bluuebunny/crossref_metadata_2025 huggingface dataset:
The Thermo-Test and Mathematics Model Study on Automobile Tube-Core-Fin Radiator
Authors: Cui Hong Jiang , Li Ming Hai , Guan Ying
Published: January 2012

.In order to improve the performance of automobile tube-core-fin radiator, the thermo-test and mathematics model method were combined together to study heat transfer and air resistance. The mathematics model was built including heat transfer and air resistance coefficient criterion equations in the certain Reynolds number range. The maximum relative error between results calculated from mathematics model and test values is less than 6.61%. The number of tube rows of the radiator can affect heat transfer and air resistance coefficient through analyzing results.
The Research on the Flexible Integrated Research Platform of the Solar Energy Photovoltaic System
Authors: Liu Qiu Shuang , Xu Xiao Li
Published: January 2012

On the basis of the general technology, high-tech, vast varieties and small-lot of the solar energy photovoltaic system, this paper comes up with the research conception of optical, mechanical and electronic integration and builds the optical, mechanical and electronic integration system. It also brings forward the design methodology and the integrated mechanism of the instant systematic integration based on the flexible interconnection, which leads to the building of the basic experimental and research environment of the automatic integrated design. The application of this new technology is based on the research of the highly-efficient Concentrator Photovoltaic System. It noticeably improves the technical level as well as the research efficiency.
Prediction of Settlement of Soft Clay Foundation in Highway Using Artifical Neural Networks
Authors: Li Xiao Yong , Bu Fan Jie
Published: January 2012

In recent years artificial neural networks (ANNs) have been applied to many geotechnical engineering problems with some degree of success. With respect to the design of Highway embankment, accurate prediction of settlement of soft clay foundation in highway is necessary to ensure appropriate structural and serviceability performance. In this paper, an ANN model is developed for predicting settlement of soft clay foundation based on the observation data of settlement. Approximately 200 data sets, obtained from the Field Tests and the published literature, are used to develop the ANN model. In addition, the paper discusses the choice of input and internal network parameters which were examined to obtain the optimum model. Finally, the paper compares the predictions obtained by the ANN with those given by a number of traditional methods. It is demonstrated that the ANN model outperforms the traditional methods and provides accurate settlement predictions for soft clay foundation in highway.
High Accuracy AMR Magnetometer and its Application to Vehicle Detection
Authors: Li Xi Sheng , Kang Rui Qing , Liu Yan Xia , Wang Zhi Hua , Shu Xiong Ying
Published: January 2012

The anisotropic magnetoresistive (AMR) sensors provide an excellent means of measuring the earth’s magnetic field. Low cost, high sensitivity, small size, noise immunity, and reliability are advantages of AMR sensor over other electrical alternatives. But the sensitivity of constant voltage biased AMR sensor changes greatly with the temperature of surrounding and cross-axis field. In this paper, constant current bias is used in order to reduce the sensitivity temperature coefficient of AMR sensor. At the same time, cross-axis field compensation is taken based on iteration. The results of experiment show that the sensitivity of HMC100x without cross-axis field compensation varies greatly with the variation of cross-axis field, the sensitivity of HMC100x with cross-axis field compensation is stable. It can be seen that proposed sensitivity compensation method is effective. Developed magnetometer is used for vehicle detection. Experimental results show that developed magnetometer is capable of detecting vehicle and its output variation curve shape is different for the ferrous cart moves over sensor along different direction.
The Research on Energy-Storaged Application of Na/S Battery
Authors: Lu Jia Yun , Jiang Quan Sheng , Qin Lei
Published: January 2012

The Na/S battery is a kind of advanced secondary battery which with β （β）- Al2O3 as the electrolyte, its negative electrode is metal sodium and positive electrode is sulphur. It has advantages of large capacity, small size, long service life and high efficiency. The raw material of the Na/S battery is widely and the production cost is low. In addition, it’s not limited by space and easy to maintain. The Na/S battery is widely used in stable supply of renewable energy such as peak load shifting, emergency power and wind power, In terms of improving the stability of the power quality, Na/S battery is a most maturely and potentially energy-storage battery in a variety of advanced secondary battery.
A Novel Miniature Printed UWB Monopole Patch Antenna
Authors: Xia Ying Qing , Luo Jia
Published: January 2012

