WorldWideScience

Sample records for load index pli

  1. Evaluation And Characterization Of Trace Metals Contamination In The Surface Sediment Using Pollution Load Index PLI And Geo-Accumulation Index Igeo Of Ona River Western Nigeria

    Directory of Open Access Journals (Sweden)

    Andem

    2015-01-01

    Full Text Available Abstract Evaluation and Characterization of Trace Metal Contamination in the Surface Sediment Using Pollution Load Index PLI and Geo-accumulation Index Igeo Index of Ona River was conducted for six months. From the result of this study the mean values of lead ranged between 0.004 mgkg and 0.330 mgkg while the mean iron was highest 5.05 mgkg in station 4 and lowest 2.26 mgkg in station 5. The mean chromium value ranged from 0.007 mgkg station 1 and 2 to 0.021 mgkg station 3 and 4. The mean copper was highest 3.97 mgkg in station 1 and lowest 0.008 mgkg in station 2. Analysis of variance ANOVA revealed the same trend in spatial variation of these heavy metals. There was a significant difference P 0.05 in lead chromium and copper among the study sampling stations and insignificant difference P0.05 in iron among the study sampling station. The PLI values recorded for all the stations were below 1. Thus the sediment of the study stretch that Ona River is unpolluted. The Igeo values for chromium and iron fall in class 0 in all the five sampling stations indicating that there is no pollution from these metals in the Ona River sediments lead fall in class 3 in station 4indicating moderately to heavily contaminated condition and class 0in station 1 2 3 and 5 and copper fall in class 3 in station 4 and 5 in class 6 in station 3 indicating extremely contaminated condition. The Igeo values were consistent with those derived for PLI. All trace metals had concentrations below the EPA regulatory limits for sediment except iron. From the results of this study sediment quality reflects the impacts of anthropogenic activities on quality of the river. However the continuous build-up of the metal contaminants can be checked if relevant government agencies ensure strict compliant of industrial standards which stipulate treatment of industrial waste before discharging such contaminated effluentswastes into River. Therefore perpetual assessment is highly recommended

  2. Damage Behaviors and Compressive Strength of Toughened CFRP Laminates with Thin Plies Subjected to Transverse Impact Loadings

    Science.gov (United States)

    Yokozeki, Tomohiro; Aoki, Yuichiro; Ogasawara, Toshio

    It has been recognized that damage resistance and strength properties of CFRP laminates can be improved by using thin-ply prepregs. This study investigates the damage behaviors and compressive strength of CFRP laminates using thin-ply and standard prepregs subjected to out-of-plane impact loadings. CFRP laminates used for the evaluation are prepared using the standard prepregs, thin-ply prepregs, and combinations of the both. Weight-drop impact test and post-impact compression test of quasi-isotropic laminates are performed. It is shown that the damage behaviors are different between the thin-ply and the standard laminates, and the compression-after-impact strength is improved by using thin-ply prepregs. Effects of the use of thin-ply prepregs and the layout of thin-ply layers on the damage behaviors and compression-after-impact properties are discussed based on the experimental results.

  3. Estimate of compressive strength of an unidirectional composite lamina using cross-ply and angle-ply laminates

    Directory of Open Access Journals (Sweden)

    M. Scafè

    2014-07-01

    Full Text Available In this work has been estimated the compressive strength of a unidirectional lamina of a carbon/epoxy composite material, using the cross-ply and angle-ply laminates. Over the years various methods have been developed to deduce compressive properties of composite materials reinforced with long fibres. Each of these methods is characterized by a specific way of applying load to the specimen. The method chosen to perform the compression tests is the Wyoming Combined Loading Compression (CLC Test Method, described in ASTM D 6641 / D 6641M-09. This method presents many advantages, especially: the load application on the specimen (end load combined with shear load, the reproducibility of measurements and the experimental equipment quite simplified. Six different laminates were tested in compressive tests. They were realized by the same unidirectional prepreg, but with different stacking sequences: two cross-ply [0/90]ns, two angle-ply [0/90/±45]ns and two unidirectional laminates [0]ns and [90]ns. The estimate of the compressive strength of the unidirectional laminates at 0°, was done by an indirect analytical method, developed from the classical lamination theory, and which uses a multiplicative parameter known as Back-out Factor (BF. The BF is determined by using the experimental values obtained from compression tests.

  4. Pollution load index for heavy metals in Mian-Ab plain soil, Khuzestan, Iran.

    Science.gov (United States)

    Jorfi, Sahand; Maleki, Rohangiz; Jaafarzadeh, Neemat; Ahmadi, Mehdi

    2017-12-01

    Soil pollution by heavy metals is a major concern in agricultural area. Potential impact of heavy metals in agricultural soil on human health by accumulating in food chain demonstrated elsewhere. In this regard Mian-Ab plain as a major agricultural site of Khuzestan province considered for Arsenic, cadmium and lead concentration as the main potential toxic pollutants in soil. 50 topsoil samples were collected and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Also Contamination level of selected heavy metals in Mian-Ab Plain, was assessed by single factor contaminant index (PI) and pollution load index (PLI). Results show mean concentration of arsenic, cadmium and lead were 2.52, 0.30 and 7.21 mg kg -1 . Base on PLI results 12 point (24%) of the studied area show moderately polluted and 38 point (76%) show unpolluted area.

  5. Estimate of compressive strength of an unidirectional composite lamina using cross-ply and angle-ply laminates

    OpenAIRE

    Scafè, M.; Raiteri, G.; Brentari, A.; Dlacic, R.; Troiani, E.; Falaschetti, M. P.; Besseghini, E.

    2014-01-01

    In this work has been estimated the compressive strength of a unidirectional lamina of a carbon/epoxy composite material, using the cross-ply and angle-ply laminates. Over the years various methods have been developed to deduce compressive properties of composite materials reinforced with long fibres. Each of these methods is characterized by a specific way of applying load to the specimen. The method chosen to perform the compression tests is the Wyoming Combined Loading Compr...

  6. First-Ply-Failure Performance of Composite Clamped Spherical Shells

    Science.gov (United States)

    Ghosh, A.; Chakravorty, D.

    2018-05-01

    The failure aspects of composites are available for plates, but studies of the literature on shells unveils that similar reports on them are very limited in number. The aim of this work was to investigate the first-ply-failure of industrially and aesthetically important spherical shells under uniform loadings. Apart from solving benchmark problems, numerical experiments were carried out with different variations of their parameters to obtain the first-ply-failure stresses by using the finite-element method. The load was increased in steps, and the lamina strains and stresses were put into well-established failure criteria to evaluate their first-ply-failure stress, the failed ply, the point of initiation of failure, and failure modes and tendencies. The results obtained are analyzed to extract the points of engineering significance.

  7. Viscoelastic damped response of cross-ply laminated shallow spherical shells subjected to various impulsive loads

    Science.gov (United States)

    Şahan, Mehmet Fatih

    2017-11-01

    In this paper, the viscoelastic damped response of cross-ply laminated shallow spherical shells is investigated numerically in a transformed Laplace space. In the proposed approach, the governing differential equations of cross-ply laminated shallow spherical shell are derived using the dynamic version of the principle of virtual displacements. Following this, the Laplace transform is employed in the transient analysis of viscoelastic laminated shell problem. Also, damping can be incorporated with ease in the transformed domain. The transformed time-independent equations in spatial coordinate are solved numerically by Gauss elimination. Numerical inverse transformation of the results into the real domain are operated by the modified Durbin transform method. Verification of the presented method is carried out by comparing the results with those obtained by the Newmark method and ANSYS finite element software. Furthermore, the developed solution approach is applied to problems with several impulsive loads. The novelty of the present study lies in the fact that a combination of the Navier method and Laplace transform is employed in the analysis of cross-ply laminated shallow spherical viscoelastic shells. The numerical sample results have proved that the presented method constitutes a highly accurate and efficient solution, which can be easily applied to the laminated viscoelastic shell problems.

  8. Modeling of Nonlinear Mechanical Response in CFRP Angle-Ply Laminates

    Science.gov (United States)

    Ogihara, Shinji

    2014-03-01

    It is known that the failure process in angle-ply laminate involves matrix cracking and delamination and that they exhibit nonlinear stress-strain relation. There may be a significant effect of the constituent blocked ply thickness on the mechanical behavior of angle-ply laminates. These days, thin prepregs whose thickness is, for example 50 micron, are developed and commercially available. Therefore, we can design wide variety of laminates with various constituent ply thicknesses. In this study, effects of constituent ply thickness on the nonlinear mechanical behavior and the damage behavior of CFRP angle-ply laminates are investigated experimentally. Based on the experimental results, the mechanical response in CFRP angle-ply laminates is modeled by using the finite strain viscoplasticity model. We evaluated the mechanical behavior and damage behavior in CFRP angle-ply laminates with different constituent ply thickness under tensile loading experimentally. It was found that as the constituent ply thickness decreases, the strength and failure strain increases. We also observed difference in damage behavior. The preliminary results of finite strain viscoplasticity model considering the damage effect for laminated composites are shown. A qualitative agreement is obtained.

  9. Transverse Compression Response of a Multi-Ply Kevlar Vest

    National Research Council Canada - National Science Library

    Raftenberg, Martin N; Scheidler, Michael J; Moy, Paul

    2004-01-01

    Each of the two 38 X 38-cm square panels, consisting of 28 plies of plain-woven 600-denier Kevlar KM2 and a Cordura case, was loaded in quasistatic, transverse compression by means of an Instron machine...

  10. Enhancement of Gas Barrier Properties of CFRP Laminates Fabricated Using Thin-Ply Prepregs

    Science.gov (United States)

    横関, 智弘; 高木, 智宏; 吉村, 彰記; Ogasawara, Toshio; 荻原, 慎二

    Composite laminates manufactured using thin-ply prepregs are expected to have superior resistance properties against microcracking compared to those using standard prepregs. In this study, comparative investigations are presented on the microcrack accumulation and gas leakage characteristics of CFRP laminates fabricated using standard and thin-ply prepregs, consisting of high-performance carbon fiber and toughened epoxy, as a fundamental research on the cryogenic composite tanks for future space vehicles. It was shown that laminates using thin-ply prepregs exhibited much higher strain at microcrack initiation compared to those using standard prepregs at room and cryogenic temperatures. In addition, helium gas leak tests using CFRP laminated tubular specimens subjected to quasi-static tension loadings were performed. It was demonstrated that CFRP laminates using thin-ply prepregs have higher gas barrier properties than those using standard prepregs.

  11. Micromechanisms in tension-compression fatigue of composite laminates containing transverse plies

    DEFF Research Database (Denmark)

    Gamstedt, E.K.; Sjögren, B.A.

    1999-01-01

    to optimise fatigue resistance. In this study, glass-fibre-reinforced vinyl-ester was used. The adverse effect of compressive load excursions was verified by counting the transverse cracks in cross-ply laminates. The mechanisms were studied in low-cycle fatigue of a specimen containing a single transverse...

  12. Minimum weight design of composite laminates for multiple loads

    International Nuclear Information System (INIS)

    Krikanov, A.A.; Soni, S.R.

    1995-01-01

    A new design method of constructing optimum weight composite laminates for multiple loads is proposed in this paper. A netting analysis approach is used to develop an optimization procedure. Three ply orientations permit development of optimum laminate design without using stress-strain relations. It is proved that stresses in minimum weight laminate reach allowable values in each ply with given load. The optimum ply thickness is defined at maximum value among tensile and compressive loads. Two examples are given to obtain optimum ply orientations, thicknesses and materials. For comparison purposes, calculations of stresses are done in orthotropic material using classical lamination theory. Based upon these calculations, matrix degrades at 30 to 50% of ultimate load. There is no fiber failure and therefore laminates withstand all applied loads in both examples

  13. ReciPlySkin

    DEFF Research Database (Denmark)

    Popovic Larsen, Olga; Andersen, Mikkel; Munk-Andersen, Niklas

    2017-01-01

    The report presents process that enbabled the production of the ReciPlySkin structure exhibited at the Circular Economy Exhibition at KADK during the Autumn 2017. The concept, design, detailed design and production are presented in this report.......The report presents process that enbabled the production of the ReciPlySkin structure exhibited at the Circular Economy Exhibition at KADK during the Autumn 2017. The concept, design, detailed design and production are presented in this report....

  14. Measurement of multiaxial ply strength by an off-axis flexure test

    Science.gov (United States)

    Crews, John H., Jr.; Naik, Rajiv A.

    1992-01-01

    An off-axis flexure (OAF) test was performed to measure ply strength under multiaxial stress states. This test involves unidirectional off-axis specimens loaded in bending, using an apparatus that allows these anisotropic specimens to twist as well as flex without the complications of a resisting torque. A 3D finite element stress analysis verified that simple beam theory could be used to compute the specimen bending stresses at failure. Unidirectional graphite/epoxy specimens with fiber angles ranging from 90 deg to 15 deg have combined normal and shear stresses on their failure planes that are typical of 45 deg plies in structural laminates. Tests for a range of stress states with AS4/3501-6 specimens showed that both normal and shear stresses on the failure plane influenced cracking resistance. This OAF test may prove to be useful for generating data needed to predict ply cracking in composite structures and may also provide an approach for studying fiber-matrix interface failures under stress states typical of structures.

  15. Enhancing PLiM/LCM through integration strategies

    International Nuclear Information System (INIS)

    Dam, R.F.; Watson, P.; Nickerson, J.H.

    2004-01-01

    Plant Life Management and Life Cycle Management activities continue to become an increasingly important part of NPP planning and O and M efforts. AECL, as a developer and provider of PLiM/LCM products and services, has been working towards providing effective and efficient tools and processes to support this activity. As these products evolve, it is becoming evident that there are significant benefits from ensuring that AECL and their utility partners engage in an Integrated PLiM approach. The integration of PLiM products and services goes far beyond simply relating the various aspects of the technology. The strategy to enhance the integration of PLiM includes three specific areas; namely the integrated aging knowledge base, the integrated assessment technology, and the integrated implementation within the plant. Through integration at all these levels the PLiM technology is able to be adaptive, providing a means for improved design and assessment capability, enhanced asset management capabilities, as well as providing for a flexible and more efficient delivery of PLiM services according to utility needs. This paper explores each of the three areas of integration, the resulting Enhanced PLiM/LCM capability, and how this capability translates to benefits for the operating stations both new and old. (author)

  16. Engineering method to build the composite structure ply database

    Directory of Open Access Journals (Sweden)

    Qinghua Shi

    Full Text Available In this paper, a new method to build a composite ply database with engineering design constraints is proposed. This method has two levels: the core stacking sequence design and the whole stacking sequence design. The core stacking sequences are obtained by the full permutation algorithm considering the ply ratio requirement and the dispersion character which characterizes the dispersion of ply angles. The whole stacking sequences are the combinations of the core stacking sequences. By excluding the ply sequences which do not meet the engineering requirements, the final ply database is obtained. One example with the constraints that the total layer number is 100 and the ply ratio is 30:60:10 is presented to validate the method. This method provides a new way to set up the ply database based on the engineering requirements without adopting intelligent optimization algorithms. Keywords: Composite ply database, VBA program, Structure design, Stacking sequence

  17. Processing mechanics of alternate twist ply (ATP) yarn technology

    Science.gov (United States)

    Elkhamy, Donia Said

    Ply yarns are important in many textile manufacturing processes and various applications. The primary process used for producing ply yarns is cabling. The speed of cabling is limited to about 35m/min. With the world's increasing demands of ply yarn supply, cabling is incompatible with today's demand activated manufacturing strategies. The Alternate Twist Ply (ATP) yarn technology is a relatively new process for producing ply yarns with improved productivity and flexibility. This technology involves self plying of twisted singles yarn to produce ply yarn. The ATP process can run more than ten times faster than cabling. To implement the ATP process to produce ply yarns there are major quality issues; uniform Twist Profile and yarn Twist Efficiency. The goal of this thesis is to improve these issues through process modeling based on understanding the physics and processing mechanics of the ATP yarn system. In our study we determine the main parameters that control the yarn twist profile. Process modeling of the yarn twist across different process zones was done. A computational model was designed to predict the process parameters required to achieve a square wave twist profile. Twist efficiency, a measure of yarn torsional stability and bulk, is determined by the ratio of ply yarn twist to singles yarn twist. Response Surface Methodology was used to develop the processing window that can reproduce ATP yarns with high twist efficiency. Equilibrium conditions of tensions and torques acting on the yarns at the self ply point were analyzed and determined the pathway for achieving higher twist efficiency. Mechanistic modeling relating equilibrium conditions to the twist efficiency was developed. A static tester was designed to zoom into the self ply zone of the ATP yarn. A computer controlled, prototypic ATP machine was constructed and confirmed the mechanistic model results. Optimum parameters achieving maximum twist efficiency were determined in this study. The

  18. Embalse PLiM/PLEx

    International Nuclear Information System (INIS)

    Ranalli, Juan M.

    2006-01-01

    The objective of the presentation is to show the current state of the Embalse PLiM/PLEx (Plant life management/Plant life extension) program (and its results) which strongly focuses on PLEx decision/implementation; to present the methodologies used and the PLEx plan is described. The objectives of the PLiM/PLEx program is to achieve the long term operation, maintaining a high level of safety and plant performance; to identify the necessary modifications for PLEx and its alternatives. This will enable to make de economic assessment and justify the life extension against other sources of energy. (author)

  19. Records for radioactive waste management up to repository closure: Managing the primary level information (PLI) set

    International Nuclear Information System (INIS)

    2004-07-01

    The objective of this publication is to highlight the importance of the early establishment of a comprehensive records system to manage primary level information (PLI) as an integrated set of information, not merely as a collection of information, throughout all the phases of radioactive waste management. Early establishment of a comprehensive records system to manage Primary Level Information as an integrated set of information throughout all phases of radioactive waste management is important. In addition to the information described in the waste inventory record keeping system (WIRKS), the PLI of a radioactive waste repository consists of the entire universe of information, data and records related to any aspect of the repository's life cycle. It is essential to establish PLI requirements based on integrated set of needs from Regulators and Waste Managers involved in the waste management chain and to update these requirements as needs change over time. Information flow for radioactive waste management should be back-end driven. Identification of an Authority that will oversee the management of PLI throughout all phases of the radioactive waste management life cycle would guarantee the information flow to future generations. The long term protection of information essential to future generations can only be assured by the timely establishment of a comprehensive and effective RMS capable of capturing, indexing and evaluating all PLI. The loss of intellectual control over the PLI will make it very difficult to subsequently identify the ILI and HLI information sets. At all times prior to the closure of a radioactive waste repository, there should be an identifiable entity with a legally enforceable financial and management responsibility for the continued operation of a PLI Records Management System. The information presented in this publication will assist Member States in ensuring that waste and repository records, relevant for retention after repository closure

  20. Two-ply channels for faster wicking in paper-based microfluidic devices.

    Science.gov (United States)

    Camplisson, Conor K; Schilling, Kevin M; Pedrotti, William L; Stone, Howard A; Martinez, Andres W

    2015-12-07

    This article describes the development of porous two-ply channels for paper-based microfluidic devices that wick fluids significantly faster than conventional, porous, single-ply channels. The two-ply channels were made by stacking two single-ply channels on top of each other and were fabricated entirely out of paper, wax and toner using two commercially available printers, a convection oven and a thermal laminator. The wicking in paper-based channels was studied and modeled using a modified Lucas-Washburn equation to account for the effect of evaporation, and a paper-based titration device incorporating two-ply channels was demonstrated.

  1. The United States Approach to PLiM for LTO

    International Nuclear Information System (INIS)

    2015-01-01

    The organizational structure for PLiM in the United States of America varies widely from plant to plant. For example, some plants may have a dedicated PLiM organization that coordinates the PLiM activities and provides the PLiM study results to the appropriate plant organizations (e.g. maintenance, engineering and operations) for implementation. Other plants may not have a dedicated PLiM organization, but rely on various organizations (e.g. design engineering, system engineering and maintenance) to conduct needed PLiM studies for LTO on a case by case (e.g. by component groups, such as piping, cables and transformers) or by individual components (turbine generator or steam generator). The organizational structure for preparing an LRA varies from utility to utility, but a typical structure is based on creating a project team to address each major discipline of the needed studies. The team members may be from utility organizations, contracted consultants who specialize in preparing LRAs, or a combination of the two groups, which is most common. A typical organizational structure is shown. The team typically consists of 10 to 20 full time members, with several other part time support members from various expert organizations (both utility and contracted consultants) needed to perform the engineering, ageing management and environmental studies and to prepare the supporting documentation for the LRA project

  2. Synergetic effects of thin plies and aligned carbon nanotube interlaminar reinforcement in composite laminates

    OpenAIRE

    Arteiro, Albertino; Borstnar, Gregor; Mavrogordato, Mark N.; Sinclair, Ian; Spearing, S. Mark; Camanho, Pedro P.; Cohen, Estelle; Kopp, Reed Alan; Furtado Pereira da Silva, Carolina; Ni, Xinchen; Wardle, Brian L

    2017-01-01

    Thin-ply carbon fiber laminates have exhibited superior mechanical properties, including higher initiation and ultimate strength, when compared to standard thickness plies and enable greater flexibility in laminate design. However, the increased ply count in thin-ply laminates also increases the number of ply-ply interfaces, thereby increasing the number of relatively weak and delamination-prone interlaminar regions. In this study, we report the first experimental realization of aligned carbo...

  3. Kinematic evaluation of the classical ballet step "plié".

    Science.gov (United States)

    Gontijo, Kaanda Nabilla Souza; Candotti, Cláudia Tarragô; Feijó, Grace Dos Santos; Ribeiro, Lais Paixão; Loss, Jefferson Fagundes

    2015-06-01

    Lack of alignment between the lowerlimb structures, such as the hips, knees, and longitudinal arches of the feet, has been described as an important predisposing factor in musculoskeletal injury among classical ballet dancers. However, no studies were found that analyzed basic ballet movements with quantification of objective criteria of the movements. The purposes of this study were: 1. to establish a methodology to quantify, using kinematic evaluation, the technical criteria that guide the correct execution of all phases of the plié (simultaneous flexion of the hips, knees, and ankle joints); and 2. to explore whether experienced ballet dancers respect those criteria when performing the plié. The technical criteria considered were the following: 1. midfoot stability; 2. pelvic positioning in a neutral alignment; 3. pelvic stability, represented by pelvic angle variation; and 4. vertical alignment of the knee joint with the second toe of the ipsilateral foot. Twenty dancers from Porto Alegre, Brazil, with 18 years of uninterrupted ballet training, were filmed while performing plié using four synchronized cameras. The descriptive statistical analysis involved calculating the median, minimum, and maximum of each of the technical criteria. Results showed that for criterion 1, the 20 dancers showed great stabilization of the midfoot; for criteria 2 and 3, 18 dancers displayed pelvic instability tending toward retroversion throughout execution of the plié; and for criterion 4, 13 dancers presented with medial misalignment of the knees at all phases of the plié. Using these criteria, it was possible to characterize the plié from a kinematic point of view.

  4. Post-impact fatigue of cross-plied, through-the-thickness reinforced carbon/epoxy composites. M.S. Thesis - Clemson Univ.

    Science.gov (United States)

    Serdinak, Thomas E.

    1994-01-01

    An experimental investigation of the post-impact fatigue response of integrally woven carbon/epoxy composites was conducted. Five different through-the-thickness (TTT) reinforcing fibers were used in an experimental textile process that produced an integrally woven (0/90/0/90/0/90/0/90/0)(sub T) ply layup with 21K AS4 carbon tow fiber. The resin was Hercules 3501-6, and the five TTT reinforcing fibers were Kevlar, Toray carbon, AS4 carbon, glass, and IM6 carbon. The purpose of this investigation was to study the post-impact fatigue response of these material systems and to identify the optimum TTT fiber. Samples were impacted with one half inch diameter aluminum balls with an average velocity of 543 ft/sec. Post-impact static compression and constant amplitude tension-compression fatigue tests were conducted. Fatigue tests were conducted with a loading ratio of R=-5, and frequency of 4 Hz. Damage growth was monitored using x-radiographic and sectioning techniques and by examining the stress-strain response (across the impact site) throughout the fatigue tests. The static compressive stress versus far-field strain response was nearly linear for all material groups. All the samples had a transverse shear failure mode. The average compressive modulus (from far-field strain) was about 10 Msi. The average post-impact static compressive strength was about 35.5 Ksi. The IM6 carbon sample had a strength of over 40 Ksi, more than 16 percent stronger than average. There was considerable scatter in the S-N data. However, the IM6 carbon samples clearly had the best fatigue response. The response of the other materials, while worse than IM6 carbon, could not be ranked definitively. The initial damage zones caused by the impact loading and damage growth from fatigue loading were similar for all five TTT reinforcing materials. The initial damage zones were circular and consisted of delaminations, matrix cracks and ply cracks. Post-impact fatigue loading caused delamination growth

  5. Criterion for matrix cracking in glass fiber reinforced cross-ply laminates. GFRP chokko sekisoban ni okeru matrix kiretsu no hattatsu kijun

    Energy Technology Data Exchange (ETDEWEB)

    Motoki, S.; Fukuda, T. (Osaka City Univ., Osaka (Japan). Faculty of Engineering); Tanaka, M. (Kobe City College of Technology, Kobe (Japan))

    1992-05-15

    In this research, with regard to GFRP cross-ply laminates, which were the most basic lamination composition, the factors governing the progress of matrix cracks at the 90{degree} layer were studied, in particular the criterion for not depending on the thickness of the 90{degree} layer was examined. For the experiment concerning the above, GFRP prepreg was laminated and three kinds of cross-ply laminates were made for use. A quasistatic tensile load was applied to these specimens and a load-displacement curve was measured, and at the same time, the matrix crack numbers generated in the 90{degree} layer were counted. As a result, it was found that the maximum value of the vertical stress in the loading direction of 90{degree} layer did not depend on the lamination composition, hence could become the criterion for the crack progress. Also it was found that in case when this stress surpassed a certain threshold value, cracks were formed, but in case when it was smaller than the threshold value, no crack was formed. 12 refs., 14 figs.

  6. Static mechanical properties of 30 x 11.5-14.5, type VII, aircraft tires of bias-ply and radial-belted design

    Science.gov (United States)

    Davis, Pamela A.; Lopez, Mercedes C.

    1987-01-01

    An investigation was conducted to determine the static mechanical characteristics of 30 x 115-14.5 bias-ply and radial aircraft tires. The tires were subjected to vertical and lateral loads and mass moment of inertia tests were conducted. Static load deflection curves, spring rates, hysteresis losses, and inertia data are presented along with a discussion of the advantages and disadvantages of one tire over the other.

  7. Postural loading assessment in assembly workers of an Iranian telecommunication manufacturing company.

    Science.gov (United States)

    Kamalinia, Mojtaba; Nasl Saraji, Gebreal; Kee, Dohyung; Hosseini, Mostafa; Choobineh, Alireza

    2013-01-01

    Changes in industries and work practices have coincided with work-related musculoskeletal disorders (MSDs). This study was conducted to determine the prevalence of MSDs and to assess postural loading in assembly workers of an Iranian telecommunication manufacturing company. Data were collected from 193 randomly selected workers in 4 units of the company. The Nordic musculoskeletal disorders questionnaire and the UBC ergonomic checklist were used as data collection tools. Loading on the upper body assessment (LUBA) was used to assess postural loading. Lower back symptoms were the most prevalent problems among the workers (67.9%). LUBA showed that most assembly workers (94.3%) had experienced considerable and high postural loading (postural load index, PLI > 5). Regression analyses revealed that lighting, rotation, contact stress, repetition, gender and age were factors associated with symptoms. Work-related MSDs occurred at a high rate among workers. Postural loading requires consideration. Any ergonomic intervention should focus on eliminating ergonomic factors associated with symptoms.

  8. Design and Optimization of a Composite Canard Control Surface of an Advanced Fighter Aircraft under Static Loading

    Directory of Open Access Journals (Sweden)

    Shrivastava Sachin

    2015-01-01

    Full Text Available The minimization of weight and maximization of payload is an ever challenging design procedure for air vehicles. The present study has been carried out with an objective to redesign control surface of an advanced all-metallic fighter aircraft. In this study, the structure made up of high strength aluminum, titanium and ferrous alloys has been attempted to replace by carbon fiber composite (CFC skin, ribs and stiffeners. This study presents an approach towards development of a methodology for optimization of first-ply failure index (FI in unidirectional fibrous laminates using Genetic-Algorithms (GA under quasi-static loading. The GAs, by the application of its operators like reproduction, cross-over, mutation and elitist strategy, optimize the ply-orientations in laminates so as to have minimum FI of Tsai-Wu first-ply failure criterion. The GA optimization procedure has been implemented in MATLAB and interfaced with commercial software ABAQUS using python scripting. FI calculations have been carried out in ABAQUS with user material subroutine (UMAT. The GA's application gave reasonably well-optimized ply-orientations combination at a faster convergence rate. However, the final optimized sequence of ply-orientations is obtained by tweaking the sequences given by GA's based on industrial practices and experience, whenever needed. The present study of conversion of an all metallic structure to partial CFC structure has led to 12% of weight reduction. Therefore, the approach proposed here motivates designer to use CFC with a confidence.

  9. Enhancing plant performance in newer CANDU plants utilizing PLiM methodologies

    International Nuclear Information System (INIS)

    Azeez, S.; Krishnan, V.S.; Nickerson, J.H.; Kakaria, B.

    2002-01-01

    Over the past 5 years, Atomic Energy of Canada Ltd. (AECL) has been working with CANDU utilities on comprehensive and integrated CANDU PLiM programs for successful and reliable operation through design life and beyond. Considerable progress has been made in the development of CANDU PLiM methodologies and implementation of the outcomes at the plants. The basis of CANDU PLiM programs is to understand the ageing degradation mechanisms, prevent/minimize the effects of these phenomena in the Critical Structures, Systems and Components (CSSCs), and maintain the CSSC condition as close as possible in the best operating condition. Effective plant practices in surveillance, maintenance, and operations are the primary means of managing ageing. From the experience to date, the CANDU PLiM program will modify and enhance, but not likely replace, existing plant programs that address ageing. However, a successful PLiM program will provide assurance that these existing plant programs are both effective and can be shown to be effective, in managing ageing. This requires a structured and managed approach to both the assessment and implementation processes

  10. Effect of number of piles [i.e. plies] on the tear resistance of paper

    Science.gov (United States)

    James T. Swartout; Vance C. Setterholm

    1963-01-01

    Tear tests made on low-finish bond paper and a 42-pound linerboard showed that the tear resistance, the degree of spreading of the plies, and the deviation from a straight line of failure increased with the increase in the number of plies tested. Tests on plies of aluminum foil indicated this degree of variation due to multiplicity of plies lay not in the tester but in...

  11. Expression of Toll-Like Receptor 2 by Dendritic Cells Is Essential for the DnaJ-ΔA146Ply-Mediated Th1 Immune Response against Streptococcus pneumoniae.

    Science.gov (United States)

    Wang, Xiaofang; Yuan, Taixian; Yuan, Jun; Su, Yufeng; Sun, Xiaoyu; Wu, Jingwen; Zhang, Hong; Min, Xun; Zhang, Xuemei; Yin, Yibing

    2018-03-01

    The fusion protein DnaJ-ΔA146Ply could induce cross-protective immunity against pneumococcal infection via mucosal and subcutaneous immunization in mice in the absence of additional adjuvants. DnaJ and Ply are both Toll-like receptor 4 (TLR4) but not TLR2 ligands. However, we found that TLR2 -/- mice immunized subcutaneously with DnaJ-ΔA146Ply showed significantly lower survival rates and higher bacterial loads in nasal washes than did wild-type (WT) mice after being challenged with pneumococcal strain D39 or 19F. The gamma interferon (IFN-γ) level in splenocytes decreased in TLR2 -/- mice, indicating that Th1 immunity elicited by DnaJ-ΔA146Ply was impaired in these mice. We explored the mechanism of protective immunity conferred by DnaJ-ΔA146Ply and the role of TLR2 in this process. DnaJ-ΔA146Ply effectively promoted dendritic cell (DC) maturation via TLR4 but not the TLR2 signaling pathway. In a DnaJ-ΔA146Ply-treated DC and naive CD4 + T cell coculture system, the deficiency of TLR2 in DCs resulted in a significant decline of IFN-γ production and Th1 subset differentiation. The same effect was observed in adoptive-transfer experiments. In addition, TLR2 -/- DCs showed remarkably lower levels of the Th1-polarizing cytokine IL-12p70 than did WT DCs, suggesting that TLR2 was indispensable for DnaJ-ΔA146Ply-induced IL-12 production and Th1 proliferation. Thus, our findings illustrate that dendritic cell expression of TLR2 is essential for optimal Th1 immune response against pneumococci in mice immunized subcutaneously with DnaJ-ΔA146Ply. Copyright © 2018 American Society for Microbiology.

  12. Structural behavior of window laminated glass plies using new interlayer materials

    Directory of Open Access Journals (Sweden)

    Mostafa El-Shami

    2018-01-01

    Full Text Available In most cases for the structural design of architectural glazing systems under a wide range of environmental conditions, the designers follow procedures provided by model building codes to design window glass. These codes commonly use design charts to determine design strength based on nominal glass thickness and aspect ratio. Glass plies are the principal components of laminated glass (LG where a thin ply of elastomeric material Polyvinyl butyral (PVB is used to bond glass plies (normally two plies to form the LG. Because of the reduction in LG design strength by most building codes and design guidelines, designers avoid architectural LG applications, other than for safety consideration. In this research a higher order mathematical model based on Mindlin plate theory is presented. LG was modeled using finite element methodology with new interlayer (NI. It consists of two plies of PVB with a hard ply of film material in between. In the FEM, properties of PVB/film material can be easily controlled regardless of their thicknesses. The finite element model (FEM was extended to account the design recommendations of ASTM (2012 to develop the design charts for LG with NI. The current FEM was verified and used to study the stresses transformation through NI. Design charts for samples of LG with NI were developed and presented. It has been found that using NI enhances the total behavior of LG and reflects on the design charts for this type of interlayer material.

  13. Glycaemic Index and Glycaemic Load of Pounded yam in Diabetic ...

    African Journals Online (AJOL)

    Incremental area under the blood glucose curve (IAUC) was used to determine the glycaemic index. Glycaemic load was determined using the percentage of available carbohydrate in the meal multiplied by the glycaemic index. Result: The glycaemic index of pounded yam was 61 and 59 in the diabetic type-2 and healthy ...

  14. Concurrent material-fabrication optimization of metal-matrix laminates under thermo-mechanical loading

    Science.gov (United States)

    Saravanos, D. A.; Morel, M. R.; Chamis, C. C.

    1991-01-01

    A methodology is developed to tailor fabrication and material parameters of metal-matrix laminates for maximum loading capacity under thermomechanical loads. The stresses during the thermomechanical response are minimized subject to failure constrains and bounds on the laminate properties. The thermomechanical response of the laminate is simulated using nonlinear composite mechanics. Evaluations of the method on a graphite/copper symmetric cross-ply laminate were performed. The cross-ply laminate required different optimum fabrication procedures than a unidirectional composite. Also, the consideration of the thermomechanical cycle had a significant effect on the predicted optimal process.

  15. Modelling approach for anisotropic inter-ply slippage in finite element forming simulation of thermoplastic UD-tapes

    Science.gov (United States)

    Dörr, Dominik; Faisst, Markus; Joppich, Tobias; Poppe, Christian; Henning, Frank; Kärger, Luise

    2018-05-01

    Finite Element (FE) forming simulation offers the possibility of a detailed analysis of thermoforming processes by means of constitutive modelling of intra- and inter-ply deformation mechanisms, which makes manufacturing defects predictable. Inter-ply slippage is a deformation mechanism, which influences the forming behaviour and which is usually assumed to be isotropic in FE forming simulation so far. Thus, the relative (fibre) orientation between the slipping plies is neglected for modelling of frictional behaviour. Characterization results, however, reveal a dependency of frictional behaviour on the relative orientation of the slipping plies. In this work, an anisotropic model for inter-ply slippage is presented, which is based on an FE forming simulation approach implemented within several user subroutines of the commercially available FE solver Abaqus. This approach accounts for the relative orientation between the slipping plies for modelling frictional behaviour. For this purpose, relative orientation of the slipping plies is consecutively evaluated, since it changes during forming due to inter-ply slipping and intra-ply shearing. The presented approach is parametrized based on characterization results with and without relative orientation for a thermoplastic UD-tape (PA6-CF) and applied to forming simulation of a generic geometry. Forming simulation results reveal an influence of the consideration of relative fibre orientation on the simulation results. This influence, however, is small for the considered geometry.

  16. Diffusion Indexes with Sparse Loadings

    DEFF Research Database (Denmark)

    Kristensen, Johannes Tang

    The use of large-dimensional factor models in forecasting has received much attention in the literature with the consensus being that improvements on forecasts can be achieved when comparing with standard models. However, recent contributions in the literature have demonstrated that care needs...... to the problem by using the LASSO as a variable selection method to choose between the possible variables and thus obtain sparse loadings from which factors or diffusion indexes can be formed. This allows us to build a more parsimonious factor model which is better suited for forecasting compared...... it to be an important alternative to PC....

  17. Microstructural analysis of human white matter architecture using Polarized Light Imaging (PLI: Views from neuroanatomy

    Directory of Open Access Journals (Sweden)

    Hubertus eAxer

    2011-11-01

    Full Text Available To date, there are several methods for mapping connectivity, ranging from the macroscopic to molecular scales. However, it is difficult to integrate this multiply-scaled data into one concept. Polarized light imaging (PLI is a method to quantify fiber orientation in gross histological brain sections based on the birefringent properties of the myelin sheaths. The method is capable of imaging fiber orientation of larger-scale architectural patterns with higher detail than diffusion MRI of the human brain. PLI analyses light transmission through a gross histological section of a human brain under rotation of a polarization filter combination. Estimates of the angle of fiber direction and the angle of fiber inclination are automatically calculated at every point of the imaged section. Multiple sections can be assembled into a 3D volume. We describe the principles of PLI and present several studies of fiber anatomy in the human brain: 6 brainstems were serially sectioned, imaged with PLI, and 3D reconstructed. Pyramidal tract and lemniscus medialis were segmented in the PLI datasets. PLI data from the internal capsule was related to results from confocal laser scanning microscopy, which is a method of smaller scale fiber anatomy. PLI fiber architecture of the extreme capsule was compared to macroscopical dissection, which represents a method of larger scale anatomy. The microstructure of the anterior human cingulum bundle was analyzed in serial sections of 6 human brains. PLI can generate highly-resolved 3D datsets of fiber orientation of the human brain and has, therefore, a high comparability to diffusion MR. To get additional information regarding axon structure and density, PLI can also be combined with classical histological stains. It brings the directional aspects of diffusion MRI into the range of histology and may represent a promising tool to close the gap between larger scale diffusion orientation and microstructural histological analysis

  18. Delamination in surface plies of graphite/epoxy caused by the edge trimming process

    Science.gov (United States)

    Colligan, K.; Ramulu, M.

    Delamination in surface plies of graphite/epoxy laminates caused by edge trimming using polycrystalline diamond (PCD) and carbide cutters is investigated. The effect of several machining variables on formation of delaminations in the surface plies of a graphite fiber reinforced composite material is presented. Machining tests were performed to assess the impact of cutter geometry, feedrate, rotation direction, and graphite fiber orientation. Three typical delamination modes were observed and documented. Feedrate was found to have a significant effect on surface ply delamination in graphite/epoxy composite materials.

  19. Influence of the soil sealing on the geoaccumulation index of heavy metals and various pollution factors.

    Science.gov (United States)

    Charzyński, Przemysław; Plak, Andrzej; Hanaka, Agnieszka

    2017-02-01

    Soil sealing belongs to the most destructive and damaging processes to the soil environment. Soil sealing interrupts or greatly restricts the exchange of matter and energy between the biosphere, hydrosphere, and atmosphere and the soil environment. The aim of this study was to compare the content of heavy metals (Cd, Cr, Cu, Hg, Fe, Ni, Pb, Zn) of Ekranic Technosols by applying indicators such as geoaccumulation index (I geo ), enrichment factor (EF), and pollution load index (PLI), which allowed to determine quantitatively the impact of the soil sealing degree on the content of heavy metals and to distinguish natural from anthropogenic sources of origin of heavy metals. In general, 42 soils from different parts of the city of Toruń (NW Poland) were sampled and divided into three groups according to the degree of soil sealing: completely sealed with asphalt or concrete (A), semi-permeable (partially sealed with cobblestones and concrete paving slabs (B)), and reference (non-sealed) (C). The results indicate that the artificial sealing in urban areas slightly affects the content of heavy metals in soils. However, based on PLI, I geo , and EF, it was found that the sealing has influence on soil properties and unsealed soil is the most exposed to the accumulation of pollutants.

  20. Assessment of soil contamination by potentially toxic trace elements (PTSD) (As, Cd, Cu, Hg, Pb, Zn) in a lower plain of the Hron River according to Law no. 219/2008 Coll., by geo-accumulation index, anthropogenic factor and Tomlinson index; Zhodnotenie kontaminacie pod potencialne toxickymi stopovymi prvkami (PTSP) (As, Cd, Cu, Hg, Pb, Zn) v dolnej casti nivy Hrona podla zakona c. 219/2008 Z.z., indexu geoakumulacie, antropogenneho faktora a Tomlinsonovho indexu

    Energy Technology Data Exchange (ETDEWEB)

    Hlodak, M [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Ustav laboratorneho vyskumu geomaterialov, 84215 Bratislava (Slovakia)

    2012-04-25

    Soil contamination by different PTSD may have different geogenic and anthropogenic origin and occurs in all countries of the world. The aim of this paper is to evaluate the soils contamination of a lower plain of the Hron River. This paper used the results of the thesis Soil contamination of the Hron River floodplain by trace elements (As, Cd, Cu, Hg, Pb, Zn) [1]. Soil contamination was evaluated by: Act. 219/2008 Coll. on the protection and use of agricultural land, by anthropogenic factor (AF), geo-accumulation index (IgeoE) and Tomlinson index - the index of the pollution load (PLI). (author)

  1. Optimum design of laminated composite under axial compressive load

    Indian Academy of Sciences (India)

    In the present study optimal design of composite laminates, with and without rectangular cut-out, is carried out for maximizing the buckling load. Optimization study is carried out for obtaining the maximum buckling load with design variables as ply thickness, cut-out size and orientation of cut-out with respect to laminate.

  2. Free vibration of symmetric angle-ply laminated circular cylindrical shells

    International Nuclear Information System (INIS)

    Viswanathan, K K; Aziz, Zainal Abdul; Amirah, H Z; Javed, Saira

    2014-01-01

    Free vibration of symmetric angle-ply laminated circular cylindrical shells is studied using Spline approximation. The equations of motions in longitudinal, circumferential and transverse displacement components, are derived using Love's first approximation theory. The coupled differential equations are solved using Spline approximation to obtain the generalized eigenvalue problem. Parametric studies are performed to analyse the frequency response of the shell with reference to the material properties, number of layers, ply orientation, length and circumferential node number and different boundary conditions

  3. Automated Ply Inspection (API) for AFP, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Automated Ply Inspection (API) system autonomously inspects layups created by high speed automated fiber placement (AFP) machines. API comprises a high accuracy...

  4. Diffusion Indexes With Sparse Loadings

    DEFF Research Database (Denmark)

    Kristensen, Johannes Tang

    2017-01-01

    The use of large-dimensional factor models in forecasting has received much attention in the literature with the consensus being that improvements on forecasts can be achieved when comparing with standard models. However, recent contributions in the literature have demonstrated that care needs...... to the problem by using the least absolute shrinkage and selection operator (LASSO) as a variable selection method to choose between the possible variables and thus obtain sparse loadings from which factors or diffusion indexes can be formed. This allows us to build a more parsimonious factor model...... in forecasting accuracy and thus find it to be an important alternative to PC. Supplementary materials for this article are available online....

  5. Asymmetric carbon nanotube-MnO2 two-ply yarn supercapacitors for wearable electronics

    Science.gov (United States)

    Su, Fenghua; Miao, Menghe

    2014-04-01

    Strong and flexible two-ply carbon nanotube yarn supercapacitors are electrical double layer capacitors that possess relatively low energy storage capacity. Pseudocapacitance metal oxides such as MnO2 are well known for their high electrochemical performance and can be coated on carbon nanotube yarns to significantly improve the performance of two-ply carbon nanotube yarn supercapacitors. We produced a high performance asymmetric two-ply yarn supercapacitor from as-spun CNT yarn and CNT@MnO2 composite yarn in aqueous electrolyte. The as-spun CNT yarn serves as negative electrode and the CNT@MnO2 composite yarn as positive electrode. This asymmetric architecture allows the operating potential window to be extended from 1.0 to 2.0 V and results in much higher energy and power densities than the reference symmetric two-ply yarn supercapacitors, reaching 42.0 Wh kg-1 at a lower power density of 483.7 W kg-1, and 28.02 Wh kg-1 at a higher power density of 19 250 W kg-1. The asymmetric supercapacitor can sustain cyclic charge-discharge and repeated folding/unfolding actions without suffering significant deterioration of specific capacitance. The combination of high strength, flexibility and electrochemical performance makes the asymmetric two-ply yarn supercapacitor a suitable power source for flexible electronic devices for applications that require high durability and wearer comfort.

  6. Cohesive Modeling of Transverse Cracking in Laminates with a Single Layer of Elements per Ply

    Science.gov (United States)

    VanDerMeer, Frans P.; Davila, Carlos G.

    2013-01-01

    This study aims to bridge the gap between classical understanding of transverse cracking in cross-ply laminates and recent computational methods for the modeling of progressive laminate failure. Specifically, the study investigates under what conditions a finite element model with cohesive X-FEM cracks can reproduce the in situ effect for the ply strength. It is shown that it is possible to do so with a single element across the thickness of the ply, provided that the interface stiffness is properly selected. The optimal value for this interface stiffness is derived with an analytical shear lag model. It is also shown that, when the appropriate statistical variation of properties has been applied, models with a single element through the thickness of a ply can predict the density of transverse matrix cracks

  7. Integrated plant life management (PLiM)-the IAEA contribution

    International Nuclear Information System (INIS)

    Kang, K.-S.; Clark, C.R.; Omoto, A.; )

    2005-01-01

    For the past couple of decades there has been a change of emphasis in the world nuclear power from that of building new Nuclear Power Plants (NPP) to that of taking measures to optimize the life cycle of operational plants. National approaches in many countries showed an increase of interest in Plant Life Management (PLiM), both in terms of plant service life assurance and in optimizing the service or operational life of NPP. A strong convergence of views is emerging from different National approaches, particularly in the area of the economic aspects of NPP operation and in the evolution in the scope of NPP PLIM. The latter can directly affect the cost of electricity from NPP in an increasingly competitive environment. The safety considerations of a NPP are paramount and those requirements have to be met to obtain and to extend/renew the operating license. To achieve the goal of the long term safe, economic and reliable operation of the plant an integrated Plant Life Management Programme (PLiM) is necessary. Some countries already have advanced PLiM Programmes while others still have none. The PLiM objective is to identify all that factors and requirements for the overall plant life cycle. The optimization of these requirements would allow for the minimum period of the investment return and maximum of the revenue from the sell of the produced electricity. Recognizing the importance of this issue and in response to the requests of the Member States the IAEA Division of Nuclear Power implements the Sub-programme on 'Engineering and Management Support for Competitive Nuclear Power'. Four projects within this sub-programme deal with different aspects of the NPP life cycle management with the aim to increase the capabilities of interested Member States in implementing and maintenance of the competitive and sustainable nuclear power. Although all four projects contain certain issues of PLiM there is one specific project on guidance on engineering and management practices

  8. Asymmetric carbon nanotube–MnO2 two-ply yarn supercapacitors for wearable electronics

    International Nuclear Information System (INIS)

    Su, Fenghua; Miao, Menghe

    2014-01-01

    Strong and flexible two-ply carbon nanotube yarn supercapacitors are electrical double layer capacitors that possess relatively low energy storage capacity. Pseudocapacitance metal oxides such as MnO 2 are well known for their high electrochemical performance and can be coated on carbon nanotube yarns to significantly improve the performance of two-ply carbon nanotube yarn supercapacitors. We produced a high performance asymmetric two-ply yarn supercapacitor from as-spun CNT yarn and CNT@MnO 2 composite yarn in aqueous electrolyte. The as-spun CNT yarn serves as negative electrode and the CNT@MnO 2 composite yarn as positive electrode. This asymmetric architecture allows the operating potential window to be extended from 1.0 to 2.0 V and results in much higher energy and power densities than the reference symmetric two-ply yarn supercapacitors, reaching 42.0 Wh kg −1 at a lower power density of 483.7 W kg −1 , and 28.02 Wh kg −1 at a higher power density of 19 250 W kg −1 . The asymmetric supercapacitor can sustain cyclic charge–discharge and repeated folding/unfolding actions without suffering significant deterioration of specific capacitance. The combination of high strength, flexibility and electrochemical performance makes the asymmetric two-ply yarn supercapacitor a suitable power source for flexible electronic devices for applications that require high durability and wearer comfort. (paper)

  9. Flexible, high performance Two-Ply Yarn Supercapacitors based on irradiated Carbon Nanotube Yarn and PEDOT/PSS

    International Nuclear Information System (INIS)

    Su, Fenghua; Miao, Menghe

    2014-01-01

    Graphical abstract: - Highlights: • Two-ply supercapacitors based on CNT yarn were prepared by a simple method. • The two-ply supercapacitors are high-performance, flexible and thread-like. • Gamma irradiation of CNT yarn improves the capacitance of the resulting supercapacitor. • PEDOT/PSS coated on the yarn surface further improve the capacitance of supercapacitors. • The two-ply supercapacitors can be easily woven or knitted into conventional textile fabrics. - Abstract: We present a simple design and a fabrication method for a high-performance, flexible, two-ply yarn supercapacitor based on irradiated CNT yarn and conductive polymer Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT/PSS). The CNT yarn is treated with gamma irradiation and the yarn surface is coated with the PEDOT/PSS to improve the energy storage capacitance of the as-spun yarn supercapacitor. A layer of PVA gel is coated on the surfaces of the CNT yarn and the composite yarn to form a separation layer containing electrolyte. The results show that the gamma irradiation greatly increases the electrical conductivity and improved the gram capacitance of the as-spun CNT two-ply yarn supercapacitor. The coating of PEDOT/PSS on the surface of the pure and irradiated CNT yarns further significantly improves the capacitance of the supercapacitors. The two-ply yarn supercapacitor constructed from the irradiation CNT yarn coated by PEDOT/PSS exhibits the large capacitance and high cyclic charge-discharge stability. Moreover, these two-ply yarn supercapacitors with fine diameters are highly flexible and can be easily woven or knitted into textile fabrics for uses in wearable electronics

  10. Design of a universal two-layered neural network derived from the PLI theory

    Science.gov (United States)

    Hu, Chia-Lun J.

    2004-05-01

    The if-and-only-if (IFF) condition that a set of M analog-to-digital vector-mapping relations can be learned by a one-layered-feed-forward neural network (OLNN) is that all the input analog vectors dichotomized by the i-th output bit must be positively, linearly independent, or PLI. If they are not PLI, then the OLNN just cannot learn no matter what learning rules is employed because the solution of the connection matrix does not exist mathematically. However, in this case, one can still design a parallel-cascaded, two-layered, perceptron (PCTLP) to acheive this general mapping goal. The design principle of this "universal" neural network is derived from the major mathematical properties of the PLI theory - changing the output bits of the dependent relations existing among the dichotomized input vectors to make the PLD relations PLI. Then with a vector concatenation technique, the required mapping can still be learned by this PCTLP system with very high efficiency. This paper will report in detail the mathematical derivation of the general design principle and the design procedures of the PCTLP neural network system. It then will be verified in general by a practical numerical example.

  11. Modeling the kinematics of multi-axial composite laminates as a stacking of 2D TIF plies

    Science.gov (United States)

    Ibañez, Ruben; Abisset-Chavanne, Emmanuelle; Chinesta, Francisco; Huerta, Antonio

    2016-10-01

    Thermoplastic composites are widely considered in structural parts. In this paper attention is paid to sheet forming of continuous fiber laminates. In the case of unidirectional prepregs, the ply constitutive equation is modeled as a transversally isotropic fluid, that must satisfy both the fiber inextensibility as well as the fluid incompressibility. When the stacking sequence involves plies with different orientations the kinematics of each ply during the laminate deformation varies significantly through the composite thickness. In our former works we considered two different approaches when simulating the squeeze flow induced by the laminate compression, the first based on a penalty formulation and the second one based on the use of Lagrange multipliers. In the present work we propose an alternative approach that consists in modeling each ply involved in the laminate as a transversally isotropic fluid - TIF - that becomes 2D as soon as incompressibility constraint and plane stress assumption are taken into account. Thus, composites laminates can be analyzed as a stacking of 2D TIF models that could eventually interact by using adequate friction laws at the inter-ply interfaces.

  12. Antimicrobial behavior of phage endolysin PlyP100 and its synergy with nisin to control Listeria monocytogenes in Queso Fresco.

    Science.gov (United States)

    Ibarra-Sánchez, Luis A; Van Tassell, Maxwell L; Miller, Michael J

    2018-06-01

    Hispanic-style fresh cheeses, such as Queso Fresco (QF), have been linked to numerous listeriosis outbreaks in the United States. In this work, we have studied the antilisterial behavior and effectiveness of the Listeria phage endolysin PlyP100 in QF, as well as the potential synergy between PlyP100 and nisin. PlyP100 showed similar bacterial reduction regardless of varying L. monocytogenes inoculum size in QF, and when the inoculation size was 1 Log CFU/g, no pathogen recovery after cheese enrichment was observed. PlyP100 was stable in QF for up to 28 days of cold storage exhibiting similar antilisterial activity regardless of when contamination with L. monocytogenes occurred. PlyP100 alone exhibited a strong listeriostatic effect in QF, on the contrary, nisin alone was not effective to control the pathogen in QF during cold storage. The combination of nisin and PlyP100 showed a strong synergy in QF with non-enumerable levels of L. monocytogenes after 4 weeks of refrigerated storage. Moreover, L. monocytogenes isolates from cheeses treated with nisin, PlyP100, and their combination did not develop resistance to nisin or PlyP100. Our results support the use of PlyP100 combined with nisin as an efficient L. monocytogenes control measure in QF. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Performance of patch repaired composite panels under fatigue loads

    International Nuclear Information System (INIS)

    Darwish, Feras H.; Hamoush, S.; Shivakumar, K.

    2006-01-01

    This paper evaluates the performance of bonded patch-scarf repairs of full scale laminated composite panels under cyclic load conditions. Nondestructive testing to characterize the quality of repairs and destructive testing to evaluate the performance of repaired panels were used in this study. Carbon/Epoxy prepreg material used was used to lay up six-ply (12 in. x 27 in. /305x686mm) (-60/60/0) s quasi-isotropic laminates. 7-ply scarf repair with a gradient of 0.5 inch (12.7mm) per layer was used to perform the repair of a damaged zone. The patch consisted of 7.5 inches (190mm) diameter adhesive film, 1 inch (25.4mm) diameter filler ply at 90fiber orientation, and six plies (2-7 inches (51-178mm) diameter) to match the lay-up of the parent material. The study was extended to include defective repairs. The defect was engineered by inserting a 1 inch (25.4 mm) circular Teflon flaw between the fifth and sixth layers of the patch. A total of 28 panels were prepared and divided into five categories: (1) three pristine panels (undamaged parental materials); (2) three damaged panels (1-inch-centered-hole); (3) two repaired panels with wrong fiber orientation; (4) nine good repaired panels, and (5) eleven defective repair panels (1 inch flaw). A nondestructive evaluation to check the conditions of the repairs was performed on most of the tested panels that include the pulse-echo C-scan and pseudo through transmission air coupled and water coupled C-scan. Based on the results of the experimental evaluation of this study, good repair restored 95% of the tensile strength while defective repair restored 90% of the tensile strength of the pristine panels. Under fatigue loading, panels repaired with a 1 inch delamination flaw within the patch layers showed a major reduction in fatigue life compared to the good repair panels under similar loading conditions. (author)

  14. Static mechanical properties of 30 x 11.5 - 14.5, type 8 aircraft tires of bias-ply and radial-belted design

    Science.gov (United States)

    Davis, Pamela A.; Lopez, Mercedes C.

    1988-01-01

    An investigation was conducted to determine the static mechanical properties of a 30 x 11.5 to 14.5, Type 8, bias-ply and radial-belted aircraft tire. The properties measured were the spring rate and damping characteristics of each tire from vertical- and lateral-loading hysteresis loops. Mass moment of inertia tests were also conducted. The results of the study are presented along with a discussion of the advantages and disadvantages of each type of tire.

  15. Combined-load stress-strain relationship for advanced fiber composites

    Science.gov (United States)

    Chamis, C. C.; Sullivan, T. L.

    1975-01-01

    It was demonstrated experimentally that only one test specimen is required to determine the combined-load stress-strain relationships of a given fiber composite system. These relationships were determined using a thin angle-plied laminate tube and subjecting it to a number of combined-loading conditions. The measured data obtained are compared with theoretical predictions. Some important considerations associated with such a test are identified, and the significance of combined-load stress-strain relationships in certain practical designs are discussed.

  16. Thermal flexural analysis of cross-ply laminated plates using trigonometric shear deformation theory

    Directory of Open Access Journals (Sweden)

    Yuwaraj Marotrao Ghugal

    Full Text Available Thermal stresses and displacements for orthotropic, two-layer antisymmetric, and three-layer symmetric square cross-ply laminated plates subjected to nonlinear thermal load through the thickness of laminated plates are presented by using trigonometric shear deformation theory. The in-plane displacement field uses sinusoidal function in terms of thickness co-ordinate to include the shear deformation effect. The theory satisfies the shear stress free boundary conditions on the top and bottom surfaces of the plate. The present theory obviates the need of shear correction factor. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. The validity of present theory is verified by comparing the results with those of classical plate theory and first order shear deformation theory and higher order shear deformation theory.

  17. Glycemic load, glycemic index, bread and incidence of overweight/obesity in a Mediterranean cohort: the SUN project.

    Science.gov (United States)

    de la Fuente-Arrillaga, Carmen; Martinez-Gonzalez, Miguel Angel; Zazpe, Itziar; Vazquez-Ruiz, Zenaida; Benito-Corchon, Silvia; Bes-Rastrollo, Maira

    2014-10-22

    To evaluate prospectively the relationship between white, or whole grain bread, and glycemic index, or glycemic load from diet and weight change in a Mediterranean cohort. We followed-up 9 267 Spanish university graduates for a mean period of 5 years. Dietary habits at baseline were assessed using a semi-quantitative 136-item food-frequency questionnaire. Average yearly weight change was evaluated according to quintiles of baseline glycemic index, glycemic load, and categories of bread consumption. We also assessed the association between bread consumption, glycemic index, or glycemic load, and the incidence of overweight/obesity. White bread and whole-grain bread were not associated with higher weight gain. No association between glycemic index, glycemic load and weight change was found.White bread consumption was directly associated with a higher risk of becoming overweight/obese (adjusted OR (≥2 portions/day) versus (≤1 portion/week): 1.40; 95% CI: 1.08-1.81; p for trend: 0.008). However, no statistically significant association was observed between whole-grain bread, glycemic index or glycemic load and overweight/obesity. Consumption of white bread (≥2 portions/day) showed a significant direct association with the risk of becoming overweight/obese.

  18. The reliability of the Extra Load Index as a measure of relative load carriage economy.

    Science.gov (United States)

    Hudson, Sean; Cooke, Carlton; Lloyd, Ray

    2017-09-01

    The aim of this study was to measure the reliability of the extra load index (ELI) as a method for assessing relative load carriage economy. Seventeen volunteers (12 males, 5 females) performed walking trials at 3 km·h -1 , 6 km·h -1 and a self-selected speed. Trial conditions were repeated 7 days later to assess test-retest reliability. Trials involved four 4-minute periods of walking, each separated by 5 min of rest. The initial stage was performed unloaded followed in a randomised order by a second unloaded period and walking with backpacks of 7 and 20 kg. Results show ELI values did not differ significantly between trials for any of the speeds (p = 0.46) with either of the additional loads (p = 0.297). The systematic bias, limits of agreement and coefficients of variation were small in all trial conditions. We conclude the ELI appears to be a reliable measure of relative load carriage economy. Practitioner Summary: This paper demonstrates that the ELI is a reliable measure of load carriage economy at a range of walking speeds with both a light and heavy load. The ELI, therefore, represents a useful tool for comparing the relative economy associated with different load carriage systems.

  19. Design and Process Development of Thin-Ply Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project evaluates automated tape placement (ATP) processing of thin ply composites, including process and design modeling, test panel fabrication and mechanical...

  20. Dynamic evaluation method of lower limbs joint alignment (MADAAMI for dancers during the plié

    Directory of Open Access Journals (Sweden)

    Kaanda Nabilla Souza Gontijo

    Full Text Available Abstract In classical ballet, the joint misalignments during the plié can generate various injuries. To evaluate potential misalignments during the plié the aim of this study was to present a method for dynamic evaluation of lower limb alignment articulation (called MADAAMI. MADAAMI was validated by 12 experts, and for the evaluation of its reproducibility and for agreement with 3D kinematics, 20 dancers were assessed using a video recording of their plié. For statistical analysis we used the Kappa coefficient (k (p 0.40 and C > 80%, and it is a suitable and valid method for use by the same examiner.

  1. Magnetic evidence for heavy metal pollution of topsoil in Shanghai, China

    Science.gov (United States)

    Wang, Guan; Liu, Yuan; Chen, Jiao; Ren, Feifan; Chen, Yuying; Ye, Fangzhou; Zhang, Weiguo

    2018-03-01

    This study presents the results obtained from magnetic susceptibility and heavy metal (Cu, Zn, Pb, and Cr) concentration measurements of soil profiles collected from arable land and urban parks in Baoshan District, an industrial district of Shanghai, China. The study focuses on the investigation of vertical variations in magnetic susceptibilities and heavy metal concentrations and on correlations between magnetic susceptibilities and heavy metal concentrations in soil profiles. The results demonstrate that magnetic enhancement in the surface layer of the soil profile is associated with increased heavy metal pollution. The enrichment factors (EF) and the Tomlinson Pollution Load Index (PLI-EF) are calculated for estimating the level of heavy metal pollution of soil profiles in the study. The significant positive correlations between heavy metal contents, enrichment factors (EF), Tomlinson pollution load index (PLI-CF), modified Tomlinson pollution load index (PLI-EF), and magnetic susceptibility (c) indicate that much of the heavy metal contamination in the study area is linked to combustion derived particulate emissions. The results confirm that the combined magnetic measurement and heavy metal concentration analysis could provide useful information for soil monitoring in urban environments. However, the use of magnetic technique to locate the heavy metal pollution boundary in the soil profile of this studied area should be confirmed by further geochemical analysis.

  2. Relation of Dietary Glycemic Index and Glycemic Load to Coronary Artery Calcium in Asymptomatic Korean Adults.

    Science.gov (United States)

    Choi, Yuni; Chang, Yoosoo; Ryu, Seungho; Cho, Juhee; Kim, Mi Kyung; Ahn, Younjhin; Lee, Jung Eun; Sung, Eunju; Kim, Boyoung; Ahn, Jiin; Kim, Chan-Won; Rampal, Sanjay; Zhao, Di; Zhang, Yiyi; Pastor-Barriuso, Roberto; Lima, Joao A C; Chung, Eun Chul; Shin, Hocheol; Guallar, Eliseo

    2015-08-15

    The relation between glycemic index, glycemic load, and subclinical coronary atherosclerosis is unknown. The aim of the study was to evaluate the associations between energy-adjusted glycemic index, glycemic load, and coronary artery calcium (CAC). This study was cross-sectional analysis of 28,429 asymptomatic Korean men and women (mean age 41.4 years) without a history of diabetes or cardiovascular disease. All participants underwent a health screening examination between March 2011 and April 2013, and dietary intake over the preceding year was estimated using a validated food frequency questionnaire. Cardiac computed tomography was used for CAC scoring. The prevalence of detectable CAC (CAC score >0) was 12.4%. In multivariable-adjusted models, the CAC score ratios (95% confidence intervals) comparing the highest to the lowest quintile of glycemic index and glycemic load were 1.74 (1.08 to 2.81; p trend = 0.03) and 3.04 (1.43 to 6.46; p trend = 0.005), respectively. These associations did not differ by clinical subgroups, including the participants at low cardiovascular risk. In conclusion, these findings suggest that high dietary glycemic index and glycemic load were associated with a greater prevalence and degree of CAC, with glycemic load having a stronger association. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Romania - NPP PLiM Between Regulatory Requirement / Oversight and Operator Safety / Financial Interest

    International Nuclear Information System (INIS)

    Goicea, Lucian

    2012-01-01

    Cernavoda Unit 1 PLiM started in the first third of its design life, to develop as regulatory requirements of the components of standards and programmes and to benefit by earlier implementation of the measures for achieving maximum operating life. CNCAN regulatory present approach on the utility PLiM combines the regulatory requirements on management system, ageing management provisions of periodic safety review, detailed technical requirements of ageing programmes and different techniques focusing only on safety issues. (author)

  4. Waveguide-loaded silica fibers for coupling to high-index micro-resonators

    Science.gov (United States)

    Latawiec, P.; Burek, M. J.; Venkataraman, V.; Lončar, M.

    2016-01-01

    Tapered silica fibers are often used to rapidly probe the optical properties of micro-resonators. However, their low refractive index precludes phase-matching when coupling to high-index micro-resonators, reducing efficiency. Here, we demonstrate efficient optical coupling from tapered fibers to high-index micro-resonators by loading the fibers with an ancillary adiabatic waveguide-coupler fabricated via angled-etching. We demonstrate greatly enhanced coupling to a silicon multimode micro-resonator when compared to coupling via the bare fiber only. Signatures of resonator optical bistability are observed at high powers. This scheme can be applied to resonators of any size and material, increasing the functional scope of fiber coupling.

  5. Assessment of Postural Load Index Using LUBA Method and the Prevalence of Musculoskeletal Disorders in Dentists

    Directory of Open Access Journals (Sweden)

    Zeinab Baroonyzade

    2014-06-01

    Full Text Available Background & Objectives : High prevalence of musculoskeletal pain in dentistry represents the importance of investigation of working conditions in this profession to reduce musculoskeletal disorders.The purpose of this study was to determine the postural load on the upper limb postural using macro LUBA technique and the prevalence of musculoskeletal disorders. Methods: This study was conducted on 30 post graduate dental students of Hamadan University of Medical Sciences . LUBA technique was used to evaluate the postural load. The Nordic questionnaire was used to assess the prevalence of musculoskeletal disorders . The results were analyzed using SPSS version 16 . Results: The prevalence of musculoskeletal disorders was as follows neck( 63.3%, back ( 43.3%, back ( 30%, knee ( 20%, shoulder( 13%, wrist ( 10%, legs (10 %, elbows( 6.7% and thigh( 0%. The maximum postural load index was 23 for women and 21for men. In total, 50 % of dentists were in group 3 , 33 % of dentists in group 4 and 16.7 % in group 2 of the corrective measures . There was no significant association b etween demographic variables and presence of musculoskeletal disorders . Besides, there was no significant association between the presence of pain in upper limbs and the postural load index (Pvalue > 0.05. Conclusions: This study showed high levels of p ostural load index and musculoskeletal disorders among dental students of Hamadan University of Medical Sciences. High levels of p ostural load index indicate a high level of risk, which requires immediate corrective action and intervention.

  6. Using the NASA Task Load Index to Assess Workload in Electronic Medical Records.

    Science.gov (United States)

    Hudson, Darren; Kushniruk, Andre W; Borycki, Elizabeth M

    2015-01-01

    Electronic medical records (EMRs) has been expected to decrease health professional workload. The NASA Task Load Index has become an important tool for assessing workload in many domains. However, its application in assessing the impact of an EMR on nurse's workload has remained to be explored. In this paper we report the results of a study of workload and we explore the utility of applying the NASA Task Load Index to assess impact of an EMR at the end of its lifecycle on nurses' workload. It was found that mental and temporal demands were the most responsible for the workload. Further work along these lines is recommended.

  7. OPTIMIZATION OF PLY STACKING SEQUENCE OF COMPOSITE DRIVE SHAFT USING PARTICLE SWARM ALGORITHM

    Directory of Open Access Journals (Sweden)

    CHANNAKESHAVA K. R.

    2011-06-01

    Full Text Available In this paper an attempt has been made to optimize ply stacking sequence of single piece E-Glass/Epoxy and Boron /Epoxy composite drive shafts using Particle swarm algorithm (PSA. PSA is a population based evolutionary stochastic optimization technique which is a resent heuristic search method, where mechanics are inspired by swarming or collaborative behavior of biological population. PSA programme is developed to optimize the ply stacking sequence with an objective of weight minimization by considering design constraints as torque transmission capacity, fundamental natural frequency, lateral vibration and torsional buckling strength having number of laminates, ply thickness and stacking sequence as design variables. The weight savings of the E-Glass/epoxy and Boron /Epoxy shaft from PAS were 51% and 85 % of the steel shaft respectively. The optimum results of PSA obtained are compared with results of genetic algorithm (GA results and found that PSA yields better results than GA.

  8. Fibre failure assessment in carbon fibre reinforced polymers under fatigue loading by synchrotron X-ray computed tomography

    OpenAIRE

    Garcea, Serafina; Sinclair, Ian; Spearing, Simon

    2016-01-01

    In situ fatigue experiments using synchrotron X-ray computed tomography (SRCT) are used to assess the underpinning micromechanisms of fibre failure in double notch carbon/epoxy coupons. Observations showed fibre breaks along the 0º ply splits, associated with the presence and failure of bridging fibres, as well as fibres failed in the bulk composite within the 0º plies. A tendency for cluster formation, with multiple adjacent breaks in the bulk composite was observed when higher peak loads we...

  9. Nutritional composition, glycemic index, glycemic load, and organoleptical quality of glucomannan-enriched soy milk ice cream

    Science.gov (United States)

    Sa'adah, S.; Candra, O. M.; Nugrahani, G.; Pramono, A.; Afifah, D. N.

