. Since the crack propagation rates through the overload affected zone were not affected by the test environment, the longer retardation cycles in 3 percent saltwater were attributed to an enlargement of the overload affected zone size. The crack propagation behavior following the application of a single tensile overload in 3 percent saltwater was well explained by the crack closure concept

Dynamic rock tensile strengths of Laurentian granite: Experimental observation and micromechanical model

Directory of Open Access Journals (Sweden)

Kaiwen Xia

2017-02-01

Full Text Available Tensile strength is an important material property for rocks. In applications where rocks are subjected to dynamic loads, the dynamic tensile strength is the controlling parameter. Similar to the study of static tensile strength, there are various methods proposed to measure the dynamic tensile strength of rocks. Here we examine dynamic tensile strength values of Laurentian granite (LG measured from three methods: dynamic direct tension, dynamic Brazilian disc (BD test, and dynamic semi-circular bending (SCB. We found that the dynamic tensile strength from direct tension has the lowest value, and the dynamic SCB gives the highest strength at a given loading rate. Because the dynamic direct tension measures the intrinsic rock tensile strength, it is thus necessary to reconcile the differences in strength values between the direct tension and the other two methods. We attribute the difference between the dynamic BD results and the direct tension results to the overload and internal friction in BD tests. The difference between the dynamic SCB results and the direct tension results can be understood by invoking the non-local failure theory. It is shown that, after appropriate corrections, the dynamic tensile strengths from the two other tests can be reduced to those from direct tension.

Work Overload.

Science.gov (United States)

Bateman, Thomas S.

1980-01-01

To investigate managerial use of work (or role) overload to increase productivity, the author studied 77 nonclerical white-collar employees and found that work overload had negative effects on productivity, supervisors' ratings, employee attitudes, job satisfaction, and health. He recommends ways for managers and employees to reduce work overload.…

High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

Science.gov (United States)

Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

2016-02-01

To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

The tensile properties of single sugar palm (Arenga pinnata) fibre

Science.gov (United States)

Bachtiar, D.; Sapuan, S. M.; Zainudin, E. S.; Khalina, A.; Dahlan, K. Z. M.

2010-05-01

This paper presents a brief description and characterization of the sugar palm fibres, still rare in the scientific community, compared to other natural fibres employed in polymeric composites. Sugar palm fibres are cellulose-based fibres extracted from the Arenga pinnata plant. The characterization consists of tensile test and the morphological examination. The average tensile properties results of fibres such as Young's modulus is equal to 3.69 GPa, tensile strength is equal to 190.29 MPa, and strain at failure is equal to 19.6%.

The tensile properties of single sugar palm (Arenga pinnata) fibre

International Nuclear Information System (INIS)

Bachtiar, D; Sapuan, S M; Zainudin, E S; Khalina, A; Dahlan, K Z M

2010-01-01

This paper presents a brief description and characterization of the sugar palm fibres, still rare in the scientific community, compared to other natural fibres employed in polymeric composites. Sugar palm fibres are cellulose-based fibres extracted from the Arenga pinnata plant. The characterization consists of tensile test and the morphological examination. The average tensile properties results of fibres such as Young's modulus is equal to 3.69 GPa, tensile strength is equal to 190.29 MPa, and strain at failure is equal to 19.6%.

Symmetrical and overloaded effect of diffusion in information filtering

Science.gov (United States)

Zhu, Xuzhen; Tian, Hui; Chen, Guilin; Cai, Shimin

2017-10-01

In physical dynamics, mass diffusion theory has been applied to design effective information filtering models on bipartite network. In previous works, researchers unilaterally believe objects' similarities are determined by single directional mass diffusion from the collected object to the uncollected, meanwhile, inadvertently ignore adverse influence of diffusion overload. It in some extent veils the essence of diffusion in physical dynamics and hurts the recommendation accuracy and diversity. After delicate investigation, we argue that symmetrical diffusion effectively discloses essence of mass diffusion, and high diffusion overload should be published. Accordingly, in this paper, we propose an symmetrical and overload penalized diffusion based model (SOPD), which shows excellent performances in extensive experiments on benchmark datasets Movielens and Netflix.

Neutron diffraction studies on lattice strain evolution around a crack-tip during tensile loading and unloading cycles

Energy Technology Data Exchange (ETDEWEB)

Sun Yinan [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States)]. E-mail: ysun1@utk.edu; Choo, Hahn [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Metals and Ceramics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Liaw, Peter K. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Lu Yulin [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Yang Bing [Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996 (United States); Brown, Donald W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Bourke, Mark A.M. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2005-10-15

Elastic lattice-strain profiles ahead of a fatigue-crack-tip were measured during tensile loading and unloading cycles using neutron diffraction. The crack-closure phenomenon after an overload was observed. Furthermore, the plastic-zone size in front of the crack-tip was estimated from the diffraction-peak broadening, which showed good agreement with the calculated result.

Effect of anabolic steroids on overloaded and overloaded suspended skeletal muscle

Science.gov (United States)

Tsika, R. W.; Herrick, R. E.; Baldwin, K. M.

1987-01-01

The effect of treatment with an anabolic steroid (nandrolone decanoate) on the muscle mass, the subcellular protein content, and the myosin patterns of normal overloaded and suspended overloaded plantaris muscle in female rat was investigated, dividing rats into six groups: normal control (NC), overload (OV), OV steroid (OV-S), normal suspended (N-sus), OV suspended (OV-sus), and OV suspended steroid (OV-sus-S). Relative to control values, overload produced a sparing effect on the muscle weight of the OV-sus group as well as increases of muscle weight of the OV group; increased protein content; and an increased expression of slow myosin in both OV and OV-sus groups. Steroid treatment of OV animals did not after the response of any parameter analyzed for the OV group, but in the OV-sus group steroid treatment induced increases in muscle weight and in protein content of the OV-sus-S group. The treatment did not alter the pattern of isomyosin expression observed in the OV or the OV-sus groups. These result suggest that the steroid acts synergistically with functional overload only under conditions in which the effect of overload is minimized by suspension.

Orientation correlation in tensile deformed [0 1 1] Cu single crystals

International Nuclear Information System (INIS)

Borbely, Andras; Szabo, Peter J.; Groma, Istvan

2005-01-01

Local crystallographic orientation of tensile deformed copper single crystals was investigated by the electron backscattering technique. Statistical evaluation of the data reveals the presence of an increased crystallographic correlation at the transition point between stages II and III of work-hardening. The transition state has the lowest probability of finding geometrically necessary dislocations in circular regions of radius smaller than 8 μm. According to the present results and other data showing that the relative fluctuation of the dislocation density has a maximum at the transition point, we conclude that the transition from stages II to III of work-hardening is similar to a second-order phase transformation of the statistical dislocation system

The association between role overload and women's mental health.

Science.gov (United States)

Glynn, Keva; Maclean, Heather; Forte, Tonia; Cohen, Marsha

2009-02-01

To determine the importance of role overload (the extent to which a person feels overwhelmed by her total responsibilities) relative to other known social determinants of women's mental health. A Canadian national, random sample, cross-sectional telephone survey in 2003 assessed the association among role overload, types and quality of roles (parent, employee, spouse), sociodemographics, and mental health (using the SF-12) using linear regression. Analysis included 716 women aged 25-54 who indicated that their youngest child living in the household was aged < or =17 years. Perceptions of greater role overload were associated with poorer mental health (p < 0.0001). Women working <35 hours per week (p = 0.04) or 35-40 hours per week (p 5 0.002) reported better mental health than nonemployed women, as did women with the highest annual household income ($70,000+)(p = 0.001). Also associated with better mental health were higher marital status quality scores for both married and single women (p < 0.001), higher job quality scores among employed women (p = 0.02), greater homemaking quality scores among unemployed women (p = 0.03), and women reporting high parental quality (p = 0.04) Role overload showed a stronger relationship to mental health than other sociodemographic variables, including income. Our findings indicate the importance of measuring women's experience of their multiple roles rather than focusing on single roles. More research is warranted on the totality of women's experiences of their many social role obligations.

Hepatic iron overload: Quantitative MR imaging

International Nuclear Information System (INIS)

Gomori, J.M.; Horev, G.; Tamary, H.; Zandback, J.; Kornreich, L.; Zaizov, R.; Freud, E.; Krief, O.; Ben-Meir, J.; Rotem, H.

1991-01-01

Iron deposits demonstrate characteristically shortened T2 relaxation times. Several previously published studies reported poor correlation between the in vivo hepatic 1/T2 measurements made by means of midfield magnetic resonance (MR) units and the hepatic iron content of iron-overloaded patients. In this study, the authors assessed the use of in vivo 1/T2 measurements obtained by means of MR imaging at 0.5 T using short echo times (13.4 and 30 msec) and single-echo-sequences as well as computed tomographic (CT) attenuation as a measure of liver iron concentration in 10 severely iron-overloaded patients with beta-thalassemia major. The iron concentrations in surgical wedge biopsy samples of the liver, which varied between 3 and 9 mg/g of wet weight (normal, less than or equal to 0.5 mg/g), correlated well (r = .93, P less than or equal to .0001) with the preoperative in vivo hepatic 1/T2 measurements. The CT attenuation did not correlate with liver iron concentration. Quantitative MR imaging is a readily available noninvasive method for the assessment of hepatic iron concentration in iron-overloaded patients, reducing the need for needle biopsies of the liver

An Improved Overloading Scheme for Downlink CDMA

Directory of Open Access Journals (Sweden)

Marc Moeneclaey

2005-04-01

Full Text Available An improved overloading scheme is presented for single-user detection in the downlink of multiple-access systems based on OCDMA/OCDMA (O/O. By displacing in time the orthogonal signatures of the two user sets that make up the overloaded system, the cross-correlation between the users of the two sets is reduced. For random O/O with square-root cosine rolloff chip pulses, the multiuser interference can be decreased by up to 50% (depending on the chip pulse bandwidth as compared to quasiorthogonal sequences (QOS that are presently part of the downlink standard of Cdma2000. This reduction of the multiuser interference gives rise to an increase of the achievable signal-to-interference-plus-noise ratio for a particular channel load.

Temperature and Pressure Dependences of the Elastic Properties of Tantalum Single Crystals Under Tensile Loading: A Molecular Dynamics Study

Science.gov (United States)

Li, Wei-bing; Li, Kang; Fan, Kan-qi; Zhang, Da-xing; Wang, Wei-dong

2018-04-01

Atomistic simulations are capable of providing insights into physical mechanisms responsible for mechanical properties of the transition metal of Tantalum (Ta). By using molecular dynamics (MD) method, temperature and pressure dependences of the elastic properties of Ta single crystals are investigated through tensile loading. First of all, a comparative study between two types of embedded-atom method (EAM) potentials is made in term of the elastic properties of Ta single crystals. The results show that Ravelo-EAM (Physical Review B, 2013, 88: 134101) potential behaves well at different hydrostatic pressures. Then, the MD simulation results based on the Ravelo-EAM potential show that Ta will experience a body-centered-cubic (BCC) to face-centered-cubic (FCC) phase transition before fracture under tensile loading at 1 K temperature, and model size and strain rate have no obvious effects on tensile behaviors of Ta. Next, from the simulation results at the system temperature from 1 to 1500 K, it can be derived that the elastic modulus of E 100 linearly decrease with the increasing temperature, while the yielding stress decrease with conforming a quadratic polynomial formula. Finally, the pressure dependence of the elastic properties is performed from 0 to 140 GPa and the observations show that the elastic modulus increases with the increasing pressure overall.

Quantification of liver fat in the presence of iron overload.

Science.gov (United States)

Horng, Debra E; Hernando, Diego; Reeder, Scott B

2017-02-01

To evaluate the accuracy of R2* models (1/T 2 * = R2*) for chemical shift-encoded magnetic resonance imaging (CSE-MRI)-based proton density fat-fraction (PDFF) quantification in patients with fatty liver and iron overload, using MR spectroscopy (MRS) as the reference standard. Two Monte Carlo simulations were implemented to compare the root-mean-squared-error (RMSE) performance of single-R2* and dual-R2* correction in a theoretical liver environment with high iron. Fatty liver was defined as hepatic PDFF >5.6% based on MRS; only subjects with fatty liver were considered for analyses involving fat. From a group of 40 patients with known/suspected iron overload, nine patients were identified at 1.5T, and 13 at 3.0T with fatty liver. MRS linewidth measurements were used to estimate R2* values for water and fat peaks. PDFF was measured from CSE-MRI data using single-R2* and dual-R2* correction with magnitude and complex fitting. Spectroscopy-based R2* analysis demonstrated that the R2* of water and fat remain close in value, both increasing as iron overload increases: linear regression between R2* W and R2* F resulted in slope = 0.95 [0.79-1.12] (95% limits of agreement) at 1.5T and slope = 0.76 [0.49-1.03] at 3.0T. MRI-PDFF using dual-R2* correction had severe artifacts. MRI-PDFF using single-R2* correction had good agreement with MRS-PDFF: Bland-Altman analysis resulted in -0.7% (bias) ± 2.9% (95% limits of agreement) for magnitude-fit and -1.3% ± 4.3% for complex-fit at 1.5T, and -1.5% ± 8.4% for magnitude-fit and -2.2% ± 9.6% for complex-fit at 3.0T. Single-R2* modeling enables accurate PDFF quantification, even in patients with iron overload. 1 J. Magn. Reson. Imaging 2017;45:428-439. © 2016 International Society for Magnetic Resonance in Medicine.

Effect of tensile mean stress on fatigue behavior of single-crystal and directionally solidified superalloys

Science.gov (United States)

Kalluri, Sreeramesh; Mcgaw, Michael A.

1990-01-01

Two nickel base superalloys, single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf, were studied in view of the potential usage of the former and usage of the latter as blade materials for the turbomachinery of the space shuttle main engine. The baseline zero mean stress (ZMS) fatigue life (FL) behavior of these superalloys was established, and then the effect of tensile mean stress (TMS) on their FL behavior was characterized. At room temperature these superalloys have lower ductilities and higher strengths than most polycrystalline engineering alloys. The cycle stress-strain response was thus nominally elastic in most of the fatigue tests. Therefore, a stress range based FL prediction approach was used to characterize both the ZMS and TMS fatigue data. In the past, several researchers have developed methods to account for the detrimental effect of tensile mean stress on the FL for polycrystalline engineering alloys. However, the applicability of these methods to single crystal and directionally solidified superalloys has not been established. In this study, these methods were applied to characterize the TMS fatigue data of single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf and were found to be unsatisfactory. Therefore, a method of accounting for the TMS effect on FL, that is based on a technique proposed by Heidmann and Manson was developed to characterize the TMS fatigue data of these superalloys. Details of this method and its relationship to the conventionally used mean stress methods in FL prediction are discussed.

Magnetic resonance imaging of splenic iron overload

International Nuclear Information System (INIS)

Arrive, L.; Thurnher, S.; Hricak, H.; Price, D.C.

1990-01-01

The value of magnetic resonance (MR) imaging in assessing iron overload in the spleen was retrospectively investigated in 40 consecutive patients. MR appearance, mesaure of signal intensity and T1-and T2-relaxation times were correlated with the histologically determined level of iron in the spleen in each patient. Histologic examination revealed no iron overload in 19 patients, mild iron overload in seven, moderate iron overload in six, and severe iron overload in eight. All 19 patients with no splenic iron overload and 11 of the other 21 patients with splenic iron overload were correctly identified by MR imaging (sensitivity 52%, specificity 100%, accuracy 75%). Splenic iron overload was diagnosed when a decrease of signal intensity of the spleen compared with those of adipose tissue and renal cortex was demonstrated. MR images demonstrated all eight cases of severe, three of the six cases of moderate, and none of the seven cases of mild iron overload. Only spleens with severe iron overload had a significant mean decrease in signal intensity and T1- and T2-relaxation times. Although specific, MR imaging is poorly sensitive to splenic iron overload. (author). 15 refs.; 5 figs.; 3 tabs

Tensile Properties of Single Jersey and 1×1 Rib Knitted Fabrics Made from 100% Cotton and Cotton/Lycra Yarns

Directory of Open Access Journals (Sweden)

Dereje Berihun Sitotaw

2017-01-01

Full Text Available The tensile properties such as tensile strength which is measured as breaking force in Newton (N and elongation percent (% at break of single jersey and 1×1 rib (knitted with full needles knitted fabrics made from 100% cotton and cotton/Lycra yarns (5% Lycra yarn content in 95% combed cotton yarn are investigated in this research. The sample fabrics are conditioned for 24 hours at 20±1°C temperature and 65±2% relative humidity before testing. Ten specimens (five for lengthwise and five for widthwise have been taken from each of the two knitted structures, those made from 100% cotton and cotton/Lycra (at 95/5 percent ratio blend yarns. According to the discussion and as found from the investigations, the tensile properties of single jersey and 1×1 rib knitted fabrics made from 100% cotton and cotton/Lycra yarns are significantly different from each other and both of the knitted fabrics have high elongation percent at break with cotton/Lycra blend yarns as compared to 100% cotton yarn. Knitted fabrics made from cotton/Lycra blended yarn have low breaking force and high elongation percent at break relative to knitted fabrics made from 100% cotton yarns.

Effect of substrate bias voltage on tensile properties of single crystal silicon microstructure fully coated with plasma CVD diamond-like carbon film

Science.gov (United States)

Zhang, Wenlei; Hirai, Yoshikazu; Tsuchiya, Toshiyuki; Tabata, Osamu

2018-06-01

Tensile strength and strength distribution in a microstructure of single crystal silicon (SCS) were improved significantly by coating the surface with a diamond-like carbon (DLC) film. To explore the influence of coating parameters and the mechanism of film fracture, SCS microstructure surfaces (120 × 4 × 5 μm3) were fully coated by plasma enhanced chemical vapor deposition (PECVD) of a DLC at five different bias voltages. After the depositions, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal desorption spectrometry (TDS), surface profilometry, atomic force microscope (AFM) measurement, and nanoindentation methods were used to study the chemical and mechanical properties of the deposited DLC films. Tensile test indicated that the average strength of coated samples was 13.2-29.6% higher than that of the SCS sample, and samples fabricated with a -400 V bias voltage were strongest. The fracture toughness of the DLC film was the dominant factor in the observed tensile strength. Deviations in strength were reduced with increasingly negative bias voltage. The effect of residual stress on the tensile properties is discussed in detail.

Effect of laser shock on tensile deformation behavior of a single crystal nickel-base superalloy

International Nuclear Information System (INIS)

Lu, G.X.; Liu, J.D.; Qiao, H.C.; Zhou, Y.Z.; Jin, T.; Zhao, J.B.; Sun, X.F.; Hu, Z.Q.

2017-01-01

This investigation focused on the tensile deformation behavior of a single crystal nickel-base superalloy, both in virgin condition and after laser shock processing (LSP) with varied technology parameters. Nanoindention tests were carried out on the sectioned specimens after LSP treatment to characterize the surface strengthening effect. Stress strain curves of tensile specimens were analyzed, and microstructural observations of the fracture surface and the longitudinal cross-sections of ruptured specimens were performed via scanning electron microscope (SEM), in an effort to clarify the fracture mechanisms. The results show that a surface hardening layer with the thickness of about 0.3–0.6 mm was gained by the experimental alloys after LSP treatment, but the formation of surface hardening layer had not affected the yield strength. Furthermore, fundamental differences in the plastic responses at different temperatures due to LSP treatment had been discovered. At 700 °C, the slip deformation was held back when it extended to the surface hardening layer and the ensuing slip steps improved the plasticity; however, at 1000 °C, surface hardening layer hindered the macro necking, which resulted in the relatively lower plasticity.

Effect of laser shock on tensile deformation behavior of a single crystal nickel-base superalloy

Energy Technology Data Exchange (ETDEWEB)

Lu, G.X. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Liu, J.D., E-mail: jdliu@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Qiao, H.C. [Shenyang Institute of Automation, Chinese Academy of Sciences, 114 Nanta Road, Shenyang 110016 (China); Zhou, Y.Z. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Jin, T., E-mail: tjin@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Zhao, J.B. [Shenyang Institute of Automation, Chinese Academy of Sciences, 114 Nanta Road, Shenyang 110016 (China); Sun, X.F.; Hu, Z.Q. [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

2017-02-16

This investigation focused on the tensile deformation behavior of a single crystal nickel-base superalloy, both in virgin condition and after laser shock processing (LSP) with varied technology parameters. Nanoindention tests were carried out on the sectioned specimens after LSP treatment to characterize the surface strengthening effect. Stress strain curves of tensile specimens were analyzed, and microstructural observations of the fracture surface and the longitudinal cross-sections of ruptured specimens were performed via scanning electron microscope (SEM), in an effort to clarify the fracture mechanisms. The results show that a surface hardening layer with the thickness of about 0.3–0.6 mm was gained by the experimental alloys after LSP treatment, but the formation of surface hardening layer had not affected the yield strength. Furthermore, fundamental differences in the plastic responses at different temperatures due to LSP treatment had been discovered. At 700 °C, the slip deformation was held back when it extended to the surface hardening layer and the ensuing slip steps improved the plasticity; however, at 1000 °C, surface hardening layer hindered the macro necking, which resulted in the relatively lower plasticity.

Resilience of electricity grids against transmission line overloads under wind power injection at different nodes.

Science.gov (United States)

Schiel, Christoph; Lind, Pedro G; Maass, Philipp

2017-09-14

A steadily increasing fraction of renewable energy sources for electricity production requires a better understanding of how stochastic power generation affects the stability of electricity grids. Here, we assess the resilience of an IEEE test grid against single transmission line overloads under wind power injection based on the dc power flow equations and a quasi-static grid response to wind fluctuations. Thereby we focus on the mutual influence of wind power generation at different nodes. We find that overload probabilities vary strongly between different pairs of nodes and become highly affected by spatial correlations of wind fluctuations. An unexpected behaviour is uncovered: for a large number of node pairs, increasing wind power injection at one node can increase the power threshold at the other node with respect to line overloads in the grid. We find that this seemingly paradoxical behaviour is related to the topological distance of the overloaded line from the shortest path connecting the wind nodes. In the considered test grid, it occurs for all node pairs, where the overloaded line belongs to the shortest path.

Crack growth retardation due to micro-roughness: a mechanism for overload effects in fatigue

International Nuclear Information System (INIS)

Suresh, S.

1982-01-01

A new mechanism for fatigue crack growth retardation following an overload is presented in this paper, based on a micro-roughness model. It is reasoned, with the aid of extensive experimental evidence available in the literature, that retardation following an overload is governed by the micromechanisms of near-threshold crack growth. This model is found to rationalize a number of hitherto unexplained experimental observations. Moreover, the present arguments, which suggest that plasticity-induced crack closure is not likely to be the primary mechanism for retardation following single overloads, do not exclude the role of residual stresses or blunting, but provide further mechanistic basis to account for the inconsistencies in the previous models. Additional sources of prolonged retardation, in terms of crack closure due to corrosion debris formed in moist environments, are suggested. It is pointed out that such environmental effects could play an important role in post-overload crack growth in certain alloy systems

Oligofructose overload induces lameness in cattle.

Science.gov (United States)

Danscher, A M; Enemark, J M D; Telezhenko, E; Capion, N; Ekstrøm, C T; Thoefner, M B

2009-02-01

The aim was to describe the clinical orthopedic implications of oligofructose overload. A group of 8 nonpregnant dairy heifers were given an oral dose of oligofructose (17 g/kg of body weight). At predefined times during a period spanning 3 d before and 9 d after oligofructose overload, the heifers underwent a clinical examination including locomotion scoring, hoof-testing, and palpation of tarso-crural joints, as well as the collection of blood and ruminal fluid samples. Locomotion sessions were videotaped; subsequently, locomotion was blind-scored. Locomotion scores increased after oligofructose overload and declined toward the end of the study period. The greatest locomotion scores were recorded on d 3 to 5 (60 to 120 h) where 12 of 42 (29%) locomotion scores were 3 and 13 of 42 (32%) were score 2. Positive reactions to hoof-testing were observed from 30 h after oligofructose overload and reached a maximum on d 7 and 9 where 12 of 28 (43%) reactions were marked positive. Distension of the tarso-crural joints was observed from 24 h after oligofructose overload, with maximum distension being observed on d 2, in which 44 of 56 (79%) of observed joints were either moderately or severely distended. The heifers developed classic signs of acute ruminal and systemic acidosis after the oligofructose overload (ruminal pH 4.3 +/- 0.07, standard base excess -10.8 +/- 2.3 at 18 h). With few exceptions, clinical and laboratory variables returned to normal within 9 d of oligofructose overload. But, good body condition and previous feeding with grass apparently predisposed the heifers to more severe systemic affection. Oligofructose overload in dairy heifers induced ruminal and systemic acidosis, diarrhea, dehydration, and, subsequently, lameness, claw pain, and joint effusion, collectively interpreted as signs of acute laminitis. Oligofructose overload at 17 g/kg of body weight represented a relatively mild laminitis model in cattle, as demonstrated by a reasonably quick

Physical activity behavior and role overload in mothers.

Science.gov (United States)

Lovell, Geoff P; Butler, Frances R

2015-01-01

We examined physical activity stages of change, physical activity behavior, and role overload in different stages of motherhood in a predominantly Australian sample. Neither physical activity behavior, stages of physical activity change, nor role overload significantly differed across motherhood groups. Role overload was significantly higher for mothers in the contemplation, planning, and action stages of physical activity than in the maintenance stage of change. Role overload had a weak, although significant, negative correlation with leisure-time physical activity. We conclude that strategies focused upon reducing role overload or perceived role overload have only limited potential to meaningfully increase leisure-time physical activity in mothers.

Polysynovitis after oligofructose overload in dairy cattle.

Science.gov (United States)

Danscher, A M; Enemark, H L; Andersen, P H; Aalbaek, B; Nielsen, O L

2010-01-01

Acute bovine laminitis is a systemic disease with local manifestations primarily affecting the claws. However, distension of the tarsocrural joints has been observed after experimental oligofructose overload in dairy heifers as a part of the complex interpreted as acute, clinical laminitis. Therefore, the aim of the present study was to study bovine synovial joints and tendon sheaths after oligofructose overload. Ten dairy heifers received oral oligofructose overload (17 g/kg body weight); four were killed 24h after overload and six after 72 h. Six control heifers received tap water and were killed after 72 or 96 h. Clinical examination included locomotion scoring and palpation of the tarsocrural joints. Ruminal fluid and blood was collected for measurements of pH and hydration status. Total protein concentrations and white blood cell (WBC) counts were determined in synovial fluid collected from tarsocrural joints after death. Synovial joints and tendon sheaths were examined and synovial membranes were studied microscopically. Swabs taken from the synovial cavities were subject to bacteriological culture. Heifers with oligofructose overload developed signs of ruminal and systemic acidosis. Lameness was observed in three of ten heifers 24h after overload and in all remaining heifers after 72 h. Distension of tarsocrural joints was observed from 18 h after overload and peaked at 30 h when all examined joints were moderately or severely distended. The synovial fluid was turbid and protein content and WBC counts were increased at both 24 and 72 h compared with controls. Bacterial culture was negative. Synovial membranes 24 and 72 h after overload had a fibrinous and neutrophil inflammatory reaction that regressed in severity between 24 and 72 h after overload. Heifers subjected to oligofructose overload therefore developed generalized sterile neutrophilic polysynovitis. Focus on this aspect of bovine laminitis may shed new light on the pathogenesis of this complex

An overload behavior detection system for engineering transport vehicles based on deep learning

Science.gov (United States)

Zhou, Libo; Wu, Gang

2018-04-01

This paper builds an overloaded truck detect system called ITMD to help traffic department automatically identify the engineering transport vehicles (commonly known as `dirt truck') in CCTV and determine whether the truck is overloaded or not. We build the ITMD system based on the Single Shot MultiBox Detector (SSD) model. By constructing the image dataset of the truck and adjusting hyper-parameters of the original SSD neural network, we successfully trained a basic network model which the ITMD system depends on. The basic ITMD system achieves 83.01% mAP on classifying overload/non-overload truck, which is a not bad result. Still, some shortcomings of basic ITMD system have been targeted to enhance: it is easy for the ITMD system to misclassify other similar vehicle as truck. In response to this problem, we optimized the basic ITMD system, which effectively reduced basic model's false recognition rate. The optimized ITMD system achieved 86.18% mAP on the test set, which is better than the 83.01% mAP of the basic ITMD system.

Sensory overload: A concept analysis.

Science.gov (United States)

Scheydt, Stefan; Müller Staub, Maria; Frauenfelder, Fritz; Nielsen, Gunnar H; Behrens, Johann; Needham, Ian

2017-04-01

In the context of mental disorders sensory overload is a widely described phenomenon used in conjunction with psychiatric interventions such as removal from stimuli. However, the theoretical foundation of sensory overload as addressed in the literature can be described as insufficient and fragmentary. To date, the concept of sensory overload has not yet been sufficiently specified or analyzed. The aim of the study was to analyze the concept of sensory overload in mental health care. A literature search was undertaken using specific electronic databases, specific journals and websites, hand searches, specific library catalogues, and electronic publishing databases. Walker and Avant's method of concept analysis was used to analyze the sources included in the analysis. All aspects of the method of Walker and Avant were covered in this concept analysis. The conceptual understanding has become more focused, the defining attributes, influencing factors and consequences are described and empirical referents identified. The concept analysis is a first step in the development of a middle-range descriptive theory of sensory overload based on social scientific and stress-theoretical approaches. This specification may serve as a fundament for further research, for the development of a nursing diagnosis or for guidelines. © 2017 Australian College of Mental Health Nurses Inc.

Effect of holes on the room temperature tensile behaviors of thin wall specimens with (210) side surface of Ni-base single crystal superalloy

Energy Technology Data Exchange (ETDEWEB)

Zhou, Z.J.; Liu, T.; Pu, S. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Xu, H. [Materials Fatigue and Fracture Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Wang, L., E-mail: wangli@imr.ac.cn [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China); Lou, L.H. [Superalloys Division, Institute of Metal Research, Chinese Academy of Sciences, No. 72, Wenhua Road, Shenyang 110016 (China)

2015-10-25

Tensile properties of Ni-base single crystal superalloy plate specimens with and without a hole at room temperature were studied in the present paper. During the testing process, an ARAMIS system based on the digital image correlation technique and in-situ scanning electron microscopy were employed to in-situ observe the strain distribution and slip traces development on the sample surfaces. It was demonstrated that the yield stress was decreased with the appearance of a hole due to the stress concentration. The results were analyzed based on the stress and strain states of specimens and the slip traces development observed on specimen surfaces. - Graphical abstract: The strain distribution for samples without and with a hole, respectively. - Highlights: • Tensile tests of plate specimens without and with a hole were performed. • Surface strain fields were in-situ observed by ARAMIS system. • Slip traces development on sample surfaces was in-situ observed by SEM. • The hole deteriorated both the tensile strength and elongation of the samples. • Tensile strength of specimens without and with a hole was discussed respectively.

Tensile testing

CERN Document Server

2004-01-01

A complete guide to the uniaxial tensile test, the cornerstone test for determining the mechanical properties of materials: Learn ways to predict material behavior through tensile testing. Learn how to test metals, alloys, composites, ceramics, and plastics to determine strength, ductility and elastic/plastic deformation. A must for laboratory managers, technicians, materials and design engineers, and students involved with uniaxial tensile testing. Tensile Testing , Second Edition begins with an introduction and overview of the test, with clear explanations of how materials properties are determined from test results. Subsequent sections illustrate how knowledge gained through tensile tests, such as tension properties to predict the behavior (including strength, ductility, elastic or plastic deformation, tensile and yield strengths) have resulted in improvements in materals applications. The Second Edition is completely revised and updated. It includes expanded coverage throughout the volume on a variety of ...

Overload protection system for power inverter

Science.gov (United States)

Nagano, S. (Inventor)

1977-01-01

An overload protection system for a power inverter utilized a first circuit for monitoring current to the load from the power inverter to detect an overload and a control circuit to shut off the power inverter, when an overload condition was detected. At the same time, a monitoring current inverter was turned on to deliver current to the load at a very low power level. A second circuit monitored current to the load, from the monitoring current inverter, to hold the power inverter off through the control circuit, until the overload condition was cleared so that the control circuit may be deactivated in order for the power inverter to be restored after the monitoring current inverter is turned off completely.

Molecular Dynamics Simulations of Tensile Behavior of Copper

OpenAIRE

Sainath, G.; Srinivasan, V. S.; Choudhary, B. K.; Mathew, M. D.; Jayakumar, T.

2014-01-01

Molecular dynamics simulations on tensile deformation of initially defect free single crystal copper nanowire oriented in {100} has been carried out at 10 K under adiabatic and isothermal loading conditions. The tensile behaviour was characterized by sharp rise in stress in elastic regime followed by sudden drop at the point of dislocation nucleation. The important finding is that the variation in dislocation density is correlated with the observed stress-strain response. Several interesting ...

Microstructure evolution of a pre-compression nickel-base single crystal superalloy during tensile creep

International Nuclear Information System (INIS)

Yu Xingfu; Tian Sugui; Du Hongqiang; Yu Huichen; Wang Minggang; Shang Lijuan; Cui Shusen

2009-01-01

By pre-compressive creep treatment, the cubical γ' phase in the nickel-base single crystal superalloy is transformed into the P-type rafted structure along the direction parallel to the applied stress axis. And the microstructure evolution of the P-type γ' rafted alloy during tensile creep is investigated by means of the measurement of the creep curve and microstructure observation. Results show that the P-type γ' rafted phase in the alloy is transformed into the N-type structure along the direction perpendicular to the applied stress axis in the initial stage of the tensile creep. In the role of the tensile stress at high temperature, the change of the element's equilibrium concentration in the different regions of P-type γ' rafted phase occurs, which promotes the inhomogeneous coarsening of the P-type γ' phase. And then, the decomposition of the P-type γ' rafted phase in the alloy occurs to form the groove structure. As of result of the directional diffusion of the elements, the fact that the P-type γ' rafted phase is decomposed to transform into the cubical-like structure is attributed to the increment of the solute elements M(Ta, Al) chemical potential in the groove regions. Further, the lattice constriction in the horizontal interfaces of the cubical-like γ' phase may repel out the Al and Ta atoms with higher radius due to the role of the shearing stress, and the lattice expanding in the upright interfaces of the cubical-like γ' phase, due to the role of the tension stress, may trap the Ta and Al atoms, which promotes the directional growing of γ' phase into the N-type rafted structure. Therefore, the change of the strain energy density in different interfaces of the cubical-like γ' phase is thought to be the driving force of the elements diffusing and the directional coarsening of γ' phase

Stress transfer in microdroplet tensile test: PVC-coated and uncoated Kevlar-29 single fiber

Science.gov (United States)

Zhenkun, Lei; Quan, Wang; Yilan, Kang; Wei, Qiu; Xuemin, Pan

2010-11-01

The single fiber/microdroplet tensile test is applied for evaluating the interfacial mechanics between a fiber and a resin substrate. It is used to investigate the influence of a polymer coating on a Kevlar-29 fiber surface, specifically the stress transfer between the fiber and epoxy resin in a microdroplet. Unlike usual tests, this new test ensures a symmetrical axial stress on the embedded fiber and reduces the stress singularity that appears at the embedded fiber entry. Using a homemade loading device, symmetrical tensile tests are performed on a Kevlar-29 fiber with or without polyvinylchloride (PVC) coating, the surface of which is in contact with two epoxy resin microdroplets during curing. Raman spectra on the embedded fiber are recorded by micro-Raman Spectroscopy under different strain levels. Then they are transformed to the distributions of fiber axis stress based on the relationship between stress and Raman shift. The Raman results reveal that the fiber axial stresses increase with the applied loads, and the antisymmetric interfacial shear stresses, obtained by a straightforward balance of shear-to-axial forces argument, lead to the appearance of shear stress concentrations at a distance to the embedded fiber entry. The load is transferred from the outer fiber to the embedded fiber in the epoxy microdroplet. As is observed by scanning electronic microscopy (SEM), the existence of a flexible polymer coating on the fiber surface reduces the stress transfer efficiency.

The tensile strength of mechanical joint prototype of lontar fiber composite

Science.gov (United States)

Bale, Jefri; Adoe, Dominggus G. H.; Boimau, Kristomus; Sakera, Thomas

2018-03-01

In the present study, an experimental activity has been programmed to investigate the effect of joint prototype configuration on tensile strength of lontar (Borassus Flabellifer) fiber composite. To do so, a series of tests were conducted to establish the tensile strength of different joint prototype configuration specimen of lontar fiber composite. In addition, post observation of macroscope was used to map damage behavior. The analysis of lontar fiber composite is a challenge since the material has limited information than others natural fiber composites materials. The results shown that, under static tensile loading, the tensile strength of 13 MPa produced by single lap joint of lontar fiber composite is highest compare to 11 MPa of tensile strength generated by step lap joint and double lap joint where produced the lowest tensile strength of 6 MPa. It is concluded that the differences of tensile strength depend on the geometric dimensions of the cross-sectional area and stress distribution of each joint prototype configuration.

Differential requirement for satellite cells during overload-induced muscle hypertrophy in growing versus mature mice.

Science.gov (United States)

Murach, Kevin A; White, Sarah H; Wen, Yuan; Ho, Angel; Dupont-Versteegden, Esther E; McCarthy, John J; Peterson, Charlotte A

2017-07-10

Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age. Pax7 CreER -R26R DTA mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day synergist ablation overload of the plantaris (n = 6-9 per group). The surgical approach minimized regeneration, de novo fiber formation, and fiber splitting while promoting muscle fiber growth. Satellite cell density (Pax7+ cells/fiber), embryonic myosin heavy chain expression (eMyHC), and muscle fiber cross sectional area (CSA) were evaluated via immunohistochemistry. Myonuclei (myonuclei/100 mm) were counted on isolated single muscle fibers. Tamoxifen treatment depleted satellite cells by ≥90% and prevented myonuclear accretion with overload in young and mature mice (p overload. Average muscle fiber CSA increased ~20% in young SC+ (p = 0.07), mature SC+ (p overload (p overload-induced hypertrophy is dependent on maturational age, and global responses to overload differ in young versus mature mice.

EFFECT OF STRAIN HARDENING ON FATIGUE CRACK CLOSURE IN ALUMINUM ALLOY UNDER CONSTANT AMPLITUDE WITH SINGLE OVERLOAD

Directory of Open Access Journals (Sweden)

Nirpesh Vikram

2015-12-01

Full Text Available In this study effect of strain hardening on crack closure has been examined with the help of experiments and finite element method on the side edge notched specimen of five different Aluminum alloy (3003 Al, 5052 Al, 6061 T6, 6063 T6, 6351 in mode I under constant amplitude fatigue loading with single overload using Abaqus® 6.10 which is very well accepted FEM application in research. Extended Finite Element Method Module has been used to determine effective stress intensity factor at the crack tip while propagation takes place. FEM results have given good agreement with experimental results. Regression analysis has also been done with SPSS® 16 and dependency of strain hardening coefficient on crack closure has analyzed. A generalized empirical formula has been developed based on strain hardening to calculate effective stress intensity range ratio and a modified Paris law has also been formulated for these aluminum alloy.

Application of Chaos Theory in Trucks' Overloading Enforcement

Directory of Open Access Journals (Sweden)

Abbas Mahmoudabadi

2013-01-01

Full Text Available Trucks' overloading is considered as one of the most substantial concerns in road transport due to a possible road surface damage, as well as, are less reliable performance of trucks' braking system. Sufficient human resource and adequate time scheduling are to be planned for surveying trucks' overloading; hence, it seems required to prepare an all-around model to be able to predict the number of overloaded vehicles. In the present research work, the concept of chaos theory has been utilized to predict the ratio of trucks which might be guessed overloaded. The largest Lyapunov exponent is utilized to determine the presence of chaos using experimental data and concluded that the ratio of overloaded trucks reflects chaotic behavior. The prediction based on chaos theory is compared with the results of simple smoothing and moving average methods according to the well-known criterion of mean square errors. The results have also revealed that the chaotic prediction model would act more capably comparing the analogous methods including simple smoothing and moving average to predict the ratio of passing trucks to be possibly overloaded.

Uncoupling and oxidative stress in liver mitochondria isolated from rats with acute iron overload

Energy Technology Data Exchange (ETDEWEB)

Pardo Andreu, G.L. [Centro de Quimica Farmaceutica, Departamento de Investigaciones Biomedicas, Ciudad de La Habana (Cuba); Inada, N.M.; Vercesi, A.E. [Universidade Estadual de Campinas, Departamento de Patologia Clinica, Faculdade de Ciencias Medicas, Campinas, SP (Brazil); Curti, C. [Universidade de Sao Paulo, Departamento de Fisica e Quimica, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, SP (Brazil)

2009-01-15

One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21{+-}4 to 130{+-}7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H{sup +} leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria. (orig.)

Fatigue History and in-situ Loading Studies of the overload Effect Using High Resolution X-ray Strain Profiling

International Nuclear Information System (INIS)

Croft, M.; Jisrawi, N.; Zhong, Z.; Holtz, R.; Sadananda, K.; Skaritka, J.; Tsakalakos, T.

2007-01-01

High-energy synchrotron X-ray diffraction experiments are used to perform local crack plane strain profiling of 4140 steel compact tension specimens fatigued at constant amplitude, subjected to a single overload cycle, then fatigued some more at constant amplitude. X-ray strain profiling results on a series of samples employing in-situ load cycling are correlated with the crack growth rate (da/dN) providing insight into the da/dN retardation known as the 'overload effect'. Immediately after the overload, the strain under maximum load is greatly reduced but the range of strain, between zero and maximum load, remains unchanged compared to the pre-overload values. At the point of maximum retardation, it is the strain range that is greatly reduced while the maximum-load strain has begun to recover to the pre-overload value. For a sample that has recovered to approximately half of the original da/dN value following the overload, the strain at maximum load is fully recovered while the strain range, though partially recovered, is still substantially reduced. The dominance of the strain range in the overload effect is clearly indicated. Subject to some assumptions, strong quantitative support for a crack growth rate driving force of the suggested form [(K max ) -p (ΔK) p ] γ is found. A dramatic nonlinear load dependence in the spatial distribution of the strain at maximum retardation is also demonstrated: at low load the response is dominantly at the overload position; whereas at high loads it is dominantly at the crack tip position. This transfer of load response away from the crack tip to the overload position appears fundamental to the overload effect for high R-ratio fatigue as studied here

Myelodysplastic syndromes and the role of iron overload.

Science.gov (United States)

Harvey, R Donald

2010-04-01

The epidemiology of myelodysplastic syndromes (MDS) and iron overload, recent clinical findings that highlight the importance of actively managing iron overload, and recommendations for initiating and maintaining iron chelation therapy (ICT) are summarized. MDS are a variety of hematological disorders with differing time courses. Disease morbidities are primarily due to cytopenias and evolution to acute myeloid leukemia. Iron overload is a serious complication in patients with MDS due to the long-term use of red blood cell transfusions in patients with symptomatic anemia. Clinical consequences of iron overload include end-organ damage and dysfunction, an increased frequency of transplant-related complications, and reduced survival rates. To prevent these complications, recommendations for initiating and maintaining ICT should be followed by clinicians caring for patients with MDS and iron overload. As current therapeutic options for patients with MDS do not always reduce the transfusion burden, many patients will still need long-term transfusion therapy. Strategies for the management of iron overload in MDS should be considered early in the disease course and in appropriate patients in order to prevent negative clinical outcomes associated with excessive iron accumulation.

Iron overload and chelation therapy in myelodysplastic syndromes.

Science.gov (United States)

Temraz, Sally; Santini, Valeria; Musallam, Khaled; Taher, Ali

2014-07-01

Iron overload remains a concern in MDS patients especially those requiring recurrent blood transfusions. The consequence of iron overload may be more relevant in patients with low and intermediate-1 risk MDS who may survive long enough to experience such manifestations. It is a matter of debate whether this overload has time to yield organ damage, but it is quite evident that cellular damage and DNA genotoxic effect are induced. Iron overload may play a critical role in exacerbating pre-existing morbidity or even unmask silent ones. Under these circumstances, iron chelation therapy could play an integral role in the management of these patients. This review entails an in depth analysis of iron overload in MDS patients; its pathophysiology, effect on survival, associated risks and diagnostic options. It also discusses management options in relation to chelation therapy used in MDS patients and the impact it has on survival, hematologic response and organ function. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Iron overload patients with unknown etiology from national survey in Japan.

Science.gov (United States)

Ikuta, Katsuya; Hatayama, Mayumi; Addo, Lynda; Toki, Yasumichi; Sasaki, Katsunori; Tatsumi, Yasuaki; Hattori, Ai; Kato, Ayako; Kato, Koichi; Hayashi, Hisao; Suzuki, Takahiro; Kobune, Masayoshi; Tsutsui, Miyuki; Gotoh, Akihiko; Aota, Yasuo; Matsuura, Motoo; Hamada, Yuzuru; Tokuda, Takahiro; Komatsu, Norio; Kohgo, Yutaka

2017-03-01

Transfusion is believed to be the main cause of iron overload in Japan. A nationwide survey on post-transfusional iron overload subsequently led to the establishment of guidelines for iron chelation therapy in this country. To date, however, detailed clinical information on the entire iron overload population in Japan has not been fully investigated. In the present study, we obtained and studied detailed clinical information on the iron overload patient population in Japan. Of 1109 iron overload cases, 93.1% were considered to have occurred post-transfusion. There were, however, 76 cases of iron overload of unknown origin, which suggest that many clinicians in Japan may encounter some difficulty in correctly diagnosing and treating iron overload. Further clinical data were obtained for 32 cases of iron overload of unknown origin; median of serum ferritin was 1860.5 ng/mL. As occurs in post-transfusional iron overload, liver dysfunction was found to be as high as 95.7% when serum ferritin levels exceeded 1000 ng/mL in these patients. Gene mutation analysis of the iron metabolism-related genes in 27 cases of iron overload with unknown etiology revealed mutations in the gene coding hemojuvelin, transferrin receptor 2, and ferroportin; this indicates that although rare, hereditary hemochromatosis does occur in Japan.

Intelligent Overload Control for Composite Web Services

NARCIS (Netherlands)

Meulenhoff, P.J.; Ostendorf, D.R.; Zivkovic, Miroslav; Meeuwissen, H.B.; Gijsen, B.M.M.

2009-01-01

In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules

Aviation noise overload in the immediate proximity of the Warsaw-Okecie airport

Science.gov (United States)

Koszarny, Z.; Maziarka, S.

1981-01-01

The results are presented for investigations on noise overload around the Warszawa-Okecie airport on persons inhabiting the area where it exceeds 100 dB for a single aircraft flight. Of 256 subjects, 91.1 percent complained about aircraft noise overload. In the population studied considerable differences were noted respecting the subjective sensitivity scale. Statistical analysis showed numerous correlations between the individual noise sensitivity threshold and the subject's state of health, age, sex, type of work, etc. At the same time investigations demonstrated various forms and levels of disturbance in the organism for individual subjects and groups. The most frequent complaint was chronic fatigue (68.1 percent), followed by nervousness (36.6 percent), frequent headaches (36.2 percent), hearing disturbances (30.0 percent) and sleep disorders (23.9 percent).

Statistical behavior of the tensile property of heated cotton fiber

Science.gov (United States)

The temperature dependence of the tensile property of single cotton fiber was studied in the range of 160-300°C using Favimat test, and its statistical behavior was interpreted in terms of structural changes. The tenacity of control cotton fiber was well described by the single Weibull distribution,...

Fluid overload in the ICU: evaluation and management.

Science.gov (United States)

Claure-Del Granado, Rolando; Mehta, Ravindra L

2016-08-02

Fluid overload is frequently found in acute kidney injury patients in critical care units. Recent studies have shown the relationship of fluid overload with adverse outcomes; hence, manage and optimization of fluid balance becomes a central component of the management of critically ill patients. In critically ill patients, in order to restore cardiac output, systemic blood pressure and renal perfusion an adequate fluid resuscitation is essential. Achieving an appropriate level of volume management requires knowledge of the underlying pathophysiology, evaluation of volume status, and selection of appropriate solution for volume repletion, and maintenance and modulation of the tissue perfusion. Numerous recent studies have established a correlation between fluid overload and mortality in critically ill patients. Fluid overload recognition and assessment requires an accurate documentation of intakes and outputs; yet, there is a wide difference in how it is evaluated, reviewed and utilized. Accurate volume status evaluation is essential for appropriate therapy since errors of volume evaluation can result in either in lack of essential treatment or unnecessary fluid administration, and both scenarios are associated with increased mortality. There are several methods to evaluate fluid status; however, most of the tests currently used are fairly inaccurate. Diuretics, especially loop diuretics, remain a valid therapeutic alternative. Fluid overload refractory to medical therapy requires the application of extracorporeal therapies. In critically ill patients, fluid overload is related to increased mortality and also lead to several complications like pulmonary edema, cardiac failure, delayed wound healing, tissue breakdown, and impaired bowel function. Therefore, the evaluation of volume status is crucial in the early management of critically ill patients. Diuretics are frequently used as an initial therapy; however, due to their limited effectiveness the use of continuous

Intermittent cardiac overload results in adaptive hypertrophy and provides protection against left ventricular acute pressure overload insult.

Science.gov (United States)

Moreira-Gonçalves, Daniel; Henriques-Coelho, Tiago; Fonseca, Hélder; Ferreira, Rita; Padrão, Ana Isabel; Santa, Cátia; Vieira, Sara; Silva, Ana Filipa; Amado, Francisco; Leite-Moreira, Adelino; Duarte, José Alberto

2015-09-01

The present study aimed to test whether a chronic intermittent workload could induce an adaptive cardiac phenotype Chronic intermittent workload induced features of adaptive hypertrophy This was paralleled by protection against acute pressure overload insult The heart may adapt favourably to balanced demands, regardless of the nature of the stimuli. The present study aimed to test whether submitting the healthy heart to intermittent and tolerable amounts of workload, independently of its nature, could result in an adaptive cardiac phenotype. Male Wistar rats were subjected to treadmill running (Ex) (n = 20), intermittent cardiac overload with dobutamine (ITO) (2 mg kg(-1) , s.c.; n = 20) or placebo administration (Cont) (n = 20) for 5 days week(-1) for 8 weeks. Animals were then killed for histological and biochemical analysis or subjected to left ventricular haemodynamic evaluation under baseline conditions, in response to isovolumetric contractions and to sustained LV acute pressure overload (35% increase in peak systolic pressure maintained for 2 h). Baseline cardiac function was enhanced only in Ex, whereas the response to isovolumetric heartbeats was improved in both ITO and Ex. By contrast to the Cont group, in which rats developed diastolic dysfunction with sustained acute pressure overload, ITO and Ex showed increased tolerance to this stress test. Both ITO and Ex developed cardiomyocyte hypertrophy without fibrosis, no overexpression of osteopontin-1 or β-myosin heavy chain, and increased expression of sarcoplasmic reticulum Ca(2+) protein. Regarding hypertrophic pathways, ITO and Ex showed activation of the protein kinase B/mammalian target of rapamycin pathway but not calcineurin. Mitochondrial complex IV and V activities were also increased in ITO and Ex. Chronic submission to controlled intermittent cardiac overload, independently of its nature, results in an adaptive cardiac phenotype. Features of the cardiac overload, such as the duration and

TIMP3 deficiency exacerbates iron overload-mediated cardiomyopathy and liver disease.

Science.gov (United States)

Zhabyeyev, Pavel; Das, Subhash K; Basu, Ratnadeep; Shen, Mengcheng; Patel, Vaibhav B; Kassiri, Zamaneh; Oudit, Gavin Y

2018-05-01

Chronic iron overload results in heart and liver diseases and is a common cause of morbidity and mortality in patients with genetic hemochromatosis and secondary iron overload. We investigated the role of tissue inhibitor of metalloproteinase 3 (TIMP3) in iron overload-mediated tissue injury by subjecting male mice lacking Timp3 ( Timp3 -/- ) and wild-type (WT) mice to 12 wk of chronic iron overload. Whereas WT mice with iron overload developed diastolic dysfunction, iron-overloaded Timp3 -/- mice showed worsened cardiac dysfunction coupled with systolic dysfunction. In the heart, loss of Timp3 was associated with increased myocardial fibrosis, greater Timp1, matrix metalloproteinase ( Mmp) 2, and Mmp9 expression, increased active MMP-2 levels, and gelatinase activity. Iron overload in Timp3 -/- mice showed twofold higher iron accumulation in the liver compared with WT mice because of constituently lower levels of ferroportin. Loss of Timp3 enhanced the hepatic inflammatory response to iron overload, leading to greater neutrophil and macrophage infiltration and increased hepatic fibrosis. Expression of inflammation-related MMPs (MMP-12 and MMP-13) and inflammatory cytokines (IL-1β and monocyte chemoattractant protein-1) was elevated to a greater extent in iron-overloaded Timp3 -/- livers. Gelatin zymography demonstrated equivalent increases in MMP-2 and MMP-9 levels in WT and Timp3 -/- iron-overloaded livers. Loss of Timp3 enhanced the susceptibility to iron overload-mediated heart and liver injury, suggesting that Timp3 is a key protective molecule against iron-mediated pathology. NEW & NOTEWORTHY In mice, loss of tissue inhibitor of metalloproteinase 3 ( Timp3) was associated with systolic and diastolic dysfunctions, twofold higher hepatic iron accumulation (attributable to constituently lower levels of ferroportin), and increased hepatic inflammation. Loss of Timp3 enhanced the susceptibility to iron overload-mediated injury, suggesting that Timp3 plays a key

Relationship between surface area for adhesion and tensile bond strength--evaluation of a micro-tensile bond test.

Science.gov (United States)

Sano, H; Shono, T; Sonoda, H; Takatsu, T; Ciucchi, B; Carvalho, R; Pashley, D H

1994-07-01

The purpose of this study was to test the null hypothesis that there is no relationship between the bonded surface area of dentin and the tensile strength of adhesive materials. The enamel was removed from the occlusal surface of extracted human third molars, and the entire flat surface was covered with resin composite bonded to the dentin to form a flat resin composite crown. Twenty-four hours later, the bonded specimens were sectioned parallel to the long axis of the tooth into 10-20 thin sections whose upper part was composed of resin composite with the lower half being dentin. These small sections were trimmed using a high speed diamond bur into an hourglass shape with the narrowest portion at the bonded interface. Surface area was varied by altering the specimen thickness and width. Tensile bond strength was measured using custom-made grips in a universal testing machine. Tensile bond strength was inversely related to bonded surface area. At surface areas below 0.4 mm2, the tensile bond strengths were about 55 MPa for Clearfil Liner Bond 2 (Kuraray Co., Ltd.), 38 MPa for Scotchbond MP (3M Dental Products), and 20 MPa for Vitremer (3M Dental Products). At these small surface areas all of the bond failures were adhesive in nature. This new method permits measurement of high bond strengths without cohesive failure of dentin. It also permits multiple measurements to be made within a single tooth.

Iron overload following bone marrow transplantation in children: MR findings

International Nuclear Information System (INIS)

Kornreich, L.; Horev, G.; Grunebaum, M.; Yaniv, I.; Stein, J.; Zaizov, R.

1997-01-01

Objective. The purpose of this study was to determine the incidence of post-transfusional iron overload in children after bone marrow transplantation by reviewing their magnetic resonance imaging (MR) findings. Materials and methods. We reviewed the abdominal MR studies of 13 children after autologous bone marrow transplantation. Nine of the children had also undergone MR prior to transplantation. Iron deposition in the liver, spleen and bone marrow was graded semi-quantitatively on both T1- and T2-weighted images. Serum ferritin levels and number of blood units given after bone marrow transplantation were recorded. Results. None of the pre-transplantation MR studies revealed iron overload. After bone marrow transplantation, three children showed normal liver and spleen. Iron overload in the liver was noted in ten patients (77 %), six of whom also showed iron overload in the spleen (46 %) and five in the bone marrow (38.5 %). The degree of hepatic iron overload was correlated significantly and splenic iron overload was correlated weakly with the number of blood transfusions (P 0.01 and P > 0.01, respectively), but neither was correlated with the serum ferritin level. Conclusion. Iron overload commonly accompanies bone marrow transplantation. The observed pattern of iron deposition, in which the spleen was uninvolved in 40 % of patients demonstrating iron overload, is not typical of post-transfusional hemochromatosis. (orig.)

Effect of normalization heat treatment on creep and tensile properties of modified 9Cr-1Mo steel

International Nuclear Information System (INIS)

Panneer Selvi, S.; Sakthivel, T.; Parameswaran, P.; Laha, K.

2016-01-01

Creep and tensile properties have been investigated on modified 9Cr-1Mo steel subjected to single and double normalization heat treatments. Optical, scanning and transmission electron microscopic investigation revealed the presence of refined prior austenite grain size and fine M 23 C 6 precipitates in the double normalized steel compared to the steel subjected to single normalization heat treatment. Increased creep strain and significant reduction in creep rupture life were observed with the double normalized steel in comparison with single normalized steel. Increased tensile ductility coupled with marginal decrease in tensile strength at higher test temperature was observed with double normalized steel compared to single normalized steel. It has been attributed to the presence of refined prior austenite grain size and coarsening of Nb rich MX precipitates in double normalized steel. (author)

Optimization of tensile method and specimen geometry in modified ring tensile test

International Nuclear Information System (INIS)

Kitano, Koji; Fuketa, Toyoshi; Sasajima, Hideo; Uetsuka, Hiroshi

2001-03-01

Several techniques in ring tensile test are proposed in order to evaluate mechanical properties of cladding under hoop loading condition caused by pellet/cladding mechanical interaction (PCMI). In the modified techniques, variety of tensile methods and specimen geometry are being proposed in order to limit deformation within the gauge section. However, the tensile method and the specimen geometry were not determined in the modified techniques. In the present study, we have investigated the tensile method and the specimen geometry through finite element method (FEM) analysis of specimen deformation and tensile test on specimens with various gauge section geometries. In using two-piece tensile tooling, the mechanical properties under hoop loading condition can be correctly evaluated when deformation part (gauge section) is put on the top of a half-mandrel, and friction between the specimen and the half-mandrel is reduced with Teflon tape. In addition, we have shown the optimum specimen geometry for PWR 17 by 17 type cladding. (author)

Experimental detection of iron overload in liver through neutron stimulated emission spectroscopy

International Nuclear Information System (INIS)

Kapadia, A J; Tourassi, G D; Sharma, A C; Crowell, A S; Kiser, M R; Howell, C R

2008-01-01

Iron overload disorders have been the focus of several quantification studies involving non-invasive imaging modalities. Neutron spectroscopic techniques have demonstrated great potential in detecting iron concentrations within biological tissue. We are developing a neutron spectroscopic technique called neutron stimulated emission computed tomography (NSECT), which has the potential to diagnose iron overload in the liver at clinically acceptable patient dose levels through a non-invasive scan. The technique uses inelastic scatter interactions between atomic nuclei in the sample and incoming fast neutrons to non-invasively determine the concentration of elements in the sample. This paper discusses a non-tomographic application of NSECT investigating the feasibility of detecting elevated iron concentrations in the liver. A model of iron overload in the human body was created using bovine liver tissue housed inside a human torso phantom and was scanned with a 5 MeV pulsed beam using single-position spectroscopy. Spectra were reconstructed and analyzed with algorithms designed specifically for NSECT. Results from spectroscopic quantification indicate that NSECT can currently detect liver iron concentrations of 6 mg g -1 or higher and has the potential to detect lower concentrations by optimizing the acquisition geometry to scan a larger volume of tissue. The experiment described in this paper has two important outcomes: (i) it demonstrates that NSECT has the potential to detect clinically relevant concentrations of iron in the human body through a non-invasive scan and (ii) it provides a comparative standard to guide the design of iron overload phantoms for future NSECT liver iron quantification studies

Iron overload in myelodysplastic syndromes (MDS).

Science.gov (United States)

Gattermann, Norbert

2018-01-01

Iron overload (IOL) starts to develop in MDS patients before they become transfusion-dependent because ineffective erythropoiesis suppresses hepcidin production in the liver and thus leads to unrestrained intestinal iron uptake. However, the most important cause of iron overload in MDS is chronic transfusion therapy. While transfusion dependency by itself is a negative prognostic factor reflecting poor bone marrow function, the ensuing transfusional iron overload has an additional dose-dependent negative impact on the survival of patients with lower risk MDS. Cardiac dysfunction appears to be important in this context, as a consequence of chronic anemia, age-related cardiac comorbidity, and iron overload. Another potential problem is iron-related endothelial dysfunction. There is some evidence that with increasing age, high circulating iron levels worsen the atherosclerotic phenotype. Transfusional IOL also appears to aggravate bone marrow failure in MDS, through unfavorable effects on mesenchymal stromal cells as well a hematopoietic cells, particularly erythroid precursors. Patient series and clinical trials have shown that the iron chelators deferoxamine and deferasirox can improve hematopoiesis in a minority of transfusion-dependent patients. Analyses of registry data suggest that iron chelation provides a survival benefit for patients with MDS, but data from a prospective randomized clinical trial are still lacking.

Transplantation in patients with iron overload: is there a place for magnetic resonance imaging? : Transplantation in iron overload.

Science.gov (United States)

Mavrogeni, Sophie; Kolovou, Genovefa; Bigalke, Boris; Rigopoulos, Angelos; Noutsias, Michel; Adamopoulos, Stamatis

2018-03-01

In iron overload diseases (thalassemia, sickle cell, and myelodysplastic syndrome), iron is deposited in all internal organs, leading to functional abnormalities. Hematopoietic stem cell transplantation (HSCT) is the only treatment offering a potential cure in these diseases. Our aim was to describe the experience in the field and the role of magnetic resonance imaging in the evaluation of iron overload before and after HSCT. Magnetic resonance imaging (MRI), using T2*, is the most commonly used tool to diagnose myocardial-liver iron overload and guide tailored treatment. Currently, HSCT offers complete cure in thalassemia major, after overcoming the immunologic barrier, and should be considered for all patients who have a suitable donor. The overall thalassemia-free survival of low-risk, HLA-matched sibling stem cell transplantation patients is 85-90%, with a 95% overall survival. The problems of rejection and engraftment are improving with the use of adequate immunosuppression. However, a detailed iron assessment of both heart and liver is necessary for pre- and post-transplant evaluation. In iron overload diseases, heart and liver iron evaluation is indispensable not only for the patients' survival, but also for evaluation before and after HSCT.

