WorldWideScience

Sample records for cadmium base rides

  1. The Recovery-Based Interprofessional Distance Education (RIDE) Rotation: Content and Rationale.

    Science.gov (United States)

    Beebe, Lora; Raynor, Hollie; Roman, Marian W; Thompson, Dixie; Ray, Shaunta

    2015-01-01

    A faculty team of two psychiatric nurse practitioners, an exercise physiologist, a registered dietician and a pharmacist developed the 8-week Recovery-Based Interprofessional Distance Education (RIDE) rotation for graduate students in the four disciplines. Organizing the RIDE rotation around the recovery model ensured an emphasis upon optimal health and quality of life. RIDE faculty engaged in project planning for several months before the RIDE rotation was offered to students. In this paper, we describe details of the 8-week program. Our next step will be to analyze student feedback and de-identified evaluation data from the first student cohort.

  2. PHYSIOLOGICAL INFORMATION FOR PAVEMENT HEALTH MONITORING BASED ON SURFACE RIDE QUALITY

    Science.gov (United States)

    Tomiyama, Kazuya; Kawamura, Akira; Takahashi, Kiyoshi; Ishida, Tateki

    Pavement ride quality testing has traditionally been based on subjective questionnaire ratings. The questionnaire survey has ability to directly measure the sense of road users' ride quality. However, it is difficult to quantify the evaluation results based on the questionnaire due to its lack of objectivity. This study examines pavement health monitoring method using physiological information such as heart rate variability (HRV) for detecting mental stress of road users toward pavement ride quality. First, a results of a driving simulator experiment shows that potential mental stress caused by road roughness can be observed in high-frequency oscillations in 0.15-0.4Hz of HRV processed by continuous wavelet transform. Then, the high-frequency oscillations of HRV is summarized as an index related to the mental stress that makes objective ride quality evaluation possible. Finally, this study indicates that the index contributes to improve the accuracy of pavement health monitoring based on surface ride quality.

  3. The study of laser beam riding guided system based on 980nm diode laser

    Science.gov (United States)

    Qu, Zhou; Xu, Haifeng; Sui, Xin; Yang, Kun

    2015-10-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  4. Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Stoeppler, M. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Angewandte Physikalische Chemie); Piscator, M. (Karolinska Inst., Stockholm (Sweden). Dept. of Environmental Hygiene) (eds.)

    1988-01-01

    The proceedings contain the 18 papers presented at the workshop. They are dealing with the following themes: Toxicity, carcinogenesis and metabolism of cadmium, epidemiology; environmental occurrence; quantitative analysis and quality assessment. (MG) With 57 figs., 79 tabs.

  5. RIDES: Robust Intrusion Detection System for IP-Based Ubiquitous Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sungwon Lee

    2009-05-01

    Full Text Available TheIP-based Ubiquitous Sensor Network (IP-USN is an effort to build the “Internet of things”. By utilizing IP for low power networks, we can benefit from existing well established tools and technologies of IP networks. Along with many other unresolved issues, securing IP-USN is of great concern for researchers so that future market satisfaction and demands can be met. Without proper security measures, both reactive and proactive, it is hard to envisage an IP-USN realm. In this paper we present a design of an IDS (Intrusion Detection System called RIDES (Robust Intrusion DEtection System for IP-USN. RIDES is a hybrid intrusion detection system, which incorporates both Signature and Anomaly based intrusion detection components. For signature based intrusion detection this paper only discusses the implementation of distributed pattern matching algorithm with the help of signature-code, a dynamically created attack-signature identifier. Other aspects, such as creation of rules are not discussed. On the other hand, for anomaly based detection we propose a scoring classifier based on the SPC (Statistical Process Control technique called CUSUM charts. We also investigate the settings and their effects on the performance of related parameters for both of the components.

  6. Second-order sliding mode control for DFIG-based wind turbines fault ride-through capability enhancement.

    Science.gov (United States)

    Benbouzid, Mohamed; Beltran, Brice; Amirat, Yassine; Yao, Gang; Han, Jingang; Mangel, Hervé

    2014-05-01

    This paper deals with the fault ride-through capability assessment of a doubly fed induction generator-based wind turbine using a high-order sliding mode control. Indeed, it has been recently suggested that sliding mode control is a solution of choice to the fault ride-through problem. In this context, this paper proposes a second-order sliding mode as an improved solution that handle the classical sliding mode chattering problem. Indeed, the main and attractive features of high-order sliding modes are robustness against external disturbances, the grids faults in particular, and chattering-free behavior (no extra mechanical stress on the wind turbine drive train). Simulations using the NREL FAST code on a 1.5-MW wind turbine are carried out to evaluate ride-through performance of the proposed high-order sliding mode control strategy in case of grid frequency variations and unbalanced voltage sags.

  7. A Novel Wind Turbine Concept Based on an Electromagnetic Coupler and the Study of Its Fault Ride-through Capability

    DEFF Research Database (Denmark)

    You, Rui; Barahona Garzón, Braulio; Chai, Jianyun

    2013-01-01

    This paper presents a novel type of variable speed wind turbine with a new drive train different from the variable speed wind turbine commonly used nowadays. In this concept, a synchronous generator is directly coupled with the grid, therefore, the wind turbine transient overload capability...... is proposed and a 2 MW wind turbine model is built to study the wind turbine fault ride-through capability. An integrated simulation environment based on the aeroelastic code HAWC2 and software Matlab/Simulink is used to study its fault ride-through capability and the impact on the structural loads during...

  8. Experimental Study on the Ride Comfort of a Crawler Power Chassis Scale Model Based on the Similitude Theory

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jianzhu; WANG Fengchen; YU Bin; TONG Pengcheng; CHEN Kuifu

    2015-01-01

    The ride comfort experimental assessment of crawler off-road vehicle is relatively overlooked, and is expensive and difficult to execute with higher and higher ride comfort performance requirements. To trade off between precise and cost, an experimental method based on the similitude theory is proposed. Under the guidance of the similitude theory, a 1:5 crawler power chassis scale model equipped with a kind of variable stiffness suspension system is used. The power spectrum density(PSD), the root mean square(RMS) of weighed acceleration, peak factor, average absorbed power(AAP) and vibration dose value(VDV) are selected as ride comfort evaluation indexes, and tests results are transformed via similarity indexes to predict the performance of full-scale power chassis. PSD shows that the low-order natural frequency of the vertical natural frequency(z axis) is 1.1 Hz, and the RMS, AAP and VDV values indicate the ride comfort performance of this kind of power chassis is between the“A little uncomfortable”and“Rather uncomfortable”. From the results, low-order vertical natural frequency, obtalned by PSD, validates that the similarity relationship between two models is satisfied, and 1:5 scale model used in experiment meets the similarity relationship with the full-scale model; consequently, the ride comfort prophase evaluation with the 1:5 scale model is feasible. The attempt of applying the similitude theory to crawler vehicle ride comfort test study decreases the cost and improves the test feasibility with sufficient test precise.

  9. Dial-a-Ride

    DEFF Research Database (Denmark)

    Jørgensen, Rene Munk

    2003-01-01

    and vehicle positions. Unfortunately data from actual Dial-a-Ride transportation systems is not readily available, so tests are based on data generated in this project. While the algorithm performs as expected, other results such as the stable performance of the different modules in the developed software...

  10. Assessment of control strategies for fault ride through of SCIG-based wind energy conversion systems

    Directory of Open Access Journals (Sweden)

    Manaullah

    2016-01-01

    Full Text Available With increasing penetration of wind energy into the power grid, researchers have started focusing more on control and coordination of wind energy conversion systems (WECS with the other components at system level, especially during fault. It is important to implement a suitable fault ride through control strategy to avoid tripping of the generators when the power system is subjected to voltage dips normally below 90% of nominal voltage. The dips below 90% may lead to a significant loss of generation and frequency collapse, followed by a blackout. This article implements and assesses the methodologies to deal with such situations for squirrel cage induction generator-based wind energy conversion systems employing fully rated power electronic converters. Three distinct control techniques—namely, balanced positive sequence control, positive negative sequence control, and dual current control—have been simulated and applied to grid side converter of SCIG-based WECS. The performance of all the three control strategies has been compared and presented in this work. During this study, the system is subjected to the most common unsymmetrical line to ground (LG fault and most severe symmetrical LLL fault on grid for the purpose of anaysis.

  11. Coordinated Control Strategies of VSC-HVDC-Based Wind Power Systems for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Xinyin Zhang

    2015-07-01

    Full Text Available The Voltage Source Converter-HVDC (VSC-HVDC system applied to wind power generation can solve large scale wind farm grid-connection and long distance transmission problems. However, the low voltage ride through (LVRT of the VSC-HVDC connected wind farm is a key technology issue that must be solved, and it is currently lacking an economic and effective solution. In this paper, a LVRT coordinated control strategy is proposed for the VSC-HVDC-based wind power system. In this strategy, the operation and control of VSC-HVDC and wind farm during the grid fault period is improved. The VSC-HVDC system not only provides reactive power support to the grid, but also effectively maintains the power balance and DC voltage stability by reducing wind-farm power output, without increasing the equipment investment. Correspondingly, to eliminate the influence on permanent magnet synchronous generator (PMSG-based wind turbine (WT systems, a hierarchical control strategy is designed. The speed and validity of the proposed LVRT coordinated control strategy and hierarchical control strategy were verified by MATLAB/Simulink simulations.

  12. Z-Source Inverter Based Power Quality Compensator with Enhanced Ride-Through Capability

    DEFF Research Database (Denmark)

    Gajanayake, C.J.; Vilathgamuwa, D.M.; Loh, P.C.;

    2007-01-01

    network. The shunt inverter is controlled to maintain a quality voltage waveform at the load bus. Whereas the series inverter enhances the ride-through capability during grid faults, protects the shunt inverter by limiting the current and also controls the power delivered to the grid. The performance...

  13. Formation and Characterization of Mixed Crystals Based on Bis (Thiourea)Cadmium Chloride and Bis (Thiourea)Cadmium Iodide

    OpenAIRE

    2014-01-01

    Bis(thiourea)cadmium chloride(BTCC) and bis(thiourea)cadmium iodide (BTCI) are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch) from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members) crystals were formed by the free evaporation method and characteriz...

  14. A Dynamic Consensus Algorithm based Low-Voltage Ride-Through Operation of Power Converters in Grid-Interactive Microgrids

    DEFF Research Database (Denmark)

    Zhao, Xin; Meng, Lexuan; Savaghebi, Mehdi

    2016-01-01

    of the converters cannot be equally shared if no extra current balancing loop is added. Accordingly, a dynamic consensus algorithm (DCA) based negative/positive sequence current sharing scheme is proposed in this paper. Finally, a lab-scale AC microgrid was designed and tested in the lab to validate the feasibility...... control based voltage support strategy has been proposed to aid MGs riding through three phase asymmetrical voltage sags. However, since the line impedance from each converter to the point of common coupling (PCC) is not identical, both positive sequence and negative sequence output current...

  15. [Principle for strategic decision based on population health risk in emergence environmental cadmium pollution control].

    Science.gov (United States)

    Shang, Qi

    2012-05-01

    The principles for strategic decision in emergence environmental pollution control was summarized based on population health risk and features of emergence events of environmental cadmium pollution. Main task and strategies for the events control was suggested in emergency treatment and post-event for water and soil cadmium pollution respectively. The work, monitoring method, key problems for both environment cadmium pollution and human health risk, and main content of health education for cadmium exposure people was proposed in follow-up action, at meanwhile, achievements of study on human health effects caused by environmental cadmium pollution was introduced briefly over recent years.

  16. iRide: A Cooperative Sensor and IP Multimedia Subsystem Based Architecture and Application for ITS Road Safety

    Science.gov (United States)

    Elkotob, Muslim; Osipov, Evgeny

    In this paper we present iRide (intelligent ride), an IP Multimedia Subsystem (IMS) application for warning drivers about hazardous situations on the road. iRide takes real-time information about road conditions and traffic situations from a wireless sensor network installed directly in the road surface. Upon logging to the iRide system, users start to receive periodic updates about the situation on the road along their route ahead. iRide is able to predict hazardous situations like slippery surface or dangerous distance to the nearest car and help drivers avoid accidents. We describe the service and the supporting network architecture of iRide. We discuss the major challenges associated with designing an IMS application for ITS, an intelligent transport system. Having a prototype implementation working on a small scale, we take it to the next step to perform system dimensioning and then verify the feasibility of having such a system using OPNET simulations.

  17. A Novel Wind Turbine Concept Based on an Electromagnetic Coupler and the Study of Its Fault Ride-through Capability

    Directory of Open Access Journals (Sweden)

    Rui You

    2013-11-01

    Full Text Available This paper presents a novel type of variable speed wind turbine with a new drive train different from the variable speed wind turbine commonly used nowadays. In this concept, a synchronous generator is directly coupled with the grid, therefore, the wind turbine transient overload capability and grid voltage support capability can be significantly improved. An electromagnetic coupling speed regulating device (EMCD is used to connect the gearbox high speed shaft and synchronous generator rotor shaft, transmitting torque to the synchronous generator, while decoupling the gearbox side and the synchronous generator, so the synchronous generator torque oscillations during a grid fault are not transmitted to the gearbox. The EMCD is composed of an electromagnetic coupler and a one quadrant operation converter with reduced capability and low cost. A control strategy for the new wind turbine is proposed and a 2 MW wind turbine model is built to study the wind turbine fault ride-through capability. An integrated simulation environment based on the aeroelastic code HAWC2 and software Matlab/Simulink is used to study its fault ride-through capability and the impact on the structural loads during grid three phase and two phase short circuit faults.

  18. FDI based on Artificial Neural Network for Low-Voltage-Ride-Through in DFIG-based Wind Turbine.

    Science.gov (United States)

    Adouni, Amel; Chariag, Dhia; Diallo, Demba; Ben Hamed, Mouna; Sbita, Lassaâd

    2016-09-01

    As per modern electrical grid rules, Wind Turbine needs to operate continually even in presence severe grid faults as Low Voltage Ride Through (LVRT). Hence, a new LVRT Fault Detection and Identification (FDI) procedure has been developed to take the appropriate decision in order to develop the convenient control strategy. To obtain much better decision and enhanced FDI during grid fault, the proposed procedure is based on voltage indicators analysis using a new Artificial Neural Network architecture (ANN). In fact, two features are extracted (the amplitude and the angle phase). It is divided into two steps. The first is fault indicators generation and the second is indicators analysis for fault diagnosis. The first step is composed of six ANNs which are dedicated to describe the three phases of the grid (three amplitudes and three angle phases). Regarding to the second step, it is composed of a single ANN which analysis the indicators and generates a decision signal that describes the function mode (healthy or faulty). On other hand, the decision signal identifies the fault type. It allows distinguishing between the four faulty types. The diagnosis procedure is tested in simulation and experimental prototype. The obtained results confirm and approve its efficiency, rapidity, robustness and immunity to the noise and unknown inputs.

  19. Negative Sequence Droop Method based Hierarchical Control for Low Voltage Ride-Through in Grid-Interactive Microgrids

    DEFF Research Database (Denmark)

    Zhao, Xin; Firoozabadi, Mehdi Savaghebi; Quintero, Juan Carlos Vasquez

    2015-01-01

    . In this paper, a voltage support strategy based on negative sequence droop control, which regulate the positive/negative sequence active and reactive power flow by means of sending proper voltage reference to the inner control loop, is proposed for the grid connected MGs to ride through voltage sags under...... complex line impedance conditions. In this case, the MGs should inject a certain amount of positive and negative sequence power to the grid so that the voltage quality at load side can be maintained at a satisfied level. A two layer hierarchical control strategy is proposed in this paper. The primary...... control loop consists of voltage and current inner loops, conventional droop control and virtual impedance loop while the secondary control loop is based on positive/negative sequence droop control which can achieve power injection under voltage sags. Experimental results with asymmetrical voltage sags...

  20. Use of salivary cortisol to evaluate the influence of rides in dromedary camels.

    Science.gov (United States)

    Majchrzak, Yasmine N; Mastromonaco, Gabriela F; Korver, Wendy; Burness, Gary

    2015-01-15

    Animals in captivity and in the wild face numerous challenges, including the risk of enduring acute or chronic stress. In captivity, facilities attempt to alleviate the risk of chronic stress by providing environmental enrichment, shown to minimize behavioral disorders and stress in several species. One potential form of enrichment in zoos is training animals to provide rides for guests, however, the effect of this activity on the welfare of individual animals has never been examined. We validated the use of saliva for assessing stress in dromedary camels (Camelus dromedarius), an animal commonly used for rides. We then measured variation in salivary cortisol in four male camels while providing rides of differing frequency for guests at the Toronto Zoo. The camels were sampled during the ride season (June to September) using four treatments: (1) in their pasture, (2) at the ride area when not performing rides, (3) while providing a low number of rides (n=50/day) and (4) while providing a high number of rides (n=150/day). Furthermore, samples were taken before and after the ride season for comparison. There was a significant difference between the post-ride season treatment and the three treatments involving guest presence during the ride season (ride area, low rides, high rides). In general, cortisol concentrations were lower during the ride season and higher during the non-ride season. Based on the metrics we used, performing rides is not a stressful experience for these dromedary camels and suggests that rides may be a form of enrichment.

  1. Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators.

    Science.gov (United States)

    Manonmani, N; Subbiah, V; Sivakumar, L

    2015-01-01

    The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs) supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs). The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation.

  2. Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators

    Directory of Open Access Journals (Sweden)

    N. Manonmani

    2015-01-01

    Full Text Available The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs. The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation.

  3. The effects of aircraft design on STOL ride quality

    Science.gov (United States)

    Jones, C. R.; Jacobson, I. D.

    1975-01-01

    Effects of aircraft dynamic characteristics on passenger ride quality are investigated to determine ride-quality isocontours similar to aircraft handling-qualities contours. Measurements are made on a moving-base simulator while varying the aircraft short-period and Dutch Roll frequencies and dampings. Both pilot ratings and subjective ride-quality ratings are obtained during flight. Ride and handling qualities were found to be complementary for the Dutch Roll mode, but not for the short-period mode. Regions of optimal ride and handling qualities are defined for the short-period mode, and the effects of turbulence levels studied.

  4. An Innovative Control Strategy to Improve the Fault Ride-Through Capability of DFIGs Based on Wind Energy Conversion Systems

    Directory of Open Access Journals (Sweden)

    Vandai Le

    2016-01-01

    Full Text Available An innovative control strategy is proposed for enhancing the low voltage ride-through (LVRT capability of a doubly fed induction generator based on wind energy conversion systems (DFIG-WECS. Within the proposed control method, the current control loops of the rotor side converter (RSC are developed based on passivity theory. The control scheme for the grid side converter (GSC is designed based on a two-term approach to keep the DC-link voltage close to a given value. The first term based on the maximal voltage of GSC is introduced in the GSC control loops as a reference reactive current. The second one reflecting the instantaneous unbalanced power flow between the RSC and GSC is also introduced in the GSC control loops as a disturbance considering the instantaneous power of the grid filter to compensate the instantaneous rotor power. The effectiveness of the proposed control strategy is verified via time domain simulation of a 2.0 MW-575 V DFIG-WECS using PSCAD/EMTP. Simulation results show that the control of the DFIG with the proposed approach can improve the LVRT capability better than with the conventional one.

  5. Enjoying the Ride!

    Science.gov (United States)

    McGinley, Michelle L.

    2011-01-01

    One of the author's favorite things to do is ride her bike. She finds bike riding to be a therapeutic outdoor adventure. In this article, the author describes how her students made their self-portrait bicycle collages. (Contains 2 online resources.)

  6. 基于虚拟样机技术的车辆平顺性研究%Research on Vehicle Ride Comfort Based on Virtual Prototype Technology

    Institute of Scientific and Technical Information of China (English)

    丁金刚; 黄志刚; 严凌; 闫伟静

    2012-01-01

    Virtual prototype technology was used in the research of vehicle ride Comfort, to build a simulation . model of a car in which suspension, steering system, tires, vehicle body, and brake system are considered inputs based on the multi-body system dynamics. According to the national standard, the car ride comfort under the pulse input and the stochastic uneven road input was simulated successfully in ADAMS/Car Ride and then the measurement data acquired from simulation analysis were input to the ride evaluation process based on MATLAB to evaluate the a-nalysis conclusion. The analytical results indicate that the car ride comfort is improved well. Based on that, the full car was simplified to two-freedom 1/4 model and the vibration model was established using Matlab/Simulink. The factors influencing ride comfort have researched, including suspension stiffness, damping, and tire stiffness. The a-nalysis show the variational rules that the vehicle body vertical acceleration changes along with the suspension stiff-ness , damping and, tire stiffness.%研究某轿车动力学模型优化,多体动力学理论,采用虚拟样机技术,对车辆行驶的平顺性,建立包含前后悬架,转向系统、车轮,制动系统、车身等在内的整车多体动力学虚拟样机模型,依据国家标准,在ADAMS/Car Ride中成功地对轿车进行脉冲输入和随机路面输入的平顺性仿真,得到的数据输入到MATLAB编制的平顺性评价程序中.对比结果表明,车平顺性较好.在此基础上,并将整车模型简化为二自由度1/4车辆模型,在Matlab/Simulink上建立振动模型,分析了悬架刚度、阻尼比、轮胎刚度对车辆平顺性的影响,得出车身加速度随悬架刚度、阻尼比及轮胎动载荷变化的规律.

  7. Dial-a-Ride

    OpenAIRE

    2003-01-01

    The Dial-a-Ride problem is a Vehicle Routing problem in its most general form. The problem was formulated in the beginning of the 1970's and since then a large number of researchers have worked on developing efficient algorithms for use in automated planning of Dial-a-Ride transportation systems. In a Dial-a-Ride transportation system, passengers request a trip between two stops with either a desired time of departure from the pickup stop or a desired time of arrival at the destination. The t...

  8. Sorption Kinetics for the Removal of Cadmium and Zinc onto Palm Kernel Shell Based Activated Carbon

    Directory of Open Access Journals (Sweden)

    Muhammad Muhammad

    2010-12-01

    Full Text Available The kinetics and mechanism of cadmium and zinc adsorption on palm kernel shell based activated carbons (PKSAC have been studied. A series of batch laboratory studies were conducted in order to investigate the suitability of palm kernel shell based activated carbon (PKSAC for the removal of cadmium (cadmium ions and zinc (zinc ions from their aqueous solutions. All batch experiments were carried out at pH 7.0 and a constant temperature of 30+-1°C using an incubator shaker that operated at 150 rpm. The kinetics investigated includes the pseudo first order, the pseudo-second order and the intraparticle diffusion models. The pseudo-second order model correlate excellently the experimental data, suggesting that chemisorption processes could be the rate-limiting step. Keywords: adsorption, cadmium, kinetics, palm kernel shell, zinc

  9. [Development of conductometric biosensor based on alkaline phosphatase for determining concentration of cadmium ions].

    Science.gov (United States)

    Sosovs'ka, O F; Berezhets'kyĭ, A L

    2007-01-01

    The paper describes a novel conductometric biosensor sensitive to cadmium ions based on alkaline phosphatase immobilized on gold planar microelectrodes used as transducers. Assays have been carried out with paranitrophenyl phosphate as substrate for the immobilized enzyme. Various parameters such as reticulation time, along with pH, ionic strength and buffer concentration of the measuring solution were studied. The optimized biosensor was stable, reproducible and it exhibited a detection limit of 4.45 microM for cadmium ions.

  10. Fault ride-through and grid support of permanent magnet synchronous generator-based wind farms with HVAC and VSC-HVDC transmission systems

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2012-01-01

    This paper describes fault ride-through and grid support of offshore wind farms based on permanent magnet synchronous generator (PMSG) wind turbines connected to the onshore AC network through two alternative transmission systems: high voltage AC (HVAC) or high voltage DC (HVDC) based on voltage...... source converters (VSC). The proposed configurations of the PMSG-based offshore wind farm and VSC-based HVDC are given as well as their control strategies under both steady state and fault state. The PMSG-based offshore wind farm is integrated into a test power transmission system via either HVAC or VSC-HVDC...

  11. Healthy Ride Trip Data

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A dataset that shows trips taken using the Healthy Ride system by quarter. The dataset includes bike number, membership type, trip start and end timestamp, and...

  12. Ride-Quality Meter

    Science.gov (United States)

    Leatherwood, J. D.; Dempsey, T. K.; Clevenson, S. A.; Stephens, D. G.

    1983-01-01

    Single- and combined-Axis discomfort are corrected by effects of noise and vibration to yield measure of total discomfort experienced by rider. Three modules transform mathematically-weighted rms accelerations, which represent physical vibration characteristics, into subjective discomfort units. Portable "ride-quality" meter measures passenger discomfort and acceptability of vehicle interior noise and vibration. Meter especially suited for determining vehicle comfort and design tradeoffs and for comparing ride quality of vehicles.

  13. Differences in urine cadmium associations with kidney outcomes based on serum creatinine and cystatin C

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Virginia M., E-mail: vweaver@jhsph.edu [Division of Occupational and Environmental Health, Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, 615N. Wolfe St., Rm. 7041, Baltimore, MD 21205 (United States); Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Kim, Nam-Soo; Lee, Byung-Kook [Institute of Industrial Medicine, SoonChunHyang University, Asan (Korea, Republic of); Parsons, Patrick J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY (United States); Spector, June [Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA (United States); Fadrowski, Jeffrey [Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, MD (United States); Jaar, Bernard G. [Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD (United States); Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Medical Institutions, Baltimore, MD (United States); Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (United States); Steuerwald, Amy J. [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, NY (United States); Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, NY (United States); Todd, Andrew C. [Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY (United States); and others

    2011-11-15

    Cadmium is a well-known nephrotoxicant; chronic exposure increases risk for chronic kidney disease. Recently, however, associations between urine cadmium and higher creatinine-based estimated glomerular filtration rate (eGFR) have been reported. Analyses utilizing alternate biomarkers of kidney function allow evaluation of potential mechanisms for these observations. We compared associations of urine cadmium with kidney function measures based on serum cystatin C to those with serum creatinine in 712 lead workers. Mean (standard deviation) molybdenum-corrected urine cadmium, Modification of Diet in Renal Disease (MDRD) eGFR and multi-variable cystatin C eGFR were 1.02 (0.65) {mu}g/g creatinine, and 97.4 (19.2) and 112.0 (17.7) mL/min/1.73 m{sup 2}, respectively. The eGFR measures were moderately correlated (r{sub s}=0.5; p<0.001). After adjustment, ln (urine cadmium) was not associated with serum cystatin-C-based measures. However, higher ln (urine cadmium) was associated with higher creatinine-based eGFRs including the MDRD and an equation incorporating serum cystatin C and creatinine (beta-coefficient=4.1 mL/min/1.73 m{sup 2}; 95% confidence interval=1.6, 6.6). Urine creatinine was associated with serum creatinine-based but not cystatin-C-based eGFRs. These results support a biomarker-specific, rather than a kidney function, effect underlying the associations observed between higher urine cadmium and creatinine-based kidney function measures. Given the routine use of serum and urine creatinine in kidney and biomarker research, additional research to elucidate the mechanism(s) for these associations is essential.

  14. Nickel cadmium batteries. Citations from the NTIS data base

    Science.gov (United States)

    Cavagnaro, D. M.

    1980-07-01

    The design, fabrication, components, testing, and assembly of nickel cadmium batteries are covered in the bibliography. The majority of these citations deal with the development of power supplies for aircraft and spacecraft. This updated bibliography contains 135 abstracts, 19 of which are new entries to the previous edition.

  15. Ecosystem-based management objectives for the North Sea: riding the forage fish rollercoaster

    DEFF Research Database (Denmark)

    Dickey-Collas, Mark; Engelhard, Georg H.; Rindorf, Anna

    2014-01-01

    The North Sea provides a useful model for considering forage fish (FF) within ecosystem-based management as it has a complex assemblage of FF species. This paper is designed to encourage further debate and dialogue between stakeholders about management objectives. Changing the management...... of fisheries on FF will have economic consequences for all fleets in the North Sea. The predators that are vulnerable to the depletion of FF are Sandwich terns, great skua and common guillemots, and to a lesser extent, marine mammals. Comparative evaluations of management strategies are required to consider......-based pool of biomass and as species components of the system by managers and modellers. Policy developers should not consider the knowledge base robust enough to embark on major projects of ecosystem engineering. Management plans appear able to maintain sustainable exploitation in the short term. Changes...

  16. Effects of Capcitor Bank on Fault Ride Through Capibility of Induction Generator Based Wind Turbines

    DEFF Research Database (Denmark)

    Hu, Y; Chen, Zhe

    2010-01-01

    power system stability and supply security. Some existing wind turbines are still based on fixed speed induction generators, the effects of capacitor bank on such generators are discussed in this paper. The simulation study shows the capacitor bank may costeffectively improve the dynamic performance...

  17. Dietary cadmium exposure and risk of postmenopausal breast cancer: a population-based prospective cohort study.

    Science.gov (United States)

    Julin, Bettina; Wolk, Alicja; Bergkvist, Leif; Bottai, Matteo; Akesson, Agneta

    2012-03-15

    The ubiquitous food contaminant cadmium has features of an estrogen mimetic that may promote the development of estrogen-dependent malignancies, such as breast cancer. However, no prospective studies of cadmium exposure and breast cancer risk have been reported. We examined the association between dietary cadmium exposure (at baseline, 1987) and the risk of overall and estrogen receptor (ER)-defined (ER(+) or ER(-)) breast cancer within a population-based prospective cohort of 55,987 postmenopausal women. During an average of 12.2 years of follow-up, 2,112 incident cases of invasive breast cancer were ascertained (1,626 ER(+) and 290 ER(-)). After adjusting for confounders, including consumption of whole grains and vegetables (which account for 40% of the dietary exposure, but also contain putative anticarcinogenic phytochemicals), dietary cadmium intake was positively associated with overall breast cancer tumors, comparing the highest tertile with the lowest [rate ratio (RR), 1.21; 95% confidence interval (CI), 1.07-1.36; P(trend) = 0.02]. Among lean and normal weight women, statistically significant associations were observed for all tumors (RR, 1.27; 95% CI, 1.07-1.50) and for ER(+) tumors (RR, 1.25; 95% CI, 1.03-1.52) and similar, but not statistically significant associations were found for ER(-) tumors (RR, 1.22; 95% CI, 0.76-1.93). The risk of breast cancer increased with increasing cadmium exposure similarly within each tertile of whole grain/vegetable consumption and decreased with increasing consumption of whole grain/vegetables within each tertile of cadmium exposure (P(interaction) = 0.73). Overall, these results suggest a role for dietary cadmium in postmenopausal breast cancer development.

  18. Ride electric bycycles

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正Last week, our school had a discussion about whether junior students could ride electric bycycles to go to school. 25 students of our class agreed with it, because they say it was convenient for them and it could take less time to go to school. But the other 35 students didn't agree with them.

  19. Advanced fault ride-through control of DFIG based wind turbines including grid connection via VSC-HVDC

    Energy Technology Data Exchange (ETDEWEB)

    Feltes, Christian

    2012-07-01

    With the growing renewable energy share in the power generation mix it becomes inevitable that also these new generation technologies participate on the provision of grid services to guarantee stable operation of the grid, especially when one considers the decreasing number of conventional power plants in operation as a result of the expansion of wind based generation plants. These so-called ancillary services include frequency / active power control, voltage / reactive power control and fault ride-through (FRT) with fast voltage control and are stipulated in modern grid codes. In the context of this thesis advanced control algorithms have been developed for wind turbines based on doubly-fed induction generator (DFIG) to allow safe FRT during symmetrical and unsymmetrical faults. This covers the control for conventional AC grid connection as well as for the connection through voltage source converter (VSC) based high voltage direct current transmission (HVDC). Currently, the DFIG is the most used generator technology in modem wind turbines, since it combines a relatively simple slip-ring induction machine with a frequency converter rated to only approx. 30% of the total power. This makes the DFIG a cost-effective concept, which offers a variable speed range and a high degree of flexibility in control. However, due to the direct coupling of the generator stator circuit to the grid, grid faults are a special challenge for the frequency converter, its protection circuits and control algorithms. As base for the detailed evaluation of the impact of grid faults to the DFIG, this thesis contains the analytical derivation of the DFIG short circuit currents under consideration of frequency converter control. The DFIG concept presented in this thesis makes use of a DC chopper in the frequency converter, which allows safe FRT with grid voltage support through both converter sides. The developed control contains a new algorithm for a clear separation and control of positive

  20. High-performance cadmium sulphide-based planar perovskite solar cell and the cadmium sulphide/perovskite interfaces

    Science.gov (United States)

    Peng, Haitao; Sun, Weihai; Li, Yunlong; Yan, Weibo; Yu, Pingrong; Zhou, Huanping; Bian, Zuqiang; Huang, Chunhui

    2016-04-01

    Planar heterojunction perovskite solar cell is one of the most competitive photovoltaic technologies, while charge transport materials play a crucial role. We successfully demonstrated an effective electron transport material, namely chemical bath deposited cadmium sulphide (CdS) film under low temperature, in perovskite-based solar cells. Power conversion efficiency of 16.1% has been achieved, which is comparable to that of devices based on TiO2 film prepared via low-temperature processes. Electronic impedance spectra reveal that the CdS-based device presents a higher recombination resistance than TiO2-based devices, which reduces carrier recombination and increases the open circuit voltage. The interface between CdS and perovskite was characterized with improved characteristics when compared to TiO2, e.g., efficient carrier extraction and reduced surface defect-associated degradation in the devices, which help to alleviate anomalous hysteresis and long-term instability. Furthermore, the entire device was fabricated via solution process with a processing temperature below 100°C, suggesting a promising method of further development of perovskite solar cells and commercial manufacturing.

  1. Little Red Riding Hood

    Institute of Scientific and Technical Information of China (English)

    胡蓉

    2011-01-01

    你一定看过并知道小红帽(Little Red Riding Hood)的故事吧!下面是英语版的小红帽,你看过吗? Once upon a time,people liked a little girl very much.Her red hood(头巾 ) fit her, so people called her Little Red Riding Hood. One day,her mother said, "Take a piece of cake and a bottle ofwine to your grandmother.She is ill and weak.These will do her good.Donot run off the road,or you may fall and break the bottle,and then yourgrandmother will get nothing.OK! Go at once."

  2. I ride a bike

    Institute of Scientific and Technical Information of China (English)

    邹玲

    2005-01-01

    <正>教学内容《I ride a bike》的核心教学内容是让学生谈论周末生活这样一个话题,其中包括8个词汇教学,以及询问其他人的周末活动所涉及的主要交际用语:

  3. 187 RIDE OR DIE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    《187 Ride or Die》是Ubisoft开发的一款对应PS2与XBOX的游戏。游戏玩法相当自由,赛车部分紧张刺激,不过可能是受到了“《横行霸道》系列”的影响,因此该游戏的暴力程度相当高。

  4. Ride quality meter

    Science.gov (United States)

    Leatherwood, J. D.; Dempsey, T. K.; Clevenson, S. A.; Stephens, D. G. (Inventor)

    1983-01-01

    A ride quality meter is disclosed that automatically transforms vibration and noise measurements into a single number index of passenger discomfort. The noise measurements are converted into a noise discomfort value. The vibrations are converted into single axis discomfort values which are then converted into a combined axis discomfort value. The combined axis discomfort value is corrected for time duration and then summed with the noise discomfort value to obtain a total discomfort value.

  5. Kinetics of cadmium uptake by chitosan-based crab shells.

    Science.gov (United States)

    Evans, Johanna R; Davids, William G; MacRae, Jean D; Amirbahman, Aria

    2002-07-01

    Crushed crab shells were chemically treated to transform the chitin present into chitosan. Three particle sizes with average diameters of 0.65, 1.43 and 3.38 mm, average pore diameters ranging from approximately 300 to 540 A, and a specific surface area of approximately 30 m2/g were obtained. Batch experiments were performed to study the uptake equilibrium and kinetics of cadmium by chitosan. Adsorption equilibrium followed a Freundlich relationship and was found to be independent of particle size indicating that adsorption takes place largely in the pore space. A high initial rate of cadmium uptake was followed by a slower uptake rate suggesting intraparticle diffusion as the rate-limiting step. The kinetic uptake data were successfully modeled using a pore diffusion model incorporating nonlinear adsorption. The effect of boundary layer resistance was modeled through inclusion of a mass transfer expression at the outside boundary. Two fitting parameters, the tortuosity factor (tau) and the mass transfer coefficient at the outside boundary (k(c)) were used. These parameters were unique for all solute and sorbent concentrations. The tortuosity factors varied from 1.5 for large particles to 5.1 for small particles. The mass transfer coefficient varied from 2 x 10(-7) m/s at 50 rpm to 2 x 10(-3) m/s at 200 rpm. At agitation rates below 100 rpm, boundary layer resistance reduced the uptake rate significantly. Its very high sorption capacity and relatively low production cost make chitosan an attractive sorbent for the removal of heavy metals from waste streams.

  6. Increase in fault ride through capability of direct drive permanent magnet based wind farm using VSC-HVDC

    Science.gov (United States)

    Maleki, Hesamaldin; Ramachandaramurthy, V. K.; Lak, Moein

    2013-06-01

    Burning of fossil fuels and green house gasses causes global warming. This has led to governments to explore the use of green energies instead of fossil fuels. The availability of wind has made wind technology a viable alternative for generating electrical power. Hence, many parts of the world, especially Europe are experiencing a growth in wind farms. However, by increasing the number of wind farms connected to the grid, power quality and voltage stability of grid becomes a matter of concern. In this paper, VSC-HVDC control strategy which enables the wind farm to ride-through faults and regulate voltage for fault types is proposed. The results show that the wind turbine output voltage fulfills the E.ON grid code requirements, when subjected to three phase to ground fault. Hence, continues operation of the wind farm is achieved.

  7. Fault Ride through Capability Improvement of Wind Turbine Based DFIG Considering an Optimized Crowbar Along with STATCOM under Grid Fault Condition

    Directory of Open Access Journals (Sweden)

    Alireza Zohoori

    2013-03-01

    Full Text Available Grid disturbances, especially grid faults, have very unfavorable effect on the performance of wind turbine based Doubly Fed Induction Generator (DFIG. In this study active and reactive powers control of DFIG with STATCOM has been carried out to improve Fault Ride Through (FRT capability of a wind turbine. In order to excel improvement of the DFIG behavior under grid fault disturbances, an optimized crowbar protection method is also considered together with STATCOM. The optimized protection crowbar resistance is achieved through Analytical Hierarchy Process (AHP algorithm. Simulations results illustrate that an optimized crowbar protection method along with STATCOM has improved the stability of wind farm and provide grid code requirement compared with that of methods without using the optimized crowbar resistance.

  8. Vehicle Ride Comfort Optimization Based on Interval Analysis%基于区间分析的汽车平顺性优化

    Institute of Scientific and Technical Information of China (English)

    谢慧超; 姜潮; 张智罡; 于盛

    2014-01-01

    An uncertainty optimization model for the ride comfort of vehicle suspension is built based on in-terval analysis technique. With suspension spring stiffness and shock absorber damping as design variables, minimi-zing the root mean square of car body acceleration as objective, and the stiffness and natural frequency of suspension as constraints, and by means of tolerance indicator and possibility degree of interval, the uncertainty optimization model is transformed into a certainty one, which is then solved with SQP and NSGA-II. On the premise of assuring the objective of ride comfort, the symmetric tolerance of design variables is maximized with manufacturing cost re-duced. Finally the scheme proposed is applied to the ride comfort optimization of suspension vibration system with both 2 DOF quarter car body model and 7 DOF whole car body model.%基于区间分析方法,建立了一种汽车悬架平顺性的不确定性优化模型。以悬架弹簧刚度和减振器阻尼为设计参数,车身加速度均方根值最小化为目标,悬架刚度和固有频率等为约束,并使用区间描述设计变量的制造和测量误差。利用公差指标和区间可能度,将该不确定性优化模型转化为确定性优化问题,并利用序列二次规划法和非支配排序遗传算法进行求解;在保证平顺性目标的前提下,使设计变量的对称公差最大化,以降低制造成本。最后,该方法被应用于两自由度1/4车身和7自由度整车车身悬架振动系统的平顺性优化。

  9. Brief review of cadmium telluride-based photovoltaic technologies

    Science.gov (United States)

    Başol, Bülent M.; McCandless, Brian

    2014-01-01

    Cadmium telluride (CdTe) is the most commercially successful thin-film photovoltaic technology. Development of CdTe as a solar cell material dates back to the early 1980s when ˜10% efficient devices were demonstrated. Implementation of better quality glass, more transparent conductive oxides, introduction of a high-resistivity transparent film under the CdS junction-partner, higher deposition temperatures, and improved Cl-treatment, doping, and contacting approaches yielded >16% efficient cells in the early 2000s. Around the same time period, use of a photoresist plug monolithic integration process facilitated the demonstration of the first 11% efficient module. The most dramatic advancements in CdTe device efficiencies were made during the 2013 to 2014 time frame when small-area cell conversion efficiency was raised to 20% range and a champion module efficiency of 17% was reported. CdTe technology is attractive in terms of its limited life-cycle greenhouse gas and heavy metal emissions, small carbon footprint, and short energy payback times. Limited Te availability is a challenge for the growth of this technology unless Te utilization rates are greatly enhanced along with device efficiencies.

  10. Horse-rider interaction in dressage riding.

    Science.gov (United States)

    Münz, Andreas; Eckardt, Falko; Witte, Kerstin

    2014-02-01

    In dressage riding the pelvis of the rider interacts with the horse physically. However, there is little information about the influence of riding skill on the interaction of the human pelvis with the horse. Therefore this paper aims to study the interaction between horse and rider in professional riders (PRO) and beginners (BEG). Twenty riders rode in walk, trot, and canter in an indoor riding hall with inertial sensors attached to their pelvis and to the horses' trunk. Statistical analysis of waveform parameters, qualitative interpretation of angle-angle plots, and cross-correlation of horse and rider were applied to the data. Significant differences between PRO and BEG could be found for specific waveform parameters. Over all gaits PRO kept their pelvis closer to the mid-position and further forward whereas BEG tilted their pelvis further to the right and more backwards. The coupling intensity of horse and rider revealed differences between the gaits. Furthermore phase shifts were found between PRO and BEG. This paper describes a sensor-based approach for the investigation of interactions of the human pelvis with the trunk of a horse under in-field conditions. First the results show that the riding level influences the posture of a rider and secondly that differences can be detected with contemporary available sensor technology and methods.

  11. Synthesis, Properties and Applications of Cadmium Based Nanoparticles Emitting from 400 - 750 nm

    OpenAIRE

    Presland, Katayune

    2010-01-01

    This thesis concerns the synthesis of cadmium based nanoparticles that emitted from 400 to the near infrared (NIR) region. Once synthesised they can be possibly used as biomarkers once encapsulated in microspheres. A brief introduction to the area of nanomaterials is also provided.The focus of this thesis is split into three main categories. Firstly core/shell nanoparticles were synthesised due to their ability to emit over a large range of wavelengths. Alloyed nanoparticles were then syn...

  12. Compensation neurosis rides again.

    Science.gov (United States)

    Levy, A

    1992-01-01

    Compensation neurosis (CN), also known as accident neurosis, has generally not been considered to be a 'real' disorder. In 1961 it was seemingly laid to rest by Henry Miller, a distinguished neurologist, in a sharp article which appeared in the British Medical Journal. Miller's view of patients who presented psychological symptoms following accidents or traumas was suspicious. Compensated or not, his view seemed to be that they should have their legal process finished as quickly as possible and then they will miraculously convalescence. Miller's work, it appeared, was the coup de grâce for this ill-defined diagnosis. Today, however, compensation neurosis seems to ride again. After a prolonged silence in the psychiatric literature, new papers are emerging, strongly suggesting that this vanishing diagnosis be reconsidered. This new trend will be presented.

  13. Examination of fault ride-through methods for off-shore wind farms connected to the grid through VSC-based HVDC transmission

    Energy Technology Data Exchange (ETDEWEB)

    Karaagac, U.; Mahseredjian, J.; Saad, H. [Ecole Polytechnique de Montreal, QC (Canada); Jensen, S.; Cai, L. [REpower Systems AG, Hamburg (Germany)

    2012-07-01

    The fault ride-through (FRT) performance of offshore wind farms (OWFs) is a challenging task when the OWF is connected to the onshore ac grid through a voltage source converter (VSC) based HVDC transmission system. The injected power from the OWF cannot be reduced by the offshore VSC during onshore ac faults and this causes a fast increase in the dc network voltage. Without any special FRT method, the dc network voltage may increase up to intolerable levels and cause operation of dc overvoltage protection. This paper compares various FRT methods based on fast reduction of power generation in OWFs. In addition, this paper proposes an improved FRT method based on controlled voltage drop for output power reduction in OWFs. The proposed improvement reduces mechanical stress on the wind turbine (WT) drive train, and electrical stress on the insulated gate bipolar transistors (IGBTs) of the HVDC and doubly-fed induction generator (DFIG) converters. Practical onshore ac fault scenarios are simulated for an OWF composed of DFIG type WTs and connected to a practical ac grid through a point-to-point modular multilevel converter (MMC) based HVDC system. (orig.)

  14. Dietary cadmium exposure and kidney stone incidence: a population-based prospective cohort study of men & women.

    Science.gov (United States)

    Thomas, Laura D K; Elinder, Carl-Gustaf; Tiselius, Hans-Göran; Wolk, Alicja; Akesson, Agneta

    2013-09-01

    Cadmium exposure is associated with increased urinary calcium excretion. Hypercalciuria is recognised as a major risk factor for kidney stone formation. Increased prevalence of kidney stones among those occupationally exposed to cadmium has previously been suggested. Food is the main source of cadmium exposure in the general population with tobacco representing an important additional source among smokers. We aimed to assess the association between dietary cadmium exposure and kidney stone incidence in two large population-based, prospective cohorts of men (Cohort of Swedish Men; COSM) and women (The Swedish Mammography Cohort; SMC). Those with a history of kidney stones were excluded. At baseline 1997, men (45-79yrs) and women (48 to 83yrs), completed a self-administered questionnaire on diet and lifestyle. During 12years of follow-up, we ascertained 707 cases of kidney stones in men and 290 in women through linkage of the cohorts to the national inpatient and outpatient registers. Individual dietary cadmium exposure was estimated using dietary data and concentrations of cadmium in food. Hazard ratios (HR) were calculated using the Cox proportional hazards regression models with adjustment for other risk factors. Estimated dietary cadmium exposure was not associated with increased kidney stone incidence among men HR 0.97 (95% confidence interval (CI): 0.77-1.23) or women HR 0.99 (95% CI: 0.89-1.43), comparing the highest tertile with the lowest. In conclusion, our results do not support a strong association between dietary cadmium and kidney stone risk at the exposure levels seen in the general population.

  15. Fancy a ride?

    CERN Document Server

    Anaïs Schaeffer

    2014-01-01

    This Sunday 7 September, don’t miss your chance to climb into a supercar, one of those exceptional machines that tear up the tracks and that you sometimes hear revving their engines on the motorway. The 2014 supercar experience day, organised by members of CERN, will allow car lovers to go for a ride in style and all for a good cause!   Supercars at the 2013 experience day. Photo: Kevin Mazzilli. If you have always dreamt of sitting in a Ferrari, feeling the vibrations of a Lamborghini, or losing yourself in the hushed calm of a classic car, don’t miss the supercar experience day taking place on Sunday, 7 September! This event has been organised by CERN’s own car enthusiasts, in collaboration with the charity Kumansansa – Children of Zambia, founded by two CERN members. It will take place for the third consecutive year in the car park of the Macumba leisure centre in Saint-Julien-en-Genevois (France). From 9.30 a.m. to 6 p.m., visitors old and young (c...

  16. Coordinated Control of Voltage Ride Through for DFIG Wind Turbine Systems Using Energy-based DVR%基于储能型DVR的双馈风电机组电压穿越协调控制

    Institute of Scientific and Technical Information of China (English)

    许建兵; 江全元; 石庆均

    2013-01-01

    针对双馈感应发电机(DFIG),提出了一种基于超级电容器(SC)储能的动态电压调节器(DVR)实现电压穿越的协调控制策略.在电网电压故障时,基于SC的DVR对DFIG端口电压进行完全补偿,使得DFIG端口电压始终维持在正常水平;并通过DFIG和基于SC的DVR协调控制,减少DFIG在故障期间输出的有功功率,从而减少故障期间所需的DVR功率和容量.在MATLAB/Simulink环境下搭建仿真模型,分别进行了对称和不对称故障下的零电压穿越、低电压穿越和高电压穿越仿真.仿真结果证明了所提出的协调控制策略的有效性.%A coordinated control strategy, which uses super capacitor (SC)-based dynamic voltage restorer (DVR) , is proposed to improve the voltage ride through capability of doubly-fed induction generators (DFIGs).The voltage level of DFIG stator is fully compensated by SC-based DVR during grid faults.The active power of DFIG is deceased by the coordinated control to minimise the power rating of DVR.A simulation model is established in MATLAB/Simulink.Zero voltage ride through, low voltage ride through and high voltage ride through during symmetrical and asymmetrical grid faults are simulated respectively.The validity of the proposed coordinate control strategy is verified by the simulation results.

  17. Bull Riding Injuries In Central Queensland

    Directory of Open Access Journals (Sweden)

    Ryan James Livingston

    2012-07-01

    Full Text Available Background Bull riding is an increasingly popular and growing professional sport in Australia. This is the first national study that investigates bull riding-related injuries. Method A six-year retrospective study of patients admitted to Rockhampton Base Hospital with acute injuries sustained whilst bull riding. Patients were identified from the Rockhampton Hospital international coding system and surgical audit excel databases. Supporting information was found from patient chart review. Results Thirty-eight patients were admitted during the study. Injuries increased from 2008. The most common injuries were to limbs (52%, chest (15% and brain (10%. Life-threatening injuries were all caused by a direct kick or trampling by the bull; 5% of patients needed air transfer to Brisbane, and 10% to Rockhampton for their acute care. The only complication was infection of open wounds. The average hospital stay was 2.2 (range= 1-5, SD= 1.1 days and 64% of patients required operative intervention. Conclusion Patients that had been kicked or trampled should be identified as having potentially life-threatening injuries, and transferred for review at an appropriate facility. Due to the high risk of infection all contaminated wounds should be washed out formally and receive antibiotics. Protective equipment should be encouraged among riders.

  18. 基于虚拟样机航空食品车行驶稳定性分析%Analysis on riding stability of catering truck based on virtual prototype

    Institute of Scientific and Technical Information of China (English)

    彭学磊; 刘斌; 田晋跃

    2011-01-01

    汽车平顺性是汽车NVH性能的评价指标之一,人们对汽车平顺性的研究越来越重视,通过调整汽车悬架能够改善汽车平顺性.以多体系统动力学理论为基础,应用机械系统动力学软件ADAMS/Car,建立了航空食品车整车的多刚体动力学模型.根据GB/F4970-1996的要求,通过调用ride四柱试验台,对整车的随机输入平顺性进行仿真分析,并将油气悬架车辆和传统被动悬架车辆的仿真数据对比.仿真结果表明:采用油气悬架的车辆较传统被动悬架车辆具有更好的行驶平顺性.%Vehile ride comfort is one of the evaluation indexes of vehicle NVH performance,which is paid more attention by peopel and can be improced through the adjustment of vehicle suspension.A multirigid-body dynamics model for full truck is built with the help of Mechanical System Simulation software of ADAMS/CAR,based on the theory of Multi-Body System Dynamics.According to GB4970-1996(method of random input running test-automotive ride comfort),the specific simulation is analyzed on the ride comfort by random inputting by applying four-post testbed and comparation of simulated data between vehicle with HPS and traditional vehicle with leaf spring suspension is made,which results show that the HPS vehicle has better ride comfort than the conventional leaf spring suspension vehicle.

  19. Design of a digital ride quality augmentation system for commuter aircraft

    Science.gov (United States)

    Hammond, T. A.; Amin, S. P.; Paduano, J. D.; Downing, D. R.

    1984-01-01

    Commuter aircraft typically have low wing loadings, and fly at low altitudes, and so they are susceptible to undesirable accelerations caused by random atmospheric turbulence. Larger commercial aircraft typically have higher wing loadings and fly at altitudes where the turbulence level is lower, and so they provide smoother rides. This project was initiated based on the goal of making the ride of the commuter aircraft as smooth as the ride experienced on the major commercial airliners. The objectives of this project were to design a digital, longitudinal mode ride quality augmentation system (RQAS) for a commuter aircraft, and to investigate the effect of selected parameters on those designs.

  20. Ride comfort optimization of a multi-axle heavy motorized wheel dump truck based on virtual and real prototype experiment integrated Kriging model

    Directory of Open Access Journals (Sweden)

    Bian Gong

    2015-06-01

    Full Text Available The optimization of hydro-pneumatic suspension parameters of a multi-axle heavy motorized wheel dump truck is carried out based on virtual and real prototype experiment integrated Kriging model in this article. The root mean square of vertical vibration acceleration, in the center of sprung mass, is assigned as the optimization objective. The constraints are the natural frequency, the working stroke, and the dynamic load of wheels. The suspension structure for the truck is the adjustable hydro-pneumatic suspension with ideal vehicle nonlinear characteristics, integrated with elastic and damping elements. Also, the hydraulic systems of two adjacent hydro-pneumatic suspension are interconnected. Considering the high complexity of the engineering model, a novel kind of meta-model called virtual and real prototype experiment integrated Kriging is proposed in this article. The interpolation principle and the construction of virtual and real prototype experiment integrated Kriging model were elucidated. Being different from traditional Kriging, virtual and real prototype experiment integrated Kriging combines the respective advantages of actual test and Computer Aided Engineering simulation. Based on the virtual and real prototype experiment integrated Kriging model, the optimization results, obtained by experimental verification, showed significant improvement in the ride comfort by 12.48% for front suspension and 11.79% for rear suspension. Compared with traditional Kriging, the optimization effect was improved by 3.05% and 3.38% respectively. Virtual and real prototype experiment integrated Kriging provides an effective way to approach the optimal solution for the optimization of high-complexity engineering problems.

  1. 14 CFR 25.1399 - Riding light.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 25.1399 Section 25.1399... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Lights § 25.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light...

  2. 14 CFR 27.1399 - Riding light.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 27.1399 Section 27.1399... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Lights § 27.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least...

  3. 14 CFR 23.1399 - Riding light.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 23.1399 Section 23.1399... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Equipment Lights § 23.1399 Riding light. (a) Each riding (anchor) light required for a seaplane or amphibian, must be installed so that...

  4. 14 CFR 29.1399 - Riding light.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Riding light. 29.1399 Section 29.1399... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Lights § 29.1399 Riding light. (a) Each riding light required for water operation must be installed so that it can— (1) Show a white light for at least...

  5. People and Horses: The Risks of Riding.

    Science.gov (United States)

    DeBenedette, Valerie

    1989-01-01

    The article looks at risks and benefits of horseback riding. Several risks can be minimized if riders take lessons, check riding equipment before each ride, wear proper headgear and footgear, and respect the horse's size and will. Medical guidelines for equestrian sports could help reduce injuries. (SM)

  6. Noise levels of amusement ride operators.

    Science.gov (United States)

    Gilbertson, Lynn R; Thies, Liza E; Vosburgh, Donna J H

    2017-04-01

    One of the leading causes of noise-induced hearing loss is occupational noise exposure; however, little attention has been given to the exposure among amusement ride operators. According to the International Association of Amusement Parks and Attractions, 600,000 ride operators are employed in the U.S. The first objective of this descriptive study was to evaluate if ride operators were exposed to noise levels over 85 dB. The second objective was to classify the ride features that led to the highest noise levels. 136 rides were measured at 17 total amusement parks, county fairs, and festivals in southern Wisconsin and northern Illinois during summer 2015. A sound level meter recorded noise measurements as close in proximity to the ride operator as possible. Each ride was measured for two or three complete ride cycles, which included loading and operating the ride. The sound level meter was programmed to measure noise as recommended by the American Conference of Governmental Industrial Hygienists and with no threshold. 18% of rides measured had projected noise levels greater than American Conference of Governmental Industrial Hygienists recommendation of 85 dB. A repeated measures model was used to analyze the complete ride cycle decibel levels. The model found that traveling carnival rides had significantly higher levels compared to the stationary amusement park rides (p levels than those without midway music (p amusement ride operators would be at risk for noise induced hearing loss and would require a hearing conservation program if the 8-hr time weighted averages were to follow the same trends as the complete ride cycle levels.

  7. Hippotherapy and Therapeutic Riding Highlight!

    Science.gov (United States)

    Apel, Laura, Comp.

    2007-01-01

    Horses have always been appreciated by humans for their strength, beauty, and gentle demeanor. Children, especially, have gravitated toward them and many experience their first horseback riding lesson at a young age. However, horses can play a very different role in the lives of children and adults with disabilities. Hippotherapy is physical,…

  8. Designing an Amusement Park Ride

    Science.gov (United States)

    Kurz, Terri L.; Robles, Rolando

    2016-01-01

    To improve access to STEM curriculum, an activity was planned that presents the opportunity to design and build using gears and other tools. In this challenge, preservice elementary school teachers were asked to mathematically analyze gears and create an amusement park ride that uses gears to spin. Although this lesson was implemented with…

  9. California Amusement Rides and Liability

    Science.gov (United States)

    Epstein, Adam

    2005-01-01

    Twenty-three-year-old Cristina Moreno traveled from Spain to California for her honeymoon in 2000. As part of her visit, she rode the Indiana Jones amusement ride at Disneyland with her new husband. On June 25, 2000, she suffered a brain injury, and she eventually died on September 1, 2000, as a result of injuries allegedly sustained while riding…

  10. Visual Disability and Horse Riding

    Science.gov (United States)

    Brickell, Diana

    2005-01-01

    It is now commonplace for horse riding to be included in the extra-curricular activities of students with physical disabilities. In this article an account is given of how visually impaired people can derive physical, mental, and emotional benefits from this supervised activity. It is argued that the rider, in learning to exercise self-control and…

  11. "Paul Revere's Ride": Awakening Abolitionists

    Science.gov (United States)

    Lepore, Jill

    2011-01-01

    Henry Wadsworth Longfellow used to be both the best-known poet in the English-speaking world and the most beloved, adored by the learned and the lowly alike, read by everyone from Nathaniel Hawthorne and Abraham Lincoln to John Ruskin and Queen Victoria--and, just as avidly, by the queen's servants. "Paul Revere's Ride" is Longfellow's best-known…

  12. The Value of Optimization in Dynamic Ride-Sharing: a Simulation Study in Metro Atlanta

    NARCIS (Netherlands)

    N.A.H. Agatz (Niels); A. Erera (Alan); M.W.P. Savelsbergh (Martin); X. Wang (Xing)

    2010-01-01

    textabstractSmartphone technology enables dynamic ride-sharing systems that bring together people with similar itineraries and time schedules to share rides on short-notice. This paper considers the problem of matching drivers and riders in this dynamic setting. We develop optimization-based approac

  13. Circular dichroism sensor based on cadmium sulfide quantum dots for chiral identification and detection of penicillamine

    Energy Technology Data Exchange (ETDEWEB)

    Ngamdee, Kessarin [Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 (Thailand); Puangmali, Theerapong [Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 (Thailand); Tuntulani, Thawatchai [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok, 10330 (Thailand); Ngeontae, Wittaya, E-mail: wittayange@kku.ac.th [Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen, 40002 (Thailand)

    2015-10-22

    A new chemical sensor based on the measuring of circular dichroism signal (CD) was fabricated from cysteamine capped cadmium sulfide quantum dots (Cys-CdS QDs). The chiral-thiol molecules, D-penicillamine (DPA) and L-penicillamine (LPA), were used to evaluate potentials of this sensor. Basically, DPA and LPA provide very low CD signals. However, the CD signals of DPA and LPA can be enhanced in the presence of Cys-CdS QDs. The CD spectra of DPA and LPA exhibited a mirror image profile. Parameters affecting the determination of DPA and LPA were thoroughly investigated in details. Under the optimized condition, the CD signals of DPA and LPA displayed a linear relationship with the concentrations of both enantiomers, ranging from 1 to 35 μM. Detection limits of this sensor were 0.49 and 0.74 μM for DPA and LPA, respectively. To demonstrate a potential application of this sensor, the proposed sensor was used to determine DPA and LPA in real urine samples. It was confirmed that the proposed detection technique was reliable and could be utilized in a broad range of applications. - Highlights: • This paper demonstrates a new CD sensor based on cadmium sulfide quantum dots. • Achiral quantum dots are used for the detection and chiral identification of thiol-chiral containing compounds. • The sensor show highest selectivity towards penicillamine. • The detection limits of the sensor less than 1 μM. • The sensor can potentially be used in physiological urine samples.