    2018-01-01

    Over the past decades, the number of childhood obesity cases has increased significantly, which led to an increase in the number of adults suffering from degenerative diseases such as diabetes mellitus (DM). Glucomannan-Enriched Soy Milk Ice Cream (GSMIC) may prevent obesity in children. The aim of the study was to test the level of carbohydrates, protein, fat, dietary fiber, glycemic index, glycemic load, and organoleptic quality of GSMIC. This experiment used a completely randomized design to test three formulations of glucomannan flour and soy milk (0.5%, 1.5%, and 2.5%). The products were tested for nutritional composition, and evaluated on glycemic index, glycemic load, and organoleptic quality. GSMIC 2.5% had higher levels of dietary fiber and high carbohydrate, protein, and fat content compared to ice cream (3.99%, 30.7%, 1.50%, 1.33%, respectively). The glycemic index of ice cream and 2.5% GSMIC were 75.83 (75%) and 51.48 (51%), respectively, while the glycemic load of ice cream and 2.5% GSMIC were 9.04 and 11.61, respectively. Based on the organoleptic analysis, formulation preferred by the panellists was 2.5% glucomannan flour. Glucomannan flour affected the level of carbohydrates, protein, fat, dietary fiber, glycemic index, glycemic load, and organoleptic quality in soy milk ice cream.

  10. Low glycaemic index, or low glycaemic load, diets for diabetes mellitus.

    Science.gov (United States)

    Thomas, Diana; Elliott, Elizabeth J

    2009-01-21

    The aim of diabetes management is to normalise blood glucose levels, since improved blood glucose control is associated with reduction in development, and progression, of complications. Nutritional factors affect blood glucose levels, however there is currently no universal approach to the optimal dietary treatment for diabetes. There is controversy about how useful the glycaemic index (GI) is in diabetic meal planning. Improved glycaemic control through diet could minimise medications, lessen risk of diabetic complications, improve quality of life and increase life expectancy. To assess the effects of low glycaemic index, or low glycaemic load, diets on glycaemic control in people with diabetes. We performed electronic searches of The Cochrane Library, MEDLINE, EMBASE and CINAHL with no language restriction. We assessed randomised controlled trials of four weeks or longer that compared a low glycaemic index, or low glycaemic load, diet with a higher glycaemic index, or load, or other diet for people with either type 1 or 2 diabetes mellitus, whose diabetes was not already optimally controlled. Two reviewers independently extracted data on study population, intervention and outcomes for each included study, using standardised data extraction forms. Eleven relevant randomised controlled trials involving 402 participants were identified. There was a significant decrease in the glycated haemoglobin A1c (HbA1c) parallel group of trials, the weighted mean difference (WMD) was -0.5% with a 95% confidence interval (CI) of - 0.9 to -0.1, P = 0.02; and in the cross-over group of trials the WMD was -0.5% with a 95% CI of -1.0 to -0.1, P = 0.03. Episodes of hypoglycaemia were significantly fewer with low compared to high GI diet in one trial (difference of -0.8 episodes per patient per month, P low-GI diet compared to measured carbohydrate exchange diet in another study (35% versus 66%, P = 0.006). No study reported on mortality, morbidity or costs. A low-GI diet can improve

  11. Load Index Metrics for an Optimized Management of Web Services: A Systematic Evaluation

    Science.gov (United States)

    Souza, Paulo S. L.; Santana, Regina H. C.; Santana, Marcos J.; Zaluska, Ed; Faical, Bruno S.; Estrella, Julio C.

    2013-01-01

    The lack of precision to predict service performance through load indices may lead to wrong decisions regarding the use of web services, compromising service performance and raising platform cost unnecessarily. This paper presents experimental studies to qualify the behaviour of load indices in the web service context. The experiments consider three services that generate controlled and significant server demands, four levels of workload for each service and six distinct execution scenarios. The evaluation considers three relevant perspectives: the capability for representing recent workloads, the capability for predicting near-future performance and finally stability. Eight different load indices were analysed, including the JMX Average Time index (proposed in this paper) specifically designed to address the limitations of the other indices. A systematic approach is applied to evaluate the different load indices, considering a multiple linear regression model based on the stepwise-AIC method. The results show that the load indices studied represent the workload to some extent; however, in contrast to expectations, most of them do not exhibit a coherent correlation with service performance and this can result in stability problems. The JMX Average Time index is an exception, showing a stable behaviour which is tightly-coupled to the service runtime for all executions. Load indices are used to predict the service runtime and therefore their inappropriate use can lead to decisions that will impact negatively on both service performance and execution cost. PMID:23874776

  12. Modeling Transverse Cracking in Laminates With a Single Layer of Elements Per Ply

    Science.gov (United States)

    Van Der Meer, Frans P.; Davila, Carlos G.

    2012-01-01

    The objective of the present paper is to investigate the ability of mesolevel X-FEM models with a single layer of elements per ply to capture accurately all aspects of matrix cracking. In particular, we examine whether the model can predict the insitu ply thickness effect on crack initiation and propagation, the crack density as a function of strain, the strain for crack saturation, and the interaction between delamination and transverse cracks. Results reveal that the simplified model does not capture correctly the shear-lag relaxation of the stress field on either side of a crack, which leads to an overprediction of the crack density. It is also shown, however, that after onset of delamination many of the inserted matrix cracks close again, and that the density of open cracks becomes similar to the density predicted by the detailed model. The degree to which the spurious cracks affect the global response is quantified and the reliability of the mesolevel approach with a single layer of elements per ply is discussed.

  13. The Effect of Nylon and Polyester Peel Ply Surface Preparation on the Bond Quality of Composite Laminates

    Science.gov (United States)

    Moench, Molly K.

    The preparation of the surfaces to be bonded is critical to the success of composite bonds. Peel ply surface preparation is attractive from a manufacturing and quality assurance standpoint, but is a well known example of the extremely system-specific nature of composite bonds. This study examined the role of the surface energy, morphology, and chemistry left by peel ply removal in resulting bond quality. It also evaluated the use of contact angle surface energy measurement techniques for predicting the resulting bond quality of a prepared surface. The surfaces created by preparing three aerospace fiber-reinforced composite prepregs were compared when prepared with a nylon vs a polyester peel ply. The prepared surfaces were characterized with contact angle measurements with multiple fluids, scanning electron microscopy (SEM), and x-ray electron spectroscopy. The laminates were bonded with aerospace grade film adhesives. Bond quality was assessed via double cantilever beam testing followed by optical and scanning electron microscopy of the fracture surfaces.The division was clear between strong bonds (GIC of 600- 1000J/m2 and failure in cohesion) and weak bonds (GIC of 80-400J/m2 and failure in adhesion). All prepared laminates showed the imprint of the peel ply texture and evidence of peel ply remnants after fabric removal, either through SEM or XPS. Within an adhesive system, large amounts of SEM-visible peel ply material transfer correlated with poor bond quality and cleaner surfaces with higher bond quality. The both sides of failed weak bonds showed evidence of peel ply remnants under XPS, showing that at least some failure is occurring through the remnants. The choice of adhesive was found to be significant. AF 555 adhesive was more tolerant of peel ply contamination than MB 1515-3. Although the bond quality results varied substantially between tested combinations, the total surface energies of all prepared surfaces were very similar. Single fluid contact angle

  14. Buckling Testing and Analysis of Honeycomb Sandwich Panel Arc Segments of a Full-Scale Fairing Barrel. Part 3; 8-ply Out-of-Autoclave Facesheets

    Science.gov (United States)

    Pineda, Evan J.; Myers, David E.; Kosareo, Daniel N.; Kellas, Sotiris

    2014-01-01

    Four honeycomb sandwich panels, representing 1/16th arc segments of a 10 m diameter barrel section of the heavy lift launch vehicle, were manufactured under the NASA Composites for Exploration program and the NASA Constellation Ares V program. Two configurations were chosen for the panels: 6-ply facesheets with 1.125 in. honeycomb core and 8-ply facesheets with 1.000 in. honeycomb core. Additionally, two separate carbon fiber/epoxy material systems were chosen for the facesheets: inautoclave IM7/977-3 and out-of-autoclave T40-800B/5320-1. Smaller 3- by 5-ft panels were cut from the 1/16th barrel sections. These panels were tested under compressive loading at the NASA Langley Research Center. Furthermore, linear eigenvalue and geometrically nonlinear finite element analyses were performed to predict the compressive response of the 3- by 5-ft panels. This manuscript summarizes the experimental and analytical modeling efforts pertaining to the panel composed of 8-ply, T40-800B/5320-1 facesheets (referred to as Panel C). To improve the robustness of the geometrically nonlinear finite element model, measured surface imperfections were included in the geometry of the model. Both the linear and nonlinear, two-dimensional (2-D) and three-dimensional (3-D), models yield good qualitative and quantitative predictions. Additionally, it was predicted correctly that the panel would fail in buckling prior to failing in strength.

  15. Association between dietary glycemic index, glycemic load, and body mass index in the Inter99 study: is underreporting a problem?

    DEFF Research Database (Denmark)

    Lau, C.; Toft, U.; Tetens, Inge

    2006-01-01

    Background: The few studies examining the potential associations between glycemic index (GI), glycemic load (GL), and body mass index (BMI) have provided no clear pictures. Underreporting of energy intake may be one explanation for this. Objective: We examined the associations between GI, GL...... a positive association between GI, GL, and BMI. Energy adjustment and the exclusion of LERs significantly affected the results of the analysis; thus, we stress the importance of energy adjustment....

  16. Hourly cooling load forecasting using time-indexed ARX models with two-stage weighted least squares regression

    International Nuclear Information System (INIS)

    Guo, Yin; Nazarian, Ehsan; Ko, Jeonghan; Rajurkar, Kamlakar

    2014-01-01

    Highlights: • Developed hourly-indexed ARX models for robust cooling-load forecasting. • Proposed a two-stage weighted least-squares regression approach. • Considered the effect of outliers as well as trend of cooling load and weather patterns. • Included higher order terms and day type patterns in the forecasting models. • Demonstrated better accuracy compared with some ARX and ANN models. - Abstract: This paper presents a robust hourly cooling-load forecasting method based on time-indexed autoregressive with exogenous inputs (ARX) models, in which the coefficients are estimated through a two-stage weighted least squares regression. The prediction method includes a combination of two separate time-indexed ARX models to improve prediction accuracy of the cooling load over different forecasting periods. The two-stage weighted least-squares regression approach in this study is robust to outliers and suitable for fast and adaptive coefficient estimation. The proposed method is tested on a large-scale central cooling system in an academic institution. The numerical case studies show the proposed prediction method performs better than some ANN and ARX forecasting models for the given test data set

  17. Static and fatigue tensile properties of cross-ply laminates containing vascules for self-healing applications

    International Nuclear Information System (INIS)

    Luterbacher, R; Trask, R S; Bond, I P

    2016-01-01

    The effect of including hollow channels (vascules) within cross-ply laminates on static tensile properties and fatigue performance is investigated. No change in mechanical properties or damage formation is observed when a single vascule is included in the 0/90 interface, representing 0.5% of the cross sectional area within the specimen. During tensile loading, matrix cracks develop in the 90° layers leading to a reduction of stiffness and strength (defined as the loss of linearity) and a healing agent is injected through the vascules in order to heal them and mitigate the caused degradation. Two different healing agents, a commercial low viscosity epoxy resin (RT151, Resintech) and a toughened epoxy blend (bespoke, in-house formulation) have been used to successfully recover stiffness under static loading conditions. The RT151 system recovered 75% of the initial failure strength, whereas the toughened epoxy blend achieved a recovery of 67%. Under fatigue conditions, post healing, a rapid decay of stiffness was observed as the healed damage re-opened within the first 2500 cycles. This was caused by the high fatigue loading intensity, which was near the static failure strength of the healing resin. However, the potential for ameliorating (via self-healing or autonomous repair) more diffuse transverse matrix damage via a vascular network has been shown. (paper)

  18. Effect of Location of Delamination on Free Vibration of Cross-Ply Conical Shells

    Directory of Open Access Journals (Sweden)

    Sudip Dey

    2012-01-01

    Full Text Available Location of delamination is a triggering parameter for structural instability of laminated composites. In this paper, a finite element method is employed to determine the effects of location of delamination on free vibration characteristics of graphite-epoxy cross-ply composite pre-twisted shallow conical shells. The generalized dynamic equilibrium equation is derived from Lagrange's equation of motion neglecting Coriolis effect for moderate rotational speeds. The formulation is exercised by using an eight noded isoparametric plate bending element based on Mindlin's theory. Multi-point constraint algorithm is utilized to ensure the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front. The standard eigen value problem is solved by applying the QR iteration algorithm. Finite element codes are developed to obtain the numerical results concerning the effects of location of delamination, twist angle and rotational speed on the natural frequencies of cross-ply composite shallow conical shells. The mode shapes are also depicted for a typical laminate configuration. Numerical results obtained from parametric studies of both symmetric and anti-symmetric cross-ply laminates are the first known non-dimensional natural frequencies for the type of analyses carried out here.

  19. An analytical study of the effects of transverse shear deformation and anisotropy on buckling loads of laminated cylinders. M.S. Thesis - George Washington Univ.

    Science.gov (United States)

    Jegley, Dawn C.

    1987-01-01

    Buckling loads of thick-walled orthotropic and anisotropic simply supported circular cylinders are predicted using a higher-order transverse-shear deformation theory. A comparison of buckling loads predicted by the conventional first-order transverse-shear deformation theory and the higher-order theory show that the additional allowance for transverse shear deformation has a negligible effect on the predicted buckling loads of medium-thick metallic isotropic cylinders. However, the higher-order theory predicts buckling loads which are significantly lower than those predicted by the first-order transverse-shear deformation theory for certain short, thick-walled cylinders which have low through-the-thickness shear moduli. A parametric study of the effects of ply orientation on the buckling load of axially compressed cylinders indicates that laminates containing 45 degree plies are most sensitive to transverse-shear deformation effects. Interaction curves for buckling loads of cylinders subjected to axial compressive and external pressure loadings indicate that buckling loads due to external pressure loadings are as sensitive to transverse-shear deformation effects as buckling loads due to axial compressive loadings. The effects of anisotropy are important over a much wider range of cylinder geometries than the effects of transverse shear deformation.

  20. Ply-based Optimization of Laminated Composite Shell Structures under Manufacturing Constraints

    DEFF Research Database (Denmark)

    Sørensen, Rene; Lund, Erik

    2012-01-01

    This work concerns a new ply-based parameterization for performing simultaneous material selection and topology optimization of fiber reinforced laminated composite structures while ensuring that a series of different manufacturing constraints are fulfilled. The material selection can either...

  1. Understanding the Glycemic Index and Glycemic Load and Their Practical Applications

    Science.gov (United States)

    Lazarim, Fernanda Lorenzi; Stancanelli, Mirtes; Brenzikofer, Rene; de Macedo, Denise Vaz

    2009-01-01

    We have introduced the study of synthesis pathways using two experiments: 1--the determination of the glycemic index (GI) of some foods and the effects of fiber and fat on the GI; 2--the determination of blood glucose levels after the ingestion of meals with high and low glycemic loads (GL). After a practice assembly, when the foods and meals that…

  2. Maximizing Efficiency and Reducing Robotic Surgery Costs Using the NASA Task Load Index.

    Science.gov (United States)

    Walters, Carrie; Webb, Paula J

    2017-10-01

    Perioperative leaders at our facility were struggling to meet efficiency targets for robotic surgery procedures while also maintaining the satisfaction of the surgical team. We developed a human resources time and motion study tool and used it in conjunction with the NASA Task Load Index to observe and analyze the required workload of personnel assigned to 25 robotic surgery procedures. The time and motion study identified opportunities to enlist the help of nonlicensed support personnel to ensure safe patient care and improve OR efficiency. Using the NASA Task Load Index demonstrated that high temporal, effort, and physical demands existed for personnel assisting with and performing robotic surgery. We believe that this process could be used to develop cost-effective staffing models, resulting in safe and efficient care for all surgical patients. Copyright © 2017 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  3. Local and global nonlinear dynamics of a parametrically excited rectangular symmetric cross-ply laminated composite plate

    International Nuclear Information System (INIS)

    Ye Min; Lu Jing; Zhang Wei; Ding Qian

    2005-01-01

    The present investigation deals with nonlinear dynamic behavior of a parametrically excited simply supported rectangular symmetric cross-ply laminated composite thin plate for the first time. The governing equation of motion for rectangular symmetric cross-ply laminated composite thin plate is derived by using von Karman equation. The geometric nonlinearity and nonlinear damping are included in the governing equations of motion. The Galerkin approach is used to obtain a two-degree-of-freedom nonlinear system under parametric excitation. The method of multiple scales is utilized to transform the second-order non-autonomous differential equations to the first-order averaged equations. Using numerical method, the averaged equations are analyzed to obtain the steady state bifurcation responses. The analysis of stability for steady state bifurcation responses in laminated composite thin plate is also given. Under certain conditions laminated composite thin plate may have two or multiple steady state bifurcation solutions. Jumping phenomenon occurs in the steady state bifurcation solutions. The chaotic motions of rectangular symmetric cross-ply laminated composite thin plate are also found by using numerical simulation. The results obtained here demonstrate that the periodic, quasi-periodic and chaotic motions coexist for a parametrically excited fore-edge simply supported rectangular symmetric cross-ply laminated composite thin plate under certain conditions

  4. Composition of The Knee Index, a novel three-dimensional biomechanical index for knee joint load, in subjects with mild to moderate knee osteoarthritis

    DEFF Research Database (Denmark)

    Clausen, Brian; Andriacchi, Tom; Nielsen, Dennis Brandborg

    Background Knee joint load is an important factor associated with progression of knee osteoarthritis. To provide an overall understanding of knee joint loading, the Knee Index (KI) has been developed to include moments from all three planes (frontal, sagittal and transversal). However, before KI...... index of joint load for the knee, in patients with mild to moderate knee osteoarthritis. Methods The contribution of frontal, sagittal and transversal plane knee moments to KI was investigated in 24 subjects (13 women, age: 58 ± 7.6 years, BMI: 27.1 ± 3.0) with clinically diagnosed mild to moderate knee...... kinematics (i.e. the knee adduction moment), and secondarily the sagittal plane kinematics (i.e. the knee flexion moment). This holds promise for using KI in clinical trials since both frontal and sagittal knee joint moments have been suggested to be associated with the knee osteoarthritis disease...

  5. Free vibration of symmetric angle ply truncated conical shells under different boundary conditions using spline method

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, K. K.; Aziz, Z. A.; Javed, Saira; Yaacob, Y. [Universiti Teknologi Malaysia, Johor Bahru (Malaysia); Pullepu, Babuji [S R M University, Chennai (India)

    2015-05-15

    Free vibration of symmetric angle-ply laminated truncated conical shell is analyzed to determine the effects of frequency parameter and angular frequencies under different boundary condition, ply angles, different material properties and other parameters. The governing equations of motion for truncated conical shell are obtained in terms of displacement functions. The displacement functions are approximated by cubic and quintic splines resulting into a generalized eigenvalue problem. The parametric studies have been made and discussed.

  6. Free vibration of symmetric angle ply truncated conical shells under different boundary conditions using spline method

    International Nuclear Information System (INIS)

    Viswanathan, K. K.; Aziz, Z. A.; Javed, Saira; Yaacob, Y.; Pullepu, Babuji

    2015-01-01

    Free vibration of symmetric angle-ply laminated truncated conical shell is analyzed to determine the effects of frequency parameter and angular frequencies under different boundary condition, ply angles, different material properties and other parameters. The governing equations of motion for truncated conical shell are obtained in terms of displacement functions. The displacement functions are approximated by cubic and quintic splines resulting into a generalized eigenvalue problem. The parametric studies have been made and discussed.

  7. Glycemic index and glycemic load in the Opuntia ficus-indica fruit

    Science.gov (United States)

    Ibarra-Salas, María de Jesús; Novelo-Huerta, Hilda Irene; De León-Salas, Marcela Alejandra; Sánchez-Murillo, Mayra Elisa; Mata-Obregón, María Del Carmen; Garza-Juárez, Aurora de Jesús

    2017-01-01

    There is evidence that support the clinical usage of glycemic index (GI) and glycemic load (GL) in the prevention of chronic disease. To determine the GI and GL of the Opuntia ficus-indica fruit. An analytic, transversal study was made involving 25 healthy volunteers accepted by an informed consent with a normal body mass index, glucose, glycoside hemoglobin, cholesterol and serum triglycerides. The homogeneity of the population was evaluated with anthropometrical and biochemical data using principal component analysis (PCA). The equivalent of 50 g of carbohydrates test food (tuna) and 50 g of dextrose as food standard was provided for the measure of the glucose curve. The GI was determined by calculating the area under the curve by the triangulation method. The CG was reported as the product of IG by carbohydrate loading provided. The IG of the tuna was 48.01 ± 17.4, classified as low, while the CG was 24.0 ± 8.7 rated as high. The chemometric analysis by PCA showed that the selection of the normal population for determining the IG, it is important to consider the values of cholesterol and triglycerides. Copyright: © 2017 SecretarÍa de Salud

  8. Heel blood flow during loading and off-loading in bedridden older adults with low and normal ankle-brachial pressure index: a quasi-experimental study.

    Science.gov (United States)

    Masaki, Nami; Sugama, Junko; Okuwa, Mayumi; Inagaki, Misako; Matsuo, Junko; Nakatani, Tosio; Sanada, Hiromi

    2013-07-01

    The purpose of this study was to evaluate the differences in heel blood flow during loading and off-loading in bedridden adults older than 65 years. The patients were divided into three groups based on ankle-brachial pressure index (ABI) and transcutaneous oxygen tension (tcPO₂): (1) patients with an ABI ≥ 0.8 (Group A); (2) patients with an ABI < 0.8 and heel tcPO₂ ≥ 10 mmHg (Group B); and (3) patients with an ABI < 0.8 and heel tcPO₂ < 10 mmHg (Group C). Heel blood flow was monitored using tcPO₂ sensors. Data were collected with the heel (1) suspended above the bed surface (preload), (2) on the bed surface for 30 min (loading), and (3) again suspended above the bed surface for 60 min (off-loading). Heel blood flow during off-loading was assessed using three parameters: oxygen recovery index (ORI), total tcPO₂ for the first 10 min, and change in tcPO₂ after 60 min of off-loading. ORI in Group C (n = 8) was significantly shorter than in Groups A (n = 22) and B (n = 15). Total tcPO₂ for the first 10 min of off-loading in Group C was significantly less than that in Groups A and B. Change in tcPO₂ after 60 min of off-loading in Group C was less than in Group A. Based on these findings, additional preventive care against heel blood flow decrease in older adults with an ABI < 0.8 and heel tcPO₂ < 10 mmHg might be necessary after loading.

  9. Thickness measuring apparatus and method for tire ply and similar materials

    International Nuclear Information System (INIS)

    Cho, B.Y.; Utt, O.L.

    1978-01-01

    The invention relates to method and apparatus for measuring the amount of material on opposite sides of the reinforcing cord of a tire ply, and more particularly relates to a backscatter X-ray radiation gauging apparatus and method for obtaining the aforesaid measurements. (author)

  10. Comparing IndexedHBase and Riak for Serving Truthy: Performance of Data Loading and Query Evaluation

    Science.gov (United States)

    2013-08-01

    evaluation We choose one popular meme “#euro2012” within the loaded dataset, as along with a time window whose length varies from 3 hours to 16...IndexedHBase. The “ meme -post-count” query falls into this category. On IndexedHBase, query evaluation can be done by simply going through the rows in meme ...index tables for each meme in the query and counting the number of qualified tweet IDs. In the case of Riak this is accomplished by issuing an HTTP

  11. Can we improve pollen season definitions by using the symptom load index in addition to pollen counts?

    International Nuclear Information System (INIS)

    Bastl, Katharina; Kmenta, Maximilian; Geller-Bernstein, Carmi; Berger, Uwe; Jäger, Siegfried

    2015-01-01

    Airborne pollen measurements are the foundation of aerobiological research and provide essential raw data for various disciplines. Pollen itself should be considered a relevant factor in air quality. Symptom data shed light on the relationship of pollen allergy and pollination. The aim of this study is to assess the spatial variation of local, regional and national symptom datasets. Ten pollen season definitions are used to calculate the symptom load index for the birch and grass pollen seasons (2013–2014) in Austria. (1) Local, (2) regional and (3) national symptom datasets are used to examine spatial variations and a consistent pattern was found. In conclusion, national datasets are suitable for first insights where no sufficient local or regional dataset is available and season definitions based on percentages provide a practical solution, as they can be applied in regions with different pollen loads and produce more constant results. - Highlights: • The definition of the pollen season has an impact on the calculated symptom load. • Pollen season definitions based on percentages of total pollen are a practical solution. • The symptom load index is a robust tool to assess the allergy burden in a population. • Local, regional and national burdens of pollen allergy sufferers are comparable. - The symptom load index is a robust tool to assess the allergy burden in a population. Local, regional and national burdens of pollen allergy sufferers are comparable

  12. Effects of stacking sequence on fracture mechanisms in quasi-isotropic Carbon/epoxy laminates under tensile loading

    International Nuclear Information System (INIS)

    Hessabi, Z. R.; Majidi, B.; Aghazadeh, J.

    2006-01-01

    The progress of damage in quasi-isotropic carbon/epoxy laminates under tensile loading has been Investigated microscopically. One significant mode of failure in laminated composites is delamination initiating at free edges. The interlaminar stress in the boundary ply along the free edges of a laminated composite is the main factor to cause delamination. The laminate stacking sequence affects the interlaminar stress distribution and consequently may change the mode of failure. It is of design importance to determine a suitable criterion based on stress analysis to obtain the best stacking sequence. In the present work, tensile properties of six samples with different stacking sequences have been examined. Results showed that stress analysis at distance very close to the free edges is a suitable criterion to predict the initiation of delamination and the stacking sequence of [90/45/0/-45] s , has the highest strength among the others. Furthermore finite element analysis showed that the adjacent ±45 plies cause premature delamination during tensile loading

  13. Microcracking in composite laminates under thermal and mechanical loading. Thesis

    Science.gov (United States)

    Maddocks, Jason R.

    1995-01-01

    Composites used in space structures are exposed to both extremes in temperature and applied mechanical loads. Cracks in the matrix form, changing the laminate thermoelastic properties. The goal of the present investigation is to develop a predictive methodology to quantify microcracking in general composite laminates under both thermal and mechanical loading. This objective is successfully met through a combination of analytical modeling and experimental investigation. In the analysis, the stress and displacement distributions in the vicinity of a crack are determined using a shear lag model. These are incorporated into an energy based cracking criterion to determine the favorability of crack formation. A progressive damage algorithm allows the inclusion of material softening effects and temperature-dependent material properties. The analysis is implemented by a computer code which gives predicted crack density and degraded laminate properties as functions of any thermomechanical load history. Extensive experimentation provides verification of the analysis. AS4/3501-6 graphite/epoxy laminates are manufactured with three different layups to investigate ply thickness and orientation effects. Thermal specimens are cooled to progressively lower temperatures down to -184 C. After conditioning the specimens to each temperature, cracks are counted on their edges using optical microscopy and in their interiors by sanding to incremental depths. Tensile coupons are loaded monotonically to progressively higher loads until failure. Cracks are counted on the coupon edges after each loading. A data fit to all available results provides input parameters for the analysis and shows them to be material properties, independent of geometry and loading. Correlation between experiment and analysis is generally very good under both thermal and mechanical loading, showing the methodology to be a powerful, unified tool. Delayed crack initiation observed in a few cases is attributed to a

  14. Glycemic index and glycemic load in relation to glucose intolerance among Greenland's Inuit population

    DEFF Research Database (Denmark)

    van Aerde, Marieke A; Witte, Daniel Rinse; Jeppesen, Charlotte

    2012-01-01

    Intake of carbohydrates which elicit a large glycemic response is hypothesized to increase the risk of diabetes. However, studies assessing the relationship between glycemic index (GI) and glycemic load (GL) and diabetes are inconsistent. Only few studies have studied the relationship between GI ...

  15. Stochastic failure modelling of unidirectional composite ply failure

    International Nuclear Information System (INIS)

    Whiteside, M.B.; Pinho, S.T.; Robinson, P.

    2012-01-01

    Stochastic failure envelopes are generated through parallelised Monte Carlo Simulation of a physically based failure criteria for unidirectional carbon fibre/epoxy matrix composite plies. Two examples are presented to demonstrate the consequence on failure prediction of both statistical interaction of failure modes and uncertainty in global misalignment. Global variance-based Sobol sensitivity indices are computed to decompose the observed variance within the stochastic failure envelopes into contributions from physical input parameters. The paper highlights a selection of the potential advantages stochastic methodologies offer over the traditional deterministic approach.

  16. Self-plied and twist-stable carbon nanotube yarn artificial muscles driven by organic solvent adsorption.

    Science.gov (United States)

    Jin, Kaiyun; Zhang, Silan; Zhou, Susheng; Qiao, Jian; Song, Yanhui; Di, Jiangtao; Zhang, Dengsong; Li, Qingwen

    2018-05-03

    Artificial yarn/fiber muscles have recently attracted considerable interest for various applications. These muscles can provide large-stroke tensile and torsional actuations, resulting from inserted twists. However, tensional tethering of twisted muscles is generally needed to avoid muscle snarling and untwisting. In this paper a carbon nanotube (CNT) yarn muscle that is tethering-free and twist-stable is reported. The yarn muscle is prepared by allowing the self-plying of a coiled CNT yarn. When driven by acetone adsorption, this muscle shows decoupled actuations, which provide fast and reversible ∼13.3% contraction strain against a constant stress corresponding to ∼38 000 times the muscle weight but almost zero torsional strokes. The cycling test shows that the self-plied muscle has very good structural stability and actuation reversibility. Applied joule heating can help increase the desorption of acetone and increase the operation frequency of the self-plied muscle. Furthermore, by controlling the coupling between the joule heating and acetone adsorption/desorption, tensile actuations from negative to positive have been achieved. This twist-stable feature could considerably facilitate the practical applications of such muscle.

  17. Historical environmental pollution trend and ecological risk assessment of trace metals in marine sediments off Adyar estuary, Bay of Bengal, India.

    Digital Repository Service at National Institute of Oceanography (India)

    Veerasingam, S.; Venkatachalapathy, R.; Ramkumar, T.

    activities. The mean anthropogenic factor (AF) values for trace metals in core sediments decreased in the following order: Cr > Ni > Zn > Cu > Pb. The pollution load index (PLI) values in Adyar core sediments ranged from 1 to 1.25 with an average of 1...

  18. Effect of mesh-peel ply variation on mechanical properties of E-glas composite by infusion vacuum method

    Science.gov (United States)

    Abdurohman, K.; Siahaan, Mabe

    2018-04-01

    Composite materials made of glass fiber EW-135 with epoxy lycal resin with vacuum infusion method have been performed. The dried glass fiber is arranged in a mold then connected to a vacuum machine and a resin tube. Then, the vacuum machine is turned on and at the same time the resin is sucked and flowed into the mold. This paper reports on the effect of using mesh- peel ply singles on upper-side laminates called A and the effect of using double mesh-peel ply on upper and lower-side laminates call B with glass fiber arrangement is normal and ± 450 in vacuum infusion process. Followed by the manufacture of tensile test specimen and tested its tensile strength with universal test machine 100kN Tensilon RTF 2410, at room temperature with constant crosshead speed. From tensile test results using single and double layers showed that double mesh-peel ply can increase tensile strength 14% and Young modulus 17%.

  19. Chimeric Ply187 endolysin kills Staphylococcus aureus more effectively than the parental enzyme.

    Science.gov (United States)

    Peptidoglycan hydrolases are an effective new source of antimicrobials. A chimeric fusion protein of the Ply187 endopeptidase domain and LysK SH3b cell wall binding domain is a potent agent against Staphylococcus aureus in three functional assays....

  20. Overall glycaemic index and glycaemic load of habitual diet and risk of heart disease

    DEFF Research Database (Denmark)

    Grau, Katrine; Tetens, Inge; Bjørnsbo, Kirsten S

    2011-01-01

    Objective To test the hypothesis that diets with high glycaemic index (GI) and glycaemic load (GL) increase the risk of heart disease. Design Overall GI and GL were assessed from 7 d diet records or diet history interviews. Setting Information on hospitalization and death due to CVD and CHD was o...

  1. Correlation bethealtyy ween dietary glycemic index and glycemic load and blood lipid levels in a group of women from Ahvaz

    OpenAIRE

    Farideh Shishebor; Zahra Shamekhi; Majid Karandish; Seyed Mahmood Latifi

    2011-01-01

    Background & Objectives: There are limited number of studies conducted on the correlation between Glycemic index and Glycemic load of a food program and metabolic factors such as blood lipids in Asian countries including Iran. Therefore, this study aimed at analyzing the correlation between Glycemic index and Glycemic load of Iranian food program and blood lipids. Materials & Methods: The subjects were 95 women working in Ahvaz University of Medical Sciences in the range of 20 to 55 years old...

  2. Braking, steering, and wear performance of radial-belted and bias-ply aircraft tires

    Science.gov (United States)

    Yager, Thomas J.; Davis, Pamela A.; Stubbs, Sandy M.; Martinson, Veloria J.

    1992-01-01

    Preliminary steering, braking, and tread wear performance results from testing of radial-belted and bias-ply aircraft tires at NASA Langley are described. An overview of the joint NASA/FAA/industry START program is presented. Attention is given to the Langley Test Facility, equipment and future activities.

  3. High-resolution fiber tract reconstruction in the human brain by means of three-dimensional polarized light imaging (3D-PLI

    Directory of Open Access Journals (Sweden)

    Markus eAxer

    2011-12-01

    Full Text Available Functional interactions between different brain regions require connecting fiber tracts, the structural basis of the human connectome. To assemble a comprehensive structural understanding of neural network elements from the microscopic to the macroscopic dimensions, a multimodal and multiscale approach has to be envisaged. However, the integration of results from complementary neuroimaging techniques poses a particular challenge. In this paper, we describe a steadily evolving neuroimaging technique referred to as three-dimensional polarized light imaging (3D-PLI. It is based on the birefringence of the myelin sheaths surrounding axons, and enables the high-resolution analysis of myelinated axons constituting the fiber tracts. 3D-PLI provides the mapping of spatial fiber architecture in the postmortem human brain at a sub-millimeter resolution, i.e. at the mesoscale. The fundamental data structure gained by 3D-PLI is a comprehensive 3D vector field description of fibers and fiber tract orientations – the basis for subsequent tractography. To demonstrate how 3D-PLI can contribute to unravel and assemble the human connectome, a multiscale approach with the same technology was pursued. Two complementary state-of-the-art polarimeters providing different sampling grids (pixel sizes of 100 μm and 1.6 μm were used. To exemplarily highlight the potential of this approach, fiber orientation maps and 3D fiber models were reconstructed in selected regions of the brain (e.g., Corpus callosum, Internal capsule, Pons. The results demonstrate that 3D-PLI is an ideal tool to serve as an interface between the microscopic and macroscopic levels of organization of the human connectome.

  4. Multi-load Optimal Design of Burner-inner-liner Under Performance Index Constraint by Second-Order Polynomial Taylor Series Method

    Directory of Open Access Journals (Sweden)

    Tu Gaoqiao

    2016-01-01

    Full Text Available Using maximum expansion pressure of n-decane, the aeroengine burner-inner-liner combustion pressure load is computed. Aerodynamic loads are obtained from internal gas pressure load and gas momentum. Multi-load second-order Taylor series equations are established using multi-variant polynomials and their sensitivities. Optimal designs are carried out using various performance index constraints. When 0.25 to 0.8 rectifications of different design variants are implemented, they converge under 5×10‒4 d-norm difference ratio.

  5. Contributors to dietary glycaemic index and glycaemic load in the Netherlands: the role of beer

    NARCIS (Netherlands)

    Sluik, D.; Atkinson, Fiona S.; Brand-Miller, J.; Fogelholm, M.; Raben, A.; Feskens, E.J.M.

    2016-01-01

    Diets high in glycaemic index (GI) and glycaemic load (GL) have been associated with a higher diabetes risk. Beer explained a large proportion of variation in GI in a Finnish and an American study. However, few beers have been tested according to International Organization for Standardization (ISO)

  6. Acute effect of meal glycemic index and glycemic load on blood glucose and insulin responses in humans

    Directory of Open Access Journals (Sweden)

    Díaz Erik

    2006-09-01

    Full Text Available Abstract Objective Foods with contrasting glycemic index when incorporated into a meal, are able to differentially modify glycemia and insulinemia. However, little is known about whether this is dependent on the size of the meal. The purposes of this study were: i to determine if the differential impact on blood glucose and insulin responses induced by contrasting GI foods is similar when provided in meals of different sizes, and; ii to determine the relationship between the total meal glycemic load and the observed serum glucose and insulin responses. Methods Twelve obese women (BMI 33.7 ± 2.4 kg/m2 were recruited. Subjects received 4 different meals in random order. Two meals had a low glycemic index (40–43% and two had a high-glycemic index (86–91%. Both meal types were given as two meal sizes with energy supply corresponding to 23% and 49% of predicted basal metabolic rate. Thus, meals with three different glycemic loads (95, 45–48 and 22 g were administered. Blood samples were taken before and after each meal to determine glucose, free-fatty acids, insulin and glucagon concentrations over a 5-h period. Results An almost 2-fold higher serum glucose and insulin incremental area under the curve (AUC over 2 h for the high- versus low-glycemic index same sized meals was observed (p Conclusion This study showed that foods of contrasting glycemic index induced a proportionally comparable difference in serum insulin response when provided in both small and large meals. The same was true for the serum glucose response but only in large meals. Glycemic load was useful in predicting the acute impact on blood glucose and insulin responses within the context of mixed meals.

  7. Failure of composite plates under static biaxial planar loading

    Science.gov (United States)

    Waas, Anthony M.; Khamseh, Amir R.

    1992-01-01

    The project involved detailed investigations into the failure mechanisms in composite plates as a function of hole size (holes centrally located in the plates) under static loading. There were two phases to the project, the first dealing with uniaxial loads along the fiber direction, and the second dealing with coplanar biaxial loading. Results for the uniaxial tests have been reported and published previously, thus this report will place emphasis on the second phase of the project, namely the biaxial tests. The composite plates used in the biaxial loading experiments, as well as the uniaxial, were composed of a single ply unidirectional graphite/epoxy prepreg sandwiched between two layers of transparent thermoplastic. This setup enabled us to examine the failure initiation and propagation modes nondestructively, during the test. Currently, similar tests and analysis of results are in progress for graphite/epoxy cruciform shaped flat laminates. The results obtained from these tests will be available at a later time.

  8. Validation of the National Aeronautics and Space Administration Task Load Index as a tool to evaluate the learning curve for endoscopy training.

    Science.gov (United States)

    Mohamed, Rachid; Raman, Maitreyi; Anderson, John; McLaughlin, Kevin; Rostom, Alaa; Coderre, Sylvain

    2014-03-01

    Although workplace workload assessments exist in different fields, an endoscopy-specific workload assessment tool is lacking. To validate such a workload tool and use it to map the progression of novice trainees in gastroenterology in performing their first endoscopies. The National Aeronautics and Space Administration Task Load Index (NASA-TLX) workload assessment tool was completed by eight novice trainees in gastroenterology and 10 practicing gastroenterologists⁄surgeons. An exploratory factor analysis was performed to construct a streamlined endoscopy-specific task load index, which was subsequently validated. The 'Endoscopy Task Load Index' was used to monitor progression of trainee exertion and self-assessed performance over their first 40 procedures. From the factor analysis of the NASA-TLX, two principal components emerged: a measure of exertion and a measure of self-efficacy. These items became the components of the newly validated Endoscopy Task Load Index. There was a steady decline in self-perceived exertion over the training period, which was more rapid for gastroscopy than colonoscopy. The self-efficacy scores for gastroscopy rapidly increased over the first few procedures, reaching a plateau after this period of time. For colonoscopy, there was a progressive increase in reported self-efficacy over the first three quartiles of procedures, followed by a drop in self-efficacy scores over the final quartile. The present study validated an Endoscopy Task Load Index that can be completed in <1 min. Practical implications of such a tool in endoscopy education include identifying periods of higher perceived exertion among novice endoscopists, facilitating appropriate levels of guidance from trainers.

  9. Asymmetric free vibrations of laminated annular cross-ply circular plates including the effects of shear deformation and rotary inertia. Spline method

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, K.K.; Kim, Kyung Su; Lee, Jang Hyun [Inha Univ., Incheon (Korea). Dept. of Naval Architecture and Ocean Engineering

    2009-12-15

    Asymmetric free vibrations of annular cross-ply circular plates are studied using spline function approximation. The governing equations are formulated including the effects of shear deformation and rotary inertia. Assumptions are made to study the cross-ply layered plates. A system of coupled differential equations are obtained in terms of displacement functions and rotational functions. These functions are approximated using Bickley- type spline functions of suitable order. Then the system is converted into the eigenvalue problem by applying the point collocation technique and suitable boundary conditions. Parametric studies have been made to investigate the effect of transverse shear deformation and rotary inertia on frequency parameter with respect to the circumferential node number, radii ratio and thickness to radius ratio for both symmetric and anti-symmetric cross-ply plates using various types of material properties. (orig.)

  10. Contributors to dietary glycaemic index and glycaemic load in the Netherlands

    DEFF Research Database (Denmark)

    Sluik, Diewertje; Atkinson, Fiona S; Brand-Miller, Jennie

    2016-01-01

    Diets high in glycaemic index (GI) and glycaemic load (GL) have been associated with a higher diabetes risk. Beer explained a large proportion of variation in GI in a Finnish and an American study. However, few beers have been tested according to International Organization for Standardization (ISO......, coffee and tea. The results were more pronounced in men than in women. In conclusion, beer is a high-GI food. Despite its relatively low carbohydrate content (approximately 4-5 g/100 ml), it still made a contribution to dietary GL, especially in men. Next to potatoes, bread, sugar and sugar...

  11. Biaxial mechanics and inter-lamellar shearing of stem-cell seeded electrospun angle-ply laminates for annulus fibrosus tissue engineering.

    Science.gov (United States)

    Driscoll, Tristan P; Nakasone, Ryan H; Szczesny, Spencer E; Elliott, Dawn M; Mauck, Robert L

    2013-06-01

    The annulus fibrosus (AF) of the intervertebral disk plays a critical role in vertebral load transmission that is heavily dependent on the microscale structure and composition of the tissue. With degeneration, both structure and composition are compromised, resulting in a loss of AF mechanical function. Numerous tissue engineering strategies have addressed the issue of AF degeneration, but few have focused on recapitulation of AF microstructure and function. One approach that allows for generation of engineered AF with appropriate (+/-)30° lamellar microstructure is the use of aligned electrospun scaffolds seeded with mesenchymal stem cells (MSCs) and assembled into angle-ply laminates (APL). Previous work indicates that opposing lamellar orientation is necessary for development of near native uniaxial tensile properties. However, most native AF tensile loads are applied biaxially, as the disk is subjected to multi-axial loads and is constrained by its attachments to the vertebral bodies. Thus, the objective of this study was to evaluate the biaxial mechanical response of engineered AF bilayers, and to determine the importance of opposing lamellar structure under this loading regime. Opposing bilayers, which replicate native AF structure, showed a significantly higher modulus in both testing directions compared to parallel bilayers, and reached ∼60% of native AF biaxial properties. Associated with this increase in biaxial properties, significantly less shear, and significantly higher stretch in the fiber direction, was observed. These results provide additional insight into native tissue structure-function relationships, as well as new benchmarks for engineering functional AF tissue constructs. Copyright © 2013 Orthopaedic Research Society.

  12. NASA Task Load Index (TLX). Volume 1.0; Computerized Version

    Science.gov (United States)

    Hart, Sandra G.

    1986-01-01

    This booklet and the accompanying diskette contain the materials necessary to collect subjective workload assessments with the NASA Task Load Index on IBM PC compatible microcomputers. This procedure for collecting workload ratings was developed by the Human Performance Group at NASA Ames Research Center during a three year research effort that involved more than 40 laboratory, simulation, and inflight experiments Although the technique is still undergoing evaluation, this package is being distributed to allow other researchers to use it in their own experiments Comments or suggestions about the procedure would be greatly appreciated This package is intended to fill a "nuts and bolts" function of describing the procedure. A bibliography provides background information about previous empirical findings and the logic that supports the procedure.

  13. The NIOSH lifting equation and low-back pain, Part 1: Association with low-back pain in the backworks prospective cohort study.

    Science.gov (United States)

    Garg, Arun; Boda, Sruthi; Hegmann, Kurt T; Moore, J Steven; Kapellusch, Jay M; Bhoyar, Parag; Thiese, Matthew S; Merryweather, Andrew; Deckow-Schaefer, Gwen; Bloswick, Donald; Malloy, Elizabeth J

    2014-02-01

    The aim of this study was to evaluate relationships between the revised NIOSH lifting equation (RNLE) and risk of low-back pain (LBP). The RNLE is commonly used to quantify job physical stressors to the low back from lifting and/or lowering of loads. There is no prospective study on the relationship between RNLE and LBP that includes accounting for relevant covariates. A cohort of 258 incident-eligible workers from 30 diverse facilities was followed for up to 4.5 years. Job physical exposures were individually measured. Worker demographics, medical history, psychosocial factors, hobbies, and current LBP were obtained at baseline. The cohort was followed monthly to ascertain development of LBP and quarterly to determine changes in job physical exposure. The relationship between LBP and peak lifting index (PLI) and peak composite lifting index (PCLI) were tested in multivariate models using proportional hazards regression. Point and lifetime prevalences of LBP at baseline were 7.1% and 75.1%, respectively. During follow-up, there were 123 incident LBP cases. Factors predicting development of LBP included job physical exposure (PLI and PCLI), history of LBP, psychosocial factors, and housework. In adjusted models, risk (hazard ratio [HR]) increased per-unit increase in PLI and PCLI (p = .05 and .02; maximum HR = 4.3 and 4.2, respectively). PLI suggested a continuous increase in risk with an increase in PLI, whereas the PCLI showed elevated, but somewhat reduced, risk at higher exposures. Job physical stressors are associated with increased risk of LBP. Data suggest that the PLI and PCLI are useful metrics for estimating exposure to job physical stressors.

  14. Validation of the National Aeronautics and Space Administration Task Load Index as a tool to evaluate-the learning curve for endoscopy training

    Science.gov (United States)

    Mohamed, Rachid; Raman, Maitreyi; Anderson, John; McLaughlin, Kevin; Rostom, Alaa; Coderre, Sylvain

    2014-01-01

    BACKGROUND: Although workplace workload assessments exist in different fields, an endoscopy-specific workload assessment tool is lacking. OBJECTIVE: To validate such a workload tool and use it to map the progression of novice trainees in gastroenterology in performing their first endoscopies. METHODS: The National Aeronautics and Space Administration Task Load Index (NASA-TLX) workload assessment tool was completed by eight novice trainees in gastroenterology and 10 practicing gastroenterologists/surgeons. An exploratory factor analysis was performed to construct a streamlined endoscopy-specific task load index, which was subsequently validated. The ‘Endoscopy Task Load Index’ was used to monitor progression of trainee exertion and self-assessed performance over their first 40 procedures. RESULTS: From the factor analysis of the NASA-TLX, two principal components emerged: a measure of exertion and a measure of self-efficacy. These items became the components of the newly validated Endoscopy Task Load Index. There was a steady decline in self-perceived exertion over the training period, which was more rapid for gastroscopy than colonoscopy. The self-efficacy scores for gastroscopy rapidly increased over the first few procedures, reaching a plateau after this period of time. For colonoscopy, there was a progressive increase in reported self-efficacy over the first three quartiles of procedures, followed by a drop in self-efficacy scores over the final quartile. DISCUSSION: The present study validated an Endoscopy Task Load Index that can be completed in <1 min. Practical implications of such a tool in endoscopy education include identifying periods of higher perceived exertion among novice endoscopists, facilitating appropriate levels of guidance from trainers. PMID:24619638

  15. Intravitreal injection of a chimeric phage endolysin Ply187 protects mice from Staphylococcus aureus endophthalmitis

    Science.gov (United States)

    Objectives: The treatment of endophthalmitis is becoming very challenging due to the emergence of multidrug-resistant bacteria. Hence, the development of novel therapeutic alternatives for ocular use is essential. Here, we evaluated the therapeutic potential of Ply187AN-KSH3b, a chimeric phage endol...

  16. Off-Axis Ratcheting Behavior of Unidirectional Carbon/Epoxy Laminate under Asymmetric Cyclic Loading at High Temperature

    Science.gov (United States)

    2011-11-01

    ply unidirectional carbon/epoxy laminates [0]12 were fabricated from the prepreg tape of P3252-20 (TORAY). They were laid up by hand and cured in...Off-Axis Ratcheting Behavior of Unidirectional Carbon/Epoxy Laminate under Asymmetric Cyclic Loading at High Temperature Takafumi Suzuki 1 and...Development of an engineering model for predicting the off-axis ratcheting behavior of a unidirectional CFRP laminate has been attempted. For this purpose

  17. Thermomechanical response of a cross-ply titanium matrix composite subjected to a generic hypersonic flight profile

    International Nuclear Information System (INIS)

    Mirdamadi, M.; Johnson, W.S.

    1993-01-01

    Cross-ply laminate behavior of Ti-15V-3Cr-3AI-3Sn (Ti-15-3) matrix reinforced with continuous silicon-carbide fibers (SCS-6) subjected to a generic hypersonic flight profile was evaluated experimentally and analytically. Thermomechanical fatigue test techniques were developed to conduct a simulation of a generic hypersonic flight profile. A micromechanical analysis was used. The analysis predicts the stress-strain response of the laminate and of the constituents in each ply during thermal and mechanical cycling by using only constituent properties as input. The fiber was modeled as elastic with transverse orthotropic and temperature-dependent properties. The matrix was modeled using a thermoviscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate the fiber-matrix interface failure. Excellent correlation was found between measured and predicted laminate stress-strain response due to generic hypersonic flight profile when fiber debonding was modeled

  18. Active investigation of material damage under load using micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Navalgund, Megha, E-mail: megha.navalgund@ge.com; Mishra, Debasish; Manoharan, V. [NDE Lab, GE Global Research - Bangalore (India); Zunjarrao, Suraj [Composites Material Behavior Lab, GE Global Research-Bangalore (India)

    2015-03-31

    Due the growth of composite materials across multiple industries such as Aviation, Wind there is an increasing need to not just standardize and improve manufacturing processes but also to design these materials for the specific applications. One of the things that this translates to is understanding how failure initiates and grows in these materials and at what loads, especially around internal flaws such as voids or features such as ply drops. Traditional methods of investigating internal damage such as CT lack the resolution to resolve ply level damage in composites. Interrupted testing with layer removal can be used to investigate internal damage using microscopy; however this is a destructive method. Advanced techniques such as such as DIC are useful for in-situ damage detection, however are limited to surface information and would not enable interrogating the volume. Computed tomography has become a state of the art technique for metrology and complete volumetric investigation especially for metallic components. However, its application to the composite world is still nascent. This paper demonstrates micro-CT’s capability as a gauge to quantitatively estimate the extent of damage and understand the propagation of damage in PMC composites while the component is under stress.

  19. Active investigation of material damage under load using micro-CT

    Science.gov (United States)

    Navalgund, Megha; Zunjarrao, Suraj; Mishra, Debasish; Manoharan, V.

    2015-03-01

    Due the growth of composite materials across multiple industries such as Aviation, Wind there is an increasing need to not just standardize and improve manufacturing processes but also to design these materials for the specific applications. One of the things that this translates to is understanding how failure initiates and grows in these materials and at what loads, especially around internal flaws such as voids or features such as ply drops. Traditional methods of investigating internal damage such as CT lack the resolution to resolve ply level damage in composites. Interrupted testing with layer removal can be used to investigate internal damage using microscopy; however this is a destructive method. Advanced techniques such as such as DIC are useful for in-situ damage detection, however are limited to surface information and would not enable interrogating the volume. Computed tomography has become a state of the art technique for metrology and complete volumetric investigation especially for metallic components. However, its application to the composite world is still nascent. This paper demonstrates micro-CT's capability as a gauge to quantitatively estimate the extent of damage & understand the propagation of damage in PMC composites while the component is under stress.

  20. Active investigation of material damage under load using micro-CT

    International Nuclear Information System (INIS)

    Navalgund, Megha; Mishra, Debasish; Manoharan, V.; Zunjarrao, Suraj

    2015-01-01

    Due the growth of composite materials across multiple industries such as Aviation, Wind there is an increasing need to not just standardize and improve manufacturing processes but also to design these materials for the specific applications. One of the things that this translates to is understanding how failure initiates and grows in these materials and at what loads, especially around internal flaws such as voids or features such as ply drops. Traditional methods of investigating internal damage such as CT lack the resolution to resolve ply level damage in composites. Interrupted testing with layer removal can be used to investigate internal damage using microscopy; however this is a destructive method. Advanced techniques such as such as DIC are useful for in-situ damage detection, however are limited to surface information and would not enable interrogating the volume. Computed tomography has become a state of the art technique for metrology and complete volumetric investigation especially for metallic components. However, its application to the composite world is still nascent. This paper demonstrates micro-CT’s capability as a gauge to quantitatively estimate the extent of damage and understand the propagation of damage in PMC composites while the component is under stress

  1. Evaluation of Thin Kevlar-Epoxy Fabric Panels Subjected to Shear Loading

    Science.gov (United States)

    Baker, Donald J.

    1996-01-01

    The results of an analytical and experimental investigation of 4-ply Kevlar-49-epoxy panels loaded by in-plane shear are presented. Approximately one-half of the panels are thin-core sandwich panels and the other panels are solid-laminate panels. Selected panels were impacted with an aluminum sphere at a velocity of either 150 or 220 ft/sec. The strength of panels impacted at 150 ft/sec was not reduced when compared to the strength of the undamaged panels, but the strength of panels impacted at 220 ft/sec was reduced by 27 to 40 percent. Results are presented for panels that were cyclically loaded from a load less than the buckling load to a load in the postbuckling load range. The thin-core sandwich panels had a lower fatigue life than the solid panels. The residual strength of the solid and sandwich panels cycled more than one million cycles exceeded the baseline undamaged panel strengths. The effect of hysteresis in the response of the sandwich panels is not significant. Results of a nonlinear finite element analysis conducted for each panel design are presented.

  2. Flexible two-ply yarn supercapacitors based on carbon nanotube/stainless steel core spun yarns decorated with Co3O4 nanoparticles and MnOx composites

    International Nuclear Information System (INIS)

    Su, Fenghua; Lyu, Xiaoming; Liu, Cansen; Miao, Menghe

    2016-01-01

    Highlights: • Carbon nanotube/stainless steel core-sheath yarns as electrode for two-ply supercapacitor. • The yarns were decorated with Co 3 O 4 nanoparticles and MnO x composites. • Yarn electrodes deposited on Co 3 O 4 and MnO x have excellent specific capacitance. • The two-ply yarn supercapacitor based on MnO x has high energy density and power density. • The yarn supercapacitors are highly flexible and strong for wearable electronics. - Abstract: High performance two-ply yarn supercapacitors are fabricated by electrodeposition of transition metal oxide pseudocapacitive materials on carbon nanotube/stainless steel (CNT/SS) core spun yarns. The SS core incorporated in the carbon nanotube yarn has dramatically improved the conductivity of the substrate and the efficiency of electrodeposition of metal oxides on the electrodes. The SS core acts as current collector in the final two-ply yarn supercapacitors with significantly improved specific capacitance and up-scaled length of supercapacitors. Manganese oxide and cobalt oxide electrodeposited on as-spun CNT/SS yarn are compared for their electrochemical performance in two-ply yarn supercapacitors. Both supercapacitors displayed improvement in capacitance, energy and power densities, especially MnO x /CNT/SS yarn supercapacitor. The solid-state supercapacitor based on MnO x /CNT/SS composite yarn shows excellent electrochemical properties with a specific capacitance of 217.61 F/cm 3 at 0.02 V/s and an energy density of 4.84 mWh/cm 3 at a power density of 435.22 mW/cm 3 .

  3. Effect of Thermo-Mechanical Treatment on the Interface Microstructure and Mechanical Properties of a STS-Al-Mg 3-ply Plate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung-Su; Lee, Sunghak; Chang, Young Won [Pohang University of Science and Technology, Pohang (Korea, Republic of); Lee, Kwang Seok; Kwon, Yong-Nam; Lee, Young-Seon [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2013-07-15

    The aim of this article is to elucidate the influence of reduction ratio during roll bonding on the microstructural evolution, mechanical properties and room-temperature formability of Al-Cu 2-ply clad metal. The evolution of the interface microstructure was first characterized by a scanning electron microscope (SEM) and transmission electron microscope (TEM) attached with energy dispersive spectroscopy (EDS). The presence of an intermetallic compound as well as severe grain refinement was detected at the interface of the Al-Cu bimetal fabricated under the highest reduction ratio of 65% adopted in this study. Taking into account the difference of the microstructure with a reduction the ratio, mechanical properties and bonding strength were then evaluated by uniaxial tensile and peel tests. It was observed that the bonding strength, elongation and tensile strength for Al-Cu 2-ply sheets were incomparably reduced by decreasing the reduction ratio during the roll bonding process, which directly correlated with the microstructural evolution at the interface. Moreover, the higher reduction ratio during the roll bonding, the more room temperature formability could be achieved for Al-Cu 2-ply sheet by applying both three-point bending and Erichsen tests.

  4. Glycemic index, glycemic load and mammographic breast density: the EPIC Florence longitudinal study.

    Directory of Open Access Journals (Sweden)

    Giovanna Masala

    Full Text Available A few studies have evaluated the association between diet and mammographic breast density (MBD and results are inconsistent. MBD, a well-recognized risk factor for breast cancer, has been proposed as a marker of cumulative exposure to hormones and growth factors. Diets with a high glycemic index (GI or glycemic load (GL may increase breast cancer risk, via an effect on the insulin-like growth factor axis. We have investigated the association between carbohydrate intake, GI, GL and MBD in a prospective study. We identified a large series of women, in the frame of the EPIC-Florence cohort, with a mammogram taken five years after enrolment, when detailed information on dietary and lifestyle habits and anthropometric measurements had been collected. Mammograms have been retrieved (1,668, 83% and MBD assessed according to Wolfe's classification. We compared women with high MBD (P2+DY Wolfe's categories with those with low MBD (N1+P1 through logistic models adjusted for age, education, body mass index, menopause, number of children, breast feeding, physical activity, non-alcohol energy, fibers, saturated fat and alcohol. A direct association between GL and high MBD emerged in the highest quintile of intake in comparison with the lowest quintile (OR = 1.73, 95%CI 1.13-2.67, p for trend = 0.048 while no association with glycemic index was evident. These results were confirmed after exclusion of women reporting to be on a diet or affected with diabetes, and when Hormone Replacement Therapy at the date of mammographic examination used to assess MBD was considered. The effect was particularly evident among leaner women, although no interaction was found. A positive association was suggested for increasing simple sugar and total carbohydrates intakes limited to the highest quintiles. In this Italian population we observed an association between glycemic load, total and rapidly absorbed carbohydrates and high MBD. These novel results warrant further

  5. NASA Task Load Index (TLX). Volume 1.0; Paper and Pencil Package

    Science.gov (United States)

    Hart, Sandra G.

    1986-01-01

    This booklet contains the materials necessary to collect subjective workload assessments with the NASA Task Load Index. This procedure for collecting workload ratings was developed by the Human Performance Group at NASA Ames Research Center during a three year research effort that involved more than 40 laboratory. simulation. and inflight experiments. Although the technique is still undergoing evaluation. this booklet is being distributed to allow other researchers to use it in their own experiments. Comments or suggestions about the procedure would be greatly appreciated. This package is intended to fill a "nuts and bolts" function of describing the procedure. A bibliography provides background information about previous empirical findings and the logic that supports the procedure.

  6. Índice glicêmico e carga glicêmica de dietas consumidas por indivíduos obesos Glycemic index and glycemic load of diets consumed by obese individuals

    Directory of Open Access Journals (Sweden)

    Helena Alves de Carvalho Sampaio

    2007-12-01

    Full Text Available OBJETIVO: Avaliar o índice glicêmico e a carga glicêmica de dietas de indivíduos obesos. MÉTODOS: Trata-se de estudo retrospectivo, que analisou as fichas clínicas de 80 adultos obesos, acompanhados em um serviço privado localizado em Fortaleza, Ceará. Determinaram-se o índice glicêmico e a carga glicêmica da dieta. Para verificação da associação entre índice glicêmico e carga glicêmica, e dessas variáveis com a ingestão energética diária e com o índice de massa corporal dos indivíduos, utilizou-se o teste de correlação de Pearson. O teste "t" de Student foi utilizado para verificar diferenças entre os dois índices e o sexo. Em ambos os testes adotou-se pOBJECTIVE: To evaluate the glycemic index and glycemic load of diets of obese individuals. METHODS: This is a retrospective study that analyzed the medical records of 80 obese adults attending a private health care service in Fortaleza, Ceará. The glycemic index and load of their diet was determined. The Pearson correlation test was used to verify if there was an association between glycemic index and glycemic load and of these variables with their daily energy intake and body mass index. The Student's "t" test was used to verify the differences between the two indexes and gender. A significance level of p<0.05 was adopted for both tests. RESULTS: Inadequate (moderate or high glycemic index prevailed at breakfast (82.9%, afternoon snack (60.0% and dinner (64.6%. The daily glycemic index was inadequate for 78.7% of the group and predominantly moderate according to the mean found (59.23, however it was less inadequate than the daily glycemic load which was high (143.8 and worse among males. The body mass index of the group, in general and according to gender, was not associated with any of the indices. Daily energy intake was associated only with glycemic load, both generally and taking gender into account. CONCLUSION: The results point toward a higher glycemic load in

  7. In vitro characterization of PlySK1249, a novel phage lysin, and assessment of its antibacterial activity in a mouse model of Streptococcus agalactiae bacteremia.

    Science.gov (United States)

    Oechslin, Frank; Daraspe, Jean; Giddey, Marlyse; Moreillon, Philippe; Resch, Grégory

    2013-12-01

    Beta-hemolytic Streptococcus agalactiae is the leading cause of bacteremia and invasive infections. These diseases are treated with β-lactams or macrolides, but the emergence of less susceptible and even fully resistant strains is a cause for concern. New bacteriophage lysins could be promising alternatives against such organisms. They hydrolyze the bacterial peptidoglycan at the end of the phage cycle, in order to release the phage progeny. By using a bioinformatic approach to screen several beta-hemolytic streptococci, a gene coding for a lysin was identified on a prophage carried by Streptococcus dysgalactiae subsp. equisimilis SK1249. The gene product, named PlySK1249, harbored an original three-domain structure with a central cell wall-binding domain surrounded by an N-terminal amidase and a C-terminal CHAP domain. Purified PlySK1249 was highly lytic and bactericidal for S. dysgalactiae (2-log10 CFU/ml decrease within 15 min). Moreover, it also efficiently killed S. agalactiae (1.5-log10 CFU/ml decrease within 15 min) but not several streptococcal commensal species. We further investigated the activity of PlySK1249 in a mouse model of S. agalactiae bacteremia. Eighty percent of the animals (n = 10) challenged intraperitoneally with 10(6) CFU of S. agalactiae died within 72 h, whereas repeated injections of PlySK1249 (45 mg/kg 3 times within 24 h) significantly protected the mice (P S. dysgalactiae, demonstrated high cross-lytic activity against S. agalactiae both in vitro and in vivo. These encouraging results indicated that PlySK1249 might represent a good candidate to be developed as a new enzybiotic for the treatment of systemic S. agalactiae infections.

  8. The Role of License Renewal in PLiM for U.S. Nuclear Power Plants

    International Nuclear Information System (INIS)

    Young, G.G.

    2012-01-01

    At the 2nd International Symposium on Nuclear Power Plant Life Management (PLiM) in 2007, it was reported that the NRC had approved renewal of operating licenses for 48 nuclear units, which would allow operation for up to 60 years (i.e., an additional 20 years from the original 40-year license term). Of the 104 operating nuclear units in the U.S. in 2007, it was anticipated that almost 100% would eventually pursue license renewal. At that time, it was also concluded that the regulatory process was stable and predictable for license renewal, and that successful PLiM activities were helping to ensure the safety, economic, and political factors in the U.S. remained favorable for continued success with license renewal. The status of license renewal in 2012 is even better than it was in 2007. As of April 2012, the NRC has approved renewal of the operating licenses for 71 nuclear units and has applications under review for 15 more units. In addition, nuclear plant owners of at least 14 more units have announced plans to submit license renewal applications over the next few years. This brings the total of renewed licenses and announced plans for license renewal to 96% of the 104 currently operating nuclear units in the U.S. The prediction that almost 100% would eventually pursue license renewal is assured. This positive trend for long term operation of nuclear power plants in the U.S. is attributed to: (1) the success of PLiM activities in achieving an excellent safety record for the nuclear power industry and in ensuring on-going positive economics for nuclear plant operation, and (2) the stable and predictable regulatory process for license renewal. U.S. efforts are now underway to consider long term operation for more than 60 years and the process of preparing a second round of license renewals for up to 80 years of operation is likely to begin within the next few years. (author)

  9. In-Situ Observations of Longitudinal Compression Damage in Carbon-Epoxy Cross Ply Laminates Using Fast Synchrotron Radiation Computed Tomography

    Science.gov (United States)

    Bergan, Andrew C.; Garcea, Serafina C.

    2017-01-01

    The role of longitudinal compressive failure mechanisms in notched cross-ply laminates is studied experimentally with in-situ synchrotron radiation based computed tomography. Carbon/epoxy specimens loaded monotonically in uniaxial compression exhibited a quasi-stable failure process, which was captured with computed tomography scans recorded continuously with a temporal resolutions of 2.4 seconds and a spatial resolution of 1.1 microns per voxel. A detailed chronology of the initiation and propagation of longitudinal matrix splitting cracks, in-plane and out-of-plane kink bands, shear-driven fiber failure, delamination, and transverse matrix cracks is provided with a focus on kink bands as the dominant failure mechanism. An automatic segmentation procedure is developed to identify the boundary surfaces of a kink band. The segmentation procedure enables 3-dimensional visualization of the kink band and conveys the orientation, inclination, and spatial variation of the kink band. The kink band inclination and length are examined using the segmented data revealing tunneling and spatial variations not apparent from studying the 2-dimensional section data.

  10. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    International Nuclear Information System (INIS)

    Lee, Seungmin; Seong, Poonghyun; Kim, Jonghyun

    2013-01-01

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load

  11. Fatigue evaluation algorithms: Review

    Energy Technology Data Exchange (ETDEWEB)

    Passipoularidis, V.A.; Broendsted, P.

    2009-11-15

    A progressive damage fatigue simulator for variable amplitude loads named FADAS is discussed in this work. FADAS (Fatigue Damage Simulator) performs ply by ply stress analysis using classical lamination theory and implements adequate stiffness discount tactics based on the failure criterion of Puck, to model the degradation caused by failure events in ply level. Residual strength is incorporated as fatigue damage accumulation metric. Once the typical fatigue and static properties of the constitutive ply are determined,the performance of an arbitrary lay-up under uniaxial and/or multiaxial load time series can be simulated. The predictions are validated against fatigue life data both from repeated block tests at a single stress ratio as well as against spectral fatigue using the WISPER, WISPERX and NEW WISPER load sequences on a Glass/Epoxy multidirectional laminate typical of a wind turbine rotor blade construction. Two versions of the algorithm, the one using single-step and the other using incremental application of each load cycle (in case of ply failure) are implemented and compared. Simulation results confirm the ability of the algorithm to take into account load sequence effects. In general, FADAS performs well in predicting life under both spectral and block loading fatigue. (author)

  12. A study of an influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material

    Directory of Open Access Journals (Sweden)

    Herbuś Krzysztof

    2017-01-01

    Full Text Available In the work are presented studies related with the influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material. For this purpose, the characteristics of the three-point bending test, according to the standard PN-EN ISO 7438, of specimens made from the composite material, where a single ply is a composition of epoxy resin and glass fibres, was mapped. The modelling process of the multi-layered composite material and its strength verification was performed in the PLM Siemens NX system. Based on the results of performed numerical studies, the relation between the value of the main angle of an arrangement of fibers in each plies of the laminate, and the distribution and values of stresses, occurring in the examined specimens has been determined.

  13. Heavy metal assessment in sediments of east coast of Tamil Nadu using energy dispersive X-ray fluorescence spectroscopy

    Directory of Open Access Journals (Sweden)

    N Harikrishnan

    2017-01-01

    Full Text Available Selected heavy metals (Cr, Co, Ni, Cu, Zn, As, and Pb in sediments from Periyakalapattu to Parangipettai of east coast of Tamil Nadu were determined to assess the contamination status and potential ecological risk. The pollution indices such as enrichment factor (EF, contamination factor (CF, geoaccumulation index (Igeo, and pollution load index (PLI were calculated to determine the contamination level and enrichment of metals in sediments. EF analysis suggested that anthropogenic influence on the environment has been significant in case of Cr. The values of CF indicate that the sediments are not contaminated with these heavy metals. Igeoresults reveal that the study area is not contaminated with respect to Cr, Co, Ni, Cu, Zn, As, and Pb. This results of Igeoare in good agreement with PLI. Based on the sediment quality guidelines, it is observed that Cr and Ni would be a concern for the ecotoxicological risk in study area.

  14. Geochemical assessment of heavy metals pollution in surface sediments of Vellar and Coleroon estuaries, southeast coast of India.

    Science.gov (United States)

    Nethaji, S; Kalaivanan, R; Arya Viswam; Jayaprakash, M

    2017-02-15

    Surface sediments were collected from Vellar and Coleroon estuaries for determine sediment texture, calcium carbonate, organic matter and heavy metals. Pollution indices such as pollution load index (PLI), contamination factor (CF), enrichment factor (EF) and geo-accumulation index (I geo ) were done for this study to know the level of heavy metals pollution in the estuarine ecosystem. Pearson correlation matrix and factor were used to assess the relationship and source of heavy metals in the estuarine sediments. The results of PLI values reveal that the study area was polluted by all the heavy metals. The calculated values of CF and I geo followed the decreasing order Cu>Ni>Pb>Co>Cr>Zn>Mn>Fe and illustrate that Cu, Ni and Pb are contaminated due to anthropogenic sources in both estuaries. Correlation and factor analysis suggest that FeMn oxyhydroxides, organic matter and fine particles are responsible for high concentration of heavy metals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. The Study of Heavy Metals on Sediment Quality of Kuala Perlis Coastal Area

    Science.gov (United States)

    Zubir, A. A. Ahmad; Saad, F. N. Mohd; Dahalan, F. A.

    2018-03-01

    The contamination of heavy metals gives bad implications to the aquatic environment. Thus, a study was conducted to assess the sediment quality by using different contamination indices such as Enrichment Factor (EF), Geo-accumulation Index (Igeo), and Pollution Load Index (PLI). Each sediment sample was collected at the surface (0-15cm) at 5 locations based on the land use activity; jetty port (A), seaside restaurant (B), roadside area (C), power plant (D) and residential area (E). All samples were undergoes acid digestion and analyzed with AAS. Four elements identified from the sediment samples which are Cr, Cu, Pb and Zn were used to calculate the respective indices. Results show that, the highest EF value of Pb which categorized as very severe enrichment was at point E. Meanwhile minor enrichment was detected at point B for Cu while Cr and Zn at point A. Based on Igeo value the sediment quality along Kuala Perlis was in the unpolluted-moderately polluted condition (class 1). As for PLI it shows that the sediment of the coastal area is unpolluted (PLI<1). Therefore, this study revealed that, the main contributor of heavy metals in this area is Pb while the sediment quality of Kuala Perlis was in minor pollution condition.