Reliability Analysis and Overload Capability Assessment of Oil-Immersed Power Transformers

Directory of Open Access Journals (Sweden)

Chen Wang

2016-01-01

Full Text Available Smart grids have been constructed so as to guarantee the security and stability of the power grid in recent years. Power transformers are a most vital component in the complicated smart grid network. Any transformer failure can cause damage of the whole power system, within which the failures caused by overloading cannot be ignored. This research gives a new insight into overload capability assessment of transformers. The hot-spot temperature of the winding is the most critical factor in measuring the overload capacity of power transformers. Thus, the hot-spot temperature is calculated to obtain the duration running time of the power transformers under overloading conditions. Then the overloading probability is fitted with the mature and widely accepted Weibull probability density function. To guarantee the accuracy of this fitting, a new objective function is proposed to obtain the desired parameters in the Weibull distributions. In addition, ten different mutation scenarios are adopted in the differential evolutionary algorithm to optimize the parameter in the Weibull distribution. The final comprehensive overload capability of the power transformer is assessed by the duration running time as well as the overloading probability. Compared with the previous studies that take no account of the overloading probability, the assessment results obtained in this research are much more reliable.

Research progress in role of iron overload in non-alcoholic fatty liver disease

Directory of Open Access Journals (Sweden)

LI Guangming

2013-12-01

Full Text Available Iron overload is an important research focus in non-alcoholic fatty liver disease (NAFLD. The relationship between iron overload and NAFLD is summarized from the assessment method for iron overload, relationship between iron load and hemochromatosis gene mutations, incidence of iron load in NAFLD, and relationship between iron load and progression of NAFLD; the action mechanism of iron overload in the progression of NAFLD is reviewed from the causes of iron overload, relationship between iron overload and lipid metabolism, and relationship between type of iron deposition and liver damage; the significance of iron overload in the diagnosis and treatment of NAFLD is discussed from iron overload as a new marker of risk stratification and potential therapeutic target in NAFLD. It is currently considered that iron overload, whether the cause or result of NAFLD progression, will promote the progression of NAFLD once it occurs; as a new marker of risk stratification and potential therapeutic target in NAFLD, iron load is worthy of further study.

Using Pattern Recognition Techniques for Server Overload Detection

NARCIS (Netherlands)

Bezemer, C.P.; Cheplygina, V.; Zaidman, A.

2011-01-01

One of the key factors in customer satisfaction is application performance. To be able to guarantee good performance, it is necessary to take appropriate measures before a server overload occurs. While in small systems it is usually possible to predict server overload using a subjective human

Overloaded and stressed: A case study of women working in the health care sector.

Science.gov (United States)

Stevenson, Maggie; Duxbury, Linda

2018-04-23

Although role overload has been shown to be prevalent and consequential, there has been little attempt to develop the associated theory. The fact that the consequences of role overload can be positive or negative implies that the relationship between role overload and perceived stress depends partly on the environment within which role overload is experienced (i.e., the perceived situation) and how the situation is evaluated (i.e., appraised). Guided by cognitive appraisal theory, this study applies qualitative methodology to identify the situation properties that contribute to variable stress reactions to role overload. In this in-depth examination, overloaded female hospital workers were asked to describe what makes role overload situations potentially stressful, to gain an insight into how role overload is appraised. A taxonomy listing 12 role overload situation properties was developed from the findings, providing the first known classification of the situation properties of role overload that can create the potential for stress. The results also reveal clues as to why some people suffer more stress during role overload than others, increase our understanding of the relationship between role overload and perceived stress, and provide a useful tool for examining the environment of role overload. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Thermal Characterization of the Overload Carbon Resistors

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Ivana Kostić

2013-01-01

Full Text Available In many applications, the electronic component is not continuously but only intermittently overloaded (e.g., inrush current, short circuit, or discharging interference. With this paper, we provide insight into carbon resistors that have to hold out a rarely occurring transient overload. Using simple electrical circuit, the resistor is overheating with higher current than declared, and dissipation is observed by a thermal camera.

Attenuated hypertrophic response to pressure overload in a lamin A/C haploinsufficiency mouse.

Science.gov (United States)

Cupesi, Mihaela; Yoshioka, Jun; Gannon, Joseph; Kudinova, Anastacia; Stewart, Colin L; Lammerding, Jan

2010-06-01

Inherited mutations cause approximately 30% of all dilated cardiomyopathy cases, with autosomal dominant mutations in the LMNA gene accounting for more than one third of these. The LMNA gene encodes the nuclear envelope proteins lamins A and C, which provide structural support to the nucleus and also play critical roles in transcriptional regulation. Functional deletion of a single allele is sufficient to trigger dilated cardiomyopathy in humans and mice. However, whereas Lmna(-/-) mice develop severe muscular dystrophy and dilated cardiomyopathy and die by 8 weeks of age, heterozygous Lmna(+/-) mice have a much milder phenotype, with changes in ventricular function and morphology only becoming apparent at 1 year of age. Here, we studied 8- to 20-week-old Lmna(+/-) mice and wild-type littermates in a pressure overload model to examine whether increased mechanical load can accelerate or exacerbate myocardial dysfunction in the heterozygotes. While overall survival was similar between genotypes, Lmna(+/-) animals had a significantly attenuated hypertrophic response to pressure overload as evidenced by reduced ventricular mass and myocyte size. Analysis of pressure overload-induced transcriptional changes suggested that the reduced hypertrophy in the Lmna(+/-) mice was accompanied by impaired activation of the mechanosensitive gene Egr-1. In conclusion, our findings provide further support for a critical role of lamins A and C in regulating the cellular response to mechanical stress in cardiomyocytes and demonstrate that haploinsufficiency of lamins A and C alone is sufficient to alter hypertrophic responses and cardiac function in the face of pressure overload in the heart. (c) 2009 Elsevier Ltd. All rights reserved.

The evolution of crack-tip stresses during a fatigue overload event

International Nuclear Information System (INIS)

Steuwer, A.; Rahman, M.; Shterenlikht, A.; Fitzpatrick, M.E.; Edwards, L.; Withers, P.J.

2010-01-01

The mechanisms responsible for the transient retardation or acceleration of fatigue crack growth subsequent to overloading are a matter of intense debate. Plasticity-induced closure and residual stresses have often been invoked to explain these phenomena, but closure mechanisms are disputed, especially under conditions approximating to generalised plane strain. In this paper we exploit synchrotron radiation to report very high spatial resolution two-dimensional elastic strain and stress maps at maximum and minimum loading measured under plane strain during a normal fatigue cycle, as well as during and after a 100% overload event, in ultra-fine grained AA5091 aluminium alloy. These observations provide direct evidence of the material stress state in the vicinity of the crack-tip in thick samples. Significant compressive residual stresses were found both in front of and behind the crack-tip immediately following the overload event. The effective stress intensity at the crack-tip was determined directly from the local stress field measured deep within the bulk (plane strain) by comparison with linear elastic fracture mechanical theory. This agrees well with that nominally applied at maximum load and 100% overload. After overload, however, the stress fields were not well described by classical K fields due to closure-related residual stresses. Little evidence of overload closure was observed sometime after the overload event, in our case possibly because the overload plastic zone was very small.

[Role of melatonin in calcium overload-induced heart injury].

Science.gov (United States)

Kong, Lingheng; Wei, Ming; Sun, Na; Zhu, Juanxia; Su, Xingli

2017-06-28

To investigate the role of melatonin in calcium overload-induced heart injury.
 Methods: Thirty-two rats were divided into 4 groups: a control group (Control), a melatonin control group (Mel), a calcium overload group (CaP), and a calcium overload plus melatonin group (Mel+CaP). Isolated Sprague Dawley male rat hearts underwent Langendorff perfusion. Left ventricular developed pressure (LVDP) was calculated to evaluate the myocardial performance. Triphenyltetrazolium chloride staining was used to measure the infarct size of myocardium. Lactate dehydrogenase (LDH) activity in the coronary flow was determined. The expressions of caspase-3 and cytochrome c were determined by Western blot. The pathological morphological changes in myocardial fiber were analyzed by HE staining.
 Results: Compared with the control group, calcium overload significantly induced an enlarged infarct size (Poverload-induced heart injury.

Magnetic and quadrupolar studies of the iron storage overload in livers

International Nuclear Information System (INIS)

Rimbert, J.N.; Dumas, F.; Richardot, G.; Kellershohn, C.

1986-01-01

Absorption 57 Fe Moessbauer spectra, performed directly on tissues of liver with iron overload due to an excessive intestinal iron absorption or induced by hypertransfusional therapeutics, have pointed out a new high spin ferric storage iron besides the ferritin and hemosiderin. Moessbauer studies, carried out on ferritin and hemosiderin fractions isolated from normal and overloaded livers, show that this compound, only present in the secondary iron overload (transfusional pathway), seems characteristic of the physiological process which induces the iron overload. (Auth.)

A new approach for primary overloads allowance in ratcheting evaluation

International Nuclear Information System (INIS)

Cabrillat, M.T.; Gatt, J.M.; Lejeail, Y.

1995-01-01

Seismic loading must be taken into account in ratchetting design analysis. In LMFBR structures it mainly produces primary overloads, which are characterised by severe magnitudes but a generally low number of occurrences. Other cases of several primary overloads can also observed in pipes during emptying operations for instance. In the RCC-MR design code rule, the maximum primary stress supported by a structure is considered as permanent. No allowance is made for temporary load. Experimental ratchetting tests conducted on different structures with and without overloads clearly point out that temporary overloads lead to less ratchetting effect. A method using the RCC-MR efficiency diagram framework is proposed. A general theoretical approach allows to extend its field of application of various cases of primary loading: constant or null primary loading or overloads. Experimental results are then used to check the validity of this new approach. (author). 2 refs., 2 figs., 2 tabs

Interactions of Aging, Overload, and Creatine Supplementation in Rat Plantaris Muscle

Directory of Open Access Journals (Sweden)

Mark D. Schuenke

2011-01-01

Full Text Available Attenuation of age-related sarcopenia by creatine supplementation has been equivocal. In this study, plantaris muscles of young (Y; 5m and aging (A; 24m Fisher 344 rats underwent four weeks of either control (C, creatine supplementation (Cr, surgical overload (O, or overload plus creatine (OCr. Creatine alone had no effect on muscle fiber cross-sectional area (CSA or heat shock protein (HSP70 and increased myonuclear domain (MND only in young rats. Overload increased CSA and HSP70 content in I and IIA fibers, regardless of age, and MND in IIA fibers of YO rats. CSA and MND increased in all fast fibers of YOCr, and CSA increased in I and IIA fibers of AOCr. OCR did not alter HSP70, regardless of age. MND did not change in aging rats, regardless of treatment. These data indicate creatine alone had no significant effect. Creatine with overload produced no additional hypertrophy relative to overload alone and attenuated overload-induced HSP70 expression.

The role of fluid overload in the prediction of outcome in acute kidney injury.

Science.gov (United States)

Selewski, David T; Goldstein, Stuart L

2018-01-01

Our understanding of the epidemiology and the impact of acute kidney injury (AKI) and fluid overload on outcomes has improved significantly over the past several decades. Fluid overload occurs commonly in critically ill children with and without associated AKI. Researchers in pediatric AKI have been at the forefront of describing the impact of fluid overload on outcomes in a variety of populations. A full understanding of this topic is important as fluid overload represents a potentially modifiable risk factor and a target for intervention. In this state-of-the-art review, we comprehensively describe the definition of fluid overload, the impact of fluid overload on kidney function, the impact of fluid overload on the diagnosis of AKI, the association of fluid overload with outcomes, the targeted therapy of fluid overload, and the impact of the timing of renal replacement therapy on outcomes.

Control over Permissible Short Emergency Overloads in Power Transformers

Directory of Open Access Journals (Sweden)

V. A. Anischenko

2010-01-01

Full Text Available The paper proposes a method for determination a permissible duration of short intermittent overloads of power transformers that permits to avoid non-permissible over-heating of winding insulation and fully utilize overloading transformer ability.

Research progress in role of iron overload in non-alcoholic fatty liver disease

OpenAIRE

LI Guangming

2013-01-01

Iron overload is an important research focus in non-alcoholic fatty liver disease (NAFLD). The relationship between iron overload and NAFLD is summarized from the assessment method for iron overload, relationship between iron load and hemochromatosis gene mutations, incidence of iron load in NAFLD, and relationship between iron load and progression of NAFLD; the action mechanism of iron overload in the progression of NAFLD is reviewed from the causes of iron overload, relationship between iro...

Mechanism Research of Arch Dam Abutment Forces during Overload

Directory of Open Access Journals (Sweden)

Yu Xia

2015-01-01

Full Text Available This paper presents research on the abutment forces of a double-curvature arch dam during overload based on numerical calculation results obtained through finite element method by Ansys. Results show that, with an increase in elevation, the abutment forces and bending moment of the arch dam increase first and then decrease from the bottom to the top of the dam. Abutment forces and bending moment reach their maximum at the middle or middle-down portion of the dam. The distributions of abutment forces and moment do not change during overload. The magnitude of each arch layer’s forces and moment increases linearly during overload. This result indicates that each arch layer transmits bearing loads to the rocks of the left and right banks steadily. This research explains the operating mechanism of an arch dam under normal and overload conditions. It provides a simple method to calculate the distribution of forces Fx and Fy and a new method to calculate the overload factor of an arch dam through the estimation of arch layers based on the redistribution characteristic of arch abutment forces.

Information Overload and Viral Marketing: Countermeasures and Strategies

Science.gov (United States)

Cheng, Jiesi; Sun, Aaron; Zeng, Daniel

Studying information diffusion through social networks has become an active research topic with important implications in viral marketing applications. One of the fundamental algorithmic problems related to viral marketing is the Influence Maximization (IM) problem: given an social network, which set of nodes should be considered by the viral marketer as the initial targets, in order to maximize the influence of the advertising message. In this work, we study the IM problem in an information-overloaded online social network. Information overload occurs when individuals receive more information than they can process, which can cause negative impacts on the overall marketing effectiveness. Many practical countermeasures have been proposed for alleviating the load of information on recipients. However, how these approaches can benefit viral marketers is not well understood. In our work, we have adapted the classic Information Cascade Model to incorporate information overload and study its countermeasures. Our results suggest that effective control of information overload has the potential to improve marketing effectiveness, but the targeting strategy should be re-designed in response to these countermeasures.

Overload Control in a SIP Signaling Network

OpenAIRE

Masataka Ohta

2007-01-01

The Internet telephony employs a new type of Internet communication on which a mutual communication is realized by establishing sessions. Session Initiation Protocol (SIP) is used to establish sessions between end-users. For unreliable transmission (UDP), SIP message should be retransmitted when it is lost. The retransmissions increase a load of the SIP signaling network, and sometimes lead to performance degradation when a network is overloaded. The paper proposes an overload control for a S...

Thallium-201 myocardial imaging for evaluation of right-ventricular overloading

International Nuclear Information System (INIS)

Kondo, M.; Kubo, A.; Yamazaki, H.; Ohsuzu, F.; Handa, S.; Tsugu, T.; Masaki, H.; Kinoshita, F.; Hashimoto, S.

1978-01-01

This study evaluated the specificity and sensitivity of Tl-201 myocardial imaging in the detection of right-ventricular (RV) overloading. Right-ventricular visualization (RVV) after administration of Tl-201 chloride was studied on 99 patients with various heart diseases. Tracer uptake in the free wall of the RV was graded in four degrees. The degree of RVV was compared with the findings of cardiac catheterization. The comparisons indicated that the uptake increased in step with the inreases in RV systolic pressure, RV end-diastolic pressure, mean pulmonary arterial pressure, total pulmonary vascular resistance, and stroke-work index of the right ventricle (P < 0.05--P < 0.001). Of the patients with visible RV, all but three had RV overloading, and all but three of those without RVV had normal RV systolic pressure. Myocardial images also reflect the type of RV overloading. In patients with RV pressure overloading, the septum showed a tendency to appear straight. In patients with atrial septal defect leading to RV volume overloading, the RV cavity was dilated, the LV image small, and the septum convex toward the RV cavity. These results indicate that Tl-201 myocardial imaging is a sensitive and specific method for the study of RV overloading

Study of the effect of varying core diameter, shell thickness and strain velocity on the tensile properties of single crystals of Cu-Ag core-shell nanowire using molecular dynamics simulations

Science.gov (United States)

Sarkar, Jit; Das, D. K.

2018-01-01

Core-shell type nanostructures show exceptional properties due to their unique structure having a central solid core of one type and an outer thin shell of another type which draw immense attention among researchers. In this study, molecular dynamics simulations are carried out on single crystals of copper-silver core-shell nanowires having wire diameter ranging from 9 to 30 nm with varying core diameter, shell thickness, and strain velocity. The tensile properties like yield strength, ultimate tensile strength, and Young's modulus are studied and correlated by varying one parameter at a time and keeping the other two parameters constant. The results obtained for a fixed wire size and different strain velocities were extrapolated to calculate the tensile properties like yield strength and Young's modulus at standard strain rate of 1 mm/min. The results show ultra-high tensile properties of copper-silver core-shell nanowires, several times than that of bulk copper and silver. These copper-silver core-shell nanowires can be used as a reinforcing agent in bulk metal matrix for developing ultra-high strength nanocomposites.

Overload road damage model

CSIR Research Space (South Africa)

Roux, MP

2005-03-01

Full Text Available Not only do overloaded vehicles pose an increased safety risk on the road (reduced stability and braking efficiency etc.), but they also accelerate the rate of deterioration of the road network and increase road maintenance costs, which in turn...

Aldosterone and mortality in hemodialysis patients: role of volume overload.

Science.gov (United States)

Hung, Szu-Chun; Lin, Yao-Ping; Huang, Hsin-Lei; Pu, Hsiao-Fung; Tarng, Der-Cherng

2013-01-01

Elevated aldosterone is associated with increased mortality in the general population. In patients on dialysis, however, the association is reversed. This paradox may be explained by volume overload, which is associated with lower aldosterone and higher mortality. We evaluated the relationship between aldosterone and outcomes in a prospective cohort of 328 hemodialysis patients stratified by the presence or absence of volume overload (defined as extracellular water/total body water >48%, as measured with bioimpedance). Baseline plasma aldosterone was measured before dialysis and categorized as low (280 pg/mL). Overall, 36% (n = 119) of the hemodialysis patients had evidence of volume overload. Baseline aldosterone was significantly lower in the presence of volume overload than in its absence. During a median follow-up of 54 months, 83 deaths and 70 cardiovascular events occurred. Cox multivariate analysis showed that by using the low aldosterone as the reference, high aldosterone was inversely associated with decreased hazard ratios for mortality (0.49; 95% confidence interval, 0.25-0.76) and first cardiovascular event (0.70; 95% confidence interval, 0.33-0.78) in the presence of volume overload. In contrast, high aldosterone was associated with an increased risk for mortality (1.97; 95% confidence interval, 1.69-3.75) and first cardiovascular event (2.01; 95% confidence interval, 1.28-4.15) in the absence of volume overload. The inverse association of aldosterone with adverse outcomes in hemodialysis patients is due to the confounding effect of volume overload. These findings support treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control.

CHARACTERIZATION AND PERFORMANCE OF ELEMENTARY HEMP FIBRES: FACTORS INFLUENCING TENSILE STRENGTH

Directory of Open Access Journals (Sweden)

Mizi Fan

2010-09-01

Full Text Available This paper presents the outcomes from an extensive investigation on the structure and geometry of single hemp fibres, as well as configurations and related tensile strength (TS of hemp fibres, with the aid of field emission scanning and optical microscopy. The results showed that 1 the TS increased with the decrease of the diameter of individual test pieces, due possibly to the stacks of multiple single fibres within the test pieces; 2 shear failure between single fibres in a test pieces played a significant role in the test results; 3 the TS was closely related to the number of both the inherent joints along the fibre length and single fibres contained in the test pieces; 4 the splits along the length and width of hemp fibres may complicate the test results, and 5 the optimized treatment prior to decortications may double the TS of hemp fibres compared to a normal retting processing. Reliable TS of single hemp fibres have been derived by a power regression, and the predicted TS were verified with an excellent agreement with experimentally tested results. The tensile strain-stress plot was found to be linear for all hemp test pieces, showing that the behaviour of single hemp fibres obeys Hooke’s law.

Tensile properties of orthodontic elastomeric ligatures.

Science.gov (United States)

Ahrari, F; Jalaly, T; Zebarjad, M

2010-01-01

Tensile properties of elastomeric ligatures become important when efficiency of orthodontic appliances is considered. The aim of this study was to compare tensile strength, extension to tensile strength, toughness and modulus of elasticity of elastomeric ligatures in both the as--received condition and after 28 days of immersion in the simulated oral environment. Furthermore, the changes that occurred in tensile properties of each brand of ligatures after 28 days were evaluated. Experimental-laboratory based. Elastomeric ligatures were obtained from different companies and their tensile properties were measured using Zwick testing machine in both the as-received condition and after 28 days of immersion in the simulated oral environment. The data were analyzed using independent sample t-tests, analysis of variance and Tukey tests. After 28 days, all the ligatures experienced a significant decrease in tensile strength, extension to tensile strength and toughness ( P tensile properties of different brands of ligatures in both conditions ( P tensile properties of different brands of ligatures, which should be considered during selection of these products.

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.

Fluid Overload and Cumulative Thoracostomy Output Are Associated With Surgical Site Infection After Pediatric Cardiothoracic Surgery.

Science.gov (United States)

Sochet, Anthony A; Nyhan, Aoibhinn; Spaeder, Michael C; Cartron, Alexander M; Song, Xiaoyan; Klugman, Darren; Brown, Anna T

2017-08-01

To determine the impact of cumulative, postoperative thoracostomy output, amount of bolus IV fluids and peak fluid overload on the incidence and odds of developing a deep surgical site infection following pediatric cardiothoracic surgery. A single-center, nested, retrospective, matched case-control study. A 26-bed cardiac ICU in a 303-bed tertiary care pediatric hospital. Cases with deep surgical site infection following cardiothoracic surgery were identified retrospectively from January 2010 through December 2013 and individually matched to controls at a ratio of 1:2 by age, gender, Risk Adjustment for Congenital Heart Surgery score, Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery category, primary cardiac diagnosis, and procedure. None. Twelve cases with deep surgical site infection were identified and matched to 24 controls without detectable differences in perioperative clinical characteristics. Deep surgical site infection cases had larger thoracostomy output and bolus IV fluid volumes at 6, 24, and 48 hours postoperatively compared with controls. For every 1 mL/kg of thoracostomy output, the odds of developing a deep surgical site infection increase by 13%. By receiver operative characteristic curve analysis, a cutoff of 49 mL/kg of thoracostomy output at 48 hours best discriminates the development of deep surgical site infection (sensitivity 83%, specificity 83%). Peak fluid overload was greater in cases than matched controls (12.5% vs 6%; p operative characteristic curve analysis, a threshold value of 10% peak fluid overload was observed to identify deep surgical site infection (sensitivity 67%, specificity 79%). Conditional logistic regression of peak fluid overload greater than 10% on the development of deep surgical site infection yielded an odds ratio of 9.4 (95% CI, 2-46.2). Increased postoperative peak fluid overload and cumulative thoracostomy output were associated with deep surgical site infection after pediatric

Iron overload: what is the role of public health?

Science.gov (United States)

Hulihan, Mary M; Sayers, Cindy A; Grosse, Scott D; Garrison, Cheryl; Grant, Althea M

2011-12-01

Hereditary hemochromatosis type 1, also known as hereditary hemochromatosis classical (HHC), is an iron overload disorder associated, in most cases, with mutations of the hemochromatosis (HFE) gene. Although suggested algorithms for diagnosing iron overload are available, there are still questions about options for genetic and biochemical screening for hemochromatosis and duration of treatment. This article provides a summary of an expert workgroup meeting convened on September 24-25, 2009, entitled "Iron Overload: What is the Role of Public Health?" The purpose of the meeting was to enable subject matter experts to share their most recent clinical and scientific iron overload information and to facilitate the discussion of future endeavors, with special emphasis on the role of public health in this field. The two main topics were the research priorities of the field, including clinical, genetic, and public health issues, and the concerns about the validity of current screening recommendations for the condition. Published by Elsevier Inc.

30 CFR 75.518-2 - Incandescent lamps, overload and short circuit protection.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Incandescent lamps, overload and short circuit...-General § 75.518-2 Incandescent lamps, overload and short circuit protection. Incandescent lamps installed... or direct current feeder circuits, need not be provided with separate short circuit or overload...

On TCP-based Session Initiation Protocol (SIP) Server Overload Control

OpenAIRE

Shen, Charles; Schulzrinne, Henning

2010-01-01

The Session Initiation Protocol (SIP) server overload management has attracted interest since SIP is being widely deployed in the Next Generation Networks (NGN) as a core signaling protocol. Yet all existing SIP overload control work is focused on SIP-over-UDP, despite the fact that TCP is increasingly seen as the more viable choice of SIP transport. This paper answers the following questions: is the existing TCP flow control capable of handling the SIP overload problem? If not, why and how c...

Glycolytic overload and the genesis of breast cancer.

Science.gov (United States)

Robson, J R

1984-03-01

It is suggested that the development of breast cancer is due to overloading of the glycolytic pathways. An excess of substrates or an excessive delivery rate of substrates to the Krebs Cycle is believed to result in the formation of acetyl CoA. Feedback mechanisms controlling the conversion of acetyl CoA to cholesterol may be overcome; the resulting high concentration of cholesterol induces the formation of pregnenolone which may then be converted into androgens, estrogens and progesterone. These steroids are in addition to those produced by gonads and adrenal glands. Glycolytic overload is also associated with an increase in fat stores which have been shown to be the site of interconversion of sex hormones. Excess sex hormones or abnormal sex hormones are believed to be the cause of breast cancer. The hypothesis presented links glycolytic overload with clinical biochemical phenomena and explains some of the anomalies observed in breast cancer experience in different ethnic groups. Changes in dietary habits during the history of man resulting in " gorging " and the consumption of highly refined sugars are possible causes of glycolytic overload. So, also, is impaired thermogenesis due to Brown Fat deficits in certain ethnic groups.

High efficient and continuous surface modification of carbon fibers with improved tensile strength and interfacial adhesion

Science.gov (United States)

Sun, Jingfeng; Zhao, Feng; Yao, Yue; Jin, Zhen; Liu, Xu; Huang, Yudong

2017-08-01

Most of the surface modification technologies for carbon fibers, no matter in laboratory scale or for commercial manufacture, are accompanied by a simultaneous decrease in tensile strength. In this paper, a feasible and high efficient strategy for carbon fiber treatment which could obviously improve both tensile strength and interfacial adhesion was proposed. Continuously moving carbon fibers were treated with atmospheric helium plasma for 1 min, followed by a 5 min pyrolytic carbon deposition using ethanol as precursor at 800 °C. The effects of the new approach were characterized by SEM, AFM, nanoindentation, XPS, Raman, wettability analysis, single fiber tensile strength testing and single fiber pull-out testing. After modification, pyrolytic carbon coating was deposited on the fiber surface uniformly, and the roughness and surface energy increased significantly. The single fiber tensile testing results indicate that the resulting fiber strength increased 15.7%, rising from 3.13 to 3.62 GPa. Meanwhile, the interfacial shear strength of its epoxy composites increased from 65.3 to 83.5 MPa. The comparative studies of carbon fibers modified with commercial anodic oxidation and sizing were also carried out. The results demonstrate that the new method can be utilized in the carbon fiber manufacture process and is more efficient than the traditional approaches.

Determination of Permissible Short-Time Emergency Overloading of Turbo-Generators and Synchronous Compensators

Directory of Open Access Journals (Sweden)

V. A. Anischenko

2011-01-01

Full Text Available The paper shows that failure to take into account variable ratio of short-time emergency overloading of turbo-generators (synchronous compensators that can lead to underestimation of overloading capacity or impermissible insulation over-heating.A method has been developed for determination of permissible duration of short-time emergency over-loading that takes into account changes of over-loading ratio in case of a failure.

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

Enzymatically modified isoquercitrin supplementation intensifies plantaris muscle fiber hypertrophy in functionally overloaded mice.

Science.gov (United States)

Kohara, Akiko; Machida, Masanao; Setoguchi, Yuko; Ito, Ryouichi; Sugitani, Masanori; Maruki-Uchida, Hiroko; Inagaki, Hiroyuki; Ito, Tatsuhiko; Omi, Naomi; Takemasa, Tohru

2017-01-01

Enzymatically modified isoquercitrin (EMIQ) is produced from rutin using enzymatic hydrolysis followed by treatment with glycosyltransferase in the presence of dextrin to add glucose residues. EMIQ is absorbed in the same way as quercetin, a powerful antioxidant reported to prevent disused muscle atrophy by targeting mitochondria and to have ergogenic effects. The present study investigated the effect of EMIQ on skeletal muscle hypertrophy induced by functional overload. In Study 1, 6-week-old ICR male mice were divided into 4 groups: sham-operated control, sham-operated EMIQ, overload-operated control, and overload-operated EMIQ groups. In Study 2, mice were divided into 3 groups: overload-operated whey control, overload-operated whey/EMIQ (low dose), and overload-operated whey/EMIQ (high dose) groups. The functional overload of the plantaris muscle was induced by ablation of the synergist (gastrocnemius and soleus) muscles. EMIQ and whey protein were administered with food. Three weeks after the operation, the cross-sectional area and minimal fiber diameter of the plantaris muscle fibers were measured. In Study 1, functional overload increased the cross-sectional area and minimal fiber diameter of the plantaris muscle. EMIQ supplementation significantly increased the cross-sectional area and minimal fiber diameter of the plantaris muscle in both the sham-operated and overload-operated groups. In Study 2, EMIQ supplementation combined with whey protein administration significantly increased the cross-sectional area and minimal fiber diameter of the plantaris muscle. EMIQ, even when administered as an addition to whey protein supplementation, significantly intensified the fiber hypertrophy of the plantaris muscle in functionally overloaded mice. EMIQ supplementation also induced fiber hypertrophy of the plantaris in sham-operated mice.

Iron overload of organism and current options of chelation treatment in onco haematology

International Nuclear Information System (INIS)

Guman, T.; Rothova, E.; Kafkova, A.; Fricova, M.; Dulova, I.; Stecova, N.; Hlebaskova, M.; Surova, M.; Takac, V.

2011-01-01

The article summarizes the biological importance of iron in the organism, primary and secondary causes of iron overload, complications in function of liver, heart and endocrine organs due to overload of iron, the pathophysiology of iron overload, transfusion risks associated with the iron overload, assessment of risk groups of patients suitable for chelation treatment fulfilling the indication criteria, treatment modalities of chelation therapy and its significance regarding the prevention and treatment effectiveness. (author)

Lactate dehydrogenase regulation in aged skeletal muscle: Regulation by anabolic steroids and functional overload.

Science.gov (United States)

Washington, Tyrone A; Healey, Julie M; Thompson, Raymond W; Lowe, Larry L; Carson, James A

2014-09-01

Aging alters the skeletal muscle response to overload-induced growth. The onset of functional overload is characterized by increased myoblast proliferation and an altered muscle metabolic profile. The onset of functional overload is associated with increased energy demands that are met through the interconversion of lactate and pyruvate via the activity of lactate dehydrogenase (LDH). Testosterone targets many of the processes activated at the onset of functional overload. However, the effect of aging on this metabolic plasticity at the onset of functional overload and how anabolic steroid administration modulates this response is not well understood. The purpose of this study was to determine if aging would alter overload-induced LDH activity and expression at the onset of functional overload and whether anabolic steroid administration would modulate this response. Five-month and 25-month male Fischer 344xF1 BRN were given nandrolone decanoate (ND) or sham injections for 14days and then the plantaris was functionally overloaded (OV) for 3days by synergist ablation. Aging reduced muscle LDH-A & LDH-B activity 70% (pyoung muscle. Our study provides evidence that aging alters aspects of skeletal muscle metabolic plasticity normally induced by overload and anabolic steroid administration. Copyright © 2014 Elsevier Inc. All rights reserved.

I just want to be left alone: Daily overload and marital behavior.

Science.gov (United States)

Sears, Meredith S; Repetti, Rena L; Robles, Theodore F; Reynolds, Bridget M

2016-08-01

Stressful, busy days have been linked with increases in angry and withdrawn marital behavior. The process by which stressors in 1 domain, such as work, affect an individual’s behavior in another domain, such as the marital relationship, is known as spillover . Using 56 days of daily diary reports in a diverse sample of 47 wives and 39 husbands, this study examined associations between daily experiences of overload and 3 marital behaviors: overt expressions of anger, disregard of the spouse’s needs (“disregard”), and reductions in affection and disclosure (“distancing”). Two potential mechanisms by which daily overload spills over into marital behavior were examined: negative mood and the desire to avoid social interaction. Among husbands, negative mood mediated the association between overload and angry behavior. Associations between overload and wives’ angry behavior, as well as overload and husbands’ and wives’ disregard of their partners’ needs, were mediated by both negative mood and the desire to withdraw socially. Desire to withdraw, but not negative mood, mediated the association between overload and distancing behavior among husbands and wives. In addition, associations between marital satisfaction and spouses’ typical marital behavior, as well as behavioral responses to overload, were examined. Husbands’ and wives’ average levels of expressed anger and disregard, and husbands’ distancing, were associated with lower marital satisfaction in 1 or both partners. Both spouses reported lower marital satisfaction if husbands tended to express marital anger, disregard, or distancing on busy, overloaded days. PsycINFO Database Record (c) 2016 APA, all rights reserved

The role of adenosine in preconditioning by brief pressure overload in rats.

Science.gov (United States)

Huang, Cheng-Hsiung; Tsai, Shen-Kou; Chiang, Shu-Chiung; Lai, Chang-Chi; Weng, Zen-Chung

2015-08-01

Brief pressure overload of the left ventricle reduced myocardial infarct (MI) size in rabbits has been previously reported. Its effects in other species are not known. This study investigates effects of pressure overload and the role of adenosine in rats in this study. MI was induced by 40-minute occlusion of the left anterior descending coronary artery followed by 3-hour reperfusion. MI size was determined by triphenyl tetrazolium chloride staining. Brief pressure overload was induced by two 10-minute episodes of partial snaring of the ascending aorta. Systolic left ventricular pressure was raised 50% above the baseline value. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions. The MI size (mean ± standard deviation), expressed as percentage of area at risk, was significantly reduced in the pressure overload group as well as in the ischemic preconditioning group (17.4 ± 3.0% and 18.2 ± 1.5% vs. 26.6 ± 2.4% in the control group, p overload and ischemic preconditioning (18.3 ± 1.5% and 18.2 ± 2.0%, respectively, p overload of the left ventricle preconditioned rat myocardium against infarction. Because SPT did not significantly alter MI size reduction, our results did not support a role of adenosine in preconditioning by pressure overload in rats. Copyright © 2013. Published by Elsevier B.V.

Can We Ever Escape from Data Overload? A Cognitive Systems Diagnosis

National Research Council Canada - National Science Library

Woods, David

1998-01-01

Data overload is a generic and tremendously difficult problem. In this report, we diagnose why this is the case and how intelligence analysis presents a particularly difficult version of data overload...

Reducing unidentified MOV failures: An innovative approach to thermal overload monitoring

International Nuclear Information System (INIS)

Hill, K.; Watson, M.E.; Ali, H.S.; Schlesinger, R.

1991-01-01

Historically the failure of motor-operated valves to actuate on demand has caused plant transients, reduced safety system reliability, and lost plant availability. The typical control and indication circuit design uses thermal overload contacts in the control circuit only. This has been recognized as a significant unidentified valve failure mode that may prevent the valve from performing its safety function when required. Different approaches have been evaluated to alert operations personnel to this thermal overload condition, but no cost-effective solution has provided indication of the thermal overload while maintaining valve position indication. Iowa Electric Light and Power Company's Duane Arnold Energy Center (DAEC) is utilizing a nuclear-qualified thermal overload monitor in valve control and indication circuits. This innovative approach has proven economical as no new cabling or indicating devices are required. Indication is provided using existing valve position indicating lights. The monitor is engineered to provide indication of a thermal overload trip as well as continuous indication of valve position, consistent with Regulatory Guide 1.97 and guidance provided by Generic Letter 89-10

Learners' perceived information overload in online learning via computer-mediated communication

Directory of Open Access Journals (Sweden)

Karen L. Murphy

2011-12-01

Full Text Available Many studies report information overload as one of the main problems that students encounter in online learning via computer-mediated communication. This study aimed to explore the sources of online students' information overload and offer suggestions for increasing students' cognitive resources for learning. Participants were 12 graduate students from two online courses in the United States. Their learning experiences in both online discussions and on the course website were explored through semi-structured interviews. They also completed a background questionnaire that assessed three constructs that limit learner readiness and are likely to lead to online students' perceived information overload: inadequate prior knowledge, inadequate English proficiency, and lack of technical skills for participating in computer-mediated communications. The findings suggest that varied learner characteristics led some students to be more susceptible than others to information overload. Emerging data-driven risk factors were: lack of efficiency in reading from computer screens, visual and auditory learning preferences, and time constraints. Difficulties associated with students' perceptions of information overload are addressed and implications for course design are offered.

Working memory overload: fronto-limbic interactions and effects on subsequent working memory function.

Science.gov (United States)

Yun, Richard J; Krystal, John H; Mathalon, Daniel H

2010-03-01

The human working memory system provides an experimentally useful model for examination of neural overload effects on subsequent functioning of the overloaded system. This study employed functional magnetic resonance imaging in conjunction with a parametric working memory task to characterize the behavioral and neural effects of cognitive overload on subsequent cognitive performance, with particular attention to cognitive-limbic interactions. Overloading the working memory system was associated with varying degrees of subsequent decline in performance accuracy and reduced activation of brain regions central to both task performance and suppression of negative affect. The degree of performance decline was independently predicted by three separate factors operating during the overload condition: the degree of task failure, the degree of amygdala activation, and the degree of inverse coupling between the amygdala and dorsolateral prefrontal cortex. These findings suggest that vulnerability to overload effects in cognitive functioning may be mediated by reduced amygdala suppression and subsequent amygdala-prefrontal interaction.

Effect of overload on the fatigue crack propagation in metastable beta Ti-V alloys

International Nuclear Information System (INIS)

Chakrabortty, S.B.; Starke, E.A. Jr.; Lee, E.W.

1984-01-01

The effects of overload on the fatigue crack propagation behavior of two Ti-V alloys having different deformation mechanisms were studied. The results are explained in terms of residual stress effects associated with the overload and the removal of these stresses during post-overload cycling. An additional effect occurs during multiple cycle overload when the deformation structure representative of the strain amplitude is believed to form in the overload reverse plastic zone. This structure must be rearranged during cycling at Delta Kb before the baseline FCGR is reached and the process is responsible for part of the delay period. 46 references

Overload Control in Smart Transformer-Fed Grid

Directory of Open Access Journals (Sweden)

Giovanni De Carne

2017-02-01

Full Text Available Renewable energy resources and new loads—such as electric vehicles—challenge grid management. Among several scenarios, the smart transformer represents a solution for simultaneously managing low- and medium-voltage grids, providing ancillary services to the distribution grid. However, unlike conventional transformers, the smart transformer has a very limited overload capability, because the junction temperature—which must always be below its maximum limit—is characterized by a short time constant. In this work, an overload control for smart transformer by means of voltage and frequency variations has been proposed and verified by means of simulations and experiments.

On modelling of lateral buckling failure in flexible pipe tensile armour layers

DEFF Research Database (Denmark)

Østergaard, Niels Højen; Lyckegaard, Anders; Andreasen, Jens H.

2012-01-01

In the present paper, a mathematical model which is capable of representing the physics of lateral buckling failure in the tensile armour layers of flexible pipes is introduced. Flexible pipes are unbounded composite steel–polymer structures, which are known to be prone to lateral wire buckling...... when exposed to repeated bending cycles and longitudinal compression, which mainly occurs during pipe laying in ultra-deep waters. On the basis of multiple single wire analyses, the mechanical behaviour of both layers of tensile armour wires can be determined. Since failure in one layer destabilises...... the torsional equilibrium which is usually maintained between the layers, lateral wire buckling is often associated with a severe pipe twist. This behaviour is discussed and modelled. Results are compared to a pipe model, in which failure is assumed not to cause twist. The buckling modes of the tensile armour...

LPTR irradiation of LLL vanadium tensile specimens and LLL Nb--1Zr tensile specimens

International Nuclear Information System (INIS)

MacLean, S.C.; Rowe, C.L.

1977-01-01

The LPTR irradiation of 14 LLL vanadium tensile specimens and 14 LLL Nb-1Zr tensile specimens is described. Sample packaging, the irradiation schedule and neutron fluences for three energy ranges are given

Fetal liver iron overload: the role of MR imaging

International Nuclear Information System (INIS)

Cassart, Marie; Avni, Freddy Efraim; Guibaud, Laurent; Molho, Marc; D'Haene, Nicky; Paupe, Alain

2011-01-01

To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload. We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n = 2), digestive tract anomalies (n = 3) and hydrops fetalis (n = 2). The average GA of the fetuses was 31 weeks. The antenatal diagnoses were compared with histological data (n = 6) and postnatal work-up (n = 1). Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n = 2) and fetopathology (n = 4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n = 2) and syndromal anomalies (n = 2)) and congenital haemochromatosis (n = 3). In all cases, the liver appeared normal on US. Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante - (in the case of recurrence) or neonatal treatment, which might improve the prognosis. (orig.)

Fetal liver iron overload: the role of MR imaging

Energy Technology Data Exchange (ETDEWEB)

Cassart, Marie; Avni, Freddy Efraim [Erasme Hospital, Medical imaging, Brussels, Brabant (Belgium); Guibaud, Laurent [Hopital femme mere enfant, Imagerie Pediatrique et Foetale, Lyon-Bron (France); Molho, Marc [C.H.I Poissy/St Germain-en-Laye, Imagerie Medicale, Poissy (France); D' Haene, Nicky [Erasme Hospital, Anatomopathology Department, Brussels (Belgium); Paupe, Alain [C.H.I Poissy/St Germain-en-Laye, Pediatrie, Poissy (France)

2011-02-15

To assess the potential role of MR imaging in the diagnosis of fetal liver iron overload. We reviewed seven cases of abnormal liver signal in fetuses referred to MR imaging in a context of suspected congenital infection (n = 2), digestive tract anomalies (n = 3) and hydrops fetalis (n = 2). The average GA of the fetuses was 31 weeks. The antenatal diagnoses were compared with histological data (n = 6) and postnatal work-up (n = 1). Magnetic resonance imaging demonstrated unexpected abnormal fetal liver signal suggestive of iron overload in all cases. The iron overload was confirmed on postnatal biopsy (n = 2) and fetopathology (n = 4). The final diagnosis was hepatic hemosiderosis (haemolytic anaemia (n = 2) and syndromal anomalies (n = 2)) and congenital haemochromatosis (n = 3). In all cases, the liver appeared normal on US. Magnetic resonance is the only imaging technique able to demonstrate liver iron overload in utero. Yet, the study outlines the fundamental role of MR imaging in cases of congenital haemochromatosis. The antenatal diagnosis of such a condition may prompt ante - (in the case of recurrence) or neonatal treatment, which might improve the prognosis. (orig.)

Information overload an international challenge to professional engineers and technical communicators

CERN Document Server

Ulijn, J M; Fazal, Zohra

2012-01-01

"This book covers the ever-increasing problem of information overload from both the professional and academic perspectives. Focusing on the needs of practicing engineers and professional communicators, it addresses the causes and costs of information overload, along with strategies and techniques for reducing and minimizing its negative effects. The theoretical framework of information overload and ideas for future research are also presented. The book brings together an international group of authors, providing a truly global point of view on this important, rarely covered topic"--

Tensile and creep data on type 316 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Sikka, V. K.; Booker, B. L.P.; Booker, M. K.; McEnerney, J. W.

1980-01-01

This report summarizes tensile and creep data on 13 heats of type 316 stainless steel. It includes ten different product forms (three plates, four pipes, and three bars) of the reference heat tested at ORNL. Tensile data are presented in tabular form and analyzed as a function of temperature by the heat centering method. This method yielded a measure of variations within a single heat as well as among different heats. The upper and lower scatter bands developed by this method were wider at the lower temperatures than at the high temperatures (for strength properties), a trend reflected by the experimental data. The creep data on both unaged and aged specimens are presented in tabular form along with creep curves for each test. The rupture time data are compared with the ASME Code Case minimum curve at each test temperature in the range from 538 to 704{sup 0}C. The experimental rupture time data are also compared with the values predicted by using the rupture model based on elevated-temperature ultimate tensile strength. A creep ductility trend curve was developed on the basis of the reference heat data and those published in the literature on nitrogen effects. To characterize the data fully, information was also supplied on vendor, product form, fabrication method, material condition (mill-annealed vs laboratory annealed and aged), grain size, and chemical composition for various heats. Test procedures used for tensile and creep results are also discussed.

Role of work overload toward turnover intention among newly hired public accountants

OpenAIRE

Pradana, Andika; Salehudin, Imam

2013-01-01

This paper aims to analyze how work overload influences turnover intentions of newly hired public accountants. Job satisfaction, work related stress and work life conflicts are used as mediating variable between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. Six proposed hypotheses was tested using Structural Equation Modeling (SEM). Results showed that work overload has significant effect in increa...

On the efficacy of using the transfer-controlled procedure during periods of STP processor overloads in SS7 networks

Science.gov (United States)

Rumsewicz, Michael

1994-04-01

In this paper, we examine call completion performance, rather than message throughput, in a Common Channel Signaling network in which the processing resources, and not transmission resources, of a Signaling Transfer Point (STP) are overloaded. Specifically, we perform a transient analysis, via simulation, of a network consisting of a single Central Processor-based STP connecting many local exchanges. We consider the efficacy of using the Transfer Controlled (TFC) procedure when the network call attempt rate exceeds the processing capability of the STP. We find the following: (1) the success of the control depends critically on the rate at which TFC's are sent; (2) use of the TFC procedure in theevent of processor overload can provide reasonable call completion rates.

Does information overload prevent chronic patients from reading self-management educational materials?

Science.gov (United States)

Liu, Chung-Feng; Kuo, Kuang-Ming

2016-05-01

Self-care management is becoming an important part of care for chronic patients. However, various kinds of self-management educational materials which government or healthcare institutions provide for patients may not achieve the expected outcome. One of the critical reasons affecting patients' use intention could be patients' perceived information overload regarding the self-management educational materials. This study proposed an extended model of the Theory of Planned Behavior (TPB), which incorporated perceived information overload, to explore if information overload will prevent chronic patients from reading educational materials for self-care management. The independent variables are attitude, subject norm, perceived behavior control and perceived information overload while the dependent variable is behavior intention to use the self-management educational materials. Perceived information overload is also referred to as an antecedent variable which may has impacts on attitude and perceived behavior control. The cross-sectional study interviewed newly diagnosed chronic patients with coronary artery disease, who are the potential users of the self-management educational materials, in a medical center in Taiwan. Data were analyzed using descriptive statistics of the basic information distribution of the respondents, and structural equation modeling to study the reliability and validity for testing hypotheses. A total of 110 respondents were enrolled in this study and successful interview data were collected from 106 respondents. The result indicates that the patients' perceived information overload of self-management educational materials was validated to have impacts on attitude and perceived behavioral control constructs of the TPB as well as contributing a direct impact on patients' intentions to use self-management educational materials. Besides, subjective norm and perceived behavioral control constructs were validated to have significant impacts on

Fuzzy ranking based non-dominated sorting genetic algorithm-II for network overload alleviation

Directory of Open Access Journals (Sweden)

Pandiarajan K.

2014-09-01

Full Text Available This paper presents an effective method of network overload management in power systems. The three competing objectives 1 generation cost 2 transmission line overload and 3 real power loss are optimized to provide pareto-optimal solutions. A fuzzy ranking based non-dominated sorting genetic algorithm-II (NSGA-II is used to solve this complex nonlinear optimization problem. The minimization of competing objectives is done by generation rescheduling. Fuzzy ranking method is employed to extract the best compromise solution out of the available non-dominated solutions depending upon its highest rank. N-1 contingency analysis is carried out to identify the most severe lines and those lines are selected for outage. The effectiveness of the proposed approach is demonstrated for different contingency cases in IEEE 30 and IEEE 118 bus systems with smooth cost functions and their results are compared with other single objective evolutionary algorithms like Particle swarm optimization (PSO and Differential evolution (DE. Simulation results show the effectiveness of the proposed approach to generate well distributed pareto-optimal non-dominated solutions of multi-objective problem

Females Are Protected From Iron-Overload Cardiomyopathy Independent of Iron Metabolism: Key Role of Oxidative Stress.

Science.gov (United States)

Das, Subhash K; Patel, Vaibhav B; Basu, Ratnadeep; Wang, Wang; DesAulniers, Jessica; Kassiri, Zamaneh; Oudit, Gavin Y

2017-01-23

Sex-related differences in cardiac function and iron metabolism exist in humans and experimental animals. Male patients and preclinical animal models are more susceptible to cardiomyopathies and heart failure. However, whether similar differences are seen in iron-overload cardiomyopathy is poorly understood. Male and female wild-type and hemojuvelin-null mice were injected and fed with a high-iron diet, respectively, to develop secondary iron overload and genetic hemochromatosis. Female mice were completely protected from iron-overload cardiomyopathy, whereas iron overload resulted in marked diastolic dysfunction in male iron-overloaded mice based on echocardiographic and invasive pressure-volume analyses. Female mice demonstrated a marked suppression of iron-mediated oxidative stress and a lack of myocardial fibrosis despite an equivalent degree of myocardial iron deposition. Ovariectomized female mice with iron overload exhibited essential pathophysiological features of iron-overload cardiomyopathy showing distinct diastolic and systolic dysfunction, severe myocardial fibrosis, increased myocardial oxidative stress, and increased expression of cardiac disease markers. Ovariectomy prevented iron-induced upregulation of ferritin, decreased myocardial SERCA2a levels, and increased NCX1 levels. 17β-Estradiol therapy rescued the iron-overload cardiomyopathy in male wild-type mice. The responses in wild-type and hemojuvelin-null female mice were remarkably similar, highlighting a conserved mechanism of sex-dependent protection from iron-overload-mediated cardiac injury. Male and female mice respond differently to iron-overload-mediated effects on heart structure and function, and females are markedly protected from iron-overload cardiomyopathy. Ovariectomy in female mice exacerbated iron-induced myocardial injury and precipitated severe cardiac dysfunction during iron-overload conditions, whereas 17β-estradiol therapy was protective in male iron-overloaded mice. �

Laser-induced generation of pure tensile stresses

International Nuclear Information System (INIS)

Niemz, M.H.; Lin, C.P.; Pitsillides, C.; Cui, J.; Doukas, A.G.; Deutsch, T.F.

1997-01-01

While short compressive stresses can readily be produced by laser ablation, the generation of pure tensile stresses is more difficult. We demonstrate that a 90 degree prism made of polyethylene can serve to produce short and pure tensile stresses. A compressive wave is generated by ablating a thin layer of strongly absorbing ink on one surface of the prism with a Q-switched frequency-doubled Nd:YAG laser. The compressive wave driven into the prism is reflected as a tensile wave by the polyethylene-air interface at its long surface. The low acoustic impedance of polyethylene makes it ideal for coupling tensile stresses into liquids. In water, tensile stresses up to -200bars with a rise time of the order of 20 ns and a duration of 100 ns are achieved. The tensile strength of water is determined for pure tensile stresses lasting for 100 ns only. The technique has potential application in studying the initiation of cavitation in liquids and in comparing the effect of compressive and tensile stress transients on biological media. copyright 1997 American Institute of Physics

Method for independent strain and temperature measurement in polymeric tensile test specimen using embedded FBG sensors

DEFF Research Database (Denmark)

Pereira, Gilmar Ferreira; McGugan, Malcolm; Mikkelsen, Lars Pilgaard

2016-01-01

to calculate independently the strain and temperature are presented in the article, together with a measurement resolution study. This multi-parameter measurement method was applied to an epoxy tensile specimen, tested in a unidirectional tensile test machine with a temperature controlled cabinet. A full......A novel method to obtain independent strain and temperature measurements using embedded Fibre Bragg Grating (FBG) in polymeric tensile test specimens is presented in this paper. The FBG strain and temperature cross-sensitivity was decoupled using two single mode FBG sensors, which were embedded...... of temperature, from 40 C to -10 C. The consistency of the expected theoretical results with the calibration procedure and the experimental validation shows that this proposed method is applicable to measure accurate strain and temperature in polymers during static or fatigue tensile testing. Two different...

Elbow arthroscopy: valgus extension overload.

Science.gov (United States)

Ahmad, Christopher S; Conway, John E

2011-01-01

Valgus torque combined with deceleration produces high compression and shear forces acting on the posteromedial olecranon and the posteromedial trochlea. This valgus extension overload process may cause posteromedial trochlea chondromalacia, chondral flap formation, osteochondrosis, subchondral erosion, a subchondral insufficiency fracture, and marginal exostosis formation. Olecranon pathologies include proximal stress reaction, a posteromedial tip stress fracture, a transverse proximal process stress fracture, exostosis formation, exostosis fragmentation, and intra-articular loose bodies. Symptoms include posteromedial elbow pain during the deceleration phase of the throwing motion. The extension impingement test reproduces posterior or posteromedial pain similar to that experienced while throwing. Special radiographic techniques and CT scans can show loose bodies and osteophyte fragmentation. Surgical treatment is indicated when symptoms persist despite nonsurgical management. Based on clinical and basic science research, all patients with valgus extension overload should be comprehensively evaluated for medial ulnar collateral ligament insufficiency. Surgical treatment is limited to the resection of osteophytes only; normal olecranon should not be resected.

Development of an overload control strategy for the Republic of Senegal

CSIR Research Space (South Africa)

Nordengen, Paul A

2006-09-01

Full Text Available , particularly because there are currently no weighbridges in the country being used for overload control law enforcement. Recognising the need for an effective overload strategy for Senegal, the Ministry of Public Works and Transport decided to initiate a study...

Role of electrocardiographic changes in discriminating acute or chronic right ventricular pressure overload.

Science.gov (United States)

Can, Mehmet Mustafa; Özveren, Olcay; Biteker, Murat; Şengül, Cihan; Uz, Ömer; Işılak, Zafer; Kırılmaz, Ata

2013-06-01

Pulmonary embolism (PE) and severe pulmonary stenosis (PS) are two distinct conditions accompanied by increased pressure load of the right ventricle (RV). Despite major advances in our understanding of the mechanisms of RV adaptation to the increased pressure, substantial gaps in our knowledge remain unsettled. One of much less known aspect of pressure overload of RV is its impact on electrocardiographic (ECG) changes. In this study, we aimed to study whether acute and chronic RV overload are accompanied by different ECG patterns. Thirty-eight patients with PE underwent ECG monitoring were compared with 20 matched patients with PS in this observational retrospective study. ECG abnormalities suggestive of RV overload were recorded and analyzed in both groups. Logistic regression analysis was used to define the predictors of chronic RV overload. Among the ECG changes studied, premature atrial contraction (OR-12.2, 95% CI, 1.3-107, p=0.008), right axis deviation (OR-20.4, 95% CI 4.2-98, poverload. Our data indicate that the ECG changes that attributed to the acute RV pressure loading states may be more prevalent in chronic RV overload as compared with acute RV overload.

Pharmacokinetics study of Zr-89-labeled melanin nanoparticle in iron-overload mice

International Nuclear Information System (INIS)

Zhang, Pengjun; Yue, Yuanyuan; Pan, Donghui; Yang, Runlin; Xu, Yuping; Wang, Lizhen; Yan, Junjie; Li, Xiaotian; Yang, Min

2016-01-01

Melanin, a natural biological pigment present in many organisms, has been found to exhibit multiple functions. An important property of melanin is its ability to chelate metal ions strongly, which might be developed as an iron chelator for iron overload therapy. Herein, we prepared the ultrasmall water-soluble melanin nanoparticle (MP) and firstly evaluate the pharmacokinetics of MP in iron-overload mice to provide scientific basis for treating iron-overload. To study the circulation time and biodistribution, MP was labeled with 89 Zr, a long half-life (78.4 h) positron-emitting metal which is suited for the labeling of nanoparticles and large bioactive molecule. MP was chelated with 89 Zr directly at pH 5, resulting in non-decay-corrected yield of 89.6% and a radiochemical purity of more than 98%. The specific activity was at least190 MBq/μmol. The 89 Zr-MP was stable in human plasma and PBS for at least 48 h. The half-life of 89 Zr-MP was about 15.70 ± 1.74 h in iron-overload mice. Biodistribution studies and MicroPET imaging showed that 89 Zr-MP mainly accumulated in liver and spleen, which are the target organ of iron-overload. The results indicate that the melanin nanoparticle is promising for further iron overload therapy.

Acute iron overload and oxidative stress in brain

International Nuclear Information System (INIS)

Piloni, Natacha E.; Fermandez, Virginia; Videla, Luis A.; Puntarulo, Susana

2013-01-01

An in vivo model in rat was developed by intraperitoneally administration of Fe-dextran to study oxidative stress triggered by Fe-overload in rat brain. Total Fe levels, as well as the labile iron pool (LIP) concentration, in brain from rats subjected to Fe-overload were markedly increased over control values, 6 h after Fe administration. In this in vivo Fe overload model, the ascorbyl (A·)/ascorbate (AH − ) ratio, taken as oxidative stress index, was assessed. The A·/AH − ratio in brain was significantly higher in Fe-dextran group, in relation to values in control rats. Brain lipid peroxidation indexes, thiobarbituric acid reactive substances (TBARS) generation rate and lipid radical (LR·) content detected by Electron Paramagnetic Resonance (EPR), in Fe-dextran supplemented rats were similar to control values. However, values of nuclear factor-kappaB deoxyribonucleic acid (NFκB DNA) binding activity were significantly increased (30%) after 8 h of Fe administration, and catalase (CAT) activity was significantly enhanced (62%) 21 h after Fe administration. Significant enhancements in Fe content in cortex (2.4 fold), hippocampus (1.6 fold) and striatum (2.9 fold), were found at 6 h after Fe administration. CAT activity was significantly increased after 8 h of Fe administration in cortex, hippocampus and striatum (1.4 fold, 86, and 47%, respectively). Fe response in the whole brain seems to lead to enhanced NF-κB DNA binding activity, which may contribute to limit oxygen reactive species-dependent damage by effects on the antioxidant enzyme CAT activity. Moreover, data shown here clearly indicate that even though Fe increased in several isolated brain areas, this parameter was more drastically enhanced in striatum than in cortex and hippocampus. However, comparison among the net increase in LR· generation rate, in different brain areas, showed enhancements in cortex lipid peroxidation, without changes in striatum and hippocampus LR· generation rate after 6

A composite mouse model of aplastic anemia complicated with iron overload.

Science.gov (United States)

Wu, Dijiong; Wen, Xiaowen; Liu, Wenbin; Xu, Linlong; Ye, Baodong; Zhou, Yuhong

2018-02-01

Iron overload is commonly encountered during the course of aplastic anemia (AA), but no composite animal model has been developed yet, which hinders drug research. In the present study, the optimal dosage and duration of intraperitoneal iron dextran injection for the development of an iron overload model in mice were explored. A composite model of AA was successfully established on the principle of immune-mediated bone marrow failure. Liver volume, peripheral hemogram, bone marrow pathology, serum iron, serum ferritin, pathological iron deposition in multiple organs (liver, bone marrow, spleen), liver hepcidin, and bone morphogenetic protein 6 (BMP6), SMAD family member 4 (SMAD4) and transferrin receptor 2 (TfR2) mRNA expression levels were compared among the normal control, AA, iron overload and composite model groups to validate the composite model, and explore the pathogenesis and features of iron overload in this model. The results indicated marked increases in iron deposits, with significantly increased liver/body weight ratios as well as serum iron and ferritin in the iron overload and composite model groups as compared with the normal control and AA groups (Poverload and AA was successfully established, and AA was indicated to possibly have a critical role in abnormal iron metabolism, which promoted the development of iron deposits.

Changes in bacteria composition and efficiency of constructed wetlands under sustained overloads: A modeling experiment.

Science.gov (United States)

Boano, F; Rizzo, A; Samsó, R; García, J; Revelli, R; Ridolfi, L

2018-01-15

The average organic and hydraulic loads that Constructed Wetlands (CWs) receive are key parameters for their adequate long-term functioning. However, over their lifespan they will inevitably be subject to either episodic or sustained overloadings. Despite that the consequences of sustained overloading are well known (e.g., clogging), the threshold of overloads that these systems can tolerate is difficult to determine. Moreover, the mechanisms that might sustain the buffering capacity (i.e., the reduction of peaks in nutrient load) during overloads are not well understood. The aim of this work is to evaluate the effect of sudden but sustained organic and hydraulic overloads on the general functioning of CWs. To that end, the mathematical model BIO_PORE was used to simulate five different scenarios, based on the features and operation conditions of a pilot CW system: a control simulation representing the average loads; 2 simulations representing +10% and +30% sustained organic overloads; one simulation representing a sustained +30% hydraulic overload; and one simulation with sustained organic and hydraulic overloads of +15% each. Different model outputs (e.g., total bacterial biomass and its spatial distribution, effluent concentrations) were compared among different simulations to evaluate the effects of such operation changes. Results reveal that overloads determine a temporary decrease in removal efficiency before microbial biomass adapts to the new conditions and COD removal efficiency is recovered. Increasing organic overloads cause stronger temporary decreases in COD removal efficiency compared to increasing hydraulic loads. The pace at which clogging develops increases by 10% for each 10% increase on the organic load. Copyright © 2017 Elsevier B.V. All rights reserved.