  14. The Trajectory of Chronic Pain: Can a Community-Based Exercise/Education Program Soften the Ride?

    Directory of Open Access Journals (Sweden)

    Ruth Dubin

    2010-01-01

    Full Text Available The entire primary care record of six patients attending a community-based education/exercise self-management program for chronic noncancer pain (YMCA Pain Exercise/Education Program [Y-PEP] was reviewed. Medical visits, consultations and hospital admissions were coded as related or unrelated to their pain diagnoses. Mood disruption, financial concerns, conflicts with employers/insurers, analgesic doses, medication side effects and major life events were also recorded. The ‘chronic pain trajectory’ resembled a roller coaster with increased health care visits at the time of initial injuries and during ‘crises’ (reinjury, conflict with insurers/employers, failed back-to-work attempts and life events. Visits decreased when conflicts were resolved. Analgesic doses increased during ‘crises’ but did not fall after resolution. After attending Y-PEP, health care use fell for four of six patients and two returned to work. Primary care physicians need to recognize the functional limitations and psychosocial complications experienced by their chronic pain patients. A program such as Y-PEP may promote active self-management strategies resulting in lowered health care use.

  15. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure.

    Science.gov (United States)

    Silva, B F; Andreani, T; Gavina, A; Vieira, M N; Pereira, C M; Rocha-Santos, T; Pereira, R

    2016-07-01

    Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same aggregation behaviour after sunlight exposure was observed for bare QDs. These results further emphasize that the shell of QDs seems to make them less harmful to aquatic biota, both under standard environmental conditions and after the exposure to a relevant abiotic factor like sunlight.

  16. Optimization and Research on Vehicle's Handling Stability and Ride Comfort Based on Approximate Model%基于近似模型的车辆操纵稳定性及平顺性的优化研究

    Institute of Scientific and Technical Information of China (English)

    杨荣山; 袁仲荣; 黄向东; 赵克刚; 陈金华

    2009-01-01

    The optimized design method of vehicle's handling stability and ride comfort was introduced based on approximate model in this paper.A car multi-body dynamics model was established by using software ADAMS/Car,the evaluating objects of vehicle's handling stability and ride comfort were also determined.The suspension spring rigidity,shock absorbers damping characteristic and anti-roll stabilizer rigidity were used as design variable,and based on the approximate optimized mathematic model,the multi-object optimization calculation of handling stability and ride comfort were carried out.h was indicated that the approximate model technology was an effective method for optimizing vehicle's performance.%简述了基于近似模型的车辆操纵稳定性及平顺性的优化设计方法.利用多体动力学软件ADAMS/Car建立了某轿车整车多体动力学模型,并确定了车辆操纵稳定性及平顺性的评价目标.以悬架弹簧刚度、减振器阻尼特性和横向稳定杆刚度为设计变量,利用近似优化数学模型对该轿车进行了操纵稳定性和行驶平顺性的多目标优化计算.结果表明,近似模型技术对于汽车性能的平衡优化是一种十分有效的方法.

  17. The Simulation of Micro Tourism Electric Vehicle Typical Road Ride Comfort Based on ADAMS/Car%基于 ADAMS/Car 微型观光电动汽车典型路面平顺性仿真

    Institute of Scientific and Technical Information of China (English)

    乔长胜; 李耀刚; 琚立颖; 冯泽; 张文明

    2014-01-01

    Based on the situation that the micro tourism electric vehicles which are made in domestic have bad ride comfort,based on the micro tourism electric vehicle of Tangshan electric vehicle key laboratory ,build a full vehicle ADAMS/Car virtual prototype model .Make this micro tourism electric vehicle at a certain speed pass long slope form convex block of the road and triangle convex block of the road for ride comfort simulation analysis of typical road surface .Draw cars center of mass vertical acceleration curve in the postprocessor module ,and then evaluate the ride comfort of the car .For the future to improve the electric car performance to provide certain theoretical basis da-ta in all respects .%基于国内以传统汽车底盘为基础进行改装设计所研制的电动汽车出现平顺性差等缺点,以唐山市电动汽车重点实验室前期研制的微型观光旅游电动汽车为基础,建立整车AD-AMS/Car虚拟样机模型。使此微型电动汽车以一定车速驶过长坡形凸块路面和三角形凸块路面进行典型路面的平顺性仿真分析。在后处理模块中绘制汽车质心垂向加速度特性曲线,进而评价此车平顺性能。为今后改善电动汽车各方面性能提供一定的理论数据基础。

  18. 基于传递路径分析的激励对汽车平顺性的影响%Influence of Excitation on Vehicle Ride Comfort Based on Transfer Path Analysis

    Institute of Scientific and Technical Information of China (English)

    潘道远; 王刚; 唐冶

    2016-01-01

    In order to explore the influence of the engine excitation and the road excitation on the ride comfort for vehicle,a full vehicle model with 13 freedom degrees containing the mounting system and the suspension system was established,and the engine excitation and the road excitation were introduced. The method of the ride comfort for vehicle based on TPA was derived. On the basis of the simulation calculating,the road test of actual vehicle was conducted. The results of simulation calculating and experiment result were consistent,which proved the correctness of this model. Based on the corresponding relationship between vehicle speed and engine speed in different gears,the ride comfort for vehicle under different excitation was analyzed. The results indicate that the influence of the road excitation is less than the engine excitation on the ride comfort for vehicle,but its influence cannot be ignored.%为研究发动机激励与路面激励对汽车平顺性的影响,建立了包含悬置系统和悬架系统的车辆13自由度数学模型,给出了发动机和路面激励模型,提出了基于 TPA 的汽车平顺性分析方法。在仿真计算基础上进行了实车试验,计算与试验结果基本吻合,验证了所建立模型的正确性。结合各挡位车速与发动机转速之间的对应关系,分析了不同激励对汽车平顺性的影响。结果表明:发动机激励对汽车平顺性的影响小于路面激励,但不容忽视。

  19. 基于路面谱随机激励的履带车辆舒适性仿真研究%Ride Comfort Simulation of Tracked Vehicles from Stochastic Excitation Based on Road Surface Spectrum

    Institute of Scientific and Technical Information of China (English)

    贾进峰; 张进秋; 张建; 刘义乐; 高永强; 岳杰

    2012-01-01

    利用随机路面激励对七自由车辆振动模型所产生的振动响应进行舒适性仿真分析。首先采用谐波叠加法、滤波白噪声及AR自回归模型法生成路面不平度并进行了对比反演验证,通过构建七自由度履带车辆模型并利用Matlab仿真软件建立舒适性评价方法,利用同一车速、不同路面下驾驶员座椅处加速度频率响应与舒适降低工作效率界限进行比较,即可对履带车辆舒适性进行评价分析。%By building a seven-degree-freedom vehicle model,chassis response could be used to evaluate ride comfort of tracked vehicles.Firstly after studying partial wave adding model,pseudo white noise model and AR auto-regressive model,different road roughness was made based on road spectrum and the contrast research on these three methods was made.Then vehicle suspension model with seven degrees of freedom was constructed and the method of ride comfort evaluation was built by Matlab software.After the same vehicle velocity and different road roughness were input at the same time,stochastic excitation under driver seat were compared with deduced comfort boundary.So,the simulation result can be used to evaluate the ride comfort.

  20. The Medical Staff Ride: an education tool for military medical leadership development.

    Science.gov (United States)

    Bricknell, Martin C M

    2016-08-01

    This paper provides a description of the Medical Staff Ride as an educational tool for military medical leadership. It is based upon two Medical Staff Rides covering the Somme Campaign 1916 and the Normandy Campaign 1944. It describes the key educational activity 'The Stand' at which history and current issues are brought together through study of a particular location on the historical battlefield. The Medical Staff Ride can be divided into six distinct phases, each of which have common question sets for analysis by attendees. The Medical Staff Ride can be shown to have valuable educational outcomes that are efficient in time and cost, and effective in achieving personal learning. The supporting Readers for the two Medical Staff Rides covered by this paper are available as electronic supplement to this edition of the journal.

  1. Essays on framing, free riding, and punishment

    OpenAIRE

    Drouvelis, Michail

    2009-01-01

    This thesis presents an experimental investigation of free riding behaviour and, more particularly, individual responses to it using, as a workhorse, the so called public goods game. This game starkly isolates the conflict between private and collective interest, providing us with a simple measure of the extent of free riding behaviour. The unifying theme of the thesis is elicitation and analysis of different indicators for how subjects perceive free riding under a number of treatment manipul...

  2. Physiologically-based toxicokinetic model for cadmium using Markov-chain Monte Carlo analysis of concentrations in blood, urine, and kidney cortex from living kidney donors.

    Science.gov (United States)

    Fransson, Martin Niclas; Barregard, Lars; Sallsten, Gerd; Akerstrom, Magnus; Johanson, Gunnar

    2014-10-01

    The health effects of low-level chronic exposure to cadmium are increasingly recognized. To improve the risk assessment, it is essential to know the relation between cadmium intake, body burden, and biomarker levels of cadmium. We combined a physiologically-based toxicokinetic (PBTK) model for cadmium with a data set from healthy kidney donors to re-estimate the model parameters and to test the effects of gender and serum ferritin on systemic uptake. Cadmium levels in whole blood, blood plasma, kidney cortex, and urinary excretion from 82 men and women were used to calculate posterior distributions for model parameters using Markov-chain Monte Carlo analysis. For never- and ever-smokers combined, the daily systemic uptake was estimated at 0.0063 μg cadmium/kg body weight in men, with 35% increased uptake in women and a daily uptake of 1.2 μg for each pack-year per calendar year of smoking. The rate of urinary excretion from cadmium accumulated in the kidney was estimated at 0.000042 day(-1), corresponding to a half-life of 45 years in the kidneys. We have provided an improved model of cadmium kinetics. As the new parameter estimates derive from a single study with measurements in several compartments in each individual, these new estimates are likely to be more accurate than the previous ones where the data used originated from unrelated data sets. The estimated urinary excretion of cadmium accumulated in the kidneys was much lower than previous estimates, neglecting this finding may result in a marked under-prediction of the true kidney burden.

  3. Toxicological impact of cadmium-based quantum dots towards aquatic biota: Effect of natural sunlight exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, B.F. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Andreani, T. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CITAB − Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes e Alto Douro, UTAD, Vila Real (Portugal); Gavina, A., E-mail: anacsgavina@gmail.com [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Vieira, M.N. [Department of Biology, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, 289, 4050-123 Porto (Portugal); Pereira, C.M. [Centro de Investigação em Química da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Department of Chemistry and Biochemistry, Faculty of Science, University of Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); Rocha-Santos, T. [Department of Chemistry and Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); and others

    2016-07-15

    Highlights: • Under sunlight exposure, all QDs form particle aggregates in the different media. • CdSeS/ZnS QDs showed lower toxic effects to V. fischeri before sunlight exposure. • Sunlight exposure decreased the toxicity of CdS 480 in all organisms. • Sunlight exposure increased the toxicity of CdS 380 QDs for D. magna. • Shell of QDs seemed to make them less harmful to aquatic organisms. - Abstract: Cadmium-based quantum dots (QDs) are increasingly applied in existent and emerging technologies, especially in biological applications due to their exceptional photophysical and functionalization properties. However, they are very toxic compounds due to the high reactive and toxic cadmium core. The present study aimed to determine the toxicity of three different QDs (CdS 380, CdS 480 and CdSeS/ZnS) before and after the exposure of suspensions to sunlight, in order to assess the effect of environmentally relevant irradiation levels in their toxicity, which will act after their release to the environment. Therefore, a battery of ecotoxicological tests was performed with organisms that cover different functional and trophic levels, such as Vibrio fischeri, Raphidocelis subcapitata, Chlorella vulgaris and Daphnia magna. The results showed that core-shell type QDs showed lower toxic effects to V. fischeri in comparison to core type QDs before sunlight exposure. However, after sunlight exposure, there was a decrease of CdS 380 and CdS 480 QD toxicity to bacterium. Also, after sunlight exposure, an effective decrease of CdSeS/ZnS and CdS 480 toxicity for D. magna and R. subcapitata, and an evident increase in CdS 380 QD toxicity, at least for D. magna, were observed. The results of this study suggest that sunlight exposure has an effect in the aggregation and precipitation reactions of larger QDs, causing the degradation of functional groups and formation of larger bulks which may be less prone to photo-oxidation due to their diminished surface area. The same

  4. RIDE: the Research Infrastructure Database for EPOS

    Science.gov (United States)

    Bailo, Daniele; Bartoloni, Alessandro; Jeffery, Keith G.; Clemenceau, Alice; Hoffmann, Thomas L.

    2013-04-01

    The European Plate Observing System (EPOS) is a European initiative which aims to promote and make possible innovative approaches for a better understanding of the physical processes laying behind natural events and geo-science phenomena (earthquakes, volcanic eruptions, unrest episodes and tsunamis etc.) by integrating existing national and trans-national Research Infrastructures (RIs). Such integration will increase access and use of the multidisciplinary data recorded by solid Earth monitoring networks, acquired in laboratory experiments and/or produced by computational simulations. Here we present the Research Infrastructures Database for EPOS (RIDE), a database containing technical information about the different RIs declared by EPOS partners and EPOS associate partners, which will eventually compose the EPOS distributed Research Infrastructure. The main goals of RIDE are (i) to allow the EPOS RI to be organized, with interactive access and information mining available to a broad community of users and stakeholders, (ii) to have a first set of information to be stored in the EPOS catalogue, which will be used as a basis for the development of EPOS Core Services, (iii) to enable EPOS partners to revise and update the current RI information, (iv) to show the contents of the EPOS integration plan to all stakeholders, (v) to facilitate the dissemination of existing data infrastructures to different communities and to promote a discussion within the community to implement the present data infrastructures. RIDE - whose driving technology is Apache CouchDB - contains at the current status detailed information on more than 200 Research Infrastructures. It enables any user to visualize RIs and sensors on a map, to carry out statistics on the stored data and to browse through the details of any RI. Based on the content of RIDE it is now possible to estimate the potential size of the new EPOS distributed RI: EPOS is going to integrate more than 7000 sensors (seismic

  5. An amperometric chloramphenicol immunosensor based on cadmium sulfide nanoparticles modified-dendrimer bonded conducting polymer.

    Science.gov (United States)

    Kim, Dong-Min; Rahman, Md Aminur; Do, Minh Hien; Ban, Changill; Shim, Yoon-Bo

    2010-03-15

    An amperometric chloramphenicol (CAP) immunosensor was fabricated by covalently immobilizing anti-chloramphenicol acetyl transferase (anti-CAT) antibody on cadmium sulfide nanoparticles (CdS) modified-dendrimer that was bonded to the conducting polymer (poly 5, 2': 5', 2''-terthiophene-3'-carboxyl acid (poly-TTCA)) layer. The AuNPs, dendrimers, and CdS nanoparticles were deposited onto the polymer layer in order to enhance the sensitivity of the sensor probes. The particle sizes were determined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The immobilization of dendrimers, CdS, and anti-CAT were confirmed using energy disruptive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and quartz crystal microbalance (QCM) techniques. The detection of CAP was based on the competitive immuno-interaction between the free- and labeled-CAP for active sites of the anti-CAT. Hydrazine was used as the label for CAP, and it electrochemically catalyzed the reduction of H(2)O(2) at -0.35 V vs. Ag/AgCl. Under optimized conditions, the proposed immunosensor exhibited a linear range of CAP detection between 50 pg/mL and 950 pg/mL, and the detection limit was 45 pg/mL. The immunosensor was examined in real meat samples for the analysis of CAP.

  6. Riding the Metalloproteinase Roller Coaster.

    Science.gov (United States)

    Murphy, Gillian

    2017-03-15

    To many of us in the field, working on Matrix Metalloproteinases (MMPs) has felt like riding a roller coaster, traveling through times of both excitement and despair. I was fortunate to join the ride when it was a mere carousel of three activities thought to target the proteins that comprise the extracellular matrix (ECM). New technologies brought the thrills of discovery, as we uncovered specific proteinase genes and defined specialised activities in different cellular processes. The MMPs and the sister families of 'A Disintegrin And Metalloproteinase' (ADAMs), ADAMs with ThromboSpondin domains (ADAM-TS) and Astacins are now recognised as key signalling 'scissors' that drive rapid changes in a plethora of cellular pathways. My many excellent colleagues and collaborators and I were enthused to contribute to the early development of the field and continue to be amazed at its growth and sophistication. In contrast, the hype and failure of early inhibitor discovery have dogged our standing with the pharmaceutical industry and grant giving bodies. However, the true believers have kept going, and knowledge of particular functions of MMPs and their contributions to disease progression has progressed. Recognition of the strategic importance of proteinase function should inspire more work harnessing new technologies such as imaging, proteomics and gene editing to generate a more precise understanding of individual situations. New approaches to inhibitor design and assessment are possible and the consequent ability to precisely abrogate specific MMP activity could contribute to the fight against a number of pathologies with unmet needs. What a ride it could be!

  7. An omics based assessment of cadmium toxicity in the green alga Chlamydomonas reinhardtii

    Energy Technology Data Exchange (ETDEWEB)

    Jamers, An; Blust, Ronny; De Coen, Wim [Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Griffin, Julian L. [Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 2QA (United Kingdom); Jones, Oliver A.H., E-mail: oliver.jones@rmit.edu.au [School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne, VIC 3001 (Australia)

    2013-01-15

    The effects of cadmium were assessed in the freshwater alga Chlamydomonas reinhardtii. Algae were exposed to concentrations of 0, 8.1 or 114.8 {mu}M of cadmium and growth rates, gene transcription and metabolite profiles were examined after 48 and 72 h of exposure. In algae exposed to 8.1 {mu}M Cd, several genes were differentially transcribed after 48 h but no adverse growth related effects were detected. A transient effect on both gene transcription patterns and metabolite profiles could be discerned after 48 h of exposure but the majority of these changes disappeared after 72 h. In contrast, all effects were more pronounced at the 114.8 {mu}M cadmium exposure. Here growth was clearly reduced and transcription of a large number of genes involved in oxidative stress defense mechanisms was differentially increased. Metabolites involved in the glutathione synthesis pathway (an important antioxidant defense) were also affected but the effects of cadmium were found to be more pronounced at the transcript level than in the metabolome, suggesting that the former exhibits greater sensitivity toward cadmium exposure.

  8. Riding Gravity Away from Doomsday

    CERN Document Server

    Sen, Ashoke

    2015-01-01

    The discovery that most of the energy density in the universe is stored in the form of dark energy has profound consequences for our future. In particular our current limited understanding of quantum theory of gravity indicates that some time in the future our universe will undergo a phase transition that will destroy us and everything else around us instantaneously. However the laws of gravity also suggest a way out -- some of our descendants could survive this catastrophe by riding gravity away from the danger. In this essay I describe the tale of this escape from doomsday.

  9. Geology Highlights for Ride the Rockies 2009

    Science.gov (United States)

    Slate, Janet

    2009-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 14 through June 19, 2009. Ride the Rockies begins and ends in Glenwood Springs, with stops in Hotchkiss, Gunnison, Salida, Leadville, Aspen, and back to Glenwood Springs, Colorado. A small, generalized geologic map also is shown.

  10. Geology highlights, Ride the Rockies 2011

    Science.gov (United States)

    Slate, Janet L.

    2011-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 12 through June 17, 2011. Ride the Rockies begins in Crested Butte, Colorado, with stops in Buena Vista, Edwards, Steamboat Springs, Granby, and Georgetown. A small, generalized geologic map also is shown.

  11. Geology highlights for Ride the Rockies 2010

    Science.gov (United States)

    Slate, J.L.; Hess, Amber; Van Sistine, D.R.

    2010-01-01

    The author provides a brief description of the geology along the route for each day of the ride, from June 13 through June 19, 2010. Ride the Rockies begins in Grand Junction, with stops in Delta, Ouray, Durango, Pagosa Springs, Alamosa, and ends in Salida, Colorado. A small, generalized geologic map also is shown.

  12. An improved low-voltage ride-through performance of DFIG based wind plant using stator dynamic composite fault current limiter.

    Science.gov (United States)

    Gayen, P K; Chatterjee, D; Goswami, S K

    2016-05-01

    In this paper, an enhanced low-voltage ride-through (LVRT) performance of a grid connected doubly fed induction generator (DFIG) has been presented with the usage of stator dynamic composite fault current limiter (SDCFCL). This protection circuit comprises of a suitable series resistor-inductor combination and parallel bidirectional semiconductor switch. The SDCFCL facilitates double benefits such as reduction of rotor induced open circuit voltage due to increased value of stator total inductance and concurrent increase of rotor impedance. Both effects will limit rotor circuit over current and over voltage situation more secured way in comparison to the conventional scheme like the dynamic rotor current limiter (RCL) during any type of fault situation. The proposed concept is validated through the simulation study of the grid integrated 2.0MW DFIG.

  13. The effects of a rhythm and music-based therapy program and therapeutic riding in late recovery phase following stroke: a study protocol for a three-armed randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Bunketorp Käll Lina

    2012-11-01

    Full Text Available Abstract Background Stroke represents one of the most costly and long-term disabling conditions in adulthood worldwide and there is a need to determine the effectiveness of rehabilitation programs in the late phase after stroke. Limited scientific support exists for training incorporating rhythm and music as well as therapeutic riding and well-designed trials to determine the effectiveness of these treatment modalities are warranted. Methods/Design A single blinded three-armed randomized controlled trial is described with the aim to evaluate whether it is possible to improve the overall health status and functioning of individuals in the late phase of stroke (1-5 years after stroke through a rhythm and music-based therapy program or therapeutic riding. About 120 individuals will be consecutively and randomly allocated to one of three groups: (T1 rhythm and music-based therapy program; (T2 therapeutic riding; or (T3 control group receiving the T1 training program a year later. Evaluation is conducted prior to and after the 12-week long intervention as well as three and six months later. The evaluation comprises a comprehensive functional and cognitive assessment (both qualitative and quantitative, and questionnaires. Based on the International classification of functioning, disability, and health (ICF, the outcome measures are classified into six comprehensive domains, with participation as the primary outcome measure assessed by the Stroke Impact Scale (SIS, version 2.0.. The secondary outcome measures are grouped within the following domains: body function, activity, environmental factors and personal factors. Life satisfaction and health related quality of life constitute an additional domain. Current status A total of 84 participants were randomised and have completed the intervention. Recruitment proceeds and follow-up is on-going, trial results are expected in early 2014. Discussion This study will ascertain whether any of the two

  14. Formation and Characterization of Mixed Crystals Based on Bis (ThioureaCadmium Chloride and Bis (ThioureaCadmium Iodide

    Directory of Open Access Journals (Sweden)

    I.S. Prameela Kumar

    2014-07-01

    Full Text Available Bis(thioureacadmium chloride(BTCC and bis(thioureacadmium iodide (BTCI are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members crystals were formed by the free evaporation method and characterized chemically, structurally, thermally, optically and electrically. The X-ray diffraction measurements indicate that (BTCCX(BTCI1-X crystals with x=1.0,0.8 and 0.6 are orthorhombic in structure with space group Pmn21 and that with x=0.5, 0.4, 0.2 and 0.0 are monoclinic in structure with space group P21/c. All the grown crystals are found to be thermally stable up to 215 °C and possessing wide optical transmission window (300-900 nm which is suitable for NLO applications. The electrical measurements indicate that the grown crystals exhibit a normal dielectric behavior. The results obtained in the present study indicate that mixed crystals can be formed from the isomorphous precursors directly even though the end member’s crystals have lattice mismatching.

  15. The Theory of Dynamic Public Transit Priority with Dynamic Stochastic Park and Ride

    Directory of Open Access Journals (Sweden)

    Chengming Zhu

    2014-01-01

    Full Text Available Public transit priority is very important for relieving traffic congestion. The connotation of dynamic public transit priority and dynamic stochastic park and ride is presented. Based on the point that the travel cost of public transit is not higher than the travel cost of car, how to determine the level of dynamic public transit priority is discussed. The traffic organization method of dynamic public transit priority is introduced. For dynamic stochastic park and ride, layout principle, scale, and charging standard are discussed. Traveler acceptability is high through the analysis of questionnaire survey. Dynamic public transit priority with dynamic stochastic park and ride has application feasibility.

  16. Ride comfort analysis with physiological parameters for an e-health train.

    Science.gov (United States)

    Lee, Youngbum; Shin, Kwangsoo; Lee, Sangjoon; Song, Yongsoo; Han, Sungho; Lee, Myoungho

    2009-12-01

    Transportation by train has numerous advantages over road transportation, especially with regard to energy efficiency, ecological features, safety, and punctuality. However, the contrast in ride comfort between standard road transportation and train travel has become a competitive issue. The ride comfort enhancement technology of tilting trains (TTX) is a particularly important issue in the development of the Korean high-speed railroad business. Ride comfort is now defined in international standards such as UIC13 and ISO2631. The Korean standards such as KSR9216 mainly address physical parameters such as vibration and noise. In the area of ride comfort, living quality parameter techniques have recently been considered in Korea, Japan, and Europe. This study introduces biological parameters, particularly variations in heart rate, as a more direct measure of comfort. Biological parameters are based on physiological responses rather than on purely external mechanical parameters. Variability of heart rate and other physiological parameters of passengers are measured in a simulation involving changes in the tilting angle of the TTX. This research is a preliminary study for the implementation of an e-health train, which would provide passengers with optimized ride comfort. The e-health train would also provide feedback on altered ride comfort situations that can improve a passenger's experience and provide a healthcare service on the train. The aim of this research was to develop a ride comfort evaluation system for the railway industry, the automobile industry, and the air industry. The degree of tilt correlated with heart rate, fatigue, and unrelieved alertness.

  17. Fever: suppress or let it ride?

    Science.gov (United States)

    Ray, Juliet J; Schulman, Carl I

    2015-12-01

    While our ability to detect and manage fever has evolved since its conceptualization in the 5(th) century BC, controversy remains over the best evidence-based practices regarding if and when to treat this physiologic derangement in the critically ill. There are two basic fields of thought: (I) fever should be suppressed because its metabolic costs outweigh its potential physiologic benefit in an already stressed host; vs. (II) fever is a protective adaptive response that should be allowed to run its course under most circumstances. The latter approach, sometime referred to as the "let it ride" philosophy, has been supported by several recent randomized controlled trials like that of Young et al. [2015], which are challenging earlier observational studies and may be pushing the pendulum away from the Pavlovian treatment response.

  18. Laser beam riding guided system principle and design research

    Science.gov (United States)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  19. 基于平顺性与操纵稳定性的悬架系统多目标优化%Multi-objective optimization of suspension system based on vehicle ride comfort and handling stability

    Institute of Scientific and Technical Information of China (English)

    刘伟; 史文库; 桂龙明; 方德广; 郭福祥

    2011-01-01

    针对汽车悬架系统开发设计中行驶平顺性和操纵稳定性两个目标相互矛盾的问题,以某轻型乘用客车后悬架系统为研究对象,建立了汽车悬架系统多目标优化模型。以汽车行驶平顺性、操纵稳定性为优化目标,选择后悬架弹簧刚度、减振器阻尼系数及稳定杆扭转刚度为优化参数,设计了一种基于改进遗传算法NSGA-Ⅱ的悬架系统多目标优化策略。悬架优化前后试验结果表明,本文提出的多目标优化策略在改善汽车行驶平顺性的同时,兼顾了操纵稳定性,具有较好的优化效果。%In view of the trade-off between the handling stability and the ride comfort in the design of the suspension system,taking the rear suspension system of alight passenger bus as a research object,a multi-objective optimization model of the suspension system parameters was established.Taking the handling stability and the ride comfort as the optimization objectives,selecting the suspension spring stiffness,the shock Absorber damping factor and the stabilizer bar torsional stiffness as the optimization variables,a multi-objective optimization strategy based on the improved genetic algorithm NSGA-Ⅱ was designed for the suspension system.The test results show that the proposed optimization approach demonstrated good results in improvement of the vehicle ride comfort without penalty on the handling stability.

  20. Robustness optimization of ride comfort for vehicle based on 6σ method%基于6σ稳健性方法的汽车行驶平顺性优化

    Institute of Scientific and Technical Information of China (English)

    莫旭辉; 赵宇航; 钟志华; 张义

    2012-01-01

    建立某轿车11自由度的整车平顺性模型,以各个座椅垂向加速度均方根最小为优化目标,以各个悬架的动行程和各个车轮的相对动载为约束条件,结合蒙特卡罗方法和6σ稳健性优化技术,分别对悬架参数进行多目标确定性优化和稳健性优化,分析设计变量波动对优化结果的影响.优化结果表明:优化后的整车平顺性明显提高;稳健性优化结果比确定性优化结果具有更高的稳健性和可靠性.%A car model with 11 degree of freedoms (DOFs) based on ride comfort was built. With the root mean square (RMS) taking each seat's acceleration as the optimization objectives, and with the dynamic displacement of each suspension and relative dynamic loads between road and tires as constraint conditions, combined with deterministic multi-objectives optimization method and 6s robust reliability multi-objectives optimization design method based on Monte Carlo simulation technique, the parameters of suspensions were optimized. The results show that the optimized vehicle's ride comfort is greatly improved. The 6s robust reliability multi-objectives optimization design method can get better optimum solutions with higher robustness and reliability.

  1. Cyclist's nodule: no smooth ride.

    Science.gov (United States)

    Stoneham, Adam; Thway, Khin; Messiou, Christina; Smith, Myles

    2016-03-10

    A fit and active amateur cyclist was referred by his general practitioner to a surgical oncology outpatient clinic with a slowly-growing perineal mass. Following clinical examination, the patient underwent imaging and biopsy at a tertiary soft tissue tumour centre, which diagnosed perineal nodular induration: a rare, benign tumour caused by repetitive trauma associated with 'saddle sports' such as cycling or horse riding. It is important to consider soft tissue tumours in patients who present with 'lumps and bumps'; they can occur anywhere in the body including the groin or perineum, where it is sometimes referred to as a 'third' or 'accessory' testicle in men. Although unusual, the case emphasises the importance of rapid specialist referral from primary care, and consideration of a patient's occupation and hobbies when formulating diagnoses.

  2. Radiative inflation and dark energy RIDEs again after BICEP2

    Energy Technology Data Exchange (ETDEWEB)

    Bari, Pasquale Di; King, Stephen F.; Merle, Alexander [Physics and Astronomy, University of Southampton, Highfield Campus, Southampton, SO17 1BJ (United Kingdom); Luhn, Christoph [Theoretische Physik 1, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Straße 3, Siegen, D-57068 (Germany); Schmidt-May, Angnis, E-mail: P.Di-Bari@soton.ac.uk, E-mail: S.F.King@soton.ac.uk, E-mail: Christoph.Luhn@uni-siegen.de, E-mail: A.Merle@soton.ac.uk, E-mail: Angnis.Schmidt-May@fysik.su.se [Department of Physics and The Oskar Klein Centre, Stockholm University, AlbaNova University Centre, Stockholm, SE-106 91 (Sweden)

    2014-08-01

    Following the ground-breaking measurement of the tensor-to-scalar ratio r=0.20{sup +0.07}{sub -0.05} by the BICEP2 collaboration, we perform a statistical analysis of a model that combines Radiative Inflation with Dark Energy (RIDE) based on the M{sup 2}|Φ|{sup 2}ln(|Φ|{sup 2}/Λ{sup 2}) potential and compare its predictions to those based on the traditional chaotic inflation M{sup 2}|Φ|{sup 2} potential. We find a best-fit value in the RIDE model of r=0.18 as compared to r=0.17 in the chaotic model, with the spectral index being n{sub S}=0.96 in both models.

  3. Detection,isolation,and identification of cadmium-resistant bacteria based on PCR-DGGE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study focused on the screening of cadmium-resistant bacterial strains from Pb-Zn tailing.We investigated the diversity of microbial community inhabiting Dong-san-cha Pb-Zn tailing in Beijing,China,by polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene of bacterial strain,and found two dominant strains in the DGGE profile.Using special culture media,We isolated two strong cadmium-resistant bacterial strains.On the basis of morphological,physiological,and biochemical characteristics,BIOLOG,and 16S rDNA sequencing,the two strains were identified as Bacillus cereus and Enterobaeter cloacae.Minimal inhibitory concentrations (MICs) of heavy metals for the bacteria were determined.E.cloacae showed higher MIC values for heavy metals and a larger range of antibiotic resistance than B.cereus.

  4. Regional Park-n-Ride Facilities

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — The Southwestern Pennsylvania Commission maintains an inventory of the region’s park-n-ride facilities that contains detailed information for each of the more than...

  5. Ride quality systems for commuter aircraft

    Science.gov (United States)

    Downing, D. R.; Hammond, T. A.; Amin, S. P.

    1983-01-01

    The state-of-the-art in Active Ride Augmentation, specifically in terms of its feasibility for commuter aircraft applications. A literature survey was done, and the principal results are presented here through discussion of different Ride Quality Augmentation System (RQAS) designs and advances in related technologies. Recommended follow-on research areas are discussed, and a preliminary RQAS configuration for detailed design and development is proposed.

  6. A New Method for Ride Quality Analysis of Vehicle

    Institute of Scientific and Technical Information of China (English)

    LIN Jian-hui; ZHANG Jie; GAO Yan; LI Tian-rui

    2006-01-01

    Current spectral analysis for evaluating the rail ride quality effectively is based on the sampling data at a uniform time interval, but the train is of fluctuation velocity in motion,which results in a non-uniform interval between consecutive sampling data. Therefore the accuracy of routine spectral analysis is in doubt when applying it in evaluating the rail ride quality. This paper presents a new way, namely, resampling with variable frequency to eliminate the influence of the train's uneven velocity. Its feature is that there is no need for precision measurement of the train's moving speed.Experiment results from the test-bed of rolling stock vibration show that it is valid.

  7. Automobile ride quality experiments correlated to iso-weighted criteria

    Science.gov (United States)

    Healey, A. J.; Young, R. K.; Smith, C. C.

    1975-01-01

    As part of an overall study to evaluate the usefulness of ride quality criteria for the design of improved ground transportation systems an experiment was conducted involving subjective and objective measurement of ride vibrations found in an automobile riding over roadways of various roughness. Correlation of the results led to some very significant relationships between passenger rating and ride accelerations. The latter were collapsed using a frequency-weighted root mean square measure of the random vibration. The results suggest the form of a design criterion giving the relationship between ride vibration and acceptable automobile ride quality. Further the ride criterion is expressed in terms that relate to rides with which most people are familiar. The design of the experiment, the ride vibration data acquisition, the concept of frequency weighting and the correlations found between subjective and objective measurements are presented.

  8. Riding Standards. The Policies and Operating Procedures of the National Riding Committee 1973-74.

    Science.gov (United States)

    Cronin, Paul D., Ed.

    This booklet details the policies and rating procedures of the National Riding Committee. Chapters are devoted to the rating of riders with oral and written tests, the appointment of judges, types of certificates issued, rated rider examination requirements (forward riding section and western section), job placement, and advertising policy and…

  9. Harvesting Energy from the Counterbalancing (Weaving Movement in Bicycle Riding

    Directory of Open Access Journals (Sweden)

    Shashank Priya

    2012-07-01

    Full Text Available Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle’s handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  10. Harvesting energy from the counterbalancing (weaving) movement in bicycle riding.

    Science.gov (United States)

    Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

    2012-01-01

    Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

  11. Cadmium and cancer.

    Science.gov (United States)

    Hartwig, Andrea

    2013-01-01

    Cadmium is an established human and animal carcinogen. Most evidence is available for elevated risk for lung cancer after occupational exposure; however, associations between cadmium exposure and tumors at other locations including kidney, breast, and prostate may be relevant as well. Furthermore, enhanced cancer risk may not be restricted to comparatively high occupational exposure, but may also occur via environmental exposure, for example in areas in close proximity to zinc smelters. The underlying mechanisms are still a matter of manifold research activities. While direct interactions with DNA appear to be of minor importance, elevated levels of reactive oxygen species (ROS) have been detected in diverse experimental systems, presumably due to an inactivation of detoxifying enzymes. Also, the interference with proteins involved in the cellular response to DNA damage, the deregulation of cell growth as well as resistance to apoptosis appears to be involved in cadmium-induced carcinogenicity. Within this context, cadmium has been shown to disturb nucleotide excision repair, base excision repair, and mismatch repair. Particularly sensitive targets appear to be proteins with zinc-binding structures, present in DNA repair proteins such as XPA, PARP-1 as well as in the tumor suppressor protein p53. Whether or not these interactions are due to displacement of zinc or due to reactions with thiol groups involved in zinc complexation or in other critical positions under realistic exposure conditions remains to be elucidated. Further potential mechanisms relate to the interference with cellular redox regulation, either by enhanced generation of ROS or by reaction with thiol groups involved in the regulation of signaling pathways. Particularly the combination of these multiple mechanisms may give rise to a high degree of genomic instability evident in cadmium-adapted cells, relevant not only for tumor initiation, but also for later steps in tumor development.

  12. Preparation of polyacrylnitrile (PAN)/ Manganese oxide based activated carbon nanofibers (ACNFs) for adsorption of Cadmium (II) from aqueous solution

    Science.gov (United States)

    Abdullah, N.; Yusof, N.; Jaafar, J.; Ismail, AF; Che Othman, F. E.; Hasbullah, H.; Salleh, W. N. W.; Misdan, N.

    2016-06-01

    In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylnitrile (PAN) and manganese oxide (MnO2) were prepared via electrospinning process. The electrospun PAN/MnO2-based ACNFs were characterised in term of its morphological structure and specific surface area using SEM and BET analysis respectively. The comparative adsorption study of cadmium (II) ions from aqueous solution between the neat ACNFs, composite ACNFs and commercial granular activated carbon was also conducted. SEM analysis illustrated that composite ACNFs have more compact fibers with presence of MnO2 beads with smaller fiber diameter of 437.2 nm as compared to the neat ACNFs which is 575.5 nm. BET analysis elucidated specific surface area of ACNFs/MnO2 to be 67 m2/g. Under adsorption study, it was found out that Cd (II) removal by ACNFs/MnO2 was the highest (97%) followed by neat ACNFs (96%) and GAC (74%).

  13. A Rapid and Cost-Effective Laser Based Synthesis of High Purity Cadmium Selenide Quantum Dots.

    Science.gov (United States)

    Gondall, M A; Qahtan, Talal F; Dastageer, M A; Yamani, Z H; Anjum, D H

    2016-01-01

    A rapid and cost effective method is developed to synthesize high purity cadmium Selenide (CdSe) quantum dots in acetone medium using second harmonic of Nd:YAG nanosecond pulsed laser of 532 nm wavelength. The thermal agglomeration due the nanosecond pulse duration of the laser was successfully eliminated by using unfocussed laser beam and thereby providing a favorable conditions for the synthesis of quantum dots having the grain size of 3 nm. The morphological and optical characterizations like XRD, HRTEM, optical absorption of the synthesized CdSe quantum dots, reveal that the material possesses the similar characteristics of the one synthesized through cumbersome wet chemical methods. Relative to the CdSe bulk material, the synthesized CdSe quantum dots showed a blue shift in the measured band gap energy from near infrared spectral region to visible region, making this material very attractive for many solar energy harvesting applications like photo-catalysis and solar cells.

  14. Ride Comfort Optimization of Mine Truck Based on Uncertainty Theory and IP-GA%基于不确定性和隔代遗传的矿用车平顺性优化

    Institute of Scientific and Technical Information of China (English)

    李伟平; 张利轩; 马义超; 唐伟

    2012-01-01

    建立了八自由度的矿用自卸车整车数学模型,并基于动态仿真模型构建设计变量和不确定变量与目标函数之间的近似模型,采用双层嵌套的隔代遗传算法,内层在不确定域上求解目标函数区间,外层对设计变量寻优,对该模型进行平顺性优化.最后与确定优化的结果进行比较,得出了不确定性优化的优越性.%A vehicle model of eight degrees of freedom was established. Then, based on dynamic simulation model, an approximate model between design variables, uncertain variables and objective function was built. Using double-nested IP-GA, the ride comfort of the model was improved. For IP-GA, the interval of objective function was obtained through the inner layer while the optimal variable was searched through the outer layer. Finally, the results were compared with those of certain optimization, which has shown the superiority of uncertain optimization.

  15. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Li Shengqing [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Supervision, Inspection and Testing Center of Microbial Products Quality (Wuhan), Ministry of Agriculture (China)], E-mail: sqingli@mail.hzau.edu.cn; Cai Shun; Hu Wei [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Chen Hao [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)], E-mail: hchenhao@mail.hzau.edu.cn; Liu Hanlan [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)

    2009-07-15

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF{sub 6}), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF{sub 6}. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 {mu}L of HMIMPF{sub 6} as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L{sup - 1}, and the characteristic mass (m{sub 0}, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L{sup - 1} Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  16. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Science.gov (United States)

    Li, Shengqing; Cai, Shun; Hu, Wei; Chen, Hao; Liu, Hanlan

    2009-07-01

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF 6), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF 6. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 µL of HMIMPF 6 as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L - 1 , and the characteristic mass ( m0, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L - 1 Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  17. Stable Matching for Dynamic Ride-sharing Systems

    NARCIS (Netherlands)

    X. Wang (Xing); N.A.H. Agatz (Niels); A. Erera (Alan)

    2015-01-01

    textabstractDynamic ride-sharing systems enable people to share rides and increase the efficiency of urban transportation by connecting riders and drivers on short notice. Automated systems that establish ride-share matches with minimal input from participants provide the most convenience and the mo

  18. 77 FR 39208 - Information Collection: Ride-Along Program

    Science.gov (United States)

    2012-07-02

    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Information Collection: Ride-Along Program AGENCY: Forest Service... information collection associated with the Ride- Along Program application, a program which allows any private citizen to apply to ride along with Forest Service law enforcement officers. DATES: Comments must...

  19. Using Video Feedback to Improve Horseback-Riding Skills

    Science.gov (United States)

    Kelley, Heather; Miltenberger, Raymond G.

    2016-01-01

    This study used video feedback to improve the horseback-riding skills of advanced beginning riders. We focused on 3 skill sets: those used in jumping over obstacles, dressage riding on the flat, and jumping position riding on the flat. Baseline consisted of standard lesson procedures. Intervention consisted of video feedback in which a recorded…

  20. Sustainable Passenger Transportation: Dynamic Ride-Sharing

    NARCIS (Netherlands)

    N.A.H. Agatz (Niels); A. Erera (Alan); M.W.P. Savelsbergh (Martin); X. Wang (Xing)

    2010-01-01

    textabstractRide-share systems, which aim to bring together travelers with similar itineraries and time schedules, may provide significant societal and environmental benefits by reducing the number of cars used for personal travel and improving the utilization of available seat capacity. Effective a

  1. Riding Third: Social Work in Ambulance Work

    Science.gov (United States)

    Campbell, Hilary; Rasmussen, Brian

    2012-01-01

    This research explored the possible role of social work alongside emergency ambulance services. An ethnographic study included semistructured interviews and direct observations collected over 300 hours while riding in ambulances in an urban setting. The data suggest that social work could play a role by providing needed psychosocial care during…

  2. Stay Safe Riding Bikes or Skating Outside

    Centers for Disease Control (CDC) Podcasts

    2011-02-02

    In this podcast for kids, the Kidtastics talk about safety when outside, riding bikes or skating.  Created: 2/2/2011 by National Center for Injury Prevention and Control (NCIPC).   Date Released: 2/2/2011.

  3. Impact of ride-through power increase of DFIG-based wind farm on power system stability%双馈风电场穿透功率增加对电力系统稳定影响综述

    Institute of Scientific and Technical Information of China (English)

    康忠健; 辛士郎; 仲崇山; 王玉振; 刘晓林

    2011-01-01

    针对装有双馈感应发电机(DFIG)风电场穿透功率增加带来的稳定性问题,从小干扰稳定性、电压稳定性、频率稳定性3个方面对国内外研究现状进行了分析和总结.综述了基于电力系统稳定器、柔性交流输电技术以及高压直流输电技术的双馈风电场并网系统的改善措施.最后对该领域的未来发展方向进行了展望,指出忽略风速波动和塔影效应,缺乏定量的评价标准对双馈风电场并网稳定性研究的影响.%The ride-through power increase of DFIG-based wind farm will impact the power system stability. Its research status quo at home and abroad is studied and summarized in three aspects: small signal stability,voltage stability,frequency stability. The improvement measures based on power system stabilizer, flexible AC transmission and HVDC transmission technology are reviewed. The future research in this field is prospected and the impact of following two facts on the research of grid-connection stability of DFIG-based wind farm is pointed out:neglect of wind speed fluctuation and tow shadow effect,lack of quantitative evaluation criteria.

  4. [Riding therapy in the rehabilitation of mobility-impaired children].

    Science.gov (United States)

    Mäenpää, Helena; Kela, Katri; Sätilä, Heli

    2016-01-01

    Riding therapy is a comprehensive and functional form of rehabilitation, in which the rehabilitee, the horse and the riding therapist collaborate in order to achieve individually assigned goals that support rehabilitation. In Finland, riding therapy is therapeutic rehabilitation carried out by riding therapists who have undergone approved training. The therapy is mainly implemented in an individual form, but small group working is also applied, e.g. in the form of pair therapy and therapeutic vaulting. In Europe, this form of rehabilitation has been divided into hippotherapy supporting motor functions and heilpedagogical riding therapy functioning in support of upbringing.

  5. Pricing Decision under Dual-Channel Structure considering Fairness and Free-Riding Behavior

    Directory of Open Access Journals (Sweden)

    Yongmei Liu

    2014-01-01

    Full Text Available Under dual-channel structure, the free-riding behavior based on different service levels between online channel and offline channel cannot be avoided, which would lead to channel unfairness. This study implies that the dual-channel supply chain is built up by online channel controlled by manufacturer and traditional channel controlled by retailer, respectively. Under this channel structure, we rebuild the linear demand function considering free-riding behavior and modify the pricing model based on channel fairness. Then the influences of fair factor and free-riding behavior on manufacturer and retailer pricing and performance are discussed. Finally, we propose some numerical analysis to provide some valuable recommendations for manufacturer and retailer improving channel management performance.

  6. Separating stimulus-driven and response-related LRP components with Residue Iteration Decomposition (RIDE).

    Science.gov (United States)

    Stürmer, Birgit; Ouyang, Guang; Zhou, Changsong; Boldt, Annika; Sommer, Werner

    2013-01-01

    When the lateralized readiness potential (LRP) is recorded in stimulus-response compatibility (SRC) tasks, two processes may overlap in the LRP, stimulus-driven response priming and activation based on response selection rules. These overlapping processes are hard to disentangle with standard analytical tools. Here, we show that Residue Iteration Decomposition (RIDE), based on latency variability, separates the overlapping LRP components from a Simon task into stimulus-driven and response-related components. SRC affected LRP amplitudes only in the stimulus-driven component, whereas LRP onsets were affected only in the response-locked component. Importantly, the compatibility effect in reaction times was more similar to the effect in the onsets of the RIDE-derived response-locked LRP component than in the unseparated LRP. Thus, RIDE-separated LRP components are devoid of distortions inherent to standard LRPs.

  7. Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques.

    Science.gov (United States)

    Van der Snickt, Geert; Dik, Joris; Cotte, Marine; Janssens, Koen; Jaroszewicz, Jakub; De Nolf, Wout; Groenewegen, Jasper; Van der Loeff, Luuk

    2009-04-01

    On several paintings of James Ensor (1860-1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (mu-XANES) experiments show that sulfur, originally present in sulfidic form (S(2-)), is oxidized during the transformation to the sulfate form (S(6+)). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO(4).2H(2)O) and ammonium cadmium sulfate [(NH(4))(2)Cd(SO(4))(2)] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1-2 microm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR micro-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.

  8. Optimization of Damper Top Mount Characteristics to Improve Vehicle Ride Comfort and Harshness

    Directory of Open Access Journals (Sweden)

    Mina M. S. Kaldas

    2014-01-01

    Full Text Available A novel optimization technique for optimizing the damper top mount characteristics to improve vehicle ride comfort and harshness is developed. The proposed optimization technique employs a new combined objective function based on ride comfort, harshness, and impact harshness evaluation. A detailed and accurate damper top mount mathematical model is implemented inside a validated quarter vehicle model to provide a realistic simulation environment for the optimization study. The ride comfort and harshness of the quarter vehicle are evaluated by analyzing the body acceleration in different frequency ranges. In addition, the top mount deformation is considered as a penalty factor for the system performance. The influence of the ride comfort and harshness weighting parameters of the proposed objective function on the optimal damper top mount characteristics is studied. The dynamic stiffness of the damper top mount is used to describe the optimum damper top mount characteristics for different optimization case studies. The proposed optimization routine is able to find the optimum characteristics of the damper top mount which improve the ride comfort and the harshness performances together.

  9. Cytotoxicity of cadmium-containing quantum dots based on a study using a microfluidic chip

    Science.gov (United States)

    Zheng, Xiannuo; Tian, Jing; Weng, Lixing; Wu, Lei; Jin, Qinghui; Zhao, Jianlong; Wang, Lianhui

    2012-02-01

    There is a lack of reliable nanotoxicity assays available for monitoring and quantifying multiple cellular events in cultured cells. In this study, we used a microfluidic chip to systematically investigate the cytotoxicity of three kinds of well-characterized cadmium-containing quantum dots (QDs) with the same core but different shell structures, including CdTe core QDs, CdTe/CdS core-shell QDs, and CdTe/CdS/ZnS core-shell-shell QDs, in HEK293 cells. Using the microfluidic chip combined with fluorescence microscopy, multiple QD-induced cellular events including cell morphology, viability, proliferation, and QD uptake were simultaneously analysed. The three kinds of QDs showed significantly different cytotoxicities. The CdTe QDs, which are highly toxic to HEK293 cells, resulted in remarkable cellular and nuclear morphological changes, a dose-dependent decrease in cell viability, and strong inhibition of cell proliferation; the CdTe/CdS QDs were moderately toxic but did not significantly affect the proliferation of HEK293 cells; while the CdTe/CdS/ZnS QDs had no detectable influence on cytotoxicity with respect to cell morphology, viability, and proliferation. Our data indicated that QD cytotoxicity was closely related to their surface structures and specific physicochemical properties. This study also demonstrated that the microfluidic chip could serve as a powerful tool to systematically evaluate the cytotoxicity of nanoparticles in multiple cellular events.

  10. Immunocytotoxicity, cytogenotoxicity and genotoxicity of cadmium-based quantum dots in the marine mussel Mytilus galloprovincialis.

    Science.gov (United States)

    Rocha, Thiago Lopes; Gomes, Tânia; Cardoso, Cátia; Letendre, Julie; Pinheiro, José Paulo; Sousa, Vânia Serrão; Teixeira, Margarida Ribau; Bebianno, Maria João

    2014-10-01

    There is an increased use of Quantum Dot (QDs) in biological and biomedical applications, but little is known about their marine ecotoxicology. So, the aim of this study was to investigate the possible immunocytotoxic, cytogenotoxic and genotoxic effects of cadmium telluride QDs (CdTe QDs) on the marine mussel Mytilus galloprovincialis. Mussels were exposed to 10 μg L(-1) of CdTe QDs or to soluble Cd [Cd(NO3)2] for 14 days and Cd accumulation, immunocytotoxicity [hemocyte density, cell viability, lysosomal membrane stability (LMS), differential cell counts (DCC)], cytogenotoxicity (micronucleus test and nuclear abnormalities assay) and genotoxicity (comet assay) were analyzed. Results show that in vivo exposure to QDs, Cd is accumulated in mussel soft tissues and hemolymph and induce immunotoxic effects mediated by a decrease in LMS, changes in DCC, as well as genotoxicity (DNA damage). However, QDs do not induce significant changes in hemocytes density, cell viability and cytogenetic parameters in opposition to Cd(2+). Soluble Cd is the most cytotoxic and cytogenotoxic form on Mytilus hemocytes due to a higher accumulation of Cd in tissues. Results indicate that immunotoxicity and genotoxicity of CdTe QDs and Cd(2+) are mediated by different modes of action and show that Mytilus hemocytes are important targets for in vivo QDs toxicity.

  11. Low-cost cadmium zinc telluride radiation detectors based on electron-transport-only designs

    Energy Technology Data Exchange (ETDEWEB)

    B. A. Brunett; J. C. Lund; J. M. Van Scyoc; N. R. Hilton; E. Y. Lee; R. B. James

    1999-01-01

    The goal of this project was to utilize a novel device design to build a compact, high resolution, room temperature operated semiconductor gamma ray sensor. This sensor was constructed from a cadmium zinc telluride (CZT) crystal. It was able to both detect total radiation intensity and perform spectroscopy on the detected radiation. CZT detectors produced today have excellent electron charge carrier collection, but suffer from poor hole collection. For conventional gamma-ray spectrometers, both the electrons and holes must be collected with high efficiency to preserve energy resolution. The requirement to collect the hole carriers, which have relatively low lifetimes, limits the efficiency and performance of existing experimental devices. By implementing novel device designs such that the devices rely only on the electron signal for energy information, the sensitivity of the sensors for detecting radiation can be increased substantially. In this report the authors describe a project to develop a new type of electron-only CZT detector. They report on their successful efforts to design, implement and test these new radiation detectors. In addition to the design and construction of the sensors the authors also report, in considerable detail, on the electrical characteristics of the CZT crystals used to make their detectors.

  12. Properties of Cadmium-(bisdodecylthiolate and Polymeric Composites Based on It

    Directory of Open Access Journals (Sweden)

    Nadezhda Agareva

    2015-12-01

    Full Text Available We study the thermo-physical and photoluminescence (PL properties of cadmium-(bisdodecylthiolate (Cd(C12H25S2. Significant attention is drawn to characterization of Cd(C12H25S2 by different methods. The laser-induced PLs of Cd(C12H25S2 and Cd(C12H25S2/(polymethyl methacrylate (PMMA composites are studied. Samples of Cd(C12H25S2/PMMA are synthesized by the polymerization method. Ultraviolet (UV-pulsed laser irradiation of the samples under relatively small fluences leads to the formation of induced PL with the maximum near the wavelength of 600 nm. This process can be attributed to the transformation of Cd(C12H25S2 within the precursor grains. Another PL peak at 450–500 nm, which appears under the higher fluences, relies on the formation of CdS complexes with a significant impact of the polymer matrix.

  13. Review of Low Voltage Ride-through Technology for Doubly-fed Induction Generator Based Wind Energy Conversion Systems%双馈型风力发电系统低电压穿越技术综述

    Institute of Scientific and Technical Information of China (English)

    杨耕; 郑重

    2011-01-01

    As the capacity of doubly-fed induction generator(DFIG) based large wind farms keep increasing,the pen etration of wind power in the power system raises gradually.In order to ensure the safe and reliable operation of the power system,it is important to enhance the low voltage ride-through(LVRT) performance of DFIG.The technical rules of LVRT for connecting wind farm into power grid are discussed.The transient characteristic of DFIG under grid voltage sag fault and the main points of implementing LVRT are analyzed.Then, the existed LVRT technologies for DFIG based wind farm are summarized.In the end,the further LVRT issues are discussed.%随着双馈感应发电机( DFIG)风电场在并网风电容量中比重的增加,为了确保电力系统的可靠运行,提高DFIG风电场的低电压穿越(LV RT)能力显得尤为重要.首先介绍了风电场并网准则对LVRT的要求,接着分析了电网电压骤降故障下DFIG的瞬态特性及其LVRT技术的难点;在系统总结和评价国内外现有DFIG系统的LVRT技术的同时,最后对LVRT技术未来的发展方向进行了展望.

  14. Adsorptive removal of lead and cadmium ions using Cross -linked CMC Schiff base: Isotherm, Kinetics and Catalytic Activity

    Directory of Open Access Journals (Sweden)

    P. Moganavally

    2016-03-01

    Full Text Available Water plays a vital role to human and other living organisms. Due to the effluent coming from chemical industries, the industrial activity, contamination of ground water level is goes on increasing nowadays. Therefore, there is a need to develop technologies that can remove toxic pollutants in wastewater. Hence the cross linked Carboxymethyl chitosan(CMC/ 2,3-dimethoxy Benzaldehyde Schiff base complex has been synthesized and characterized by using FT-IR and SEM analysis. All these results revealed that cross linked Schiff base has formed with high adsorption capacity. The prepared effective adsorbent used for the removal of heavy metals like lead (II and cadmium (II ions from aqueous solution and the adsorption data follow the Freundlich model, which follows pseudo first order kinetics. Effect of various parameters like solution pH, adsorbent dose and contact time for the removal of heavy metals has been studied. The synthesized sample undergoes catalytic oxidation process significantly at 24 hrs. The results showed that cross linked Schiff base is an effective, eco-friendly, low-cost adsorbent.

  15. Analysis of Vehicle Ride Comfort Based on Vehicle Dynamic Model with Ten Degrees of Freedom%基于十自由度车辆模型的汽车平顺性分析

    Institute of Scientific and Technical Information of China (English)

    吴颖熹; 周铉; 王二兵; 罗先银

    2011-01-01

    通过建立十自由度车辆动力学模型,对汽车平顺性进行分析.运用振动理论分析了车辆的传递函数和振动特性,并通过讨论选择了车身质心加速度、悬架动挠度、车轮相对动载荷、车身俯仰角加速度等参量作为平顺性评价标准.通过Matlab/Simulink对车辆振动特性进行仿真,讨论了轮胎刚度和动力总成悬置刚度对平顺性的影响.结果表明,两者的增加均导致汽车平顺性变差.通过仿真实例可见,该动力学模型可利用设计初期的车辆参数对汽车平顺性进行预测和评估,从而减少样车开发成本.%Vehicle ride comfort was analyzed on the vibration theory by establishing a ten DOFs dynamic model.Through discussing the vibration characteristics of the vehicle system,parameters,including vehicle centroidal acceleration,suspension dynamic deflection,relative wheel dynamic load and pitch angular acceleration,were chosen as targets to evaluate vehicle ride comfort.Influences on the ride comfort by vehicle parameters were studied through the simulation by Matlab/Simulink,which shows the increase of tire and mount stiffness both lead to bad ride comfort.As a result,with the vehicle dynamic model and simulation method,vehicle ride quality can be predicted and evaluated in product design.

  16. Review of Low Voltage Ride-Through Technology for VSC-HVDC Based Wind Power Generation Systems%基于VSC-HVDC的风电系统低电压穿越技术综述

    Institute of Scientific and Technical Information of China (English)

    章心因; 吴在军; 郝思鹏; 程桂林

    2013-01-01

      轻型高压直流输电系统(VSC-HVDC)是风电技术的重要发展方向。随着风电比重快速增加,电网对风电机组及其并网系统地低电压穿越(LVRT)能力提出了更高的要求。本文首先分析了电压跌落对VSC-HVDC系统和风电机组的影响,继而简要地总结了风电机组LVRT技术,然后对各种适合于VSC-HVDC风电系统的LVRT方案进行了分析评价,并重点讨论了该风电系统的LVRT协调控制技术。%Long-distance large-capacity wind farm connected to the grid by the VSC-HVDC transmission system will be an important trend of the wind power technology development. With the rapid increase in the proportion of wind power, the grid has a higher demand for the Low Voltage Ride-through(LVRT) ability of the wind turbine and its grid systems. The influence of voltage drop on the VSC-HVDC system and wind turbine is firstly analyzed. Meanwhile, the LVRT technology for the wind turbine is summarized briefly. Then, several types of LVRT solutions for the VSC-HVDC based wind power systems are analyzed and evaluated. In the end, the LVRT coordination control methods are mainly discussed.