  16. On the thermally-induced residual stresses in thick fiber-thermoplastic matrix (PEEK) cross-ply laminated plates

    Science.gov (United States)

    Hu, Shoufeng; Nairn, John A.

    1992-01-01

    An analytical method for calculating thermally-induced residual stresses in laminated plates is applied to cross-ply PEEK laminates. We considered three cooling procedures: slow cooling (uniform temperature distribution); convective and radiative cooling; and rapid cooling by quenching (constant surface temperature). Some of the calculated stresses are of sufficient magnitude to effect failure properties such as matrix microcracking.

  17. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seungmin; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jonghyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-05-15

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load.

  18. Local fatigue behavior in tapered areas of large offshore wind turbine blades

    DEFF Research Database (Denmark)

    Raeis Hosseiny, Seyed Aydin; Jakobsen, Johnny

    2016-01-01

    failure of an entire blade structure. The local strength degradation under an ultimate static loading, subsequent to several years of fatigue, is predicted for an offshore wind turbine blade. Fatigue failure indexes of different damage modes are calculated using a sub-modeling approach. Multi axial...... knock-down factors for ply-drop effects in wind turbine blades under multi-axial static and fatigue loadings can be obtained.......Thickness transitions in load carrying elements lead to improved geometries and efficient material utilization. However, these transitions may introduce localized areas with high stress concentrations and may act as crack initiators that could potentially cause delamination and further catastrophic...

  19. Metal contamination of agricultural soils in the copper mining areas of Singhbhum shear zone in India

    Science.gov (United States)

    Giri, Soma; Singh, Abhay Kumar; Mahato, Mukesh Kumar

    2017-06-01

    The study was intended to investigate the heavy metal contamination in the agricultural soils of the copper mining areas in Singhbhum shear zone, India. The total concentrations of the metals were determined by inductively coupled plasma-mass spectrometer (ICPMS). Pollution levels were assessed by calculating enrichment factor (EF), geo-accumulation index (I_geo), contamination factors (CF), pollution load index ( PLI), Nemerow index and ecological risk index (RI). The metal concentrations in the soil samples exceeded the average shale values for almost all the metals. Principal component analysis resulted in extraction of three factors explaining 82.6% of the data variability and indicated anthropogenic contribution of Cu, Ni, Co, Cr, Mn and Pb. The EF and I_geo values indicated very high contamination with respect to Cu followed by As and Zn in the agricultural soils. The values of PLI, RI and Nemerow index, which considered the overall effect of all the studied metals on the soils, revealed that 50% of the locations were highly polluted with respect to metals. The pollution levels varied with the proximity to the copper mining and processing units. Consequently, the results advocate the necessity of periodic monitoring of the agricultural soils of the area and development of proper management strategies to reduce the metal pollution.

  20. Dietary glycemic index, glycemic load and metabolic profile in children with phenylketonuria.

    Science.gov (United States)

    Moretti, F; Pellegrini, N; Salvatici, E; Rovelli, V; Banderali, G; Radaelli, G; Scazzina, F; Giovannini, M; Verduci, E

    2017-02-01

    No data exist in the current literature on the glycemic index (GI) and glycemic load (GL) of the diet of phenylketonuric (PKU) children. The aims of this study were to examine the dietary GI and GL in PKU children on a low-phenylalanine (Phe)-diet and to evaluate whether an association may exist between the carbohydrate quality and the metabolic profile. Twenty-one PKU children (age 5-11 years) and 21 healthy children, gender and age matched, were enrolled. Dietary (including GI and GL) and blood biochemical assessments were performed. No difference was observed for daily energy intake between PKU and healthy children. Compared to healthy controls, PKU children consumed less protein (p = 0.001) and fat (p = 0.028), and more carbohydrate (% of total energy, p = 0.004) and fiber (p = 0.009). PKU children had higher daily GI than healthy children (mean difference (95% confidence interval), 13.7 (9.3-18.3)) and higher GL (31.7 (10.1-53.2)). PKU children exhibited lower blood total and low density lipoprotein cholesterol (LDL) levels (p triglyceride level (p = 0.014) than healthy children, while glucose and insulin concentrations did not differ. In PKU children the dietary GL was associated with triglyceride glucose index (Spearman's correlation coefficient = 0.515, p = 0.034). In PKU children a relationship of the dietary treatment with GI and GL, blood triglycerides and triglyceride glucose index may exist. Improvement towards an optimal diet for PKU children could include additional attention to the management of dietary carbohydrate quality. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  1. Assessing heavy metal toxicity in sediments of Chennai Coast of Tamil Nadu using Energy Dispersive X-Ray Fluorescence Spectroscopy (EDXRF) with statistical approach.

    Science.gov (United States)

    Tholkappian, M; Ravisankar, R; Chandrasekaran, A; Jebakumar, J Prince Prakash; Kanagasabapathy, K V; Prasad, M V R; Satapathy, K K

    2018-01-01

    The concentration of some heavy metals: Al, Ca, K, Fe, Ti, Mg, Mn, V, Cr, Zn, Ni and Co in sediments from Pulicat Lake to Vadanemmeli along Chennai Coast, Tamil Nadu has been determined using EDXRF technique. The mean concentrations of Mg, Al, K, Ca, Ti, Fe, V, Cr, Mn, Co, Ni, and Zn were found to be 1918, 25436, 9832, 9859, 2109, 8209, 41.58, 34.14, 160.80, 2.85. 18.79 and 29.12 mg kg -1 respectively. These mean concentrations do not exceed the world crustal average. The level of pollution attributed to heavy metals was evaluated using several pollution indicators in order to determine anthropogenically derived contaminations. Enrichment Factor (EF), Geoaccumulation Index (I geo ), Contamination Factor (CF) and Pollution Load Index (PLI) were used in evaluating the contamination status of sediments. Enrichment Factors (EF) reveal the anthropogenic sources of V, Cr, Ni and Zn Geoaccumulation Index (I geo ) results reveal that the study area is not contaminated by the heavy metals. Similar results were also obtained by using pollution load index (PLI). The results of pollution indices indicates that most of the locations were not polluted by heavy metals. Multivariate statistical analysis performed using principal components and clustering techniques were used to identify the source of the heavy metals. The result of statistical procedures indicate that heavy metals in sediments are mainly of natural origin. This study provides a relatively novel technique for identifying and mapping the distribution of metal pollutants and their sources in sediment.

  2. 3. International Conference on Nuclear Power Plant Life Management (PLiM) for Long Term Operations (LTO). Keynotes, papers, presentations, posters

    International Nuclear Information System (INIS)

    2012-01-01

    The world's fleet of nuclear power plants is, on average, more than 20 years old. Even though the design life of a nuclear power plant is typically 30-40 years, many plants will operate in excess of their design lives, provided that nuclear power plant engineers demonstrate by analysis, equipment and system upgrades, increased vigilance, testing and ageing management that the plant will operate safely. In the operation of nuclear power plants, safety should always be the prime consideration. Plant operators and regulators must always ensure that plant safety is maintained and, where possible, enhanced during its operating lifetime. Nuclear power plant life management (PLiM) has gained increased attention over the past decade, and effective ageing management of systems, structures and components (SSCs) is a key element in PLiM for the safe and reliable long term operation of nuclear power plants. A PLiM programme is an effective tool that allows an operator to safely and cost effectively manage ageing effects in SSCs for long term operation (LTO). A PLiM programme helps facilitate decisions concerning when and how to repair, replace or modify SSCs in an economically optimized way, while assuring that a high level of safety is maintained. The option for extended nuclear power plant operation has been recognized by operators and regulators alike, as evidenced in the number of licence renewal programmes that are being developed by Member States. After the severe accident at the Fukushima Daiichi nuclear power plant, the safe operation of nuclear power plants has become even more important; not only in terms of technical or ageing issues, but also in terms of management system and qualified workforce related issues. Application of an integrated management system and structured workforce planning are needed throughout the plant life in order to ensure effective plant organization and management. The IAEA organized the first and second International Conference on Nuclear

  3. Ecological risk evaluation of sediment core samples, Lake Tortum (Erzurum, NE Turkey using environmental indices

    Directory of Open Access Journals (Sweden)

    Hakan Kaya

    2017-11-01

    Full Text Available This study aimed to determine the vertical distribution of heavy metals in a 72 cm-long core sample from Lake Tortum in order to shed light on the implications of potential ecological risks. Analysis was based on the use of environmental indices such as the Integrated Pollution Load Index (PLI and Potential Ecological Risk Index (PER. Results reveal that, except for Pb, Mn and Hg, the lowest concentrations of heavy metals occur at a core depth of between 2 cm and 20 cm for Cu, Zn, Ni, Fe, As, Cd, Cr and Al. The highest concentration was found at sampling intervals of 36 cm and 50 cm, with the exception of Pb, Mn, Hg and Ni. The PLI values from bottom to top are less than 1 while the level with the nearest value to the background value lies at a depth between 24 cm and 26 cm. The PER index results suggest a low ecological risk level for Cu, Pb, Zn, Ni, Mn, Fe, As, Cr, and Al; however, Cd and Hg constitute an ecological threat to the lake ecosystem.

  4. Comparison of Damage Models for Predicting the Non-Linear Response of Laminates Under Matrix Dominated Loading Conditions

    Science.gov (United States)

    Schuecker, Clara; Davila, Carlos G.; Rose, Cheryl A.

    2010-01-01

    Five models for matrix damage in fiber reinforced laminates are evaluated for matrix-dominated loading conditions under plane stress and are compared both qualitatively and quantitatively. The emphasis of this study is on a comparison of the response of embedded plies subjected to a homogeneous stress state. Three of the models are specifically designed for modeling the non-linear response due to distributed matrix cracking under homogeneous loading, and also account for non-linear (shear) behavior prior to the onset of cracking. The remaining two models are localized damage models intended for predicting local failure at stress concentrations. The modeling approaches of distributed vs. localized cracking as well as the different formulations of damage initiation and damage progression are compared and discussed.

  5. Air Quality Assessment of Faisalabad and Gujranwala Cities of Pakistan: Application of Pollution Indices

    International Nuclear Information System (INIS)

    Faiz, Y.; Waheed, S.; Siddique, N.

    2015-01-01

    Urban air quality of industrial cities of Pakistan, namely Gujranwala and Faisalabad was assessed in terms of pollution level indicators such as pollution load index (PLI), geo-accumulation index (I/sub geo/), pollution index (PI) and integrated pollution index (IPI). It was found that both cities have elevated metal concentration indicating heavy to extreme contamination for most of the sites. Local anthropogenic activities and elevated geo-accumulation indices for different suite of elements were used to indicate possible pollutant sources in these two industrial cities to be traffic derived emissions, suspended soil, road dust, construction materials, fossil fuel and industrial emissions, tanneries, chrome plating units and metal smelters. Comparison of the pollution indices shows that Ba, Br, Ca, Cd, Na, Pb, Sb and Zn have mean PLI, I/sub geo/, PI and IPI for both cities which are in the highly polluted category. Cu, La, Sc, V and Zr have pollution indices corresponding to high or extreme levels in Faisalabad only while Cr and Ti are highly polluting only in Gujranwala. In Faisalabad and Gujranwala it was found that 91.43% and 85.29% respectively of the PI data occurs in high level of pollution implying that to some extent Faisalabad is more polluted as compared to Gujranwala. (author)

  6. A fast and robust bulk-loading algorithm for indexing very large digital elevation datasets II. Experimental results

    Science.gov (United States)

    Rodríguez, Félix R.; Barrena, Manuel

    2011-07-01

    The spatial indexing of eventually all the available topographic information of Earth is a highly valuable tool for different geoscientific application domains. The Shuttle Radar Topography Mission (SRTM) collected and made available to the public one of the world's largest digital elevation models (DEMs). With the aim of providing on easier and faster access to these data by improving their further analysis and processing, we have indexed the SRTM DEM by means of a spatial index based on the kd-tree data structure, called the Q-tree. This paper is the second in a two-part series that includes a thorough performance analysis to validate the bulk-load algorithm efficiency of the Q-tree. We investigate performance measuring elapsed time in different contexts, analyzing disk space usage, testing response time with typical queries, and validating the final index structure balance. In addition, the paper includes performance comparisons with Oracle 11g that helps to understand the real cost of our proposal. Our tests prove that the proposed algorithm outperforms Oracle 11g using around a 9% of the elapsed time, taking six times less storage with more than 96% of page utilization, and getting faster response times to spatial queries issued on 4.5 million points. In addition to this, the behavior of the spatial index has been successfully tested on both an open GIS (VT Builder) and a visualizer tool derived from the previous one.

  7. [Assessment of heavy metal pollution and potential ecological risks of urban soils in Kaifeng City, China].

    Science.gov (United States)

    Li, Yi-Meng; Ma, Jian-Hua; Liu, De-Xin; Sun, Yan-Li; Chen, Yan-Fang

    2015-03-01

    Ninety-nine topsoil (0-15 cm) samples were collected from Kaifeng City, China using the grid method, and then the concentrations of As, Cd, Cr, Cu, Ni, Pb and Zn in the samples were measured by standard methods. Soil pollution levels and potential ecological risks of the heavy metals were assessed using the pollution load index (PLI) and potential ecological risk index (RI), respectively. Ordinary Kriging interpolation technique was employed to investigate the spatial distribution of PLI and RI of the city. The results showed that high pollution of Cd occurred in Kaifeng urban soils, and there was moderate pollution of Zn, slight pollution of Pb and Cu, and no pollution of Ni, Cr and As. Very high ecological risk was posed by Cd and low risk by other metals. The mean PLI of the 7 metals from all sample points was 2.53, which was categorized as moderate pollution. The average RI was 344.58 which represented a considerable ecological risk. PLI and RI shared a similar spatial distribution with high values centralized in the old industrial area in the southeast and railway stations for passengers and goods in the south of the city, followed by the old town within the ancient city wall, and low values located in the north and west areas. Cadmium was the main factor for both soil pollution and potential ecological risk primarily due to farmland topsoil in the eastern suburb of Kaifeng City with high Cd concentrations resulted from sewage irrigation deposited in the urban area by wind, human activities such as soot discharged from the chemical fertilizer plant of Kaifeng, transportation and coal combustion.

  8. Buckling and postbuckling behavior of square compression-loaded graphite-epoxy plates with circular cutouts

    Science.gov (United States)

    Nemeth, Michael P.

    1990-01-01

    Results are presented for unidirectional (0, 10)(sub s) and (90,10)(sub s) plates, ((0/90)(sub 5)(sub s)) plates, and for aluminum plates. Results are also presented for ((+/- theta)(sub 6)(sub s)) angle-ply plates for values of theta = 30, 45, and 60 degrees. The results indicate that the change in axial stiffness of a plate at buckling is strongly dependent upon cutout size and plate orthotropy. The presence of a cutout gives rise to an internal load distribution that changes, sometimes dramatically, as a function of cutout size coupled with the plate orthotropy. In the buckled state, the role of orthotropy becomes more significant since bending in addition to membrane orthotropy is present. Most of the plates with cutouts exhibited less postbuckling stiffness than the corresponding plate without a cutout, and the postbuckling stiffness decreased with increasing cutout size. However, some of the highly orthotropic plates with cutouts exhibited more postbuckling stiffness than the corresponding plate without a cutout. These results suggest the possibility of tailoring the cutout size and the stacking sequence of a composite plate to optimize postbuckling stiffness. It was found that plates with large radius cutouts do exhibit some postbuckling strength. The results also indicate that a cutout can influence modal interaction in a plate. Specifically, results are presented that show a plate with a relatively small cutout buckling at a higher load than the corresponding plate without a cutout, due to modal interaction. Other results are presented that indicate the presence of nonlinear prebuckling deformations, due to material nonlinearity, in the angle-ply plates with theta = 45 and 60 degrees. The nonlinear prebuckling deformations are more pronounced in the plates with theta = 45 degrees and become even more pronounced as the cutout size increases. Results are also presented that show how load-path eccentricity due to improper machining of the test specimens

  9. Probabilistic Analysis of a Composite Crew Module

    Science.gov (United States)

    Mason, Brian H.; Krishnamurthy, Thiagarajan

    2011-01-01

    An approach for conducting reliability-based analysis (RBA) of a Composite Crew Module (CCM) is presented. The goal is to identify and quantify the benefits of probabilistic design methods for the CCM and future space vehicles. The coarse finite element model from a previous NASA Engineering and Safety Center (NESC) project is used as the baseline deterministic analysis model to evaluate the performance of the CCM using a strength-based failure index. The first step in the probabilistic analysis process is the determination of the uncertainty distributions for key parameters in the model. Analytical data from water landing simulations are used to develop an uncertainty distribution, but such data were unavailable for other load cases. The uncertainty distributions for the other load scale factors and the strength allowables are generated based on assumed coefficients of variation. Probability of first-ply failure is estimated using three methods: the first order reliability method (FORM), Monte Carlo simulation, and conditional sampling. Results for the three methods were consistent. The reliability is shown to be driven by first ply failure in one region of the CCM at the high altitude abort load set. The final predicted probability of failure is on the order of 10-11 due to the conservative nature of the factors of safety on the deterministic loads.

  10. Glycemic index and glycemic load of commercial Italian foods.

    Science.gov (United States)

    Scazzina, F; Dall'Asta, M; Casiraghi, M C; Sieri, S; Del Rio, D; Pellegrini, N; Brighenti, F

    2016-05-01

    The glycemic index (GI) and glycemic load (GL) are useful parameters in the nutritional classification of carbohydrate foods. Diets characterized by a low GI and/or a low GL have been repeatedly and independently associated with decreased risk of diabetes and other chronic diseases. The aim of this study is to report the GI and GL value of carbohydrate-rich foods available on the Italian market and mostly consumed in Italy. GI values were determined according to FAO/WHO (1997) and ISO (2010). Overall, the 141 commercial foods that were analyzed represent food categories that are the source of >80% carbohydrate intake in Italy. The food items chosen were based mainly on the market share of the brand within each food category and grouped into 13 food categories: 1) beverages: fermented milk drink, juice, smoothie, soft drink; 2) biscuits; 3) breads; 4) bread substitutes; 5) breakfast cereals; 6) cakes and snacks; 7) candy and confectionery; 8) cereals; 9) desserts and ice-creams; 10) marmalade and jam; 11) pasta; 12) pizza; 13) sugar and sweetener. This database of commercial Italian foods partly overcomes the lack of information on GI and GL of local foods, contributing to a better understanding of the association between GI/GL and health and providing a more informed choice to Italian consumers and health practitioners. Copyright © 2016 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  11. Geometrically nonlinear transient vibrations of actively damped anti-symmetric angle ply laminated composite shallow shell using active fibre composite (AFC) actuators

    Science.gov (United States)

    Ashok, M. H.; Shivakumar, J.; Nandurkar, Santosh; Khadakbhavi, Vishwanath; Pujari, Sanjay

    2018-02-01

    In present work, the thin laminated composite shallow shell as smart structure with AFC material’s ACLD treatment is analyzed for geometrically nonlinear transient vibrations. The AFC material is used to make the constraining layer of the ACLD treatment. Golla-Hughes-McTavish (GHM) is used to model the constrained viscoelastic layer of the ACLD treatment in time domain. Along with a simple first-order shear deformation theory the Von Kármán type non-linear strain displacement relations are used for deriving this electromechanical coupled problem. A 3-dimensional finite element model of smart composite panels integrated with the ACLD treated patches has been modelled to reveal the performance of ACLD treated patches on improving the damping properties of slender anti-symmetric angle-ply laminated shallow shell, in controlling the transient vibrations which are geometrically nonlinear. The mathematical results explain that the ACLD treated patches considerably enhance the damping properties of anti-symmetric angle-ply panels undergoing geometrically nonlinear transient vibrations.

  12. Aspects of alienation and symptom load among adolescents.

    Science.gov (United States)

    Rayce, Signe L B; Holstein, Bjørn E; Kreiner, Svend

    2009-01-01

    The purpose was to examine the association between aspects of alienation and symptom load among adolescents. Furthermore an integrated purpose was to construct and validate an index of alienation. Cross-sectional data from 5205 school children aged 11-15 years from a random sample of schools in Denmark were used. Data stems from the Danish contribution to the cross-national study Health and Behaviour in School-aged Children (HBSC). Alienation was measured with a new index fulfilling four criteria: (i) theoretical foundation, (ii) inter-correlation between items, (iii) correlation between each of the index's items and the outcomes and (iv) no differential item functioning. The final index included three indicators of alienation: helplessness, feeling left out of things and lack of confidentiality with parents. Symptom load was measured by HBSC Symptom Checklist and divided into physical and psychological symptoms respectively. High symptom load was defined as experiencing at least one symptom on a daily basis. The odds-ratio (OR) for high symptom load increased with the degree of alienation. For students with all three indicators of alienation, the OR for high physical symptom load was 2.49 (1.05-5.87). The OR for high psychological symptom load for the corresponding degree of alienation was 6.50 (3.11-13.56). The index of alienation fulfilled psychometric criteria for scalability. Furthermore the analyses showed a graded and significant association between alienation and high symptom load. This suggests alienation to be taken into account in future health interventions among adolescents. In school settings this may be done using principles of empowerment.

  13. Analysis of Damage in Laminated Architectural Glazing Subjected to Wind Loading and Windborne Debris Impact

    Directory of Open Access Journals (Sweden)

    Daniel S. Stutts

    2013-05-01

    Full Text Available Wind loading and windborne debris (missile impact are the two primary mechanisms that result in window glazing damage during hurricanes. Wind-borne debris is categorized into two types: small hard missiles; such as roof gravel; and large soft missiles representing lumber from wood-framed buildings. Laminated architectural glazing (LAG may be used in buildings where impact resistance is needed. The glass plies in LAG undergo internal damage before total failure. The bulk of the published work on this topic either deals with the stress and dynamic analyses of undamaged LAG or the total failure of LAG. The pre-failure damage response of LAG due to the combination of wind loading and windborne debris impact is studied. A continuum damage mechanics (CDM based constitutive model is developed and implemented via an axisymmetric finite element code to study the failure and damage behavior of laminated architectural glazing subjected to combined loading of wind and windborne debris impact. The effect of geometric and material properties on the damage pattern is studied parametrically.

  14. The association between dietary glycemic index, glycemic load and diet quality indices in Iranian adults: results from Isfahan Healthy Heart Program.

    Science.gov (United States)

    Azadbakht, Leila; Mohammadifard, Noushin; Akhavanzanjani, Mohsen; Taheri, Marzieh; Golshahi, Jafar; Haghighatdoost, Fahimeh

    2016-01-01

    To assess the association between dietary glycemic index (GI), glycemic load (GL) and dietary quality indices in Iranian adults. This cross section was conducted among 1571 Iranian adults aged  ≥19 years. GI, GL and diet quality indices were estimated by 24-h recall and DDS was calculated using a validated 48-item food frequency questionnaire. Participants who were in the top tertile of GI had lower healthy eating index (HEI) (57.2 ± 7.8 versus 55.6 ± 8.7; p diet quality indices may suggest the relevance of carbohydrate source in determining the diet quality indices.

  15. Identification of Streptococcus pneumoniae lytA, plyA and psaA genes in pleural fluid by multiplex real-time PCR.

    Science.gov (United States)

    Sanz, Juan Carlos; Ríos, Esther; Rodríguez-Avial, Iciar; Ramos, Belén; Marín, Mercedes; Cercenado, Emilia

    2017-08-14

    The aim was to evaluate the utility of a multiplex real-time PCR to detect Streptococcus pneumoniae lytA, plyA and psaA genes in pleural fluid (PF). A collection of 81 PF samples was used. Sixty were considered positive for S. pneumoniae according to previous results (54 by an in-house lytA gene PCR and eight by universal rRNA PCR). The sensitivity for detection of the lytA, plyA and psaA genes by multiplex PCR was 100% (60/60), 98.3% (59/60) and 91.7% (55/60), respectively. The detection of all three genes was negative in 21 samples formerly confirmed as negative for S. pneumoniae (100% specificity) by the other procedures (9 by in-house lytA PCR and 12 by rRNA PCR). The use of this multiplex PCR may be a useful option to identify S. pneumoniae directly in PF samples. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  16. Designing an application for managing distribution transformer load

    Directory of Open Access Journals (Sweden)

    Olga Liliana Sánchez

    2006-09-01

    Full Text Available This paper presents a software application for distribution transformer load management and calculating the elec- tricity distribution network service quality index (i.e. EDS and EFS indexes. Transformer operation state, calculating core and coil losses and selecting distribution transformers based on technical-economic criteria using daily-load curves are the load management strategies presented here. The application consists of a programme allowing to data acquisition input, an Excel-based spread-sheet having the equations for calculating load management data and a user-interface presenting the load management application’s results. The application was validated by technical-economic evaluation of three distribution transformers when supplying demand.

  17. [Work-related Stress and the Allostatic Load Index - A Systematic Review].

    Science.gov (United States)

    Mauss, D; Li, J; Schmidt, B; Angerer, P; Jarczok, M N

    2017-12-01

    Work-related stress is a growing social challenge and has been associated with reduced employee health, well-being, and productivity. One tool to measure the stress-related wear and tear of the body is the Allostatic Load Index (ALI). This review summarizes recent evidence on the association between work-related stress and ALI in working adults. A systematic literature search following the PRISMA-Statement was conducted in 21 databases including Medline, PubPsych, MedPilot, and Cochrane Register. Publications addressing work related-stress and medical parameters using ALI were considered. Data on study population, analytic techniques, and results were tabulated. Methodological quality was evaluated using a standardized checklist. 9 articles were identified with a total of 3 532 employees from 5 countries reporting cross-sectional data from the years 2003-2013. Overall, 7 studies reported a positive and significant association between work-related stress and ALI, while 2 studies showed no or an insignificant association. Substantial heterogeneity was observed in methods applied and study quality. This systematic review provides evidence that work-related stress is associated with ALI in cross-sectional studies. This association needs to be demonstrated by future studies using longitudinal data on working populations. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Assessment of the pharmacological effects of alprazolam on electroencephalography using connectivity indexes not affected by volume conduction

    Directory of Open Access Journals (Sweden)

    Joan Francesc Alonso

    2015-04-01

    The fact that the considered indexes were not able to find significant differences in the beta band might indicate that phase-coupling changes induced by the drug are weak or too subtle to be detected, given that all measures are corrected by a baseline recording. This might discourage their use in psychopharmacological studies when assessing low doses, mild effects, or when working with a reduced number of participants. However, correlations with plasma concentrations remained high, indicating that PLI, WPLI and IC should not be totally discarded as means of evaluating pharmacological effects on the brain via EEG recordings.

  19. Mechanics of Multifunctional Materials and Microsystems

    Science.gov (United States)

    2013-03-07

    substrate Fragmentation of a 2-µm thick ZnO/Si solar cell bonded on (±45°)4 laminate loaded according to the arrows. The vertically parallel strips are...unlimited 46  Successfully processed the 1st self-healing prepreg in continuous production mode SEM image of E-glass fiber tow (200 count) with 3.3...μm diameter PU/UF microcapsules Fiber tow Sized fiber Dried fiber 0◦ : 1ply 90◦ : 10 plies [0/905 ]s 0◦ : 1ply  Cross-ply laminates of self

  20. Deflection of Cross-Ply Composite Laminates Induced by Piezoelectric Actuators

    Directory of Open Access Journals (Sweden)

    Chi-Sheng Lin

    2010-01-01

    Full Text Available The coupling effects between the mechanical and electric properties of piezoelectric materials have drawn significant attention for their potential applications as sensors and actuators. In this investigation, two piezoelectric actuators are symmetrically surface bonded on a cross-ply composite laminate. Electric voltages with the same amplitude and opposite sign are applied to the two symmetric piezoelectric actuators, resulting in the bending effect on the laminated plate. The bending moment is derived by using the classical laminate theory and piezoelectricity. The analytical solution of the flexural displacement of the simply supported composite plate subjected to the bending moment is solved by using the plate theory. The analytical solution is compared with the finite element solution to show the validation of present approach. The effects of the size and location of the piezoelectric actuators on the response of the composite laminate are presented through a parametric study. A simple model incorporating the classical laminate theory and plate theory is presented to predict the deformed shape of the simply supported laminate plate.

  1. Damage in woven CFRP laminates under impact loading

    Science.gov (United States)

    Ullah, H.; Harland, A. R.; Silberschmidt, V. V.

    2012-08-01

    Carbon fibre-reinforced polymer (CFRP) composites used in sports products can be exposed to different in-service conditions such as large dynamic bending deformations caused by impact loading. Composite materials subjected to such loads demonstrate various damage modes such as matrix cracking, delamination and, ultimately, fabric fracture. Damage evolution affects both in-service properties and performance of CFRP that can deteriorate with time. These failure modes need adequate means of analysis and investigation, the major approaches being experimental characterisation and numerical simulations. This research deals with a deformation behaviour and damage in composite laminates due to dynamic bending. Experimental tests are carried out to characterise the behaviour of a woven CFRP material under large-deflection dynamic bending in impact tests carried out to obtain the force-time and absorbed energy profiles for CFRP laminates. Damage in the impacted laminates is analysed using optical microscopy. Numerical simulations are performed to study the deformation behaviour and damage in CFRP for cases of large-deflection bending based on three-dimensional finite-element models implemented in the commercial code Abaqus/Explicit. Multiple layers of bilinear cohesive-zone elements are employed to model the initiation and progression of inter-ply delamination observed in the microscopy studies. The obtained results of simulations show good agreement with experimental data.

  2. Heavy metal pollution of coal mine-affected agricultural soils in the northern part of Bangladesh.

    Science.gov (United States)

    Bhuiyan, Mohammad A H; Parvez, Lutfar; Islam, M A; Dampare, Samuel B; Suzuki, Shigeyuki

    2010-01-15

    Total concentrations of heavy metals in the soils of mine drainage and surrounding agricultural fields in the northern part of Bangladesh were determined to evaluate the level of contamination. The average concentrations of Ti, Mn, Zn, Pb, As, Fe, Rb, Sr, Nb and Zr exceeded the world normal averages and, in some cases, Mn, Zn, As and Pb exceeded the toxic limit of the respective metals. Soil pollution assessment was carried out using enrichment factor (EF), geoaccumulation index (I(geo)) and pollution load index (PLI). The soils show significant enrichment with Ti, Mn, Zn, Pb, As, Fe, Sr and Nb, indicating inputs from mining activities. The I(geo) values have revealed that Mn (1.24+/-0.38), Zn (1.49+/-0.58) and Pb (1.63+/-0.38) are significantly accumulated in the study area. The PLIs derived from contamination factors indicate that the distal part of the coal mine-affected area is the most polluted (PLI of 4.02). Multivariate statistical analyses, principal component and cluster analyses, suggest that Mn, Zn, Pb and Ti are derived from anthropogenic sources, particularly coal mining activities, and the extreme proximal and distal parts are heavily contaminated with maximum heavy metals.

  3. A rational evaluation of structural design loads

    International Nuclear Information System (INIS)

    Tasaka, S.

    1993-01-01

    The reliability-based seismic design of structures is a design method ensuring that the structural seismic capacity is not less than the maximum seismic load or load effect for a prescribed value of the reliability index, wherein the design reference period, n, is used to specify the n-year maximum load. In the conventional Load and Resistance Factor Design (LRFD) method the design load is commonly determined on the basis of the n-year maximum the probability distribution of which may be given in some different ways. However, in contrast with the structural capacity the n-year maximum load usually involves much larger variabilities. The effort to decrease the variability would, hence, be effective for the purpose of avoiding nuclear power plant (NPP) structures having unnecessarily large capacities. A possible way to do this is to consider the joint probability distribution of the n-year 1st and 2nd maxima of the seismic load derived from the formula of extreme order statistics. Since the reliability index is conventionally associated with the n-year 1st maximum, the conditional probability distribution rather than the joint one of the n-year 1st maximum given a value of the n-year 2nd one will be considered. Three conditional extreme value distributions, which correspond to the usual extreme value distributions of Types I, II and III, and their statistical moments up to the second order are presented. Within the framework of the first-order second moment method, the conditional statistical moments are utilized to calculate the reliability index as well as the design value of the seismic load. The seismic load considered herein is represented by the peak ground acceleration (PGA) in n years. The present scheme is applied to evaluate the design PGA's at II sites in Japan where samples of the annual 1st and 2nd PGA's have been obtained by using historical seismic data. In this application the following two points are of our interest: (a) Define the reliability

  4. Effects of moisture, elevated temperature, and fatigue loading on the behavior of graphite/epoxy buffer strip panels with center cracks

    Science.gov (United States)

    Bigelow, C. A.

    1988-01-01

    The effects of fatigue loading combined with moisture and heat on the behavior of graphite epoxy panels with either Kevlar-49 or S-glass buffer strips were studied. Buffer strip panels, that had a slit in the center to represent damage, were moisture conditioned or heated, fatigue loaded, and then tested in tension to measure their residual strength. The buffer strips were parallel to the loading direction and were made by replacing narrow strips of the 0 deg graphite plies with Kevlar-49 epoxy or S-glass epoxy on a 1-for-1 basis. The panels were subjected to a fatigue loading spectrum. One group of panels was preconditioned by soaking in 60 C water to produce a 1 percent weight gain then tested at room temperature. One group was heated to 82 C during the fatigue loading. Another group was moisture conditioned and then tested at 82 C. The residual strengths of the buffer panels were not highly affected by the fatigue loading, the number of repetitions of the loading spectrum, or the maximum strain level. The moisture conditioning reduced the residual strengths of the S-glass buffer strip panel by 10 to 15 percent below the ambient results. The moisture conditioning did not have a large effect on the Kevlar-49 panels.

  5. Fatigue and Damage Tolerance Analysis of a Hybrid Composite Tapered Flexbeam

    Science.gov (United States)

    Murri, Gretchen B.; Schaff, Jeffrey R.; Dobyns, Al

    2001-01-01

    The behavior of nonlinear tapered composite flexbeams under combined axial tension and cyclic bending loading was studied using coupon test specimens and finite element (FE) analyses. The flexbeams used a hybrid material system of graphite/epoxy and glass/epoxy and had internal dropped plies, dropped in an overlapping stepwise pattern. Two material configurations, differing only in the use of glass or graphite plies in the continuous plies near the midplane, were studied. Test specimens were cut from a full-size helicopter tail-rotor flexbeam and were tested in a hydraulic load frame under combined constant axialtension load and transverse cyclic bending loads. The first determination damage observed in the specimens occurred at the area around the tip of the outermost ply-drop group in the tapered region of the flexbeam, near the thick end. Delaminations grew slowly and stably, toward the thick end of the flexbeam, at the interfaces above and below the dropped-ply region. A 2D finite element model of the flexbeam was developed. The model was analyzed using a geometrically non-linear analysis with both the ANSYS and ABAQUS FE codes. The global responses of each analysis agreed well with the test results. The ANSYS model was used to calculate strain energy release rates (G) for delaminations initiating at two different ply-ending locations. The results showed that delaminations were more inclined to grow at the locations where they were observed in the test specimens. Both ANSYS and ABAQUS were used to calculate G values associated with delamination initiating at the observed location but growing in different interfaces, either above or below the ply-ending group toward the thick end, or toward the thin end from the tip of the resin pocket. The different analysis codes generated the same trends and comparable peak values, within 5-11 % for each delamination path. Both codes showed that delamination toward the thick region was largely mode II, and toward the thin

  6. Determination of glycaemic index; some methodological aspects related to the analysis of carbohydrate load and characteristics of the previous evening meal.

    Science.gov (United States)

    Granfeldt, Y; Wu, X; Björck, I

    2006-01-01

    To determine the possible differences in glycaemic index (GI) depending on (1) the analytical method used to calculate the 'available carbohydrate' load, that is, using carbohydrates by difference (total carbohydrate by difference, minus dietary fibre (DF)) as available carbohydrates vs available starch basis (total starch minus resistant starch (RS)) of a food rich in intrinsic RS and (2) the effect of GI characteristics and/or the content of indigestible carbohydrates (RS and DF) of the evening meal prior to GI testing the following morning. Blood glucose and serum insulin responses were studied after subjects consuming (1) two levels of barley kernels rich in intrinsic RS (15.2%, total starch basis) and (2) after a standard breakfast following three different evening meals varying in GI and/or indigestible carbohydrates: pasta, barley kernels and white wheat bread, respectively. Healthy adults with normal body mass index. (1) Increasing the portion size of barley kernels from 79.6 g (50 g 'available carbohydrates') to 93.9 g (50 g available starch) to adjust for its RS content did not significantly affect the GI or insulin index (11). (2) The low GI barley evening meal, as opposed to white wheat bread and pasta evening meals, reduced the postprandial glycaemic and insulinaemic (23 and 29%, respectively, P base carbohydrate load on specific analyses of the available carbohydrate content. (2) A low GI barley evening meal containing high levels of indigestible carbohydrates (RS and DF) substantially reduced the GI and II of white wheat bread determined at a subsequent breakfast meal.

  7. Predictions of Poisson's ratio in cross-ply laminates containing matrix cracks and delaminations

    Science.gov (United States)

    Harris, Charles E.; Allen, David H.; Nottorf, Eric W.

    1989-01-01

    A damage-dependent constitutive model for laminated composites has been developed for the combined damage modes of matrix cracks and delaminations. The model is based on the concept of continuum damage mechanics and uses second-order tensor valued internal state variables to represent each mode of damage. The internal state variables are defined as the local volume average of the relative crack face displacements. Since the local volume for delaminations is specified at the laminate level, the constitutive model takes the form of laminate analysis equations modified by the internal state variables. Model implementation is demonstrated for the laminate engineering modulus E(x) and Poisson's ratio nu(xy) of quasi-isotropic and cross-ply laminates. The model predictions are in close agreement to experimental results obtained for graphite/epoxy laminates.

  8. Dietary glycaemic index and glycaemic load in Danish children in relation to body fatness

    DEFF Research Database (Denmark)

    Nielsen, B. M.; Bjørnsbo, K. B.; Tetens, Inge

    2005-01-01

    The aim of this study was to describe dietary glycaemic index (GI) and glycaemic load (GL) values in the diets of Danish children, and to examine the associations between dietary GI, GL and body fatness. Data were collected during 1997-8 as part of the European Youth Heart Study. The study...... population comprised 485 children aged 10 years and 364 children aged 16 years from Odense County, Denmark. Dietary GI and GL were estimated using international food tables, and the associations between energy-adjusted dietary GI, GL and body fatness were analysed by multiple linear regression. The mean...... associations were observed between dietary GI and Sigma SF (beta=0 center dot 60, SE=0 center dot 21, P=0 center dot 006), and between dietary GL and Sigma SF (beta=0 center dot 15, SE=0.06, P=0 center dot 009). In conclusion, dietary GI and GL were positively associated with body fatness among Danish boys...

  9. Ultimate compression after impact load prediction in graphite/epoxy coupons using neural network and multivariate statistical analyses

    Science.gov (United States)

    Gregoire, Alexandre David

    2011-07-01

    The goal of this research was to accurately predict the ultimate compressive load of impact damaged graphite/epoxy coupons using a Kohonen self-organizing map (SOM) neural network and multivariate statistical regression analysis (MSRA). An optimized use of these data treatment tools allowed the generation of a simple, physically understandable equation that predicts the ultimate failure load of an impacted damaged coupon based uniquely on the acoustic emissions it emits at low proof loads. Acoustic emission (AE) data were collected using two 150 kHz resonant transducers which detected and recorded the AE activity given off during compression to failure of thirty-four impacted 24-ply bidirectional woven cloth laminate graphite/epoxy coupons. The AE quantification parameters duration, energy and amplitude for each AE hit were input to the Kohonen self-organizing map (SOM) neural network to accurately classify the material failure mechanisms present in the low proof load data. The number of failure mechanisms from the first 30% of the loading for twenty-four coupons were used to generate a linear prediction equation which yielded a worst case ultimate load prediction error of 16.17%, just outside of the +/-15% B-basis allowables, which was the goal for this research. Particular emphasis was placed upon the noise removal process which was largely responsible for the accuracy of the results.

  10. Dynamic control of a bistable wing under aerodynamic loading

    International Nuclear Information System (INIS)

    Bilgen, Onur; Arrieta, Andres F; Friswell, Michael I; Hagedorn, Peter

    2013-01-01

    The aerodynamic evaluation of a dynamic control technique applied to a bistable unsymmetrical cross-ply composite plate with surface bonded piezoelectric actuators is presented. The plate is clamped on one end to form a low-aspect-ratio wing. A previously proposed dynamic control method, utilizing bending resonance in different stable equilibrium positions, is used to induce snap-through between the two equilibrium states. Compared to quasi-static actuation, driving the bistable plate near resonance using surface bonded piezoelectric materials requires, theoretically, a lower peak excitation voltage to achieve snap-through. First, a set of extensive wind tunnel experiments are conducted on the passive bistable wing to understand the change in the dynamic behavior under various aerodynamic conditions. The passive wing demonstrated sufficient bending stiffness to sustain its shape under aerodynamic loading while preserving the desired bistable behavior. Next, by the use of the resonant control technique, the plate is turned into an effectively monostable structure, or alternatively, both stable equilibrium positions can be reached actively from the other stable equilibrium. Dynamic forward and reverse snap-through is demonstrated in the wind tunnel which shows both the effectiveness of the piezoelectric actuation as well as the load carrying capability of both states of the bistable wing. (paper)

  11. Probabilistic Simulation of Combined Thermo-Mechanical Cyclic Fatigue in Composites

    Science.gov (United States)

    Chamis, Christos C.

    2011-01-01

    A methodology to compute probabilistically-combined thermo-mechanical fatigue life of polymer matrix laminated composites has been developed and is demonstrated. Matrix degradation effects caused by long-term environmental exposure and mechanical/thermal cyclic loads are accounted for in the simulation process. A unified time-temperature-stress-dependent multifactor-interaction relationship developed at NASA Glenn Research Center has been used to model the degradation/aging of material properties due to cyclic loads. The fast probability-integration method is used to compute probabilistic distribution of response. Sensitivities of fatigue life reliability to uncertainties in the primitive random variables (e.g., constituent properties, fiber volume ratio, void volume ratio, ply thickness, etc.) computed and their significance in the reliability-based design for maximum life is discussed. The effect of variation in the thermal cyclic loads on the fatigue reliability for a (0/+/-45/90)s graphite/epoxy laminate with a ply thickness of 0.127 mm, with respect to impending failure modes has been studied. The results show that, at low mechanical-cyclic loads and low thermal-cyclic amplitudes, fatigue life for 0.999 reliability is most sensitive to matrix compressive strength, matrix modulus, thermal expansion coefficient, and ply thickness. Whereas at high mechanical-cyclic loads and high thermal-cyclic amplitudes, fatigue life at 0.999 reliability is more sensitive to the shear strength of matrix, longitudinal fiber modulus, matrix modulus, and ply thickness.

  12. Low-glycemic-load diets: impact on obesity and chronic diseases.

    Science.gov (United States)

    Bell, Stacey J; Sears, Barry

    2003-01-01

    Historically, carbohydrates have been thought to play only a minor role in promoting weight gain and in predicting the risk of development of chronic disease. Most of the focus had been on reducing total dietary fat. During the last 20 years, fat intake decreased, while the number of individuals who were overweight or developed a chronic conditions have dramatically increased. Simultaneously, the calories coming from carbohydrate have also increased. Carbohydrates can be classified by their post-prandial glycemic effect, called the glycemic index or glycemic load. Carbohydrates with high glycemic indexes and high glycemic loads produce substantial increases in blood glucose and insulin levels after ingestion. Within a few hours after their consumption, blood sugar levels begin to decline rapidly due to an exaggerated increase in insulin secretion. A profound state of hunger is created. The continued intake of high-glycemic load meals is associated with an increased risk of chronic diseases such as obesity, cardiovascular disease, and diabetes. In this review, the terms glycemic index and glycemic load are defined, coupled with an overview of short- and long-term changes that occur from eating diets of different glycemic indexes and glycemic loads. Finally, practical strategies for how to design low-glycemic-load diets consisting primarily of low-glycemic carbohydrates are provided.

  13. Analysis of thin-walled cylindrical composite shell structures subject to axial and bending loads: Concept development, analytical modeling and experimental verification

    Science.gov (United States)

    Mahadev, Sthanu

    Continued research and development efforts devoted in recent years have generated novel avenues towards the advancement of efficient and effective, slender laminated fiber-reinforced composite members. Numerous studies have focused on the modeling and response characterization of composite structures with particular relevance to thin-walled cylindrical composite shells. This class of shell configurations is being actively explored to fully determine their mechanical efficacy as primary aerospace structural members. The proposed research is targeted towards formulating a composite shell theory based prognosis methodology that entails an elaborate analysis and investigation of thin-walled cylindrical shell type laminated composite configurations that are highly desirable in increasing number of mechanical and aerospace applications. The prime motivation to adopt this theory arises from its superior ability to generate simple yet viable closed-form analytical solution procedure to numerous geometrically intense, inherent curvature possessing composite structures. This analytical evaluative routine offers to acquire a first-hand insight on the primary mechanical characteristics that essentially govern the behavior of slender composite shells under typical static loading conditions. Current work exposes the robustness of this mathematical framework via demonstrating its potential towards the prediction of structural properties such as axial stiffness and bending stiffness respectively. Longitudinal ply-stress computations are investigated upon deriving the global stiffness matrix model for composite cylindrical tubes with circular cross-sections. Additionally, this work employs a finite element based numerical technique to substantiate the analytical results reported for cylindrically shaped circular composite tubes. Furthermore, this concept development is extended to the study of thin-walled, open cross-sectioned, curved laminated shells that are geometrically

  14. Counting Carbs? Understanding Glycemic Index and Glycemic Load

    Science.gov (United States)

    ... compare how single servings of different foods affect blood sugar. It takes into account both the quality and quantity of carbs in a serving. . Some studies suggest that sticking to foods with a low glycemic index may help prevent ...

  15. Application and the importance of aging management within the PLiM/PLEx programs

    International Nuclear Information System (INIS)

    Cojan, Mihai

    2004-01-01

    The PLiM/PLEx Program applied to the Cernavoda NPP has the goal of ensuring the lifetime target of the plant and its extension in conditions of a continuous, secure and reliable operation by fulfilling at the same time the general licensing requirements as established by the regulation authority CNCAN. The aging management is, according to the organization model, a systematic process implying the following activities specific to the operation: - Planning: Coordination of the aging management activities; - Exploitation: Controlling the aging mechanisms; - Testing: Detection and evaluation of the aging effects; - Maintenance: Controlling the aging effects. All these are interdependent with specific activities in INR Pitesti, related to the research and development which are key elements for controlling effectively the aging process. The model of organizing the aging management developed in this work is applied to the Cernavoda NPP Unit 1

  16. Glycemic index and glycemic load of selected Chinese traditional foods.

    Science.gov (United States)

    Chen, Ya-Jun; Sun, Feng-Hua; Wong, Stephen Heung-Sang; Huang, Ya-Jun

    2010-03-28

    To determine the glycemic index (GI) and glycemic load (GL) values of Chinese traditional foods in Hong Kong. Fifteen healthy subjects (8 males and 7 females) volunteered to consume either glucose or one of 23 test foods after 10-14 h overnight fast. The blood glucose concentrations were analyzed immediately before, 15, 30, 45, 60, 90 and 120 min after food consumption using capillary blood samples. The GI value of each test food was calculated by expressing the incremental area under the blood glucose response curve (IAUC) value for the test food as a percentage of each subject's average IAUC value for the glucose. The GL value of each test food was calculated as the GI value of the food multiplied by the amount of the available carbohydrate in a usual portion size, divided by 100. Among all the 23 Chinese traditional foods tested, 6 of them belonged to low GI foods (Tuna Fish Bun, Egg Tart, Green Bean Dessert, Chinese Herbal Jelly, Fried Rice Vermicelli in Singapore-style, and Spring Roll), 10 of them belonged to moderate GI foods (Baked Barbecued Pork Puff, Fried Fritter, "Mai-Lai" Cake, "Pineapple" Bun, Fried Rice Noodles with Sliced Beef, Barbecue Pork Bun, Moon Cakes, Glutinous Rice Ball, Instant Sweet Milky Bun, and Salted Meat Rice Dumpling), the others belonged to high GI foods (Fried Rice in Yangzhou-Style, Sticky Rice Wrapped in Lotus Leaf, Steamed Glutinous Rice Roll, Jam and Peanut Butter Toast, Plain Steamed Vermicelli Roll, Red Bean Dessert, and Frozen Sweet Milky Bun). The GI and GL values for these Chinese traditional foods will provide some valuable information to both researchers and public on their food preference.

  17. Using Electroencephalography to Measure Cognitive Load

    Science.gov (United States)

    Antonenko, Pavlo; Paas, Fred; Grabner, Roland; van Gog, Tamara

    2010-01-01

    Application of physiological methods, in particular electroencephalography (EEG), offers new and promising approaches to educational psychology research. EEG is identified as a physiological index that can serve as an online, continuous measure of cognitive load detecting subtle fluctuations in instantaneous load, which can help explain effects of…

  18. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23) with High Potential to Control American Foulbrood.

    Science.gov (United States)

    Oliveira, Ana; Leite, Marta; Kluskens, Leon D; Santos, Sílvio B; Melo, Luís D R; Azeredo, Joana

    2015-01-01

    Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23) encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0), showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  19. Practical Hydrogen Loading of Air Silica Fibres

    DEFF Research Database (Denmark)

    Sørensen, Henrik Rokkjær; Jensen, Jesper Bevensee; Jensen, Jesper Bo Damm

    2005-01-01

    A method for hydrogen-loading air-silica optical fibres has been developed allowing out-diffusion times comparable to standard step-index fibres. Examples of the first grating written in Ge-doped air-silica fibres using a 266nm UV-laser are shown.......A method for hydrogen-loading air-silica optical fibres has been developed allowing out-diffusion times comparable to standard step-index fibres. Examples of the first grating written in Ge-doped air-silica fibres using a 266nm UV-laser are shown....

  20. Free Vibration Study of Anti-Symmetric Angle-Ply Laminated Plates under Clamped Boundary Conditions

    Science.gov (United States)

    Viswanathan, K. K.; Karthik, K.; Sanyasiraju, Y. V. S. S.; Aziz, Z. A.

    2016-11-01

    Two type of numerical approach namely, Radial Basis Function and Spline approximation, used to analyse the free vibration of anti-symmetric angle-ply laminated plates under clamped boundary conditions. The equations of motion are derived using YNS theory under first order shear deformation. By assuming the solution in separable form, coupled differential equations obtained in term of mid-plane displacement and rotational functions. The coupled differential is then approximated using Spline function and radial basis function to obtain the generalize eigenvalue problem and parametric studies are made to investigate the effect of aspect ratio, length-to-thickness ratio, number of layers, fibre orientation and material properties with respect to the frequency parameter. Some results are compared with the existing literature and other new results are given in tables and graphs.

  1. Pollution level assessment of road dust from islamabad expressway

    International Nuclear Information System (INIS)

    Faiz, Y.; Siddiqui, N.

    2013-01-01

    Thirteen road dust and four soil samples were analyzed using Instrumental Neutron Activation Analysis (INAA) and Flame Atomic Absorption Spectroscopy (FAAS) to determine the elemental composition of road dust collected from Islamabad Expressway. Pollution parameters and indicators such as Enrichment Factors (EFs), Pollution Load Index (PLI), Geoaccumulation Index (I G eo), Pollution Index (PI) and Integrated Pollution Index (IPI) were calculated and showed that the area around Islamabad Expressway is low to moderately polluted especially by elements such as Mg and Sb. The IPI of the elements was found to vary in the order; Mg>Sb>Cu>Sr ≅Pb>Ga>Na >Sn≅ Zn>Yb>Se>Hf. The 5 samples collected around the busy intersections of Faizabad and Zero Point have higher amounts of most of the elements determined. Moreover the pollution indices for these samples indicate that these sites are more contaminated than the remaining 8 sampling sites. (author)

  2. Glycemic index and glycemic load of tropical fruits and the potential risk for chronic diseases

    Directory of Open Access Journals (Sweden)

    Tatiana Uchôa Passos

    2015-03-01

    Full Text Available The objective was to determine the glycemic index and glycemic load of tropical fruits and the potential risk for chronic diseases. Nine fruits were investigated: coconut water (for the purpose of this study, coconut water was classified as a “fruit”, guava, tamarind, passion fruit, custard apple, hog plum, cashew, sapodilla, and soursop. The GI and GL were determined according to the Food and Agriculture Organization protocol. The GL was calculated taking into consideration intake recommendation guidelines; 77.8% of the fruits had low GI although significant oscillations were observed in some graphs, which may indicate potential risks of disease. Coconut water and custard apple had a moderate GI, and all fruits had low GL. The fruits evaluated are healthy and can be consumed following the daily recommended amount. However, caution is recommended with fruits causing early glycemic peak and the fruits with moderated GI (coconut water and custard apple.

  3. Assessment of various failure theories for weight and cost optimized laminated composites using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, T. [Indian Institute of Technology Kanpur. Dept. of Aerospace Engineering, UP (India); Gupta, R. [Infotech Enterprises Ltd., Hyderabad (India)

    2012-07-01

    In this work, minimum weight-cost design for laminated composites is presented. A genetic algorithm has been developed for the optimization process. Maximum-Stress, Tsai-Wu and Tsai-Hill failure criteria have been used along with buckling analysis parameter for the margin of safety calculations. The design variables include three materials; namely Carbon-Epoxy, Glass-Epoxy, Kevlar-Epoxy; number of plies; ply orientation angles, varying from -75 deg. to 90 deg. in the intervals of 15 deg. and ply thicknesses which depend on the material in use. The total cost is a sum of material cost and layup cost. Layup cost is a function of the ply angle. Validation studies for solution convergence and weight-cost inverse proportionality are carried out. One set of results for shear loading are also validated from literature for a particular case. A Pareto-Optimal solution set is demonstrated for biaxial loading conditions. It is then extended to applied moments. It is found that global optimum for a given loading condition is a function of the failure criteria for shear loading, with Maximum Stress criteria giving the lightest-cheapest and Tsai-Wu criteria giving the heaviest-costliest optimized laminates. Optimized weight results are plotted from the three criteria to do a comparative study. This work gives a global optimized laminated composite and also a set of other local optimum laminates for a given set of loading conditions. The current algorithm also provides with adequate data to supplement the use of different failure criteria for varying loadings. This work can find use in the industry and/or academia considering the increased use of laminated composites in modern wind blades. (Author)

  4. Risk Assessment of Potentially Toxic Elements (PTEs Pollution at a Rural Industrial Wasteland in an Abandoned Metallurgy Factory in North China

    Directory of Open Access Journals (Sweden)

    Zheng Sun

    2018-01-01

    Full Text Available The potential toxic elements (PTEs pollution problems in many rural industrial wastelands have been observed to be conspicuous. Therefore, 40 top soil samples were collected from the wasteland of a typical rural metallurgy factory in Baoding, China. The total concentrations of six key PTEs were measured. The soil properties and speciation of the PTEs were also identified. Extremely high concentrations of As, Cd, Pb, and Zn were observed in the surface soils. Using the PTEs concentration in the top soils of the rural industrial wasteland, the following indices of pollution were calculated: the pollution load index (PLI, the geo-accumulation Index (Igeo, the risk assessment code (RAC, and the health risk assessment (HRA. The analysis of the PLI and Igeo indicated that site #1 was relatively clean, while sites #2 and #3 were heavily polluted. The results of the RAC showed that PTEs in top soils at sites #2 and #3 were significantly increased (p <  0.05 for Cd and Zn. The HRA indicated that both As and Pb presented non-carcinogenic risks to children and adults at sites #2 and #3. Our findings can be a reference for risk prevention of industrially abandoned land in rural China.

  5. Risk Assessment of Potentially Toxic Elements (PTEs) Pollution at a Rural Industrial Wasteland in an Abandoned Metallurgy Factory in North China.

    Science.gov (United States)

    Sun, Zheng; Chen, Jiajun

    2018-01-06

    The potential toxic elements (PTEs) pollution problems in many rural industrial wastelands have been observed to be conspicuous. Therefore, 40 top soil samples were collected from the wasteland of a typical rural metallurgy factory in Baoding, China. The total concentrations of six key PTEs were measured. The soil properties and speciation of the PTEs were also identified. Extremely high concentrations of As, Cd, Pb, and Zn were observed in the surface soils. Using the PTEs concentration in the top soils of the rural industrial wasteland, the following indices of pollution were calculated: the pollution load index (PLI), the geo-accumulation Index (I geo ), the risk assessment code (RAC), and the health risk assessment (HRA). The analysis of the PLI and I geo indicated that site #1 was relatively clean, while sites #2 and #3 were heavily polluted. The results of the RAC showed that PTEs in top soils at sites #2 and #3 were significantly increased ( p <  0.05) for Cd and Zn. The HRA indicated that both As and Pb presented non-carcinogenic risks to children and adults at sites #2 and #3. Our findings can be a reference for risk prevention of industrially abandoned land in rural China.

  6. Investigation of the effect of bending twisting coupling on the loads in wind turbines with superelement blade definition

    International Nuclear Information System (INIS)

    Gözcü, M O; Kayran, A

    2014-01-01

    Bending-twisting coupling in the composite blades is exploited for load alleviation in the whole turbine system. For the purpose of the study, inverse design of a reference blade is performed such that sectional beam properties of the 3D blade design approximately match the sectional beam properties of NREL's 5MW turbine blade. In order to appropriately account for the bending-twisting coupling effect, dynamic superelement of the blade is created and introduced into the multi-body dynamic model of the wind turbine system. Initially, a comparative study is conducted on the performance of wind turbines which have blades defined as superelements and geometrically nonlinear beams, and conclusions are inferred with regard to the appropriateness of the use of superelement blade definition in the transient analysis of the 5MW wind turbine system that is set up in the present study. Multi-body dynamic simulations of the wind turbine system are performed for the power production load case with the constant wind and the normal turbulence model as external wind loadings. For the internal loads, fatigue damage equivalent load is used as the metric to assess the effect of bending-twisting coupling on the load alleviation in the whole wind turbine system. Results show that in the overall, through the bending-twisting coupling induced with the use of off-axis plies in the main spar caps of the blade, damage equivalent loads associated with the critical load components can be reduced in the wind turbine system

  7. The First Paenibacillus larvae Bacteriophage Endolysin (PlyPl23 with High Potential to Control American Foulbrood.

    Directory of Open Access Journals (Sweden)

    Ana Oliveira

    Full Text Available Endolysins, which are peptidoglycan-degrading enzymes expressed during the terminal stage of the reproduction cycle of bacteriophages, have great potential to control Gram-positive pathogens. This work describes the characterization of a novel endolysin (PlyPl23 encoded on the genome of Paenibacillus larvae phage phiIBB_Pl23 with high potential to control American foulbrood. This bacterial disease, caused by P. larvae, is widespread in North America and Europe and causes important economic losses in apiculture. The restriction to antibiotic residues in honey imposed by the EU legislation hinders its therapeutic use to combat American foulbrood and enforces the development of alternative antimicrobial methods. The new endolysin described herein has an N-acetylmuramoyl-L-alanine amidase catalytic domain and exhibits a broad-spectrum activity against common P. larvae genotypes. Moreover, the enzyme displays high antimicrobial activity in a range of pH that matches environmental conditions (pH between 5.0 and 7.0, showing its feasible application in the field. At pH 7.0, a concentration of 0.2 μM of enzyme was enough to lyse 104 CFU.mL-1 of P. larvae in no more than 2 h. The presence of sucrose and of the substances present in the larvae gut content did not affect the enzyme activity. Interestingly, an increase of activity was observed when PlyPl23 was previously incubated in royal jelly. Furthermore, in vivo safety evaluation assays demonstrated that this enzyme is not toxic to the bee larvae. The present work describes for the first time an endolysin encoded in a P. larvae phage that presents high potential to integrate a commercial product to control the problematic American foulbrood.

  8. Reliability Constrained Priority Load Shedding for Aerospace Power System Automation

    Science.gov (United States)

    Momoh, James A.; Zhu, Jizhong; Kaddah, Sahar S.; Dolce, James L. (Technical Monitor)

    2000-01-01

    The need for improving load shedding on board the space station is one of the goals of aerospace power system automation. To accelerate the optimum load-shedding functions, several constraints must be involved. These constraints include congestion margin determined by weighted probability contingency, component/system reliability index, generation rescheduling. The impact of different faults and indices for computing reliability were defined before optimization. The optimum load schedule is done based on priority, value and location of loads. An optimization strategy capable of handling discrete decision making, such as Everett optimization, is proposed. We extended Everett method to handle expected congestion margin and reliability index as constraints. To make it effective for real time load dispatch process, a rule-based scheme is presented in the optimization method. It assists in selecting which feeder load to be shed, the location of the load, the value, priority of the load and cost benefit analysis of the load profile is included in the scheme. The scheme is tested using a benchmark NASA system consisting of generators, loads and network.

  9. Fuzzy-TLX: using fuzzy integrals for evaluating human mental workload with NASA-Task Load indeX in laboratory and field studies.

    Science.gov (United States)

    Mouzé-Amady, Marc; Raufaste, Eric; Prade, Henri; Meyer, Jean-Pierre

    2013-01-01

    The aim of this study was to assess mental workload in which various load sources must be integrated to derive reliable workload estimates. We report a new algorithm for computing weights from qualitative fuzzy integrals and apply it to the National Aeronautics and Space Administration -Task Load indeX (NASA-TLX) subscales in order to replace the standard pair-wise weighting technique (PWT). In this paper, two empirical studies were reported: (1) In a laboratory experiment, age- and task-related variables were investigated in 53 male volunteers and (2) In a field study, task- and job-related variables were studied on aircrews during 48 commercial flights. The results found in this study were as follows: (i) in the experimental setting, fuzzy estimates were highly correlated with classical (using PWT) estimates; (ii) in real work conditions, replacing PWT by automated fuzzy treatments simplified the NASA-TLX completion; (iii) the algorithm for computing fuzzy estimates provides a new classification procedure sensitive to various variables of work environments and (iv) subjective and objective measures can be used for the fuzzy aggregation of NASA-TLX subscales. NASA-TLX, a classical tool for mental workload assessment, is based on a weighted sum of ratings from six subscales. A new algorithm, which impacts on input data collection and computes weights and indexes from qualitative fuzzy integrals, is evaluated through laboratory and field studies. Pros and cons are discussed.

  10. Assessment of sediment quality collected from the Tunku Abdul Rahman National Park, Sabah

    International Nuclear Information System (INIS)

    Mohd Suhaimi Elias; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Siong, Wee Boon; Nazaratul Ashifa Abdullah Salim

    2012-01-01

    Assessment of source and sediment quality was carried out on marine sediments collected from the Tuanku Abdul Rahman National Park. Enrichment factors (EF), pollution load index (PLI) and geo-accumulation index (Igeo) were used to identify the sources of pollution, degree of contamination and sediment quality, respectively. Elemental analyses of marine sediment samples were performed by using the Instrumental Neutron Activation Analysis (INAA). Results from the Tunku Abdul Rahman National Park of Sabah indicated that most of the elements are considered to be from lithological or natural origin with EF values of less than 2 except for As (10 stations), Cr (3 stations), Lu (5 stations), Mg (2 stations), Sb (6 stations) and U (3 stations). For the sediment quality, most of the study area can be categorised as unpolluted for most of the elements (Igeo value < 2) except for As, Cr, Lu, Mg, Sb and U. A few study areas were slightly low contaminated with As, Cr, Lu, Mg, Sb and U. The contamination of As, Cr, Lu, Mg, Sb and U in the study area can be categorised as moderate with Igeo values ranged from 1 to 2. Meanwhile, the results of PLI value for sediment were ranged from 0.93 to 1.47 (PLI < 50) indicating there are not required to perform drastic rectification measures for the screening of the elements in the Tunku Abdul Rahman Park. Overall, assessment of the sediment quality at the Tunku Abdul Rahman National Park showed a few elements such as As, Cr, Lu, Mg, Sb and U were slightly enriched while most of the elements were similar to background values. (author)

  11. Aspects of alienation and symptom load among adolescents

    DEFF Research Database (Denmark)

    Rayce, Signe L B; Holstein, Bjørn E; Kreiner, Svend

    2009-01-01

    BACKGROUND: The purpose was to examine the association between aspects of alienation and symptom load among adolescents. Furthermore an integrated purpose was to construct and validate an index of alienation. METHODS: Cross-sectional data from 5205 school children aged 11-15 years from a random...... sample of schools in Denmark were used. Data stems from the Danish contribution to the cross-national study Health and Behaviour in School-aged Children (HBSC). Alienation was measured with a new index fulfilling four criteria: (i) theoretical foundation, (ii) inter-correlation between items, (iii......) correlation between each of the index's items and the outcomes and (iv) no differential item functioning. The final index included three indicators of alienation: helplessness, feeling left out of things and lack of confidentiality with parents. Symptom load was measured by HBSC Symptom Checklist and divided...

  12. Effect of Heavy Smoking on Dental Implants Placed in Male Patients Posterior Mandibles: A Prospective Clinical Study.

    Science.gov (United States)

    Sun, Cong; Zhao, Jinxiu; Jianghao, Chen; Hong, Tao

    2016-12-01

    The objective of this study was to evaluate the implant stability and peri-implant tissue response in heavy smokers receiving dental implants due to partially edentulous posterior mandibles. Forty-five ITI Straumann dental implants were placed into the partially edentulous posterior mandibles of 16 heavy smokers and 16 nonsmokers. One implant in each patient was evaluated for implant stability after surgery and before loading, and for the modified plaque index (mPLI), modified sulcus bleeding index (mSBI), probing depth (PD), and marginal bone loss (MBL) after loading. Meanwhile, the osteogenic capability of jaw marrow samples collected from patients was evaluated via an in vitro mineralization test. For both groups, the implant stability quotient (ISQ) initially decreased from the initial ISQ achieved immediately after surgery and then increased starting from 2 weeks postsurgery. However, at 3, 4, 6, and 8 weeks postsurgery, the ISQ differed significantly between nonsmokers and heavy smokers. All implants achieved osseointegration without complications at least by the end of the 12th week postsurgery. At 6 or 12 months postloading, the MBL and PD were significantly higher in heavy smokers than in nonsmokers, whereas the mSBI and mPLI did not differ significantly between the 2 groups. The 1-year cumulative success rate of implants was 100% for both groups. Within the limitations of the present clinical study (such as small sample size and short study duration), which applied the loading at 3 months postoperation, heavy smoking did not affect the cumulative survival rate of dental implants placed at the posterior mandible in male patients, but heavy smoking did negatively affect bone healing around dental implants by decreasing the healing speed. These results implied that it might be of importance to select the right time point to apply the implant loading for heavy smokers. In addition, heavy smoking promoted the loss of marginal bone and the further development

  13. Assessment of the transportation route of oversize and excessive loads in relation to the load-bearing capacity of existing bridges

    Science.gov (United States)

    Doležel, Jiří; Novák, Drahomír; Petrů, Jan

    2017-09-01

    Transportation routes of oversize and excessive loads are currently planned in relation to ensure the transit of a vehicle through critical points on the road. Critical points are level-intersection of roads, bridges etc. This article presents a comprehensive procedure to determine a reliability and a load-bearing capacity level of the existing bridges on highways and roads using the advanced methods of reliability analysis based on simulation techniques of Monte Carlo type in combination with nonlinear finite element method analysis. The safety index is considered as a main criterion of the reliability level of the existing construction structures and the index is described in current structural design standards, e.g. ISO and Eurocode. An example of a single-span slab bridge made of precast prestressed concrete girders of the 60 year current time and its load bearing capacity is set for the ultimate limit state and serviceability limit state. The structure’s design load capacity was estimated by the full probability nonlinear MKP analysis using a simulation technique Latin Hypercube Sampling (LHS). Load-bearing capacity values based on a fully probabilistic analysis are compared with the load-bearing capacity levels which were estimated by deterministic methods of a critical section of the most loaded girders.

  14. Damage assessment in CFRP laminates exposed to impact fatigue loading

    International Nuclear Information System (INIS)

    Tsigkourakos, George; Silberschmidt, Vadim V; Ashcroft, I A

    2011-01-01

    Demand for advanced engineering composites in the aerospace industry is increasing continuously. Lately, carbon fibre reinforced polymers (CFRPs) became one of the most important structural materials in the industry due to a combination of characteristics such as: excellent stiffness, high strength-to-weight ratio, and ease of manufacture according to application. In service, aerospace composite components and structures are exposed to various transient loads, some of which can propagate in them as cyclic impacts. A typical example is an effect of the wind gusts during flight. This type of loading is known as impact fatigue (IF); it is a repetition of low-energy impacts. Such loads can cause various types of damage in composites: fibre breaking, transverse matrix cracking, de-bonding between fibres and matrix and delamination resulting in reduction of residual stiffness and loss of functionality. Furthermore, this damage is often sub-surface, which reinforces the need for more regular inspection. The effects of IF are of major importance due its detrimental effect on the structural integrity of components that can be generated after relatively few impacts at low force levels compared to those in a standard fatigue regime. This study utilises an innovative testing system with the capability of subjecting specimens to a series of repetitive impacts. The primary subject of this paper is to assess the damaging effect of IF on the behaviour of drilled CFRP specimens, exposed to such loading. A detailed damage analysis is implemented utilising an X-ray micro computed tomography system. The main findings suggested that at early stages of life damage is governed by o degree splits along the length of the specimens resulting in a 20% reduction of stiffness. The final failure damage scenario indicated that transverse crasks in the 90 degree plies are the main reason for complete delamination which can be translated to a 50% stiffness reduction.

  15. Macrophyte Community Response to Nitrogen Loading and ...

    Science.gov (United States)

    Empirical determination of nutrient loading thresholds that negatively impact seagrass communities have been elusive due to the multitude of factors involved. Using a mesocosm system that simulated Pacific Northwest estuaries, we evaluated macrophyte metrics across gradients of NO3 loading (0, 1.5, 3 and 6x ambient) and temperature (10 and 20 °C). Macroalgal growth, biomass, and C:N responded positively to increased NO3 load and floating algal mats developed at 20 ºC. Zostera japonica metrics, including C:N, responded more to temperature than to NO3 loading. Z. marina biomass exhibited a negative temperature effect and in some cases a negative NO3 effect, while growth rate increased with temperature. Shoot survival decreased at 20 ºC but was not influenced by NO3 loading. Wasting disease index exhibited a significant temperature by NO3 interaction consistent with increased disease susceptibility. Community shifts observed were consistent with the nutrient loading hypothesis at 20 ºC, but there was no evidence of other eutrophication symptoms due to the short residence time. The Nutrient Pollution Index tracked the NO3 gradient at 10 ºC but exhibited no response at 20 ºC. We suggest that systems characterized by cool temperatures, high NO3 loads, and short residence time may be resilient to many symptoms of eutrophication. Estuarine systems characterized by cool temperatures, high nutrient loads and rapid flushing may be resilient to some symptoms

  16. Investigation of the Leak Response of a Carbon-Fiber Laminate Loaded in Biaxial Tension

    Science.gov (United States)

    Jackson, Wade C.; Ratcliffe, James G.