Work Overload and Turnover Intention of Junior Auditors in Greater Jakarta, Indonesia

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Andika Pradana

2015-11-01

Full Text Available This paper aims to analyze how work overload influences turnover intentions of newly hired junior auditors in public accounting offices. Job satisfaction, work related stress and work life conflicts are used as mediating variables between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. The sample was selected using purposive sampling. Three mediation hypotheses were tested using Structural Equation Modeling (SEM. The results show that work overload has a significant effect on increasing turnover intention through both job satisfaction and work related stress. In comparison, work overload does not influence turnover intention through work life balance. This may be due to the nature of the respondents, in which a majority of the newly hired accountants employed in this study are unmarried.

Role overload, pain and physical dysfunction in early rheumatoid or undifferentiated inflammatory arthritis in Canada.

Science.gov (United States)

Mustafa, Sally Sabry; Looper, Karl Julian; Zelkowitz, Phyllis; Purden, Margaret; Baron, Murray

2012-05-03

Inflammatory arthritis impairs participation in societal roles. Role overload arises when the demands by a given role set exceed the resources; time and energy, to carry out the required tasks. The present study examines the association between role overload and disease outcomes in early inflammatory arthritis (EIA). Patients (n = 104) of 7.61 months mean duration of inflammatory arthritis completed self-report questionnaires on sociodemographics, disease characteristics and role overload. Pain was assessed using the Short Form McGill Pain Questionnaire (MPQ) and physical functioning was measured with the Medical Outcomes Study Short Form 36 (SF-36) physical functioning score. Role overload was measured by the Role Overload Scale. Patients indicated the number of social roles they occupied from a total of the three typical roles; marital, parental and paid work. Participants' mean age was 56 years and 70.2% were female. Role overload was not correlated to the number of social roles, however, it was positively associated with pain (p = 0.004) and negatively associated with physical functioning (p = 0.001). On multivariate analysis, role overload was negatively associated with physical functioning after controlling for the relevant sociodemographic variables. This study identifies a possible reciprocal relationship between role overload and physical functioning in patients with EIA.

Effect of short-term overloads on crack propagation under creep

International Nuclear Information System (INIS)

Sushok, V.V.; Sobolev, N.D.; Zolotukhin, S.Yu.

1986-01-01

Kinetics of crack propagation after overload has been studied using plane samples of Kh18N10T steel. Tests of samples with a notch have been carried out in the air at 293 K. Observation of the crack growth has been carried out by the microscope and the method of electric potential difference. It is established that during overload besides crack tip blunting, decrease of creep rate of the material stregthened near it, that leads to crack retardation, decrease of plasticity and formation of microcracks in front of the tip of the main-line crack occurs. It is marked that, estimating serviceability of a member, it is necessary to take into account the decrease of crack propagation rate after short term overloads

Surface orientation effects on bending properties of surgical mesh are independent of tensile properties.

Science.gov (United States)

Simon, David D; Andrews, Sharon M; Robinson-Zeigler, Rebecca; Valdes, Thelma; Woods, Terry O

2018-02-01

Current mechanical testing of surgical mesh focuses primarily on tensile properties even though implanted devices are not subjected to pure tensile loads. Our objective was to determine the flexural (bending) properties of surgical mesh and determine if they correlate with mesh tensile properties. The flexural rigidity values of 11 different surgical mesh designs were determined along three textile directions (machine, cross-machine, and 45° to machine; n = 5 for each) using ASTM D1388-14 while tracking surface orientation. Tensile testing was also performed on the same specimens using ASTM D882-12. Linear regressions were performed to compare mesh flexural rigidity to mesh thickness, areal mass density, filament diameter, ultimate tensile strength, and maximum extension. Of 33 mesh specimen groups, 30 had significant differences in flexural rigidity values when comparing surface orientations (top and bottom). Flexural rigidity and mesh tensile properties also varied with textile direction (machine and cross-machine). There was no strong correlation between the flexural and tensile properties, with mesh thickness having the best overall correlation with flexural rigidity. Currently, surface orientation is not indicated on marketed surgical mesh, and a single mesh may behave differently depending on the direction of loading. The lack of correlation between flexural stiffness and tensile properties indicates the need to examine mesh bending stiffness to provide a more comprehensive understanding of surgical mesh mechanical behaviors. Further investigation is needed to determine if these flexural properties result in the surgical mesh behaving mechanically different depending on implantation direction. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 854-862, 2018. © 2017 Wiley Periodicals, Inc.

HFE gene mutation and iron overload in Egyptian pediatric acute lymphoblastic leukemia survivors: a single-center study.

Science.gov (United States)

El-Rashedi, Farida H; El-Hawy, Mahmoud A; El-Hefnawy, Sally M; Mohammed, Mona M

2017-08-01

Hereditary hemochromatosis gene (HFE) mutations have a role in iron overload in pediatric acute lymphoblastic leukemia (ALL) survivors. We aimed to evaluate the genotype frequency and allelic distribution of the two HFE gene mutations (C282Y and H63D) in a sample of Egyptian pediatric ALL survivors and to detect the impact of these two mutations on their iron profile. This study was performed on 35 ALL survivors during their follow-up visits to the Hematology and Oncology Unit, Pediatric Department, Menoufia University Hospitals. Thirty-five healthy children of matched age and sex were chosen as controls. After completing treatment course, ALL survivors were screened for the prevalence of these two mutations by polymerase chain reaction-restriction fragment length polymorphism. Serum ferritin levels were measured by an enzyme-linked immunosorbent assay technique (ELISA). C282Y mutation cannot be detected in any of the 35 survivors or the 35 controls. The H63D heterozygous state (CG) was detected in 28.6% of the survivors group and in 20% of controls, while the H63D homozygous (GG) state was detected in 17.1% of survivors. No compound heterozygosity (C282Y/H63D) was detected at both groups with high G allele frequency (31.4%) in survivors more than controls (10%). There were significant higher levels of iron parameters in homozygote survivors than heterozygotes and the controls. H63D mutation aggravates the iron overload status in pediatric ALL survivors.

Iron overload impact on P-ATPases.

Science.gov (United States)

Sousa, Leilismara; Pessoa, Marco Tulio C; Costa, Tamara G F; Cortes, Vanessa F; Santos, Herica L; Barbosa, Leandro Augusto

2018-03-01

Iron is a chemical element that is active in the fundamental physiological processes for human life, but its burden can be toxic to the body, mainly because of the stimulation of membrane lipid peroxidation. For this reason, the action of iron on many ATPases has been studied, especially on P-ATPases, such as the Na + ,K + -ATPase and the Ca 2+ -ATPase. On the Fe 2+ -ATPase activity, the free iron acts as an activator, decreasing the intracellular Fe 2+ and playing a protection role for the cell. On the Ca 2+ -ATPase activity, the iron overload decreases the enzyme activity, raising the cytoplasmic Ca 2+ and decreasing the sarco/endoplasmic reticulum and the Golgi apparatus Ca 2+ concentrations, which could promote an enzyme oxidation, nitration, and fragmentation. However, the iron overload effect on the Na + ,K + -ATPase may change according to the tissue expressions. On the renal cells, as well as on the brain and the heart, iron promotes an enzyme inactivation, whereas its effect on the erythrocytes seems to be the opposite, directly stimulating the ATPase activity, or stimulating it by signaling pathways involving ROS and PKC. Modulations in the ATPase activity may impair the ionic transportation, which is essential for cell viability maintenance, inducing irreversible damage to the cell homeostasis. Here, we will discuss about the iron overload effect on the P-ATPases, such as the Na + ,K + -ATPase, the Ca 2+ -ATPase, and the Fe 2+ -ATPase.

Learners' Perceived Information Overload in Online Learning via Computer-Mediated Communication

Science.gov (United States)

Chen, Chun-Ying; Pedersen, Susan; Murphy, Karen L.

2011-01-01

Many studies report information overload as one of the main problems that students encounter in online learning via computer-mediated communication. This study aimed to explore the sources of online students' information overload and offer suggestions for increasing students' cognitive resources for learning. Participants were 12 graduate students…

Overload prevention in model supports for wind tunnel model testing

Directory of Open Access Journals (Sweden)

Anton IVANOVICI

2015-09-01

Full Text Available Preventing overloads in wind tunnel model supports is crucial to the integrity of the tested system. Results can only be interpreted as valid if the model support, conventionally called a sting remains sufficiently rigid during testing. Modeling and preliminary calculation can only give an estimate of the sting’s behavior under known forces and moments but sometimes unpredictable, aerodynamically caused model behavior can cause large transient overloads that cannot be taken into account at the sting design phase. To ensure model integrity and data validity an analog fast protection circuit was designed and tested. A post-factum analysis was carried out to optimize the overload detection and a short discussion on aeroelastic phenomena is included to show why such a detector has to be very fast. The last refinement of the concept consists in a fast detector coupled with a slightly slower one to differentiate between transient overloads that decay in time and those that are the result of aeroelastic unwanted phenomena. The decision to stop or continue the test is therefore conservatively taken preserving data and model integrity while allowing normal startup loads and transients to manifest.

Influence of overloads on dwell time fatigue crack growth in Inconel 718

Energy Technology Data Exchange (ETDEWEB)

Saarimäki, Jonas, E-mail: jonas.saarimaki@liu.se [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Moverare, Johan [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden); Siemens Industrial Turbomachinery AB, Materials Technology, SE-61283 Finspång (Sweden); Eriksson, Robert; Johansson, Sten [Division of Engineering Materials, Department of Management and Engineering, Linköping University, SE-58183 Linköping (Sweden)

2014-08-26

Inconel 718 is one of the most commonly used superalloys for high temperature applications in gasturbines and aeroengines and is for example used for components such as turbine discs. Turbine discs can be subjected to temperatures up to ∼700 °C towards the outer radius of the disc. During service, the discs might start to develop cracks due to fatigue and long dwell times. Additionally, temperature variations during use can lead to large thermal transients during start-up and shutdown which can lead to overload peaks in the normal dwell time cycle. In this study, tests at 550 °C with an overload prior to the start of each dwell time, have been performed. The aim of the investigation was to get a better understanding of the effects of overloads on the microstructure and crack mechanisms. The microstructure was studied using electron channelling contrast imaging (ECCI). The image analysis toolbox in Matlab was used on cross sections of the cracks to quantify: crack length, branch length, and the number of branches in each crack. It was found that the amount of crack branching increases with an increasing overload and that the branch length decreases with an increasing overload. When the higher overloads were applied, the dwell time effect was almost cancelled out. There is a strong tendency for an increased roughness of the crack path with an increasing crack growth rate.

Secoisolariciresinol diglucoside abrogates oxidative stress-induced damage in cardiac iron overload condition.

Directory of Open Access Journals (Sweden)

Stephanie Puukila

Full Text Available Cardiac iron overload is directly associated with cardiac dysfunction and can ultimately lead to heart failure. This study examined the effect of secoisolariciresinol diglucoside (SDG, a component of flaxseed, on iron overload induced cardiac damage by evaluating oxidative stress, inflammation and apoptosis in H9c2 cardiomyocytes. Cells were incubated with 50 μ5M iron for 24 hours and/or a 24 hour pre-treatment of 500 μ M SDG. Cardiac iron overload resulted in increased oxidative stress and gene expression of the inflammatory mediators tumor necrosis factor-α, interleukin-10 and interferon γ, as well as matrix metalloproteinases-2 and -9. Increased apoptosis was evident by increased active caspase 3/7 activity and increased protein expression of Forkhead box O3a, caspase 3 and Bax. Cardiac iron overload also resulted in increased protein expression of p70S6 Kinase 1 and decreased expression of AMP-activated protein kinase. Pre-treatment with SDG abrogated the iron-induced increases in oxidative stress, inflammation and apoptosis, as well as the increased p70S6 Kinase 1 and decreased AMP-activated protein kinase expression. The decrease in superoxide dismutase activity by iron treatment was prevented by pre-treatment with SDG in the presence of iron. Based on these findings we conclude that SDG was cytoprotective in an in vitro model of iron overload induced redox-inflammatory damage, suggesting a novel potential role for SDG in cardiac iron overload.

Influence of overloads on dwell time fatigue crack growth in Inconel 718

International Nuclear Information System (INIS)

Saarimäki, Jonas; Moverare, Johan; Eriksson, Robert; Johansson, Sten

2014-01-01

Inconel 718 is one of the most commonly used superalloys for high temperature applications in gasturbines and aeroengines and is for example used for components such as turbine discs. Turbine discs can be subjected to temperatures up to ∼700 °C towards the outer radius of the disc. During service, the discs might start to develop cracks due to fatigue and long dwell times. Additionally, temperature variations during use can lead to large thermal transients during start-up and shutdown which can lead to overload peaks in the normal dwell time cycle. In this study, tests at 550 °C with an overload prior to the start of each dwell time, have been performed. The aim of the investigation was to get a better understanding of the effects of overloads on the microstructure and crack mechanisms. The microstructure was studied using electron channelling contrast imaging (ECCI). The image analysis toolbox in Matlab was used on cross sections of the cracks to quantify: crack length, branch length, and the number of branches in each crack. It was found that the amount of crack branching increases with an increasing overload and that the branch length decreases with an increasing overload. When the higher overloads were applied, the dwell time effect was almost cancelled out. There is a strong tendency for an increased roughness of the crack path with an increasing crack growth rate

Managing Information Overload for Senior Leaders in the 21st Century

Science.gov (United States)

Jackson, Jason M.

2013-01-01

Information overload is a state where information input exceeds processing capability by an individual, and adverse effects of information overload, such as becoming less productive, making bad decisions, and becoming highly selective, are growing. Guided by Glaser and Strauss' work on grounded theory, this study examined adverse impact of…

WORK OVERLOAD AND TURNOVER INTENTION OF JUNIOR AUDITORS IN GREATER JAKARTA, INDONESIA

Directory of Open Access Journals (Sweden)

Andika Pradana

2015-11-01

Full Text Available This paper aims to analyze how work overload influences turnover intentions of newly hired junior auditors in public accounting offices. Job satisfaction, work related stress and work life conflicts are used as mediating variables between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. The sample was selected using purposive sampling. Three mediation hypotheses were tested using Structural Equation Modeling (SEM. The results show that work overload has a significant effect on increas- ing turnover intention through both job satisfaction and work related stress. In comparison, work overload does not influence turnover intention through work life balance. This may be due to the nature of the respondents, in which a majority of the newly hired accountants employed in this study are unmarried.

Status of automated tensile machine

International Nuclear Information System (INIS)

Satou, M.; Hamilton, M.L.; Sato, S.; Kohyama, A.

1992-01-01

The objective of this work is to develop the Monbusho Automated Tensile machine (MATRON) and install and operate it at the Pacific Northwest Laboratory (PNL). The machine is designed to provide rapid, automated testing of irradiated miniature tensile specimen in a vacuum at elevated temperatures. The MATRON was successfully developed and shipped to PNL for installation in a hot facility. The original installation plan was modified to simplify the current and subsequent installations, and the installation was completed. Detailed procedures governing the operation of the system were written. Testing on irradiated miniature tensile specimen should begin in the near future

Mild iron overload in patients carrying the HFE S65C gene mutation: a retrospective study in patients with suspected iron overload and healthy controls

OpenAIRE

Holmström, P; Marmur, J; Eggertsen, G; Gåfvels, M; Stål, P

2002-01-01

Background and aims: The role of the HFE S65C mutation in the development of hepatic iron overload is unknown. The aim of the present study was: (A) to determine the HFE S65C frequency in a Northern European population; and (B) to evaluate whether the presence of the HFE S65C mutation would result in a significant hepatic iron overload.

Role of T1 mapping as a complementary tool to T2* for non-invasive cardiac iron overload assessment.

Science.gov (United States)

Torlasco, Camilla; Cassinerio, Elena; Roghi, Alberto; Faini, Andrea; Capecchi, Marco; Abdel-Gadir, Amna; Giannattasio, Cristina; Parati, Gianfranco; Moon, James C; Cappellini, Maria D; Pedrotti, Patrizia

2018-01-01

Iron overload-related heart failure is the principal cause of death in transfusion dependent patients, including those with Thalassemia Major. Linking cardiac siderosis measured by T2* to therapy improves outcomes. T1 mapping can also measure iron; preliminary data suggests it may have higher sensitivity for iron, particularly for early overload (the conventional cut-point for no iron by T2* is 20ms, but this is believed insensitive). We compared T1 mapping to T2* in cardiac iron overload. In a prospectively large single centre study of 138 Thalassemia Major patients and 32 healthy controls, we compared T1 mapping to dark blood and bright blood T2* acquired at 1.5T. Linear regression analysis was used to assess the association of T2* and T1. A "moving window" approach was taken to understand the strength of the association at different levels of iron overload. The relationship between T2* (here dark blood) and T1 is described by a log-log linear regression, which can be split in three different slopes: 1) T2* low, 30ms, weak relationship. All subjects with T2*20ms, 38% had low T1 with most of the subjects in the T2* range 20-30ms having a low T1. In established cardiac iron overload, T1 and T2* are concordant. However, in the 20-30ms T2* range, T1 mapping appears to detect iron. These data support previous suggestions that T1 detects missed iron in 1 out of 3 subjects with normal T2*, and that T1 mapping is complementary to T2*. The clinical significance of a low T1 with normal T2* should be further investigated.

A low noise preamplifier with optoelectronic overload protection for radioactivity measurement

International Nuclear Information System (INIS)

Sephton, J.P.; Williams, J.M.; Johansson, L.C.; Philips, H.C.

2012-01-01

Pulses from detectors used for radioactivity measurement can vary in size by several orders of magnitude. Large pulses will lead to saturation at the preamplifier output and extension of the pulse length. As a consequence, the dead time of the system increases and pulses may be lost. Electronic design techniques employed to protect against overloading tend to increase the amplifier noise level. However, an optoelectronic method of overload protection has been devised which has only a negligible effect on noise. An infrared light emitting diode interfaced to the output of the preamplifier is linked by fibre optic cable to an ultra-low leakage photodiode at the input. The conduction of the photodiode increases with the amplitude of the preamplifier output signal. Excess current is thereby prevented from entering the preamplifier and causing saturation. The preamplifier has been tested on 4π beta–gamma and gas counting systems and found to give good protection against overloading. - Highlights: ► A preamplifier for radioactivity measurements has been developed. ► Low noise. ► Current sensitive. ► Optoelectronic overload protection.

Fetal development and renal function in adult rats prenatally subjected to sodium overload.

Science.gov (United States)

Cardoso, Henriqueta D; Cabral, Edjair V; Vieira-Filho, Leucio D; Vieyra, Adalberto; Paixão, Ana D O

2009-10-01

The aims of this study were (1) to evaluate two factors that affect fetal development--placental oxidative stress (Ox) and plasma volume (PV)--in dams with sodium overload and (2) to correlate possible alterations in these factors with subsequent modifications in the renal function of adult offspring. Wistar dams were maintained on 0.17 M NaCl instead of water from 20 days before mating until either the twentieth pregnancy day/parturition or weaning. Colorimetric methods were used to measure Ox in maternal and offspring tissues, PV, 24-h urinary protein (U(Prot24 h)) and serum triacylglycerols (TG) and cholesterol (Chol). Renal hemodynamics was evaluated in the offspring at 90 days of age using a blood pressure transducer, a flow probe and inulin clearance to measure mean arterial pressure (MAP), renal blood flow and glomerular filtration rate (GFR), respectively. The number of nephrons (NN) was counted in kidney suspensions. Dams showed unchanged PV, placental Ox and fetal weight but increased U(Prot24 h) (150%, P sodium-overloaded pups showed increased U(Prot24 h) (45%, P sodium-overloaded rats showed increased U(Prot24 h) (27%, P sodium-overloaded group. We conclude that salt overload from the prenatal stage until weaning leads to alterations in lipid metabolism and in the renal function of the pups, which are additional to those alterations seen in rats only overloaded prenatally.

Plasma insulin levels are increased by sertraline in rats under oral glucose overload

Directory of Open Access Journals (Sweden)

Gomez R.

2001-01-01

Full Text Available Recognition and control of depression symptoms are important to increase patient compliance with treatment and to improve the quality of life of diabetic patients. Clinical studies indicate that selective serotonin reuptake inhibitors (SSRI are better antidepressants for diabetic patients than other drugs. However, preclinical trials have demonstrated that not all SSRI reduce plasma glucose levels. In fact, fluoxetine increases and sertraline decreases glycemia in diabetic and non-diabetic rats. In the present study we evaluated plasma insulin levels during fasting and after glucose overload after treatment with sertraline. Adult male Wistar rats were fasted and treated with saline or 30 mg/kg sertraline and submitted or not to glucose overload (N = 10. Blood was collected and plasma insulin was measured. The mean insulin levels were: fasting group: 25.9 ± 3.86, sertraline + fasting group: 31.10 ± 2.48, overload group: 34.1 ± 3.40, and overload + sertraline group: 43.73 ± 5.14 µU/ml. Insulinemia was significantly increased in the overload + sertraline group. There were no differences between the other groups. No difference in glucose/insulin ratios could be detected between groups. The overload + sertraline group was the only one in which a significant number of individuals exceeded the upper confidence limit of insulin levels. This study demonstrates that sertraline increases glucose-stimulated insulin secretion without any change in peripheral insulin sensitivity.

Melatonin protects bone marrow mesenchymal stem cells against iron overload-induced aberrant differentiation and senescence.

Science.gov (United States)

Yang, Fan; Yang, Lei; Li, Yuan; Yan, Gege; Feng, Chao; Liu, Tianyi; Gong, Rui; Yuan, Ye; Wang, Ning; Idiiatullina, Elina; Bikkuzin, Timur; Pavlov, Valentin; Li, Yang; Dong, Chaorun; Wang, Dawei; Cao, Yang; Han, Zhenbo; Zhang, Lai; Huang, Qi; Ding, Fengzhi; Bi, Zhengang; Cai, Benzhi

2017-10-01

Bone marrow mesenchymal stem cells (BMSCs) are an expandable population of stem cells which can differentiate into osteoblasts, chondrocytes and adipocytes. Dysfunction of BMSCs in response to pathological stimuli contributes to bone diseases. Melatonin, a hormone secreted from pineal gland, has been proved to be an important mediator in bone formation and mineralization. The aim of this study was to investigate whether melatonin protected against iron overload-induced dysfunction of BMSCs and its underlying mechanisms. Here, we found that iron overload induced by ferric ammonium citrate (FAC) caused irregularly morphological changes and markedly reduced the viability in BMSCs. Consistently, osteogenic differentiation of BMSCs was significantly inhibited by iron overload, but melatonin treatment rescued osteogenic differentiation of BMSCs. Furthermore, exposure to FAC led to the senescence in BMSCs, which was attenuated by melatonin as well. Meanwhile, melatonin was able to counter the reduction in cell proliferation by iron overload in BMSCs. In addition, protective effects of melatonin on iron overload-induced dysfunction of BMSCs were abolished by its inhibitor luzindole. Also, melatonin protected BMSCs against iron overload-induced ROS accumulation and membrane potential depolarization. Further study uncovered that melatonin inhibited the upregulation of p53, ERK and p38 protein expressions in BMSCs with iron overload. Collectively, melatonin plays a protective role in iron overload-induced osteogenic differentiation dysfunction and senescence through blocking ROS accumulation and p53/ERK/p38 activation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Clinical consequences of iron overload in patients with myelodysplastic syndromes: the case for iron chelation therapy.

Science.gov (United States)

Shammo, Jamile M; Komrokji, Rami S

2018-06-14

Patients with myelodysplastic syndromes (MDS) are at increased risk of iron overload due to ineffective erythropoiesis and chronic transfusion therapy. The clinical consequences of iron overload include cardiac and/or hepatic failure, endocrinopathies, and infection risk. Areas covered: Iron chelation therapy (ICT) can help remove excess iron and ultimately reduce the clinical consequences of iron overload. The authors reviewed recent (last five years) English-language articles from PubMed on the topic of iron overload-related complications and the use of ICT (primarily deferasirox) to improve outcomes in patients with MDS. Expert Commentary: While a benefit of ICT has been more firmly established in other transfusion-dependent conditions such as thalassemia, its role in reducing iron overload in MDS remains controversial due to the lack of prospective controlled data demonstrating a survival benefit. Orally administered chelation agents (e.g., deferasirox), are now available, and observational and/or retrospective data support a survival benefit of using ICT in MDS. The placebo-controlled TELESTO trial (NCT00940602) is currently examining the use of deferasirox in MDS patients with iron overload, and is evaluating specifically whether use of ICT to alleviate iron overload can also reduce iron overload-related complications in MDS and improve survival.

Why cross-national differences in role overload? Don't overlook ambient temperature!

NARCIS (Netherlands)

Van de Vliert, E.; Van Yperen, N.W.

The finding that, across nations, power distance (expected and accepted unequal interpersonal influence) Is positively related to role overload (Peterson et al., 1995) might he an artifact of the relation between role overload and ambient temperature or other third factors. We related data on power

Role Overload, Job Satisfaction, Leisure Satisfaction, and Psychological Health among Employed Women

Science.gov (United States)

Pearson, Quinn M.

2008-01-01

Role overload, job satisfaction, leisure satisfaction, and psychological health were measured for 155 women who were employed full time. Role overload was negatively correlated with psychological health, job satisfaction, and leisure satisfaction. Job satisfaction and leisure satisfaction were positively correlated with psychological health.…

Changes in cardiac output and incidence of volume overload in cirrhotics receiving 20% albumin infusion.

Science.gov (United States)

Shasthry, Saggere M; Kumar, Manoj; Khumuckham, Jelen S; Sarin, Shiv Kumar

2017-08-01

Patients with cirrhosis are prone to develop volume over load, have increased capillary permeability and latent or overt cardiomyopathy. Whether albumin infusion causes volume overload in cirrhotics has not been adequately studied. Ninety nine consecutive cirrhotic patients receiving 1gm per kg albumin infusion were evaluated for development of volume overload. Clinical, echocardiographic and haemodynamic changes were closely monitored during and after albumin infusion. Thirty (30.30%) patients developed volume overload. Patients with higher BMI (P=.003), lower CTP (P=.01) and MELD (P=.034) were more often associated with the development of volume overload. Though baseline diastolic dysfunction was present in 82.8% of the patients, it did not influence the development of volume overload or changes in the cardiac output. The cardiac output increased significantly after albumin infusion (4.9±1.554 L/min to 5.86±1.85 L/min, Palbumin infusion develop volume overload, specially, those with higher BMI and lower severity of liver disease. Cardiac output increases after albumin infusion, and, baseline diastolic dysfunction has little effect on the development of volume overload or changes in cardiac output. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ratcheting Strain and Microstructure Evolution of AZ31B Magnesium Alloy under a Tensile-Tensile Cyclic Loading.

Science.gov (United States)

Yan, Zhifeng; Wang, Denghui; Wang, Wenxian; Zhou, Jun; He, Xiuli; Dong, Peng; Zhang, Hongxia; Sun, Liyong

2018-03-28

In this paper, studies were conducted to investigate the deformation behavior and microstructure change in a hot-rolled AZ31B magnesium alloy during a tensile-tensile cyclic loading. The relationship between ratcheting effect and microstructure change was discussed. The ratcheting effect in the material during current tensile-tensile fatigue loading exceeds the material's fatigue limit and the development of ratcheting strain in the material experienced three stages: initial sharp increase stage (Stage I); steady stage (Stage II); and final abrupt increase stage (Stage III). Microstructure changes in Stage I and Stage II are mainly caused by activation of basal slip system. The Extra Geometrically Necessary Dislocations (GNDs) were also calculated to discuss the relationship between the dislocation caused by the basal slip system and the ratcheting strain during the cyclic loading. In Stage III, both the basal slip and the {11-20} twins are found active during the crack propagation. The fatigue crack initiation in the AZ31B magnesium alloy is found due to the basal slip and the {11-20} tensile twins.

Hepatic iron overload is associated with hepatocyte apoptosis during Clonorchis sinensis infection.

Science.gov (United States)

Han, Su; Tang, Qiaoran; Chen, Rui; Li, Yihong; Shu, Jing; Zhang, Xiaoli

2017-08-01

Hepatic iron overload has been implicated in many liver diseases; however, whether it is involved in clonorchiasis remains unknown. The purpose of this study is to investigate whether Clonorchis sinensis (C. sinensis) infection causes hepatic iron overload, analyze the relationship between the iron overload and associated cell apoptosis, so as to determine the role of excess iron plays in C. sinensis-induced liver injury. The Perls' Prussian staining and atomic absorption spectrometry methods were used to investigate the iron overload in hepatic sections of wistar rats and patients infected with C. sinensis. The hepatic apoptosis was detected by transferase uridyl nick end labeling (TUNEL) methods. Spearman analysis was used for determining the correlation of the histological hepatic iron index and the apoptotic index. Blue iron particles were deposited mainly in the hepatocytes, Kupffer cells and endothelial cells, around the liver portal and central vein area of both patients and rats. The total iron score was found to be higher in the infected groups than the respective control from 8 weeks. The hepatic iron concentration was also significantly higher in treatment groups than in control rats from 8 weeks. The hepatocyte apoptosis was found to be significantly higher in the portal area of the liver tissue and around the central vein. However, spearman's rank correlation coefficient revealed that there was a mildly negative correlation between the iron index and hepatocyte apoptosis. This present study confirmed that hepatic iron overload was found during C. sinensis infection. This suggests that iron overload may be associated with hepatocyte apoptosis and involved in liver injury during C. sinensis infection. Further studies are needed to investigate the molecular mechanism involved here.

Overload training inhibits phagocytosis and ROS generation of peritoneal macrophages: role of IGF-1 and MGF.

Science.gov (United States)

Xiao, Weihua; Chen, Peijie; Wang, Ru; Dong, Jingmei

2013-01-01

We tested the hypothesis that overload training inhibits the phagocytosis and the reactive oxygen species (ROS) generation of peritoneal macrophages (Mϕs), and that insulin-like growth factor-1(IGF-1) and mechano-growth factor (MGF) produced by macrophages may contribute to this process. Rats were randomized to two groups, sedentary control group (n = 10) and overload training group (n = 10). The rats of overload training group were subjected to 11 weeks of experimental training protocol. Blood sample was used to determine the content of hemoglobin, testosterone, and corticosterone. The phagocytosis and the ROS generation of Mϕs were measured by the uptake of neutral red and the flow cytometry, respectively. IGF-1 and MGF mRNA levels in Mϕs were determined by real-time PCR. In addition, we evaluated the effects of IGF-1 and MGF peptide on phagocytosis and ROS generation of Mϕs in vitro. The data showed that overload training significantly decreased the body weight (19.3 %, P overload training significantly decreased the phagocytosis (27 %, P overload training group increased significantly compared with the control group (21-fold and 92-fold, respectively; P overload training inhibits the phagocytosis and the ROS generation of peritoneal macrophages, and that MGF produced by macrophages may play a key role in this process. This may represent a novel mechanism of immune suppression induced by overload training.

Clinical outcomes of transfusion-associated iron overload in patients with refractory chronic anemia

Directory of Open Access Journals (Sweden)

Gao C

2014-04-01

Full Text Available Chong Gao, Li Li, Baoan Chen, Huihui Song, Jian Cheng, Xiaoping Zhang, Yunyu SunDepartment of Hematology and Oncology, Key Department of Jiangsu Medicine, Zhongda Hospital, Medical School, Southeast University, Nanjing, Jiangsu Province, People’s Republic of ChinaBackground: The purpose of this study was to evaluate the clinical outcomes of transfusion-associated iron overload in patients with chronic refractory anemia.Methods: Clinical manifestations, main organ function, results of computed tomography (CT, endocrine evaluation, and serum ferritin levels were analyzed retrospectively in 13 patients who were transfusion-dependent for more than 1 year (receiving >50 units of red blood cells to determine the degree of iron overload and efficacy of iron-chelating therapy.Results: Serum ferritin levels increased to 1,830–5,740 ng/mL in all patients. Ten patients had abnormal liver function. The CT Hounsfield units in the liver increased significantly in eleven patients, and were proportional to their serum ferritin levels. Skin pigmentation, liver dysfunction, and endocrine dysfunction were observed in nine patients with serum ferritin >3,500 ng/mL, eight of whom have since died. Interestingly, serum ferritin levels did not decrease significantly in nine transfusion-dependent patients who had received 15–60 days of iron-chelating therapy.Conclusion: Transfusion-dependent patients may progress to secondary iron overload with organ impairment, which may be fatal in those who are heavily iron-overloaded. The CT Hounsfield unit is a sensitive indicator of iron overload in the liver. Iron chelation therapy should be initiated when serum ferritin is >1,000 ng/mL and continued until it is <1,000 ng/mL in transfusional iron-overloaded patients.Keywords: anemia, aplastic, iron overload, myelodysplastic syndromes

Tensile Strength of Water Exposed to Pressure Pulses

DEFF Research Database (Denmark)

Andersen, Anders Peter; Mørch, Knud Aage

2012-01-01

at an extended water-solid interface by imposing a tensile stress pulse which easily causes cavitation. Next, a compressive pulse of duration ~1 ms and a peak intensity of a few bar is imposed prior to the tensile stress pulse. A dramatic increase of the tensile strength is observed immediately after......It is well known that pressurization for an extended period of time increases the tensile strength of water, but little information is available on the effect of pressure pulses of short duration. This is addressed in the present paper where we first measure the tensile strength of water...

The analysis of overloaded trucks in indonesia based on weigh in motion data (east of sumatera national road case study

Directory of Open Access Journals (Sweden)

Jihanny Jongga

2018-01-01

Full Text Available Overloaded trucks phenomena generally common in developing countries where the traffic control is poor. In Indonesia, the percentage of overloaded trucks can reach more than 60% in the total number of trucks and may be one of the substantial factors that reduce the service life of the road pavements. This paper presents the analysis results of the weigh in motion survey data at East of Sumatera National Road (Jalintim in Indonesia and the impact of overloaded trucks on the pavement. For the analysis the simplified approach was used, the axle loads were converted into representative single-axle loads based on 4th power formula by AASHTO 1993 equation. The vehicle damage factor of vehicles is presented and will be compared with the Highways National Standard to estimate the remaining service life of pavement and IRI value prediction. The analysis showed that the vehicle damage factor that determined from weigh in motion data is extremely greater than vehicle damage factor of the national standard in Indonesia which may lead to accelerated deterioration, reducing the service life of the pavement structures and significantly influence the IRI value.

Information Diffusion in Facebook-Like Social Networks Under Information Overload

Science.gov (United States)

Li, Pei; Xing, Kai; Wang, Dapeng; Zhang, Xin; Wang, Hui

2013-07-01

Research on social networks has received remarkable attention, since many people use social networks to broadcast information and stay connected with their friends. However, due to the information overload in social networks, it becomes increasingly difficult for users to find useful information. This paper takes Facebook-like social networks into account, and models the process of information diffusion under information overload. The term view scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated is proposed to characterize the information diffusion efficiency. Through theoretical analysis, we find that factors such as network structure and view scope number have no impact on the information diffusion efficiency, which is a surprising result. To verify the results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly.

Formal Constraints on Memory Management for Composite Overloaded Operations

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Damian W.I. Rouson

2006-01-01

Full Text Available The memory management rules for abstract data type calculus presented by Rouson, Morris & Xu [15] are recast as formal statements in the Object Constraint Language (OCL and applied to the design of a thermal energy equation solver. One set of constraints eliminates memory leaks observed in composite overloaded expressions with three current Fortran 95/2003 compilers. A second set of constraints ensures economical memory recycling. The constraints are preconditions, postconditions and invariants on overloaded operators and the objects they receive and return. It is demonstrated that systematic run-time assertion checking inspired by the formal constraints facilitated the pinpointing of an exceptionally hard-to-reproduce compiler bug. It is further demonstrated that the interplay between OCL's modeling capabilities and Fortran's programming capabilities led to a conceptual breakthrough that greatly improved the readability of our code by facilitating operator overloading. The advantages and disadvantages of our memory management rules are discussed in light of other published solutions [11,19]. Finally, it is demonstrated that the run-time assertion checking has a negligible impact on performance.

The attenuating effect of role overload on relationships linking self-efficacy and goal level to work performance.

Science.gov (United States)

Brown, Steven P; Jones, Eli; Leigh, Thomas W

2005-09-01

The reported research examines the moderating effects of role overload on the antecedents and consequences of self-efficacy and personal goal level in a longitudinal study conducted in an industrial selling context. The results indicate that role overload moderates the antecedent effect of perceived organizational resources on self-efficacy beliefs. They also show that role overload moderates the direct effects of both self-efficacy and goal level on performance, such that these relationships are positive when role overload is low but not significant when role overload is high. Further, the results reveal a pattern of moderated mediation, in which goal level mediates the indirect effect of self-efficacy on performance when role overload is low but not when it is high. Implications for theory and managerial practice are discussed. Copyright 2005 APA, all rights reserved.

Effect of overload on SCC growth in stainless steels in high temperature water

International Nuclear Information System (INIS)

Xue, He; Peng, Qunjia; Shoji, Tetsuo

2009-01-01

By incorporating the film slip-dissolution/oxidation model and the elastic-plastic finite element method (EPFEM), the effect of the overload on stress corrosion cracking (SCC) growth rate of stainless steel in high temperature water is discussed in this paper. Results show that SCC growth rate of a 20% cold worked 316L stainless steel in high temperature water decrease in the overload affected zone ahead of the growing crack tip. Therefore, a reasonable overload could availably reduce the SCC growth rate during a certain in-service period. (author)

Iron homeostasis and its disruption in mouse lung in iron deficiency and overload.

Science.gov (United States)

Giorgi, Gisela; D'Anna, María Cecilia; Roque, Marta Elena

2015-10-01

What is the central question of this study? The aim was to explore the role and hitherto unclear mechanisms of action of iron proteins in protecting the lung against the harmful effects of iron accumulation and the ability of pulmonary cells to mobilize iron in iron deficiency. What is the main finding and its importance? We show that pulmonary hepcidin appears not to modify cellular iron mobilization in the lung. We propose pathways for supplying iron to the lung in iron deficiency and for protecting the lung against iron excess in iron overload, mediated by the co-ordinated action of iron proteins, such as divalent metal transporter 1, ZRT-IRE-like-protein 14, transferrin receptor, ferritin, haemochromatosis-associated protein and ferroportin. Iron dyshomeostasis is associated with several forms of chronic lung disease, but its mechanisms of action remain to be elucidated. The aim of the present study was to determine the role of the lung in whole-animal models with iron deficiency and iron overload, studying the divalent metal transporter 1 (DMT1), ZRT-IRE-like protein 14 (ZIP14), transferrin receptor (TfR), haemochromatosis-associated protein (HFE), hepcidin, ferritin and ferroportin (FPN) expression. In each model, adult CF1 mice were divided into the following groups (six mice per group): (i) iron-overload model, iron saccharate i.p. and control group (iron adequate), 0.9% NaCl i.p.; and (ii) iron-deficiency model, induced by repeated bleeding, and control group (sham operated). Proteins were assessed by immunohistochemistry and Western blot. In control mice, DMT1 was localized in the cytoplasm of airway cells, and in iron deficiency and overload it was in the apical membrane. Divalent metal transporter 1 and TfR increased in iron deficiency, without changes in iron overload. ZRT-IRE-like protein 14 decreased in airway cells in iron deficiency and increased in iron overload. In iron deficiency, HFE and FPN were immunolocalized close to the apical membrane

Iron overload promotes erythroid apoptosis through regulating HIF-1a/ROS signaling pathway in patients with myelodysplastic syndrome.

Science.gov (United States)

Zheng, Qing-Qing; Zhao, You-Shan; Guo, Juan; Zhao, Si-da; Song, Lu-Xi; Fei, Cheng-Ming; Zhang, Zheng; Li, Xiao; Chang, Chun-Kang

2017-07-01

Erythroid apoptosis increases significantly in myelodysplastic syndrome (MDS) patients with iron overload, but the underlying mechanism is not fully clear. In this study, we aim to explore the effect of HIF-1a/ROS on erythroid apoptosis in MDS patients with iron overload. We found that iron overload injured cellular functions through up-regulating ROS levels in MDS/AML cells, including inhibited cell viability, increased cell apoptosis and blocked cell cycle at G0/G1 phase. Interestingly, overexpression of hypoxia inducible factor-1a (HIF-1a), which was under-expressed in iron overload models, reduced ROS levels and attenuated cell damage caused by iron overload in MDS/AML cells. And gene knockdown of HIF-1a got the similar results as iron overload in MDS/AML cells. Furthermore, iron overload caused high erythroid apoptosis was closely related with ROS in MDS patients. Importantly, the HIF-1a protein levels of erythrocytes elevated obviously after incubation with desferrioxamine (DFO) from MDS patients with iron overload, accompanied by ROS levels inhibited and erythroid apoptosis reduced. Taken together, our findings determine that the HIF-1a/ROS signaling pathway plays a key role in promoting erythroid apoptosis in MDS patients with iron overload. Copyright © 2017 Elsevier Ltd. All rights reserved.

Designing immersive surgical training against information technology-related overload in the operating room

NARCIS (Netherlands)

Pluyter, J.R.

2012-01-01

On a theoretical level, this dissertation demonstrates that the “classical” conceptualization of overload in the field of Information Systems being an excessive amount of information is too simplistic. Based on the Emotional-Cognitive Overload Model by Rutkowski and Saunders (2011) this dissertation

Overload-induced skeletal muscle hypertrophy is not impaired in STZ-diabetic rats

Science.gov (United States)

Fortes, Marco Aurélio S; Pinheiro, Carlos Hermano J; Guimarães-Ferreira, Lucas; Vitzel, Kaio F; Vasconcelos, Diogo A A; Curi, Rui

2015-01-01

The aim of this study was to evaluate the effect of overload-induced hypertrophy on extensor digitorum longus (EDL) and soleus muscles of streptozotocin-induced diabetic rats. The overload-induced hypertrophy and absolute tetanic and twitch forces increases in EDL and soleus muscles were not different between diabetic and control rats. Phospho-Akt and rpS6 contents were increased in EDL muscle after 7 days of overload and returned to the pre-overload values after 30 days. In the soleus muscle, the contents of total and phospho-Akt and total rpS6 were increased in both groups after 7 days. The contents of total Akt in controls and total rpS6 and phospho-Akt in the diabetic rats remained increased after 30 days. mRNA expression after 7 days of overload in the EDL muscle of control and diabetic animals showed an increase in MGF and follistatin and a decrease in myostatin and Axin2. The expression of FAK was increased and of MuRF-1 and atrogin-1 decreased only in the control group, whereas Ankrd2 expression was enhanced only in diabetic rats. In the soleus muscle caused similar changes in both groups: increase in FAK and MGF and decrease in Wnt7a, MuRF-1, atrogin-1, and myostatin. Differences between groups were observed only in the increased expression of follistatin in diabetic animals and decreased Ankrd2 expression in the control group. So, insulin deficiency does not impair the overload-induced hypertrophic response in soleus and EDL muscles. However, different mechanisms seem to be involved in the comparable hypertrophic responses of skeletal muscle in control and diabetic animals. PMID:26197932

Information Overload in Multi-Stage Selection Procedures

NARCIS (Netherlands)

S.S. Ficco (Stefano); V.A. Karamychev (Vladimir)

2004-01-01

textabstractThe paper studies information processing imperfections in a fully rational decision-making network. It is shown that imperfect information transmission and imperfect information acquisition in a multi-stage selection game yield information overload. The paper analyses the mechanisms

Coping with Overload and Stress: Men and Women in Dual-Earner Families

Science.gov (United States)

Higgins, Chris A.; Duxbury, Linda E.; Lyons, Sean T.

2010-01-01

This study tested gender differences in a model positing relationships between work and family demands, overload, 4 coping mechanisms, and stress. The coping mechanisms were hypothesized to moderate the relationship between overload and stress. The sample consisted of 1,404 men and 1,623 women in dual-earner families. Respondents relied on 2…

Testing of camera performance standards at steady and local overloading

International Nuclear Information System (INIS)

Keszthelyine Landori, S.; Adorjanne Farkas, M.; Csirik, J.

1983-01-01

Camera performance standards are usually given for low count rates and uniform irradiation. A conventional analog gamma camera system (Gamma MB 9100 manufactured under the know-how of Picker DC 4/12 in Hungary) was studied on the basis of the Picker test procedure and the NEMA standard system. Uniformity, linearity, spatial and energy resolution were measured at high count rates and uniform irradiation (steady overloading). Linearity was studied at local overloading. Linearity, spatial and energy resolution were measured by a 1024-channel analyzer-computer system of KFKI, Hungary. The data were evaluated on the basis of NEMA standards, while uniformity was measured by the Gamma data processing system and evaluated by special SEGAMS programs. Performance variations were studied between 7500 cps and 75.000 cps pulse rates. Spatial and energy resolution were influenced strongly, uniformity slightly by pulse rates, while linearity did not change at all. Linearity was not influenced even by local overloading. (author)

Association between filial responsibility when caring for parents and the caregivers overload

Directory of Open Access Journals (Sweden)

Marinês Aires

Full Text Available ABSTRACT Objective: To analyze the association between filial responsibility and the overload of the children when caring for their older parents. Method: Cross-sectional study with 100 caregiver children of older adults. Filial liability was assessed by the attitudes of the responsible child (scale of expectation and filial duty and by care behaviors (assistance in activities of daily living, emotional and financial support, and keeping company. The overload was assessed by the Caregiver Burden Inventory. To assess the associations, the correlation coefficients of Pearson and Spearman, Kruskal-Wallis Test, and Mann-Whitney were employed. Variables that presented p-value<0.20 in the bivariate analysis were inserted in a multivariate linear regression model. Results: The factors associated with overload were: formal employment (p=0.002, feelings regarding family life (p<0.001, financial support (p=0.027, and assistance with Activities of Daily Living (ADLs (p<0.001. Conclusion: Children who were more involved with the ADLs and provided financial support showed higher levels of overload.

Overloaded CDMA Systems with Displaced Binary Signatures

Directory of Open Access Journals (Sweden)

Vanhaverbeke Frederik

2004-01-01

Full Text Available We extend three types of overloaded CDMA systems, by displacing in time the binary signature sequences of these systems: (1 random spreading (PN, (2 multiple-OCDMA (MO, and (3 PN/OCDMA (PN/O. For each of these systems, we determine the time shifts that minimize the overall multiuser interference power. The achievable channel load with coded and uncoded data is evaluated for the conventional (without displacement and improved (with displacement systems, as well as for systems based on quasi-Welch-bound-equality (QWBE sequences, by means of several types of turbo detectors. For each system, the best performing turbo detector is selected in order to compare the performance of these systems. It is found that the improved systems substantially outperform their original counterparts. With uncoded data, (improved PN/O yields the highest acceptable channel load. For coded data, MO allows for the highest acceptable channel load over all considered systems, both for the conventional and the improved systems. In the latter case, channel loads of about 280% are achievable with a low degradation as compared to a single user system.

Over-exposed portraits : Technology overload and the identities of the young

OpenAIRE

Lutz, Christoph; Ranzini, Giulia; Meckel, Miriam

2013-01-01

Technostress and information overload represent serious challenges of the Information Age. An alarming number of people exhibit dangerously intensive media consumption, while Internet and mobile phone addictions are a widespread phenomenon, especially among teens. Despite increasing evidence for technostress and information overload within the literature, the consequences of new media overexposure on young individuals are so far understudied. When it comes to Social Network Sites (SNS), in pa...

30 CFR 75.518 - Electric equipment and circuits; overload and short circuit protection.

Science.gov (United States)

2010-07-01

... short circuit protection. 75.518 Section 75.518 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.518 Electric equipment and circuits; overload and short circuit protection... installed so as to protect all electric equipment and circuits against short circuit and overloads. Three...

Trust in management as a buffer of the relationships between overload and strain.

Science.gov (United States)

Harvey, Steve; Kelloway, E Kevin; Duncan-Leiper, Leslie

2003-10-01

This study examined the role of trust in management as a moderating factor in work overload's impact on personal strain (i.e., burnout, psychological strain, and work's interference with family). Participants were 94 employees of an accounting firm responding to a survey. The results were supportive of all study propositions. Both work overload and trust in management had the expected negative and positive main effects on the outcomes variables, respectively. The impact of work overload on the outcome variables was moderated by employees' trust in management. The significance of these results and areas of future research are discussed. 2003 APA

Dilatometer for use in tensile tests

NARCIS (Netherlands)

Coumans, W.J.; Heikens, D.

1980-01-01

An accurate dilatometer is described which permits simultaneous and automatic recording of sample vol. change during tensile tests on a com. tester. Liq. displacements in the dilatometer capillary, which correspond to vol. changes of the sample, are detected by a cond. meter. Tensile load is

Novel development of the micro-tensile test at elevated temperature using a test structure with integrated micro-heater

Science.gov (United States)

Ang, W. C.; Kropelnicki, P.; Soe, Oak; Ling, J. H. L.; Randles, A. B.; Hum, A. J. W.; Tsai, J. M. L.; Tay, A. A. O.; Leong, K. C.; Tan, C. S.

2012-08-01

This paper describes the novel development of a micro-tensile testing method that allows testing at elevated temperatures. Instead of using a furnace, a titanium/platinum thin film micro-heater was fabricated on a conventional dog-bone-shaped test structure to heat up its gauge section locally. An infrared (IR) camera with 5 µm resolution was employed to verify the temperature uniformity across the gauge section of the test structure. With this micro-heater-integrated test structure, micro-tensile tests can be performed at elevated temperatures using any conventional tensile testing system without any major modification to the system. In this study, the tensile test of the single crystal silicon (SCS) thin film with (1 0 0) surface orientation and tensile direction was performed at room temperature and elevated temperatures, up to 300 °C. Experimental results for Young's modulus as a function of temperature are presented. A micro-sized SCS film showed a low dependence of mechanical properties on temperature up to 300 °C.

Experimental Analysis of Tensile Mechanical Properties of Sprayed FRP

Directory of Open Access Journals (Sweden)

Zhao Yang

2016-01-01

Full Text Available To study the tensile mechanical properties of sprayed FRP, 13 groups of specimens were tested through uniaxial tensile experiments, being analyzed about stress-strain curve, tensile strength, elastic modulus, breaking elongation, and other mechanical properties. Influencing factors on tensile mechanical properties of sprayed FRP such as fiber type, resin type, fiber volume ratio, fiber length, and composite thickness were studied in the paper too. The results show that both fiber type and resin type have an obvious influence on tensile mechanical properties of sprayed FRP. There will be a specific fiber volume ratio for sprayed FRP to obtain the best tensile mechanical property. The increase of fiber length can lead to better tensile performance, while that of composite thickness results in property degradation. The study can provide reference to popularization and application of sprayed FRP material used in structure reinforcement.

Update on the use of deferasirox in the management of iron overload

Directory of Open Access Journals (Sweden)

Ali Taher

2009-10-01

Full Text Available Ali Taher,1 Maria Domenica Cappellini21American University of Beirut, Beirut, Lebanon; 2Universitá di Milano, Policlinico Foundation IRCCS, Milan, ItalyAbstract: Regular blood transfusions as supportive care for patients with chronic anemia inevitably lead to iron overload as humans cannot actively remove excess iron. The cumulative effects of iron overload cause significant morbidity and mortality if not effectively treated with chelation therapy. Based on a comprehensive clinical development program, the once-daily, oral iron chelator deferasirox (Exjade® is approved for the treatment of transfusional iron overload in adult and pediatric patients with various transfusion-dependent anemias, including β-thalassemia and the myelodysplastic syndromes. Deferasirox dose should be titrated for each individual patient based on transfusional iron intake, current iron burden and whether the goal is to decrease or maintain body iron levels. Doses of >30 mg/kg/day have been shown to be effective with a safety profile consistent with that observed at doses <30 mg/kg/day. Recent data have highlighted the ability of deferasirox to decrease cardiac iron levels and to prevent the accumulation of iron in the heart. The long-term efficacy and safety of deferasirox for up to 5 years of treatment have now been established. The availability of this effective and generally well tolerated oral therapy represents a significant advance in the management of transfusional iron overload. Keywords: deferasirox, Exjade, oral, iron chelation, iron overload, cardiac iron 

Quantitative estimation of the right ventricular overloading by thallium-201 myocardial scintigraphy

International Nuclear Information System (INIS)

Owada, Kenji; Machii, Kazuo; Tsukahara, Yasunori

1982-01-01

Thallium-201 myocardial scintigraphy was performed on 55 patients with various types of right ventricular overloading. The right ventricular (RV) free wall was visualized in 39 out of the 55 patients (71%). The mean values of right ventricular systolic pressure (RVSP) and pulmonary artery mean pressure (PAMP) in the visualized cases (uptakers) were 54.6 +- 24.1 and 30.5 +- 15.3 mmHg, respectively. These values were significantly higher than those of the non-visualized cases (non-uptakers). There were 12 RVSP-''normotensive'' uptakers and 15 PAMP-''normotensive'' uptakers. The RV free wall images were classified into three types according to their morphological features. Type I was predominantly seen in cases of RV pressure overloading, type II in RV volume overloading and type III in combined ventricular overloading. RVSP in the type III group was significantly higher than that in other two groups. The radioactivity ratio in RV free wall and interventricular septum (IVS), the RV/IVS uptake ratio was calculated using left anterior oblique (LAO) view images. The RV/IVS uptake ratio closely correlated with RVSP and PAMP (r = 0.88 and 0.82, respectively). In each group of RV free wall image, there were also close correlations between the RV/IVS uptake ratio and both RVSP and PAMP. Our results indicate that the RV/IVS uptake ratio can be used as a parameter for the semi-quantitative estimation of right ventricular overloading. (author)

AMPKγ3 is dispensable for skeletal muscle hypertrophy induced by functional overload.

Science.gov (United States)

Riedl, Isabelle; Osler, Megan E; Björnholm, Marie; Egan, Brendan; Nader, Gustavo A; Chibalin, Alexander V; Zierath, Juleen R

2016-03-15

Mechanisms regulating skeletal muscle growth involve a balance between the activity of serine/threonine protein kinases, including the mammalian target of rapamycin (mTOR) and 5'-AMP-activated protein kinase (AMPK). The contribution of different AMPK subunits to the regulation of cell growth size remains inadequately characterized. Using AMPKγ3 mutant-overexpressing transgenic Tg-Prkag3(225Q) and AMPKγ3-knockout (Prkag3(-/-)) mice, we investigated the requirement for the AMPKγ3 isoform in functional overload-induced muscle hypertrophy. Although the genetic disruption of the γ3 isoform did not impair muscle growth, control sham-operated AMPKγ3-transgenic mice displayed heavier plantaris muscles in response to overload hypertrophy and underwent smaller mass gain and lower Igf1 expression compared with wild-type littermates. The mTOR signaling pathway was upregulated with functional overload but unchanged between genetically modified animals and wild-type littermates. Differences in AMPK-related signaling pathways between transgenic, knockout, and wild-type mice did not impact muscle hypertrophy. Glycogen content was increased following overload in wild-type mice. In conclusion, our functional, transcriptional, and signaling data provide evidence against the involvement of the AMPKγ3 isoform in the regulation of skeletal muscle hypertrophy. Thus, the AMPKγ3 isoform is dispensable for functional overload-induced muscle growth. Mechanical loading can override signaling pathways that act as negative effectors of mTOR signaling and consequently promote skeletal muscle hypertrophy. Copyright © 2016 the American Physiological Society.

Ischemic preconditioning improves mitochondrial tolerance to experimental calcium overload.

Science.gov (United States)

Crestanello, Juan A; Doliba, Nicolai M; Babsky, Andriy M; Doliba, Natalia M; Niibori, Koki; Whitman, Glenn J R; Osbakken, Mary D

2002-04-01

Ca(2+) overload leads to mitochondrial uncoupling, decreased ATP synthesis, and myocardial dysfunction. Pharmacologically opening of mitochondrial K(ATP) channels decreases mitochondrial Ca(2+) uptake, improving mitochondrial function during Ca(2+) overload. Ischemic preconditioning (IPC), by activating mitochondrial K(ATP) channels, may attenuate mitochondrial Ca(2+) overload and improve mitochondrial function during reperfusion. The purpose of these experiments was to study the effect of IPC (1) on mitochondrial function and (2) on mitochondrial tolerance to experimental Ca(2+) overload. Rat hearts (n = 6/group) were subjected to (a) 30 min of equilibration, 25 min of ischemia, and 30 min of reperfusion (Control) or (b) two 5-min episodes of ischemic preconditioning, 25 min of ischemia, and 30 min of reperfusion (IPC). Developed pressure (DP) was measured. Heart mitochondria were isolated at end-Equilibration (end-EQ) and at end-Reperfusion (end-RP). Mitochondrial respiratory function (state 2, oxygen consumption with substrate only; state 3, oxygen consumption stimulated by ADP; state 4, oxygen consumption after cessation of ADP phosphorylation; respiratory control index (RCI, state 3/state 4); rate of oxidative phosphorylation (ADP/Deltat), and ADP:O ratio) was measured with polarography using alpha-ketoglutarate as a substrate in the presence of different Ca(2+) concentrations (0 to 5 x 10(-7) M) to simulate Ca(2+) overload. IPC improved DP at end-RP. IPC did not improve preischemic mitochondrial respiratory function or preischemic mitochondrial response to Ca(2+) loading. IPC improved state 3, ADP/Deltat, and RCI during RP. Low Ca(2+) levels (0.5 and 1 x 10(-7) M) stimulated mitochondrial function in both groups predominantly in IPC. The Control group showed evidence of mitochondrial uncoupling at lower Ca(2+) concentrations (1 x 10(-7) M). IPC preserved state 3 at high Ca(2+) concentrations. The cardioprotective effect of IPC results, in part, from

Role of (Pro)Renin Receptor in Albumin Overload-Induced Nephropathy in Rats.

Science.gov (United States)

Fang, Hui; Deng, Mokan; Zhang, Linlin; Lu, Aihua; Su, Jiahui; Xu, Chuanming; Zhou, Li; Wang, Lei; Ou, Jing-Song; Wang, Weidong; Yang, Tianxin

2018-05-30

Proteinuria is not only a common feature of chronic kidney diseases (CKD) but also an independent risk factor promoting CKD progression to end-stage renal failure. However, the underlying molecular mechanisms for protein overload-induced renal injury remain elusive. The present study examined the role of (pro)renin receptor (PRR) in pathogenesis of albumin overload (AO)-induced nephropathy and activation of intrarenal renin-angiotensin system (RAS) in rats. Wistar rats underwent unilateral nephrectomy and were treated for 7 weeks with vehicle, bovine serum albumin (5 g/kg/d via a single i.p. injection) alone or in conjunction with a PRR decoy inhibitor PRO20 (500 μg/kg/d via 3 s.c. injections). The AO rat model exhibited severe proteinuria, tubular necrosis, and interstitial fibrosis, oxidative stress, inflammation, accompanied by elevated urinary N-acetyl-beta-D-glucosaminidase activity and urinary β2-microglobulin secretion, all of which were significantly attenuated by PRO20. Urinary and renal levels of renin, angiotensinogen (AGT), and Ang II were elevated by AO and suppressed by PRO20, contrasting to largely unaltered plasma levels of the RAS parameters. The AO model also showed increased renal expression of full-length PRR and soluble PRR (sPRR) and urinary excretion of sPRR. Taken together, we conclude that PRR antagonism with PRO20 alleviates AO-induced nephropathy via inhibition of intrarenal RAS.

Mice lacking liver-specific β-catenin develop steatohepatitis and fibrosis after iron overload.

Science.gov (United States)

Preziosi, Morgan E; Singh, Sucha; Valore, Erika V; Jung, Grace; Popovic, Branimir; Poddar, Minakshi; Nagarajan, Shanmugam; Ganz, Tomas; Monga, Satdarshan P

2017-08-01

Iron overload disorders such as hereditary hemochromatosis and iron loading anemias are a common cause of morbidity from liver diseases and increase risk of hepatic fibrosis and hepatocellular carcinoma (HCC). Treatment options for iron-induced damage are limited, partly because there is lack of animal models of human disease. Therefore, we investigated the effect of iron overload in liver-specific β-catenin knockout mice (KO), which are susceptible to injury, fibrosis and tumorigenesis following chemical carcinogen exposure. Iron overload diet was administered to KO and littermate control (CON) mice for various times. To ameliorate an oxidant-mediated component of tissue injury, N-Acetyl-L-(+)-cysteine (NAC) was added to drinking water of mice on iron overload diet. KO on iron diet (KO +Fe) exhibited remarkable inflammation, followed by steatosis, oxidative stress, fibrosis, regenerating nodules and occurrence of occasional HCC. Increased injury in KO +Fe was associated with activated protein kinase B (AKT), ERK, and NF-κB, along with reappearance of β-catenin and target gene Cyp2e1, which promoted lipid peroxidation and hepatic damage. Addition of NAC to drinking water protected KO +Fe from hepatic steatosis, injury and fibrosis, and prevented activation of AKT, ERK, NF-κB and reappearance of β-catenin. The absence of hepatic β-catenin predisposes mice to hepatic injury and fibrosis following iron overload, which was reminiscent of hemochromatosis and associated with enhanced steatohepatitis and fibrosis. Disease progression was notably alleviated by antioxidant therapy, which supports its chemopreventive role in the management of chronic iron overload disorders. Lack of animal models for iron overload disorders makes it hard to study the disease process for improving therapies. Feeding high iron diet to mice that lack the β-catenin gene in liver cells led to increased inflammation followed by fat accumulation, cell death and wound healing that mimicked

Iron overload induces hypogonadism in male mice via extrahypothalamic mechanisms.