  17. A Low Voltage Ride Through Control Strategy for PMSG Based on Electromechanical Energy Storage%基于机电储能的永磁同步发电机低电压穿越控制策略

    Institute of Scientific and Technical Information of China (English)

    田野; 王冕; 张艺枥; 李军; 杨恩星; 陈国柱

    2012-01-01

    This paper summarizes the existing low voltage ride through(LVRT) methods from power flow prospective,and proposes a LVRT control strategy based on the electromechanical energy storage.The generator-side converter maintains DC-link voltage while the grid-side converter tracks the maximum power point of wind energy.This control strategy combines braking resistor with greatly reduced cooling requirements and variable-pitch structure technology,can make full use of the wind turbines' inertial characteristics to store the imbalanced energy and realize LVRT smoothly,without increasing control complexity and system costs significantly.The correctness and validity of this LVRT control strategy is verified through MATLAB simulation of a 1.5 MW permanent magnet synchronous generator(PMSG) wind generation system.%从功率流向角度对已有低电压穿越(LVRT)方法进行归纳总结,在此基础上提出一种LVRT控制策略:基于机电储能,利用机侧变流器稳定直流母线电压,网侧变流器实现最大风能跟踪。该控制策略结合散热要求大大降低的制动电阻与变桨距调节技术,可以在不增加控制复杂度、不显著增加系统成本的情况下,充分利用风电机组惯性,存储电网电压跌落时系统的不平衡能量,平稳实现LVRT。通过对1.5MW永磁直驱风电系统的MATLAB仿真,验证了所提出的LVRT控制策略的正确性和有效性。

  18. Research on the fault ride-through optimal control strategy of PMSG-based wind turbine%永磁直驱风电机组故障穿越优化控制策略研究

    Institute of Scientific and Technical Information of China (English)

    王丹; 刘崇茹; 李庚银

    2015-01-01

    永磁同步发电机构成的直驱型变速恒频风力发电系统通过全功率变流器与电网连接,当电网发生严重故障时,不仅对HVDC设备造成损害,甚至可能影响风力发电系统的整体安全稳定运行。对系统故障期间直流电压失稳的机理进行了分析,基于永磁同步发电机转子的惯性储能特性以及网侧换流器的无功补偿能力,提出一种适用于提高永磁直驱风电机组故障穿越能力的优化控制策略。在网侧故障期间通过分段式转速控制调整风机侧输入的有功并对网侧无功进行补偿,减小了中间直流系统注入的不平衡功率,抑制了故障期间直流电压的骤升。应用PSCAD/EMTDC电磁暂态仿真软件建立单机系统模型,仿真结果验证了所提出的控制策略的有效性。%The directly-driven variable speed constant frequency wind power generation system, which consists of the permanent magnet synchronous generator (PMSG), is connected to the grid by full size power converters. When severe faults occur in grid, the faults would not only cause serious damage to HVDC devices, but also have an adverse impact on the stable operation of overall wind power generation system. The disability mechanism of DC voltage during faults is analyzed. Based on the inertial energy storage characteristics of PMSG rotor and the reactive power compensation capability of grid-side converter, a novel coordinated control strategy aimed at improving the fault ride-through capability of PMSG is proposed. In order to decrease the imbalance power injected to the DC-link and suppress the overvoltage of DC-link, the proposed control strategy adopts an optimal generator-side segmented rotor speed controller to adjust the active power from wind turbine and increase the reactive power to grid on the basis of the grid-side converter with reactive power adjusting capability. A single-machine infinite-bus power system model in PSCAD/EMTDC is

  19. Toxicological effects induced by cadmium in gills of Manila clam ruditapes philippinarum using NMR-based metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Linbao; Liu, Xiaoli; You, Liping; Zhou, Di [Key Laboratory of Coastal Zone Environment Processes, CAS, Shandong Provincial Key Laboratory of Coastal Zone Environment Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai (China); The Graduate School of Chinese Academy of Sciences, Beijing (China); Yu, Junbao; Zhao, Jianmin; Wu, Huifeng [Key Laboratory of Coastal Zone Environment Processes, CAS, Shandong Provincial Key Laboratory of Coastal Zone Environment Processes, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai (China); Feng, Jianghua [Department of Electronic Science, Fujian Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen (China)

    2011-11-15

    Cadmium (Cd) has become an important heavy metal contaminant in the sediment and seawater along the Bohai Sea and been of great ecological risk due to its toxic effects to marine organisms. In this work, the toxicological effects caused by environmentally relevant concentrations (10 and 40 {mu}g L{sup -1}) of Cd were studied in the gill tissues of Manila clam Ruditapes philippinarum after exposure for 24, 48, and 96 h. Both low (10 {mu}g L{sup -1}) and high (40 {mu}g L{sup -1}) doses of Cd caused the disturbances in energy metabolism and osmotic regulation and neurotoxicity based on the metabolic biomarkers such as succinate, alanine, branched chain amino acids, betaine, hypotaurine, and glutamate in clam gills after 24 h of exposure. However, the recovery of toxicological effects of Cd after exposure for 96 h was obviously observed in clam to Cd exposures. Overall, these results indicated that NMR-based metabolomics was applicable to elucidate the toxicological effects of heavy metal contaminants in the marine bioindicator. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. NMR-based metabolomic studies on the toxicological effects of cadmium and copper on green mussels Perna viridis

    Energy Technology Data Exchange (ETDEWEB)

    Wu Huifeng [Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong); Wang Wenxiong, E-mail: wwang@ust.hk [Section of Marine Ecology and Biotechnology, Division of Life Science, Hong Kong University of Science and Technology (HKUST), Clear Water Bay, Kowloon (Hong Kong)

    2010-11-15

    Traditional toxicology studies have focused on selected biomarkers to characterize the biological stress induced by metals in marine organisms. In this study, a system biology tool, metabolomics, was applied to the marine mussel Perna viridis to investigate changes in the metabolic profiles of soft tissue as a response to copper (Cu) and cadmium (Cd), both as single metal and as a mixture. The major metabolite changes corresponding to metal exposure are related to amino acids, osmolytes, and energy metabolites. Following metal exposure for 1 week, there was a significant increase in the levels of branched chain amino acids, histidine, glutamate, glutamine, hypotaurine, dimethylglycine, arginine and ATP/ADP. For the Cu + Cd co-exposed mussels, the levels of lactate, branched chain amino acid, succinate, and NAD increased, whereas the levels of glucose, glycogen, and ATP/ADP decreased, indicating a different metabolic profile for the single metal exposure groups. After 2 weeks of exposure, the mussels showed acclimatization to Cd exposure based on the recovery of some metabolites. However, the metabolic profile induced by the metal mixture was very similar to that from Cu exposure, suggesting that Cu dominantly induced the metabolic disturbances. Both Cu and Cd may lead to neurotoxicity, disturbances in energy metabolism, and osmoregulation changes. These results demonstrate the high applicability and reliability of NMR-based metabolomics in interpreting the toxicological mechanisms of metals using global metabolic biomarkers.

  1. Cadmium and zinc relationships.

    Science.gov (United States)

    Elinder, C G; Piscator, M

    1978-08-01

    Cadmium and zinc concentrations in kidney and liver have been measured under different exposure situations in different species including man. The results show that zinc increases almost equimolarly with cadmium in kidney after long-term low-level exposure to cadmium, e.g., in man, horse, pig, and lamb. In contrast, the increase of zinc follows that of cadmium to only a limited extent, e.g., in guinea pig, rabbit, rat, mouse, and chicks. In liver, the cadmium--zinc relationship seems to be reversed in such a way that zinc increases with cadmium more markedly in laboratory animals than in higher mammals. These differences between cadmium and zinc relationships in humans and large farm animals and those in commonly used laboratory animals must be considered carefully before experimental data on cadmium and zinc relationships in laboratory animals can be extrapolated to humans.

  2. Scaling Law of Urban Ride Sharing

    CERN Document Server

    Tachet, Remi; Santi, Paolo; Resta, Giovanni; Szell, Michael; Strogatz, Steven; Ratti, Carlo

    2016-01-01

    Sharing rides could drastically improve the efficiency of car and taxi transportation. Unleashing such potential, however, requires understanding how urban parameters affect the fraction of individual trips that can be shared, a quantity that we call shareability. Using data on millions of taxi trips in New York City, San Francisco, Singapore, and Vienna, we compute the shareability curves for each city, and find that a natural rescaling collapses them onto a single, universal curve. We explain this scaling law theoretically with a simple model that predicts the potential for ride sharing in any city, using a few basic urban quantities and no adjustable parameters. Accurate extrapolations of this type will help planners, transportation companies, and society at large to shape a sustainable path for urban growth.

  3. Scaling Law of Urban Ride Sharing

    Science.gov (United States)

    Tachet, R.; Sagarra, O.; Santi, P.; Resta, G.; Szell, M.; Strogatz, S. H.; Ratti, C.

    2017-03-01

    Sharing rides could drastically improve the efficiency of car and taxi transportation. Unleashing such potential, however, requires understanding how urban parameters affect the fraction of individual trips that can be shared, a quantity that we call shareability. Using data on millions of taxi trips in New York City, San Francisco, Singapore, and Vienna, we compute the shareability curves for each city, and find that a natural rescaling collapses them onto a single, universal curve. We explain this scaling law theoretically with a simple model that predicts the potential for ride sharing in any city, using a few basic urban quantities and no adjustable parameters. Accurate extrapolations of this type will help planners, transportation companies, and society at large to shape a sustainable path for urban growth.

  4. Air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A; Brown, Wesley D; Sexton, Thomas D; Jones, Russell B

    2016-07-19

    An air riding seal between a rotor and a stator in a turbine of a gas turbine engine, where an annular piston is movable in an axial direction within a housing that extends from the stator, and a bellows is secured to the annular piston to form a flexible air passageway from a compressed air inlet through the annular piston and into a cushion cavity that forms an air riding seal between the annular piston and the rotor sealing surface. In another embodiment, a flexible seal secured to and extending from the annular piston forms a sealing surface between the annular piston chamber and the annular piston to provide a seal and allow for axial movement.

  5. Immunoassay for Cadmium Detection and Quantification

    Institute of Scientific and Technical Information of China (English)

    GONG-LIANG LIU; JU-FANG WANG; ZHI-YONG LI; SHI-ZHONG LIANG; XIAO-NING WANG

    2009-01-01

    Objective To detect cadmium in environmental and food samples by graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma atomic emission spectroscopy (ICPAES). Methods An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was developed based on a cadmium-specific monoclonal antibody.IC-ELISA for cadmium in environmental and food samples was evaluated. Results IC-ELISA showed an IC50 of 45.6 μg/L with a detection limit of 1.95 μg/L for cadmium,and showed a mean recovery ranging 97.67%-107.08%.The coefficient of variations for intra- and iuterassay was 3.41%-6.61% and 4.70%-9.21%,respectively.The correlation coefficient between IC-ELISA and GFAAS was 0.998. Conclusion IC-ELISA can detect and quantify cadmium residue in environmental or food samples.

  6. Cadmium a metalloestrogen: are we convinced?

    Science.gov (United States)

    Silva, Nalinda; Peiris-John, Roshini; Wickremasinghe, Rajitha; Senanayake, Hemantha; Sathiakumar, Nalini

    2012-05-01

    Metalloestrogens are inorganic metal ions that bind to and activate oestrogen receptors. They are implicated in the aetiology of oestrogen-dependent diseases such as cancers of the breast and endometrium as well as endometriosis. Cadmium is one of the most studied metalloestrogens. In this review, scientific evidence for the oestrogenic effects of cadmium is critically evaluated to determine if there is sufficient evidence to support cadmium as an aetiological factor of oestrogen-dependent disease in humans. Results of the review indicated that, although the in vitro and in vivo evidence of the oestrogenic properties of cadmium was persuasive, evidence from population-based human studies remains conflicting. Considerable knowledge gaps exist on the potential oestrogenic effect of cadmium in humans. Research that focuses on bridging these knowledge gaps would be useful in preventing and managing oestrogen-dependent disease in humans.

  7. Riding to School in a Wheelchair

    Science.gov (United States)

    Buning, Mary Ellen; Shutrump, Sue; Manary, Miriam A.

    2007-01-01

    Riding on a school bus is one of the safest forms of transportation in the U.S. Every year 450,000 public school buses travel more than 4.3 billion miles to transport 23.5 million children to and from school and school related activities. Students are reportedly eight times safer on the school bus than they are in cars. However, the percentage of…

  8. A circular dichroism sensor for Ni(2+) and Co(2+) based on L-cysteine capped cadmium sulfide quantum dots.

    Science.gov (United States)

    Tedsana, Wimonsiri; Tuntulani, Thawatchai; Ngeontae, Wittaya

    2015-03-31

    A new circular dichroism sensor for detecting Ni(2+) and Co(2+) was proposed for the first time using chiral chelating quantum dots. The detection principle was based on changing of circular dichroism signals of the chiral quantum dots when forming a chiral complex with Ni(2+) or Co(2+). L-Cysteine capped cadmium sulfide quantum dots (L-Cyst-CdS QDs) were proposed as a chiral probe. The CD spectrum of L-Cyst-CdS QDs was significantly changed in the presence of Ni(2+) and Co(2+). On the other hand, other studied cations did not alter the original CD spectrum. Moreover, when increasing the concentration of Ni(2+) or Co(2+), the intensity of the CD spectrum linearly increased as a function of concentration and could be useful for the quantitative analysis. The proposed CD sensor showed linear working concentration ranges of 10-60 μM and 4-80 μM with low detection limits of 7.33 μМ and 1.13 μM for the detection of Ni(2+) and Co(2+), respectively. Parameters possibly affected the detection sensitivity such as solution pH and incubation time were studied and optimized. The proposed sensor was applied to detect Ni(2+) and Co(2+) in real water samples, and the results agreed well with the analysis using the standard ICP-OES.

  9. The electrical properties of photodiodes based on nanostructure gallium doped cadmium oxide/p-type silicon junctions

    Science.gov (United States)

    Çavaş, M.; Yakuphanoğlu, F.; Karataş, Ş.

    2017-01-01

    Gallium doped cadmium-oxide (CdO: Ga) thin films were successfully deposited by sol-gel spin coating method on p-type Si substrate. The electrical properties of the photodiode based on nanostructure Ga doped n-CdO/p-Si junctions were investigated. The current-voltage (I-V) characteristics of the structure were investigated under various light intensity and dark. It was observed that generated photocurrent of the Au/n-CdO/p-Si junctions depended on light intensity. The capacitance-voltage and conductance-voltage measurements were carried out for this diode in the frequency range between 100 and 1000 kHz at room temperature by steps of 100 kHz. The capacitance decreased with increasing frequency due to a continuous distribution of the interface states. These results suggested that the Au/n-CdO/p-Si Schottky junctions could be utilized as a photosensor. Furthermore, the voltage and frequency dependence of series resistance were calculated from the C-V and G/ω-V measurements and plotted as functions of voltage and frequency. The distribution profile of R S -V gave a peak in the depletion region at low frequencies and disappeared with increasing frequencies.

  10. Ride quality criteria and the design process. [standards for ride comfort

    Science.gov (United States)

    Ravera, R. J.

    1975-01-01

    Conceptual designs for advanced ground transportation systems often hinge on obtaining acceptable vehicle ride quality while attempting to keep the total guideway cost (initial and subsequent maintenance) as low as possible. Two ride quality standards used extensively in work sponsored by the U.S. Department of Transportation (DOT) are the DOT-Urban Tracked Air Cushion Vehicle (UTACV) standard and the International Standards Organization (ISO) reduced ride comfort criteria. These standards are reviewed and some of the deficiencies, which become apparent when trying to apply them in practice, are noted. Through the use of a digital simulation, the impact of each of these standards on an example design process is examined. It is shown that meeting the ISO specification for the particular vehicle/guideway case investigated is easier than meeting the UTACV standard.

  11. Minimum Junction Temperature Swing for DFIG to Ride Through Symmetrical Voltage Dips

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    Doubly-Fed Induction Generator (DFIG) system is popular for wind turbines above 1 MW. Existing issues for a DFIG system to ride through a symmetrical grid fault are addressed in terms of the internal and external challenges. Based on the conventional demagnetizing current control, the design...

  12. Crystal Growth, Characterization and Fabrication of Cadmium Zinc Telluride-based Nuclear Detectors

    Science.gov (United States)

    Krishna, Ramesh M.

    In today's world, nuclear radiation is seeing more and more use by humanity as time goes on. Nuclear power plants are being built to supply humanity's energy needs, nuclear medical imaging is becoming more popular for diagnosing cancer and other diseases, and control of weapons-grade nuclear materials is becoming more and more important for national security. All of these needs require high-performance nuclear radiation detectors which can accurately measure the type and amount of radiation being used. However, most current radiation detection materials available commercially require extensive cooling, or simply do not function adequately for high-energy gamma-ray emitting nuclear materials such as uranium and plutonium. One of the most promising semiconductor materials being considered to create a convenient, field-deployable nuclear detector is cadmium zinc telluride (CdZnTe, or CZT). CZT is a ternary semiconductor compound which can detect high-energy gamma-rays at room temperature. It offers high resistivity (≥ 1010 O-cm), a high band gap (1.55 eV), and good electron transport properties, all of which are required for a nuclear radiation detector. However, one significant issue with CZT is that there is considerable difficulty in growing large, homogeneous, defect-free single crystals of CZT. This significantly increases the cost of producing CZT detectors, making CZT less than ideal for mass-production. Furthermore, CZT suffers from poor hole transport properties, which creates significant problems when using it as a high-energy gamma-ray detector. In this dissertation, a comprehensive investigation is undertaken using a successful growth method for CZT developed at the University of South Carolina. This method, called the solvent-growth technique, reduces the complexity required to grow detector-grade CZT single crystals. It utilizes a lower growth temperature than traditional growth methods by using Te as a solvent, while maintaining the advantages of

  13. Myocardial perfusion imaging with a cadmium zinc telluride-based gamma camera versus invasive fractional flow reserve

    Energy Technology Data Exchange (ETDEWEB)

    Mouden, Mohamed [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Ottervanger, Jan Paul; Timmer, Jorik R. [Isala klinieken, Department of Cardiology, Zwolle (Netherlands); Knollema, Siert; Reiffers, Stoffer; Oostdijk, Ad H.J.; Jager, Pieter L. [Isala klinieken, Department of Nuclear Medicine, Zwolle (Netherlands); Boer, Menko-Jan de [University Medical Centre Nijmegen, Department of Cardiology, Nijmegen (Netherlands)

    2014-05-15

    Recently introduced ultrafast cardiac SPECT cameras with cadmium zinc telluride-based (CZT) detectors may provide superior image quality allowing faster acquisition with reduced radiation doses. Although the level of concordance between conventional SPECT and invasive fractional flow reserve (FFR) measurement has been studied, that between FFR and CZT-based SPECT is not yet known. Therefore, we aimed to assess the level of concordance between CZT SPECT and FFR in a large patient group with stable coronary artery disease. Both invasive FFR and myocardial perfusion imaging with a CZT-based SPECT camera, using Tc-tetrofosmin as tracer, were performed in 100 patients with stable angina and intermediate grade stenosis on invasive coronary angiography. A cut-off value of <0.75 was used to define abnormal FFR. The mean age of the patients was 64 ± 11 years, and 64 % were men. SPECT demonstrated ischaemia in 31 % of the patients, and 20 % had FFR <0.75. The concordance between CZT SPECT and FFR was 73 % on a per-patient basis and 79 % on a per-vessel basis. Discordant findings were more often seen in older patients and were mainly (19 %) the result of ischaemic SPECT findings in patients with FFR ≥0.75, whereas only 8 % had an abnormal FFR without ischaemia as demonstrated by CZT SPECT. Only 20 - 30 % of patients with intermediate coronary stenoses had significant ischaemia as assessed by CZT SPECT or invasive FFR. CZT SPECT showed a modest degree of concordance with FFR, which is comparable with previous results with conventional SPECT. Further investigations are particularly necessary in patients with normal SPECT and abnormal FFR, especially to determine whether these patients should undergo revascularization. (orig.)

  14. Chemical characterisation of zircon-cadmium sulfoselenide ceramic pigments; Caracterizacion quimica de pigmentos ceramicos a base de sulfoseleniuro de cadmio

    Energy Technology Data Exchange (ETDEWEB)

    Gazulla Barreda, M. F.; Rodrigo Edo, M.; Blasco Roca, E.; Orduna Cordero, M.

    2013-07-01

    The present paper addresses the development of a methodology that allows the complete chemical characterisation of zircon cadmium sulfoselenide ceramic pigments including minor and major elements. To develop the methodology, five zircon-cadmium sulfoselenide pigments with different hues were selected, studying the different measurement process steps, from sample preparation to the optimisation of the measurement of the different components of the pigments by spectroscopic techniques (WD-XRF and elemental analysis by combustion and IR detection). The chemical characterisation method developed was validated with synthetic standards prepared from the mixture of certified reference materials and pure oxides because no certified referenced materials of this type of pigments were commercially available. The developed method can be used for a complete chemical characterization of zircon-cadmium sulfoselenide ceramic pigments with a very low uncertainty for all the elements analysed. (Author)

  15. Chronic subdural haematoma after riding a roller coaster.

    Science.gov (United States)

    Yamakami, Iwao; Mine, Seiichiro; Yamaura, Akira; Fukutake, Toshio

    2005-01-01

    We report a 20-year-old man who developed a chronic subdural haematoma (CSDH) after riding a "giant" roller coaster. The patient had a past history of a subdural hygroma, diagnosed six weeks after a motorcycle accident. Three months after this accident, he rode on a roller coaster, but suffered no direct head trauma during the ride. Three weeks later, he developed a CSDH requiring surgical evacuation. Roller coaster riding, associated with high velocities and extreme acceleration/deceleration forces is a modern cause of CSDH in the young, which may be increasing due to ever-faster rides.

  16. Transcriptomic changes during maize roots development responsive to Cadmium (Cd) pollution using comparative RNAseq-based approach

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Hua [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Sichuan Tourism College, Chengdu, 610000, Sichuan (China); He, Xiujing [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Gao, Jian [Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing (China); Ma, Haixia; Zhang, Zhiming; Shen, Yaou [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Pan, Guangtang, E-mail: pangt@sicau.edu.cn [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China); Lin, Haijian, E-mail: linhj521@gmail.com [Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, Sichuan, 611130 (China)

    2015-09-04

    The heavy metal cadmium (Cd), acts as a widespread environmental contaminant, which has shown to adversely affect human health, food safety and ecosystem safety in recent years. However, research on how plant respond to various kinds of heavy metal stress is scarcely reported, especially for understanding of complex molecular regulatory mechanisms and elucidating the gene networks of plant respond to Cd stress. Here, transcriptomic changes during Mo17 and B73 seedlings development responsive to Cd pollution were investigated and comparative RNAseq-based approach in both genotypes were performed. 115 differential expression genes (DEGs) with significant alteration in expression were found co-modulated in both genotypes during the maize seedling development; of those, most of DGEs were found comprised of stress and defense responses proteins, transporters, as well as transcription factors, such as thaumatin-like protein, ZmOPR2 and ZmOPR5. More interestingly, genotype-specific transcriptional factors changes induced by Cd stress were found contributed to the regulatory mechanism of Cd sensitivity in both different genotypes. Moreover, 12 co-expression modules associated with specific biological processes or pathways (M1 to M12) were identified by consensus co-expression network. These results will expand our understanding of complex molecular mechanism of response and defense to Cd exposure in maize seedling roots. - Highlights: • Transcriptomic changes responsive to Cd pollution using comparative RNAseq-based approach. • 115 differential expression genes (DEGs) were found co-modulated in both genotypes. • Most of DGEs belong to stress and defense responses proteins, transporters, transcription factors. • 12 co-expression modules associated with specific biological processes or pathways. • Genotype-specific transcriptional factors changes induced by Cd stress were found.

  17. 基于可变频变压器的双馈风电系统低电压穿越控制%Low Voltage Ride Through Control of Doubly-Fed Induction Generator Based on Variable Frequency Transformer

    Institute of Scientific and Technical Information of China (English)

    方泽钦; 杨俊华; 陈思哲; 吴捷

    2016-01-01

    在电网电压发生跌落故障期间,基于Crowbar电路的双馈风力发电( DFIG)系统需吸收大量无功功率。为提高DFIG风电机组并网运行稳定性,提出增设可变频变压器( VFT)新方案。 VFT由双馈电机、直流电机及驱动器构成。 Crowbar电路动作后,通过控制低电压穿越( LVRT)期间的VFT转速来抑制系统转差率,减小系统无功功率吸收量,基于 MATLAB/Simulink 平台,进行了暂态仿真研究。结果表明,故障期间在Crowbar电路起动后,所提控制策略能避免系统从电网中吸收过量无功功率,避免发电机转差率越限,有助于电网电压的恢复,DFIG风电机组的LVRT性能提高。%The vast grid reactive power would be absorbed by the crowbar-based doubly-fed induction generator ( DFIG) wind turbine when grid voltage dip fault. To improve the stability of power grid with DFIG wind turbines, a new low voltage ride-through ( LVRT ) control strategy was proposed for DFIG wind turbine by adding a variable frequency transformer ( VFT) between DFIG and grid. The VFT was composed of a doubly-fed induction machine, a DC motor and its drive system. During the crowbar circuit active, the slip of DFIG could be restrained with controlling the rotary speed of VFT during LVRT to reduce the amount of reactive power consumption. With MATLAB/Simulink simulation platform, the dynamic process of DFIG system was simulated during the voltage sag. The simulation results showed that the amount of reactive power absorbed by DFIG system from grid could be decreased and the slip ratio of DFIG could be limit below the critical value with the proposed control strategy during voltage sag, which contributes to the recovery of the grid voltage and improves the LVRT performance of DFIG wind turbine.

  18. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    Directory of Open Access Journals (Sweden)

    Brian G. Luckett

    2012-01-01

    Full Text Available Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana. We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P≤0.0001. Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88 and high consumption levels of red meat (4th quartile OR = 6.18 and grains (4th quartile OR = 3.38. Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen.

  19. Cadmium-induced cancers in animals and in humans.

    Science.gov (United States)

    Huff, James; Lunn, Ruth M; Waalkes, Michael P; Tomatis, Lorenzo; Infante, Peter F

    2007-01-01

    Discovered in the early 1800s, the use of cadmium and various cadmium salts started to become industrially important near the close of the 19th century, rapidly thereafter began to flourish, yet has diminished more recently. Most cadmium used in the United States is a byproduct from the smelting of zinc, lead, or copper ores, and is used to manufacture batteries. Carcinogenic activity of cadmium was discovered first in animals and only subsequently in humans. Cadmium and cadmium compounds have been classified as known human carcinogens by the International Agency for Research on Cancer and the National Toxicology Program based on epidemiologic studies showing a causal association with lung cancer, and possibly prostate cancer, and studies in experimental animals, demonstrating that cadmium causes tumors at multiple tissue sites, by various routes of exposure, and in several species and strains. Epidemiologic studies published since these evaluations suggest that cadmium is also associated with cancers of the breast, kidney, pancreas, and urinary bladder. The basic metal cationic portion of cadmium is responsible for both toxic and carcinogenic activity, and the mechanism of carcinogenicity appears to be multifactorial. Available information about the carcinogenicity of cadmium and cadmium compounds is reviewed, evaluated, and discussed.

  20. Effects of vehicle-ride exposure on cervical pathology: a meta-analysis.

    Science.gov (United States)

    Kollock, Roger; Games, Kenneth; Wilson, Alan E; Sefton, JoEllen M

    2015-01-01

    Research to date on the effect vehicle-ride exposure has on the development of cervical pathologies in mounted Warfighters is conflicting. The purpose of this study was to determine if the literature suggests a definite effect of vehicle-ride exposure on cervical pathology. Databases were searched using multiple combinations of select terms. Twelve studies meeting the inclusion criteria were included in the meta-analysis. The results of the meta-analysis revealed that overall vehicle-ride exposure was likely to increase cervical pathology (p=0.01, odds ratio=1.59, 95% CI=1.16-2.17). Using vehicle type as a moderator it was found that vehicle-ride exposure in ground-based vehicles (p=0.01, odds ratio=2.33, 95% CI=1.41-3.85) and fixed-wing aircraft (p=0.01, odds ratio =1.59, 95% CI=1.13-2.23) were likely to increase cervical pathology. Using operator/other personnel moderator it was found that in the populations tested, fighter pilots or fighter jet weapons systems operators were more likely to develop a cervical pathology (p<0.001, odds ratio=1.78, 95% CI=1.26-2.50). The available studies indicate an increase in cervical pathology for personnel exposed to ground-based vehicles and fixed-wing aircraft.

  1. Control Strategy and Experiment of High Voltage Ride Through for DFIG-based Wind Turbines%双馈风电机组高电压穿越控制策略与试验

    Institute of Scientific and Technical Information of China (English)

    李少林; 王伟胜; 王瑞明; 孙勇; 陈晨

    2016-01-01

    In research of frequent tripping of wind turbines under high voltage conditions , the requirements for high voltage ride through ( HVRT) of the main grid integration guide to wind power are introduced . A comparative analysis of electromagnetic transient characteristics of doubly‐fed induction generator (DFIG) based wind turbines is carried out under dip and voltage swell conditions , and the full control of the DFIG‐based wind turbines HVRT process is demonstrated if the voltage is less than 1 .3 nominal voltage . Then , a collaborative HVRT control strategy for DFIG‐based wind turbines based on main controller and the convertor is proposed , which is implemented just by software improvement without hardware modification , and avoids the adverse effect of Crowbar or Chopper protection action on the characteristics of HVRT . A 2 MW DFIG‐based wind turbines model for HVRT research is built in MATLAB/Simulink , and the HVRT process of DFIG‐based wind turbines is simulated . The field test is carried out on a 2 MW DFIG‐based wind turbines by high voltage generator for the first time . The simulation and experimental results support the theoretical analysis and verifies the effectiveness of the proposed control strategy .%针对风电的高电压脱网问题,介绍了主要风电并网导则对高电压穿越的要求,对比分析了双馈风电机组低电压和高电压的电磁暂态特性,论证了双馈风电机组1.3倍额定电压的高电压穿越过程全程可控的可行性。提出了一种基于双馈变流器动态无功控制的高电压穿越控制策略和风电机组主控系统与变流器协同控制完成高电压穿越的实现方法,避免了 Crowbar 或 Chopper 保护动作对高电压穿越特性的不利影响。在 MATLAB/Simulink 中建立了2 MW 双馈风电机组高电压穿越仿真模型,实现了高电压穿越全过程仿真;利用高电压发生装置,在2 MW 双馈风电机组上进行了高电压穿越

  2. Neurologic complication after a roller coaster ride.

    Science.gov (United States)

    Sa Leitao, Davi; Mendonca, Dercio; Iyer, Harish; Kao, Cheng-Kai

    2012-01-01

    Neurologic complications after roller coaster rides are uncommon but potentially catastrophic. Physicians should have a high index of suspicion and prompt appropriate investigation. A 22-year-old healthy African American man presented with a 2-day history of constant occipital headache associated with vertigo, nausea, vomiting, and ambulatory dysfunction. Physical examination showed gait ataxia, slight dysmetria, and vertical nystagmus. Magnetic resonance imaging (MRI) of the brain showed early subacute ischemic infarct in the right cerebellum in the distribution of the right posterior inferior cerebellar artery. Magnetic resonance angiography of the neck showed focal dissection of the right vertebral artery at C1 through C2 level. On subsequent questioning, the patient recollected riding a roller coaster 2 weeks before the onset of symptoms. Anticoagulation with heparin was started, and the patient was bridged to oral warfarin. After a 5-day uneventful hospital course, symptoms improved and patient was discharged on oral anticoagulation. Cervicocephalic arterial dissections after roller coaster rides are rarely described in literature. The acceleration and abrupt changes of direction might lead to indirect trauma that is applied to mobile portions of the cervicocephalic arteries leading to intimal tears. Magnetic resonance angiography combined with axial T1-weighted cervical MRI is preferred because it is a high-sensitive, noninvasive test. The rationale for the use of anticoagulants or antiplatelets in patients with cervicocephalic arterial dissection is to prevent early recurrence and infarction. However, a meta-analysis failed to show significant difference in the rates of disability or death between both groups. Therefore, the decision for medical treatment should be made in a case-by-case basis.

  3. Calming the Waters or Riding the Waves?

    DEFF Research Database (Denmark)

    Rydén, Pernille; Kottika, Efthymia; Hossain, Muhammad Ismail;

    Traditional consumer anger management tends to be compromising rather than empowering the brand. This paper conceptualizes and provides a case example on how consumer empowerment and negative emotions can in fact create opportunities for companies to ride the waves of consumer anger in a way...... that strengthens their brand. The consumers are empowered by ‘letting this anger out’, from which firms can gain huge attention. Companies can utilize such situations to inform people on their brands’ core values, and initiate discussions of larger societal relevance, which improves the brand awareness and value...

  4. Floating air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  5. Feasibility Checking for Dial-a-Ride Problems

    DEFF Research Database (Denmark)

    Haugland, Dag; Ho, Sin C.

    Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue...

  6. Feasibility testing for dial-a-ride problems

    DEFF Research Database (Denmark)

    Haugland, Dag; Ho, Sin C.

    Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue...

  7. Feasibility Testing for Dial-a-Ride Problems

    DEFF Research Database (Denmark)

    Haugland, Dag; Ho, Sin C.

    2010-01-01

    Hunsaker and Savelsbergh have proposed an algorithm for testing feasibility of a route in the solution to the dial-a-ride problem. The constraints that are checked are load capacity constraints, time windows, ride time bounds and wait time bounds. The algorithm has linear running time. By virtue...

  8. Examination of a University-Affiliated Safe Ride Program

    Science.gov (United States)

    Gieck, D. Joseph; Slagle, David M.

    2010-01-01

    A university-affiliated safe ride program was evaluated to determine whether these programs can reduce drunk-driving related costs. Data was collected from 187 safe ride passengers during three nights of operation. Among the passengers, 93% were enrolled at a local University, 31% were younger than 21, and 40% reported a prior alcohol-related…

  9. Enhancing Urban Mobility: Integrating Ride-sharing and Public Transit

    NARCIS (Netherlands)

    M. Stiglic (Mitja); N.A.H. Agatz (Niels); M.W.P. Savelsbergh (Martin); M. Gradisar (Mirko)

    2016-01-01

    textabstractSeamless integration of ride-sharing and public transit may offer fast, reliable, and affordable transfer to and from transit stations in suburban areas thereby enhancing mobility of residents. We investigate the potential benefits of such a system, as well as the ride-matching technolog

  10. Analyzing Forces on Amusement Park Rides with Mobile Devices

    Science.gov (United States)

    Vieyra, Rebecca E.; Vieyra, Chrystian

    2014-01-01

    Mobile device accelerometers are a simple and easy way for students to collect accurate and detailed data on an amusement park ride. The resulting data can be graphed to assist in the creation of force diagrams to help students explain their physical sensations while on the ride. This type of activity can help students overcome some of the…

  11. Coordination of Advertising Free Riding in Hybrid Channel Supply Chain

    Directory of Open Access Journals (Sweden)

    Jin Sha

    2016-01-01

    Full Text Available Advertising is a crucial tool for demand creation and market expansion; enterprises in supply chain use it widely to increase sales and improve profits. But the homogeneity of products sold in hybrid channel supply chain magnifies the positive externalities of advertising and leads to serious free-riding problem. To coordinate the supply chain effectively, firstly, this paper classifies hybrid channel supply chain based on the relationship between members and selects horizontally integrated, vertically integrated, and decentralized hybrid channel supply chains as research objects. Then, a demand function considering the common effect of price and advertising is proposed and coordination schemes for different types of supply chains are designed. Finally, a sensitivity analysis is performed to assess the impact of parameters on coordination using orthogonal experiment.

  12. L-Ornithine Schiff base-copper and -cadmium complexes as new proteasome inhibitors and apoptosis inducers in human cancer cells.

    Science.gov (United States)

    Zhang, Zhongyu; Bi, Caifeng; Fan, Yuhua; Zhang, Nan; Deshmukh, Rahul; Yan, Xingchen; Lv, Xiuwen; Zhang, Pengfei; Zhang, Xia; Dou, Q Ping

    2015-01-01

    Ubiquitin-proteasome system (UPS) plays a crucial role in many cellular processes such as cell cycle, proliferation and apoptosis. Aberrant activation of UPS may result in cellular transformation or other altered pathological conditions. Previous studies have shown that metal-based complexes could inhibit proteasome activity and induce apoptosis in certain human cancer cells. In the current study, we report that the cadmium and copper complexes with heterocycle-ornithine Schiff base are potent inhibitors of proteasomal chymotrypsin-like (CT-like) activity, leading to induction of apoptosis in cancer cells. Two novel copper-containing complexes and two novel cadmium-containing complexes with different heterocycle-ornithine Schiff base structures as ligands were synthesized and characterized. We found that complexes Cu1, Cd1 and Cd2 show proteasome-inhibitory activities in human breast cancer MDA-MB-231 and human prostate cancer LNCaP cells, resulting in the accumulation of p27, a natural proteasome substrate and other ubiquitinated proteins, followed by the induction of apoptosis. Our results suggest that metal complexes with heterocycle-ornithine Schiff base have proteasome-inhibitory capabilities and have the potential to be developed into novel anticancer drugs.

  13. Cadmium and zinc relationships

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.; Piscator, M.

    1978-08-01

    Higher mammals, such as homo sapiens, accumulate zinc in kidney cortex almost equimolarly with cadmium. A different pattern seems to be present in liverthere is a limited increase of zinc in two species of large farm animals compared with a marked increase in the laboratory. In large farm animals, an equimolar increase of zinc with cadmium in renal cortex seems to indicate that the form of metallothionein that binds equal amounts of cadmium and zinc in present. Differences in cadmium and zinc relationships in large animals and humans compared with laboratory animals must be carefully considered. (4 graphs, 26 references)

  14. Exposure dose response relationships of the freshwater bivalve Hyridella australis to cadmium spiked sediments

    Energy Technology Data Exchange (ETDEWEB)

    Marasinghe Wadige, Chamani P.M., E-mail: chamani.marasinghe.wadige@canberra.edu.au; Maher, William A.; Taylor, Anne M.; Krikowa, Frank

    2014-07-01

    organisms, which suggests that H. australis has some tolerance to cadmium. The metallothionein like protein fraction played an important role in the sequestration and detoxification of cadmium and the amount sequestered in this fraction increased with increased cadmium exposure. The highest percentage of biologically active cadmium was associated with the lysosome + microsome and mitochondrial fractions. Cadmium concentrations in these two fractions of cadmium exposed organisms were significantly higher with respect to controls. Total antioxidant capacity decreased with increased cadmium exposure and tissue dose. Lipid peroxidation increased and lysosomal membrane stability decreased significantly with increased cadmium exposure and tissue dose. Based on exposure–dose–response analysis in this study, H. australis would be a suitable organism for assessing cadmium sediment exposure and toxicity.

  15. Intense pulsed light treatment of cadmium telluride nanoparticle-based thin films.

    Science.gov (United States)

    Dharmadasa, Ruvini; Lavery, Brandon; Dharmadasa, I M; Druffel, Thad

    2014-04-09

    The search for low-cost growth techniques and processing methods for semiconductor thin films continues to be a growing area of research; particularly in photovoltaics. In this study, electrochemical deposition was used to grow CdTe nanoparticulate based thin films on conducting glass substrates. After material characterization, the films were thermally sintered using a rapid thermal annealing technique called intense pulsed light (IPL). IPL is an ultrafast technique which can reduce thermal processing times down to a few minutes, thereby cutting production times and increasing throughput. The pulses of light create localized heating lasting less than 1 ms, allowing films to be processed under atmospheric conditions, avoiding the need for inert or vacuum environments. For the first time, we report the use of IPL treatment on CdTe thin films. X-ray diffraction (XRD), optical absorption spectroscopy (UV-Vis), scanning electron microscopy (SEM) and room temperature photoluminescence (PL) were used to study the effects of the IPL processing parameters on the CdTe films. The results found that optimum recrystallization and a decrease in defects occurred when pulses of light with an energy density of 21.6 J cm(-2) were applied. SEM images also show a unique feature of IPL treatment: the formation of a continuous melted layer of CdTe, removing holes and voids from a nanoparticle-based thin film.

  16. Modelling of Cadmium Transport in Soil-Crop System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for simulating cadmium transport in a soil-plant system was built using a commercial simu lating program named Powersim on the basis of input-output processes happening in the soil-plant system.Convective and dispersive transport processes of cadmium in soil profile are embedded. Simulations on a daily base have been done up to a total simulating time of 250 years. Results show that applications of sewage sludge and fertilizer at the simulated rates would only cause slight cadmium accumulations in each layer of the soil, and cadmium accumulation would be levelling off, reaching an equilibrium concentrations layer by layer downward after certain time. The time scale to reach an equilibrium concentration varies from 10 years for the top three layers to over 250 years for the bottom layers. Plant cadmium uptake would increase from 52 ug m-2 under initial soil cadmium concentrations to 65 μg m-2 under equilibrium soil cadmium concentrations, which would not exceed the maximum allowable cadmium concentration in wheat grains. Main parameters which influence cadmium accumulation and transport in soil are total cadmium input, rainfall, evaporation, plant uptake and soil properties.

  17. Tissue specific responses to cadmium-based quantum dots in the marine mussel Mytilus galloprovincialis

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Thiago Lopes [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Gomes, Tânia [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo (Norway); Mestre, Nélia C.; Cardoso, Cátia [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Bebianno, Maria João, E-mail: mbebian@ualg.pt [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2015-12-15

    Highlights: • Mussel gills are the main target for oxidative stress induced by Cd-based QDs. • Antioxidants responses induced by Cd-based QDs and dissolved Cd are mediated by different mechanisms. • CdTe QDs are more pro-oxidant Cd form when compared to dissolved Cd. • Differential tissue response indicated nano-specific effects. - Abstract: In recent years, Cd-based quantum dots (QDs) have generated interest from the life sciences community due to their potential applications in nanomedicine, biology and electronics. However, these engineered nanomaterials can be released into the marine environment, where their environmental health hazards remain unclear. This study investigated the tissue-specific responses related to alterations in the antioxidant defense system induced by CdTe QDs, in comparison with its dissolved counterpart, using the marine mussel Mytilus galloprovincialis. Mussels were exposed to CdTe QDs and dissolved Cd for 14 days at 10 μgCd L{sup −1} and biomarkers of oxidative stress [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (total, Se-independent and Se-dependent GPx) and glutathione-S-transferase (GST) activities] were analyzed along with Cd accumulation in the gills and digestive gland of mussels. Results show that both Cd forms changed mussels’ antioxidant responses with distinct modes of action (MoA). There were tissue- and time-dependent differences in the biochemical responses to each Cd form, wherein QDs are more pro-oxidant when compared to dissolved Cd. The gills are the main tissue affected by QDs, with effects related to the increase of SOD, GST and GPx activities, while those of dissolved Cd was associated to the increase of CAT activity, Cd accumulation and exposure time. Digestive gland is a main tissue for accumulation of both Cd forms, but changes in antioxidant enzyme activities are smaller than in gills. A multivariate analysis revealed that the antioxidant patterns are tissue dependent

  18. Frequency weighting filter design for automotive ride comfort evaluation

    Science.gov (United States)

    Du, Feng

    2016-07-01

    Few study gives guidance to design weighting filters according to the frequency weighting factors, and the additional evaluation method of automotive ride comfort is not made good use of in some countries. Based on the regularities of the weighting factors, a method is proposed and the vertical and horizontal weighting filters are developed. The whole frequency range is divided several times into two parts with respective regularity. For each division, a parallel filter constituted by a low- and a high-pass filter with the same cutoff frequency and the quality factor is utilized to achieve section factors. The cascading of these parallel filters obtains entire factors. These filters own a high order. But, low order filters are preferred in some applications. The bilinear transformation method and the least P-norm optimal infinite impulse response(IIR) filter design method are employed to develop low order filters to approximate the weightings in the standard. In addition, with the window method, the linear phase finite impulse response(FIR) filter is designed to keep the signal from distorting and to obtain the staircase weighting. For the same case, the traditional method produces 0.330 7 m • s-2 weighted root mean square(r.m.s.) acceleration and the filtering method gives 0.311 9 m • s-2 r.m.s. The fourth order filter for approximation of vertical weighting obtains 0.313 9 m • s-2 r.m.s. Crest factors of the acceleration signal weighted by the weighting filter and the fourth order filter are 3.002 7 and 3.011 1, respectively. This paper proposes several methods to design frequency weighting filters for automotive ride comfort evaluation, and these developed weighting filters are effective.

  19. Frequency Weighting Filter Design for Automotive Ride Comfort Evaluation

    Institute of Scientific and Technical Information of China (English)

    DU Feng

    2016-01-01

    Few study gives guidance to design weighting filters according to the frequency weighting factors, and the additional evaluation method of automotive ride comfort is not made good use of in some countries. Based on the regularities of the weighting factors, a method is proposed and the vertical and horizontal weighting filters are developed. The whole frequency range is divided several times into two parts with respective regularity. For each division, a parallel filter constituted by a low-and a high-pass filter with the same cutoff frequency and the quality factor is utilized to achieve section factors. The cascading of these parallel filters obtains entire factors. These filters own a high order. But, low order filters are preferred in some applications. The bilinear transformation method and the least P-norm optimal infinite impulse response(IIR) filter design method are employed to develop low order filters to approximate the weightings in the standard. In addition, with the window method, the linear phase finite impulse response(FIR) filter is designed to keep the signal from distorting and to obtain the staircase weighting. For the same case, the traditional method produces 0.330 7 m•s–2 weighted root mean square(r.m.s.) acceleration and the filtering method gives 0.311 9 m•s–2 r.m.s. The fourth order filter for approximation of vertical weighting obtains 0.313 9 m•s–2 r.m.s. Crest factors of the acceleration signal weighted by the weighting filter and the fourth order filter are 3.002 7 and 3.011 1, respectively. This paper proposes several methods to design frequency weighting filters for automotive ride comfort evaluation, and these developed weighting filters are effective.

  20. Tissue specific responses to cadmium-based quantum dots in the marine mussel Mytilus galloprovincialis.

    Science.gov (United States)

    Rocha, Thiago Lopes; Gomes, Tânia; Mestre, Nélia C; Cardoso, Cátia; Bebianno, Maria João

    2015-12-01

    In recent years, Cd-based quantum dots (QDs) have generated interest from the life sciences community due to their potential applications in nanomedicine, biology and electronics. However, these engineered nanomaterials can be released into the marine environment, where their environmental health hazards remain unclear. This study investigated the tissue-specific responses related to alterations in the antioxidant defense system induced by CdTe QDs, in comparison with its dissolved counterpart, using the marine mussel Mytilus galloprovincialis. Mussels were exposed to CdTe QDs and dissolved Cd for 14 days at 10 μgCd L(-1) and biomarkers of oxidative stress [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (total, Se-independent and Se-dependent GPx) and glutathione-S-transferase (GST) activities] were analyzed along with Cd accumulation in the gills and digestive gland of mussels. Results show that both Cd forms changed mussels' antioxidant responses with distinct modes of action (MoA). There were tissue- and time-dependent differences in the biochemical responses to each Cd form, wherein QDs are more pro-oxidant when compared to dissolved Cd. The gills are the main tissue affected by QDs, with effects related to the increase of SOD, GST and GPx activities, while those of dissolved Cd was associated to the increase of CAT activity, Cd accumulation and exposure time. Digestive gland is a main tissue for accumulation of both Cd forms, but changes in antioxidant enzyme activities are smaller than in gills. A multivariate analysis revealed that the antioxidant patterns are tissue dependent, indicating nano-specific effects possibly associated to oxidative stress and changes in redox homeostasis.

  1. Head motions while riding roller coasters: implications for brain injury.

    Science.gov (United States)

    Pfister, Bryan J; Chickola, Larry; Smith, Douglas H

    2009-12-01

    The risk of traumatic brain injury (TBI) while riding roller coasters has received substantial attention. Case reports of TBI around the time of riding roller coasters have led many medical professionals to assert that the high gravitational forces (G-forces) induced by roller coasters pose a significant TBI risk. Head injury research, however, has shown that G-forces alone cannot predict TBI. Established head injury criterions and procedures were employed to compare the potential of TBI between daily activities and roller coaster riding. Three-dimensional head motions were measured during 3 different roller coaster rides, a pillow fight, and car crash simulations. Data was analyzed and compared with published data, using similar analyses of head motions. An 8.05 m/s car crash lead to the largest head injury criterion measure of 28.1 and head impact power of 3.41, over 6 times larger than the roller coaster rides of 4.1 and 0.36. Notably, the linear and rotational components of head acceleration during roller coaster rides were milder than those induced by many common activities. As such, there appears to be an extremely low risk of TBI due to the head motions induced by roller coaster rides.

  2. Cadmium exposure and breast cancer risk.

    Science.gov (United States)

    McElroy, Jane A; Shafer, Martin M; Trentham-Dietz, Amy; Hampton, John M; Newcomb, Polly A

    2006-06-21

    Cadmium, a highly persistent heavy metal, has been categorized as a probable human carcinogen by the U.S. Environmental Protection Agency. Primary exposure sources include food and tobacco smoke. We carried out a population-based case-control study of 246 women, aged 20-69 years, with breast cancer and 254 age-matched control subjects. We measured cadmium levels in urine samples by inductively coupled plasma mass spectrometry and conducted interviews by telephone to obtain information on known breast cancer risk factors. Odds ratios (ORs) and 95% confidence intervals (CIs) for breast cancer by creatinine-adjusted cadmium levels were calculated by multivariable analysis. Statistical tests were two-sided. Women in the highest quartile of creatinine-adjusted cadmium level (> or = 0.58 microg/g) had twice the breast cancer risk of those in the lowest quartile (cadmium level (P(trend) = .01). Based on this study, the absolute risk difference is 45 (95% CI = 0 to 77) per 100,000 given an overall breast cancer rate of 124 per 100,000. Whether increased cadmium is a causal factor for breast cancer or reflects the effects of treatment or disease remains to be determined.

  3. Synthesis, Crystal Structure, and Luminescent Properties of New Zinc(II and Cadmium(II Metal-Organic Frameworks Based on Flexible Bis(imidazol-1-ylalkane Ligands

    Directory of Open Access Journals (Sweden)

    Marina Barsukova

    2016-10-01

    Full Text Available New metal-organic frameworks (MOFs based on zinc and cadmium ions, terephthalic acid, and flexible ligands 1,5-bis(imidazol-1-ylpentane or 1,6-bis(imidazol-1-ylhexane were prepared and characterized by X-ray diffraction, thermorgavimetric analysis and IR spectroscopy. The imidazolyl ligands were prepared by a new robust procedure involving the reaction between imidazole and 1,5-dibromopentane or 1,6-dibromohexane in a superbasic medium (KOH in DMSO. MOFs based on 1,5-bis(imidazol-1-ylpentane had diamond topology (dia and are triply interpenetrated. Ligands with longer spacer 1,6-bis(imidazol-1-ylhexane, terephthalate ions and zinc(II ions formed five-fold interpenetrated metal-organic framework also with dia topology, while cadmium(II ions with the same ligands formed eight-connected uninodal net with a very rare self-penetrated topological type ilc and a point symbol 424.5.63. The influence of the chemical composition of MOFs on their photoluminescent properties is investigated and discussed in detail.

  4. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  5. Analyzing Forces on Amusement Park Rides with Mobile Devices

    Science.gov (United States)

    Vieyra, Rebecca E.; Vieyra, Chrystian

    2014-03-01

    Mobile device accelerometers are a simple and easy way for students to collect accurate and detailed data on an amusement park ride. The resulting data can be graphed to assist in the creation of force diagrams to help students explain their physical sensations while on the ride. This type of activity can help students overcome some of the conceptual difficulties often associated with understanding centripetal force and typical "elevator-type problems" that are inherent in so many amusement park rides that move, lift, and drop riders. This article provides some sample data and examples from a visit to Six Flags Great America.

  6. Dual-channel optical sensing platform for detection of diminazene aceturate based on thioglycolic acid-wrapped cadmium telluride/cadmium sulfide quantum dots.

    Science.gov (United States)

    Hao, Chenxia; Zhou, Tao; Liu, Shaopu; Wang, Linlin; Huang, Bowen; Kuang, Nianxi; He, Youqiu

    2016-06-15

    A dual-channel optical sensing platform which combines the advantages of dual-wavelength overlapping resonance Rayleigh scattering (DWO-RRS) and fluorescence has been designed for the detection of diminazene aceturate (DA). It is based on the use of thioglycolic acid-wrapped CdTe/CdS quantum dots (Q-dots). In the absence of DA, the thioglycolic acid-wrapped CdTe/CdS Q-dots exhibit the high fluorescence spectrum and low RRS spectrum, so are selected to develop an easy-to-get system. In the presence of DA, the thioglycolic acid-wrapped CdTe/CdS Q-dots and DA form a complex through electrostatic interaction, which result in the RRS intensity getting enhanced significantly with new RRS peaks appearing at 317 and 397 nm; the fluorescence is powerfully quenched. Under optimum conditions, the scattering intensities of the two peaks are proportional to the concentration of DA in the range of 0.0061-3.0 μg mL(-1). The detection limits for the two single peaks are 4.1 ng mL(-1) and 3.3 ng mL(-1), while that of the DWO-RRS method is 1.8 ng mL(-1), indicating that the DWO-RRS method has high sensitivity. Besides, the fluorescence also exhibits good linear range from 0.0354 to 10.0 μg mL(-1) with a detection limit of 10.6 ng mL(-1). In addition, the system has been applied to the detection of DA in milk samples with satisfactory results.

  7. Construction of a carbon ionic liquid paste electrode based on multi-walled carbon nanotubes-synthesized Schiff base composite for trace electrochemical detection of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas, E-mail: afkhami@basu.ac.ir [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Khoshsafar, Hosein [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Bagheri, Hasan [Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran (Iran, Islamic Republic of); Madrakian, Tayyebeh [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

    2014-02-01

    A simple, highly sensitive and selective carbon nanocomposite electrode has been developed for the electrochemical trace determination of cadmium. This sensor was designed by incorporation of multi-walled carbon nanotubes (MWCNTs) and a new synthesized Schiff base into the carbon paste ionic liquid electrode (CPE{sub IL}) which provides remarkably improved sensitivity and selectivity for the electrochemical stripping assay of Cd(II). The detection limit of the method was found to be 0.08 μg L{sup −1} (S/N = 3) that is lower than the maximum contaminant level of Cd(II) allowed by the Environmental Protection Agency (EPA) in standard drinking waters. The proposed electrode exhibits good applicability for monitoring Cd(II) in various real samples. - Highlights: • A new nanocomposite was prepared and applied to the modification of CPE. • The prepared nanocomposite was characterized by scanning electron microscopy. • The electrode was used to the rapid and selective determination of Cd(II)

  8. Cadmium Alternatives

    Science.gov (United States)

    2012-08-01

    pollutant, hazardous substance, hazardous air pollutant, & hazardous waste Safety and environmental regulations RoHS, ELV, WEEE, REACH, et. al...Electro- passivated) High Phos 20 um EN PTFE 5 umHigh Phos 20 um Top LayerBase Layer * “Pass” indicates no blistering , peeling, flaking or separation

  9. Discourage free riding in Peer-to-Peer file sharing systems with file migration and workload balancing approach

    Institute of Scientific and Technical Information of China (English)

    YU Yijiao; JIN Hai

    2007-01-01

    Free riding is a great challenge to the development and maintenance of Peer-to-Peer(P2P)networks.A file migration and workload balancing based approach (FMWBBA)to discourage free riding is proposed in this paper.The heart of our mechanism is to migrate some shared files from the overloaded peers to the neighboring free riders automatically and transparently,which enforces free riders to offer services when altruistic peers are heavily overloaded.File migration is a key issue in our approach,and some related strategies are discussed.A simulation is designed to verify this approach,and the results show that it can not only alleviate free riding,but also improve the Quality of Service(QoS)and robustness of P2P networks efficiently.

  10. Overcoming limitations of the ERP method with Residue Iteration Decomposition (RIDE): a demonstration in go/no-go experiments.

    Science.gov (United States)

    Ouyang, Guang; Schacht, Annekathrin; Zhou, Changsong; Sommer, Werner

    2013-03-01

    The usefulness of the event-related potential (ERP) method can be compromised by violations of the underlying assumptions, for example, confounding variations of latency and amplitude of ERP components within and between conditions. Here we show how the ERP subtraction method might yield misleading information due to latency variability of ERP components. We propose a solution to this problem by correcting for latency variability using Residue Iteration Decomposition (RIDE), demonstrated with data from representative go/no-go experiments. The overlap of N2 and P3 components in go/no-go data gives rise to spurious topographical localization of the no-go-N2 component. RIDE decomposes N2 and P3 based on their latency variability. The decomposition restored the N2 topography by removing the contamination from latency-variable late components. The RIDE-derived N2 and P3 give a clearer insight about their functional relevance in the go/no-go paradigm.

  11. Residue iteration decomposition (RIDE): A new method to separate ERP components on the basis of latency variability in single trials.

    Science.gov (United States)

    Ouyang, Guang; Herzmann, Grit; Zhou, Changsong; Sommer, Werner

    2011-12-01

    Event-related brain potentials (ERPs) are important research tools because they provide insights into mental processing at high temporal resolution. Their usefulness, however, is limited by the need to average over a large number of trials, sacrificing information about the trial-by-trial variability of latencies or amplitudes of specific ERP components. Here we propose a novel method based on an iteration strategy of the residues of averaged ERPs (RIDE) to separate latency-variable component clusters. The separated component clusters can then serve as templates to estimate latencies in single trials with high precision. By applying RIDE to data from a face-priming experiment, we separate priming effects and show that they are robust against latency shifts and within-condition variability. RIDE is useful for a variety of data sets that show different degrees of variability and temporal overlap between ERP components.

  12. Analysis on the vehicle ride comfort based on vehicle-bridge coupled vibration%基于车桥耦合振动的车辆舒适性分析

    Institute of Scientific and Technical Information of China (English)

    王贵春; 李武生

    2016-01-01

    A 3-dimensional model of a highway cable-stayed bridge with a long span and a vehicle spatial model with 9 degrees of freedom were respectively established according to finite element method and D'Alembert theory.The two subsystems of vehicle and bridge were coupled by compatible conditions of displacement and force to solve the vibration differential equations of the vehicle-bridge coupled system.The iterative calculation command stream to solve differential coupled vibration equations of vehicle-bridge systems was compiled in APDL language in ANSYS computer software.The method to evaluate the vehicle ride comfort was established according to the criteria in ISO2631 -1 -1997.The vehicle dynamic responses and ride comfort were analyzed considering different vehicle speeds and vehicle gravities when multiple vehicles crossed the Fujian Changmen cable-stayed bridge,which has a main span of 550 m.The calculations indicate that the dynamic responses of vehicles increase with increases in vehicle speed,making the ride less comfortable;the dynamic responses of vehicles decrease as vehicle gravity increases,making the ride more comfortable.%研究车桥耦合振动引起的车辆舒适性问题对合理设计桥梁结构,从而减小车桥耦合振动响应和提高司乘人员的乘坐质量具有重要意义。分别利用有限元法和达郎伯原理建立了大跨度公路斜拉桥三维模型和9个自由度的车辆空间模型。通过位移和力的协调条件将车桥两个子系统耦合起来,求解车桥系统的振动微分方程。基于计算机软件ANSYS 中的 APDL 语言编写了求解振动微分方程迭代计算的命令流,以 ISO2631-1-1997标准建立了评价车辆舒适性的方法,并据此分析了主跨为550 m 的福建长门大桥在多车辆通过时考虑不同车速和车重时的车辆动力响应和车辆舒适性。计算结果表明,随着车速的增加,车辆的动力响应增加,舒适性变差;而随着车

  13. Mechanical characterization based in the impact test of the cadmium-zinc and cadmium-zinc-copper alloys; Caracterizacion mecanica basada en la prueba de impacto de las aleaciones cadmio-zinc y cadmio-zinc-cobre

    Energy Technology Data Exchange (ETDEWEB)

    Casolco, S.R.; Torres V, G. [Instituto de Investigacion en Materiales, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-360, 04510 Mexico D.F. (Mexico)

    1999-11-01

    The present work is a study carried out in the Institute for Materials Research of the UNAM, of the alloys cadmium-zinc and cadmium-zinc-copper with the fundamental objective of knowing their behavior to the impact that which will allow to establish structural applications of these alloys. This work consists mainly on impact tests of the type Charpy at different temperatures in a range of - 150 Centigrade to 250 Centigrade and to study their fracture morphologies with the help of a scanning electron microscope to recognize the tendency of the material toward the fracture of the fragile type and to determine the ductile-fragile transition. (Author)

  14. Bipolar resistive switching based on bis(8-hydroxyquinoline)cadmium complex: Mechanism and non-volatile memory application

    Institute of Scientific and Technical Information of China (English)

    Wang Ying; Yang Ting; Xie Ji-Peng; Lü Wen-Li; Fan Guo-Ying; Liu Su

    2013-01-01

    Stable and persistent bipolar resistive switching was observed in an organic diode with the structure of indium-tin oxide (ITO)/bis(8-hydroxyquinoline) cadmium (Cdq2)/Al.Aggregate formation and electric field driven trapping and detrapping of charge carriers in the aggregate states that lie in the energy gap of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the organic molecule were proposed as the mechanism of the observed bipolar resistive switching,and this was solidly supported by the results of AFM investigations.Repeatedly set,read,and reset measurements demonstrated that the device is potentially applicable in non-volatile memories.

  15. Low voltage ride through strategies for SCIG wind turbines in distributed power generation systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Teodorescu, Remus; Rodriguez, Pedro;

    2008-01-01

    for the existing ones, as, at the present time, the classical squirrel cage induction generatorpsilas wind turbines still represent a 30% of the wind power production. Reinforcing the operation of such facilities can be performed taking advantage of the increasing number of modern power systems that are linked...... improving the fault-ride-through capability of a classical fixed speed wind turbine, based on a squirrel cage induction generator, installed in its neighborhood....

  16. Evaluation of ride quality prediction methods for operational military helicopters

    Science.gov (United States)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots' discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  17. Port Authority of Allegheny County Park and Rides

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset includes the GIS shapefile for Port Authority of Allegheny County's Park and Ride facilities. This layer is updated annually or on an as-needed basis...