    2013-01-01

    Designers of pressurized structures have been reluctant to use composite materials because of concerns over leakage. Biaxial stress states are expected to be the worst-case loading condition for allowing leakage to occur through microcracks. To investigate the leakage behavior under in-plane biaxial loading, a cruciform composite specimen was designed that would have a relatively large test section with a uniform 1:1 biaxial loading ratio. A 7.6-cm-square test section was desired for future investigations of the leakage response as a result of impact damage. Many iterations of the cruciform specimen were evaluated using finite element analysis to reduce stress concentrations and maximize the size of the uniform biaxial strain field. The final design allowed the specimen to go to relatively high biaxial strain levels without incurring damage away from the test section. The specimen was designed and manufactured using carbon/epoxy fabric with a four-ply-thick, quasi-isotropic, central test section. Initial validation and testing were performed on a specimen without impact damage. The specimen was tested to maximum biaxial strains of approximately 4500micro epsilon without apparent damage. A leak measurement system containing a pressurized cavity was clamped to the test section and used to measure the flow rate through the specimen. The leakage behavior of the specimen was investigated for pressure differences up to 172 kPa

  17. Accumulation and environmental risk assessment of heavy metals in soil and plants of four different ecosystems in a former polymetallic ores mining and smelting area (Slovakia).

    Science.gov (United States)

    Demková, Lenka; Árvay, Július; Bobuľská, Lenka; Tomáš, Ján; Stanovič, Radovan; Lošák, Tomáš; Harangozo, Luboš; Vollmannová, Alena; Bystrická, Judita; Musilová, Janette; Jobbágy, Ján

    2017-04-16

    Heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in soils and plants of four different ecosystems (forest, grassland, agro and urban ecosystem) at different distances from the source of the pollution were analyzed in order to assess and compare soil contamination in the various ecosystems and determine the potential accumulation of plants depending on the place they inhabit. Correlation relationships among heavy metals in soils differ depending on the ecosystem, and between soil and plant, the heavy metals showed significant correlation for Cu, Mn, Ni, Pb and Zn. Contamination factor (C f ), degree of contamination (C d ) and pollution load index (PLI) were used in order to determine the level of environmental contamination of the study area. All studied ecosystems were rated as moderately contaminated (except agroecosystem, which was found as low contamination ecosystem) according to C d and extremely polluted according to PLI. The highest pollution in both cases was found in urban ecosystem, and Cd, Cu and Fe were determined as the biggest pollutants.

  18. Impacts from Land Use Pattern on Spatial Distribution of Cultivated Soil Heavy Metal Pollution in Typical Rural-Urban Fringe of Northeast China.

    Science.gov (United States)

    Li, Wenbo; Wang, Dongyan; Wang, Qing; Liu, Shuhan; Zhu, Yuanli; Wu, Wenjun

    2017-03-22

    Under rapid urban sprawl in Northeast China, land conversions are not only encroaching on the quantity of cultivated lands, but also posing a great threat to black soil conservation and food security. This study's aim is to explore the spatial relationship between comprehensive cultivated soil heavy metal pollution and peri-urban land use patterns in the black soil region. We applied spatial lag regression to analyze the relationship between PLI (pollution load index) and influencing factors of land use by taking suburban cultivated land of Changchun Kuancheng District as an empirical case. The results indicate the following: (1) Similar spatial distribution characteristics are detected between Pb, Cu, and Zn, between Cr and Ni, and between Hg and Cd. The Yitong River catchment in the central region, and the residential community of Lanjia County in the west, are the main hotspots for eight heavy metals and PLI. Beihu Wetland Park, with a larger-area distribution of ecological land in the southeast, has low level for both heavy metal concentrations and PLI values. Spatial distribution characteristics of cultivated heavy metals are related to types of surrounding land use and industry; (2) Spatial lag regression has a better fit for PLI than the ordinary least squares regression. The regression results indicate the inverse relationship between heavy metal pollution degree and distance from long-standing residential land and surface water. Following rapid urban land expansion and a longer accumulation period, residential land sprawl is going to threaten cultivated land with heavy metal pollution in the suburban black soil region, and cultivated land irrigated with urban river water in the suburbs will have a higher tendency for heavy metal pollution.

  19. Impacts from Land Use Pattern on Spatial Distribution of Cultivated Soil Heavy Metal Pollution in Typical Rural-Urban Fringe of Northeast China

    Science.gov (United States)

    Li, Wenbo; Wang, Dongyan; Wang, Qing; Liu, Shuhan; Zhu, Yuanli; Wu, Wenjun

    2017-01-01

    Under rapid urban sprawl in Northeast China, land conversions are not only encroaching on the quantity of cultivated lands, but also posing a great threat to black soil conservation and food security. This study’s aim is to explore the spatial relationship between comprehensive cultivated soil heavy metal pollution and peri-urban land use patterns in the black soil region. We applied spatial lag regression to analyze the relationship between PLI (pollution load index) and influencing factors of land use by taking suburban cultivated land of Changchun Kuancheng District as an empirical case. The results indicate the following: (1) Similar spatial distribution characteristics are detected between Pb, Cu, and Zn, between Cr and Ni, and between Hg and Cd. The Yitong River catchment in the central region, and the residential community of Lanjia County in the west, are the main hotspots for eight heavy metals and PLI. Beihu Wetland Park, with a larger-area distribution of ecological land in the southeast, has low level for both heavy metal concentrations and PLI values. Spatial distribution characteristics of cultivated heavy metals are related to types of surrounding land use and industry; (2) Spatial lag regression has a better fit for PLI than the ordinary least squares regression. The regression results indicate the inverse relationship between heavy metal pollution degree and distance from long-standing residential land and surface water. Following rapid urban land expansion and a longer accumulation period, residential land sprawl is going to threaten cultivated land with heavy metal pollution in the suburban black soil region, and cultivated land irrigated with urban river water in the suburbs will have a higher tendency for heavy metal pollution. PMID:28327541

  20. Fuzzy Load-Shedding Strategy Considering Photovoltaic Output Fluctuation Characteristics and Static Voltage Stability

    Directory of Open Access Journals (Sweden)

    Sheng Li

    2018-03-01

    Full Text Available Based on the equilibrium point equations of a classic three-node system integrated with a large-scale photovoltaic cell (PV power plant, the impact of PV output fluctuation on the saddle-node bifurcation (SNB was derived and analyzed. When PV runs in a unity power factor and the PV output active power Ppv is not too large (several hundred MW and below, the PV output fluctuation has little effect on the SNB point position and load margin index, so that the load margin index can be calculated online using the SNB point at Ppv = 0 pu. On the other hand, the local reactive power compensation in the load center can effectively raise the load bus voltage and make the voltage stability problem become more concealed; the traditional under-voltage load-shedding (UVLS strategy only carries out load shedding when the bus voltage amplitude is below the specified value and cannot effectively maintain the system static voltage stability in some occasions. In this paper, a fuzzy load-shedding strategy considering the impact of PV output fluctuations for the large-scale PV grid-connected system was designed, taking the load bus voltage amplitude and load margin index as fuzzy input variables, and the load-shedding command as a fuzzy output variable. Nine fuzzy IF-THEN rules were extracted for the fuzzy controller and the corresponding practical calculation method of load-shedding quantity was put forward. The simulation results of the classic three-node system and IEEE 14-bus system, both with a 100 MW PV power plant, verified the effectiveness of the fuzzy load-shedding controller whose input variable load margin index was calculated using the SNB point when the PV active power output was 0. The designed fuzzy load-shedding strategy can compensate for the defect—that the traditional UVLS strategy cannot effectively guarantee the system static voltage stability—and it can be widely used in power grids integrated with PV power plants whose scales are at a

  1. Manpower and Personnel Integration (MANPRINT) and Network Integration Evaluation 13.2: Observations on Cognitive Load in Mission Command

    Science.gov (United States)

    2014-03-01

    using scales like NASA’s Task Load Index ( TLX ) (Hart and Staveland, 1988). At present, there are no comparable measurement scales for cognitive...Staveland, L. E. Development of NASA- TLX (Task Load Index): Results of empirical and theoretical research. In Human Mental Workload; Hancock, P. A...Requests for Information SA situation awareness TLX Task Load Index TOC tactical operations center WSMR White Sands Missile Range XO executive

  2. User's guide for GSMP, a General System Modeling Program. [In PL/I

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J. M.

    1979-10-01

    GSMP is designed for use by systems analysis teams. Given compiled subroutines that model the behavior of components plus instructions as to how they are to be interconnected, this program links them together to model a complete system. GSMP offers a fast response to management requests for reconfigurations of old systems and even initial configurations of new systems. Standard system-analytic services are provided: parameter sweeps, graphics, free-form input and formatted output, file storage and recovery, user-tested error diagnostics, component model and integration checkout and debugging facilities, sensitivity analysis, and a multimethod optimizer with nonlinear constraint handling capability. Steady-state or cyclic time-dependence is simulated directly, initial-value problems only indirectly. The code is written in PL/I, but interfaces well with FORTRAN component models. Over the last five years GSMP has been used to model theta-pinch, tokamak, and heavy-ion fusion power plants, open- and closed-cycle magneto-hydrodynamic power plants, and total community energy systems.

  3. THE WORKLOAD ANALYSIS OF EMPLOYEE BY USING NATIONAL AERONAUTICS AND SPACE ADMINISTRATION-TASK LOAD INDEX METHOD (NASA-TLX

    Directory of Open Access Journals (Sweden)

    Nur Azemil

    2017-09-01

    Full Text Available Development of manufacturing and service institutions can not be separated from the role of human resources. Human resources have an important role in fulfilling vision and mission. University of A is one of the private educational institutions in East Java to achieve the goal must be managed properly that can be utilized optimally, this can be done by analyzing workload and performance or optimizing the number of employees. The purpose this research is measure workload and effect the employee’s performance. Measurement of workload is using National Aeronautics and Space Administration-Task Load Index (NASA-TLX method, NASA-TLX method is rating multidimentional subjective mental workload  that divides the workload based on the average load of 6 dimensions, and the measurement of performance is using questionnaire with 5 scales by likert scale. The results showed that employees who have Medium workload is 8%, High workload is 84% and Very high workload is 8%. The result of the questionnaire showed the category of employee’s performance, simply performance is 24% and satisfactory performance is 76%. From the statistical test by using Chi Square method, it is known that the value = 5,9915 and = 2,2225, the result shows  < , then  is accepted and  is rejected. Thus, there is influence between the workload of employees and the employees’s performance.

  4. Treadmill walking with load carriage increases aortic pressure wave reflection.

    Science.gov (United States)

    Ribeiro, Fernando; Oliveira, Nórton L; Pires, Joana; Alves, Alberto J; Oliveira, José

    2014-01-01

    The study examined the effects of treadmill walking with load carriage on derived measures of central pressure and augmentation index in young healthy subjects. Fourteen male subjects (age 31.0 ± 1.0 years) volunteered in this study. Subjects walked 10 minutes on a treadmill at a speed of 5 km/h carrying no load during one session and a load of 10% of their body weight on both upper limbs in two water carboys with handle during the other session. Pulse wave analysis was performed at rest and immediately after exercise in the radial artery of the right upper limb by applanation tonometry. The main result indicates that walking with load carriage sharply increased augmentation index at 75 bpm (-5.5 ± 2.2 to -1.4 ± 2.2% vs. -5.2 ± 2.8 to -5.5 ± 2.1%, p<0.05), and also induced twice as high increments in central pulse pressure (7.4 ± 1.5 vs. 3.1 ± 1.4 mmHg, p<0.05) and peripheral (20.5 ± 2.7 vs. 10.3 ± 2.5 mmHg, p<0.05) and central systolic pressure (14.7 ± 2.1 vs. 7.4 ± 2.0 mmHg, p<0.05). Walking with additional load of 10% of their body weight (aerobic exercise accompanied by upper limb isometric contraction) increases derived measures of central pressure and augmentation index, an index of wave reflection and arterial stiffness. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  5. Evaluation of self-assembled HCPT-loaded PEG-b-PLA nanoparticles by comparing with HCPT-loaded PLA nanoparticles.

    Science.gov (United States)

    Yang, Xiangrui; Wu, Shichao; Wang, Yange; Li, Yang; Chang, Di; Luo, Yin; Ye, Shefang; Hou, Zhenqing

    2014-12-01

    We present a dialysis technique to prepare the 10-hydroxycamptothecin (HCPT)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly(D,L-lactide) (PEG-b-PLA) and PLA, respectively. Both HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs were characterized by differential scanning calorimetry (DSC), dynamic light scattering (DLS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). The results showed that the HCPT-loaded PEG-b-PLA NPs and HCPT-loaded PLA NPs presented a hydrodynamic particle size of 120.1 and 226.8 nm, with a polydispersity index of 0.057 and 0.207, a zeta potential of -31.2 and -45.7 mV, drug encapsulation efficiency of 44.52% and 44.94%, and drug-loaded content of 7.42% and 7.49%, respectively. The HCPT-loaded PEG-b-PLA NPs presented faster drug release rate compared to the HCPT-loaded PLA NPs. The HCPT-loaded PEG-b-PLA NPs presented higher cytotoxicity than the HCPT-loaded PLA NPs. These results suggested that the HCPT-loaded PEG-b-PLA NPs presented better characteristics for drug delivery compared to HCPT-loaded PLA NPs.

  6. Optimization of composite sandwich cover panels subjected to compressive loadings

    Science.gov (United States)

    Cruz, Juan R.

    1991-01-01

    An analysis and design method is presented for the design of composite sandwich cover panels that include the transverse shear effects and damage tolerance considerations. This method is incorporated into a sandwich optimization computer program entitled SANDOP. As a demonstration of its capabilities, SANDOP is used in the present study to design optimized composite sandwich cover panels for for transport aircraft wing applications. The results of this design study indicate that optimized composite sandwich cover panels have approximately the same structural efficiency as stiffened composite cover panels designed to satisfy individual constraints. The results also indicate that inplane stiffness requirements have a large effect on the weight of these composite sandwich cover panels at higher load levels. Increasing the maximum allowable strain and the upper percentage limit of the 0 degree and +/- 45 degree plies can yield significant weight savings. The results show that the structural efficiency of these optimized composite sandwich cover panels is relatively insensitive to changes in core density. Thus, core density should be chosen by criteria other than minimum weight (e.g., damage tolerance, ease of manufacture, etc.).

  7. Analysis of Heavy Metals in Surface Sediments from Agh Gel Wetland, Iran

    Directory of Open Access Journals (Sweden)

    Soheil Sobhanardakani

    2016-06-01

    Full Text Available Background: Soil and sediment serve as major reservoir for contaminants as they possess ability to bind various chemicals together. In this study the concentrations of heavy metals Cd, Cr and Cu were analyzed in surface sediments of Agh Gel Wetland in west of Iran. Methods: The sediment samples were taken from 10 stations. The samples were subjected to bulk digestion and chemical partitioning and Cd, Cr and Cu concentrations of the sediments were determined by ICP-OES. Geo-accumulation index (I-geo, Contamination factor (CF and Pollution load index (PLI were used to evaluate the magnitude of contaminants in the sediment profile. Results: The mean sediment concentrations (mg kg-1 dry weight ranged within 0.20-0.29 (Cd, 58-71 (Cr and 23-36 (Cu. According to the I-geo values, the sediments' qualities are classified as unpolluted to moderately polluted category. According to the CF values, the sediments' qualities are classified as low to moderate contamination. Furthermore, the PLI values indicated that there were no metal pollution exists for all sampling stations. Conclusion: The Agh Gel Wetland is potential to be threatened by chemical pollutants such as agricultural effluent. So to preserve the environment of the Agh Gel Wetland from deterioration, periodically monitoring of the water and sediment qualities is recommended.

  8. Seasonal variation in coat characteristics, tick loads, cortisol levels, some physiological parameters and temperature humidity index on Nguni cows raised in low- and high-input farms

    Science.gov (United States)

    Katiyatiya, C. L. F.; Muchenje, V.; Mushunje, A.

    2015-06-01

    Seasonal variations in hair length, tick loads, cortisol levels, haematological parameters (HP) and temperature humidity index (THI) in Nguni cows of different colours raised in two low-input farms, and a commercial stud was determined. The sites were chosen based on their production systems, climatic characteristics and geographical locations. Zazulwana and Komga are low-input, humid-coastal areas, while Honeydale is a high-input, dry-inland Nguni stud farm. A total of 103 cows, grouped according to parity, location and coat colour, were used in the study. The effects of location, coat colour, hair length and season were used to determine tick loads on different body parts, cortisol levels and HP in blood from Nguni cows. Highest tick loads were recorded under the tail and the lowest on the head of each of the animals ( P cows recorded the highest tick loads under the tails of all the cows used in the study from the three farms ( P cows with long hairs. Hair lengths were longest during the winter season in the coastal areas of Zazulwana and Honeydale ( P cows had significantly longer ( P heat stress in Nguni cows.

  9. Index-based reactive power compensation scheme for voltage regulation

    Science.gov (United States)

    Dike, Damian Obioma

    2008-10-01

    Increasing demand for electrical power arising from deregulation and the restrictions posed to the construction of new transmission lines by environment, socioeconomic, and political issues had led to higher grid loading. Consequently, voltage instability has become a major concern, and reactive power support is vital to enhance transmission grid performance. Improved reactive power support to distressed grid is possible through the application of relatively unfamiliar emerging technologies of "Flexible AC Transmission Systems (FACTS)" devices and "Distributed Energy Resources (DERS)." In addition to these infrastructure issues, a lack of situational awareness by system operators can cause major power outages as evidenced by the August 14, 2003 widespread North American blackout. This and many other recent major outages have highlighted the inadequacies of existing power system indexes. In this work, a novel "Index-based reactive compensation scheme" appropriate for both on-line and off-line computation of grid status has been developed. A new voltage stability index (Ls-index) suitable for long transmission lines was developed, simulated, and compared to the existing two-machine modeled L-index. This showed the effect of long distance power wheeling amongst regional transmission organizations. The dissertation further provided models for index modulated voltage source converters (VSC) and index-based load flow analysis of both FACTS and microgrid interconnected power systems using the Newton-Raphson's load flow model incorporated with multi-FACTS devices. The developed package has been made user-friendly through the embodiment of interactive graphical user interface and implemented on the IEEE 14, 30, and 300 bus systems. The results showed reactive compensation has system wide-effect, provided readily accessible system status indicators, ensured seamless DERs interconnection through new islanding modes and enhanced VSC utilization. These outcomes may contribute

  10. Testing and Life Prediction for Composite Rotor Hub Flexbeams

    Science.gov (United States)

    Murri, Gretchen B.

    2004-01-01

    A summary of several studies of delamination in tapered composite laminates with internal ply-drops is presented. Initial studies used 2D FE models to calculate interlaminar stresses at the ply-ending locations in linear tapered laminates under tension loading. Strain energy release rates for delamination in these laminates indicated that delamination would likely start at the juncture of the tapered and thin regions and grow unstably in both directions. Tests of glass/epoxy and graphite/epoxy linear tapered laminates under axial tension delaminated as predicted. Nonlinear tapered specimens were cut from a full-size helicopter rotor hub and were tested under combined constant axial tension and cyclic transverse bending loading to simulate the loading experienced by a rotorhub flexbeam in flight. For all the tested specimens, delamination began at the tip of the outermost dropped ply group and grew first toward the tapered region. A 2D FE model was created that duplicated the test flexbeam layup, geometry, and loading. Surface strains calculated by the model agreed very closely with the measured surface strains in the specimens. The delamination patterns observed in the tests were simulated in the model by releasing pairs of MPCs along those interfaces. Strain energy release rates associated with the delamination growth were calculated for several configurations and using two different FE analysis codes. Calculations from the codes agreed very closely. The strain energy release rate results were used with material characterization data to predict fatigue delamination onset lives for nonlinear tapered flexbeams with two different ply-dropping schemes. The predicted curves agreed well with the test data for each case studied.

  11. Electrical behavior of laminated composites with intralaminar degradation: A comprehensive micro-meso homogenization procedure

    KAUST Repository

    Selvakumaran, Lakshmi

    2014-03-01

    Electrical Resistance Tomography (ERT) is a promising health monitoring technique to assess damage in laminated composites. Yet, the missing link between the various complex degradation mechanisms within the laminate and its global change in resistivity prevents ERT from being used as a quantitative technique. We propose an electrical mesomodel that can establish this link between the various microscale degradations and the resistivity changes in the measurements. The mesoscale homogenization of transverse cracks with local delamination of the ply is first described for in-plane electrical loading for both the outer and the inner plies. The mesoscale model is then extended to include the out-of-plane loading. The relationship between the mesoscale damage indicators and the degradation morphology is identified. These damage indicators are found to be intrinsic to the ply. As such, this defines the first step towards the interpretation of resistivity measurement in terms of micromechanical damage. © 2013 Elsevier Ltd.

  12. A novel economy reflecting short-term load forecasting approach

    International Nuclear Information System (INIS)

    Lin, Cheng-Ting; Chou, Li-Der

    2013-01-01

    Highlights: ► We combine MA line of TAIEX and SVR to overcome the load demands over-prediction problems caused by the economic downturn. ► The Taiwan island-wide electricity power system was used as the case study. ► Short- to middle-term MA lines of TAIEX are found to be good economic input variables for load forecasting models. - Abstract: The global economic downturn in 2008 and 2009, which was spurred by the bankruptcy of Lehman Brothers, sharply reduced the demand for electricity load. Conventional load-forecasting approaches were unable to respond to sudden changes in the economy, because these approaches do not consider the effect of economic factors. Therefore, the over-prediction problem occurred. To overcome this problem, this paper proposes a novel, economy-reflecting, short-term load forecasting (STLF) approach based on theories of moving average (MA) line of stock index and machine learning. In this approach, the stock indices decision model is designed to reflect fluctuations in the Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) series, which is selected as an optimal input variable in support vector regression load forecasting model at an appropriate timing. The Taiwan island-wide hourly electricity load demands from 2008 to 2010 are used as the case study for performance benchmarking. Results show that the proposed approach with a 60-day MA of the TAIEX as economic learning pattern achieves good forecasting performance. It outperforms the conventional approach by 29.16% on average during economic downturn-affected days. Overall, the proposed approach successfully overcomes the over-prediction problems caused by the economic downturn. To the best of our knowledge, this paper is the first attempt to apply MA line theory of stock index on STLF.

  13. High-efficiency water-loaded microwave antenna in ultra-high-frequency band

    Science.gov (United States)

    Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

    2018-03-01

    High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

  14. Part-load pumping operation, control and behaviour

    International Nuclear Information System (INIS)

    1988-01-01

    Twenty one papers are printed. Their main concern is with pump performance under abnormal operating conditions or when operating at part-load. The effect of part-load operation on pump performance, pump internal flow and pump cavitation and noise were considered. The pumps considered are used in a variety of situations and some case studies were discussed. One paper about part-load operation of the boiler pumps for French pressurized water reactors and one paper on pressure pulsations of centrifugal pumps at very low flowrate, are indexed separately. (U.K.)

  15. Evaluation of healthy and sensory indexes of sweetened beverages using an electronic tongue

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Luís G., E-mail: ldias@ipb.pt [CIMO – Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança (Portugal); Sequeira, Cédric, E-mail: cedric.b.s@hotmail.com [CIMO – Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança (Portugal); Veloso, Ana C.A., E-mail: anaveloso@isec.pt [Instituto Politécnico de Coimbra, ISEC, DEQB, Rua Pedro Nunes, Quinta da Nora, 3030-199 Coimbra (Portugal); CEB – Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Sousa, Mara E.B.C., E-mail: mebsousadias@gmail.com [CIMO – Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança (Portugal); Peres, António M., E-mail: peres@ipb.pt [LSRE – Laboratory of Separation and Reaction Engineering – Associate Laboratory LSRE/LCM, Escola Superior Agrária, Instituto Politécnico de Bragança, Campus Santa Apolónia, Apartado 1172, 5301-855 Bragança (Portugal)

    2014-10-27

    Highlights: • Overconsumption of soft-drinks and fruit-beverages may enhance health risks. • Beverage’s healthy and sensory indexes were calculated using chromatographic data. • A potentiometric electronic tongue with multivariate linear models was applied. • E-tongue discriminated samples according to glycemic load or fructose-intolerance levels. • Healthy and sensory indexes were accurately quantified using E-tongue data. - Abstract: Overconsumption of sugar-sweetened beverages may increase the risk of health problems and so, the evaluation of their glycemic load and fructose-intolerance level is essential since it may allow establishing possible relations between physiologic effects of sugar-rich beverages and health. In this work, an electronic tongue was used to accurately classify beverages according to glycemic load (low, medium or high load) as well to their adequacy for people suffering from fructose malabsorption syndrome (tolerable or not): 100% of correct classifications (leave-one-out cross-validation) using linear discriminant models based on potentiomentric signals selected by a meta-heuristic simulated annealing algorithm. These results may be partially explained by the electronic tongue’s capability to mimic the human sweetness perception and total acid flavor of beverages, which can be related with glycemic load and fructose-intolerance index. Finally, the E-tongue was also applied to quantify, accurately, healthy and sensory indexes using multiple linear regression models (leave-one-out cross-validation: R{sub adj} > 0.99) in the following dynamic ranges: 4.7 < glycemic load ≤ 30; 0.4 < fructose intolerance index ≤ 1.5; 32 < sweetness perception < 155; 1.3 < total acid flavor, g L{sup −1} < 8.3; and, 5.8 < well-balanced flavor ≤ 74. So, the proposed electronic tongue could be used as a practical, fast, low-cost and green tool for beverage’s healthy and sensory evaluation.

  16. Evaluation of healthy and sensory indexes of sweetened beverages using an electronic tongue

    International Nuclear Information System (INIS)

    Dias, Luís G.; Sequeira, Cédric; Veloso, Ana C.A.; Sousa, Mara E.B.C.; Peres, António M.

    2014-01-01

    Highlights: • Overconsumption of soft-drinks and fruit-beverages may enhance health risks. • Beverage’s healthy and sensory indexes were calculated using chromatographic data. • A potentiometric electronic tongue with multivariate linear models was applied. • E-tongue discriminated samples according to glycemic load or fructose-intolerance levels. • Healthy and sensory indexes were accurately quantified using E-tongue data. - Abstract: Overconsumption of sugar-sweetened beverages may increase the risk of health problems and so, the evaluation of their glycemic load and fructose-intolerance level is essential since it may allow establishing possible relations between physiologic effects of sugar-rich beverages and health. In this work, an electronic tongue was used to accurately classify beverages according to glycemic load (low, medium or high load) as well to their adequacy for people suffering from fructose malabsorption syndrome (tolerable or not): 100% of correct classifications (leave-one-out cross-validation) using linear discriminant models based on potentiomentric signals selected by a meta-heuristic simulated annealing algorithm. These results may be partially explained by the electronic tongue’s capability to mimic the human sweetness perception and total acid flavor of beverages, which can be related with glycemic load and fructose-intolerance index. Finally, the E-tongue was also applied to quantify, accurately, healthy and sensory indexes using multiple linear regression models (leave-one-out cross-validation: R adj > 0.99) in the following dynamic ranges: 4.7 < glycemic load ≤ 30; 0.4 < fructose intolerance index ≤ 1.5; 32 < sweetness perception < 155; 1.3 < total acid flavor, g L −1 < 8.3; and, 5.8 < well-balanced flavor ≤ 74. So, the proposed electronic tongue could be used as a practical, fast, low-cost and green tool for beverage’s healthy and sensory evaluation

  17. Assessment of heavy metal contamination, levels in topsoil at selected auto-workshops in Accra, Ghana

    International Nuclear Information System (INIS)

    Ziblim, M. Y.

    2015-07-01

    The research was conducted to assess the levels of contamination of heavy metals in the topsoil at selected auto-workshops in Accra to determine the anthropogenic and crustal contributions and the human heath risk associated with them. Soil samples collected from four auto-workshops were analysed using Atomic Absorption Spectrometer. Eleven (11) elements: Co, Fe, Cu, Mn, Cr, As, Hg, Zn, Pb, Ni, and Cd were identified in each sample collected from the auto-workshops. Pollution indices; contamintion factor (Cf) index of geoaccumulation (Igeo) and pollution load index (PLI) were used to assess the contamination levels. It revealed the extent of contamination at the auto-workshops for most of the elements which range from low to considerate contamintion. Lead (Pb) recorded the greatest contamination levels at the auto-electrical location. The results from the index of geoccumulation showed no pollution to highly pollution indicting high variations of pollution levels at different locations. The results of the PLI in almost all locations ranged from moderately to extremely polluted. Noncancer effect on children and adults due to exposure to the topsoil were also estimated with some selected metal elements. The hazard quotient (HQ) evaluation, showed ingestion to be the route of exposure to soil dust that results in a higher risk for heavy metals, followed by dermal contact. The effect due to inhalation of resuspended dust particles through the mouth and nose is relatively low. It was observed that, the auto-workshops are generally polluted with heavy metals and therefore posing ill-health effect to the humans and the environment. (au)

  18. Risk assessment of particle dispersion and trace element contamination from mine-waste dumps.

    Science.gov (United States)

    Romero, Antonio; González, Isabel; Martín, José María; Vázquez, María Auxiliadora; Ortiz, Pilar

    2015-04-01

    In this study, a model to delimit risk zones influenced by atmospheric particle dispersion from mine-waste dumps is developed to assess their influence on the soil and the population according to the concentration of trace elements in the waste. The model is applied to the Riotinto Mine (in SW Spain), which has a long history of mining and heavy land contamination. The waste materials are separated into three clusters according to the mapping, mineralogy, and geochemical classification using cluster analysis. Two of the clusters are composed of slag, fresh pyrite, and roasted pyrite ashes, which may contain high concentrations of trace elements (e.g., >1 % As or >4 % Pb). The average pollution load index (PLI) calculated for As, Cd, Co, Cu, Pb, Tl, and Zn versus the baseline of the regional soil is 19. The other cluster is primarily composed of sterile rocks and ochreous tailings, and the average PLI is 3. The combination of particle dispersion calculated by a Gaussian model, the PLI, the surface area of each waste and the wind direction is used to develop a risk-assessment model with Geographic Information System GIS software. The zone of high risk can affect the agricultural soil and the population in the study area, particularly if mining activity is restarted in the near future. This model can be applied to spatial planning and environmental protection if the information is complemented with atmospheric particulate matter studies.

  19. Allocation of Load-Loss Cost Caused by Voltage Sag

    Science.gov (United States)

    Gao, X.

    2017-10-01

    This paper focuses on the allocation of load-loss cost caused by voltage sag in the environment of electricity market. To compensate the loss of loads due to voltage sags, the load-loss cost is allocated to both sources and power consumers. On the basis of Load Drop Cost (LDC), a quantitative evaluation index of load-loss cost caused by voltage sag is identified. The load-loss cost to be allocated to power consumers themselves is calculated according to load classification. Based on the theory of power component the quantitative relation between sources and loads is established, thereby a quantitative calculation method for load-loss cost allocated to each source is deduced and the quantitative compensation from individual source to load is proposed. A simple five-bus system illustrates the main features of the proposed method.

  20. Bending Response of Cross-Ply Laminated Composite Plates with Diagonally Perturbed Localized Interfacial Degeneration

    Directory of Open Access Journals (Sweden)

    Chee Zhou Kam

    2013-01-01

    Full Text Available A laminated composite plate element with an interface description is developed using the finite element approach to investigate the bending performance of two-layer cross-ply laminated composite plates in presence of a diagonally perturbed localized interfacial degeneration between laminae. The stiffness of the laminate is expressed through the assembly of the stiffnesses of lamina sub-elements and interface element, the latter of which is formulated adopting the well-defined virtually zero-thickness concept. To account for the extent of both shear and axial weak bonding, a degeneration ratio is introduced in the interface formulation. The model has the advantage of simulating a localized weak bonding at arbitrary locations, with various degeneration areas and intensities, under the influence of numerous boundary conditions since the interfacial description is expressed discretely. Numerical results show that the bending behavior of laminate is significantly affected by the aforementioned parameters, the greatest effect of which is experienced by those with a localized total interface degeneration, representing the case of local delamination.

  1. Experimental investigation of the failure envelope of unidirectional carbon-epoxy composite under high strain rate transverse and off-axis tensile loading

    Directory of Open Access Journals (Sweden)

    Kuhn Peter

    2015-01-01

    Full Text Available The mechanical response of the carbon-epoxy material system HexPly IM7-8552 was investigated under transverse tension and combined transverse tension / in-plane shear loading at quasi-static and dynamic strain rates. The dynamic tests of the transverse tension and off-axis tension specimens were carried out on a split-Hopkinson tension bar system, while the quasi-static reference tests were performed on a standard electro-mechanical testing machine. Digital image correlation was used for data reduction at both strain rate regimes. For the high rate tests, the strain rate in loading direction was adjusted to reach approximately the same strain rate value in the fracture plane for each specimen. The measured axial strengths were transformed from the global coordinate system into the combined transverse tension-shear stress space of the material coordinate system and compared with the Puck Mode A criterion for inter-fibre failure. A good correlation between the experimental data and the predicted failure envelopes was found for both investigated strain rate regimes.

  2. Analysis of Mesh Distribution Systems Considering Load Models and Load Growth Impact with Loops on System Performance

    Science.gov (United States)

    Kumar Sharma, A.; Murty, V. V. S. N.

    2014-12-01

    The distribution system is the final link between bulk power system and consumer end. A distinctive load flow solution method is used for analysis of the load flow of radial and weakly meshed network based on Kirchhoff's Current Law (KCL) and KVL. This method has excellent convergence characteristics for both radial as well as weakly meshed structure and is based on bus injection to branch current and branch-current to bus-voltage matrix. The main contribution of the paper is: (i) an analysis has been carried out for a weekly mesh network considering number of loops addition and its impact on the losses, kW and kVAr requirements from a system, and voltage profile, (ii) different load models, realistic ZIP load model and load growth impact on losses, voltage profile, kVA and kVAr requirements, (iii) impact of addition of loops on losses, voltage profile, kVA and kVAr requirements from substation, and (iv) comparison of system performance with radial distribution system. Voltage stability is a major concern in planning and operation of power systems. This paper also includes identifying the closeness critical bus which is the most sensitive to the voltage collapse in radial distribution networks. Node having minimum value of voltage stability index is the most sensitive node. Voltage stability index values are computed for meshed network with number of loops added in the system. The results have been obtained for IEEE 33 and 69 bus test system. The results have also been obtained for radial distribution system for comparison.

  3. Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring

    International Nuclear Information System (INIS)

    Oh, Sung Ha; Choi, Bok Lok

    2014-01-01

    This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses

  4. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Hyejin; Cho, Chongdu [Inha University, Incheon (Korea, Republic of)

    2017-08-15

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  5. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    International Nuclear Information System (INIS)

    Bang, Hyejin; Cho, Chongdu

    2017-01-01

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  6. Bio-geochemical studies of indus delta mangrove ecosystem through heavy metal assessment

    International Nuclear Information System (INIS)

    Ismail, S.; Saifullah, S.M.

    2014-01-01

    In the present study monitoring of heavy metal pollution was done in the mangrove habitats of Indus Delta. Different levels of four heavy metal (Pb, Cu, Cd, and Zn) in abiotic component (sediments and water) and biotic components (mangrove plants parts like, (Pneumatophores, bark, leaves, flowers, and fruits) were determined. The highest average concentration of heavy metals (111 ppm Zn, 60.0 ppm Pb, 52.2 ppm Cu, 1.43 ppm Cd) were measured in sediments and the lowest in the water (0.13 ppm Zn, 0.0014 ppm Cu, 0.0007 ppm Pb , 0.00061 ppm Cd). Among the four heavy metals, Zn was the most abundant metal in all components of the ecosystem, followed by Cu, Pb, and Cd (Zn>Cu>Pb>Cd), and hence A. marina can be proposed as a hyper-accumulator for Zn, which opens doors for further research. The pollution load index (PLI) had values higher than 1 and varied between 2.02-1.70 at Indus Delta, whereas at MianiHor the PLI was 0.65, which indicated that Indus Delta mangrove Ecosystem was under threat of pollution under the present scenario. (author)

  7. Cognitive Load in Voice Therapy Carry-Over Exercises

    DEFF Research Database (Denmark)

    Iwarsson, Jenny; Morris, David Jackson; Balling, Laura Winther

    2017-01-01

    Purpose The cognitive load generated by online speech production may vary with the nature of the speech task. This article examines 3 speech tasks used in voice therapy carry-over exercises, in which a patient is required to adopt and automatize new voice behaviors, ultimately in daily spontaneous...... to automation of revised speech behavior and that self-reports may be a reliable index of cognitive load....

  8. Regular consumption of Lactobacillus reuteri-containing lozenges reduces pregnancy gingivitis: an RCT.

    Science.gov (United States)

    Schlagenhauf, Ulrich; Jakob, Lena; Eigenthaler, Martin; Segerer, Sabine; Jockel-Schneider, Yvonne; Rehn, Monika

    2016-11-01

    This randomized controlled trial assessed the impact of Lactobacillus reuteri on pregnancy gingivitis in healthy women. Forty-five healthy women (24 test/21 placebo) with pregnancy gingivitis in the third trimester of pregnancy were enrolled. At baseline Gingival Index (GI) and Plaque Index (PlI) were assessed at the Ramfjord teeth and venous blood taken for TNF-α analysis. Subsequently participants were randomly provided with lozenges to be consumed 2 × daily until birth (approx. 7 weeks) containing ≥10 8 CFU L. reuteri ATCC PTA 5289 and ≥10 8 CFU L. reuteri DSM 17938 (test) or being devoid of L. reuteri (placebo). Within 2 days after birth recording of GI, PlI and blood sampling were repeated. At baseline, mean GI and mean PlI did not differ significantly between both groups. In the test group mean TNF-α serum level was significantly (p gingivitis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. Comparison of closed-form and finite-element solutions of thick laminated anisotropic rectangular plates

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, J N; Chao, W C [Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Engineering Science and Mechanics

    1981-04-01

    In this study the effects of reduced integration, mesh size, and element type (i.e. linear or quadratic) on the accuracy of a penalty-finite element based on the theory governing thick, laminated, anisotropic composite plates are investigated. In order to assess the accuracy of the present finite element, exact closed-form solutions are developed for cross-ply and antisymmetric angle-ply rectangular plates simply supported and subjected to sinusoidally distributed mechanical and/or thermal loadings, and free vibration.

  10. Glycaemic index and glycaemic load of selected popular foods consumed in Southeast Asia.

    Science.gov (United States)

    Sun, Lijuan; Lee, Davina Elizabeth Mei; Tan, Wei Jie Kevin; Ranawana, Dinesh Viren; Quek, Yu Chin Rina; Goh, Hui Jen; Henry, Christiani Jeyakumar

    2015-03-14

    The objective of the present study was to determine the glycaemic index (GI) and glycaemic load (GL) values of standard portion sizes of Southeast Asian traditional foods. A total of fifteen popular Southeast Asian foods were evaluated. Of these foods, three were soft drinks, while the other twelve were solid foods commonly consumed in this region. In total, forty-seven healthy participants (eighteen males and twenty-nine females) volunteered to consume either glucose at least twice or one of the fifteen test foods after a 10-12 h overnight fast. Blood glucose concentrations were analysed before consumption of the test food, and 15, 30, 45, 60, 90 and 120 min after food consumption, using capillary blood samples. The GI value of each test food was calculated by expressing the incremental area under the blood glucose response curve (IAUC) value of the test food as a percentage of each participant's average IAUC value, with glucose as the reference food. Among the fifteen foods tested, six belonged to low-GI foods (Ice Green Tea, Beehoon, Pandan Waffle, Curry Puff, Youtiao and Kaya Butter Toast), three belonged to medium-GI foods (Barley Drink, Char Siew Pau and Nasi Lemak), and the other six belonged to high-GI foods (Ice Lemon Tea, Chinese Carrot Cake, Chinese Yam Cake, Chee Cheong Fun, Lo Mai Gai and Pink Rice Cake). The GI and GL values of these traditional foods provide valuable information to consumers, researchers and dietitians on the optimal food choice for glycaemic control. Moreover, our dataset provides GI values of fifteen foods that were not previously tested extensively, and it presents values of foods commonly consumed in Southeast Asia.

  11. Effect of length to thickness ratio on free vibration analysis of thick fiber reinforced plastic skew cross-ply laminate with circular cutout

    Science.gov (United States)

    Srividya, K.; Reddy, Ch. Kishore; Sumanth, Ch. Mohan; Krishnaiah, P. Gopala; Kishan, V. Mallikharjuna

    2018-04-01

    The present investigation deals with the free vibration analysis of a thick four-layered symmetric cross-ply skew laminated composite plate with a circular cutout. Three dimensional finite element models (FEM) which use the elasticity theory for the determination of stiffness matrices are modeled in ANSYS software to evaluate first five natural frequencies of the laminate. The variations of the first five natural frequencies with respect to length to thickness ratio (S) for different diameter to length ratios (d/l) are presented. It is observed that, the natural frequencies decreases with increase of thickness ratio(S).

  12. Low velocity impact properties of intra-ply hybrid composites based on basalt and nylon woven fabrics

    International Nuclear Information System (INIS)

    Dehkordi, Majid Tehrani; Nosraty, Hooshang; Shokrieh, Mahmood Mehrdad; Minak, Giangiacomo; Ghelli, Daniele

    2010-01-01

    In this paper, the low velocity impact behavior of homogenous and hybrid composite laminates reinforced by basalt-nylon intra-ply fabrics was experimentally investigated. Epoxy resin was used as matrix material. The purpose of using this hybrid composite is to combine the good mechanical properties of basalt fiber with the excellent impact resistant of nylon fiber. Five different types of woven fabrics were used as reinforcement with different volume percentages of nylon (0%, 25%, 33.3%, 50% and 100%). The effect of nylon/basalt fiber content on maximum force, maximum deflection, residual deflection, total absorbed energy, elastic energy, size and type of damage were studied at several low velocity impact nominal energy levels (16, 30 and 40 J). The results indicate that impact performance of these composites is significantly affected by the nylon/basalt fiber content. The visual inspection and ultrasonic C-scan of the impact damaged specimens reveals that content of nylon/basalt fiber controls the type and size of damage.

  13. Interfacial bonding and friction in silicon carbide (filament)-reinforced ceramic- and glass-matrix composites

    International Nuclear Information System (INIS)

    Bright, J.D.; Shetty, D.K.

    1989-01-01

    This paper reports interfacial shear strength and interfacial sliding friction stress assessed in unidirectional SiC-filament-reinforced reaction-bonded silicon nitride (RBSN) and borosilicate glass composites and 0/90 cross-ply reinforced borosilicate glass composite using a fiber pushout test technique. The interface debonding load and the maximum sliding friction load were measured for varying lengths of the embedded fibers by continuously monitoring the load during debonding and pushout of single fibers in finite-thickness specimens. The dependences of the debonding load and the maximum sliding friction load on the initial embedded lengths of the fibers were in agreement with nonlinear shear-lag models. An iterative regression procedure was used to evaluate the interfacial properties, shear debond strength (τ d ), and sliding friction stress (τ f ), from the embedded fiber length dependences of the debonding load and the maximum frictional sliding load, respectively. The shear-lag model and the analysis of sliding friction permit explicit evaluation of a coefficient of sliding friction (μ) and a residual compressive stress on the interface (σ 0 ). The cross-ply composite showed a significantly higher coefficient of interfacial friction as compared to the unidirectional composites

  14. Estimating Brain Load from the EEG

    Directory of Open Access Journals (Sweden)

    Anu Holm

    2009-01-01

    Full Text Available Modern work requires cognitively demanding multitasking and the need for sustained vigilance, which may result in work-related stress and may increase the possibility of human error. Objective methods for estimating cognitive overload and mental fatigue of the brain on-line, during work performance, are needed. We present a two-channel electroencephalography (EEG–based index, theta Fz/alpha Pz ratio, potentially implementable into a compact wearable device. The index reacts to both acute external and cumulative internal load. The index increased with the number of tasks to be performed concurrently (p = 0.004 and with increased time awake, both after normal sleep (p = 0.002 and sleep restriction (p = 0.004. Moreover, the increase of the index was more pronounced in the afternoon after sleep restriction (p = 0.006. As a measure of brain state and its dynamics, the index can be considered equivalent to the heartbeat, an indicator of the cardiovascular state, thus inspiring the name "brainbeat".

  15. The effect of some ecological factors on the intestinal parasite loads ...

    Indian Academy of Sciences (India)

    Some ecological factors that might potentially influence intestinal parasite loads in the Asian elephant (Elephas maximus Linn.) were investigated in the Nilgiris, southern India. Fresh dung samples from identified animals were analysed, and the number of eggs/g of dung used as an index of parasite load. Comparisons ...

  16. What does germane load mean? An empirical contribution to the cognitive load theory.

    Science.gov (United States)

    Debue, Nicolas; van de Leemput, Cécile

    2014-01-01

    While over the last decades, much attention has been paid to the mental workload in the field of human computer interactions, there is still a lack of consensus concerning the factors that generate it as well as the measurement methods that could reflect workload variations. Based on the multifactorial Cognitive Load Theory (CLT), our study aims to provide some food for thought about the subjective and objective measurement that can be used to disentangle the intrinsic, extraneous, and germane load. The purpose is to provide insight into the way cognitive load can explain how users' cognitive resources are allocated in the use of hypermedia, such as an online newspaper. A two-phase experiment has been conducted on the information retention from online news stories. Phase 1 (92 participants) examined the influence of multimedia content on performance as well as the relationships between cognitive loads and cognitive absorption. In Phase 2 (36 participants), eye-tracking data were collected in order to provide reliable and objective measures. Results confirmed that performance in information retention was impacted by the presence of multimedia content such as animations and pictures. The higher number of fixations on these animations suggests that users' attention could have been attracted by them. Results showed the expected opposite relationships between germane and extraneous load, a positive association between germane load and cognitive absorption and a non-linear association between intrinsic and germane load. The trends based on eye-tracking data analysis provide some interesting findings about the relationship between longer fixations, shorter saccades and cognitive load. Some issues are raised about the respective contribution of mean pupil diameter and Index of Cognitive Activity.

  17. Trees or Grids? Indexing Moving Objects in Main Memory

    DEFF Research Database (Denmark)

    Sidlauskas, Darius; Saltenis, Simonas; Christiansen, Christian Winther

    2009-01-01

    New application areas, such as location-based services, rely on the efficient management of large collections of mobile objects. Maintaining accurate, up-to-date positions of these objects results in massive update loads that must be supported by spatial indexing structures and main-memory indexes...... are usually necessary to provide high update performance. Traditionally, the R-tree and its variants were used for indexing spatial data, but most of the recent research assumes that a simple, uniform grid is the best choice for managing moving objects in main memory. We perform an extensive experimental...

  18. Overall glycemic index and glycemic load of vegan diets in relation to plasma lipoproteins and triacylglycerols.

    Science.gov (United States)

    Waldmann, Annika; Ströhle, Alexander; Koschizke, Jochen W; Leitzmann, Claus; Hahn, Andreas

    2007-01-01

    To investigate the overall glycemic index (GI), glycemic load (GL), and intake of dietary fiber, and to examine the associations between these factors and plasma lipoproteins and triacylglycerols in adult vegans in the German Vegan Study (GVS). Cross-sectional study, Germany. Healthy men (n = 67) and women (n = 87), who fulfilled the study criteria (vegan diet for >or=1 year prior to study start; minimum age of 18 years; no pregnancy/childbirth during the last 12 months) and who participated in all study segments. The average dietary GL of the GVS population was 144, and the average GI was 51.4. The adjusted geometric mean total, HDL, and LDL cholesterol concentrations decreased across the increasing quartiles of GL, carbohydrate and dietary fiber intake. The associations between total cholesterol, HDL cholesterol, LDL cholesterol and GL density and GI were inconsistent. Also, associations between GI, GL, the intake of carbohydrates, and triacylglycerol concentration were not observed. Fiber-rich vegan diets are characterized by a low GI and a low to moderate GL. The data do not support the hypothesis that a carbohydrate-rich diet per se is associated with unfavorable effects on triaclyglycerols that would be predicted to increase the risk of coronary heart disease. Copyright (c) 2007 S. Karger AG, Basel.

  19. Evaluation of Heavy Metal Contamination Ecological Risk in a Food-Producing Ecosystem

    Directory of Open Access Journals (Sweden)

    mohsen Mirzaei

    2017-09-01

    Full Text Available Introduction and purpose: The consumption of agricultural products cultivated in soils contaminated with heavy metals is very health-threatening. Therefore, the implementation of an inclusive and multilateral assessment of the heavy metal risk on the verge of their entrance to the food chain is a matter of fundamental importance. Regarding this, the present study was conducted with the aim of monitoring the concentration of heavy metals in the surface soil of grape gardens and zoning the area in terms of geoaccumulation index (Igeo, contamination factor, degree of contamination, modified degree of contamination (MDC, pollution load index (PLI, and ecological risk index (RI. Methods: For the purpose of the study, 31 grape gardens were selected in Gahru region (i.e., the main center of grape production through simple random sampling technique. The surface soil samples were transferred to the laboratory for the analysis of the concentration of cadmium, lead, chromium, copper, and zinc. Results: According to the results, the concentration of the metals in the region was Zn > Cu > Pb > Cr > Cd with the mean total concentrations of 74.87, 55.31, 22.32, 9.81, and 0.91 mg/kg, respectively. Based on the results of the PLI, six grape gardens were classified as insignificantly contaminated (1≤PLI≤2, and the remaining gardens were classified as noncontaminated (PLI300, medium (150

  20. Computer Simulation and Experimental Study of Deformation in a Radial Tire under Different Static Loads Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Mir Hamid Reza Ghoreishy

    2014-10-01

    Full Text Available This research work is devoted to the simulation of a steel-belted radial tire under different static loads. The nonlinear finite element calculations were performed using the MSC.MARC code, installed on a computer system equipped with a parallel processing technology. Hybrid elements in conjunction with two hyperelastic models, namely Marlow and Yeoh, and rebar layer implemented in surface elements were used for the modeling of rubbery and reinforcing parts, respectively. Linear elastic material models were also used for the modeling of the reinforcing elements including steel cord in belts, polyester cord in carcass and nylon cord in cap ply section. Two-dimensional axisymmetric elements were used for the modeling of rim-mounting and inflation and three-dimensional models were developed for the application of the radial, tangential, lateral and torsional loads. Different finite element models were developed, in which both linear and quadratic elements were used in conjunction with different mesh densities in order to find the optimum finite element model. Based on the results of the load deflection (displacement data, the tire stiffness under radial, tangential, lateral and torsional loads were calculated and compared with their corresponding experimentally measured values. The comparison was verified by the accuracy of the measured radial stiffness. However, due to the neglecting of the stiffness in shear and bending modes in cord-rubber composites, modeled with rebar layer methodology, the difference between computed values and real data are not small enough so that a more robust material models and element formulation are required to be developed.

  1. Thermal stability and practical applications of UV induced index changes in silica glasses

    DEFF Research Database (Denmark)

    Rathje, Jacob

    2000-01-01

    This thesis represents the partial fulfilment of the requirements for the danish ph.d. degree. I have been involved in both basic research of UV induced refractive index changes in silica glasses and in concrete applications. I have performed work on the thermal stability of UV-induced index...... the asymmetry showed good agreement with the obeserved data. The results were used to make a direction sensitive bend sensor of only one fiber. The sensor has further the advantage that it is insensitve to cross sensitivity from temperature, strin, and other external factors. Finally, an investigation of Nragg...... changes in silica glasses where a new continuous isochronal annealing method was introduced. The method was applied to gratings written in D2-loaded fibers and non-loaded fibers. For the non-loaded fibers the obtained results are in good agreement with what has previously been observed. For the D2-loaded...

  2. Thermal analysis of smart composite laminated angle-ply using higher order shear deformation theory with zig zag function

    Science.gov (United States)

    YagnaSri, P.; Siddiqui, Maimuna; Vijaya Nirmala, M.

    2018-03-01

    The objective of the work is to develop the higher order theory for piezoelectric composite laminated plates with zigzag function and to determine the thermal characteristics of piezoelectric laminated plate with zig zag function for different aspect ratios (a/h), thickness ratios (z/h) and voltage and also to evaluate electric potential function by solving second order differential equation satisfying electric boundary conditions along the thickness direction of piezoelectric layer. The related functions and derivations for equation of motion are obtained using the dynamic version of the principle of virtual work or Hamilton’s principle. The solutions are obtained by using Navier’s stokes method for anti-symmetric angle-ply with specific type of simply supported boundary conditions. Computer programs have been developed for realistic prediction of stresses and deflections for various sides to thickness ratios (a/h) and voltages.

  3. Validation of ozone monitoring instrument ultraviolet index against ground-based UV index in Kampala, Uganda.

    Science.gov (United States)

    Muyimbwa, Dennis; Dahlback, Arne; Ssenyonga, Taddeo; Chen, Yi-Chun; Stamnes, Jakob J; Frette, Øyvind; Hamre, Børge

    2015-10-01

    The Ozone Monitoring Instrument (OMI) overpass solar ultraviolet (UV) indices have been validated against the ground-based UV indices derived from Norwegian Institute for Air Research UV measurements in Kampala (0.31° N, 32.58° E, 1200 m), Uganda for the period between 2005 and 2014. An excessive use of old cars, which would imply a high loading of absorbing aerosols, could cause the OMI retrieval algorithm to overestimate the surface UV irradiances. The UV index values were found to follow a seasonal pattern with maximum values in March and October. Under all-sky conditions, the OMI retrieval algorithm was found to overestimate the UV index values with a mean bias of about 28%. When only days with radiation modification factor greater than or equal to 65%, 70%, 75%, and 80% were considered, the mean bias between ground-based and OMI overpass UV index values was reduced to 8%, 5%, 3%, and 1%, respectively. The overestimation of the UV index by the OMI retrieval algorithm was found to be mainly due to clouds and aerosols.

  4. On crack initiation in notched, cross-plied polymer matrix composites

    Science.gov (United States)

    Yang, Q. D.; Schesser, D.; Niess, M.; Wright, P.; Mavrogordato, M. N.; Sinclair, I.; Spearing, S. M.; Cox, B. N.

    2015-05-01

    The physics of crack initiation in a polymer matrix composite are investigated by varying the modeling choices made in simulations and comparing the resulting predictions with high-resolution in situ images of cracks. Experimental data were acquired using synchrotron-radiation computed tomography (SRCT) at a resolution on the order of 1 μm, which provides detailed measurement of the location, shape, and size of small cracks, as well as the crack opening and shear displacements. These data prove sufficient to discriminate among competing physical descriptions of crack initiation. Simulations are executed with a high-fidelity formulation, the augmented finite element method (A-FEM), which permits consideration of coupled damage mechanisms, including both discrete cracks and fine-scale continuum damage. The discrete cracks are assumed to be nonlinear fracture events, governed by reasonably general mixed-mode cohesive laws. Crack initiation is described in terms of strength parameters within the cohesive laws, so that the cohesive law provides a unified model for crack initiation and growth. Whereas the cracks investigated are typically 1 mm or less in length, the fine-scale continuum damage refers to irreversible matrix deformation occurring over gauge lengths extending down to the fiber diameter (0.007 mm). We find that the location and far-field stress for crack initiation are predicted accurately only if the variations of local stress within plies and in the presence of stress concentrators (notches, etc.) are explicitly computed and used in initiation criteria; stress redistribution due to matrix nonlinearity that occurs prior to crack initiation is accounted for; and a mixed-mode criterion is used for crack initiation. If these factors are not all considered, which is the case for commonly used failure criteria, predictions of the location and far-field stress for initiation are not accurate.

  5. Deep Constrained Siamese Hash Coding Network and Load-Balanced Locality-Sensitive Hashing for Near Duplicate Image Detection.

    Science.gov (United States)

    Hu, Weiming; Fan, Yabo; Xing, Junliang; Sun, Liang; Cai, Zhaoquan; Maybank, Stephen

    2018-09-01

    We construct a new efficient near duplicate image detection method using a hierarchical hash code learning neural network and load-balanced locality-sensitive hashing (LSH) indexing. We propose a deep constrained siamese hash coding neural network combined with deep feature learning. Our neural network is able to extract effective features for near duplicate image detection. The extracted features are used to construct a LSH-based index. We propose a load-balanced LSH method to produce load-balanced buckets in the hashing process. The load-balanced LSH significantly reduces the query time. Based on the proposed load-balanced LSH, we design an effective and feasible algorithm for near duplicate image detection. Extensive experiments on three benchmark data sets demonstrate the effectiveness of our deep siamese hash encoding network and load-balanced LSH.

  6. Effect of macronutrients and fiber on postprandial glycemic responses and meal glycemic index and glycemic load value determinations123

    Science.gov (United States)

    Meng, Huicui; Matthan, Nirupa R; Ausman, Lynne M; Lichtenstein, Alice H

    2017-01-01

    Background: The potential confounding effect of different amounts and proportions of macronutrients across eating patterns on meal or dietary glycemic index (GI) and glycemic load (GL) value determinations has remained partially unaddressed. Objective: The study aimed to determine the effects of different amounts of macronutrients and fiber on measured meal GI and GL values. Design: Four studies were conducted during which participants [n = 20–22; women: 50%; age: 50–80 y; body mass index (in kg/m2): 25–30)] received food challenges containing different amounts of the variable nutrient in a random order. Added to the standard 50 g available carbohydrate from white bread was 12.5, 25, or 50 g carbohydrate; 12.5, 25, or 50 g protein; and 5.6, 11.1, or 22.2 g fat from rice cereal, tuna, and unsalted butter, respectively, and 4.8 or 9.6 g fiber from oat cereal. Arterialized venous blood was sampled for 2 h, and measured meal GI and GL and insulin index (II) values were calculated by using the incremental area under the curve (AUCi) method. Results: Adding carbohydrate to the standard white-bread challenge increased glucose AUCi (P < 0.0001), measured meal GI (P = 0.0066), and mean GL (P < 0.0001). Adding protein (50 g only) decreased glucose AUCi (P = 0.0026), measured meal GI (P = 0.0139), and meal GL (P = 0.0140). Adding fat or fiber had no significant effect on these variables. Adding carbohydrate (50 g), protein (50 g), and fat (11.1 g) increased the insulin AUCi or II; fiber had no effect. Conclusions: These data indicate that uncertainty in the determination of meal GI and GL values is introduced when carbohydrate-containing foods are consumed concurrently with protein (equal amount of carbohydrate challenge) but not with carbohydrate-, fat-, or fiber-containing foods. Future studies are needed to evaluate whether this uncertainty also influences the prediction of average dietary GI and GL values for eating patterns. This trial was registered at

  7. Allostatic Load Is Linked to Cortical Thickness Changes Depending on Body-Weight Status

    Directory of Open Access Journals (Sweden)

    Jonatan Ottino-González

    2017-12-01

    Full Text Available Objective: Overweight (body mass index or BMI ≥ 25 kg/m2 and stress interact with each other in complex ways. Overweight promotes chronic low-inflammation states, while stress is known to mediate caloric intake. Both conditions are linked to several avoidable health problems and to cognitive decline, brain atrophy, and dementia. Since it was proposed as a framework for the onset of mental illness, the allostatic load model has received increasing attention. Although changes in health and cognition related to overweight and stress are well-documented separately, the association between allostatic load and brain integrity has not been addressed in depth, especially among overweight subjects.Method: Thirty-four healthy overweight-to-obese and 29 lean adults underwent blood testing, neuropsychological examination, and magnetic resonance imaging to assess the relationship between cortical thickness and allostatic load, represented as an index of 15 biomarkers (this is, systolic and diastolic arterial tension, glycated hemoglobin, glucose, creatinine, total cholesterol, HDL and LDL cholesterol, triglycerides, c-reactive protein, interleukin-6, insulin, cortisol, fibrinogen, and leptin.Results: Allostatic load indexes showed widespread positive and negative significant correlations (p < 0.01 with cortical thickness values depending on body-weight status.Conclusion: The increase of allostatic load is linked to changes in the gray matter composition of regions monitoring behavior, sensory-reward processing, and general cognitive function.

  8. Allostatic Load Is Linked to Cortical Thickness Changes Depending on Body-Weight Status

    Science.gov (United States)

    Ottino-González, Jonatan; Jurado, María A.; García-García, Isabel; Segura, Bàrbara; Marqués-Iturria, Idoia; Sender-Palacios, María J.; Tor, Encarnació; Prats-Soteras, Xavier; Caldú, Xavier; Junqué, Carme; Garolera, Maite

    2017-01-01

    Objective: Overweight (body mass index or BMI ≥ 25 kg/m2) and stress interact with each other in complex ways. Overweight promotes chronic low-inflammation states, while stress is known to mediate caloric intake. Both conditions are linked to several avoidable health problems and to cognitive decline, brain atrophy, and dementia. Since it was proposed as a framework for the onset of mental illness, the allostatic load model has received increasing attention. Although changes in health and cognition related to overweight and stress are well-documented separately, the association between allostatic load and brain integrity has not been addressed in depth, especially among overweight subjects. Method: Thirty-four healthy overweight-to-obese and 29 lean adults underwent blood testing, neuropsychological examination, and magnetic resonance imaging to assess the relationship between cortical thickness and allostatic load, represented as an index of 15 biomarkers (this is, systolic and diastolic arterial tension, glycated hemoglobin, glucose, creatinine, total cholesterol, HDL and LDL cholesterol, triglycerides, c-reactive protein, interleukin-6, insulin, cortisol, fibrinogen, and leptin). Results: Allostatic load indexes showed widespread positive and negative significant correlations (p < 0.01) with cortical thickness values depending on body-weight status. Conclusion: The increase of allostatic load is linked to changes in the gray matter composition of regions monitoring behavior, sensory-reward processing, and general cognitive function. PMID:29375342

  9. Effect of macronutrients and fiber on postprandial glycemic responses and meal glycemic index and glycemic load value determinations.

    Science.gov (United States)

    Meng, Huicui; Matthan, Nirupa R; Ausman, Lynne M; Lichtenstein, Alice H

    2017-04-01

    Background: The potential confounding effect of different amounts and proportions of macronutrients across eating patterns on meal or dietary glycemic index (GI) and glycemic load (GL) value determinations has remained partially unaddressed. Objective: The study aimed to determine the effects of different amounts of macronutrients and fiber on measured meal GI and GL values. Design: Four studies were conducted during which participants [ n = 20-22; women: 50%; age: 50-80 y; body mass index (in kg/m 2 ): 25-30)] received food challenges containing different amounts of the variable nutrient in a random order. Added to the standard 50 g available carbohydrate from white bread was 12.5, 25, or 50 g carbohydrate; 12.5, 25, or 50 g protein; and 5.6, 11.1, or 22.2 g fat from rice cereal, tuna, and unsalted butter, respectively, and 4.8 or 9.6 g fiber from oat cereal. Arterialized venous blood was sampled for 2 h, and measured meal GI and GL and insulin index (II) values were calculated by using the incremental area under the curve (AUC i ) method. Results: Adding carbohydrate to the standard white-bread challenge increased glucose AUC i ( P < 0.0001), measured meal GI ( P = 0.0066), and mean GL ( P < 0.0001). Adding protein (50 g only) decreased glucose AUC i ( P = 0.0026), measured meal GI ( P = 0.0139), and meal GL ( P = 0.0140). Adding fat or fiber had no significant effect on these variables. Adding carbohydrate (50 g), protein (50 g), and fat (11.1 g) increased the insulin AUC i or II; fiber had no effect. Conclusions: These data indicate that uncertainty in the determination of meal GI and GL values is introduced when carbohydrate-containing foods are consumed concurrently with protein (equal amount of carbohydrate challenge) but not with carbohydrate-, fat-, or fiber-containing foods. Future studies are needed to evaluate whether this uncertainty also influences the prediction of average dietary GI and GL values for eating patterns. This trial was registered at

  10. Optimal Planning Method of On-load Capacity Regulating Distribution Transformers in Urban Distribution Networks after Electric Energy Replacement Considering Uncertainties

    Directory of Open Access Journals (Sweden)

    Yu Su

    2018-06-01

    Full Text Available Electric energy replacement is the umbrella term for the use of electric energy to replace oil (e.g., electric automobiles, coal (e.g., electric heating, and gas (e.g., electric cooking appliances, which increases the electrical load peak, causing greater valley/peak differences. On-load capacity regulating distribution transformers have been used to deal with loads with great valley/peak differences, so reasonably replacing conventional distribution transformers with on-load capacity regulating distribution transformers can effectively cope with load changes after electric energy replacement and reduce the no-load losses of distribution transformers. Before planning for on-load capacity regulating distribution transformers, the nodal effective load considering uncertainties within the life cycle after electric energy replacement was obtained by a Monte Carlo method. Then, according to the loss relation between on-load capacity regulating distribution transformers and conventional distribution transformers, three characteristic indexes of annual continuous apparent power curve and replacement criteria for on-load capacity regulating distribution transformers were put forward in this paper, and a set of distribution transformer replaceable points was obtained. Next, based on cost benefit analysis, a planning model of on-load capacity regulating distribution transformers which consists of investment profitability index within the life cycle, investment cost recouping index and capacity regulating cost index was put forward. The branch and bound method was used to solve the planning model within replaceable point set to obtain upgrading and reconstruction scheme of distribution transformers under a certain investment. Finally, planning analysis of on-load capacity regulating distribution transformers was carried out for electric energy replacement points in one urban distribution network under three scenes: certain load, uncertain load and nodal

  11. What does germane load mean? An empirical contribution to the cognitive load theory

    Directory of Open Access Journals (Sweden)

    Nicolas eDebue

    2014-10-01

    Full Text Available While over the last decades, much attention has been paid to the mental workload in the field of human computer interactions, there is still a lack of consensus concerning the factors that generate it as well as the measurement methods that could reflect workload variations. Based on the multifactorial Cognitive Load Theory, our study aims to provide some food for thought about the subjective and objective measurement that can be used to disentangle the intrinsic, extraneous and germane load. The purpose is to provide insight into the way cognitive load can explain how users’ cognitive resources are allocated in the use of hypermedia, such as an online newspaper. A two-phase experiment has been conducted on the information retention from online news stories. Phase 1 (92 participants examined the influence of multimedia content on performance as well as the relationships between cognitive loads and cognitive absorption. In Phase 2 (36 participants, eye-tracking data were collected in order to provide reliable and objective measures. Results confirmed that performance in information retention was impacted by the presence of multimedia content such as animations and pictures. The higher number of fixations on these animations suggests that users’ attention could have been attracted by them. Results showed the expected opposite relationships between Germane and Extraneous Load, a positive association between GL and cognitive absorption and a nonlinear association between Intrinsic and Germane Load. The trends based on eye-tracking data analysis provide some interesting findings about the relationships between longer fixations, shorter saccades and cognitive load. Some issues are raised about the respective contribution of mean pupil diameter and Index of Cognitive Activity.

  12. The Cytotoxicity, Characteristics, and Optimization of Insulin-loaded Nanoparticles

    Directory of Open Access Journals (Sweden)

    Yasemin Budama-Kilinc

    2017-04-01

    Full Text Available Controlled release systems for insulin are frequent subjects of research, because it is rapidly degraded by proteolytic enzymes in the gastrointestinal tract and minimally absorbed after oral administration. Controlled release systems also provide significant contribution to its stability.  Different techniques are used for the preparation of drug-loaded nanoparticles, and many novel techniques are being developed. The size and morphology of insulin-loaded nanoparticles may vary according to performed techniques, even if the same polymer is used. The aim of this study was to demonstrate the cytotoxicity of insulin loaded nanoparticles and the effect of various synthesis parameters on the particle size, polydispersity index (PdI, loading efficiency, and particle morphology. In the experiments, poly(lactic-co-glycolic acid (PLGA and insulin-loaded PLGA nanoparticles were prepared using the double emulsion (w/o/w method. The characterization of the nanoparticles were performed with a UV spectrometer, the Zeta-sizer system, FTIR spectroscopy, and a scanning probe microscope. Cell toxicity of different concentrations was assayed with MTT methods on L929 fibroblast cells. The optimum size of the insulin-loaded PLGA nanoparticle was obtained with a 96.5% encapsulation efficiency, a 224.5 nm average particle size, and a 0.063 polydispersity index. This study obtained and characterized spherical morphology, determined that the nanoparticles have very low toxicity, and showed the effect of different parameters on particle size and polydispersity. DOI: http://dx.doi.org/10.17807/orbital.v9i1.934 

  13. Composite Thickness Optimization of Offshore Wind Turbine Blade with Fixed outer Geometry

    DEFF Research Database (Denmark)

    Sjølund, Jonas Heidemann; Lund, Erik

    2017-01-01

    With the objective of mass minimization, a 73-m offshore wind turbine blade is optimized using a gradient based approach on a Finite Element (FE) model. Constant loads and a fixed outer geometry are assumed. Plies of the same material and same orientation are grouped together in plygroups. The th....... The thicknesses of the plygroups are chosen as design variables. Manufacturing constraints such as ply-drops are taken into account using linear constraints. Structural constraints include buckling, tip displacement and max. strain failure indices....

  14. Childhood Cumulative Risk and Later Allostatic Load

    DEFF Research Database (Denmark)

    Doan, Stacey N; Dich, Nadya; Evans, Gary W

    2014-01-01

    State, followed for 8 years (between the ages 9 and 17). Poverty- related stress was computed using the cumulative risk approach, assessing stressors across 9 domains, including environmental, psychosocial, and demographic factors. Allostatic load captured a range of physiological responses, including......Objective: The present study investigated the long-term impact of exposure to poverty-related stressors during childhood on allostatic load, an index of physiological dysregulation, and the potential mediating role of substance use. Method: Participants (n = 162) were rural children from New York...... cardiovascular, hypothalamic pituitary adrenal axis, sympathetic adrenal medullary system, and metabolic activity. Smoking and alcohol/drug use were tested as mediators of the hypothesized childhood risk-adolescent allostatic load relationship. Results: Cumulative risk exposure at age 9 predicted increases...

  15. Glycemic Index Biscuits Formulation of Pedada Flour (Sonneratia caseolaris) with Tubers Starch

    Science.gov (United States)

    Jariyah; Susiloningsih, E. K. B.; Nilasari, K.