Science.gov (United States)

Macchi, Chiara; Steffani, Liliana; Oleari, Roberto; Lettieri, Antonella; Valenti, Luca; Dongiovanni, Paola; Romero-Ruiz, Antonio; Tena-Sempere, Manuel; Cariboni, Anna; Magni, Paolo; Ruscica, Massimiliano

2017-10-15

Iron overload leads to multiple organ damage including endocrine organ dysfunctions. Hypogonadism is the most common non-diabetic endocrinopathy in primary and secondary iron overload syndromes. To explore the molecular determinants of iron overload-induced hypogonadism with specific focus on hypothalamic derangements. A dysmetabolic male murine model fed iron-enriched diet (IED) and cell-based models of gonadotropin-releasing hormone (GnRH) neurons were used. Mice fed IED showed severe hypogonadism with a significant reduction of serum levels of testosterone (-83%) and of luteinizing hormone (-86%), as well as reduced body weight gain, body fat and plasma leptin. IED mice had a significant increment in iron concentration in testes and in the pituitary. Even if iron challenge of in vitro neuronal models (GN-11 and GT1-7 GnRH cells) resulted in 10- and 5-fold iron content increments, respectively, no iron content changes were found in vivo in hypothalamus of IED mice. Conversely, mice placed on IED showed a significant increment in hypothalamic GnRH gene expression (+34%) and in the intensity of GnRH-neuron innervation of the median eminence (+1.5-fold); similar changes were found in the murine model HFE -/- , resembling human hemochromatosis. IED-fed adult male mice show severe impairment of hypothalamus-pituitary-gonadal axis without a relevant contribution of the hypothalamic compartment, which thus appears sufficiently protected from systemic iron overload. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of intracellular iron overload on cell death and identification of potent cell death inhibitors.

Science.gov (United States)

Fang, Shenglin; Yu, Xiaonan; Ding, Haoxuan; Han, Jianan; Feng, Jie

2018-06-11

Iron overload causes many diseases, while the underlying etiologies of these diseases are unclear. Cell death processes including apoptosis, necroptosis, cyclophilin D-(CypD)-dependent necrosis and a recently described additional form of regulated cell death called ferroptosis, are dependent on iron or iron-dependent reactive oxygen species (ROS). However, whether the accumulation of intracellular iron itself induces ferroptosis or other forms of cell death is largely elusive. In present study, we study the role of intracellular iron overload itself-induced cell death mechanisms by using ferric ammonium citrate (FAC) and a membrane-permeable Ferric 8-hydroxyquinoline complex (Fe-8HQ) respectively. We show that FAC-induced intracellular iron overload causes ferroptosis. We also identify 3-phosphoinositide-dependent kinase 1 (PDK1) inhibitor GSK2334470 as a potent ferroptosis inhibitor. Whereas, Fe-8HQ-induced intracellular iron overload causes unregulated necrosis, but partially activates PARP-1 dependent parthanatos. Interestingly, we identify many phenolic compounds as potent inhibitors of Fe-8HQ-induced cell death. In conclusion, intracellular iron overload-induced cell death form might be dependent on the intracellular iron accumulation rate, newly identified cell death inhibitors in our study that target ferroptosis and unregulated oxidative cell death represent potential therapeutic strategies against iron overload related diseases. Copyright © 2018 Elsevier Inc. All rights reserved.

Making High-Tensile-Strength Amalgam Components

Science.gov (United States)

Grugel, Richard

2008-01-01

Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams

The Family in Care for the Elderly: Managing the Overload and Coping with Difficulties

Directory of Open Access Journals (Sweden)

Lisete dos Santos Mendes Mónico

2017-08-01

Full Text Available Introduction: Family is considered the main support of the elderly in a situation of dependency. Caregiving often results in overloading, leading to diverse problems. Aim: To evaluate the self-perception of the family caregiver’s overload and the strategies used to provide informal care to the dependent elderly considering their level of dependence. Method: The sample consisted of 21 children, 16 spouses, and nine other relatives of elderly dependents who responded to the Caregiver’s Overload Scale (Sequeira, 2007, the Portuguese version of Caregivers’ Assessment Management Index (CAMI, Nolan, Keady, & Grant, 1995 and the Barthel Index (Mahoney & Barthel, 1965. Results: The Barthel Index showed 34.8% of the elderly as severely dependent and 37.0% as totally dependent. The care most provided respected to medication, hygiene, food, and monitoring. Above 56.5% of the caregivers had an intense overload, both at the objective (impact of care and interpersonal relationship and subjective (F3-Expectations regarding care and F4-Perceived self-efficacy levels. The main reason for maintaining caregivers was family/personal obligation (95.7%. Caregivers reasonably assessed the effectiveness of their strategies in dealing with their dependent elderly (CAMI; M = 101.0, SD = 15.0. There was a negative relationship between the perception of the caregiver’s overload and the age and health status of the elderly, as well as between the number of strategies used by the caregiver to overcome difficulties and the self-perception of the overload. Conclusion: The multiplicity of daily tasks performed in support of a family member in a situation of severe dependence translates into situations of intense overload, negatively impacting on care, interpersonal relationship, expectations regarding caring, and perception of self-efficacy of care.

Both cardiomyocyte and endothelial cell Nox4 mediate protection against hemodynamic overload-induced remodelling.

Science.gov (United States)

Zhang, Min; Mongue-Din, Heloise; Martin, Daniel; Catibog, Norman; Smyrnias, Ioannis; Zhang, Xiaohong; Yu, Bin; Wang, Minshu; Brandes, Ralf P; Schröder, Katrin; Shah, Ajay M

2018-03-01

NADPH oxidase-4 (Nox4) is an important reactive oxygen species (ROS) source that is upregulated in the haemodynamically overloaded heart. Our previous studies using global Nox4 knockout (Nox4KO) mice demonstrated a protective role of Nox4 during chronic abdominal aortic banding, involving a paracrine enhancement of myocardial capillary density. However, other authors who studied cardiac-specific Nox4KO mice reported detrimental effects of Nox4 in response to transverse aortic constriction (TAC). It has been speculated that these divergent results are due to cell-specific actions of Nox4 (i.e. cardiomyocyte Nox4 detrimental but endothelial Nox4 beneficial) and/or differences in the model of pressure overload (i.e. abdominal banding vs. TAC). This study aimed to (i) investigate whether the effects of Nox4 on pressure overload-induced cardiac remodelling vary according to the pressure overload model and (ii) compare the roles of cardiomyocyte vs. endothelial cell Nox4. Global Nox4KO mice subjected to TAC developed worse cardiac remodelling and contractile dysfunction than wild-type littermates, consistent with our previous results with abdominal aortic banding. Next, we generated inducible cardiomyocyte-specific Nox4 KO mice (Cardio-Nox4KO) and endothelial-specific Nox4 KO mice (Endo-Nox4KO) and studied their responses to pressure overload. Both Cardio-Nox4KO and Endo-Nox4KO developed worse pressure overload-induced cardiac remodelling and dysfunction than wild-type littermates, associated with significant decrease in protein levels of HIF1α and VEGF and impairment of myocardial capillarization. Cardiomyocyte as well as endothelial cell Nox4 contributes to protection against chronic hemodynamic overload-induced cardiac remodelling, at least in part through common effects on myocardial capillary density. © The Author 2017 Published by Oxford University Press on behalf of the European Society of Cardiology.

Iron overload detection in rats by means of a susceptometer operating at room temperature

International Nuclear Information System (INIS)

Marinelli, M; Gianesin, B; Avignolo, C; Parodi, S; Minganti, V

2008-01-01

Biosusceptometry is a non-invasive procedure for determination of iron overload in a human body; it is essentially an assessment of the diamagnetic (water) and paramagnetic (iron) properties of tissues. We measured in vivo iron overload in the liver region of 12 rats by a room temperature susceptometer. The rats had been injected with sub-toxic doses of iron dextran. A quantitative relationship has been observed between the measurements and the number of treatments. The assessment of iron overload requires evaluating the magnetic signal corresponding to the same rat ideally without the overload. This background value was extrapolated on the basis of the signal measured in control rats versus body weight (R 2 = 0.73). The mean iron overload values for the treated rats, obtained after each iron injection, were significantly different from the means of the corresponding control rats (p 2 = 0.89). The magnetic moment of iron atoms in liver tissues was measured to be 3.6 Bohr magneton. Evaluation of the background signal is the limit to the measure; the error corresponds to about 30 mg (1 SD) of iron while the instrument sensitivity is more than a factor of 10 better.

A new approach to quantify the additional effect of primary overloads on ratcheting

International Nuclear Information System (INIS)

Waeckel, N.; Faure, O.; Sperandio, M.; Cousin, M.; Taleb, L.

1991-01-01

Taking into account the temporary nature of overloads reduces the conservatism of the current RCC-MR rules for prevention of ratcheting. An empirical K factor determined by the BITUBE tests carried out at INSA LYON, permits to quantify the influence of short-term mechanical overloads by comparison with the case without overload. The prediction of ratcheting risks by the RCC-MR efficiency diagram using a fictitious increased primary load by a K-factor is more fitted to the design of structures submitted to seisms. From then on, taking advantage of the workability of the experimental device BITUBE a new tests program has begun to confirm the results expressed above. (author)

Bandgap-customizable germanium using lithographically determined biaxial tensile strain for silicon-compatible optoelectronics.

Science.gov (United States)

Sukhdeo, David S; Nam, Donguk; Kang, Ju-Hyung; Brongersma, Mark L; Saraswat, Krishna C

2015-06-29

Strain engineering has proven to be vital for germanium-based photonics, in particular light emission. However, applying a large permanent biaxial tensile strain to germanium has been a challenge. We present a simple, CMOS-compatible technique to conveniently induce a large, spatially homogenous strain in circular structures patterned within germanium nanomembranes. Our technique works by concentrating and amplifying a pre-existing small strain into a circular region. Biaxial tensile strains as large as 1.11% are observed by Raman spectroscopy and are further confirmed by photoluminescence measurements, which show enhanced and redshifted light emission from the strained germanium. Our technique allows the amount of biaxial strain to be customized lithographically, allowing the bandgaps of different germanium structures to be independently customized in a single mask process.

2D mapping of plane stress crack-tip fields following an overload

Directory of Open Access Journals (Sweden)

P. J. Withers

2015-07-01

Full Text Available The evolution of crack-tip strain fields in a thin (plane stress compact tension sample following an overload (OL event has been studied using two different experimental techniques. Surface behaviour has been characterised by Digital Image Correlation (DIC, while the bulk behaviour has been characterised by means of synchrotron X-ray diffraction (XRD. The combination of both surface and bulk information allowed us to visualise the through-thickness evolution of the strain fields before the OL event, during the overload event, just after OL and at various stages after it. Unlike previous work, complete 2D maps of strains around the crack-tip were acquired at 60m spatial resolution by XRD. The DIC shows less crack opening after overload and the XRD a lower crack-tip peak stress after OL until the crack has grown past the compressive crack-tip residual stress introduced by the overload after which the behaviour returned to that for the baseline fatigue response. While the peak crack-tip stress is supressed by the compressive residual stress, the crack-tip stress field changes over each cycle are nevertheless the same for all Kmax cycles except at OL.

Designing a Personalized Guide Recommendation System to Mitigate Information Overload in Museum Learning

Science.gov (United States)

Huang, Yong-Ming; Liu, Chien-Hung; Lee, Chun-Yi; Huang, Yueh-Min

2012-01-01

Museum learning has received a lot of attention in recent years. Museum learning refers to people's use of museums to acquire knowledge. However, a problem with information overload has caused in engaging in such learning. Information overload signifies that users encounter a mass of information and need to determine whether certain information…

Worse cardiac remodeling in response to pressure overload in type 2 diabetes mellitus.

Science.gov (United States)

Gonçalves, N; Gomes-Ferreira, C; Moura, C; Roncon-Albuquerque, R; Leite-Moreira, A F; Falcão-Pires, I

2016-08-15

Diabetic cardiomyopathy is characterized by cardiac structural and functional abnormalities. Additionally, chronic pressure overload conditions are highly prevalent amongst diabetic population and this association leads to a more severe myocardial impairment. The differences in myocardial pathophysiology between type 1 and type 2 diabetes mellitus (DM) still remain to be clarified. Thus, we aimed to investigate biventricular structural and functional changes promoted by the two types of DM and the impact of concomitant chronic pressure overload. Wistar rats were injected with streptozotocin (Type 1 DM, T1DM) or fed with a hypercaloric diet (Type 2 DM, T2DM). Pressure overload was imposed in DM animals by aortic constriction and after 5weeks of DM the cardiac function and structure were evaluated. Both types of DM promoted hypertrophy, increased fibrosis and advanced glycation end-products deposition, in the two ventricles. Interestingly, the induced myocardial alterations were distinct. While T1DM stimulated a pronounced hypertrophy and extracellular matrix remodeling, T2DM induced functional impairment. The negative impact of the association of DM with aortic constriction was more pronounced in T2DM, promoting impaired function and increased stiffness, particularly in the right ventricle. Our study demonstrated that the two types of diabetes induce distinct cardiac alterations per se or when combined with chronic pressure overload. T1DM promoted a more extensive remodeling in cardiac structure while T2DM significantly impaired ventricular function. The impact of pressure overload was more notorious in T2DM as observed by worse myocardial remodeling, suggesting a higher susceptibility to the deleterious effects of chronic pressure overload, namely hypertension, among this diabetic population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

In Situ Radiography During Tensile Tests

Science.gov (United States)

Baaklini, George Y.; Bhatt, Ramakrishna T.

1994-01-01

Laboratory system for testing specimens of metal-, ceramic-, and intermetallic-matrix composite materials incorporates both electromechanical tensile-testing subsystem and either of two imaging subsystems that take x-ray photographs of specimens before, during, and after tensile tests. Used to test specimens of reaction-bonded silicon nitride reinforced with silicon carbide fibers (SiC/RBSN) considered for high-temperature service in advanced aircraft turbine engines. Provides data on effects of preexisting flaws (e.g., high-density impurities and local variations of density) on fracture behavior. Accumulated internal damage monitored during loading. X-ray source illuminates specimen in load frame while specimen is pulled. X-ray images on film correlated with stress-vs.-strain data from tensile test.

Overload effects on a ferritic-baintic steel and a cast aluminium alloy: two very different behaviours

Energy Technology Data Exchange (ETDEWEB)

Saintier, N. [Arts et Metiers Paris Tech, I2M, UMR CNRS, Universite Bordeaux 1, Talene Cedex (France); El Dsoki, C.; Kaufmann, H.; Sonsino, C.M. [Fraunhofer-Institute for Structural Durability and System Reliability LBF, Darmstadt (Germany); Dumas, C. [RENAULT, Technocentre, Guyancourt Cedex (France); Voellmecke, F.J. [BORBET GmbH, Hallenberg-Hesborn (Germany); Palin-Luc, T.; Bidonard, H.

2011-10-15

Load controlled fatigue tests were performed up to 10{sup 7} cycles on flat notched specimens (K{sub t} = 2.5) under constant amplitude and variable amplitude loadings with and without periodical overloads. Two materials are studied: a ferritic-bainitic steel (HE400M steel) and a cast aluminium alloy (AlSi7Mg0.3). These materials have a very different cyclic behaviour: the steel exhibits cyclic strain softening whereas the Al alloy shows cyclic strain hardening. The fatigue tests show that, for the steel, periodical overload applications reduce significantly the fatigue life for fully reversed load ratio (R{sub {sigma}} = -1), while they have no influence under pulsating loading (R{sub {sigma}} = 0). For the Al alloy overloads have an effect (fatigue life decreasing) only for variable amplitude loadings. The detrimental effect of overloads on the steel is due to ratcheting at the notch root which evolution is overload's dependent. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Influences of overload on low cycle fatigue behaviors of elbow pipe with local wall thinning

International Nuclear Information System (INIS)

Sato, Kyohei; Ogino, Kanako; Takahashi, Koji; Ando, Kotoji; Urabe, Yoshio

2011-01-01

Low cycle fatigue tests were conducted using 100A elbow pipe specimens with or without local wall thinning. Local wall thinning was machined on the inside of the extrados of test elbows to simulate metal loss due to flow-accelerated corrosion or liquid droplet impingement erosion. Low cycle fatigue tests were carried out under displacement control with an inner pressure of 9 MPa. To simulate seismic events, low cycle fatigue tests were carried out on elbow pipe subjected to cyclic overloads. Regardless of local wall thinning, fatigue life of overload pipe was not so different from that of the non-overload pipe in appearance. Miner's rule can be applied to evaluate fatigue life of the elbow pipes with and without wall thinning, even if overload is applied. (author)

Dietary iron rural blacks overload In southern African

African Journals Online (AJOL)

1990-09-15

Sep 15, 1990 ... suggest that iron overload from any cause may predispose to infection7 and there are .... consumption and acute inflammatory diseases. However, it ..... Addison GM, Beamish MR, Hales C ',Hodgkins M, Jacobs A, Llewellin P.

The overloaded right heart and ventricular interdependence.

Science.gov (United States)

Naeije, Robert; Badagliacca, Roberto

2017-10-01

The right and the left ventricle are interdependent as both structures are nested within the pericardium, have the septum in common and are encircled with common myocardial fibres. Therefore, right ventricular volume or pressure overloading affects left ventricular function, and this in turn may affect the right ventricle. In normal subjects at rest, right ventricular function has negligible interaction with left ventricular function. However, the right ventricle contributes significantly to the normal cardiac output response to exercise. In patients with right ventricular volume overload without pulmonary hypertension, left ventricular diastolic compliance is decreased and ejection fraction depressed but without intrinsic alteration in contractility. In patients with right ventricular pressure overload, left ventricular compliance is decreased with initial preservation of left ventricular ejection fraction, but with eventual left ventricular atrophic remodelling and altered systolic function. Breathing affects ventricular interdependence, in healthy subjects during exercise and in patients with lung diseases and altered respiratory system mechanics. Inspiration increases right ventricular volumes and decreases left ventricular volumes. Expiration decreases both right and left ventricular volumes. The presence of an intact pericardium enhances ventricular diastolic interdependence but has negligible effect on ventricular systolic interdependence. On the other hand, systolic interdependence is enhanced by a stiff right ventricular free wall, and decreased by a stiff septum. Recent imaging studies have shown that both diastolic and systolic ventricular interactions are negatively affected by right ventricular regional inhomogeneity and prolongation of contraction, which occur along with an increase in pulmonary artery pressure. The clinical relevance of these observations is being explored. Published on behalf of the European Society of Cardiology. All rights

Work Overload and Turnover Intention of Junior Auditors in Greater Jakarta, Indonesia

OpenAIRE

Andika Pradana; Imam Salehudin

2015-01-01

This paper aims to analyze how work overload influences turnover intentions of newly hired junior auditors in public accounting offices. Job satisfaction, work related stress and work life conflicts are used as mediating variables between work overload and turnover intention. This study employed 141 auditors from several accounting firms operating in the Greater Jakarta region. The sample was selected using purposive sampling. Three mediation hypotheses were tested using Structural Equation M...

Tensile and fracture behavior of polymer foams

International Nuclear Information System (INIS)

Kabir, Md. E.; Saha, M.C.; Jeelani, S.

2006-01-01

Tensile and mode-I fracture behavior of cross-linked polyvinyl chloride (PVC) and rigid polyurethane (PUR) foams are examined. Tension tests are performed using prismatic bar specimens and mode-I fracture tests are performed using single edge notched bend (SENB) specimens under three-point bending. Test specimens are prepared from PVC foams with three densities and two different levels of cross-linking, and PUR foam with one density. Tension and quasi-static fracture tests are performed using a Zwick/Rowell test machine. Dynamic fracture tests are performed using a DYNATUP model 8210 instrumented drop-tower test set up at three different impact energy levels. Various parameters such as specimen size, loading rate, foam density, cross-linking, crack length, cell orientation (flow and rise-direction) and solid polymer material are studied. It is found that foam density and solid polymer material have a significant effect on tensile strength, modulus, and fracture toughness of polymer foams. Level of polymer cross-linking is also found to have a significant effect on fracture toughness. The presence of cracks in the rise- and flow direction as well as loading rate has minimal effect. Dynamic fracture behavior is found to be different as compared to quasi-static fracture behavior. Dynamic fracture toughness (K d ) increases with impact energy. Examination of fracture surfaces reveals that the fracture occurs in fairly brittle manner for all foam materials

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

International Nuclear Information System (INIS)

Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

2013-01-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Costa, Fernando Ferreira [Universidade Estadual de Campinas, Campinas, SP (Brazil); Silveira, Paulo Augusto Achucarro [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Wood, John [University of Southern California, California (United States); Hamerschlak, Nelson [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

2013-07-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging.

Science.gov (United States)

Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

2013-12-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

Study of root tensile strength of softwood and hardwood tree species: Implications for slope stability

Science.gov (United States)

Esmaiili, Marzieh; Abdi, Ehsan; Jafary, Mohammad; Majnounian, Baris

2017-04-01

Landslides are known as one of the major natural hazards and often incurring economics and human life losses. The role of tree roots in slope stability is very important, especially when human lives and infrastructure are at risk. The anchorage of roots and improvement of slope stability mainly depend on specific properties of root network systems, such as tensile strength. These properties of the roots which govern the degree of reinforcement are different among tree species. Although, many studies have been conducted about plant biotechnical properties of species, yet there is lack of knowledge on comparing root systems of softwood and hardwood tree species for similar site conditions. Therefore this study was conducted to assess the tensile strength of the root system of Picea abies (softwood species) and Fraxinus excelsior (hardwood species) planted on two forested hillslopes. To this aim, single root specimens were sampled for each species and their tensile strength were then measured in laboratory using a computer controlled Instron Universal Testing Machine. According to the results root tensile strength tends to decrease with diameter according to a power law for both species. Based on analysis of covariance (ANCOVA), a significant difference has been observed in the tensile strength between the two studied species. Also the results showed that the value of mean root tensile strength for Picea abies (19.31 ± 2.64 MPa) was much more than that of Fraxinus excelsior (16.98 ± 1.01 MPa) within all root diameter classes. The data presented in this study may expand the knowledge of biotechnical properties of Picea abies and Fraxinus excelsior, as biomaterial for soil bioengineering.

Tensile-property characterization of thermally aged cast stainless steels

International Nuclear Information System (INIS)

Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K.

1994-02-01

The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components

Extracellular high-mobility group box 1 mediates pressure overload-induced cardiac hypertrophy and heart failure.

Science.gov (United States)

Zhang, Lei; Liu, Ming; Jiang, Hong; Yu, Ying; Yu, Peng; Tong, Rui; Wu, Jian; Zhang, Shuning; Yao, Kang; Zou, Yunzeng; Ge, Junbo

2016-03-01

Inflammation plays a key role in pressure overload-induced cardiac hypertrophy and heart failure, but the mechanisms have not been fully elucidated. High-mobility group box 1 (HMGB1), which is increased in myocardium under pressure overload, may be involved in pressure overload-induced cardiac injury. The objectives of this study are to determine the role of HMGB1 in cardiac hypertrophy and cardiac dysfunction under pressure overload. Pressure overload was imposed on the heart of male wild-type mice by transverse aortic constriction (TAC), while recombinant HMGB1, HMGB1 box A (a competitive antagonist of HMGB1) or PBS was injected into the LV wall. Moreover, cardiac myocytes were cultured and given sustained mechanical stress. Transthoracic echocardiography was performed after the operation and sections for histological analyses were generated from paraffin-embedded hearts. Relevant proteins and genes were detected. Cardiac HMGB1 expression was increased after TAC, which was accompanied by its translocation from nucleus to both cytoplasm and intercellular space. Exogenous HMGB1 aggravated TAC-induced cardiac hypertrophy and cardiac dysfunction, as demonstrated by echocardiographic analyses, histological analyses and foetal cardiac genes detection. Nevertheless, the aforementioned pathological change induced by TAC could partially be reversed by HMGB1 inhibition. Consistent with the in vivo observations, mechanical stress evoked the release and synthesis of HMGB1 in cultured cardiac myocytes. This study indicates that the activated and up-regulated HMGB1 in myocardium, which might partially be derived from cardiac myocytes under pressure overload, may be of crucial importance in pressure overload-induced cardiac hypertrophy and cardiac dysfunction. © 2015 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Ultrasound transmission measurements for tensile strength evaluation of tablets.

Science.gov (United States)

Simonaho, Simo-Pekka; Takala, T Aleksi; Kuosmanen, Marko; Ketolainen, Jarkko

2011-05-16

Ultrasound transmission measurements were performed to evaluate the tensile strength of tablets. Tablets consisting of one ingredient were compressed from dibasic calcium phosphate dehydrate, two grades of microcrystalline cellulose and two grades of lactose monohydrate powders. From each powder, tablets with five different tensile strengths were directly compressed. Ultrasound transmission measurements were conducted on every tablet at frequencies of 2.25 MHz, 5 MHz and 10 MHz and the speed of sound was calculated from the acquired waveforms. The tensile strength of the tablets was determined using a diametrical mechanical testing machine and compared to the calculated speed of sound values. It was found that the speed of sound increased with the tensile strength for the tested excipients. There was a good correlation between the speed of sound and tensile strength. Moreover, based on the statistical tests, the groups with different tensile strengths can be differentiated from each other by measuring the speed of sound. Thus, the ultrasound transmission measurement technique is a potentially useful method for non-destructive and fast evaluation of the tensile strength of tablets. Copyright © 2011 Elsevier B.V. All rights reserved.

Volume overload and adverse outcomes in chronic kidney disease: clinical observational and animal studies.

Science.gov (United States)

Hung, Szu-Chun; Lai, Yi-Shin; Kuo, Ko-Lin; Tarng, Der-Cherng

2015-05-05

Volume overload is frequently encountered and is associated with cardiovascular risk factors in patients with chronic kidney disease (CKD). However, the relationship between volume overload and adverse outcomes in CKD is not fully understood. A prospective cohort of 338 patients with stage 3 to 5 CKD was followed for a median of 2.1 years. The study participants were stratified by the presence or absence of volume overload, defined as an overhydration index assessed by bioimpedance spectroscopy exceeding 7%, the 90th percentile for the healthy population. The primary outcome was the composite of estimated glomerular filtration rate decline ≥50% or end-stage renal disease. The secondary outcome included a composite of morbidity and mortality from cardiovascular causes. Animal models were used to simulate fluid retention observed in human CKD. We found that patients with volume overload were at a higher risk of the primary and secondary end points in the adjusted Cox models. Furthermore, overhydration appears to be more important than hypertension in predicting an elevated risk. In rats subjected to unilateral nephrectomy and a high-salt diet, the extracellular water significantly increased. This fluid retention was associated with an increase in blood pressure, proteinuria, renal inflammation with macrophage infiltration and tumor necrosis factor-α overexpression, glomerular sclerosis, and cardiac fibrosis. Diuretic treatment with indapamide attenuated these changes, suggesting that fluid retention might play a role in the development of adverse outcomes. Volume overload contributes to CKD progression and cardiovascular diseases. Further research is warranted to clarify whether the correction of volume overload would improve outcomes for CKD patients. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Tensile behavior and tension stiffening of reinforced concrete

International Nuclear Information System (INIS)

Choun, Young Sun; Seo, Jeong Moon

2001-03-01

For the ultimate behavior analysis of containment buildings under severe accident conditions, a clear understanding of tensile behaviors of plain and reinforced concrete is necessary. Nonlinear models for tensile behaviors of concrete are also needed. This report describe following items: tensile behaviors of plain concrete, test results of reinforced concrete panels in uniaxial and biaxial tension, tension stiffening. The tensile behaviors of reinforced concrete are significantly influenced by the properties of concrete and reinforcing steel. Thus, for a more reliable evaluation of tensile behavior and ultimate pressure capacity of a reinforced or prestressed concrete containment building, an advanced concrete model which can be considered rebar-concrete interaction effects should be developed. In additions, a crack behavior analysis method and tension stiffening models, which are based on fracture mechanics, should be developed. The model should be based on the various test data from specimens considering material and sectional properties of the containment building

Autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury induced by albumin overload.

Science.gov (United States)

Tan, Jin; Wang, Miaohong; Song, Shuling; Miao, Yuyang; Zhang, Qiang

2018-01-10

Proteinuria (albuminuria) is an important cause of aggravating tubulointerstitial injury. Previous studies have shown that autophagy activation can alleviate renal tubular epithelial cell injury caused by urinary protein, but the mechanism is not clear. Here, we investigated the role of clearance of damaged mitochondria in this protective effect. We found that albumin overload induces a significant increase in turnover of LC3-II and decrease in p62 protein level in renal proximal tubular (HK-2) cells in vitro. Albumin overload also induces an increase in mitochondrial damage. ALC, a mitochondrial torpent, alleviates mitochondrial damage induced by albumin overload and also decreases autophagy, while mitochondrial damage revulsant CCCP further increases autophagy. Furthermore, pretreatment of HK-2 cells with rapamycin reduced the amount of damaged mitochondria and the level of apoptosis induced by albumin overload. In contrast, blocking autophagy with chloroquine exerted an opposite effect. Taken together, our results indicated autophagy activation promotes removal of damaged mitochondria and protects against renal tubular injury caused by albumin overload. This further confirms previous research that autophagy activation is an adaptive response in renal tubular epithelial cells after urinary protein overload.

Evaluation of ring tensile test results

International Nuclear Information System (INIS)

Chatterjee, S.; Anantharaman, S.; Balakrishnan, K.S.; Sivaramakrish, K.S.

1990-01-01

Ring specimens of 5-mm width cut from Zircaloy-2 cladding of reactor operated fuel elements that had experienced 5000 to 15,000 MWD/T of fuel burnup were subjected to ring tensile testing. The true stress-true strain data points up to the onset of necking from the individual load-elongation curves of these specimens were used as input data in Voce's equation. The results reveal that the uniform elongation (UE) values generated using Voce's equation were within (UE-2)% of the experimental percent uniform elongation (UE%). The corresponding ultimate tensile strength values were within ±1%. The uncertainty inherently associated in the determination of gauge length introduces extraneous deformation in the rings tested. Previous results had shown that a 14% increase in cladding diameter caused the gauge length to increase by 40%. To simulate the contribution of extraneous deformation due to an increase in cladding diameter, an analysis of the variation of the tensile parameters (uniform elongation and ultimate tensile strength) due to increase in the gauge length in the range of 10 to 40% was carried out. The results are discussed

Impact of tensile strain on the thermal transport of zigzag hexagonal boron nitride nanoribbon: An equilibrium molecular dynamics study

Science.gov (United States)

Navid, Ishtiaque Ahmed; Intisar Khan, Asir; Subrina, Samia

2018-02-01

The thermal conductivity of single layer strained hexagonal boron nitride nanoribbon (h-BNNR) has been computed using the Green—Kubo formulation of Equilibrium Molecular Dynamics (EMD) simulation. We have investigated the impact of strain on thermal transport of h-BNNR by varying the applied tensile strain from 1% upto 5% through uniaxial loading. The thermal conductivity of h-BNNR decreases monotonically with the increase of uniaxial tensile strain keeping the sample size and temperature constant. The thermal conductivity can be reduced upto 86% for an applied uniaxial tensile strain of 5%. The impact of temperature and width variation on the thermal conductivity of h-BNNR has also been studied under different uniaxial tensile strain conditions. With the increase in temperature, the thermal conductivity of strained h-BNNR exhibits a decaying characteristics whereas it shows an opposite pattern with the increasing width. Such study would provide a good insight on the strain tunable thermal transport for the potential device application of boron nitride nanostructures.

Controlling Price-Responsive Heat Pumps for Overload Elimination in Distribution Systems

DEFF Research Database (Denmark)

Csetvei, Zsuzsa; Østergaard, Jacob; Nyeng, Preben

2011-01-01

This paper investigates the possibility of applying electric heat pumps with the control-by-price-concept in order to avoid overload in a local distribution system. The proposed control algorithm is based upon a centrally dispatched real-time market price, reflecting the state of a larger power...... system, and is extended with a local price control for overload elimination on the corresponding feeder. The paper presents the mathematical models of a two-node system with price-responsive heat pumps, the chosen methodology of the central price calculation, and the proposed local feedback control...

Heat shock transcription factor 1-deficiency attenuates overloading-associated hypertrophy of mouse soleus muscle.

Science.gov (United States)

Koya, Tomoyuki; Nishizawa, Sono; Ohno, Yoshitaka; Goto, Ayumi; Ikuta, Akihiro; Suzuki, Miho; Ohira, Tomotaka; Egawa, Tatsuro; Nakai, Akira; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Beppu, Moroe; Goto, Katsumasa

2013-01-01

Hypertrophic stimuli, such as mechanical stress and overloading, induce stress response, which is mediated by heat shock transcription factor 1 (HSF1), and up-regulate heat shock proteins (HSPs) in mammalian skeletal muscles. Therefore, HSF1-associated stress response may play a key role in loading-associated skeletal muscle hypertrophy. The purpose of this study was to investigate the effects of HSF1-deficiency on skeletal muscle hypertrophy caused by overloading. Functional overloading on the left soleus was performed by cutting the distal tendons of gastrocnemius and plantaris muscles for 4 weeks. The right muscle served as the control. Soleus muscles from both hindlimbs were dissected 2 and 4 weeks after the operation. Hypertrophy of soleus muscle in HSF1-null mice was partially inhibited, compared with that in wild-type (C57BL/6J) mice. Absence of HSF1 partially attenuated the increase of muscle wet weight and fiber cross-sectional area of overloaded soleus muscle. Population of Pax7-positive muscle satellite cells in HSF1-null mice was significantly less than that in wild-type mice following 2 weeks of overloading (pmuscle hypertrophy might be attributed to the greater and prolonged enhancement of IL-6 expression. HSF1 and/or HSF1-mediated stress response may, in part, play a key role in loading-induced skeletal muscle hypertrophy.

Mitochondrial Ca2+ overload underlies Abeta oligomers neurotoxicity providing an unexpected mechanism of neuroprotection by NSAIDs.

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Sara Sanz-Blasco

Full Text Available Dysregulation of intracellular Ca(2+ homeostasis may underlie amyloid beta peptide (Abeta toxicity in Alzheimer's Disease (AD but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+ in neurons and promote mitochondrial Ca(2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+ overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i mitochondrial Ca(2+ overload underlies the neurotoxicity induced by Abeta oligomers and ii inhibition of mitochondrial Ca(2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.

Mitochondrial Ca2+ overload underlies Abeta oligomers neurotoxicity providing an unexpected mechanism of neuroprotection by NSAIDs.

Science.gov (United States)

Sanz-Blasco, Sara; Valero, Ruth A; Rodríguez-Crespo, Ignacio; Villalobos, Carlos; Núñez, Lucía

2008-07-23

Dysregulation of intracellular Ca(2+) homeostasis may underlie amyloid beta peptide (Abeta) toxicity in Alzheimer's Disease (AD) but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42) oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+) in neurons and promote mitochondrial Ca(2+) overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+) overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs) including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+) overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i) mitochondrial Ca(2+) overload underlies the neurotoxicity induced by Abeta oligomers and ii) inhibition of mitochondrial Ca(2+) overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.

Model for field-induced reorientation strain in magnetic shape memory alloy with tensile and compressive loads

International Nuclear Information System (INIS)

Zhu Yuping; Dui Guansuo

2008-01-01

A model based on the micromechanical and the thermodynamic theory is presented for field-induced martensite reorientation in magnetic shape memory alloy (MSMA) single crystals. The influence of variants morphology and the material property to constitutive behavior is considered. The nonlinear and hysteretic strain and magnetization response of MSMA are investigated for two main loading cases, namely the magnetic field-induced reorientation of variants under constant compressive stress and tensile stress. The predicted results have shown that increasing tensile loading reduces the required field for actuation, while increasing compressive loads result in the required magnetic field growing considerably. It is helpful to design the intelligent composite with MSMA fibers

Texture development during tensile deformation in Al-Mg alloys

Energy Technology Data Exchange (ETDEWEB)

Ohtani, S.; Inagaki, H. [Shonan Inst. of Tech., Fujisawashi (Japan)

2002-07-01

Tensile tests were made on commercial A1050 pure Al, A5182 Al-4.4% Mg alloy and A2017 Al-4% Cu alloy by varying the test temperature and the strain rate. Textures developed at various stages of the tensile deformation were investigated with the orientation distribution function analysis. It was found that, during the tensile test of the 1050 pure Al with the strain rate of 3 x 10{sup -4}S{sup -1} at 20 C, tensile axis readily rotated toward left angle 111 right angle stable end orientation. However, such rotation occurred only at the latest stage of the tensile deformation near the ultimate tensile stress, where stress strain curve was almost flattened and work hardening was almost saturated. It was strongly suggested that, since fine and complex dislocation cell structures were developed in such a work-hardened state, smooth and long range dislocation glide such as assumed in the classical Taylor theory would not be possible. To explain the observed texture development, cooperative movement of the dislocations in the cell walls might be necessary. In fact, addition of Mg and Cu, which suppressed strongly the development of well defined cell structures due to P-L effect or dynamic strain ageing, significantly retarded the rotation of tensile axes toward left angle 111 right angle. Interesting enough, textures developed in all these materials investigated were not affected by the strain rate and the temperature of the tensile test. (orig.)

Fracture behavior of nuclear graphites under tensile impact loading

International Nuclear Information System (INIS)

Ugachi, Hirokazu; Ishiyama, Shintaro; Eto, Motokuni

1994-01-01

Impact tensile strength test was performed with two kinds of HTTR graphites, fine grained isotropic graphite, IG-11 and coarse grained near isotropic graphite, PGX and deformation and fracture behavior under the strain rate of over 100s -1 was measured and the following results were derived: (1) Tensile strength for IG-11 graphite does not depend on the strain rate less than 1 s -1 , but over 1 s -1 , tensile strength for IG-11 graphite increase larger than that measured under 1 s -1 . At the strain rate more than 100 s -1 , remarkable decrease of tensile strength for IG-11 graphite was found. Tensile strength of PGX graphite does not depend on the strain rate less than 1 s -1 , but beyond this value, the sharp tensile strength decrease occurs. (2) Under 100 s -1 , fracture strain for both graphites increase with increase of strain rate and over 100 s -1 , drastic increase of fracture strain for IG-11 graphite was found. (3) At the part of gage length, volume of specimen increase with increase of tensile loading level and strain rate. (4) Poisson's ratio for both graphites decrease with increase of tensile loading level and strain rate. (5) Remarkable change of stress-strain curve for both graphites under 100 s -1 was not found, but over 100 s -1 , the slope of these curve for IG-11 graphite decrease drastically. (author)

When more is less: An examination of the relationship between hours in telework and role overload.

Science.gov (United States)

Duxbury, Linda; Halinski, Michael

2014-01-01

Proponents of telework arrangements assert that those who telework have more control over their work and family domains than their counterparts who are not permitted to work from home. Using Karasek's theory we hypothesized that the relationship between demands (hours in work per week; hours in childcare per week) and strain (work role overload; family role overload) would be moderated by the number of hours the employee spent per week teleworking (control). To determine how the number of telework hours relates to work role overload and family role overload, we follow the test for moderation and mediation using hierarchical multiple regression analysis as outlined by Frazier et al. [50] We used survey data collected from 1,806 male and female professional employees who spent at least one hour per week working from home during regular hours (i.e. teleworking). As hypothesized, the number of hours in telework per week negatively moderated the relation between work demands (total hours in paid employment per week) and work strain (work role overload). Contrary to our hypothesis, the number of hours in telework per week only partially mediated the relation between family demands (hours a week in childcare) and family role overload (strain). The findings from this study support the idea that the control offered by telework is domain specific (helps employees meet demands at work but not at home).

VOLUME OVERLOAD IS ASSOCIATED WITH MALNUTRITION IN PERITONEAL DIALYSIS

Directory of Open Access Journals (Sweden)

Jin Joo Cha

2012-06-01

Volume overload is associated with malnutrition and seems to be an independent predictor of mortality in PD population. Further study should evaluate the effects of intervention of volume control in PD patients.

Information Overload in the New World of Work: Qualitative Study into the Reasons and Countermeasures

NARCIS (Netherlands)

ter Heerdt, Jeroen; Bondarouk, Tatiana; Ruel, Hubertus Johannes Maria; Guiderdoni-Jourdain, Karine; Oiry, Ewan

2009-01-01

In this chapter the authors present a revision of the information overload concept elaborated by Eppler and Mengis (2004). The main elements of our approach are literature synopsis and analysis, qualitative semi-structured interviews, and discussion. Their review of the information overload concept

Glass interface effect on high-strain-rate tensile response of a soft polyurethane elastomeric polymer material

NARCIS (Netherlands)

Fan, J.T.; Weerheijm, J.; Sluys, L.J.

2015-01-01

The glass interface effect on dynamic tensile response of a soft polyurethane elastomeric polymer material has been investigated by subjecting a glass-polymer system of this polymer material matrix embedded a single 3 mm-diameter glass particle to impact loading in a split Hopkinson tension bar

Crucial role of rho-kinase in pressure overload-induced right ventricular hypertrophy and dysfunction in mice.

Science.gov (United States)

Ikeda, Shohei; Satoh, Kimio; Kikuchi, Nobuhiro; Miyata, Satoshi; Suzuki, Kota; Omura, Junichi; Shimizu, Toru; Kobayashi, Kenta; Kobayashi, Kazuto; Fukumoto, Yoshihiro; Sakata, Yasuhiko; Shimokawa, Hiroaki

2014-06-01

Right ventricular (RV) failure is the leading cause of death in various cardiopulmonary diseases, including pulmonary hypertension. It is generally considered that the RV is vulnerable to pressure overload as compared with the left ventricle (LV). However, as compared with LV failure, the molecular mechanisms of RV failure are poorly understood, and hence therapeutic targets of the disorder remain to be elucidated. Thus, we aimed to identify molecular therapeutic targets for RV failure in a mouse model of pressure overload. To induce pressure overload to respective ventricles, we performed pulmonary artery constriction or transverse aortic constriction in mice. We first performed microarray analysis and found that the molecules related to RhoA/Rho-kinase and integrin pathways were significantly upregulated in the RV with pulmonary artery constriction compared with the LV with transverse aortic constriction. Then, we examined the responses of both ventricles to chronic pressure overload in vivo. We demonstrated that compared with transverse aortic constriction, pulmonary artery constriction caused greater extents of mortality, Rho-kinase expression (especially ROCK2 isoform), and oxidative stress in pressure-overloaded RV, reflecting the weakness of the RV in response to pressure overload. Furthermore, mice with myocardial-specific overexpression of dominant-negative Rho-kinase showed resistance to pressure overload-induced hypertrophy and dysfunction associated with reduced oxidative stress. Finally, dominant-negative Rho-kinase mice showed a significantly improved long-term survival in both pulmonary artery constriction and transverse aortic constriction as compared with littermate controls. These results indicate that the Rho-kinase pathway plays a crucial role in RV hypertrophy and dysfunction, suggesting that the pathway is a novel therapeutic target of RV failure in humans. © 2014 American Heart Association, Inc.

Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle.

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Satoshi Nakada

Full Text Available External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK, moderate (MO, middle (MI, and strong (ST overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity increased with increasing overload, with increases of 1.8-fold (MO, 2.2-fold (MI, and 2.5-fold (ST, respectively, relative to non-overloaded muscle (NL in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98. The phosphorylated form of p70S6K (a positive regulator of translational efficiency showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO, 17.4-fold (MI, and 18.2-fold (ST, respectively, relative to NL in the WK group. These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size.

Correlation between Ribosome Biogenesis and the Magnitude of Hypertrophy in Overloaded Skeletal Muscle.

Science.gov (United States)

Nakada, Satoshi; Ogasawara, Riki; Kawada, Shigeo; Maekawa, Takahiro; Ishii, Naokata

2016-01-01

External loads applied to skeletal muscle cause increases in the protein translation rate, which leads to muscle hypertrophy. Although some studies have demonstrated that increases in the capacity and efficiency of translation are involved in this process, it remains unclear how these two factors are related to the magnitude of muscle hypertrophy. The present study aimed to clarify the roles played by the capacity and efficiency of translation in muscle hypertrophy. We used an improved synergist ablation in which the magnitude of compensatory hypertrophy could be controlled by partial removal of synergist muscles. Male rats were assigned to four groups in which the plantaris muscle was unilaterally subjected to weak (WK), moderate (MO), middle (MI), and strong (ST) overloading by four types of synergist ablation. Fourteen days after surgery, the weight of the plantaris muscle per body weight increased by 8%, 22%, 32% and 45%, in the WK, MO, MI and ST groups, respectively. Five days after surgery, 18+28S rRNA content (an indicator of translational capacity) increased with increasing overload, with increases of 1.8-fold (MO), 2.2-fold (MI), and 2.5-fold (ST), respectively, relative to non-overloaded muscle (NL) in the WK group. rRNA content showed a strong correlation with relative muscle weight measured 14 days after surgery (r = 0.98). The phosphorylated form of p70S6K (a positive regulator of translational efficiency) showed a marked increase in the MO group, but no further increase was observed with further increase in overload (increases of 22.6-fold (MO), 17.4-fold (MI), and 18.2-fold (ST), respectively, relative to NL in the WK group). These results indicate that increases in ribosome biogenesis at the early phase of overloading are strongly dependent on the amount of overloading, and may play an important role in increasing the translational capacity for further gain of muscular size.

Quasi-static and dynamic experimental studies on the tensile strength and failure pattern of concrete and mortar discs.

Science.gov (United States)

Jin, Xiaochao; Hou, Cheng; Fan, Xueling; Lu, Chunsheng; Yang, Huawei; Shu, Xuefeng; Wang, Zhihua

2017-11-10

As concrete and mortar materials widely used in structural engineering may suffer dynamic loadings, studies on their mechanical properties under different strain rates are of great importance. In this paper, based on splitting tests of Brazilian discs, the tensile strength and failure pattern of concrete and mortar were investigated under quasi-static and dynamic loadings with a strain rate of 1-200 s -1 . It is shown that the quasi-static tensile strength of mortar is higher than that of concrete since coarse aggregates weaken the interface bonding strength of the latter. Numerical results confirmed that the plane stress hypothesis lead to a lower value tensile strength for the cylindrical specimens. With the increase of strain rates, dynamic tensile strengths of concrete and mortar significantly increase, and their failure patterns change form a single crack to multiple cracks and even fragment. Furthermore, a relationship between the dynamic increase factor and strain rate was established by using a linear fitting algorithm, which can be conveniently used to calculate the dynamic increase factor of concrete-like materials in engineering applications.

Information overload, choice deferral, and moderating role of need for cognition: Empirical evidence

Directory of Open Access Journals (Sweden)

Luis Eduardo Pilli

2016-03-01

Full Text Available ABSTRACT Choice deferral due to information overload is an undesirable result of competitive environments. The neoclassical maximization models predict that choice avoidance will not increase as more information is offered to consumers. The theories developed in the consumer behavior field predict that some properties of the environment may lead to behavioral effects and an increase in choice avoidance due to information overload. Based on stimuli generated experimentally and tested among 1,000 consumers, this empirical research provides evidence for the presence of behavioral effects due to information overload and reveals the different effects of increasing the number of options or the number of attributes. This study also finds that the need for cognition moderates these behavioral effects, and it proposes psychological processes that may trigger the effects observed.

Vitamin D attenuates pressure overload-induced cardiac remodeling and dysfunction in mice.

Science.gov (United States)

Zhang, Liang; Yan, Xiao; Zhang, Yun-Long; Bai, Jie; Hidru, Tesfaldet Habtemariam; Wang, Qing-Shan; Li, Hui-Hua

2018-04-01

Vitamin D (VD) and its analogues play critical roles in metabolic and cardiovascular diseases. Recent studies have demonstrated that VD exerts a protective role in cardiovascular diseases. However, the beneficial effect of VD on pressure overload-induced cardiac remodeling and dysfunction and its underlying mechanisms are not fully elucidated. In this study, cardiac dysfunction and hypertrophic remodeling in mice were induced by pressure overload. Cardiac function was evaluated by echocardiography, and myocardial histology was detected by H&E and Masson's trichrome staining. Cardiomyocyte size was detected by wheat germ agglutinin staining. The protein levels of signaling mediators were examined by western blotting while mRNA expression of hypertrophic and fibrotic markers was examined by qPCR analysis. Oxidative stress was detected by dihydroethidine staining. Our results showed that administration of VD3 significantly ameliorates pressure overload-induced contractile dysfunction, cardiac hypertrophy, fibrosis and inflammation in mice. In addition, VD3 treatment also markedly inhibited cardiac oxidative stress and apoptosis. Moreover, protein levels of calcineurin A, ERK1/2, AKT, TGF-β, GRP78, cATF6, and CHOP were significantly reduced whereas SERCA2 level was upregulated in the VD3-treated hearts compared with control. These results suggest that VD3 attenuates cardiac remodeling and dysfunction induced by pressure overload, and this protective effect is associated with inhibition of multiple signaling pathways. Copyright © 2018 Elsevier Ltd. All rights reserved.

PENGARUH WORK OVERLOAD DAN WORK FAMILY CONFLICT TERHADAP TURNOVER INTENTION YANG DIMEDIASI OLEH WORK EXHAUSTION

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Nurul Hidayatin Nisa

2016-01-01

Full Text Available The purpose of this research was to examine factors that determine turnover intention in medical representative at PT. APL. To be known before that medical representatives have high percentage in turnover. The research using work exhaustion as mediation to determine the relationship between works overload and work family conflict of turnover intention. Research method is quantitative approach in causal research. The analysis tools are AMOS and T-Sobel. Findings of this research are both work overload and work family conflict berpengaruh with work exhaustion and turnover intention, work exhaustion mediated work overload and work family conflict over turnover intention.

Random fluid limit of an overloaded polling model

NARCIS (Netherlands)

M. Frolkova (Masha); S.G. Foss (Sergey); A.P. Zwart (Bert)

2014-01-01

htmlabstractIn the present paper, we study the evolution of an overloaded cyclic polling model that starts empty. Exploiting a connection with multitype branching processes, we derive fluid asymptotics for the joint queue length process. Under passage to the fluid dynamics, the server switches

Random fluid limit of an overloaded polling model

NARCIS (Netherlands)

M. Frolkova (Masha); S.G. Foss (Sergey); A.P. Zwart (Bert)

2013-01-01

htmlabstractIn the present paper, we study the evolution of an~overloaded cyclic polling model that starts empty. Exploiting a~connection with multitype branching processes, we derive fluid asymptotics for the joint queue length process. Under passage to the fluid dynamics, the server switches

Impact of iron overload and potential benefit from iron chelation in low-risk myelodysplastic syndrome.

Science.gov (United States)

Shenoy, Niraj; Vallumsetla, Nishanth; Rachmilewitz, Eliezer; Verma, Amit; Ginzburg, Yelena

2014-08-07

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal bone marrow disorders characterized by ineffective hematopoiesis, peripheral blood cytopenias, and potential for malignant transformation. Lower/intermediate-risk MDSs are associated with longer survival and high red blood cell (RBC) transfusion requirements resulting in secondary iron overload. Recent data suggest that markers of iron overload portend a relatively poor prognosis, and retrospective analysis demonstrates that iron chelation therapy is associated with prolonged survival in transfusion-dependent MDS patients. New data provide concrete evidence of iron's adverse effects on erythroid precursors in vitro and in vivo. Renewed interest in the iron field was heralded by the discovery of hepcidin, the main serum peptide hormone negative regulator of body iron. Evidence from β-thalassemia suggests that regulation of hepcidin by erythropoiesis dominates regulation by iron. Because iron overload develops in some MDS patients who do not require RBC transfusions, the suppressive effect of ineffective erythropoiesis on hepcidin may also play a role in iron overload. We anticipate that additional novel tools for measuring iron overload and a molecular-mechanism-driven description of MDS subtypes will provide a deeper understanding of how iron metabolism and erythropoiesis intersect in MDSs and improve clinical management of this patient population. © 2014 by The American Society of Hematology.

Peculiarities on voltage - current characteristics of HTS tapes at overloading conditions cooled by liquid nitrogen

International Nuclear Information System (INIS)

Vysotsky, V S; Fetisov, S S; Sytnikov, V E

2008-01-01

Electro - technical devices are considered as the most prospective use for high temperature superconductors. For such devices the overload currents due to faults in grids are the operational reality. In these cases the fault currents may forcibly go to superconductors being sometimes dozens times more than the critical currents of HTS. Overloads are the working modes for fault current limiters also. To understand the behavior of HTS devices at overloads it is important to study voltage-current characteristics (VCC) of basic HTS tapes in real cooling conditions. The knowledge of VCC permits to model and to simulate properly HTS devices behavior at overloads. We performed the study of VCC of several HTS tapes at currents several times more than their critical ones. Both, 1-G and 2-G tapes were tested. There were found peculiarities or 'spikes' on VCC at rising currents that vanished at decaying currents. It was shown that such peculiarities are determined by the change of cooling conditions from the convective heat exchange to the nucleate boiling. Nucleate boiling activation and development times were determined. Their dependencies on heat release were measured. The data obtained can be used in simulation of heating of real superconducting devices at overload conditions

HIGH TEMPERATURE TENSILE PROPERTIES OF NEW FE-CR-MN DEVELOPED STEEL

OpenAIRE

M. Mahmoudiniya; Sh. Kheirandish; M. Asadi Asadabad

2017-01-01

Nowadays, Ni-free austenitic stainless steels are being developed rapidly and high price of nickel is one of the most important motivations for this development. At present research a new FeCrMn steel was designed and produced based on Fe-Cr-Mn-C system. Comparative studies on microstructure and high temperature mechanical properties of  new steel and AISI 316 steel were done. The results showed that new FeCrMn developed steel has single austenite phase microstructure, and its tensile st...

Designing immersive surgical training against information technology-related overload in the operating room

OpenAIRE

Pluyter, J.R.

2012-01-01

On a theoretical level, this dissertation demonstrates that the “classical” conceptualization of overload in the field of Information Systems being an excessive amount of information is too simplistic. Based on the Emotional-Cognitive Overload Model by Rutkowski and Saunders (2011) this dissertation outlines the importance of the personal mental organization of Long-Term Memory (LTM) and the congruence of the information stimulus with cognitive schemata encoded in LTM.

In-situ measurement of the strain distribution in a tensile specimen by using a digital speckle pattern interferometer

International Nuclear Information System (INIS)

Park, Seung-Kyu; Baik, Sung-Hoon; Cha, Hyung-Ki; Kim, Young-Suk; Cheong, Yong-Moo

2010-01-01

Less sensitivity to environmental vibrations is essential for industrial applications of a digital speckle pattern interferometer (DSPI) to measure micro deformations. In this paper, a robust DSPI using single fringe to mechanical vibrations is designed for measuring the strain distribution of a tensile specimen. This system adopts a noise-immune signal processing algorithm to acquire a 3D strain distribution image. To acquire an accurate strain distribution for a tensile-specimen, locally-averaged and directionally-oriented filters operating in the frequency domain are used. This system uses a path-independent least-squares phase-unwrapping algorithm to acquire the 3D shape of the strain distribution. As for the initial experiments to measure the strain distribution of a tensile specimen in a vibration field, this system demonstrated a feasibility for industrial applications by providing reliable strain data.

Brief pressure overload of the left ventricle reduces myocardial infarct size via activation of protein kinase C.

Science.gov (United States)

Tang, Chia-Yu; Lai, Chang-Chi; Chiang, Shu-Chiung; Tseng, Kuo-Wei; Huang, Cheng-Hsiung

2015-09-01

We have previously reported that brief pressure overload of the left ventricle reduced myocardial infarct (MI) size. However, the role of protein kinase C (PKC) remains uncertain. In this study, we investigated whether pressure overload reduces MI size by activating PKC. MI was induced by a 40-minute occlusion of the left anterior descending coronary artery and a 3-hour reperfusion in anesthetized Sprague-Dawley rats. MI size was determined using triphenyl tetrazolium chloride staining. Brief pressure overload was achieved by two 10-minute partial snarings of the ascending aorta, raising the systolic left ventricular pressure 50% above the baseline value. Ischemic preconditioning was elicited by two 10-minute coronary artery occlusions and 10-minute reperfusions. Dimethyl sulfoxide (vehicle) or calphostin C (0.1 mg/kg, a specific inhibitor of PKC) was administered intravenously as pretreatment. The MI size, expressed as the percentage of the area at risk, was significantly reduced in the pressure overload group and the ischemic preconditioning group (19.0 ± 2.9% and 18.7 ± 3.0% vs. 26.1 ± 2.6% in the control group, where p overload and ischemic preconditioning (25.2 ± 2.4% and 25.0 ± 2.3%, where p overload of the left ventricle reduced MI size. Since calphostin C significantly limited the decrease of MI size, our results suggested that brief pressure overload reduces MI size via activation of PKC. Copyright © 2015. Published by Elsevier Taiwan.

SIRT1 may play a crucial role in overload-induced hypertrophy of skeletal muscle.

Science.gov (United States)

Koltai, Erika; Bori, Zoltán; Chabert, Clovis; Dubouchaud, Hervé; Naito, Hisashi; Machida, Shuichi; Davies, Kelvin Ja; Murlasits, Zsolt; Fry, Andrew C; Boldogh, Istvan; Radak, Zsolt

2017-06-01

Silent mating type information regulation 2 homologue 1 (SIRT1) activity and content increased significantly in overload-induced hypertrophy. SIRT1-mediated signalling through Akt, the endothelial nitric oxide synthase mediated pathway, regulates anabolic process in the hypertrophy of skeletal muscle. The regulation of catabolic signalling via forkhead box O 1 and protein ubiquitination is SIRT1 dependent. Overload-induced changes in microRNA levels regulate SIRT1 and insulin-like growth factor 1 signalling. Significant skeletal muscle mass guarantees functional wellbeing and is important for high level performance in many sports. Although the molecular mechanism for skeletal muscle hypertrophy has been well studied, it still is not completely understood. In the present study, we used a functional overload model to induce plantaris muscle hypertrophy by surgically removing the soleus and gastrocnemius muscles in rats. Two weeks of muscle ablation resulted in a 40% increase in muscle mass, which was associated with a significant increase in silent mating type information regulation 2 homologue 1 (SIRT1) content and activity (P overload-induced hypertrophy. These findings, along with the well-known regulatory roles that SIRT1 plays in modulating both anabolic and catabolic pathways, allow us to propose the hypothesis that SIRT1 may actually play a crucial causal role in overload-induced hypertrophy of skeletal muscle. This hypothesis will now require rigorous direct and functional testing. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Damage-induced tensile instability

International Nuclear Information System (INIS)

Hult, J.

1975-01-01

The paper presents a unified description of ductile and brittle rupture phenomena in structural components under tensile loading with particular emphasis on creep rupture. Two structural elements are analyzed in detail: 1) the uniform tensile bar subject to a Heaviside history of tensile force and superimposed such loadings, i.e. staircase histories, and 2) the thinwalled spherical pressure vessel subject to a Heaviside history of internal pressure. For both these structures the conditions for instantaneous as well as delayed rupture are analysed. It is shown that a state of mechanical instability will be reached at a certain load or after a certain time. The cases of purely ductile rupture and purely brittle fracture are identified as two limiting cases of this general instability phenomenon. The Kachanov-Rabotnov damage law implies that a structural component will fail in tension only when it has reached a state of complete damage, i.e. zero load carrying capacity. The extended law predicts failure at an earlier stage of the deterioration process and is therefore more compatible with experimental observation. Further experimental support is offered by predictions for staircase loading histories, both step-up and step-down type. The presented damage theory here predicts strain histories which are in closer agreement with test data than predictions based on other phenomenological theories

Performance analysis of SS7 congestion controls under sustained overload

Science.gov (United States)

Manfield, David R.; Millsteed, Gregory K.; Zukerman, Moshe

1994-04-01

Congestion controls are a key factor in achieving the robust performance required of common channel signaling (CCS) networks in the face of partial network failures and extreme traffic loads, especially as networks become large and carry high traffic volume. The CCITT recommendations define a number of types of congestion control, and the parameters of the controls must be well set in order to ensure their efficacy under transient and sustained signalling network overload. The objective of this paper is to present a modeling approach to the determination of the network parameters that govern the performance of the SS7 congestion controls under sustained overload. Results of the investigation by simulation are presented and discussed.

Iron deficiency and overload in relation to nutrition

NARCIS (Netherlands)

Spanjersberg MQI; Jansen EHJM; LEO

2000-01-01

Nutritional iron intake in the Netherlands has been reviewed with respect to both iron deficiency and iron overload. In general, iron intake and iron status in the Netherlands are adequate and therefore no change in nutrition policy is required. The following aspects and developments, however, need

The difference of tensile bond strength between total and self etch adhesive systems in dentin

Directory of Open Access Journals (Sweden)

Selly Yusalina

2010-03-01

Full Text Available Total etch adhesive system has been widely used in teeth conservation area as an adhesive agent before implicating composite resin restoration agent. The aim of this research is to prove the difference of tensile bond strength between total etch (Single Bond and self etch adhesive system (Adper prompt L-Pop on dentin surface in vitro. The extracted and non carries maxillary premolar teeth were used in this research and were divided into 2 groups. The first group comprised 15 specimen teeth etched in phosphoric acid and was applicated with the Single Bond adhesive agent. The second group comprised 15 specimen teeth, applicated with the Adper Prompt-L-Pop. The composite resin (Z 350, 3M was applied incrementally and each of the layers was rayed for 20 seconds. The specimens were stored in physiologic solution before they were tested. Tensile bond strength was measured by LRX Plus Lloyd Instrument, with 1 N load and 1 mm/minute speed, and the measurement result was in Mpa unit. The result was evaluated statistically by the Student t-test with α = 0.05. Single Bond (the 5th generation showed a better bond strength compared to the Adper Prompt-L-Pop (the 6th generation.

Data Overload Impact on Project Management: How Knowledge Management Systems Can Improve Federal Agencies Effectiveness

Science.gov (United States)

Rodriguez, Jacinto

2013-01-01

This mixed method exploratory case study was used to explore the effect data overload has on project management, how data overload affects project management effectiveness, how prepared program office staff is to manage multiple projects effectively, and how the program office's organizational structure and data management systems affect project…

Predicting Role Conflict, Overload and Contagion in Adult Women University Students with Families and Jobs.

Science.gov (United States)

Home, Alice M.