  18. An association between urinary cadmium and urinary stone disease in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    Energy Technology Data Exchange (ETDEWEB)

    Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Limpatanachote, Pisit; Krintratun, Somyot [Department of Internal Medicine, Mae Sot General Hospital, Tak 63110 (Thailand)

    2011-05-15

    Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: {yields} Excessive calciuria is the major risk of urinary stone formation. {yields} We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. {yields} The rate of urinary stones increases with increasing urinary cadmium. {yields} Urinary calcium excretion increases with increasing urinary cadmium. {yields} Elevated calciuria induced by cadmium may increase the risk of urinary stones.

  19. Stability of a Light Sail Riding on a Laser Beam

    CERN Document Server

    Manchester, Zachary

    2016-01-01

    The stability of a light sail riding on a laser beam is analyzed both analytically and numerically. Conical sails on Gaussian beams, which have been studied in the past, are shown to be unstable in general. A new architecture for a passively stable sail and beam configuration is proposed. The novel spherical shell sail design is capable of "beam riding" without the need for active feedback control. Full three-dimensional ray-tracing simulations are performed to verify our analytical results.

  20. Vehicle Ride Height Change Due To Radial Expansion Of Tires

    Directory of Open Access Journals (Sweden)

    Čavoj Ondřej

    2015-11-01

    Full Text Available In general, tire deformations caused by wheel rotation are not taken into account when developing vehicle aerodynamics. On the road the tires radially expand as speed increases, which affects the actual ride height of a vehicle. In turn this often increases the real aerodynamic drag compared to values obtained using CFD or a wind tunnel as the mass flow across the relatively rough underbody increases with ground clearance. In this study, on-road ride heights were measured while running a vehicle in a straight line with fixed velocity whilst the aerodynamic lift of the vehicle was determined in a wind tunnel. Subsequently, the relationships between ride height and axle load were obtained by loading the vehicle at standstill with ballast. By comparing the ride heights at high and very low velocities with expected vertical displacement caused purely by aerodynamic lift force as computed according to the ride height - axle load equations, the ride height change due to tire radial expansion was determined.

  1. Zinc(II) and Cadmium(II) complexes with N4-coordinate pyrazole based ligand: Syntheses, characterization and structure

    Science.gov (United States)

    Solanki, Ankita; Sadhu, Mehul H.; Kumar, Sujit Baran; Mitra, Partho

    2014-11-01

    A series of six new mononuclear zinc(II) complexes of the type [Zn(X)(dbdmp)]Y (1-6) (X = N3-/NCO-/NCS-, Y = ClO4-/PF6-, and dbdmp = N,N-diethyl-N‧,N‧-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)ethane-1,2-diamine), two binuclear cadmium(II) complexes [{Cd(dbdmp)}2(μ-N3)2](Y)2 (7-8) and three mononuclear cadmium(II) complexes [Cd(NCO)(dbdmp)]Y (Y = ClO4-/PF6-) (9-10) and [Cd(NCS)2(dbdmp)] (11) have been synthesized and characterized by physico-chemical methods. Crystal structures of the complexes [Zn(N3)(dbdmp)]ClO4 (1), [{Cd(dbdmp)}2(μ-N3)2](ClO4)2 (7), [Cd(NCO)(dbdmp)]ClO4 (9) and [Cd(NCS)2(dbdmp)] (11) have been solved by single crystal X-ray diffraction studies and showed that [Zn(N3)(dbdmp)]ClO4 (1) and [Cd(NCO)(dbdmp)]ClO4 (9) have distorted trigonal bipyramidal geometry, [Cd(NCS)2(dbdmp)] (11) and [(dbdmp)Cd(μ-N3)]2(ClO4)2 (7) have distorted octahedral geometry.

  2. Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2014-06-01

    Full Text Available This paper presents a fast coordinated control scheme of the rotor side converter (RSC, the Direct Current (DC chopper and the grid side converter (GSC of doubly fed induction generator (DFIG wind turbine generators (WTGs to improve the low voltage ride through (LVRT and high voltage ride through (HVRT capability of the DFIG WTGs. The characteristics of DFIG WTGs under voltage sags and swells were studied focusing on the DFIG WTG stator flux and rotor voltages during the transient periods of grid voltage changes. The protection schemes of the rotor crowbar circuit and the DC chopper circuit were proposed considering the characteristics of the DFIG WTGs during voltage changes. The fast coordinated control of RSC and GSC were developed based on the characteristic analysis in order to realize efficient LVRT and HVRT of the DFIG WTGs. The proposed fast coordinated control schemes were verified by time domain simulations using Matlab-Simulink.

  3. A DFIG wind turbine ride-through system. Influence on the energy production

    Science.gov (United States)

    Petersson, A.; Lundberg, S.; Thiringer, T.

    2005-07-01

    The influence of a voltage sag ride-through system on the energy production of a doubly-fed induction generator (DFIG) wind turbine is investigated. Using simulations, a candidate ride-through system based on insulated gate bipolar transistor (IGBT) modules with high current rating and with the option of having antiparallel thyristors, which can quickly disconnect the stator of the DFIG from the grid, is developed. It has been found that, by increasing the current rating of the converter IGBTs, the losses of the converter can be reduced. However, if antiparallel thyristors have to be connected between the stator and the grid in order to achieve a fast disconnection of the stator circuit, the overall losses of the total system increase instead. Copyright

  4. Cadmium induces transcription independently of intracellular calcium mobilization.

    Directory of Open Access Journals (Sweden)

    Brooke E Tvermoes

    Full Text Available BACKGROUND: Exposure to cadmium is associated with human pathologies and altered gene expression. The molecular mechanisms by which cadmium affects transcription remain unclear. It has been proposed that cadmium activates transcription by altering intracellular calcium concentration ([Ca(2+](i and disrupting calcium-mediated intracellular signaling processes. This hypothesis is based on several studies that may be technically problematic; including the use of BAPTA chelators, BAPTA-based fluorescent sensors, and cytotoxic concentrations of metal. METHODOLOGY/PRINCIPAL FINDING: In the present report, the effects of cadmium on [Ca(2+](i under non-cytotoxic and cytotoxic conditions was monitored using the protein-based calcium sensor yellow cameleon (YC3.60, which was stably expressed in HEK293 cells. In HEK293 constitutively expressing YC3.60, this calcium sensor was found to be insensitive to cadmium. Exposing HEK293::YC3.60 cells to non-cytotoxic cadmium concentrations was sufficient to induce transcription of cadmium-responsive genes but did not affect [Ca(2+](i mobilization or increase steady-state mRNA levels of calcium-responsive genes. In contrast, exposure to cytotoxic concentrations of cadmium significantly reduced intracellular calcium stores and altered calcium-responsive gene expression. CONCLUSIONS/SIGNIFICANCE: These data indicate that at low levels, cadmium induces transcription independently of intracellular calcium mobilization. The results also support a model whereby cytotoxic levels of cadmium activate calcium-responsive transcription as a general response to metal-induced intracellular damage and not via a specific mechanism. Thus, the modulation of intracellular calcium may not be a primary mechanism by which cadmium regulates transcription.

  5. ERGONOMIC ANALYSIS OF A HORSE-DRAWN CARRIAGE USED FOR A JOY RIDE IN INDIA.

    Science.gov (United States)

    Mukhopadhyay, Prabir; Vinzuda, Vipul; Naik, Suhas; Karthikeyan, Vignesh; Kumar, Pawan

    2014-06-01

    Horse-drawn carriages popularly known as Tanga in India provide a popularjoy ride. Such vehicles were selected from two cites in Central India and the other from a city in Western India, based on complaints from the users that these vehicles were not comfortable to ride. Twelve male and twelve female participants were selected for the user study. Two of the members of the research team travelled on the vehicle on twelve trips over a 7 kilometer stretch (considered to be the maximum stretch for a Tanga ride). The study comprised three phases; direct observation and activity analysis, a questionnaire study and another questionnaire study of body part discomfort, with the aim to get an insight into the ergonomic design issues of the vehicle. There were gross mismatches in the design and human anthropometric dimensions together with other issues like safety and reliability involved. Based on the initial observations, four concept prototypes were developed which were later handed to the respective authorities for further implementation.

  6. Annoyance rate evaluation method on ride comfort of vehicle suspension system

    Science.gov (United States)

    Tang, Chuanyin; Zhang, Yimin; Zhao, Guangyao; Ma, Yan

    2014-03-01

    The existing researches of the evaluation method of ride comfort of vehicle mainly focus on the level of human feelings to vibration. The level of human feelings to vibration is influenced by many factors, however, the ride comfort according to the common principle of probability and statistics and simple binary logic is unable to reflect these uncertainties. The random fuzzy evaluation model from people subjective response to vibration is adopted in the paper, these uncertainties are analyzed from the angle of psychological physics. Discussing the traditional evaluation of ride comfort during vehicle vibration, a fuzzily random evaluation model on the basis of annoyance rate is proposed for the human body's subjective response to vibration, with relevant fuzzy membership function and probability distribution given. A half-car four degrees of freedom suspension vibration model is described, subject to irregular excitations from the road surface, with the aid of software Matlab/Simulink. A new kind of evaluation method for ride comfort of vehicles is proposed in the paper, i.e., the annoyance rate evaluation method. The genetic algorithm and neural network control theory are used to control the system. Simulation results are obtained, such as the comparison of comfort reaction to vibration environments between before and after control, relationship of annoyance rate to vibration frequency and weighted acceleration, based on ISO 2631/1(1982), ISO 2631-1(1997) and annoyance rate evaluation method, respectively. Simulated assessment results indicate that the proposed active suspension systems prove to be effective in the vibration isolation of the suspension system, and the subjective response of human being can be promoted from very uncomfortable to a little uncomfortable. Furthermore, the novel evaluation method based on annoyance rate can further estimate quantitatively the number of passengers who feel discomfort due to vibration. A new analysis method of vehicle

  7. Cadmium status in Egypt

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is inferred from these studies that releases of Cd are still increasing and it is recommended that measures must be taken to reduce emissions of cadmium. Any cadmium discharged into the Egyptian environment may move from one compartment to another at varying rates,resulting in an accumulation in compartments such as soils and biota. Such accumulation can be expected to increase with continued emissions,and attention should be given to all sources of cadmium, natural as well as anthropogenic especially in the industrial cities in Egypt. Cadmium present in sewage, as well as industrial effluent (also, other liquid and solid wastes) and sewage sludge will increase levels in soils and is xpected to contribute to dietary levels and body burdens. The current information indicates that such effects may have to be evaluated over long periods of time, possibly as long as 50 - 100 years.

  8. Cooperative control of VSC-HVDC connected offshore wind farm with Low-Voltage Ride-Through capability

    DEFF Research Database (Denmark)

    Liu, Yan; Wang, Xiongfei; Chen, Zhe

    2012-01-01

    The Low-Voltage Ride-Through (LVRT) has become an important grid requirement for offshore wind farms connecting with Voltage Source Converter based High Voltage Direct Current (VSC-HVDC) links. In this paper, a cooperative control strategy with LVRT ability is proposed for a VSC-HVDC connected va...

  9. Evaluation of Asphalt Concrete Pavement Based on Passenger Ride Comfort Level%基于驾乘舒适性的沥青混凝土路面评价

    Institute of Scientific and Technical Information of China (English)

    王锋; 张金喜

    2014-01-01

    In order to provide a theoretical basis for the ride comfort level evaluation, daily management,and maintenance of asphalt concrete pavement,the performance parameters and three-directional acceleration data of highway pavements were measured indoors and outdoors. Using these data,the relationship between the mean square of weighted acceleration and the pavement performance was studied. A linear regression equation that reflects the relationship between the root mean square of weighed acceleration,speed,and roughness was obtained by fitting 214 groups of experimental data. In addition,the outdoor experimental results were verified using a driving simulator. The results show that the root mean square of weighed acceleration is strongly correlated with roughness,moderately correlated with the speed,and weakly correlated with the dynamic friction coefficient. Given a certain dynamic friction coefficient,the ride comfort level of an asphalt concrete pavement reduces with its roughness and driving speed increasing. When the roughness is 1. 35 and 3. 05 mm/m,the maximum speed with an appropriate ride comfort level is 124. 1 and 88. 7 km/h,respectively.%为给沥青混凝土路面舒适性评价及日常管理养护提供理论依据,在测得室内外大量道路路面性能参数及三向加速度数据的基础上,研究了加权加速度均方根值与道路路面性能参数之间的关系.运用214组有效室外实验数据,拟合了加权加速度均方根、行驶速度与平整度关系的线性回归方程,并用驾驶模拟舱对室外实验结论进行了验证.结果表明:加权加速度均方根与平整度强相关,与速度中等程度相关,与动态摩擦系数弱相关,在动态摩擦系数一定的条件下,驾乘舒适性随平整度及行驶速度的增加而降低;当平整度为1.35和3.05 mm/m时,满足驾乘舒适性的最大速度分别为124.1和88.7 km/h.

  10. Prediction and Risk Management on Geochemical Accumulation of Soil Cadmium based on Time-Space Model in Zhujiang River Delta%珠三角土壤镉含量时空分布及风险管理

    Institute of Scientific and Technical Information of China (English)

    李勇; 余天虹; 赵志忠; 周永章; 窦磊; 何翔

    2015-01-01

    基于珠三角地区98个同点位土样,探讨了土壤Cd含量的时空分布特征及风险管理策略。研究表明,两批次土壤Cd含量富集程度均很高,土壤Cd平均含量Cˉ2001和Cˉ2007均为0.28 mg/kg,是广东省土壤背景值的5倍;两者均值多重比较表明,Cd的均值变化达到显著水平。土壤Cd的变异系数分别为0.83和0.72,暗示了Cd主要来源于人为成因。经估算,土壤Cd区域性年均累积速率KC2007-C2001、KC2012-C2007分别为0.016和0.014 mg/kg。采用“时空模式”和“空时模式”模型预测土壤Cd含量的时空分布态势,在时间序列资料较少的情形下,“时空模式”预测结果较稳健。2020年研究区大部分区域土壤Cd有污染,未来的风险管理应对无污染区域采取预防策略;对有污染区域采取控制策略;对重污染区域采取修复策略。%In order to measure the contents of Cadmium (Cd), 98 topsoil samples were collected from the same points of the Zhujiang River Delta in the years of 2001 and 2007, respectively. Based on 98 soil samples, the spatial and temporal distribution of soil Cadmium concentrations was explored, in which risk management strategies were discussed. The results showed that the extent of soil Cadmium was highly enriched, the mean concentrations of soil Cadmium in the two periods was 0.28 mg/kg, which was 5 times more than its soil back-ground values of Guangdong Province (0.06 mg/kg);Both mean values for multiple comparisons showed that the Cadmium mean change reached a significant level. The coefficients of variation of soil Cadmium were 0.83 and 0.72, respectively, which indicated that the Cadmium sources were mainly from anthropogenic activi-ty. Based on the model of Soil heavy metal accumulation rate of two periods,the annual regional soil Cadmi-um accumulation rates from 2001 to 2007 were 0.016 mg/kg, while from 2007 to 2012 the average annual re-gional soil Cadmium accumulation rate was 0

  11. Application of Cold-Induced Aggregation Microextraction Based on Ionic Liquid for Determination of Trace Amount of Cadmium and Lead in Powder Milk Samples

    Directory of Open Access Journals (Sweden)

    Mostafa Delavar

    2014-06-01

    Full Text Available Background: cold-induced aggregation micro extraction based (CIAME based on ionic liquid was used as a rapid and simple method for determination trace amounts of cadmium and lead in milk powder by analysis with flame atomic absorption spectrometry (FAAS. Methods: Sample solution containing of Cd2+ and Pb2+ in dynamic range, phosphate buffer (pH = 9, 3 ml, diethyl dithiocarbamate (complexing agent, Triton X-100, NaPF6 ,[HMIM][PF6] (extraction solvent were transferred into conical bottom glass tube. Sample was kept in a thermostated bath and then ice bath; a cloudy solution was formed. Two phases separated by centrifugation. After removing of aqueous phase, IL-phase was dissolved in methanol and diluted was injected to the FAAS by microsampler introduction. Results: ILs, containing imidazoliumcation and hexafluoro phosphate anion, [HMIM][PF6](70mg, 200 mg NaPF6 ,0.01 mol.L-1 DDTC, 0.015% of Triton X-100 obtained, pH 9 and centrifuge time; 5 min (4000 rmp was chosen. Detection limit were obtained 0.12 µgL-1, 1.61µgL-1, RSD 0.95%, 2.2% and enrichment factor of 70, 67 for Cd and Pb, respectively. Conclusion: CIAME allows determination of cadmium and lead in real samples in a simple, rapid and safe method with only a small amount of ionic liquid was used. In comparison with the organic solvent extraction, CIAME is much safer and the determination of species in high ionic strength samples is possible.

  12. Rapid identification of soil cadmium pollution risk at regional scale based on visible and near-infrared spectroscopy.

    Science.gov (United States)

    Chen, Tao; Chang, Qingrui; Clevers, J G P W; Kooistra, L

    2015-11-01

    Soil heavy metal pollution due to long-term sewage irrigation is a serious environmental problem in many irrigation areas in northern China. Quickly identifying its pollution status is an important basis for remediation. Visible-near-infrared reflectance spectroscopy (VNIRS) provides a useful tool. In a case study, 76 soil samples were collected and their reflectance spectra were used to estimate cadmium (Cd) concentration by partial least squares regression (PLSR) and back propagation neural network (BPNN). To reduce noise, six pre-treatments were compared, in which orthogonal signal correction (OSC) was first used in soil Cd estimation. Spectral analysis and geostatistics were combined to identify Cd pollution hotspots. Results showed that Cd was accumulated in topsoil at the study area. OSC can effectively remove irrelevant information to improve prediction accuracy. More accurate estimation was achieved by applying a BPNN. Soil Cd pollution hotspots could be identified by interpolating the predicted values obtained from spectral estimates.

  13. 基于PSCAD的风电场低电压穿越无功支撑仿真研究%Modeling and Simulation of the Reactive Power Support of Low Voltage Ride-through in Wind Farm Based on PSCAD

    Institute of Scientific and Technical Information of China (English)

    刘云; 刘亚丽; 胡晓辉; 陈婷; 崔雪

    2014-01-01

    首先分析风电场低电压穿越(low voltage ride-through,LVRT)能力,然后介绍以双馈感应发电机(doubly-fed induction generator,DFIG)为主体的风电场模型以及静止同步补偿器(static synchronous compensator,STATCOM)的控制策略.最后将STATCOM和静止无功补偿器(static var compensator,SVC)分别应用到含风电场的无穷大系统中,在电力系统仿真软件PSCAD上搭建模型,并对系统故障状态进行仿真,在此基础上分析STATCOM和SVC的无功补偿特性,并对补偿效果进行比较.仿真结果表明无功补偿装置可以在系统故障后提供无功支撑,提高了风电场的低电压穿越能力,并且STATCOM无功补偿性能较SVC更优.

  14. A tale of 2 continents and 4 cities about the inuence of demographics and social constraints on ride-sharing

    CERN Document Server

    Cici, Blerim; Laoutaris, Nikolaos

    2013-01-01

    Ride-sharing on the daily home-work-home commute can help individuals save on gasoline and other car-related costs, while at the same time reduce traffic and pollution. This paper presents a quantitative study of the potential of ride-sharing in two European and two US cities based on mobility data extracted from 3G Call Description Records (CDRs) and Online Social Networks (OSN) geo-tagging. We start with ride-sharing among neighbors for which we derive up- per bounds based on the assumption that commutes occur synchronously and that any passenger can be matched with any driver. We show that a small detour distance of 0.8 Km leads to an impressive 55% reduction of traffic. This value reduces to 26% for asynchronous commutes and a pick-up tolerance of 10 minutes. The latter result can be improved to 47% by permitting additional passengers to be picked-up en-route using e.g., smartphone apps. We then introduce social constraints on the relationship between drivers and passengers. Riding only with immediate fri...

  15. Correlations of urinary cadmium with hypertension and diabetes in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    Energy Technology Data Exchange (ETDEWEB)

    Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Limpatanachote, Pisit; Krintratun, Somyot [Department of Internal Medicine, Mae Sot General Hospital, Tak (Thailand)

    2010-08-15

    Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4{+-}2.3 {mu}g/g creatinine) was significantly greater than that for men (2.0{+-}2.2 {mu}g/g creatinine). Hypertension was presented in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.

  16. Use of cultured rat embryos to evaluate the teratogenic activity of serum: cadmium and cyclophosphamide. [Serum-based culture media for growing rat embryos is used to determine the teratogenicity of cadmium and cyclophosphamide

    Energy Technology Data Exchange (ETDEWEB)

    Klein, N. W.; Vogler, M. A.; Chatot, C. L.; Pierro, L. J.

    1979-01-01

    Head fold stage rat embryos were cultured for 48 hrs in vitro on serum taken at various intervals from rats that had been injected ip with either cadmium or cyclophosphamide. Their response was compared to that of embryos cultured for the same period on control serum to which these substances were added directly. One and 4 hr sera from cadmium injected rats (2.13 mg Cd/sup + +//kg) were lethal. Eight hr serum allowed survival but embryos were exencephalic and contained reduced amounts of protein and DNA. The response to direct cadmium was characteristically different and was related to dosage and the extent to which zero-time embryos had progressed through the head fold stage. At 1.6 ..mu..M, Cd/sup + +/-susceptible embryos were hemorrhagic but not exencephalic. One hr serum from rats given cyclophosphamide (180 mg/kg) was lethal. On 4 hr serum, embryos survived but were exencephalic and contained less protein and DNA than controls. Embryos were resistant to direct cyclophosphamide up to 800 ..mu..g per ml of medium. At this concentration, embryos appeared morphologically normal but contained reduced amounts of protein.

  17. Plausible Mechanisms of Cadmium Carcinogenesis

    Science.gov (United States)

    Cadmium is a transition metal and an ubiquitous environmental and industrial pollutant. Laboratory animal studies and epidemiological studies have shown that exposure to cadmium is associated with various organ toxicities and carcinogenic effects. Several national and internation...

  18. Recycling of Spent Nickel-Cadmium Batteries

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A technique for recycling spent nickel-cadmium batteries, which makes separation of cadmium and nickel possible, is developed by laboratory-scale experiments. NH3-H2CO3 aqueous solution was used in this leaching technique. Since neutralization and/or solvent extraction were not required in the separation procedure of nickel and cadmium, the closed systemization of the process becomes possible. Experimental results show that, (1) if the NH3 concentration of leaching solution is sufficiently high and the ratio of H2CO3 to NH3 is properly adjusted, both Ni(OH)2 and Cd(OH)2 react with NH3 and quickly dissolve into leaching solution, and (2) Ni(OH)2 can be converted into insoluble NiO by calcination at 500€癈, and CdO from Cd(OH)2 by calcination maintains good solubility in NH3-H2CO3 aqueous solution. As a conclusion, the recycling technique characterized by two step leaching can be developed based on such changes in dissolution behavior by calcination. Meanwhile, the yields of 99.8% for nickel and 97.6% for cadmium are obtained, and the purities of recovered nickel and cadmium are 99.9% and 98.6%, respectively.

  19. Cadmium Removal from Aqueous Solutions by Ground Pine Cone

    Directory of Open Access Journals (Sweden)

    H Izanloo, S Nasseri

    2005-01-01

    Full Text Available A study on the removal of cadmium ions from aqueous solutions by pine cone was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were obtained. The influence of different experimental parameters such as contact time, initial concentration of cadmium, pine cone mass and particle size, and temperature on the kinetics of cadmium removal was studied. Results showed that the main parameters that played an important role in removal phenomenon were initial cadmium concentration, particle size and pine cone mass. The necessary time to reach equilibrium was between 4 and 7 hours based on the initial concentration of cadmium. The capacity of cadmium adsorption at equilibrium increased with the decrease of pine cone particle size. The capacity of cadmium adsorption at equilibrium by pine cone increased with the quantity of pine cone introduced (1–4 g/L. Temperature in the range of 20-30°C showed a restricted effect on the removal kinetics (13.56 mg/g at 20°C and a low capacity of adsorption about 11.48 mg/g at 30°C. The process followed pseudo second-order kinetics. The cadmium uptake of pine cone was quantitatively evaluated using adsorption isotherms. Results indicated that the Langmuir model gave a better fit to the experimental data in comparison with the Freundlich equation.

  20. Hydro-pneumatic suspension parameters dynamical optimization design based on ride comfort%基于平顺性的油气悬架参数动态分析与优化

    Institute of Scientific and Technical Information of China (English)

    蔡祥文; 谷正气; 李伟平; 梁小波; 彭国谱

    2011-01-01

    以提高汽车行驶平顺性为目的,对油气悬架系统参数进行优化.建立油气悬架系统的二自由度1/4车辆数学模型.基于数学模型,在Matlab/Simulink软件中利用模块组合的方法建立仿真模型,并构建以车身垂直方向的加权加速度均方根值为目标函数的优化模型.优化算法采用遗传算法,通过编程将仿真模型、优化模型结合起来,实现Simulink、遗传算法对油气悬架系统参数的动态联合优化设计.利用该方法对某矿用自卸车前油气悬架设计阶段的结构参数进行优化,仿真结果表明:由该方法确定的油气悬架结构参数使车身垂直方向的加权加速度均方根值下降29.35%,加速度功率谱密度共振峰值降低23.6%,从而明显改善了汽车的行驶平顺性,同时也为其他类型的非线性悬架系统的动态优化设计提供了借鉴.%To improve vehicle ride comfort, hydro-pneumatic suspension system parameters were optimized.Mathematic model of a 2-DOF quarter-car model with hydro-pneumatic suspension system was established and then,the simulation model was developed by means of combination modules of Simulink, and optimal design model uses the root mean square value of body vertical acceleration as the objective function.Optimization using genetic algorithms, by programming the simulation model combined optimization model,and the optimal hydro-pneumatic suspension parameters were obtained after the combined optimization design between Simulink and Genetic Algorithm (GA).The structural parameters of front hydro-pneumatic of a mining dump truck were optimized during design stage using this method, the simulation results show that:the root mean square value of body vertical acceleration was brought down by 29.35% ,power spectral density of body vertical acceleration was decreased by 23.6% ,so the vehicle ride comfort can be significantly improved, which also provided references for the dynamic optimization design of

  1. Evaluation of Park and Ride Scenarios for Eskisehir with AHP

    Science.gov (United States)

    Yaliniz, Polat; Ustun, Ozden; Bilgiç, Safak; Vitosoglu, Yasar

    2016-10-01

    Nowadays, limiting individual transportation and increasing share of mass transit represent an important place in planning a sustainable urban transportation system. In order to attract private automobile users into public transportation, a number of applications can be employed. Among these applications, “park and ride” system comes in first. Therefore, in this study, park and ride system as well as the other applicable scenarios have been evaluated with Analytical Hierarchy Process (AHP) method. The alternatives evaluated include the Protection of the Current Situation, the Introduction of Only Restrictive Factors and the Park and Ride Implementation. Consequently, the overall relative priority values of alternatives were calculated and found to be the highest in the case of Park and Ride Implementation. Hence, it was determined that the “park and ride” application provided a clear superiority compared to other alternatives.

  2. A Study on the Ride Comfort of Vehicle Seats Based on Body Pressure Distribution%基于体压分布的汽车座椅舒适性研究

    Institute of Scientific and Technical Information of China (English)

    张志飞; 袁琼; 徐中明; 黄深荣; 贺岩松

    2014-01-01

    In this paper, both body pressure distribution measurement and vibration comfort test are con-ducted to study the ride comfort of vehicle seat. Through body pressure distribution measurement, the quantitative indicators, including average pressure, total resultant force and contact area are obtained and the characteristics of static body pressure distribution and the variation law of dynamic body pressure distribution are analyzed, showing that all dynamic body pressure indicators except maximum pressure are larger than static ones and increase with the rise in vehicle speed. By vibration comfort test the correlation between dynamic body distribution and vibration is analyzed with a result indicating that there is a strong correlation between mean pressure and weighted vibration ac-celeration.%本文中通过体压分布测试和振动舒适性试验研究汽车座椅舒适性。通过体压分布测试,获得平均压强、总压力和接触面积等体压分布量化指标,并分析静态体压分布的特征和动态体压分布的变化规律,结果表明动态工况下除最大压强以外的其它体压指标均大于静态工况,且随车速增加而增加。而通过振动舒适性试验,分析动态体压分布与振动的相关性,结果表明平均压强与振动加权加速度有很强的相关性。

  3. Sensitive determination of cadmium in water samples by room temperature ionic liquid-based preconcentration and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martinis, Estefania M. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Olsina, Roberto A. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis (Argentina); Altamirano, Jorgelina C. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina); Wuilloud, Rodolfo G. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)], E-mail: rwuilloud@mendoza-conicet.gov.ar

    2008-10-17

    A sensitive preconcentration methodology for Cd determination at trace levels in water samples was developed in this work. 1-Butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}MIM][PF{sub 6}]) room temperature ionic liquid (RTIL) was successfully used for Cd preconcentration, as cadmium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex [Cd-5-Br-PADAP]. Subsequently, Cd was back-extracted from the RTIL phase with 500 {mu}L of 0.5 mol L{sup -1} nitric acid and determined by electrothermal atomic absorption spectrometry (ETAAS). A preconcentration factor of 40 was achieved with 20 mL of sample. The limit of detection (LOD) obtained under optimum conditions was 3 ng L{sup -1} and the relative standard deviation (R.S.D.) for 10 replicates at 1 {mu}g L{sup -1} Cd{sup 2+} concentration level was 3.5%, calculated at peak heights. The calibration graph was linear from concentration levels near the detection limits up to at least 5 {mu}g L{sup -1}. A correlation coefficient of 0.9997 was achieved. Validation of the methodology was performed by standard addition method and analysis of certified reference material (CRM). The method was successfully applied to the determination of Cd in river and tap water samples.

  4. Technical and Programmatic Challenges for Dedicated Ride Share Missions

    OpenAIRE

    Kehrl, Gregory; Steele, Matt

    2012-01-01

    The Athena RideShare™ launch service, announced by Lockheed Martin and ATK in 2011, is a game-changing approach that lowers launch costs and provides scheduled access to space for small satellites and cubesats. The Athena RideShare launch service is an extension of a familiar concept, the Post Office’s Priority Mail Flat Rate Boxes. If payload fits into the designated volume envelope and mass limit, the customer pays one low flat rate to get to space. Despite the simplicity of the model, ther...

  5. 75 FR 65437 - Defense Federal Acquisition Regulation Supplement; Defense Cargo Riding Gang Members (DFARS Case...

    Science.gov (United States)

    2010-10-25

    ... Acquisition Regulation Supplement; Defense Cargo Riding Gang Members (DFARS Case 2007-D002) AGENCY: Defense... 3504 addresses requirements that apply to riding gang members and DoD- exempted individuals who perform.... 109-364). Section 3504 addresses requirements that apply to riding gang members and...

  6. Fabrication of a highly selective cadmium (II) sensor based on 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane as a supramolecular ionophore

    Energy Technology Data Exchange (ETDEWEB)

    Ghaemi, Arezoo, E-mail: arezooghaemi@yahoo.com; Tavakkoli, Haman; Mombeni, Tayebeh

    2014-05-01

    A new cadmium (II) ion selective sensor based on 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane (kryptofix5) as a supramolecular carrier has been developed. The membrane solutions containing polyvinyl chloride (PVC), plasticizer, sodium tetraphenylborate (NaTPB) as a lipophilic ionic additive and kryptofix5 as an ionophore were directly coated on the surface of graphite rods. The best composition of the coated membrane (w/w%) was found to be: 30.0% PVC, 61.0% dioctyl sebacate (DOS), 6.0% NaTPB and 3.0% kryptofix5. The sensor indicates a good linear response for Cd{sup 2+} cation over a wide concentration range from 1.0 × 10{sup −5} to 1.0 × 10{sup −1} M with a Nernstian slope of 29.8 ± 0.1 mV/decade and the detection limit is 8.4 × 10{sup −6} M. The response time of the sensor is 15 s and it can be used for 7 weeks without significant drift in potential. The sensor operates in the wide pH range of 1.0–6.0. This sensor reveals a very good selectivity toward Cd{sup 2+} ion over a wide range of alkali, transition and heavy metal cations. The sensor was used as an indicator electrode for potentiometric titration of Cd{sup 2+} using sodium fluoride and ethylenediaminetetraacetic acid (EDTA) solutions with a sharp potential change that occurred at the end point. In addition, the proposed sensor was successfully used for determination of Cd{sup 2+} cation in real water samples. - Graphical abstract: Fabrication of a highly selective cadmium (II) sensor based on 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane as a supramolecular ionophore. - Highlights: • Fabrication of a novel Cd{sup 2+} selective sensor with high sensitivity and selectivity • Using fabricated sensor in a wide pH range with fast response time • Replacing expensive techniques with this low cost sensor with low detection limit • Excellent capability of this sensor for measuring Cd{sup 2+} in real samples.

  7. 29 CFR 1910.1027 - Cadmium.

    Science.gov (United States)

    2010-07-01

    ... battery Plate making, plate preparation 50 All other processes 15 Zinc/Cadmium refining* Cadmium refining... as an airborne concentration of cadmium of 2.5 micrograms per cubic meter of air (2.5 µg/m3... air cadmium level to which an employee is exposed means the exposure to airborne cadmium that...

  8. Cadmium concentration in sea bottom sediment and its potential risk in the upper Gulf of Thailand.

    Science.gov (United States)

    Ei Tun, Zin Hnin; Parkpian, Preeda; Delaune, R D; Gambrell, R P; Jugsujinda, Aroon

    2009-02-15

    Untreated or partially treated waste water discharge from industrial and domestic sources entering the Upper Gulf of Thailand have been reported to increase cadmium concentration in bottom sediment. This study was directed at providing a better understanding of cadmium transformation in the sediment from the area. Sediment samples collected from Chao Phraya River mouth (CPY), Bang Pakong River mouth (BPK) and Klong Dan estuary (KD) located in the Upper Gulf of Thailand were analyzed for cadmium concentration in various sediment particle size fractions. Using laboratory microcosms, cadmium release from sediment as affected by salinity and sediment redox condition was studied. A higher concentration of cadmium (0.2-0.6 microg/g dry weight) was measured in finer sediment particle size fractions (<0.075 mm) as compared to courser fractions at all sampling stations. Cadmium release from the sediment to water was influenced by both salinity and redox condition. Sediment was spiked with 10 ppm cadmium which is the cadmium level in sediment adopted by the Australia and New Zealand sediment quality guidelines which can cause adverse environmental impacts. Experiments conducted showed soluble cadmium concentration at sediment oxidation reduction conditions representative of bottom sediment were at levels that can adversely impact aquatic organisms, according to the PCADMIUM water quality guideline. In Thailand, there is no sediment quality guideline. Based on these experiments, 10 ppm of cadmium in sediment was recommended as a regulatory guidelines for allowable levels of cadmium in sediment in the study area.

  9. NMR-Based Metabolomic Investigations on the Differential Responses in Adductor Muscles from Two Pedigrees of Manila Clam Ruditapes philippinarum to Cadmium and Zinc

    Directory of Open Access Journals (Sweden)

    Junbao Yu

    2011-09-01

    Full Text Available Manila clam Ruditapes philippinarum is one of the most important economic species in shellfishery in China due to its wide geographic distribution and high tolerance to environmental changes (e.g., salinity, temperature. In addition, Manila clam is a good biomonitor/bioindicator in “Mussel Watch Programs” and marine environmental toxicology. However, there are several pedigrees of R. philippinarum distributed in the marine environment in China. No attention has been paid to the biological differences between various pedigrees of Manila clams, which may introduce undesirable biological variation in toxicology studies. In this study, we applied NMR-based metabolomics to detect the biological differences in two main pedigrees (White and Zebra of R. philippinarum and their differential responses to heavy metal exposures (Cadmium and Zinc using adductor muscle as a target tissue to define one sensitive pedigree of R. philippinarum as biomonitor for heavy metals. Our results indicated that there were significant metabolic differences in adductor muscle tissues between White and Zebra clams, including higher levels of alanine, glutamine, hypotaurine, phosphocholine and homarine in White clam muscles and higher levels of branched chain amino acids (valine, leucine and isoleucine, succinate and 4-aminobutyrate in Zebra clam muscles, respectively. Differential metabolic responses to heavy metals between White and Zebra clams were also found. Overall, we concluded that White pedigree of clam could be a preferable bioindicator/biomonitor in marine toxicology studies and for marine heavy metals based on the relatively high sensitivity to heavy metals.

  10. Cadmium - is it hazardous

    Energy Technology Data Exchange (ETDEWEB)

    Zartner-Nyilas, G.; Valentin, H.; Schaller, K.H.; Schiele, R.

    1983-01-01

    The report summarizes the state of knowledge and experience on cadmium. Biological, toxicological and epidemiological data have been evaluated. Cd pollution of the environment is reviewed under the aspect of human health. Uptake in food, threshod values of Cd exposure of the population, types and extent of health hazards, possible carcinogenic effects and future fields of research are discussed.

  11. Passenger ride quality within a noise and vibration environment

    Science.gov (United States)

    Dempsey, T. K.; Leatherwood, J. D.; Drezek, A. B.

    1976-01-01

    The subjective response to noise and vibration stimuli was studied in a ride quality simulator to determine their importance in the prediction of passenger ride quality. Subjects used category scales to rate noise discomfort, vibration discomfort, both noise and vibration discomfort, and overall discomfort in an effort to evaluate parametric arrangements of noise and vibration. The noise stimuli were composed of octave frequency bands centered at 125, 250, 2,000 and 4,000 Hz, each presented at 70, 75, 80, and 85 dB(A). The vertical vibration stimuli were 5 Hz bandwidth random vibrations centered at 3, 5, 7, and 9 Hz, each presented at 0.03, 0.06, 0.09, and 0.12 grms. Analyses were directed at (1) a determination of the subject's ability to separate noise and vibration as contributors to discomfort, (2) an assessment of the physical characteristics of noise and vibration that are needed for prediction of ride quality in this type of multifactor environment, and (3) an evaluation of the relative contribution of noise and vibration to passenger ride quality.

  12. Riding the Wave: A Self-Portrait Study

    Science.gov (United States)

    Skophammer, Karen

    2009-01-01

    Creating a self-portrait of having fun "riding a wave" is a very enlightening and engaging experience for students of all ages, but the author's second-graders had an especially wonderful time with this art experience. To begin the unit of study, the author and her students looked at self-portraits created by Vincent van Gogh, Rembrandt,…

  13. Solving the Dial-a-Ride Problem using Genetic Algorithms

    DEFF Research Database (Denmark)

    Jørgensen, Rene Munk; Larsen, Jesper; Bergvinsdottir, Kristin Berg

    2007-01-01

    In the Dial-a-Ride problem (DARP), customers request transportation from an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and capacity demand. The aim of DARP is to minimize transportation cost while satisfying...

  14. Promoting bike-and-ride : the Dutch experience

    NARCIS (Netherlands)

    Martens, C.J.C.M.

    2007-01-01

    The number of policy initiatives to promote the use of bike-and-ride, or the combined use of bicycle and public trans-port for one trip, has grown considerably over the past decade as part of the search for more sustainable transport solu-tions. This paper discusses the experiences with, and impacts

  15. Pensionäride suurkogu tuleb kokku / Heimar Lenk

    Index Scriptorium Estoniae

    Lenk, Heimar, 1946-

    2005-01-01

    Ilmunud ka: Videvik 22. september lk. 1. 30. september koguneb pensionäride esinduskogu Tallinnas, andmaks märku eakate aktiivsest eluhoiakust ja soovist riigi arengule kaasa rääkida. Vt. samal teemal ka Heimar Lenk. Valga pensionäri Tallinna suurkogule! 29. sept. Valgamaalane lk. 2

  16. Science 101: How Do People Design Safe Amusement Park Rides?

    Science.gov (United States)

    Robertson, Bill

    2015-01-01

    To address the question of how people design safe amusement park rides, Bill Robertson focuses on the factors designers must consider so that human bodies don't experience too large an acceleration (any change in speed and/or direction) or "g-force" (the acceleration an object undergoes while freely falling, with no air resistance, under…

  17. Undoing Quantitative Easing: Janet Yellen's Tiger Ride

    Science.gov (United States)

    Niederjohn, M. Scott; Schug, Mark C.; Wood, William C.

    2014-01-01

    "One who rides a tiger is afraid to dismount," says a colorful proverb from an earlier time. This may be an apt saying for the situation facing the new head of the Federal Reserve, Janet L. Yellen, who takes over at a time when successive rounds of Fed policy have taken the central bank into uncharted territory. By historical standards,…

  18. The Benefits of Meeting Points in Ride-sharing Systems

    NARCIS (Netherlands)

    M. Stiglic (Mitja); N.A.H. Agatz (Niels); M.W.P. Savelsbergh (Martin); M. Gradisar (Mirko)

    2015-01-01

    textabstractWe investigate the potential benefits of introducing meeting points in a ride-sharing system. With meeting points, riders can be picked up and dropped off either at their origin and destination or at a meeting point that is within a certain distance from their origin or destination. The

  19. Using forecast information for storm ride-through control

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Trombe, Pierre-Julien; Vincent, Claire Louise;

    2013-01-01

    Using probabilistic forecast information in control algorithms can improve the performance of wind farms during periods of extreme winds. This work presents a wind farm supervisor control concept that uses probabilistic forecast information to ride-through a storm with softer ramps of power. Wind...

  20. Updating and validating a new framework for restoring and analyzing latency-variable ERP components from single trials with residue iteration decomposition (RIDE).

    Science.gov (United States)

    Ouyang, Guang; Sommer, Werner; Zhou, Changsong

    2015-06-01

    Trial-to-trial latency variability pervades cognitive EEG responses and may mix and smear ERP components but is usually ignored in conventional ERP averaging. Existing attempts to decompose temporally overlapping and latency-variable ERP components show major limitations. Here, we propose a theoretical framework and model of ERPs consisting of temporally overlapping components locked to different external events or varying in latency from trial to trial. Based on this model, a new ERP decomposition and reconstruction method was developed: residue iteration decomposition (RIDE). Here, we describe an update of the method and compare it to other decomposition methods in simulated and real datasets. The updated RIDE method solves the divergence problem inherent to previous latency-based decomposition methods. By implementing the model of ERPs as consisting of time-variable and invariable single-trial component clusters, RIDE obtains latency-corrected ERP waveforms and topographies of the components, and yields dynamic information about single trials.

  1. Advanced Control Strategy of DFIG Wind Turbines for Power System Fault Ride Through

    DEFF Research Database (Denmark)

    Yang, Lihui; Xu, Zhao; Ostergaard, Jacob;

    2012-01-01

    This paper presents an advanced control strategy for the rotor and grid side converters of the doubly fed induction generator (DFIG) based wind turbine (WT) to enhance the low-voltage ride-through (LVRT) capability according to the grid connection requirement. Within the new control strategy...... the oscillations in the stator and rotor currents and the DC bus voltage. The effectiveness of the proposed control strategy has been demonstrated through various simulation cases. Compared with conventional crowbar protection, the proposed control method can not only improve the LVRT capability of the DFIG WT......, but also help maintaining continuous active and reactive power control of the DFIG during the grid faults....

  2. Tour Planning and Ride Matching for an Urban Social Carpooling Service

    Directory of Open Access Journals (Sweden)

    Jamal J.

    2016-01-01

    Full Text Available SocialCar is a research project aiming at integrating carpooling with existing transportation systems in urban and peri-urban environments. The system, that also takes benefit from social network interactions, is based on tour planning and ride matching algorithms to suggest the users the available alternatives for their trips. In this paper we overview some approaches to model general public transportation networks and carpooling services. A route planning algorithm, able to integrate different types of public transportation, bike rentals and carpooling services is finally presented.

  3. Disability, Riding, and Identity: A Qualitative Study on the Influence of Riding on the Identity Construction of People with Disabilities

    Science.gov (United States)

    Lundquist Wanneberg, Pia

    2014-01-01

    Semi-structured face-to-face interviews were used to examine the influence of riding on the identity construction of people with disabilities. The 15 participants, three men and 12 women, were between 15 and 65 years old and have various physical disabilities. The data analysis derives from identity theory, a social-psychological theory that…

  4. Accumulation and distribution of arsenic and cadmium by tea plants

    Institute of Scientific and Technical Information of China (English)

    Yuan-zhi SHI; Jian-yun RUAN; Lifeng MA; Wen-yan HAN; Fang WANG

    2008-01-01

    It is important to research the rules about accumulation and distribution of arsenic and cadmium by tea plants, which will give us some scientific ideas about how to control the contents of arsenic and cadmium in tea. In this study, by field inves- tigation and pot trial, we found that mobility of arsenic and cadmium in tea plants was low. Most arsenic and cadmium absorbed were fixed in feeding roots and only small amount was transported to the above-ground parts. Distribution of arsenic and cadmium, based on their concentrations of unit dry matter, in tea plants grown on un-contaminated soil was in the order: feeding roots>stems≈main roots>old leaves>young leaves. When tea plants were grown on polluted soils simulated by adding salts of these two metals, feeding roots possibly acted as a buffer and defense, and arsenic and cadmium were transported less to the above- ground parts. The concentration of cadmium in soil significantly and negatively correlated with chlorophyll content, photosyn- thetic rate, transpiration rate and biomass production of tea plants.

  5. The role of lead and cadmium in psychiatry

    Directory of Open Access Journals (Sweden)

    Orish Ebere Orisakwe

    2014-01-01

    Full Text Available Psychiatric disorders are associated with long-term disability and huge social and economic costs. The possible influence of heavy metals exposure on public health remains a matter of concern. A recurring research question that persisted among researchers in neuropsychiatry has been "are psychiatric patients more likely to have a high body burden of lead or other heavy metals?" This is an update account on the role of lead and cadmium in psychiatry. This review, which has employed search words like "lead and cadmium in psychiatry" , "lead and cadmium in schizophrenia", "lead and cadmium in psychosis" in citation indices such as PubMed, Google Scholar, Scirus, and Scopus. A total of 415 articles were found; 60 fulfiled the inclusion criteria. Evidence-based information suggests that lead and cadmium may be involved in psychiatry. Should environmental lead and cadmium be implicated in the etiogenesis of psychiatry given the characteristic high environmental pollution in Sub Sahara Africa, it is worthwhile for toxicologists and scientists in Sub-Sahara Africa to investigate if lead and cadmium can become additional biomarkers in the diagnosis of psychiatric disorders.

  6. Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals.

    Science.gov (United States)

    Yadav, Manju; Mishra, Neelima; Sharma, Nutan; Chandra, Sulekh; Kumar, Dinesh

    2014-11-11

    This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X=O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV-Vis, NMR ((1)H, (119)Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37°C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively.

  7. Microwave assisted synthesis, characterization and biocidal activities of some new chelates of carbazole derived Schiff bases of cadmium and tin metals

    Science.gov (United States)

    Yadav, Manju; Mishra, Neelima; Sharma, Nutan; Chandra, Sulekh; Kumar, Dinesh

    2014-11-01

    This study is planned to report the advancement of green microwave approach in the fabrication of a new series of biologically potent (N^X, where X = O/S) donor Schiff bases and their cadmium(II) and tin(II) complexes. The ligands and their metal complexes have been characterized in terms of elemental analysis, molar ionic conductance, magnetic moment and spectral (IR, UV-Vis, NMR (1H, 119Sn), FAB-mass, thermal and XRD) data. The data revealed that the ligands coordinated to the metal center via nitrogen and oxygen/sulfur atoms and form an octahedral arrangement of the ligands around central metal atom. All compounds were evaluated for their in vitro antimicrobial activities against two pathogenic bacteria Bacillus subtilis and Escherichia coli and two fungi Aspergillus niger and Aspergillus flavus by standard disc diffusion method. The discs were stored in an incubator at 37 °C. The compounds were dissolved in DMF at 500 and 1000 ppm concentrations for screening biocidal activity. The compounds were dissolved in DMF to get the 100 and 200 ppm concentration of test solutions for screening fungicidal activity. The inhibition zone around each disc was measured (in mm) after 24 h and 96 h for biocidal and fungicidal activities respectively.

  8. Cadmium in Sweden - environmental risks

    Energy Technology Data Exchange (ETDEWEB)

    Parkman, H.; Iverfeldt, Aa. [Swedish Environmental Research Inst. (Sweden); Borg, H.; Lithner, G. [Stockholm Univ. (Sweden). Inst. for Applied Environmental Research

    1998-03-01

    This report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buffering capacity, severely affected by acidification. In addition, the low salinity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soils is mobilized at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish environment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricultural soils, and fresh-waters in Sweden are enhanced compared to `back-ground concentrations`, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bio-available `free` cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. 90 refs, 23 figs, 2 tabs. With 3 page summary in Swedish

  9. Renal cadmium overload without nephrotoxicity.

    OpenAIRE

    1981-01-01

    A redundant nickel/cadmium battery worker was investigated for non-specific fatigue after completing five years in the industry. Sensitive techniques for in-vivo organ cadmium measurement showed a moderate accumulation in the liver but a very large concentration in the kidneys. Despite this, overall glomerular and tubular function were not impaired. It was concluded that the mechanism of proteinuria observed in some cadmium workers is obscure and not clearly related to the degree of kidney sa...

  10. CADMIUM – ENVIRONMENTAL HAZARD

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available The paper presents some information about current status of cadmium as an environmental health problem. Agricultural uses of phosphate fertilizers, sewage sludge and industrial uses of Cd are the major source of widespread of this metal at trace levels into the general environment and human foodstuffs. It is well known that high cadmium (Cd exposure causes renal damage, anemia, enteropathy, osteoporosis, osteomalacia, whereas the dose-response relationship at low levels exposure is less established. During the last decade an increasing number of studies have found an adverse health effects due to low environmental exposure to Cd. Many authors try to determine the relationship between Cd intake and Cd toxicity indicators, especially dealing renal tubular damage. The level of b2-microglobulin in urine is regarded as the most sensitive biomarker of renal disfunction due to low environmental Cd concentrations.

  11. Speciation of Dissolved Cadmium

    DEFF Research Database (Denmark)

    Holm, Peter Engelund; Andersen, Sjur; Christensen, Thomas Højlund

    1995-01-01

    Equilibrium dialysis and ion exchange methods, as well as computer calculations (GEOCHEM), were applied for speciation of dissolved cadmium (Cd) in test solutions and leachate samples. The leachate samples originated from soil, compost, landfill waste and industrial waste. The ion exchange (IE...... leachates showed different Cd speciation patterns as expected. Some leachates were dominated by free divalent Cd (1-70%), some by inorganic complexes (1-87%), and some by organic complexes (7-98%)....

  12. Lead and cadmium in breast milk

    Energy Technology Data Exchange (ETDEWEB)

    Sternowsky, H.J.; Wessolowski, R.

    1985-04-01

    Breast milk from 10 women each from the city of Hamburg and from a rural area was analyzed by atomic absorption spectrometry for contamination with lead and cadmium. Samples were examined at regular intervals for 3 months after birth. On day 5 a diurnal profile was analyzed; on the other days milk was taken before and after the morning feed. For breast milk as the main source of nutrition in infants, this study shows values of 9.1 +- 2.5 (SD) ..mu..g/l for lead in the rural population, with a tendency to decrease towards the end of lactation. Urban mothers had 13.3 +- 5.5 (SD) ..mu..g/l, with a tendency to increase. Mean cadmium content in rural mothers was 17.3 +- 4.9 ..mu..g/l, with much higher values in the colostrum and a decrease after 15 days. Urban mothers had 24.6 +- 7.3 ..mu..g/l, again with high colostrum values and a subsequent decrease. Calculated daily intake according to these values is presented, based on 840 ml breast milk for a 5.5 kg infant per day. Rural infants ingested 0.9-1.3 ..mu..g/kg/day of lead, and in the city 1.5-2.3 ..mu..g/kg/day. Cadmium intake in rural infants amounted from 1.2-1.8 ..mu..g/kg/day; in Hamburg it was 1.6-2.2 ..mu..g/kg/day. Thus the daily ingestion of lead was just below the DPI, cadmium ingestion was higher than the DPI for adults. The rural population had lower values in breast milk for both heavy metals than the urban population, although not statistically significant. Compared to earlier reports there was a slight increase in lead concentration and a more significant increase for cadmium.

  13. Riding pontic: a tool to keep patients smiling.

    Science.gov (United States)

    Sharma, Narendra Shriram

    2013-05-01

    All patients expect a beautiful smile at the completion of orthodontic treatment, but some patients show concern regarding their appearance while undergoing treatment. The appearance of a gap from a missing tooth can be a concern, especially if it is in the display zone of a patient's smile. If the treatment plan includes prosthetic replacement of the missing tooth rather then space closure, then space maintenance is also an issue. In an appearance conscious patient use of riding pontic as space maintainers is a good option during treatment. How to cite this article: Sharma NS. Riding Pontic: A Tool to Keep Patients Smiling. Int J Clin Pediatr Dent 2013;6(2): 127-131.

  14. Riding Pontic: A Tool to Keep Patients Smiling

    Science.gov (United States)

    Sharma, Narendra Shriram

    2013-01-01

    ABSTRACT All patients expect a beautiful smile at the completion of orthodontic treatment, but some patients show concern regarding their appearance while undergoing treatment. The appearance of a gap from a missing tooth can be a concern, especially if it is in the display zone of a patient's smile. If the treatment plan includes prosthetic replacement of the missing tooth rather then space closure, then space maintenance is also an issue. In an appearance conscious patient use of riding pontic as space maintainers is a good option during treatment. How to cite this article: Sharma NS. Riding Pontic: A Tool to Keep Patients Smiling. Int J Clin Pediatr Dent 2013;6(2): 127-131. PMID:25206207

  15. Analysis of impact of suspension rubber mounts on ride comfort

    Science.gov (United States)

    Chen, Bao; Chen, Zheming; Lei, Gang

    2017-01-01

    Two multi-body car models with rubber mounts and without rubber mounts have been built up to research how the suspension rubber mounts impact ride comfort. The comfort mount was used to simulate the impact process. Two scenarios have been set up, and time integrations have been performed to get the acceleration-time histories of seat surface in the x-, y-, and z-direction. A MATLAB program was compiled to calculate the weighted RMS acceleration. For the first scenario, the relative difference of weighted RMS acceleration between the car models with rubber mounts and without rubber mounts gradually decreases as the road roughness increases. For the second scenario, the relative difference increases as the driving speed increases. The conclusion shows that the change of driving speed or road roughness impacts ride comfort. Especially for high driving speed this impact is quite obvious.

  16. Ride control of surface effect ships using distributed control

    Directory of Open Access Journals (Sweden)

    Asgeir J. Sørensen

    1994-04-01

    Full Text Available A ride control system for active damping of heave and pitch accelerations of Surface Effect Ships (SES is presented. It is demonstrated that distributed effects that are due to a spatially varying pressure in the air cushion result in significant vertical vibrations in low and moderate sea states. In order to achieve a high quality human comfort and crew workability it is necessary to reduce these vibrations using a control system which accounts for distributed effects due to spatial pressure variations in the air cushion. A mathematical model of the process is presented, and collocated sensor and actuator pairs are used. The process stability is ensured using a controller with appropriate passivity properties. Sensor and actuator location is also discussed. The performance of the ride control system is shown by power spectra of the vertical accelerations obtained from full scale experiments with a 35 m SES.

  17. Electronic-structure calculations of large cadmium chalcogenide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Frenzel, Johannes [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum (Germany); Joswig, Jan-Ole [Physikalische Chemie, Technische Universitaet Dresden (Germany)

    2012-02-15

    In this paper, we will review our studies of large cadmium chalcogenide nanoparticles and present some new results on cadmium telluride systems. All calculations have been performed using density-functional based methods. The studies deal with the structural properties of saturated and unsaturated nanoparticles where the surfactants generally are hydrogen atoms or thiol groups. We have focused on the investigation of the density of states, the Mulliken charges, the eigenvalue spectra, and the spatial distributions of the frontier orbitals. Optical excitation spectra of pure CdS and CdSe/CdS core-shell systems have been calculated using a linear-response formalism. The reviewed studies are compared to the state of the art of modeling large cadmium chalcogenide particles. Optical excitations in large saturated cadmium chalcogenide nanoparticles with several thousand atoms. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Long-Lasting Virtual Motorcycle-Riding Trainer Effectiveness

    Directory of Open Access Journals (Sweden)

    Giulio eVidotto

    2015-10-01

    Full Text Available This work aimed to test the long-lasting effects of learning acquired with a virtual motorcycle-riding trainer as a tool to improve hazard perception. During the simulation, the rider can interact with other road actors and experience the most common potential accident situations in order to learn to modify his or her behavior to anticipate hazards and avoid crashes. We compared performance to the riding simulator of the two groups of participants: the experimental group, which was trained with the same simulator one year prior, and the control group that had not received any type of training with a riding or driving simulator. All of the participants had ridden a moped in the previous 12 months. The experimental group showed greater abilities to avoid accidents and recognize hazards in comparison to their performance observed a year before, whereas the performance of the control group was similar to that of the experimental group one year before in the first two sessions, and even better in the third. We interpreted this latter result as a consequence of their prior on-road experience. Also, the fact that the performance of the experimental group at the beginning of the follow-up is better than that recorded at the end of the training—one year before—is in line with the idea of a transfer from the on-road experience to the simulator. The present data confirm our main expectation that the effectiveness of the riding training simulator on the ability to cope with potentially dangerous situations persists over time and provides additional evidence in favor of the idea that simulators may be considered useful tools for training the ability to detect and react to hazards, leading to an improvement of this higher-order cognitive skill that persists over time. Implications for the reciprocal influence of the training with the simulator and the on-the road experience are discussed as well.

  19. Long-lasting virtual motorcycle-riding trainer effectiveness.

    Science.gov (United States)

    Vidotto, Giulio; Tagliabue, Mariaelena; Tira, Michael D

    2015-01-01

    This work aimed to test the long-lasting effects of learning acquired with a virtual motorcycle-riding trainer as a tool to improve hazard perception. During the simulation, the rider can interact with other road actors and experience the most common potential accident situations in order to learn to modify his or her behavior to anticipate hazards and avoid crashes. We compared performance to the riding simulator of the two groups of participants: the experimental group, which was trained with the same simulator one year prior, and the control group that had not received any type of training with a riding or driving simulator. All of the participants had ridden a moped in the previous 12 months. The experimental group showed greater abilities to avoid accidents and recognize hazards in comparison to their performance observed a year before, whereas the performance of the control group was similar to that of the experimental group 1 year before in the first two sessions, and even better in the third. We interpreted this latter result as a consequence of their prior on-road experience. Also, the fact that the performance of the experimental group at the beginning of the follow-up is better than that recorded at the end of the training-1 year before-is in line with the idea of a transfer from the on-road experience to the simulator. The present data confirm our main expectation that the effectiveness of the riding training simulator on the ability to cope with potentially dangerous situations persists over time and provides additional evidence in favor of the idea that simulators may be considered useful tools for training the ability to detect and react to hazards, leading to an improvement of this higher-order cognitive skill that persists over time. Implications for the reciprocal influence of the training with the simulator and the on-the road experience are discussed as well.

  20. Moral judgments in social dilemmas: How bad is free riding?

    OpenAIRE

    Robin P. Cubitt; Drouvelis, Michalis; Gaechter, Simon; Kabalin, Ruslan

    2010-01-01

    In the last thirty years, economists and other social scientists have investigated people’s normative views on distributive justice. Here we study people’s normative views in social dilemmas, which underlie many situations of economic and social significance. Using insights from moral philosophy and psychology we provide an analysis of the morality of free riding. We use experimental survey methods to investigate people’s moral judgments empirically. We vary others’ contributions, the framing...

  1. Horizontal Cooperation in Dial-a-Ride Services

    OpenAIRE

    2016-01-01

    A dial-a-ride system is an application of demand-dependent, collective people transportation. Each user requests a trip between an origin and a destination of choice, to which a number of service level requirements are linked. The service provider attempts to develop efficient vehicle routes and time schedules, respecting these requirements and the technical constraints of a pickup and delivery problem. A frequent objective is to minimize operational costs subject to full demand satisfaction ...

  2. Is cadmium hazardous to health. Cadmium - ein Gesundheitsrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Zartner-Nyilas, G.; Valentin, H.; Schaller, K.H.; Schiele, R.

    1983-01-01

    This study entitled ''Is cadmium hazardous to health'' summarizes the current state of knowledge on and experience with cadmium. The authors have made efforts to take into account the more recent literature relating to cadmium. The data evaluated were, especially, biological, toxicological, and epidemiological ones. A principal object was to try to assess the importance of the presence of cadmium in the environment to man. The interest was focused on the uptake of heavy metals with food, danger thresholds for the cadmium exposure of the population, nature and extent of eventual damage to health including possible carcinogenous effects, and suggestions for further points of main emphasis in research. 3 figs., 12 tabs.