    2018-01-01

    The glycemic index of food is the level of food according to its effect on blood glucose levels. Foods with low glycemic index have been shown to improve glucose and fat levels in people with diabetes mellitus and improve insulin resistance. Pedada Fruits (Sonneratia caseolaris) is the one of mangrove fruits has a high fiber content, so it can be used as a raw material in biscuits production. The aim of this research to evaluate the glycemic index on the formula biscuit from the pedada flour and starch from white sweet potato, arrowroot, taro, potato and cassava mixed. This research used completely randomized design in factorial patern with one factor and five levels on formulation biscuit of pedada flour with tubers starch (20% : 80%). The biscuits product were measured of the proximate, crude fiber, glycemic index and glycemic load on wistar rats. The best treatment was 20% of pedada flour with 80% of taro starch which produced biscuit with 76.24% of yield, 2.58% of protein, 15.55% of fat, 2.72% of crude fiber, 48.83 of glycemic index and 7.39 of glycemic load.

  16. A Review of the Relationship between Dietary Glycemic Index and Glycemic Load and Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Fahime Zeinali

    2016-10-01

    Full Text Available Background: In recent decades, studies on type 2 diabetes (T2D, have adopted a new approach to the field of a more complete collection of variables related to the lifestyles and diet of people. Diet is an important factor in increasing the rate of T2D among individuals. Considering the consumption of a high-carbohydrate diet, little attention has been paid to the type of carbohydrates consumed in the incidence of T2D. The present study aimed to review the literature on the relationship between the glycemic index (GI, the glycemic load, (GL and T2D, it also targets at evaluating and comparing the results of similar studies in other countries Methods: Using search engines, including PubMed, Science Direct, Embase and Scopus, and key words such as GI, GL, diabetes; articles with cross-sectional, clinical trial, Prospective and retrospective cohort designs between 2000 to 2016 were selected. Moreover, non-English language articles were not investigate. Results: The results of these studies showed that a diet containing low GI and GL has beneficial effects on the metabolism of glucose in the body and is also considered as a factor to protect the body against T2D and its complications. Conclusions: Monitoring eating habits of people with T2D can have beneficial effects on T2D and its associated risk factors.

  17. Spatial and temporal variation of heavy metal risk and source in sediments of Dongting Lake wetland, mid-south China.

    Science.gov (United States)

    Liang, Jie; Liu, Jiayu; Yuan, Xingzhong; Zeng, Guangming; Lai, Xu; Li, Xiaodong; Wu, Haipeng; Yuan, Yujie; Li, Fei

    2015-01-01

    Surface sediments of Dongting Lake wetland were collected from ten sites to investigate variation trend, risk and sources of heavy metal distribution in dry seasons of 2011∼2013. The three-year mean concentrations (mg/kg) of Cr, Cu, Pb, Cd, Hg and As were 91.33, 36.27, 54.82, 4.39, 0.19 and 25.67, respectively, which were all higher than the corresponding background values. Sediment quality guidelines (SQGs) and Geo-accumulation index (Igeo) were used for the assessment of pollution level of heavy metals. The pollution risk of Cd, Hg and As were great and that of Cr needed urgent attention because of its obvious increase. Pollution load index (PLI) and geographic information system (GIS) methods were conducted to assess spatial and temporal variation of heavy metal contamination. Results confirmed an increased contamination contribution inflow from Xiang River. Multivariate statistical analyses were applied to identify contribution sources of heavy metal, which showed anthropogenic origin mainly from mining, smelting, chemical industry and agricultural activity.

  18. Assessment of atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana using epiphytic lichens

    Energy Technology Data Exchange (ETDEWEB)

    Boamponsem, L.K. [Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology, University Post Office, Kumasi (Ghana); Department of Laboratory Technology, School of Physical Sciences, University of Cape Coast, Cape Coast (Ghana); Adam, J.I. [Department of Theoretical and Applied Biology, College of Science, Kwame Nkrumah University of Science and Technology, University Post Office, Kumasi (Ghana); Dampare, S.B., E-mail: dampare@cc.okayama-u.ac.j [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon-Accra (Ghana); Department of Earth Sciences, Okayama University, 1-1, Tsushima-Naka 3-Chome, Okayama 700-8530 (Japan); Nyarko, B.J.B. [National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG 80, Legon-Accra (Ghana); Essumang, D.K. [Department of Laboratory Technology, School of Physical Sciences, University of Cape Coast, Cape Coast (Ghana)

    2010-05-01

    In situ lichens (Parmelia sulcata) have been used to assess atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana. Total heavy metal concentrations obtained by instrumental neutron activation analysis (INAA) were processed by positive matrix factorization (PMF), principal component (PCA) and cluster (CA) analyses. The pollution index factor (PIF) and pollution load index (PLI) criteria revealed elevated levels of Sb, Mn, Cu, V, Al, Co, Hg, Cd and As in excess of the background values. The PCA and CA classified the examined elements into anthropogenic and natural sources, and PMF resolved three primary sources/factors: agricultural activities and other non-point anthropogenic origins, natural soil dust, and gold mining activities. Gold mining activities, which are characterized by dominant species of Sb, Th, As, Hg, Cd and Co, and significant contributions of Cu, Al, Mn and V, are the main contributors of heavy metals in the atmosphere of the study area.

  19. Assessment of atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana using epiphytic lichens

    International Nuclear Information System (INIS)

    Boamponsem, L.K.; Adam, J.I.; Dampare, S.B.; Nyarko, B.J.B.; Essumang, D.K.

    2010-01-01

    In situ lichens (Parmelia sulcata) have been used to assess atmospheric heavy metal deposition in the Tarkwa gold mining area of Ghana. Total heavy metal concentrations obtained by instrumental neutron activation analysis (INAA) were processed by positive matrix factorization (PMF), principal component (PCA) and cluster (CA) analyses. The pollution index factor (PIF) and pollution load index (PLI) criteria revealed elevated levels of Sb, Mn, Cu, V, Al, Co, Hg, Cd and As in excess of the background values. The PCA and CA classified the examined elements into anthropogenic and natural sources, and PMF resolved three primary sources/factors: agricultural activities and other non-point anthropogenic origins, natural soil dust, and gold mining activities. Gold mining activities, which are characterized by dominant species of Sb, Th, As, Hg, Cd and Co, and significant contributions of Cu, Al, Mn and V, are the main contributors of heavy metals in the atmosphere of the study area.

  20. Platelet aggregation according to body mass index in patients undergoing coronary stenting: should clopidogrel loading-dose be weight adjusted?

    Science.gov (United States)

    Angiolillo, Dominick J; Fernández-Ortiz, Antonio; Bernardo, Esther; Barrera Ramírez, Carlos; Sabaté, Manel; Fernandez, Cristina; Hernández-Antolín, Rosana; Escaned, Javier; Alfonso, Fernando; Macaya, Carlos

    2004-04-01

    A 300 mg clopidogrel loading-dose (LD) is widely used as an adjunct antithrombotic treatment to reduce the risk of thrombotic events early after coronary stenting (CS). Antithrombotic drugs commonly used during percutaneous coronary interventions, such as heparin and platelet glycoprotein IIb/IIIa inhibitors, but not clopidogrel LD, are weight-adjusted, and few data are available on which is the most effective clopidogrel LD regimen. The aim of this study was to assess whether body mass index (BMI) influenced platelet response to clopidogrel LD in patients undergoing CS. Adenosine diphosphate (ADP)-induced platelet aggregation (PA) was assessed by light transmittance aggregometry in 48 patients on aspirin treatment undergoing CS receiving a 300 mg clopidogrel LD at intervention time. PA was assessed at baseline and up to 24 hours after intervention. Patients were divided into 2 groups according to BMI: overweight (BMI greater than or equal to 25 kg/m2; 29 patients) and normal weight (BMI<25 kg/m2; 19 patients). PA was significantly higher in overweight than in normal weight patients at baseline (60.1+/-18.6%; versus 47.6+/-13.5%; p=0.01), at 24 hours (42.3+/-18.4% versus 38.5+/-18.3%; p=0.02) and during the overall study time (p=0.025). Percentage of inhibition of PA 24 hours following clopidogrel LD was suboptimal (<40%) in 59% and 26% of overweight and normal weight patients, respectively (p=0.04). An elevated BMI was the only independent predictor of suboptimal platelet response. These data suggest that overweight patients may need a higher loading-dose of clopidogrel and/or an adjunct antithrombotic treatment to adequately inhibit platelet aggregation early after CS.

  1. Loads and loads and loads: The influence of prospective load, retrospective load, and ongoing task load in prospective memory

    Directory of Open Access Journals (Sweden)

    Beat eMeier

    2015-06-01

    Full Text Available In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load can affect prospective memory performance. The existence of multiple target events increases prospective load and adding complexity to the to-be-remembered action increases retrospective load. In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of prospective load on costs in the ongoing task for categorical targets (Experiment 2, but not for specific targets (Experiment 1. Retrospective load and ongoing task load both affected remembering the retrospective component of the prospective memory task. We suggest that prospective load can enhance costs in the ongoing task due to additional monitoring requirements. Retrospective load and ongoing task load seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

  2. Parametric analysis of parameters for electrical-load forecasting using artificial neural networks

    Science.gov (United States)

    Gerber, William J.; Gonzalez, Avelino J.; Georgiopoulos, Michael

    1997-04-01

    Accurate total system electrical load forecasting is a necessary part of resource management for power generation companies. The better the hourly load forecast, the more closely the power generation assets of the company can be configured to minimize the cost. Automating this process is a profitable goal and neural networks should provide an excellent means of doing the automation. However, prior to developing such a system, the optimal set of input parameters must be determined. The approach of this research was to determine what those inputs should be through a parametric study of potentially good inputs. Input parameters tested were ambient temperature, total electrical load, the day of the week, humidity, dew point temperature, daylight savings time, length of daylight, season, forecast light index and forecast wind velocity. For testing, a limited number of temperatures and total electrical loads were used as a basic reference input parameter set. Most parameters showed some forecasting improvement when added individually to the basic parameter set. Significantly, major improvements were exhibited with the day of the week, dew point temperatures, additional temperatures and loads, forecast light index and forecast wind velocity.

  3. Allostatic Load and Effort-Reward Imbalance: Associations over the Working-Career.

    Science.gov (United States)

    Coronado, José Ignacio Cuitún; Chandola, Tarani; Steptoe, Andrew

    2018-01-24

    Although associations between work stressors and stress-related biomarkers have been reported in cross-sectional studies, the use of single time measurements of work stressors could be one of the reasons for inconsistent associations. This study examines whether repeated reports of work stress towards the end of the working career predicts allostatic load, a measure of chronic stress related physiological processes. Data from waves 2 to 6 of the English Longitudinal Study of Ageing (ELSA) were analysed, with a main analytical sample of 2663 older adults (aged 50+) who had at least one measurement of effort-reward imbalance between waves 2-6 and a measurement of allostatic load at wave 6. Cumulative work stress over waves 2-6 were measured by the effort-reward imbalance model. ELSA respondents who had reported two or more occasions of imbalance had a higher (0.3) estimate of the allostatic load index than those who did not report any imbalance, controlling for a range of health and socio-demographic factors, as well as allostatic load at baseline. More recent reports of imbalance were significantly associated with a higher allostatic load index, whereas reports of imbalance from earlier waves of ELSA were not. The accumulation of work related stressors could have adverse effects on chronic stress biological processes.

  4. Potentially toxic elements in soil of the Khyber Pakhtunkhwa province and Tribal areas, Pakistan: evaluation for human and ecological risk assessment.

    Science.gov (United States)

    Saddique, Umar; Muhammad, Said; Tariq, Mohsin; Zhang, Hua; Arif, Mohammad; Jadoon, Ishtiaq A K; Khattak, Nimat Ullah

    2018-03-22

    Potentially toxic elements (PTEs) contaminations in the soil ecosystem are considered as extremely hazardous due to toxicity, persistence and bioaccumulative nature. Therefore, this study was aimed to summarize the results of published PTEs in soil of Khyber Pakhtunkhwa and Tribal areas, Pakistan. Results were evaluated for the pollution quantification factors, including contamination factor (CF), pollution load index (PLI), ecological risk index (ERI) and human health risk assessment. The highest CF (797) and PLI (7.35) values were observed for Fe and ERI (857) values for Cd. Soil PTEs concentrations were used to calculate the human exposure for the risk assessment, including chronic or non-carcinogenic risks such as the hazard quotient (HQ) and carcinogenic or cancer risk (CR). The values of HQ were > 1 for the Cd, Co and Cr in Khyber Pakhtunkhwa and Tribal areas. Tribal areas showed higher values of ERI, HQ, and CR as compared to the Khyber Pakhtunkhwa that were attributed to the mining activities, weathering and erosion of mafic and ultramafic bedrocks hosting ophiolites. This study strongly recommends that best control measures need to be taken for soil PTEs with the intent to alleviate any continuing potential threat to the human health, property and environment, which otherwise could enter ecosystem and ultimately the living beings. Further studies are recommended to combat the soil PTEs concentrations and toxicity in the Tribal areas for a best picture of understanding the element effects on human, and environment can be achieved that will lead to a sustainable ecological harmony.

  5. Assessment of metals pollution in sediment cores from the Sabah-Sarawak coastal waters

    International Nuclear Information System (INIS)

    Zal Uyun Wan Mahmood; Zaharudin Ahmad; Che Abdul Rahim Mohamed; Abdul Kadir Ishak; Norfaizal Mohammed

    2011-01-01

    The distribution, enrichment and pollution status of metals in sediment cores from the Sabah-Sarawak coastal waters were studied. Seven sediment cores were taken in July 2004 using a gravity box corer. The metals of Cu, Zn and Pb were analyzed by ICP-MS to assess the pollution status of the sediments. The sediment fine fraction and organic carbon content was also analyzed. Enrichment Factor (EF), Geo accumulation Index (Igeo) and Pollution Load Index (PLI) was calculated as criteria of possible contamination. The results showed that collected sediments were composed with clay, silt and sand as 12 - 74 %, 27 - 72 % and 0 - 20 %, respectively. Meanwhile, organic carbon contents were relatively low and constant over time, based on sediment depth profiles, and it did not exceed 5 % at any sampling station. The average metal concentrations in sediment cores at all sampling station were distributed in the ranges of 1.66 ± 1.36 - 6.61 ± 0.12 μgg -1 for Cu, 26.55 ± 1.04 - 57.94 ± 1.58 μgg -1 for Zn and 3.99 ± 0.10 - 14.48 ± 0.32 μgg -1 for Pb. According to calculations of EF, I geo and PLI, it can be concluded that concentrations of Cu, Zn and Pb were not significantly affected by pollution from anthropogenic sources at the seven sampling locations. Thus, the metal content of Cu, Zn and Pb in sediment should not cause pollution problem to the marine environment of Sabah-Sarawak coastal waters and further response measures are not needed. (author)

  6. Prediction of fatigue damage in tapered laminates

    DEFF Research Database (Denmark)

    Raeis Hosseiny, Seyed Aydin; Jakobsen, Johnny

    2017-01-01

    Effective implementation of ply-drops configurations substantially improve the damage tolerant design of flexible and aero-elastic wind turbine blades. Terminating a number of layers for an optimized blade design creates local bending effects. Inter-laminar stress states in tapered areas give rise...... to delamination and premature structural failure. Precise calculation of the stress levels for embedded ply-drops is required to predict failure initiation within acceptable limits. Multi-axial stress states in orthotropic laminates subjected to diverse loading mechanisms nucleate microscopic cracks....... By increasing the cracks density, damage occurs when residual material properties reduce to a critical level. Residual strength and stiffness of simple laminates are assigned in a set of fatigue failure criteria to assess the remaining life of the components by increasing number of loading cycles. The mode...

  7. MATHEMATICAL MODEL DESIGNATED FOR THE ASSESSMENT OF THE INTEGRATED ENVIRONMENTAL LOAD PRODUCED BY A BUILDING PROJECT

    OpenAIRE

    Lapidus Azariy Abramovich; Berezhnyy Aleksandr Yurevich

    2012-01-01

    In the paper, the author proposes a mathematical model designated for the assessment of the ecological impact produced on the environment within the territory of the construction site. Integrated index EI (Environmental Index) is introduced as a vehicle designated for the evaluation of the ecological load. EI represents the intensity of the ecological load, or a generalized and optimized parameter reflecting the intensity of the anthropogenic impact of the construction site onto the natural e...

  8. Using the system maintenance datastore to characterize lifetime maintenance for PLiM

    International Nuclear Information System (INIS)

    Watson, P.; Dam, R.; Nickerson, J.

    2004-01-01

    A comprehensive Plant Life Management (PLiM) program involves evaluating a large amount of information. For any plant, there are numerous maintenance, surveillance and inspection programs for the important systems, structures and components. There is extensive industry experience on component failure modes, degradation mechanisms and recommended maintenance practices. This information forms the basis of the aging assessment work, through which improvements to these plant programs are identified. AECL has developed several tools to manage the quantities of information required in aging assessment studies, such as the SYSTMS (SYtematic approach for the development of STrategy for Maintenance and Surveillance) tool and the System Maintenance Datastore (SMD). The SMD has been developed to serve as a hub to a Systematic based Adaptive Maintenance Program (SAMP), by storing maintenance resource requirements for recommended maintenance tasks for use by the other processes in a SAMP. The SMD can be used to (a) quantify the savings or cost of optimising a maintenance program, (b) characterize and understand long term trends in condition-based maintenance due to component aging, (c) quantify the resource savings due to optimum timing of component replacement or general plant refurbishment, and (d) provide aging assessment cost information for input to plant asset evaluation. The SMD contains data for regular maintenance program tasks, plant condition assessment recommendations, and equipment refurbishment costs. A prototype SMD has been developed with data tables populated with information from operating CANDU stations. The SMD is now available to be used either with a SYSTMS evaluation or with a plant's database of maintenance tasks. (author)

  9. Market and own load bulletin - December 1993

    International Nuclear Information System (INIS)

    1993-12-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors and in the five Brazilian regions during december of 1993 is described. The industrial production indexes, the cost of tariffs and fuel consumption and the evolution of own load energy and the energy demand are also shown. (C.G.C.)

  10. Market and own load bulletin - December 1992

    International Nuclear Information System (INIS)

    1992-12-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors and in the five Brazilian regions during december of 1992 is described. The industrial production indexes, the cost of tariffs and fuel consumption and the evolution of own load energy and the energy demand are also shown. (C.G.C.)

  11. The effect of swimming on oral health status: competitive versus non-competitive athletes

    Directory of Open Access Journals (Sweden)

    Simonetta D’ERCOLE

    2016-04-01

    Full Text Available ABSTRACT Young swimmers are particularly susceptible to the onset of oral diseases. Objective To evaluate the oral health status in young competitive and non-competitive swimmers, involving an assessment of salivary cariogenic bacteria and secretory IgA (S-IgA concentration. Material and Methods Before training sessions (T1, 54 competitive and 69 non-competitive swimmers had the following parameters assessed: decayed, missing, and filled teeth (DMFT, Plaque Index (PlI, and Gingival Index (GI. At T1 and after training sessions (T2, stimulated saliva was collected and microbiological and immunological analyses were performed. Results Competitive swimmers trained 2.02±0.09 hours 5 times a week, while non-competitive swimmers trained 2.03±0.18 hours a week. A total of 14.7% of competitive swimmers suffered dental trauma related to sports. Only 11.76% of the competitive swimmers took a daily dose of fluoride, against 32.65% of non-competitive swimmers (p=0.029. Neither group followed an established diet or presented statistically significant differences in terms of nutritional supplement drink and chocolate intake. There were statistically significant differences in terms of oral hygiene. No significant difference in clinical indexes (DMFT, PlI, and GI was present. S. mutans was harbored by 18.6% of competitive and the 32.2% of non-competitive swimmers. S. sobrinus was detected in 22.03% of competitive and 91.6% of non-competitive swimmers (p<0.05. S. sanguinis was found only in the saliva of competitive swimmers. The average S-IgA of competitive swimmers decreased significantly at T2 (p<0.05. The pool water had a daily average pH of 7.22. Conclusions Microbial markers, immune status and sporting characteristics are important for establishing guidelines for management of training load in order to minimize physical stress and the risk of oral infection.

  12. Application of the robust design concept for fuel loading pattern

    International Nuclear Information System (INIS)

    Endo, Tomohiro; Ohori, Kazuma; Yamamoto, Akio

    2011-01-01

    Application of the robust design concept for fuel loading pattern design is proposed as a new approach to improve the prediction accuracy of core characteristics. The robust design is a design concept that establishes a resistant (robust) system for perturbations or noises, by properly setting design variables. In order to apply the concept of robust design to fuel loading pattern design, we focus on a theoretical approach based on the higher order perturbation method. This approach indicates that the eigenvalue separation is one of the effective indices to measure the robustness of a designed fuel loading pattern. In order to verify the effectiveness of the eigenvalue separation as an index of robustness, numerical analysis is carried out for typical 3-loop PWR cores, and we evaluated the correlation between the eigenvalue separation and the variation of relative assembly power due to the perturbation of the cross section. The numerical results show that the variation of relative power decreases as the eigenvalue separation increases; thus, it is confirmed that the eigenvalue separation is an effective index of robustness. Based on the eigenvalue separation of a fuel loading pattern, we discuss design guidelines of a fuel loading pattern to improve the robustness. For example, if each fuel assembly has independent uncertainty on its cross section, the robustness of the core can be enhanced by increasing the relative power at the center of the core. The proposed guidelines will be useful to design a loading pattern that has robustness for uncertainties due to cross section, calculation method, and so on. (author)

  13. Fatigue of cord-rubber composites for tires

    Science.gov (United States)

    Song, Jaehoon

    Fatigue behaviors of cord-rubber composite materials forming the belt region of radial pneumatic tires have been characterized to assess their dependence on stress, strain and temperature history as well as materials composition and construction . Using actual tires, it was found that interply shear strain is one of the crucial parameters for damage assessment from the result that higher levels of interply shear strain of actual tires reduce the fatigue lifetime. Estimated at various levels of load amplitude were the fatigue life, the extent and rate of resultant strain increase ("dynamic creep"), cyclic strains at failure, and specimen temperature. The interply shear strain of 2-ply 'tire belt' composite laminate under circumferential tension was affected by twisting of specimen due to tension-bending coupling. However, a critical level of interply shear strain, which governs the gross failure of composite laminate due to the delamination, appeared to be independent of different lay-up of 2-ply vs. symmetric 4-ply configuration. Reflecting their matrix-dominated failure modes such as cord-matrix debonding and delamination, composite laminates with different cord reinforcements showed the same S-N relationship as long as they were constructed with the same rubber matrix, the same cord angle, similar cord volume, and the same ply lay-up. Because of much lower values of single cycle strength (in terms of gross fracture load per unit width), the composite laminates with larger cord angle and the 2-ply laminates exhibited exponentially shorter fatigue lifetime, at a given stress amplitude, than the composite laminates with smaller cord angle and 4-ply symmetric laminates, respectively. The increase of interply rubber thickness lengthens their fatigue lifetime at an intermediate level of stress amplitude. However, the increase in the fatigue lifetime of the composite laminate becomes less noticeable at very low stress amplitude. Even with small compressive cyclic

  14. Structural Analysis and Optimization of a Composite Fan Blade for Future Aircraft Engine

    Science.gov (United States)

    Coroneos, Rula M.; Gorla, Rama Subba Reddy

    2012-09-01

    This paper addresses the structural analysis and optimization of a composite sandwich ply lay-up of a NASA baseline solid metallic fan blade comparable to a future Boeing 737 MAX aircraft engine. Sandwich construction with a polymer matrix composite face sheet and honeycomb aluminum core replaces the original baseline solid metallic fan model made of Titanium. The focus of this work is to design the sandwich composite blade with the optimum number of plies for the face sheet that will withstand the combined pressure and centrifugal loads while the constraints are satisfied and the baseline aerodynamic and geometric parameters are maintained. To satisfy the requirements a sandwich construction for the blade is proposed with composite face sheets and a weak core made of honeycomb aluminum material. For aerodynamic considerations, the thickness of the core is optimized where as the overall blade thickness is held fixed in order not to alter the original airfoil geometry. Weight reduction is taken as the objective function by varying the core thickness of the blade within specified upper and lower bounds. Constraints are imposed on radial displacement limitations and ply failure strength. From the optimum design, the minimum number of plies, which will not fail, is back-calculated. The ply lay-up of the blade is adjusted from the calculated number of plies and final structural analysis is performed. Analyses were carried out by utilizing the OpenMDAO Framework, developed at NASA Glenn Research Center combining optimization with structural assessment.

  15. Market and own load bulletin - October 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors, and in the five Brazilian regions, during January-October 93, and November 92-October 93 is described. The industrial production indexes, the cost of tariffs and fuel consumption, the evolution of own load energy and energy demand are also shown. (C.G.C.)

  16. Market and own load bulletin - June 1993

    International Nuclear Information System (INIS)

    1993-06-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors and in the five Brazilian regions during the month of June 1993 is described. The industrial production indexes, the cost of tariffs and fuel consumption and the evolution of own load energy and the energy demand are also shown. (C.G.C.)

  17. Market and own load bulletin - August 1993

    International Nuclear Information System (INIS)

    1993-08-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors and in the five Brazilian regions during the month of August 1993 is described. The industrial production indexes, the cost of tariffs and fuel consumption and the evolution of own load energy and the energy demand are also shown. (C.G.C.)

  18. Market and own load bulletin - November 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors, and in the five Brazilian regions, during January-November 93, and December 92-November 93 is described. The industrial production indexes, the cost of tariffs and fuel consumption, the evolution of own load energy and energy demand are also shown. (C.G.C.)

  19. Market and own load bulletin - July 1993

    International Nuclear Information System (INIS)

    1993-07-01

    The electric power consumption in the residential, commercial and industrial Brazilian sectors and in the five Brazilian regions during the month of July 1993 is described. The industrial production indexes, the cost of tariffs and fuel consumption and the evolution of own load energy and the energy demand are also shown. (C.G.C.)

  20. Glycaemic index and glycaemic load values of a selection of popular foods consumed in Hong Kong.

    Science.gov (United States)

    Lok, Kris Y; Chan, Ruth; Chan, Dicken; Li, Liz; Leung, Grace; Woo, Jean; Lightowler, Helen J; Henry, C Jeya K

    2010-02-01

    The objective of the present paper is to provide glycaemic index (GI) and glycaemic load (GL) values for a variety of foods that are commonly consumed in Hong Kong and expand on the international GI table of Chinese foods. Fasted healthy subjects were given 50 g of available carbohydrate servings of a glucose reference, which was tested twice, and test foods of various brands of noodles (n 5), instant cereals (n 3) and breads (n 2), which were tested once, on separate occasions. For each test food, tests were repeated in ten healthy subjects. Capillary blood glucose was measured via finger-prick samples in fasting subjects ( - 5, 0 min) and at 15, 30, 45, 60, 90 and 120 min after the consumption of each test food. The GI of each test food was calculated geometrically by expressing the incremental area under the blood glucose response curve (IAUC) of each test food as a percentage of each subject's average IAUC for the reference food. GL was calculated as the product of the test food's GI and the amount of available carbohydrate in a reference serving size. The majority of GI values of foods tested were medium (a GI value of 56-69) to high (a GI value of 70 or more) and compared well with previously published values. More importantly, our dataset provides GI values of ten foods previously untested and presents values for foods commonly consumed in Hong Kong.

  1. Rock index properties for geoengineering in underground development

    International Nuclear Information System (INIS)

    O'Rourke, J.E.

    1989-01-01

    This paper describes the use of index testing to obtain rock properties that are useful in the design and construction planning of an underground development for civil engineering or mining projects. The index properties discussed include: point load; Schmidt hammer hardness; abrasion hardness; and total hardness. The first two index properties correlate to uniaxial compressive strength (UCS) and Young's modulus. Discussions are given on empirical, normalized relationships of UCS to rock mass properties and the integrated use with semi-empirical, geotechnical design methods. The hardness property indices correlate to construction performance parameters and some relevant experience is cited. Examples of data are presented from an index testing program carried out primarily on siltstone, sandstone and limestone rock core samples retrieved from depths up to 1005 m (3300 ft) in a borehole drilled in the Paradox Basin in eastern Utah. The borehole coring was done for a nuclear waste repository site investigation

  2. Allostatic Load and Effort-Reward Imbalance: Associations over the Working-Career

    Directory of Open Access Journals (Sweden)

    José Ignacio Cuitún Coronado

    2018-01-01

    Full Text Available Although associations between work stressors and stress-related biomarkers have been reported in cross-sectional studies, the use of single time measurements of work stressors could be one of the reasons for inconsistent associations. This study examines whether repeated reports of work stress towards the end of the working career predicts allostatic load, a measure of chronic stress related physiological processes. Data from waves 2 to 6 of the English Longitudinal Study of Ageing (ELSA were analysed, with a main analytical sample of 2663 older adults (aged 50+ who had at least one measurement of effort-reward imbalance between waves 2–6 and a measurement of allostatic load at wave 6. Cumulative work stress over waves 2–6 were measured by the effort-reward imbalance model. ELSA respondents who had reported two or more occasions of imbalance had a higher (0.3 estimate of the allostatic load index than those who did not report any imbalance, controlling for a range of health and socio-demographic factors, as well as allostatic load at baseline. More recent reports of imbalance were significantly associated with a higher allostatic load index, whereas reports of imbalance from earlier waves of ELSA were not. The accumulation of work related stressors could have adverse effects on chronic stress biological processes.

  3. Load Balancing Scheme on the Basis of Huffman Coding for P2P Information Retrieval

    Science.gov (United States)

    Kurasawa, Hisashi; Takasu, Atsuhiro; Adachi, Jun

    Although a distributed index on a distributed hash table (DHT) enables efficient document query processing in Peer-to-Peer information retrieval (P2P IR), the index costs a lot to construct and it tends to be an unfair management because of the unbalanced term frequency distribution. We devised a new distributed index, named Huffman-DHT, for P2P IR. The new index uses an algorithm similar to Huffman coding with a modification to the DHT structure based on the term distribution. In a Huffman-DHT, a frequent term is assigned to a short ID and allocated a large space in the node ID space in DHT. Throuth ID management, the Huffman-DHT balances the index registration accesses among peers and reduces load concentrations. Huffman-DHT is the first approach to adapt concepts of coding theory and term frequency distribution to load balancing. We evaluated this approach in experiments using a document collection and assessed its load balancing capabilities in P2P IR. The experimental results indicated that it is most effective when the P2P system consists of about 30, 000 nodes and contains many documents. Moreover, we proved that we can construct a Huffman-DHT easily by estimating the probability distribution of the term occurrence from a small number of sample documents.

  4. The influence of lay-up and thickness on composite impact damage and compression strength

    Science.gov (United States)

    Guynn, E. G.; Obrien, T. K.

    1985-01-01

    The effects of composite stacking sequence, thickness, and percentage of zero-degree plies on the size, shape, and distribution of delamination through the laminate thickness and on residual compression strength following impact were studied. Graphite/epoxy laminates were impacted with an 0.5 inch diameter aluminum sphere at a specific low or high velocity. Impact damage was measured nondestructively by ultrasonic C-scans and X-radiography and destructively by the deply technique, and compression strength tests were performed. It was found that differences in compression failure strain due to stacking sequence were small, while laminates with very low percentages of zero-degree plies had similar failure loads but higher failure strains than laminates with higher percentages of zero-degree plies. Failure strain did not correlate with planar impact damage area, and delaminations in impact regions were associated with matrix cracking.

  5. Automated nuclear fuel rod pattern loading system

    International Nuclear Information System (INIS)

    Lambert, D.V.; Nyland, T.W.; Byers, J.W.; Haley, D.E. Jr.; Cioffi, J.V.

    1990-01-01

    This patent describes an apparatus for loading fuel rods in a desired pattern. It comprises: a carousel having a plurality of movable gondolas for stocking thereon fuel rods of known enrichments; an elongated magazine defining a matrix of elongated slots being open at their forward ends for receiving fuel rods; a workstation defining a fuel rod feed path; and a holder and indexing mechanism for movably supporting the magazine and being actuatable for moving the magazine along X-Y axes to successively align one at a time selected ones of the slots with the feed path for loading in the magazine the successive fuel rods in a desired enrichment pattern

  6. Glycemic Index and Glycemic Load and Their Association with C-Reactive Protein and Incident Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Geertruida J. van Woudenbergh

    2011-01-01

    Full Text Available Objective. To investigate whether the Glycemic Index (GI or Glycemic Load (GL of a diet is associated with C-reactive Protein (CRP and risk of type 2 diabetes in a prospective study. Materials and Methods. Our analysis included 4,366 participants who did not have diabetes at baseline. During follow-up 456 diabetes cases were confirmed. Dietary GI and GL were derived from a food-frequency questionnaire and its association with CRP was examined cross-sectionally using linear regression models. The association of GI and GL with diabetes incidence was examined using Cox proportional hazard models. Results. GL, but not GI, was associated with lnCRP at baseline (bGL=0.11 per 50 units; P=.01. When comparing the highest to the lowest tertile of GI with respect to diabetes incidence, a Relative Risk (RR of 0.95 [95%CI 0.75, 1.21] was found after adjustment for lifestyle and nutritional factors. For GL the RR for diabetes incidence was 1.00 [95%CI 0.74, 1.36]. Additional adjustment for CRP did not change RRs. Conclusion. Since GI was not associated with CRP and risk of type 2 diabetes, it is unlikely that a high GI diet induces the previously shown positive association between CRP and risk of type 2 diabetes by increasing CRP concentrations.

  7. Characterization of carbon fiber polymer matrix composites subjected to simultaneous application of electric current pulse and low velocity impact

    Science.gov (United States)

    Hart, Robert James

    2011-12-01

    The use of composite materials in aerospace, electronics, and wind industries has become increasingly common, and these composite components are required to carry mechanical, electrical, and thermal loads simultaneously. A unique property of carbon fiber composites is that when an electric current is applied to the specimen, the mechanical strength of the specimen increases. Previous studies have shown that the higher the electric current, the greater the increase in impact strength. However, as current passes through the composite, heat is generated through Joule heating. This Joule heating can cause degradation of the composite and thus a loss in strength. In order to minimize the negative effects of heating, it is desired to apply a very high current for a very short duration of time. This thesis investigated the material responses of carbon fiber composite plates subjected to electrical current pulse loads of up to 1700 Amps. For 32 ply unidirectional IM7/977-3 specimens, the peak impact load and absorbed energy increased slightly with the addition of a current pulse at the time of an impact event. In 16 ply cross-ply IM7/977-2 specimens, the addition of the current pulse caused detrimental effects due to electrical arcing at the interface between the composite and electrodes. Further refinement of the experimental setup should minimize the risk of electrical arcing and should better elucidate the effects of a current pulse on the impact strength of the specimens.

  8. Contributors to dietary glycaemic index and glycaemic load in the Netherlands: the role of beer.

    Science.gov (United States)

    Sluik, Diewertje; Atkinson, Fiona S; Brand-Miller, Jennie C; Fogelholm, Mikael; Raben, Anne; Feskens, Edith J M

    2016-04-14

    Diets high in glycaemic index (GI) and glycaemic load (GL) have been associated with a higher diabetes risk. Beer explained a large proportion of variation in GI in a Finnish and an American study. However, few beers have been tested according to International Organization for Standardization (ISO) methodology. We tested the GI of beer and estimated its contribution to dietary GI and GL in the Netherlands. GI testing of pilsner beer (Pilsner Urquell) was conducted at The University of Sydney according to ISO international standards with glucose as the reference food. Subsequently, GI and GL values were assigned to 2556 food items in the 2011 Dutch food composition table using a six-step methodology and consulting four databases. This table was linked to dietary data from 2106 adults in the Dutch National Food Consumption Survey 2007-2010. Stepwise linear regression identified contribution to inter-individual variation in dietary GI and GL. The GI of pilsner beer was 89 (SD 5). Beer consumption contributed to 9·6 and 5·3% inter-individual variation in GI and GL, respectively. Other foods that contributed to the inter-individual variation in GI and GL included potatoes, bread, soft drinks, sugar, candy, wine, coffee and tea. The results were more pronounced in men than in women. In conclusion, beer is a high-GI food. Despite its relatively low carbohydrate content (approximately 4-5 g/100 ml), it still made a contribution to dietary GL, especially in men. Next to potatoes, bread, sugar and sugar-sweetened beverages, beer captured a considerable proportion of between-person variability in GI and GL in the Dutch diet.

  9. Global-Local Analysis and Optimization of a Composite Civil Tilt-Rotor Wing

    Science.gov (United States)

    Rais-Rohani, Masound

    1999-01-01

    This report gives highlights of an investigation on the design and optimization of a thin composite wing box structure for a civil tilt-rotor aircraft. Two different concepts are considered for the cantilever wing: (a) a thin monolithic skin design, and (b) a thick sandwich skin design. Each concept is examined with three different skin ply patterns based on various combinations of 0, +/-45, and 90 degree plies. The global-local technique is used in the analysis and optimization of the six design models. The global analysis is based on a finite element model of the wing-pylon configuration while the local analysis uses a uniformly supported plate representing a wing panel. Design allowables include those on vibration frequencies, panel buckling, and material strength. The design optimization problem is formulated as one of minimizing the structural weight subject to strength, stiffness, and d,vnamic constraints. Six different loading conditions based on three different flight modes are considered in the design optimization. The results of this investigation reveal that of all the loading conditions the one corresponding to the rolling pull-out in the airplane mode is the most stringent. Also the frequency constraints are found to drive the skin thickness limits, rendering the buckling constraints inactive. The optimum skin ply pattern for the monolithic skin concept is found to be (((0/+/-45/90/(0/90)(sub 2))(sub s))(sub s), while for the sandwich skin concept the optimal ply pattern is found to be ((0/+/-45/90)(sub 2s))(sub s).

  10. Relationship of locus of control with plaque and gingival status before and after oral health education in a group of college students - an experimental study.

    Science.gov (United States)

    Potdar, S; Lakshminarayan, N; Goud Reddy, S

    2015-02-01

    In health psychology, several models are being constructed to understand human behaviour. Multidimensional health locus of control (MHLC) is one among them. We sought to know the relationship of MHLC with dental plaque and gingival status before and after oral health education programme among 286 college students, aged 18-21 years in Davangere city. Multidimensional health locus of control questionnaire consisting of questions measuring internal health locus of control (IHLC), powerful others health locus of control (PHLC) and chance health locus of control (CHLC) was administered to students. Dental plaque and gingival health status were recorded using Plaque Index (PLI) and Gingival Index (GI), 1967. Oral health education was provided using power point presentation after the baseline oral examination. After 10 weeks of intervention, the students were given the same proforma followed by the assessment of plaque and gingival status. A negative correlation was observed between PHLC and IHLC with PLI and GI and positive correlation of CHLC with PLI and GI at a level of P education was found to be effective and this could change the behaviour of individuals. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Glycaemic index and glycaemic load of breakfast predict cognitive function and mood in school children: a randomised controlled trial.

    Science.gov (United States)

    Micha, Renata; Rogers, Peter J; Nelson, Michael

    2011-11-01

    The macronutrient composition of a breakfast that could facilitate performance after an overnight fast remains unclear. As glucose is the brain's major energy source, the interest is in investigating meals differing in their blood glucose-raising potential. Findings vary due to unaccounted differences in glucoregulation, arousal and cortisol secretion. We investigated the effects of meals differing in glycaemic index (GI) and glycaemic load (GL) on cognition and mood in school children. A total of seventy-four school children were matched and randomly allocated either to the high-GL or low-GL group. Within each GL group, children received high-GI and low-GI breakfasts. Cognitive function (CF) and mood were measured 95-140 min after breakfast. Blood glucose and salivary cortisol were measured at baseline, before and after the CF tests. Repeated-measures ANOVA was used to identify differences in CF, mood, glucose and cortisol levels between the breakfasts. Low-GI meals predicted feeling more alert and happy, and less nervous and thirsty (P breakfast, and high-GI meals increased cortisol levels (P breakfast may help to improve learning, and of potential value in informing government education policies relating to dietary recommendations and implementation concerning breakfast.

  12. Impact of heat stress on conception rate of dairy cows in the moderate climate considering different temperature-humidity index thresholds, periods relative to breeding, and heat load indices.

    Science.gov (United States)

    Schüller, L K; Burfeind, O; Heuwieser, W

    2014-05-01

    The objectives of this retrospective study were to investigate the relationship between temperature-humidity index (THI) and conception rate (CR) of lactating dairy cows, to estimate a threshold for this relationship, and to identify periods of exposure to heat stress relative to breeding in an area of moderate climate. In addition, we compared three different heat load indices related to CR: mean THI, maximum THI, and number of hours above the mean THI threshold. The THI threshold for the influence of heat stress on CR was 73. It was statistically chosen based on the observed relationship between the mean THI at the day of breeding and the resulting CR. Negative effects of heat stress, however, were already apparent at lower levels of THI, and 1 hour of mean THI of 73 or more decreased the CR significantly. The CR of lactating dairy cows was negatively affected by heat stress both before and after the day of breeding. The greatest negative impact of heat stress on CR was observed 21 to 1 day before breeding. When the mean THI was 73 or more in this period, CR decreased from 31% to 12%. Compared with the average maximum THI and the total number of hours above a threshold of more than or 9 hours, the mean THI was the most sensitive heat load index relating to CR. These results indicate that the CR of dairy cows raised in the moderate climates is highly affected by heat stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Control of disturbing loads in residential and commercial buildings via geometric algebra.

    Science.gov (United States)

    Castilla, Manuel-V

    2013-01-01

    Many definitions have been formulated to represent nonactive power for distorted voltages and currents in electronic and electrical systems. Unfortunately, no single universally suitable representation has been accepted as a prototype for this power component. This paper defines a nonactive power multivector from the most advanced multivectorial power theory based on the geometric algebra (GA). The new concept can have more importance on harmonic loads compensation, identification, and metering, between other applications. Likewise, this paper is concerned with a pioneering method for the compensation of disturbing loads. In this way, we propose a multivectorial relative quality index δ(~) associated with the power multivector. It can be assumed as a new index for power quality evaluation, harmonic sources detection, and power factor improvement in residential and commercial buildings. The proposed method consists of a single-point strategy based of a comparison among different relative quality index multivectors, which may be measured at the different loads on the same metering point. The comparison can give pieces of information with magnitude, direction, and sense on the presence of disturbing loads. A numerical example is used to illustrate the clear capabilities of the suggested approach.

  14. Damage Detection of a Concrete Column Subject to Blast Loads Using Embedded Piezoceramic Transducers.

    Science.gov (United States)

    Xu, Kai; Deng, Qingshan; Cai, Lujun; Ho, Siuchun; Song, Gangbing

    2018-04-28

    Some of the most severe structural loadings come in the form of blast loads, which may be caused by severe accidents or even terrorist activities. Most commonly after exposure to explosive forces, a structure will suffer from different degrees of damage, and even progress towards a state of collapse. Therefore, damage detection of a structure subject to explosive loads is of importance. This paper proposes a new approach to damage detection of a concrete column structure subjected to blast loads using embedded piezoceramic smart aggregates (SAs). Since the sensors are embedded in the structure, the proposed active-sensing based approach is more sensitive to internal or through cracks than surface damage. In the active sensing approach, the embedded SAs act as actuators and sensors, that can respectively generate and detect stress waves. If the stress wave propagates across a crack, the energy of the wave attenuates, and the reduction of the energy compared to the healthy baseline is indicative of a damage. With a damage index matrix constructed by signals obtained from an array of SAs, cracks caused by blast loads can be detected throughout the structure. Conventional sensing methods such as the measurement of dynamic strain and acceleration were included in the experiment. Since columns are critical elements needed to prevent structural collapse, knowledge of their integrity and damage conditions is essential for safety after exposure to blast loads. In this research, a concrete column with embedded SAs was chosen as the specimen, and a series of explosive tests were conducted on the column. Experimental results reveal that surface damages, though appear severe, cause minor changes in the damage index, and through cracks result in significant increase of the damage index, demonstrating the effectiveness of the active sensing, enabled by embedded SAs, in damage monitoring of the column under blast loads, and thus providing a reliable indication of structural

  15. Smart aggregate based damage detection of circular RC columns under cyclic combined loading

    International Nuclear Information System (INIS)

    Moslehy, Yashar; Belarbi, Abdeldjelil; Mo, Y L; Gu, Haichang; Song, Gangbing

    2010-01-01

    Structural health monitoring is an important issue for the maintenance of large-scale civil infrastructures, especially for bridge columns. In this paper, an innovative piezoceramic-based approach is developed for the structural health monitoring of reinforced concrete columns. An innovative piezoceramic-based device, the smart aggregate, is utilized as a transducer for the purpose of health monitoring. To investigate the seismic behavior of reinforced concrete (RC) bridge columns, structural health monitoring tests were performed on two bridge columns under combined reversed cyclic loading at the Missouri University of Science and Technology. The proposed smart aggregate based approach successfully evaluated the health status of concrete columns during the loading procedure. Sensor energy plots and 3D normalized sensor energy plots demonstrated that the damage inside attenuated the transmitted energy. The wavelet packet based damage index and sensor history damage index evaluate the damage development in concrete columns under cyclic loading

  16. Peak load demand forecasting using two-level discrete wavelet decomposition and neural network algorithm

    Science.gov (United States)

    Bunnoon, Pituk; Chalermyanont, Kusumal; Limsakul, Chusak

    2010-02-01

    This paper proposed the discrete transform and neural network algorithms to obtain the monthly peak load demand in mid term load forecasting. The mother wavelet daubechies2 (db2) is employed to decomposed, high pass filter and low pass filter signals from the original signal before using feed forward back propagation neural network to determine the forecasting results. The historical data records in 1997-2007 of Electricity Generating Authority of Thailand (EGAT) is used as reference. In this study, historical information of peak load demand(MW), mean temperature(Tmean), consumer price index (CPI), and industrial index (economic:IDI) are used as feature inputs of the network. The experimental results show that the Mean Absolute Percentage Error (MAPE) is approximately 4.32%. This forecasting results can be used for fuel planning and unit commitment of the power system in the future.

  17. Mechanical characterization of composite repairs for fiberglass wind turbine blades

    Science.gov (United States)

    Chawla, Tanveer Singh

    While in service, wind turbine blades experience various modes of loading. An example is impact loading in the form of hail or bird strikes, which might lead to localized damage or formation of cracks a few plies deep on the blade surface. One of the methods to conduct repairs on wind turbine blades that are damaged while in service is hand lay-up of the repair part after grinding out the damaged portion and some of its surrounding area. The resin used for such repairs usually differs from the parent plate resin in composition and properties such as gel time, viscosity, etc. As a result the properties of the repaired parts are not the same as that of the undamaged blades. Subsequent repetitive loading can be detrimental to weak repairs to such an extent so as to cause delamination at the parent-repair bondline causing the repairs to eventually fall off the blade. Thus the strength and toughness of the repair are of critical importance. Initial part of this work consists of an effort to increase repair strength by identifying an optimum hand layup repair resin for fiberglass wind turbine blades currently being manufactured by a global company. As delamination of the repair from the parent blade is a major concern and unidirectional glass fibers along with a polymer resin are used to manufacture blades under consideration, testing method detailed in ASTM D 5528 (Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites) was followed to determine propagation fracture toughness values of the prospective vinyl ester repair resin candidates. These values were compared to those for a base polyester repair resin used by the company. Experimental procedure and results obtained from the above mentioned testing using double cantilever beam (DCB) specimens are detailed. Three new repair resins were shortlisted through mode I testing. It was also found that variation in the depth of the ground top ply of the parent part

  18. Large Deformation Dynamic Bending of Composite Beams

    Science.gov (United States)

    Derian, E. J.; Hyer, M. W.

    1986-01-01

    Studies were conducted on the large deformation response of composite beams subjected to a dynamic axial load. The beams were loaded with a moderate eccentricity to promote bending. The study was primarily experimental but some finite element results were obtained. Both the deformation and the failure of the beams were of interest. The static response of the beams was also studied to determine potential differences between the static and dynamic failure. Twelve different laminate types were tested. The beams were loaded dynamically with a gravity driven impactor traveling at 19.6 ft/sec and quasi-static tests were conducted on identical beams in a displacement controlled manner. For laminates of practical interest, the failure modes under static and dynamic loadings were identical. Failure in most of the laminate types occurred in a single event involving 40% to 50% of the plies. However, failure in laminates with 30 deg or 15 deg off-axis plies occured in several events. All laminates exhibited bimodular elastic properties. Using empirically determined flexural properties, a finite element analysis was reasonably accurate in predicting the static and dynamic deformation response.

  19. Impact of Electric Vehicle Charging Station Load on Distribution Network

    Directory of Open Access Journals (Sweden)

    Sanchari Deb

    2018-01-01

    Full Text Available Recent concerns about environmental pollution and escalating energy consumption accompanied by the advancements in battery technology have initiated the electrification of the transportation sector. With the universal resurgence of Electric Vehicles (EVs the adverse impact of the EV charging loads on the operating parameters of the power system has been noticed. The detrimental impact of EV charging station loads on the electricity distribution network cannot be neglected. The high charging loads of the fast charging stations results in increased peak load demand, reduced reserve margins, voltage instability, and reliability problems. Further, the penalty paid by the utility for the degrading performance of the power system cannot be neglected. This work aims to investigate the impact of the EV charging station loads on the voltage stability, power losses, reliability indices, as well as economic losses of the distribution network. The entire analysis is performed on the IEEE 33 bus test system representing a standard radial distribution network for six different cases of EV charging station placement. It is observed that the system can withstand placement of fast charging stations at the strong buses up to a certain level, but the placement of fast charging stations at the weak buses of the system hampers the smooth operation of the power system. Further, a strategy for the placement of the EV charging stations on the distribution network is proposed based on a novel Voltage stability, Reliability, and Power loss (VRP index. The results obtained indicate the efficacy of the VRP index.

  20. Biomonitoring along the Tropical Southern Indian Coast with Multiple Biomarkers.

    Directory of Open Access Journals (Sweden)

    Sivanandham Vignesh

    Full Text Available We assessed the spatial and temporal variations of pollution indicators and geochemical and trace metal parameters (23 in total from water and sediment (144 samples of three different eco-niches (beach, fishing harbor, and estuary in larger coastal cities of southern India (Cuddalore and Pondicherry for one year. A total of 120 marine Pseudomonas isolates were challenged against different concentrations of copper solutions and 10 different antibiotics in heavy metal and antibiotic resistance approaches, respectively. The study shows that 4.16% of the isolates could survive in 250 mM of copper; 70% were resistant to minimum concentrations. Strains were resistant (98.4% to at least one antibiotic in Cuddalore compared to the Pondicherry (78.4% region. Pollution index (PI (0-14.55 and antibiotic resistance index (ARI (0.05-0.10 ratio indicated that high bacterial and antibiotic loads were released into the coastal environment. The degree of trace metal contamination in sediments were calculated by enrichment factor (EF, contamination factor (CF, pollution load index (PLI, and geo-accumulation index (Igeo. Statistical parameters like two-way analysis of variance (ANOVA, correlation, factor analysis and scatter matrix tools were employed between the 23 parameters in order to find sources, pathways, disparities and interactions of environmental pollutants. It indicates that geochemical and biological parameters were not strongly associated with each other (except a few and were affected by different sources. Factor analysis elucidated, 'microbe-metal' interaction (Factor 1-48.86%, 'anthropogenic' factor (Factor 2-13.23% and 'Pseudomonas-Cadmium' factor (Factor 3-11.74%, respectively.

  1. Mass burden and estimated flux of heavy metals in Pakistan coast: sedimentary pollution and eco-toxicological concerns.

    Science.gov (United States)

    Ali, Usman; Malik, Riffat Naseem; Syed, Jabir Hussain; Mehmood, Ch Tahir; Sánchez-García, Laura; Khalid, Azeem; Chaudhry, Muhammad Jamshed Iqbal

    2015-03-01

    Heavy-metal contamination in coastal areas poses a serious threat to aquatic life and public health due to their high toxicity and bio-accumulation potential. In the present study, levels of different heavy metals (Cu, Cd, Cr, Ni, Co, Pb, Zn, and Mn), their spatial distribution, geochemical status, and enrichment indices (Cu, Cd, Cr, Ni, Co, Pb, Zn) were investigated in the sediment samples from 18 coastal sites of Pakistan. The analyses of coastal sediments indicated the presence of heavy metals in order such as Cr > Zn > Cu > Pb > Ni > Mn > Co > Cd. Geo-accumulation index (I geo), enrichment factor (EF), and contamination factor (CF) showed diverse range in heavy-metal enrichment site by site. Pollution load index (PLI) has shown that average pollution load along the entire coastal belt was not significant. Based on the mean effect range medium quotient, coastal sediments of Pakistan had 21% probability of toxicity. The estimated sedimentary load of selected heavy metals was recorded in the range of 0.3-44.7 g/cm(2)/year, while the depositional flux was in the range of 0.07-43.5 t/year. Heavy-metal inventories of 9.8 × 10(2)-3.8 × 10(5) t were estimated in the coastal sediments of Pakistan. The enrichment and contamination factors (EF and CF) suggested significant influence of anthropogenic and industrial activities along the coastal belt of Pakistan.

  2. Shading effect on microclimate and thermal comfort indexes in integrated crop-livestock-forest systems in the Brazilian Midwest.

    Science.gov (United States)

    Karvatte, Nivaldo; Klosowski, Elcio Silvério; de Almeida, Roberto Giolo; Mesquita, Eduardo Eustáquio; de Oliveira, Caroline Carvalho; Alves, Fabiana Villa

    2016-12-01

    The objective of this paper was to perform a microclimate evaluation and determine the indexes of thermal comfort indexes, in sun and shade, in integrated crop-livestock-forest systems with different arrangements of eucalyptus and native trees, in the Brazilian Midwest. The experiment was conducted at Embrapa Beef Cattle in Campo Grande, state of Mato Grosso do Sul, Brazil, from July to September 2013. The evaluations were conducted on four consecutive days, from 8:00 a.m. to 5:00 p.m., local time (GMT -4:00), with 1 hour intervals, recording the microclimate parameters: air temperature (°C), black globe temperature (°C), wet bulb temperature (°C), relative humidity (%), and wind speed (m.s -1 ), for the subsequent calculation of the Temperature and Humidity Index, the Black Globe Temperature and Humidity Index, and the Radiant Thermal Load. The largest changes in microclimate parameters were found in the full sun, between 12:00 p.m. and 1:00 p.m., in less dense eucalyptus system, followed by the scattered native trees system, resulting in a maximum Temperature and Humidity Index of 81, Black Globe Temperature and Humidity Index of 88 and Radiant Thermal Load of 794 W m -2 . Therefore, it is observed that with the presence of trees in pastures were possible reductions of up to 3.7 % in Temperature and Humidity Index, 10.2 % in the Black Globe Temperature and Humidity Index, and 28.3 % of the Radiant Thermal Load in the shade. Thus, one can conclude that the presence of trees and their arrangement in the systems provide better microclimate conditions and animal thermal comfort in pastures.

  3. Hydrochemical and isotope study to trace the movement of pollutants from the Akuosu - Sukobri tributary into the Owabi reservoir

    International Nuclear Information System (INIS)

    Frimpong, E.O.

    2011-01-01

    Surface water and sediment samples of the Akuosu - Sukobri tributary were analyzed to asses the movement of heavy metal pollution into the Owabi reservoir. Whilst the Akuosu - Sukobri tributary is acidic, the Owabi reservoir is basic. The concentration of Na, K, Mg, Ca, Cl, SO 4 , As, Mn, Cr, Cu, Zn are all below world normal averages in the water but they exceed these world averages in the sediments. HEI, HPI and C d show that the part of the Akuosu - Sukobri tributary at Suame Magazine, Anomagye Township and Bohyen are polluted whilst pollution is minimal at the part of the tributary in the Owabi Forest Reserve as well as the Owabi reservoir. Sediment pollution assessment was carried out using enrichment factor (EF), geoaccumulation index (I geo ) and pollution load index (PLI). EF shows that the sediments are enriched in the heavy metals. The I geo values revealed that the sediments are significantly accumulated with Pb, Cu and Cr whilst the PLI suggest that the sediments are moderately polluted. An integrated approach of pollution indices, principal component analysis (PCA) and cluster analysis (CA) was employed to evaluate the intensity and sources of pollution in the tributary and the reservoir. This showed that the major ions mainly originated from domestic waste whilst the heavy metals come from the various anthropogenic activities along the tributary especially the Suame Magazine part of the Akuosu - Sukobri tributary. Isotope analysis of the water showed that the water is mainly of meteoric origin with very little enrichment probably due to evaporation and mixing along the way before the Akuoso-Sukobri tributary joins the Owabi reservoir. (au)

  4. Seaweeds as bioindicators of heavy metals off a hot spot area on the Egyptian Mediterranean Coast during 2008-2010.

    Science.gov (United States)

    Shams El-Din, N G; Mohamedein, L I; El-Moselhy, Kh M

    2014-09-01

    Concentrations of Cu, Zn, Cd, Pb, Ni, Co, Fe, Mn, and Hg were measured successively in water, sediments, and six macroalgal species belonging to three algal classes during 3 years (2008-2010) from Abu Qir Bay, Alexandria, Egypt: Chlorophyceae (Enteromorpha compressa, Ulva fasciata), Phaeophyceae (Padina boryana), and Rhodophyceae (Jania rubens, Hypnea musciformis, Pterocladia capillacea). The study aimed to assess the bioaccumulation potential of the seaweeds, as well as to evaluate the extent of heavy metal contamination in the selected study site. Metals were analyzed using atomic absorption spectrophotometry coupled with MH-10 hydride system. The obtained data showed that the highest mean concentrations of Cu, Zn, Fe, and Mn were recorded in E. compressa; Cd, Ni, and Hg exhibited their highest mean concentrations in P. boryana, while Pb and Co were found in J. rubens. Abundance of the heavy metals in the algal species was as follow: Fe > Mn > Zn > Pb > Ni > Co > Cu > Cd > Hg. E. compressa showed the maximum metal pollution index (MPI) which was 11.55. Bioconcentration factor (BCF) for the metals in algae was relatively high with a maximum value for Mn. The Tomlinson pollution load index (PLI) values for the recorded algal species were low, which ranged between 1.00 in P. boryana and 2.72 in E. compressa. Enrichment factors for sediments were low fluctuating between 0.43 for Hg to 2.33 for Mn. Accordingly, the green alga E. compressa, brown alga P. boryana, and red alga J. rubens can be nominated as bioindicators. Based on MPI and PLI indices, Abu Qir Bay in the present study is considered as low-contaminated area.

  5. 3D imaging of damage in biaxially loaded composites at cryogenic temperatures using a novel micro-CT experiment

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to provide an unprecedented insight into ply-level initiation and evolution of damage in composite materials subjected to extreme...

  6. Estimation of the strength of Nubian sandstone formation from point load test index and other simple parameters

    Directory of Open Access Journals (Sweden)

    Zein Abdul Karim M.

    2018-01-01

    Full Text Available This study investigates the correlation of the uniaxial compressive strength (UCS and the point load test (PLT index Is(50, bulk density, water absorption and the RQD properties of the Sudanese Nubian sandstone formation. The UCS being is the rock property needed in engineering practice but its determination is tedious, time consuming and expensive. Alternatively, the UCS may be indirectly evaluated through establishing relationships with rock parameters which are easier, cheaper and more convenient to determine in the laboratory or in the field. An extensive laboratory testing was executed to determine the above rock properties for many NSF samples taken from Khartoum State and other areas. Statistical analysis was performed on the test data and a reliable linear regression equation has been developed with a UCS to PLT Is(50 conversion factor of 10.18 and may be applied to estimate the strength of the Sudanese sandstone formation. The developed correlation is in good agreement with few of the many methods published for similar rock types which indicates that large errors may result in from applying an inappropriate UCS prediction method. Thus, it is important to establish separate correlations or validate published correlations to check their suitability for a specific rock types and local geologies. Useful correlation relationships of reasonable accuracy were also established for rough estimation of the UCS from the bulk density, water absorption and the RQD properties of the Nubian sandstone formation.

  7. Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory

    Science.gov (United States)

    Meier, Beat; Zimmermann, Thomas D.

    2015-01-01

    In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially. PMID:26082709

  8. Loads and loads and loads: the influence of prospective load, retrospective load, and ongoing task load in prospective memory.

    Science.gov (United States)

    Meier, Beat; Zimmermann, Thomas D

    2015-01-01

    In prospective memory tasks different kinds of load can occur. Adding a prospective memory task can impose a load on ongoing task performance. Adding ongoing task load (OTL) can affect prospective memory performance. The existence of multiple target events increases prospective load (PL) and adding complexity to the to-be-remembered action increases retrospective load (RL). In two experiments, we systematically examined the effects of these different types of load on prospective memory performance. Results showed an effect of PL on costs in the ongoing task for categorical targets (Experiment 2), but not for specific targets (Experiment 1). RL and OTL both affected remembering the retrospective component of the prospective memory task. We suggest that PL can enhance costs in the ongoing task due to additional monitoring requirements. RL and OTL seem to impact the division of resources between the ongoing task and retrieval of the retrospective component, which may affect disengagement from the ongoing task. In general, the results demonstrate that the different types of load affect prospective memory differentially.

  9. Heavy metals in industrially emitted particulate matter in Ile-Ife, Nigeria.

    Science.gov (United States)

    Ogundele, Lasun T; Owoade, Oyediran K; Hopke, Philip K; Olise, Felix S

    2017-07-01

    Iron and steel smelting facilities generate large quantities of airborne particulate matter (PM) through their various activities and production processes. The resulting PM that contains a variety of heavy metals has potentially detrimental impacts on human health and the environment. This study was conducted to assess the potential health effects of the pollution from the heavy metals in the airborne PM sampled in the vicinity of secondary smelting operations in Ile-Ife, Nigeria. X-ray fluorescence (XRF) was used to determine the elemental concentration of Pb, Cr, Cd, Zn, Mn, As, Fe, Cu, and Ni in the size-segregated PM samples. Pollution Indices (PI) consisting of Contamination Factor (CF), Degree of Contamination (DC) and Pollution Index Load (PLI) and Target Hazard Quotient (THQ) were employed to assess the pollution risk associated with the heavy metals in the PM. CF, DC and PLI values were 332 and >1, respectively for the three sites, indicating deterioration of the ambient air quality in the vicinity of the smelter. The heavy metals in the airborne PM pose a severe health risk to people living in vicinity of the facility and to its workers. The diminished air quality with the associated health risks directly depends on the industrial emissions from steel production and control measures are recommended to mitigate the likely risks. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Design and Performance Evaluation Study of a Prototype of a Tactical Unmanned Aerial Vehicle

    Science.gov (United States)

    2007-12-01

    balsa wood and the winglets were made of 1/32” aircraft ply. 3. Components and Loading The prototype was first tested for its aerodynamic ...14 IV. AERODYNAMICS STUDIES..................................................................................17 A. BASIC... AERODYNAMICS FOR GLIDERS ..............................................17 B. SIMULATION USING ANALYTICAL TECHNIQUES ..........................18 1

  11. Automatic Control of Reactor Temperature and Power Distribution for a Daily Load following Operation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Keuk Jong; Kim, Han Gon [Korea Hydro and Nuclear Power Institute, Daejeon (Korea, Republic of)

    2010-10-15

    An automatic control method of reactor power and power distribution was developed for a daily load following operation of APR1400. This method used a model predictive control (MPC) methodology having second-order plant data. And it utilized a reactor power ratio and axial shape index as control variables. However, the reactor regulating system of APR1400 is operated by the difference between the average temperature of the reactor core and the reference temperature, which is proportional to the turbine load. Thus, this paper reports on the model predictive control methodology using fourth-order plant data and a reactor temperature instead of the reactor power shape. The purpose of this study is to develop a revised automatic controller and analyze the behavior of the nuclear reactor temperature (Tavg) and the axial shape index (ASI) using the MPC method during a daily load following operation

  12. Short-term Probabilistic Load Forecasting with the Consideration of Human Body Amenity

    Directory of Open Access Journals (Sweden)

    Ning Lu

    2013-02-01

    Full Text Available Load forecasting is the basis of power system planning and design. It is important for the economic operation and reliability assurance of power system. However, the results of load forecasting given by most existing methods are deterministic. This study aims at probabilistic load forecasting. First, the support vector machine regression is used to acquire the deterministic results of load forecasting with the consideration of human body amenity. Then the probabilistic load forecasting at a certain confidence level is given after the analysis of error distribution law corresponding to certain heat index interval. The final simulation shows that this probabilistic forecasting method is easy to implement and can provide more information than the deterministic forecasting results, and thus is helpful for decision-makers to make reasonable decisions.

  13. Cytokine-producing microglia have an altered beta-amyloid load in aged APP/PS1 Tg mice

    DEFF Research Database (Denmark)

    Babcock, Alicia A; Ilkjær, Laura; Clausen, Bettina H

    2015-01-01

    of CD11b, TNF, and IL-1Ra. Cytokine production and Aβ load were assessed in neocortical CD11b(+)(CD45(+)) microglia by flow cytometry. Whereas most microglia in aged mice produced IL-1Ra, relatively low proportions of microglia produced TNF, IL-1α, and IL-1β. However, microglial production......, however the inter-relationship between these processes is poorly understood. Here we show that % Aβ plaque load followed a sigmoidal trajectory with age in the neocortex of APPswe/PS1ΔE9 Tg mice, and correlated positively with soluble Aβ40 and Aβ42. Aβ measures were moderately correlated with mRNA levels...... of these latter cytokines was generally increased in APP/PS1 Tg mice. Microglia that phagocytosed endogenously-produced Aβ were only observed in APP/PS1 Tg mice. Differences in phagocytic index and total Aβ load were observed in microglia with specific cytokine profiles. Both phagocytic index and total Aβ load...

  14. Dual drug-loaded paclitaxel–thymoquinone nanoparticles for effective breast cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Soni, Parth; Kaur, Jasmine; Tikoo, Kulbhushan, E-mail: tikoo.k@gmail.com [National Institute of Pharmaceutical Education and Research (NIPER), Laboratory of Epigenetics and Diseases, Department of Pharmacology and Toxicology (India)

    2015-01-15

    The present study highlights the beneficial synergistic blend of anticancer drug paclitaxel (PTX) and thymoquinone (TQ) in MCF-7 breast cancer cells. We aimed to augment the therapeutic index of PTX using a polymeric nanoparticle system loaded with PTX and TQ. PLGA nanoparticles encapsulating the two drugs, individually or in combination, were prepared by single emulsion solvent evaporation method. The formulated nanoparticles were homogenous with an overall negative charge and their size ranging between 200 and 300 nm. Entrapment efficiency of PTX and TQ in the dual drug-loaded nanoparticles was found to be 82.4 ± 2.18 and 65.8 ± 0.45 %, respectively. The release kinetics of PTX and TQ from the nanoparticles exhibited a biphasic pattern characterised by an initial burst, followed by a gradual and continuous release. The anticancer activity of nanoparticles encapsulating both the drugs was higher as compared to the free drugs in MCF-7 breast cancer cells. The combination index for the dual drug-loaded NPs was found to be 0.688 which is indicative of synergistic interaction. Thus, here, we propose the synthesis and use of dual drug-loaded TQ and PTX NPs which exhibits enhanced anticancer activity and can additionally help to alleviate the toxic effects of PTX by lowering its effective dose.

  15. Dual drug-loaded paclitaxel–thymoquinone nanoparticles for effective breast cancer therapy

    International Nuclear Information System (INIS)

    Soni, Parth; Kaur, Jasmine; Tikoo, Kulbhushan

    2015-01-01

    The present study highlights the beneficial synergistic blend of anticancer drug paclitaxel (PTX) and thymoquinone (TQ) in MCF-7 breast cancer cells. We aimed to augment the therapeutic index of PTX using a polymeric nanoparticle system loaded with PTX and TQ. PLGA nanoparticles encapsulating the two drugs, individually or in combination, were prepared by single emulsion solvent evaporation method. The formulated nanoparticles were homogenous with an overall negative charge and their size ranging between 200 and 300 nm. Entrapment efficiency of PTX and TQ in the dual drug-loaded nanoparticles was found to be 82.4 ± 2.18 and 65.8 ± 0.45 %, respectively. The release kinetics of PTX and TQ from the nanoparticles exhibited a biphasic pattern characterised by an initial burst, followed by a gradual and continuous release. The anticancer activity of nanoparticles encapsulating both the drugs was higher as compared to the free drugs in MCF-7 breast cancer cells. The combination index for the dual drug-loaded NPs was found to be 0.688 which is indicative of synergistic interaction. Thus, here, we propose the synthesis and use of dual drug-loaded TQ and PTX NPs which exhibits enhanced anticancer activity and can additionally help to alleviate the toxic effects of PTX by lowering its effective dose

  16. Application of Classification Methods for Forecasting Mid-Term Power Load Patterns

    Science.gov (United States)

    Piao, Minghao; Lee, Heon Gyu; Park, Jin Hyoung; Ryu, Keun Ho

    Currently an automated methodology based on data mining techniques is presented for the prediction of customer load patterns in long duration load profiles. The proposed approach in this paper consists of three stages: (i) data preprocessing: noise or outlier is removed and the continuous attribute-valued features are transformed to discrete values, (ii) cluster analysis: k-means clustering is used to create load pattern classes and the representative load profiles for each class and (iii) classification: we evaluated several supervised learning methods in order to select a suitable prediction method. According to the proposed methodology, power load measured from AMR (automatic meter reading) system, as well as customer indexes, were used as inputs for clustering. The output of clustering was the classification of representative load profiles (or classes). In order to evaluate the result of forecasting load patterns, the several classification methods were applied on a set of high voltage customers of the Korea power system and derived class labels from clustering and other features are used as input to produce classifiers. Lastly, the result of our experiments was presented.

  17. Effect of Obesity on Arch Index in Young Adults

    Directory of Open Access Journals (Sweden)

    Sneha Sameer Ganu

    2013-01-01

    Full Text Available Background: Excessive increases in weight bearing forces caused by obesity may negatively affect the lower limbs and feet but minimal research has examined the long-term loading effects of obesity on the musculoskeletal system, particularly in reference to the feet. Objectives: The purpose of the study was to investigate the effect of obesity on medial longitudinal arch of foot in young adults. Method: 60 subjects, 30 obese & 30 non obese were assessed for height & weight using standard technique. Radiographic images under static condition were used for calculating the arch index. Result: The arch index of obese subjects was significantly lower than the non obese subjects & there is a negative correlation between the BMI & the arch index. Conclusion: These results suggests that obesity lowers the medial longitudinal arch of foot.