1998-01-01

Data from 443 women combining work, family, and schooling showed that lower income increased their vulnerability to role conflict. Perceived intensity of student demands was the strongest predictor of role conflict, overload, and contagion (preoccupation with one role while performing another). Conflict and overload were eased somewhat by distance…

LRRC10 is required to maintain cardiac function in response to pressure overload.

Science.gov (United States)

Brody, Matthew J; Feng, Li; Grimes, Adrian C; Hacker, Timothy A; Olson, Timothy M; Kamp, Timothy J; Balijepalli, Ravi C; Lee, Youngsook

2016-01-15

We previously reported that the cardiomyocyte-specific leucine-rich repeat containing protein (LRRC)10 has critical functions in the mammalian heart. In the present study, we tested the role of LRRC10 in the response of the heart to biomechanical stress by performing transverse aortic constriction on Lrrc10-null (Lrrc10(-/-)) mice. Mild pressure overload induced severe cardiac dysfunction and ventricular dilation in Lrrc10(-/-) mice compared with control mice. In addition to dilation and cardiomyopathy, Lrrc10(-/-) mice showed a pronounced increase in heart weight with pressure overload stimulation and a more dramatic loss of cardiac ventricular performance, collectively suggesting that the absence of LRRC10 renders the heart more disease prone with greater hypertrophy and structural remodeling, although rates of cardiac fibrosis and myocyte dropout were not different from control mice. Lrrc10(-/-) cardiomyocytes also exhibited reduced contractility in response to β-adrenergic stimulation, consistent with loss of cardiac ventricular performance after pressure overload. We have previously shown that LRRC10 interacts with actin in the heart. Here, we show that His(150) of LRRC10 was required for an interaction with actin, and this interaction was reduced after pressure overload, suggesting an integral role for LRRC10 in the response of the heart to mechanical stress. Importantly, these experiments demonstrated that LRRC10 is required to maintain cardiac performance in response to pressure overload and suggest that dysregulated expression or mutation of LRRC10 may greatly sensitize human patients to more severe cardiac disease in conditions such as chronic hypertension or aortic stenosis. Copyright © 2016 the American Physiological Society.

Iron overload in patients with myelodysplastic syndromes: An updated overview.

Science.gov (United States)

Moukalled, Nour M; El Rassi, Fuad A; Temraz, Sally N; Taher, Ali T

2018-06-15

Myelodysplastic syndromes (MDS) encompass a heterogeneous group of clonal hematopoietic stem cell disorders characterized by a broad clinical spectrum related to ineffective hematopoiesis leading to unilineage or multilineage cytopenias, with a high propensity for transformation to acute myeloid leukemia. Iron overload has been recently identified as one of the important conditions complicating the management of these diverse disorders. The accumulation of iron is mainly related to chronic transfusions; however, evidence suggests a possible role for ineffective erythropoiesis and increased intestinal absorption of iron, related to altered hepcidin and growth differentiation factor-15 levels in the development of hemosiderosis in patients with MDS. In addition to its suggested role in the exacerbation of ineffective erythropoiesis, multiple reports have identified a prognostic implication for the development of iron overload in patients with MDS, with an improvement in overall survival after the initiation of iron chelation therapy. This review includes a detailed discussion of iron overload in patients with MDS whether they are undergoing supportive therapy or curative hematopoietic stem cell transplantation, with a focus on the mechanism, diagnosis, and effect on survival as well as the optimal management of this highly variable complication. Cancer 2018. © 2018 American Cancer Society. © 2018 American Cancer Society.

Evaluation Of The Overload Of Care In Families Of Psychiatric Patients In Psychosocial Care Center

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Mayron Morais Almeida

2017-07-01

Full Text Available Introduction: The burden of care in family refers to the weight caused by the primary caregiver role to psychiatric patients and the difficulties encountered in performing this function in daily life. Objectives: Assessing the objective and subjective overload of family members who live with the reality of psychiatric disorder in a child day-care psychosocial care center. Methods: Cross-sectional study, descriptive-exploratory, of quantitative approach, with non-probabilistic samples of accidental type with 80 families of psychiatric patients held in a Psychosocial Care Center. For overload evaluation, the subscales "B" and "D" of the Family Overload Rating Scale (FBIS-BR were used. Results: The study was conducted with 80 families of psychiatric patients. The average age of female caregivers was 39,6 years old, and 40,7 years old for male caregivers, with female predominance (87,5% compared to men (12,5%, with low education for both genres. Family caregivers presented high objective burden due to excessive demand attention (p<0,001, heteroaggressiveness (p<0,001 and perplexing behavior of psychiatric patients regarding the supervision of problematic behaviors (p<0,001. The items on the impact on the family's daily routine have not helped to generate objective overload for the family members. On subjective overload, it was clear to observe familiar members with high degree of disturbance in all the dimensions assessed (p < 0,001. Conclusion: The high degree of care overload observed in family members indicates the need to develop contacts with the family of the psychiatric patient to answer questions, offer support and assistance to the family caregiver. Keywords: Caregivers. Patients. Mental Health Services.

Evolution of tensile design stresses for lumber

Science.gov (United States)

William L. Galligan; C. C. Gerhards; R. L. Ethington

1979-01-01

Until approximately 1965, allowable design stresses for lumber in tension were taken as equal to those assigned for bending. As interest in tensile properties increased, testing machines were designed specifically to stress lumber in tension. Research results that accumulated on tensile tests of full-size lumber suggested lower design stresses for tension than for...

Tensile and Compressive Responses of Ceramic and Metallic Nanoparticle Reinforced Mg Composites

Directory of Open Access Journals (Sweden)

Quy Bau Nguyen

2013-05-01

Full Text Available In the present study, room temperature mechanical properties of pure magnesium, Mg/ZrO2 and Mg/(ZrO2 + Cu composites with various compositions are investigated. Results revealed that the use of hybrid (ZrO2 + Cu reinforcements in Mg led to enhanced mechanical properties when compared to that of single reinforcement (ZrO2. Marginal reduction in mechanical properties of Mg/ZrO2 composites were observed mainly due to clustering of ZrO2 particles in Mg matrix and lack of matrix grain refinement. Addition of hybrid reinforcements led to grain size reduction and uniform distribution of hybrid reinforcements, globally and locally, in the hybrid composites. Macro- and micro- hardness, tensile strengths and compressive strengths were all significantly increased in the hybrid composites. With respect to unreinforced magnesium, failure strain was almost unchanged under tensile loading while it was reduced under compressive loading for both Mg/ZrO2 and Mg/(ZrO2 + Cu composites.

Evaluation of a new tablet formulation of deferasirox to reduce chronic iron overload after long-term blood transfusions

Directory of Open Access Journals (Sweden)

Chalmers AW

2016-02-01

Full Text Available Anna W Chalmers, Jamile M Shammo Department of Internal Medicine, Division of Hematology/Oncology, Rush University Medical Center, Chicago, IL, USA Abstract: Transfusion-dependent anemia is a common feature in a wide array of hematological disorders, including thalassemia, sickle cell disease, aplastic anemia, myelofibrosis, and myelodysplastic syndromes. In the absence of a physiological mechanism to excrete excess iron, chronic transfusions ultimately cause iron overload. Without correction, iron overload can lead to end-organ damage, resulting in cardiac, hepatic, and endocrine dysfunction/failure. Iron chelating agents are utilized to reduce iron overload, as they form a complex with iron, leading to its clearance. Iron chelation has been proven to decrease organ dysfunction and improve survival in certain transfusion-dependent anemias, such as β-thalassemia. Several chelating agents have been approved by the United States Food and Drug Administration for the treatment of iron overload, including deferoxamine, deferiprone, and deferasirox. A variety of factors have to be considered when choosing an iron chelator, including dosing schedule, route of administration, tolerability, and side effect profile. Deferasirox is an orally administered iron chelator with proven efficacy and safety in multiple hematological disorders. There are two formulations of deferasirox, a tablet for suspension, and a new tablet form. This paper is intended to provide an overview of iron overload, with a focus on deferasirox, and its recently approved formulation Jadenu® for the reduction of transfusional iron overload in hematological disorders. Keywords: iron chelation therapy, transfusional iron overload, deferasirox

Thermal and electrodynamical formation mechanisms of overloaded AC states and charging rate influence on their stable dynamics

International Nuclear Information System (INIS)

Romanovskii, V.; Watanabe, K.; Awaji, S.

2013-01-01

Highlights: •Overloaded AC states are investigated to understand the mechanisms of there formation. •There exist characteristic time windows defining the existence of stable overloaded AC states. •Limiting values of the electric field, current and temperature are higher than the quench ones. -- Abstract: The macroscopic thermal and electrodynamical phenomena occurring in high-T c superconductors during overloaded AC states are theoretically investigated to understand the basic physical mechanisms, which are characteristic for the stable formation of the operating modes when the peak current exceeds the critical current of a superconductor during AC modes. It is shown that there exist characteristic time windows defining the existence of stable overloaded AC states. They identify the stability boundary of the overloaded AC states. Therefore, there is the maximum allowable value of a peak current of stable overloaded AC regimes at the given charging rate, cooling conditions and properties of a superconductor and a matrix. The results obtained prove that the limiting peak current is higher than the corresponding quench current defining the stability margin of DC states. It monotonically increases with the charging rate. Besides, in the stable overloaded AC states, the peak values of the electric field and temperature may be also noticeably higher than the corresponding quench values. They depend on the peak current and charging rate at the given cooling conditions. As a result, high-T c superconducting tapes can stably work under intensive AC modes without instability onset when the peak of applied currents may significantly exceed not only the critical current but also the corresponding values of DC-quench currents

30 CFR 77.506-1 - Electric equipment and circuits; overload and short circuit protection; minimum requirements.

Science.gov (United States)

2010-07-01

... short circuit protection; minimum requirements. 77.506-1 Section 77.506-1 Mineral Resources MINE SAFETY...-1 Electric equipment and circuits; overload and short circuit protection; minimum requirements. Devices providing either short circuit protection or protection against overload shall conform to the...

Effect of Root Moisture Content and Diameter on Root Tensile Properties

Science.gov (United States)

Yang, Yuanjun; Chen, Lihua; Li, Ning; Zhang, Qiufen

2016-01-01

The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most popular tree species used for slope stabilization in the rocky mountainous areas of northern China, were used in this study. A tensile test was conducted after root samples were grouped by diameter and moisture content. The results showedthat:1) root moisture content had a significant influence on tensile properties; 2) slightly loss of root moisture content could enhance tensile strength, but too much loss of water resulted in weaker capacity for root elongation, and consequently reduced tensile strength; 3) root diameter had a strong positive correlation with tensile resistance; and4) the roots of Betula platyphylla had the best tensile properties when both diameter and moisture content being controlled. These findings improve our understanding of root tensile properties with root size and moisture, and could be useful for slope stabilization using vegetation. PMID:27003872

Use of run statistics to validate tensile tests

International Nuclear Information System (INIS)

Eatherly, W.P.

1981-01-01

In tensile testing of irradiated graphites, it is difficult to assure alignment of sample and train for tensile measurements. By recording location of fractures, run (sequential) statistics can readily detect lack of randomness. The technique is based on partitioning binomial distributions

HIGH TEMPERATURE TENSILE PROPERTIES OF NEW FE-CR-MN DEVELOPED STEEL

Directory of Open Access Journals (Sweden)

M. Mahmoudiniya

2017-03-01

Full Text Available Nowadays, Ni-free austenitic stainless steels are being developed rapidly and high price of nickel is one of the most important motivations for this development. At present research a new FeCrMn steel was designed and produced based on Fe-Cr-Mn-C system. Comparative studies on microstructure and high temperature mechanical properties of  new steel and AISI 316 steel were done. The results showed that new FeCrMn developed steel has single austenite phase microstructure, and its tensile strength and toughness were higher than those of 316 steel at 25, 200,350 and 500°C. In contrast with 316 steel, the new FeCrMn steel did not show strain induced transformation and dynamic strain aging phenomena during tensile tests that represented higher austenite stability of new developed steel. Lower density and higher strength of the new steel caused higher specific strength in comparison with the 316 one that can be considered as an important advantage in structural applications but in less corrosive environment

Effect of Hereditary Hemochromatosis Gene H63D and C282Y Mutations on Iron Overload in Sickle Cell Disease Patients

Directory of Open Access Journals (Sweden)

Yunus Kasım Terzi

2016-12-01

Full Text Available Objective: Hemochromatosis is an autosomal recessive disease that is one of the most important reasons for iron overload. Sickle cell disease is a hemoglobinopathy that occurs as a result of a homozygous mutation in the hemoglobin gene. Erythrocyte transfusion is frequently used in the treatment of this disease. Iron overload as a result of transfusion is important in the mortality and morbidity of sickle cell anemia patients as well as in other hemoglobinopathies. In this study, the effect of hemochromatosis gene (HFE p.H63D and p.C282Y mutations on transfusion-related cardiac and liver iron overload in sickle cell disease patients who carry homozygous hemoglobin S mutation has been investigated. Materials and Methods: This is a prospective single-center crosssectional study in patients with homozygous hemoglobin S mutation between the years 2008 and 2013. The patients were divided into two groups. The first group (group A, n=31 was receiving chelation therapy and the second group (group B, n=13 was not. Direct and indirect iron loads were analyzed by magnetic resonance imaging and biochemically, respectively. HFE gene mutations were analyzed by polymerase chain reaction-restriction fragment length polymorphism method. Statistical analyses were performed by independent samples t-test. Results: p.H63D mutation was detected in 10 (32.3% patients in group A and in only 1 patient (7.7% in group B. When the 2 groups were compared for iron overload, iron deposition in the liver was significantly higher in group B (p=0.046. In addition, in group A, iron deposition was significantly higher in HFE mutation carriers compared to patients without the mutation (p=0.05. Conclusion: Results of this study showed that HFE gene mutations are important in iron deposition in the liver in patients with sickle cell disease.

Miniature tensile test specimens for fusion reactor irradiation studies

International Nuclear Information System (INIS)

Klueh, R.L.

1985-01-01

Three miniature sheet-type tensile specimens and a miniature rod-type specimen are being used to determine irradiated tensile properties for alloy development for fusion reactors. The tensile properties of type 316 stainless steel were determined with these different specimens, and the results were compared. Reasonably good agreement was observed. However, there were differences that led to recommendations on which specimens are preferred. 4 references, 9 figures, 6 tables

Tensile Behaviour of Open Cell Ceramic Foams

Czech Academy of Sciences Publication Activity Database

Řehořek, Lukáš; Dlouhý, Ivo; Chlup, Zdeněk

2009-01-01

Roč. 53, č. 4 (2009), s. 237-241 ISSN 0862-5468 R&D Projects: GA ČR GA101/09/1821; GA ČR GD106/09/H035 Institutional research plan: CEZ:AV0Z20410507 Keywords : Tensile test * Ceramics foam * Open porosity * Tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.649, year: 2009

Tensile Properties of Under-Matched Weld Joints for 950 MPa Steel.

Science.gov (United States)

Yamamoto, Kouji; Arakawa, Toshiaki; Akazawa, Nobuki; Yamamoto, Kousei; Matsuo, Hiroki; Nakagara, Kiyoyuki; Suita, Yoshikazu

In welding of 950 MPa-class high tensile strength steel, preheating is crucial in order to avoid cold cracks, which, however, eventually increases welding deformations. One way to decrease welding deformations is lowering preheating temperature by using under-matched weld metal. Toyota and others clarify that although breaking elongation can decrease due to plastic constraint effect under certain conditions, static tensile of under-matched weld joints is comparable to that of base metal. However, there has still been no report about joint static tensile of under-matched weld joints applied to 950 MPa-class high tensile strength steel. In this study, we aim to research tensile strength and fatigue strength of under-matched weld joints applied to 950 MPa-class high tensile steel.

Effects of conventional welding and laser welding on the tensile strength, ultimate tensile strength and surface characteristics of two cobalt-chromium alloys: a comparative study.

Science.gov (United States)

Madhan Kumar, Seenivasan; Sethumadhava, Jayesh Raghavendra; Anand Kumar, Vaidyanathan; Manita, Grover

2012-06-01

The purpose of this study was to evaluate the efficacy of laser welding and conventional welding on the tensile strength and ultimate tensile strength of the cobalt-chromium alloy. Samples were prepared with two commercially available cobalt-chromium alloys (Wironium plus and Diadur alloy). The samples were sectioned and the broken fragments were joined using Conventional and Laser welding techniques. The welded joints were subjected to tensile and ultimate tensile strength testing; and scanning electron microscope to evaluate the surface characteristics at the welded site. Both on laser welding as well as on conventional welding technique, Diadur alloy samples showed lesser values when tested for tensile and ultimate tensile strength when compared to Wironium alloy samples. Under the scanning electron microscope, the laser welded joints show uniform welding and continuous molt pool all over the surface with less porosity than the conventionally welded joints. Laser welding is an advantageous method of connecting or repairing cast metal prosthetic frameworks.

Nursing management of sensory overload in psychiatry – Theoretical densification and modification of the framework model

Science.gov (United States)

Scheydt, Stefan; Needham, Ian; Behrens, Johann

2017-01-01

Background: Within the scope of the research project on the subjects of sensory overload and stimulus regulation, a theoretical framework model of the nursing care of patients with sensory overload in psychiatry was developed. In a second step, this theoretical model should now be theoretically compressed and, if necessary, modified. Aim: Empirical verification as well as modification, enhancement and theoretical densification of the framework model of nursing care of patients with sensory overload in psychiatry. Method: Analysis of 8 expert interviews by summarizing and structuring content analysis methods based on Meuser and Nagel (2009) as well as Mayring (2010). Results: The developed framework model (Scheydt et al., 2016b) could be empirically verified, theoretically densificated and extended by one category (perception modulation). Thus, four categories of nursing care of patients with sensory overload can be described in inpatient psychiatry: removal from stimuli, modulation of environmental factors, perceptual modulation as well as help somebody to help him- or herself / coping support. Conclusions: Based on the methodological approach, a relatively well-saturated, credible conceptualization of a theoretical model for the description of the nursing care of patients with sensory overload in stationary psychiatry could be worked out. In further steps, these measures have to be further developed, implemented and evaluated regarding to their efficacy.

Evaluation of the tensile strength of the human ureter--preliminary results.

Science.gov (United States)

Shilo, Yaniv; Pichamuthu, Joseph E; Averch, Timothy D; Vorp, David A

2014-12-01

Ureteral injuries such as avulsion are directly related to mechanical damage of the ureter. Understanding the tensile strength of this tissue may assist in prevention of iatrogenic injuries. Few published studies have looked at the mechanical properties of the animal ureter and, of those, none has determined the tensile strength of the human ureter. Therefore, the purpose of this work was to determine the tensile strength of the human ureter. We harvested 11 human proximal ureters from patients who were undergoing nephrectomy for either kidney tumors or nonfunctioning kidney. The specimens were then cut into multiple circumferentially and longitudinally oriented tissue strips for tensile testing. Strips were uniaxially stretched to failure in a tensile testing machine. The corresponding force and displacement were recorded. Finally, stress at failure was noted as the tensile strength of the sample. Circumferential tensile strength was also compared in the proximal and distal regions of the specimens. The tensile strength of the ureter in circumferential and longitudinal orientations was found to be 457.52±33.74 Ncm(-2) and 902.43±122.08 Ncm(-2), respectively (Ptensile strength of the ureter was found to be significantly lower than the longitudinal strength. Circumferential tensile strength was also lower with more proximal parts of the ureter. This information may be important for the design of "intelligent" devices and simulators to prevent complications.

Thermal degradation and tensile strength of sansevieria trifasciata-polypropylene composites

Science.gov (United States)

Abral, H.; Kenedy, E.

2015-07-01

The paper exhibits thermal degradation and tensile strength of Sansevieria Trifasciata (ST) fibers and polypropylene (PP) composites. Thermal degradation of ST fibers PP composites was conducted by using thermogravimetry (TGA) instrument, meanwhile tensile strength of the composite was done by using tensile equipment. The results show that the thermal resistance of ST fibers PP composites was higher than that of virgin PP only. Increases in volume fraction of fibers in the composites enhance the tensile strength. Scanning Electron Microscope (SEM) observation exhibits good interface bonding between ST fibers and PP matrix.

Thermal degradation and tensile strength of sansevieria trifasciata-polypropylene composites

International Nuclear Information System (INIS)

Abral, H; Kenedy, E

2015-01-01

The paper exhibits thermal degradation and tensile strength of Sansevieria Trifasciata (ST) fibers and polypropylene (PP) composites. Thermal degradation of ST fibers PP composites was conducted by using thermogravimetry (TGA) instrument, meanwhile tensile strength of the composite was done by using tensile equipment. The results show that the thermal resistance of ST fibers PP composites was higher than that of virgin PP only. Increases in volume fraction of fibers in the composites enhance the tensile strength. Scanning Electron Microscope (SEM) observation exhibits good interface bonding between ST fibers and PP matrix. (paper)

"Something's Gotta Give:" Advanced-Degree Seeking Women's Experiences of Sexism, Role Overload, and Psychological Distress

Science.gov (United States)

West, Lindsey M.

2014-01-01

With the rise in advanced-degree seeking women and the minimal research on the dual impact of sexism and role overload, the current study aims to better understand the impact of sexism and role overload on psychological distress in a particular sample of advanced-degree seeking women. Seventy-six female medical student participants (mean age 24.7)…

Effect of pre-existing shear bands on the tensile mechanical properties of a bulk metallic glass

International Nuclear Information System (INIS)

Cao, Q.P.; Liu, J.W.; Yang, K.J.; Xu, F.; Yao, Z.Q.; Minkow, A.; Fecht, H.J.; Ivanisenko, J.; Chen, L.Y.; Wang, X.D.; Qu, S.X.; Jiang, J.Z.

2010-01-01

Bulk Zr 64.13 Cu 15.75 Ni 10.12 Al 10 metallic glass has been rolled at room temperature in two different directions, and the dependences of microstructure and tensile mechanical property on the degree of deformation and rolling directions have been investigated. No deformation-induced crystallization occurs except for shear bands. Shear band formation in conjugated directions is achieved in the specimen rolled in two directions, while rolling in one direction induces shear band formation only in a single direction. Pre-existing properly spaced soft inhomogeneities can stabilize shear bands and lead to tensile plastic strain, and the efficient intersection of shear bands in conjugated directions results in work-hardening behavior, which is further confirmed by in situ tensile scanning electron microscopic observation. Based on the experimental results obtained in two different specimen geometries and finite element analysis, it is deduced that a normal-stress-modified maximum shear stress criterion rather than a shear plane criterion can describe the conditions for the formation of shear bands in uniaxial tension.

Modeling of Unidirectional-Overloaded Transition in Catalytic Tubular Microjets

NARCIS (Netherlands)

Klingner, Anke; Khalil, Islam S. M.; Magdanz, Veronika; Fomin, Vladimir M.; Schmidt, Oliver G.; Misra, Sarthak

2017-01-01

A numerical time-resolved model is presented for predicting the transition between unidirectional and overloaded motion of catalytic tubular microjets (Ti/Fe/Pt rolled-up microtubes) in an aqueous solution of hydrogen peroxide. Unidirectional movement is achieved by periodic ejection of gas bubbles

Stress 2.0: Social Media Overload among Swiss Teenagers

NARCIS (Netherlands)

Lutz, Christoph; Ranzini, Giulia; Meckel, Miriam

2014-01-01

Technostress and information overload are serious challenges of the information age. An alarming number of people exhibit dangerously intensive media consumption, while Internet and mobile phone addictions are a widespread phenomenon. At the same time, new media overexposure among young people is

Effects of material properties and speed of compression on microbial survival and tensile strength in diclofenac tablet formulations.

Science.gov (United States)

Ayorinde, J O; Itiola, O A; Odeniyi, M A

2013-03-01

A work has been done to study the effects of material properties and compression speed on microbial survival and tensile strength in diclofenac tablet formulations. Tablets were produced from three formulations containing diclofenac and different excipients (DC, DL and DDCP). Two types of machines (Hydraulic hand press and single punch press), which compress the tablets at different speeds, were used. The compression properties of the tablets were analyzed using Heckel and Kawakita equations. A 3-dimensional plot was produced to determine the relationship between the tensile strength, compression speed and percentage survival of Bacillus subtilis in the diclofenac tablets. The mode of consolidation of diclofenac was found to depends on the excipient used in the formulation. DC deformed mainly by plastic flow with the lowest Py and Pk values. DL deformed plastically at the initial stage, followed by fragmentation at the later stage of compression, whereas DDCP deformed mainly by fragmentation with the highest Py and Pk values. The ranking of the percentage survival of B. subtilis in the formulations was DDCP > DL > DC, whereas the ranking of the tensile strength of the tablets was DDCP > DL > DC. Tablets produced on a hydraulic hand press with a lower compression speed had a lower percentage survival of microbial contaminants than those produced on a single punch press, which compressed the tablets at a much higher speed. The mode of consolidation of the materials and the speed at which tablet compression is carried out have effects on both the tensile strength of the tablets and the extent of destruction of microbial contaminants in diclofenac tablet formulations.

Radionuclide stroke count ratios for assessment of right and left ventricular volume overload in children

International Nuclear Information System (INIS)

Parrish, M.D.; Graham, T.P. Jr.; Born, M.L.; Jones, J.P.; Boucek, R.J. Jr.; Artman, M.; Partain, C.L.

1983-01-01

The ratio of left ventricular to right ventricular stroke counts measured by radionuclide angiography has been used in adults to estimate the severity of left-sided valvular regurgitation. The validation of this technique in children for assessment of right and left ventricular volume overload is reported herein. Radionuclide stroke count ratios in 60 children aged 0.5 to 19 years (mean 11) were determined. Based on their diagnoses, the patients were divided into 3 groups: (1) normal--40 patients with no shunts or valvular regurgitation, (2) left ventricular volume overload--13 patients with mitral or aortic regurgitation, or both, and (3) right ventricular volume overload--7 patients, 2 with severe tricuspid regurgitation, 3 with atrial septal defects, and 2 with total anomalous pulmonary venous drainage. The radionuclide stroke count ratio clearly differentiated these groups (p less than 0.05): normal patients had a stroke count ratio of 1.04 +/- 0.17 (mean +/- 1 standard deviation), the left ventricular volume overload group had a stroke count ratio of 2.43 +/- 0.86, and the right ventricular volume overload group had a stroke count ratio of 0.44 +/- 0.17. In 22 of our 60 patients, radionuclide stroke count ratios were compared with cineangiographic stroke volume ratios, resulting in a correlation coefficient of 0.88. It is concluded that radionuclide ventriculography is an excellent tool for qualitative and quantitative assessment of valvular regurgitation in children

Tensile-Creep Test Specimen Preparation Practices of Surface Support Liners

Science.gov (United States)

Guner, Dogukan; Ozturk, Hasan

2017-12-01

Ground support has always been considered as a challenging issue in all underground operations. Many forms of support systems and supporting techniques are available in the mining/tunnelling industry. In the last two decades, a new polymer based material, Thin Spray-on Liner (TSL), has attained a place in the market as an alternative to the current areal ground support systems. Although TSL provides numerous merits and has different application purposes, the knowledge on mechanical properties and performance of this material is still limited. In laboratory studies, since tensile rupture is the most commonly observed failure mechanism in field applications, researchers have generally studied the tensile testing of TSLs with modification of American Society for Testing and Materials (ASTM) D-638 standards. For tensile creep testing, specimen preparation process also follows the ASTM standards. Two different specimen dimension types (Type I, Type IV) are widely preferred in TSL tensile testing that conform to the related standards. Moreover, molding and die cutting are commonly used specimen preparation techniques. In literature, there is a great variability of test results due to the difference in specimen preparation techniques and practices. In this study, a ductile TSL product was tested in order to investigate the effect of both specimen preparation techniques and specimen dimensions under 7-day curing time. As a result, ultimate tensile strength, tensile yield strength, tensile modulus, and elongation at break values were obtained for 4 different test series. It is concluded that Type IV specimens have higher strength values compared to Type I specimens and moulded specimens have lower results than that of prepared by using die cutter. Moreover, specimens prepared by molding techniques have scattered test results. Type IV specimens prepared by die cutter technique are suggested for preparation of tensile test and Type I specimens prepared by die cutter technique

Fatigue crack growth due to overloads in plain concrete using ...

Indian Academy of Sciences (India)

cation of overload on concrete structures, acceleration in the crack growth process .... study by the same authors, Ray & Chandra Kishen (2010), they have employed the population growth ...... Institute of Technology, University of Trondheim.

Using hardness to model yield and tensile strength

Energy Technology Data Exchange (ETDEWEB)

Hawk, Jeffrey A.; Dogan, Omer N.; Schrems, Karol K.

2005-02-01

The current direction in hardness research is towards smaller and smaller loads as nano-scale materials are developed. There remains, however, a need to investigate the mechanical behavior of complex alloys for severe environment service. In many instances this entails casting large ingots and making numerous tensile samples as the bounds of the operating environment are explored. It is possible to gain an understanding of the tensile strength of these alloys using room and elevated temperature hardness in conjunction with selected tensile tests. The approach outlined here has its roots in the work done by Tabor for metals and low alloy and carbon steels. This research seeks to extend the work to elevated temperatures for multi-phase, complex alloys. A review of the approach will be given after which the experimental data will be examined. In particular, the yield stress and tensile strength will be compared to their corresponding hardness based values.

THE EFFECT OF HAEMOCHROMATOSIS MUTATION ON IRON OVERLOAD IN THALASSAEMIA MAJOR PATIENTS

Directory of Open Access Journals (Sweden)

Tapas Ranjan Behera

2016-11-01

Full Text Available BACKGROUND Haemochromatosis is a genetic form of iron overload due to a defective HFE gene. Secondary iron overload is the main complication in transfusion-dependent thalassaemia major patients. This study aims at evaluating the degree of iron overload in β-thalassaemia major patients with and without HFE mutations (C282Y, H63D and S65C. MATERIALS AND METHODS A descriptive observational study was conducted including fifty diagnosed -thalassaemia major cases. Detailed clinical history and iron profile was estimated. DNA analysis by PCR-RFLP method for HFE gene mutations was performed. RESULTS After DNA analysis of all the thalassaemia major cases, two groups were identified, one with HFE gene mutation and other without HFE gene mutation. Iron profile of both the groups (with and without HFE gene mutation was estimated and compared. Only H63D mutation (out of three HFE gene mutations was detected in 16% cases (8 out of 50 cases, which comprised the group with mutation. Comparison of iron parameters between two groups (with and without HFE gene mutation showed significant difference in percent transferrin saturation (p=0.02, while other iron parameters (serum iron and serum ferritin did not show significant difference. CONCLUSION No significant difference between serum ferritin values (a marker of iron overload of groups with and without mutation (mean ferritin level 4641±2166 ng/mL and 4170±2461 ng/mL, respectively was found (p=0.61, in a patient population in whom transfusion protocol and proper chelation regimen was followed.

Ethylene propylene cable degradation during LOCA research tests: tensile properties at the completion of accelerated aging

International Nuclear Information System (INIS)

Bustard, L.D.

1982-05-01

Six ethylene-propylene rubber (EPR) insulation materials were aged at elevated temperature and radiation stress exposures common in cable LOCA qualification tests. Material samples were subjected to various simultaneous and sequential aging simulations in preparation for accident environmental exposures. Tensile properties subsequent to the aging exposure sequences are reported. The tensile properties of some, but not all, specimens were sensitive to the order of radiation and elevated temperature stress exposure. Other specimens showed more severe degradation when simultaneously exposed to radiation and elevated temperature as opposed to the sequential exposure to the same stresses. Results illustrate the difficulty in defining a single test procedure for nuclear safety-related qualification of EPR elastomers. A common worst-case sequential aging sequence could not be identified

Thermal overload protection for electric motors on safety-related motor-operated valves: Generic Issue II.E.6.1

International Nuclear Information System (INIS)

Rothberg, O.

1988-06-01

NRC regulatory positions, as stated in Regulatory Guide 1.106, Revision 1, have been identified by the Office for Analysis and Evaluation of Operational Data (AEOD) as potential contributors to valve motor burnout. AEOD is particularly concerned about the allowed policy of bypassing thermal overload devices during normal or accident conditions. Regulatory Guide 1.106 favors compromising the function of thermal overload devices in favor of completing the safety-related action of valves. The purpose of this study was to determine if the guidance contained in Regulatory Guide 1.106 is appropriate and, if not, to recommend the necessary changes. This report describes thermal overload devices commonly used to protect safety-related valve operator motors. The regulatory guidelines stated in Regulatory Guide 1.106 along with the limitations of thermal overload protection are discussed. Supplements and alternatives to thermal overload protection are also described. Findings and conclusions of several AEOD reports are discussed. Information obtained from the standard review plan, standard technical specifications, technical specifications from representative plants, and several papers are cited

Developing of tensile property database system

International Nuclear Information System (INIS)

Park, S. J.; Kim, D. H.; Jeon, J.; Ryu, W. S.

2002-01-01

The data base construction using the data produced from tensile experiment can increase the application of test results. Also, we can get the basic data ease from database when we prepare the new experiment and can produce high quality result by compare the previous data. The development part must be analysis and design more specific to construct the database and after that, we can offer the best quality to customers various requirements. In this thesis, the tensile database system was developed by internet method using JSP(Java Server pages) tool

Evaluation of the tensile strength of the human ureter - Preliminary results.

Science.gov (United States)

Shilo, Yaniv; Pichamuthu, Joseph E; Averch, Timothy D; Vorp, David A

2014-09-15

Introduction: Ureteral injuries such as avulsion are directly related to mechanical damage of the ureter. Understanding the tensile strength of this tissue may assist in prevention of iatrogenic injuries. Few published studies have looked at the mechanical properties of the animal ureter, and of those none have determined the tensile strength of the human ureter. Therefore, the purpose of this work was to determine the tensile strength of the human ureter. Materials and Methods: We harvested 11 human proximal ureters from patients who were undergoing nephrectomy for either kidney tumors or non-functioning kidney. The specimens were then cut into multiple circumferentially and longitudinally-oriented tissue strips for tensile testing. Strips were uniaxially stretched to failure in a tensile testing machine. The corresponding force and displacement were recorded. Finally, stress at failure was noted as the tensile strength of the sample. Circumferential tensile strength was also compared in the proximal and distal regions of the specimens. Results: The tensile strength of the ureter in circumferential and longitudinal orientations was found to be 457.52±33.74 Ncm-2 and 902.43±122.08 Ncm-2, respectively (ptensile strength of the ureter was found to be significantly lower than the longitudinal strength. Circumferential tensile strength was also lower with more proximal parts of the ureter. This information may be important for the design of "intelligent" devices and simulators in order to prevent complications.

Numerical Investigation of Size and Structure Effect on Tensile Characteristics of Symmetric and Asymmetric CNTs

Directory of Open Access Journals (Sweden)

Mahnaz Zakeri

2016-06-01

Full Text Available In this research, the influence of structure on the tensile properties of single- walled carbon nanotubes (CNTs is evaluated using molecular mechanics technique and finite element method. The effects of diameter, length and chiral angle on elastic modulus and Poisson’s ratio of armchair, zigzag and chiral structures are investigated. To simulate the CNTs, a 3D FEM code is developed using the ANSYS commercial software. Considering the carbon-carbon covalent bonds as connecting load-carrying beam elements, and the atoms as joints of the elements, CNTs are simulated as space-frame structures. The atomic potentials are estimated using harmonic simple functions. The numerical results show that by increasing the diameter and length to a certain amount, the size effect on tensile behavior of modeled nanotubes is omitted. In fact, for nanotubes with diameter over 2 nm and length over 36.5 nm the chiral angle is the only effective factor on the tensile properties. Also, it is found that the structure has a little effect on the elasticity modulus, which is about 4%. However, Poisson’s ratio can be affected significantly with chiral angle. Asymmetric structures with angles θ

Relationship between the tensile strengths and diameters of human umbilical cords.

Science.gov (United States)

Fernando, D M G; Gamage, S M K; Ranmohottige, S; Weerakkody, I; Abeyruwan, H; Parakrama, H

2018-05-01

Mothers of alleged infanticides might claim that umbilical cord broke during precipitate delivery causing injuries detected on baby at autopsy. There is paucity of evidence regarding this possibility. The objective of the study was to determine relationship between tensile strength and diameter or weight per unit length of cord. Diameters and weights per unit length of fresh umbilical cords were determined. Tensile strengths were measured by Hounsfield Testing Machine. Relationship between tensile strength versus cord diameter and weight per unit length were analyzed. Of 122 cords, average tensile strength, diameter and weight per centimeter were 50.4 N, 7.73 mm and 6.87 g respectively. The tensile strengths were directly proportional to diameter. There was no association between tensile strength and weight per centimeter. Measurement of the diameter of cord is important during autopsy to predict tensile strength and thereby to presume whether cord could have broken by the weight of the baby. Copyright © 2018 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Thermal and tensile properties of alumina filled PET nanocomposites

Science.gov (United States)

Nikam, Pravin N.; Deshpande, Vineeta D.

2018-05-01

In the present investigation, nanocomposites of poly(ethylene terephathalate)(PET) with different content (0 to 5 wt.%) of alumina nanoparticles (n-Al2O3) were prepared by melt-extrusion technique. Morphological characterization of samples was examined by transmission electron microscopy (TEM). Morphological analysis revealed that degree of dispersion of alumina nanoparticles (ANPs) was increased at lower content (i.e. upto 2 wt.%), which observed by TEM. Thermal and tensile measurements were carried out using and differential scanning calorimetry (DSC) and universal testing machine (UTM). The thermal analysis showed that the glass transition termperature (Tg), melting temperature (Tm), crystallization temperature (Tc) of PET/alumina nanocomposites (PNCs) were higher than neat PET (PET0). The heat enthalpy (ΔHm) of crystallization for PNCs was increased compared to PET0, which indicates that degree of crystallinity of PNCs also increased compared to PET0. The half-time (t0.5) of crystallization of PNCs were decreased compared to PET0 which indicates that the incorporation of ANPs nucleate the PET molecular chains and allowing the easily crystallization during nonisothermal process. The tensile analysis revealed that the tensile elastic modulus (i.e. Young's modulus) of PNCs increased almost linearly with increasing the content of ANPs while tensile elongation at break decreased nonlinearly. The tensile strength of PNCs increased with a 1 wt.% of ANPs whereas the higher content of ANPs decreased the tensile strength.

Indigenous Design for Automatic Testing of Tensile Strength Using Graphical User Interface

OpenAIRE

Ali Rafay; Junejo Faraz; Imtiaz Rafey; Shamsi Usama Sultan

2016-01-01

Tensile Testing is a fundamental material test to measure the tenacity and tensile strength. Tensile strength means ability to take tensile stress. This Universal Testing Machine is designed using Dual Cylinder Technique in order to comply with the maximun load (tensile force) with the reduction of minimum physical effort and minimized losses.It is to provide material testing opportunity to the students of different institutions, locally and globally, at lowest price; so that they can have a ...

Tensile properties of the modified 13Cr martensitic stainless steels

Energy Technology Data Exchange (ETDEWEB)

Mabruri, Efendi, E-mail: effe004@lipi.go.id; Anwar, Moch Syaiful, E-mail: moch.syaiful.anwar@lipi.go.id; Prifiharni, Siska, E-mail: siska.prifiharni@lipi.go.id; Romijarso, Toni B.; Adjiantoro, Bintang [Research Center for Metallurgy and Materials, Indonesian Institute of Sciences (LIPI) Kawasan Puspiptek Gd. 470 Serpong, Tangerang Selatan 15314 (Indonesia)

2016-04-19

This paper reports the influence of Mo and Ni on the tensile properties of the modified 13Cr martensitic stainless steels in tempered condition. Four steels with different content of Mo and Ni were prepared by induction melting followed by hot forging, quenching and tempering. The experimental results showed that the addition of about 1% and 3% Mo has a beneficial effect to increase both the tensile strength and the elongation of the steels. On the contrary, the addition of about 3% Ni into the martensitic stainless steel results in decreasing of both the tensile strength and the elongation. Among the alloys investigated the 13Cr3Mo type steel exhibited largest tensile strength of 1348 MPa and largest elongation of 12%. The observation on the tensile fractured surfaces by using scanning electron microscope supported these findings.

Tensile properties of the modified 13Cr martensitic stainless steels

International Nuclear Information System (INIS)

Mabruri, Efendi; Anwar, Moch Syaiful; Prifiharni, Siska; Romijarso, Toni B.; Adjiantoro, Bintang

2016-01-01

This paper reports the influence of Mo and Ni on the tensile properties of the modified 13Cr martensitic stainless steels in tempered condition. Four steels with different content of Mo and Ni were prepared by induction melting followed by hot forging, quenching and tempering. The experimental results showed that the addition of about 1% and 3% Mo has a beneficial effect to increase both the tensile strength and the elongation of the steels. On the contrary, the addition of about 3% Ni into the martensitic stainless steel results in decreasing of both the tensile strength and the elongation. Among the alloys investigated the 13Cr3Mo type steel exhibited largest tensile strength of 1348 MPa and largest elongation of 12%. The observation on the tensile fractured surfaces by using scanning electron microscope supported these findings.

Diagnosis, management and response criteria of iron overload in myelodysplastic syndromes (MDS): updated recommendations of the Austrian MDS platform.

Science.gov (United States)

Valent, Peter; Stauder, Reinhard; Theurl, Igor; Geissler, Klaus; Sliwa, Thamer; Sperr, Wolfgang R; Bettelheim, Peter; Sill, Heinz; Pfeilstöcker, Michael

2018-02-01

Despite the availability of effective iron chelators, transfusion-related morbidity is still a challenge in chronically transfused patients with myelodysplastic syndromes (MDS). In these patients, transfusion-induced iron overload may lead to organ dysfunction or even organ failure. In addition, iron overload is associated with reduced overall survival in MDS. Areas covered: During the past 10 years, various guidelines for the management of MDS patients with iron overload have been proposed. In the present article, we provide our updated recommendations for the diagnosis, prevention and therapy of iron overload in MDS. In addition, we propose refined treatment response criteria. As in 2006 and 2007, recommendations were discussed and formulated by participants of our Austrian MDS platform in a series of meetings in 2016 and 2017. Expert commentary: Our updated recommendations should support early recognition of iron overload, optimal patient management and the measurement of clinical responses to chelation treatment in daily practice.

Tensile Properties of Open Cell Ceramic Foams

Czech Academy of Sciences Publication Activity Database

Dlouhý, Ivo; Řehořek, Lukáš; Chlup, Zdeněk

2009-01-01

Roč. 409, - (2009), s. 168-175 ISSN 1013-9826. [Fractography of Advanced Ceramics /3./. Stará Lesná, 07.09.2008-10.09.2008] R&D Projects: GA ČR(CZ) GA106/06/0724; GA ČR GD106/05/H008 Institutional research plan: CEZ:AV0Z20410507 Keywords : tensile test * ceramics foam * open porosity * tensile strength Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

Analysis of overload conditions in distance relay under severe system contingencies

Energy Technology Data Exchange (ETDEWEB)

Halim Abu Bakar, Ab. [Department of Electrical Engineering, Universiti Malaya (Malaysia); Yatim, Fazilah Mat; Othman, Mohd Ridzal [Transmission Division, Tenaga Nasional Berhad (Malaysia); Yusof, Sallehuddin [Advanced Powor Solutions (Malaysia)

2010-06-15

Distance relay protection is widely used worldwide for protection scheme on high voltage transmission lines. This protection tends to be prone to load encroachment condition causing possible undesired tripping condition. Investigations of two system disturbances that occurred in TNB's (Tenaga Nasional Berhad) Grid in the year 2003 and 2005 have clearly revealed the occurrence of load encroachment condition following line overloads after large number of line tripping. Examination of the impedance locus trajectory during the overload events have enabled a distinction be made between power swing and load encroachment phenomena. This paper presents the analysis and findings of the investigation of the load encroachment phenomena of the two events, including other related transmission line contingencies. (author)

Effect of tensile stress on cavitation damage formation in mercury

Energy Technology Data Exchange (ETDEWEB)

Naoe, Takashi, E-mail: naoe.takashi@jaea.go.j [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kogawa, Hiroyuki [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Yamaguchi, Yoshihito [Nuclear Safety Research Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Futakawa, Masatoshi [J-PARC Center, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan)

2010-03-15

Cavitation erosion or so called pitting damage was investigated under tensile stress conditions in mercury. In MW-class liquid metal spallation targets, pitting damage is a critical issue to satisfy required power and/or lifetime of the target vessel. Cavitation occurs by negative pressure which is induced through pressure wave propagation due to proton beam injection. Pitting damage is formed by microjet and/or shock wave during cavitation bubble collapse. A mercury target vessel suffers tensile stress due to thermal stress or welding. In order to investigate the effect of tensile stress on pitting damage formation, cavitation erosion tests were performed using stress imposed specimens in mercury. An ultrasonic vibratory horn and electro-Magnetic IMpact Testing Machine (MIMTM) were used to vary the cavitation intensity. In the incubation period of pitting damage, damaged area was slightly increased with increasing imposed tensile stress. In the steady state period, a mean depth of erosion was increased by the tensile stress. Additionally, in order to quantitatively evaluate the effect of tensile stress, an indentation test with Vickers indenter was carried out to quasi-statically simulate the impact load. From the measurement of the diagonal length of the indent aspect ratio and hardness, it is recognized that the threshold of the deformation, i.e. pitting damage formation, was decreased by the tensile stress.

The role of MR imaging in detection of hepatic iron overload in patients with cirrhosis of different origins.

Science.gov (United States)

Szurowska, Edyta; Sikorska, Katarzyna; Izycka-Swieszewska, E; Nowicki, Tomasz; Romanowski, Tomasz; Bielawski, Krzysztof P; Studniarek, Michał

2010-01-27

There are many pathological conditions with hepatic iron overload. Classical definite diagnostic methods of these disorders are invasive and based on a direct tissue biopsy material. For the last years the role of MR imaging in liver diagnostics has been increasing. MRI shows changes of liver intensity in patients with hepatic iron overload. Changes in MR signal are an indirect consequence of change of relaxation times T2 and T2*, that can be directly measured. The purpose of the study was to evaluate usefulness of MR imaging in the detection of hepatic iron overload in patients with cirrhosis of different origins. MR imaging at 1.5T was prospectively performed in 44 patients with liver cirrhosis who had undergone liver biopsy with histopathological assessment of hepatic iron deposits. In all patients the following sequences were used: SE, Express, GRE in T2 and T1-weighted images. Signal intensity (SI) was measured on images obtained with each T2 weighted sequence by means of regions of interest, placed in the liver and paraspinal muscles. The correlation between iron overload, histopathological score, serum ferritin and SI ratio was analyzed. In 20 patients with iron overload confirmed by the biopsy, the liver parenchyma demonstrated lower signal intensity than that of paraspinal muscles. This effect was visible only in 8 patients with hepatic iron overload in Express T2-weighted images. Higher signal intensity of liver than that of skeletal muscles on GRE - T2 weighted images was noted in 24 patients with cirrhosis and without elevated hepatic iron concentration. We observed a correlation between low and high iron concentration and liver to muscle SI ratio. MR imaging is a useful and fast noninvasive diagnostic tool for the detection of liver iron overload in patients with cirrhosis of different origins.Liver to muscle SI ratio in GRE-T2-weighted sequence facilitates to differentiate patients with low and high degree of hepatic iron overload, which correlates

Dangers of bypassing thermal overload relays in nuclear power plant motor operated valve circuits

International Nuclear Information System (INIS)

Baxter, F.D.

1980-01-01

Operation of motor operated valves is analyzed under various abnormal conditions such as frozen bearing, tight packing, mid-travel obstruction, torque switch failure, limit switch failure, and post-accident operation. Each condition has been reviewed to show that an adverse situation results if the thermal overload relays in the circuit are bypassed. In conclusion, there appears to be no technical basis for bypassing or oversizing the thermal overload relay provided it is selected correctly

Influence of subject choice, work overload and work stress on expatriate higher education teachers.

OpenAIRE

Naithani, Pranav

2013-01-01

Subject choice, work overload and work stress influence personal and professional lives of higher education teachers. Though the majority of higher education teachers in the Gulf Cooperation Council (GCC) countries are expatriates, yet research on expatriate higher education teachers working in the GCC countries is limited. This paper presents one part of the work life balance survey and focuses on the influence of subject choice, work overload and work stress on higher education teachers in ...

Biochemical competition makes fatty-acid β-oxidation vulnerable to substrate overload.

Directory of Open Access Journals (Sweden)

Karen van Eunen

Full Text Available Fatty-acid metabolism plays a key role in acquired and inborn metabolic diseases. To obtain insight into the network dynamics of fatty-acid β-oxidation, we constructed a detailed computational model of the pathway and subjected it to a fat overload condition. The model contains reversible and saturable enzyme-kinetic equations and experimentally determined parameters for rat-liver enzymes. It was validated by adding palmitoyl CoA or palmitoyl carnitine to isolated rat-liver mitochondria: without refitting of measured parameters, the model correctly predicted the β-oxidation flux as well as the time profiles of most acyl-carnitine concentrations. Subsequently, we simulated the condition of obesity by increasing the palmitoyl-CoA concentration. At a high concentration of palmitoyl CoA the β-oxidation became overloaded: the flux dropped and metabolites accumulated. This behavior originated from the competition between acyl CoAs of different chain lengths for a set of acyl-CoA dehydrogenases with overlapping substrate specificity. This effectively induced competitive feedforward inhibition and thereby led to accumulation of CoA-ester intermediates and depletion of free CoA (CoASH. The mitochondrial [NAD⁺]/[NADH] ratio modulated the sensitivity to substrate overload, revealing a tight interplay between regulation of β-oxidation and mitochondrial respiration.

Evaluation of cardiac and hepatic iron overload in thalassemia major patients with T2* magnetic resonance imaging.

Science.gov (United States)

Wahidiyat, Pustika Amalia; Liauw, Felix; Sekarsari, Damayanti; Putriasih, Siti Ayu; Berdoukas, Vasili; Pennell, Dudley J

2017-09-01

Recent advancements have promoted the use of T2* magnetic resonance imaging (MRI) in the non-invasive detection of iron overload in various organs for thalassemia major patients. This study aims to determine the iron load in the heart and liver of patients with thalassemia major using T2* MRI and to evaluate its correlation with serum ferritin level and iron chelation therapy. This cross-sectional study included 162 subjects diagnosed with thalassemia major, who were classified into acceptable, mild, moderate, or severe cardiac and hepatic iron overload following their T2* MRI results, respectively, and these were correlated to their serum ferritin levels and iron chelation therapy. The study found that 85.2% of the subjects had normal cardiac iron stores. In contrast, 70.4% of the subjects had severe liver iron overload. A significant but weak correlation (r = -0.28) was found between cardiac T2* MRI and serum ferritin, and a slightly more significant correlation (r = 0.37) was found between liver iron concentration (LIC) and serum ferritin. The findings of this study are consistent with several other studies, which show that patients generally manifest with liver iron overload prior to cardiac iron overload. Moreover, iron accumulation demonstrated by T2* MRI results also show a significant correlation to serum ferritin levels. This is the first study of its kind conducted in Indonesia, which supports the fact that T2* MRI is undoubtedly valuable in the early detection of cardiac and hepatic iron overload in thalassemia major patients.

Culinary plants and their potential impact on metabolic overload.

Science.gov (United States)

Kim, Ji Yeon; Kwon, Oran

2011-07-01

Contemporary human behavior has led a large proportion of the population to metabolic overload and obesity. Postprandial hyperlipidemia and hyperglycemia evoke redox imbalance in the short term and lead to complex chronic disease in the long term with repeated occurrence. Complex diseases are best prevented with complex components of plants; thus, current nutrition research has begun to focus on the development of plant-based functional foods and dietary supplements for health and well-being. Furthermore, given the wide range of species, parts, and secondary metabolites, culinary plants can contribute significant variety and complexity to the human diet. Although understanding the health benefits of culinary plants has been one of the great challenges in nutritional science due to their inherent complexity, it is an advantageous pursuit. This review will address the challenges and opportunities relating to studies of the health benefits of culinary plants, with an emphasis on obesity attributed to metabolic overload. © 2011 New York Academy of Sciences.

Brazilian Tensile Strength of Anisotropic Rocks: Review and New Insights

Directory of Open Access Journals (Sweden)

Tianshou Ma

2018-01-01

Full Text Available Strength anisotropy is one of the most distinct features of anisotropic rocks, and it also normally reveals strong anisotropy in Brazilian test Strength (“BtS”. Theoretical research on the “BtS” of anisotropic rocks is seldom performed, and in particular some significant factors, such as the anisotropic tensile strength of anisotropic rocks, the initial Brazilian disc fracture points, and the stress distribution on the Brazilian disc, are often ignored. The aim of the present paper is to review the state of the art in the experimental studies on the “BtS” of anisotropic rocks since the pioneering work was introduced in 1964, and to propose a novel theoretical method to underpin the failure mechanisms and predict the “BtS” of anisotropic rocks under Brazilian test conditions. The experimental data of Longmaxi Shale-I and Jixi Coal were utilized to verify the proposed method. The results show the predicted “BtS” results show strong agreement with experimental data, the maximum error is only ~6.55% for Longmaxi Shale-I and ~7.50% for Jixi Coal, and the simulated failure patterns of the Longmaxi Shale-I are also consistent with the test results. For the Longmaxi Shale-I, the Brazilian disc experiences tensile failure of the intact rock when 0° ≤ βw ≤ 24°, shear failure along the weakness planes when 24° ≤ βw ≤ 76°, and tensile failure along the weakness planes when 76° ≤ βw ≤ 90°. For the Jixi Coal, the Brazilian disc experiences tensile failure when 0° ≤ βw ≤ 23° or 76° ≤ βw ≤ 90°, shear failure along the butt cleats when 23° ≤ βw ≤ 32°, and shear failure along the face cleats when 32° ≤ βw ≤ 76°. The proposed method can not only be used to predict the “BtS” and underpin the failure mechanisms of anisotropic rocks containing a single group of weakness planes, but can also be generalized for fractured rocks containing multi-groups of weakness planes.

Diagnosis of hepatic iron overload: a family study illustrating pitfalls in diagnosing hemochromatosis.

Science.gov (United States)

Schranz, Melanie; Talasz, Heribert; Graziadei, Ivo; Winder, Thomas; Sergi, Consolato; Bogner, Klaus; Vogel, Wolfgang; Zoller, Heinz

2009-03-01

Recent identification of genetic variants in iron storage disease has changed the classification system and diagnostic algorithms for hemochromatosis. Clinical diagnosis of the disease requires phenotypic evidence of iron overload because the commonly disease-associated HFE genotypes have an incomplete penetrance. Furthermore, approximately 20% of patients with a clinical diagnosis of hemochromatosis have no disease-associated genotype, which underlines the importance of clear phenotypic criteria of hemochromatosis. A diagnosis of hemochromatosis cannot be made even in patients with liver cirrhosis simply on the basis of genetic testing that indicates that iron overload is the cause of the disease and not its consequence. Proper diagnosis requires integration of clinical presentation, family history, and the results of biochemical and histopathologic tests. Here we propose a rational diagnostic algorithm for hepatic iron overload syndromes and illustrate potential pitfalls by presenting a family study in a pedigree with rare HFE variants (H63D and E168Q), in cis on the same chromosome. Although the clinical suspicion of hemochromatosis was confirmed by histology, chemical analysis of liver tissue revealed a normal hepatic iron concentration, which is compatible with the genetic finding of 1 normal and 1 doubly mutated allele. In conclusion, clinical suspicion of hemochromatosis and elevated serum iron parameters should prompt HFE genotyping for C282Y and H63D. Should they be uninformative, further genetic tests should be recommended only if iron overload in liver tissue has been confirmed chemically.

Effect of Numbers of Load Cycling on the Micro Tensile Bond Strength of Total Etch Adhesives to Dentin

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AR Daneshkazemi

2013-06-01

Full Text Available Introduction: Today load cycling is used for similarity of invitro and invivo studies, though different results were reported in different studies. Therefore, this study aimed to investigate the effect of load cycling on micro tensile bond strength of two total etch adhesives to dentin. Methods: Enamel of 48 molar teeth were removed to expose the superficial dentin. The teeth were randomly divided into two equal groups, and were restored with Single bond (SB, ExciTE and Synergy composite. Then the teeth of each group were divided to 4 equal sub groups. Moreover, load cycling of 0, 50, 100, 200 k load cycle with 50 newton load was used. In each sub group, 12 hour glass slabs with 1mm2 thickness were made. Then the samples were loaded by Dartec testing machine (Model HC/10 with 1 mm/min cross head speed to make the fracture occur. Data were analyzed by ANOVA, t-test, Bonferroni tests. Results: The most micro tensile bond strength belonged to ExciTE without load cycling and lowest refered to SB with 200 k. There was a significant difference between the groups (p ExciTE= 0.0001, p SB = 0.001. Micro tensile bond strength in SB group was significantly lower than ExciTE (p= 0.001. Moreover, load cycling had negative effect on micro tensile bond strength. Conclusion: By increasing load cycling, micro tensile bond strength of both bondings decreased significantly

A user's manual for managing database system of tensile property

International Nuclear Information System (INIS)

Ryu, Woo Seok; Park, S. J.; Kim, D. H.; Jun, I.

2003-06-01

This manual is written for the management and maintenance of the tensile database system for managing the tensile property test data. The data base constructed the data produced from tensile property test can increase the application of test results. Also, we can get easily the basic data from database when we prepare the new experiment and can produce better result by compare the previous data. To develop the database we must analyze and design carefully application and after that, we can offer the best quality to customers various requirements. The tensile database system was developed by internet method using Java, PL/SQL, JSP(Java Server Pages) tool

MicroRNA-145 suppresses ROS-induced Ca2+ overload of cardiomyocytes by targeting CaMKIIδ

International Nuclear Information System (INIS)

Cha, Min-Ji; Jang, Jin-Kyung; Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon; Lee, Chang Yeon; Park, Jun-Hee; Lee, Jiyun; Seo, Hyang-Hee; Choi, Eunhyun; Jeon, Woo-min; Hwang, Hye Jin; Shin, Hyun-Taek

2013-01-01

Highlights: •CaMKIIδ mediates H 2 O 2 -induced Ca 2+ overload in cardiomyocytes. •miR-145 can inhibit Ca 2+ overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca 2+ ) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca 2+ signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca 2+ -mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H 2 O 2 -mediated Ca 2+ overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca 2+ overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca 2+ -related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca 2+ overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses

Interference mitigation enhancement of switched-based scheme in over-loaded femtocells

KAUST Repository

Gaaloul, Fakhreddine

2012-06-01

This paper proposes adequate methods to improve the interference mitigation capability of a recently investigated switched-based interference reduction scheme in short-range open-access and over-loaded femtocells. It is assumed that the available orthogonal channels for the femtocell network are distributed among operating access points in close vicinity, where each of which knows its allocated channels a priori. For the case when the feedback links are capacity-limited and the available channels can be universally shared and simultaneously used, the paper presents enhanced schemes to identify a channel to serve the desired scheduled user by maintaining the interference power level within a tolerable range. They attempt to either complement the switched-based scheme by minimum interference channel selection or adopt different interference thresholds on available channels, while aiming to reduce the channels examination load. The performance of the proposed schemes is quantified and then compared with those of the single-threshold switched-based scheme via numerical and simulation results. © 2012 IEEE.

Assessment of Iron Overload in Homozygous and Heterozygous Beta Thalassemic Children below 5 Years of Age

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Dhiraj J. Trivedi

2014-07-01

Full Text Available Background: Thalassemia is a genetic disease having 3-7% carrier rate in Indians. It is transfusion dependent anemia having high risk of iron overloading. A clinical symptom of iron overload becomes detectable in second decade causing progressive liver, heart and endocrine glands damage. There is a need to assess iron overload in thalassemics below 5 years of age to protect them from complications at later age of life. Aims and objectives: Present study was undertaken to estimate serum iron status and evaluate serum transferrin saturation in both homozygous & heterozygous form of thalassemia as an index of iron overload among children of one to five years of age. Materials and Methods: Clinically diagnosed thirty cases of β thalassemia major & thirty cases of β thalassemia minor having severe anemia, hepatospleenomegaly and between 1 year to 5 years of age were included in study group and same age matched healthy controls were included in the study. RBC indices and HbA, HbA2 and HbF were estimated along with serum iron & serum Total Iron Binding Capacity (TIBC and serum transferrin levels. Results: Significant difference was observed in hemoglobin levels between control and both beta thalassemia groups. Mean Corpuscular Volume (MCV and Mean Corpuscular Hemoglobin (MCH values were reduced. Hemoglobin electrophoresis showed the elevated levels of HbF and HbA2 in both beta thalassemia groups. Among serum iron parameters, serum iron, TIBC and transferrin saturation were elevated whereas serum transferrin levels were low in thalassemia major in children below 5 years of age. Conclusion: Although clinical symptoms of iron overload have been absent in thalassemic children below five years of age, biochemical iron overloading has started at much lower age which is of great concern.

Role of liver magnetic resonance imaging in hyperferritinaemia and the diagnosis of iron overload.