  3. Roadway deformation during riding mining in soft rock

    Institute of Scientific and Technical Information of China (English)

    Zhao Guozhen; Ma Zhanguo; Zhu Qinghua; Mao Xianbiao; Feng Meimei

    2012-01-01

    "Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.

  4. Minimum Makespan Multi-vehicle Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

    2009-01-01

    -a-Ride problem, there are q vehicles each having capacity k and where each vehicle j ∈ [q] has its own depot-vertex rj ∈ V. A feasible schedule consists of a capacitated route for each vehicle (where vehicle j originates and ends at its depot rj) that together move all objects from their sources to destinations....... The objective is to find a feasible schedule that minimizes the maximum completion time (i.e. makespan) of vehicles, where the completion time of vehicle j is the time when it returns to its depot rj at the end of its route. We consider the preemptive version of multi-vehicle Dial-a-Ride, where an object may......Dial-a-Ride problems consist of a set V of n vertices in a metric space (denoting travel time between vertices) and a set of m objects represented as source-destination pairs {(si,ti)}mi=1, where each object requires to be moved from its source to destination vertex. In the multi-vehicle Dial...

  5. Development of an experimental methodology to evaluate the influence of a bamboo frame on the bicycle ride comfort

    Science.gov (United States)

    Thite, A. N.; Gerguri, S.; Coleman, F.; Doody, M.; Fisher, N.

    2013-09-01

    In the current environment of increased emphasis on sustainable transport, there is manifold increase in the use of bicycles for urban transport. One concern which might restrict the use is the ride comfort and fatigue. There has been limited research in addressing the difficulty in bicycle ride comfort quantification. The current study aims to develop a methodology to quantify bicycle discomfort so that performance of bicycles constructed from bamboo and aluminium alloy can be compared. Experimentally obtained frequency response functions are used to establish a relation between the road input and the seat and rider response. A bicycle track input profile based on standard road profiles is created so as to estimate the acceleration responses. The whole-body-vibration frequency weighting is applied to quantify the perception of vibration intensity so that eventual discomfort ranking can be obtained. The measured frequency response functions provide an insight into the effect of frame dynamics on the overall resonant behaviour of the bicycles. The beneficial effect of frame compliance and damping on lower modes of vibration is very clear in the case of bamboo frame, in turn affecting seat and rider response. In the bamboo frame, because of multiple resonances, the frequency response of the handlebar is smaller at higher frequencies suggesting effective isolation. Further improvements may have come from the joints made from natural composites. Overall, based on the comparative analysis and the methodology developed, bamboo frame shows significant improvement in ride comfort performance compared with the aluminium frame.

  6. Isolation, identification, characterization, and evaluation of cadmium removal capacity of Enterobacter species.

    Science.gov (United States)

    Abbas, Syed Zaghum; Rafatullah, Mohd; Ismail, Norli; Lalung, Japareng

    2014-12-01

    This study focused on the isolation and characterization of high cadmium-resistant bacterial strains, possible exploitation of its cadmium-accumulation and cadmium-induced proteins. Cadmium-resistant bacterial strains designated as RZ1 and RZ2 were isolated from industrial wastewater of Penang, Malaysia. These isolates were identified as Enterobacter mori and Enterobacter sp. WS12 on the basis of phenotypic, biochemical and 16S rDNA sequence based molecular phylogenetic characteristics. Both isolates were Gram negative, cocci, and growing well in Lauria-Bertani broth medium at 35 °C temperature and pH 7.0. Results also indicated that Enterobacter mori and Enterobacter sp. WS12are capable to remove 87.75 and 85.11% of the cadmium from 100 µg ml(-1) concentration, respectively. This study indicates that these strains can be useful as an inexpensive and efficient bioremediation technology to remove and recover the cadmium from wastewater.

  7. Digital gene expression profiling (DGE) of cadmium-treated Drosophila melanogaster.

    Science.gov (United States)

    Guan, Delong; Mo, Fei; Han, Yan; Gu, Wei; Zhang, Min

    2015-01-01

    Cadmium is highly toxic and can cause oxidative damage, metabolic disorders, and reduced lifespan and fertility in animals. In this study, we investigated the effects of cadmium in Drosophila melanogaster, performing transcriptome analysis by using tag-based digital gene expression (DGE) profiling. Among 1970 candidate genes, 1443 were up-regulated and 527 were down-regulated following cadmium exposure. Using Gene Ontology analysis, we found that cadmium stress affects three processes: transferase activity, stress response, and the cell cycle. Furthermore, we identified five differentially expressed genes (confirmed by real-time PCR) involved in all three processes: Ald, Cdc2, skpA, tefu, and Pvr. Pathway analysis revealed that these genes were involved in the cell cycle pathway and fat digestion and absorption pathway. This study reveals the gene expression response to cadmium stress in Drosophila, it provides insights into the mechanisms of this response, and it could contribute to our understanding of cadmium toxicity in humans.

  8. Coordinated Low Voltage Ride through strategies for Permanent Magnet Direct Drive Synchronous Generators

    Directory of Open Access Journals (Sweden)

    Zhang Ge

    2016-01-01

    Full Text Available By analyzing the mechanism of the low voltage ride through on the permanent magnet direct drive synchronous wind power generating units, this paper proposes a coordinated control strategy for permanent magnet synchronous generator. In order to avoid over speed operation of the generation units, over voltage on DC capacitor and over current on convert, the improved pitch angle control and inverter control are used. When the grid voltage drops, the captured wind power is cut down by the variable pitch system, which limits the speed of the generator, the generator side converter keeps the DC capacitor voltage stabile; and the grid side converter provides reactive power to the grid to help the grid voltage recover. The control strategy does not require any additional hardware equipment, with existing control means, the unit will be able to realize low voltage ride through. Finally, based on Matlab/Simulink to build permanent magnet direct drive wind power generation system, the simulation results verify the correctness and effectiveness of the control strategy.

  9. Cadmium exposure in the Swedish environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report gives a thorough description of cadmium in the Swedish environment. It comprises three parts: Cadmium in Sweden - environmental risks;, Cadmium in goods - contribution to environmental exposure;, and Cadmium in fertilizers, soil, crops and foods - the Swedish situation. Separate abstracts have been prepared for all three parts

  10. Cadmium carcinogenesis – some key points

    OpenAIRE

    2011-01-01

    The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney) induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  11. Cadmium carcinogenesis – some key points

    Directory of Open Access Journals (Sweden)

    Loreta Strumylaite

    2011-09-01

    Full Text Available The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  12. Pensionäride probleemid jõuavad Euroopa Komisjoni / Arvo Einre ; interv. Asse Soomets

    Index Scriptorium Estoniae

    Einre, Arvo, 1931-2012

    2005-01-01

    Eesti Pensionäride Ühendus sai Euroopa Komisjoni eakate nõukojalt (The European Older People Platform) kutse 31. märtsil Brüsselis toimuvale AGE töökoosolekule, kus käsitletakse pensionäride olukorda EL-i liikmesriikides. Eesti esindajana sõidab üritusele Eesti Pensionäride Ühenduse aseesimees Arvo Einre

  13. Robust Semi-Active Ride Control Under Stochastic Excitation (Briefing Charts)

    Science.gov (United States)

    2014-03-04

    ROBUST SEMI-ACTIVE RIDE CONTROL UNDER STOCHASTIC EXCITATION Jeremy Kolansky- Virginia Tech Amandeep Singh, Jill Goryca- US Army TARDEC...4. TITLE AND SUBTITLE ROBUST SEMI-ACTIVE RIDE CONTROL UNDER STOCHASTIC EXCITATION 5a. CONTRACT NUMBER W56hzv-04-2-0001 5b. GRANT NUMBER 5c...range • Robust for unknown input • Comparison • Conclusions Outline 3 2014-01-0145 UNCLASSIFIED SAE INTERNATIONAL Ride comfort for

  14. Subdural hematoma in a teenager related to roller-coaster ride.

    Science.gov (United States)

    Roldan-Valadez, Ernesto; Facha, M T; Martinez-Lopez, Manuel; Herrera-Mora, Patricia

    2006-07-01

    Reports about neurological injury related to roller-coaster rides mostly involve adults; we present a case of subdural hematoma in a pediatric patient presented 14 days after a roller-coaster ride. These rides show extreme up-and-down, to-and-fro, and rotatory acceleration/deceleration forces that could produce tensile and shearing stresses with tearing of bridging cerebral veins resulting in subdural hemorrhage. Pediatricians should consider roller-coaster riding a modern cause of subdural hematoma, as well as a possible cause of unexplained neurologic events in otherwise healthy adolescents.

  15. Cadmium-induced oxidative stress and histological damage in the myocardium. Effects of a soy-based diet

    Energy Technology Data Exchange (ETDEWEB)

    Ferramola, Mariana L.; Pérez Díaz, Matías F.F. [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina); Honoré, Stella M.; Sánchez, Sara S. [Department of Development Biology, INSIBIO, National University of Tucumán, CONICET-UNT, Tucumán (Argentina); Antón, Rosa I. [Department of Chemistry, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, INQUISAL, CONICET, San Luis (Argentina); Anzulovich, Ana C. [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina); Giménez, María S., E-mail: mgimenez@unsl.edu.ar [Department of Biochemistry and Biological Sciences, Faculty of Chemistry, Biochemistry and Pharmacy, National University of San Luis, IMIBIO-SL, CONICET, San Luis (Argentina)

    2012-12-15

    Cd exposure has been associated to an augmented risk for cardiovascular disease. We investigated the effects of 15 and 100 ppm of Cd on redox status as well as histological changes in the rat heart and the putative protective effect of a soy-based diet. Male Wistar rats were separated into 6 groups and treated during 60 days as follows: groups (1), (2) and (3) were fed a casein-based diet; groups (4), (5) and (6), a soy-based diet; (1) and (4) were given tap water; (2) and (5) tap water containing 15 ppm of Cd{sup 2+}; and (3) and (6) tap water containing 100 ppm of Cd{sup 2+}. Serum lipid peroxides increased and PON-1 activity decreased in group (3). Lipoperoxidation also increased in the heart of all intoxicated groups; however protein oxidation only augmented in (3) and reduced glutathione levels diminished in (2) and (3). Catalase activity increased in groups (3) and (6) while superoxide dismutase activity increased only in (6). Glutathione peroxidase activity decreased in groups (3) and (6). Nrf2 expression was higher in groups (3) and (6), and MTI expression augmented in (3). Histological examination of the heart tissue showed the development of hypertrophic and fusion of cardiomyocytes along with foci of myocardial fiber necrosis. The transmission electron microscopy analysis showed profound ultra-structural damages. No protection against tissue degeneration was observed in animals fed the soy-based diet. Our findings indicate that even though the intake of a soy-based diet is capable of ameliorating Cd induced oxidative stress, it failed in preventing cardiac damage. -- Highlights: ► Cd intoxication produces extracellular and ultrastructural damage in the myocardium. ► The intake of a soy-based diet ameliorated Cd-induced oxidative stress. ► Cd-induced myocardial damage wasn't prevented by the intake of a soy-based diet. ► Cd-induced myocardial degeneration may not be caused by oxidative stress generation. ► Histology evaluation is needed to

  16. 基于反馈线性化技术的直驱永磁同步风电机组低电压穿越研究%A low voltage ride through scheme of PMSG wind power systems based on feedback linearization technology

    Institute of Scientific and Technical Information of China (English)

    魏杰; 邱晓燕; 陈光堂; 崔伟; 张冰冰; 庄哲; 郑乔

    2013-01-01

    This paper proposes aAfter analyzing the wind turbine with a direct-driven PMSG, a low voltage ride through scheme of PMSG wind power systems based on feedback linearization through anis proposedalyzing the wind turbine with a direct-driven PMSG. The DC-Linklink voltage is maintained and regulated by generator-side converter. Considering the nonlinear relationship between the DC -Linklink voltage and the generator rotor speed, the controller of DC -Linklink voltage uses a feedback linearization technology. The grid-side converter which controls the grid-side active power according to the maximum power point tracking adds a judgment link for the generator speed reference.. The model of 2 MW PMSG wind power system was simulated by using PSCAD. The simulation results has have verified the validity of the proposed control scheme.%通过对直驱永磁同步风电系统的研究,提出了一种基于反馈线性化的低电压穿越控制策略.直流母线电压由发电机侧整流器来维持调节,考虑到直流母线电压和发电机转子转速的非线性关系,直流母线电压的控制采用了反馈线性化技术.网侧逆变器根据最大风能跟踪原则来控制网侧有功功率,并加入了转子速度参考值的判定环节.运用PSCAD仿真平台建立了一个2 MW的直驱永磁同步风电系统,验证了其正确性和有效性.

  17. CORSA: An Open Solution for Social Oriented Real-time Ride Sharing

    Directory of Open Access Journals (Sweden)

    Bonarrigo Simone

    2015-01-01

    Full Text Available The combination of the interest in environmental questions on one hand and the massive use of web based social networks on the other recently led to a revival of carpooling. In particular, the exploitation of social networks promotes the information spreading for an effective service (e.g. reducing the lack of confidence among users and endorses carpooling companies via viral marketing, finally acting as a basis for trust based users recommendation system In this work we outline CORSA, an open source solution for a real time ride sharing (RTRS carpooling service that endorses the role of social networks by using them as a conveying scenario for the virtual credits reward mechanism CORSA is based on.

  18. Bike Riding and the Art of Learning

    Science.gov (United States)

    Kraft, Robert G.

    1978-01-01

    Suggestions for becoming an effective teacher and motivating students to think creatively are proposed based on the author's personal experience and theories of Rogers, Dewey, Piaget, and Maslow. Maslow's hierarchy of human needs is adapted to stages of learning readiness. (LBH)

  19. Cadmium immobilization by hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Smičiklas Ivana D.

    2003-01-01

    Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

  20. A circular dichroism sensor for Ni{sup 2+} and Co{sup 2+} based on L-cysteine capped cadmium sulfide quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Tedsana, Wimonsiri [Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Tuntulani, Thawatchai [Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand); Ngeontae, Wittaya, E-mail: wittayange@kku.ac.th [Materials Chemistry Research Center, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand)

    2015-03-31

    Highlights: • Demonstrated a new efficient sensor platform based quantum dots. • Used chiral quantum dots as CD sensor for the detection of heavy metal ions for the first time. • The proposed CD sensor showed highest selectivity towards Ni{sup 2+} and Co{sup 2+}. • Low detection limits of 7.33 μM and 1.13 μM for Ni{sup 2+} and Co{sup 2+}, respectively. • Can be used in real water samples comparing with ICP-OES. - Abstract: A new circular dichroism sensor for detecting Ni{sup 2+} and Co{sup 2+} was proposed for the first time using chiral chelating quantum dots. The detection principle was based on changing of circular dichroism signals of the chiral quantum dots when forming a chiral complex with Ni{sup 2+} or Co{sup 2+}. L-Cysteine capped cadmium sulfide quantum dots (L-Cyst-CdS QDs) were proposed as a chiral probe. The CD spectrum of L-Cyst-CdS QDs was significantly changed in the presence of Ni{sup 2+} and Co{sup 2+}. On the other hand, other studied cations did not alter the original CD spectrum. Moreover, when increasing the concentration of Ni{sup 2+} or Co{sup 2+}, the intensity of the CD spectrum linearly increased as a function of concentration and could be useful for the quantitative analysis. The proposed CD sensor showed linear working concentration ranges of 10–60 μM and 4–80 μM with low detection limits of 7.33 μM and 1.13 μM for the detection of Ni{sup 2+} and Co{sup 2+}, respectively. Parameters possibly affected the detection sensitivity such as solution pH and incubation time were studied and optimized. The proposed sensor was applied to detect Ni{sup 2+} and Co{sup 2+} in real water samples, and the results agreed well with the analysis using the standard ICP-OES.

  1. Solid phase extraction and trace monitoring of cadmium ions in environmental water and food samples based on modified magnetic nanoporous silica

    Energy Technology Data Exchange (ETDEWEB)

    Omidi, Fariborz [Department of Occupational Health Engineering, School of Public Health, Shahroud University of Medical Sciences, Shahroud (Iran, Islamic Republic of); Behbahani, Mohammad, E-mail: mohammadbehbahai89@yahoo.com [Department of Chemistry, Shahid Beheshti University, Evin, Tehran (Iran, Islamic Republic of); Kalate Bojdi, Majid [Faculty of Chemistry, Kharazmi (Tarbiat Moallem) University, Tehran (Iran, Islamic Republic of); Shahtaheri, Seyed Jamaleddin [Department of Occupational Health Engineering, School of Public Health and Institute for Environmental Research, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2015-12-01

    A new method has been developed for trace separation/preconcentration of cadmium ions using pyridine-functionalized magnetic nanoporous silica material (called Py-Fe{sub 3}O{sub 4}@MCM-41) as a new magnetic sorbent and their determination by flame atomic absorption spectrometry (FAAS). The Py-Fe{sub 3}O{sub 4}@MCM-41 sorbent was characterized by thermogravimetric analysis, differential thermal analysis, transmission electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The modified Fe{sub 3}O{sub 4}@MCM-41 can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, amount of functionalized Fe{sub 3}O{sub 4}@MCM-41, extraction time, type and quantity of eluent, desorption time, and interfering ions on the extraction efficiency were evaluated and optimized. Under the optimized conditions, the detection limit and relative standard deviation was 0.04 μg L{sup –1} and 2.9%, respectively and the maximum adsorption capacity of the synthesized sorbent for cadmium ions was 154 mg g{sup −1}. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, rice, onion, carrot, lettuce, parsley, basil, tap water, river water and seawater with satisfactory results. - Highlights: • The introducing of modified magnetic mesoporous silica as a novel magnetic sorbent. • Trace monitoring of cadmium ions. • The limit of detection (LOD) by the proposed solid phase extraction method was 0.04 ng mL{sup −1} for the cadmium ions. • High surface areas and magnetic characteristic of the sorbent. • Maximum adsorption capacity of the sorbent was 154 mg g{sup −1}.

  2. Zinc to cadmium replacement in the A. thaliana SUPERMAN Cys₂ His₂ zinc finger induces structural rearrangements of typical DNA base determinant positions.

    Science.gov (United States)

    Malgieri, Gaetano; Zaccaro, Laura; Leone, Marilisa; Bucci, Enrico; Esposito, Sabrina; Baglivo, Ilaria; Del Gatto, Annarita; Russo, Luigi; Scandurra, Roberto; Pedone, Paolo V; Fattorusso, Roberto; Isernia, Carla

    2011-11-01

    Among heavy metals, whose toxicity cause a steadily increasing of environmental pollution, cadmium is of special concern due to its relatively high mobility in soils and potential toxicity at low concentrations. Given their ubiquitous role, zinc fingers domains have been proposed as mediators for the toxic and carcinogenic effects exerted by xenobiotic metals. To verify the structural effects of zinc replacement by cadmium in zinc fingers, we have determined the high resolution structure of the single Cys₂ His₂ zinc finger of the Arabidopsis thaliana SUPERMAN protein (SUP37) complexed to the cadmium ion by means of UV-vis and NMR techniques. SUP37 is able to bind Cd(II), though with a dissociation constant higher than that measured for Zn(II). Cd-SUP37 retains the ββα fold but experiences a global structural rearrangement affecting both the relative orientation of the secondary structure elements and the position of side chains involved in DNA recognition: among them Ser17 side chain, which we show to be essential for DNA binding, experiences the largest displacement.

  3. Dinuclear cadmium(II), zinc(II), and manganese(II), trinuclear nickel(II), and pentanuclear copper(II) complexes with novel macrocyclic and acyclic Schiff-base ligands having enantiopure or racemic camphoric diamine components.

    Science.gov (United States)

    Jiang, Jue-Chao; Chu, Zhao-Lian; Huang, Wei; Wang, Gang; You, Xiao-Zeng

    2010-07-05

    Four novel [3 + 3] Schiff-base macrocyclic ligands I-IV condensed from 2,6-diformyl-4-substituted phenols (R = CH(3) or Cl) and enantiopure or racemic camphoric diamines have been synthesized and characterized. Metal-ion complexations of these enantiopure and racemic [3 + 3] macrocyclic ligands with different cadmium(II), zinc(II), manganese(II), nickel(II), and copper(II) salts lead to the cleavage of Schiff-base C horizontal lineN double bonds and subsequent ring contraction of the macrocyclic ligands due to the size effects and the spatial restrictions of the coordination geometry of the central metals, the steric hindrance of ligands, and the counterions used. As a result, five [2 + 2] and one [1 + 2] dinuclear cadmium(II) complexes (1-6), two [2 + 2] dinuclear zinc(II) (7 and 8), and two [2 + 2] dinuclear manganese(II) (9 and 10) complexes together with one [1 + 1] trinuclear nickel(II) complex (11) and one [1 + 2] pentanuclear copper(II) complex (12), bearing enantiopure or racemic ligands, different substituent groups in the phenyl rings, and different anionic ligands (Cl(-), Br(-), OAc(-), and SCN(-)), have been obtained in which the chiral carbon atoms in the camphoric backbones are arranged in different ways (RRSS for the enantiopure ligands in 1, 2, 4, 5, and 7-10 and RSRS for the racemic ligands in 3, 6, 11, and 12). The steric hindrance effects of the methyl group bonded to one of the chiral carbon atoms of camphoric diamine units are believed to play important roles in the formation of the acyclic [1 + 1] trinuclear complex 11 and [1 + 2] dinuclear and pentanuclear complexes 6 and 12. In dinuclear cadmium(II), zinc(II), and manganese(II) complexes 1-10, the sequence of separations between the metal centers is consistent with that of the ionic radii shortened from cadmium(II) to manganese(II) to zinc(II) ions. Furthermore, UV-vis, circular dichroism, (1)H NMR, and fluorescence spectra have been used to characterize and compare the structural

  4. Fault Ride-Through Capability Enhancement of VSC HVDC connected Offshore Wind Power Plants

    DEFF Research Database (Denmark)

    Sharma, Ranjan; Wu, Qiuwei; Cha, Seung-Tae;

    2015-01-01

    This paper presents a feed forward direct current (DC) voltage control based fault ride-through (FRT) scheme for voltage source converter (VSC) high voltage DC (HVDC) connected offshore wind power plants (WPPs) in order to achieve active control of the WPP collector network AC voltage magnitude......, and to improve the FRT capability. During steady state operation, an open loop AC voltage control is implemented at the WPP side VSC of the HVDC system such that any possible control interactions between the WPP side VSC and the wind turbine VSC are minimized. Whereas during any grid faults, a dynamic AC voltage...... reference is applied based on both the DC voltage error and the AC active-current from the WPP collector system which ensures fast and robust FRT of the VSC HVDC connected offshore WPPs. Under unbalanced fault conditions in the host power system, the resulting oscillatory DC voltage is directly used...

  5. Carter’s Rewriting of Red Riding Hood

    Institute of Scientific and Technical Information of China (English)

    黄文诣

    2014-01-01

    "Little Red Riding Hood" is known worldwide and almost every child in China has heard this story. The Chinese one(Xiao Hongmao) is mainly derived from the Brothers Grimm’s version, while a less known version in China, called "The Company of Wolves", is written by a British female writer, Angela Carter. By putting different revisions of the same materials side by side, Carter makes a talk with herself. In this article, the author will mainly talk about what Carter learns from the previous version and what she wants to tell us from this exotic short story.

  6. Carter’s Rewriting of Red Riding Hood

    Institute of Scientific and Technical Information of China (English)

    黄文诣

    2014-01-01

    "Little Red Riding Hood" is known worldwide and almost every child in China has heard this story. The Chinese one (Xiao Hongmao) is mainly derived from the Brothers Grimm’s version, while a less known version in China, called“The Company of Wolves”, is written by a British female writer, Angela Carter. By putting different revisions of the same materials side by side, Carter makes a talk with herself. In this article, the author will mainly talk about what Carter learns from the previous version and what she wants to tell us from this exotic short story.

  7. Split ring floating air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A

    2015-11-03

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, and a central passage connecting the annular cavity to the annular piston chamber to supply compressed air to the seal face, where the annular piston assembly is a split piston assembly to maintain a tight seal as coning of the rotor disk occurs.

  8. Compression fractures of the vertebrae during a "bumpy" boat ride.

    LENUS (Irish Health Repository)

    Chukwunyerenwa, C K

    2012-01-31

    INTRODUCTION: Compression fracture of the vertebrae is common, often the result of falls from height and motor vehicle accidents in the younger age groups. It can occur following minor trauma in the elderly and in those with osteoporosis. MATERIALS AND METHODS: We present an interesting case of compression fracture of the vertebral bodies occurring simultaneously in a couple during a boat ride while on holiday. One individual had fracture of the T8, while the other fractured the L1 vertebrae. Both injuries were treated conservatively with Taylor braces. CONCLUSION: We highlight one of the potential hazards of this recreational activity, and the almost identical fracture pattern in this couple.

  9. A Comprehensive Review of Low-Voltage-Ride-Through Methods for Fixed-Speed Wind Power Generators

    DEFF Research Database (Denmark)

    Moghadasi, Amirhasan; Sarwat, Arif; Guerrero, Josep M.

    2016-01-01

    This paper presents a comprehensive review of various techniques employed to enhance the low voltage ride through (LVRT) capability of the fixed-speed induction generators (FSIGs)-based wind turbines (WTs), which has a non-negligible 20% contribution of the existing wind energy in the world....... As the FSIG-based WT system is directly connected to the grid with no power electronic interfaces, terminal voltage or reactive power output may not be precisely controlled. Thus, various LVRT strategies based on installation of the additional supporting technologies have been proposed in the literature...

  10. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Michael David [Iowa State Univ., Ames, IA (United States)

    2001-05-01

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn,Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  11. Numerical Simulation of the Performance Characteristics, Instability, and Effects of Band Gap Grading in Cadmium Telluride Based Photovoltaic Devices

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, Michael David [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Using computer simulations, the performance of several CdTe based photovoltaic structures has been studied. The advantages and disadvantages of band gap grading, through the use of (Zn, Cd)Te, have also been investigated in these structures. Grading at the front interface between a CdS window layer and a CdTe absorber layer, can arise due to interdiffusion between the materials during growth or due to the intentional variation of the material composition. This grading has been shown to improve certain performance metrics, such as the open-circuit voltage, while degrading others, such as the fill factor, depending on the amount and distance of the grading. The presence of a Schottky barrier as the back contact has also been shown to degrade the photovoltaic performance of the device, resulting in a characteristic IV curve. However, with the appropriate band gap grading at the back interface, it has been shown that the performance can be enhanced through more efficient carrier collection. These results were then correlated with experimental observations of the performance degradation in devices subjected to light and heat stress.

  12. Accumulation of cadmium by durum wheat roots: bases for citrate-mediated exceptions to the free ion model.

    Science.gov (United States)

    Berkelaar, Edward; Hale, Beverley A

    2003-05-01

    The accumulation of Cd in durum wheat (Triticum turgidum) roots from hydroponic solutions, with the proportion of total Cd (8.9-445 nM Cd) as Cd2+ varied by the addition of citrate, was determined to test the free-ion model (FIM) of metal bioavailability for higher plants. Calcium, Mg, and K were also varied. Citrate enhanced root-Cd accumulation at higher Cd2+ concentrations but not lower relative to the same Cd2+ concentrations in solutions containing 0 mM citrate. Elevating Ca2+ and Mg2+ concentrations in the citrate solution to the same as those in control solutions alleviated some of the citrate-mediated enhancement but not all. Solutions containing 66% less Ca or Mg than control but the same Cd2+ concentration and no citrate also resulted in increased root Cd. Elevated K+ did not influence Cd accumulation. Regression relationships between root-Cd accumulation and total Cd in solution were similar for the control and pooled amended solutions, whereas they were different for root-Cd accumulation and solution Cd2+. These results contribute to the growing body of evidence that the FIM alone is likely insufficient to predict plant accumulation of metals from soils, although it may be a useful probe for the mechanistic bases of metal bioavailability.

  13. Cadmium effects on the thyroid gland.

    Science.gov (United States)

    Jancic, Snezana A; Stosic, Bojan Z

    2014-01-01

    Cadmium has been listed as one of the 126 priority pollutants and a category I carcinogen. Carcinogenic effects of cadmium on the lungs, testicles, and prostate are widely recognized, but there has been insufficient research on the effect of cadmium on the thyroid gland. Cadmium has the affinity to accumulate not only in the liver, kidneys, and pancreas but also in the thyroid gland. It has been established that cadmium blood concentration correlates positively with its accumulation in the thyroid gland. Women of fertile age have higher cadmium blood and urine concentrations than men. In spite of its redox inertia, cadmium brings about oxidative stress and damage to the tissue by indirect mechanisms. Mitochondria are considered to be the main intracellular targets for cadmium. Colloid cystic goiter, adenomatoid follicular hyperplasia with low-grade dysplasia and thyroglobulin hypo- and asecretion, and parafollicular cell diffuse and nodular hyperplasia and hypertrophy are often found in chronic cadmium toxicity.

  14. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    for the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium chloride in rats. An experiment where 40 rats were divided into 4 groups and a control group and dosed...... with whole linseed, crushed linseed, cocoa and CdCl2 for 3 weeks was performed. Linseed or cocoa made up 10% of the feed (by weight) and was added as a replacement for carbohydrate source. The rats were dosed for 3 weeks and the cadmium content in the rats' kidneys was measured by ICPMS as a biomarker...... be measured in the kidney compared to the calculated total intake was as follows: Control 2.0 %, Crushed linseed 0.9 %, whole linseed, 1.5 %, cocoa 0.7 % and CdCl2 4.6 %. Based on this study it could not be concluded that the bioavailability in rats form whole linseed is lower that for crushed linseed...

  15. Occupation, cadmium exposure, and prostate cancer.

    Science.gov (United States)

    Elghany, N A; Schumacher, M C; Slattery, M L; West, D W; Lee, J S

    1990-03-01

    A population-based case-control study was used to investigate associations between prostate cancer and cadmium exposure, longest industry held, and longest occupation held. The study included 358 men with newly diagnosed prostate cancer and 679 control men identified from the Utah population. Occupational exposures to cadmium were ascertained from self-reported data, through several a priori suspect industries and occupations, through an occupation-exposure linkage system, and through dietary food frequency questionnaires. Overall, cadmium exposure appeared to result in a small increased relative risk for prostate cancer, most apparent for aggressive tumors (OR = 1.7, CI = 1.0-3.1 for any occupational exposure, high dietary intake, or smoking cigarettes). Cases were more likely to have worked in the following industries: mining, paper and wood, medicine and science, and entertainment and recreation. Among men younger than 67, cases were also more likely to have worked in the food and tobacco industries (OR = 3.6, CI = 1.0-12.8). Cases were less likely to have worked in industries involved with glass, clay and stone, or rubber, plastics, and synthetics. Men employed as janitors and in other building service occupations showed increased relative risk for aggressive tumors (OR = 7.0, CI = 2.5-19.6). Agricultural occupations did not appear to be related to prostate cancer, although an increased relative risk for aggressive tumors was detected among younger men (OR = 2.6, CI = 0.6-12.1).

  16. Fast Coordinated Control of DFIG Wind Turbine Generators for Low and High Voltage Ride-Through

    DEFF Research Database (Denmark)

    Wang, Yun; Wu, Qiuwei; Xu, Honghua

    2014-01-01

    This paper presents a fast coordinated control scheme of the rotor side converter (RSC), the DC chopper and the grid side converter (GSC) of doubly fed induction generator (DFIG) wind turbine generators (WTGs) which is to improve the low voltage ride through (LVRT) and high voltage ride through (...... verified by time domain simulations using MATLAB-Simulink....

  17. Review of ride quality technology needs of industry and user groups

    Science.gov (United States)

    Mckenzie, J. R.; Brumaghim, S. H.

    1975-01-01

    A broad survey of ride quality technology state-of-the-art and a review of user evaluation of this technology were conducted. During the study 17 users of ride quality technology in 10 organizations representing land, marine and air passenger transportation modes were interviewed. Interim results and conclusions of this effort are reported.

  18. Riding a tsunami in ocean science education

    Science.gov (United States)

    Reed, Donald L.

    1998-08-01

    An experiment began in late 1994 in which the WWW plays a critical role in the instruction of students in an oceanography course for non-majors. The format of the course consists of an equal blend of traditional lectures, tutorial-style exercises delivered from the course WWW site, classroom activities, such as poster presentations and group projects, and field excursions to local marine environments. The driving force behind the technology component of the course is to provide high-quality educational materials that can be accessed at the convenience of the student. These materials include course information and handouts, lecture notes, self-paced exercises, a virtual library of electronic resources, information on newsworthy marine events, and late-breaking oceanographic research that impacts the population of California. The course format was designed to partially meet the demands of today's students, involve students in the learning process, and prepare students for using technology in work following graduation. Students have reacted favorably to the use of the WWW and comments by peers have been equally supportive. Students are more focused in their efforts during the computer-based exercises than while listening to lecture presentations. The implementation of this form of learning, however, has not, as yet, reduced the financial cost of the course or the amount of instructor effort in providing a high quality education. Interactions between the instructor and students have increased significantly as the informality of a computer laboratory promotes individual discussions and electronic communication provides students with easy (and frequent) access to the instructor outside of class.

  19. Enrichment of cadmium in biomasses

    Energy Technology Data Exchange (ETDEWEB)

    Gwenner, C.; Wittig, H.; Glombitza, F.

    1986-01-01

    The uptake of cadmium ions from an aqueous solution by living, resting, and dead biomasses was investigated. The dependence of the uptaked amounts on pH-value of the medium, temperature and concentration of cadmium ions is demonstrated as well as the rate of uptake. Maximum realisable concentrations were 12 mg/g biomass in living cells and about 20 mg/g biomass in resting or dead cells, respectively.

  20. DIOSCÓRIDES RESCATADO POR LOS ÁRABES

    Directory of Open Access Journals (Sweden)

    Ricardo H Elía

    2009-01-01

    Full Text Available La historia oficial afirma que Occidente heredó directamente el legado cultural de Grecia y Roma. Pero si la mayoría de los manuscritos griegos y latinos fueron destruidos a partir del saqueo de la Biblioteca de Alejandría en 391, los archivos de Roma fueron devastados en sendas ocasiones entre 410 y 476 por visigodos y hérulos, y los escasos vestigios clásicos que quedaban en Atenas fueron arrasados por Justiniano I en 529, ¿cuál fue la conexión que logró transmitir esa literatura y pudo ser aprovechada en un período anterior al renacimiento? La salvación de las piezas literarias se realizó durante ochocientos afios de activa y responsable tarea de recopilación por parte de los árabes durante la línea de tiempo que oscila entre 650-1450 en la que fueron rescatados, traducidos y retransmitidos hacia los cuatro puntos cardinales. Los científicos árabes, al igual que Arquímedes o Herón, nunca se separaron del saber empírico, por el contrario, lo profundizaron. El movimiento científico árabe no sólo interpretó el saber de los antiguos sino desarrolló una nueva ciencia donde la razón sustentaba a la fe y viceversa. Esta fue la base esencial que permitió construir el Renacimiento y la Ilustración, que a su vez posibilitaron la Modernidad. En este contexto, fue de capital importancia la traducción al árabe de la obra de Dioscórides ya que no sólo fue de gran utilidad para la farmacología y medicina en el mundo musulmán sino que a través de éste las recetas del médico griego de Nerón reingresaron a la Europa latina donde fueron recibidas como una panacea.Official history affirms that the West directly inherited the cultural legacy of Greece and Rome. But if most of the Greek and latin manuscripts they were destroyed at the sacking of the Library of Alexandria in 391, the archives of Rome were devastated in several occasions between 410 and 476 by Visigoth and heruls, and the little classic vestiges that were in

  1. Effects of horseback riding exercise therapy on hormone levels in elderly persons

    Science.gov (United States)

    Cho, Sung-Hyoun; Kim, Jin-Woo; Kim, Seon-Rye; Cho, Byung-Jun

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effect of riding exercise on hormone levels in normal elderly people who were taught horseback riding for 8 weeks. [Subjects] Subjects were classified into an exercise group (n=10) and control group (n=10). [Methods] The two groups, horseback riding exercise group of 10 and control group of 10, were each tested for 15 minutes, 3 times, over 8 weeks. Post-exercise tests were implemented in both groups in the same way as pre-study tests. [Results] The horseback riding group showed a significant difference in the pre- and post-exercise serotonin and cortisol levels. Additionally, serotonin and cortisol levels showed significant differences between the two groups. [Conclusion] Serotonin and cortisol levels significantly increased in the experimental group, suggesting that horseback riding exercise is effective for improving the levels of these hormones. PMID:26311966

  2. Study on the ride comfort of vehicles driven by in-wheel motors

    Directory of Open Access Journals (Sweden)

    Liqiang Jin

    2016-02-01

    Full Text Available Vehicles driven by in-wheel motors have received more and more attention. However, due to the introduction of in-wheel motors, the ratio between unsprung and sprung mass is increased. In this article, to study the influence of this change on ride comfort of vehicles driven by in-wheel motors, an 11 degrees of freedom of vehicle ride comfort model will be presented and studied with MATLAB/Simulink. Then, road tests will be conducted to corroborate the simulation results. It can be obtained that the vehicle ride comfort becomes poor with the increasing unsprung mass. Finally, semi-active air-suspension proportional–integral–derivative control system will be proposed to improve the vehicle ride comfort. Through the simulation results, one can come to a conclusion that the proportional–integral–derivative control system for air suspension is feasible and effective to improve the ride comfort of the vehicles driven by in-wheel motors.

  3. Hardness of Preemptive Finite Capacity Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li

    2006-01-01

    In the Finite Capacity Dial-a-Ride problem the input is a metric space, a set of objects, each specifying a source and a destination, and an integer k---the capacity of the vehicle used for making the deliveries. The goal is to compute a shortest tour for the vehicle in which all objects can...... be delivered from their sources to their destinations while ensuring that the vehicle carries at most k objects at any point in time. In the preemptive version an object may be dropped at intermediate locations and picked up later and delivered. Let N be the number of nodes in the input graph. Charikar...... and Raghavachari [FOCS '98] gave a min{O(log N),O(k)}-approximation algorithm for the preemptive version of the problem. In this paper we show that the preemptive Finite Capacity Dial-a-Ride problem has no $min{O(log^{1/4-\\epsilon}N),k^{1-\\epsilon}}$-approximation algorithm for any $\\epsilon>0$ unless all problems...

  4. Free-riding behavior in vaccination decisions: an experimental study.

    Directory of Open Access Journals (Sweden)

    Yoko Ibuka

    Full Text Available Individual decision-making regarding vaccination may be affected by the vaccination choices of others. As vaccination produces externalities reducing transmission of a disease, it can provide an incentive for individuals to be free-riders who benefit from the vaccination of others while avoiding the cost of vaccination. This study examined an individual's decision about vaccination in a group setting for a hypothetical disease that is called "influenza" using a computerized experimental game. In the game, interactions with others are allowed. We found that higher observed vaccination rate within the group during the previous round of the game decreased the likelihood of an individual's vaccination acceptance, indicating the existence of free-riding behavior. The free-riding behavior was observed regardless of parameter conditions on the characteristics of the influenza and vaccine. We also found that other predictors of vaccination uptake included an individual's own influenza exposure in previous rounds increasing the likelihood of vaccination acceptance, consistent with existing empirical studies. Influenza prevalence among other group members during the previous round did not have a statistically significant effect on vaccination acceptance in the current round once vaccination rate in the previous round was controlled for.

  5. Minimum Makespan Multi-Vehicle Dial-a-Ride

    DEFF Research Database (Denmark)

    Gørtz, Inge Li; Nagarajan, Viswanath; Ravi, R.

    2015-01-01

    Dial-a-Ride problem, there are q vehicles, each having capacity k and where each vehicle j epsilon [q] has its own depot-vertex r(j) epsilon V. A feasible schedule consists of a capacitated route for each vehicle (where vehicle j originates and ends at its depot r(j)) that together move all objects...... from their sources to destinations. The objective is to find a feasible schedule that minimizes the maximum completion time (i.e., makespan) of vehicles, where the completion time of vehicle j is the time when it returns to its depot r(j) at the end of its route. We study the preemptive version......Dial-a-Ride problems consist of a set V of n vertices in a metric space (denoting travel time between vertices) and a set of m objects represented as source-destination pairs {(s(i), t(i))}(i-1)(m), where each object requires to be moved from its source to destination vertex. In the multi-vehicle...

  6. Predictors of urinary cadmium levels in adult females

    Energy Technology Data Exchange (ETDEWEB)

    McElroy, Jane A. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States)]. E-mail: jamcelroy@wisc.edu; Shafer, Martin M. [University of Wisconsin, Environmental Chemistry and Technology Program, 600 N Park Street, Madison, WI 53706 (United States); Hampton, John M. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States); Newcomb, Polly A. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States); Fred Hutchinson Cancer Research Center, Cancer Prevention Program, 1100 Fairview Ave N, M4-B402 PO Box 19024, Seattle, WA 98109 (United States)

    2007-09-01

    Ubiquitous exposure to low levels of cadmium has raised concern about adverse health effects. The aim of this study was to identify characteristics of non-occupationally exposed adult females that correlated with creatinine-adjusted urinary cadmium levels. In our population-based study, trained interviewers collected information from 254 female Wisconsin residents aged 20-69 years on tobacco use, limited dietary consumption patterns, reproductive history, demographics, and residential history. Participants provided spot-urine specimens collected at home. Urine cadmium concentrations were quantified using inductively-coupled plasma mass spectrometry and creatinine levels were also determined. Least square means and 95% confidence intervals for the natural log of the creatinine-adjusted urinary cadmium levels were calculated for each characteristic using multivariate analysis of variance adjusting for age and smoking status. Results were calculated on the log scale and then transformed to the original scale by taking the exponent of each of the values. We observed statistically significant increasing creatinine-adjusted urinary cadmium mean levels relative to smoking status, older age, parity, lower body surface area, mineral zinc supplement consumption, and high income. We did not observe a difference relative to consumption of organ meats, crustaceans, alcohol, multivitamins, multiminerals or homegrown vegetables, age of menopause, menarche of participant or oldest daughter, menopausal status or urban-rural residential location. Approximately 40% of the variance in creatinine-adjusted urinary cadmium levels in adult women was explained by several characteristics. Similar to other studies, age and smoking were the strongest determinants of creatinine-adjusted urinary cadmium concentration.

  7. Inclination to speeding and its correlates among two-wheeler riding Indian youth

    Directory of Open Access Journals (Sweden)

    Rajeev J Michael

    2014-01-01

    Full Text Available Context: Concerns about road safety have been increasingly associated with two-wheeler riding and especially with young commuters in India. Aims: The study was designed to explore inclination to speeding and to profile the driving behaviors in two-wheeler riding young men and women who reported a tendency to ride faster than their peers. Design: A cross-sectional survey design was used. Materials and Methods: On the basis of three focus group discussions and review of literature, a survey was prepared to tap domains such as affect states associated with riding/speeding, factors contributing to speeding, inclination for competing, perceived speed and safety, etc. The study sample comprised of 961 two-wheeler riding college-going young men and women in Bangalore. Statistical Analysis: Descriptive and inferential statistical procedures were used including Chi-square, Spearman′s rank correlation, and independent sample t-test. Results: The sample was divided into two subgroups on the basis of self-report of greater speeding than one′s peers. A subgroup of 349 participants endorsed the item regarding inclination to ride faster than one′s peers, whereas, the remaining 612 participants did not endorse it. The profiles of these two subgroups were obtained in terms of sociodemographic variables, riding behaviors, and associated domains. Significant differences between the subgroups emerged on domains such as motives for riding fast, tendency for competing, perceived safety and frequency of minor accidents while riding. Conclusions: Several correlates of the tendency to speeding among young two-wheeler riders emerged that have implications for enhancing safe riding.

  8. Improved Control Strategy for DFIG Wind Turbines for Low Voltage Ride Through

    Directory of Open Access Journals (Sweden)

    Chanxia Zhu

    2013-02-01

    Full Text Available This paper presents an improved control strategy for both the rotor side converter (RSC and grid side converter (GSC of a doubly fed induction generator (DFIG-based wind turbine (WT system to enhance the low voltage ride through (LVRT capability. Within the proposed control strategy, the RSC control introduces transient feed-forward compensation terms to mitigate the high frequency harmonic components and reduce the surge in the rotor currents. The proposed GSC control scheme also introduces a compensation term reflecting the instantaneous variation of the output power of the rotor side converter with consideration of the instantaneous power of grid filter impendence to keep the dc-link voltage nearly constant during the grid faults. To provide precise control, non-ideal proportional resonant (PR controllers for both the RSC and GSC current regulation are employed to further improve dynamic performance. Simulations performed in Matlab/Simulink verify the effectiveness of the proposed control strategy.

  9. Improving Low Voltage Ride Through Capability of Wind Generators Using Dynamic Voltage Restorer

    Science.gov (United States)

    Sivasankar, Gangatharan; Suresh Kumar, Velu

    2014-08-01

    The increasing wind power integration with power grid has forced the situation to improve the reliability of wind generators for stable operation. One important problem with induction generator based wind farm is its low ride through capability to the grid voltage disturbance. Any disturbance such as voltage dip may cause wind farm outages. Since wind power contribution is in predominant percentage, such outages may lead to stability problem. The proposed strategy is to use dynamic voltage controller (DVR) to compensate the voltage disturbance. The DVR provides the wind generator the ability to remain connected in grid and improve the reliability. The voltage dips due to symmetrical and unsymmetrical faults are considered for analysis. The vector control scheme is employed for fault compensation which uses software phase locked loop scheme and park dq0 transformation technique. Extensive simulation results are included to illustrate the control and operation of DVR.

  10. Aircraft ride quality controller design using new robust root clustering theory for linear uncertain systems

    Science.gov (United States)

    Yedavalli, R. K.

    1992-01-01

    The aspect of controller design for improving the ride quality of aircraft in terms of damping ratio and natural frequency specifications on the short period dynamics is addressed. The controller is designed to be robust with respect to uncertainties in the real parameters of the control design model such as uncertainties in the dimensional stability derivatives, imperfections in actuator/sensor locations and possibly variations in flight conditions, etc. The design is based on a new robust root clustering theory developed by the author by extending the nominal root clustering theory of Gutman and Jury to perturbed matrices. The proposed methodology allows to get an explicit relationship between the parameters of the root clustering region and the uncertainty radius of the parameter space. The current literature available for robust stability becomes a special case of this unified theory. The bounds derived on the parameter perturbation for robust root clustering are then used in selecting the robust controller.

  11. New approaches to provide ride-through for critical loads in electric power distribution systems

    Science.gov (United States)

    Montero-Hernandez, Oscar C.

    2001-07-01

    The extensive use of electronic circuits has enabled modernization, automation, miniaturization, high quality, low cost, and other achievements regarding electric loads in the last decades. However, modern electronic circuits and systems are extremely sensitive to disturbances from the electric power supply. In fact, the rate at which these disturbances happen is considerable as has been documented in recent years. In response to the power quality concerns presented previously, this dissertation is proposing new approaches to provide ride-through for critical loads during voltage disturbances with emphasis on voltage sags. In this dissertation, a new approach based on an AC-DC-AC system is proposed to provide ride-through for critical loads connected in buildings and/or an industrial system. In this approach, a three-phase IGBT inverter with a built in Dc-link voltage regulator is suitably controlled along with static by-pass switches to provide continuous power to critical loads. During a disturbance, the input utility source is disconnected and the power from the inverter is connected to the load. The remaining voltage in the AC supply is converted to DC and compensated before being applied to the inverter and the load. After detecting normal utility conditions, power from the utility is restored to the critical load. In order to achieve an extended ride-through capability a second approach is introduced. In this case, the Dc-link voltage regulator is performed by a DC-DC Buck-Boost converter. This new approach has the capability to mitigate voltage variations below and above the nominal value. In the third approach presented in this dissertation, a three-phase AC to AC boost converter is investigated. This converter provides a boosting action for the utility input voltages, right before they are applied to the load. The proposed Pulse Width Modulation (PWM) control strategy ensures independent control of each phase and compensates for both single-phase or poly

  12. Metaheuristics for the dynamic stochastic dial-a-ride problem with expected return transports.

    Science.gov (United States)

    Schilde, M; Doerner, K F; Hartl, R F

    2011-12-01

    The problem of transporting patients or elderly people has been widely studied in literature and is usually modeled as a dial-a-ride problem (DARP). In this paper we analyze the corresponding problem arising in the daily operation of the Austrian Red Cross. This nongovernmental organization is the largest organization performing patient transportation in Austria. The aim is to design vehicle routes to serve partially dynamic transportation requests using a fixed vehicle fleet. Each request requires transportation from a patient's home location to a hospital (outbound request) or back home from the hospital (inbound request). Some of these requests are known in advance. Some requests are dynamic in the sense that they appear during the day without any prior information. Finally, some inbound requests are stochastic. More precisely, with a certain probability each outbound request causes a corresponding inbound request on the same day. Some stochastic information about these return transports is available from historical data. The purpose of this study is to investigate, whether using this information in designing the routes has a significant positive effect on the solution quality. The problem is modeled as a dynamic stochastic dial-a-ride problem with expected return transports. We propose four different modifications of metaheuristic solution approaches for this problem. In detail, we test dynamic versions of variable neighborhood search (VNS) and stochastic VNS (S-VNS) as well as modified versions of the multiple plan approach (MPA) and the multiple scenario approach (MSA). Tests are performed using 12 sets of test instances based on a real road network. Various demand scenarios are generated based on the available real data. Results show that using the stochastic information on return transports leads to average improvements of around 15%. Moreover, improvements of up to 41% can be achieved for some test instances.

  13. On-line Ultrasound-Assisted Dispersive Micro-Solid-Phase Extraction Based on Amino Bimodal Mesoporous Silica Nanoparticles for the Preconcentration and Determination of Cadmium in Human Biological Samples.

    Science.gov (United States)

    Shirkhanloo, H; Falahnejad, M; Zavvar Mousavi, H

    2016-06-01

    On-line ultrasound-assisted dispersive micro-solid-phase extraction (USA-DμSPE) has been developed for preconcentration and separation of trace amounts of Cd(II) ions in 0.5 mL of human biological samples. In a syringe with a nylon membrane, new synthetic bulky amino bimodal mesoporous silica nanoparticles (NH2-UVM7) were dispersed as a nanoadsorbent in 5 mL of diluted serum sample (1:10), and after ultrasonic shaking, the liquid phase was separated from the solid phase. At the optimized pH, the chemical and physical adsorption of cadmium ions occurred, respectively, based on complexation with amine groups of UVM7 (Cd:NH2-UVM7) and silica nanoparticles. The analyte was then back-extracted from the sorbent with nitric acid solution (0.2 M), and its concentration was determined by electrothermal atomic absorption spectrometry (ETAAS). Under the optimized conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were obtained as 0.01-0.56 μg L(-1), 0.002 μg L(-1), and 25, respectively. The adsorption capacity of NH2-UVM7 was found to be 108.6 mg g(-1) of cadmium. The validation of the methodology was performed by the human standard reference material (HSRM).

  14. Phenols and phenol oxidases are involved in cadmium accumulation in the water plants Nymphoides peltata (Menyanthaceae) and Nymphaeae (Nymphaeaceae).

    Science.gov (United States)

    Lavid, N; Schwartz, A; Lewinsohn, E; Tel-Or, E

    2001-12-01

    This comparative study investigates the mechanism of cadmium accumulation in the semiaquatic plant Nymphoides peltata (Menyanthaceae) and the aquatic plant Nymphaea (Nymphaeaceae). It was conducted as part of an ongoing study of the use of water plants for phytoremediation. Epidermal structures, known as hydropotes, are located on the abaxial epidermis of the leaf laminae of Nymphoides peltata and are shown to contain phenols, peroxidase and polyphenol oxidase activities. When plants are subjected to 50 mg/l of cadmium in the growth medium, these hydropotes accumulate cadmium. Cadmium-induced increases in phenols, peroxidase and polyphenol oxidase activities were determined in plant extracts. Cadmium binding by polymerized phenols was demonstrated in vivo. In comparison with Nymphaeae epidermal glands, N. peltata hydropotes are larger, open, and create bigger crystal, the latter principally composed of calcium and, proportionally, less cadmium. Although both plants showed similar levels of cadmium accumulation, N. peltata was sensitive while Nymphaeae was resistant to this cadmium level. It is suggested that in these water plants the main mechanism for cadmium accumulation is based on the trapping of cadmium crystals by polymerized phenols in specialized epidermal structures and this is due to peroxidase and polyphenol oxidase activities. Nymphaeae, with greater peroxidase activity and more polyphenols, is more resistant to this heavy metal than N. peltata.

  15. High blood cadmium levels are not associated with consumption of traditional food among the Inuit of Nunavik

    Energy Technology Data Exchange (ETDEWEB)

    Rey, M. [Instituto Nacional de Cancerologia, Bogota (Colombia); Turcotte, F.; Lapointe, C. [Universite Laval, Quebec City (Canada)] [and others

    1997-09-01

    High levels of cadmium in the liver and kidneys of caribous and sea mammals of the Canadian Arctic have led to recommendations to remove such offal from the traditional diet. Blood cadmium levels have been found to be very high in samples of Inuit volunteers, hence the hypothesis that the Inuit might be exposed to cadmium through their diet. This survey of a population-based random sample of Nunavik residents (n = 518) confirms that blood cadmium of Inuit is indeed very high by comparison to published reports. Blood cadmium levels are closely associated with the current smoking status and are independent of dietary patterns among nonsmokers. Plasma omega-3 fatty acids concentrations have been used to assess the reliability of the dietary information collected by questionnaires and to test for any association of blood cadmium with the consumption of sea mammals. Blood cadmium levels are not related to the reported consumption of sea mammals. Blood cadmium levels are very high among smokers and are associated with levels of exposure to tobacco. Among nonsmoking Inuit, blood cadmium levels are comparable with those reported in nonsmokers elsewhere in the world. In reference to international standards, blood cadmium concentrations are high enough among the Inuit to warrant energetic public health interventions. 28 refs., 5 tabs.

  16. Study on Low Voltage Ride Through Enhancement of Grid-Connected Wind Farm Based on Doubly Fed Induction Generator%改善基于双馈感应发电机并网风电场的低电压穿越能力研究

    Institute of Scientific and Technical Information of China (English)

    赵海岭; 王维庆; 姚秀萍; 常喜强

    2012-01-01

    To maintain stability of the power system, large grid-connected wind farms are required to have capability of low voltage ride through (LVRT). These years, the research on LVRT of doubly-fed induction generators (DFIG) has become a hot issue The paper introduces the device of braking resistor and its effect contributed to the transient characteristics of DFIG. Contributions of the braking resistor to capability of LVRT of DFIG with a voltage dip on the grid side are analyzed in detail. The enhancement of capability of LVRT based on DFIG is analyzed with the braking resistor placed respectively at the low side of the transformer of wind farm and at the terminal of DFIG. The result shows that the braking resistor of the proper size can substantially improve the capability of LVRT in the grid -connected wind farm, and the enhancement is better with the braking resistor placed at the low side of the transformer of the wind farm rather than the terminal of doubly-fed induction generators.%为保持系统稳定,必须要求大规模并网风电场具有低电压穿越能力.双馈感应发电机(DFIG)低电压穿越功能已成为研究热点.介绍了串联制动电阻装置对双馈感应发电机暂稳特性贡献的机理.详细分析了在电网故障情况下,制动电阻装置对双馈风电场低电压穿越能力的贡献,分别就制动电阻接在风电场升压变处与接在双馈感应发电机机端对低电压穿越的改善效果进行分析.试验结果表明:故障期间投入适当大小制动电阻,能较好地提高双馈风电场低电压穿越功能;将制动电阻放置在风电场升压变处贡献效果优于将制动电阻装置放置在双馈感应发电机机端处.

  17. 模块化多电平直流输电联网风电场时的低电压穿越技术%Low Voltage Ride-Through Technology for Wind Farms Connected to Power Grid via MMC-Based HVDC Transmission

    Institute of Scientific and Technical Information of China (English)

    赵静; 赵成勇; 孙一莹; 张建坡; 敬华兵

    2013-01-01

    It is a better scheme for grid-connection of large-capacity long-distance offshore wind farms via HVDC flexible.Aiming at the problem of applying modular multilevel converter-based HVDC (MMC-HVDC) to grid-connection of large-scale offshore wind farms,corresponding steady-state control strategy for MMC-HVDC is analyzed and researched,and the feasibility of such a scheme is verified by simulation.To ensure that when unsymmetrical fault occurred at the grid-connection point,where the grid-connection system is connected to AC power grid,the not-off-grid operation of wind farm can be sustained,a controller for MMC-HVDC during unsymmetrical fault is designed to isolate the wind farm from the fault and transmit power to AC grid as possible to improve the low voltage ride-through capability of the wind farm.The feasibility and effectiveness of the proposed method are verified by the simulation carried out in PSCAD/EMTDC.%柔性直流输电并网方式对于大容量远距离海上风电场是一种较好的并网方案.针对模块化多电平直流输电(modular multilevel converter-HVDC,MMC-HVDC)应用于大规模风电场联网问题,分析研究了相应的MMC-HVDC稳态控制策略,仿真验证了其可行性.为保证当联网系统与交流系统的并网点发生不对称故障时风电场可以不脱网持续运行,设计了MMC-HVDC不对称故障期间的控制器,以将风电场与故障隔离并尽可能将功率传送至交流系统中,提高了风电场的低电压穿越能力,并在PSCAD/EMTDC中搭建的仿真模型上验证了此方法的可行性及有效性.

  18. 基于二阶滑模控制的驾束制导导弹一体化制导系统设计%Integrated Guidance-Control System for Beam-riding Guidance Missiles Based on Second Order Sliding Mode Control

    Institute of Scientific and Technical Information of China (English)

    周军; 王婷

    2007-01-01

    针对驾束制导导弹,运用超扭曲二阶滑模控制理论,提出了一种一体化制导控制算法.通过充分考虑目标不确定因素以及控制回路未建模状态,建立了一体化制导控制回路的四阶状态方程.运用该状态方程的转移矩阵,重新定义了零能脱靶量(ZEM),使其不再需要估计剩余时间,并将此作为滑模切换面,设计了一体化超扭曲二阶滑模制导律.通过对目标的拦截仿真,结果表明制导线偏差可在有限时间内收敛到零,从而验证了选择新定义的ZEM作为制导律的滑模切换面是有效的.数字仿真结果也表明了该一体化设计方法明显优于不考虑控制回路的传统制导律设计方法.%An Integrated Guidance-Control(IGC) law is proposed , using the super-twisting second order Sliding Mode Control(SMC) method, for the beam-riding guidance missiles . The fourth order state equation for integrated guidance and control loop was formulated taking into consideration the target uncertainties and control loop dynamics. Based on the transition matrix of the state equation, the zero-effort miss (ZEM) was redefined without calculating the time-to-go. By choosing the ZEM as a single sliding surface, the integrated super-twisting second order sliding mode guidance law was obtained. Simulation results show that ZEM and guidance range error could converge to zero in a finite time almost without any overshoot. The advantages of the integrated guidance are also validated by comparing with the conventional guidance without considering control loop.

  19. Zinc-induced protection against cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  20. 基于刚柔耦合模型的电动轮自卸车平顺性分析与优化%Analysis and Optimization of Ride Comfort of Electric Wheel Dump Truck Based on a Rigid-flexible Coupling Model

    Institute of Scientific and Technical Information of China (English)

    伍文广; 谷正气; 米承继

    2014-01-01

    In order to evaluate and optimize the ride comfort of the dump truck ,this paper presen-ted a domestic large-scale electric wheel dump truck ride comfort test ,in an open pit mine ,and the vi-bration acceleration of the position such as the deck and the chair etc .were obtained .The results show that the ride is poorer ,and should be optimized .In order to improve the model’s accuracy ,a coupled multi-body dynamics model of this truck was built ,containing flexible main-frame ,and model were verified by the test data .The results show that the precision is increased by 11.5% than that from pure rigid body dynamics model .According to the characteristics of the nonlinear hydro-pneumatic suspension ,using the hydro-pneumatic suspension parameters as the design variables ,and using the ride comfort evaluation value as objective function ,an approximate surrogate model of ride comfort was built ,the Pointer algorithm was adopted to ride comfort optimization ,the results show that the ride comfort of the truck improves by 27% after optimization .%为了分析和优化自卸车的平顺性,在国内某矿山上对某国产大型电动轮自卸车进行了平顺性试验,得到了其甲板、座椅等位置的振动加速度并进行了分析,结果表明,其行驶平顺性较差,应当对其进行优化。为了提高平顺性分析动力学模型的精确性,建立了包含柔性化车架的整车刚柔耦合多体动力学模型,并通过试验数据对模型进行了验证,结果表明,所建立的模型精度比纯刚体动力学模型提高了11.5%。针对非线性油气悬架的特点,以油气悬架结构参数为设计变量,以平顺性综合评价值为目标函数,建立了平顺性优化近似模型,采用Pointer算法对其平顺性进行了优化,结果表明,优化后自卸车的平顺性提高了27%。

  1. Metallothionein and bioaccumulation of cadmium in juvenile bluegills exposed to aqueous and sediment-associated cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Cope, W.G.