  18. A two-dimensional uniplanar transmission-line metamaterial with a negative index of refraction

    International Nuclear Information System (INIS)

    Elek, Francis; Eleftheriades, George V

    2005-01-01

    A uniplanar transmission-line (TL) network has been loaded with lumped elements (chip or printed), enabling one to achieve a two-dimensional (2D) uniplanar negative-refractive-index (NRI) metamaterial. The metamaterial consists of a 2D array of unit cells, composed of TL sections connected in series and loaded in a specified manner. The unit cell dimensions can be designed to be much smaller than the operating wavelength, enabling one to identify the structure as an effective medium, with a negative index of refraction. This NRI metamaterial supports transverse electric (TE) waves, as opposed to related previous work on NRI-TL media that supported transverse magnetic (TM) waves. The dispersion characteristics are calculated using a simple, fast 2D loaded TL model with periodic (Bloch) boundary conditions. Subsequently the dispersion relation is simplified in the homogeneous limit, thus allowing one to identify effective permittivities and permeabilities, which are shown to be simultaneously negative. Simulations demonstrating the negative refraction of a plane wave on an interface between such a NRI uniplanar metamaterial and a commensurate positive-refractive-index (PRI) metamaterial verify the validity of the proposed concept and theory. A fully printed unit cell is presented at microwave frequencies (∼10 GHz) along with a prescription for synthesizing an isotropic 3D transmission line NRI metamaterial based on this unit cell

  19. Immunomodulatory effect of ganoderma lucidum polysaccharides (GLP) on long-term heavy-load exercising mice.

    Science.gov (United States)

    Shi, Yali; Cai, Dehua; Wang, Xiaojie; Liu, Xinshen

    2012-12-01

    Long-term heavy-load exercise can lead to a decrease in the organism's immune response. In this study, we used 100 Kunming (KM) mice to investigate the immune-regulatory effects of Ganoderma lucidum polysaccharides (GLP) on long-term heavy-load exercising mice. Peripheral white blood cells (WBC), the absolute value of neutrophils (NEUT), the phagocytic function of macrophages, serum agglutination valence, and the number of plaque-forming cells (PFC) were evaluated 4 weeks after gavaging long-term heavy-load exercising mice with GLP. After exercise, the WBC count in peripheral blood, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells were significantly reduced in the mice not fed GLP. Both medium and high doses of GLP drastically increased peripheral WBC, absolute neutrophil count, macrophage phagocytic index, serum agglutination valence, and the number of plaque-forming cells in long-term heavy-load exercising mice. High doses of GLP increased peritoneal macrophage phagocytic rate considerably. With this study, we demonstrate that 4 weeks of heavy-load exercise can lead to exercise-induced immunosuppression in mice. A supplement of GLP fed to these mice improves both non-specific and specific immune responses among these mice. The effect for the high-dose GLP treatment is especially significant.

  20. Adding glycaemic index and glycaemic load functionality to DietPLUS, a Malaysian food composition database and diet intake calculator.

    Science.gov (United States)

    Shyam, Sangeetha; Wai, Tony Ng Kock; Arshad, Fatimah

    2012-01-01

    This paper outlines the methodology to add glycaemic index (GI) and glycaemic load (GL) functionality to food DietPLUS, a Microsoft Excel-based Malaysian food composition database and diet intake calculator. Locally determined GI values and published international GI databases were used as the source of GI values. Previously published methodology for GI value assignment was modified to add GI and GL calculators to the database. Two popular local low GI foods were added to the DietPLUS database, bringing up the total number of foods in the database to 838 foods. Overall, in relation to the 539 major carbohydrate foods in the Malaysian Food Composition Database, 243 (45%) food items had local Malaysian values or were directly matched to International GI database and another 180 (33%) of the foods were linked to closely-related foods in the GI databases used. The mean ± SD dietary GI and GL of the dietary intake of 63 women with previous gestational diabetes mellitus, calculated using DietPLUS version3 were, 62 ± 6 and 142 ± 45, respectively. These values were comparable to those reported from other local studies. DietPLUS version3, a simple Microsoft Excel-based programme aids calculation of diet GI and GL for Malaysian diets based on food records.

  1. Perceptual load manipulation reveals sensitivity of the face-selective N170 to attention.

    Science.gov (United States)

    Mohamed, Tarik N; Neumann, Markus F; Schweinberger, Stefan R

    2009-05-27

    It has been controversial whether the face-sensitive N170 is affected by selective attention. We manipulated attention sensu Lavie's perceptual load theory to short (200 ms) presentations of task-irrelevant unfamiliar faces or houses, while participants identified superimposed target letters 'X' versus 'N'. These targets were strings of either six identical (low load) or six different letters (high load). Under low load, we found a prominent face-selective N170 response. Under high load, however, we not only observed a dramatic reduction of the face N170 but also an unexpected enhancement of the house N170, such that face selectivity was almost completely lost. We conclude that the early stages of face processing indexed by the N170 strongly depend on selective attention.

  2. The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth.

    Science.gov (United States)

    Dula, Linda J; Shala, Kujtim Sh; Pustina-Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F

    2015-01-01

    The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probing depth (PD) (mm) and tooth mobility (TM) index. These clinical measurements were taken immediately before insertion the RPD, then one and 3 months after insertion. The level of significance was set at (P abutment teeth and non-abutment teeth were no statistically significant at the time of insertion of RPD. After 1-month, PLI was statistically significant (0.57 ± 0.55 for abutment and 0.30 ± 0.46 for non-abutment teeth). After 3 months, there were significant differences between abutment and non-abutment teeth with regard to the BOP (1.53 ± 0.50 and 1.76 ± 0.43 respectively), PD (0.28 ± 0.45 and 0.12 ± 0.33 respectively) and PLI (1.20 ± 0.46 and 0.75 ± 0.64 respectively). No significant mean difference in TM and CI was found between the abutment and non-abutment teeth (P > 0.05). With carefully planned prosthetic treatment and adequate maintenance of the oral and denture hygiene, we can prevent the periodontal diseases.

  3. Optimal Dispatching of Active Distribution Networks Based on Load Equilibrium

    Directory of Open Access Journals (Sweden)

    Xiao Han

    2017-12-01

    Full Text Available This paper focuses on the optimal intraday scheduling of a distribution system that includes renewable energy (RE generation, energy storage systems (ESSs, and thermostatically controlled loads (TCLs. This system also provides time-of-use pricing to customers. Unlike previous studies, this study attempts to examine how to optimize the allocation of electric energy and to improve the equilibrium of the load curve. Accordingly, we propose a concept of load equilibrium entropy to quantify the overall equilibrium of the load curve and reflect the allocation optimization of electric energy. Based on this entropy, we built a novel multi-objective optimal dispatching model to minimize the operational cost and maximize the load curve equilibrium. To aggregate TCLs into the optimization objective, we introduced the concept of a virtual power plant (VPP and proposed a calculation method for VPP operating characteristics based on the equivalent thermal parameter model and the state-queue control method. The Particle Swarm Optimization algorithm was employed to solve the optimization problems. The simulation results illustrated that the proposed dispatching model can achieve cost reductions of system operations, peak load curtailment, and efficiency improvements, and also verified that the load equilibrium entropy can be used as a novel index of load characteristics.

  4. Evaluation of construct and criterion validity for the 'Liverpool Osteoarthritis in Dogs' (LOAD clinical metrology instrument and comparison to two other instruments.

    Directory of Open Access Journals (Sweden)

    Myles Benjamin Walton

    Full Text Available To test the 'Liverpool Osteoarthritis in Dogs' (LOAD questionnaire for construct and criterion validity, and to similarly test the Helsinki Chronic Pain Index (HCPI and the Canine Brief Pain Inventory (CBPI.Prospective Study.222 dogs with osteoarthritis.Osteoarthritis was diagnosed in a cohort of dogs on the basis of clinical history and orthopedic examination. Force-platform analysis was performed and a "symmetry index" for peak vertical force (PVF was calculated. Owners completed LOAD, CBPI and HCPI instruments. As a test of construct validity, inter-instrument correlations were calculated. As a test of criterion validity, the correlations between instrument scores and PVF symmetry scores were calculated. Additionally, internal consistency of all instruments was calculated and compared to those previously reported. Factor analysis is reported for the first time for LOAD, and is compared to that previously reported for CBPI and HCPI.Significant moderate correlations were found between all instruments, implying construct validity for all instruments. Significant weak correlations were found between LOAD scores and PVF symmetry index, and between CBPI scores and PVF symmetry index.LOAD is an owner-completed clinical metrology instrument that can be recommended for the measurement of canine osteoarthritis. It is convenient to use, validated and, as demonstrated here for the first time, has a correlation with force-platform data.

  5. Identifying the optimal resistive load for complex training in male rugby players.

    Science.gov (United States)

    Comyns, Thomas M; Harrison, Andrew J; Hennessy, Liam; Jensen, Randall L

    2007-01-01

    Alternating a resistance exercise with a plyometric exercise is referred to as "complex training". In this study, we examined the effect of various resistive loads on the biomechanics of performance of a fast stretch-shortening cycle activity to determine if an optimal resistive load exists for complex training. Twelve elite rugby players performed three drop jumps before and after three back squat resistive loads of 65%, 80%, and 93% of a single repetition maximum (1-RM) load. All drop jumps were performed on a specially constructed sledge and force platform apparatus. Flight time, ground contact time, peak ground reaction force, reactive strength index, and leg stiffness were the dependent variables. Repeated-measures analysis of variance found that all resistive loads reduced (P benefit performance. However, it is unknown if these acute changes will produce any long-term adaptations to muscle function.

  6. Effect of benign familial neutropenia on the periodontium of Yemenite Jews.

    Science.gov (United States)

    Stabholz, A; Soskolne, V; Machtei, E; Or, R; Soskolne, W A

    1990-01-01

    The purpose of this study was to compare the periodontal status of Yemenite Jews with and without benign familial neutropenia (BFN). Thirty-four volunteers were examined at baseline and after 3 years. Plaque index (PlI), bleeding index (BI) probing depth (PD), and attachment levels (AL) were recorded. Differential blood counts were done on at least three occasions during the study. Volunteers with at least one count of less than 2000 neutrophils were considered neutropenic. The majority of patients received oral hygiene instructions and scaling at the initial visit. During the study there was a significant drop in PlI (P less than 0.01) and BI (P less than 0.05). At baseline the BFN and non-BFN volunteers had similar PlI, but the BI was significantly greater in the BFN group. At follow-up, there was a significantly greater number of teeth with pockets greater than or equal to 6 mm in the BFN group (P less than 0.05). These results indicate that volunteers with BFN, a phenomenon that has not previously been associated with any pathology, are more susceptible to gingival inflammation and attachment loss than unaffected volunteers and that they respond more favorably to an improvement in oral hygiene.

  7. Field Test of Driven Pile Group under Lateral Loading

    Science.gov (United States)

    Gorska, Karolina; Rybak, Jaroslaw; Wyjadlowski, Marek

    2017-12-01

    All the geotechnical works need to be tested because the diversity of soil parameters is much higher than in other fields of construction. Horizontal load tests are necessary to determine the lateral capacity of driven piles subject to lateral load. Various load tests were carried out altogether on the test field in Kutno (Poland). While selecting the piles for load tests, different load combinations were taken into account. The piles with diverse length were chosen, on the basis of the previous tests of their length and integrity. The subsoil around the piles consisted of mineral soils: clays and medium compacted sands with the density index ID>0.50. The pile heads were free. The points of support of the “base” to which the dial gauges (displacement sensors) were fastened were located at the distance of 0.7 m from the side surface of the pile loaded laterally. In order to assure the independence of measurement, additional control (verifying) geodetic survey of the displacement of the piles subject to the load tests was carried out (by means of the alignment method). The trial load was imposed in stages by means of a hydraulic jack. The oil pressure in the actuator was corrected by means of a manual pump in order to ensure the constant value of the load in the on-going process of the displacement of the pile under test. On the basis of the obtained results it is possible to verify the numerical simulations of the behaviour of piles loaded by a lateral force.

  8. Evaluation of complex lifting index in Ahvaz Soft Drink Industries using equation of NIOSH

    Directory of Open Access Journals (Sweden)

    M Amozadeh

    2005-10-01

    Full Text Available Background and Aim: Most of normal activities and jobs requires handling of load with the helpof hands and body which is called as "Manual Materials Handling". Manual handling whether forlong of short time causes problems as tear, break, tension in cardiovascular system as increase ofheart pulse and blood hypertension, muscles tire and muscles-bones disorders specially for spinalcords and finally to the back. For instance a report from Britain proved that 61% accidents causingpremature retirement (12.5% of total accidents was about back injury for which 74% was due tolifting and handling.Method: In this research complex lifting index is evaluated in Ahwaz soft drink industries throughequation of National Institute for Occupational Safety and Health (NIOSH 1994 of Units State ofAmerica. Section for handling empty soft drink boxes toward washing area was selected asworking station for this research. Boxes are piled up for 5 pieces and the worker must put them onthe conveyance belt one by one. Since there is complex manual handling system in this stationthus lifting index after determination of NIOSH equation parameters is calculated in the form ofcomplex and then interpreted on the basis of advice of NIOSH.Results:First stage is for determination of (FIRWL and Frequency Independent Lifting Index.The results proved that FIRWL for every box of soft drinks is higher than weight of the land(FIRWL>1 and the rate of Frequency Independent Lifting Index for every floor is less than 1(FILI 1. Lifting index for every floor of soft drink boxes except fifth floor is less than 1.(STLI1to3 1. This proves physical stressof worker in fifth floor. Third stage is for determination of Complex Lifting Index (CLI. Indeedthis index shows cumulative effects of lifting resulted from 5 floors of soft drink boxes. Based onobtained results this index is 2.68. (CLI 2.68 which proves physical stress among the workersduring handling soft drink boxes.Conclusion: In this

  9. Extravascular Lung Water Does Not Increase in Hypovolemic Patients after a Fluid-Loading Protocol Guided by the Stroke Volume Variation

    Directory of Open Access Journals (Sweden)

    Carlos Ferrando

    2012-01-01

    Full Text Available Introduction. Circulatory failure secondary to hypovolemia is a common situation in critical care patients. Volume replacement is the first option for the treatment of hypovolemia. A possible complication of volume loading is pulmonary edema, quantified at the bedside by the measurement of extravascular lung water index (ELWI. ELWI predicts progression to acute lung injury (ALI in patients with risk factors for developing it. The aim of this study was to assess whether fluid loading guided by the stroke volume variation (SVV, in patients presumed to be hypovolemic, increased ELWI or not. Methods. Prospective study of 17 consecutive postoperative, fully mechanically ventilated patients diagnosed with circulatory failure secondary to presumed hypovolemia were included. Cardiac index (CI, ELWI, SVV, and global end-diastolic volume index (GEDI were determined using the transpulmonary thermodilution technique during the first 12 hours after fluid loading. Volume replacement was done with a strict hemodynamic protocol. Results. Fluid loading produced a significant increase in CI and a decrease in SVV. ELWI did not increase. No correlation was found between the amount of fluids administered and the change in ELWI. Conclusion. Fluid loading guided by SVV in hypovolemic and fully mechanically ventilated patients in sinus rhythm does not increase ELWI.

  10. The effect of grain size and cement content on index properties of weakly solidified artificial sandstones

    Science.gov (United States)

    Atapour, Hadi; Mortazavi, Ali

    2018-04-01

    The effects of textural characteristics, especially grain size, on index properties of weakly solidified artificial sandstones are studied. For this purpose, a relatively large number of laboratory tests were carried out on artificial sandstones that were produced in the laboratory. The prepared samples represent fifteen sandstone types consisting of five different median grain sizes and three different cement contents. Indices rock properties including effective porosity, bulk density, point load strength index, and Schmidt hammer values (SHVs) were determined. Experimental results showed that the grain size has significant effects on index properties of weakly solidified sandstones. The porosity of samples is inversely related to the grain size and decreases linearly as grain size increases. While a direct relationship was observed between grain size and dry bulk density, as bulk density increased with increasing median grain size. Furthermore, it was observed that the point load strength index and SHV of samples increased as a result of grain size increase. These observations are indirectly related to the porosity decrease as a function of median grain size.

  11. Preparation and Optimization OF Palm-Based Lipid Nanoparticles Loaded with Griseofulvin.

    Science.gov (United States)

    Huei Lim, Wen; Jean Tan, Yann; Sin Lee, Choy; Meng Er, Hui; Fung Wong, Shew

    2017-01-01

    Palm-based lipid nanoparticle formulation loaded with griseofulvin was prepared by solvent-free hot homogenization method. The griseofulvin loaded lipid nanoparticles were prepared via stages of optimisation, by altering the high pressure homogenisation (HPH) parameters, screening on palm-based lipids and Tween series surfactants and selection of lipid to surfactant ratios. A HPLC method has been validated for the drug loading capacity study. The optimum HPH parameter was determined to be 1500 bar with 5 cycles and among the palm-based lipid materials; Lipid C (triglycerides) was selected for the preparation of lipid nanoparticles. Tween 80 was chosen from the Tween series surfactants for its highest saturated solubility of griseofulvin at 53.1 ± 2.16 µg/mL. The optimum formulation of the griseofulvin loaded lipid nanoparticles demonstrated nano-range of particle size (179.8 nm) with intermediate distribution index (PDI) of 0.306, zeta potential of -27.9 mV and drug loading of 0.77%. The formulation was stable upon storage for 1 month at room temperature (25 ° C) and 45 ° C with consistent drug loading capacity.

  12. Automatic Power Control for Daily Load-following Operation using Model Predictive Control Method

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Keuk Jong; Kim, Han Gon [KH, Daejeon (Korea, Republic of)

    2009-10-15

    Under the circumstances that nuclear power occupies more than 50%, nuclear power plants are required to be operated on load-following operation in order to make the effective management of electric grid system and enhanced responsiveness to rapid changes in power demand. Conventional reactors such as the OPR1000 and APR1400 have a regulating system that controls the average temperature of the reactor core relation to the reference temperature. This conventional method has the advantages of proven technology and ease of implementation. However, this method is unsuitable for controlling the axial power shape, particularly the load following operation. Accordingly, this paper reports on the development of a model predictive control method which is able to control the reactor power and the axial shape index. The purpose of this study is to analyze the behavior of nuclear reactor power and the axial power shape by using a model predictive control method when the power is increased and decreased for a daily load following operation. The study confirms that deviations in the axial shape index (ASI) are within the operating limit.

  13. High cycle fatigue of austenitic stainless steels under random loading

    International Nuclear Information System (INIS)

    Gauthier, J.P.; Petrequin, P.

    1987-08-01

    To investigate reactor components, load control random fatigue tests were performed at 300 0 C and 550 0 C, on specimens from austenitic stainless steels plates in the transverse orientation. Random solicitations are produced on closed loop servo-hydraulic machines by a mini computer which generates random load sequence by the use of reduced Markovian matrix. The method has the advantage of taking into account the mean load for each cycle. The solicitations generated are those of a stationary gaussian process. Fatigue tests have been mainly performed in the endurance region of fatigue curve, with scattering determination using stair case method. Experimental results have been analysed aiming at determining design curves for components calculations, depending on irregularity factor and temperature. Analysis in term of mean square root fatigue limit calculation, shows that random loading gives more damage than constant amplitude loading. Damage calculations following Miner rule have been made using the probability density function for the case where the irregularity factor is nearest to 100 %. The Miner rule is too conservative for our results. A method using design curves including random loading effects with irregularity factor as an indexing parameter is proposed

  14. Fourier Transform Infrared Spectroscopy Analysis Of Oil Of Menthaarvensis Grown At Sites Varying With Vehicular Traffic Loads In Lucknow City, India

    Directory of Open Access Journals (Sweden)

    Nidhi Prakash

    2013-12-01

    Full Text Available The demand of the essential oil of mint species; widely used in food, pharmaceutical and cosmetic industries, is growing throughout the world. Owing its significance, it was felt important to know the changes in chemical characteristics of the oil, if any, for economic value when the crop of Mentha is grown near highways, railway tracks or areas having heavy traffic loads. To assess the effect of vehicular emissions on menthol (mint oil, transfer experiment study was conducted. Firstly, within the municipal premises of Lucknow city, five sites (Road stretches were identified based on survey of Lucknow city and the available data on air pollution loads. Sites were selected which were differing from each other significantly in terms of the number of vehicles (source of pollution plying on them but were quite similar to each other in other eco-physiological factors. On the select sites equal number of potted Menthaarvensis plants of the same age, height and vigour of saccham variety obtained from CSIR-CIMAP was kept to get exposed to auto-exhaust pollutants for one year. Irrigation regime at all sites was kept uniform to avoid the influence of any other variable other than vehicular emissions. An analysis of hydro-distillated essential oil of Menthaarvensis variety Sascham under FTIR (Fourier Transform Infrared Spectroscopy revealed some qualitative changes in the organic-compounds of the oil from plants grown at sites of Lucknow city loaded with high vehicular load (auto-exhaust pollutants over plants kept under relatively pollution free site. Several indicator bands that are pertained to functional groups represent chemical components or metabolic products. The quantity of the peppermint oil extracted from plants of site having highest traffic loads, in turn maximum ambient pollutants (NO2, SO2, O3, SPM & RSPM was also found less as compared to plants grown in less polluted site. International Journal of Environment, Volume-2, Issue-1, Sep

  15. The use of point load test for Dubai weak calcareous sandstones

    Directory of Open Access Journals (Sweden)

    Amr Farouk Elhakim

    2015-08-01

    Full Text Available Intact rock is typically described according to its uniaxial compressive strength (UCS. The UCS is needed in the design of geotechnical engineering problems including stability of rock slopes and design of shallow and deep foundations resting on and/or in rocks. Accordingly, a correct measurement/evaluation of the UCS is essential to a safe and economic design. Typically, the UCS is measured using the unconfined compression tests performed on cylindrical intact specimens with a minimum length to width ratio of 2. In several cases, especially for weak and very weak rocks, it is not possible to extract intact specimens with the needed minimum dimensions. Thus, alternative tests (e.g. point load test, Schmidt hammer are used to measure rock strength. The UCS is computed based on the results of these tests through empirical correlations. The literature includes a plethora of these correlations that vary widely in estimating rock strength. Thus, it is paramount to validate these correlations to check their suitability for estimating rock strength for a specific location and geology. A review of the available correlations used to estimate the UCS from the point load test results is performed and summarized herein. Results of UCS, point load strength index and Young's modulus are gathered for calcareous sandstone specimens extracted from the Dubai area. A correlation for estimating the UCS from the point load strength index is proposed. Furthermore, the Young's modulus is correlated to the UCS.

  16. Visualization index for image-enabled medical records

    Science.gov (United States)

    Dong, Wenjie; Zheng, Weilin; Sun, Jianyong; Zhang, Jianguo

    2011-03-01

    With the widely use of healthcare information technology in hospitals, the patients' medical records are more and more complex. To transform the text- or image-based medical information into easily understandable and acceptable form for human, we designed and developed an innovation indexing method which can be used to assign an anatomical 3D structure object to every patient visually to store indexes of the patients' basic information, historical examined image information and RIS report information. When a doctor wants to review patient historical records, he or she can first load the anatomical structure object and the view the 3D index of this object using a digital human model tool kit. This prototype system helps doctors to easily and visually obtain the complete historical healthcare status of patients, including large amounts of medical data, and quickly locate detailed information, including both reports and images, from medical information systems. In this way, doctors can save time that may be better used to understand information, obtain a more comprehensive understanding of their patients' situations, and provide better healthcare services to patients.

  17. Coronary flow reserve index corrected by exercise load using Tl-201 SPECT

    International Nuclear Information System (INIS)

    Kubota, Yasushi; Sugihara, Hiroki; Azuma, Akihiro

    1990-01-01

    For simple, non-invasive evaluation of coronary flow reserve during exercise, we investigated the coronary flow reserve index using the ratio of change of fractional distribution in the regional myocardium to oxygen demand. The subjects included 24 patients with effort angina pectoris and 11 normal volunteers. PTCA was peformed for 11 patients. Using the biological properties of Tl-201 single photon emission computed tomography (SPECT) was performed at submaximal exercise and at rest by two successive injections of Tl-201 within a short time interval (double dose method). The correlation between the fractional distribution in the myocardium (Δ-Fract) and the oxygen demand during exercise and at rest were evaluated. Δ-Fract correlated well with the rate of change of the pressure rate product (Δ-PRP), and Δ-Fract/Δ-PRP (CRI) was a good indicator of the coronary flow reserve index. CRI in the ischemic region correlated well with the percent area stenosis of the supplying coronary artery and improved with resolution of percent area stenosis of the target coronary artery after PTCA, but in some cases they were not above the normal range. CRI as obtained by exercise SPECT using the double dose method is useful for non-invasively estimating the coronary flow reserve during exercise, and it can be used for evaluating the effect before and after PTCA. (author)

  18. Bus Operation Monitoring Oriented Public Transit Travel Index System and Calculation Models

    Directory of Open Access Journals (Sweden)

    Jiancheng Weng

    2013-01-01

    Full Text Available This study proposed a two-dimensional index system which is concerned essentially with urban travel based on travel modes and user satisfaction. First, the public transit was taken as an example to describe the index system establishing process. In consideration of convenience, rapid, reliability, comfort, and safety, a bus service evaluation index system was established. The indicators include the N-minute coverage of bus stops, average travel speed, and fluctuation of travel time between stops and bus load factor which could intuitively describe the characteristics of public transport selected to calculate bus travel indexes. Then, combined with the basic indicators, the calculation models of Convenience Index (CI, Rapid Index (RI, Reliability Index (RBI, and Comfort Index (CTI were established based on the multisource data of public transit including the real-time bus GPS data and passenger IC card data. Finally, a case study of Beijing bus operation evaluation and analysis was conducted by taking real bus operation data including GPS data and passenger transaction recorder (IC card data. The results showed that the operation condition of the public transit was well reflected and scientifically classified by the bus travel index models.

  19. Two-Ply Composite Membranes with Separation Layers from Chitosan and Sulfoethylcellulose on a Microporous Support Based on Poly(diphenylsulfone-N-phenylphthalimide

    Directory of Open Access Journals (Sweden)

    Svetlana V. Kononova

    2017-12-01

    Full Text Available Two-ply composite membranes with separation layers from chitosan and sulfoethylcellulose were developed on a microporous support based on poly(diphenylsulfone-N-phenylphthalimide and investigated by use of X-ray diffraction and scanning electron microscopy methods. The pervaporation properties of the membranes were studied for the separation of aqueous alcohol (ethanol, propan-2-ol mixtures of different compositions. When the mixtures to be separated consist of less than 15 wt % water in propan-2-ol, the membranes composed of polyelectrolytes with the same molar fraction of ionogenic groups (-NH3+ for chitosan and -SO3− for sulfoethylcellulose show high permselectivity (the water content in the permeate was 100%. Factors affecting the structure of a non-porous layer of the polyelectrolyte complex formed on the substrate surface and the contribution of that complex to changes in the transport properties of membranes are discussed. The results indicate significant prospects for the use of chitosan and sulfoethylcellulose for the formation of highly selective pervaporation membranes.

  20. Ranking Method for Peak-Load Shifting Considering Different Types of Data

    DEFF Research Database (Denmark)

    Wang, Peng; Wen, Fushuan; Pinson, Pierre

    2016-01-01

    , an evaluation system for the purpose of peak-load shifting is established from three aspects: economic, social, and environmental impacts. Then a mixed-data dominance method is employed in this work to determine the comprehensive closeness degree of each user under each index, and an optimal comprehensive...

  1. Child Maltreatment and Allostatic Load: Consequences for Physical and Mental Health in Children from Low-Income Families

    Science.gov (United States)

    Rogosch, Fred A.; Dackis, Melissa N.; Cicchetti, Dante

    2012-01-01

    Child maltreatment and biomarkers of allostatic load were investigated in relation to child health problems and psychological symptomatology. Participants attended a summer research day camp and included 137 maltreated and 110 nonmaltreated low-income children, who were aged 8 to 10 years (M = 9.42) and racially and ethnically diverse; 52% were male. Measurements obtained included salivary cortisol and DHEA, body-mass index, waist-hip ratio, and blood pressure; these indicators provided a composite index of allostatic load. Child self-report and camp adult-rater reports of child symptomatology were obtained; mothers provided information on health problems. The results indicated that higher allostatic load and child maltreatment status independently predicted poorer health outcomes and greater behavior problems. Moderation effects indicated that allostatic load was related to somatic complaints, attention problems, and thought problems only among maltreated children. Risks associated with high waist-hip ratio, low morning cortisol, and high morning DHEA also were related to depressive symptoms only for maltreated children. The results support an allostatic load conceptualization of the impact of high environmental stress and child abuse and neglect on child health and behavioral outcomes and have important implications for long-term physical and mental health. PMID:22018084

  2. Correlation between plaque control and gingival health using short and extended oral hygiene intervals.

    Science.gov (United States)

    De David, S C; Mário, T G; De Freitas, G C; Kantorski, K Z; Wikesjö, U M E; Moreira, Carlos Heitor Cunha

    2018-02-15

    To evaluate the correlation between dental plaque formation and gingival health in subjects performing high oral hygiene standards over short or extended intervals. Fifty-two non-dental students volunteered for this study. The subjects, trained to perform high oral hygiene standards, were randomized to perform oral hygiene at 12-, 24-, 48-, or 72-h interval over 30 days. The plaque index (PlI) and the gingival index (GI) were evaluated at baseline, 15, and 30 days. For the statistical analysis, oral hygiene intervals were collapsed into daily (12 and 24 h; G12/24) and extended (48 and 72 h; G48/72) intervals. Summary statistics (mean ± SD) and Spearman correlations between the PlI and the GI at baseline, 15, and 30 days were estimated. At baseline, correlation coefficients between PlI and GI were positive for both groups (r = 0.29 and r = 0.25). At day 15 and 30, correlation was maintained with similar baseline values for the G48/72 group. GI levels did not increase despite an increase in PlI for the G12/24 group, and the correlation was lower than that observed at baseline (r = 0.13 vs. r = 0.29). In subjects with high oral hygiene standards, the oral hygiene frequency governs the correlation between dental plaque formation and gingival health. Subjects performing high oral hygiene standards at daily intervals will maintain gingival health in difference to subjects using extended hygiene intervals. Subjects performing high oral hygiene standards at daily intervals will maintain gingival health in difference to subjects using extended hygiene intervals.

  3. Failure analysis of multiple delaminated composite plates due

    Indian Academy of Sciences (India)

    The present work aims at the first ply failure analysis of laminated composite plates with arbitrarily located multiple delaminations subjected to transverse static load as well as impact. The theoretical formulation is based on a simple multiple delamination model. Conventional first order shear deformation is assumed using ...

  4. Planning of continuity of service: The nuisance index, a measurement of the impact of interruptions

    International Nuclear Information System (INIS)

    Naggar, R.

    1992-01-01

    An improved approach has been developed by Hydro-Quebec to integrate its customers' needs into the planning for service continuity. A nuisance index has been developed to measure the impact of service interruptions and is currently being tested with a pilot project in the Richelieu service area. The analytic framework used differentiates three categories of customers for which a normative cost of interrptions is calculated. The classification of networks according to load density and use characteristics allows the utility to define appropriate service continuity objectives. Service continuity is measured using an indicator which is directly deduced from the cost of interruptions. The index takes into account the circumstances surrounding each interruption and an individual nuisance index is calculated for each customer. Then an average individual nuisance index is computed for customers within each category. Finally, an aggregated nuisance index is calculated for all categories as a whole. The cost of interruptions may then be derived through multiplying the nuisance indexes by the energy consumption of the corresponding set of customers and by a constant. It is possible to check whether a customer is receiving acceptable service continuity. An indicator determines the share of energy consumption for which a tolerance threshold has been exceeded. Once integrated into the planning process, these concepts enable optimal distribution network design and operation. Adjustments of network classes that match both the evolution of customers and load contribute to the permanent improvement of networks and their operation. 4 figs

  5. Computational Fatigue Life Analysis of Carbon Fiber Laminate

    Science.gov (United States)

    Shastry, Shrimukhi G.; Chandrashekara, C. V., Dr.

    2018-02-01

    In the present scenario, many traditional materials are being replaced by composite materials for its light weight and high strength properties. Industries like automotive industry, aerospace industry etc., are some of the examples which uses composite materials for most of its components. Replacing of components which are subjected to static load or impact load are less challenging compared to components which are subjected to dynamic loading. Replacing the components made up of composite materials demands many stages of parametric study. One such parametric study is the fatigue analysis of composite material. This paper focuses on the fatigue life analysis of the composite material by using computational techniques. A composite plate is considered for the study which has a hole at the center. The analysis is carried on (0°/90°/90°/90°/90°)s laminate sequence and (45°/-45°)2s laminate sequence by using a computer script. The life cycles for both the lay-up sequence are compared with each other. It is observed that, for the same material and geometry of the component, cross ply laminates show better fatigue life than that of angled ply laminates.

  6. A High Precision Artificial Neural Networks Model for Short-Term Energy Load Forecasting

    Directory of Open Access Journals (Sweden)

    Ping-Huan Kuo

    2018-01-01

    Full Text Available One of the most important research topics in smart grid technology is load forecasting, because accuracy of load forecasting highly influences reliability of the smart grid systems. In the past, load forecasting was obtained by traditional analysis techniques such as time series analysis and linear regression. Since the load forecast focuses on aggregated electricity consumption patterns, researchers have recently integrated deep learning approaches with machine learning techniques. In this study, an accurate deep neural network algorithm for short-term load forecasting (STLF is introduced. The forecasting performance of proposed algorithm is compared with performances of five artificial intelligence algorithms that are commonly used in load forecasting. The Mean Absolute Percentage Error (MAPE and Cumulative Variation of Root Mean Square Error (CV-RMSE are used as accuracy evaluation indexes. The experiment results show that MAPE and CV-RMSE of proposed algorithm are 9.77% and 11.66%, respectively, displaying very high forecasting accuracy.

  7. Limitations of subjective cognitive load measures in simulation-based procedural training.

    Science.gov (United States)

    Naismith, Laura M; Cheung, Jeffrey J H; Ringsted, Charlotte; Cavalcanti, Rodrigo B

    2015-08-01

    The effective implementation of cognitive load theory (CLT) to optimise the instructional design of simulation-based training requires sensitive and reliable measures of cognitive load. This mixed-methods study assessed relationships between commonly used measures of total cognitive load and the extent to which these measures reflected participants' experiences of cognitive load in simulation-based procedural skills training. Two groups of medical residents (n = 38) completed three questionnaires after participating in simulation-based procedural skills training sessions: the Paas Cognitive Load Scale; the NASA Task Load Index (TLX), and a cognitive load component (CLC) questionnaire we developed to assess total cognitive load as the sum of intrinsic load (how complex the task is), extraneous load (how the task is presented) and germane load (how the learner processes the task for learning). We calculated Pearson's correlation coefficients to assess agreement among these instruments. Group interviews explored residents' perceptions about how the simulation sessions contributed to their total cognitive load. Interviews were audio-recorded, transcribed and subjected to qualitative content analysis. Total cognitive load scores differed significantly according to the instrument used to assess them. In particular, there was poor agreement between the Paas Scale and the TLX. Quantitative and qualitative findings supported intrinsic cognitive load as synonymous with mental effort (Paas Scale), mental demand (TLX) and task difficulty and complexity (CLC questionnaire). Additional qualitative themes relating to extraneous and germane cognitive loads were not reflected in any of the questionnaires. The Paas Scale, TLX and CLC questionnaire appear to be interchangeable as measures of intrinsic cognitive load, but not of total cognitive load. A more complete understanding of the sources of extraneous and germane cognitive loads in simulation-based training contexts is

  8. Assessment of heavy metal contamination in water and sediments of Trepça and Sitnica rivers, Kosovo, using pollution indicators and multivariate cluster analysis.

    Science.gov (United States)

    Ferati, Flora; Kerolli-Mustafa, Mihone; Kraja-Ylli, Arjana

    2015-06-01

    The concentrations of As, Cd, Cr, Co, Cu, Ni, Pb, and Zn in water and sediment samples from Trepça and Sitnica rivers were determined to assess the level of contamination. Six water and sediment samples were collected during the period from April to July 2014. Most of the water samples was found within the European and Kosovo permissible limits. The highest concentration of As, Cd, Pb, and Zn originates primarily from anthropogenic sources such discharge of industrial water from mining flotation and from the mine waste eroded from the river banks. Sediment contamination assessment was carried out using the pollution indicators such as contamination factor (CF), degree of contamination (Cd), modified degree of contamination (mCd), pollution load index (PLI), and geo-accumulation index (Igeo). The CF values for the investigated metals indicated a high contaminated nature of sediments, while the Cd values indicated a very high contamination degree of sediments. The mCd values indicate a high degree of contamination of Sitnica river sediment to ultrahigh degree of contamination of Trepça river sediment. The PLI values ranged from 1.89 to 14.1 which indicate that the heavy metal concentration levels in all investigated sites exceeded the background values and sediment quality guidelines. The average values of Igeo revealed the following ranking of intensity of heavy metal contamination of the Trepça and Sitnica river sediments: Cd > As > Pb > Zn > Cu > Co > Cr > Ni. Cluster analysis suggests that As, Cd, Cr, Co, Cu, Ni, Pb, and Zn are derived from anthropogenic sources, particularly discharges from mining flotation and erosion form waste from a zinc mine plant. In order to protect the sediments from further contamination, the designing of a monitoring network and reducing the anthropogenic discharges are suggested.

  9. Carbohydrate, dietary glycaemic index and glycaemic load, and colorectal cancer risk: a case-control study in China.

    Science.gov (United States)

    Huang, Jing; Fang, Yu-Jing; Xu, Ming; Luo, Hong; Zhang, Nai-Qi; Huang, Wu-Qing; Pan, Zhi-Zhong; Chen, Yu-Ming; Zhang, Cai-Xia

    2018-04-01

    A carbohydrate-rich diet results in hyperglycaemia and hyperinsulinaemia; it may further induce the carcinogenesis of colorectal cancer. However, epidemiological evidence among Chinese population is quite limited. The aim of this study was to investigate total carbohydrate, non-fibre carbohydrate, total fibre, starch, dietary glycaemic index (GI) and glycaemic load (GL) in relation to colorectal cancer risk in Chinese population. A case-control study was conducted from July 2010 to April 2017, recruiting 1944 eligible colorectal cancer cases and 2027 age (5-year interval) and sex frequency-matched controls. Dietary information was collected by using a validated FFQ. The OR and 95 % CI of colorectal cancer risk were assessed by multivariable logistic regression models. There was no clear association between total carbohydrate intake and colorectal cancer risk. The adjusted OR was 0·85 (95 % CI 0·70, 1·03, P trend=0·08) comparing the highest with the lowest quartile. Total fibre was related to a 53 % reduction in colorectal cancer risk (adjusted ORquartile 4 v. 1 0·47; 95 % CI 0·39, 0·58). However, dietary GI was positively associated with colorectal cancer risk, with an adjusted ORquartile 4 v. 1 of 3·10 (95 % CI 2·51, 3·85). No significant association was found between the intakes of non-fibre carbohydrate, starch and dietary GL and colorectal cancer risk. This study indicated that dietary GI was positively associated with colorectal cancer risk, but no evidence supported that total carbohydrate, non-fibre carbohydrate, starch or high dietary GL intake were related to an increased risk of colorectal cancer in a Chinese population.

  10. Relationships of cognitive load on eating and weight-related behaviors of young adults.

    Science.gov (United States)

    Byrd-Bredbenner, Carol; Quick, Virginia; Koenings, Mallory; Martin-Biggers, Jennifer; Kattelmann, Kendra K

    2016-04-01

    Little is known about the relationship between weight-related behaviors and cognitive load (working memory available to complete mental activities like those required for planning meals, selecting foods, and other health-related decisions). Thus, the purpose of this study was to explore associations between cognitive load and eating behaviors, physical activity, body mass index (BMI), and waist circumference of college students. College students (n=1018) from 13 institutions completed an online survey assessing eating behaviors (e.g., routine and compensatory restraint, emotional eating, and fruit/vegetable intake), stress level, and physical activity level. BMI and waist circumference were measured by trained researchers. A cognitive load score was derived from stress level, time pressure/income needs, race and nationality. High cognitive load participants (n=425) were significantly (Pcognitive loads (n=593). Compared to low cognitive load participants, high cognitive load participants were significantly more likely to eat cognitive load scores had a non-significant trend toward higher BMIs, waist circumferences, and drinking more alcohol than low cognitive load counterparts. In conclusion, cognitive load may be an important contributor to health behaviors. Understanding how cognitive load may affect eating and other weight-related behaviors could potentially lead to improvements in the effectiveness of obesity prevention and intervention programs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Delamination-Debond Behaviour of Composite T- Joints in Wind Turbine Blades

    International Nuclear Information System (INIS)

    Gulasik, H; Coker, D

    2014-01-01

    Wind turbine industry utilizes composite materials in turbine blade structural designs because of their high strength/stiffness to weight ratio. T-joint is one of the design configurations of composite wind turbine blades. T-joints consist of a skin panel and a stiffener co-bonded or co-cured together with a filler material between them. T-joints are prone to delaminations between skin/stiffener plies and debonds between skin-stiffener-filler interfaces. In this study, delamination/debond behavior of a co-bonded composite T-joint is investigated under 0° pull load condition by 2D finite element method. Using Abaqus® commercial FE software, zero-thickness cohesive elements are used to simulate delamination/debond in ply interfaces and bonding lines. Pulling load at 0° is applied and load-displacement behavior and failure scenario are observed. The failure sequence consists of debonding of filler/stringer interface during one load drop followed by a second drop in which the 2nd filler/stringer debonds, filler/skin debonding and skin delamination leading to total loss of load carrying capacity. This type of failure initiation has been observed widely in the literature. When the debond strength is increased 30%, failure pattern is found to change in addition to increasing the load capacity by 200% before total loss of loading carrying capacity occurs. Failure initiation and propagation behavior, initial and max failure loads and stress fields are affected by the property change. In all cases mixed-mode crack tip loading is observed in the failure initiation and propagation stages. In this paper, the detailed delamination/debonding history in T-joints is predicted with cohesive elements for the first time

  12. INDEXING AND INDEX FUNDS

    Directory of Open Access Journals (Sweden)

    HAKAN SARITAŞ

    2013-06-01

    Full Text Available Proponents of the efficient market hypothesis believe that active portfolio management is largely wasted effort and unlikely to justify the expenses incurred. Therefore, they advocate a passive investment strategy that makes no attempt to outsmart the market. One common strategy for passive management is indexing where a fund is designed to replicate the performance of a broad-based index of stocks and bonds. Traditionally, indexing was used by institutional investors, but today, the use of index funds proliferated among individual investors. Over the years, both international and domestic index funds have disproportionately outperformed the market more than the actively managed funds have.

  13. Extreme Value Predictions using Monte Carlo Simulations with Artificially Increased Load Spectrum

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher

    2011-01-01

    In the analysis of structures subjected to stationary stochastic load processes the mean out-crossing rate plays an important role as it can be used to determine the extreme value distribution of any response, usually assuming that the sequence of mean out-crossings can be modelled as a Poisson...... be scaled down to its actual value. In the present paper the usefulness of this approach is investigated, considering problems related to wave loads on marine structures. Here the load scale parameter is conveniently taken as the square of the significant wave height....... be found using the First Order Reliability Method (FORM). The FORM analysis also shows that the reliability index is strictly inversely proportional to the square root of the magnitude of the load spectrum, irrespectively of the non-linearity in the system. However, the FORM analysis only gives...

  14. Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

    KAUST Repository

    Wu, Ying

    2013-05-06

    In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

  15. Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

    KAUST Repository

    Wu, Ying; Li, Jichun

    2013-01-01

    In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

  16. Metal pollution and ecological risk assessment in marine sediments of Karachi Coast, Pakistan.

    Science.gov (United States)

    Mashiatullah, Azhar; Chaudhary, Muhammad Zaman; Ahmad, Nasir; Javed, Tariq; Ghaffar, Abdul

    2013-02-01

    Concentrations of 12 metals (Fe, Mn, Cr, Mo, Ni, Pb, Se, Sr, U, V, Zn, and Zr) in surface sediments of Karachi Coast, Pakistan were determined to evaluate their distribution and pollution assessment. The measured metals in the sediments were found to be in the range of Fe, 0.84-6.96 %; Mn, 300-1,300 μg/g; Cr, 12.0-319.84 μg/g; Mo, 0.49-2.03 μg/g; Ni, 1.53-58.86 μg/g; Pb, 9.0-49.46 μg/g; Se, 0.25-.86 μg/g; Sr, 192-1185 μg/g; U, 0.19-1.66 μg/g; V, 15.80-118.20 μg/g; Zn, 15.60-666.28 μg/g; and Zr, 44.02-175.26 μg/g. The mean contents of the metal studied were: Fe, 3.07 %, Mn, 0.05 %; Cr, 96.75 μg/g; Mo, 1.34 μg/g; Ni, 31.39 μg/g; Pb, 23.24 μg/g; Se, 0.61 μg/g; Sr, 374.83 μg/g; U, 0.64 μg/g; V, 61.75 μg/g; Zn, 204.75 μg/g; and Zr:76.27 μg/g, and arrangement of the metals from higher to lower mean content in this area is: Fe > Zn > Mn > Sr > Zn > Cr > Zr > V > Ni > Pb > Mo > U > Se. There is no significant correlation among most of these metals, indicating different anthropogenic and natural sources. To assess ecotoxic potential of marine sediments, Numerical Sediment Quality Guidelines were also applied. The concentration of Pb in all the sediments except one was lower than the threshold effect concentration (TECs) showing that there are no harmful effects to marine life from Pb. On the other hand, the concentrations of Cr, Ni, and Zn exceeded TEC in three stations, indicating their potential risk. The degree of pollution in sediments for metals was assessed by calculating enrichment factor (EF) and pollution load index (PLI). The results indicated that sediments of Layari River Mouth Area, Fish Harbour, and KPT Boat Building Area are highly enriched with Cr and Zn (EF > 5). Sediments of Layari River Outfall Zone were moderately enriched with Ni and Pb (EF > 2). The pollution load index was found in the range of 0.98 to 1.34. Lower values of PLI (≤ 1) at most of sampling locations imply no appreciable input from anthropogenic sources. However

  17. Assessment of streambed sediment contamination by heavy metals: The case of the Gabes Catchment, South-eastern Tunisia

    Science.gov (United States)

    Dahri, Noura; Atoui, Abdelfattah; Ellouze, Manel; Abida, Habib

    2018-04-01

    This study deals with the assessment of the behaviour of seven heavy metals (Cd, Zn, Cu, Pb, Ni, Cr and As) in streambed sediments within the Gabes Catchment, located in South-eastern Tunisia. To understand the effect of intense human activities in the Gabes Basin on the quality of the environment, 22 sediment samples, spread all over the study basin, were taken and analyzed for heavy metals. Heavy metal concentrations were shown to vary in the following order: Zn > Pb > Cu > Cr > Ni > Cd > As. Sediment quality was assessed based on the evaluation of various indices. A total of 27% of the sampling stations are characterised by sediment Enrichment Factors (EF) exceeding 40, reflecting extremely severe pollution. This result was also confirmed by different indices, including Sediment Pollution Index (SPI), Pollution Load Index (PLI) and Geo-accumulation index. The calculation of Mean Effect Range-Median Quotient (M-ERM-Q) indicated that in stream discharge, all metals have a probability of 21% to be toxic. The ecological toxicity risk of heavy metals increases close to urban (traffic activity) and industrial activities (industrial complex of Gabes). Close to Gabes City, the situation and the degree of contamination that may be transferred into marine ecosystems is worrisome and requires immediate intervention.

  18. Management of gaseous radioactive wastes. Technical progress report, September 1, 1974--August 31, 1975

    International Nuclear Information System (INIS)

    First, M.W.

    1975-01-01

    Multi-ply absolute filter units were manufactured and are undergoing tests for penetration, loading, and heat resistance characteristics. All-metal fiber prefilters are under test with salt aerosols to investigate their particle retention characteristics at elevated temperatures and ability to protect downstream absolute filters from fire and smoke damage. (auth)

  19. Lie construction affects information storage under high memory load condition.

    Directory of Open Access Journals (Sweden)

    Yuqiu Liu

    Full Text Available Previous studies indicate that lying consumes cognitive resources, especially working memory (WM resources. Considering the dual functions that WM might play in lying: holding the truth-related information and turning the truth into lies, the present study examined the relationship between the information storage and processing in the lie construction. To achieve that goal, a deception task based on the old/new recognition paradigm was designed, which could manipulate two levels of WM load (low-load task using 4 items and high-load task using 6 items during the deception process. The analyses based on the amplitude of the contralateral delay activity (CDA, a proved index of the number of representations being held in WM, showed that the CDA amplitude was lower in the deception process than that in the truth telling process under the high-load condition. In contrast, under the low-load condition, no CDA difference was found between the deception and truth telling processes. Therefore, we deduced that the lie construction and information storage compete for WM resources; when the available WM resources cannot meet this cognitive demand, the WM resources occupied by the information storage would be consumed by the lie construction.

  20. Lie construction affects information storage under high memory load condition.

    Science.gov (United States)

    Liu, Yuqiu; Wang, Chunjie; Jiang, Haibo; He, Hongjian; Chen, Feiyan

    2017-01-01

    Previous studies indicate that lying consumes cognitive resources, especially working memory (WM) resources. Considering the dual functions that WM might play in lying: holding the truth-related information and turning the truth into lies, the present study examined the relationship between the information storage and processing in the lie construction. To achieve that goal, a deception task based on the old/new recognition paradigm was designed, which could manipulate two levels of WM load (low-load task using 4 items and high-load task using 6 items) during the deception process. The analyses based on the amplitude of the contralateral delay activity (CDA), a proved index of the number of representations being held in WM, showed that the CDA amplitude was lower in the deception process than that in the truth telling process under the high-load condition. In contrast, under the low-load condition, no CDA difference was found between the deception and truth telling processes. Therefore, we deduced that the lie construction and information storage compete for WM resources; when the available WM resources cannot meet this cognitive demand, the WM resources occupied by the information storage would be consumed by the lie construction.

  1. Importance of background values in assessing the impact of heavy metals in river ecosystems: case study of Tisza River, Serbia.

    Science.gov (United States)

    Štrbac, Snežana; Kašanin Grubin, Milica; Vasić, Nebojša

    2017-11-30

    The main objective of this paper is to evaluate how a choice of different background values may affect assessing the anthropogenic heavy metal pollution in sediments from Tisza River (Serbia). The second objective of this paper is to underline significance of using geochemical background values when establishing quality criteria for sediment. Enrichment factor (EF), geoaccumulation index (I geo ), pollution load index (PLI), and potential ecological risk index (PERI) were calculated using different background values. Three geochemical (average metal concentrations in continental crust, average metal concentrations in shale, and average metal concentrations in non-contaminated core sediment samples) and two statistical methods (delineation method and principal component analyses) were used for calculating background values. It can be concluded that obtained information of pollution status can be more dependent on the use of background values than the index/factor chosen. The best option to assess the potential river sediment contamination is to compare obtained concentrations of analyzed elements with concentrations of mineralogically and texturally comparable, uncontaminated core sediment samples. Geochemical background values should be taken into account when establishing quality criteria for soils, sediments, and waters. Due to complexity of the local lithology, it is recommended that environmental monitoring and assessment include selection of an appropriate background values to gain understanding of the geochemistry and potential source of pollution in a given environment.

  2. Probability Based Evaluation of Vehicular Bridge Load using Weigh-in-Motion Data

    Directory of Open Access Journals (Sweden)

    Widi Nugraha

    2016-02-01

    Full Text Available Load and Resistance Factored Design (LRFD method for designing bridge in Indonesia have been implemented for more than 25 years. LRFD method treating loads and strengths variables as random variables with specific safety factors for different loads and strengths variables type. The nominal loads, load factors, reduction factors, and other criteria for bridge design code can be determined to meet the reliability criteria. Statistical data of weigh-in-motion (WIM vehicular loads measurement in Northern Java highway, Cikampek - Pamanukan, West Java (2011, used in as statistical loads variable. A 25 m simple span bridge with reinforced concrete T-girder is used as a model for structural analysis due to WIM measured and nominal vehicular load based on RSNI T-02-2005, with applied bending moment of girder as the output. The distribution fitting result of applied bending moment due to WIM measured vehicular loads is lognormal. The maximum bending moment due to RSNI T-02-2005 nominal vehicular load is 842.45 kN-m and has probability of exceedance of 5x10-5. It can be concluded, for this study, that the bridge designed using RSNI T-02-2005 is safely designed, since it has reliability index, β of 5.02, higher than target reliability, β ranging from 3.50 or 3.72.

  3. Parallel In Situ Indexing for Data-intensive Computing

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinoh; Abbasi, Hasan; Chacon, Luis; Docan, Ciprian; Klasky, Scott; Liu, Qing; Podhorszki, Norbert; Shoshani, Arie; Wu, Kesheng

    2011-09-09

    As computing power increases exponentially, vast amount of data is created by many scientific re- search activities. However, the bandwidth for storing the data to disks and reading the data from disks has been improving at a much slower pace. These two trends produce an ever-widening data access gap. Our work brings together two distinct technologies to address this data access issue: indexing and in situ processing. From decades of database research literature, we know that indexing is an effective way to address the data access issue, particularly for accessing relatively small fraction of data records. As data sets increase in sizes, more and more analysts need to use selective data access, which makes indexing an even more important for improving data access. The challenge is that most implementations of in- dexing technology are embedded in large database management systems (DBMS), but most scientific datasets are not managed by any DBMS. In this work, we choose to include indexes with the scientific data instead of requiring the data to be loaded into a DBMS. We use compressed bitmap indexes from the FastBit software which are known to be highly effective for query-intensive workloads common to scientific data analysis. To use the indexes, we need to build them first. The index building procedure needs to access the whole data set and may also require a significant amount of compute time. In this work, we adapt the in situ processing technology to generate the indexes, thus removing the need of read- ing data from disks and to build indexes in parallel. The in situ data processing system used is ADIOS, a middleware for high-performance I/O. Our experimental results show that the indexes can improve the data access time up to 200 times depending on the fraction of data selected, and using in situ data processing system can effectively reduce the time needed to create the indexes, up to 10 times with our in situ technique when using identical parallel settings.

  4. Seasonal variations of natural radionuclides, minor and trace elements in lake sediments and water in a lignite mining area of North-Western Greece.

    Science.gov (United States)

    Noli, Fotini; Tsamos, Panagiotis

    2018-05-01

    The radiological and chemical pollution of a cluster of four lakes in a lignite mining area of North-Western Greece was investigated using a variety of analytical techniques. Alpha spectrometry was applied to measure the activity concentrations of the uranium radioisotopes (U-234, U-235, and U-238) in waters. The mass activities of U-238, Th-232, and K-40 in sediments were measured by high-resolution gamma spectrometry. Furthermore, the determination of the minor and trace elements was carried out by instrumental neutron activation analysis (INAA) in both water and sediments samples, respectively. Pollution levels were also evaluated by calculating enrichment factors (EFs), contamination factors (CFs) and pollution load index (PLI). The data were discussed taking into account several parameters such as the distance from the pollution source, temperature, and location and showed that the environmental impact in this region could not be considered as negligible. The deviation of the isotopic ratio of U-234/U-238 from the equilibrium value indicated waters with intensive dissolution of uranium. The activity values in both waters and sediments found to be low in cool periods and increased in warm periods. Moreover, the concentrations of the elements U, Zn, and Fe were raised in water samples indicating possible pollution as well as the CFs and PLI denoted accumulation in the sediments and moderate to severe contamination for Zn and Cr in some cases.

  5. Heavy metal contamination in sand and sediments near to disposal site of reject brine from desalination plant, Arabian Gulf: Assessment of environmental pollution.

    Science.gov (United States)

    Alshahri, Fatimh

    2017-01-01

    Accumulation of heavy metals in environment may cause series potential risk in the living system. This study was carried out to investigate heavy metal contamination in sand samples and sediments along the beach near to disposal site of reject brine from Alkhobar desalination plant, which is one of the oldest and largest reverse osmosis desalination plants in eastern Saudi Arabia, Arabian Gulf. Fourteen heavy metals (U, Ca, Fe, Al, Ti, Sr, Rb, Ni, Pb, Cd, Cr, Cu, As, and Zr) were measured using gamma-ray spectrometry, atomic absorption spectrometer (AAS) and energy dispersive X-ray fluorescence spectrometer (EDX). The obtained data revealed that the concentrations of these metals were higher than the values in sediment and soil for other studies in Arabian Gulf. Furthermore, the mean values of Fe, Mn, Cr, Cu, As, Sr, and Zr concentrations in sand and sediments were higher than the geochemical background values in shale. The contamination factor (CF), modified degree of contamination (mC d ) and pollution load index (PLI) were assessed. According to contamination factors (CF > 1), the results showed elevated levels of Cu, Cr, Mn, Zr, and As in all samples. The highest value of contamination factor was found for As. Based on PLI (PLI > 1), the values of all sampling sites indicate a localized pollution in the study area. Current study could be useful as baseline data for heavy metals in sand and sediments nearby a desalination plant.

  6. Structural Analysis and Optimization of a Composite Fan Blade for Future Aircraft Engine

    Science.gov (United States)

    Coroneos, Rula M.

    2012-01-01

    This report addresses the structural analysis and optimization of a composite fan blade sized for a large aircraft engine. An existing baseline solid metallic fan blade was used as a starting point to develop a hybrid honeycomb sandwich construction with a polymer matrix composite face sheet and honeycomb aluminum core replacing the original baseline solid metallic fan model made of titanium. The focus of this work is to design the sandwich composite blade with the optimum number of plies for the face sheet that will withstand the combined pressure and centrifugal loads while the constraints are satisfied and the baseline aerodynamic and geometric parameters are maintained. To satisfy the requirements, a sandwich construction for the blade is proposed with composite face sheets and a weak core made of honeycomb aluminum material. For aerodynamic considerations, the thickness of the core is optimized whereas the overall blade thickness is held fixed so as to not alter the original airfoil geometry. Weight is taken as the objective function to be minimized by varying the core thickness of the blade within specified upper and lower bounds. Constraints are imposed on radial displacement limitations and ply failure strength. From the optimum design, the minimum number of plies, which will not fail, is back-calculated. The ply lay-up of the blade is adjusted from the calculated number of plies and final structural analysis is performed. Analyses were carried out by utilizing the OpenMDAO Framework, developed at NASA Glenn Research Center combining optimization with structural assessment.

  7. An objective decision model of power grid environmental protection based on environmental influence index and energy-saving and emission-reducing index

    Science.gov (United States)

    Feng, Jun-shu; Jin, Yan-ming; Hao, Wei-hua

    2017-01-01

    Based on modelling the environmental influence index of power transmission and transformation project and energy-saving and emission-reducing index of source-grid-load of power system, this paper establishes an objective decision model of power grid environmental protection, with constraints of power grid environmental protection objectives being legal and economical, and considering both positive and negative influences of grid on the environmental in all-life grid cycle. This model can be used to guide the programming work of power grid environmental protection. A numerical simulation of Jiangsu province’s power grid environmental protection objective decision model has been operated, and the results shows that the maximum goal of energy-saving and emission-reducing benefits would be reached firstly as investment increasing, and then the minimum goal of environmental influence.

  8. Analysis of the Impact of Urban Microclimate on Air Conditioning Load Control

    Directory of Open Access Journals (Sweden)

    Hu Xiaoqing

    2016-01-01

    Full Text Available Due to the presence of urban heat island effect (UHIE, high humidity and other urban microclimate, temperature of city central area rises. This causes that the actual air-conditioning energy consumption (ACEC in the urban central area is much higher than that in the suburbs. Load control of air-conditioners (ACs is considered to be equivalent to a power plant of the same capacity, and it can greatly reduce the system pressure to peak load shift. In this paper, a simplified second order transfer function control model of ACs is presented, and its parameters will be influenced by the ambient temperature and urban microclimate. The temperature is obtained by using the temperature inversion algorithm of the heat island effect. Then, the heat index is calculated by combining temperature and humidity. The ambient temperature index of urban central area is modified based on the above microclimate, and the second order linear time invariant model of aggregated ACs is upgraded to the linear time varying model. Furthermore, the consequent parameter changes of the second order transfer function model are studied and the influence of urban microclimate on AC load control is analyzed. The proposed method is verified on numerical examples

  9. The NASA Task Load Index as a measure of overall workload among neonatal, paediatric and adult intensive care nurses.

    Science.gov (United States)

    Tubbs-Cooley, Heather L; Mara, Constance A; Carle, Adam C; Gurses, Ayse P

    2018-02-12

    The NASA Task Load Index (NASA-TLX) is a subjective workload assessment scale developed for use in aviation and increasingly applied to healthcare. The scale purports to measure overall workload as a single variable calculated by summing responses to six items. Since no data address the validity of this scoring approach in health care, we evaluated the single factor structure of the NASA-TLX as a measure of overall workload among intenisive care nurses. Confirmatory factor analysis of data from two studies of nurse workload in neonatal, paediatric, and adult intensive care units. Study 1 data were obtained from 136 nurses in one neonatal intensive care unit. Study 2 data were collected from 300 nurses in 17 adult, paediatric and neonatal units. Nurses rated their workload using the NASA-TLX's paper version. A single factor model testing whether all six items measured a single overall workload variable fit least well (RMSEA = 0.14; CFI = 0.91; TLI = 0.85). A second model that specified two items as outcomes of overall workload had acceptable fit (RMSEA = 0.08; CFI = 0.97; TLI = 0.95) while a third model of four items fit best (RMSEA = 0.06; CFI > 0.99; TLI = 0.99). A summed score from four of six NASA-TLX items appears to most reliably measure a single overall workload variable among intensive care nurses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Transparent bulk-size nanocomposites with high inorganic loading

    International Nuclear Information System (INIS)

    Chen, Shi; Gaume, Romain

    2015-01-01

    With relatively high nanoparticle loading in polymer matrices, hybrid nanocomposites made by colloidal dispersion routes suffer from severe inhomogeneous agglomeration, a phenomenon that deteriorates light transmission even when the refractive indices of the inorganic and organic phases are closely matched. The dispersion of particles in a matrix is of paramount importance to obtain composites of high optical quality. Here, we describe an innovative, yet straightforward method to fabricate monolithic transparent hybrid nanocomposites with very high particle loading and high refractive index mismatch tolerance between the inorganic and organic constituents. We demonstrate 77% transmission at 800 nm in a 2 mm-thick acrylate polymer nanocomposite containing 61 vol. % CaF 2 nanoparticles. Modeling shows that similar performance could easily be obtained with various inorganic phases relevant to a number of photonic applications

  11. Development of Self Fire Retardant Melamine-Animal Glue Formaldehyde (MGF) Resin for the Manufacture of BWR Ply Board

    Science.gov (United States)

    Khatua, Pijus Kanti; Dubey, Rajib Kumar; Roymahapatra, Gourisankar; Mishra, Anjan; Shahoo, Shadhu Charan; Kalawate, Aparna

    2017-10-01

    Wood is one of the most sustainable, naturally growing materials that consist mainly of combustible organic carbon compounds. Since plywood are widely used nowadays especially in buildings, furniture and cabinets. Too often the fire behavior of ply-board may be viewed as a drawback. Amino-plastic based thermosetting resin adhesives are the important and most widely used in the plywood panel industries. The fire retardant property of wood panel products by adding animal glue as an additive in the form of MGF resin and used as substitute of melamine for manufacture of plywood. Environment concerns and higher cost of petroleum based resins have resulted in the development of technologies to replace melamine partially by biomaterials for the manufacturing of resin adhesive. Natural bio-based materials such as tannin, CNSL (cardanol), lignin, soya etc. are used as partial substitution of melamine. This article presents the development of melamine-animal glue formaldehyde resin as plywood binder. About 30 % melamine was substituted by animal glue and optimized. The different physico-mechanical and fire retardant property properties tested as per IS: 1734-1983 and IS: 5509-2000 respectively are quite satisfactory. The production of adhesive from melamine with compatible natural proteinous material is cost effective, eco-friendly and enhance the fire retardant property.

  12. Damage Model of Reinforced Concrete Members under Cyclic Loading

    Science.gov (United States)

    Wei, Bo Chen; Zhang, Jing Shu; Zhang, Yin Hua; Zhou, Jia Lai

    2018-06-01

    Based on the Kumar damage model, a new damage model for reinforced concrete members is established in this paper. According to the damage characteristics of reinforced concrete members subjected to cyclic loading, four judgment conditions for determining the rationality of damage models are put forward. An ideal damage index (D) is supposed to vary within a scale of zero (no damage) to one (collapse). D should be a monotone increasing function which tends to increase in the case of the same displacement amplitude. As for members under large displacement amplitude loading, the growth rate of D should be greater than that of D under small amplitude displacement loading. Subsequently, the Park-Ang damage model, the Niu-Ren damage model, the Lu-Wang damage model and the proposed damage model are analyzed for 30 experimental reinforced concrete members, including slabs, walls, beams and columns. The results show that current damage models do not fully matches the reasonable judgment conditions, but the proposed damage model does. Therefore, a conclusion can be drawn that the proposed damage model can be used for evaluating and predicting damage performance of RC members under cyclic loading.

  13. Effects of Brazilian Propolis on Dental Plaque and Gingiva in Patients with Oral Cleft Malformation Treated with Multibracket and Removable Appliances: A Comparative Study.

    Science.gov (United States)

    Machorowska-Pieniążek, Agnieszka; Skucha-Nowak, Małgorzata; Mertas, Anna; Tanasiewicz, Marta; Niedzielska, Iwona; Morawiec, Tadeusz; Baron, Stefan

    2016-01-01

    Orthodontic appliances modify the local environment of the oral cavity, increase the accumulation of dental plaque, and affect the condition of the gingiva. The aim of this study is assessment of Brazilian propolis toothpaste's effect on plaque index (PLI) and gingival index (GI) in patients with CL/CLP treated using orthodontic appliances in the 35-day study period. The study population included 96 patients of an Orthodontic Outpatient Clinic, ACSiMS in Bytom. All the patients participated in the active phase of orthodontic treatment using buccal multibracket appliances or removable appliances. During the first examination, each patient was randomly qualified to the propolis group or control group. A statistically significant decrease in GI and PLI in the entire propolis group (P appliances. The orthodontic appliance type did not affect the final dental plaque amount and gingival condition in patients using the propolis toothpaste. These results may be clinically useful to improve prevention and control oral infectious diseases during orthodontic treatment patients with oral cleft.

  14. Damage evolution under cyclic multiaxial stress state: A comparative analysis between glass/epoxy laminates and tubes

    DEFF Research Database (Denmark)

    Quaresimin, M.; Carraro, P.A.; Mikkelsen, Lars Pilgaard

    2014-01-01

    In this work an experimental investigation on damage initiation and evolution in laminates under cyclic loading is presented. The stacking sequence [0/θ2/0/-θ2]s has been adopted in order to investigate the influence of the local multiaxial stress state in the off-axis plies and the possible effect...

  15. ()OSSII3 LITIES I~ COU~T : ~.

    African Journals Online (AJOL)

    although almost certainly organised and sup- plied and very ... course of an insurgency can be divided into several .... for the insurgency to be in different stages ..... for some time. The police's main functions will thus lie in preparation and co-operation ... able to achieve this. ... and thus reducing the work load later, when.

  16. No association of cortical amyloid load and EEG connectivity in older people with subjective memory complaints

    Directory of Open Access Journals (Sweden)

    Stefan Teipel

    2018-01-01

    Full Text Available Changes in functional connectivity of cortical networks have been observed in resting-state EEG studies in healthy aging as well as preclinical and clinical stages of AD. Little information, however, exists on associations between EEG connectivity and cortical amyloid load in people with subjective memory complaints. Here, we determined the association of global cortical amyloid load, as measured by florbetapir-PET, with functional connectivity based on the phase-lag index of resting state EEG data for alpha and beta frequency bands in 318 cognitively normal individuals aged 70–85 years with subjective memory complaints from the INSIGHT-preAD cohort. Within the entire group we did not find any significant associations between global amyloid load and phase-lag index in any frequency band. Assessing exclusively the subgroup of amyloid-positive participants, we found enhancement of functional connectivity with higher global amyloid load in the alpha and a reduction in the beta frequency bands. In the amyloid-negative participants, higher amyloid load was associated with lower connectivity in the low alpha band. However, these correlations failed to reach significance after controlling for multiple comparisons. The absence of a strong amyloid effect on functional connectivity may represent a selection effect, where individuals remain in the cognitively normal group only if amyloid accumulation does not impair cortical functional connectivity.

  17. A comparison of economy and sagittal plane trunk movements among back-, back/front- and head-loading.

    Science.gov (United States)

    Hudson, Sean; Cooke, Carlton; Davies, Simeon; West, Sacha; Gamieldien, Raeeq; Low, Chris; Lloyd, Ray

    2018-05-14

    It has been suggested that freedom of movement in the trunk could influence load carriage economy. This study aimed to compare the economy and sagittal plane trunk movements associated with three load carriage methods that constrain posture differently. Eighteen females walked at 3 km.h -1 with loads of 0, 3, 6, 9, 12, 15 and 20 kg carried on the back, back/front and head. Load carriage economy was assessed using the Extra Load Index (ELI). Change in sagittal plane trunk forward lean and trunk angle excursion from unloaded to loaded walking were assessed. Results show no difference in economy between methods (p = 0.483), despite differences in the change in trunk forward lean (p = 0.001) and trunk angle excursion (p = 0.021) from unloaded to loaded walking. We conclude that economy is not different among the three methods of load carriage, despite significant differences in sagittal plane trunk movements.

  18. Assessment of heavy metal contamination and sediment quality in the Cimadur river, Banten

    International Nuclear Information System (INIS)

    Rina Mulyaningsih; Siti Suprapti

    2015-01-01

    River sediment quality assessment can be done by the calculation of pollution index. The existence of gold mining activities in Cikotok suspected to have an impact on Cimadur river quality degradation. Calculations pollution index by heavy metal Hg, As, Cr, Co and Zn contained in river sediment Cimadur Cikotok Banten have been performed. Sediment sampling has conducted at 9 locations along the Cimadur River. Quantification of heavy metals in the samples was done by using the neutron activation analysis technique. The result of assessment based on enrichment factor showed that there has been an increase in concentration of heavy metals Hg, As, Cr, Co and Zn due to anthropogenic factors. Based on the value of index geo accumulation it was known that the sampling location has been polluted, predominantly by Hg and As. Heavy metals contained in the sediments provide ecological risk to the environment with following order: Cr < Zn < As < Hg. Based on the value of pollution load index (PLI), all locations were polluted by heavy metals Hg, As, Cr, Co and Zn. The sources of heavy metals could be from natural rocks or gold mining activities. Evaluation based on potential ecological risk index, showed that heavy metal pollution will give impact of ecological risk to the surrounding environment from low level to high, so it is necessary to do environmental monitoring and management appropriate for reducing the pollution in that location. (author)

  19. Using satellite fire detection to calibrate components of the fire weather index system in Malaysia and Indonesia.

    Science.gov (United States)

    Dymond, Caren C; Field, Robert D; Roswintiarti, Orbita; Guswanto

    2005-04-01

    Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and

  20. The Impact Response of Carbon/Epoxy Laminates (Center Director's Discretionary Fund, Project No. 94-13)

    Science.gov (United States)

    Nettles, A. T.; Hodge, A. J.