Science.gov (United States)

Ruefer, Axel; Bapst, Christine; Benz, Rudolf; Bremerich, Jens; Cantoni, Nathan; Infanti, Laura; Samii, Kaveh; Schmid, Mathias; Vallée, Jean-Paul

2017-11-09

Hyperferritinaemia is a frequent clinical problem. Elevated serum ferritin levels can be detected in different genetic and acquired diseases and can occur with or without anaemia. It is therefore important to determine whether hyperferritinaemia is due to iron overload or due to a secondary cause. The main causes of iron overload are intestinal iron hyperabsorption disorders and transfusion-dependent disorders. Iron homeostasis and iron overload are quantified by different diagnostic approaches. The evaluation of serum ferritin and transferrin saturation is the first diagnostic step to identify the cause of hyperferritinaemia. The assessment of liver iron concentration by liver biopsy or magnetic resonance imaging (MRI) may guide the further diagnostic and therapeutic workup. Liver biopsy is invasive and poorly accepted by patients and should only be carried out in selected patients with hereditary haemochromatosis. As a non-invasive approach, MRI is considered the standard method to diagnose and to monitor both hepatic iron overload and the effectiveness of iron chelation therapy in many clinical conditions such as thalassaemia and myelodysplastic syndromes. Accurate evaluation and monitoring of iron overload has major implications regarding adherence, quality of life and prognosis. There are different technical MRI approaches to measuring the liver iron content. Of these, T2 and T2* relaxometry are considered the standard of care. MRI with cardiac T2* mapping is also suitable for the assessment of cardiac iron. Currently there is no consensus which technique should be preferred. The choice depends on local availability and patient population. However, it is important to use the same MRI technique in subsequent visits in the same patient to get comparable results. Signal intensity ratio may be a good adjunct to R2 and R2* methods as it allows easy visual estimation of the liver iron concentration. In this review a group of Swiss haematologists and radiologists

Vacuum fused deposition modelling system to improve tensile ...

African Journals Online (AJOL)

In the printing process, the interlayer bonding is made too quick thus the layers are not fully fused together causing the reduced tensile strength. This paper presents a possible solution to this problem by incorporating vacuum technology in FDM system to improve tensile strength of 3D printed specimens. In this study, a ...

In-Situ tensile testing of propellants in SEM: influence of temperature

NARCIS (Netherlands)

Di Benedetto, G.L.; Ramshorst, M.C.J.; Duvalois, W.; Hooijmeijer, P.; Heijden, A. van der

2017-01-01

A tensile module system placed within a Scanning Electron Microscope (SEM) was utilized to conduct insitu tensile testing of propellant samples. The tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under

Signaling pathway-focused gene expression profiling in pressure overloaded hearts

Directory of Open Access Journals (Sweden)

Marco Musumeci

2011-01-01

Full Text Available The β-blocker propranolol displays antihypertrophic and antifibrotic properties in the heart subjected to pressure overload. Yet the underlying mechanisms responsible for these important effects remain to be completely understood. The purpose of this study was to determine signaling pathway-focused gene expression profile associated with the antihypertrophic action of propranolol in pressure overloaded hearts. To address this question, a focused real-time PCR array was used to screen left ventricular RNA expression of 84 gene transcripts representative of 18 different signaling pathways in C57BL/6 mice subjected to transverse aortic constriction (TAC or sham surgery. On the surgery day, mice received either propranolol (80 mg/kg/day or vehicle for 14 days. TAC caused a 49% increase in the left ventricular weight-to-body weight (LVW/BW ratio without changing gene expression. Propranolol blunted LVW/BW ratio increase by approximately 50% while causing about a 3-fold increase in the expression of two genes, namely Brca1 and Cdkn2a, belonging to the TGF-beta and estrogen pathways, respectively. In conclusion, after 2 weeks of pressure overload, TAC hearts show a gene expression profile superimposable to that of sham hearts. Conversely, propranolol treatment is associated with an increased expression of genes which negatively regulate cell cycle progression. It remains to be established whether a mechanistic link between gene expression changes and the antihypertrophic action of propranolol occurs.

Mechanical properties of graphene nanoribbons under uniaxial tensile strain

Science.gov (United States)

Yoneyama, Kazufumi; Yamanaka, Ayaka; Okada, Susumu

2018-03-01

Based on the density functional theory with the generalized gradient approximation, we investigated the mechanical properties of graphene nanoribbons in terms of their edge shape under a uniaxial tensile strain. The nanoribbons with armchair and zigzag edges retain their structure under a large tensile strain, while the nanoribbons with chiral edges are fragile against the tensile strain compared with those with armchair and zigzag edges. The fracture started at the cove region, which corresponds to the border between the zigzag and armchair edges for the nanoribbons with chiral edges. For the nanoribbons with armchair edges, the fracture started at one of the cove regions at the edges. In contrast, the fracture started at the inner region of the nanoribbons with zigzag edges. The bond elongation under the tensile strain depends on the mutual arrangement of covalent bonds with respect to the strain direction.

Albumin Overload and PINK1/Parkin Signaling-Related Mitophagy in Renal Tubular Epithelial Cells.

Science.gov (United States)

Tan, Jin; Xie, Qi; Song, Shuling; Miao, Yuyang; Zhang, Qiang

2018-03-01

BACKGROUND Albumin, as a major urinary protein component, is a risk factor for chronic kidney disease progression. Mitochondrial dysfunction is one of the main causes of albumin-induced proximal tubule cells injury. Mitophagy is considered as a pivotal protective mechanism for the elimination of dysfunctional mitochondria. The objective of this research was to determine whether albumin overload-induced mitochondrial dysfunction can activate PINK1/Parkin-mediated mitophagy in renal tubular epithelial cells (TECs). MATERIAL AND METHODS Immunofluorescence assay and Western blot assay were used to detect the effects of albumin overload on autophagy marker protein LC3. Transmission electron microscopy and Western blot assay were used to investigate the role of albumin in mitochondrial injury. Western blot assay and co-localization of acidic lysosomes and mitochondria assay were employed to detect the activation of mitophagy induced by albumin. Finally, we explored the role of PINK1/Parkin signaling in albumin-induced mitophagy by inhibiting mitophagy by knockdown of PARK2 (Parkin) level. RESULTS Immunofluorescence and Western blot results showed that the expression level of LC3-II increased, and the maximum increase point was observed after 8 h of albumin treatment. Transmission electron microscopy results demonstrated that albumin overload-induced mitochondrial injury and quantity of autophagosomes increased. Additionally, expression of PINK1 and cytosolic cytochrome C increased and mitochondria cytochrome C decreased in the albumin group. The co-localization of acidic lysosomes and mitochondria demonstrated that the number of albumin overload-induced mitophagy-positive dots increased. The transient transfection of PARK2 siRNA result showed knockdown of the expression level of PARK2 can inhibit mitophagy induced by albumin. CONCLUSIONS In conclusion, our study suggests that mitochondrial dysfunction activates the PINK1/Parkin signaling and mitophagy in renal tubular

Iatrogenic Iron Overload in Dialysis Patients at the Beginning of the 21st Century.

Science.gov (United States)

Rostoker, Guy; Vaziri, Nosratola D; Fishbane, Steven

2016-05-01

Iron overload used to be considered rare in hemodialysis patients but its clinical frequency is now increasingly realized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosideroses and genetic hemochromatosis. Magnetic resonance imaging is now the gold standard method for LIC estimation and monitoring in non-renal patients. Studies of LIC in hemodialysis patients by quantitative magnetic resonance imaging and magnetic susceptometry have demonstrated a strong relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Three long-term observational studies have recently suggested that excessive IV iron doses may be associated with an increased risk of cardiovascular events and death in hemodialysis patients. We postulate that iatrogenic iron overload in the era of erythropoiesis-stimulating agents may silently increase complications in dialysis patients without creating frank clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It is therefore tempting to postulate that the main pathophysiological pathway leading to these events may involve the pleiotropic master hormone hepcidin (synergized by fibroblast growth factor 23), which regulates iron metabolism. Oxidative stress as a result of IV iron infusions and iron overload, by releasing labile non-transferrin-bound iron, might represent a 'second hit' on the vascular bed. Finally, iron deposition in the myocardium of patients with severe iron overload might also play a role in the pathogenesis of sudden death in some patients.

Tensile behavior of dissimilar friction stir welded joints of aluminium alloys

International Nuclear Information System (INIS)

Shanmuga Sundaram, N.; Murugan, N.

2010-01-01

The heat treatable aluminium alloy AA2024 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. The non-heat treatable aluminium alloy AA5083 possesses medium strength and high ductility and used typically in structural applications, marine, and automotive industries. When compared to fusion welding processes, friction stir welding (FSW) process is an emerging solid state joining process which is best suitable for joining these alloys. The friction stir welding parameters such as tool pin profile, tool rotational speed, welding speed, and tool axial force influence the mechanical properties of the FS welded joints significantly. Dissimilar FS welded joints are fabricated using five different tool pin profiles. Central composite design with four parameters, five levels, and 31 runs is used to conduct the experiments and response surface method (RSM) is employed to develop the model. Mathematical regression models are developed to predict the ultimate tensile strength (UTS) and tensile elongation (TE) of the dissimilar friction stir welded joints of aluminium alloys 2024-T6 and 5083-H321, and they are validated. The effects of the above process parameters and tool pin profile on tensile strength and tensile elongation of dissimilar friction stir welded joints are analysed in detail. Joints fabricated using Tapered Hexagon tool pin profile have the highest tensile strength and tensile elongation, whereas the Straight Cylinder tool pin profile have the lowest tensile strength and tensile elongation. The results are useful to have a better understanding of the effects of process parameters, to fabricate the joints with desired tensile properties, and to automate the FS welding process.

Tensile properties of unirradiated path A PCA

International Nuclear Information System (INIS)

Braski, D.N.; Maziasz, P.J.

1983-01-01

The tensile properties of PCA in the Al (solution annealed), A3 (25%-cold worked), and B2 (aged, cold worked, and reaged) conditions were determined from room temperature to 600 0 C. The tensile behavior of PCA-A1 and -A3 was generally similar to that of titanium-modified type 316 stainless steel with similar microstructures. The PCA-B2 was weaker than PCA-A3, especially above 500 0 C, but demonstrated slightly better ducility

Work Processes, Role Conflict, and Role Overload: The Case of Nurses and Engineers in the Public Sector.

Science.gov (United States)

Bacharach, Samuel B.; And Others

1990-01-01

Study of five sets of work process variables and their relationship to role conflict and overload among public sector nurses and engineers found managerial strategies appropriate for minimizing role conflict not necessarily appropriate for minimizing role overload. Some work process predictors may be similar across professions, and managerial…

Shift Work, Role Overload, and the Transition to Parenthood

Science.gov (United States)

Perry-Jenkins, Maureen; Goldberg, Abbie E.; Pierce, Courtney P.; Sayer, Aline G.

2007-01-01

This article examines how the work hours, work schedules, and role overload of working-class couples are related to depressive symptoms and relationship conflict across the transition to parenthood. Data are from 132 dual-earner couples interviewed 5 times across the transition. Multilevel modeling analyses revealed that working evening or night…

Occlusal overload investigations by noninvasive technology: fluorescence microscopy and en-face optical coherence tomography

Science.gov (United States)

Marcauteanu, Corina; Negrutiu, Meda; Sinescu, Cosmin; Demjan, Enikö; Hughes, Michael; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

2009-07-01

The aim of this study is the early detection and monitoring of occlusal overload in bruxing patients. En-Face Optical coherence tomography (eF-OCT) and fluorescence microscopy (FM) were used for the imaging of several anterior teeth extracted from patients with light active bruxism. We found a characteristic pattern of enamel cracks, that reached the tooth surface. We concluded that the combination of the en-Face OCT and FM is a promising non-invasive alternative technique for reliable monitoring of occlusal overload.

Thermal properties of graphene under tensile stress

Science.gov (United States)

Herrero, Carlos P.; Ramírez, Rafael

2018-05-01

Thermal properties of graphene display peculiar characteristics associated to the two-dimensional nature of this crystalline membrane. These properties can be changed and tuned in the presence of applied stresses, both tensile and compressive. Here, we study graphene monolayers under tensile stress by using path-integral molecular dynamics (PIMD) simulations, which allows one to take into account quantization of vibrational modes and analyze the effect of anharmonicity on physical observables. The influence of the elastic energy due to strain in the crystalline membrane is studied for increasing tensile stress and for rising temperature (thermal expansion). We analyze the internal energy, enthalpy, and specific heat of graphene, and compare the results obtained from PIMD simulations with those given by a harmonic approximation for the vibrational modes. This approximation turns out to be precise at low temperatures, and deteriorates as temperature and pressure are increased. At low temperature, the specific heat changes as cp˜T for stress-free graphene, and evolves to a dependence cp˜T2 as the tensile stress is increased. Structural and thermodynamic properties display non-negligible quantum effects, even at temperatures higher than 300 K. Moreover, differences in the behavior of the in-plane and real areas of graphene are discussed, along with their associated properties. These differences show up clearly in the corresponding compressibility and thermal expansion coefficient.

Tensile strength and durability characteristics of high-performance fiber reinforced concrete

International Nuclear Information System (INIS)

Ramadoss, P.; Nagamani, K.

2008-01-01

This paper presents investigations towards developing a better understanding of the contribution of steel fibers to the tensile strength of high-performance fiber reinforced concrete (HPFRC). For 32 series of mixes, flexural and splitting tensile strengths were determined at 28 days. The variables investigated were fiber volume fraction (0%, 0.5%, 1% and 1.5% with an aspect of 80), silica fume replacement level (SF/CM=0.05 and 0.10) and matrix composition (w/cm ratios ranging from 0.25 t 0.40). The influence of fiber content in terms of fiber reinforcing index on the flexural and splitting tensile strengths of HPFRC is presented. Comparative studies were performed on the tensile behavior of SFRC measured by two different loading tests: flexural test and splitting test. Based on the test results, using the least square method, empirical expressions were developed to predict 28-day tensile strength of HPFRC in terms of fiber reinforcing index. Durability tests were carried out to examine the performance of the SFRC. Relationship between flexural and splitting tensile strengths has been developed using regression analysis. The experimental values of previous researchers were compared with the values predicted by the empirical equations and the absolute variation obtained was within 6% and 5% for flexural and splitting tensile strengths respectively. (author)

EXPERIMENTAL INVESTIGATION ON TENSILE STRENGTH OF JACQUARD KNITTED FABRICS

Directory of Open Access Journals (Sweden)

BRAD Raluca

2015-05-01

Full Text Available An objective approach to select the best fabric for technical and home textiles consists in mechanical properties evaluation. The goal of this study is to analyze the behavior of knitted fabrics undergoing stretch stress. In this respect, three types of 2 colors Rib structure (backstripes jacquard, twillback jacquard and double-layered 3x3 rib fabric have been presented and tested for tensile strength and elongation on three directions. First, the elasticity and the behavior of knitted Rib fabrics were described The fabrics were knitted using 100% PAN yarns with Nm 1/15x2 on a E5 CMS 330 Stoll V-bed knitting machine, and have been tested using INSTROM 5587 Tensile Testing Machine in respect of standards conditions. After a relaxation period, 15 specimens were prepared, being disposed at 0°, 45 and 90 angles to the wale direction on the flat knitted panel. The tensile strength and the elongation values were recorded and mean values were computed. After strength and tensile elongation testing for 3 types of rib based knitted fabrics, one can see that the double layer knit presents the best mechanical behavior, followed by birds-eyebacking 2 colors Jacquard and then back striped Jacquard. For tensile stress in bias direction, the twillbacking Jacquard has a good breakage resistance value due to the higher number of rib sinker loops in structure that are positioned on the same direction with the tensile force. The twillbacking Jacquard structure could be considered as an alternative for the base material for decorative and home textile products.

Comparison study on mechanical properties single step and three step artificial aging on duralium

Science.gov (United States)

Tsamroh, Dewi Izzatus; Puspitasari, Poppy; Andoko, Sasongko, M. Ilman N.; Yazirin, Cepi

2017-09-01

Duralium is kind of non-ferro alloy that used widely in industrial. That caused its properties such as mild, high ductility, and resistance from corrosion. This study aimed to know mechanical properties of duralium on single step and three step articial aging process. Mechanical properties that discussed in this study focused on toughness value, tensile strength, and microstructure of duralium. Toughness value of single step artificial aging was 0.082 joule/mm2, and toughness value of three step artificial aging was 0,0721 joule/mm2. Duralium tensile strength of single step artificial aging was 32.36 kgf/mm^2, and duralium tensile strength of three step artificial aging was 32,70 kgf/mm^2. Based on microstructure photo of duralium of single step artificial aging showed that precipitate (θ) was not spreading evenly indicated by black spot which increasing the toughness of material. While microstructure photo of duralium that treated by three step artificial aging showed that it had more precipitate (θ) spread evenly compared with duralium that treated by single step artificial aging.

Polystyrene cryostat facilitates testing tensile specimens under liquid nitrogen

Science.gov (United States)

Shogan, R. P.; Skalka, R. J.

1967-01-01

Lightweight cryostat made of expanded polystyrene reduces eccentricity in a tensile system being tested under liquid nitrogen. The cryostat is attached directly to the tensile system by a special seal, reducing misalignment effects due to cryostat weight, and facilitates viewing and loading of the specimens.

Effects of quercetin on hemoglobin-dependent redox reactions: relationship to iron-overload rat liver injury.

Science.gov (United States)

Lu, Nai-Hao; Chen, Chao; He, Ying-Jie; Tian, Rong; Xiao, Qiang; Peng, Yi-Yuan

2013-01-01

Flavonoids have been widely reported to protect liver injury in iron-overload diseases, where the mechanism of this therapeutic action is dependent on their antioxidant effects, including free radical scavenging and metal-chelating. In this study, in contrast to the significant decrease in iron content, quercetin (Qu) from lower diet (0.3%, w/w) showed pro-oxidant ability on protein carbonyl formation and exhibited unobvious effect on iron-overload rat liver injury. Furthermore, the anti- and pro-oxidant activities of Qu on hemoglobin (Hb)-dependent redox reactions (i.e. the oxidative stability of Hb and its cytotoxic ferryl intermediate, Hb-induced protein oxidation) were investigated to illustrate the elevated protein oxidation in lower Qu-treated iron-overload rat. It was found that superoxide (O₂·⁻) and hydrogen peroxide (H₂O₂) were generated during the reaction between Qu and Hb. Qu, however, effectively reduced ferryl intermediate back to ferric Hb in a biphasic kinetic reaction. Moreover, Qu could significantly aggravate Hb-H₂O₂-induced protein oxidation at low concentrations and exhibit protective effects at high concentrations. Different from the classic antioxidant mechanisms of Qu, the dual effects on Hb redox reactions in vitro, therefore, may provide new insights into the physiological and pharmacological implications of Qu with iron-overload disease.

Design of overload vehicle monitoring and response system based on DSP

Science.gov (United States)

Yu, Yan; Liu, Yiheng; Zhao, Xuefeng

2014-03-01

The overload vehicles are making much more damage to the road surface than the regular ones. Many roads and bridges are equipped with structural health monitoring system (SHM) to provide early-warning to these damage and evaluate the safety of road and bridge. However, because of the complex nature of SHM system, it's expensive to manufacture, difficult to install and not well-suited for the regular bridges and roads. Based on this application background, this paper designs a compact structural health monitoring system based on DSP, which is highly integrated, low-power, easy to install and inexpensive to manufacture. The designed system is made up of sensor arrays, the charge amplifier module, the DSP processing unit, the alarm system for overload, and the estimate for damage of the road and bridge structure. The signals coming from sensor arrays go through the charge amplifier. DSP processing unit will receive the amplified signals, estimate whether it is an overload signal or not, and convert analog variables into digital ones so that they are compatible with the back-end digital circuit for further processing. The system will also restrict certain vehicles that are overweight, by taking image of the car brand, sending the alarm, and transferring the collected pressure data to remote data center for further monitoring analysis by rain-flow counting method.

A multilevel cross-cultural examination of role overload and organizational commitment: investigating the interactive effects of context.

Science.gov (United States)

Fisher, David M

2014-07-01

Considering the influential nature of context, the current investigation examined whether the relationship between role overload and organizational commitment was affected by various contextual factors. Drawing on the occupational stress literature, structural empowerment and cooperative climate were examined as factors that would mitigate the negative effects of role overload on organizational commitment. In addition, national culture was examined to determine whether empowerment and cooperative climate had consistent moderating effects across cultures. The relationships among these variables were examined using hierarchical linear modeling in a sample of 6,264 employees working at a multinational organization in 337 different work locations across 18 countries. Results suggested that the negative effect of role overload on organizational commitment did not vary as a function of culture in the current sample, but empowerment and cooperative climate had a moderating influence on this relationship. Furthermore, a 3-way interaction was observed between the cultural variable of power distance, empowerment, and role overload in predicting organizational commitment, suggesting that factors that serve to mitigate the negative effects of role overload in one culture may be ineffectual in another. This 3-way interaction was observed regardless of whether Hofstede's (2001) cultural value indices were used or the cultural practice scores from the Global Leadership and Organizational Behavior Effectiveness (GLOBE) project (R. J. House, Hanges, Javidan, Dorfman, & Gupta, 2004).

Tensile behavior of Cu50Zr50 metallic glass nanowire with a B2 crystalline precipitate

Science.gov (United States)

Sepulveda-Macias, Matias; Amigo, Nicolas; Gutierrez, Gonzalo

2018-02-01

A molecular dynamics study of the effect of a single B2-CuZr precipitate on the mechanical properties of Cu50Zr50 metallic glass nanowires is presented. Four different samples are considered: three with a 2, 4 and 6 nm radii precipitate and a precipitate-free sample. These systems are submitted to uniaxial tensile test up to 25% of strain. The interface region between the precipitate and the glass matrix has high local atomic shear strain, activating shear transformation zones, which concentrates in the neighborhood of the precipitate. The plastic regime is dominated by necking, and no localized shear band is observed for the samples with a 4 and 6 nm radii precipitate. In addition, the yield stress decreases as the size of the precipitate increases. Regarding the precipitate structure, no martensitic phase transformation is observed, since neither the shear band hit the precipitate nor the stress provided by the tensile test is enough to initiate the transformation. It is concluded that, in contrast to the case when multiple precipitates are present in the sample, a single precipitate concentrates the shear strain around its surface, eventually causing the failure of the nanowire.

Sport coaching officials and their stressors: Work overload, role ...

African Journals Online (AJOL)

Sport officials' concerns over job stressors have become common due to the adverse effect on health. The study sought to examine the associations of work overload, role ambiguity and role conflict, as well as their predictive influence on job satisfaction of sport coaches in Gauteng, South Africa. Data were collected from a ...

Microstructure evolution of titanium after tensile test

International Nuclear Information System (INIS)

Wronski, S.; Wierzbanowski, K.; Jędrychowski, M.; Tarasiuk, J; Wronski, M.; Baczmanski, A.; Bacroix, B.

2016-01-01

The qualitative and quantitative behavior of titanium T40 during tensile loading with a special emphasis on the presence of deformation twins in the observed microstructures is described. The samples for tensile tests were cut out from the rolled titanium sheet along the rolling and transverse directions. Several microstructure maps were determined using Electron Backscatter Diffraction technique (EBSD). These data were used to obtain crystallographic textures, misorientation distributions, grain size, twin boundary length, grain orientation spread, low and high angle boundary fractions and Schmid and Taylor factors. The deformation mechanisms and microstructure characteristics are different in the samples stretched along rolling and transverse directions. A strong appearance of tensile twins was observed in the samples deformed along transverse direction. On the other hand, more frequent subgrain formation and higher orientation spread was observed in the sample deformed along rolling direction, which caused’‘orientation blurring’ leading to an increase of grain size with deformation, as determined from OIM analysis.

Protein quality control in protection against systolic overload cardiomyopathy: the long term role of small heat shock proteins.

Science.gov (United States)

Kumarapeli, Asangi R K; Horak, Kathleen; Wang, Xuejun

2010-07-21

Molecular chaperones represent the first line of defense of intracellular protein quality control. As a major constituent of molecular chaperones, heat shock proteins (HSP) are known to confer cardiomyocyte short-term protection against various insults and injuries. Previously, we reported that the small HSP alphaB-crystallin (CryAB) attenuates cardiac hypertrophic response in mice subjected to 2 weeks of severe pressure overload. However, the long-term role of small HSPs in cardiac hypertrophy and failure has rarely been studied. The present study investigates the cardiac responses to chronic severe pressure overload in CryAB/HSPB2 germ line ablated (KO) and cardiac-specific CryAB overexpressingtransgenic (TG) mice. Pressure overload was induced by transverse aortic constriction in KO, TG, and non-transgenic wild type (NTG) control mice and 10 weeks later molecular, cellular, and whole organ level hypertrophic responses were analyzed. As we previously described, CryAB/HSPB2 KO mice showed abnormal baseline cardiac physiology that worsened into a restrictive cardiomyopathic phenotype with aging. Severe pressure overload in these mice led to rapid deterioration of heart function and development of congestive cardiac failure. Contrary to their short term protective phenotype, CryAB TG mice showed no significant effects on cardiac hypertrophic responses and very modest improvement of hemodynamics during chronic systolic overload. These findings indicate that small HSPs CryAB and/or HSPB2 are essential to maintain cardiac structure and function but overex-pression of CryAB is not sufficient to confer a sustained protection against chronic systolic overload.

Role overload, pain and physical dysfunction in early rheumatoid or undifferentiated inflammatory arthritis in Canada

OpenAIRE

Mustafa Sally; Looper Karl; Zelkowitz Phyllis; Purden Margaret; Baron Murray

2012-01-01

Abstract Background Inflammatory arthritis impairs participation in societal roles. Role overload arises when the demands by a given role set exceed the resources; time and energy, to carry out the required tasks. The present study examines the association between role overload and disease outcomes in early inflammatory arthritis (EIA). Methods Patients (n = 104) of 7.61 months mean duration of inflammatory arthritis completed self-report questionnaires on sociodemographics, disease character...

Quantitative evaluation of right ventricular overload with thallium-201 myocardial perfusion scintigraphy

International Nuclear Information System (INIS)

Watanabe, Toshiya; Miyakoda, Hiroyuki; Koike, Yoshihiro; Itatsu, Hidetaka; Kawai, Naoki; Sotobata, Iwao.

1983-01-01

Thallium-201 myocardial perfusion scintigraphy and right-heart catheterization were performed on patients with right ventricular pressure overload (RVPO) or right ventricular volume overload (RVVO). In 18 patients with RVPO, right ventricular systolic pressure correlated significantly both with the RV/LV wall thallium-201 uptake ratios (r=0.54, p<0.02) and the RV wall/background thallium-201 uptake ratios (r=0.70, p<0.01). RV/LV work ratios also significantly correlated with RV/LV wall thallium-201 uptake ratios (r=0.57, p<0.02). In 19 patients with RVVO, Qp/Qs and RV/LV work ratios both significantly correlated with RV/LV wall thallium-201 uptake ratios (r=0.78 and 0.87, respectively; p<0.001 for both) and RV wall/background thallium-201 uptake ratios (r=0.69, p<0.01 for both parameters). Right ventricular systolic pressure also correlated with RV/LV wall thallium-201 uptake ratios (r=0.57, p<0.02). Feasibility of the differentiation between RVPO and RVVO was suggested with use of ''transitional view angle'' and RV/LV diameter ratios obtained from the scintigram. In patients who underwent cardiac surgery, post-operative alleviations of the right ventricular overload were evaluated. There was a significant decrease in RV/LV wall thallium-201 uptake ratios, but no significant decrease in RV wall/background thallium-201 uptake ratios in patients with RVPO. On the other hand, there was a significant decrease both in RV/LV wall thallium-201 uptake ratios and RV wall/background thallium-201 uptake ratios in patients with RVVO. No significant changes were observed between the scintigraphic measurements obtained 1 month and 1 year after the surgery, irrespective of the type of right ventricular overloading. (J.P.N.)

New Scanning Electron Microscope Used for Cryogenic Tensile Testing

CERN Multimedia

Maximilien Brice

2013-01-01

At CERN engineering department's installation for cryogenic tensile testing, the new scanning electron microscope (SEM) allows for detailed optical observations to be carried out. Using the SEM, surface coatings and tensile properties of materials can investigated in order to better understand how they behave under different conditions.

Probabilistic modeling of material resistance to crack initiation due to hydrided region overloads in CANDU Zr-2.5%Nb pressure tubes

International Nuclear Information System (INIS)

Gutkin, L.; Scarth, D.A.

2014-01-01

Zr-2.5%Nb pressure tubes in CANDU nuclear reactors are susceptible to hydride-assisted cracking at the locations of stress concentration, such as in-service flaws. Probabilistic methodology is being developed to evaluate such flaws for crack initiation due to hydrided region overloads, which occur when the applied stress acting on a flaw with an existing hydrided region at its tip exceeds the stress at which the hydrided region is formed. As part of this development, probabilistic modeling of pressure tube material resistance to overload crack initiation has been performed on the basis of a set of test data specifically designed to study the effects of non-ratcheting hydride formation conditions and load reduction prior to hydride formation. In the modeling framework, the overload resistance is represented as a power-law function of the material resistance to initiation of delayed hydride cracking under constant loading, where both the overload crack initiation coefficient and the overload crack initiation exponent vary with the flaw geometry. In addition, the overload crack initiation coefficient varies with the extent of load reduction prior to hydride formation as well as the number of non-ratcheting hydride formation thermal cycles. (author)

Probabilistic modeling of material resistance to crack initiation due to hydrided region overloads in CANDU Zr-2.5%Nb pressure tubes

Energy Technology Data Exchange (ETDEWEB)

Gutkin, L.; Scarth, D.A. [Kinectrics Inc., Toronto, ON (Canada)

2014-07-01

Zr-2.5%Nb pressure tubes in CANDU nuclear reactors are susceptible to hydride-assisted cracking at the locations of stress concentration, such as in-service flaws. Probabilistic methodology is being developed to evaluate such flaws for crack initiation due to hydrided region overloads, which occur when the applied stress acting on a flaw with an existing hydrided region at its tip exceeds the stress at which the hydrided region is formed. As part of this development, probabilistic modeling of pressure tube material resistance to overload crack initiation has been performed on the basis of a set of test data specifically designed to study the effects of non-ratcheting hydride formation conditions and load reduction prior to hydride formation. In the modeling framework, the overload resistance is represented as a power-law function of the material resistance to initiation of delayed hydride cracking under constant loading, where both the overload crack initiation coefficient and the overload crack initiation exponent vary with the flaw geometry. In addition, the overload crack initiation coefficient varies with the extent of load reduction prior to hydride formation as well as the number of non-ratcheting hydride formation thermal cycles. (author)

Non-contact tensile viscoelastic characterization of microscale biological materials

Science.gov (United States)

Li, Yuhui; Hong, Yuan; Xu, Guang-Kui; Liu, Shaobao; Shi, Qiang; Tang, Deding; Yang, Hui; Genin, Guy M.; Lu, Tian Jian; Xu, Feng

2018-06-01

Many structures and materials in nature and physiology have important "meso-scale" structures at the micron length-scale whose tensile responses have proven difficult to characterize mechanically. Although techniques such as atomic force microscopy and micro- and nano-identation are mature for compression and indentation testing at the nano-scale, and standard uniaxial and shear rheometry techniques exist for the macroscale, few techniques are applicable for tensile-testing at the micrometre-scale, leaving a gap in our understanding of hierarchical biomaterials. Here, we present a novel magnetic mechanical testing (MMT) system that enables viscoelastic tensile testing at this critical length scale. The MMT system applies non-contact loading, avoiding gripping and surface interaction effects. We demonstrate application of the MMT system to the first analyses of the pure tensile responses of several native and engineered tissue systems at the mesoscale, showing the broad potential of the system for exploring micro- and meso-scale analysis of structured and hierarchical biological systems.

Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

Science.gov (United States)

Heard, W.; Song, B.; Williams, B.; Martin, B.; Sparks, P.; Nie, X.

2018-01-01

This review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior of geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Uniqueness and limitations for each experimental technique are also discussed.

Dietary Fat Overload Reprograms Brown Fat Mitochondria

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DANIELE eLETTIERI BARBATO

2015-09-01

Full Text Available Chronic nutrient overload accelerates the onset of several aging-related diseases reducing life expectancy. Although the mechanisms by which overnutrition affects metabolic processes in many tissues are known, its role on BAT physiology is still unclear. Herein, we investigated the mitochondrial responses in BAT of female mice exposed to high fat diet (HFD at different steps of life. Although adult mice showed an unchanged mitochondrial amount, both respiration and OxPHOS subunits were strongly affected. Differently, offspring pups exposed to HFD during pregnancy and lactation displayed reduced mitochondrial mass but high oxidative efficiency that, however, resulted in increased bioenergetics state of BAT rather than augmented uncoupling respiration. Interestingly, the metabolic responses triggered by HFD were accompanied by changes in mitochondrial dynamics characterized by decreased content of the fragmentation marker Drp1 both in mothers and offspring pups. HFD-induced inactivation of the FoxO1 transcription factor seemed to be the up-stream modulator of Drp1 levels in brown fat cells. Furthermore, HFD offspring pups weaned with normal diet only partially reverted the mitochondrial dysfunctions caused by HFD. Finally these mice failed in activating the thermogenic program upon cold exposure. Collectively our findings suggest that maternal dietary fat overload irreversibly commits BAT unresponsiveness to physiological stimuli such as cool temperature and this dysfunction in the early stage of life might negatively modulates health and lifespan.

Investigating turnover intentions by role overload, job satisfaction and social support moderation

Directory of Open Access Journals (Sweden)

J Pienaar

2007-01-01

Full Text Available Gold mining in South Africa has played a significant role in the economic development of the country. However, the current economic, personnel and rationalisation pressures could imply a loss of production in this industry. The focus of this research fell on investigating the role that social support may play in the translation of employees’ role overload and job satisfaction on their intentions to leave the organisation. A cross-sectional survey design with a random sample was used (n = 206. Results indicate that job satisfaction is the most significant predictor of turnover intention, but that collegial support plays an important role in moderating the effects of role overload on turnover intention.

Calcium channel blockers ameliorate iron overload-associated hepatic fibrosis by altering iron transport and stellate cell apoptosis

Energy Technology Data Exchange (ETDEWEB)

Zhang, Ying [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Department of Pathology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Chinese Medicine Research on Cardio-Cerebrovascular Disease, Shijiazhuang 050200, Hebei (China); Zhao, Xin [Department of Hepatobiliary Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang 050051, Hebei (China); Chang, Yanzhong [Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang 050024, Hebei (China); Zhang, Yuanyuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Xi [Department of Pharmacy, The Forth Hospital of Hebei Medical University, Shijiazhuang 050011, Hebei (China); Zhang, Xuan [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Liu, Zhenyi; Guo, Hui [Department of Medicinal Chemistry, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Wang, Na [Department of Physiology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Gao, Yonggang [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Zhang, Jianping, E-mail: zhangjianping14@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Chu, Li, E-mail: chuli0614@126.com [Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang 050200, Hebei (China); Hebei Key Laboratory of Integrative Medicine on Liver-Kidney Patterns, Shijiazhuang 050200, Hebei (China)

2016-06-15

Liver fibrosis is the principal cause of morbidity and mortality in patients with iron overload. Calcium channel blockers (CCBs) can antagonize divalent cation entry into renal and myocardial cells and inhibit fibrogenic gene expression. We investigated the potential of CCBs to resolve iron overload-associated hepatic fibrosis. Kunming mice were assigned to nine groups (n = 8 per group): control, iron overload, deferoxamine, high and low dose verapamil, high and low dose nimodipine, and high and low dose diltiazem. Iron deposition and hepatic fibrosis were measured in mouse livers. Expression levels of molecules associated with transmembrane iron transport were determined by molecular biology approaches. In vitro HSC-T6 cells were randomized into nine groups (the same groups as the mice). Changes in proliferation, apoptosis, and metalloproteinase expression in cells were detected to assess the anti-fibrotic effects of CCBs during iron overload conditions. We found that CCBs reduced hepatic iron content, intracellular iron deposition, the number of hepatic fibrotic areas, collagen expression levels, and hydroxyproline content. CCBs rescued abnormal expression of α1C protein in L-type voltage-dependent calcium channel (LVDCC) and down-regulated divalent metal transporter-1 (DMT-1) expression in mouse livers. In iron-overloaded HSC-T6 cells, CCBs reduced iron deposition, inhibited proliferation, induced apoptosis, and elevated expression of matrix metalloproteinase-13 (MMP-13) and tissue inhibitor of metalloproteinase-1 (TIMP-1). CCBs are potential therapeutic agents that can be used to address hepatic fibrosis during iron overload. They resolve hepatic fibrosis probably correlated with regulating transmembrane iron transport and inhibiting HSC growth. - Highlights: • Calcium channel blockers (CCBs) reduced hepatic iron content. • CCBs decreased hepatic fibrotic areas and collagen expression levels. • CCBs resolve fibrosis by regulating iron transport and

Decreased erythrocyte CCS content is a biomarker of copper overload in rats.

Science.gov (United States)

Bertinato, Jesse; Sherrard, Lindsey; Plouffe, Louise J

2010-07-02

Copper (Cu) is an essential trace metal that is toxic in excess. It is therefore important to be able to accurately assess Cu deficiency or overload. Cu chaperone for Cu/Zn superoxide dismutase (CCS) protein expression is elevated in tissues of Cu-deficient animals. Increased CCS content in erythrocytes is particularly sensitive to decreased Cu status. Given the lack of a non-invasive, sensitive and specific biomarker for the assessment of Cu excess, we investigated whether CCS expression in erythrocytes reflects Cu overload. Rats were fed diets containing normal or high levels of Cu for 13 weeks. Diets contained 6.3 +/- 0.6 (Cu-N), 985 +/- 14 (Cu-1000) or 1944 +/- 19 (Cu-2000) mg Cu/kg diet. Rats showed a variable response to the high Cu diets. Some rats showed severe Cu toxicity, while other rats showed no visible signs of toxicity and grew normally. Also, some rats had high levels of Cu in liver, whereas others had liver Cu concentrations within the normal range. Erythrocyte CCS protein expression was 30% lower in Cu-2000 rats compared to Cu-N rats (P CCS (47% reduction, P CCS content is associated with Cu overload in rats and should be evaluated further as a potential biomarker for assessing Cu excess in humans.

Provider role attitudes, marital satisfaction, role overload, and housework: a dyadic approach.

Science.gov (United States)

Helms, Heather M; Walls, Jill K; Crouter, Ann C; McHale, Susan M

2010-10-01

Treating the marital dyad as the unit of analysis, this study examined the within-couple patterning of 272 dual-earner spouses' provider role attitudes and their longitudinal associations with marital satisfaction, role overload, and the division of housework. Based on the congruence of husbands' and wives' provider role attitudes, couples were classified into one of four types: (a) main-secondary, (b) coprovider, (c) ambivalent coprovider, and (d) mismatched couples. Nearly half of all spouses differed in their attitudes about breadwinning. A series of mixed model ANCOVAs revealed significant between- and within-couple differences in human capital characteristics, spouses' perceptions of marital satisfaction and role overload, and the division of housework across 3 years of measurement. Coprovider couples reported higher levels of marital satisfaction and a more equitable division of housework than the other couple groups. Wives in the ambivalent coprovider couples' group reported higher levels of role overload than their husbands to a greater extent than was found in the other couple groups. As the first study to adopt a dyadic approach that considers the meanings that both spouses in dual-earner couples ascribe to paid employment, these findings advance understanding of how dual-earner spouses' provider role attitudes serve as contexts for marital quality, behavior, and role-related stress.

Differential Effects of Superoxide Dismutase Mimetics after Mechanical Overload of Articular Cartilage

Directory of Open Access Journals (Sweden)

Mitchell C. Coleman

2017-11-01

Full Text Available Post-traumatic osteoarthritis can develop as a result of the initial mechanical impact causing the injury and also as a result of chronic changes in mechanical loading of the joint. Aberrant mechanical loading initiates excessive production of reactive oxygen species, oxidative damage, and stress that appears to damage mitochondria in the surviving chondrocytes. To probe the benefits of increasing superoxide removal with small molecular weight superoxide dismutase mimetics under severe loads, we applied both impact and overload injury scenarios to bovine osteochondral explants using characterized mechanical platforms with and without GC4403, MnTE-2-PyP, and MnTnBuOE-2-PyP. In impact scenarios, each of these mimetics provides some dose-dependent protection from cell death and loss of mitochondrial content while in repeated overloading scenarios only MnTnBuOE-2-PyP provided a clear benefit to chondrocytes. These results support the hypothesis that superoxide is generated in excess after impact injuries and suggest that superoxide production within the lipid compartment may be a critical mediator of responses to chronic overload. This is an important nuance distinguishing roles of superoxide, and thus superoxide dismutases, in mediating damage to cellular machinery in hyper-acute impact scenarios compared to chronic scenarios.

Tensile Mechanical Property of Oil Palm Empty Fruit Bunch Fiber Reinforced Epoxy Composites

Science.gov (United States)

Ghazilan, A. L. Ahmad; Mokhtar, H.; Shaik Dawood, M. S. I.; Aminanda, Y.; Ali, J. S. Mohamed

2017-03-01

Natural, short, untreated and randomly oriented oil palm empty fruit bunch fiber reinforced epoxy composites were manufactured using vacuum bagging technique with 20% fiber volume composition. The performance of the composite was evaluated as an alternative to synthetic or conventional reinforced composites. Tensile properties such as tensile strength, modulus of elasticity and Poisson’s ratio were compared to the tensile properties of pure epoxy obtained via tensile tests as per ASTM D 638 specifications using Universal Testing Machine INSTRON 5582. The tensile properties of oil palm empty fruit bunch fiber reinforced epoxy composites were lower compared to plain epoxy structure with the decrement in performances of 38% for modulus of elasticity and 61% for tensile strength.

In situ investigation of the tensile deformation of laser welded Ti{sub 2}AlNb joints

Energy Technology Data Exchange (ETDEWEB)

Zhang, Kezhao; Ni, Longchang; Lei, Zhenglong, E-mail: leizhenglong@hit.edu.cn; Chen, Yanbin; Hu, Xue

2017-01-15

The tensile deformation behavior of laser welded Ti{sub 2}AlNb joints was investigated using in situ analysis methods. The fracture mode of the single-B2-phase fusion zone was quasi-cleavage at room temperature and intergranular at 650 °C, while that of base metal was microvoid coalescence at both room temperature and 650 °C. Tensile deformation at room temperature was observed using in situ SEM tensile testing. In base metal, microcracks nucleated and propagated mainly within the O phase or along O/B2 phase boundaries. While both the cross- and multi-slips were found in the single-B2-phase fusion zone, a confocal laser scanning microscopy was used to observe the crack initiation and propagation process in situ at 650 °C. Cracks mainly formed along the B2/O phase boundaries in base metal, along the fragile grain boundaries of B2 phase in the fusion zone. The thermal simulation experiment and following TEM analysis indicated that the precipitation of continuous O-phase films along the B2 grain boundaries resulted in the high temperature brittleness of laser welded Ti{sub 2}AlNb joints. - Highlights: •Cracks formed within O phase or along B2/O boundaries in the base metal. •Cross- and multi-slips relieved stress in the fusion zone at room temperature. •Cracks mainly formed along the B2/O boundaries at 650 °C. •In the fusion zone, intergranular cracks were in situ observed at 650 °C. •O-phase films along B2 grain boundaries caused the high temperature brittleness.

A Prediction Method of Tensile Young's Modulus of Concrete at Early Age

Directory of Open Access Journals (Sweden)

Isamu Yoshitake

2012-01-01

Full Text Available Knowledge of the tensile Young's modulus of concrete at early ages is important for estimating the risk of cracking due to restrained shrinkage and thermal contraction. However, most often, the tensile modulus is considered equal to the compressive modulus and is estimated empirically based on the measurements of compressive strength. To evaluate the validity of this approach, the tensile Young's moduli of 6 concrete and mortar mixtures are measured using a direct tension test. The results show that the tensile moduli are approximately 1.0–1.3-times larger than the compressive moduli within the material's first week of age. To enable a direct estimation of the tensile modulus of concrete, a simple three-phase composite model is developed based on random distributions of coarse aggregate, mortar, and air void phases. The model predictions show good agreement with experimental measurements of tensile modulus at early age.

On the utility of vacancies and tensile strain-induced quality factor enhancement for mass sensing using graphene monolayers

International Nuclear Information System (INIS)

Kim, Sung Youb; Park, Harold S

2010-01-01

We have utilized classical molecular dynamics to investigate the mass sensing potential of graphene monolayers, using gold as the model adsorbed atom. In doing so, we report two key findings. First, we find that while perfect graphene monolayers are effective mass sensors at very low (T < 10 K) temperatures, their mass sensing capability is lost at higher temperatures due to diffusion of the adsorbed atom at elevated temperatures. We demonstrate that even if the quality (Q) factors are significantly elevated through the application of tensile mechanical strain, the mass sensing resolution is still lost at elevated temperatures, which demonstrates that high Q-factors alone are insufficient to ensure the mass sensing capability of graphene. Second, we find that while the introduction of single vacancies into the graphene monolayer prevents the diffusion of the adsorbed atom, the mass sensing resolution is still lost at higher temperatures, again due to Q-factor degradation. We finally demonstrate that if the Q-factors of the graphene monolayers with single vacancies are kept acceptably high through the application of tensile strain, then the high Q-factors, in conjunction with the single atom vacancies to stop the diffusion of the adsorbed atom, enable graphene to maintain its mass sensing capability across a range of technologically relevant operating temperatures.

Production and several properties of single crystal austenitic stainless steels

International Nuclear Information System (INIS)

Okamoto, Kazutaka; Yoshinari, Akira; Kaneda, Junya; Aono, Yasuhisa; Kato, Takahiko

1998-01-01

The single crystal austenitic stainless steels Type 316L and 304L were grown in order to improve the resistance to stress corrosion cracking (SCC) using a unidirectional solidification method which can provide the large size single crystals. The mechanical properties and the chemical properties were examined. The orientation and temperature dependence of tensile properties of the single crystals were measured. The yield stress of the single crystal steels are lower than those of the conventional polycrystal steels because of the grain boundary strength cannot be expected in the single crystal steels. The tensile properties of the single crystal austenitic stainless steel Type 316L depend strongly on the orientation. The tensile strength in orientation are about 200 MPa higher than those in the and orientations. The microstructure of the single crystal consists of a mixture of the continuous γ-austenitic single crystal matrix and the δ-ferrite phase so that the effects of the γ/δ boundaries on the chemical properties were studied. The effects of the δ-ferrite phases and the γ/δ boundaries on the resistance to SCC were examined by the creviced bent beam test (CBB test). No crack is observed in all the CBB test specimens of the single crystals, even at the γ/δ boundaries. The behavior of the radiation induced segregation (RIS) at the γ/δ boundaries in the single crystal austenitic stainless steel Type 316L was evaluated by the electron irradiation test in the high voltage electron microscope (HVEM). The depletion of oversized solute chromium at the γ/δ boundary in the single crystal austenitic stainless steel Type 316L is remarkably lower than that at the grain boundary in the polycrystalline-type 316L. (author)

Hepatic iron overload following liver transplantation of a C282y homozygous allograft: a case report and literature review.

LENUS (Irish Health Repository)

Dwyer, Jeremy P

2011-11-01

Hereditary haemochromatosis is a common genetic disease associated with progressive iron overload and parenchymal organ damage including liver, pancreas and heart. We report a case of inadvertent transplantation of a liver from a haemochromatosis donor to a 56-year-old Asian female. Progressive iron overload occurred over a 2 year follow up as assessed by liver biopsy and iron studies in the absence of a secondary cause of iron overload, supporting a primary role of liver rather than small intestine in the regulation of iron homeostasis in hereditary haemochromatosis.

The impact of faulty response of overload protection systems on the reliability of electricity supply

International Nuclear Information System (INIS)

Schweigert, J.; Schnuerer, G.

1988-01-01

Protection equipment of the engineered safety system which is to prevent the triggering of actions via signals from the reactor protection system is to be made so reliable that it has no impact on the non-availability of the supplied systems. Design and functional mode of the various overload protection equipment and the relevant switching device and combinations are explained together with the requirements such as choice, design, and adjustment of the protection equipment, followed by a survey of possible causes of faulty response of overload protection device and of the means and measures available for improvement. The now presented version of September 1987 of the 'overload protection report deals basically with all main topics of the Juli 1985 version, but has been updated and extended by material taking into account practice-oriented data on the new developments in convoy power plant design. (orig./HP) [de

Cardiac iron overload in chronically transfused patients with thalassemia, sickle cell anemia, or myelodysplastic syndrome.

Directory of Open Access Journals (Sweden)

Mariane de Montalembert

Full Text Available The risk and clinical significance of cardiac iron overload due to chronic transfusion varies with the underlying disease. Cardiac iron overload shortens the life expectancy of patients with thalassemia, whereas its effect is unclear in those with myelodysplastic syndromes (MDS. In patients with sickle cell anemia (SCA, iron does not seem to deposit quickly in the heart. Our primary objective was to assess through a multicentric study the prevalence of cardiac iron overload, defined as a cardiovascular magnetic resonance T2*8 ECs in the past year, and age older than 6 years. We included from 9 centers 20 patients with thalassemia, 41 with SCA, and 25 with MDS in 2012-2014. Erythrocytapharesis did not consistently prevent iron overload in patients with SCA. Cardiac iron overload was found in 3 (15% patients with thalassemia, none with SCA, and 4 (16% with MDS. The liver iron content (LIC ranged from 10.4 to 15.2 mg/g dry weight, with no significant differences across groups (P = 0.29. Abnormal T2* was not significantly associated with any of the measures of transfusion or chelation. Ferritin levels showed a strong association with LIC. Non-transferrin-bound iron was high in the thalassemia and MDS groups but low in the SCA group (P<0.001. Hepcidin was low in thalassemia, normal in SCA, and markedly elevated in MDS (P<0.001. Two mechanisms may explain that iron deposition largely spares the heart in SCA: the high level of erythropoiesis recycles the iron and the chronic inflammation retains iron within the macrophages. Thalassemia, in contrast, is characterized by inefficient erythropoiesis, unable to handle free iron. Iron accumulation varies widely in MDS syndromes due to the competing influences of abnormal erythropoiesis, excess iron supply, and inflammation.

Incidental splenic nodules found on MR imaging done for assessment of iron overload in children

International Nuclear Information System (INIS)

Ahyad, Rayan A.; Lam, Christopher Z.; Navarro, Oscar M.; Shearkhani, Omid

2017-01-01

MR imaging is used to assess iron overload in patients with hemoglobinopathies and in those who have undergone multiple blood transfusions. Sometimes splenic nodules are found incidentally on these examinations and this may cause diagnostic uncertainty. To determine the prevalence, imaging characteristics and evolution of splenic nodules found on MR imaging for iron overload evaluation. Retrospective review of all MR imaging examinations performed for iron overload assessment from 2005 to 2015 in a tertiary pediatric hospital. The presence of focal splenic nodules including number, size, signal characteristics and changes on follow-up MR imaging were recorded. Relevant patient clinical information including underlying hematological disease was also documented. A total of 318 patients had MR imaging for iron overload assessment. Of these, 25 (8%) had at least one incidental splenic nodule. Sickle cell disease was present in 22 patients (88%) and thalassemia in 3 (12%). On intermediate-weighted spin-echo images, the nodules had high signal intensity compared to the remainder of the spleen in 23 patients (92%) and low signal intensity in the remaining 2 (8%). In all patients (100%) the nodules showed progressive loss of signal intensity with increasing echo time values. Follow-up MR imaging was performed in 20 (80%) patients, which showed an increase in the size of the splenic nodules in 7 patients (35%) stability in 11 (55%) and a decrease in size in 2 (10%). It is not uncommon to find splenic nodules during MR evaluation of iron overload. In patients with sickle cell disease, most of these nodules are thought to represent preserved splenic tissue and appear hyperintense compared to the remainder of the spleen. They frequently remain stable on follow-up imaging, although about a third of them may show growth. Awareness of these nodules is important to avoid concern for potential malignancy and unnecessary investigations. (orig.)

Incidental splenic nodules found on MR imaging done for assessment of iron overload in children

Energy Technology Data Exchange (ETDEWEB)

Ahyad, Rayan A.; Lam, Christopher Z.; Navarro, Oscar M. [University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada); Shearkhani, Omid [The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada)

2017-06-15

MR imaging is used to assess iron overload in patients with hemoglobinopathies and in those who have undergone multiple blood transfusions. Sometimes splenic nodules are found incidentally on these examinations and this may cause diagnostic uncertainty. To determine the prevalence, imaging characteristics and evolution of splenic nodules found on MR imaging for iron overload evaluation. Retrospective review of all MR imaging examinations performed for iron overload assessment from 2005 to 2015 in a tertiary pediatric hospital. The presence of focal splenic nodules including number, size, signal characteristics and changes on follow-up MR imaging were recorded. Relevant patient clinical information including underlying hematological disease was also documented. A total of 318 patients had MR imaging for iron overload assessment. Of these, 25 (8%) had at least one incidental splenic nodule. Sickle cell disease was present in 22 patients (88%) and thalassemia in 3 (12%). On intermediate-weighted spin-echo images, the nodules had high signal intensity compared to the remainder of the spleen in 23 patients (92%) and low signal intensity in the remaining 2 (8%). In all patients (100%) the nodules showed progressive loss of signal intensity with increasing echo time values. Follow-up MR imaging was performed in 20 (80%) patients, which showed an increase in the size of the splenic nodules in 7 patients (35%) stability in 11 (55%) and a decrease in size in 2 (10%). It is not uncommon to find splenic nodules during MR evaluation of iron overload. In patients with sickle cell disease, most of these nodules are thought to represent preserved splenic tissue and appear hyperintense compared to the remainder of the spleen. They frequently remain stable on follow-up imaging, although about a third of them may show growth. Awareness of these nodules is important to avoid concern for potential malignancy and unnecessary investigations. (orig.)

Analysis/design of tensile property database system

International Nuclear Information System (INIS)

Park, S. J.; Kim, D. H.; Jeon, I.; Lyu, W. S.

2001-01-01

The data base construction using the data produced from tensile experiment can increase the application of test results. Also, we can get the basic data ease from database when we prepare the new experiment and can produce high quality result by compare the previous data. The development part must be analysis and design more specific to construct the database and after that, we can offer the best quality to customers various requirements. In this thesis, the analysis and design was performed to develop the database for tensile extension property

Tensile properties of interwoven hemp/PET (Polyethylene Terephthalate) epoxy hybrid composites

Science.gov (United States)

Ahmad, M. A. A.; Majid, M. S. A.; Ridzuan, M. J. M.; Firdaus, A. Z. A.; Amin, N. A. M.

2017-10-01

This paper describes the experimental investigation of the tensile properties of interwoven Hemp/PET hybrid composites. The effect of hybridization of hemp (warp) with PET fibres (weft) on tensile properties was of interest. Hemp and PET fibres were selected as the reinforcing material while epoxy resin was chosen as the matrix. The interwoven Hemp/PET fabric was used to produce hybrid composite using a vacuum infusion process. The tensile test was conducted using Universal Testing Machine in accordance to the ASTM D638. The tensile properties of the interwoven Hemp/PET hybrid composite were then compared with the neat woven hemp/epoxy composite. The results show that the strength of hemp/PET with the warp direction was increased by 8% compared to the neat woven hemp composite. This enhancement of tensile strength was due to the improved interlocking structure of interwoven Hemp/PET hybrid fabric.

The theoretical tensile strength of fcc crystals predicted from shear strength calculations

International Nuclear Information System (INIS)

Cerny, M; Pokluda, J

2009-01-01

This work presents a simple way of estimating uniaxial tensile strength on the basis of theoretical shear strength calculations, taking into account its dependence on a superimposed normal stress. The presented procedure enables us to avoid complicated and time-consuming analyses of elastic stability of crystals under tensile loading. The atomistic simulations of coupled shear and tensile deformations in cubic crystals are performed using first principles computational code based on pseudo-potentials and the plane wave basis set. Six fcc crystals are subjected to shear deformations in convenient slip systems and a special relaxation procedure controls the stress tensor. The obtained dependence of the ideal shear strength on the normal tensile stress seems to be almost linearly decreasing for all investigated crystals. Taking these results into account, the uniaxial tensile strength values in three crystallographic directions were evaluated by assuming a collapse of the weakest shear system. Calculated strengths for and loading were found to be mostly lower than previously calculated stresses related to tensile instability but rather close to those obtained by means of the shear instability analysis. On the other hand, the strengths for loading almost match the stresses related to tensile instability.

Competitive On-Line Scheduling for Overloaded Real-Time Systems

Science.gov (United States)

1993-09-01

Real - Time Systems by Gilad Koren a dissertation submitted in partial fulfillment of the requirements...Overloaded Real - Time Systems 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK...1.1 Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 2 1.1.1 Real - Time Systems : : : : : : : : : : : : : : : : : : : : : : : : : : : :

A Confirmatory Factor Analysis of Reilly's Role Overload Scale

Science.gov (United States)

Thiagarajan, Palaniappan; Chakrabarty, Subhra; Taylor, Ronald D.

2006-01-01

In 1982, Reilly developed a 13-item scale to measure role overload. This scale has been widely used, but most studies did not assess the unidimensionality of the scale. Given the significance of unidimensionality in scale development, the current study reports a confirmatory factor analysis of the 13-item scale in two samples. Based on the…

A hybrid approach to predict the relationship between tablet tensile strength and compaction pressure using analytical powder compression.

Science.gov (United States)

Persson, Ann-Sofie; Alderborn, Göran

2018-04-01

The objective was to present a hybrid approach to predict the strength-pressure relationship (SPR) of tablets using common compression parameters and a single measurement of tablet tensile strength. Experimental SPR were derived for six pharmaceutical powders with brittle and ductile properties and compared to predicted SPR based on a three-stage approach. The prediction was based on the Kawakita b -1 parameter and the in-die Heckel yield stress, an estimate of maximal tensile strength, and a parameter proportionality factor α. Three values of α were used to investigate the influence of the parameter on the SPR. The experimental SPR could satisfactorily be described by the three stage model, however for sodium bicarbonate the tensile strength plateau could not be observed experimentally. The shape of the predicted SPR was to a minor extent influenced by the Kawakita b -1 but the width of the linear region was highly influenced by α. An increased α increased the width of the linear region and thus also the maximal predicted tablet tensile strength. Furthermore, the correspondence between experimental and predicted SPR was influenced by the α value and satisfactory predictions were in general obtained for α = 4.1 indicating the predictive potential of the hybrid approach. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Hypertrophic response to hemodynamic overload: role of load vs. renin-angiotensin system activation

Science.gov (United States)

Koide, M.; Carabello, B. A.; Conrad, C. C.; Buckley, J. M.; DeFreyte, G.; Barnes, M.; Tomanek, R. J.; Wei, C. C.; Dell'Italia, L. J.; Cooper, G. 4th;

Matrix metalloproteinase-2 plays a critical role in overload induced skeletal muscle hypertrophy.

Science.gov (United States)

Zhang, Qia; Joshi, Sunil K; Lovett, David H; Zhang, Bryon; Bodine, Sue; Kim, Hubert T; Liu, Xuhui

2014-01-01

extracellular matrix (ECM) components are instrumental in maintaining homeostasis and muscle fiber functional integrity. Skeletal muscle hypertrophy is associated with ECM remodeling. Specifically, recent studies have reported the involvement of matrix metalloproteinases (MMPs) in muscle ECM remodeling. However, the functional role of MMPs in muscle hypertrophy remains largely unknown. in this study, we examined the role of MMP-2 in skeletal muscle hypertrophy using a previously validated method where the plantaris muscle of mice were subjected to mechanical overload due to the surgical removal of synergist muscles (gastrocnemius and soleus). following two weeks of overload, we observed a significant increase in MMP-2 activity and up-regulation of ECM components and remodeling enzymes in the plantaris muscles of wild-type mice. However, MMP-2 knockout mice developed significantly less hypertrophy and ECM remodeling in response to overload compared to their wild-type littermates. Investigation of protein synthesis rate and Akt/mTOR signaling revealed no difference between wild-type and MMP-2 knockout mice, suggesting that a difference in hypertrophy was independent of protein synthesis. taken together, our results suggest that MMP-2 is a key mediator of ECM remodeling in the setting of skeletal muscle hypertrophy.

Tensile strength of glulam laminations of Nordic spruce

DEFF Research Database (Denmark)

Hoffmeyer, Preben; Bräuner, Lise; Boström, Lars

1999-01-01

Design of glulam according to the European timber code Eurocode 5 is based on the standard document prEN1194 , according to which glulam beam strength is to be established either by full scale testing or by calculation. The calculation must be based on a knowledge of lamination tensile strength....... This knowledge may be obtained either by adopting a general rule that the characteristic tensile strength is sixty percent of the characteristic bending strength, or by performing tensile tests on an adequate number of laminations representative of the whole population. The present paper presents...... an investigation aimed at establishing such an adequate experimental background for the assignment of strength classes for glulam made of visually strength graded laminations from Nordic sawmills. The investigation includes more than 1800 boards (laminations) of Norway spruce (Picea abies) sampled from eight...

Tensile strength of two soldered alloys (Minalux and Verabond2

Directory of Open Access Journals (Sweden)

Mir Mohammad Rezaee S

2002-07-01

Full Text Available Recently. Minalux alloy, a base metal free from Be, has been presented on the market while no special soldering has been recommended for it. On the other hand, based on the manufacturer's claim, this alloy is similar to Verabond2. The aim of this study was to investigate the tensile strength of Minalux and Verabond2, soldered by Verasolder. Twelve standard dambble shape samples, with the length of 18 mm and the diameter of 3mm, were prepared from each alloy. Six samples of each alloy were divided into two pieces with carboradom disk. Soldering gap distance was 0.3mm, measured by a special jig and they were soldered by Verasolder alloy. Six other samples, of both Iranian and foreign unsoldered alloys were considered as control group. Then samples were examined under tensile force and their tensile strength was recorded. Two- way variance analysis showed that the tensile strength of Minalux alloy and Verabond2 were not statistically significant (Verasoler 686, Minalux 723, but after soldering, such difference became significant (Minalux 308, Verabond2 432. Verabond2 showed higher tensile strength after soldering.

Tensile and shear methods for measuring strength of bilayer tablets.