    1991-01-01

    The author evaluated metallothionein (MT), free (unbound) hepatic cadmium and whole body cadmium as indicators of cadmium exposure in juvenile bluegills Lepomis macrochirus in laboratory tests. Two types of cadmium exposure were tested; aqueous and sediment-associated. In the aqueous tests, fish were exposed to cadmium (0.0 to 32.3 [mu]g/L) in an intermittent-flow diluter. In the sediment-associated cadmium test, fish were exposed to resuspended river sidment containing 1.3 to 21.4 [mu]g Cd/g (dry weight) at a nominal total suspended solids concentration of 1,000 mg/L in revolving, circular glass exposure chambers. Total cadmium concentrations were measured in various bluegill liver fractions, whole bluegill, water, and resuspended sediment to assess the partitioning and bioaccumulation of cadmium after the tests. Mean concentrations of MT and free cadmium in bluegill livers and concentrations of cadmium in whole bluegills were positively correlated with aqueous cadmium concentration and were equally suitable as indicators of aqueous cadmium exposure. Sediment-associated cadmium was biologically available, but to a lesser extent than aqueous cadmium. Cadmium concentrations in whole bluegills exposed to resuspended river sediment were 1.5- to 3.5-fold the concentrations in bluegills in sediment-free controls. Free cadmium and MT concentrations in bluegill liver and whole-body cadmium concentrations in bluegills were positively correlated with the cadmium concentrations in filtered water, resuspended sediment, and bulk river sediment; however, whole-body cadmim concentrations were a more sensitive indicator of exposure to sediment-associated cadmium than either free cadmium or MT concentratons in liver.

  2. Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium

    Directory of Open Access Journals (Sweden)

    Lawrence Ikechukwu Ezemonye

    2011-12-01

    Full Text Available Adult Bufo maculatus was exposed to sublethal cadmium concentrations of 0.25, 0.50, 1.00 and 2.00 mg/L. The toxicant from which the cadmium concentrations were prepared was cadmium chloride (CdCl2.H2O. There were three replicate tanks per treatment and three individuals per tank including control groups. The hematologic alterations based on the examination of blood indices during the 28 days of exposure showed that total erythrocyte count (TEC, hematocrit (Hct and hemoglobin (Hb concentration decreased (P<0.05 relative to controls. The decline was concentration- dependent as concentration of cadmium increased. The decline in hemoglobin and hematocrit in the experimental organism could be due to a decrease in the synthesis or release of erythrocytes into the circulation or an increase in the rate of erythrocyte destruction inflicted by cadmium toxicity. There was significant (P<0.05 elevation in total leuko- leukocyte count (TLC with increase in the concen- cyte concentration of cadmium. The increase in total leukocyte count observed in this study could be attributed to a stimulation of the immune system in response to tissue damage caused by cadmium toxicity. The study has shown that the exposure of the Bufo maculatus toad to cadmium can inflict alterations in the hematologic indices, which could induce unfavorable physiological changes in the amphibian, which may lead to death. There is, therefore, the need to protect amphibians in order to sustain the biodiversity in the Nigerian Niger Delta ecological zone.

  3. Human pelvis motions when walking and when riding a therapeutic horse.

    Science.gov (United States)

    Garner, Brian A; Rigby, B Rhett

    2015-02-01

    A prevailing rationale for equine assisted therapies is that the motion of a horse can provide sensory stimulus and movement patterns that mimic those of natural human activities such as walking. The purpose of this study was to quantitatively measure and compare human pelvis motions when walking to those when riding a horse. Six able-bodied children (inexperienced riders, 8-12years old) participated in over-ground trials of self-paced walking and leader-paced riding on four different horses. Five kinematic measures were extracted from three-dimensional pelvis motion data: anteroposterior, superoinferior, and mediolateral translations, list angle about the anteroposterior axis, and twist angle about the superoinferior axis. There was generally as much or more variability in motion range observed between riding on the different horses as between riding and walking. Pelvis trajectories exhibited many similar features between walking and riding, including distorted lemniscate patterns in the transverse and frontal planes. In the sagittal plane the pelvis trajectory during walking exhibited a somewhat circular pattern whereas during riding it exhibited a more diagonal pattern. This study shows that riding on a horse can generate movement patterns in the human pelvis that emulate many, but not all, characteristics of those during natural walking.

  4. Solid phase extraction and trace monitoring of cadmium ions in environmental water and food samples based on modified magnetic nanoporous silica

    Science.gov (United States)

    Omidi, Fariborz; Behbahani, Mohammad; Kalate Bojdi, Majid; Shahtaheri, Seyed Jamaleddin

    2015-12-01

    A new method has been developed for trace separation/preconcentration of cadmium ions using pyridine-functionalized magnetic nanoporous silica material (called Py-Fe3O4@MCM-41) as a new magnetic sorbent and their determination by flame atomic absorption spectrometry (FAAS). The Py-Fe3O4@MCM-41 sorbent was characterized by thermogravimetric analysis, differential thermal analysis, transmission electron microscopy, Fourier transform infrared spectrometry and X-ray diffraction. The modified Fe3O4@MCM-41 can be easily separated from an aqueous solution by applying an external magnetic field. Effects of pH, amount of functionalized Fe3O4@MCM-41, extraction time, type and quantity of eluent, desorption time, and interfering ions on the extraction efficiency were evaluated and optimized. Under the optimized conditions, the detection limit and relative standard deviation was 0.04 μg L-1 and 2.9%, respectively and the maximum adsorption capacity of the synthesized sorbent for cadmium ions was 154 mg g-1. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, rice, onion, carrot, lettuce, parsley, basil, tap water, river water and seawater with satisfactory results.

  5. Distributed Low Voltage Ride-Through Operation of Power Converters in Grid-Connected Microgrids under Voltage Sags

    DEFF Research Database (Denmark)

    Zhao, Xin; Meng, Lexuan; Dragicevic, Tomislav;

    2015-01-01

    the voltage in all phases at AC common bus. However, since the line admittances from each converter to point of common coupling (PCC) are not identical, the injected reactive power may not be equally shared. In order to achieve low voltage ride through (LVRT) capability along with a good power sharing...... accuracy, a hierarchical control strategy is proposed in this paper. Droop control and virtual impedance is applied in primary control loop while secondary control loop is based on dynamic consensus algorithm (DCA). Experiments are conducted to verify the effectiveness of the proposed control strategy....

  6. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data ...... or crushed linseed nor the intake of cocoa and chocolate....

  7. A parametric investigation of ride quality rating scales

    Science.gov (United States)

    Dempsey, T. K.; Coates, G. D.; Leatherwood, J. D.

    1976-01-01

    The relative merits of various category scales for the prediction of human discomfort response to vibration and the mathematical relationships that allow for transformations of subjective data from one scale to another scale were determined. A total of 16 category scales were studied and these represented various parametric combinations of polarity, scale type, and number of scalar points. Sixteen subject groups were used and each subject group evaluated its comfort/discomfort to vertical sinusoidal vibration using one of the rating scales. The passenger ride quality apparatus which can expose six subjects simultaneously to predetermined vibrations was utilized. The vibration stimuli were composed of repeats of selected sinusoidal frequencies applied at each of nine peak floor acceleration levels. A higher degree of reliability and discriminability was generally obtained from unipolar continuous type scales containing either seven or nine scalar points as opposed to the other scales investigated.

  8. Riding the waves of culture understanding cultural diversity in business

    CERN Document Server

    Trompenaars, Fons

    1993-01-01

    The definitive guide to cross-cultural management--updated to help you lead effectively during a time of unprecedented globalization First published nearly 20 years ago, Riding the Waves of Culture became the standard guide to conducting business in an international context. Now, the third edition provides you with important new information and groundbreaking methods for leading effectively in the most globalized business landscape ever. Fons Trompenaars is a world expert on international management and founder and director of Trompenaars Hampden-Turner (THT), a consulting firm in the field of intercultural management. Charles Hampden-Turner is a Senior Research Associate at the Judge Business School at the University of Cambridge and cofounder and Director of Research and Development at the Trompenaars-Hampden-Turner Group.

  9. Capability of DFIG WTS to ride through recurring asymmetrical grid faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Blaabjerg, Frede; Chen, Min;

    2014-01-01

    The Wind Turbine Systems (WTS) are required to ride through recurring grid faults in some countries. In this paper, the capability of Doubly Fed Induction Generator (DFIG) WTS to ride through recurring asymmetrical grid faults is evaluated and compared with the ride through capability under single...... asymmetrical grid fault. A mathematical model of the DFIG under recurring asymmetrical grid faults is represented. The analysis are verified by simulations on a 1.5MW DFIG model and by experiments on a reduced-scale DFIG test system....

  10. Hybrid search and the dial-a-ride problem with transfer scheduling constraints

    OpenAIRE

    2015-01-01

    In a conventional dial-a-ride-system passengers are moved with the same vehicle between their pickup and their drop-off location. In a dial-a-ride-system with transfer, it is possible (or even standard) that passengers change the vehicle once or several times. Transfer Scheduling Constraints (TSC) are imposed in order to ensure that the comfort of the transfer remains on an acceptable level by avoiding too short or too long transfer times but also for limiting the total riding time between th...

  11. Oral cadmium chloride intoxication in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect....... Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered...

  12. 停车换乘设施选址研究城市轨道交通%Studies on Park-and-Ride Facility Location for Transit

    Institute of Scientific and Technical Information of China (English)

    王显光; 任伟; 刘振国

    2013-01-01

    From viewpoint of two aspects of location and size of park-and-ride facility for urban rail transit, new and expanded projects shall take them into consideration. By using path-based user equilibrium assignment model and multi-mode assignment method, a model based on minimization of investment at park-and-ride facility location for city outskirts is established.%从选址和规模2方面考虑新建和扩建城市轨道交通停车换乘设施,采用基于路径的用户平衡配流模型和多方式配流方法,建立了基于投资最小化的城市外围停车换乘设施选址模型。

  13. Arsenic-cadmium interaction in rats.

    Science.gov (United States)

    Díaz-Barriga, F; Llamas, E; Mejía, J J; Carrizales, L; Santoyo, M E; Vega-Vega, L; Yáñez, L

    1990-11-01

    Simultaneous exposure to cadmium and arsenic is highly probable in the urban area of San Luis Potosi, Mexico due to common localization of copper and zinc smelters. Therefore, in this work, rats were intraperitoneally exposed either to cadmium or arsenic alone, or simultaneously to both metals. The effects of these treatments on three different toxicological parameters were studied. Cadmium modified the LD50 of arsenic and conversely arsenic modified the LD50 for cadmium. At the histopathological level, arsenic appeared to protect against the cadmium effects, especially on testes. This protective effect seemed to be related to the glutathione levels found in this tissue: rats exposed to both arsenic and cadmium, presented glutathione values intermediate to those observed after exposure to either metal alone; arsenic had the highest value and cadmium the lowest. In liver, rats exposed to arsenic, cadmium or arsenic and cadmium, presented glutathione values below those in the saline group, with the lowest value corresponding to the arsenic and cadmium treatment. The results appear to support the proposed interaction between arsenic and cadmium and coexposure to both metals seems to alter certain effects produced by either metal alone.

  14. Insulin Expression in Rats Exposed to Cadmium

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objectives To investigate the effects of cadmium exposure on insulin expression in rats. Methods Eighteen adult SD assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-β-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured,and the oral glucose tolerance tests (OGTT) were carried out. Results The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas.not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression the change of the expression of insulin, MT-Ⅰ and MT-Ⅱ genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.

  15. Improving Low Voltage Ride Through Capability of Wind Farm Grid-Connected via Dynamic Chopper Controlled Breaking Resistor Based MMC-HVDC Transmission System%含动态直流泄能电阻的MMC-HVDC提高风电场低电压穿越能力研究

    Institute of Scientific and Technical Information of China (English)

    李文津; 汤广福; 康勇

    2014-01-01

    提出了基于动态直流泄能电阻的模块化多电平柔性输电直流方案,以提高基于感应双馈电机风电场的低电压穿越能力。基于矢量控制及无源电压跟随控制分别设计了系统侧、风场侧柔性直流换流器在风电场稳态运行时的控制策略。当交流系统故障导致电压跌落时,详细分析了动态直流泄能电阻的工作原理、动作判据及导通持续时间,以实现风电场低电压穿越;同时研究了其与系统侧模块化多电平换流器在故障清除后电压恢复期的协调控制,以快速恢复风电场有功输出能力。仿真结果表明:当交流系统故障时,含动态直流泄能电阻的柔性直流输电系统能够维持直流电压且不改变风电场输出电压电流;当故障清除后,风电场输出功率恢复速率远大于电力系统行业标准相关技术指标。%A modular multilevel voltage sourced converter-based HVDC (MMC-HVDC) power transmission scheme based on dynamic chopper controlled breaking resistor (DCCBR) is proposed to improve the low-voltage ride through (LVRT) capability of wind farm composed of doubly fed induction generators (DFIG). Based on vector control and network voltage tracing control the control strategies for grid side modular multilevel converter (GSMMC) and wind farm side modular multilevel converter (WFMMC) under steady state operation of wind farm are designed respectively. Under voltage sag caused by fault in AC power grid, the working principle, operating criterion and turn-on duration time of DCCBR are analyzed in depth to realize LVRT of wind farm;meanwhile, to recover the active power output capability of wind farm rapidly the coordinated control for DCCBR and GSMMC during the voltage recovery after clearing of the fault is researched. Simulation results show that during the fault in AC power grid the flexible HVDC transmission system containing DCCBR can maintain the DC voltage of HVDC system while

  16. Ride Control Systems - Reduced Motions on the Cost of Increased Sectional Forces ?

    DEFF Research Database (Denmark)

    Folsø, R.; Nielsen, Ulrik Dam; Torti, F.

    2003-01-01

    Implementation of passive and active ride control systems into both linear frequency and non-linear time domain strip theories is described. The ride control systems considered can consist of T-foils, fins or a combination of these. These appendages are taken into account by considering the lift...... by adding the lift forces to the exciting forces in the equations of motion. One of the advantages in the time domain is that the angle of attack can be limited easily, as is often the case in real full scale ride control systems. This way cavitation and finally stalling can be avoided. In the frequency...... domain limits on the angle of attack cannot be set. Since the lift coefficient is treated linearly the calculated lift force is severely overestimated in rough sea. Secondly the effect of including ride control systems in the calculations is demonstrated through comparisons of RMS values and of response...

  17. Evaluation of ride quality prediction methods for helicopter interior noise and vibration environments

    Science.gov (United States)

    Leatherwood, J. D.; Clevenson, S. A.; Hollenbaugh, D. D.

    1984-01-01

    The results of a simulator study conducted to compare and validate various ride quality prediction methods for use in assessing passenger/crew ride comfort within helicopters are presented. Included are results quantifying 35 helicopter pilots discomfort responses to helicopter interior noise and vibration typical of routine flights, assessment of various ride quality metrics including the NASA ride comfort model, and examination of possible criteria approaches. Results of the study indicated that crew discomfort results from a complex interaction between vibration and interior noise. Overall measures such as weighted or unweighted root-mean-square acceleration level and A-weighted noise level were not good predictors of discomfort. Accurate prediction required a metric incorporating the interactive effects of both noise and vibration. The best metric for predicting crew comfort to the combined noise and vibration environment was the NASA discomfort index.

  18. Motorcycle riding under the influence of alcohol: results from the SARTRE-4 survey.

    Science.gov (United States)

    Papadimitriou, Eleonora; Theofilatos, Athanasios; Yannis, George; Cestac, Julien; Kraïem, Sami

    2014-09-01

    Riding a motorcycle under the influence of alcohol is a dangerous activity, especially considering the high vulnerability of motorcyclists. The present research investigates the factors that affect the declared frequency of drink-riding among motorcyclists in Europe and explores regional differences. Data were collected from the SARTRE-4 (Social Attitudes to Road Traffic Risk in Europe) survey, which was conducted in 19 countries. A total sample of 4483 motorcyclists was interviewed by using a face-to-face questionnaire. The data were analyzed by means of multilevel ordered logit models. The results revealed significant regional differences (between Northern, Eastern and Southern European countries) in drink-riding frequencies in Europe. In general, declared drinking and riding were positively associated with gender (males), increased exposure, underestimation of risk, friends' behaviour, past accidents and alcohol ticket experience. On the other hand, it was negatively associated with underestimation of the amount of alcohol allowed before driving, and support for more severe penalties.

  19. Control of Doubly-Fed Induction Generator to Ride-Through Recurring Grid Faults

    DEFF Research Database (Denmark)

    Chen, Wenjie; Xu, Dehong; Zhu, Nan;

    2016-01-01

    The wind turbine system (WTS) is required to ride-through recurring grid faults by the new grid codes. Under single grid faults, the fault ride-through (FRT) strategy with rotor-side crowbar is normally used for the doubly-fed induction generator (DFIG) WTS. However, under recurring faults, larger.......5-MW DFIG model and by experiments on a 30-kW DFIG test system....

  20. Fault ride-through and voltage support of permanent magnet synchronous generator wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Michalke, G.; Hartkopf, T. [Darmstadt Technical Univ., Dept. of Renewable Energies (Germany); Hansen, A.D. [Risoe National Lab., DTU, Wind Energy Dept. (Denmark)

    2007-11-15

    This paper presents a control strategy of direct driven multipole PMSG wind turbines, which enhances the fault ride-through and voltage support capability of such wind turbines during grid faults. A dynamic simulation model of the turbine is implemented in the simulation software DIgSILENT. Simulation results approve the effectiveness of the developed control strategy. It is shown that PMSG wind turbines equipped with such control even enable nearby connected conventional wind turbines to ride-through grid faults. (au)

  1. Dietary cadmium intake and risk of breast, endometrial and ovarian cancer in Danish postmenopausal women: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Kirsten T Eriksen

    Full Text Available Cadmium is a human lung carcinogen and possesses estrogen-like activity. This combination of carcinogenic and estrogenic activity makes cadmium a contaminant of high concern for hormone-related cancers. Diet and smoking are the main sources of cadmium exposure. The aim of this study was to investigate the association between dietary cadmium intake and risk of breast, endometrial and ovarian cancer in Danish postmenopausal woman.We estimated dietary cadmium intake in the Diet, Cancer and Health cohort at enrolment 1993-97. The estimates were based on food frequency questionnaires and cadmium contents in all foods. Among 23,815 postmenopausal women we identified 1390 breast, 192 endometrial, and 146 ovarian cancer cases from enrolment through December 31, 2010 using the Danish Cancer Registry. Cox regression was used to analyse the association between dietary cadmium intake and cancer risk.Mean dietary cadmium intake was 14 µg/day. Cadmium was not associated with breast cancer, incidence rate ratio (IRR = 0.99, 95% confidence interval (CI: 0.87-1.13 per 10 µg higher dietary cadmium intake/day; endometrial cancer, IRR = 1.08, 95% CI: 0.76-1.53; or ovarian cancer, IRR = 1.15, 95% CI: 0.78-1.70. We found a positive association between cadmium and endometrial cancer for the women with BMI<25 (IRR = 1.50, 95% CI: 0.94-2.39, whereas an inverse association was seen for the women with BMI≥25 (IRR = 0.69, 95% CI: 0.42-1.12; p value for interaction = 0.02.Our study does not indicate that our estimated dietary cadmium intake is associated with hormone-related cancers in women.

  2. 用于平顺性仿真的七自由度非线性模型%Seven degree of freedom nonlinear model for ride comfort simulation

    Institute of Scientific and Technical Information of China (English)

    汤望; 海辰光

    2014-01-01

    为了解决传统平顺性振动模型对悬架非线性环节描述不足的问题,开发了一个用于平顺性仿真的七自由度非线性时域模型。此模型以线性七自由度模型为基础,通过对悬架迟滞非线性和减振器非线性的准确建模,实现悬架非线性特性的准确描述。通过典型工况仿真,验证所建模型能够更为真实的描述悬架非线性环节对平顺性的恶化现象,进一步提升了平顺性模型的仿真精度。利用所建模型对影响平顺性的典型因素进行仿真研究,研究结果表明可以通过降低悬架刚度、合理匹配减振器阻尼等措施来提升平顺性。%The current ride comfort model does not have the ability to accurate simulate the suspension nonlinear.In order to solve this problem,a seven degree of freedom nonlinear model for ride comfort simulation, was developed.This model was based on seven degree of freedom linear model,through accurate modeling of suspension nonlinear hysteresis and damper nonlinear,to accurately describe suspension nonlinear characteristics. Through the simulation of typical operating conditions,to verify the model have the ability to really describe ride comfort deterioration caused by the suspension nonlinear factor,to further improve the simulation accuracy of ride comfort model.Conduct simulation study about the key factors of ride comfort,the research results show that,it is can improve the ride comfort by reducing suspension stiffness and reasonable matching damping.

  3. A simple method to reduce the risk of cadmium exposure from consumption of Iceland scallops (Chlamys islandica) fished in Greenland.

    Science.gov (United States)

    Bach, Lis; Sonne, Christian; Rigét, Frank F; Dietz, Rune; Asmund, Gert

    2014-08-01

    This paper studied the levels and organ distribution of the toxic heavy metal cadmium in scallops from unpolluted Greenlandic waters. The scallops had an average cadmium concentration of 2.93 ± 0.94 μg/g wet weight in the total soft tissues and no concentration dependent effect was found for gender or size (both p>0.05). The kidney was the primary organ for cadmium accumulation with a mean of 226.2 ± 111.7 μg/g wet weight, and despite the small weight of the kidney, it appeared as the principal contributor of cadmium with 92% of the total cadmium body burden. The cadmium concentrations in the total soft tissues far exceeded the EU-limit of 1 μg/g wet weight for cadmium in bivalves. Based on this, selective evisceration of the cadmium-rich kidney and digestive gland during processing can be regarded as a reliable measure to be taken in order to reduce the cadmium content of scallops used for human consumption.

  4. Effects of horseback riding exercise therapy on background electroencephalograms of elderly people

    Science.gov (United States)

    Kim, Seon-Rye; Cho, Sung-Hyoun; Kim, Jin-Woo; Lee, Hyo-Cheol; Brienen, Marten; Cho, Byung-Jun

    2015-01-01

    [Purpose] This study investigated the effect of horseback riding exercise on the background electroencephalograms of elderly people who performed horseback riding for 8 weeks. [Subjects] Twenty elderly people were divided into the horseback riding exercise and control group (n = 10 each). [Methods] The exercise was performed for 15 minutes, 3 times per week for 8 weeks. Electroencephalograms were analyzed. Post-exercise evaluation was performed after 8 weeks. [Results] After the horseback riding exercise, the relative slower alpha power index was active in the T3 and P4 domains but suppressed in the Fp1, Fp2, F3, F4, T4, and P3 domains. Moreover, the relative faster alpha power index was active in all domains of the horseback riding exercise group but was suppressed in all domains of the control group. There was a significant difference between groups in the F3 domain. [Conclusion] The alpha power index increased significantly after horseback riding exercise, suggesting the exercise improved background electroencephalogram. PMID:26311985

  5. The effect of alcohol hangover on the ability to ride a bicycle.

    Science.gov (United States)

    Hartung, Benno; Schwender, Holger; Mindiashvili, Nona; Ritz-Timme, Stefanie; Malczyk, Axel; Daldrup, Thomas

    2015-07-01

    To investigate the effects of alcohol on the ability to ride a bicycle, practical cycling tests were carried out at different blood alcohol concentrations (BAC). For this purpose, various alcoholic beverages could be consumed from around 2 p.m. until 11 p.m. Afterwards, the test persons spent the night on the trial site and were provided with dormitory sleeping accommodation. On the following morning, beginning at around 8 a.m., a final cycling test was performed. The performances of those test persons who had returned to state of soberness and of those with residual blood alcohol levels were compared to the performances on the day before. The practical ability to ride a bicycle was significantly reduced in the postalcoholic state compared to the rides of the day before. The relative cycling performance in the postalcoholic state was comparable to the rides under the influence of BAC of around 0.30 g/kg. There were no remarkable differences between the groups with and without residual blood alcohol levels regarding the rides on the next morning. Therefore, it can be assumed that the direct influence of residual blood alcohol levels plays a minor role for the ability to ride a bicycle in the postalcoholic state. Instead, the side effects of the high amounts of alcohol that were consumed the night before are crucial.

  6. Modulation of cadmium bioaccumulation and enhancing cadmium tolerance in Pichia kudriavzevii by sodium chloride preincubation.

    Science.gov (United States)

    Ma, Ning; Li, Chunsheng; Zhang, Dandan; Yu, Jinzhi; Xu, Ying

    2016-07-01

    Application of growing microorganisms for cadmium removal is limited by the sensitivity of living cells to cadmium. The effects of sodium chloride (NaCl) preincubation on the cadmium bioaccumulation and tolerance of Pichia kudriavzevii and Saccharomyces cerevisiae were investigated in this study. NaCl preincubation significantly reduced the intracellular and cell-surface cadmium bioaccumulation of P. kudriavzevii at both 6 and 20 mg L(-1) cadmium, while no obvious effect was observed in S. cerevisiae except that the intracellular cadmium bioaccumulation at 20 mg L(-1) cadmium was reduced obviously by 20-60 g L(-1)  NaCl. For both yeasts, the improved contents of protein and proline after NaCl preincubation contributed to the cadmium tolerance. The thiol contents in P. kudriavzevii under cadmium stress were alleviated by NaCl preincubation, which might be due to the decrease of intracellular cadmium bioaccumulation. NaCl preincubation enhanced the contents of glycerol and trehalose in P. kudriavzevii under cadmium stress, while no acceleration was observed in S. cerevisiae. The results suggested that NaCl preincubation could be applied in cadmium removal by growing P. kudriavzevii to increase the cadmium tolerance of the yeast.

  7. Using an epiphytic moss to identify previously unknown sources of atmospheric cadmium pollution

    Energy Technology Data Exchange (ETDEWEB)

    Donovan, Geoffrey H., E-mail: gdonovan@fs.fed.us [USDA Forest Service, PNW Research Station, 620 SW Main, Suite 400, Portland, OR 97205 (United States); Jovan, Sarah E., E-mail: sjovan@fs.fed.us [USDA Forest Service, PNW Research Station, 620 SW Main, Suite 400, Portland, OR 97205 (United States); Gatziolis, Demetrios, E-mail: dgatziolis@fs.fed.us [USDA Forest Service, PNW Research Station, 620 SW Main, Suite 400, Portland, OR 97205 (United States); Burstyn, Igor, E-mail: igor.burstyn@drexel.edu [Dornsife School of Public Health, Drexel University, Nesbitt Hall, 3215 Market St, Philadelphia, PA 19104 (United States); Michael, Yvonne L., E-mail: ylm23@drexel.edu [Dornsife School of Public Health, Drexel University, Nesbitt Hall, 3215 Market St, Philadelphia, PA 19104 (United States); Amacher, Michael C., E-mail: mcamacher1@outlook.com [USDA Forest Service, Logan Forest Sciences Laboratory, 860 North 1200 East, Logan, UT 84321 (United States); Monleon, Vicente J., E-mail: vjmonleon@fs.fed.us [USDA Forest Service, PNW Research Station, 3200 SW Jefferson Way, Corvallis, OR 97331 (United States)

    2016-07-15

    Urban networks of air-quality monitors are often too widely spaced to identify sources of air pollutants, especially if they do not disperse far from emission sources. The objectives of this study were to test the use of moss bio-indicators to develop a fine-scale map of atmospherically-derived cadmium and to identify the sources of cadmium in a complex urban setting. We collected 346 samples of the moss Orthotrichum lyellii from deciduous trees in December, 2013 using a modified randomized grid-based sampling strategy across Portland, Oregon. We estimated a spatial linear model of moss cadmium levels and predicted cadmium on a 50 m grid across the city. Cadmium levels in moss were positively correlated with proximity to two stained-glass manufacturers, proximity to the Oregon–Washington border, and percent industrial land in a 500 m buffer, and negatively correlated with percent residential land in a 500 m buffer. The maps showed very high concentrations of cadmium around the two stained-glass manufacturers, neither of which were known to environmental regulators as cadmium emitters. In addition, in response to our findings, the Oregon Department of Environmental Quality placed an instrumental monitor 120 m from the larger stained-glass manufacturer in October, 2015. The monthly average atmospheric cadmium concentration was 29.4 ng/m{sup 3}, which is 49 times higher than Oregon's benchmark of 0.6 ng/m{sup 3}, and high enough to pose a health risk from even short-term exposure. Both stained-glass manufacturers voluntarily stopped using cadmium after the monitoring results were made public, and the monthly average cadmium levels precipitously dropped to 1.1 ng/m{sup 3} for stained-glass manufacturer #1 and 0.67 ng/m{sup 3} for stained-glass manufacturer #2. - Highlights: • Bio-indicators are a valid method for measuring atmospheric pollutants • We used moss to map atmospheric cadmium in Portland, Oregon • Using a spatial linear model, we identified two

  8. Double preconcentration of trace amounts of cadmium in nail samples and measurement by differential pulse voltammetry.

    Science.gov (United States)

    Shahi, Somayeh; Nateghi, Mohammad Reza

    2015-04-01

    Cadion was coated on carbon powder and used as a solid phase for selective extraction and preconcentration of cadmium ions. Complexed cadmium ions were eluted from solid phase by 5 mL, nitric acid (2.0 M) with the flow rate of 2 mL min(-1).The resulted solution was used for accumulation of the cadmium metal at the surface of the carbon paste electrode at -1.3 V reduction potential. Finally, cadmium was reoxidized and the differential pulse voltammogram recorded at the potential range of -0.55 to -0.2 V. Calibration graph was plotted in the concentration range of 0.5-50 μg L(-1) of cadmium. Detection limit 0.06 μg L(-1) was calculated based on the 3 Sb/m. The RSD was 9.13 % (n = 4) for cadmium concentration of 10 μg L(-1) with preconcentration factor of 100. Method was successfully used for the determination of cadmium in finger nail samples and after spiking the samples, the recoveries were evaluated >96 %.

  9. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future.

  10. Integrating stochastic time-dependent travel speed in solution methods for the dynamic dial-a-ride problem.

    Science.gov (United States)

    Schilde, M; Doerner, K F; Hartl, R F

    2014-10-01

    In urban areas, logistic transportation operations often run into problems because travel speeds change, depending on the current traffic situation. If not accounted for, time-dependent and stochastic travel speeds frequently lead to missed time windows and thus poorer service. Especially in the case of passenger transportation, it often leads to excessive passenger ride times as well. Therefore, time-dependent and stochastic influences on travel speeds are relevant for finding feasible and reliable solutions. This study considers the effect of exploiting statistical information available about historical accidents, using stochastic solution approaches for the dynamic dial-a-ride problem (dynamic DARP). The authors propose two pairs of metaheuristic solution approaches, each consisting of a deterministic method (average time-dependent travel speeds for planning) and its corresponding stochastic version (exploiting stochastic information while planning). The results, using test instances with up to 762 requests based on a real-world road network, show that in certain conditions, exploiting stochastic information about travel speeds leads to significant improvements over deterministic approaches.

  11. Cadmium content of plants as affected by soil cadmium concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  12. Synthesis, structure and properties of hexacoordinated compounds of cadmium(II) halides/pseudohalides containing a pentadentate N-donor Schiff base

    Science.gov (United States)

    Sarkar, Bhola Nath; Choubey, Somnath; Bhar, Kishalay; Chattopadhyay, Soumi; Mitra, Partha; Ghosh, Barindra Kumar

    2011-05-01

    Five hexacoordinated compounds of type [Cd(L)(X)]Y· nMeCN ( 1- 5) [L = N,N'-(bis(pyridin-2-yl)benzylidene)diethylenetriamine; Y=PF6-, n = 1; X = Cl - ( 1), Br - ( 2), I - ( 3) and Y=PF6-, n = 0, X=N3-, ( 4); Y=ClO4-, n = 0, X = NCO -, ( 5)] are synthesized and characterized. Structures of all the compounds are solved by X-ray diffraction measurements. Structural analyses reveal that each cadmium(II) center adopts a distorted octahedral geometry bound by five N atoms of L along with terminal halide in 1- 3 and N atom of terminal pseudohalide in 4 and 5. Intermolecular N sbnd H⋯O, C sbnd H⋯O, N sbnd H⋯F and C sbnd H⋯F hydrogen bondings and C sbnd H⋯π interactions as is the case lead to different crystalline aggregates in 1- 5. The complexes display intraligand 1(π sbnd π *) fluorescence in DMF solutions at room temperature.

  13. Syntheses, structures and properties of cadmium(II) carboxylates containing polyamine/Schiff base: Variation of coordination numbers, and molecular and crystalline architectures by changing ligands

    Science.gov (United States)

    Kundu, Subhasish; Roy, Subhasis; Choubey, Somnath; Bhar, Kishalay; Ghosh, Prabhat Kumar; Mitra, Partha; Ghosh, Barindra Kumar

    2013-11-01

    One-pot synthesis of the building components in methanol at room temperature affords two dinuclear compounds [Cd2(L1)2(μ-tp)](ClO4)2 (1) and [Cd2(L2)2(μ-ap)(OH2)2](ClO4)2ṡ2H2OṡCH3OH (2) [L1 = N,N'-bis(3-aminopropyl)-1,2-ethanediamine, L2 = N,N'-(bis(pyridin-2-yl)benzylidene)-1,3-propanediamine, tp = terephthalate dianion, ap = adipate dianion]. The complexes 1 and2 are characterized using microanalytical, spectroscopic and other physicochemical results. Structures of 1 and2 are solved by single crystal X-ray diffraction measurements. Structural analyses reveal that each cadmium(II) center in 1/2 adopts a distorted square pyramidal/octahedral geometry with CdN4O/CdN4O2 chromophore. Terephthalate/adipate binds the metal center in 1/2 in bis(monodentate) fashion. Intermolecular Nsbnd H⋯O, Csbnd H⋯O hydrogen bonds in 1 and Osbnd H⋯O, Csbnd H⋯N hydrogen bonds and π⋯π interaction in2 promote different dimensionalities. The compounds show intraligand (π-π*) fluorescence in DMF solutions at room temperature.

  14. [Predicting the cadmium bioavailability in the soil of sugarcane field based on the diffusive gradients in thin films with binding phase of sodium polyacrylate].

    Science.gov (United States)

    Wang, Fang-Li; Song, Ning-Ning; Zhao, Yu-Jie; Zhang, Chang-Bo; Shen, Yue; Liu, Zhong-Qi

    2012-10-01

    The diffusive gradients in thin films (DGT) technique with solid-state binding phases has been widely used for in situ collection and measurement of available heavy metals in waters, soils or sediments, whereas DGT with liquid binding phase is primarily used in the in situ analysis of heavy metals in waters. In this paper, rhizosphere soils of sugarcane were collected in Guangxi and the concentrations of cadmium (Cd) were determined by DGT with a solid-state binding phase of chelex100 (chelex100-DGT) and modified DGT with a liquid binding phase of sodium polyacrylate (CDM-PAAS-DGT). The result showed that the Cd contents in soils measured by DGT with both binding phases and Cd in the roots, leaves and unpolished stems of sugarcane had significant positive correlation. The extraction ability of the CDM-PAAAS-DGT was much higher than that of the chelex100-DGT. In addition, multivariate analyses were used to assess the impact of pH, cation exchange capacity (CEC), soil organic matter (OM) and texture. Two principal components were extracted and the linear regression models were established. The Cd bioavailability in soils could be accurately predicted by the CDM-PAAAS-DGT technique, which expanded its applicable area.

  15. Effects of cadmium on the health of the population

    Energy Technology Data Exchange (ETDEWEB)

    Piscator, M.

    1973-11-01

    Investigations on workers who have been exposed to cadmium dust or fumes in the breathing air have shown that lung damage, special emphysema and damage to the renal tubuli are the most frequently occurring symptoms for exposed industrial workers. The main characteristic of kidney damage is tubular proteinuria. An increased excretion of amino acids, glucose, calcium and phosphorus is likewise possible. Finally, disorders in the calcium and phosphorus metabolism can have demineralization of the bones for a consequence. According to estimates, the critical concentration in the cortex of the kidneys is ca 200 ..mu..g Cd/g wet weight. At this concentration, functional disorders of the kidneys can appear for the most sensitive individuals of a particular population. This estimate is based on results of investigations on humans and animals, although these were conducted with relatively imprecise methods; accordingly, the value may even lie below 200 ppm. From the toxicological viewpoint there is not too great a safety margin between the present cadmium level in adults and the critical value. It can be expected that this margin will become smaller in the future when additional cadmium loading of the environment occurs, since the retention of cadmium is practically equal to the uptake on account of the small excretion rate.

  16. A method for partitioning cadmium bioaccumulated in small aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J. [Univ. of Stirling (United Kingdom). Institute of Aquaculture

    1995-09-01

    A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 {micro}g Cd{center_dot}L{sup {minus}1} in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 {micro}m{center_dot}L{sup {minus}1}, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on the results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 {micro}g Cd{center_dot}L{sup {minus}1} for 72 h, processed through the rinse procedures, and analyzed for total Cd. The EDTA rinse treatment significantly reduced (p<0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.

  17. Effect of Cadmium on the population growth of the marine diatom Chaetoceros gracilis Schutt

    Directory of Open Access Journals (Sweden)

    Giovana Vera

    2014-06-01

    Full Text Available Phytoplankton constitutes the base of the trophic webs in the marine environment, so it is important to know the possible effects of pollutants on the algal populations. In the present paper the effect of cadmium on the population growth of the diatom Chaetoceros gracilis was assessed. The microalgae were cultured in the a modified “f/2” Guillard medium, and were exposed to different concentrations of cadmium between 50 and 100000 µg.–1, which produced an inhibitory effect from 20% to 99% on the population growth of Chaetoceros gracilis. Based on the dose (cadmium-response (inhibition relationship, a mean effective concentration (EC50% equal to 591 µg.L–1 of cadmium was obtained.

  18. 风力发电机组故障穿越问题综述%Summarizing for fault ride through characteristics of wind turbines

    Institute of Scientific and Technical Information of China (English)

    艾斯卡尔; 朱永利; 唐斌伟

    2013-01-01

    The national grid codes of main wind power markets in the world are introduced and more attentions are paid for the different kinds of fault ride through capabilities of wind turbines, such as low voltage ride through (LVRT), high voltage ride through (HVRT) and frequency ride through (FRT). After that, the interactions between the electricity network and three kinds of main wind turbines which equipped with real GFRT engineering devices are analyzed and engineering implementation scheme of three kinds of main LVRT capabilities of wind turbines is summarized. Finally, based on years of working experience and the above researches, 12 main technical factors which are very important to the LVRT characteristics of wind turbines are summarized.%介绍了当今世界主流风电市场的风电并网规程,进一步研究后重点综述了风电机组故障穿越诸多问题,如低电压穿越、高电压穿越、频率穿越。还分析了三种主流风电机组故障穿越能力和电力系统之间的相互影响,汇总了三种主流风电机组低电压穿越能力的工程实现方案。最后结合多年的实际工程经验,以各国电网风电接入规程和各种风电机组故障穿越特性为线索,探讨了需要重点注意的故障穿越技术问题,并总结出了决定风电机组低电压穿越特性的12项技术要素。

  19. Tolerance to cadmium and cadmium-binding ligands in Great Salt Lake brine shrimp (Artemia salina)

    Energy Technology Data Exchange (ETDEWEB)

    Jayasekara, S.; Drown, D.B.; Sharma, R.P.

    1986-02-01

    Information on the accumulation of cadmium in cytosolic proteins of Great Lake brine shrimp (Artemia salina) was obtained from animals collected directly from the lake and also from animal hatched and maintained in three sublethal concentrations of cadmium (0.5, 2.0, 5.0 ppm) in saltwater aquaria. Brine shrimp growth under these conditions was monitored by measuring body lengths during a 7-day exposure period. Heat-stable, cadmium-binding ligands were isolated and identified by Sephadex G-75 chromatography and atomic absorption spectrophotometry. Cadmium was found to be equally distributed between high and low molecular weight proteins in animals collected from the lake and the 0.5 ppm cadmium group. There was also a slight growth stimulation noted in the 0.5-pm group. Higher cadmium incorporation was noted in low molecular weight fractions with increasing cadmium concentration in the exposure media. Low molecular weight fractions were also found to have high uv absorption characteristics at 250 nm and low absorption at 280 nm. Molecular weight of the cadmium-binding ligands was found to be 11,000 as estimated by the gel filtration method. De novo synthesis of this protein was increased as a function of cadmium concentration in the media. However, slow accumulation of cadmium in other protein fractions was also noticed in higher cadmium exposure groups, suggesting the existence of possible tolerance mechanisms in brine shrimp exposed to suspected acute cadmium concentrations.

  20. Low-Voltage Ride-Through Capability of a Single-Stage Single-Phase Photovoltaic System Connected to the Low-Voltage Grid

    Directory of Open Access Journals (Sweden)

    Yongheng Yang

    2013-01-01

    Full Text Available The progressive growing of single-phase photovoltaic (PV systems makes the Distribution System Operators (DSOs update or revise the existing grid codes in order to guarantee the availability, quality, and reliability of the electrical system. It is expected that the future PV systems connected to the low-voltage grid will be more active with functionalities of low-voltage ride-through (LVRT and the grid support capability, which is not the case today. In this paper, the operation principle is demonstrated for a single-phase grid-connected PV system in a low-voltage ride-through operation in order to map future challenges. The system is verified by simulations and experiments. Test results show that the proposed power control method is effective and the single-phase PV inverters connected to low-voltage networks are ready to provide grid support and ride-through voltage fault capability with a satisfactory performance based on the grid requirements for three-phase renewable energy systems.

  1. Zone refining of cadmium and related characterization

    Indian Academy of Sciences (India)

    N R Munirathnam; D S Prasad; Ch Sudheer; J V Rao; T L Prakash

    2005-06-01

    We present the zone refining results of cadmium using horizontal resistive zone refiner under constant flow of moisture free hydrogen gas. The boron impurity in cadmium can be avoided using quartz (GE 214 grade) boat in lieu of high pure graphite boat. The analytical results using inductively coupled plasma optical emission spectrometry (ICPOES) show that majority of the impurities are less than the detection limits. Comparatively, zinc is the most difficult impurity element to remove in cadmium matrix by zone refining.

  2. Fault Ride-through Capability Enhancement of VSC-HVDC-connected Offshore Wind Power Plants

    Institute of Scientific and Technical Information of China (English)

    Ranjan SHARMA; Qiuwei WU; Seung Tae CHA; Kim Høj ENSEN; Tony Wederberg RASMUSSEN; Jacob ØSTERGAARD

    2015-01-01

    To achieve active control of the AC voltage magnitude of wind power plant(WPP) collector network and improve the fault ride-through (FRT) capability,an FRT scheme based on feed forward DC voltage control is presented for voltage source converter-high voltage direct current(VSC-HVDC) connected offshore WPPs.During steady state operation,an open loop AC voltage control is implemented at the WPP-side VSC of the HVDC system so that any possible control interactions between WPP-side VSC and VSC of wind turbine are minimized.Whereas during any grid fault,a dynamic AC voltage reference is made according to both the DC voltage error and AC active current from the WPP collector system,thus ensuring fast and robust FRT of the VSC-HVDC-connected offshore WPPs.Under the unbalanced fault condition in the host power system,the resulting oscillatory DC voltage is directly used in the VSC AC voltage controller at the WPP side so that the WPP collector system voltage also reflects the unbalance in the main grid.Time domain simulations are performed to verify the efficacy of the FRT scheme based on the proposed feed forward DC voltage control.Simulation results show satisfactory FRT responses of the VSC-HVDC-connected offshore WPP under balanced and unbalanced faults in the host power system,as is shown under a serious fault in the WPP collector network.

  3. The Epigenetic Effects of Prenatal Cadmium Exposure.

    Science.gov (United States)

    Vilahur, Nadia; Vahter, Marie; Broberg, Karin

    2015-06-01

    Prenatal exposure to the highly toxic and common pollutant cadmium has been associated with adverse effects on child health and development. However, the underlying biological mechanisms of cadmium toxicity remain partially unsolved. Epigenetic disruption due to early cadmium exposure has gained attention as a plausible mode of action, since epigenetic signatures respond to environmental stimuli and the fetus undergoes drastic epigenomic rearrangements during embryogenesis. In the current review, we provide a critical examination of the literature addressing prenatal cadmium exposure and epigenetic effects in human, animal, and in vitro studies. We conducted a PubMed search and obtained eight recent studies addressing this topic, focusing almost exclusively on DNA methylation. These studies provide evidence that cadmium alters epigenetic signatures in the DNA of the placenta and of the newborns, and some studies indicated marked sexual differences for cadmium-related DNA methylation changes. Associations between early cadmium exposure and DNA methylation might reflect interference with de novo DNA methyltransferases. More studies, especially those including environmentally relevant doses, are needed to confirm the toxicoepigenomic effects of prenatal cadmium exposure and how that relates to the observed health effects of cadmium in childhood and later life.

  4. Risky riding: Naturalistic methods comparing safety behavior from conventional bicycle riders and electric bike riders.

    Science.gov (United States)

    Langford, Brian Casey; Chen, Jiaoli; Cherry, Christopher R

    2015-09-01

    As electric bicycles (e-bikes) have emerged as a new transportation mode, their role in transportation systems and their impact on users have become important issues for policy makers and engineers. Little safety-related research has been conducted in North America or Europe because of their relatively small numbers. This work describes the results of a naturalistic GPS-based safety study between regular bicycle (i.e., standard bicycle) and e-bike riders in the context of a unique bikesharing system that allows comparisons between instrumented bike technologies. We focus on rider safety behavior under four situations: (1) riding in the correct direction on directional roadway segments, (2) speed on on-road and shared use paths, (3) stopping behavior at stop-controlled intersections, and (4) stopping behavior at signalized intersections. We find that, with few exceptions, riders of e-bike behave very similarly to riders of bicycles. Violation rates were very high for both vehicles. Riders of regular bicycles and e-bikes both ride wrong-way on 45% and 44% of segments, respectively. We find that average on-road speeds of e-bike riders (13.3kph) were higher than regular bicyclists (10.4kph) but shared use path (greenway) speeds of e-bike riders (11.0kph) were lower than regular bicyclists (12.6kph); both significantly different at >95% confidence. At stop control intersections, both bicycle and e-bike riders violate the stop signs at the similar rate with bicycles violating stop signs at a slightly higher rate at low speed thresholds (∼80% violations at 6kph, 40% violations at 11kph). Bicycles and e-bikes violate traffic signals at similar rates (70% violation rate). These findings suggest that, among the same population of users, e-bike riders exhibit nearly identical safety behavior as regular bike riders and should be regulated in similar ways. Users of both technologies have very high violation rates of traffic control devices and interventions should occur to

  5. On the Skill of Balancing While Riding a Bicycle.

    Directory of Open Access Journals (Sweden)

    Stephen M Cain

    Full Text Available Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle and less steer control (quantified by cross-correlating steer rate and bicycle roll rate than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate and less rider lean angle variation (measured by the standard deviation of the rider lean angle independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  6. On the Skill of Balancing While Riding a Bicycle.

    Science.gov (United States)

    Cain, Stephen M; Ashton-Miller, James A; Perkins, Noel C

    2016-01-01

    Humans have ridden bicycles for over 200 years, yet there are no continuous measures of how skill differs between novice and expert. To address this knowledge gap, we measured the dynamics of human bicycle riding in 14 subjects, half of whom were skilled and half were novice. Each subject rode an instrumented bicycle on training rollers at speeds ranging from 1 to 7 m/s. Steer angle and rate, steer torque, bicycle speed, and bicycle roll angle and rate were measured and steering power calculated. A force platform beneath the roller assembly measured the net force and moment that the bicycle, rider and rollers exerted on the floor, enabling calculations of the lateral positions of the system centers of mass and pressure. Balance performance was quantified by cross-correlating the lateral positions of the centers of mass and pressure. The results show that all riders exhibited similar balance performance at the slowest speed. However at higher speeds, the skilled riders achieved superior balance performance by employing more rider lean control (quantified by cross-correlating rider lean angle and bicycle roll angle) and less steer control (quantified by cross-correlating steer rate and bicycle roll rate) than did novice riders. Skilled riders also used smaller steering control input with less variation (measured by average positive steering power and standard deviations of steer angle and rate) and less rider lean angle variation (measured by the standard deviation of the rider lean angle) independent of speed. We conclude that the reduction in balance control input by skilled riders is not due to reduced balance demands but rather to more effective use of lean control to guide the center of mass via center of pressure movements.

  7. Walk or ride? Phoretic behaviour of amblyceran and ischnoceran lice.

    Science.gov (United States)

    Bartlow, Andrew W; Villa, Scott M; Thompson, Michael W; Bush, Sarah E

    2016-04-01

    Phoresy is a behaviour where one organism hitches a ride on another more mobile organism. This is a common dispersal mechanism amongst relatively immobile species that specialise on patchy resources. Parasites specialise on patchily distributed resources: their hosts. Although host individuals are isolated in space and time, parasites must transmit between hosts or they will die with their hosts. Lice are permanent obligate ectoparasites that complete their entire life cycle on their host. They typically transmit when hosts come into direct contact; however, lice are also capable of transmitting phoretically. Yet, phoresy is rare amongst some groups of lice. Fundamental morphological differences have traditionally been used to explain the phoretic differences amongst different suborders of lice; however, these hypotheses do not fully explain observed patterns. We propose that a more fundamental natural history trait may better explain variation in phoresy. Species able to disperse under their own power should be less likely to engage in phoresy than more immobile species. Here we experimentally tested the relationship between independent louse mobility and phoresy using a system with four species of lice (Phthiraptera: Ischnocera and Amblycera) that all parasitize a single host species, the Rock Pigeon (Columba livia). We quantified the relative ability of all four species of lice to move independently off the host, and we quantified their ability to attach to, and remain attached to, hippoboscid flies (Pseudolynchia canariensis). Our results show that the most mobile louse species is the least phoretic, and the most phoretic species is quite immobile off the host. Our findings were consistent with the hypothesis that phoretic dispersal should be rare amongst species of lice that are capable of independent dispersal; however other factors such as interspecific competition may also play a role.

  8. Electroanalytical studies on cadmium(II) selective potentiometric sensors based on t-butyl thiacalix[4]arene and thiacalix[4]arene in poly(vinyl chloride)

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Vinod K. [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India)], E-mail: vinodfcy@iitr.ernet.in; Jain, Ajay K. [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India); Ludwig, Rainer [Institute for Inorganic and Analytical Chemistry, Freie Universitaet, Berlin 14195 (Germany); Maheshwari, Gaurav [Department of Chemistry, Indian Institute of Technology, Roorkee 247667, Uttaranchal (India)

    2008-01-01

    Cd{sup 2+}-selective sensors have been fabricated from poly(vinyl chloride) (PVC) matrix membranes containing t-butyl thiacalix[4]arene (I) and thiacalix[4]arene (II) as electroactive materials. The addition of sodium tetraphenylborate and the plasticizer 2-nitrophenyl octyl ether has been found to improve the performance of the sensors substantially. The membranes of various compositions of the two thiacalixarenes have been investigated and it was found that the best performance was obtained for the membrane of composition II:PVC:NaTPB:NPOE in the ratio 5:120:3:150. The sensor shows a linear potential response for Cd{sup 2+} over a wide activity range 3.2 x 10{sup -6} to 1.0 x 10{sup -1} M with Nernstian compliance (29.5 mV decade{sup -1} of activity) in pH range 4.5-6.5 and a fast response time of {approx}8 s. The potentiometric selectivity coefficient values determined by matched potential method indicate excellent selectivity for Cd{sup 2+} ions over mono-, di- and trivalent interfering cations. The sensor exhibits adequate shelf life ({approx}3 months) with good reproducibility (S.D. {+-}0.2 mV) and can also be used in partially non-aqueous media having up to 20% (v/v) methanol, ethanol or acetone content with no significant change in the value of slope or working activity range. The sensor has been used in the potentiometric titration of Cd{sup 2+} with EDTA. The sensor could be successfully used for the quantification of cadmium in river water samples.

  9. SemiSPECT: a small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays.

    Science.gov (United States)

    Kim, Hyunki; Furenlid, Lars R; Crawford, Michael J; Wilson, Donald W; Barber, H Bradford; Peterson, Todd E; Hunter, William C J; Liu, Zhonglin; Woolfenden, James M; Barrett, Harrison H

    2006-02-01

    The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cm x 2.7 cm x -0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64 x 64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of -180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using 99mTc. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3 x 3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5 x 10(-4) with the energy window of +/-10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts in mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT.

  10. Soil seed banks and their germination responses to cadmium and salinity stresses in coastal wetlands affected by reclamation and urbanization based on indoor and outdoor experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Junhong, E-mail: junhongbai@163.com; Huang, Laibin, E-mail: seahuanglaibin@gmail.com; Gao, Zhaoqin; Lu, Qiongqiong; Wang, Junjing; Zhao, Qingqing

    2014-09-15

    Highlights: • A higher germination rate of soil seed bank was observed in the indoor experiment. • The outdoor experiment showed larger number and destiny of germinated seedlings. • Urbanization had greater impacts on soil seed banks than wetland reclamation. • Soil seed banks for wetland restoration were more suitable in the reclaimed region. • Suitable salt or Cd levels could activate seedling emergence in the soil seed bank. - Abstract: Indoor and outdoor seedling emergence experiments were conducted to thoroughly investigate germination patterns as affected by reclamation and urbanization, the ecological characteristics of soil seed banks, and their relationships with environmental factors in both urbanized and reclaimed regions of the Pearl River Delta in coastal wetlands. The germination rate of the soil seed bank was higher in the indoor experiment compared with that in the outdoor experiment, whereas the number and destiny of the germinated seedlings were greater in the outdoor experiment. The species diversity and number, as well as the richness and evenness indices, were higher in the urbanized region compared with the reclaimed region. However, the dominance and Sørensen similarity indices were greater in the reclaimed region compared with those indices in the urbanized region. Higher salinity and Cadmium (Cd) levels could inhibit seed germination; however, their suitable ranges (i.e. [0–2000 mg kg{sup −1}] for salinity and [0–4.0 mg kg{sup −1}] for available Cd) can activate seedling emergence, and more seedlings germinated under the intersectional levels at 0.34 mg kg{sup −1} available Cd and 778.6 mg kg{sup −1} salinity. Seawater intrusion caused by the sea level rise will possibly result in the salt-tolerant community in this area due to increasing salinity.

  11. The directors’ roles in containing the Robben Island Diversity Experience (RIDE

    Directory of Open Access Journals (Sweden)

    Frans Cilliers

    2012-01-01

    Full Text Available Orientation: Robben Island represents past denigration and present day liberation. The researchers report on their experiences of containing the learning, consciously and unconsciously, in the Robben Island Diversity Experience.Research purpose: The purpose of the research was to describe the experiences of the directors of RIDE in the last 10 years.Motivation for the study: Of the many and different diversity events that South African organisations present, RIDE is the only systems psycho-dynamically designed and presented event. This research was an effort to explore the nature of the directors’ roles in working with unconscious diversity dynamics in such a provocative venue.Research design, approach and method: The researchers conducted qualitative, descriptive and double hermeneutic research. The various RIDE events served as case studies. The data consisted of researcher field notes collected during the 10 years. Thematic analysis resulted in four themes, for which the researchers formulated working hypotheses. They integrated them into the research hypothesis.Main findings: Four themes emerged. They were the diversity characteristics of the directors as containers, working on the boundary between RIDE and the macro role players, attacks on the programme as container and challenges from participants.Practical/managerial implications: The research highlighted the important roles of directors’ authorisation as a resilience factor in containing RIDE.Contribution/value-add: The research contributed towards the awareness of intergroup relations between role players during diversity dynamic events and of how authorisation cements relationships.

  12. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-01

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems. PMID:28049820

  13. On-demand high-capacity ride-sharing via dynamic trip-vehicle assignment.

    Science.gov (United States)

    Alonso-Mora, Javier; Samaranayake, Samitha; Wallar, Alex; Frazzoli, Emilio; Rus, Daniela

    2017-01-17

    Ride-sharing services are transforming urban mobility by providing timely and convenient transportation to anybody, anywhere, and anytime. These services present enormous potential for positive societal impacts with respect to pollution, energy consumption, congestion, etc. Current mathematical models, however, do not fully address the potential of ride-sharing. Recently, a large-scale study highlighted some of the benefits of car pooling but was limited to static routes with two riders per vehicle (optimally) or three (with heuristics). We present a more general mathematical model for real-time high-capacity ride-sharing that (i) scales to large numbers of passengers and trips and (ii) dynamically generates optimal routes with respect to online demand and vehicle locations. The algorithm starts from a greedy assignment and improves it through a constrained optimization, quickly returning solutions of good quality and converging to the optimal assignment over time. We quantify experimentally the tradeoff between fleet size, capacity, waiting time, travel delay, and operational costs for low- to medium-capacity vehicles, such as taxis and van shuttles. The algorithm is validated with ∼3 million rides extracted from the New York City taxicab public dataset. Our experimental study considers ride-sharing with rider capacity of up to 10 simultaneous passengers per vehicle. The algorithm applies to fleets of autonomous vehicles and also incorporates rebalancing of idling vehicles to areas of high demand. This framework is general and can be used for many real-time multivehicle, multitask assignment problems.

  14. Cadmium burden and the risk and phenotype of prostate cancer

    Directory of Open Access Journals (Sweden)

    Wu Tony T

    2009-12-01

    Full Text Available Abstract Background Studies on the association between prostate cancer and cadmium exposure have yielded conflicting results. This study explored cadmium burden on the risk and phenotype of prostate cancer in men with no evident environmental exposure. Methods Hospital-based 261 prostate cancer cases and 267 controls with benign diseases were recruited from four hospitals in Taiwan. Demographic, dietary and lifestyle data were collected by standardized questionnaires. Blood cadmium (BCd and creatinine-adjusted urine cadmium (CAUCd levels were measured for each participant. Statistical analyses measured the prostate cancer risk associated with BCd and CAUCd separately, controlling for age, smoking and institution. BCd and CAUCd levels within cases were compared in relation to the disease stage and the Gleason score. Results High family income, low beef intake, low dairy product consumption and positive family history were independently associated with the prostate carcinogenesis. There was no difference in BCd levels between cases and controls (median, 0.88 versus 0.87 μg/l, p = 0.45. Cases had lower CAUCd levels than controls (median, 0.94 versus 1.40 μg/g creatinine, p = 0.001. However, cases with higher BCd and CAUCd levels tended to be at more advanced stages and to have higher Gleason scores. The prostate cancer cases with Gleason scores of ≥ 8 had an odds ratio of 2.89 (95% confidence interval 1.25-6.70, compared with patients with scores of 2-6. Conclusion Higher CAUCd and BCd levels may be associated with advanced cancer phenotypes, but there was only a tenuous association between cadmium and prostate cancer.

  15. Exploring the Mode Change Behavior of Park-and-Ride Users

    Directory of Open Access Journals (Sweden)

    Shahi Taphsir Islam

    2015-01-01

    Full Text Available This paper investigates the mode change behavior of park-and-ride (P&R users, which is of considerable significance to analyze the effectiveness of P&R site on the commuters’ travel mode change as well as the increase of public transport mode share. Data from an intercept interview survey conducted at different P&R facilities in Metropolitan Melbourne is used. A questionnaire containing revealed preference (RP and stated preference (SP questions is used to interview the individuals who park at the facility and catch public transport to go to city. This study firstly aims to know the factors affecting current travel behavior using RP data and secondly to investigate the importance of the factors on influencing the commuters’ decision of travel mode choice using the SP data. The empirical models using multinomial logistic regression reveal that travel time taken by transit vehicle and transfer time at P&R stations are the primary factors affecting individuals’ decision on choosing public transport whereas parking fare is the additional factor affecting commuters’ choice of driving. Based on the results of this study, the effectiveness of P&R scheme on commuters’ travel mode change is evaluated which would be helpful to shed lights on the future construction of P&R sites.