    1997-01-01

    Low velocity dropweight impact tests were conducted on carbon/epoxy laminates under various boundary conditions. The composite plates were 8-ply (+45,0,-45,90)s laminates supported in a clamped-clamped/free-free configuration with varying amounts of in-plane load, N(sub x), applied. Specimens were impacted at energies of 3.4, 4.5, and 6 Joules (2.5, 3.3, and 4.4 ft-lb). The amount of damage induced into the specimen was evaluated using instrumented impact techniques, x-ray inspection, and cross-sectional photomicroscopy. Some static identation tests were performed to examine if the impact events utilized in this study were of a quasi-static nature and also to gain insight into the shape of the deflected surface at various impact load combinations. Load-displacement curves from these tests were compared to those of the impact tests, as was damage determined from x-ray inspection. The finite element technique was used to model the impact event and determine the stress field within the laminae. Results showed that for a given impact energy level, more damage was induced into the specimen as the external in-plane load, N(sub x), was increased. The majority of damage observed consisted of back face splitting of the matrix parallel to the fibers in that ply, associated with delaminations emanating from these splits. The analysis showed qualitatively the results of impact conditions on maximum load of impact, maximum transverse deflection, and first failure mode and location.

  1. A strategy to load balancing for non-connectivity MapReduce job

    Science.gov (United States)

    Zhou, Huaping; Liu, Guangzong; Gui, Haixia

    2017-09-01

    MapReduce has been widely used in large scale and complex datasets as a kind of distributed programming model. Original Hash partitioning function in MapReduce often results the problem of data skew when data distribution is uneven. To solve the imbalance of data partitioning, we proposes a strategy to change the remaining partitioning index when data is skewed. In Map phase, we count the amount of data which will be distributed to each reducer, then Job Tracker monitor the global partitioning information and dynamically modify the original partitioning function according to the data skew model, so the Partitioner can change the index of these partitioning which will cause data skew to the other reducer that has less load in the next partitioning process, and can eventually balance the load of each node. Finally, we experimentally compare our method with existing methods on both synthetic and real datasets, the experimental results show our strategy can solve the problem of data skew with better stability and efficiency than Hash method and Sampling method for non-connectivity MapReduce task.

  2. Benzocaine loaded biodegradable poly-(D,L-lactide-co-glycolide) nanocapsules: factorial design and characterization

    International Nuclear Information System (INIS)

    Morales Moraes, Carolina; Prado de Matos, Angelica; Paula, Eneida de; Rosa, Andre Henrique; Fernandes Fraceto, Leonardo

    2009-01-01

    Local anesthetics are able to induce pain relief since they bind to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Benzocaine (BZC) is a local anesthetic that presents limited application in topical formulations due to its low water-solubility. This study aimed to develop polymeric nanocapsules as a drug delivery system for the local anesthetic benzocaine (BZC). To do so, BZC loaded poly(D,L-lactide-co-glycolide) (PLGA) nanocapsules were prepared using the nanoprecipitation method and were characterized. The factorial experimental design was used to study the influence of four different independent variables on response to nanocapsules drug loading. The physical characteristics of PLGA nanocapsules were evaluated by analyzing the particle size, the polydispersion index and the zeta potential, using a particle size analyzer. The results of the optimized formulation showed a size distribution with a polydispersity index of 0.12, an average diameter of 123 nm, zeta potential of -33.6 mV and a drug loading of more than 69%. The release profiles showed a significant difference in the release behavior for the pure drug in solution when compared with that containing benzocaine loaded PLGA nanocapsules. Thus, the prepared nanocapsules described here may be of clinical importance in both the processes of stabilization and delivery of benzocaine for pain treatment.

  3. Benzocaine loaded biodegradable poly-(D,L-lactide-co-glycolide) nanocapsules: factorial design and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Morales Moraes, Carolina; Prado de Matos, Angelica; Paula, Eneida de [Department of Biochemistry, Institute of Biology, State University of Campinas, Campinas, SP (Brazil); Rosa, Andre Henrique [Department of Environmental Engineering, State University of Sao Paulo, Sorocaba, Sao Paulo (Brazil); Fernandes Fraceto, Leonardo, E-mail: leonardo@sorocaba.unesp.b [Department of Biochemistry, Institute of Biology, State University of Campinas, Campinas, SP (Brazil); Department of Environmental Engineering, State University of Sao Paulo, Sorocaba, Sao Paulo (Brazil)

    2009-12-15

    Local anesthetics are able to induce pain relief since they bind to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Benzocaine (BZC) is a local anesthetic that presents limited application in topical formulations due to its low water-solubility. This study aimed to develop polymeric nanocapsules as a drug delivery system for the local anesthetic benzocaine (BZC). To do so, BZC loaded poly(D,L-lactide-co-glycolide) (PLGA) nanocapsules were prepared using the nanoprecipitation method and were characterized. The factorial experimental design was used to study the influence of four different independent variables on response to nanocapsules drug loading. The physical characteristics of PLGA nanocapsules were evaluated by analyzing the particle size, the polydispersion index and the zeta potential, using a particle size analyzer. The results of the optimized formulation showed a size distribution with a polydispersity index of 0.12, an average diameter of 123 nm, zeta potential of -33.6 mV and a drug loading of more than 69%. The release profiles showed a significant difference in the release behavior for the pure drug in solution when compared with that containing benzocaine loaded PLGA nanocapsules. Thus, the prepared nanocapsules described here may be of clinical importance in both the processes of stabilization and delivery of benzocaine for pain treatment.

  4. The strength study of the rotating device driver indexing spatial mechanism

    Science.gov (United States)

    Zakharenkov, N. V.; Kvasov, I. N.

    2018-04-01

    The indexing spatial mechanisms are widely used in automatic machines. The mechanisms maximum load-bearing capacity measurement is possible based on both the physical and numerical models tests results. The paper deals with the driven disk indexing spatial cam mechanism numerical model at the constant angular cam velocity. The presented mechanism kinematics and geometry parameters and finite element model are analyzed in the SolidWorks design environment. The calculation initial data and missing parameters having been found from the structure analysis were identified. The structure and kinematics analysis revealed the mechanism failures possible reasons. The numerical calculations results showing the structure performance at the contact and bending stresses are represented.

  5. Central load reduces peripheral processing: Evidence from incidental memory of background speech.

    Science.gov (United States)

    Halin, Niklas; Marsh, John E; Sörqvist, Patrik

    2015-12-01

    Is there a trade-off between central (working memory) load and peripheral (perceptual) processing? To address this question, participants were requested to undertake an n-back task in one of two levels of central/cognitive load (i.e., 1-back or 2-back) in the presence of a to-be-ignored story presented via headphones. Participants were told to ignore the background story, but they were given a surprise memory test of what had been said in the background story, immediately after the n-back task was completed. Memory was poorer in the high central load (2-back) condition in comparison with the low central load (1-back) condition. Hence, when people compensate for higher central load, by increasing attentional engagement, peripheral processing is constrained. Moreover, participants with high working memory capacity (WMC) - with a superior ability for attentional engagement - remembered less of the background story, but only in the low central load condition. Taken together, peripheral processing - as indexed by incidental memory of background speech - is constrained when task engagement is high. © 2015 The Authors. Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  6. Influence of Axial Load on Electromechanical Impedance (EMI) of Embedded Piezoceramic Transducers in Steel Fiber Concrete.

    Science.gov (United States)

    Wang, Zhijie; Chen, Dongdong; Zheng, Liqiong; Huo, Linsheng; Song, Gangbing

    2018-06-01

    With the advantages of high tensile, bending, and shear strength, steel fiber concrete structures have been widely used in civil engineering. The health monitoring of concrete structures, including steel fiber concrete structures, receives increasing attention, and the Electromechanical Impedance (EMI)-based method is commonly used. Structures are often subject to changing axial load and ignoring the effect of axial forces may introduce error to Structural Health Monitoring (SHM), including the EMI-based method. However, many of the concrete structure monitoring algorithms do not consider the effects of axial loading. To investigate the influence of axial load on the EMI of a steel fiber concrete structure, concrete specimens with different steel fiber content (0, 30, 60, 90, 120) (kg/m³) were casted and the Lead Zirconate Titanate (PZT)-based Smart Aggregate (SA) was used as the EMI sensor. During tests, the step-by-step loading procedure was applied on different steel fiber content specimens, and the electromechanical impedance values were measured. The Normalized root-mean-square deviation Index (NI) was developed to analyze the EMI information and evaluate the test results. The results show that the normalized root-mean-square deviation index increases with the increase of the axial load, which clearly demonstrates the influence of axial load on the EMI values for steel fiber concrete and this influence should be considered during a monitoring or damage detection procedure if the axial load changes. In addition, testing results clearly reveal that the steel fiber content, often at low mass and volume percentage, has no obvious influence on the PZT's EMI values. Furthermore, experiments to test the repeatability of the proposed method were conducted. The repeating test results show that the EMI-based indices are repeatable and there is a great linearity between the NI and the applied loading.

  7. Influence of Axial Load on Electromechanical Impedance (EMI of Embedded Piezoceramic Transducers in Steel Fiber Concrete

    Directory of Open Access Journals (Sweden)

    Zhijie Wang

    2018-06-01

    Full Text Available With the advantages of high tensile, bending, and shear strength, steel fiber concrete structures have been widely used in civil engineering. The health monitoring of concrete structures, including steel fiber concrete structures, receives increasing attention, and the Electromechanical Impedance (EMI-based method is commonly used. Structures are often subject to changing axial load and ignoring the effect of axial forces may introduce error to Structural Health Monitoring (SHM, including the EMI-based method. However, many of the concrete structure monitoring algorithms do not consider the effects of axial loading. To investigate the influence of axial load on the EMI of a steel fiber concrete structure, concrete specimens with different steel fiber content (0, 30, 60, 90, 120 (kg/m3 were casted and the Lead Zirconate Titanate (PZT-based Smart Aggregate (SA was used as the EMI sensor. During tests, the step-by-step loading procedure was applied on different steel fiber content specimens, and the electromechanical impedance values were measured. The Normalized root-mean-square deviation Index (NI was developed to analyze the EMI information and evaluate the test results. The results show that the normalized root-mean-square deviation index increases with the increase of the axial load, which clearly demonstrates the influence of axial load on the EMI values for steel fiber concrete and this influence should be considered during a monitoring or damage detection procedure if the axial load changes. In addition, testing results clearly reveal that the steel fiber content, often at low mass and volume percentage, has no obvious influence on the PZT’s EMI values. Furthermore, experiments to test the repeatability of the proposed method were conducted. The repeating test results show that the EMI-based indices are repeatable and there is a great linearity between the NI and the applied loading.

  8. Allostatic Load Assessment for Early Detection of Stress in the Workplace in Egypt.

    Science.gov (United States)

    Ali, Ola Sayed; Badawy, Nadia; Rizk, Sanaa; Gomaa, Hend; Saleh, Mai Sabry

    2016-09-15

    Workplace stress is hazardous for its harmful impact on employees' health and organizational productivity. The aim of the study is to apply the Allostatic Load Index (ALI) which is a multi-component measure for health risk assessment and early detection of stress among workers in Egypt. Sixty-two working adults randomly selected from two different working environments in Egypt were included in the study. Participants completed a self-reported questionnaire for socio-demographic and work variables. Andrews and Withey test for Job Satisfaction was filled and 3 ml blood samples were collected. Markers assessed for Allostatic Load were serum cortisol, c-reactive protein, dehydroepiandrosterone-sulphate, total thyroxine, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein, total cholesterol to high-density lipoprotein ratio, systolic and diastolic blood pressures, waist to hip ratio and body mass index. The risk quartile method was used for calculation of ALI. ALI value of four or more indicates high Allostatic Load. Job satisfaction scale defined about a quarter of the study population (24%) to be dissatisfied with Allostatic Load of 2.4 as the mean value. Population percentage with ALI ≥4 reached 12.9% with 100% of them females. A significant association was found between Allostatic Load of primary mediators and age, the presence of chronic diseases, place of work and female gender. Female gender and the old age of the Egyptian workforce under study are at higher risk of chronic diseases. Using an alternative way -for example, the cut-point method- instead of the risk quartiles for dichotomization of markers used in ALI calculation could be more precise for early detection of stress among healthy individuals.

  9. Embryonic Stem Cells-loaded Gelatin Microcryogels Slow Progression of Chronic Kidney Disease

    Science.gov (United States)

    Geng, Xiao-Dong; Zheng, Wei; Wu, Cong-Mei; Wang, Shu-Qiang; Hong, Quan; Cai, Guang-Yan; Chen, Xiang-Mei; Wu, Di

    2016-01-01

    Background: Chronic kidney disease (CKD) has become a public health problem. New interventions to slow or prevent disease progression are urgently needed. In this setting, cell therapies associated with regenerative effects are attracting increasing interest. We evaluated the effect of embryonic stem cells (ESCs) on the progression of CKD. Methods: Adult male Sprague–Dawley rats were subjected to 5/6 nephrectomy. We used pedicled greater omentum flaps packing ESC-loaded gelatin microcryogels (GMs) on the 5/6 nephrectomized kidney. The viability of ESCs within the GMs was detected using in vitro two-photon fluorescence confocal imaging. Rats were sacrificed after 12 weeks. Renal injury was evaluated using serum creatinine, urea nitrogen, 24 h protein, renal pathology, and tubular injury score results. Structural damage was evaluated by periodic acid-Schiff and Masson trichrome staining. Results: In vitro, ESCs could be automatically loaded into the GMs. Uniform cell distribution, good cell attachment, and viability were achieved from day 1 to 7 in vitro. After 12 weeks, in the pedicled greater omentum flaps packing ESC-loaded GMs on 5/6 nephrectomized rats group, the plasma urea nitrogen levels were 26% lower than in the right nephrectomy group, glomerulosclerosis index was 62% lower and tubular injury index was 40% lower than in the 5/6 nephrectomized rats group without GMs. Conclusions: In a rat model of established CKD, we demonstrated that the pedicled greater omentum flaps packing ESC-loaded GMs on the 5/6 nephrectomized kidney have a long-lasting therapeutic rescue function, as shown by the decreased progression of CKD and reduced glomerular injury. PMID:26879011

  10. Spatial Variation and Assessment of Heavy Metal and Radioactive Risk in Farmland around a Retired Uranium Mine

    Science.gov (United States)

    Liang, Jie; Shi, Chen-hao; Zeng, Guang-ming; Zhong, Min-zhou; Yuan, Yu-jie

    2017-07-01

    In recent years, heavy metal contamination in the environment has been attracted worldwide attention due to their toxicity, persistence,extensive sources and non-biodegradable properties. We herein investigate variation trend and risk of heavy metal and radiation distribution in the former mine stope, former mineral ore stockyard, and mine road with surface soils of a retired uranium mine in the mid-south of China. The mean concentrations (mg/kg) of Pb,Cd,Cu,Zn,As,Hg,Cr,Mn,Ni,U, and 232Th were analyzed according to the corresponding background values in Hunan, China. The Geo-accumulation index (Igeo ) were used for the assessment of pollution level of heavy metals and the radioactive elements of U and 232Th. Then, Pollution load index (PLI) and GIS techniquewere integrated to assess spatial distribution of heavy metal contamination and radioactive contamination. Results confirmed that three areas in the retired uranium mine was a primary source of pollution, which showed anthropogenic origin mainly from agricultural runoff, hydrometallurgy from chemical industries, radioactive tailings, and electroplating industriesfinally drained into Zishui River and Xiangjiang River. Based on the actual situation, some suggestions were put forward for the treatment of the retired uranium mine in conclusion.

  11. Effect of loading pattern on longitudinal bowing in flexible roll forming

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hyun; Woo, Young Yun; Hwang, Tae Woo; Han, Sang Wook; Moon, Young Hoon [School of Mechanical Engineering, Engineering Research Center for Net Shape and Die Manufacturing, Pusan National University,Busan (Korea, Republic of)

    2016-12-15

    The flexible roll forming process can be used to fabricate products with a variable cross-section profile in the longitudinal direction. Transversal nonuniformity of the longitudinal strain is one of the fundamental characteristics of blank deformation in flexible roll forming. Longitudinal bowing is a shape defect caused by transversal nonuniformity of the longitudinal strain. In this study, loading patterns in flexible roll forming are investigated in order to reduce the longitudinal bowing in a roll-formed blank. To analyze the effects of loading patterns on longitudinal bowing, two different forming schedules are implemented. In schedule 1, loading patterns with different bending angle increments are designed under fixed initial and final bending angles. In schedule 2, loading patterns with different initial bending angles under the fixed final bending angle are designed. Our results show that the bowing heights are significantly affected by the loading patterns. The bowing susceptibilities vary with blank shape such as trapezoid, convex, and concave shapes. In addition to the peak longitudinal strain at the respective roll stands, the cumulative longitudinal strain from the initial to final stands is shown to be a reliable index in predicting the tendency of longitudinal bowing.

  12. Respiratory Changes in Response to Cognitive Load: A Systematic Review.

    Science.gov (United States)

    Grassmann, Mariel; Vlemincx, Elke; von Leupoldt, Andreas; Mittelstädt, Justin M; Van den Bergh, Omer

    2016-01-01

    When people focus attention or carry out a demanding task, their breathing changes. But which parameters of respiration vary exactly and can respiration reliably be used as an index of cognitive load? These questions are addressed in the present systematic review of empirical studies investigating respiratory behavior in response to cognitive load. Most reviewed studies were restricted to time and volume parameters while less established, yet meaningful parameters such as respiratory variability have rarely been investigated. The available results show that respiratory behavior generally reflects cognitive processing and that distinct parameters differ in sensitivity: While mentally demanding episodes are clearly marked by faster breathing and higher minute ventilation, respiratory amplitude appears to remain rather stable. The present findings further indicate that total variability in respiratory rate is not systematically affected by cognitive load whereas the correlated fraction decreases. In addition, we found that cognitive load may lead to overbreathing as indicated by decreased end-tidal CO2 but is also accompanied by elevated oxygen consumption and CO2 release. However, additional research is needed to validate the findings on respiratory variability and gas exchange measures. We conclude by outlining recommendations for future research to increase the current understanding of respiration under cognitive load.

  13. Preparation of lumen-loaded kenaf pulp with magnetite (Fe3O4)

    International Nuclear Information System (INIS)

    Zakaria, S.; Ong, B.H.; Ahmad, S.H.; Abdullah, M.; Yamauchi, T.

    2005-01-01

    Magnetic pulps were prepared from unbleached kenaf (hibiscus cannabinus L.) kraft pulps. Fe 3 O 4 or magnetite powder was used to load into the pulp's lumen and pit. Aluminum sulphate [Al 2 (SO 4 ) 3 ] (alum) and polyethylenimine (PEI), both mainly function as retention aid were used throughout the experiment and found to be beneficial in the preparation of this magnetic pulps. The ash content method was used to determine the amount of magnetite retained in the lumen and pit. The utilization of PEI up to 2% per pulp fibres was found to be the best result on lumen loading. The deposition of magnetite powder in lumen and pit is found decrease as the addition of PEI used is more than 2% per pulp fibres. Scanning electron microscope (SEM) clearly shows the distribution of magnetite deposited in the lumen. Tensile index and folding endurance of the loaded fibre decreased slightly as the percentage of loading pigment increased

  14. Daily Air Temperature and Electricity Load in Spain.

    Science.gov (United States)

    Valor, Enric; Meneu, Vicente; Caselles, Vicente

    2001-08-01

    Weather has a significant impact on different sectors of the economy. One of the most sensitive is the electricity market, because power demand is linked to several weather variables, mainly the air temperature. This work analyzes the relationship between electricity load and daily air temperature in Spain, using a population-weighted temperature index. The electricity demand shows a significant trend due to socioeconomic factors, in addition to daily and monthly seasonal effects that have been taken into account to isolate the weather influence on electricity load. The results indicate that the relationship is nonlinear, showing a `comfort interval' of ±3°C around 18°C and two saturation points beyond which the electricity load no longer increases. The analysis has also revealed that the sensitivity of electricity load to daily air temperature has increased along time, in a higher degree for summer than for winter, although the sensitivity in the cold season is always more significant than in the warm season. Two different temperature-derived variables that allow a better characterization of the observed relationship have been used: the heating and cooling degree-days. The regression of electricity data on them defines the heating and cooling demand functions, which show correlation coefficients of 0.79 and 0.87, and predicts electricity load with standard errors of estimate of ±4% and ±2%, respectively. The maximum elasticity of electricity demand is observed at 7 cooling degree-days and 9 heating degree-days, and the saturation points are reached at 11 cooling degree-days and 13 heating degree-days, respectively. These results are helpful in modeling electricity load behavior for predictive purposes.

  15. Scarf Repair of Composite Laminates

    Directory of Open Access Journals (Sweden)

    Xie Zonghong

    2016-01-01

    Full Text Available The use of composite materials, such as carbon-fiber reinforced plastic (CFRP composites, aero-structures has led to an increased need of advanced assembly joining and repair technologies. Adhesive bonded repairs as an alternative to recover full or part of initial strength were investigated. Tests were conducted with the objective of evaluating the effectiveness of techniques used for repairing damage fiber reinforced laminated composites. Failure loads and failure modes were generated and compared with the following parameters: scarf angles, roughness of grind tool and number of external plies. Results showed that scarf angle was the critical parameter and the largest tensile strength was observed with the smallest scarf angle. Besides, the use of external plies at the outer surface could not increase the repairs efficiency for large scarf angle. Preparing the repair surfaces by sanding them with a sander ranging from 60 to 100 grit number had significant effect on the failure load. These results allowed the proposal of design principles for repairing CFRP structures.

  16. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Chunxia, E-mail: cxzhang@mail.iggcas.ac.cn [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Qiao Qingqing [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China); Piper, John D.A. [Geomagnetism Laboratory, Department of Earth and Ocean Science, University of Liverpool, Liverpool L69 7ZE (United Kingdom); Huang, Baochun [State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, No. 19 Bei Tucheng Xilu, Chaoyang Dist., Beijing 100029 (China)

    2011-10-15

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: > Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. > HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. > A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. > The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  17. Comparison of bacillary index on slit skin smear with bacillary index of granuloma in leprosy and its relevance to present therapeutic regimens

    Directory of Open Access Journals (Sweden)

    Sendhil M Kumaran

    2015-01-01

    Full Text Available Background: As the world moves toward elimination of leprosy, persistence of infective cases in endemic pockets remains a significant problem. The use of clinical criteria to decide the paucibacillary (PB versus multibacillary (MB regimens has greatly simplified therapy at the field setting. However, a small but significant risk of under-treatment of so-called "PB" cases which actually have significant bacillary load exists. This study was undertaken to assess this risk and compare two methods of assessment of bacillary load, namely bacillary index on slit skin smear (BIS versus bacillary index of granuloma (BIG. Aims: To compare BIS with BIG on skin biopsy in consecutive untreated cases of leprosy. Materials and Methods: This prospective study was conducted over a period of 12 months, wherein new untreated patients with leprosy were consecutively recruited. After a thorough clinical examination, each patient underwent slit skin smear (SSS where the BIS was calculated. The same patient also underwent a skin biopsy from a clinical lesion where, the BIG was calculated. SSS and skin biopsy for BIS and BIG respectively were repeated for all patients at the end of therapy for comparison. All patients received therapy according to World Health Organization-Multidrug Therapy Guidelines. Results: The BIG was positive in all cases where the BIS was positive. Significantly, BIG was positive in three cases of borderline tuberculoid leprosy with <5 lesions who received PB regimen, whereas the BIS was negative in all three cases. Conclusion: This study suggests that BIG may be a better indicator of the true bacillary load in leprosy as compared to BIS. Its role in management is significant, at least in tertiary care centers to prevent "under-treatment" of so called PB cases, which may actually warrant MB regimens.

  18. FIBER OPTICS: Role of point defects in the photosensitivity of hydrogen-loaded phosphosilicate glass

    Science.gov (United States)

    Larionov, Yu V.

    2010-08-01

    It is shown that point defect modifications in hydrogen-loaded phosphosilicate glass (PSG) do not play a central role in determining its photosensitivity. Photochemical reactions that involve a two-step point defect modification and pre-exposure effect are incapable of accounting for photoinduced refractive index changes. It seems likely that a key role in UV-induced refractive index modifications is played by structural changes in the PSG network. Experimental data are presented that demonstrate intricate network rearrangement dynamics during UV exposure of PSG.

  19. Load research manual. Volume 1. Load research procedures

    Energy Technology Data Exchange (ETDEWEB)

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

  20. Olmesartan medoxomil-loaded mixed micelles: Preparation, characterization and in-vitro evaluation

    Directory of Open Access Journals (Sweden)

    Mohamed A. El-Gendy

    2017-12-01

    Full Text Available Olmesartan medoxomil (OLM is highly lipophilic in nature (log p = 4.31 which attributes to its low aqueous solubility contributing to its low bioavailability 25.6%. OLM was loaded into mixed micelles carriers in a trial to enhance its solubility, thus improving its oral bioavailability. OLM-loaded mixed micelles were prepared, using a Pluronic® mixture of F127 and P123, adopting the thin-film hydration method. Three drug: Pluronic® mixture ratios (1:40, 1:50and 1: 60 and various F127: P123 ratios were prepared. OLM Loaded mixed micelles showed stability up to 12 h. The particle size of the systems varied from 364.00 nm (F3 to 13.73 nm (F18 with accepted Poly dispersity index (PDI values. The in-vitro release studies of OLM from mixed micelles versus drug aqueous suspension were assessed using the reverse dialysis technique in a USP Dissolution tester apparatus (type II. The highest RE% (43% was achieved with OLM-loaded mixed micelles (F8 when compared to (35% of drug suspension.

  1. Enhancing antibacterium and strength of cellulosic paper by coating triclosan-loaded nanofibrillated cellulose (NFC).

    Science.gov (United States)

    Liu, Kai; Chen, Lihui; Huang, Liulian; Ni, Yonghao; Sun, Bo

    2015-03-06

    The nanofibrillated cellulose (NFC) was used as substrates to carry triclosan (TCS), which was then applied as a coating agent for impacting antibacterial property to paper while also improving its strength. The TCS-loaded NFC material was further characterized. UV-vis spectra results showed that a characteristic absorption band at 282 nm was observed, which was attributed to triclosan, confirming its successful loading onto NFC. The antibacterial activity tests indicated that the coated paper exhibited excellent antibacterial activity against Escherichia coli, and the growth inhibition of bacteria (GIB) increased as the loading amount of triclosan coated on paper increased. The GIB can reach 98.7% when the 0.023 g TCS-loaded NFC was coated on paper. Meanwhile, the tensile and tear index of the coated paper increased by 18.0% and 26.4%, respectively compared to the blank paper. Therefore, the triclosan-loaded paper could be potentially used in the medical field. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Equitable fund allocation, an economical approach for sustainable waste load allocation.

    Science.gov (United States)

    Ashtiani, Elham Feizi; Niksokhan, Mohammad Hossein; Jamshidi, Shervin

    2015-08-01

    This research aims to study a novel approach for waste load allocation (WLA) to meet environmental, economical, and equity objectives, simultaneously. For this purpose, based on a simulation-optimization model developed for Haraz River in north of Iran, the waste loads are allocated according to discharge permit market. The non-dominated solutions are initially achieved through multiobjective particle swarm optimization (MOPSO). Here, the violation of environmental standards based on dissolved oxygen (DO) versus biochemical oxidation demand (BOD) removal costs is minimized to find economical total maximum daily loads (TMDLs). This can save 41% in total abatement costs in comparison with the conventional command and control policy. The BOD discharge permit market then increases the revenues to 45%. This framework ensures that the environmental limits are fulfilled but the inequity index is rather high (about 4.65). For instance, the discharge permit buyer may not be satisfied about the equity of WLA. Consequently, it is recommended that a third party or institution should be in charge of reallocating the funds. It means that the polluters which gain benefits by unfair discharges should pay taxes (or funds) to compensate the losses of other polluters. This intends to reduce the costs below the required values of the lowest inequity index condition. These compensations of equitable fund allocation (EFA) may help to reduce the dissatisfactions and develop WLA policies. It is concluded that EFA in integration with water quality trading (WQT) is a promising approach to meet the objectives.

  3. Load power device, system and method of load control and management employing load identification

    Science.gov (United States)

    Yang, Yi; Luebke, Charles John; Schoepf, Thomas J.

    2018-01-09

    A load power device includes a power input, at least one power output for at least one load, a plurality of sensors structured to sense voltage and current at the at least one power output, and a processor. The processor provides: (a) load identification based upon the sensed voltage and current, and (b) load control and management based upon the load identification.

  4. Hygrothermal Analysis and Failure Analysis of Composite Beams under Moving Loads

    Science.gov (United States)

    Hanif, Moiz

    Excellent combination of high structural stiffness and low weight are the qualities of composite material leading to the extensive work on such materials. In order to achieve the desired performance requirements, the designer has to take into consideration the structural requirements and the functional characteristics. Thus, in this study, the effect of hygrothermal conditions on fiber reinforced composite laminates with moving loads have been extensively studied and has been carried out that accompanies Classical Laminate Plate Theory (CLPT) as well as First Order Shear Deformation Theory (FSDT) on MATLAB. A glass/epoxy composite system has been chosen for study with which similar results may be expected for other laminated composites. The hygrothermal effect is incorporated by adjusting the stiffness coefficients of the laminate to its level of moisture concentration using empirical relations. The failure analysis is done using the maximum normal stress criterion and the factor of safety for the lamina calculated and compared with respect to the corresponding maximum stresses and strengths. Different fiber volume fraction with varying fiber orientation of the plies in the laminate were modeled and studied. The results presented show the effect of stresses and strains in dry conditions, whereas for hygrothermal analysis, they also indicate that not all the laminates behave in a similar fashion and so it is possible by selecting the proper laminate configuration, the effect of moisture can be reduced. Also deducing, that due to hygrothermal effects, changes in the stiffness coefficients of a laminate do not appear to affect the deflection results significantly.

  5. Performance Analysis of Radial Distribution Systems with UPQC and D-STATCOM

    Science.gov (United States)

    Gupta, Atma Ram; Kumar, Ashwani

    2017-08-01

    This paper presents an effective method for finding optimum location of unified power quality conditioner (UPQC) and distributed static compensator (D-STATCOM) in radial distribution system. The bus having the minimum losses is selected as the candidate bus for UPQC placement and the optimal location of D-STATCOM is found by power loss index (PLI) method. The PLI values of all the buses are calculated and the bus having the highest PLI value is the most favorable bus and thus selected as candidate bus for D-STATCOM placement. Main contribution of this paper are: (i) finding optimum location of UPQC in radial distribution system (RDS) based on minimum power loss; (ii) finding the optimal size of UPQC which offers minimum losses; (iii) calculation of annual energy saving using UPQC and D-STATCOM; (iv) cost analysis with and without UPQC and D-STATCOM placement; and (v) comparison of results with and without UPQC and D-STATCOM placement in RDS. The algorithm is tested on IEEE 33-bus and 69-bus radial distribution systems by using MATLAB software.

  6. Lifting index of the niosh lifting equation and low back pain

    Directory of Open Access Journals (Sweden)

    Eliana Remor Teixeira

    2011-09-01

    Full Text Available The purpose of this study is to assess the relationship of the Lifting Index obtained through the application of the NIOSH Lifting Equation and the incidence of low back pain among forty-eight workers involved in manual lifting tasks. It was applied the equation in eleven tasks and the workers were interviewed. The most unfavorable conditions presented themselves in the lifting destination. The variables that most contributed to the inadequate values of the Lifting Index were: the horizontal location, the lifting frequency and the vertical distance, beyond the high weight of the load. The incidence of low back pain in the last twelve months was 19%, whereas the incidence of work-related low back pain in the same period was 10%. In 72.7% of the tasks evaluated the Composite Lifting Index was more than three, which are considered as high ergonomic risk.

  7. Advanced aircraft service life monitoring method via flight-by-flight load spectra

    Science.gov (United States)

    Lee, Hongchul

    This research is an effort to understand current method and to propose an advanced method for Damage Tolerance Analysis (DTA) for the purpose of monitoring the aircraft service life. As one of tasks in the DTA, the current indirect Individual Aircraft Tracking (IAT) method for the F-16C/D Block 32 does not properly represent changes in flight usage severity affecting structural fatigue life. Therefore, an advanced aircraft service life monitoring method based on flight-by-flight load spectra is proposed and recommended for IAT program to track consumed fatigue life as an alternative to the current method which is based on the crack severity index (CSI) value. Damage Tolerance is one of aircraft design philosophies to ensure that aging aircrafts satisfy structural reliability in terms of fatigue failures throughout their service periods. IAT program, one of the most important tasks of DTA, is able to track potential structural crack growth at critical areas in the major airframe structural components of individual aircraft. The F-16C/D aircraft is equipped with a flight data recorder to monitor flight usage and provide the data to support structural load analysis. However, limited memory of flight data recorder allows user to monitor individual aircraft fatigue usage in terms of only the vertical inertia (NzW) data for calculating Crack Severity Index (CSI) value which defines the relative maneuver severity. Current IAT method for the F-16C/D Block 32 based on CSI value calculated from NzW is shown to be not accurate enough to monitor individual aircraft fatigue usage due to several problems. The proposed advanced aircraft service life monitoring method based on flight-by-flight load spectra is recommended as an improved method for the F-16C/D Block 32 aircraft. Flight-by-flight load spectra was generated from downloaded Crash Survival Flight Data Recorder (CSFDR) data by calculating loads for each time hack in selected flight data utilizing loads equations. From

  8. Heavy metal enrichment and ecological risk assessment of surface sediments in Khorramabad River, West Iran.

    Science.gov (United States)

    Rastmanesh, F; Safaie, S; Zarasvandi, A R; Edraki, M

    2018-04-11

    The ecological health of rivers has often been threatened in urbanized catchments due to the expansion of industrial activities and the population growth. Khorramabad River which flows through Khorramabad city, west of Iran, is an example of such settings. The river water is used for agricultural purposes downstream. In this study, the effect of Khorramabad city on heavy metal and metalloid (Cu, Pb, Zn, Ni, Cr, and As) loads in Khorramabad River sediments was investigated. To evaluate sediment pollution and potential adverse biological effects, surface sediment samples were collected at selected locations along the river and were characterized for their geochemical properties. Contamination factor (CF), pollution load index (PLI), and ecological risk assessment (RI) were calculated. Also, sediment quality guidelines (SQGs) were used to screen contaminants of concern in the study area. The results showed that sediments were moderately polluted, with stations located in more densely populated areas showing higher pollution indicators. Copper, Zn, and Pb sources could be attributed to urban wastewater, whereas Ni, Cr, and As had both natural and anthropogenic sources. Moreover, ecological risk assessments showed that sediments could be classified in the category of low risk. The results of the present study showed the effect of anthropogenic activities on heavy metal loads of the river sediments and these findings can be used to mitigate potential impacts on the environment and human health.

  9. Assessment of the distribution, bioavailability and ecological risks of heavy metals in the lake water and surface sediments of the Caohai plateau wetland, China

    Science.gov (United States)

    Hu, Jing; Zhou, Shaoqi; Wu, Pan; Qu, Kunjie

    2017-01-01

    In this study, selected heavy metals (Hg, As, Cd, Pb, Cr, Cu and Zn) in the lake water and sediments from the Caohai wetland, which is a valuable state reserve for migrant birds in China, were investigated to assess the spatial distribution, sources, bioavailability and ecological risks. The results suggested that most of the higher concentrations were found in the eastern region of the lakeshore. The concentration factor (CF) revealed that Hg, Cd and Zn were present from moderate risk levels to considerable risk levels in this study; thus, based on the high pollution load index (PLI) values, the Caohai wetland can be considered polluted. According to the associated effects-range classification, Cd may present substantial environmental hazards. An investigation of the chemical speciation suggested that Cd and Zn were unstable across most of the sites, which implied a higher risk of quick desorption and release. Principal component analysis (PCA) indicated that the heavy metal contamination originated from both natural and anthropogenic sources. PMID:29253896

  10. Seasonal comparison of moss bag technique against vertical snow samples for monitoring atmospheric pollution.

    Science.gov (United States)

    Salo, Hanna; Berisha, Anna-Kaisa; Mäkinen, Joni

    2016-03-01

    This is the first study seasonally applying Sphagnum papillosum moss bags and vertical snow samples for monitoring atmospheric pollution. Moss bags, exposed in January, were collected together with snow samples by early March 2012 near the Harjavalta Industrial Park in southwest Finland. Magnetic, chemical, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), K-means clustering, and Tomlinson pollution load index (PLI) data showed parallel spatial trends of pollution dispersal for both materials. Results strengthen previous findings that concentrate and slag handling activities were important (dust) emission sources while the impact from Cu-Ni smelter's pipe remained secondary at closer distances. Statistically significant correlations existed between the variables of snow and moss bags. As a summary, both methods work well for sampling and are efficient pollutant accumulators. Moss bags can be used also in winter conditions and they provide more homogeneous and better controlled sampling method than snow samples. Copyright © 2015. Published by Elsevier B.V.

  11. Assessment of the distribution, bioavailability and ecological risks of heavy metals in the lake water and surface sediments of the Caohai plateau wetland, China.

    Directory of Open Access Journals (Sweden)

    Jing Hu

    Full Text Available In this study, selected heavy metals (Hg, As, Cd, Pb, Cr, Cu and Zn in the lake water and sediments from the Caohai wetland, which is a valuable state reserve for migrant birds in China, were investigated to assess the spatial distribution, sources, bioavailability and ecological risks. The results suggested that most of the higher concentrations were found in the eastern region of the lakeshore. The concentration factor (CF revealed that Hg, Cd and Zn were present from moderate risk levels to considerable risk levels in this study; thus, based on the high pollution load index (PLI values, the Caohai wetland can be considered polluted. According to the associated effects-range classification, Cd may present substantial environmental hazards. An investigation of the chemical speciation suggested that Cd and Zn were unstable across most of the sites, which implied a higher risk of quick desorption and release. Principal component analysis (PCA indicated that the heavy metal contamination originated from both natural and anthropogenic sources.

  12. An Elastic Charging Service Fee-Based Load Guiding Strategy for Fast Charging Stations

    Directory of Open Access Journals (Sweden)

    Shu Su

    2017-05-01

    Full Text Available Compared with the traditional slow charging loads, random integration of large scale fast charging loads will exert more serious impacts on the security of power network operation. Besides, to maximize social benefits, effective scheduling strategies guiding fast charging behaviors should be formulated rather than simply increasing infrastructure construction investments on the power grid. This paper first analyzes the charging users’ various responses to an elastic charging service fee, and introduces the index of charging balance degree to a target region by considering the influence of fast charging loads on the power grid. Then, a multi-objective optimization model of the fast charging service fee is constructed, whose service fee can be further optimized by employing a fuzzy programming method. Therefore, both users’ satisfaction degree and the equilibrium of charging loads can be maintained simultaneously by reasonably guiding electric vehicles (EVs to different fast charging stations. The simulation results demonstrate the effectiveness of the proposed dynamic charging service pricing and the corresponding fast charging load guidance strategy.

  13. Sleep restriction and cognitive load affect performance on a simulated marksmanship task.

    Science.gov (United States)

    Smith, Carl D; Cooper, Adam D; Merullo, Donna J; Cohen, Bruce S; Heaton, Kristin J; Claro, Pedro J; Smith, Tracey

    2017-11-24

    Sleep restriction degrades cognitive and motor performance, which can adversely impact job performance and increase the risk of accidents. Military personnel are prone to operating under sleep restriction, and previous work suggests that military marksmanship may be negatively affected under such conditions. Results of these studies, however, are mixed and have often incorporated additional stressors (e.g. energy restriction) beyond sleep restriction. Moreover, few studies have investigated how the degree of difficulty of a marksmanship task impacts performance following sleep restriction. The purpose of the current experiment was to study the effects of sleep restriction on marksmanship while minimizing the potential influence of other forms of stress. A friend-foe discrimination challenge with greater or lesser degrees of complexity (high versus low load) was used as the primary marksmanship task. Active duty Soldiers were recruited, and allowed 2 h of sleep every 24 h over a 72-h testing period. Marksmanship tasks, cognitive assessment metrics and the NASA-Task Load Index were administered daily. Results indicated that reaction times to shoot foe targets and signal friendly targets slowed over time. In addition, the ability to correctly discriminate between friend and foe targets significantly decreased in the high-cognitive-load condition over time despite shot accuracy remaining stable. The NASA-Task Load Index revealed that, although marksmanship performance degraded, participants believed their performance did not change over time. These results further characterize the consequences of sleep restriction on marksmanship performance and the perception of performance, and reinforce the importance of adequate sleep among service members when feasible. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  14. The influence of removable partial dentures on the periodontal health of abutment and non-abutment teeth

    OpenAIRE

    Dula, Linda J.; Shala, Kujtim Sh.; Pustina–Krasniqi, Teuta; Bicaj, Teuta; Ahmedi, Enis F.

    2015-01-01

    Objective: The aim of this study was to evaluate the influence of removable partial dentures (RPD) on the periodontal health of abutment and non-abutment teeth. Materials and Methods: A total 107 patients with RPD participated in this study. It was examined 138 RPD, they were 87 with clasp-retained and 51 were RPD with attachments. The following periodontal parameters were evaluated for abutment and non-abutment teeth, plaque index (PLI), calculus index (CI), bleeding on probing (BOP), probin...

  15. TyG index, HOMA score and viral load in patients with chronic hepatitis C due to genotype 1.

    Science.gov (United States)

    Petta, S; Di Marco, V; Di Stefano, R; Cabibi, D; Cammà, C; Marchesini, G; Craxì, A

    2011-07-01

    The triglycerides × glucose (TyG) index is a recently proposed surrogate marker of insulin resistance (IR), calculated from fasting plasma triglyceride and glucose concentrations. We tested the host and viral factors associated with Tyg and homeostasis model assessment (HOMA) scores, comparing their associations with histological features and with sustained virological response (SVR) in patients with genotype 1 chronic hepatitis C(G1CHC). Three hundred and forty consecutive patients with G1CHC were considered. All had a liver biopsy scored by one pathologist for staging and grading (Scheuer), and graded for steatosis, which was considered moderate-severe if ≥30%. Anthropometric and metabolic measurements, including IR measured by both HOMA and TyG, were registered. By linear regression analysis, TyG was independently associated with waist circumference (WC), total cholesterol, presence of arterial hypertension, Log10 HCV-RNA and steatosis. Similarly, WC and steatosis were significantly associated with HOMA. Older age (OR, 1.036; 95%CI, 1.004-1.070, P = 0.02), higher WC (1.031; 1.004-1.060; P = 0.02) and higher TyG (11.496; 3.163-41.784; P HOMA-IR in the model, the latter remained significantly associated with steatosis ≥30% (1.237; 1.058-1.448; P = 0.008). Receiver operating characteristic curves showed a similar performance of TyG (AUC 0.682) and HOMA-IR (AUC 0.699) in predicting moderate-severe steatosis. No independent associations were found between both TyG and HOMA and fibrosis or SVR. In patients with G1CHC , TyG, an easy-to-calculate and low-cost surrogate marker of IR, is linked to liver steatosis and shows an independent association with viral load. © 2011 Blackwell Publishing Ltd.

  16. Analysis and Tests of Reinforced Carbon-Epoxy/Foam-Core Sandwich Panels with Cutouts

    Science.gov (United States)

    Baker, Donald J.; Rogers, Charles

    1996-01-01

    The results of a study of a low-cost structurally efficient minimum-gage shear-panel design that can be used in light helicopters are presented. The shear-panel design is based on an integrally stiffened syntactic-foam stabilized-skin with an all-bias-ply tape construction for stabilized-skin concept with an all-bias-ply tape construction for the skins. This sandwich concept is an economical way to increase the panel bending stiffness weight penalty. The panels considered in the study were designed to be buckling resistant up to 100 lbs/in. of shear load and to have an ultimate strength of 300 lbs/in. The panel concept uses unidirectional carbon-epoxy tape on a syntactic adhesive as a stiffener that is co-cured with the skin and is an effective concept for improving panel buckling strength. The panel concept also uses pultruded carbon-epoxy rods embedded in a syntactic adhesive and over-wrapped with a bias-ply carbon-epoxy tape to form a reinforcing beam which is an effective method for redistributing load around rectangular cutout. The buckling strength of the reinforced panels is 83 to 90 percent of the predicted buckling strength based on a linear buckling analysis. The maximum experimental deflection exceeds the maximum deflection predicted by a nonlinear analysis by approximately one panel thickness. The failure strength of the reinforced panels was two and a half to seven times of the buckling strength. This efficient shear-panel design concept exceeds the required ultimate strength requirement of 300 lbs/in by more than 100 percent.

  17. Comments on derivation of an index for evaluating economics of cogeneration systems and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, R [Indian Inst. of Tech., Bombay (India). Dept. of Mechanical Engineering

    1990-04-01

    Industrial cogeneration systems usually must satisfy a power load and heat loads at different temperatures. The limitations of the economic index proposed by Pak and Suzuki for such cogeneration systems is discussed in this paper. The importance of a rational exergetic basis for evaluation of different grades of energy is emphasised. Thermodynamic criteria, e.g. the exergetic efficiency, relative fuel savings and fuel chargeable to power, are shown to provide useful information regarding cogeneration options. Any assessment scheme for cogeneration schemes must incorporate thermodynamic criteria in addition to economic criteria. (author).

  18. Experimental study on behavior of steel channel strengthened with CFRP

    Directory of Open Access Journals (Sweden)

    Tang Hongyuan

    2017-11-01

    Full Text Available This paper describes the behaviour of axially loaded long and eccentrically loaded short thin-walled steel channels, strengthened with transversely bonded carbon fibre reinforced polymer (CFRP sheets. Seven long members, each 1400 mm long, and seven short members, each 750mmlong, were tested. The main parameters were the number of CFRP plies (one or two and the clear spacing between the CFRP strips (50, 100 or 150 mm. The effect of CFRP sheet layer and clear spacing was studied. All the ultimate load capacity of the reinforced members was improved in different extent. A maximum strength gain of 9.13% was achieved for long members with two CFRP layers and 50 mm spacing of CFRP strips. The experimental results show that the global buckling happens to all the long specimens. For short members, the maximum strength gain of 12.1% was achieved with two CFRP layers and 50 mm spacing of CFRP strips. With the exception of the most heavily reinforced (2 plies at 50 and 100 mm, local buckling was observed prior to global buckling for short members, which was completely opposite of the control specimens. Meanwhile, when the clear spacing of CFRP strips is greater than theweb height of steel channel, the transversely bonded CFRP does not have a significant improvement in buckling load capacity of the short- and long-channel components. While the clear spacing is less than the web height, the more number of CFRP layer, the more enhancement of buckling load capacity.

  19. The effect of consumption of low-glycemic-index and low-glycemic-load desserts on anthropometric parameters and inflammatory markers in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Argiana, Vasiliki; Kanellos, Panagiotis Τ; Makrilakis, Konstantinos; Eleftheriadou, Ioanna; Tsitsinakis, Georgios; Kokkinos, Alexander; Perrea, Despina; Tentolouris, Nikolaos

    2015-10-01

    The aim of the present study was to examine the effects of consumption of desserts with low glycemic index (GI) and low glycemic load (GL), as part of a balanced hypo-caloric diet, on anthropometric and biochemical parameters in patients with type 2 diabetes mellitus (T2DM). A total of 61 subjects with T2DM were randomly assigned to the intervention (n = 30) or to the control group (n = 31). Both groups followed the same hypo-caloric (-500 kcal) diet for 12 weeks. Consumption of four portions of low-GI/low-GL desserts/week was included in the diet in the intervention group while one portion of a favorite usual sweet/week was allowed to be consumed in the control group. Thirty subjects in the control and 28 subjects in the intervention group completed the trial. Body weight, body mass index, and waist circumference were reduced significantly in both groups. Arterial blood pressure, fasting blood glucose, glycosylated hemoglobin, insulin, and γ-GT were reduced significantly only in the intervention group; however, there were no significant differences between the two groups at endpoint. C-reactive protein was reduced in the intervention, and HDL cholesterol was also reduced in the control group; the reductions were significantly different at the end of the trial. No significant changes were observed in the other plasma lipids, uric acid, leptin, adiponectin, and interleukin-6 in either study group. Consumption of desserts with low GI/GL in a balanced hypo-caloric diet has a positive impact on anthropometric and metabolic parameters of patients with T2DM.

  20. Metal pollution assessment in the surface sediment of Lake Nasser, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed E. Goher

    2014-01-01

    Full Text Available Eight heavy metals were measured seasonally in the sediment of Lake Nasser during 2013. 27 sites were chosen through 9 sectors across the main channel of the lake from Abu-Simbel to Aswan High Dam to assess the levels of the selected metals. The abundance of these metals was in the order of Fe > Mn > Zn > Cr > Ni > Cu > Pb > Cd, with mean concentrations of 12.41 mg/g, 279.56, 35.38, 30.79, 27.56, 21.78, 11.21 and 0.183 μg/g, respectively. Heavy metals are positively correlated with fine particles (mud fractions and organic matter accumulation. The results showed perspicuous spatial high significant differences (P < 0.01 for all the measured metals. Fe, Cr, Ni, Pb and Cd exhibited temporally high significant differences (P < 0.01 before and after the flood period. Four Pollution Indices were used for the environmental assessment of Lake Nasser sediment. The indices included three single indices, Enrichment Factor (EF, Index of Geo-accumulation (Igeo and Contamination Factor (CF. While the fourth, Pollution Load Index (PLI was an integrated index. The pollution indexes confirmed that the Lake Nasser sediment was not contaminated with these elements. Sediments of Lake Nasser may be represented as a reference for the pre-industrial background of River Nile Sediments downstream Aswan High Dam.

  1. Development and implementation of a novel measure for quantifying training loads in rowing: the T2minute method.

    Science.gov (United States)

    Tran, Jacqueline; Rice, Anthony J; Main, Luana C; Gastin, Paul B

    2014-04-01

    The systematic management of training requires accurate training load measurement. However, quantifying the training of elite Australian rowers is challenging because of (a) the multicenter, multistate structure of the national program; (b) the variety of training undertaken; and (c) the limitations of existing methods for quantifying the loads accumulated from varied training formats. Therefore, the purpose of this project was to develop a new measure for quantifying training loads in rowing (the T2minute method). Sport scientists and senior coaches at the National Rowing Center of Excellence collaborated to develop the measure, which incorporates training duration, intensity, and mode to quantify a single index of training load. To account for training at different intensities, the method uses standardized intensity zones (T zones) established at the Australian Institute of Sport. Each zone was assigned a weighting factor according to the curvilinear relationship between power output and blood lactate response. Each training mode was assigned a weighting factor based on whether coaches perceived it to be "harder" or "easier" than on-water rowing. A common measurement unit, the T2minute, was defined to normalize sessions in different modes to a single index of load; one T2minute is equivalent to 1 minute of on-water single scull rowing at T2 intensity (approximately 60-72% VO2max). The T2minute method was successfully implemented to support national training strategies in Australian high performance rowing. By incorporating duration, intensity, and mode, the T2minute method extends the concepts that underpin current load measures, providing 1 consistent system to quantify loads from varied training formats.

  2. A systemic ecological risk assessment based on spatial distribution and source apportionment in the abandoned lead acid battery plant zone, China.

    Science.gov (United States)

    Zhang, Yimei; Li, Shuai; Chen, Zhuang; Wang, Fei; Chen, Jie; Wang, Liqun

    2018-07-15

    In China, potential heavy metal hazard around abandoned lead-acid battery plant (ALBP) area has been a great concern but without detailed report. The distribution and sources of heavy metals in soils and so by risk assessment associated with ALBP are conducted in this contribution, based on geographies and statistics. Pb and Zn are quantitively identified to be still emitted from ALBP soil, and Cd as well As are from agricultural activity. We investigate vertical metal distribution, and fortunately find that metals migrate within limit of 40 cm below topsoil, which is higher than groundwater table. The visualized stable depths are Zn 40 cm, Pb, As 20 cm, and Cd 40 cm. The mapped pollution load index (PLI) suggests a high pollution level exists in ALBP soil. The estimation of potential ecological risk index (PERI) indicates a light ecological risk in studied area, while As and Cd mainly from agricultural activity possess 54% of total E ri . Health risk index (THI) is 0.178 for children, indicating non-cancer risks may be ignored in observed area. Though calculated risk is temporarily affordable, soil remediation and reduction of agricultural chemical reagents are recommended for preventing potential cumulative risk from further bioconcentration of heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. On the Mechanical Behavior of Advanced Composite Material Structures

    Science.gov (United States)

    Vinson, Jack

    During the period between 1993 and 2004, the author, as well as some colleagues and graduate students, had the honor to be supported by the Office of Naval Research to conduct research in several aspects of the behavior of structures composed of composite materials. The topics involved in this research program were numerous, but all contributed to increasing the understanding of how various structures that are useful for marine applications behaved. More specifically, the research topics focused on the reaction of structures that were made of fiber reinforced polymer matrix composites when subjected to various loads and environmental conditions. This included the behavior of beam, plate/panel and shell structures. It involved studies that are applicable to fiberglass, graphite/carbon and Kevlar fibers imbedded in epoxy, polyester and other polymeric matrices. Unidirectional, cross-ply, angle ply, and woven composites were involved, both in laminated, monocoque as well as in sandwich constructions. Mid-plane symmetric as well as asymmetric laminates were studied, the latter involving bending-stretching coupling and other couplings that only can be achieved with advanced composite materials. The composite structures studied involved static loads, dynamic loading, shock loading as well as thermal and hygrothermal environments. One major consideration was determining the mechanical properties of composite materials subjected to high strain rates because the mechanical properties vary so significantly as the strain rate increases. A considerable number of references are cited for further reading and study for those interested.

  4. Design and Analysis of Tow-Steered Composite Shells Using Fiber Placement

    Science.gov (United States)

    Wu, K. Chauncey

    2008-01-01

    In this study, a sub-scale advanced composite shell design is evaluated to determine its potential for use on a future aircraft fuselage. Two composite shells with the same nominal 8-ply [+/-45/+/-Theta](sub s) layup are evaluated, where Theta indicates a tow-steered ply. To build this shell, a fiber placement machine would be used to steer unidirectional prepreg tows as they are placed around the circumference of a 17-inch diameter right circular cylinder. The fiber orientation angle varies continuously from 10 degrees (with respect to the shell axis of revolution) at the crown, to 45 degrees on the side, and back to 10 degrees on the keel. All 24 tows are placed at each point on every fiber path in one structure designated as the shell with overlaps. The resulting pattern of tow overlaps causes the laminate thickness to vary between 8 and 16 plies. The second shell without tow overlaps uses the capability of the fiber placement machine to cut and add tows at any point along the fiber paths to fabricate a shell with a nearly uniform 8-ply laminate thickness. Issues encountered during the design and analysis of these shells are presented and discussed. Static stiffness and buckling loads of shells with tow-steered layups are compared with the performance of a baseline quasi-isotropic shell using both finite element analyses and classical strength of materials theory.

  5. Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method

    International Nuclear Information System (INIS)

    Lee, Seokje; Kim, Ingul; Jang, Moonho; Kim, Jaeki; Moon, Jungwon

    2013-01-01

    Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using Callosum and Meatball interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle

  6. Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seokje; Kim, Ingul [Chungnam National Univ., Daejeon (Korea, Republic of); Jang, Moonho; Kim, Jaeki; Moon, Jungwon [LIG Nex1, Yongin (Korea, Republic of)

    2013-04-15

    Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using Callosum and Meatball interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle.

  7. Fatigue life prediction in woven carbon fabric polyester composites

    International Nuclear Information System (INIS)

    Khan, Z.; Al-Sulaiman, F.S.; Farooqi, J.K.

    1999-01-01

    An analytical model, based on stiffness degradation during fatigue loading, which has been used for fatigue life predictions in the Fiber Reinforced Plastics (FRP), is employed to examine its validity to the fatigue life predictions in the Woven Fabric Reinforced Plastics. The rate of stiffness degradation (dE/dN) has been obtained from the constant amplitude fatigue testing of 8-ply coupons made from prepreg plain-weave woven carbon-carbon fabric having a polyester resin as the matrix material. The test coupons had three different ply stacking sequences, namely, the unidirectional (0)8,and two off axis plied (0,0,+45,-45)s, and (+45,-45,0,0)s orientations. The estimated fatigue lives obtained from the damage rate function dD/dN, which in turn was a function of the stiffness degradation rate dE/dN, were compared with the experimentally observed fatigue life data. It is shown that the stiffness degradation model provides reasonably good correlation between the analytically determined fatigue lives and the experimentally observed fatigue for the plain-weave woven Carbon-Carbon Fabric Reinforced Plastic Composites. (author)

  8. Micromechanics and Piezo Enhancements of HyperSizer

    Science.gov (United States)

    Arnold, Steven M.; Bednarcyk, Brett A.; Yarrington, Phillip; Collier, Craig S.

    2006-01-01

    The commercial HyperSizer aerospace-composite-material-structure-sizing software has been enhanced by incorporating capabilities for representing coupled thermal, piezoelectric, and piezomagnetic effects on the levels of plies, laminates, and stiffened panels. This enhancement is based on a formulation similar to that of the pre-existing HyperSizer capability for representing thermal effects. As a result of this enhancement, the electric and/or magnetic response of a material or structure to a mechanical or thermal load, or its mechanical response to an applied electric or magnetic field can be predicted. In another major enhancement, a capability for representing micromechanical effects has been added by establishment of a linkage between HyperSizer and Glenn Research Center s Micromechanics Analysis Code With Generalized Method of Cells (MAC/GMC) computer program, which was described in several prior NASA Tech Briefs articles. The linkage enables Hyper- Sizer to localize to the fiber and matrix level rather than only to the ply level, making it possible to predict local failures and to predict properties of plies from those of the component fiber and matrix materials. Advanced graphical user interfaces and database structures have been developed to support the new HyperSizer micromechanics capabilities.

  9. Acoustic analysis with vocal loading test in occupational voice disorders: outcomes before and after voice therapy.

    Science.gov (United States)

    Niebudek-Bogusz, Ewa; Kotyło, Piotr; Politański, Piotr; Sliwińska-Kowalska, Mariola

    2008-01-01

    To assess the usefulness of acoustic analysis with vocal loading test for evaluating the treatment outcomes in occupational voice disorders. Fifty-one female teachers with dysphonia were examined (Voice Handicap Index--VHI, laryngovideostroboscopy and acoustic analysis with vocal loading) before and after treatment. The outcomes of teachers receiving vocal training (group I) were referred to outcomes of group II receiving only voice hygiene instructions. The results of subjective assessment (VHI score) and objective evaluation (acoustic analysis) improved more significantly in group I than in group II. The post-treatment examination revealed a decreased percentage of subjects with deteriorated jitter parameters after vocal loading, particularly in group I. Acoustic analysis with vocal loading test can be a helpful tool in the diagnosis and evaluation of treatment efficacy in occupational dysphonia.

  10. Distribution load forecast with interactive correction of horizon loads

    International Nuclear Information System (INIS)

    Glamochanin, V.; Andonov, D.; Gagovski, I.

    1994-01-01

    This paper presents the interactive distribution load forecast application that performs the distribution load forecast with interactive correction of horizon loads. It consists of two major parts implemented in Fortran and Visual Basic. The Fortran part is used for the forecasts computations. It consists of two methods: Load Transfer Coupling Curve Fitting (LTCCF) and load Forecast Using Curve Shape Clustering (FUCSC). LTCCF is used to 'correct' the contaminated data because of load transfer among neighboring distribution areas. FUCSC uses curve shape clustering to forecast the distribution loads of small areas. The forecast for each small area is achieved by using the shape of corresponding cluster curve. The comparison of forecasted loads of the area with historical data will be used as a tool for the correction of the estimated horizon load. The Visual Basic part is used to provide flexible interactive user-friendly environment. (author). 5 refs., 3 figs

  11. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    An effort is made to study the thermoelastic behaviour of a cross-ply laminated composite skew plate with elliptical cutout subjected to pressure and non-linearly varying temperature loading in the present analysis. Orientation of the elliptical cut out is varied from 0° to 180° with respect to horizontal at an interval of 30° in the ...

  12. Deformation response of gellan gum based bone scaffold subjected to uniaxial quasi-static loading

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Krčmářová, Nela; Šleichrt, Jan; Fíla, Tomáš; Koudelka_ml., Petr; Gantar, A.; Novak, S.

    2017-01-01

    Roč. 57, č. 1 (2017), s. 14-21 ISSN 1210-2709 EU Projects: European Commission(XE) ATCZ38 Institutional support: RVO:68378297 Keywords : gellan gum scaffold * reinforcement * uni-axial loading Subject RIV: JJ - Other Materials OBOR OECD: Materials engineering https://ojs.cvut.cz/ojs/index.php/ap/article/view/3885

  13. Study on the Measurement and Calculation of Environmental Pollution Bearing Index of China’s Pig Scale

    Science.gov (United States)

    Leng, Bi-Bin; Gong, Jian; Zhang, Wen-bo; Ji, Xue-Qiang

    2017-11-01

    According to the environmental pollution caused by large-scale pig breeding, the SPSS statistical software and factor analysis method were used to calculate the environmental pollution bearing index of China’s breeding scale from 2006 to 2015. The results showed that with the increase of scale the density of live pig farming and the amount of fertilizer application in agricultural production increased. However, due to the improvement of national environmental awareness, industrial waste water discharge is greatly reduced. China's hog farming environmental pollution load index is rising.

  14. Effect of dietary iron loading on recognition memory in growing rats.

    Directory of Open Access Journals (Sweden)

    Murui Han

    Full Text Available While nutritional and neurobehavioral problems are associated with both iron deficiency during growth and overload in the elderly, the effect of iron loading in growing ages on neurobehavioral performance has not been fully explored. To characterize the role of dietary iron loading in memory function in the young, weanling rats were fed iron-loading diet (10,000 mg iron/kg diet or iron-adequate control diet (50 mg/kg for one month, during which a battery of behavioral tests were conducted. Iron-loaded rats displayed elevated non-heme iron levels in serum and liver, indicating a condition of systemic iron overload. In the brain, non-heme iron was elevated in the prefrontal cortex of iron-loaded rats compared with controls, whereas there was no difference in iron content in other brain regions between the two diet groups. While iron loading did not alter motor coordination or anxiety-like behavior, iron-loaded rats exhibited a better recognition memory, as represented by an increased novel object recognition index (22% increase from the reference value than control rats (12% increase; P=0.047. Western blot analysis showed an up-regulation of dopamine receptor 1 in the prefrontal cortex from iron-loaded rats (142% increase; P=0.002. Furthermore, levels of glutamate receptors (both NMDA and AMPA and nicotinic acetylcholine receptor (nAChR were significantly elevated in the prefrontal cortex of iron-loaded rats (62% increase in NR1; 70% increase in Glu1A; 115% increase in nAChR. Dietary iron loading also increased the expression of NMDA receptors and nAChR in the hippocampus. These results support the idea that iron is essential for learning and memory and further reveal that iron supplementation during developmental and rapidly growing periods of life improves memory performance. Our investigation also demonstrates that both cholinergic and glutamatergic neurotransmission pathways are regulated by dietary iron and provides a molecular basis for the

  15. The effect of epoch length on estimated EEG functional connectivity and brain network organisation

    Science.gov (United States)

    Fraschini, Matteo; Demuru, Matteo; Crobe, Alessandra; Marrosu, Francesco; Stam, Cornelis J.; Hillebrand, Arjan

    2016-06-01

    Objective. Graph theory and network science tools have revealed fundamental mechanisms of functional brain organization in resting-state M/EEG analysis. Nevertheless, it is still not clearly understood how several methodological aspects may bias the topology of the reconstructed functional networks. In this context, the literature shows inconsistency in the chosen length of the selected epochs, impeding a meaningful comparison between results from different studies. Approach. The aim of this study was to provide a network approach insensitive to the effects that epoch length has on functional connectivity and network reconstruction. Two different measures, the phase lag index (PLI) and the amplitude envelope correlation (AEC) were applied to EEG resting-state recordings for a group of 18 healthy volunteers using non-overlapping epochs with variable length (1, 2, 4, 6, 8, 10, 12, 14 and 16 s). Weighted clustering coefficient (CCw), weighted characteristic path length (L w) and minimum spanning tree (MST) parameters were computed to evaluate the network topology. The analysis was performed on both scalp and source-space data. Main results. Results from scalp analysis show a decrease in both mean PLI and AEC values with an increase in epoch length, with a tendency to stabilize at a length of 12 s for PLI and 6 s for AEC. Moreover, CCw and L w show very similar behaviour, with metrics based on AEC more reliable in terms of stability. In general, MST parameters stabilize at short epoch lengths, particularly for MSTs based on PLI (1-6 s versus 4-8 s for AEC). At the source-level the results were even more reliable, with stability already at 1 s duration for PLI-based MSTs. Significance. The present work suggests that both PLI and AEC depend on epoch length and that this has an impact on the reconstructed network topology, particularly at the scalp-level. Source-level MST topology is less sensitive to differences in epoch length, therefore enabling the comparison of brain

  16. Preparation of lumen-loaded kenaf pulp with magnetite (Fe{sub 3}O{sub 4})

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, S.; Ong, B.H.; Ahmad, S.H.; Abdullah, M.; Yamauchi, T

    2005-02-15

    Magnetic pulps were prepared from unbleached kenaf (hibiscus cannabinus L.) kraft pulps. Fe{sub 3}O{sub 4} or magnetite powder was used to load into the pulp's lumen and pit. Aluminum sulphate [Al{sub 2}(SO{sub 4}){sub 3}] (alum) and polyethylenimine (PEI), both mainly function as retention aid were used throughout the experiment and found to be beneficial in the preparation of this magnetic pulps. The ash content method was used to determine the amount of magnetite retained in the lumen and pit. The utilization of PEI up to 2% per pulp fibres was found to be the best result on lumen loading. The deposition of magnetite powder in lumen and pit is found decrease as the addition of PEI used is more than 2% per pulp fibres. Scanning electron microscope (SEM) clearly shows the distribution of magnetite deposited in the lumen. Tensile index and folding endurance of the loaded fibre decreased slightly as the percentage of loading pigment increased.

  17. Periodontal parameters and BANA test in patients with chronic renal failure undergoing hemodialysis

    Science.gov (United States)

    TORRES, Sérgio Aparecido; ROSA, Odila Pereira da Silva; HAYACIBARA, Mitsue Fujimaki; GUIMARÃES, Maria do Carmo Machado; HAYACIBARA, Roberto M.; BRETZ, Walter Antônio

    2010-01-01

    Objectives The aim of this study was to analyze the periodontal parameters of patients with chronic renal failure. Material and Methods The periodontal status of 16 Brazilian patients aged 29 to 53 (41.7±7.2) years with chronic renal failure (CRF) and another matched group of 14 healthy controls with periodontitis was assessed clinically and microbiologically. Probing pocket depth (PPD), gingival recession (GR), dental plaque index (PLI), gingival index (GI), and dental calculus index (CI) were the clinical parameters recorded for the entire dentition (at least 19 teeth), while the anaerobic periodontopathogen colonization in four sites with the highest PPD was evaluated using the BANA test (“PerioScan”; Oral B). Results The results for the CRF group and control group, respectively were: PPD: 1.77±0.32 and 2.65±0.53; GR: 0.58±0.56 and 0.51±0.36; PLI: 1.64±0.56 and 1.24±0.67; GI: 0.64±0.42 and 0.93±0.50; CI: 1.17±0.54 and 0.87±0.52. Comparison between groups using the "t" test revealed a significantly increased PPD (pperiodontal conditions than periodontitis patients, which is an evidence of altered response to local irritants. PMID:20857011

  18. Load theory behind the wheel; perceptual and cognitive load effects.

    Science.gov (United States)

    Murphy, Gillian; Greene, Ciara M

    2017-09-01

    Perceptual Load Theory has been proposed as a resolution to the longstanding early versus late selection debate in cognitive psychology. There is much evidence in support of Load Theory but very few applied studies, despite the potential for the model to shed light on everyday attention and distraction. Using a driving simulator, the effect of perceptual and cognitive load on drivers' visual search was assessed. The findings were largely in line with Load Theory, with reduced distractor processing under high perceptual load, but increased distractor processing under high cognitive load. The effect of load on driving behaviour was also analysed, with significant differences in driving behaviour under perceptual and cognitive load. In addition, the effect of perceptual load on drivers' levels of awareness was investigated. High perceptual load significantly increased inattentional blindness and deafness, for stimuli that were both relevant and irrelevant to driving. High perceptual load also increased RTs to hazards. The current study helps to advance Load Theory by illustrating its usefulness outside of traditional paradigms. There are also applied implications for driver safety and roadway design, as the current study suggests that perceptual and cognitive load are important factors in driver attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  19. Evaluation of pond lands utilization and study of organic matter spatial distribution of Vanname shrimp (Litopenaeus vannamei aquaculture in the coastal area of Lamongan Regency

    Directory of Open Access Journals (Sweden)

    Insani L.

    2018-04-01

    Full Text Available Coastal areas have a wide range of resources that can be utilized in multiple ways. Land utilization of coastal areas has been done for various interests, one of which is for shrimp aquaculture (farming. Continuous shrimp farming activities will lead to environmental degradation, characterized by decreased water quality. Besides, the area or spatial arrangement of shrimp aquaculture development that does not pay attention to the environmental carrying capacity due to improper management can cause environmental problems with all aspects of its complications in a long period of time, one of which is the problem emerging from shrimp farming with the use of intensive technology. Intensive shrimp farming can produce organic wastes, primarily from the residual feed, feces, and dissolved matters discharged into waters that significantly affect the quality of the coastal environment. This study aimed to determine the distribution pattern of organic matters resulted from Vanname shrimp (Litopenaeus vannamei aquaculture in the coastal area of Lamongan Regency. This study was conducted from January to March 2018. The study used a descriptive method with Geographical Information System (GIS approach. The spatial distribution analysis of organic materials was carried out using geostatistical analysis, by interpolating point data into areas (polygons using IDW method. The interpolation results of each water quality of the ponds, river, and coastal waters were arranged in the form of thematic maps. The value pollution load index (PLI value of the shrimp farming activities was determined based on six main indicators, namely dissolved oxygen, BOD5, TOM, Ammonia, Nitrate, and Phosphate. Based on the results obtained, the highest spatial distribution value of organic matters was showed by the BOD parameter of 3.12 mg/l – 3.25 mg/l, included in the medium-polluted category. Meanwhile, the measurement result of the phosphate content as an indicator of water

  20. Working memory load reduces the late positive potential and this effect is attenuated with increasing anxiety.

    Science.gov (United States)

    MacNamara, Annmarie; Ferri, Jamie; Hajcak, Greg

    2011-09-01

    Emotion regulation decreases the processing of arousing stimuli, as indexed by the late positive potential (LPP), an electrocortical component that varies in amplitude with emotional arousal. Emotion regulation increases activity in the prefrontal areas associated with cognitive control, including the dosolateral prefrontal cortex (DLPFC). The present study manipulated working memory load, known to activate the DLPFC, and recorded the LPP elicited by aversive and neutral IAPS pictures presented during the retention interval. The LPP was larger on low-load compared to high-load trials, and on trials with aversive compared to neutral pictures. These LPP data suggest that emotional content and working memory load have opposing effects on attention to distracting stimuli. State anxiety was associated with reduced modulation of the LPP by working memory load. Results are discussed in terms of competition for attention between emotion and cognition and suggest a relationship between DLPFC activation and the allocation of attentional resources to distracting visual stimuli-a relationship that may be disrupted with increasing anxiety.