Science.gov (United States)

Chang, Shao-Yu; Li, Jian-Xin; Sun, Changquan Calvin

2017-05-15

Both shear and tensile measurement methods have been used to quantify interfacial bonding strength of bilayer tablets. The shear method is more convenient to perform, but reproducible strength data requires careful control of the placement of tablet and contact point for shear force application. Moreover, data obtained from the shear method depend on the orientation of the bilayer tablet. Although more time-consuming to perform, the tensile method yields data that are straightforward to interpret. Thus, the tensile method is preferred in fundamental bilayer tableting research to minimize ambiguity in data interpretation. Using both shear and tensile methods, we measured the mechanical strength of bilayer tablets made of several different layer combinations of lactose and microcrystalline cellulose. We observed a good correlation between strength obtained by the tensile method and carefully conducted shear method. This suggests that the shear method may be used for routine quality test of bilayer tablets during manufacturing because of its speed and convenience, provided a protocol for careful control of the placement of the tablet interface, tablet orientation, and blade is implemented. Copyright © 2017 Elsevier B.V. All rights reserved.

Tensile strength of woven yarn kenaf fiber reinforced polyester composites

Directory of Open Access Journals (Sweden)

A.E. Ismail

2015-12-01

Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

Effect of size on fracture and tensile manipulation of gold nanowires

International Nuclear Information System (INIS)

Wang, Fenying; Dai, Yanfeng; Zhao, Jianwei; Li, Qianjin; Zhang, Bin

2014-01-01

The fracture of metallic nanowires has attracted much attention owing to its reliability of application in nanoelectromechanical system. In this paper, we studied the fracture of [100] single-crystal gold nanowire subjected to uniaxial tension. The statistical breaking position distributions showed that the size effects had dominated the deformation and fracture of nanowires, and the quasi-static tensile deformations are insensitive to the styles of tensile rates. Furthermore, it was observed that the small-sized nanowire broke in the middle with disordered crystalline structure; for the middle-sized nanowire, although slippage plane had maintained the lattice degree, the fracture also happened in the middle due to symmetric tension; for the large-sized nanowire, the slippage was destroyed by symmetric tension, which induced the broken neck at one end of the nanowire. When the nanowire width is less than 5a (“a” means lattice constant, 0.408 nm for gold), the mechanical strength is relatively strong with obvious uncertainty, which can be attributed to the surface atom effect; when the width is larger than 5a, the influence of size on the mechanical property is more obvious at the constant strain rate than that at the absolute rate. Finally, the mechanical strength of the nanowire decreases with the size increasing

Tensile properties of compressed moulded Napier/glass fibre reinforced epoxy composites

Science.gov (United States)

Fatinah, T. S.; Majid, M. S. Abdul; Ridzuan, M. J. M.; Hong, T. W.; Amin, N. A. M.; Afendi, M.

2017-10-01

This paper describes the experimental investigation of the tensile properties of compressed moulded Napier grass fibres reinforced epoxy composites. The effect of treatment 5% sodium hydroxide (NaOH) concentrated solution and hybridization of Napier with CSM E-glass fibres on tensile properties was also studied. The untreated and treated Napier fibres with 25% fibre loading were fabricated with epoxy resin by a cold press process. 7% fibre loading of CSM glass fibre was hybrid as the skin layer for 18% fibre loading of untreated Napier grass fibre. The tensile tests were conducted using Universal Testing Machine in accordance with ASTM D638. The tensile properties of the untreated Napier/epoxy composites were compared with treated Napier/epoxy and untreated Napier/CSM/epoxy composites. The results demonstrated that the tensile performance of untreated Napier fibre composites was significantly improved by both of the modification; alkali treatment and glass fibre hybridization. Napier grass fibres showed promising potentials to be used as reinforcement in the polymer based composites.

Dynamic tensile response of alumina-Al composites

International Nuclear Information System (INIS)

Atisivan, R.; Bandyopadhyay, A.; Gupta, Y. M.

2002-01-01

Plate impact experiments were carried out to examine the high strain-rate tensile response of alumina-aluminum (Al) composites with tailored microstructures. A novel processing technique was used to fabricate interpenetrating phase alumina-aluminum composites with controlled microstructures. Fused deposition modeling (FDM), a commercially available rapid prototyping technique, was used to produce the controlled porosity mullite ceramic preforms. Alumina-Al composites were then processed via reactive metal infiltration of porous mullite ceramics. With this approach, both the micro as well as the macro structures can be designed via computer aided design (CAD) to tailor the properties of the composites. Two sets of dynamic tensile experiments were performed. In the first, the metal content was varied between 23 and 39 wt. percent. In the second, the microstructure was varied while holding the metal content nearly constant. Samples with higher metal content, as expected, displayed better spall resistance. For a given metal content, samples with finer metal diameter showed better spall resistance. Relationship of the microstructural parameters on the dynamic tensile response of the structured composites is discussed here

SOLID BURNT BRICKS’ TENSILE STRENGTH

Directory of Open Access Journals (Sweden)

Aneta Maroušková

2017-11-01

Full Text Available This paper deals with experimental testing of solid burnt bricks and mortar in pure (axial tension. The obtained working diagrams will be further use for a detailed numerical analysis of whole brick masonry column under concentric compressive load. Failure mechanism of compressed brick masonry column is characterized by the appearance and development of vertical tensile cracks in masonry units (bricks passing in the direction of principal stresses and is accompanied by progressive growth of horizontal deformations. These cracks are caused by contraction and interaction between two materials with different mechanical characteristics (brick and mortar. The aim of this paper is more precisely describe the response of quasi-brittle materials to uniaxial loading in tension (for now only the results from three point bending test are available. For these reasons, bricks and mortar tensile behavior is experimentally tested and the obtained results are discussed.

Decision processes in choice overload: a product of delay and probability discounting?

Science.gov (United States)

Kaplan, Brent A; Reed, Derek D

2013-07-01

Recent research in the behavioral decision making literature has demonstrated that humans hyperbolically discount the subjective value of options as the number of options increases (Reed et al., 2012). These findings provide a cognitive-behavioral synthesis of the "choice overload" phenomenon, also known as the "paradox of choice." Specifically, these findings suggest that temporal discounting may serve as the underlying process contributing to this effect. As an extension, this study examined the effects of reward magnitude sizes had on rates temporal and options discounting. This manipulation was conducted to determine what role temporal discounting plays in discounting of options. The present results suggest that temporal discounting may not be the only process contributing to the choice overload effect. Copyright © 2013 Elsevier B.V. All rights reserved.

Preliminary study on tensile properties and fractography of the recycled aluminum cast product

International Nuclear Information System (INIS)

Hishamuddin Hussain; Mohd Harun; Hafizal Yazid; Shaiful Rizam Shamsudin; Zaiton Selamat; Mohd Shariff Sattar

2004-01-01

Among many mechanical properties of materials, tensile properties are probably the most frequently considered, evaluated, and referred by the industry. This paper presents the result of preliminary study regarding the tensile properties and fractography of the recycled aluminum cast product. For this purpose, three sets of specimen were prepared for tensile testing by using permanent mold casting technique. The cast products are in durable shaped tensile specimens with the gauge length of 50mm. The tensile testing was conducted in accordance with BS EN 10002-1 and ISO 6892 standards. Fracture surface analysis was also conducted to understand materials behaviour. (Author)

MicroRNA-145 suppresses ROS-induced Ca{sup 2+} overload of cardiomyocytes by targeting CaMKIIδ

Energy Technology Data Exchange (ETDEWEB)

Cha, Min-Ji [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jang, Jin-Kyung [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); Ham, Onju; Song, Byeong-Wook; Lee, Se-Yeon [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Lee, Chang Yeon; Park, Jun-Hee [Department of Integrated Omics for Biomedical Sciences, Graduate School, Yonsei University, 50 Yonsei-ro, Seodamun-gu, Seoul 120-759 (Korea, Republic of); Lee, Jiyun; Seo, Hyang-Hee [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Choi, Eunhyun [Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University Health System, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Jeon, Woo-min [Department of Animal Resource, Sahmyook University, Seoul 139-742 (Korea, Republic of); Hwang, Hye Jin [Cardiovascular Research Institute, Yonsei University College of Medicine, 250 Seongsanno, Seodamun-gu, Seoul 120-752 (Korea, Republic of); Shin, Hyun-Taek [College of Pharmacy, Sookmyung Women’s University, 52 HyoChangWon-Gil, Yongsan-ku, Seoul 140-742 (Korea, Republic of); and others

2013-06-14

Highlights: •CaMKIIδ mediates H{sub 2}O{sub 2}-induced Ca{sup 2+} overload in cardiomyocytes. •miR-145 can inhibit Ca{sup 2+} overload. •A luciferase assay confirms that miR-145 functions as a CaMKIIδ-targeting miRNA. •Overexpression of miR-145 regulates CaMKIIδ-related genes and ameliorates apoptosis. -- Abstract: A change in intracellular free calcium (Ca{sup 2+}) is a common signaling mechanism of reperfusion-induced cardiomyocyte death. Calcium/calmodulin dependent protein kinase II (CaMKII) is a critical regulator of Ca{sup 2+} signaling and mediates signaling pathways responsible for functions in the heart including hypertrophy, apoptosis, arrhythmia, and heart disease. MicroRNAs (miRNA) are involved in the regulation of cell response, including survival, proliferation, apoptosis, and development. However, the roles of miRNAs in Ca{sup 2+}-mediated apoptosis of cardiomyocytes are uncertain. Here, we determined the potential role of miRNA in the regulation of CaMKII dependent apoptosis and explored its underlying mechanism. To determine the potential roles of miRNAs in H{sub 2}O{sub 2}-mediated Ca{sup 2+} overload, we selected and tested 6 putative miRNAs that targeted CaMKIIδ, and showed that miR-145 represses CaMKIIδ protein expression and Ca{sup 2+} overload. We confirmed CaMKIIδ as a direct downstream target of miR-145. Furthermore, miR-145 regulates Ca{sup 2+}-related signals and ameliorates apoptosis. This study demonstrates that miR-145 regulates reactive oxygen species (ROS)-induced Ca{sup 2+} overload in cardiomyocytes. Thus, miR-145 affects ROS-mediated gene regulation and cellular injury responses.

The role of magnetic resonance imaging in the evaluation of transfusional iron overload in myelodysplastic syndromes.

Science.gov (United States)

Petrou, Emmanouil; Mavrogeni, Sophie; Karali, Vasiliki; Kolovou, Genovefa; Kyrtsonis, Marie-Christine; Sfikakis, Petros P; Panayiotidis, Panayiotis

2015-01-01

Myelodysplastic syndromes represent a group of heterogeneous hematopoietic neoplasms derived from an abnormal multipotent progenitor cell, characterized by a hyperproliferative bone marrow, dysplasia of the cellular hemopoietic elements and ineffective erythropoiesis. Anemia is a common finding in myelodysplastic syndrome patients, and blood transfusions are the only therapeutic option in approximately 40% of cases. The most serious side effect of regular blood transfusion is iron overload. Currently, cardiovascular magnetic resonance using T2 is routinely used to identify patients with myocardial iron overload and to guide chelation therapy, tailored to prevent iron toxicity in the heart. This is a major validated non-invasive measure of myocardial iron overloading and is superior to surrogates such as serum ferritin, liver iron, ventricular ejection fraction and tissue Doppler parameters. The indication for iron chelation therapy in myelodysplastic syndrome patients is currently controversial. However, cardiovascular magnetic resonance may offer an excellent non-invasive, diagnostic tool for iron overload assessment in myelodysplastic syndromes. Further studies are needed to establish the precise indications of chelation therapy and the clinical implications of this treatment on survival in myelodysplastic syndromes. Copyright © 2014 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Left ventricular function in right ventricular overload

International Nuclear Information System (INIS)

Iwanaga, Shiro; Handa, Shunnosuke; Abe, Sumihisa; Onishi, Shohei; Nakamura, Yoshiro; Kunieda, Etsuo; Ogawa, Koichi; Kubo, Atsushi

1989-01-01

This study clarified regional and global functions of the distorted left ventricle due to right ventricular overload by gated radionuclide ventriculography (RNV). Cardiac catheterization and RNV were performed in 13 cases of atrial septal defect (ASD), 13 of pure mitral stenosis (MS), 10 of primary pulmonary hypertension (PPH), and 10 of normal subjects (NL). Right ventricular systolic pressure (RVSP) was 32.9±13.9, 45.0±12.2, 88.3±17.1, and 21.2±4.5 mmHg, respectively. The end-systolic LAO view of the left ventricle was halved into septal and free-wall sides. The end-diastolic halves were determined in the same plane. Ejection fractions of the global left ventricle (LVEF), global right ventricle (RVEF), the septal half of the left ventricle (SEPEF), and the free-wall half of the left ventricle (FWEF) were obtained. LVEF was 56.8±9.8% in NL, 52.8±10.5% in ASD, and 49.5±12.9% in PPH. In MS, LVEF (47.0±13.0%) was smaller than those in the other groups. RVEF was 37.0±5.2% in NL, 43.7±15.5% in ASD, and 32.8±11.5% in MS. In PPH, RVEF (25.0±10.6%) was smaller than those in the other groups. SEPEF was smaller in ASD (42.5±13.2%), MS (40.4±13.1%), PPH (40.5±12.5%) than in NL (53.5±8.5%). Systolic function of the septal half of the left ventricle was disturbed by right ventricular overload. RVEF (r=-0.35, p<0.05) and SEPEF (r=-0.51, p<0.01) had negative correlations with RVSP. As RVSP rose, systolic function of the septal half of the left ventricle was more severely disturbed. FWEF was the same among the four groups; NL (57.0±12.6%), ASD (48.6±15.2%), MS (50.5±12.0%), and PPH (51.1±12.3%). There was a good correlation between SEPEF and LVEF in NL (r=0.81), although in PPH this correlation was poor (r=0.64). These data showed that the distorted left ventricular due to right ventricular overload maintains its global function with preserved function of the free-wall side. (J.P.N.)

Investigations on the tensile strength of high performance concrete incorporating silica fume

International Nuclear Information System (INIS)

Santanu Bhanja; Bratish Sengupta

2005-01-01

Though the literature is rich in reporting on silica fume concrete the technical data on tensile strength is quite limited. The present paper is directed towards developing a better understanding on the isolated contribution of silica fume on the tensile strengths of High Performance Concrete. Extensive experimentation was carried out over water-binder ratios ranging from 0.26 to 0.42 and silica fume binder ratios from 0.0 to 0.3. For all the mixes compressive, flexural and split tensile strengths were determined at 28 days. The results of the present investigation indicate that silica fume incorporation results in significant improvements in the tensile strengths of concrete. It is also observed that the optimum replacement percentage, which led to maximization of strength, is not a constant one but depends on the water- cementitious material ratio of the mix. Compared to split tensile strengths, flexural strengths have exhibited greater percentage gains in strength. Increase in split tensile strength beyond 15% silica fume replacement is almost insignificant whereas sizeable gains in flexural tensile strength have occurred even up to 25% replacements. For the present investigation transgranular failure of concrete was observed which indicate that silica fume incorporation results in significant improvements in the strength of both paste and transition zone. (authors)

Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

Directory of Open Access Journals (Sweden)

W. H. Haniffah

2015-01-01

Full Text Available This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity. The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

Females Are Protected From Iron?Overload Cardiomyopathy Independent of Iron Metabolism: Key Role of Oxidative Stress

OpenAIRE

Das, Subhash K.; Patel, Vaibhav B.; Basu, Ratnadeep; Wang, Wang; DesAulniers, Jessica; Kassiri, Zamaneh; Oudit, Gavin Y.

2017-01-01

Background Sex?related differences in cardiac function and iron metabolism exist in humans and experimental animals. Male patients and preclinical animal models are more susceptible to cardiomyopathies and heart failure. However, whether similar differences are seen in iron?overload cardiomyopathy is poorly understood. Methods and Results Male and female wild?type and hemojuvelin?null mice were injected and fed with a high?iron diet, respectively, to develop secondary iron overload and geneti...

Tensile strength of Zr-2.5 Nb pressure tubes: A statistical study

Energy Technology Data Exchange (ETDEWEB)

Shah, Priti Kotak, E-mail: pritik@barc.gov.in [Senior Scientist, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Dubey, J.S.; Datta, D.; Shriwastaw, R.S.; Rath, B.N.; Singh, R.N. [Senior Scientist, Bhabha Atomic Research Centre, Mumbai, 400 085 (India); Anantharaman, S. [Head, Post Irradiation Examination Division, Bhabha Atomic Research Centre, Mumbai (India); Chakravartty, J.K. [Director, Materials Group, Bhabha Atomic Research Centre, Mumbai (India)

2015-12-15

Highlights: • Tensile properties in axial and transverse direction for a number of Indian Zr-2.5 Nb PHWR pressure tubes. • Distribution of tensile properties of double-melted and quadruple-melted pressure tubes. • Tensile properties at front-end and back-end of the quadruple melted pressure tubes at room temperature and at 300 °C. - Abstract: In order to get an idea of the statistical variation in the tensile properties of the double-melted as well as quadruple melted Zr-2.5 Nb pressure tubes (PTs) and also the variation in tensile properties between the two ends of the pressure tubes, tension tests were carried out on around 50 pressure tube off-cuts. Longitudinal and transverse tensile specimens were prepared from these off-cuts of pressure tubes of double-melted and quadruple melted types. For quadruple melted pressure tubes the specimens were tested from both front-end and back-end off-cuts. Miniature flat tensile specimens having 1.8 mm width and 1.5 mm thickness and 7.6 mm gauge length were prepared from the pressure tube off-cuts without any flattening treatment. Tension tests were carried out in a screw-driven machine at room temperature and 300 °C for both front-end and back-end off-cuts of each of 16 pressure tubes. In general the transverse specimens showed higher yield strength (YS) and ultimate tensile strength (UTS) compared to the longitudinal specimens. Transverse specimens showed less strain hardening compared to the longitudinal specimens. The axial specimens showed higher uniform (UE) and total elongation (TE) compared to the transverse specimens. Double-melted pressure tubes showed relatively higher strength and lower elongation and larger standard deviation compared to the quadruple melted pressure tubes. Mean values of tensile properties showed that back-end off-cuts were relatively stronger and less ductile compared to the front-end off-cuts.

The effects of sterilization on the tensile strength of orthodontic wires.

Science.gov (United States)

Staggers, J A; Margeson, D

1993-01-01

The purpose of this study was to evaluate the effect of sterilization on the tensile strength of 0.016" beta-titanium, nickel titanium and stainless steel wires. Three common methods of sterilization--autoclaving, dry heat and ethylene oxide--were evaluated in three test trials involving zero, one and five sterilization cycles. For each of the test trials, five pieces each of 0.016" TMA, 0.016" Sentalloy and 0.016" Tru-chrome stainless steel wires were sterilized using a standard autoclave. Five other pieces of each of the same wires were sterilized in a dryclave, while an additional five pieces of each of the three wire types were sterilized using ethylene oxide. The ultimate tensile strengths of the wires were then determined using an Instron Universal Testing Machine. The data were compared for statistical differences using analysis of variance. The results showed that dry heat sterilization significantly increased the tensile strength of TMA wires after one cycle, but not after five cycles. Autoclaving and ethylene oxide sterilization did not significantly alter the tensile strength of TMA wires. Dry heat and autoclave sterilization also significantly increased the tensile strength of Sentalloy wires, but the mean strength after five sterilization cycles was not significantly different than after one cycle. Ethylene oxide sterilization of Sentalloy wires did not significantly alter the tensile strengths of that wire. There were no significant differences in the tensile strengths of the stainless steel wires following zero, one or five cycles for any of the sterilization methods.

Monitoring tensile damage evolution in Nextel 312/BlackglasTM composites

International Nuclear Information System (INIS)

Kim, Jeongguk; Liaw, Peter K.

2005-01-01

Tensile damage evolution was monitored with the aid of nondestructive evaluation (NDE) techniques. Several NDE methods, such as ultrasonic testing (UT), infrared (IR) thermography, and acoustic emission (AE) techniques, were employed to analyze damage evolution during tensile testing of Nextel 312/Blackglas TM composites. Prior to tensile testing, UT was used to characterize the initial defect distribution of the samples. During tensile testing, AE sensors and an IR camera were used for in situ monitoring of the progressive damage of the samples. AE provided the amounts of damage evolution in terms of the AE intensity and/or energy, and the IR camera was used to obtain the temperature changes during the test. Microstructural characterization using scanning electron microscopy (SEM) was performed to investigate the fracture mechanisms and modes of Nextel 312/Blackglas TM samples. Moreover, SEM characterization was used to document failure behavior, and to show comparable results with NDE signatures

Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

Energy Technology Data Exchange (ETDEWEB)

Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

Tensile Test of Welding Joint Parts for a Plate-type Fuel Assembly

International Nuclear Information System (INIS)

Yoon, K. H.; Kim, J. Y.; Kim, H. J.; Yim, J. S.

2013-01-01

The tensile tests were performed using an INSTRON 4505 (universal tensile) testing machine. These welding joints are composed of two parts for the soundness of the fuel assembly; one is the side plate with a fixing bar and the other is a side plate with an end fitting. These two joint parts are fabricated by TIG welding method. The tensile tests of the welding joints of a plate-type FA are executed by a tensile test. The fixture configurations for the specimen are very important to obtain the strict test results. The maximum strength has an approximately linear correlation with the unit bonding length of the welding joints. In spite of these results, the maximum strengths of the welding joints are satisfied according to the minimum requirement. These tensile tests of the joint parts for a plate-type fuel assembly (FA) have to be executed to evaluate the structural strength. For the tensile test, the joint parts of a FA used in the test are made of aluminum alloy (Al6061-T6)

Influences of hot-isostatic-pressing temperature on microstructure, tensile properties and tensile fracture mode of Inconel 718 powder compact

International Nuclear Information System (INIS)

Chang, Litao; Sun, Wenru; Cui, Yuyou; Yang, Rui

2014-01-01

Inconel 718 powders have been hot-isostatic-pressed (HIPed) at representative temperatures to investigate the variations in microstructure, tensile properties and tensile fracture mode of the powder compact. Microstructure of the powder compacts were characterized by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and so on. The results showed that the interdendritic precipitates inherited from the powders were partially retained in the powder compacts when the powders were HIPed at or below 1210 °C but were eliminated when HIPed at and above 1260 °C. The grain size uniformity of the powder compacts first increases and then decreases with increasing HIPing temperature. Prior particle boundaries (PPBs) were observed in the powder compacts HIPed at and below 1260 °C but was eliminated when HIPed at 1275 °C. The PPBs were decorated with carbide particles, the amount of the carbide particles at the PPBs decreases with increasing HIPing temperature. Most of the PPBs were pinned by the carbide particles in the compacts HIPed at 1140 °C. When the HIPing temperature was increased to 1210 °C and 1260 °C, a large number of PPBs de-pinned and moved beyond the pinning carbide particles, leading to grain growth and leaving carbide particles at the site of the original PPBs within the new grains. With increasing HIPing temperature, the 0.2% yield strength of the powder compacts at 650 °C decreases, the tensile elongation increases, and the tensile fracture mode changed from inter-particle dominant fracture to fully dimple ductile fracture

Influences of hot-isostatic-pressing temperature on microstructure, tensile properties and tensile fracture mode of Inconel 718 powder compact

Energy Technology Data Exchange (ETDEWEB)

Chang, Litao [Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); University of Chinese Academy of Sciences, Beijing (China); Sun, Wenru; Cui, Yuyou [Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China); Yang, Rui, E-mail: ryang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China)

2014-04-01

Inconel 718 powders have been hot-isostatic-pressed (HIPed) at representative temperatures to investigate the variations in microstructure, tensile properties and tensile fracture mode of the powder compact. Microstructure of the powder compacts were characterized by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and so on. The results showed that the interdendritic precipitates inherited from the powders were partially retained in the powder compacts when the powders were HIPed at or below 1210 °C but were eliminated when HIPed at and above 1260 °C. The grain size uniformity of the powder compacts first increases and then decreases with increasing HIPing temperature. Prior particle boundaries (PPBs) were observed in the powder compacts HIPed at and below 1260 °C but was eliminated when HIPed at 1275 °C. The PPBs were decorated with carbide particles, the amount of the carbide particles at the PPBs decreases with increasing HIPing temperature. Most of the PPBs were pinned by the carbide particles in the compacts HIPed at 1140 °C. When the HIPing temperature was increased to 1210 °C and 1260 °C, a large number of PPBs de-pinned and moved beyond the pinning carbide particles, leading to grain growth and leaving carbide particles at the site of the original PPBs within the new grains. With increasing HIPing temperature, the 0.2% yield strength of the powder compacts at 650 °C decreases, the tensile elongation increases, and the tensile fracture mode changed from inter-particle dominant fracture to fully dimple ductile fracture.

The impact of iron overload and its treatment on quality of life: results from a literature review.

Science.gov (United States)

Abetz, Linda; Baladi, Jean-Francois; Jones, Paula; Rofail, Diana

2006-09-28

To assess the literature for the impact of iron overload and infusion Iron Chelation Therapy (ICT) on patients' quality of life (QoL), and the availability of QoL instruments for patients undergoing infusion ICT. Also, to obtain patients' experiences of having iron overload and receiving infusion ICT, and experts' clinical opinions about the impact of treatment on patients' lives. A search of studies published between 1966 and 2004 was conducted using Medline and the Health Economic Evaluation Database (HEED). Qualitative results from patient and expert interviews were analysed. Hand searching of relevant conference abstracts completed the search. Few studies measuring the impact of ICT with deferoxamine (DFO) on patients QoL were located (n = 15). QoL domains affected included: depression; fatigue; dyspnoea; physical functioning; psychological distress; decrease in QoL during hospitalization. One theme in all articles was that oral ICT should improve QoL. No iron overload or ICT-specific QoL instruments were located in the articles. Interviews revealed that the impact of ICT on patients with thalassemia, sickle cell disease, and myelodysplastic syndromes is high. A limited number of studies assessed the impact of ICT or iron overload on QoL. All literature suggested a need for easily administered, efficacious and well tolerated oral iron overload treatments, given the impact of current ICT on adherence. Poor adherence to ICT was documented to negatively impact survival. Further research is warranted to continue the qualitative and quantitative study of QoL using validated instruments in patients receiving ICT to further understanding the issues and improve patients QoL.

A natural antioxidant, tannic acid mitigates iron-overload induced hepatotoxicity in Swiss albino mice through ROS regulation.

Science.gov (United States)

Basu, Tapasree; Panja, Sourav; Shendge, Anil Khushalrao; Das, Abhishek; Mandal, Nripendranath

2018-05-01

Tannic acid (TA), a water soluble natural polyphenol with 8 gallic acids groups, is abundantly present in various medicinal plants. Previously TA has been investigated for its antimicrobial and antifungal properties. Being a large polyphenol, TA chelates more than 1 metal. Hence TA has been explored for potent antioxidant activities against reactive oxygen species (ROS), reactive nitrogen species (RNS) and as iron chelator in vitro thereby mitigating iron-overload induced hepatotoxicity in vivo. Iron dextran was injected intraperitoneally in Swiss albino mice to induce iron-overload triggered hepatotoxicity, followed by oral administration of TA for remediation. After treatment, liver, spleen, and blood samples were processed from sacrificed animals. The liver iron, serum ferritin, serum markers, ROS, liver antioxidant status, and liver damage parameters were assessed, followed by histopathology and protein expression studies. Our results show that TA is a prominent ROS and RNS scavenger as well as iron chelator in vitro. It also reversed the ROS levels in vivo and restricted the liver damage parameters as compared to the standard drug, desirox. Moreover, this natural polyphenol exclusively ameliorates the histopathological and fibrotic changes in liver sections reducing the iron-overload, along with chelation of liver iron and normalization of serum ferritin. The protective role of TA against iron-overload induced apoptosis in liver was further supported by changed levels of caspase 3, PARP as well as Bax/BCl-2 ratio. Thus, TA can be envisaged as a better orally administrable iron chelator to reduce iron-overload induced hepatotoxicity through ROS regulation. © 2018 Wiley Periodicals, Inc.

In-situ observation of strain evolution in CP-Ti during uniaxial tensile loading

Science.gov (United States)

Bettles, C. J.; Gibson, M. A.; Stevenson, A. W.; Tomus, D.; Lynch, P. A.

2010-07-01

First results are presented for in-situ tensile loading experiments performed on the Powder Diffraction beamline at the Australian Synchrotron facility. For direct measurement of strain evolution, the beamline was fitted with a uniaxial tensile stage and a high-resolution CCD detector. Precise calibration of the experimental diffraction geometry, taking into account slight misalignment of the detector (pitch, roll, yaw), was achieved by simulation of the ring patterns recorded from the standard reference material LaB 6 (660). The material examined was a commercially pure titanium strip, which from prior electron microscopy studies, was found to have an average grain size of ˜20-30 μm. Tensile specimens conformed to ASTM E8, with a gauge length of 25 mm. To probe the bulk material properties all experiments were performed at 20 keV. In these preliminary experiments, measurement of the relative change in the interplanar lattice spacing was used to monitor the elastic response in seven crystallographic orientations during the loading cycle. To overcome problems encountered with grain size and associated discontinuous Debye-Scherrer ring patterns, two strategies were implemented to measure the Bragg peak (2 θB) positions. In cases where the radial integration routine provided inconsistent results for peak determination, a new approach based on determining the averaged sum of 2 θB positions from individual spots making up the ring pattern was utilised. Results obtained for the diffraction elastic modulus were found to be in agreement with predictions based on the single-crystal and Neerfield-Hill crystal coupling models.

Study of gonadal hormones in Egyptian female children with sickle cell anemia in correlation with iron overload: Single center study.

Science.gov (United States)

Hagag, Adel A; El-Farargy, Mohamed S; Elrefaey, Shaymaa; Abo El-enein, Amany M

2016-03-01

Sickle cell disease is a hereditary hemoglobinopathy characterized by abnormal hemoglobin production, hemolytic anemia, and intermittent occlusion of small blood vessels, leading to tissue ischemia, chronic organ damage, and organ dysfunction including endocrine organs. The aim of this work was to evaluate some gonadal hormones in female children with sickle cell anemia (SCA) in correlation with iron overload. This study was conducted on 40 female children with SCA with a serum ferritin of > 1000ng/mL, who were attendants at the Hematology Unit, Pediatric Department, Tanta University, Tanta, Egypt in the period from May 2012 to April 2014. Their ages ranged from 11 years to 15years and the mean age value was 12.63±1.36 years (Group I). Forty female children with SCA of matched age with no iron overload served as a control Group (Group II). For all patients in Groups I and II the following were performed/assessed: complete blood count, hemoglobin electrophoresis, serum iron status, serum estrogen, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). There were significantly higher serum ferritin and serum iron levels and significantly lower total iron binding capacity, FSH, LH, and estrogen levels in Group I compared with Group II (mean serum ferritin was 2635.1±918.9 in Group I vs. 292.55±107.2 in Group II with a p value of .001; mean serum iron was 196.3±55.6 in Group I vs. 120±16.57 in Group II with a p value of .001 and mean serum total iron binding capacity was 247.3±28.6 in Group I vs. 327.8.7±21.96 in Group II with a p value of .001; mean FSH level was 1.36±0.22mIU/mL in Group I vs. 2.64±0.81mIU/mL in Group II with a p value of .021; mean LH level was 0.11±0.006mIU/mL in Group I vs. 1.78±1.12mIU/mL in Group II with a p value of .003; mean estrogen level was 21.45±10.23pg/mL in Group I vs. 42.36±15.44pg/mL in Group II with a p value of 0.001) with significant negative correlation between serum gonadal hormones and serum ferritin (r

Loss of Akap1 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy and Heart Failure

Directory of Open Access Journals (Sweden)

Gabriele G. Schiattarella

2018-05-01

Full Text Available Left ventricular hypertrophy (LVH is a major contributor to the development of heart failure (HF. Alterations in cyclic adenosine monophosphate (cAMP-dependent signaling pathways participate in cardiomyocyte hypertrophy and mitochondrial dysfunction occurring in LVH and HF. cAMP signals are received and integrated by a family of cAMP-dependent protein kinase A (PKA anchor proteins (AKAPs, tethering PKA to discrete cellular locations. AKAPs encoded by the Akap1 gene (mitoAKAPs promote PKA mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cell survival. To determine the role of mitoAKAPs in LVH development, in the present investigation, mice with global genetic deletion of Akap1 (Akap1-/-, Akap1 heterozygous (Akap1+/-, and their wild-type (wt littermates underwent transverse aortic constriction (TAC or SHAM procedure for 1 week. In wt mice, pressure overload induced the downregulation of AKAP121, the major cardiac mitoAKAP. Compared to wt, Akap1-/- mice did not display basal alterations in cardiac structure or function and cardiomyocyte size or fibrosis. However, loss of Akap1 exacerbated LVH and cardiomyocyte hypertrophy induced by pressure overload and accelerated the progression toward HF in TAC mice, and these changes were not observed upon prevention of AKAP121 degradation in seven in absentia homolog 2 (Siah2 knockout mice (Siah2-/-. Loss of Akap1 was also associated to a significant increase in cardiac apoptosis as well as lack of activation of Akt signaling after pressure overload. Taken together, these results demonstrate that in vivo genetic deletion of Akap1 enhances LVH development and accelerates pressure overload-induced cardiac dysfunction, pointing at Akap1 as a novel repressor of pathological LVH. These results confirm and extend the important role of mitoAKAPs in cardiac response to stress.

Loss of Akap1 Exacerbates Pressure Overload-Induced Cardiac Hypertrophy and Heart Failure.

Science.gov (United States)

Schiattarella, Gabriele G; Boccella, Nicola; Paolillo, Roberta; Cattaneo, Fabio; Trimarco, Valentina; Franzone, Anna; D'Apice, Stefania; Giugliano, Giuseppe; Rinaldi, Laura; Borzacchiello, Domenica; Gentile, Alessandra; Lombardi, Assunta; Feliciello, Antonio; Esposito, Giovanni; Perrino, Cinzia

2018-01-01

Left ventricular hypertrophy (LVH) is a major contributor to the development of heart failure (HF). Alterations in cyclic adenosine monophosphate (cAMP)-dependent signaling pathways participate in cardiomyocyte hypertrophy and mitochondrial dysfunction occurring in LVH and HF. cAMP signals are received and integrated by a family of cAMP-dependent protein kinase A (PKA) anchor proteins (AKAPs), tethering PKA to discrete cellular locations. AKAPs encoded by the Akap1 gene (mitoAKAPs) promote PKA mitochondrial targeting, regulating mitochondrial structure and function, reactive oxygen species production, and cell survival. To determine the role of mitoAKAPs in LVH development, in the present investigation, mice with global genetic deletion of Akap1 ( Akap1 -/- ), Akap1 heterozygous ( Akap1 +/- ), and their wild-type ( wt ) littermates underwent transverse aortic constriction (TAC) or SHAM procedure for 1 week. In wt mice, pressure overload induced the downregulation of AKAP121, the major cardiac mitoAKAP. Compared to wt, Akap1 -/- mice did not display basal alterations in cardiac structure or function and cardiomyocyte size or fibrosis. However, loss of Akap1 exacerbated LVH and cardiomyocyte hypertrophy induced by pressure overload and accelerated the progression toward HF in TAC mice, and these changes were not observed upon prevention of AKAP121 degradation in seven in absentia homolog 2 ( Siah2 ) knockout mice ( Siah2 -/- ). Loss of Akap1 was also associated to a significant increase in cardiac apoptosis as well as lack of activation of Akt signaling after pressure overload. Taken together, these results demonstrate that in vivo genetic deletion of Akap1 enhances LVH development and accelerates pressure overload-induced cardiac dysfunction, pointing at Akap1 as a novel repressor of pathological LVH. These results confirm and extend the important role of mitoAKAPs in cardiac response to stress.

Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

Energy Technology Data Exchange (ETDEWEB)

Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

Measurement of the tensile forces during bone lengthening.

Science.gov (United States)

Ohnishi, Isao; Kurokawa, Takahide; Sato, Wakyo; Nakamura, Kozo

2005-05-01

The purpose of this study was to investigate the effects of lengthening frequency on mechanical environment in limb lengthening. Tensile forces were continuously monitored using a load sensor attached to a unilateral external fixator. Twenty patients were monitored. Ten patients were with acquired femoral shortening, and five of them underwent quasi-continuous lengthening of 1440 steps per day, and the other five received step lengthening twice a day. The other 10 patients were with achondropalsia. Five of them underwent the same quasi-continuous lengthening, and the other five received the same step lengthening. The circadian change and the daily course of the tensile forces were assessed and compared between quasi-continuous lengthening and step lengthening. As for circadian change, an acute increase in the force took place simultaneously with each step of lengthening in the step-lengthening group, but very little change of the baseline force level was seen during quasi-continuous lengthening. As for daily course of the tensile force, it increased almost linearly in both lengthening frequency groups in the initial stage of lengthening. No significant difference of the average force increment rate in this phase was recognized between the quasi-continuous and step lengthening groups irrespective of the etiologies. The lengthening frequency greatly affected the circadian change of the tensile force, but did not affect the increment rate of the force in the linear phase.

Iron overload and HFE gene mutations in Polish patients with liver cirrhosis.

Science.gov (United States)

Sikorska, Katarzyna; Romanowski, Tomasz; Stalke, Piotr; Iżycka-Świeszewska, Ewa; Bielawski, Krzysztof Piotr

2011-06-01

Increased liver iron stores may contribute to the progression of liver injury and fibrosis, and are associated with a higher risk of hepatocellular carcinoma development. Pre-transplant symptoms of iron overload in patients with liver cirrhosis are associated with higher risk of infectious and malignant complications in liver transplant recipients. HFE gene mutations may be involved in the pathogenesis of liver iron overload and influence the progression of chronic liver diseases of different origins. This study was designed to determine the prevalence of iron overload in relation to HFE gene mutations among Polish patients with liver cirrhosis. Sixty-one patients with liver cirrhosis included in the study were compared with a control group of 42 consecutive patients subjected to liver biopsy because of chronic liver diseases. Liver function tests and serum iron markers were assessed in both groups. All patients were screened for HFE mutations (C282Y, H63D, S65C). Thirty-six of 61 patients from the study group and all controls had liver biopsy performed with semiquantitative assessment of iron deposits in hepatocytes. The biochemical markers of iron overload and iron deposits in the liver were detected with a higher frequency (70% and 47% respectively) in patients with liver cirrhosis. There were no differences in the prevalence of all HFE mutations in both groups. In patients with a diagnosis of hepatocellular carcinoma, no significant associations with iron disorders and HFE gene mutations were found. Iron disorders were detected in patients with liver cirrhosis frequently but without significant association with HFE gene mutations. Only the homozygous C282Y mutation seems to occur more frequently in the selected population of patients with liver cirrhosis. As elevated biochemical iron indices accompanied liver iron deposits more frequently in liver cirrhosis compared to controls with chronic liver disease, there is a need for more extensive studies searching for

Global transcriptional response to Hfe deficiency and dietary iron overload in mouse liver and duodenum.

Directory of Open Access Journals (Sweden)

Alejandra Rodriguez

2009-09-01

Full Text Available Iron is an essential trace element whose absorption is usually tightly regulated in the duodenum. HFE-related hereditary hemochromatosis (HH is characterized by abnormally low expression of the iron-regulatory hormone, hepcidin, which results in increased iron absorption. The liver is crucial for iron homeostasis as it is the main production site of hepcidin. The aim of this study was to explore and compare the genome-wide transcriptome response to Hfe deficiency and dietary iron overload in murine liver and duodenum. Illumina arrays containing over 47,000 probes were used to study global transcriptional changes. Quantitative RT-PCR (Q-RT-PCR was used to validate the microarray results. In the liver, the expression of 151 genes was altered in Hfe(-/- mice while dietary iron overload changed the expression of 218 genes. There were 173 and 108 differentially expressed genes in the duodenum of Hfe(-/- mice and mice with dietary iron overload, respectively. There was 93.5% concordance between the results obtained by microarray analysis and Q-RT-PCR. Overexpression of genes for acute phase reactants in the liver and a strong induction of digestive enzyme genes in the duodenum were characteristic of the Hfe-deficient genotype. In contrast, dietary iron overload caused a more pronounced change of gene expression responsive to oxidative stress. In conclusion, Hfe deficiency caused a previously unrecognized increase in gene expression of hepatic acute phase proteins and duodenal digestive enzymes.

Temperature dependency of tensile properties of GFRP composite for wind turbine blades

Energy Technology Data Exchange (ETDEWEB)

Huh, Yong Hak; Kim, Jong Il; Kim, Dong Jin; Lee, Gun Chang [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2012-09-15

In this study, the temperature dependency of the tensile properties of a glass fiber reinforced plastic (GFRP) used in wind turbine blades was examined. The tensile strength, elastic modulus, and Poisson's ratio of the tensile specimen manufactured from uniaxial (0 .deg.) and triaxial (0/{+-}45.deg) laminate composite plates were measured at four different testing temperatures-room temperature, -30 .deg. C, -50 .deg. C, and 60 .deg. C. It was found that the tensile strengths and elastic moduli of the uniaxial laminates were greater than those of the triaxial laminates over the testing temperature range. The tensile strength of the two laminates was significantly dependent on the testing temperature, while the dependency of the elastic modulus on the temperature was insignificant. Furthermore, it could be considered that the Poisson's ratio changed slightly with a change in the testing temperature.

Temperature dependency of tensile properties of GFRP composite for wind turbine blades

International Nuclear Information System (INIS)

Huh, Yong Hak; Kim, Jong Il; Kim, Dong Jin; Lee, Gun Chang

2012-01-01

In this study, the temperature dependency of the tensile properties of a glass fiber reinforced plastic (GFRP) used in wind turbine blades was examined. The tensile strength, elastic modulus, and Poisson's ratio of the tensile specimen manufactured from uniaxial (0 .deg.) and triaxial (0/±45.deg) laminate composite plates were measured at four different testing temperatures-room temperature, -30 .deg. C, -50 .deg. C, and 60 .deg. C. It was found that the tensile strengths and elastic moduli of the uniaxial laminates were greater than those of the triaxial laminates over the testing temperature range. The tensile strength of the two laminates was significantly dependent on the testing temperature, while the dependency of the elastic modulus on the temperature was insignificant. Furthermore, it could be considered that the Poisson's ratio changed slightly with a change in the testing temperature

Effect of Andrographolide‭ Extract on Blood Glucose and Lipid Profile in Rats with Secondary Iron Overload

Directory of Open Access Journals (Sweden)

َArash Mehri Pirayvatlo

2017-01-01

Full Text Available Background & objectives: Iron overload is involved in the pathophysiology of many diseases including diabetes. In fact, the excess iron by creating free radicals makes damage to pancreas and leads to insulin resistance and diabetes. Andrographolide extract has hypoglycemic and antioxidant properties. This study has surveyed the effects of andrographolide on blood glucose and lipid profile in rats with secondary iron overload. Methods: In this experimental study, 36 male Wistar rats were randomly divided into 6 groups: the healthy control group, secondary iron overload group, secondary iron overload groups treated with a dose of 3.5 and 7 mg/kg of andrographolide extract, and andrographolide groups treated with a dose of 3.5 and 7 mg/kg of extract. Iron and extract were injected for 6 and 12 days, respectively. Blood samples were taken for measurement of blood glucose and lipid profiles. Data were analyzed using ANOVA test. Results: The pathological results of samples from liver of animals receiving iron showed that the iron was deposited in the liver tissues. Iron injection significantly increased blood glucose levels compared to healthy control group (p<0.05. In the iron overload group, andrographolide extract with a dose of 3.5 mg/kg or 7 mg/kg significantly decreased blood glucose levels (p<0.05. Iron injections did not increase the serum triglyceride and cholesterollevels. Injections of andrographolide extract with a dose of 3.5 mg/kg and 7 mg/kg, significantly decreased the cholesterol levels compared to iron receiving group (p<0.05. Conclusion: Results of this study showed that the andrographolide with different doses may be effective in the treatment of diabetes by reducing serum glucose and cholesterol levels.

Low-intensity pulsed ultrasound enhances angiogenesis and ameliorates contractile dysfunction of pressure-overloaded heart in mice.

Directory of Open Access Journals (Sweden)

Tsuyoshi Ogata

Full Text Available Chronic left ventricular (LV pressure overload causes relative ischemia with resultant LV dysfunction. We have recently demonstrated that low-intensity pulsed ultrasound (LIPUS improves myocardial ischemia in a pig model of chronic myocardial ischemia through enhanced myocardial angiogenesis. In the present study, we thus examined whether LIPUS also ameliorates contractile dysfunction in LV pressure-overloaded hearts.Chronic LV pressure overload was induced with transverse aortic constriction (TAC in mice. LIPUS was applied to the whole heart three times in the first week after TAC and was repeated once a week for 7 weeks thereafter (n = 22. Animals in the control groups received the sham treatment without LIPUS (n = 23. At 8 weeks after TAC, LV fractional shortening was depressed in the TAC-Control group, which was significantly ameliorated in the TAC-LIPUS group (30.4±0.5 vs. 36.2±3.8%, P<0.05. Capillary density was higher and perivascular fibrosis was less in the LV in the TAC-LIPUS group than in the TAC-Control group. Myocardial relative ischemia evaluated with hypoxyprobe was noted in the TAC-Control group, which was significantly attenuated in the TAC-LIPUS group. In the TAC-LIPUS group, as compared with the control group, mRNA expressions of BNP and collagen III were significantly lower (both P<0.05 and protein expressions of VEGF and eNOS were significantly up-regulated associated with Akt activation (all P<0.05. No adverse effect related to the LIPUS therapy was noted.These results indicate that the LIPUS therapy ameliorates contractile dysfunction in chronically pressure-overloaded hearts through enhanced myocardial angiogenesis and attenuated perivascular fibrosis. Thus, the LIPUS therapy may be a promising, non-invasive treatment for cardiac dysfunction due to chronic pressure overload.

Tensile fracture behaviors of T-ZnOw/polyamide 6 composites

International Nuclear Information System (INIS)

Shi Jing; Wang Yong; Liu Li; Bai Hongwei; Wu Jun; Jiang Chongxi; Zhou, Zuowan

2009-01-01

As a part of serial work about the application of tetra-needle-shaped zinc oxide whisker (T-ZnOw) in polymer composites, this work is focused on the crystallization and tensile fracture behaviors of T-ZnOw/polyamide 6 (T-ZnOw/PA6) composites. Our results show that the addition of T-ZnOw improves the composites tensile strength greatly. For virgin PA6, the stress-strain curve exhibits double-yielding phenomenon. Surface modified T-ZnOw reinforced PA6 composites exhibit higher yield stress and smaller strain-to-fracture compared with virgin PA6. The morphologies of tensile-fractured surfaces show that, addition of T-ZnOw changes the fracture mode from crazing-tearing/brittle fracture mode of virgin PA6 into fibrillation/brittle fracture mode of PA6 composites. Especially, the fracture process of T-ZnOw in composites during the tensile test has been characterized by scanning electronic microscope (SEM) and the corresponding reinforcement mechanism has been discussed.

All-solid-state carbon nanotube torsional and tensile artificial muscles.

Science.gov (United States)

Lee, Jae Ah; Kim, Youn Tae; Spinks, Geoffrey M; Suh, Dongseok; Lepró, Xavier; Lima, Mácio D; Baughman, Ray H; Kim, Seon Jeong

2014-05-14

We report electrochemically powered, all-solid-state torsional and tensile artificial yarn muscles using a spinnable carbon nanotube (CNT) sheet that provides attractive performance. Large torsional muscle stroke (53°/mm) with minor hysteresis loop was obtained for a low applied voltage (5 V) without the use of a relatively complex three-electrode electromechanical setup, liquid electrolyte, or packaging. Useful tensile muscle strokes were obtained (1.3% at 2.5 V and 0.52% at 1 V) when lifting loads that are ∼25 times heavier than can be lifted by the same diameter human skeletal muscle. Also, the tensile actuator maintained its contraction following charging and subsequent disconnection from the power supply because of its own supercapacitor property at the same time. Possible eventual applications for the individual tensile and torsional muscles are in micromechanical devices, such as for controlling valves and stirring liquids in microfluidic circuits, and in medical catheters.

A quantitative approach to modeling the information processing of NPP operators under input information overload

International Nuclear Information System (INIS)

Kim, Jong Hyun; Seong, Poong Hyun

2002-01-01

This paper proposes a quantitative approach to modeling the information processing of NPP operators. The aim of this work is to derive the amount of the information processed during a certain control task under input information overload. We primarily develop the information processing model having multiple stages, which contains information flow. Then the uncertainty of the information is quantified using the Conant's model, a kind of information theory. We also investigate the applicability of this approach to quantifying the information reduction of operators under the input information overload

Mechanical stability of individual austenite grains in TRIP steel studied by synchrotron X-ray diffraction during tensile loading

Energy Technology Data Exchange (ETDEWEB)

Blondé, R. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Jimenez-Melero, E. [Dalton Cumbrian Facility, The University of Manchester, Westlakes Science and Technology Park, Moor Row, Cumbria, CA24 3HA (United Kingdom); Zhao, L. [Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Wright, J.P. [European Synchrotron Radiation Facility, 6 Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex (France); Brück, E. [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); Zwaag, S. van der [Novel Aerospace Materials Group, Faculty of Aerospace Engineering, Delft University of Technology, Kluyverweg 1, 2629 HS, Delft (Netherlands); Dijk, N.H. van, E-mail: N.H.vanDijk@tudelft.nl [Fundamental Aspects of Materials and Energy, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

2014-11-17

The stability of individual metastable austenite grains in low-alloyed TRIP steels has been studied during tensile loading using high-energy X-ray diffraction. The carbon concentration, grain volume and grain orientation with respect to the loading direction was monitored for a large number of individual grains in the bulk microstructure. Most austenite grains transform into martensite in a single transformation step once a critical load is reached. The orientation-dependent stability of austenite grains was found to depend on their Schmid factor with respect to the loading direction. Under the applied tensile stress the average Schmid factor decreased from an initial value of 0.44 to 0.41 at 243 MPa. The present study reveals the complex interplay of microstructural parameters on the mechanical stability of individual austenite grains, where the largest grains with the lowest carbon content tend to transform first. Under the applied tensile stress the average carbon concentration of the austenite grains increased from an initial value of 0.90 to 1.00 wt% C at 243 MPa, while the average grain volume of the austenite grains decreased from an initial value of 19 to 15 µm{sup 3} at 243 MPa.

Handbook for tensile properties of austenitic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Kim, D. W.; Ryu, W. S.; Jang, J. S.; Kim, S. H.; Kim, W. G.; Chung, M. K.; Han, C. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-03-01

Database system of nuclear materials has not been developed and the physical and mechanical properties of materials used in nuclear power plant are not summarized systematically in Korea. Although Korea designs nuclear power plant, many materials used in nuclear power plant are imported because we do not have database system of nuclear material yet and it was hard to select a proper material for the structural materials of nuclear power plant. To develop database system of nuclear materials, data of mechanical, corrosion, irradiation properties are needed. Of theses properties, tensile properties are tested and summarized in this report. Tensile properties of stainless steel used in nuclear reactor internal were investigated. Data between Korea Atomic Energy Research Institute and foreign laboratory were compared to determine the precision of the result. To develope database system, materials, chemical composition, heat treatment, manufacturing process, and grain size were classified. Tensile properties were tested and summarized to use input data of database system. 9 figs., 9 tabs. (Author)

Technologies for dealing with information overload : an engineers' point of view

NARCIS (Netherlands)

Calders, T.G.K.; Fletcher, G.H.L.; Kamiran, F.; Pechenizkiy, M.; Strother, J.B.; Ulijn, J.M.; Fazal, Z.

2012-01-01

In this chapter, we provide an overview of the technological side of the information overload problem. We discuss the challenges and opportunities offered by the ever-growing and emerging stream of information from an engineering point of view. More concretely, we survey storage and querying

On the dynamic stability of shear deformable beams under a tensile load

Science.gov (United States)

Caddemi, S.; Caliò, I.; Cannizzaro, F.

2016-07-01

Loss of stability of beams in a linear static context due to the action of tensile loads has been disclosed only recently in the scientific literature. However, tensile instability in the dynamic regime has been only marginally covered. Several aspects concerning the role of shear deformation on the tensile dynamic instability on continuous and discontinuous beams are still to be addressed. It may appear as a paradox, but also for the case of the universally studied Timoshenko beam model, despite its old origin, frequency-axial load diagrams in the range of negative values of the load (i.e. tensile load) has never been brought to light. In this paper, for the first time, the influence of a conservative tensile axial loads on the dynamic behaviour of the Timoshenko model, according to the Haringx theory, is assessed. It is shown that, under increasing tensile loads, regions of positive/negative fundamental frequency variations can be distinguished. In addition, the beam undergoes eigen-mode changes, from symmetric to anti-symmetric shapes, until tensile instability of divergence type is reached. As a further original contribution on the subject, taking advantage of a new closed form solution, it is shown that the same peculiarities are recovered for an axially loaded Euler-Bernoulli vibrating beam with multiple elastic sliders. This latter model can be considered as the discrete counterpart of the Timoshenko beam-column in which the internal sliders concentrate the shear deformation that in the Timoshenko model is continuously distributed. Original aspects regarding the evolution of the vibration frequencies and the relevant mode shapes with the tensile load value are highlighted.

Tensile deformation and failure of North American porcupine quills

Energy Technology Data Exchange (ETDEWEB)

Chou, S.F.; Overfelt, R.A., E-mail: overfra@auburn.edu

2011-12-01

Although the mechanical properties of some keratin-based biological materials have been extensively studied (i.e., wool) and others are beginning to be studied (e.g., horn, hooves and avian quills), data on the properties of porcupine quill are less common. Porcupine quill is a keratin-based biological material composed of a cylindrical outer shell with an inner foam core. The present paper reports on the physical characteristics, tensile properties and fracture behavior of North American porcupine quills conditioned at relative humidities of 65% and 100%. Increasing the water content decreased the tensile stiffness and strength and increased the strain at fracture of the porcupine quills. The tensile fracture strength of porcupine quill was found to be 146 MPa at 65% RH and 60 MPa at 100% RH. Although these values compare favorably with reported values for African porcupine quill, reported values of the tensile strengths of wool with similar moisture contents are considerably higher. The initial moduli of porcupine quill (2700 MPa at 65% RH and 1000 MPa at 100% RH) compare favorably to those reported for wool but are considerably less than previous reports for African porcupine quill. The engineering strains at fracture were measured as 25% at 65% RH and 49% at 100% RH and these values are also comparable to other keratin-based mammalian materials. Scanning electron microscopy of the fracture surfaces of porcupine quills revealed that the cylindrical outer shells of quills are composed of 2-3 layers with distinctly different fracture characteristics, especially when the samples contain 100% RH. The outer layer of the porcupine quill shell appears to resist the plasticizing effects of moisture and appears to exhibit considerably less ductility than the inner layers, perhaps due to the presence of hydrophobic lipids in the outer layer. Highlights: {yields} We characterize the tensile properties of north American porcupine quill. {yields} Elastic modulus, tensile

Blunted angiogenesis and hypertrophy are associated with increased fatigue resistance and unchanged aerobic capacity in old overloaded mouse muscle.

Science.gov (United States)

Ballak, Sam B; Busé-Pot, Tinelies; Harding, Peter J; Yap, Moi H; Deldicque, Louise; de Haan, Arnold; Jaspers, Richard T; Degens, Hans

2016-04-01

We hypothesize that the attenuated hypertrophic response in old mouse muscle is (1) partly due to a reduced capillarization and angiogenesis, which is (2) accompanied by a reduced oxidative capacity and fatigue resistance in old control and overloaded muscles, that (3) can be rescued by the antioxidant resveratrol. To investigate this, the hypertrophic response, capillarization, oxidative capacity, and fatigue resistance of m. plantaris were compared in 9- and 25-month-old non-treated and 25-month-old resveratrol-treated mice. Overload increased the local capillary-to-fiber ratio less in old (15 %) than in adult (59 %) muscle (P muscles of old mice had a higher succinate dehydrogenase (SDH) activity (P < 0.05) and a slower fiber type profile (P < 0.05), the isometric fatigue resistance was similar in 9- and 25-month-old mice. In both age groups, the fatigue resistance was increased to the same extent after overload (P < 0.01), without a significant change in SDH activity, but an increased capillary density (P < 0.05). Attenuated angiogenesis during overload may contribute to the attenuated hypertrophic response in old age. Neither was rescued by resveratrol supplementation. Changes in fatigue resistance with overload and aging were dissociated from changes in SDH activity, but paralleled those in capillarization. This suggests that capillarization plays a more important role in fatigue resistance than oxidative capacity.

Finite Element Simulation of Aluminium/GFRP Fibre Metal Laminate under Tensile Loading

Science.gov (United States)

Merzuki, M. N. M.; Rejab, M. R. M.; Romli, N. K.; Bachtiar, D.; Siregar, J.; Rani, M. F.; Salleh, Salwani Mohd

2018-03-01

The response of a fibre metal laminate (FML) model to the tensile loading is predicted through a computational approach. The FML consisted with layers of aluminum alloy and embedded with one layer of composite material, Glass fibre Reinforced Plastic (GFRP). The glass fibre and aluminium alloy 2024-0 was laminated by using thermoset epoxy. A compression moulding technique was used in the process of a FML fabrication. The aluminium has been roughen by a metal sanding method which to improve the bonding between the fibre and metal layer. The main objective of this paper is to determine the failure behaviour of the FML under the tensile loading. The responses on the FML under the tensile loading were numerically performed. The FML was modelled and analysed by using Abaqus/CAE 6.13 version. Based on the experimental and FE data of the tensile, the ultimate tensile stress is 120 MPa where delamination and fibre breakage happened. A numerical model was developed and agreed well with the experimental results. The laminate has an inelastic respond to increase the tensile loads which due to the plasticity of the aluminium layers.

Tools to Reduce Overload in the School Social Worker Role

Science.gov (United States)

Leyba, Erin Gleason

2009-01-01

This article addresses how school social workers can decrease overload in their roles. A two-step process of envisioning an ideal role is outlined: (1) indentifying priorities and activities that are effective or in need of expansion and (2) weeding out activities that could be done differently or no longer serve their purpose. The author…

Tensile, swelling and morphological properties of bentonite-filled acrylonitrile butadiene rubber composites

Science.gov (United States)

Lotfi, Muhamad Nadhli Amin; Ismail, Hanafi; Othman, Nadras

2017-10-01

Tensile, swelling and morphological properties of bentonite filled acrylonitrile butadiene rubber (NBR/Bt) composites were studied. The experiments were conducted at room temperature by using two rolled mill, universal testing machine (INSTRON), and American Standard Testing Method (ASTM) D471 for compounding, tensile testing, and swelling test, respectively. Results obtained indicated that a better tensile strength, elongation at break and tensile modulus were recorded as compared to the pure NBR particularly up to 90 phr of Bt loading. However, swelling (%) exhibited the opposite trend where the liquid uptake by the composites was indirectly proportional with the increasing of Bt loading. Scanning electron microscopy (SEM) used on the tensile fractured surface of the NBR/Bt composites have shown that the fillers were well embedded in the NBR matrix, for Bt loading up to 90 phr. The agglomeration of fillers occurred for Bt loading exceeding 90 phr.

The ''red'' decline of Norway spruce or ''røde rødgraner'' - is it ammonium overload or top-dying?

DEFF Research Database (Denmark)

Engvild, K.C.

2005-01-01

by nitrogen overload was investigated. A sensitive biochemical indicator of nitrogen status of conifer trees is the content of free amino acids of the urea cycle,arginine and ornithine. In pot experiments with four times overload of N as ammonium nitrate the free arginine content increased more than 100 times....... There was no indication of nitrogen overload. The “red” Norway spruce maysuffer from “top-dying” a common disorder of Norway spruce in Great Britain, believed to be caused by several mild winters in a row. In that case the symptoms should diminish after the very cold winter 1995-96....

Influence of relative humidity on tensile and compressive creep of ...

African Journals Online (AJOL)

This paper presents an experimental study on the influence of ambient relative humidity on tensile creep of plain concrete amended with Ground Granulated Blast - furnace Slag and compares it with its influence on compressive creep. Tensile and compressive creep tests were carried out on concrete specimens of 34.49 ...

The impact of iron overload and its treatment on quality of life: results from a literature review

Directory of Open Access Journals (Sweden)

Jones Paula

2006-09-01

Full Text Available Abstract Background To assess the literature for the impact of iron overload and infusion Iron Chelation Therapy (ICT on patients' quality of life (QoL, and the availability of QoL instruments for patients undergoing infusion ICT. Also, to obtain patients' experiences of having iron overload and receiving infusion ICT, and experts' clinical opinions about the impact of treatment on patients' lives. Methods A search of studies published between 1966 and 2004 was conducted using Medline and the Health Economic Evaluation Database (HEED. Qualitative results from patient and expert interviews were analysed. Hand searching of relevant conference abstracts completed the search. Results Few studies measuring the impact of ICT with deferoxamine (DFO on patients QoL were located (n = 15. QoL domains affected included: depression; fatigue; dyspnoea; physical functioning; psychological distress; decrease in QoL during hospitalization. One theme in all articles was that oral ICT should improve QoL. No iron overload or ICT-specific QoL instruments were located in the articles. Interviews revealed that the impact of ICT on patients with thalassemia, sickle cell disease, and myelodysplastic syndromes is high. Conclusion A limited number of studies assessed the impact of ICT or iron overload on QoL. All literature suggested a need for easily administered, efficacious and well tolerated oral iron overload treatments, given the impact of current ICT on adherence. Poor adherence to ICT was documented to negatively impact survival. Further research is warranted to continue the qualitative and quantitative study of QoL using validated instruments in patients receiving ICT to further understanding the issues and improve patients QoL.