  16. Riding the research roller coaster: what went right, what went wrong?

    Science.gov (United States)

    Netta-Turner, Denise; Bucher, Linda; Dixon, Lois; Layton, Norma Jean

    2008-01-01

    Evidence-based practice drives nursing procedures and standards of care. Supporting practice with valid research can be a challenge. After identifying a knowledge- and problem-focused trigger, a group of WOC nurses began a research journey. Our purpose was to determine the effectiveness of the rectal trumpet compared to the fecal collector in maintaining skin integrity in patients with fecal incontinence. The methodology included a convenience sample of 100 patients randomized to rectal trumpet or fecal collector versus standard care. Data were collected on signs of increased skin breakdown or healing, stool leakage around device, dislodgement, and discomfort from device. This article will reveal our journey in conducting this clinical research. After many challenges, the study was terminated, but the experiences and lessons learned during our efforts were invaluable. Even well-planned studies can encounter problems that prevent completion. It is important to evaluate these problems so that lessons can be learned and shared. This is our roller coaster ride in the research world.

  17. Control Strategy of Three-Phase Photovoltaic Inverter under Low-Voltage Ride-Through Condition

    Directory of Open Access Journals (Sweden)

    Xianbo Wang

    2015-01-01

    Full Text Available The new energy promoting community has recently witnessed a surge of developments in photovoltaic power generation technologies. To fulfill the grid code requirement of photovoltaic inverter under low-voltage ride-through (LVRT condition, by utilizing the asymmetry feature of grid voltage, this paper aims to control both restraining negative sequence current and reactive power fluctuation on grid side to maintain balanced output of inverter. Two mathematical inverter models of grid-connected inverter containing LCL grid-side filter under both symmetrical and asymmetric grid are proposed. PR controller method is put forward based on inverter model under asymmetric grid. To ensure the stable operation of the inverter, grid voltage feedforward method is introduced to restrain current shock at the moment of voltage drop. Stable grid-connected operation and LVRT ability at grid drop have been achieved via a combination of rapid positive and negative sequence component extraction of accurate grid voltage synchronizing signals. Simulation and experimental results have verified the superior effectiveness of our proposed control strategy.

  18. Improvement of cadmium phytoremediation after soil inoculation with a cadmium-resistant Micrococcus sp.

    Science.gov (United States)

    Sangthong, Chirawee; Setkit, Kunchaya; Prapagdee, Benjaphorn

    2016-01-01

    Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L.

  19. Cadmium Toxicity Induced Alterations in the Root Proteome of Green Gram in Contrasting Response towards Iron Supplement

    Directory of Open Access Journals (Sweden)

    Sowbiya Muneer

    2014-04-01

    Full Text Available Cadmium signifies a severe threat to crop productivity and green gram is a notably iron sensitive plant which shows considerable variation towards cadmium stress. A gel-based proteomics analysis was performed with the roots of green gram exposed to iron and cadmium combined treatments. The resulting data show that twenty three proteins were down-regulated in iron-deprived roots either in the absence (−Fe/−Cd or presence (−Fe/+Cd of cadmium. These down-regulated proteins were however well expressed in roots under iron sufficient conditions, even in the presence of cadmium (+Fe/+Cd. The functional classification of these proteins determined that 21% of the proteins are associated with nutrient metabolism. The other proteins in higher quantities are involved in either transcription or translation regulation, and the rest are involved in biosynthesis metabolism, antioxidant pathways, molecular chaperones and stress response. On the other hand, several protein spots were also absent in roots in response to iron deprivation either in absence (−Fe/−Cd or presence (−Fe/+Cd of cadmium but were well expressed in the presence of iron (+Fe/+Cd. Results suggest that green gram plants exposed to cadmium stress are able to change the nutrient metabolic balance in roots, but in the mean time regulate cadmium toxicity through iron supplements.

  20. Cadmium toxicity induced alterations in the root proteome of green gram in contrasting response towards iron supplement.

    Science.gov (United States)

    Muneer, Sowbiya; Hakeem, Khalid Rehman; Mohamed, Rozi; Lee, Jeong Hyun

    2014-04-15

    Cadmium signifies a severe threat to crop productivity and green gram is a notably iron sensitive plant which shows considerable variation towards cadmium stress. A gel-based proteomics analysis was performed with the roots of green gram exposed to iron and cadmium combined treatments. The resulting data show that twenty three proteins were down-regulated in iron-deprived roots either in the absence (-Fe/-Cd) or presence (-Fe/+Cd) of cadmium. These down-regulated proteins were however well expressed in roots under iron sufficient conditions, even in the presence of cadmium (+Fe/+Cd). The functional classification of these proteins determined that 21% of the proteins are associated with nutrient metabolism. The other proteins in higher quantities are involved in either transcription or translation regulation, and the rest are involved in biosynthesis metabolism, antioxidant pathways, molecular chaperones and stress response. On the other hand, several protein spots were also absent in roots in response to iron deprivation either in absence (-Fe/-Cd) or presence (-Fe/+Cd) of cadmium but were well expressed in the presence of iron (+Fe/+Cd). Results suggest that green gram plants exposed to cadmium stress are able to change the nutrient metabolic balance in roots, but in the mean time regulate cadmium toxicity through iron supplements.

  1. Nickel-cadmium cell residual charge analyser

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, W.G.; Leek, R.; Hampson, N.A.; Lovelock, G.R.

    1984-09-01

    This paper describes a portable unit for measuring the charge remaining in nickel-cadmium secondary cells. Exhaustive frequency response tests have confirmed that cell impedance varies very little with charge state, with the possible exception of that at very low frequencies (< 50 mHz). In the interim before further work in this area is carried out, a microprocessor-based test unit has been built which uses a current pulse discharge method to arrive at a residual charge reading. When the cell is discharged according to a particular regime, the unit produces results accurate to within 10-15% over the entire range of charge. Further development involving the inclusion of cell history parameters promises to make the unit useful for military and other applications.

  2. Dietary exposure to cadmium and health effects: impact of environmental changes.

    Science.gov (United States)

    Piscator, M

    1985-11-01

    Cadmium exposure, metabolism, and effects are described especially in relation to dietary intakes. Data on dietary intakes in several countries have been complied from studies using the duplicate diet method or fecal analysis. These two methods seem to give more accurate data than estimates based on cadmium concentrations in food classes and food consumption (composite method). The present data on absorption and retention of ingested cadmium indicate that normally less than 5% is ingested, but absorption may increase in women who have iron deficiency. Earlier estimates of the critical concentration in renal cortex being about 200 mg/kg wet weight still seem to be valid. New information is available on present renal levels and their distribution in the general population. The present margin of safety with regard to risk for renal effects is small. To predict future health risks from increases in dietary cadmium due to environmental changes such as acid deposition, it is necessary that the models used are based on correct assumptions. Of interest are the distributions of dietary intake, gastrointestinal absorption, and renal cadmium concentrations. These distributions are normal or lognormal, and since standard deviations are used when estimating risks, it is of paramount importance that the standard deviations are estimated as accurately as possible. At present it is not possible to quantify the effects attributed to acid rain only; account must be also be taken of cadmium added to, e.g., soil by use of sewage sludge and other fertilizers. In addition to risks to human health, cadmium also poses a threat to horses, which generally have renal cadmium concentrations several times higher than adult humans. It is recommended that horses should be monitored in areas when acid deposition is high. Such monitoring might provide valuable information about impact of acid rain.

  3. FUZZY LOGIC CONTROLLER OF DFIG TO RIDE THROUGH RECURRING GRID FAULTS

    Directory of Open Access Journals (Sweden)

    Mani Kumar Gutti

    2016-09-01

    Full Text Available The penetration of Wind Turbine Systems (WTS is increasing in recent years. The new grid codes saying that the WTS must remain connected to utility grid at voltages below rated and also under recurring grid faults. The rotor side crowbar with vector control can ride through single grid fault. The rotor side crowbar fails to Ride Through recurring grid faults due to large electromagnetic torque fluctuations. This may affect mechanical system which leads to damage the gear box of WTS. This paper presents fuzzy logic control to investigate Doubly Fed Induction Generator (DFIG WTS to fault ride through (FRT recurring symmetrical grid faults. A rotor natural current is injected into the rotor circuit during voltage recovery under grid faults. By this the decay time of stator natural flux can be minimized. This will suppress the electromagnetic torque fluctuations and improves the mechanical system. The system is modeled by using MATLAB software.

  4. Travel Cost Model for an Agrifarm Specialised in Horse Riding Activities

    Directory of Open Access Journals (Sweden)

    M. Antoušková

    2014-12-01

    Full Text Available Agritourism, as a form of tourism, brings tourists a valuable contact with nature. To assess such a value, several methods can be used. One of these methods is the travel cost method, which is used in conducted research. Especially, a single site model is applied to recreation in a farm specialised in horse riding activities. It is not only tourists staying in the farms that take part in horse riding activities, these are also visitors staying in other places and coming to farms for horse riding as an accompanying activity to their recreation. Therefore, two separate travel cost models are estimated, for tourists and for visitors. Results show that the parameter of travel costs has a negative influence on the number of visits, which confirms the economic theory. The parameters involved in the estimated models for visitors and tourists show similar tendencies, except for the parameter of education.

  5. Hybrid column generation and large neighborhood search for the dial-a-ride problem

    Science.gov (United States)

    Parragh, Sophie N.; Schmid, Verena

    2013-01-01

    Demographic change towards an ever aging population entails an increasing demand for specialized transportation systems to complement the traditional public means of transportation. Typically, users place transportation requests, specifying a pickup and a drop off location and a fleet of minibuses or taxis is used to serve these requests. The underlying optimization problem can be modeled as a dial-a-ride problem. In the dial-a-ride problem considered in this paper, total routing costs are minimized while respecting time window, maximum user ride time, maximum route duration, and vehicle capacity restrictions. We propose a hybrid column generation and large neighborhood search algorithm and compare different hybridization strategies on a set of benchmark instances from the literature. PMID:23471127

  6. Hybrid column generation and large neighborhood search for the dial-a-ride problem.

    Science.gov (United States)

    Parragh, Sophie N; Schmid, Verena

    2013-01-01

    Demographic change towards an ever aging population entails an increasing demand for specialized transportation systems to complement the traditional public means of transportation. Typically, users place transportation requests, specifying a pickup and a drop off location and a fleet of minibuses or taxis is used to serve these requests. The underlying optimization problem can be modeled as a dial-a-ride problem. In the dial-a-ride problem considered in this paper, total routing costs are minimized while respecting time window, maximum user ride time, maximum route duration, and vehicle capacity restrictions. We propose a hybrid column generation and large neighborhood search algorithm and compare different hybridization strategies on a set of benchmark instances from the literature.

  7. Electrodialytic Removal of Cadmium from Straw Ash

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne;

    1999-01-01

    A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days...

  8. Cadmium and children : Exposure and health effects

    NARCIS (Netherlands)

    Schoeters, G.; Hond, E. Den; Zuurbier, M.; Naginiene, R.; Hazel, P.J. van den; Stilianakis, N.; Ronchetti, R.; Koppe, J.G.

    2006-01-01

    Cadmium exposure and accumulation in the body start at young age. Exposure routes in children are mainly via food, environmental tobacco smoke and house dust. Excretion from the body is limited. Cadmium accumulation in the kidney is responsible for effects such as nephrotoxicity and osteoporosis whi

  9. Cadmium and children: exposure and health effects.

    Science.gov (United States)

    Schoeters, Greet; Den Hond, Elly; Zuurbier, Moniek; Naginiene, Rima; van den Hazel, Peter; Stilianakis, Nikolaos; Ronchetti, Roberto; Koppe, Janna G

    2006-10-01

    Cadmium exposure and accumulation in the body start at young age. Exposure routes in children are mainly via food, environmental tobacco smoke and house dust. Excretion from the body is limited. Cadmium accumulation in the kidney is responsible for effects such as nephrotoxicity and osteoporosis which are observed at adult age. Cadmium exposure through inhalation is also associated with lung cancer in adulthood. Although transfer to the neonate through the placenta and through breast milk is limited, teratogenic and developmental effects were observed in experimental animals. The database on human studies involving children is limited, yet effects on motoric and perceptual behaviour in children have been associated with elevated in utero cadmium exposure. In school age children urinary cadmium levels were associated with immune suppressive effects. More studies are needed to confirm these results. Experimental data in vitro and in animals refer to effects of cadmium on the hypothalamus-pituitary axis at different levels. This may lead to disorders of the endocrine and/or immune system. Cadmium exposure at early age should be limited as much as possible to prevent direct effects on children and to prevent accumulation of cadmium which may have serious health effects only becoming manifest at older age.

  10. Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Mera, Roi; Torres, Enrique, E-mail: torres@udc.es; Abalde, Julio

    2014-03-01

    Highlights: • Sulphate effect on cadmium toxicity in the microalga Chlamydomonas moewusii Gerloff. • Cadmium increases the sulphur requirements in Chlamydomonas moewusii. • Kinetic coefficients for sulphate utilization and cadmium effect on them. • Sulphate and cadmium influence on the biosynthesis of low-molecular mass thiols. • Cadmium toxicity reduction by sulphate due to higher biosynthesis of thiols. - Abstract: Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu–Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1 mM sulphate. The maximum EC{sub 50} value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1 m

  11. Diagnostic methods applied to analysis of an outbreak of equine influenza in a riding school in which vaccine failure occurred

    NARCIS (Netherlands)

    Maanen, van C.; Essen, van G.J.; Minke, J.; Daly, J.M.; Yates, P.J.

    2003-01-01

    An outbreak of equine influenza H3N8 in a riding school is described retrospectively with emphasis on diagnosis and putative vaccine failure. In March 1995 an outbreak of equine influenza occurred among 11 horses in a riding school, where most horses had received basic primary immunizations and seve

  12. Canadian House Dust Study: Population-based concentrations, loads and loading rates of arsenic, cadmium, chromium, copper, nickel, lead, and zinc inside urban homes

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Pat E. [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Levesque, Christine [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Chénier, Marc; Gardner, H. David [Exposure and Biomonitoring Division, Healthy Environments and Consumer Safety Branch, Health Canada, 50 Colombine Driveway, Ottawa, ON, Canada K1A 0K9 (Canada); Department of Earth Sciences, University of Ottawa, 140 Louis Pasteur, Ottawa, ON, Canada K1N 6N5 (Canada); Jones-Otazo, Heather [Regions and Programs Branch, Health Canada, 180 Queen Street West, Toronto, ON, Canada M5V 3L7 (Canada); Petrovic, Sanya [Contaminated Sites Division, Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Ave West, Ottawa, ON, Canada K1A 0K9 (Canada)

    2013-01-15

    The Canadian House Dust Study was designed to obtain nationally representative urban house dust metal concentrations (μg g{sup −1}) and metal loadings (μg m{sup −2}) for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn). Consistent sampling of active dust of known age and provenance (area sampled) also permitted the calculation of indoor loading rates (mg m{sup −2} day{sup −1} for dust and μg m{sup −2} day{sup −1} for metals) for the winter season (from 2007 to 2010) when houses are most tightly sealed. Geomean/median indoor dust loading rates in homes located more than 2 km away from industry of any kind (9.6/9.1 mg m{sup −2} day{sup −1}; n = 580) were significantly lower (p < .001) than geomean (median) dust loading rates in homes located within 2 km of industry (13.5/13.4 mg m{sup −2} day{sup −1}; n = 421). Proximity to industry was characterized by higher indoor metal loading rates (p < .003), but no difference in dust metal concentrations (.29 ≥ p ≤ .97). Comparisons of non-smokers' and smokers' homes in non-industrial zones showed higher metal loading rates (.005 ≥ p ≤ .038) in smokers' homes, but no difference in dust metal concentrations (.15 ≥ p ≤ .97). Relationships between house age and dust metal concentrations were significant for Pb, Cd and Zn (p < .001) but not for the other four metals (.14 ≥ p ≤ .87). All seven metals, however, displayed a significant increase in metal loading rates with house age (p < .001) due to the influence of higher dust loading rates in older homes (p < .001). Relationships between three measures of metals in house dust – concentration, load, and loading rate – in the context of house age, smoking behavior and urban setting consistently show that concentration data is a useful indicator of the presence of metal sources in the home, whereas dust mass is the overriding influence on metal loadings and loading rates

  13. Cd-Resistant Strains of B. cereus S5 with Endurance Capacity and Their Capacities for Cadmium Removal from Cadmium-Polluted Water.

    Science.gov (United States)

    Wu, Huiqing; Wu, Qingping; Wu, Guojie; Gu, Qihui; Wei, Linting

    2016-01-01

    The goal of this study was to identify Cd-resistant bacterial strains with endurance capacity and to evaluate their ability to remove cadmium ions from cadmium-polluted water. The Bacillus cereusS5 strain identified in this study had the closest genetic relationship with B. cereus sp. Cp1 and performed well in the removal of Cd2+ions from solution. The results showed that both the live and dead biomasses of the Cd2+-tolerant B. cereus S5 strain could absorb Cd2+ ions in solution but that the live biomass of the B. cereus S5 strain outperformed the dead biomass at lower Cd2+concentrations. An analysis of the cadmium tolerance genes of B. cereus S5 identified ATPase genes that were associated with cadmium tolerance and involved in the ATP pumping mechanism. The FTIR spectra revealed the presence of amino, carboxyl and hydroxyl groups on the pristine biomass and indicated that the cadmium ion removal ability was related to the structure of the strain. The maximum absorption capacity of the B. cereus S5 strain in viable spore biomass was 70.16 mg/g (dry weight) based on a pseudo-second-order kinetic model fit to the experimental data. The Langmuir and Langmuir-Freundlich isotherm adsorption models fit the cadmium ion adsorption data well, and the kinetic curves indicated that the adsorption rate was second-order. For Cd2+ concentrations (mg/L) of 1-109 mg/L, good removal efficiency (>80%) was achieved using approximately 3.48-10.3 g/L of active spore biomass of the B. cereus S5 strain. A cadmium-tolerant bacteria-activated carbon-immobilized column could be used for a longer duration and exhibited greater treatment efficacy than the control column in the treatment of cadmium-polluted water. In addition, a toxicity assessment using mice demonstrated that the biomass of the B. cereus S5 strain and its fermentation products were non-toxic. Thus, the isolated B. cereus S5 strain can be considered an alternative biological adsorbent for use in emergency responses to severe

  14. 镉真空蒸馏的热力学模型与过程%Thermodynamic Model and Experiment of Vacuum Distillation of Cadmium

    Institute of Scientific and Technical Information of China (English)

    王林军; 郭燕明; 桑文斌; 史伟民; 顾永明; 钱永彪; 闵嘉华; 吴汶海; 居建华; 夏义本

    2001-01-01

    In this paper, a novel approach for highly efficient purification of cadmium by vacuum distillation was reported. During the cadmium vacuum distillation, a small quantity of cadmium oxide film, produced under lower vacuum, was intentionally induced into the evaporator, and the presence of cadmium oxide changed the behavior of impurities. Meantime, a thermodynamic model of the process, which described the phase composition in the evaporator and condenser during evaporation of cadmium, was established. The model was used to classify the impurities according to their behavior in the purification process. On the base of the model, the purification of cadmium by one-stage and two-stage distillation and the validity of the model were also discussed.

  15. 镉真空蒸馏的热力学模型与过程%Thermodynamic Model and Experiment of Vacuum Distillation of Cadmium

    Institute of Scientific and Technical Information of China (English)

    王林军; 郭燕明; 桑文斌; 史伟民; 顾永明; 钱永彪; 闵嘉华; 吴汶海; 居建华; 夏义本

    2000-01-01

    In this paper, a novel approach for highly efficient purification of cadmium by vacuum distillation was reported. During the cadmium vacuum distillation, a small quantity of cadmium oxide film, produced under lower vacuum, was intentionally induced into the evaporator, and the presence of cadmium oxide changed the behavior of impurities. Meantime, a thermodynamic model of the process, which described the phase composition in the evaporator and condenser during evaporation of cadmium, was established. The model was used to classify the impurities according to their behavior in the purification process. On the base of the model, the purification of cadmium by one-stage and two-stage distillation and the validity of the model were also discussed.

  16. Non conventional psychiatric rehabilitation in schizophrenia using therapeutic riding: the FISE multicentre Pindar project

    Directory of Open Access Journals (Sweden)

    Stefania Cerino

    2011-12-01

    Full Text Available The FISE (Federazione Italiana Sport Equestri Pindar is a multicentre research project aimed at testing the potential effects of therapeutic riding on schizophrenic patients. Twenty-four subjects with a diagnosis of schizophrenia were enrolled for a 1 year-treatment involving therapeutic riding sessions. All subjects were tested at the beginning and at the end of treatment with a series of validated test batteries (BPRS and 8 items-PANSS. The results discussed in this paper point out an improvement in negative symptoms, a constant disease remission in both early onset and chronic disease subjects, as well as a reduced rate of hospitalization.

  17. Influence of Horse and Rider on Stress during Horse-riding Lesson Program

    OpenAIRE

    Kang, Ok-Deuk; Yun, Young-Min

    2016-01-01

    The present study aims to confirm the influence of a horse-riding lesson program (HRLP) on the stress level of horses and riders by respectively analyzing their salivary cortisol concentration. Twenty-four healthy horses and 23 riders participated in this study. The horses were randomly classified into two groups for the horse riding lesson program: Class 1 (for the beginner lesson) and Class 2 (for the intermediate lesson). The Class 1 group consisted of 12 horses and 12 riders, while the Cl...

  18. Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

    DEFF Research Database (Denmark)

    Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.

    2016-01-01

    This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...... panel. By controlling the shoot-through duty cycle, the quasi Z source inverter can theoretically produce any desired output AC voltage, even greater than the line voltage. Three different control strategies to improve the low-voltage ride-through capability are proposed when there is voltage sag from...

  19. Temperature-controlled ionic liquid-based ultrasound-assisted microextraction for preconcentration of trace quantity of cadmium and nickel by using organic ligand in artificial saliva extract of smokeless tobacco products

    Science.gov (United States)

    Arain, Sadaf Sadia; Kazi, Tasneem Gul; Arain, Asma Jabeen; Afridi, Hassan Imran; Baig, Jameel Ahmed; Brahman, Kapil Dev; Naeemullah; Arain, Salma Aslam

    2015-03-01

    A new approach was developed for the preconcentration of cadmium (Cd) and nickel (Ni) in artificial saliva extract of dry snuff (brown and black) products using temperature-controlled ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (TIL-UDLLμE) followed by electrothermal atomic absorption spectrometry (ETAAS). The Cd and Ni were complexed with ammonium pyrrolidinedithiocarbamate (APDC), extracted in ionic liquid drops, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6]. The multivariate strategy was applied to estimate the optimum values of experimental variables influence the % recovery of analytes by TIL-UDLLμE method. At optimum experimental conditions, the limit of detection (3s) were 0.05 and 0.14 μg L-1 while relative standard deviations (% RSD) were 3.97 and 3.55 for Cd and Ni respectively. After extraction, the enhancement factors (EF) were 87 and 79 for Cd and Ni, respectively. The RSD for six replicates of 10 μg L-1 Cd and Ni were 3.97% and 3.55% respectively. To validate the proposed method, certified reference material (CRM) of Virginia tobacco leaves was analyzed, and the determined values of Cd and Ni were in good agreement with the certified values. The concentration of Cd and Ni in artificial saliva extracts corresponds to 39-52% and 21-32%, respectively, of the total contents of both elements in dry brown and black snuff products.

  20. Cadmium mobility and accumulation in soils of the European Communities

    NARCIS (Netherlands)

    Fraters B; van Beurden AUCJ

    1993-01-01

    In this overview of the effects of cadmium pollution on agricultural soils in the European Community, both the cadmium loads on agricultural land and the soil sensitivity to cadmium accumulation have been estimated. Cadmium loads have been estimated separately for arable land and grassland. The ef

  1. Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans

    Directory of Open Access Journals (Sweden)

    Yona J. Essig

    2016-02-01

    Full Text Available Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS, an enzyme involved in the biosynthesis of phytochelatins (PCs, plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1 is transcriptionally non-responsive to a chronic (48 h insult of high levels of zinc (500 μM or acute (3 h exposures to high levels of cadmium (300 μM. However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748 knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans.

  2. Deletion of Phytochelatin Synthase Modulates the Metal Accumulation Pattern of Cadmium Exposed C. elegans

    Science.gov (United States)

    Essig, Yona J.; Webb, Samuel M.; Stürzenbaum, Stephen R.

    2016-01-01

    Environmental metal pollution is a growing health risk to flora and fauna. It is therefore important to fully elucidate metal detoxification pathways. Phytochelatin synthase (PCS), an enzyme involved in the biosynthesis of phytochelatins (PCs), plays an important role in cadmium detoxification. The PCS and PCs are however not restricted to plants, but are also present in some lower metazoans. The model nematode Caenorhabditis elegans, for example, contains a fully functional phytochelatin synthase and phytochelatin pathway. By means of a transgenic nematode strain expressing a pcs-1 promoter-tagged GFP (pcs-1::GFP) and a pcs-1 specific qPCR assay, further evidence is presented that the expression of the C. elegans phytochelatin synthase gene (pcs-1) is transcriptionally non-responsive to a chronic (48 h) insult of high levels of zinc (500 μM) or acute (3 h) exposures to high levels of cadmium (300 μM). However, the accumulation of cadmium, but not zinc, is dependent on the pcs-1 status of the nematode. Synchrotron based X-ray fluorescence imaging uncovered that the cadmium body burden increased significantly in the pcs-1(tm1748) knockout allele. Taken together, this suggests that whilst the transcription of pcs-1 may not be mediated by an exposure zinc or cadmium, it is nevertheless an integral part of the cadmium detoxification pathway in C. elegans. PMID:26907254

  3. CADMIUM AND ZINC CONCENTRATIONS IN THE HAIR AFTER OF ADULTS MAGNESIUM SUPPLEMENTATION

    Directory of Open Access Journals (Sweden)

    Anna Sałacka

    2010-03-01

    Full Text Available Background: Cadmium is a biological zinc antagonist and may interfere with metabolic zinc-regulated or zincdependent processes. The aim of this study was to assess the relationship between cadmium and zinc concentrations in the hair of adults after oral supplementation with magnesium. Material and methods: The levels of elements in the hair were determined by the inverse voltammetry. The analysis was performed on the hair of 32 people from the study group and 10 from the control group. Supplementation was performed using Slow-Mag B6. Results: Cadmium concentration in the study group before supplementation ranged from indeterminable levels, to 1,92 µg per gram of dry matter. The range of cadmium concentration after supplementation was between the indeterminable level, and 0,45 µg per gram of dry matter. Based on the statistical analysis, we found that cadmium concentration was significantly lower after magnesium supplementation with a significance level of p*0,02. Zinc level before supplementation was between 11,66 and 250,48 µg per gram of dry matter, and after supplementation between 68,31 and 185,24 µg per gram of dry matter. Conclusion: The results obtained suggest that supplementation with magnesium contributed to the lowering of cadmium concentration in the hair of the people examined.

  4. Challenges to Grid Synchronization of Single-Phase Grid-Connected Inverters in Zero-Voltage Ride-Through Operation

    DEFF Research Database (Denmark)

    Zhang, Zhen; Yang, Yongheng; Blaabjerg, Frede;

    2016-01-01

    methods have been evaluated for single-phase grid-connected PV systems in the case of Zero-Voltage Ride-Through (ZVRT) operation. The performances of the prior-art PLL methods in response to zero voltage faults in terms of detection precision and dynamic response are assessed in this paper. Simulation......With the fast development in Photovoltaic (PV) technology, the relevant grid-connection requirements/standards are continuously being updated, and more challenges have been imposed on both single-phase and three-phase grid-connected PV systems. For instance, PV systems are currently required...... results show that the Enhanced PLL (EPLL) and the Second Order Generalized Integrator based PLL (SOGI-PLL) are the most applicable to single-phase PV systems for ZVRT operation....

  5. Sealed nickel-cadmium battery

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-15

    Overcharge protection, and especially the chargeability of a sealed Ni/Cd battery with high currents is improved by rolling a carbon-containing powdered material into the surface of the negative electrode, which material catalyzes the reduction of oxygen. Wetting of the electrode with a Tylose dispersion prior to application of the powder (by powdering, vibration or in an agitator) improves the adhesion of the powder. The cadmium electrode thus prepared combines in itself the functions of a negative principal electrode and of an auxiliary oxygen electrode.

  6. 网约车对城市居民出行方式影响的建模与分析%Modeling the Impacts of Ride-sourcing Platforms on Urban Transportation Market

    Institute of Scientific and Technical Information of China (English)

    刘名敏; 王晓蕾

    2016-01-01

    近年来,滴滴、 Uber等网约车平台的出现给城市居民出行带来了新的选择,网约车的合法地位得到交通运输部的认可。在一部分人将网约车看成解决城市出行难问题的利器的同时,另一部分人指出网约车的出现会加剧城市拥堵。文章通过数学建模分析了网约车平台出现后居民的出行模式选择,为定量评价网约车平台对城市居民出行造成的影响提供了理论模型。%The recent development of ride-sourcing platforms, e.g., Didi and Uber, brings about new mode choices to urban citi-zens. While many people believe that these ride-sourcing platforms help to make travel easier for citizens, the rest criticize that ride sourcing service increases road traffic congestion. In this paper, we develop a mathematical model to reveal travelers' mode choices after the emergence of a ride-sourcing platform, considering the complex interactions between travelers' mode choices and the attractiveness of ride-sourcing service. Based on the model, a numerical example is provided to show the possible positive and negative impacts on urban traffic condition.

  7. Lead, Cadmium and Nickel Contents of Some Medicinal Agents

    Science.gov (United States)

    Nessa, Fazilatun; Khan, S. A.; Abu Shawish, K.Y.I.

    2016-01-01

    Thirty nine brands of pharmaceutical dosage forms (28 tablets, 4 syrups, 6 suspensions and one chewing gum) that are available in United Arab Emirates pharmaceutical markets were investigated for the presence of three heavy metals; lead, cadmium and nickel. Amongst the samples, 13 products were manufactured locally in United Arab Emirates and 26 products were imported from around the world. The samples were prepared by acid digestion procedure and the resultant solutions were analyzed for heavy metals by using a validated graphite furnace atomic absorption spectrometric method. Calibration curves were achieved using different concentration of lead, nickel and cadmium ranged from 0.001 to 0.05 μg/ml. The mean recoveries of metals from the samples were 86.4 to 97%. The %relative standard deviation for the intraassay and interday precision for the metals were <5%. Amongst the 39 samples of pharmaceutical dosage form all exhibited a positive response for lead, cadmium and nickel except three products whose Ni levels were below quantification level. The products contained variable amounts of heavy metals as of 0.0017 to 11.88 μg lead; 0.0011 to 0.5559 μg cadmium and 0.0011 to 2.6428 μg nickel, respectively. Based on maximum recommended daily dose (g) of these products, maximum daily ingested mass of lead was 0.0034 to 11.88 μg/d, 0.0013 to 0.56 μg/d for cadmium and 0.0011 to 2.64 μg/d for nickel, respectively. The results were compared with those of oral permitted daily exposure levels of United State Pharmacopeial National Formulary 2013. All the products were safe to consume and contained lower level of lead, cadmium and nickel than Oral Permitted Daily Exposure levels, except three products which showed higher level of lead than oral permitted daily exposure levels. Hence the raw materials used in manufacturing of these medicinal agents might be responsible for the presence of higher level of lead. PMID:27168689

  8. Response of Saccharomyces cerevisiae to cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  9. Response of Pleurotus ostreatus to cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Favero, N.; Bressa, G.; Costa, P. (Univ. of Padua (Italy))

    1990-08-01

    The possibility of utilizing agroindustrial wastes in the production of edible, high-quality products (e.g., mushrooms) implies the risk of bringing toxic substances, such as heavy metals, into the human food chain. Thus, growth in the presence of cadmium and cadmium accumulation limits have been studied in the industrially cultivated fungus P. ostreatus. Fruit body production is substantially unaffected in the presence of 25, 139, and 285 mg Cd/kg of dried substrate. Cadmium concentration in fruit bodies is related to cadmium substrate level, the metal being present at higher levels in caps (22-56 mg/kg dry wt) than in stems (13-36 mg/kg dry wt). Concentration factor (CF), very low in the controls (about 2), further decreases in treated specimens. The presence of a cadmium control mechanism in this fungi species is suggested. Fruit body cadmium levels could, however, represent a risk for P. ostreatus consumers, according to FAO/WHO limits related to weekly cadmium intake.

  10. Interactions of cadmium and zinc during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Sorell, T.L.

    1988-01-01

    The interactions of cadmium exposure and zinc during pregnancy were investigated by studying rats exposed to 0, 5, 50, or 100 ppm cadmium (as CdCl{sub 2}) in the drinking water from day 6 to day 20 of pregnancy. On day 20 of pregnancy, fetuses of rats exposed to 50 and 100 ppm of cadmium were slightly but significantly smaller than those of control animals. Fetal weight was negatively correlated with fetal cadmium concentration and positively correlated with fetal cadmium concentration. Significant fetal cadmium accumulation occurred in both the 50 and 100 ppm cadmium exposure groups; fetal zinc concentrations were decreased. Maternal liver and kidney zinc concentrations were slightly elevated, and the possible role of maternal organ sequestration of available zinc is discussed. The activity of two zinc metalloenzymes, alkaline phosphatase and {delta}-aminolevulinic acid dehydratase, was decreased in maternal and fetal tissues, providing evidence of an alteration in zinc metabolism. In addition, the placental transport of {sup 65}Zn was characterized in control animals and compared to exposed groups; placental zinc transport was significantly decreased in the 50 and 100 ppm exposure groups.

  11. Cadmium inhalation and male reproductive toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, H.A.; Mast, T.J. (Battelle Pacific Northwest Laboratories, Richland, WA (USA))

    1990-01-01

    Cadmium is a highly toxic element that is cumulative and has a long biological half-life in mammals. The severe toxicity of cadmium in man has been known for more than 100 years. Despite the knowledge that cadmium is toxic, only 20 human cases of poisoning via ingestion were recorded prior to 1941, whereas in the ensuing five-year period more than 680 cases of cadmium poisonings from accidental oral ingestion of this metal were documented. Some of the recorded effects of exposure to cadmium in laboratory animals include renal tubular damage, placental and testicular necrosis, structural and functional liver damage, osteomalacia, testicular tumors, teratogenic malformations, anemia, hypertension, pulmonary edema, chronic pulmonary emphysema, and induced deficiencies of iron, copper, and zinc. Some of these effects have also been observed in human after accidental exposures to cadmium oxide fumes and are characteristic of the syndrome described in Japan as Itai Itai disease in which ingestion of cadmium is the inciting chemical.134 references.

  12. An in vitro model for the in vivo mobilization of cadmium by chelating agents using 113Cd-NMR spectroscopy.

    Science.gov (United States)

    Beaty, J A; Jones, M M; Wilson, D J; Ma, L

    1992-01-01

    An in vitro method, based on 113Cd-NMR spectroscopy, that provides an alternative to the use of animals for an initial screening of cadmium antagonists is presented. The relative values of the effective stability constants of potential chelating antagonists for cadmium are estimated by using 113Cd-NMR spectroscopy to determine the concentrations of the cadmium species involved in appropriate competitive equilibria. This is accomplished via an examination of the competition between the proposed antagonist and EDTA (ethylenediaminetetraacetic acid) for cadmium-113; previously, EDTA has been shown to be capable of removing cadmium from such in vivo binding sites as metallothionein. The reactions proceed via the stepwise addition of three dithiocarbamate groups to the cadmium accompanied by the concurrent stepwise release of donor groups from the EDTA. The resulting 113Cd-NMR data allow for the determination of the overall stability constant for the complex formed between cadmium and N-methyl-D-glucamine dithiocarbamate, iminodiacetic acid dithiocarbamate, proline dithiocarbamate, sarcosine dithiocarbamate. The use of 113Cd-NMR spectroscopy has the potential for providing direct evidence on the effectiveness of chelate antagonists to compete with endogenous ligands for other toxic metal ions. This technique could prove very useful for other compounds that are not stable enough toward acid and/or base to be examined by standard titrimetric methods.

  13. [Association between cadmium and breast cancer].

    Science.gov (United States)

    Strumylaite, Loreta; Bogusevicius, Algirdas; Ryselis, Stanislovas; Pranys, Darius; Poskiene, Lina; Kregzdyte, Rima; Abdrachmanovas, Olegas; Asadauskaite, Rūta

    2008-01-01

    Cadmium is a known human lung carcinogen, although some studies indicate a link between cadmium exposure and human breast cancer. The objective of this study was to assess cadmium concentration in breast tissue samples of patients with breast cancer and benign breast tumor. MATERIAL AND METHODS. The concentration of cadmium was determined in breast tissue samples of 21 breast cancer and 19 benign tumor patients. Two samples of breast tissue from each patient, i.e. tumor and normal tissue close to tumor, were taken for the analysis. Cadmium was determined by atomic absorption spectrometry (Perkin-Elmer, Zeeman 3030). RESULTS. In patients with breast cancer, the mean cadmium concentration was 33.1 ng/g (95% CI, 21.9-44.4) in malignant breast tissue and 10.4 ng/g (95% CI, 5.6-15.2) in normal breast tissue (P=0.002). In patients with benign tumor, the corresponding values were 17.5 ng/g (95% CI, 8.4-26.5) and 11.8 ng/g (95% CI, 5.1-18.5) (P=0.3144). There was a statistically significant difference in cadmium concentration between malignant and benign breast tissues (P=0.009). CONCLUSION. The data obtained show that cadmium concentration is significantly higher in malignant breast tissue as compared with normal breast tissue of the same women or benign breast tissue. Further studies are necessary to determine the association between cadmium concentration in malignant breast tissue and estrogen receptor level, and smoking.

  14. How challenging is a riding horse’s life? Field studies on fitness, workload and welfare

    NARCIS (Netherlands)

    Munsters, C.C.B.M.

    2013-01-01

    The objectives of this thesis were to evaluate in practice workload, fitness and welfare of riding horses under work and training conditions. Chapter II presents an overview of the parameters used in earlier studies on training, behaviour and equine welfare, and describes the evaluation of the physi

  15. Hypothalamic-pituitary-adrenal axis responses of horses to therapeutic riding program: effects of different riders.

    Science.gov (United States)

    Fazio, Esterina; Medica, Pietro; Cravana, Cristina; Ferlazzo, Adriana

    2013-06-13

    In order to determine whether therapeutic riding could result in higher levels of stress than recreational riding, hypothalamic-pituitary-adrenal (HPA) axis response was evaluated in six horses by monitoring circulating β-endorphin, ACTH and cortisol concentrations. Horses were already accustomed to be trained both for therapy and riding school activity since 2004. Intervention consisted of 60-minute therapeutic sessions, two times per week for 6weeks with different riders: disabled and recreational riders (session A and B respectively). The therapeutic riders' group (A) consisted of six children with psychomotor disabilities; the recreational riders' group (B) consisted of six healthy children without any previous horse riding experience. Horses were asked to perform the same gaits and exercises at all sessions, both with disabled and healthy users. The statistical analysis showed that during both sessions the mean basal β-endorphin and ACTH levels of horses did not show any significant changes, while the one way RM-ANOVA showed significant effects of sessions A on the cortisol (F=11.50; PHorses submitted to sessions A showed lower cortisol levels both at 5min (Phorses and for the variables settled, HPA axis was less responsive to disabled than healthy, recreational riders. Among the endocrine responses, cortisol was one of the indicators of HPA axis stress response.

  16. Therapeutic Riding for a Student with Multiple Disabilities and Visual Impairment: A Case Study.

    Science.gov (United States)

    Lehrman, Jennifer; Ross, David B.

    2001-01-01

    A 9-year-old with multiple disabilities and visual impairments was the focus of a 10-week developmental therapeutic riding program incorporating hippotherapy. The program has led to increased mobility, an increase in visual attention span and fixation time, signs of greater verbal communication, and the acquisition of new functional signs.…

  17. Therapist-Designed Adaptive Riding in Children With Cerebral Palsy : Results of a Feasibility Study

    NARCIS (Netherlands)

    Angsupaisal, Mattana; Visser, Baudina; Alkema, Anne; Meinsma-van der Tuin, Marja; Maathuis, Carel G. B.; Reinders-Messelink, Heleen; Hadders-Algra, Mijna

    2015-01-01

    Background. It is debatable whether adaptive riding (AR) in children with cerebral palsy (CP) improves postural control and gross motor development. Objective. The study aim was to explore the feasibility of an extensive assessment protocol for a randomized controlled trial of therapist-designed ada

  18. Fault Ride-Through of a Grid-connected Photovoltaic System with Quasi Z Source Inverter

    DEFF Research Database (Denmark)

    Al-Durra, Ahmed; Fayyad, Yara; Muyeen, S.M.;

    2016-01-01

    This article presents fault ride-through schemes for a three-phase quasi Z source single-stage photovoltaic (PV) inverter that is connected to the grid after the distribution network. The quasi Z source inverter employs a unique LC network to couple the inverter main circuit to the input of the PV...

  19. Economic analysis of the organisation of a riding centre; application of the linear programming approach

    Directory of Open Access Journals (Sweden)

    Jaka ŽGAJNAR

    2015-12-01

    Full Text Available In this contribution, the economics of an equestrian centre, which in addition to a variety of riding school activities also includes breeding and livery, are analysed. We consider the conditions for a hypothetical holding operating in central Slovenia. Methods of mathematical programming are applied in order to attempt to optimise the holding’s activities. Their use may in the given situation facilitate the evaluation of development prospects from different perspectives and indicate the opportunities of increasing value-added. On the basis of maximizing the gross margin, we try to address the various questions and challenges that arise in managing and planning for such an equestrian centre. The obtained results indicate that breeding is unfavourable in the given price-cost ratio, both for the renewal of the working horses herd and for sale. This reflects the current adverse situation in the field of horse breeding. Livery is an important activity on such holdings and through opportunity perspective provides an optimal set of activities. Activities of the riding school for children are interesting in terms of income diversification, as well as an additional source of revenue. A riding school with one riding instructor and an indoor arena needs 4.6 horses in order to cover the costs of full-time employment.

  20. Cardiorespiratory and Biomechanical Responses to Simulated Recreational Horseback Riding in Healthy Children

    Science.gov (United States)

    Rigby, Brandon R.; Papadakis, Zacharias; Bane, Annie A.; Park, Jin K.; Grandjean, Peter W.

    2015-01-01

    Purpose: The purpose of this study was to determine the reliability of cardiorespiratory and pelvic kinematic responses to simulated horseback riding (SHBR) and to characterize responses to SHBR relative to walking in apparently healthy children. Method: Fifteen healthy children (Mage = 9.5 ± 2.6 years) completed SHBR on a commercially available…

  1. A Current Limiting Strategy to Improve Fault Ride-Through of Inverter Interfaced Autonomous Microgrids

    DEFF Research Database (Denmark)

    Sadeghkhani, Iman; Esmail Hamedani Golshan, Mohamad; Guerrero, Josep M.;

    2017-01-01

    With high penetration of distributed energy resources (DER), fault management strategy is of great importance for the distribution network operation. The objective of this paper is to propose a current and voltage limiting strategy to enhance fault ride-through (FRT) capability of inverter...

  2. Overuse Injuries Associated with Mountain Biking: Is Single-Speed Riding a Predisposing Factor?

    Directory of Open Access Journals (Sweden)

    Michael T. Lebec

    2014-01-01

    Full Text Available Though mountain bikers are at significant risk for overuse injury, there is minimal quality research describing this relationship. Single-speed mountain biking, in which participants pedal a bike with only a single gear, may place riders at even greater risk for overuse problems due to the disproportionate physical effort associated with this type of riding. The focus of this study was to provide additional perspective on overuse injuries sustained by mountain bikers and to determine if single-speed mountain biking places participants at greater risk for overuse conditions. Four hundred and four (404 mountain bikers were surveyed concerning overuse injuries sustained during the previous year. Findings indicate that 63% of respondents reported an overuse injury affecting at least one area with the most commonly reported areas being the lumbar spine, knees, hand/wrist, and cervical spine. Individuals riding single-speed mountain bikes did not have a higher incidence of overuse injuries than riders of multiple-geared bikes. However, respondents who split time between riding single-speed and multiple-geared bikes were significantly more likely to report an overuse syndrome than those only riding single-speed or multiple-geared bikes (p = 0.0104. This group of riders may be at greater risk for overuse injury due to excessive fatigue and poor biomechanics.

  3. Coordination between Fault-Ride-Through Capability and Overcurrent Protection of DFIG Generatorsfor Wind Farms

    DEFF Research Database (Denmark)

    Bak-Jensen, Birgitte; Kawady, Tamer A.; Abdel-Rahman, Mansour H.

    2009-01-01

    , the Coor-dination between Fault Ride-Through Capability and Overcur-rent Protection of DFIG Wind Generators in MV Networks is in-vestigated. Simulation test cases using MATLAB-Simulink are implemented on a 345-MW wind farm in AL-Zaafarana, Egypt. The simulation results show the influence of FRT capability...

  4. The Dynamics of Plant Closings: An Extended Emotional Roller Coaster Ride.

    Science.gov (United States)

    Hurst, Joe B.; Shepard, John W.

    1986-01-01

    Millions of United States' workers are unemployed, many of them dislocated from their jobs and careers by extended layoffs, drastic manpower reductions, and plant closings. Describes a model of the emotional roller coaster ride taken by employees displaced by a plant closing and suggests approaches to helping them and their families. (Author/ABB)

  5. Acceleration and Rotation in a Pendulum Ride, Measured Using an iPhone 4

    Science.gov (United States)

    Pendrill, Ann-Marie; Rohlen, Johan

    2011-01-01

    Many modern cell phones have built-in sensors that may be used as a resource for physics education. Amusement rides offer examples of many different types of motion, where the acceleration leads to forces experienced throughout the body. A comoving 3D-accelerometer gives an electronic measurement of the varying forces acting on the rider, but a…

  6. Low Voltage Ride-Through of Variable Speed Wind Turbines with Permanent Magnet Synchronous Generator

    DEFF Research Database (Denmark)

    Hu, Weihao; Chen, Zhe; Wang, Yue

    2009-01-01

    This paper presents a simulation model of a MW-level variable speed wind turbine with a permanent magnet synchronous generator (PMSG) and a full-scale converter developed in the simulation tool of PSCAD/EMTDC. The low voltage ride-through (LVRT) capability of the wind turbine is investigated. A n...

  7. Horses: An Introduction to Horses: Racing, Ranching, and Riding for Blind and Physically Handicapped Individuals.

    Science.gov (United States)

    Cylke, Frank Kurt, Ed.

    This annotated bibliography of materials focuses on horses, racing, ranching, and riding. Two articles are presented in full. They are: "Diary of a Blind Horseman: Confidence Springs from a Horse Named Sun" (Richard Vice and Steve Stone) and "Young Rider: Her Horses Show the Way" (Helen Mason). Each article tells the true story…

  8. Horse Riding 101: The Role of Experience in Reframing Teacher Education Practices

    Science.gov (United States)

    Garbett, Dawn

    2011-01-01

    For this self-study of my teacher education practice, I positioned myself as a novice in the unfamiliar context of learning to ride a horse. This gave me an opportunity to re-experience being an authentic learner and thereby to deepen my understanding of how an individual learns to teach. I recorded my experiences in an electronic journal and…

  9. Low Voltage Ride-Through of Single-Phase Transformerless Photovoltaic Inverters

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2014-01-01

    , e.g. Low Voltage Ride-Through (LVRT) under grid faults and grid support service. In order to map future challenges, the LVRT capability of three mainstream single-phase transformerless PV inverters under grid faults are explored in this paper. Control strategies with reactive power injections...

  10. Low voltage ride-through of single-phase transformerless photovoltaic inverters

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede; Wang, Huai

    2013-01-01

    .g. Low Voltage Ride-Through (LVRT) under grid faults and grid support service. In order to map future challenges, the LVRT capability of three mainstream single-phase transformerless PV inverters under grid faults are explored in this paper. Control strategies with reactive power injections are also...

  11. The Effectiveness of Simulated Developmental Horse-Riding Program in Children with Autism

    Science.gov (United States)

    Wuang, Yee-Pay; Wang, Chih-Chung; Huang, Mao-Hsiung; Su, Chwen-Yng

    2010-01-01

    This study investigated the effectiveness of a 20-week Simulated Developmental Horse-Riding Program (SDHRP) by using an innovative exercise equipment (Joba[R]) on the motor proficiency and sensory integrative functions in 60 children with autism (age: 6 years, 5 months to 8 years, 9 months). In the first phase of 20 weeks, 30 children received the…

  12. Electromagnetic validation of fault-ride through capabilities of wind turbines

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Garcia-Valle, Rodrigo; Sharma, Ranjan

    2010-01-01

    Scope of the present project is the development and validation of electro-magnetic transient model of fixed-speed wind turbines. The research work is focused on the development of a fixed-speed wind turbine model with fault-ride through capabilities during transient over-voltages. The model...

  13. A Motion Simulator Ride Associated With Headache and Subdural Hematoma: First Case Report.

    Science.gov (United States)

    Scranton, Robert A; Evans, Randolph W; Baskin, David S

    2016-02-01

    We report the first case report of symptomatic bilateral subdural hematomas (SDH) associated with riding a centrifugal motion simulator ride. A previously healthy 55-year-old male developed new onset daily headaches 1 week after going on the ride that were due to symptomatic bilateral SDH requiring operative intervention with a full recovery. There was no history of other trauma or other systemic or intracranial abnormality to account for the development of the SDH. We review the headaches and other clinical features associated with chronic SDH. Twelve cases of roller coaster headaches due to SDH associated with riding roller coasters have been reported. The pathophysiology is reviewed, which we believe is the same mechanism that may be responsible in this case. Although it is possible that this neurovascular injury is truly rare, it is also possible that this injury is underreported as patients and physicians may not make the association or physicians have not reported additional cases. The risk of this injury likely increases with age, as the size of the subdural space increases, and may support the maxim that "roller coasters and simulators are for kids."

  14. The contribution of park and ride to a robust mobility system

    NARCIS (Netherlands)

    Snelder, M.; Egeter, B.; Hendriks, T.; Immers, L.H.

    2011-01-01

    P+R-plus is a new layer of P+R (Park and Ride) on top of existing P+R facilities at many public transport stops. Someone who parks his car at a P+R-plus location is guaranteed that he can reach all important locations within a metropolitan region with a maximum of one transfer and with metro quality

  15. Improving Fault Ride-Through Capability of Variable Speed Wind Turbines in Distribution Networks

    DEFF Research Database (Denmark)

    Mokryani, Geev; Siano, P.; Piccolo, Antonio;

    2013-01-01

    In this paper, a fuzzy controller for improving the fault ride-through (FRT) capability of variable speed wind turbines (WTs) equipped with a doubly fed induction generator (DFIG) is presented. DFIGs can be used as reactive power sources to control the voltage at the point of common coupling (PCC...

  16. A flexible low-voltage ride-through operation for the distributed generation converters

    DEFF Research Database (Denmark)

    Chen, Hsin-Chih; Lee, Chia-Tse; Cheng, Po-Tai;

    2013-01-01

    -sequence current injection method is proposed to meet the low-voltage ride through (LVRT) requirement. The proposed method predefined a current constraint to avoid the overcurrent during the LVRT operation and adjust the positive-sequence reactive current to reduce the DC-bus voltage ripple. Comparisons...

  17. Biochemical Effects of Cadmium Exposure and the Potential Pharmacologic Significance of Cadmium Mediated Hydrolase Inhibition

    Science.gov (United States)

    1997-04-18

    increase Cd absorption from the intestines (Larson and Piscator 1971; Itokawa, Abe et al. 197 4; Pond and Walker 1975). Pyridoxine, vitamin B 6 , is...considerations on uptake and retention of cadmium in human kidney cortex. Cadmium in the Environment. L. Friberg, M. Piscator and G. F. Nordberg. Cleveland...Columbia, Missouri, University of Missouri. Larson, S.-E. and M. Piscator (1971). "Effect of cadmium on skeletal tissue in normal and calcium

  18. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, R.; Riget, F. F.;

    as laboratory mammals. We have studied possible cadmium induced histopathological changes in the kidneys as well as a demineralisation of the skeletal system (DXA-scanning of lumbal vertebraes). No obvious cadmium induced toxic changes were found. Food composition and physiological adaptations may explain......Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...

  19. Orthopaedic health status of horses from 8 riding schools - a pilot study

    Directory of Open Access Journals (Sweden)

    Egenvall Agneta

    2010-08-01

    Full Text Available Abstract Background Orthopaedic injury is the most common reason for lameness and wastage in sport and leisure horses. Studies on racehorses have shown differences in injury risk between trainers and training strategies. The aim was to study between riding school variation in orthopaedic health status by clinical examination and horses age, and control for change of examiner, in schools with previous high (n = 4 and low (n = 4 insurance utilisation. Methods Horses (n = 99 at 8 riding schools were examined for conformation, movement in all gaits, standing flexion tests and palpation by two veterinary surgeons (in some schools only one. Indexes of findings were created for total health, movements, limbs, conformation and back palpation. Results Logistic regression analyses showed that findings increased with age (walk, trot, canter, conformation left hind limb, palpation fore limbs, hooves and flexion tests or decreased with age (conformation right fore limb. Significant differences in findings were found between riding schools and examiner for seven and eight criteria each (partly overlapping. Increasing indexes were significantly associated with one examiner (total health, movements, back palpation, increasing age (total health, movements or more time at the school (limbs. The back palpation index was highest at 5 Conclusion The age distribution differed markedly between riding schools and age affected several types of findings. This, combined with the two opposite groups of insurance use, shows that schools with low insurance utilisation had previously been able to "avoid" using the insurance, maybe even on similar types of cases if these were more promptly/differently handled indicating differential coverage of disease data in the insurance database. The examiner effect was clearly demonstrated. For some findings, the amount of clinical observations differed by school, even when examiner and age was adjusted for. Most findings were of minor

  20. Paediatric ride-on mower related injuries and plastic surgical management.

    Science.gov (United States)

    Laing, T A; O'Sullivan, J B; Nugent, N; O'Shaughnessy, M; O'Sullivan, S T

    2011-05-01

    Lawnmower related injuries cause significant morbidity in children and young teenagers. The 'ride-on' mowers which are more powerful than the 'walk behind' mowers are becoming increasingly popular. The incidence and severity of injuries from either type of lawnmower appears to be steadily rising as is the burden placed on local plastic surgical and emergency services in managing the care of these patients. The aims of the study were to demonstrate changing trends in lawnmower-related injuries to children presenting to a single unit over a ten-year period and to identify any association between injury severity and machine subtype ('ride-on' versus 'walk-behind'). Hospital databases, theatre records and medical case notes were reviewed retrospectively of all patients under the age of 16 treated for lawnmower related injuries over a 10 year period from July 1998 to June 2008. Data gathered included patient demographics, injury site and severity, management (type and number of surgical procedures), length of hospital stay and outcome. Injury severity score was also calculated for each case. Controlling for estimated regional population changes, there was a significant increase in the number of ride-on mower related accidents in the time period 2003-2008, compared to the time period 1998-2003. Ride-on injuries had significantly higher injury severity scores, longer hospital stays and were more likely to involve amputations as compared with walk-behind injuries. Children can sustain significant injuries with unsafe lawnmower use. The current study demonstrates the increasing incidence of ride-on mower related injuries in children and identifies a greater morbidity associated with such injuries. Such presentations place intense demands on local plastic surgical services.

  1. Paediatric ride-on mower related injuries and plastic surgical management.

    LENUS (Irish Health Repository)

    Laing, T A

    2011-05-01

    Lawnmower related injuries cause significant morbidity in children and young teenagers. The \\'ride-on\\' mowers which are more powerful than the \\'walk behind\\' mowers are becoming increasingly popular. The incidence and severity of injuries from either type of lawnmower appears to be steadily rising as is the burden placed on local plastic surgical and emergency services in managing the care of these patients. The aims of the study were to demonstrate changing trends in lawnmower-related injuries to children presenting to a single unit over a ten-year period and to identify any association between injury severity and machine subtype (\\'ride-on\\' versus \\'walk-behind\\'). Hospital databases, theatre records and medical case notes were reviewed retrospectively of all patients under the age of 16 treated for lawnmower related injuries over a 10 year period from July 1998 to June 2008. Data gathered included patient demographics, injury site and severity, management (type and number of surgical procedures), length of hospital stay and outcome. Injury severity score was also calculated for each case. Controlling for estimated regional population changes, there was a significant increase in the number of ride-on mower related accidents in the time period 2003-2008, compared to the time period 1998-2003. Ride-on injuries had significantly higher injury severity scores, longer hospital stays and were more likely to involve amputations as compared with walk-behind injuries. Children can sustain significant injuries with unsafe lawnmower use. The current study demonstrates the increasing incidence of ride-on mower related injuries in children and identifies a greater morbidity associated with such injuries. Such presentations place intense demands on local plastic surgical services.

  2. Remote sensing applications in evaluation of cadmium pollution effects

    Science.gov (United States)

    Kozma-Bognar, Veronika; Martin, Gizella; Berke, Jozsef

    2013-04-01

    According to the 21st century developments in information technology the remote sensing applications open new perspectives to the data collection of our environment. Using the images in different spectral bands we get more reliable and accurate information about the condition, process and phenomena of the earth surface compared to the traditional aircraft image technologies (RGB images). The effects of particulate pollution originated from road traffic were analysed by the research team of Department of Meteorology and Water Management (University of Pannonia, Georgikon Faculty) with the application of visible, near infrared and thermal infrared remote sensing aircraft images. In the scope of our research was to detect and monitor the effects of heavy metal contamination in plant-atmosphere system under field experiments. The testing area was situated at Agro-meteorological Research Station in Keszthely (Hungary), where maize crops were polluted once a week (0,5 M concentration) by cadmium. In our study we simulated the effects of cadmium pollution because this element is one of the most common toxic heavy metals in our environment. During two growing seasons (2011, 2012) time-series analyses were carried out based on the remote sensing data and parallel collected variables of field measurement. In each phenological phases of plant we took aerial images, in order to follow the changes of the structure and intensity values of plots images. The spatial resolution of these images were under 10x10 cm, which allowed to use a plot-level evaluation. The structural and intensity based measurement evaluation methods were applied to examine cadmium polluted and control maize canopy after data pre-processing. Research activities also focused on the examination of the influence of the irrigation and the comparison of aerial and terrain parameters. As conclusion, it could be determined the quantification of cadmium pollution effects is possible on maize plants by using remote

  3. Mechanisms of cadmium-caused eye hypoplasia and hypopigmentation in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ting, E-mail: zting@webmail.hzau.edu.cn; Zhou, Xin-Ying, E-mail: 290356082@qq.com; Ma, Xu-Fa, E-mail: xufama@mail.hzau.edu.cn; Liu, Jing-Xia, E-mail: ichliu@mail.hzau.edu.cn

    2015-10-15

    Highlights: Using high-throughput in situ hybridization screening, we found that genes labeling the neural crest and its derivative pigment cells were sensitive to cadmium toxicity during zebrafish organogenesis, which might contribute to the molecular mechanisms underlying the phenotype defects of head and eye hypoplasia and hypopigmentation in cadmium-exposed embryos. Based on neural crest markers, we identified the doses and times of cadmium exposure that cause damage to the zebrafish organogenesis, and we also found that compounds BIO or RA could neutralize the toxic effects of cadmium. - Abstract: Cadmium-caused head and eye hypoplasia and hypopigmentation has been recognized for a long time, but knowledge of the underlying mechanisms is limited. In this study, we found that high mortality occurred in exposed embryos after 24 hpf, when cadmium (Cd) dosage was above 17.8 μM. Using high-throughput in situ hybridization screening, we found that genes labelling the neural crest and its derivative pigment cells exhibited obviously reduced expression in Cd-exposed embryos from 24 hpf, 2 days earlier than head and eye hypoplasia and hypopigmentation occurred. Moreover, based on expression of crestin, a neural crest marker, we found that embryos before the gastrula stage were more sensitive to cadmium toxicity and that damage caused by Cd on embryogenesis was dosage dependent. In addition, by phenotype observation and detection of neural crest and pigment cell markers, we found that BIO and retinoic acid (RA) could neutralize the toxic effects of Cd on zebrafish embryogenesis. In this study, we first determined that Cd blocked the formation of the neural crest and inhibited specification of pigment cells, which might contribute to the molecular mechanisms underlying the phenotype defects of head and eye hypoplasia and hypopigmentation in Cd-exposed embryos. Moreover, we found that compounds BIO or RA could neutralize the toxic effects of Cd.

  4. Spinal Cord Injuries in Wave-Riding Sports: The Influence of Environmental and Sport-Specific Factors.

    Science.gov (United States)

    Falconi, Audrey; Flick, David; Ferguson, Jason; Glorioso, John E

    2016-01-01

    Spinal cord injury is a nonfatal, catastrophic consequence of wave-riding sports. With surfing at the core, a multitude of activities have evolved that attempt to harness the power of ocean waves. The unique qualities of each wave-riding sport, in combination with the environmental factors of the ocean, define the risk for potential injuries. As wave-riding sports have become more advanced, athletes continue to push physical barriers. Taller waves are attempted while incorporating aerial maneuvers, all without protective equipment.