  1. Design and characterization of dielectric-loaded plasmonic directional couplers

    DEFF Research Database (Denmark)

    Stær, Tobias Holmgaard; Chen, Zhuo; Bozhevolnyi, Sergey

    2009-01-01

    Ultracompact directional couplers (DCs) based on dielectric-loaded surface plasmon-polariton waveguides (DLSPPWs) are analyzed using the effective index method (EIM), with the coupling, both in the parallel interaction region and in- and out-coupling regions, being taken into account. Near-field...... characterization of fabricated DCs performed with a scanning near-field optical microscope verifies the applicability of the EIM in the analysis and design of DLSPPW-based wavelength-selective DCs. The design approach applicable to a large variety of integrated optical waveguides is developed, enabling...

  2. Plastic limit loads for cylindrical shell intersections under combined loading

    International Nuclear Information System (INIS)

    Skopinsky, V.N.; Berkov, N.A.; Vogov, R.A.

    2015-01-01

    In this research, applied methods of nonlinear analysis and results of determining the plastic limit loads for shell intersection configurations under combined internal pressure, in-plane moment and out-plane moment loadings are presented. The numerical analysis of shell intersections is performed using the finite element method, geometrically nonlinear shell theory in quadratic approximation and plasticity theory. For determining the load parameter of proportional combined loading, the developed maximum criterion of rate of change of relative plastic work is employed. The graphical results for model of cylindrical shell intersection under different two-parameter combined loadings (as generalized plastic limit load curves) and three-parameter combined loading (as generalized plastic limit load surface) are presented on the assumption that the internal pressure, in-plane moment and out-plane moment loads were applied in a proportional manner. - Highlights: • This paper presents nonlinear two-dimensional FE analysis for shell intersections. • Determining the plastic limit loads under combined loading is considered. • Developed maximum criterion of rate of change of relative plastic work is employed. • Plastic deformation mechanism in shell intersections is discussed. • Results for generalized plastic limit load curves of branch intersection are presented

  3. Solar Load Inputs for USARIEM Thermal Strain Models and the Solar Radiation-Sensitive Components of the WBGT Index

    National Research Council Canada - National Science Library

    Matthew, William

    2001-01-01

    This report describes processes we have implemented to use global pyranometer-based estimates of mean radiant temperature as the common solar load input for the Scenario model, the USARIEM heat strain...

  4. Opposite effects of capacity load and resolution load on distractor processing.

    Science.gov (United States)

    Zhang, Weiwei; Luck, Steven J

    2015-02-01

    According to the load theory of attention, an increased perceptual load reduces distractor processing whereas an increased working memory load facilitates distractor processing. Here we raise the possibility that the critical distinction may instead be between an emphasis on resolution and an emphasis on capacity. That is, perceptual load manipulations typically emphasize resolution (fine-grained discriminations), whereas working memory load manipulations typically emphasize capacity (simultaneous processing of multiple relevant stimuli). To test the plausibility of this hypothesis, we used a visual working memory task that emphasized either the number of items to be stored (capacity load, retaining 2 vs. 4 colors) or the precision of the representations (resolution load, detecting small vs. large color changes). We found that an increased capacity load led to increased flanker interference (a measure of distractor processing), whereas an increased resolution load led to reduced flanker interference. These opposite effects of capacity load and resolution load on distractor processing mirror the previously described opposite effects of perceptual load and working memory load.

  5. Separating relational from item load effects in paired recognition: temporoparietal and middle frontal gyral activity with increased associates, but not items during encoding and retention.

    Science.gov (United States)

    Phillips, Steven; Niki, Kazuhisa

    2002-10-01

    Working memory is affected by items stored and the relations between them. However, separating these factors has been difficult, because increased items usually accompany increased associations/relations. Hence, some have argued, relational effects are reducible to item effects. We overcome this problem by manipulating index length: the fewest number of item positions at which there is a unique item, or tuple of items (if length >1), for every instance in the relational (memory) set. Longer indexes imply greater similarity (number of shared items) between instances and higher load on encoding processes. Subjects were given lists of study pairs and asked to make a recognition judgement. The number of unique items and index length in the three list conditions were: (1) AB, CD: four/one; (2) AB, CD, EF: six/one; and (3) AB, AD, CB: four/two, respectively. Japanese letters were used in Experiments 1 (kanji-ideograms) and 2 (hiragana-phonograms); numbers in Experiment 3; and shapes generated from Fourier descriptors in Experiment 4. Across all materials, right dominant temporoparietal and middle frontal gyral activity was found with increased index length, but not items during study. In Experiment 5, a longer delay was used to isolate retention effects in the absence of visual stimuli. Increased left hemispheric activity was observed in the precuneus, middle frontal gyrus, and superior temporal gyrus with increased index length for the delay period. These results show that relational load is not reducible to item load.

  6. Load Adaptability in Patients With Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Amsallem, Myriam; Boulate, David; Aymami, Marie; Guihaire, Julien; Selej, Mona; Huo, Jennie; Denault, Andre Y; McConnell, Michael V; Schnittger, Ingela; Fadel, Elie; Mercier, Olaf; Zamanian, Roham T; Haddad, Francois

    2017-09-01

    Right ventricular (RV) adaptation to pressure overload is a major prognostic factor in patients with pulmonary arterial hypertension (PAH). The objectives were first to define the relation between RV adaptation and load using allometric modeling, then to compare the prognostic value of different indices of load adaptability in PAH. Both a derivation (n = 85) and a validation cohort (n = 200) were included. Load adaptability was assessed using 3 approaches: (1) surrogates of ventriculo-arterial coupling (e.g., RV area change/end-systolic area), (2) simple ratio of function and load (e.g., tricuspid annular plane systolic excursion/right ventricular systolic pressure), and (3) indices assessing the proportionality of adaptation using allometric pressure-function or size modeling. Proportional hazard modeling was used to compare the hazard ratio for the outcome of death or lung transplantation. The mean age of the derivation cohort was 44 ± 11 years, with 80% female and 74% in New York Heart Association class III or IV. Mean pulmonary vascular resistance index (PVRI) was 24 ± 11 with a wide distribution (1.6 to 57.5 WU/m 2 ). Allometric relations were observed between PVRI and RV fractional area change (R 2  = 0.53, p adaptation. In right heart parameters, RVESAI was the strongest predictor of outcomes (hazard ratio per SD = 1.93, 95% confidence interval 1.37 to 2.75, p adaptability indices provided stronger discrimination of outcome than simple RV adaptation metrics in either the derivation or the validation cohort. In conclusion, allometric modeling enables quantification of the proportionality of RV load adaptation but offers small incremental prognostic value to RV end-systolic dimension in PAH. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  8. Assessment of heavy metal pollution from a Fe-smelting plant in urban river sediments using environmental magnetic and geochemical methods

    International Nuclear Information System (INIS)

    Zhang Chunxia; Qiao Qingqing; Piper, John D.A.; Huang, Baochun

    2011-01-01

    Environmental magnetic proxies provide a rapid means of assessing the degree of industrial heavy metal pollution in soils and sediments. To test the efficiency of magnetic methods for detecting contaminates from a Fe-smelting plant in Loudi City, Hunan Province (China) we investigated river sediments from Lianshui River. Both magnetic and non-magnetic (microscopic, chemical and statistical) methods were used to characterize these sediments. Anthropogenic heavy metals coexist with coarse-grained magnetic spherules. It can be demonstrated that the Pollution Load Index of industrial heavy metals (Fe, V, Cr, Mo, Zn, Pb, Cd, Cu) and the logarithm of saturation isothermal remanent magnetization, a proxy for magnetic concentration, are significantly correlated. The distribution heavy metal pollution in the Lianshui River is controlled by surface water transport and deposition. Our findings demonstrate that magnetic methods have a useful and practical application for detecting and mapping pollution in and around modern industrial cities. - Highlights: → Assessment of heavy metal (HM) pollution in river sediment using magnetic and chemical methods. → HMs from an Fe-smelting plant coexist with coarse-grained magnetic spherules. → A linear correlation between the Pollution Load Index (PLI) of industrial HMs and a magnetic concentration parameter is demonstrated. → The distribution of HM pollution in river sediments is controlled by surface water flow and deposition. - Heavy metal (HM) contamination of river sediments from industrial input by surface water transport and deposition can be detected by using magnetic methods providing a convenient assessment of HM pollution in industrialized cities.

  9. Coordination Between Wind Power, Hydro Storage Facility and Conventional Generating Units According to the Annual Growth Load

    Directory of Open Access Journals (Sweden)

    Shahrokh Shojaeean

    2013-04-01

    Full Text Available Considering the growing trend of the consumption of the electric power and the global tendency to substitute new renewable sources of energy, this paper proposes a Monte Carlo based method to determine an optimal level of this change. Considering the limitation of the wind farms in continuous supply of electric power, hydrostatic power storage facilities are used beside wind farms so that the electric power could be stored and fed in a continuous flow into power systems. Due to the gradual exclusion of conventional generators and 5 percent annual load increments, LOLE index was used in order to calculate the amount of the wind power and the capacity of the necessary power storage facility. To this end, LOLE index was calculated for the first year as the reference index for the estimation of the amount of wind power and the capacity of the storage facility in consequent years. For the upcoming years, calculations have been made to account for the gradual exclusion of conventional generators in proportion to load increments. The proposed method has been implemented and simulated on IEEE-RTS test system.

  10. Rock index properties for geoengineering in the Paradox Basin

    International Nuclear Information System (INIS)

    O'Rourke, J.E.; Rey, P.H.; Alviti, E.; Capps, C.C.

    1986-02-01

    Previous researchers have investigated the use of a number of rapid index tests that can be used on core samples, or in situ, to determine rock properties needed for geoengineering design, or to predict construction performance in these rock types. Selected research is reviewed, and the correlations of index tests with laboratory tests of rock properties found by the earlier investigators are discussed. The selection and testing of rock core samples from the Gibson Dome No. 1 borehole in Paradox Basin are described. The samples consist primarily of non-salt rock above salt cycle 6, but include some samples of anhydrite and salt cycle 6. The index tests included the point load test, Schmidt hammer rebound test, and abrasion hardness test. Statistical methods were used to analyze the correlations of index test data with laboratory test data of rock properties for the same core. Complete statistical results and computer-generated graphics are presented; these results are discussed in relation to the work of earlier investigations for index testing of similar rock types. Generally, fair to good correlations were obtained for predicting unconfined compressive strength and Young's modulus for sandstone and siltstone, while poorer correlations were found for limestone. This may be due to the large variability of limestone properties compared to the small number of samples. Overall, the use of index tests to assess rock properties at Paradox Basin appears to be practial for some conceptual and preliminary design needs, and the technique should prove useful at any salt repository site. However, it is likely that specific correlations should be demonstrated separately for each site, and the data base for establishing the correlations should probably include at least several hundred data points for each type

  11. 46 CFR 154.1730 - Ethylene oxide: Loading and off loading.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ethylene oxide: Loading and off loading. 154.1730... Operating Requirements § 154.1730 Ethylene oxide: Loading and off loading. (a) The master shall ensure that before ethylene oxide is loaded into a cargo tank: (1) The tank is thoroughly clean, dry, and free of...

  12. The Role of Language Glossing in a Rooted Theory: The Involvement Load Hypothesis

    Directory of Open Access Journals (Sweden)

    Hassan Soleimani

    2014-07-01

    Full Text Available This study builds on the innovative construct of task-induced involvement. It investigates different first and second language glossing in “involvement load hypothesis”. In order to do our study, 66 learners from two different English institutes were classified into two major high and low proficient groups based on Nelson Proficiency Test. Among them 22 low proficient students were randomly assigned to two different subgroups in order to complete two different types of tasks with different language glossing. The behaviors of the two groups in the immediate and delayed posttests did not confirm the predictions of involvement load hypothesis. Although the second task had a higher involvement index, no sign of superiority was observed in its performance. The study suggests that the predictions of involvement load hypothesis need to be more finely grained especially when the tasks have different language glossing.

  13. Field accumulation risks of heavy metals in soil and vegetable crop irrigated with sewage water in western region of Saudi Arabia

    Science.gov (United States)

    Balkhair, Khaled S.; Ashraf, Muhammad Aqeel

    2015-01-01

    Wastewater irrigated fields can cause potential contamination with heavy metals to soil and groundwater, thus pose a threat to human beings . The current study was designed to investigate the potential human health risks associated with the consumption of okra vegetable crop contaminated with toxic heavy metals. The crop was grown on a soil irrigated with treated wastewater in the western region of Saudi Arabia during 2010 and 2011. The monitored heavy metals included Cd, Cr, Cu, Pb and Zn for their bioaccumulation factors to provide baseline data regarding environmental safety and the suitability of sewage irrigation in the future. The pollution load index (PLI), enrichment factor (EF) and contamination factor (CF) of these metals were calculated. The pollution load index of the studied soils indicated their level of metal contamination. The concentrations of Ni, Pb, Cd and Cr in the edible portions were above the safe limit in 90%, 28%, 83% and 63% of the samples, respectively. The heavy metals in the edible portions were as follows: Cr > Zn > Ni > Cd > Mn > Pb > Cu > Fe. The Health Risk Index (HRI) was >1 indicating a potential health risk. The EF values designated an enhanced bio-contamination compared to other reports from Saudi Arabia and other countries around the world. The results indicated a potential pathway of human exposure to slow poisoning by heavy metals due to the indirect utilization of vegetables grown on heavy metal-contaminated soil that was irrigated by contaminated water sources. The okra tested was not safe for human use, especially for direct consumption by human beings. The irrigation source was identified as the source of the soil pollution in this study. PMID:26858563

  14. Dietary glycemic index, glycemic load, fiber, simple sugars, and insulin resistance - The Inter99 study

    DEFF Research Database (Denmark)

    Lau, Cathrine; Pedersen, Oluf; Færch, Kristine

    2005-01-01

    , and insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Multiple regressions were performed with HOMA-IR as the dependent variable and carbohydrate-related factors as explanatory variables. All models were adjusted for age, sex, smoking, physical activity......, total energy intake, BMI, and waist circumference. RESULTS - intake of lactose was positively associated with HOMA-IR (P < 0.0001), whereas daily glycemic load and intake of glucose, fructose, dietary fiber, total carbohydrate, fruit, and vegetables were inversely associated with HOMA-IR (P < 0...

  15. Spatial distribution and potential biological risk of some metals in relation to granulometric content in core sediments from Chilika Lake, India.

    Science.gov (United States)

    Barik, Saroja K; Muduli, Pradipta R; Mohanty, Bita; Rath, Prasanta; Samanta, Srikanta

    2018-01-01

    The article presents first systematic report on the concentration of selected major elements [iron (Fe) and manganese (Mn)] and minor elements [zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), and cobalt (Co)] from the core sediment of Chilika Lake, India. The analyzed samples revealed higher content of Pb than the background levels in the entire study area. The extent of contamination from minor and major elements is expressed by assessing (i) the metal enrichments in the sediment through the calculations of anthropogenic factor (AF), pollution load index (PLI), Enrichment factor (EF), and geoaccumulation index (Igeo) and (ii) potential biological risks by the use of sediment quality guidelines like effect range median (ERM) and effect range low (ERL) benchmarks. The estimated indices indicated that sediment is enriched with Pb, Ni, Cr, Cu and Co. The enrichment of these elements seems to be due to the fine granulometric characteristics of the sediment with Fe and Mn oxyhydroxides being the main metal carriers and fishing boats using low grade paints, fuel, and fishing technology using lead beads fixed to fishing nets. Trace element input to the Chilika lake needs to be monitored with due emphasis on Cr and Pb contaminations since the ERM and ERL benchmarks indicated potential biological risk with these metals.

  16. Geochemical speciation and pollution assessment of heavy metals in surface sediments from Nansi Lake, China.

    Science.gov (United States)

    Yang, Liyuan; Wang, Longfeng; Wang, Yunqian; Zhang, Wei

    2015-05-01

    Sixteen surface sediment samples were collected from Nansi Lake to analyze geochemical speciation of heavy metals including Cd, As, Pb, Cr, and Zn, assess their pollution level, and determine the spatial distribution of the non-residual fraction. Results showed that Cd had higher concentrations in water-soluble and exchangeable fractions. As and Pb were mainly observed as humic acid and reducible fractions among the non-residual fractions, while Cr and Zn were mostly locked up in a residual fraction. The mean pollution index (P i) values revealed that the lower lake generally had a higher enrichment degree than the upper lake. Cd (2.73) and As (2.05) were in moderate level of pollution, while the pollution of Pb (1.80), Cr (1.27), and Zn (1.02) appeared at low-level pollution. The calculated pollution load index (PLI) suggested the upper lake suffered from borderline moderate pollution, while the lower lake showed moderate to heavy pollution. Spatial principle component analysis showed that the first principal component (PC1) including Cd, As, and Pb could explain 56.18 % of the non-residual fraction. High values of PC1 were observed mostly in the southern part of Weishan Lake, which indicated greater bioavailability and toxicity of Cd, As, and Pb in this area.

  17. Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa in Some Estuaries and Lagoons Along the Coast of Ghana

    Directory of Open Access Journals (Sweden)

    D. K. Essumang

    2010-01-01

    Full Text Available The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae, brown goby (Chonophorus lateristriga Gobiidae, shrimp (Macrobrachium vollenhovenii Palaemonidae, and mangrove oysters (Crassostrea tulipa Ostreidae in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  18. Childhood abuse and depression in adulthood: The mediating role of allostatic load.

    Science.gov (United States)

    Scheuer, Sandra; Wiggert, Nicole; Brückl, Tanja Maria; Awaloff, Yvonne; Uhr, Manfred; Lucae, Susanne; Kloiber, Stefan; Holsboer, Florian; Ising, Marcus; Wilhelm, Frank H

    2018-04-22

    Traumatic experiences during childhood are considered a major risk factor for depression in adulthood. Childhood trauma may induce physiological dysregulation with long-term effects of increased allostatic load until adulthood, which may lead to depression. Thus, our aim was to investigate whether allostatic load - which represents a multi-system measure of physiological dysregulation - mediates the association between childhood trauma and adult depression. The study sample consisted of 324 depressed inpatients participating in the Munich Antidepressant Response Signature (MARS) project and 261 mentally healthy control participants. The mediation analysis using a case-control approach included childhood trauma, i.e., physical and sexual abuse, as predictor variables and an allostatic load index comprised of 12 stress-related biomarkers as mediator. Age and sex were included as covariates. Mediation analyses revealed that the influence of physical abuse, but not sexual abuse, during childhood on depression in adulthood was mediated by allostatic load. This effect was moderated by age: particularly young (18-42 years) and middle-aged (43-54 years) adults with a history of physical abuse during childhood exhibited high allostatic load, which in turn was associated with increased rates of depression, but this was not the case for older participants (55-81 years). Results support the theoretical assumption of allostatic load mediating the effect of physical abuse during childhood on depression in adulthood. This predominantly holds for younger participants, while depression in older participants was independent of physical abuse and allostatic load. The effect of sexual abuse on depression, however, was not mediated by allostatic load. Identifying allostatic load biomarkers prospectively in the developmental course of depression is an important target for future research. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Peak load-impulse characterization of critical pulse loads in structural dynamics

    International Nuclear Information System (INIS)

    Abrahamson, G.R.; Lindberg, H.E.

    1975-01-01

    In presenting the characterization scheme, some general features are described first. A detailed analysis is given for the rigid-plastic system of one degree of freedom to illustrate the calculation of critical load curves in terms of peak load and impulse. This is followed by the presentation of critical load curves for uniformly loaded rigid-plastic beams and plates and for dynamic buckling of cylindrical shells under uniform lateral loads. The peak load-impulse characterization of critical pulse loads is compared with the dynamic load factor characterization, and some aspects of the history of the peak load-pulse scheme are presented. (orig./HP) [de

  20. An Improved Design Methodology for Modeling Thick-Section Composite Structures Using a Multiscale Approach

    Science.gov (United States)

    2012-09-01

    case study no. 2. The multiaxial loading combined with XZ and YZ Poisson ratio effects contributes to strains in the Z-direction of the sample. The...E. A Continuum Damage Model for Fiber Reinforced Laminates Based on Ply Failure Mechanisms, Composite Structures. Fifteenth International...output parameters, stiffness ratios , to analyze the nonlinear response and progressive failure of the composite structure is developed. These new

  1. Development of Tools for Engineering Analysis and Design of High-Performance FRP-Composite Structural Elements

    DEFF Research Database (Denmark)

    Mortensen, Fl.

    as general specification of loads and boundary conditions. For all the structural problems addressed, the analyses are carried out following the same principal approach, which is based on an explicit formulation of the governing set of differential equations. The governing differential equations...... in ESAComp. The solution procedures for the adhesive bonded joints have been used to conduct a parametric study, where the influence of using laminated adherends has been investigated. Based on this, a set of general design guidelines has been given in order to improve the structural performance and strength...... for joints with laminated adherends. The guidelines are also valid for the ply drop problems, since their mechanical behaviour are very similar. The results obtained for adhesive bonded joints, ply drops and insert problems have been compared with finite element analysis results. The results obtained...

  2. Enhanced water use efficiency in global terrestrial ecosystems under increasing aerosol loadings

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaoliang; Chen, Min; Liu, Yaling; Miralles, Diego G.; Wang, Faming

    2017-05-01

    Aerosols play a crucial role in the climate system, affecting incoming radiation and cloud formation. Based on a modelling framework that couples ecosystem processes with the atmospheric transfer of radiation, we analyze the effect of aerosols on surface incoming radiation, gross primary productivity (GPP), water losses from ecosystems through evapotranspiration (ET) and ecosystem water use efficiency (WUE, defined as GPP/ET) for 2003–2010 and validate them at global FLUXNET sites. The total diffuse radiation increases under relatively low or intermediate aerosol loadings, but decreases under more polluted conditions. We find that aerosol-induced changes in GPP depend on leaf area index, aerosol loading and cloudiness. Specifically, low and moderate aerosol loadings cause increases in GPP for all plant types, while heavy aerosol loadings result in enhancement (decrease) in GPP for dense (sparse) vegetation. On the other hand, ET is mainly negatively affected by aerosol loadings due to the reduction in total incoming radiation. Finally, WUE shows a consistent rise in all plant types under increasing aerosol loadings. Overall, the simulated daily WUE compares well with observations at 43 eddy-covariance tower sites (R2=0.84 and RMSE=0.01gC (kg H2O)-1) with better performance at forest sites. In addition to the increasing portions of diffuse light, the rise in WUE is also favored by the reduction in radiation- and heat-stress caused by the aerosols, especially for wet and hot climates.

  3. Modeling drivers of phosphorus loads in Chesapeake Bay tributaries and inferences about long-term change

    Science.gov (United States)

    Ryberg, Karen R.; Blomquist, Joel; Sprague, Lori A.; Sekellick, Andrew J.; Keisman, Jennifer

    2018-01-01

    Causal attribution of changes in water quality often consists of correlation, qualitative reasoning, listing references to the work of others, or speculation. To better support statements of attribution for water-quality trends, structural equation modeling was used to model the causal factors of total phosphorus loads in the Chesapeake Bay watershed. By transforming, scaling, and standardizing variables, grouping similar sites, grouping some causal factors into latent variable models, and using methods that correct for assumption violations, we developed a structural equation model to show how causal factors interact to produce total phosphorus loads. Climate (in the form of annual total precipitation and the Palmer Hydrologic Drought Index) and anthropogenic inputs are the major drivers of total phosphorus load in the Chesapeake Bay watershed. Increasing runoff due to natural climate variability is offsetting purposeful management actions that are otherwise decreasing phosphorus loading; consequently, management actions may need to be reexamined to achieve target reductions in the face of climate variability.

  4. Multi-objective Extremum Seeking Control for Enhancement of Wind Turbine Power Capture with Load Reduction

    Science.gov (United States)

    Xiao, Yan; Li, Yaoyu; Rotea, Mario A.

    2016-09-01

    The primary objective in below rated wind speed (Region 2) is to maximize the turbine's energy capture. Due to uncertainty, variability of turbine characteristics and lack of inexpensive but precise wind measurements, model-free control strategies that do not use wind measurements such as Extremum Seeking Control (ESC) have received significant attention. Based on a dither-demodulation scheme, ESC can maximize the wind power capture in real time despite uncertainty, variabilities and lack of accurate wind measurements. The existing work on ESC based wind turbine control focuses on power capture only. In this paper, a multi-objective extremum seeking control strategy is proposed to achieve nearly optimum wind energy capture while decreasing structural fatigue loads. The performance index of the ESC combines the rotor power and penalty terms of the standard deviations of selected fatigue load variables. Simulation studies of the proposed multi-objective ESC demonstrate that the damage-equivalent loads of tower and/or blade loads can be reduced with slight compromise in energy capture.

  5. System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

    Science.gov (United States)

    Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

    2014-12-23

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

  6. Glycemic index and glycemic load are associated with some cardiovascular risk factors among the PREMIER study participants

    Directory of Open Access Journals (Sweden)

    Pao-Hwa Lin

    2012-06-01

    Full Text Available Background: The clinical significance of glycemic index (GI and glycemic load (GL is inconclusive. Objective : This study was conducted to examine the association of GI and GL with clinical cardiovascular disease (CVD risk factors including body weight, blood pressure (BP, serum lipids, fasting glucose, insulin and homocysteine over time among the PREMIER participants. Design: PREMIER was an 18-month randomized lifestyle intervention trial, conducted from 2000 to 2002, designed to help participants reduce BP by following the Dietary Approaches to Stop Hypertension (DASH dietary pattern, losing weight, reducing sodium and increasing physical activity. GI and GL were estimated from 24 h diet recall data at baseline, 6 and 18 months after intervention. PROC MIXED model was used to examine the association of changes in GI or GL with changes in CVD risk factors. Results: A total of 756 randomized participants, 62% females and 34% African Americans and who averaged 50.0±0.3 years old and 95.3±0.7 kg, were included in this report. Neither GI nor GL changes was associated with changes in any risk factors at 6 months. At 18 months, however, the GI change was significantly and positively associated with total cholesterol (TC change only (p<0.05, β = 23.80±12.11 mg/dL or 0.62±0.31 mmol/L with a significant age interaction. The GL change was significantly associated with TC (p=0.02, β = 0.28±0.15 mg/dL or 0.01±0.00 mmol/L positively and with low density lipoprotein cholesterol (LDL-C changes negatively (p=0.03, β = − 0.01±0.00 mg/dL or −0.00±0.00 mmol/L, and significant age interactions were observed for both. Conclusion: GI and GL was associated with TC and LDL-C after controlling for energy, fat and fiber intake and other potential confounders and the associations were modified by age. Further investigation into this relationship is important because of its potential clinical impact.

  7. System and method employing a self-organizing map load feature database to identify electric load types of different electric loads

    Science.gov (United States)

    Lu, Bin; Harley, Ronald G.; Du, Liang; Yang, Yi; Sharma, Santosh K.; Zambare, Prachi; Madane, Mayura A.

    2014-06-17

    A method identifies electric load types of a plurality of different electric loads. The method includes providing a self-organizing map load feature database of a plurality of different electric load types and a plurality of neurons, each of the load types corresponding to a number of the neurons; employing a weight vector for each of the neurons; sensing a voltage signal and a current signal for each of the loads; determining a load feature vector including at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the loads; and identifying by a processor one of the load types by relating the load feature vector to the neurons of the database by identifying the weight vector of one of the neurons corresponding to the one of the load types that is a minimal distance to the load feature vector.

  8. A physical workload index to evaluate a safe resident handling program for nursing home personnel.

    Science.gov (United States)

    Kurowski, Alicia; Buchholz, Bryan; Punnett, Laura

    2014-06-01

    The aim of this study was to obtain a comprehensive analysis of the physical workload of clinical staff in long-term care facilities, before and after a safe resident handling program (SRHP). Ergonomic exposures of health care workers include manual handling of patients and many non-neutral postures. A comprehensive assessment requires the integration of loads from these varied exposures into a single metric. The Postures, Activities, Tools, and Handling observational protocol, customized for health care, was used for direct observations of ergonomic exposures in clinical jobs at 12 nursing homes before the SRHP and 3, 12, 24, and 36 months afterward. Average compressive forces on the spine were estimated for observed combinations of body postures and manual handling and then weighted by frequencies of observed time for the combination. These values were summed to obtain a biomechanical index for nursing assistants and nurses across observation periods. The physical workload index (PWI) was much higher for nursing assistants than for nurses and decreased more after 3 years (-24% versus -2.5%). Specifically during resident handling, the PWI for nursing assistants decreased by 41% of baseline value. Spinal loading was higher for nursing assistants than for nurses in long-term care centers. Both job groups experienced reductions in physical loading from the SRHP, especially the nursing assistants and especially while resident handling. The PWI facilitates a comprehensive investigation of physical loading from both manual handling and non-neutral postures. It can be used in any work setting to identify high-risk tasks and determine whether reductions in one exposure are offset by increases in another.

  9. Dynamic load indicators for take-off-landing sequence in blocks and attacks of elite female volleyball players.

    Science.gov (United States)

    Kabaciński, Jarosław; Dworak, Lechosław Bogdan; Murawa, Michał; Rzepnicka, Agata

    2016-01-01

    Dynamic loads during landings determined by the ground reaction forces (GRFs) may elaborate internal loads and increase the risk of overload knee injuries as a result of performing volleyball jumps many times. The study dealt with a biomechanical assessment of dynamic load indicators in female volleyball players for the motion sequence of take-off-landing in blocks and attacks. Twelve professional female volleyball players participated in the study. Blocks and attacks were filmed by two cameras. GRFs vs. time graphs were recorded with the use of a force platform. Values of dynamic load indicators in terms of the relations of peak of vertical component of GRF, build-up index of this force (BIF), and power output (P) during landing to the vGRF, BIF and P during take-off (L/T) were calculated. The statistically significant ( p volleyball players.

  10. Demand Response Load Following of Source and Load Systems

    DEFF Research Database (Denmark)

    Hu, Jianqiang; Cao, Jinde; Yong, Taiyou

    2017-01-01

    This paper presents a demand response load following strategy for an interconnected source and load system, in which we utilize traditional units and population of cooling thermostatically controlled loads (TCLs) to follow the mismatched power caused by the load activities and the renewable power...... injection in real time. In the demand side of power systems, these TCLs are often affiliated to a bus load agent and can be aggregated to multiple TCL aggregators. Firstly, aggregate evaluation of the TCL aggregator is carried out based on a bilinear aggregate model so as to derive the available regulation...

  11. Cognitive Load Theory: How Many Types of Load Does It Really Need?

    Science.gov (United States)

    Kalyuga, Slava

    2011-01-01

    Cognitive load theory has been traditionally described as involving three separate and additive types of load. Germane load is considered as a learning-relevant load complementing extraneous and intrinsic load. This article argues that, in its traditional treatment, germane load is essentially indistinguishable from intrinsic load, and therefore…

  12. Stress index development for piping with trunnion attachment under pressure and moment loading

    International Nuclear Information System (INIS)

    Lee, D. H.; Kim, J. M.; Park, S. H.

    1997-01-01

    A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized into the average (membrane) stress, the linearly varying (bending) stress and the peak stress through the thickness. The resulting stresses are interpreted per section III of the ASME boiler and pressure vessel code from which the Primary (B 1 ), Secondary (C 1 ) and Peak (K 1 ) stress indices for pressure, the Primary (B 2 ), Secondary (C 2 ) and Peak (K 2 ) stress indices for moment are developed. Based on the comparison between stress value by stress indices derived in this paper and stress value represented by the ASME Code Case N-391-1, the empirical equations for stress indices are effectively used in the piping stress analysis. Therefore, the use of empirical equations can simplify the procedure of evaluating the local stress in the piping design stage. (author)

  13. The "Pulse Time Index of Norm" highly correlates with the left ventricular mass index in patients with arterial hypertension.

    Science.gov (United States)

    Posokhov, Igor N; Kulikova, Natalya N; Starchenkova, Irina V; Grigoricheva, Elena A; Evdokimov, Vitaly V; Orlov, Artemy V; Rogoza, Anatoly N

    2014-01-01

    Arterial stiffness, as measured by the pulse wave velocity (PWV), is recommended for routine use in clinical practice as an important parameter for the evaluation of cardiovascular risk.1 New 24-hour monitors (eg, with Vasotens technology; Petr Telegin Company, Nizhny Novgorod, Russian Federation) provide single PWV measurements as well as several PWV measurements over a period of 24 hours.2 Such 24-hour pulse wave analysis led to the development of the novel Pulse Time Index of Norm (PTIN), which is defined as the percentage of a 24-hour period during which the PWV does not exceed the 10 m/second PWV threshold. The aim of this study is to test the new PTIN for correlation with the left ventricular mass index (LVMI). Oscillometrically generated waveform files (n=137) used for clinical research studies were reanalyzed using the new 2013 version of the Vasotens technology program, which enables PTIN calculations. A good correlation (r=-0.72) between the PTIN and the LVMI was shown, which was significantly above the blood pressure load (r=0.41). The PTIN generated by the Vasotens technology can be recommended as an indicator of end organ damage via hypertension.

  14. Determination of muscle fatigue index for strength training in patients with Duchenne dystrophy

    Directory of Open Access Journals (Sweden)

    Adriano Rodrigues Oliveira

    Full Text Available INTRODUCTION: Muscle weakness is the most prominent impairment in Duchenne muscular dystrophy (DMD and often involves the loss of functional ability as well as other limitations related to daily living. Thus, there is a need to maintain muscle strength in large muscle groups, such as the femoral quadriceps, which is responsible for diverse functional abilities. However, the load and duration of training for such rehabilitation has proven to be a great unknown, mainly due to the undesired appearance of muscle fatigue, which is a severe factor for the injury of muscle fibers. OBJECTIVES: The aim of the present study was to determine a fatigue index by means of surface electromyography (EMG for the parameterization of muscle strengthening physiotherapy training. METHODS: A cross-sectional study (case series was carried out involving four patients with DMD. Three pairs of surface electrodes were placed on the motor point of the Rectus femoris, Vastus lateralis and Vastus medialis of the dominant limb, maintaining the knee at 60º of flexion. The participants were instructed to perform the extension movement of this joint at four strength levels (100%, 80%, 60% and 40% of maximal voluntary isometric contraction. RESULTS: The slope of the linear regression line was used for the determination of the fatigue index, performed by Pearson's test on the median frequency of each strength level. CONCLUSION: Electromyographic measurements of the strength index for muscle training proved to be a simple accessible assessment method, as well as an extremely valuable tool, allowing the design of a muscle strength training program with an individualized load threshold.

  15. Pre-form ceramic matrix composite cavity and method of forming and method of forming a ceramic matrix composite component

    Science.gov (United States)

    Monaghan, Philip Harold; Delvaux, John McConnell; Taxacher, Glenn Curtis

    2015-06-09

    A pre-form CMC cavity and method of forming pre-form CMC cavity for a ceramic matrix component includes providing a mandrel, applying a base ply to the mandrel, laying-up at least one CMC ply on the base ply, removing the mandrel, and densifying the base ply and the at least one CMC ply. The remaining densified base ply and at least one CMC ply form a ceramic matrix component having a desired geometry and a cavity formed therein. Also provided is a method of forming a CMC component.

  16. [The salivary factors related to caries and periodontal disease in children and adolescents with diabetes mellitus].

    Science.gov (United States)

    Wang, Meng-xing; Wang, Xin; Zhang, Zhi; Qin, Man

    2013-09-01

    To detect the salivary factors related to caries and periodontal disease and to analyze the risk of caries and periodontal disease in children and adolescents with diabetes mellitus. The study comprised 30 children with diabetic mellitus, aged 7-15 years old, and 60 healthy age-and gender-matched children. Caries and periodontal indexes were recorded and saliva related factors were analyzed. Caries indexes of diabetes children [permanent teeth: decay missing filling tooth (DMFT) M (Q1,Q3) = 0(0, 4), deciduous teeth: decay missing filling tooth (dmft) M (Q1,Q3) = 0(0, 1)] were not significantly different with those of healthy children [DMFT M (Q1,Q3) = 1(0, 3), dmft M (Q1,Q3) = 0(0, 4)], but plaque index (PLI) (1.25 ± 0.33) and bleeding index (BI) (0.74 ± 0.45) of diabetes children were significantly higher than those of healthy children (PLI was 0.93 ± 0.31,BI was 0.34 ± 0.22) (P 0.05). Salivary glucose, immunoglobulin sIgA and sIgG were not significantly different between the two groups (P > 0.05).Salivary lysozyme of diabetes children was significantly higher than that of healthy children (P 0.05). Diabetes mellitus can lead to the changes of some salivary factors related to gingivitis in diabetes children. Children and adolescents with diabetes mellitus may have a higher risk of periodontal disease.

  17. Dynamical load factor of impact loaded shell structures

    International Nuclear Information System (INIS)

    Hammel, J.

    1977-01-01

    Dynamical loaded structures can be analysed by spectral representations, which usually lead to an enormous computational effort. If it is possible to find a fitting dynamical load factor, the dynamical problem can be reduced to a statical one. The computation of this statical problem is much simpler. The disadvantage is that the dynamical load factor usually leads to a very rough approximation. In this paper it will be shown, that by combination of these two methods, the approximation of the dynamical load factor can be improved and the consumption of computation time can be enormously reduced. (Auth.)

  18. Research of Impact Load in Large Electrohydraulic Load Simulator

    Directory of Open Access Journals (Sweden)

    Yongguang Liu

    2014-01-01

    Full Text Available The stronger impact load will appear in the initial phase when the large electric cylinder is tested in the hardware-in-loop simulation. In this paper, the mathematical model is built based on AMESim, and then the reason of the impact load is investigated through analyzing the changing tendency of parameters in the simulation results. The inhibition methods of impact load are presented according to the structural invariability principle and applied to the actual system. The final experimental result indicates that the impact load is inhibited, which provides a good experimental condition for the electric cylinder and promotes the study of large load simulator.

  19. Effect of natural ageing on surface of silver loaded TPE and its influence in antimicrobial efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Tomacheski, Daiane, E-mail: daitomacheski@gmail.com [Department of Materials Engineering, Laboratory of Polymers – LAPOL, Universidade Federal do Rio Grande do Sul, UFRGS, 9500 Bento Gonçalves Avenue, Postal Code 15010, Porto Alegre 91501-970 (Brazil); Softer Brasil Compostos Termoplásticos LTDA, 275 Edgar Hoffmeister Avenue, Campo Bom 93700-000 (Brazil); Pittol, Michele [Softer Brasil Compostos Termoplásticos LTDA, 275 Edgar Hoffmeister Avenue, Campo Bom 93700-000 (Brazil); Simões, Douglas Naue; Ribeiro, Vanda Ferreira [Department of Materials Engineering, Laboratory of Polymers – LAPOL, Universidade Federal do Rio Grande do Sul, UFRGS, 9500 Bento Gonçalves Avenue, Postal Code 15010, Porto Alegre 91501-970 (Brazil); Softer Brasil Compostos Termoplásticos LTDA, 275 Edgar Hoffmeister Avenue, Campo Bom 93700-000 (Brazil); Santana, Ruth Marlene Campomanes [Department of Materials Engineering, Laboratory of Polymers – LAPOL, Universidade Federal do Rio Grande do Sul, UFRGS, 9500 Bento Gonçalves Avenue, Postal Code 15010, Porto Alegre 91501-970 (Brazil)

    2017-05-31

    Highlights: • Ag loaded TPE lost their antimicrobial efficacy after polymer degradation. • Modifications in Ag loaded TPE surface provide conditions to bacteria settlement. • Rough TPE surface and the low γ{sub S}{sup +} was more favorable for bacterial development. - Abstract: The aim of this study is to characterize the modifications in silver loaded TPE surfaces exposed to weathering and their relation to susceptibility to microbial attack. Silver loaded TPE materials were exposed to natural ageing for nine months and modifications in antimicrobial properties and surface characteristics were evaluated. Chemical changes were investigated by using the infrared spectra. The average surface roughness and topography were determined by atomic force microscopy. Contact angle was measured to verify wettability conditions and surface free energy (SFE). After nine months of exposure, a decrease in the antimicrobial properties of loaded TPE compounds was observed. A reduction in surface roughness and improvement in wettability and high values of polar component of SFE were verified. The best antibacterial action was noticed in the sample with high Lewis acid force, lower roughness and lower carbonyl index.

  20. Load research manual. Volume 2. Fundamentals of implementing load research procedures

    Energy Technology Data Exchange (ETDEWEB)

    Brandenburg, L.; Clarkson, G.; Grund, Jr., C.; Leo, J.; Asbury, J.; Brandon-Brown, F.; Derderian, H.; Mueller, R.; Swaroop, R.

    1980-11-01

    This three-volume manual presents technical guidelines for electric utility load research. Special attention is given to issues raised by the load data reporting requirements of the Public Utility Regulatory Policies Act of 1978 and to problems faced by smaller utilities that are initiating load research programs. In Volumes 1 and 2, procedures are suggested for determining data requirements for load research, establishing the size and customer composition of a load survey sample, selecting and using equipment to record customer electricity usage, processing data tapes from the recording equipment, and analyzing the data. Statistical techniques used in customer sampling are discussed in detail. The costs of load research also are estimated, and ongoing load research programs at three utilities are described. The manual includes guides to load research literature and glossaries of load research and statistical terms.

  1. Preparation and characterization of clove essential oil-loaded liposomes.

    Science.gov (United States)

    Sebaaly, Carine; Jraij, Alia; Fessi, Hatem; Charcosset, Catherine; Greige-Gerges, Hélène

    2015-07-01

    In this study, suitable formulations of natural soybean phospholipid vesicles were developed to improve the stability of clove essential oil and its main component, eugenol. Using an ethanol injection method, saturated (Phospholipon 80H, Phospholipon 90H) and unsaturated soybean (Lipoid S100) phospholipids, in combination with cholesterol, were used to prepare liposomes at various eugenol and clove essential oil concentrations. Liposomal batches were characterized and compared for their size, polydispersity index, Zeta potential, loading rate, encapsulation efficiency and morphology. The liposomes were tested for their stability after storing them for 2 months at 4°C by monitoring changes in their mean size, polydispersity index and encapsulation efficiency (EE) values. It was found that liposomes exhibited nanometric oligolamellar and spherical shaped vesicles and protected eugenol from degradation induced by UV exposure; they also maintained the DPPH-scavenging activity of free eugenol. Liposomes constitute a suitable system for encapsulation of volatile unstable essential oil constituents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Minimization of complementary energy to predict shear modulus of laminates with intralaminar cracks

    International Nuclear Information System (INIS)

    Giannadakis, K; Varna, J

    2012-01-01

    The most common damage mode and the one examined in this work is the formation of intralaminar cracks in layers of laminates. These cracks can occur when the composite structure is subjected to mechanical and/or thermal loading and eventually lead to degradation of thermo-elastic properties. In the present work, the shear modulus reduction due to cracking is studied. Mathematical models exist in literature for the simple case of cross-ply laminates. The in-plane shear modulus of a damaged laminate is only considered in a few studies. In the current work, the shear modulus reduction in cross-plies will be analysed based on the principle of minimization of complementary energy. Hashin investigated the in-plane shear modulus reduction of cross-ply laminates with cracks in inside 90-layer using this variational approach and assuming that the in-plane shear stress in layers does not depend on the thickness coordinate. In the present study, a more detailed and accurate approach for stress estimation is followed using shape functions for this dependence with parameters obtained by minimization. The results for complementary energy are then compared with the respective from literature and finally an expression for shear modulus degradation is derived.

  3. Effect of ripple loads on sustained-load cracking in titanium alloys

    International Nuclear Information System (INIS)

    Pao, P.S.; Meyn, D.A.; Bayles, R.A.; Feng, C.R.; Yoder, G.R.

    1995-01-01

    In the present paper, the authors have extended their study on the effect of the ripple loads on the sustained-load cracking (SLC) behavior of two titanium alloys, Ti-6Al-4V (an α-β alloy) and Ti-15V-3Cr-3Al-3Sn (a β-α alloy), in an ambient air environment. The methodology which has been used successfully to treat ripple effects on stress-corrosion cracking (SCC) is employed again to address the influence of ripple loads on sustained-load cracking. Ripple loads can significantly reduce the apparent sustained load cracking resistance of titanium alloys in a relatively benign environment such as ambient air. For a ripple-load amplitude equal to 5% of the sustained load, the ripple-load cracking thresholds (K IRLC ) of beta-annealed Ti-6Al-4V and Ti-15V-3Cr-3al-3Sn are less than half of the respective sustained-load cracking thresholds (K ISLC ). The extent of ripple-load degradation for these alloys in ambient air -- relative to K ISLC , were found comparable to those observed in a much more aggressive 3.5% NaCl aqueous solution

  4. [Accumulation, distribution and pollution assessment of heavy metals in surface sediment of Caohai plateau wetland, Guizhou province].

    Science.gov (United States)

    Zhang, Qing-Hai; Lin, Chang-Hu; Tan, Hong; Lin, Shao-Xia; Yang, Hong-Bo

    2013-03-01

    The objective of this paper is to investigate the concentrations and distribution characteristics of heavy metals in surface sediments of different areas in the Caohai plateau wetland. 16 samples of surface sediments were collected and 7 heavy metals were analyzed. Heavy metal pollution in surface sediments of different areas in the Caohai plateau wetland was estimated by the Tomlinson Pollution Load Index (PLI) method. The analyzed results indicated that the average contents of Cd, Hg, As, Pb, Cr, Cu, Zn were 0.985, 0.345, 15.8, 38.9, 38.6, 22.8 and 384 mg x kg(-1), respectively. The heavy metal distributions varied with regional environment changes, the order of average contents of Cd and Hg in different regions was E (the eastern region) > S (the southern region) > N (the northern region), the order of the average content of Pb was N > E > S, and that of Zn was S > E > N. The results also suggested a medium heavy metal pollution level in the surface sediment of the Caohai plateau wetland with the PLI(zone) reaching 1.17. The order of pollution level in surface sediments of different regions was E > S > N. The results showed medium pollution levels in E and Hg which reached the extreme intensity pollution level were also the major polluted elements in surface sediments of the Caohai plateau wetland. And also, results showed medium pollution levels of Cd and Pb in surface sediments of Caohai plateau wetland. Cluster analysis results showed similar pollution sources of Cd, Zn, Pb and Hg, which should be attached great importance in terms of the prevention of the Caohai plateau wetland.

  5. Influence of mineralogical and heavy metal composition on natural radionuclide concentrations in the river sediments

    International Nuclear Information System (INIS)

    Suresh, G.; Ramasamy, V.; Meenakshisundaram, V.; Venkatachalapathy, R.; Ponnusamy, V.

    2011-01-01

    The natural radiation level has been determined for the sediment samples of the Ponnaiyar River with an aim of evaluating the radiation hazard. The mineralogical characterizations of the sediments have been carried out using the Fourier Transform Infrared (FTIR) spectroscopic technique. The relative distribution of major minerals is determined by calculating extinction coefficient. The concentration and spatial distribution of heavy metals (Pb, Cr, Cu, Zn and Ni) have been studied to understand the heavy metal contamination and its level of toxicity. To evaluate the potential toxicity, heavy metal concentrations are compared with different toxicological and geological reference values. The comparison results suggest that the present metals create an adverse effect on the aquatic ecosystems associated with this river. To assess the sediment contamination due to the studied heavy metals, the Pollution Load Index (PLI) is calculated. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis) were carried out between the parameters obtained from radioactivity, mineralogical and geochemical analysis to know the existing relations. Obtained results showed that the effect of mineralogy on level of radioactivity should be significant. However, mineralogy effect on heavy metal composition in the sediments should be limited, indicating that other factors such as vicinity of the pollution sources are more important. Also, the influence of mineralogical characterization on level of radioactivity is significant, whereas the influence of the heavy metal composition on level of radioactivity should be limited. - Highlights: →Sediments radioactivity, mineralogical and heavy metal characterization have been analyzed. → Absorbed dose rate, PLI and kaolinite increase towards the river mouth. → Influence of minerals and heavy metals on level of radioactivity is assessed.

  6. Influence of mineralogical and heavy metal composition on natural radionuclide concentrations in the river sediments

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, G., E-mail: gsureshphy_1983@yahoo.co.in [Department of Physics Thiruvalluvar College of Engg and Tech, Ponnur hills, Vandavasi, Tamilnadu 604 505 (India); Ramasamy, V. [Department of Physics, Annamalai University, Tamilnadu (India); Meenakshisundaram, V. [Health and Safety Division, IGCAR, Kalpakkam, Tamilnadu (India); Venkatachalapathy, R. [CAS in Marine Biology, Faculty of Marine Sciences, Annamalai University, Tamilnadu (India); Ponnusamy, V. [Department of Physics, MIT Campus, Anna University Chennai, Tamilnadu (India)

    2011-10-15

    The natural radiation level has been determined for the sediment samples of the Ponnaiyar River with an aim of evaluating the radiation hazard. The mineralogical characterizations of the sediments have been carried out using the Fourier Transform Infrared (FTIR) spectroscopic technique. The relative distribution of major minerals is determined by calculating extinction coefficient. The concentration and spatial distribution of heavy metals (Pb, Cr, Cu, Zn and Ni) have been studied to understand the heavy metal contamination and its level of toxicity. To evaluate the potential toxicity, heavy metal concentrations are compared with different toxicological and geological reference values. The comparison results suggest that the present metals create an adverse effect on the aquatic ecosystems associated with this river. To assess the sediment contamination due to the studied heavy metals, the Pollution Load Index (PLI) is calculated. Multivariate Statistical analyses (Pearson Correlation, Cluster and Factor analysis) were carried out between the parameters obtained from radioactivity, mineralogical and geochemical analysis to know the existing relations. Obtained results showed that the effect of mineralogy on level of radioactivity should be significant. However, mineralogy effect on heavy metal composition in the sediments should be limited, indicating that other factors such as vicinity of the pollution sources are more important. Also, the influence of mineralogical characterization on level of radioactivity is significant, whereas the influence of the heavy metal composition on level of radioactivity should be limited. - Highlights: >Sediments radioactivity, mineralogical and heavy metal characterization have been analyzed. > Absorbed dose rate, PLI and kaolinite increase towards the river mouth. > Influence of minerals and heavy metals on level of radioactivity is assessed.

  7. Relationships between magnetic susceptibility and heavy metals in urban topsoils in the arid region of Isfahan, central Iran

    Science.gov (United States)

    Karimi, Rezvan; Ayoubi, Shamsollah; Jalalian, Ahmad; Sheikh-Hosseini, Ahmad Reza; Afyuni, Majid

    2011-05-01

    Recently methods dealing with magnetometry have been proposed as a proper proxy for assessing the heavy metal pollution of soils. A total of 113 topsoil samples were collected from public parks and green strips along the rim of roads with high-density traffic within the city of Isfahan, central Iran. The magnetic susceptibility (χ) of the collected soil samples was measured at both low and high frequency (χlf and χhf) using the Bartington MS2 dual frequency sensor. As, Cd, Cr, Ba, Cu, Mn, Pb, Zn, Sr and V concentrations were measured in the all collected soil samples. Significant correlations were found between Zn and Cu (0.85) and between Zn and Pb (0.84). The χfd value of urban topsoil varied from 0.45% to 7.7%. Low mean value of χfd indicated that the magnetic properties of the samples are predominately contributed by multi-domain grains, rather than by super-paramagnetic particles. Lead, Cu, Zn, and Ba showed positive significant correlations with magnetic susceptibility, but As, Sr, Cd, Mn, Cr and V, had no significant correlation with the magnetic susceptibility. There was a significant correlation between pollution load index (PLI) and χlf. PLI was computed to evaluate the soil environmental quality of selected heavy metals. Moreover, the results of multiple regression analysis between χlf and heavy metal concentrations indicated the LnPb, V and LnCu could explain approximately 54% of the total variability of χlf in the study area. These results indicate the potential of the magnetometric methods to evaluate the heavy metal pollution of soils.

  8. Preparation and characterization of Tribulus terrestris-loaded nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Khanavi*

    2017-11-01

    Full Text Available Background and objectives: Tribulus terrestris is a flowering herb (Zygophyllaceae with several properties in folk medicine such as diuretic, tonic, aphrodisiac, analgesic, astringent, and stomachic-lithotripter activities. Although, some extracts and phytochemicals represent excellent bio-activity in vitro, less or no in vivo activity is observed due to their improper molecular size. The intend of this research was investigation of the feasibility of encapsulating T. terrestris into [poly (lactic-co-glycolic acid] PLGA nanoparticles. Methods: Aerial parts of the plant were extracted with aqueous ethanol 85% by percolation apparatus. The nanoparticles of T. terrestris-loaded were prepared using a modified simultaneous double-emulsion solvent evaporation/diffusion method. Elucidations were made on the basis of scanning electron microscopy (SEM and differential scanning calorimetry (DSC. The content of nanoparticles was analyzed by HPLC with indirect method. Results: The results stated that increasing the portion of plant extract could cause bigger size with no considerable increase in polydispersity index (PDI. The encapsulation efficiency of T. terrestris-loaded nanoparticles was 40.3 to 78.5 and the drug loadings were 0.806 to 6.104, with different ratios of extract. The overall pattern of the release in SDS 1% in dialysis bag in all formulations showed similar and biphasic release kinetic, an initial burst release in the first day followed by constant release over 10 days. Conclusion: An effective approach for the preparation of T. terrestris-loaded PLGA nanoparticles was performed. The controlled release profile showed that these biodegradable PLGA nanoparticles had great potential and should be given particular consideration in further biological researches.

  9. Individual differences at high perceptual load: the relation between trait anxiety and selective attention.

    Science.gov (United States)

    Sadeh, Naomi; Bredemeier, Keith

    2011-06-01

    Attentional control theory (Eysenck et al., 2007) posits that taxing attentional resources impairs performance efficiency in anxious individuals. This theory, however, does not explicitly address if or how the relation between anxiety and attentional control depends upon the perceptual demands of the task at hand. Consequently, the present study examined the relation between trait anxiety and task performance using a perceptual load task (Maylor & Lavie, 1998). Sixty-eight male college students completed a visual search task that indexed processing of irrelevant distractors systematically across four levels of perceptual load. Results indicated that anxiety was related to difficulty suppressing the behavioural effects of irrelevant distractors (i.e., decreased reaction time efficiency) under high, but not low, perceptual loads. In contrast, anxiety was not associated with error rates on the task. These findings are consistent with the prediction that anxiety is associated with impairments in performance efficiency under conditions that tax attentional resources.

  10. Low cognitive load strengthens distractor interference while high load attenuates when cognitive load and distractor possess similar visual characteristics.

    Science.gov (United States)

    Minamoto, Takehiro; Shipstead, Zach; Osaka, Naoyuki; Engle, Randall W

    2015-07-01

    Studies on visual cognitive load have reported inconsistent effects of distractor interference when distractors have visual characteristic that are similar to the cognitive load. Some studies have shown that the cognitive load enhances distractor interference, while others reported an attenuating effect. We attribute these inconsistencies to the amount of cognitive load that a person is required to maintain. Lower amounts of cognitive load increase distractor interference by orienting attention toward visually similar distractors. Higher amounts of cognitive load attenuate distractor interference by depleting attentional resources needed to process distractors. In the present study, cognitive load consisted of faces (Experiments 1-3) or scenes (Experiment 2). Participants performed a selective attention task in which they ignored face distractors while judging a color of a target dot presented nearby, under differing amounts of load. Across these experiments distractor interference was greater in the low-load condition and smaller in the high-load condition when the content of the cognitive load had similar visual characteristic to the distractors. We also found that when a series of judgments needed to be made, the effect was apparent for the first trial but not for the second. We further tested an involvement of working memory capacity (WMC) in the load effect (Experiment 3). Interestingly, both high and low WMC groups received an equivalent effect of the cognitive load in the first distractor, suggesting these effects are fairly automatic.

  11. Effects of morphine on respiratory load detection, load magnitude perception and tactile sensation in obstructive sleep apnea.

    Science.gov (United States)

    Tomazini Martins, Rodrigo; Carberry, Jayne C; Gandevia, Simon C; Butler, Jane E; Eckert, Danny J

    2018-04-26

    Pharyngeal and respiratory sensation is impaired in obstructive sleep apnea (OSA). Opioids may further diminish respiratory sensation. Thus, protective pharyngeal neuromuscular and arousal responses to airway occlusion that rely on respiratory sensation could be impaired with opioids to worsen OSA severity. However, little is known about the effects of opioids on upper airway and respiratory sensation in people with OSA. This study was designed to determine the effects of 40mg of MS-Contin on tactile sensation, respiratory load detection and respiratory magnitude perception in people with OSA during wakefulness. A double-blind, randomized, cross-over design (1 week wash-out) was used. 21 men with untreated OSA (apnea/hypopnea index=26{plus minus}17events/h) recruited from a larger clinical study completed the protocol. Tactile sensation using von Frey filaments on the back of the hand, internal mucosa of the cheek, uvula and posterior pharyngeal wall were not different between placebo and morphine (e.g. posterior wall=0.16[0.16,0.4]vs. 0.4[0.14,1.8]g, p=0.261). Similarly, compared to placebo, morphine did not alter respiratory load detection thresholds (nadir mask pressure detected=-2.05[-3.37,-1.55] vs. -2.19[-3.36,-1.41]cmH 2 O, p=0.767), or respiratory load magnitude perception (mean Borg scores during a 5 resistive load [range: 5-126cmH 2 O/L/s] protocol=4.5{plus minus}1.6 vs. 4.2{plus minus}1.2, p=0.347) but did reduce minute ventilation during quiet breathing (11.4{plus minus}3.3 vs. 10.7{plus minus}2.6L/min, prespiratory sensation in men with mild to moderate, untreated, OSA. This suggests that altered respiratory sensation to acute mechanical stimuli is not likely to be a mechanism that contributes to worsening of OSA with a moderate dose of morphine.

  12. Formulation, characterization and pharmacokinetics of praziquantel-loaded hydrogenated castor oil solid lipid nanoparticles.

    Science.gov (United States)

    Xie, Shuyu; Pan, Baoliang; Wang, Ming; Zhu, Luyan; Wang, Fenghua; Dong, Zhao; Wang, Xiaofang; Zhou, WenZhong

    2010-07-01

    The purpose of this study was to formulate praziquantel (PZQ)-loaded hydrogenated castor oil (HCO) solid lipid nanoparticles (SLN) to enhance the bioavailability and prolong the systemic circulation of the drug. PZQ was encapsulated into HCO nanoparticles by a hot homogenization and ultrasonication method. The physicochemical characteristics of SLN were investigated by optical microscope, scanning electron microscopy and photon correlation spectroscopy. Pharmacokinetics were studied after oral, subcutaneous and intramuscular administration in mice. The diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 344.0 +/- 15.1 nm, 0.31 +/- 0.08, -16.7 +/- 0.5 mV, 62.17 +/- 6.53% and 12.43 +/- 1.31%, respectively. In vitro release of PZQ-loaded HCO-SLN exhibited an initial burst release followed by a sustained release. SLN increased the bioavailability of PZQ by 14.9-, 16.1- and 2.6-fold, and extended the mean residence time of the drug from 7.6, 6.6 and 8.2 to 95.9, 151.6 and 48.2 h after oral, subcutaneous and intramuscular administration, respectively. The PZQ-loaded HCO-SLN could be a promising formulation to enhance the pharmacological activity of PZQ.

  13. The use of 5-fluorouracil-loaded nanobubbles combined with low-frequency ultrasound to treat hepatocellular carcinoma in nude mice.

    Science.gov (United States)

    Li, Qiaoya; Li, Hongyang; He, Chengjun; Jing, Zhouhong; Liu, Changan; Xie, Juan; Ma, Wenwen; Deng, Huisheng

    2017-11-21

    This study aimed to investigate the therapeutic effects of 5-fluorouracil (5-FU)-loaded nanobubbles irradiated with low-intensity, low-frequency ultrasound in nude mice with hepatocellular carcinoma (HCC). A transplanted tumor model of HCC in nude mice was established in 40 mice, which were then randomly divided equally into four groups: group A (saline), group B (5-FU-loaded nanobubbles), group C (5-FU-loaded nanobubbles with non-low-frequency ultrasound), and group D (5-FU-loaded nanobubbles with low-frequency ultrasound). The tumor size in each mouse was observed via ultrasound before and after the treatments. Inhibition of the tumor growth in each group was compared, and survival curves were generated. Tumor tissues were removed to determine the apoptotic index using the TUNEL method and quantitative analysis. Tumor tissues with CD34-positive microvessels were observed by immunohistochemistry, and the tumor microvessel densities were calculated. The growth rate of the tumor volumes in group D was significantly slower than that in the other groups, while the tumor inhibition rates and apoptotic index in group D were significantly higher than those of the other groups. The number of microvessels staining positive for CD34 was decreased in group D. Therefore, group D presented the most significant inhibitory effects. Therefore, 5-FU-loaded nanobubbles subjected to irradiation with low-frequency ultrasound could further improve drug targeting and effectively inhibit the growth of transplanted tumors, which is expected to become an ideal drug carrier and targeted drug delivery system for the treatment of HCC in the future.

  14. Pollution level and health risk assessment of road dust from Islamabad expressway, Pakistan

    International Nuclear Information System (INIS)

    Faiz, Y.; Siddique, N.

    2012-01-01

    Thirteen road dust and four soil samples were analyzed using instrumental neutron activation analysis (INAA) to determine the elemental composition of road dust collected from Islamabad Expressway. The amounts of most of the elements determined were generally in the lower range of the global data with the exception of Ce, Nd, Sn and Zr which were measured at higher concentrations in Islamabad. Pollution parameters and indicators such as Enrichment Factors (EFs), Pollution Load Index (PLI), Geo accumulation Index (Igeo), Pollution Index (PI) and Integrated Pollution Index (IPI) showed that the area around Islamabad Expressway is low to moderately polluted especially by elements such as Mg and Sb. The IPI of the elements was found to vary in the order; Mg>Sb>Cu>Sr Pb>Ga>Na >Sn Zn>Yb>Se>Hf. Elemental health risk was assessed through dose calculations for carcinogenic and non carcinogenic metals; and by the determination of LADD (lifetime average daily dose). The carcinogenic metals studied showed the following variation in their LADD values; Cr>Ni>Co>Cd>As. Dose calculations for non-cancerous and cancerous elements showed the data obtained to lie within the safe threshold of 10 3 10 6 mg kg/sup -1/ day/sup -1/ for most elements. The soil based elements Al, Fe, K, Mg, Na and Ti were the exception and originated from the exposed soil around the highway. Moreover highest Hazard Index (HI) was found to be associated with the presence of Al, Cr, Pb and V in road dust showing soil, transport and industry to be the major sources of road dust. (orig./A.B.)

  15. Dielectric-loaded surface plasmon-polariton nanowaveguides fabricated by two-photon polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Hao; Li, Yan; Cui, Hai-Bo; Yang, Hong; Gong, Qi-Huang [Peking University, State Key Laboratory for Mesoscopic Physics and Department of Physics, Beijing (China)

    2009-11-15

    The design, fabrication, and characterization of dielectric-loaded surface plasmon-polariton nanowave-guides on a gold film are presented. The nanostructures are produced by two-photon polymerization with femtosecond laser pulses, and the minimum ridge height is {proportional_to}170 nm. Leakage radiation microscopy shows that these surface plasmon-polariton waveguides are single mode with strong mode confinement at the wavelength of 830 nm. The experimental results are in good agreement with the simulation by the effective-index method. (orig.)

  16. Distribution load estimation (DLE)

    Energy Technology Data Exchange (ETDEWEB)

    Seppaelae, A; Lehtonen, M [VTT Energy, Espoo (Finland)

    1998-08-01

    The load research has produced customer class load models to convert the customers` annual energy consumption to hourly load values. The reliability of load models applied from a nation-wide sample is limited in any specific network because many local circumstances are different from utility to utility and time to time. Therefore there is a need to find improvements to the load models or, in general, improvements to the load estimates. In Distribution Load Estimation (DLE) the measurements from the network are utilized to improve the customer class load models. The results of DLE will be new load models that better correspond to the loading of the distribution network but are still close to the original load models obtained by load research. The principal data flow of DLE is presented

  17. Double-Lap Shear Test For Honeycomb Core

    Science.gov (United States)

    Nettles, Alan T.; Hodge, Andrew J.

    1992-01-01

    Double-lap test measures shear strength of panel made of honeycomb core with 8-ply carbon-fiber/epoxy face sheets. Developed to overcome three principal disadvantages of prior standard single-lap shear test: specimen had to be more than 17 in. long; metal face sheets had to be used; and test introduced torque, with consequent bending and peeling of face sheets and spurious tensile or compressive loading of honeycomb.

  18. Distribution, source identification and health risk assessment of soil heavy metals in urban areas of Isfahan province, Iran

    Science.gov (United States)

    Rastegari Mehr, Meisam; Keshavarzi, Behnam; Moore, Farid; Sharifi, Reza; Lahijanzadeh, Ahmadreza; Kermani, Maryam

    2017-08-01

    The present study examines some heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) contents in urban soils of 23 cities in Isfahan province, central Iran. For this purpose, 83 topsoil samples were collected and analyzed by ICP-MS. Results showed that the concentrations of As, Cd, Cu, Pb and Zn are higher than background values, while Co, Cr and Ni concentrations are close to the background. Compared with heavy metal concentrations in selected cities around the world, As, Cd, Cu, Pb and Zn concentrations in urban soils of Isfahan are relatively enriched. Moreover, natural background concentrations of Co, Cr and Ni in Isfahan province soil are high and the apparent enrichment relative to other major cities of the world is due to this high background contents. Calculated contamination factor (CF) confirmed that As, Cd, Cu, Pb and Zn are extremely enriched in the urban soils. Furthermore, pollution load index (PLI) and Geoaccumulation index (Igeo) highlighted that highly contaminated cities are mostly affected by pollution from traffic, industries and Shahkuh Pb-Zn mine. Based on hazard quotients (HQ), hazard index (HI) and cancer risk (CR) calculated in this study, human health risk (particularly for Pb and Cd) have reached alarming scales. Results from principle component analysis (PCA) and positive matrix factorization (PMF) introduces three sources for soils heavy metals including mine and industries (mainly for Pb, Zn, Cd and As); urban activities (particularly for Cu, Pb and Zn); and geogenic source (Ni, Co and Cr).

  19. Effects of conversion of mangroves into gei wai ponds on sediment heavy metals accumulation in tidal flat estuary, South China

    Science.gov (United States)

    Li, R.; Qiu, G.; Chai, M.; Li, R.

    2017-12-01

    Gei wai ponds act as important component in mangrove ecosystem, but the conversion of mangroves into gei wai ponds and its ecological function on heavy metal accumulation is still not clear. The study quantified the sediment heavy metal concentration and speciation in gei wai pond, Avicennia marina marsh and mudflat in Futian mangrove wetlands, South China. The results showed that gei wai pond acidified the sediment and reduced its fertility due to reduced pH, electronic conductivity (EC) and total organic carbon (TOC) compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all depth in gei wai pond sediment were also lower than other sites, indicating reduced storage function on heavy metals. Multiple analysis implied that heavy metals in all sites could be attributed to anthropogenic sources, with Cr as natural and anthropogenic sources in gei wai pond. Gei wai pond sediment had lower heavy metal pollution based on multiple evaluation methods, including potential ecological risk coefficient (Eir), potential ecological risk index (RI), geo-accumulation index (Igeo), mean PEL quotients (m-PEL-q), pollution load index (PLI), mean ERM quotients (m-ERM-q) and total toxic unit (∑TU). Heavy metal speciation analysis indicated that gei wai pond improved the conversion from the immobilized Cd and Cr to the mobilized fraction. SEM-AVS analysis indicated no adverse toxicity occurred in all sites, and the role of TOC in relieving sediment heavy metal toxicity of gei wai pond is limited.

  20. Relationships between static foot alignment and dynamic plantar loads in runners with acute and chronic stages of plantar fasciitis: a cross-sectional study

    Science.gov (United States)

    Ribeiro, Ana P.; Sacco, Isabel C. N.; Dinato, Roberto C.; João, Silvia M. A.

    2016-01-01

    BACKGROUND: The risk factors for the development of plantar fasciitis (PF) have been associated with the medial longitudinal arch (MLA), rearfoot alignment and calcaneal overload. However, the relationships between the biomechanical variables have yet to be determined. OBJECTIVE: The goal of this study was to investigate the relationships between the MLA, rearfoot alignment, and dynamic plantar loads in runners with unilateral PF in acute and chronic phases. METHOD: Cross-sectional study which thirty-five runners with unilateral PF were evaluated: 20 in the acute phase (with pain) and 15 with previous chronic PF (without pain). The MLA index and rearfoot alignment were calculated using digital images. The contact area, maximum force, peak pressure, and force-time integral over three plantar areas were acquired with Pedar X insoles while running at 12 km/h, and the loading rates were calculated from the vertical forces. RESULTS: The multiple regression analyses indicated that both the force-time integral (R 2=0.15 for acute phase PF; R 2=0.17 for chronic PF) and maximum force (R 2=0.35 for chronic PF) over the forefoot were predicted by an elevated MLA index. The rearfoot valgus alignment predicted the maximum force over the rearfoot in both PF groups: acute (R 2=0.18) and chronic (R 2=0.45). The rearfoot valgus alignment also predicted higher loading rates in the PF groups: acute (R 2=0.19) and chronic (R 2=0.40). CONCLUSION: The MLA index and the rearfoot alignment were good predictors of plantar loads over the forefoot and rearfoot areas in runners with PF. However, rearfoot valgus was demonstrated to be an important clinical measure, since it was able to predict the maximum force and both loading rates over the rearfoot. PMID:26786073