5-lipoxygenase activation is involved in the mechanisms of chronic hepatic injury in a rat model of chronic aluminum overload exposure

Energy Technology Data Exchange (ETDEWEB)

Mai, Shaoshan [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); He, Qin [Department of Heptobiliary Surgery, 1st Affiliated Hospital, Chongqing Medical University, Chongqing 400016 (China); Wang, Hong; Hu, Xinyue; Luo, Ying; Yang, Yang; Kuang, Shengnan; Tian, Xiaoyan; Ma, Jie [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China); Yang, Junqing, E-mail: 1139627371@qq.com [Department of Pharmacology, Chongqing Medical University, Key Laboratory of Biochemistry and Molecular Pharmacology, Chongqing 400016 (China)

2016-08-15

We previously confirmed that rats overloaded with aluminum exhibited hepatic function damage and increased susceptibility to hepatic inflammation. However, the mechanism of liver toxicity by chronic aluminum overload is poorly understood. In this study, we investigated changes in the 5-lipoxygenase (5-LO) signaling pathway and its effect on liver injury in aluminum-overloaded rats. A rat hepatic injury model of chronic aluminum injury was established via the intragastric administration of aluminum gluconate (Al{sup 3+} 200 mg/kg per day, 5 days a week for 20 weeks). The 5-LO inhibitor, caffeic acid (10 and 30 mg/kg), was intragastrically administered 1 h after aluminum administration. Hematoxylin and eosin staining was used to visualize pathological changes in rat liver tissue. A series of biochemical indicators were measured with biochemistry assay or ELISAs. Immunochemistry and RT-PCR methods were used to detect 5-LO protein and mRNA expression in the liver, respectively. Caffeic acid administration protected livers against histopathological injury, decreased plasma ALT, AST, and ALP levels, decreased TNF-α, IL-6, IL-1β and LTs levels, increased the reactive oxygen species content, and down-regulated the mRNA and protein expressions of 5-LO in aluminum overloaded rats. Our results indicate that 5-lipoxygenase activation is mechanistically involved in chronic hepatic injury in a rat model of chronic aluminum overload exposure and that the 5-LO signaling pathway, which associated with inflammation and oxidative stress, is a potential therapeutic target for chronic non-infection liver diseases. - Highlights: • 5-LO signaling contributes to mechanisms of hepatotoxicity of aluminum overload. • Oxidative and inflammatory reaction involve in chonic aluminum hepatotoxicity. • 5-LO inhibitor has a protective effect on aluminum-overload liver injury. • 5-LO signaling is a potential therapeutic target for non-infection liver diseases.

Examination of parameters affecting overload fracture behavior of flaw-tip hydrides in Zr-2.5Nb pressure tubes in Candu reactors

International Nuclear Information System (INIS)

Cui, J.; Shek, G.K.; Wang, Z.R.

2007-01-01

Service-induced flaws in Zr-2.5Nb alloy pressure tubes in Candu (Canada Deuterium Uranium Reactors) nuclear reactors are susceptible to a crack initiation and growth mechanism known as Delayed Hydride Cracking (DHC), which is a repetitive process that involves hydrogen diffusion, hydride precipitation, growth and fracture of a hydride region at the flaw-tip under a constant load. Crack initiation may also occur under another loading condition when the hydride region is subjected to an overload. An overload occurs when the hydride region at the flaw tip is loaded to a stress higher than that at which this region is formed such as when the reactor experiences a transient pressure higher than the normal operating pressure where the hydride region is formed. Flaw disposition requires justification that the hydride region overload will not fracture the hydride region, and initiate DHC. In this work, monotonically increasing load experiments were performed on unirradiated Zr-2.5Nb pressure tube specimens containing simulated debris frets (V-notch) and bearing pad frets (BPF, U-shape notch) to examine overload fracture behavior of flaw-tip hydrides formed under hydride ratcheting conditions. Hydride cracking in the overload tests was detected by the acoustic emission technique and confirmed by post-test metallurgical examination. Test results indicate that the resistance to overload fracture is affected by a number of parameters including hydride formation stress, flaw shape (V-notch vs. BPF) and flaw radius (0.015 mm vs. 0.1 mm). The notch-tip hydride morphologies were examined by optical microscopy and scanning electron microscopy (SEM) which show that they are affected by the hydride formation conditions, resulting in different overload fracture resistance. Finite element stress analyses were also performed to obtain flaw-tip stress distributions for interpretation of the test results. (authors)

Grafting Carbon Nanotubes on Glass Fiber by Dip Coating Technique to Enhance Tensile and Interfacial Shear Strength

Directory of Open Access Journals (Sweden)

Bahador Dastorian Jamnani

2015-01-01

Full Text Available The effects of noncovalent bonding and mechanical interlocking of carbon nanotubes (CNT coating on tensile and interfacial strength of glass fiber were investigated. CNT were coated over glass fiber by a simple dip coating method. Acid treated CNT were suspended in isopropanol solution containing Nafion as binding agent. To achieve uniform distribution of CNT over the glass fiber, an optimized dispersion process was developed by two parameters: CNT concentration and soaking time. CNT concentration was varied from 0.4 to 2 mg/mL and soaking time was varied from 1 to 180 min. The provided micrographs demonstrated appropriate coating of CNT on glass fiber by use of CNT-Nafion mixture. The effects of CNT concentration and soaking time on coating layer were studied by performing single fiber tensile test and pull-out test. The obtained results showed that the optimum CNT concentration and soaking time were 1 mg/mL and 60 min, respectively, which led to significant improvement of tensile strength and interfacial shear stress. It was found that, at other concentrations and soaking times, CNT agglomeration or acutely curly tubes appeared over the fiber surface which caused a reduction of nanotubes interaction on the glass fiber.

Tensile behavior of humid aged advanced composites for helicopter external fuel tank development

Directory of Open Access Journals (Sweden)

Condruz Mihaela

2018-01-01

Full Text Available Influence of humid aging on tensile properties of two polymeric composites was studied. The purpose of the study was to evaluate the suitability of the materials for a naval helicopter external fuel tank. Due to the application, the humid environment was kerosene and saline solution to evaluate the sea water effect on the composite tensile strength. The composite samples were immersed in kerosene for 168 hours, respective 1752 hours and in saline solution for 168 hours. Tensile tests were performed after the immersion. The composite sample tensile tests showed that kerosene and saline solution had no influence on the elastic modulus of the materials, but it was observed a slight improvement of the tensile strength of the two polymeric composites.

TNF-α as a potential mediator of cardiac dysfunction due to intracellular Ca2+-overload

International Nuclear Information System (INIS)

Zhang Ming; Xu Yanjun; Saini, Harjot K.; Turan, Belma; Liu, Peter P.; Dhalla, Naranjan S.

2005-01-01

TNF-α has been shown to be involved in cardiac dysfunction during ischemia/reperfusion injury; however, no information regarding the status of TNF-α production in myocardial injury due to intracellular Ca 2+ -overload is available in the literature. The intracellular Ca 2+ -overload was induced in the isolated rat hearts subjected to 5 min Ca 2+ -depletion and 30 min Ca 2+ -repletion (Ca 2+ -paradox). The Ca 2+ -paradox hearts exhibited a dramatic depression in left ventricular developed pressure, a marked elevation in left ventricular end diastolic pressure, and more than a 4-fold increase in TNF-α content. The ratio of cytosolic to homogenate nuclear factor-κB (NFκB) was decreased whereas the ratio of phospho-NFκB to total NFκB was increased in the Ca 2+ -paradox hearts. All these changes due to Ca 2+ -paradox were significantly attenuated upon treating the hearts with 100 μM pentoxifylline. These results suggest that activation of NFκB and increased production of TNF-α may play an important role in cardiac injury due to intracellular Ca 2+ -overload

Analysis of occupational stress in a high fashion clothing factory with upper limb biomechanical overload.

Science.gov (United States)

Forcella, Laura; Bonfiglioli, Roberta; Cutilli, Piero; Siciliano, Eugenio; Di Donato, Angela; Di Nicola, Marta; Antonucci, Andrea; Di Giampaolo, Luca; Boscolo, Paolo; Violante, Francesco Saverio

2012-07-01

To study job stress and upper limb biomechanical overload due to repetitive and forceful manual activities in a factory producing high fashion clothing. A total of 518 workers (433 women and 85 men) were investigated to determine anxiety, occupational stress (using the Italian version of the Karasek Job Content Questionnaire) and perception of symptoms (using the Italian version of the Somatization scale of Symptom Checklist SCL-90). Biomechanical overload was analyzed using the OCRA Check list. Biomechanical assessment did not reveal high-risk jobs, except for cutting. Although the perception of anxiety and job insecurity was within the normal range, all the workers showed a high level of job strain (correlated with the perception of symptoms) due to very low decision latitude. Occupational stress resulted partially in line with biomechanical risk factors; however, the perception of low decision latitude seems to play a major role in determining job strain. Interactions between physical and psychological factors cannot be demonstrated. Anyway, simultaneous long-term monitoring of occupational stress features and biomechanical overload could guide workplace interventions aimed at reducing the risk of adverse health effects.

Black Tea High-Molecular-Weight Polyphenol-Rich Fraction Promotes Hypertrophy during Functional Overload in Mice

Directory of Open Access Journals (Sweden)

Yuki Aoki

2017-03-01

Full Text Available Mitochondria activation factor (MAF is a high-molecular-weight polyphenol extracted from black tea that stimulates training-induced 5′ adenosine monophosphate-activated protein kinase (AMPK activation and improves endurance capacity. Originally, MAF was purified from black tea using butanol and acetone, making it unsuitable for food preparation. Hence, we extracted a MAF-rich sample “E80” from black tea, using ethanol and water only. Here, we examined the effects of E80 on resistance training. Eight-week old C57BL/6 mice were fed with a normal diet or a diet containing 0.5% E80 for 4, 7 and 14 days under conditions of functional overload. It was found that E80 administration promoted overload-induced hypertrophy and induced phosphorylation of the Akt/mammalian target of rapamycin (mTOR pathway proteins, such as Akt, P70 ribosomal protein S6 kinase (p70S6K, and S6 in the plantaris muscle. Therefore, functional overload and E80 administration accelerated mTOR signaling and increased protein synthesis in the muscle, thereby inducing hypertrophy.

Theory of the tensile actuation of fiber reinforced coiled muscles

Science.gov (United States)

Lamuta, C.; Messelot, S.; Tawfick, S.

2018-05-01

There is a strong need for compact artificial muscles capable of applying large contractile strokes and lift heavy weights. Coiled fibers recently emerged as attractive candidates for these purposes, owing to their simple construction and the possibility of their thermal, electrical and chemical actuation. An intuitive theoretical understanding of the mechanics of actuation of these muscles is essential for the enhancement of their performance and can pave the way for the development of new applications and technologies. In this paper, a complete theoretical model for the tensile actuation of fiber reinforced artificial muscles is presented and experimentally validated. The model demonstrates that all muscles made from the same material have a universal behavior, which can be described by a single master curve. It enables the systematic design and understanding of coiled muscles for specific performance owing to a comprehensive mathematical correlation among the geometry, materials properties, and actuation. Carbon fibers (CF)/polydimethylsiloxane coiled muscles are demonstrated as simple to fabricate yet powerful muscles owing to the availability of high strength CF. In addition to showing excellent agreement with the theoretical models, they can be actuated by joule heating or chemical swelling, lift up to 12 600 times their own weight, support up to 60 MPa of mechanical stress, provide tensile strokes higher than 25%, and a specific work up to 758 J kg‑1, the latter is more than 18 times higher than that of natural muscles.

Effects of Iron Overload on the Activity of Na,K-ATPase and Lipid Profile of the Human Erythrocyte Membrane.

Directory of Open Access Journals (Sweden)

Leilismara Sousa

Full Text Available Iron is an essential chemical element for human life. However, in some pathological conditions, such as hereditary hemochromatosis type 1 (HH1, iron overload induces the production of reactive oxygen species that may lead to lipid peroxidation and a change in the plasma-membrane lipid profile. In this study, we investigated whether iron overload interferes with the Na,K-ATPase activity of the plasma membrane by studying erythrocytes that were obtained from the whole blood of patients suffering from iron overload. Additionally, we treated erythrocytes of normal subjects with 0.8 mM H2O2 and 1 μM FeCl3 for 24 h. We then analyzed the lipid profile, lipid peroxidation and Na,K-ATPase activity of plasma membranes derived from these cells. Iron overload was more frequent in men (87.5% than in women and was associated with an increase (446% in lipid peroxidation, as indicated by the amount of the thiobarbituric acid reactive substances (TBARS and an increase (327% in the Na,K-ATPase activity in the plasma membrane of erythrocytes. Erythrocytes treated with 1 μM FeCl3 for 24 h showed an increase (132% in the Na,K-ATPase activity but no change in the TBARS levels. Iron treatment also decreased the cholesterol and phospholipid content of the erythrocyte membranes and similar decreases were observed in iron overload patients. In contrast, erythrocytes treated with 0.8 mM H2O2 for 24 h showed no change in the measured parameters. These results indicate that erythrocytes from patients with iron overload exhibit higher Na,K-ATPase activity compared with normal subjects and that this effect is specifically associated with altered iron levels.

Tensile strength and the mining of black holes.

Science.gov (United States)

Brown, Adam R

2013-11-22

There are a number of important thought experiments that involve raising and lowering boxes full of radiation in the vicinity of black hole horizons. This Letter looks at the limitations placed on these thought experiments by the null energy condition, which imposes a fundamental bound on the tensile-strength-to-weight ratio of the materials involved, makes it impossible to build a box near the horizon that is wider than a single wavelength of the Hawking quanta, and puts a severe constraint on the operation of "space elevators" near black holes. In particular, it is shown that proposals for mining black holes by lowering boxes near the horizon, collecting some Hawking radiation, and dragging it out to infinity cannot proceed nearly as rapidly as has previously been claimed. As a consequence of this limitation, the boxes and all the moving parts are superfluous and black holes can be destroyed equally rapidly by threading the horizon with strings.

Effect of tungsten on tensile properties and flow behaviour of RAFM steel

Energy Technology Data Exchange (ETDEWEB)

Vanaja, J., E-mail: jvanaja@igcar.gov.in [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Laha, K.; Nandagopal, M. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Sam, Shiju [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India); Mathew, M.D.; Jayakumar, T. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Rajendra Kumar, E. [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India)

2013-02-15

Effect of tungsten in the range of 1–2 wt.% on tensile properties and flow behaviour of 9Cr–W–Ta–V Reduced Activation Ferritic–Martensitic (RAFM) steel has been investigated. The tungsten in the investigated range was found to have only minor effect on the tensile properties of the steel over the temperature range of 300–873 K and at a strain rate of 3 × 10{sup −3} s{sup −1}. The tensile flow behaviour of the RAFM steels was adequately described by the Voce’s constitutive equation. The tensile strength of the steels were predicted well from the parameters of the Voce’s constitutive equation. The Voce’s strain hardening parameter ‘n{sub v}’ was found to be quite sensitive to the tungsten content and predicted the onset of dislocation climbing process at relatively higher testing temperature with the increase in tungsten content. The equivalence between tensile and creep deformations and the influence of tungsten have been discussed.

Effect of tungsten on tensile properties and flow behaviour of RAFM steel

International Nuclear Information System (INIS)

Vanaja, J.; Laha, K.; Nandagopal, M.; Sam, Shiju; Mathew, M.D.; Jayakumar, T.; Rajendra Kumar, E.

2013-01-01

Effect of tungsten in the range of 1–2 wt.% on tensile properties and flow behaviour of 9Cr–W–Ta–V Reduced Activation Ferritic–Martensitic (RAFM) steel has been investigated. The tungsten in the investigated range was found to have only minor effect on the tensile properties of the steel over the temperature range of 300–873 K and at a strain rate of 3 × 10 −3 s −1 . The tensile flow behaviour of the RAFM steels was adequately described by the Voce’s constitutive equation. The tensile strength of the steels were predicted well from the parameters of the Voce’s constitutive equation. The Voce’s strain hardening parameter ‘n v ’ was found to be quite sensitive to the tungsten content and predicted the onset of dislocation climbing process at relatively higher testing temperature with the increase in tungsten content. The equivalence between tensile and creep deformations and the influence of tungsten have been discussed

Effect of fluoride mouthwash on tensile strength of stainless steel orthodontic archwires

Science.gov (United States)

Fatimah, D. I.; Anggani, H. S.; Ismah, N.

2017-08-01

Patients with orthodontic treatment are commonly recommended to use a fluoride mouthwash for maintaining their oral hygiene and preventing dental caries. However, fluoride may affect the characteristics of stainless steel orthodontic archwires used during treatment. The effect of fluoride mouthwash on the tensile strength of stainless steel orthodontic archwires is still unknown. The purpose of this study is to know the effect of fluoride mouthwash on the tensile strength of stainless steel orthodontic archwires. Examine the tensile strength of 0.016 inch stainless steel orthodontic archwires after immersion in 0.05%, 100 ml fluoride mouthwash for 30, 60, and 90 min. There is no statistically significant difference in the tensile strength of stainless steel orthodontic archwires after immersed in fluoride mouthwash. The p-values on immersion fluoride mouthwash for 30, 60, and 90 min consecutively are 0.790; 0.742; and 0.085 (p > 0.05). The use of fluoride mouthwash did not have an effect on the tensile strength of stainless Steel orthodontic archwires.

Transfusion-associated circulatory overload in adult, medical emergency patients with perspectives on early warning practice

DEFF Research Database (Denmark)

Gosmann, Fanny; Nørgaard, Astrid; Rasmussen, Maj-Britt

2018-01-01

of transfusion-associated dyspnoea. Vital signs and changes in dyspnoea and blood pressure were registered within the frame of the Early Warning Score, and one case was documented as being transfusion-related in the medical record. No cases were reported to the haemovigilance system. DISCUSSION: The incidence...... to the haemovigilance system. The clinical implications are discussed within the frame of the Early Warning Score. METHODS: We conducted a retrospective audit of electronic hospital medical records of patients receiving blood transfusion in a single medical emergency unit. Patients were admitted during a 6-month period...... and data on symptoms and vital signs were extracted from the records. RESULTS: Of 4,353 consecutively admitted patients, 156 patients were transfused with a total of 411 blood components. The audit identified five cases of transfusion-associated circulatory overload (incidence 3.2%) and four cases...

Work overload, burnout, and psychological ill-health symptoms: a three-wave mediation model of the employee health impairment process.

Science.gov (United States)

de Beer, Leon T; Pienaar, Jaco; Rothmann, Sebastiaan

2016-07-01

The study reported here investigated the causal relationships in the health impairment process of employee well-being, and the mediating role of burnout in the relationship between work overload and psychological ill-health symptoms, over time. The research is deemed important due to the need for longitudinal evidence of the health impairment process of employee well-being over three waves of data. A quantitative survey design was followed. Participants constituted a longitudinal sample of 370 participants, at three time points, after attrition. Descriptive statistics and structural equation modeling methods were implemented. Work overload at time one predicted burnout at time two, and burnout at time two predicted psychological ill-health symptoms at time three. Indirect effects were found between work overload time one and psychological ill-health symptoms time three via burnout time two, and also between burnout time one and psychological ill-health symptoms time three, via burnout time two. The results provided supportive evidence for an "indirect-only" mediation effect, for burnout's causal mediation mechanism in the health impairment process between work overload and psychological ill-health symptoms.

Role of iron overload-induced macrophage apoptosis in the pathogenesis of peritoneal endometriosis.

Science.gov (United States)

Pirdel, Leila; Pirdel, Manijeh

2014-06-01

This article presents an overview of the involvement of iron overload-induced nitric oxide (NO) overproduction in apoptosis of peritoneal macrophages of women with endometriosis. We have postulated that the peritoneal iron overload originated from retrograde menstruation or bleeding lesions in the ectopic endometrium, which may contribute to the development of endometriosis by a wide range of mechanisms, including oxidative damage and chronic inflammation. Excessive NO production may also be associated with impaired clearance of endometrial cells by macrophages, which promotes cell growth in the peritoneal cavity. Therefore, further research of the mechanisms and consequences of macrophage apoptosis in endometriosis helps discover novel therapeutic strategies that are designed to prevent progression of endometriosis. © 2014 Society for Reproduction and Fertility.

Reversed association between aldosterone and mortality in hemodialysis patients: Role of volume overload.

Science.gov (United States)

Hung, Szu-Chun; Tarng, Der-Cherng

2016-07-01

The role of aldosterone has expanded from its genomic effects that involve renal sodium transport to nongenomic effects such as cardiac and renal fibrosis. Elevated aldosterone levels are associated with increased mortality in the general population. However, the association is reversed in patients with end-stage renal disease on maintenance hemodialysis. We have shown that the inverse association between aldosterone and mortality in hemodialysis patients is due to the confounding effect of volume overload. Volume overload, which is prevalent in patients with chronic kidney disease, is associated with both lower aldosterone concentrations and higher mortality. Our findings support salt and water restriction and treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control. Copyright © 2016 Elsevier Inc. All rights reserved.

MISSE 6 Polymer Film Tensile Experiment

Science.gov (United States)

Miller, Sharon K. R.; Dever, Joyce A.; Banks, Bruce A.; Waters, Deborah L.; Sechkar, Edward; Kline, Sara

2010-01-01

The Polymer Film Tensile Experiment (PFTE) was flown as part of Materials International Space Station Experiment 6 (MISSE 6). The purpose of the experiment was to expose a variety of polymer films to the low Earth orbital environment under both relaxed and tension conditions. The polymers selected are those commonly used for spacecraft thermal control and those under consideration for use in spacecraft applications such as sunshields, solar sails, and inflatable and deployable structures. The dog-bone shaped samples of polymers that were flown were exposed on both the side of the MISSE 6 Passive Experiment Container (PEC) that was facing into the ram direction (receiving atomic oxygen, ultraviolet (UV) radiation, ionizing radiation, and thermal cycling) and the wake facing side (which was supposed to have experienced predominantly the same environmental effects except for atomic oxygen which was present due to reorientation of the International Space Station). A few of the tensile samples were coated with vapor deposited aluminum on the back and wired to determine the point in the flight when the tensile sample broke as recorded by a change in voltage that was stored on battery powered data loggers for post flight retrieval and analysis. The data returned on the data loggers was not usable. However, post retrieval observation and analysis of the samples was performed. This paper describes the preliminary analysis and observations of the polymers exposed on the MISSE 6 PFTE.

In-situ electron microscopy studies on the tensile deformation mechanisms in aluminium 5083 alloy

CSIR Research Space (South Africa)

Motsi, G

2014-10-01

Full Text Available In this study tensile deformation mechanisms of aluminium alloy 5083 were investigated under observations made from SEM equipped with a tensile stage. Observations during tensile testing revealed a sequence of surface deformation events...

An atomic resolution scanning tunneling microscope that applies external tensile stress and strain in an ultrahigh vacuum

International Nuclear Information System (INIS)

Fujita, D; Kitahara, M; Onishi, K; Sagisaka, K

2008-01-01

We have developed an ultrahigh vacuum scanning tunneling microscope with an in situ external stress application capability in order to determine the effects of stress and strain on surface atomistic structures. It is necessary to understand these effects because controlling them will be a key technology that will very likely be used in future nanometer-scale fabrication processes. We used our microscope to demonstrate atomic resolution imaging under external tensile stress and strain on the surfaces of wafers of Si(111) and Si(001). We also successfully observed domain redistribution induced by applying uniaxial stress at an elevated temperature on the surface of a wafer of vicinal Si(100). We confirmed that domains for which an applied tensile stress is directed along the dimer bond become less stable and shrink. This suggests that it may be feasible to fabricate single domain surfaces in a process that controls surface stress and strain

Dynamic tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix composites

International Nuclear Information System (INIS)

Chen Xuan; Li Yulong

2011-01-01

Graphical abstract: The dynamic tensile behavior of 2D C/SiC composites was experimentally investigated by means of SHTB. Both the fracture surface and bundle fracture surfaces of composites were observed. The strain rate sensitivity of in-bundle interface was concluded as the dominant contributor to the strain rate sensitivity of the tensile strength. Highlights: → The tensile strength increases with strain rate. → The tensile failure strain remains independent of strain rate. → Macro-structural morphology reveals rough fracture surface under dynamic loading. → SEM morphology reveals integrated bundle pull-out under dynamic loading. → Strain rate sensitivity of in-bundle interface leads to that of the tensile strength. - Abstract: An investigation has been undertaken to determine the dynamic and quasi-static tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix (2D-C/SiC) composites by means of the split Hopkinson tension bar and an electronic universal test machine respectively. The results indicate that the tensile strength of 2D C/SiC composites is increased at high strain rate. Furthermore, coated specimens show not only a 15% improvement in tensile strength but heightened strain rate sensitivity compared with uncoated ones. It is also shown that the tensile failure strain is strain rate insensitive and remains around 0.4%. Optical macrograph of failed specimens under dynamic loading revealed jagged fracture surfaces characterized by delamination and crack deviation, together with obvious fiber pull-out/splitting, in contrast with the smooth fracture surfaces under quasi-static loading. Scanning electron microscopy micrograph of fracture surface under dynamic loading clearly displayed integrated bundle pull-out which implies suppressed in-bundle debonding and enhanced in-bundle interfacial strengthening, in contrast with extensive in-bundle debonding under quasi-static loading. Thus we conclude that, with 2D C

Relationship between micro-porosity and tensile properties of 6063 alloy

Directory of Open Access Journals (Sweden)

Li Xiehua

2013-01-01

Full Text Available The micro-porosity is usually present in the as-cast microstructure, which decreases the tensile strength and ductility and therefore limit the application of cast aluminum parts. Although much work has been done to investigate the effects of various casting parameters on the formation of porosity in various aluminum alloys, up to now, little information has been available for the relationship between micro-porosity and tensile properties of 6063 alloy. In this study, the influences of size and area fraction of micro-porosity on the tensile properties and fracture behavior of 6063 aluminum alloy were investigated by means of tensile testing, optical microscopy (OM, and scanning electron microscopy (SEM. The tensile tests were conducted in air at 100 ℃, 200 ℃ and 300 ℃, respectively. Results show that the large micro-porosity with sizes between 100 μm and 800 μm located at the center and top of the ingot, while the small micro-porosity with size between 2 μm and 60 μm distributed at the edge and bottom of the ingot. The area fraction of micro-porosity at the center of the ingot is much bigger than that at the edge of the ingot. When tested at 100 ℃, with the decrease in the area fraction of micro-porosity from the top of the ingot to the bottom of the ingot, the ultimate tensile strength, yield strength and the elongation are increased from 82 to 99 MPa, 32 to 66 MPa and 7% to 11%, respectively. When the temperature is no more than 200 ℃, the strain hardening exponent decreases with an increase in the area fraction of micro-porosity; while the deviation disappears when the temperature reaches 300 ℃. The fracture mode of the alloy is greatly influenced by the size and area fraction of the micro-porosity.

Porosity Defect Remodeling and Tensile Analysis of Cast Steel

Directory of Open Access Journals (Sweden)

Linfeng Sun

2016-02-01

Full Text Available Tensile properties on ASTM A216 WCB cast steel with centerline porosity defect were studied with radiographic mapping and finite element remodeling technique. Non-linear elastic and plastic behaviors dependent on porosity were mathematically described by relevant equation sets. According to the ASTM E8 tensile test standard, matrix and defect specimens were machined into two categories by two types of height. After applying radiographic inspection, defect morphologies were mapped to the mid-sections of the finite element models and the porosity fraction fields had been generated with interpolation method. ABAQUS input parameters were confirmed by trial simulations to the matrix specimen and comparison with experimental outcomes. Fine agreements of the result curves between simulations and experiments could be observed, and predicted positions of the tensile fracture were found to be in accordance with the tests. Chord modulus was used to obtain the equivalent elastic stiffness because of the non-linear features. The results showed that elongation was the most influenced term to the defect cast steel, compared with elastic stiffness and yield stress. Additional visual explanations on the tensile fracture caused by void propagation were also given by the result contours at different mechanical stages, including distributions of Mises stress and plastic strain.

Performance improvement of switched-based interference mitigation for channel assignment in over-loaded small-cell networks

KAUST Repository

Gaaloul, Fakhreddine

2013-05-01

This paper proposes adequate methods to improve the interference mitigation capability of a recently investigated switched-based interference reduction scheme for single downlink channel assignment in over-loaded small-cell networks. The model assumes that the available orthogonal channels for small cells are distributed among access points in close vicinity, where each access point knows its allocated channels a priori. Each cell has a single antenna, employs the open access strategy, and can reuse its allocated channels simultaneously, while scheduling concurrent service requests. Moreover, the access points can not coordinate their transmissions, and can receive limited feedback from active users. The paper presents low-complexity schemes to identify a suitable channel to serve the scheduled user by maintaining the interference power level within a tolerable range. They attempt to either complement the switched-based scheme by minimum interference channel selection or adopt different interference thresholds on available channels, while reducing the channel examination load. The optimal thresholds for interference mitigation at the desired receive station are quantified for various performance criteria. The performance and processing load of the proposed schemes are obtained analytically, and then compared to those of the single-threshold scheme via numerical and simulation results. © 2002-2012 IEEE.

Aconitine-induced Ca2+ overload causes arrhythmia and triggers apoptosis through p38 MAPK signaling pathway in rats

International Nuclear Information System (INIS)

Sun, Gui-bo; Sun, Hong; Meng, Xiang-bao; Hu, Jin; Zhang, Qiang; Liu, Bo; Wang, Min; Xu, Hui-bo; Sun, Xiao-bo

2014-01-01

Aconitine is a major bioactive diterpenoid alkaloid with high content derived from herbal aconitum plants. Emerging evidence indicates that voltage-dependent Na + channels have pivotal roles in the cardiotoxicity of aconitine. However, no reports are available on the role of Ca 2+ in aconitine poisoning. In this study, we explored the importance of pathological Ca 2+ signaling in aconitine poisoning in vitro and in vivo. We found that Ca 2+ overload lead to accelerated beating rhythm in adult rat ventricular myocytes and caused arrhythmia in conscious freely moving rats. To investigate effects of aconitine on myocardial injury, we performed cytotoxicity assay in neonatal rat ventricular myocytes (NRVMs), as well as measured lactate dehydrogenase level in the culture medium of NRVMs and activities of serum cardiac enzymes in rats. The results showed that aconitine resulted in myocardial injury and reduced NRVMs viability dose-dependently. To confirm the pro-apoptotic effects, we performed flow cytometric detection, cardiac histology, transmission electron microscopy and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay. The results showed that aconitine stimulated apoptosis time-dependently. The expression analysis of Ca 2+ handling proteins demonstrated that aconitine promoted Ca 2+ overload through the expression regulation of Ca 2+ handling proteins. The expression analysis of apoptosis-related proteins revealed that pro-apoptotic protein expression was upregulated, and anti-apoptotic protein BCL-2 expression was downregulated. Furthermore, increased phosphorylation of MAPK family members, especially the P-P38/P38 ratio was found in cardiac tissues. Hence, our results suggest that aconitine significantly aggravates Ca 2+ overload and causes arrhythmia and finally promotes apoptotic development via phosphorylation of P38 mitogen-activated protein kinase. - Highlights: • Aconitine-induced Ca 2+ overload causes arrhythmia in rats

Geiger-mueller radiation detector with means for detecting and indicating the existence of radiation overload

International Nuclear Information System (INIS)

Kovacs, T.; Mills, A.P.; Pfeiffer, L.N.

1981-01-01

When subjected to radiation overload existing geiger-mueller counters may give an erroneously low reading, resulting in possible hazard to personnel. The instant invention discloses simple and inexpensive apparatus to remedy this dangerous shortcoming. Depending on the geometry of the detector tube, two possible failure modes have been identified, and circuitry is disclosed to detect the existence of these respective failure modes. The disclosed apparatus indicates the absence of an overload condition, in addition to signaling, by both visible and audible means, the existence of excessive radiation that might result in erroneously low reading of the geiger-mueller counter

Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

International Nuclear Information System (INIS)

Chen, C.; Zhang, F.C.; Wang, F.; Liu, H.; Yu, B.D.

2017-01-01

The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10 −4 , 5×10 −3 , and 5×10 −2 s −1 were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

Tensile behavior of laser treated Fe-Si-B metallic glass

Energy Technology Data Exchange (ETDEWEB)

Joshi, Sameehan S.; Samimi, Peyman; Ghamarian, Iman; Katakam, Shravana; Collins, Peter C.; Dahotre, Narendra B., E-mail: narendra.dahotre@unt.edu [Department of Materials Science and Engineering, University of North Texas, 1150 Union Circle 305310, Denton, Texas 76203-5017 (United States)

2015-10-28

Fe-Si-B metallic glass foils were treated with a linear laser track using a continuous wave Nd-YAG laser and its effect on the overall tensile behavior was investigated. Microstructure and phase evolutions were evaluated using X-ray diffraction, resistivity measurements, and transmission electron microscopy. Crystallization fraction was estimated via the differential scanning calorimetry technique. Metallic glass foils treated with the lower laser fluences (<0.49 J/mm{sup 2}) experienced structural relaxation, whereas higher laser fluences led to crystallization within the laser treated region. The overall tensile behavior was least impacted by structural relaxation, whereas crystallization severely reduced the ultimate tensile strength of the laser treated metallic glass foils.

An effective uniaxial tensile stress-strain relationship for prestressed concrete

International Nuclear Information System (INIS)

Chitnuyanondh, L.; Rizkalla, S.; Murray, D.W.; MacGregor, J.G.

1979-02-01

This report evaluates the direct tensile strength and an equivalent uniaxial tensile stress-strain relationship for prestressed concrete using data from specimens tested at the University of Alberta which represent segments from the wall of a containment vessel. The stress-strain relationship, when used in conjunction with the BOSOR5 program, enables prediction of the response of prestressed concrete under any biaxial combination of compressive and/or tensile stresses. Comparisons between the experimental and analytical (BOSOR5) load-strain response of the wall segments are also presented. It is concluded that the BOSOR5 program is able to predict satisfactorily the response of the wall segments and multi-layered shell structures. (author)

A cryogenic tensile testing apparatus for micro-samples cooled by miniature pulse tube cryocooler

International Nuclear Information System (INIS)

Chen, L B; Liu, S X; Gu, K X; Zhou, Y; Wang, J J

2015-01-01

This paper introduces a cryogenic tensile testing apparatus for micro-samples cooled by a miniature pulse tube cryocooler. At present, tensile tests are widely applied to measure the mechanical properties of materials; most of the cryogenic tensile testing apparatus are designed for samples with standard sizes, while for non-standard size samples, especially for microsamples, the tensile testing cannot be conducted. The general approach to cool down the specimens for tensile testing is by using of liquid nitrogen or liquid helium, which is not convenient: it is difficult to keep the temperature of the specimens at an arbitrary set point precisely, besides, in some occasions, liquid nitrogen, especially liquid helium, is not easily available. To overcome these limitations, a cryogenic tensile testing apparatus cooled by a high frequency pulse tube cryocooler has been designed, built and tested. The operating temperatures of the developed tensile testing apparatus cover from 20 K to room temperature with a controlling precision of ±10 mK. The apparatus configurations, the methods of operation and some cooling performance will be described in this paper. (paper)

Deformation of a layered half-space due to a very long tensile fault

Indian Academy of Sciences (India)

The problem of the coseismic deformation of an earth model consisting of an elastic layer of uniform thickness overlying an elastic half-space due to a very long tensile fault in the layer is solved analytically. Integral expressions for the surface displacements are obtained for a vertical tensile fault and a horizontal tensile fault.

Comparative evaluation of tensile strength of Gutta-percha cones with a herbal disinfectant.

Science.gov (United States)

Mahali, Raghunandhan Raju; Dola, Binoy; Tanikonda, Rambabu; Peddireddi, Suresh

2015-01-01

To evaluate and compare the tensile strength values and influence of taper on the tensile strength of Gutta-percha (GP) cones after disinfection with sodium hypochlorite (SH) and Aloe vera gel (AV). Sixty GP cones of size 110, 2% taper, 60 GP cones F3 ProTaper, and 60 GP of size 30, 6% taper were obtained from sealed packs as three different groups. Experimental groups were disinfected with 5.25% SH and 90% AV gel except the control group. Tensile strengths of GP were measured using the universal testing machine. The mean tensile strength values for Group IA, IIA and IIIA are 11.8 MPa, 8.69 MPa, and 9.24 MPa, respectively. Results were subjected to statistical analysis one-way analysis of variance test and Tukey post-hoc test. 5.25% SH solutions decreased the tensile strength of GP cones whereas with 90% AV gel it was not significantly altered. Ninety percent Aloe vera gel as a disinfectant does not alter the tensile strength of GP cones.

The tensile deformation behavior of nuclear-grade isotropic graphite posterior to hydrostatic loading

International Nuclear Information System (INIS)

Yoda, S.; Eto, M.

1983-01-01

The effects of prehydrostatic loading on microstructural changes and tensile deformation behavior of nuclear-grade isotropic graphite have been examined. Scanning electron micrographs show that formation of microcracks associated with delamination between basal planes occurs under hydrostatic loading. Hydrostatic loading on specimens results in the decrease in tensile strength and increase in residual strain generated by the applied tensile stress at various levels, indicating that the graphite material is weakened by hydrostatic loading. A relationship between residual strain and applied tensile stress for graphite hydrostatically-loaded at several pressure levels can be approximately expressed as element of= (AP + B) sigmasup(n) over a wide range hydrostatic pressure, where element of, P and sigma denote residual strain, hydrostatic pressure and applied tensile stress, respectively; A, B and n are constant. The effects of prehydrostatic loading on the tensile stress-strain behavior of the graphite were examined in more detail. The ratio of stress after hydrostatic loading to that before hydrostatic loading on the stress-strain relationship remains almost unchanged irrespective of strain. (orig.)

Microscopic Characterization of Tensile and Shear Fracturing in Progressive Failure in Marble

Science.gov (United States)

Cheng, Yi; Wong, Louis Ngai Yuen

2018-01-01

Compression-induced tensile and shear fractures were reported to be the two fundamental fracture types in rock fracturing tests. This study investigates such tensile and shear fracturing process in marble specimens containing two different flaw configurations. Observations first reveal that the development of a tensile fracture is distinct from shear fracture with respect to their nucleation, propagation, and eventual formation in macroscale. Second, transgranular cracks and grain-scale spallings become increasingly abundant in shear fractures as loading increases, which is almost not observed in tensile fractures. Third, one or some dominant extensional microcracks are commonly observed in the center of tensile fractures, while such development of microcracks is almost absent in shear fractures. Microcracks are generally of a length comparable to grain size and distribute uniformly within the damage zone of the shear fracture. Fourth, the width of densely damaged zone in the shear fracture is nearly 10 times of that in the tensile fracture. Quantitative measurement on microcrack density suggests that (1) microcrack density in tensile and shear fractures display distinct characteristics with increasing loading, (2) transgranular crack density in the shear fracture decreases logarithmically with the distance away from the shear fracture center, and (3) whatever the fracture type, the anisotropy can only be observed for transgranular cracks with a large density, which partially explains why microcrack anisotropy usually tends to be unobvious until approaching peak stress in specimens undergoing brittle failure. Microcracking characteristics observed in this work likely shed light to some phenomena and conclusions generalized in seismological studies.

Tensile Strength of the Eggshell Membranes

Czech Academy of Sciences Publication Activity Database

Strnková, J.; Nedomová, Š.; Kumbár, V.; Trnka, Jan

2016-01-01

Roč. 64, č. 1 (2016), s. 159-164 ISSN 1211-8516 Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : eggshell membrane * tesile test * loading rate * tensile strength * fracture strain Subject RIV: GM - Food Processing

Iron overload across the spectrum of non-transfusion-dependent thalassaemias: role of erythropoiesis, splenectomy and transfusions.

Science.gov (United States)

Porter, John B; Cappellini, Maria Domenica; Kattamis, Antonis; Viprakasit, Vip; Musallam, Khaled M; Zhu, Zewen; Taher, Ali T

2017-01-01

Non-transfusion-dependent thalassaemias (NTDT) encompass a spectrum of anaemias rarely requiring blood transfusions. Increased iron absorption, driven by hepcidin suppression secondary to erythron expansion, initially causes intrahepatic iron overload. We examined iron metabolism biomarkers in 166 NTDT patients with β thalassaemia intermedia (n = 95), haemoglobin (Hb) E/β thalassaemia (n = 49) and Hb H syndromes (n = 22). Liver iron concentration (LIC), serum ferritin (SF), transferrin saturation (TfSat) and non-transferrin-bound iron (NTBI) were elevated and correlated across diagnostic subgroups. NTBI correlated with soluble transferrin receptor (sTfR), labile plasma iron (LPI) and nucleated red blood cells (NRBCs), with elevations generally confined to previously transfused patients. Splenectomised patients had higher NTBI, TfSat, NRBCs and SF relative to LIC, than non-splenectomised patients. LPI elevations were confined to patients with saturated transferrin. Erythron expansion biomarkers (sTfR, growth differentiation factor-15, NRBCs) correlated with each other and with iron overload biomarkers, particularly in Hb H patients. Plasma hepcidin was similar across subgroups, increased with >20 prior transfusions, and correlated inversely with TfSat, NTBI, LPI and NRBCs. Hepcidin/SF ratios were low, consistent with hepcidin suppression relative to iron overload. Increased NTBI and, by implication, risk of extra-hepatic iron distribution are more likely in previously transfused, splenectomised and iron-overloaded NTDT patients with TfSat >70%. © 2016 The Authors. British Journal of Haematology published by John Wiley & Sons Ltd.

In vitro tensile strength of luting cements on metallic substrate.

Science.gov (United States)

Orsi, Iara A; Varoli, Fernando K; Pieroni, Carlos H P; Ferreira, Marly C C G; Borie, Eduardo

2014-01-01

The aim of this study was to determine the tensile strength of crowns cemented on metallic substrate with four different types of luting agents. Twenty human maxillary molars with similar diameters were selected and prepared to receive metallic core castings (Cu-Al). After cementation and preparation the cores were measured and the area of crown's portion was calculated. The teeth were divided into four groups based on the luting agent used to cement the crowns: zinc phosphate cement; glass ionomer cement; resin cement Rely X; and resin cement Panavia F. The teeth with the crowns cemented were subjected to thermocycling and later to the tensile strength test using universal testing machine with a load cell of 200 kgf and a crosshead speed of 0.5 mm/min. The load required to dislodge the crowns was recorded and converted to MPa/mm(2). Data were subjected to Kruskal-Wallis analysis with a significance level of 1%. Panavia F showed significantly higher retention in core casts (3.067 MPa/mm(2)), when compared with the other cements. Rely X showed a mean retention value of 1.877 MPa/mm(2) and the zinc phosphate cement with 1.155 MPa/mm(2). Glass ionomer cement (0.884 MPa/mm(2)) exhibited the lowest tensile strength value. Crowns cemented with Panavia F on cast metallic posts and cores presented higher tensile strength. The glass ionomer cement showed the lowest tensile strength among all the cements studied.

Mobility enhancement in tensile-strained Ge grown on InAlP metamorphic templates

International Nuclear Information System (INIS)

Wang, Kai; Gong, Qian; Zhou, Haifei; Kang, Chuanzhen; Yan, Jinyi; Liu, Qingbo; Wang, Shumin

2014-01-01

We investigated the growth of tensile-strained Ge on InAlP metamorphic templates by gas source molecular beam epitaxy. Good control of biaxial tensile strain in the Ge layer was demonstrated in the range of 0.5–2.0% by adjusting the In content of the metamorphic template. It was found that the growth of Ge was layer-by-layer (2D) even under high tensile strain of 2.0%, resulting in a smooth surface with roughness less than 1.5 nm. Hall results showed that the electron mobility of Ge increased monotonically with tensile strain.

An Investigation of Data Overload in Team-Based Distributed Cognition Systems

Science.gov (United States)

Hellar, David Benjamin

2009-01-01

The modern military command center is a hybrid system of computer automated surveillance and human oriented decision making. In these distributed cognition systems, data overload refers simultaneously to the glut of raw data processed by information technology systems and the dearth of actionable knowledge useful to human decision makers.…

Microstructure and tensile properties of high strength duplex ferrite-martensite (DFM) steels

International Nuclear Information System (INIS)

Chakraborti, P.C.; Mitra, M.K.

2007-01-01

Duplex ferrite-martensite (DFM) steels containing 38-80% martensite of varying morphologies were developed by batch intercritical annealing of a commercial variety vanadium bearing 0.2% C-Mn steel at different temperatures. Microstructures before intercritical annealing were found to control the morphological distribution of the phase constituents of the developed DFM steels. Tensile test results revealed best strength-ductility combination for finely distributed lamellar ferrite-martensite phase aggregate containing ∼60% martensite developed from a prior martensitic structure. Taking consideration of the modified law of mechanical mixture the experimental tensile strength data of the developed DFM steels has been formulated with some success and very good estimation for tensile strengths of pure ferrite and low carbon martensite has been made from tensile strength data of DFM steels

Tensile and Flexural Test on Kenaf Hybrid Composites

Science.gov (United States)

Salleh, Z.; Yunus, S.; Masdek, N. R. N. M.; Taib, Y. M.; Azhar, I. I. S.; Hyie, K. M.

2018-03-01

The widely use of synthetic materials like carbon and fiberglass in various industries such as automotive and aircraft has lead to human health and environment problems. Therefore, the use of natural fibres such as kenaf has received higher attention as reinforcement. Kenaf or the scientific name is Hibiscus Cannabinus. L is one of the group of Malvecea plant which in the early days, the application of kenaf served only rope and canvas. However, it has more advantages than synthetic materials such as; widely availaible, renewable, lightweight, non-abbrasiveness during processing, high specific strength, free from health hazard and biodegradeable. This study was carried out to investigate the effects of different arrangement of kenaf and fiberglass composites on Young’s Modulus. The material composite was hardened with polyester resin and their properties was characterized. The tensile and the flexural properties is determined using an Instron universal tensile testing machine and carried out by following ASTM D3039 for tensile and ASTM D790 for a flexural test. The experimental program was designed to correlate the flexural and tensile Young’s Modulus of kenaf and fiberglass composite under the same load condition but different arrangement of kenaf and fiberglass on the mold . The resistance to change in shape was described by the behavior and characteristic of the composite materials. The stiffness or the elastic modulus of the composite material was determined at the end of the experiment. The results obtained show that the [±90FG/0/90/90/0/±90FG] kenaf/fiberglass composite arrangement has the highest elastic value.

Tensile properties in zircaloy-II after 590 MeV proton irradiation

Energy Technology Data Exchange (ETDEWEB)

Dai, Y. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Victoria, M. [Ecole Polytechnique Federale, Lausanne (Switzerland)

1997-09-01

In order to investigate radiation potential damage effects on the SINQ Zircaloy-rod target, four Zircaloy-II tensile specimens were irradiated at the PIREX facility in 1995 to a proton fluence about 3x10{sup 20} p/cm{sup 2}, which produced a radiation damage of about 1.35 displacements per atom (dpa). Tensile test results show that, although there is some reduction in tensile elongation, substantial ductility still exists after such irradiation dose which corresponds to the peak value obtained in the SINQ target for 23 days operation at 1 mA. (author) 1 fig., 2 refs.

Current concepts on ventricular fibrillation: A Vicious Circle of Cardiomyocyte Calcium Overload in the Initiation, Maintenance, and Termination of Ventricular Fibrillation

Directory of Open Access Journals (Sweden)

Christian E. Zaugg

2004-04-01

Full Text Available Based on recent experimental studies, this review article introduces the novel concept that cardiomyocyte Ca2+ and ventricular fibrillation (VF are mutually related, forming a self-maintaining vicious circle in the initiation, maintenance, and termination of VF. On the one hand, elevated myocyte Ca2+ can cause delayed afterdepolarizations, triggered activity, and consequently life-threatening ventricular tachyarrhythmias in various pathological conditions such as digitalis toxicity, myocardial ischemia, or heart failure. On the other hand, VF itself directly and rapidly causes progressive myocyte Ca2+ overload that maintains VF and renders termination of VF increasingly difficult. Accordingly, energy levels for successful electrical defibrillation (defibrillation thresholds increase as both VF and Ca2+ overload progress. Furthermore, VF-induced myocyte Ca2+ overload can promote re-induction of VF after defibrillation and/or postfibrillatory myocardial dysfunction (postresuscitation stunning due to reduced myofilament Ca2+ responsiveness. The probability of these adverse events is best reduced by early detection and rapid termination of VF to prevent or limit Ca2+ overload. Early additional therapy targeting transsarcolemmal Ca2+ entry, particularly during the first 2 min of VF, may partially prevent myocyte Ca2+ overload and thus, increase the likelihood of successful defibrillation as well as prevent postfibrillatory myocardial dysfunction.

Effect of N+Cr alloying on the microstructures and tensile properties of Hadfield steel

Energy Technology Data Exchange (ETDEWEB)

Chen, C. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, F.C., E-mail: zfc@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004 (China); Wang, F. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, H.; Yu, B.D. [China Railway Shanhaiguan Bridge Group Co. LTD, Qinhuangdao 066205 (China)

2017-01-02

The microstructures and tensile behaviors of traditional Hadfield steel, named Mn12 steel, and Hadfield steel alloyed with N+Cr, named Mn12CrN steel were studied through optical microscopy, transmission electron microscopy, and scanning electron microscopy, among others. Three different tensile strain rates of 5×10{sup −4}, 5×10{sup −3}, and 5×10{sup −2} s{sup −1} were selected in the tensile test. The deformation microstructures and fracture morphologies of the two steels after fracture in the tensile test were observed to analyze the tensile deformation response to different tensile strain rates. Results showed that the grain size of Mn12CrN steel was evidently refined after alloying with N+Cr. The grain would not become abnormally coarse even with increasing austenitizing temperature. During tensile deformation, the strength and plasticity of Mn12CrN steel were superior to those of Mn12 steel at the same strain rate. With increasing the strain rate, the changes in strength and plasticity of Mn12CrN steel were less sensitive to tensile strain rate compared with Mn12 steel. The effects of grain refinement and N+Cr alloying on dynamic strain aging and deformation twining behaviors were responsible for this lack of sensitivity to strain rate.

Development of Tensile Softening Model for Plain Concrete

Energy Technology Data Exchange (ETDEWEB)

Lee, S.K.; Song, Y.C. [Korea Electric Power Research Institute, Taejon (Korea)

2002-07-01

Large-scale direct tensile softenng tests using plate concrete specimens(4000, 5000psi) with notch were performed under uniaxial stress. There were presented the basic physical properties and the complete load-CMOD(Crack Mouth Opening Displacement) curves for them And them the fracture energy was evaluated using the complete load-CMOD curves respectively, and there was presents optimal tensile softening model which is modified by a little revision of an existing one. Therefore, here provided the real verification data through the tests for developing other nonlinear concrete finite element models. (author). 32 refs., 38 figs., 4 tabs.

Ply Tensile Properties of Banana Stem and Banana Bunch Fibres ...

African Journals Online (AJOL)

Natural rubber composite lamina reinforced with BSF which were treated with a mixture of NaOH and Na2SO3 had a superior tensile strength of 4.0 MPa and Young's modulus of 147.34MPa over the untreated BSF with tensile strength and Young's Modulus of 3.7MPa and 84.30MPa respectively. Both the treated and ...

Guidelines to come to minimized tensile strength loss upon cellulase application

NARCIS (Netherlands)

Lenting, H.B.M.; Lenting, H.B.M.; Warmoeskerken, Marinus

2001-01-01

Application of cellulase technology in the textile production process often results in a certain loss of tensile strength along with the desired performance. In this paper guidelines are given how to come to minimization or even prevention of tensile strength loss. Part of the considerations is

Tensile behavior of borated stainless steels

International Nuclear Information System (INIS)

Stephens, J.J. Jr.; Sorenson, K.B.

1991-01-01

Borated stainless steel tensile testing is being conducted at Sandia National Laboratories (SNL). The goal of the test program is to provide data to support a code case inquiry to the ASME Boiler and Pressure Vessel Code, Section III. The adoption by ASME facilitates a material's qualification for structural use in transport cask applications. For transport cask basket applications, the potential advantage to using borated stainless steel arises from the fact that the structural and criticality control functions can be combined into one material. This can result in a decrease in net section thickness of the basket web (increased payload capacity) and eliminates the fabrication process and cost of attaching a discrete boron poison material to the basket web. In addition, adding borate stainless steel to the inventory of acceptable structural material provides the Department of Energy (DOE) and its cask contractors an alternative to current proposed materials which have not been qualified for structural service. The test program at SNL involves procuring material, machining test specimens, and conducting the tensile tests. From test measurements obtained so far, general trends indicate that tensile properties (yield strength and ultimate strength) increase with boron content and are in all cases superior to the minimum required properties established in A-240, Type 304, a typical grade of austenitic stainless steel. Therefore, in a designed basket, web thicknesses using borated stainless steel would be comparable to or thinner tan an equivalent basket manufactured from a typical stainless steel without boron additions. General trends from test results indicate that ductilities decrease with increasing boron content

Evaluation of a miniature magnetostrictive actuator using Galfenol under tensile stress

International Nuclear Information System (INIS)

Ueno, Toshiyuki; Miura, Hidemitsu; Yamada, Sotoshi

2011-01-01

We are, at present, developing miniature actuators using an iron-gallium alloy (Galfenol). Galfenol is an iron-based magnetostrictive material with magnetostriction exceeding 200 ppm, Young's modulus of 70 GPa and a high relative permeability (>100). The advantages of an actuator using this material are capability of miniaturization, stability against external force, low voltage driving and high power. In this study, a miniature vibrator using an E core of Galfenol under tensile stress up to 20 MPa was investigated. The vibrator did not fracture and maintained the magnetostriction even under a high tensile stress. In addition, the resonance frequency, unchanged under the tensile stress, was lower than the cutoff frequency, hence the vibrator can be driven with a low voltage even in resonance driving. The temperature rise in resonance driving was low and creep was not observed in resonance driving under tensile stress. The vibrator will be applicable in flat panel or bone conductive speakers.

Evaluation of a miniature magnetostrictive actuator using Galfenol under tensile stress

Science.gov (United States)

Ueno, Toshiyuki; Miura, Hidemitsu; Yamada, Sotoshi

2011-02-01

We are, at present, developing miniature actuators using an iron-gallium alloy (Galfenol). Galfenol is an iron-based magnetostrictive material with magnetostriction exceeding 200 ppm, Young's modulus of 70 GPa and a high relative permeability (>100). The advantages of an actuator using this material are capability of miniaturization, stability against external force, low voltage driving and high power. In this study, a miniature vibrator using an E core of Galfenol under tensile stress up to 20 MPa was investigated. The vibrator did not fracture and maintained the magnetostriction even under a high tensile stress. In addition, the resonance frequency, unchanged under the tensile stress, was lower than the cutoff frequency, hence the vibrator can be driven with a low voltage even in resonance driving. The temperature rise in resonance driving was low and creep was not observed in resonance driving under tensile stress. The vibrator will be applicable in flat panel or bone conductive speakers.

A technique to remove the tensile instability in weakly compressible SPH

Science.gov (United States)

Xu, Xiaoyang; Yu, Peng

2018-01-01

When smoothed particle hydrodynamics (SPH) is directly applied for the numerical simulations of transient viscoelastic free surface flows, a numerical problem called tensile instability arises. In this paper, we develop an optimized particle shifting technique to remove the tensile instability in SPH. The basic equations governing free surface flow of an Oldroyd-B fluid are considered, and approximated by an improved SPH scheme. This includes the implementations of the correction of kernel gradient and the introduction of Rusanov flux into the continuity equation. To verify the effectiveness of the optimized particle shifting technique in removing the tensile instability, the impacting drop, the injection molding of a C-shaped cavity, and the extrudate swell, are conducted. The numerical results obtained are compared with those simulated by other numerical methods. A comparison among different numerical techniques (e.g., the artificial stress) to remove the tensile instability is further performed. All numerical results agree well with the available data.

High-rate tensile behavior of steel fiber-reinforced concrete for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Jin; Park, Gi-Joon [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Kim, Dong Joo, E-mail: djkim75@sejong.ac.kr [Department of Civil and Environmental Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Moon, Jae Heum; Lee, Jang Hwa [Korea Institute of Construction Technology, 2311 Daewha-Dong, Ilsan-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea, Republic of)

2014-01-15

Highlights: • The final goal is to develop a fiber reinforced concrete for containment buildings. • High rate tensile behavior of FRC was investigated. • Strain energy frame impact machine was used for tensile impact tests. • Different rate sensitivity of FRC was found according to the type fiber. • Adding more fibers by increasing S/a is positive for higher impact resistance of FRC. -- Abstract: The direct tensile behavior of fiber-reinforced concrete (FRC) at high strain rates were investigated for their potential to enhance the resistance of the containment building of nuclear power plants (NPPs) against aircraft impact. Two types of deformed steel, hooked (H) and twisted (T) fibers were employed. To improve the tensile resistance of FRCs even at higher rates by adding more fibers, the mixture of concrete was modified by either increasing the sand-to-coarse aggregate ratio or decreasing the maximum size of coarse aggregate. All FRC specimens produced two to six times greater tensile strength and one to five times higher toughness at high strain rates (4–53 s{sup −1}) than those at a static rate (0.000167 s{sup −1}). T-fiber generally produced higher tensile strength and toughness than H-fiber at both static and high rates. Although both fibers showed favorable rate sensitivity, T-fiber produced much greater enhancement, at higher strain rates, in tensile strength and slightly lower enhancement in toughness than H-fiber. As the maximum size of coarse aggregate decreased from 19 to 5 mm, the tensile strength and toughness of FRCs with T-fibers noticeably increased at both static and high strain rates.

Tensile Strength of GFRP Reinforcing Bars with Hollow Section

Directory of Open Access Journals (Sweden)

Young-Jun You

2015-01-01

Full Text Available Fiber reinforced polymer (FRP has been proposed to replace steel as a reinforcing bar (rebar due to its high tensile strength and noncorrosive material properties. One obstacle in using FRP rebars is high price. Generally FRP is more expensive than conventional steel rebar. There are mainly two ways to reduce the cost. For example, one is making the price of each composition cost of FRP rebar (e.g., fibers, resin, etc. lower than steel rebar. Another is making an optimized design for cross section and reducing the material cost. The former approach is not easy because the steel price is very low in comparison with component materials of FRP. For the latter approach, the cost could be cut down by reducing the material cost. Therefore, an idea of making hollow section over the cross section of FRP rebar was proposed in this study by optimizing the cross section design with acceptable tensile performance in comparison with steel rebar. In this study, glass reinforced polymer (GFRP rebars with hollow section and 19 mm of outer diameter were manufactured and tested to evaluate the tensile performance in accordance with the hollowness ratio. From the test results, it was observed that the tensile strength decreased almost linearly with increase of hollowness ratio and the elastic modulus decreased nonlinearly.

Comparison of interfacial properties of electrodeposited single carbon fiber/epoxy composites using tensile and compressive fragmentation tests and acoustic emission.

Science.gov (United States)

Park, Joung-Man; Kim, Jin-Won; Yoon, Dong-Jin

2002-03-01

Interfacial and microfailure properties of carbon fiber/epoxy composites were evaluated using both tensile fragmentation and compressive Broutman tests with an aid of acoustic emission (AE). A monomeric and two polymeric coupling agents were applied via the electrodeposition (ED) and the dipping applications. A monomeric and a polymeric coupling agent showed significant and comparable improvements in interfacial shear strength (IFSS) compared to the untreated case under both tensile and compressive tests. Typical microfailure modes including cone-shaped fiber break, matrix cracking, and partial interlayer failure were observed under tension, whereas the diagonal slipped failure at both ends of the fractured fiber exhibited under compression. Adsorption and shear displacement mechanisms at the interface were described in terms of electrical attraction and primary and secondary bonding forces. For both the untreated and the treated cases AE distributions were separated well in tension, whereas AE distributions were rather closely overlapped in compression. It might be because of the difference in molecular failure energies and failure mechanisms between tension and compression. The maximum AE voltage for the waveform of either carbon or large-diameter basalt fiber breakages in tension exhibited much larger than that in compression. AE could provide more likely the quantitative information on the interfacial adhesion and microfailure.

Cardiac-specific overexpression of aldehyde dehydrogenase 2 exacerbates cardiac remodeling in response to pressure overload

Directory of Open Access Journals (Sweden)

Sujith Dassanayaka

2018-07-01

Full Text Available Pathological cardiac remodeling during heart failure is associated with higher levels of lipid peroxidation products and lower abundance of several aldehyde detoxification enzymes, including aldehyde dehydrogenase 2 (ALDH2. An emerging idea that could explain these findings concerns the role of electrophilic species in redox signaling, which may be important for adaptive responses to stress or injury. The purpose of this study was to determine whether genetically increasing ALDH2 activity affects pressure overload-induced cardiac dysfunction. Mice subjected to transverse aortic constriction (TAC for 12 weeks developed myocardial hypertrophy and cardiac dysfunction, which were associated with diminished ALDH2 expression and activity. Cardiac-specific expression of the human ALDH2 gene in mice augmented myocardial ALDH2 activity but did not improve cardiac function in response to pressure overload. After 12 weeks of TAC, ALDH2 transgenic mice had larger hearts than their wild-type littermates and lower capillary density. These findings show that overexpression of ALDH2 augments the hypertrophic response to pressure overload and imply that downregulation of ALDH2 may be an adaptive response to certain forms of cardiac pathology. Keywords: Heart failure, Hypertrophy, Oxidative stress, Aldehydes, Cardiac remodeling, Hormesis

The Influence of Domestic Overload on the Association between Job Strain and Ambulatory Blood Pressure among Female Nursing Workers

Directory of Open Access Journals (Sweden)

Luciana Fernandes Portela

2013-11-01

Full Text Available Evidence suggests that the workplace plays an important etiologic role in blood pressure (BP alterations. Associations in female samples are controversial, and the domestic environment is hypothesized to be an important factor in this relationship. This study assessed the association between job strain and BP within a sample of female nursing workers, considering the potential role of domestic overload. A cross-sectional study was conducted in a group of 175 daytime workers who wore an ambulatory BP monitor for 24 h during a working day. Mean systolic and diastolic BP were calculated. Job strain was evaluated using the Demand-Control Model. Domestic overload was based on the level of responsibility in relation to four household tasks and on the number of beneficiaries. After adjustments no significant association between high job strain and BP was detected. Stratified analyses revealed that women exposed to both domestic overload and high job strain had higher systolic BP at home. These results indicate a possible interaction between domestic overload and job strain on BP levels and revealed the importance of domestic work, which is rarely considered in studies of female workers.

Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

Energy Technology Data Exchange (ETDEWEB)