  5. Fault Ride Though Control of Photovoltaic Grid-connected Inverter with Current-limited Capability under Offshore Unbalanced Voltage Conditions

    DEFF Research Database (Denmark)

    Liu, Wenzhao; Guo, Xiaoqiang; Savaghebi, Mehdi;

    2016-01-01

    of the excessive current phenomenon with the conventional fault ride through control is discussed. The quantitative analysis of the current peak value is conducted and a new current-limiting control strategy is proposed to achieve the flexible power control and successful fault ride through in a safe current......The photovoltaic (PV) inverter installed on board experiences the excessive current stress in case of the offshore unbalanced voltage fault ride through (FRT), which significantly affects the operation reliability of the power supply system. In order to solve the problem, the inherent mechanism...

  6. RISK ASSESSMENT AND MANAGEMENT OF ENVIRONMENTAL CADMIUM

    Science.gov (United States)

    Cadmium consumed in foods grown on soils contaminated by industrial Cd+Zn discharge has caused renal tubular dysfunction in exposed humans in discrete situations. However, lack of understanding about environmental Cd has caused wide concern that generalpopulations may...

  7. Some Aspects of Sealed Nickel Cadmium Cells

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    1967-11-01

    Full Text Available Sealed Nickel Cadmium Cell system is termed till today as the most reliable power pack for electronic apparatus specially in low temperature use. This paper brings out the development and production of sealed nickel cadmium cells of pocket plate construction. The author who has gained experience in production of Ni-Cd cells in East Germany discusses also the major problems faced by the battery manufactures of to-day.

  8. Screening micro-organisms for cadmium absorption from aqueous solution and cadmium absorption properties of Arthrobacter nicotianae.

    Science.gov (United States)

    Tsuruta, Takehiko; Umenai, Daishi; Hatano, Tomonobu; Hirajima, Tsuyoshi; Sasaki, Keiko

    2014-01-01

    To obtain basic information on how microbial cells absorb cadmium from aqueous solution, we examined cadmium absorption in various micro-organisms. Of 51 micro-organism strains tested, we found that some Gram-positive bacteria, such as, Arthrobacter nicotianae and Bacillus subtilis, and some actinomycetes, such as, Streptomyces flavoviridis and S. levoris were highly capable of absorbing cadmium from an aqueous solution. A. nicotianae absorbed the largest amount of cadmium, over 800 μmol cadmium per gram of dry wt. cells. However, cadmium absorption by A. nicotianae was affected by the solution pH, cadmium concentration, and cell density. The absorption of cadmium was very rapid. Some factors that affected cadmium absorption by A. nicotianae cells were also discussed.

  9. 回转窑托轮支承力测量方法%Support force measurement method for riding wheel of rotary kiln

    Institute of Scientific and Technical Information of China (English)

    翟敏辰; 达布希拉图; 刘珍; 包晓艳

    2015-01-01

    The rotary kiln is a core equipment in cement and some industrial production. It is important whether the roller support force is balanced and reasonable or not for service lifetime and safe operation of the equipment. As the complexity of the kiln structure and working conditions,it is very difficult to measure the actual load of each riding wheel. Taking a dry cement ro⁃tary kiln with three⁃support as an example,based on the analysis of riding wheel bearing seat structure and stress characteris⁃tics,the testing scheme of riding wheel load was designed,the validation measurement was carried out. The test results show that the method is feasible though the measurement sensitivity is insufficient.%回转窑是水泥等工业生产中的核心设备,托轮支承力是否均衡合理对设备的安全运行与寿命至关重要。由于窑体结构和工作条件的复杂性,使得通过测量获取每个托轮的实际载荷具有较大难度。以三档支撑的干法水泥生产回转窑为例,在分析托轮瓦座结构和受力特点的基础上设计了托轮载荷测试方案并进行了验证性测量。试验结果表明测试灵敏度偏低,但是方法可行。

  10. Re-examination of Chinese semantic processing and syntactic processing: evidence from conventional ERPs and reconstructed ERPs by residue iteration decomposition (RIDE).

    Science.gov (United States)

    Wang, Fang; Ouyang, Guang; Zhou, Changsong; Wang, Suiping

    2015-01-01

    A number of studies have explored the time course of Chinese semantic and syntactic processing. However, whether syntactic processing occurs earlier than semantics during Chinese sentence reading is still under debate. To further explore this issue, an event-related potentials (ERPs) experiment was conducted on 21 native Chinese speakers who read individually-presented Chinese simple sentences (NP1+VP+NP2) word-by-word for comprehension and made semantic plausibility judgments. The transitivity of the verbs was manipulated to form three types of stimuli: congruent sentences (CON), sentences with a semantically violated NP2 following a transitive verb (semantic violation, SEM), and sentences with a semantically violated NP2 following an intransitive verb (combined semantic and syntactic violation, SEM+SYN). The ERPs evoked from the target NP2 were analyzed by using the Residue Iteration Decomposition (RIDE) method to reconstruct the ERP waveform blurred by trial-to-trial variability, as well as by using the conventional ERP method based on stimulus-locked averaging. The conventional ERP analysis showed that, compared with the critical words in CON, those in SEM and SEM+SYN elicited an N400-P600 biphasic pattern. The N400 effects in both violation conditions were of similar size and distribution, but the P600 in SEM+SYN was bigger than that in SEM. Compared with the conventional ERP analysis, RIDE analysis revealed a larger N400 effect and an earlier P600 effect (in the time window of 500-800 ms instead of 570-810ms). Overall, the combination of conventional ERP analysis and the RIDE method for compensating for trial-to-trial variability confirmed the non-significant difference between SEM and SEM+SYN in the earlier N400 time window. Converging with previous findings on other Chinese structures, the current study provides further precise evidence that syntactic processing in Chinese does not occur earlier than semantic processing.

  11. 镉对山梨和山荆子叶片气体交换和叶绿素荧光参数的影响%Influence of Cadmium on the Leaves Gas Exchange and Parameters of Chlorophyll Fluorescence Based on Pyrus ussuriensis Maxim.and Malus baccata Linn.Borkh

    Institute of Scientific and Technical Information of China (English)

    李亚藏; 曹玲; 王庆成

    2013-01-01

    以北方阔叶树种山梨(Pyrus ussuriensis Maxim.)和山荆子(Malus baccata (Linn).Borkh.)1年生苗木为材料,采用土壤和风化砂混合物作为盆栽基质,设置0(CK)、10、50、100、200 mg· kg-15种土壤镉质量分数,研究了土壤镉污染对苗木叶片气体交换和叶绿素荧光参数的影响。结果表明:随着土壤镉质量分数增加,两树种的净光合速率(Pn)和瞬时水分利用效率(WU,E)先升后降、气孔导度(Gs)持续下降、胞间二氧化碳摩尔分数(Ci)先下降后上升,山梨和山荆子蒸腾速率( Tr )总体分别为升高、下降,说明镉污染导致两树种Pn 的下降是由非气孔限制因素所致;随土壤镉质量分数的增加,山梨和山荆子的Fv/Fm 和qN、山梨的Fv/Fo 逐渐降低,二者的ФP,SⅡ和qP、山荆子的Fv/Fo 先升后降,说明镉通过影响光合作用过程的顺利进行而导致Pn 的下降。综合各项参数分析山荆子对土壤镉的抗性大于山梨,并初步推断100 mg· kg-1 Cd2+是山梨和山荆子对土壤镉污染的耐受极限。%We studied the influence of soil cadmium pollution on the seedling leaves gas exchange and parameters of chlorophyll fluorescence based on the one-year-old seedlings northern hardwood species Pyrus ussuriensis Maxim.and Malus baccata Linn.Borkh with the mixture of soil and weathered sand as potting, and the soil cadmium separately set 0 (CK), 10, 50, 100 and 200 mg· kg-1 .The net photosynthetic rate ( Pn ) and instantaneous water efficiency ( WU,E ) of two species rose and later decreased with increasing of content of soil Cd, but the stomatal conductance (Gs) continued to decline.Inter-cellular carbon dioxide content (Ci) decreased and then increased.P.ussuriensis Maxim transpiration rate (Tr) was in-creasing, but M.baccata Linn.Borkh.was on the contrary.Therefore, cadmium pollution can make two species’ Pn de-cline because of non

  12. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E. [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas (Ecuador); He, Z.L., E-mail: zhe@ufl.edu [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Stoffella, P.J. [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Mylavarapu, R.S. [University of Florida, Institute of Food and Agricultural Science, Soil and Water Science Department, Gainesville, FL 33611 (United States); Li, Y.C. [University of Florida, Institute of Food and Agricultural Science, Tropical Research and Education Center, Homestead, FL 33031 (United States); Moyano, B. [Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas (Ecuador); Baligar, V.C. [United State Department of Agriculture, ARS, Beltsville, MD 20705 (United States)

    2015-11-15

    Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg{sup −1}) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0–5, 5–15, 15–30, and 30–50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg{sup −1}, respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg{sup −1}. Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg{sup −1}), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans > shell > > leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg{sup −1}, and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0–5 and 5–15 cm depths (r = 0.80 and 0.82 for M3, and r = 0.78 and 0.82 for HCl; P < 0.01). These results indicate that accumulation of Cd in surface layers results in excessive Cd in cacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils. - Highlights: • > 60% of the studied sites had a Cd content in cacao beans above the critical level. • Bean Cd concentration was closely correlated with available Cd in soil. • Soil

  13. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador.

    Science.gov (United States)

    Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R S; Li, Y C; Moyano, B; Baligar, V C

    2015-11-15

    Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; Pcacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils.

  14. Reviews of the environmental effects of pollutants: IV. Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

    1978-06-01

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 ..mu..g per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels.

  15. Transfer functions for solid solution partitioning of cadmium for Australian soils

    NARCIS (Netherlands)

    Vries, de W.; Mc Laughlin, M.J.; Groenenberg, J.E.

    2011-01-01

    To assess transport and ecotoxicological risks of metals, such as cadmium (Cd) in soils, models are needed for partitioning and speciation. We derived regression-based “partition-relations” based on adsorption and desorption experiments for main Australian soil types. First, batch adsorption experim

  16. Cadmium-regulated gene fusions in Pseudomonas fluorescens.

    Science.gov (United States)

    Rossbach, S; Kukuk, M L; Wilson, T L; Feng, S F; Pearson, M M; Fisher, M A

    2000-08-01

    To study the mechanisms soil bacteria use to cope with elevated concentrations of heavy metals in the environment, a mutagenesis with the lacZ-based reporter gene transposon Tn5B20 was performed. Random gene fusions in the genome of the common soil bacterium Pseudomonas fluorescens strain ATCC 13525 were used to create a bank of 5,000 P. fluorescens mutants. This mutant bank was screened for differential gene expression in the presence of the toxic metal cadmium. Fourteen mutants were identified that responded with increased or reduced gene expression to the presence of cadmium. The mutants were characterized with respect to their metal-dependent gene expression and their metal tolerance. Half the identified mutants reacted with differential gene expression specifically to the metal cadmium, whereas some of the other mutants also responded to elevated concentrations of copper and zinc ions. One of the mutants, strain C8, also showed increased gene expression in the presence of the solvent ethanol, but otherwise no overlap between cadmium-induced gene expression and general stress response was detected. Molecular analysis of the corresponding genetic loci was performed using arbitrary polymerase chain reaction (PCR), DNA sequencing and comparison of the deduced protein products with sequences deposited in genetic databases. Some of the genetic loci targeted by the transposon did not show any similarities to any known genes; thus, they may represent 'novel' loci. The hypothesis that genes that are differentially expressed in the presence of heavy metals play a role in metal tolerance was verified for one of the mutants. This mutant, strain C11, was hypersensitive to cadmium and zinc ions. In mutant C11, the transposon had inserted into a genetic region displaying similarity to genes encoding the sensor/regulator protein pairs of two-component systems that regulate gene expression in metal-resistant bacteria, including czcRS of Ralstonia eutropha, czrRS of Pseudomonas

  17. Differences of cadmium absorption and accumulation in selected vegetable crops

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A pot experiment and a sandy culture experiment grown with three vegetable crops of Chinese cabbage (B.chinensis L.,cv.Zao-Shu 5),winter greens (B.var.rosularis Tsen et Lee,cr.Shang-Hai-Qing) and celery (A.graveolens L.var.dulce DC.,cv.Qing-Qin)were conducted,respectively.The initial soil and four incubated soils with different extractable Cd (0.15,0.89,1.38,1.84 and 2.30 mg Cd/kg soil) were used for the pot experiment.Five treatments were designed (0,0.0625,0.125,0.250 and 0.500 mg Cd/L) in nutrient solution in the sandy culture experiment.Each treatment in pot and sandy culture experiments was trireplieated.The objectives of the study were to examine Cd accumulation in edible parts of selected vegetable crops,its correlation with Cd concentrations in vegetable garden soil or in nutrient solution,and evaluate the criteria of Cd pollution in vegetable garden soil and in nutrient solution based on the hygienic limit of Cd in vegetables.Cadmium concentrations in edible parts of the three selected vegetable crops were as follows:0.01-0.15 mg/kg fresh weight for Chinese cabbage,0.02-0.17 mg/kg fresh weight for winter greens,and 0.02-0.24 rag/kg fresh weight for celery in the pot experiment,and 0.1-0.4 mg/kg fresh weight for Chinese cabbage,0.1-1.4 mg/kg fresh weight for winter greens,and 0.05-0.5 rag/kg fresh weight for celery in the pot experiment(except no-Cd treatment).The order of the three test vegetable crops for cadmium accumulation in the edible parts was celery > winter greens > Chinese cabbage in both the pot experiment and the sandy culture experiment.Cadmium accumulation in edible parts or roots of the vegetable crops increased with increasing of cadmium concentration in the medium( soil or nutrient solution).And cadmium concentrations in edible parts of the test vegetable crops were significantly linearly related to the Cd levels in the growth media (soil and antrient solution).Based on the regression equations established and the limit of cadmium

  18. Design of intelligent management system for nickel-cadmium charging battery based on AT89S52%基于AT89S52的镍镉充电电池智能管理系统设计

    Institute of Scientific and Technical Information of China (English)

    陈继栋; 施崇阳; 周乐意

    2011-01-01

    As a kind of alkaline battery, nickel-cadmium charging battery has special requirments for using, management and maintenance. It would result in aging, losing efficacy or even abandonment without good using, management and timely maintenance. This item is designed for nickel-cadmium charging batteries which are used widely and stored centrally in army and factory. Using single chip processor control technology, the system can achieve intelligent battery management of nickel-cadmium charging battery such as automatic state examination, charge and discharge management, function maintenance, etc. Through automatic management of nickel-cadmium charging battery, it is able to eliminate blindness and arbitrariness in using and management of nickel-cadmium charging battery effectively, it improves the efficiency of nickel-cadmium charging battery and lengthens its service life.%镍镉充电电池作为一种碱性电池,对使用、管理和维护有特殊要求,如果管理不善、使用不当、维护不及时,很容易导致电池老化、失效甚至报废。针对部队、厂矿大量使用并集中存放的不同种类镍镉充电电池,运用单片微型计算机控制技术,设计了电池智能管理系统,对镍镉充电电池进行状态自动检测、充放电管理、性能维护等智能化管理。通过对镍镉充电电池的自动管理,有效消除镍镉充电电池使用管理上的盲目性和随意性,提高镍镉充电电池的使用效能,延长镍镉充电电池的使用寿命。

  19. Identification of three relationships linking cadmium accumulation to cadmium tolerance and zinc and citrate accumulation in lettuce.

    Science.gov (United States)

    Zorrig, Walid; Rouached, Aïda; Shahzad, Zaigham; Abdelly, Chedly; Davidian, Jean-Claude; Berthomieu, Pierre

    2010-10-15

    Lettuce (Lactuca sativa) is a plant species that shows high accumulation of cadmium, a toxic heavy metal. Lettuce is therefore a good model both for identifying determinants controlling cadmium accumulation in plant tissues and for developing breeding strategies aimed at limiting cadmium accumulation in edible tissues. In this work, 14-day-old plants from three lettuce varieties were grown for 8 days on media supplemented with cadmium concentrations ranging from 0 to 50 microM. Growth, as well as Cd(2+), Zn(2+), K(+), Ca(2+), NO(3)(-), SO(4)(2-), Cl(-), phosphate, malate and citrate root an shoot contents were analyzed. The three lettuce varieties Paris Island Cos, Red Salad Bowl and Kordaat displayed differential abilities to accumulate cadmium in roots and shoots, Paris Island Cos displaying the lowest cadmium content and Kordaat the highest. From the global analysis of the three varieties, three main trends were identified. First, a common negative correlation linked cadmium tissue content and relative dry weight reduction in response to cadmium treatments in the three varieties. Second, increasing cadmium concentration in the culture medium resulted in a parallel increase in zinc tissue content in all lettuce varieties. A common strong positive correlation between cadmium and zinc contents was observed for all varieties. This suggested that systems enabling zinc and cadmium transport were induced by cadmium. Finally, the cadmium treatments had a contrasting effect on anion contents in tissues. Interestingly, citrate content in shoots was correlated with cadmium translocation from roots to shoots, suggesting that citrate might play a role in cadmium transport in the xylem vessels. Altogether, these results shed light on three main strategies developed by lettuce to cope with cadmium, which could help to develop breeding strategies aimed at limiting cadmium accumulation in lettuce.

  20. Cadmium exposure induces hematuria in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Seok [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Myounghee, E-mail: dkkim73@gmail.com [Department of Dental Hygiene, College of Health Science, Eulji University, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Su Mi [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jung Pyo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Sejoong [Department of Internal Medicine, Seoul National University Bundang Hospital, Gyeonggi-do 463-707 (Korea, Republic of); Joo, Kwon Wook [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lim, Chun Soo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Yon Su; Kim, Dong Ki [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

    2013-07-15

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

  1. Taurine protects DNA of lymphocytes against oxidative alteration in riding horses

    DEFF Research Database (Denmark)

    Sokól, Janusz Leszek; Sawosz, Ewa; Niemiec, Tomasz

    2009-01-01

    . The addition of taurine to feed caused smaller oxidative stress, manifested by lower concentration of TBA-RS in plasma and of 8-oxo-dG in lymphocytes. The taurine lowered the lipid peroxidation intensity that occurred in horses due to the oxidative stress caused by physical effort. Furthermore, taurine......The study aimed at evaluation the effect of dietary supplement of taurine on the oxidation-reduction status in riding horses, and especially on the extent of oxidative DNA degradation in lymphocytes. Ten Thoroughbred and half-bred geldings aged 6-13 years were classified according to breed...... and amount of work done into two groups - control (C, n=5) and experimental (E, n=5), the latter fed the diet with addition of 40 g taurine/horse/day. Blood samples were withdrawn from the horses' jugular vein before commencing the riding season and then after 30 days of working. In the blood some selected...

  2. STATCOM for wind farms fault ride through improvement and grid code compliance

    Energy Technology Data Exchange (ETDEWEB)

    Viawan, Ferry A.; Sannino, Ambra [ABB, Corporate Research, Vaesteras (Sweden); Romero, Ines [ABB Consulting unit, Madrid (Spain); Maibach, Philippe [ABB, Power Electronics (Switzerland)

    2008-07-01

    This paper presents the application of static synchronous compensator (STATCOM) to improve the fault ride through capability of a wind farm (WF), and to enable the WF to inject reactive power to the grid during a fault, in order to meet the grid code requirements. The WF under consideration is composed of wind turbines (WTs) with squirrel cage induction generators directly connected to the grid, also known as fixed-speed wind turbines (FSWTs). A case study of application of the STATCOM to a WF with FSWT is presented. Simulation results show that, by the installation of STATCOM, the fault ride through capability of the WF can improved and the WF is able to inject reactive power to the grid during the fault. The results indicate that STATCOM is a potential solution for retrofitting of existing WFs in order to meet the present grid code. (orig.)

  3. Resolution of sudden sensorineural hearing loss following a roller coaster ride.

    Science.gov (United States)

    Kumar, Aman; Sinha, Amrita; Al-Waa, Ahmad M

    2011-07-01

    We report a case of sudden unilateral sensorineural hearing loss of sudden onset during an aeroplane flight, which completely resolved during a roller coaster ride at Alton Towers theme park. A review of the literature concerning sudden idiopathic sensorineural hearing loss and spontaneous resolution are discussed. Initially, pure-tone audiometry showed a profound sensorineural hearing loss in the right ear and mild sensorineural hearing loss in the left ear (of note, the hearing was normal prior to the episode). Following resolution of the patient's symptoms during a roller coaster ride, pure-tone audiometry showed normal hearing thresholds in both ears. Sudden sensorineural hearing loss is a symptom of cochlear injury and the mechanism of the patient's symptoms was attributed to a patent cochlear aqueduct.

  4. Ride quality evaluation of a vehicle with a planar suspension system

    Science.gov (United States)

    Zhu, Jian Jun; Khajepour, Amir; Esmailzadeh, Ebrahim; Kasaiezadeh, Alireza

    2012-03-01

    The longitudinal connection between a chassis and a wheel in a conventional vehicle suspension system is commonly very stiff than the vertical connection. Such a mechanism can efficiently isolate vibrations and absorb shocks in the vertical direction but cannot sufficiently attenuate the impact in the longitudinal direction. In order to overcome such a limitation, a planar suspension system (PSS) with spring-damper struts in both the longitudinal and vertical directions is proposed so that the vibration along any direction in the wheel rotation plane can be isolated. In this paper, the dynamic responses of a vehicle with PSS due to a single bump and random road unevenness are investigated. The ride quality of the vehicle with PSS is evaluated in accordance with ISO 2631. A comparison with that of a similar conventional vehicle is conducted to demonstrate the promising potentials of the PSS in improving the vehicle ride quality.

  5. AN INTEGRAL EQUATION DESCRIBING RIDING WAVES IN SHALLOW WATER OF FINITE DEPTH

    Institute of Scientific and Technical Information of China (English)

    An Shu-ping; Le Jia-chun; Dai Shi-qiang

    2003-01-01

    An integral equation describing riding waves, i.e., small-scale perturbation waves superposed on unperturbed surface waves, in shallow water of finite depth was studied via explicit Hamiltonian formulation, and the water was regarded as ideal incompressible fluid of uniform density. The kinetic energy, density of the perturbed fluid motion was formulated with Hamiltonian canonical variables[1], elevation of the free surface and the velocity potential at the free surface. Then the variables were expanded to the first order at the free surface of unperturbed waves. An integal equation for velocity potential of perturbed waves on the unperturbed free surface was derived by conformal mapping and the Fourier transformation. The integral equation could replace the Hamiltonian canonical equations which are difficult to solve. An explicit expression of Lagrangian density function could be obtained by solving the integral equation. The method used in this paper provides a new path to study the Hamiltonian formulation of riding waves and wave interaction problems.

  6. The effect of cannabis on regular cannabis consumers' ability to ride a bicycle.

    Science.gov (United States)

    Hartung, Benno; Schwender, Holger; Roth, Eckhard H; Hellen, Florence; Mindiashvili, Nona; Rickert, Annette; Ritz-Timme, Stefanie; Grieser, Almut; Monticelli, Fabio; Daldrup, Thomas

    2016-05-01

    To assess the effects of cannabis on the ability required to ride a bicycle, repetitive practical cycling tests and medical examinations were carried out before and after inhalative consumption of cannabis. A maximum of three joints with body weight-adapted THC content (300 μg THC per kg body weight) could be consumed by each test subject. Fourteen regular cannabis-consuming test subjects were studied (12 males, 2 females). In summary, only a few driving faults were observed even under the influence of very high THC concentrations. A defined THC concentration that leads to an inability to ride a bicycle cannot be presented. The test subjects showed only slight distinctive features that can be documented using a medical test routinely run for persons under suspicion of driving under the influence of alcohol or drugs.

  7. Ride 2 Recovery's Project HERO: using cycling as part of rehabilitation.

    Science.gov (United States)

    Springer, Barbara A

    2013-05-01

    Ride 2 Recovery was founded in 2008 by a former world-class cycling competitor and coach to enhance the physical and psychological recovery of our nation's wounded, ill and injured service members and veterans through the sport of cycling. Ride 2 Recovery's most notable endeavor is Project HERO (Healing Exercise Rehabilitation Opportunity) which uses staff members and volunteers to promote cycling as an integral part of rehabilitation at select military facilities to enhance physical, psychological, spiritual and social recovery. Project HERO is directed by a retired military physical therapist that spent the last decade caring for service men and women wounded in Iraq and Afghanistan. This article describes all facets of the Project HERO initiative and highlights the profound impact it has had in the lives of US military members and veterans.

  8. Low Voltage Ride-Through Capability Solutions for Permanent Magnet Synchronous Wind Generators

    Directory of Open Access Journals (Sweden)

    Victor F. Mendes

    2016-01-01

    Full Text Available Due to the increasing number of wind power plants, several countries have modified their grid codes to include specific requirements for the connection of this technology to the power system. One of the requirements is the ride-through fault capability (RTFC, i.e., the system capability to sustain operation during voltage sags. In this sense, the present paper intends to investigate the behavior of a full-converter wind generator with a permanent magnet synchronous machine during symmetrical and asymmetrical voltage sags. Two solutions to improve the low voltage ride-through capability (LVRT of this technology are analyzed: discharging resistors (brake chopper and resonant controllers (RCs. The design and limitations of these solutions and the others proposed in the literature are discussed. Experimental results in a 34 kW test bench, which represents a scaled prototype of a real 2 MW wind conversion system, are presented.

  9. Hazards to wildlife from soil-borne cadmium reconsidered

    Science.gov (United States)

    Beyer, W.N.

    2000-01-01

    Cadmium is a toxic element that should be included in environmental risk assessments of contaminated soils. This paper argues, however, that hazards to wildlife from cadmium have often been overstated. The literature contains only meager evidence that wild animals have been seriously harmed by cadmium, even at severely contaminated sites. Although some researchers have reported that wildlife have accumulated concentrations of cadmium in their kidneys that were above suggested injury thresholds, the thresholds may be disputed, since they were well below the World Health Organization criterion of 200 mg/kg (wet weight) of cadmium in the renal cortex for protecting human health. Recent risk assessments have concluded that soil cadmium concentrations less than 1 mg/kg are toxic to soil organisms and wildlife, which implies that background concentrations of cadmium naturally found in soils are hazardous. An examination of the databases used to support these assessments suggested that the toxicity of cadmium has been exaggerated.

  10. Equestrian expertise affecting physical fitness, body compositions, lactate, heart rate and calorie consumption of elite horse riding players

    Science.gov (United States)

    Sung, Bong-Ju; Jeon, Sang-Yong; Lim, Sung-Ro; Lee, Kyu-Eon; Jee, Hyunseok

    2015-01-01

    Horse riding (HR) is a sport harmonized with rider and horse. HR is renowned as an effective sport for young and old women and men. There is rare study regarding comparison between elite horse riders and amateurs. We aimed to investigate comprehensive ranges of parameters such as change of lactate, heart rate, calorie, VO2max, skeletal muscle mass, body water, body fat, etc between amateurs and professionals to emphasize HR not only as a sport training but also as a therapeutic aspect. We performed 3 experiments for comparing physical fitness, body compositions, lactate value, heart rate and calorie consumption change before and after riding between amateurs and elites. Around 3 yr riding experienced elites are preeminent at balance capability compared to 1 yr riding experienced amateurs. During 18 min horse riding, skeletal muscle mass and body fat were interestingly increased and decreased, respectively. Lactate response was more sensitive in elites rather than amateurs and its recovery was reversely reacted. Exercise intensity estimated from heart rate was significantly higher in elites (PHorse riding possibly induces various physiological (muscle strength, balance, oxidative capability, flexibility, and metabolic control) changes within body and is thus highly recommended as combined exercise for women, children, and aged as therapeutic and leisure sport activity. PMID:26171385

  11. Cadmium Extraction from Solutions by Solid-Phase and its Trace Determination

    Energy Technology Data Exchange (ETDEWEB)

    Ashrafi, F.; Attaran, A. M. [Payame Noor University, Sari (Iran, Islamic Republic of); Kermani, N. Memar [Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2008-04-15

    A new sensitive and selective spectrophotometric method for determination of trace amounts of cadmium using a polyvinyl chloride membrane containing bis-(2-ethylhexyl)phthalate as a solid phase extraction medium was investigated. Bis-(2-ethylhexyl)phthalate has used as a plasticizer. Cd(II) in an aqueous solution was trapped on the membrane in the form of colorful Cd (II)-I{sup -} - MG complexes (which MG is malachite green) and the cadmium complex was concentrated in the membrane. The absorbance of the green membrane was measured at 629 nm using a spectrophotometer, and then, the concentration of the cadmium was calculated using a calibration curve, which expressed the relationship between the Cd(II) concentration and the membrane absorbance after coloring for 25 min. The calibration curve was linear in the range of 10-760 μgL{sup -1} cadmium in the test solution. The detection limit based on the 3S{sub bl} criterion was 1.8199 μgL{sup -1} and the relative standard deviations (RSD) were less than 4 % (n=5). The proposed method has been successfully applied to the determination of trace amounts of cadmium in the Tadjan River water sample (Sari-Iran), and the mean value of 28.7 μgL{sup -1} was obtained.

  12. Environmental cadmium and lead exposure and anti-Müllerian hormone in pregnant women

    DEFF Research Database (Denmark)

    Christensen, P S; Bonde, J P; Bungum, L

    2016-01-01

    -AMH. MATERIALS AND METHOD: The associations between serum-AMH and whole blood cadmium or lead were investigated by general linear models in a population-based sample of 117 pregnant women. RESULTS: The mean concentrations of blood cadmium and lead were 0.71μg/L and 17.4μg/L, respectively. The mean serum......BACKGROUND: Anti-Müllerian Hormone (AMH) has been suggested as a marker for ovarian function. Cadmium and lead have been suggested to reduce female fecundity. In this study we aimed to investigate whether environmental exposure to cadmium and lead was associated with alterations in serum......-AMH was 17.3pmol/L. No association between lead and AMH was detected. In the cadmium analysis the adjusted mean AMH level (95% CI) in the highest exposure tertile was 12.4 (6.4;23.8) compared to 5.6 (2.7;11.4) in the lowest exposure tertile (p=0.06). CONCLUSION: The study provides suggestive evidence...

  13. Cloud point extraction thermospray flame quartz furnace atomic absorption spectrometry for determination of ultratrace cadmium in water and urine

    Science.gov (United States)

    Wu, Peng; Zhang, Yunchang; Lv, Yi; Hou, Xiandeng

    2006-12-01

    A simple, low cost and highly sensitive method based on cloud point extraction (CPE) for separation/preconcentration and thermospray flame quartz furnace atomic absorption spectrometry was proposed for the determination of ultratrace cadmium in water and urine samples. The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution and a Triton X-114 solution. When the temperature of the system was higher than the cloud point of Triton X-114, the complex of cadmium-PDC entered the surfactant-rich phase and thus separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, the limit of detection was 0.04 μg/L for cadmium with a sample volume of 10 mL. The analytical results of cadmium in water and urine samples agreed well with those by ICP-MS.

  14. Cloud point extraction-thermospray flame quartz furnace atomic absorption spectrometry for determination of ultratrace cadmium in water and urine

    Energy Technology Data Exchange (ETDEWEB)

    Wu Peng [Analytical and Testing Center, Sichuan University, Chengdu, Sichuan 610064 (China); Zhang Yunchang [College of Chemistry, Sichuan University, Chengdu, Sichuan 610064 (China); Lv Yi [College of Chemistry, Sichuan University, Chengdu, Sichuan 610064 (China); Hou Xiandeng [Analytical and Testing Center, Sichuan University, Chengdu, Sichuan 610064 (China) and College of Chemistry, Sichuan University, Chengdu, Sichuan 610064 (China)]. E-mail: houxd@scu.edu.cn

    2006-12-15

    A simple, low cost and highly sensitive method based on cloud point extraction (CPE) for separation/preconcentration and thermospray flame quartz furnace atomic absorption spectrometry was proposed for the determination of ultratrace cadmium in water and urine samples. The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution and a Triton X-114 solution. When the temperature of the system was higher than the cloud point of Triton X-114, the complex of cadmium-PDC entered the surfactant-rich phase and thus separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, the limit of detection was 0.04 {mu}g/L for cadmium with a sample volume of 10 mL. The analytical results of cadmium in water and urine samples agreed well with those by ICP-MS.

  15. How challenging is a riding horse’s life? Field studies on fitness, workload and welfare

    OpenAIRE

    Munsters, C.C.B.M.

    2013-01-01

    The objectives of this thesis were to evaluate in practice workload, fitness and welfare of riding horses under work and training conditions. Chapter II presents an overview of the parameters used in earlier studies on training, behaviour and equine welfare, and describes the evaluation of the physiological and behavioural responses of horses in field work. Chapter III describes a study on the fitness and responses to training of young Friesian horses. The fitness of horses appeared to improv...

  16. "Riding the Wave": Transforming Sport and Exercise Psychology within an Interdisciplinary Vision

    Science.gov (United States)

    Weiss, Maureen R.

    2008-01-01

    A metaphor of "riding the wave" is used as a means of envisioning the future of sport and exercise psychology given what we know about past and present waves in the field. First, I review the waves of the 1980s, 1990s, and 2000s to understand critical issues in the field and to evaluate the waves as smooth, choppy, or turbulent today. Second,…

  17. Rüütel pensionäride elujärje garandina / Janno Reiljan

    Index Scriptorium Estoniae

    Reiljan, Janno, 1951-

    2006-01-01

    Ilmunud ka: Severnoje Poberezhje (2006) 17. aug., lk. 2, Meie Maa (2006) 18. aug., lk. 2, Nädaline (2006) 22. aug., lk. 2, Vooremaa (2006) 22. aug., lk. 2, Valgamaalane (2006) 24. aug., lk. 2. Autor selgitab Eesti pensionäride elujärje kujunemise näitel, miks Rahvaliit ja Keskerakond nimetasid oma koostöölepingu garandiks president Arnold Rüütli

  18. Bilateral vertebral artery dissection possibly precipitated in delayed fashion as a result of roller coaster rides.

    Science.gov (United States)

    Schneck, Michael; Simionescu, Monica; Bijari, Armita

    2008-01-01

    A 34-year-old woman presented with a 5-month history of persistent vertigo after multiple roller coaster rides, followed by neck pain for 1 month and then 2 weeks of blurred vision related to diplopia. She was ultimately found to have bilateral cervical vertebral artery dissection. The images are described and the literature is reviewed regarding late diagnosis of vertebral dissection and prior cases of roller coaster-associated dissection.

  19. Resolution of Sudden Sensorineural Hearing Loss Following a Roller Coaster Ride

    OpenAIRE

    Kumar, Aman; Sinha, Amrita; Al-Waa, Ahmad M.

    2011-01-01

    We report a case of sudden unilateral sensorineural hearing loss of sudden onset during an aeroplane flight, which completely resolved during a roller coaster ride at Alton Towers theme park. A review of the literature concerning sudden idiopathic sensorineural hearing loss and spontaneous resolution are discussed. Initially, pure-tone audiometry showed a profound sensorineural hearing loss in the right ear and mild sensorineural hearing loss in the left ear (of note, the hearing was normal p...

  20. Voltage Sags Ride-Through of Motion Sensorless Controlled PMSG for Wind Turbines

    DEFF Research Database (Denmark)

    Fatu, Marius; Lascu, Cristian; Andreescu, Gheorghe-Daniel;

    2007-01-01

    is used to robustly estimate the grid voltage positivesequence for control in the case of asymmetric voltages. The paper investigates the ride-through performance of this system during asymmetric power grid voltage sags. Design details for various parts of the control system are presented, together...... with experimental results for single-, two-, and three-phase voltage source sags. Smooth transition through asymmetric voltage sags is demonstrated by all experiments....

  1. As I ride the late night freeways (2014-15) For soprano and orchestra

    OpenAIRE

    2015-01-01

    As I ride the late night freeways is a work for soprano and orchestra. The music is a setting of Census, a poem by Cathy Park Hong written specifically for this project. The score engages the notion of California freeway driving to suggest compositional processes and musical parameters to unify the musical work. Ideas derived from the parametric aesthetic provide a significant “streamlining” influence, echoed in the development of musical processes that take a variety of forms: from harmonic ...

  2. Histopathological assessment and inflammatory response in the digestive gland of marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Thiago Lopes [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Laboratory of Cellular Behavior, Biological Sciences Institute, Federal University of Goiás, Goiânia, Goiás (Brazil); Sabóia-Morais, Simone Maria Teixeira [Laboratory of Cellular Behavior, Biological Sciences Institute, Federal University of Goiás, Goiânia, Goiás (Brazil); Bebianno, Maria João, E-mail: mbebian@ualg.pt [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2016-08-15

    Highlights: • Digestive gland of marine mussels is target for Cd-based QDs toxicity. • Both Cd forms increase the frequency of atrophic digestive tubules in a time dependent pattern. • QDs induce higher inflammatory responses when compared to dissolved Cd. • Multiparametric tissue-levels biomarkers show distinct mode of action in the digestive gland. - Abstract: Although tissue-level biomarkers have been widely applied in environmental toxicology studies, the knowledge using this approach in marine invertebrates exposed to engineered nanomaterials (ENMs) remains limited. This study investigated histopathological alterations and inflammatory responses induced by Cd-based quantum dots (QDs), in comparison with their dissolved counterparts, in the marine mussel Mytilus galloprovincialis. Mussels were exposed to CdTe QDs and dissolved Cd at the same concentration (10 μg Cd L{sup −1}) for 14 days and a total of 15 histopathological alterations and 17 histomorphometric parameters were analysed in the digestive gland along with the determination of histopathological condition indices (I{sub h}). A multivariate analysis showed that the mussel response to QDs was more related to exposure time, inflammatory conditions (frequency of haemocytic infiltration and granulocytomas) and changes of cell-type composition (especially the rate between basophilic and digestive cells) when compared to dissolved Cd, while the response to dissolved Cd was associated with histomorphometric parameters of the epithelium and lumen of digestive tubules and increase of the atrophic tubule frequency. Both Cd forms induced higher I{sub h} compared to unexposed mussels indicating a significant decrease in the health status of digestive gland in a Cd form and time-dependent pattern. Results indicate that the multiparametric tissue-level biomarkers in the digestive gland provide a suitable approach to assess the ecotoxicity and mode of action of metal-based ENMs in marine bivalves.

  3. Flame atomic absorption spectrometric determination of trace quantities of cadmium in water samples after cloud point extraction in Triton X-114 without added chelating agents

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of)]. E-mail: afkhami@basu.ac.ir; Madrakian, Tayyebeh [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of); Siampour, Hajar [Department of Chemistry, Faculty of Science, Bu-Ali Sina University, Hamadan (Iran, Islamic Republic of)

    2006-11-16

    A new micell-mediated phase separation method for preconcentration of ultra-trace quantities of cadmium as a prior step to its determination by flame atomic absorption spectrometry has been developed. The method is based on the cloud point extraction (CPE) of cadmium in iodide media with Triton X-114 in the absence of any chelating agent. The optimal extraction and reaction conditions (e.g., acid concentration, iodide concentration, effect of time) were studied, and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 3-300 ng mL{sup -1} of cadmium. The detection limit of the method is 1.0 ng mL{sup -1} of cadmium. The interference effect of some anions and cations was also tested. The method was applied to the determination of cadmium in tap water, waste water, and sea water samples.

  4. Demographic and psychological variables affecting test subject evaluations of ride quality

    Science.gov (United States)

    Duncan, N. C.; Conley, H. W.

    1975-01-01

    Ride-quality experiments similar in objectives, design, and procedure were conducted, one using the U.S. Air Force Total In-Flight Simulator and the other using the Langley Passenger Ride Quality Apparatus to provide the motion environments. Large samples (80 or more per experiment) of test subjects were recruited from the Tidewater Virginia area and asked to rate the comfort (on a 7-point scale) of random aircraft motion typical of that encountered during STOL flights. Test subject characteristics of age, sex, and previous flying history (number of previous airplane flights) were studied in a two by three by three factorial design. Correlations were computed between one dependent measure, the subject's mean comfort rating, and various demographic characteristics, attitudinal variables, and the scores on Spielberger's State-Trait Anxiety Inventory. An effect of sex was found in one of the studies. Males made higher (more uncomfortable) ratings of the ride than females. Age and number of previous flights were not significantly related to comfort ratings. No significant interactions between the variables of age, sex, or previous number of flights were observed.

  5. Influence of Horse and Rider on Stress during Horse-riding Lesson Program.

    Science.gov (United States)

    Kang, Ok-Deuk; Yun, Young-Min

    2016-06-01

    The present study aims to confirm the influence of a horse-riding lesson program (HRLP) on the stress level of horses and riders by respectively analyzing their salivary cortisol concentration. Twenty-four healthy horses and 23 riders participated in this study. The horses were randomly classified into two groups for the horse riding lesson program: Class 1 (for the beginner lesson) and Class 2 (for the intermediate lesson). The Class 1 group consisted of 12 horses and 12 riders, while the Class 2 group consisted of 12 horses and 11 riders. Salivettes cotton wool swabs were used for saliva collection and the saliva analyses were conducted using a two-way analysis of variance for repeated measures with SAS version 8. As for the results, the average salivary cortisol concentration of all horses before HRLP significantly increased compared to the baseline (priders were similar to the horses' results. However, there was no difference during the HRLP between Class 1 and Class 2 in the horse or rider groups. The results suggest that the HRLP did not influence the stress level of the horses or riders. Thus, this study provides the necessary information and guidelines for future studies on stress in horses during riding and gives insight into better horse welfare and management options.

  6. Horse Allergy: Curly Horses Allow Horse Allergic Riders To Ride Again.

    Science.gov (United States)

    Mitlehner, W; Mitlehner, H C; Niggemann, B

    2015-12-01

    To test the hypothesis that so called hypoallergenic horses (Curly horses) allow horse allergic riders to ride again, we investigated 40 horse allergic riders in a period of 37 months. Methods: We tested these patients (pts.) by skin prick test (SPT) with different non-curly and Curly horses and studied the riding hours and horse brushing by measurements of peak expiratory flow (PEF) and Tiffeneau tests (FEV1) as well as peak nasal inspiratory flow (PNIF) over 12 months. The results in 37/40 pts. showed no relevant reactions of the lower airways or nasal flow. Only in 3/40 patients an initial significant fall of FEV1 was observed, reversed by a single inhalation of salbutamol and not repeated despite further riding contact. In contrast to other allergic events (e. g. baker's asthma) a further and regular contact with these horses abolished the mild allergic reactions of the start period of contact. This may be due to hypoallergenic properties of these horses, whose test material produces weaker reactions in the SPT than that of normal horses. After a period of three years, a loss of reactivity to normal horses could be confirmed in some of the riders. Conclusion: The tested purebreed Curly horses may be a suitable alternative for horse allergic riders if the methodological precautions of this study are followed.

  7. Introducing heterogeneous users and vehicles into models and algorithms for the dial-a-ride problem.

    Science.gov (United States)

    Parragh, Sophie N

    2011-08-01

    Dial-a-ride problems deal with the transportation of people between pickup and delivery locations. Given the fact that people are subject to transportation, constraints related to quality of service are usually present, such as time windows and maximum user ride time limits. In many real world applications, different types of users exist. In the field of patient and disabled people transportation, up to four different transportation modes can be distinguished. In this article we consider staff seats, patient seats, stretchers and wheelchair places. Furthermore, most companies involved in the transportation of the disabled or ill dispose of different types of vehicles. We introduce both aspects into state-of-the-art formulations and branch-and-cut algorithms for the standard dial-a-ride problem. Also a recent metaheuristic method is adapted to this new problem. In addition, a further service quality related issue is analyzed: vehicle waiting time with passengers aboard. Instances with up to 40 requests are solved to optimality. High quality solutions are obtained with the heuristic method.

  8. Modeling cadmium in the feed chain and cattle organs

    NARCIS (Netherlands)

    Fels-Klerx, van der H.J.; Romkens, P.F.A.M.; Franz, E.; Raamsdonk, van L.W.D.

    2011-01-01

    The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH,

  9. Module process optimization and device efficiency improvement for stable, low-cost, large-area, cadmium telluride-based photovoltaic module production

    Energy Technology Data Exchange (ETDEWEB)

    Albright, S.P.; Ackerman, B.; Chamberlin, R.R.; Jordan, J.F. (Photon Energy, Inc., El Paso, TX (United States))

    1992-04-01

    This report describes work under a three-year phased subcontract to develop CdS/CdTe devices and modules and to further improve the technology base at Photon Energy, Inc. (PEI) to better address the commercialization issues and objectives of the PEI and the US Department of Energy. During this reporting period we (1) achieved efficiencies of 12.7% on small area devices, (2) achieved 1-ft{sup 2} modules with over 8% aperture-area efficiency (and active area efficiencies up to {approximately}10%), (3) tested 4-ft{sup 2} modules at NREL at 23.1 (21.3) watts, normalized (6.3% efficiency), and (4) found no inherent stability problems with CdTe technology during life testing, at both NREL and PEI. 7 refs.

  10. Epidemiological aspects of cadmium in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Piscator, M.

    1973-01-01

    Cadmium is highly toxic to man and it has an extremely long biological half-time. Under long-term low level exposure about one third of the total body burden is in the kidneys. In some European countries and USA mean renal cortical concentrations of cadmium 24-50 ppM wet weight at age 50 have been reported. In three areas in Japan the corresponding concentrations were 60 to 125 ppM wet weight. These normal concentrations have been thought to cause hypertension but so far epidemiological data are not available to support such a hypothesis. Renal tubular dysfunction may begin at a renal cortical concentration of about 200 ppM wet weight. In Japan extensive investigations have been carried out in several areas polluted by cadmium. Available data indicate that the prevalence of proteinuria is higher in the cadmium polluted areas and that the proteinuria is of the tubular type. Studies on dose-response relationships must include accurate and sensitive methods for the detection of low molecular weight proteinuria, which is an early sign in cadmium intoxication. 6 references, 1 table.

  11. Subcellular partitioning kinetics, metallothionein response and oxidative damage in the marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Thiago Lopes [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Gomes, Tânia [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, NO-0349 Oslo (Norway); Durigon, Emerson Giuliani [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Bebianno, Maria João, E-mail: mbebian@ualg.pt [CIMA, Faculty of Science and Technology, University of Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2016-06-01

    The environmental health impact of metal-based nanomaterials is of emerging concern, but their metabolism and detoxification pathways in marine bioindicator species remain unclear. This study investigated the role of subcellular partitioning kinetics, metallothioneins (MTs) response and oxidative damage (lipid peroxidation – LPO) in the marine mussel Mytilus galloprovincialis exposed to CdTe quantum dots (QDs) in comparison with its dissolved counterpart. Mussels were exposed to QDs and dissolved Cd for 21 days at 10 μg Cd L{sup −1} followed by a 50 days depuration. Higher Cd concentrations were detected in fractions containing mitochondria, nucleus and lysosomes, suggesting potential subcellular targets of QDs toxicity in mussel tissues. Tissue specific metabolism patterns were observed in mussels exposed to both Cd forms. Although MT levels were directly associated with Cd in both forms, QDs subcellular partitioning is linked to biologically active metal (BAM), but no increase in LPO occurred, while in the case of dissolved Cd levels are in the biologically detoxified metal (BDM) form, indicating nano-specific effects. Mussel gills showed lower detoxification capability of QDs, while the digestive gland is the major tissue for storage and detoxification of both Cd forms. Both mussel tissues were unable to completely eliminate the Cd accumulated in the QDs form (estimated half-life time > 50 days), highlighting the potential source of Cd and QDs toxicity for human and environmental health. Results indicate tissue specific metabolism patterns and nano-specific effects in marine mussel exposed to QDs. - Highlights: • Subcellular partitioning and MT response are Cd form, tissue and time dependent. • Tissue specific metabolism of Cd-based quantum dots (QDs) in marine mussels. • QDs are slower biologically detoxified when compared to dissolved Cd. • Subcellular partitioning and biomarker responses indicate nano-specific effects. • Subcellular

  12. Recovery of cadmium by high-temperature vaccum evaporation from Ni-Cd batteries

    Institute of Scientific and Technical Information of China (English)

    朱建新; 李金惠; 聂永丰; 于波

    2003-01-01

    High-temperature vaccum evaporation is a recycling technology that includes a selective material recovering process. The fundamental research on a process of disassembling and recovering selected materials from Ni-Cd batteries was conducted using self-designed experimental apparatus. An effective recycling technology based on the evaporation phenomenon of batteries and the elements of cadmium under the laboratory condition was studied. The results show that: (1)Ni/Cd can be effectively recovered by vacuum distillation at appropriate temperature, pressure and time, and high purity cadmium (>99%) can be obtained through the process; (2)the effective distillatory temperature should be at the range of 573-1173K; (3)the higher the evaporation temperature, the lower the purity of cadmium in condensate metal

  13. Effect of anions on Toxicity of Cadmium Applied to MIcrobial Biomass in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; XIEZHENGMIAO; 等

    1997-01-01

    A laboratory incubation experiment was conducted to elucidat the effects of associated anions on toxicity of cadmium applied to microbial biomass in the red soil. Cadmium was applied at six different levels,i.e.,O(background),5,15,30,60 and 100μg g-1 soil in the form of either cadmium acetate or cadmium chloride. Application of cadmium as cadmium acetate markedly reduced the soil microbial biomass carbon compared to cadmium applied as cadmium chlorde at all the tested levels.Similarly,organic carbon to biomass carbon ration in the soil was markedly increased by increasing the level of the cadmium in the soil as cadmium acetate,while the change wa much smaller in the case of cadmium chloride at the same cadmium levels.The results suggested that due consideration should be given to the source of cadmium while deciding the cadmium levles in experiments.

  14. Performances of Dye-sensitized Solar Cell Based on ZnO Photoanode Sensitized with Cadmium Complexes Cd (phen) 2 (NO3) (NO2)%金属配合物Cd(phen)2(NO3)(NO2)对ZnO光阳极的敏化特性

    Institute of Scientific and Technical Information of China (English)

    张凌云; 杨玉林; 范瑞清; 张艳娇; 王平; 李亮

    2013-01-01

    采用具有紫外光区吸收的金属配合物Cd(phen)2(NO3)(NO2)和N719对ZnO光阳极进行共敏化.结果表明,配合物能够对ZnO光阳极进行共敏化,同时被电解液还原再生,共敏化增加电池对光的吸收,电池光电流密度增加63%,共敏化降低了电池各个界面电阻,有利于电子在界面的传输,电池的光电转换效率提高了37%.%The ZnO photoanode was co-sensitized with cadmium complexe Cd (phen) 2 (NO3) (NO2) absorbed in the ultraviolet light region and dye N719.The performances of co-sensitized dye-sensitized solar cell (DSSC) and the properties of cadmium complexe were investigated by the cyclic voltammetry measurement,UV-Visible absorption spectroscopy,fluorescence spectrum,electrochemical impedance spectroscopy and photocurrent-photovoltage curve.The results show that cadmium complexe is suitable for sensitization of ZnO photoanode,and the complexe can be reduced by the electrolyte.The light absorption of DSSC is enhanced and the current density is improved 63% by co-sensitization.The decreased resistance of interface of DSSC is in favor of the electron transport.The conversion efficiency of DSSC based on ZnO photoanode is improved 37% by co-sensitization.

  15. Cobalt- and Cadmium-Based Metal-Organic Frameworks as High-Performance Anodes for Sodium Ion Batteries and Lithium Ion Batteries.

    Science.gov (United States)

    Dong, Caifu; Xu, Liqiang

    2017-03-01

    Two multifunctional metal-organic frameworks (MOFs) with the same coordination mode, [Co(L)(H2O)]n·2nH2O [defined as "Co(L) MOF"] and [Cd(L)(H2O)]n·2nH2O [defined as "Cd(L) MOF"] (L = 5-aminoisophthalic acid) have been fabricated via a simple and versatile scalable solvothermal approach at 85 °C for 24 h. The relationship between the structure of the electrode materials (especially the coordination water and different metal ions) and the electrochemical properties of MOFs have been investigated for the first time. And then the possible electrochemical mechanisms of the electrodes have been studied and proposed. In addition, MOFs/RGO hybrid materials were prepared via ball milling, which demonstrated better electrochemical performances than those of individual Co(L) MOF and Cd(L) MOF. For example, when Co(L) MOF/RGO was applied as anode for sodium ion batteries (SIBs), it retained 206 mA h g(-1) after 330 cycles at 500 mA g(-1) and 1185 mA h g(-1) could be obtained after 50 cycles at 100 mA g(-1) for lithium-ion batteries (LIBs). The high-discharge capacity, excellent cyclic stability combined with the facile synthesis procedure enable Co(L) MOF- and Cd(L) MOF-based materials to be prospective anode materials for SIBs and LIBs.

  16. Subcellular partitioning kinetics, metallothionein response and oxidative damage in the marine mussel Mytilus galloprovincialis exposed to cadmium-based quantum dots.

    Science.gov (United States)

    Rocha, Thiago Lopes; Gomes, Tânia; Durigon, Emerson Giuliani; Bebianno, Maria João

    2016-06-01

    The environmental health impact of metal-based nanomaterials is of emerging concern, but their metabolism and detoxification pathways in marine bioindicator species remain unclear. This study investigated the role of subcellular partitioning kinetics, metallothioneins (MTs) response and oxidative damage (lipid peroxidation - LPO) in the marine mussel Mytilus galloprovincialis exposed to CdTe quantum dots (QDs) in comparison with its dissolved counterpart. Mussels were exposed to QDs and dissolved Cd for 21 days at 10 μg Cd L(-1) followed by a 50 days depuration. Higher Cd concentrations were detected in fractions containing mitochondria, nucleus and lysosomes, suggesting potential subcellular targets of QDs toxicity in mussel tissues. Tissue specific metabolism patterns were observed in mussels exposed to both Cd forms. Although MT levels were directly associated with Cd in both forms, QDs subcellular partitioning is linked to biologically active metal (BAM), but no increase in LPO occurred, while in the case of dissolved Cd levels are in the biologically detoxified metal (BDM) form, indicating nano-specific effects. Mussel gills showed lower detoxification capability of QDs, while the digestive gland is the major tissue for storage and detoxification of both Cd forms. Both mussel tissues were unable to completely eliminate the Cd accumulated in the QDs form (estimated half-life time>50 days), highlighting the potential source of Cd and QDs toxicity for human and environmental health. Results indicate tissue specific metabolism patterns and nano-specific effects in marine mussel exposed to QDs.

  17. Effects on rat testes of the thiosemicarbazone derivative Schiff base (4-(1-phenylmethylcyclobutane-3-yl)-2-(2-hydroxybenzylidenehydrazino)thiazole) and its cadmium(II) complex.

    Science.gov (United States)

    Oner, Hakan; Karatepe, Mustafa; Karatas, Fikret; Oner, Jale; Yilmaz, Ibrahim; Cukurovali, Alaaddin

    2005-01-01

    The aim of this study was to investigate structural and biochemical changes in testes of rats treated with the thiosemicarbazone derivative thiazole ring Schiff base, (4-(1-phenyl-methylcyclobutane-3-yl)-2-(2-hydroxybenzylidene-hydrazino) thiazole (L), and its Cd(II) complex (CdL(2)). The animals were divided into three groups. Group I was designated as control. The rats in groups II and III were injected subcutaneously with L or CdL(2) respectively at 150-mg kg(-1) doses at 3-day intervals for 15 days. At the end of the study, blood samples were collected for biochemical analysis, and testes were removed for histological examinations. Serum levels of vitamin A, E and MDA of the L-injected group were similar to the control group. While CdL(2) treatment decreased serum vitamin A and E levels, it increased the MDA level compared to other groups. Histologically, the testes structures of L-treated animals were similar to the control. Spermatogenic cells in seminiferous tubules of CdL(2)-treated animals displayed necrosis. Nuclei of spermatogonia and primary spermatocytes were pyknotic and heterochromatic. Homogenous pink particles were present in place of the spermatids. The interstitial areas were oedematous and intertubular vessels were plugged. In conclusion, the present results indicate that L does not cause biochemical and morphological alterations, but its Cd(II) complex has degenerative effects in normal rat testes.

  18. Sulphate, more than a nutrient, protects the microalga Chlamydomonas moewusii from cadmium toxicity.

    Science.gov (United States)

    Mera, Roi; Torres, Enrique; Abalde, Julio

    2014-03-01

    Sulphur is an essential macroelement that plays important roles in living organisms. The thiol rich sulphur compounds, such as cysteine, γ-Glu-Cys, glutathione and phytochelatins participate in the tolerance mechanisms against cadmium toxicity. Plants, algae, yeasts and most prokaryotes cover their demand for reduced sulphur by reduction of inorganic sulphate. The aim of this study was to investigate, using a bifactorial experimental design, the effect of different sulphate concentrations in the nutrient solution on cadmium toxicity in the freshwater microalga Chlamydomonas moewusii. Cell growth, kinetic parameters of sulphate utilization and intracellular concentrations of low-molecular mass thiol compounds were determined. A mathematical model to describe the growth of this microalga based on the effects of sulphate and cadmium was obtained. An ANOVA revealed an interaction between them, 16% of the effect sizes was explained by this interaction. A higher amount of sulphate in the culture medium allowed a higher cadmium tolerance due to an increase in the thiol compound biosynthesis. The amount of low-molecular mass thiol compounds, mainly phytochelatins, synthesized by this microalga was significantly dependent on the sulphate and cadmium concentrations; the higher phytochelatin content was obtained in cultures with 4 mg Cd/L and 1mM sulphate. The maximum EC50 value (based on nominal cadmium concentration) reached for this microalga was 4.46 ± 0.42 mg Cd/L when the sulphate concentration added to the culture medium was also 1mM. An increase in the sulphate concentration, in deficient environments, could alleviate the toxic effect of this metal; however, a relative excess is also negative. The results obtained showed a substrate inhibition for this nutrient. An uncompetitive model for sulphate was chosen to establish the mathematical model that links both factors.

  19. Metallomics and NMR-based metabolomics of Chlorella sp. reveal the synergistic role of copper and cadmium in multi-metal toxicity and oxidative stress.

    Science.gov (United States)

    Zhang, Wenlin; Tan, Nicole G J; Fu, Baohui; Li, Sam F Y

    2015-03-01

    Industrial wastewaters often contain high levels of metal mixtures, in which metal mixtures may have synergistic or antagonistic effects on aquatic organisms. A combination of metallomics and nuclear magnetic resonance spectroscopy (NMR)-based metabolomics was employed to understand the consequences of multi-metal systems (Cu, Cd, Pb) on freshwater microalgae. Morphological characterization, cell viability and chlorophyll a determination of metal-spiked Chlorella sp. suggested synergistic effects of Cu and Cd on growth inhibition and toxicity. While Pb has no apparent effect on Chlorella sp. metabolome, a substantial decrease of sucrose, amino acid content and glycerophospholipid precursors in Cu-spiked microalgae revealed Cu-induced oxidative stress. Addition of Cd to Cu-spiked cultures induced more drastic metabolic perturbations, hence we confirmed that Cu and Cd synergistically influenced photosynthesis inhibition, oxidative stress and membrane degradation. Total elemental analysis revealed a significant decrease in K, and an increase in Na, Mg, Zn and Mn concentrations in Cu-spiked cultures. This indicated that Cu is more toxic to Chlorella sp. as compared to Cd or Pb, and the combination of Cu and Cd has a strong synergistic effect on Chlorella sp. oxidative stress induction. Oxidative stress is confirmed by liquid chromatography tandem mass spectrometry analysis, which demonstrated a drastic decrease in the GSH/GSSG ratio solely in Cu-spiked cultures. Interestingly, we observed Cu-facilitated Cd and Pb bioconcentration in Chlorella sp. The absence of phytochelatins and an increment of extracellular polymeric substances (EPS) yields in Cu-spiked cultures suggested that the mode of bioconcentration of Cd and Pb is through adsorption of free metals onto the algal EPS rather than intracellular chelation to phytochelatins.

  20. 骑浪横甩薄弱性衡准技术的发展%Development of Surf-riding Broaching Vulnerability Criteria Technology

    Institute of Scientific and Technical Information of China (English)

    唐哲

    2014-01-01

    This article introduces the physical background and the vulnerability criterion development process for the first layer and the second layer of surf-riding/broaching. Also it analyzes the preliminary criteria and the vulnerability criteria method for calculating of surf-riding/broaching. Mastering the development state of this technology can be useful for the research of relative area, and would become the base for the second general criteria technology.%介绍了骑浪/横甩的物理背景,以及骑浪/横甩第一层和第二层薄弱性衡准发展过程,并分析了骑浪横甩薄弱性衡准计算方法及初步衡准,掌握骑浪横甩薄弱性衡准技术的发展现状,有助于骑浪/横甩相关技术领域的研究,为船舶第二代完整稳性的技术发展奠定基础。