A novel monopole patch antenna with very simple structure to fabricate on a printed circuit board is proposed to operate from 3.05 to 11.8GHz for UWB application. Ellipse technique is used to optimize its main parameters when an improvement of its compact profile is achieved. The designed antenna has miniature total volume of 18.6mm×18mm×1mm, and quasi-omnidirectional pattern in the X-Y plane across the major bandwidth.
Reconfigurable Testing System for Automobile Parts and Equipment
Authors: Liu Zhen Zhong , Wang Tai Yong , Liu Qing Jian , Qiao Zhi Feng
Published: January 2012

For the purpse of meeting the needs of modern automobile parts and equipment test, a modular reconfigurable testing system for automobile parts and equipment was carried out. In the testing system, industrial computer as host computer performs human computer interaction, and the client computer is extended based on FPGA(Field Programmable Gate Array). FPGA excutes real-time task that can be configured according to mission requirements. The procedure of modular testing system which was designed with the Microsoft Visual C++ 6.0 is divided into human computer interaction and driver layer. The result showed that the system can be used for rapid design of auto parts and equipment testing system. The result of the present work implied that the reconfigurable testing system has good flexibility and expansibility.
Identification of Natural Frequency of Bearing Rotor Based on GA-SVM
Authors: Ma Tian Ran , Qin Fei Hu , Liu Rui Xue , Zhang Feng Jie
Published: January 2012

During identify natural frequency of bearing rotor, due to the complex non-linear relationship among the factors which influence natural frequency, so it is hard to establish a complete and accurate theoretical model. Based on the generalization and approximation of non-linear mapping capability of support vector machine (SVM) and the powerful ability of global optimization of the genetic algorithm (GA), the paper through optimizing the SVM by GA, establishes combined Genetic Support Vector Machine (GA-SVM). The method establishes the mapping between the natural frequency of a rolling bearing rotor and the various parameters, which reduces the rotor structure for the study similar to the natural frequency of the calculation of the workload greatly. Using the model to indentify the natural frequency of bearing rotor under different parameters, then compare identification value with experimental values shows that projections in good agreement with the experimental data.
A New Anti-Surge Control System for Underwater Vehicle
Authors: He Qing Bo , Tang Zhi Jie , Luo Jun
Published: January 2012

This paper presents a new anti-surge control system hardware structure for Underwater vehicle and Stress analysis. Based on the considered environmental impact of surge in Shallow waters, a space-based six degree of freedom equation of motion simulation model is built for the special movement. A new integrated control system for the underwater vehicle, including a fuzzy PID control part with a state prediction is obtained by solving the surge problems to deal with the poor working condition under the action of the surge in Shallow waters, and its aim at the characteristics of low static error, fast response and control overshoot suppression. Some simulations verify the performance.
Delivering Way of Horizon Disturbance to Vertical Vibration in Temper Rolling Mill
Authors: Xiong Zhi Qiang , Zeng Chun , Li You Rong , Wang Zhi Gang , Xiong Zhi Bin
Published: January 2012

Developed a mathematics model of temper rolling mill’s dynamic rigidity change with the oil film’s thickness which is varying with working roll’s horizontal chattering velocity. The delivering way from the horizontal chattering to vertical chattering is revealed on the above analyzing. Combined with actual chatter marks of strip steel produced by one temper rolling mill, the influence of one horizontal disturbance to vertical chatter has been validated by the use of numerical simulation with Simulink software package. It provides theoretical and practical value on research of vibration in temper rolling mill.
Nonlinear Calibration of Thermocouple Sensor Using Least Squares Support Vector Regression
Authors: Yu Yao Jun
Published: January 2012

Calibration is an important operation in the instrumentation industry for determining the relationship between the output (s) (or response) of a measuring instrument and the value of the input (s). This paper proposes a nonlinear calibration method based on least squares support vector regression (LS-SVR) with the output voltage of thermocouple sensor as input and the measured temperature output to eliminate the nonlinear errors in detection process. Firstly, the nonlinear calibrator, expressed by power series, was established based on the principle of inverse model. And then the parameters of the calibrator were identified by LS-SVR. Through this calibrator, the desired linear characteristics of thermocouple sensor could be obtained. Finally, platinum-rhodium 30– platinum-rhodium 6-thermocouple (B-type) was taken as an example, and experimental results show that the proposed calibration method is efficient in the temperature range from 400°C to 1800°C. And the method has an advantage of analytical expression of the calibration model.
Study on Piezoelectric Effect of Ceramic Capacitors in Daya Bay Neutrino Experiment
Authors: Jiang Wen Qi , Wang Zheng
Published: January 2012

The Daya Bay Neutrino Experiment is a neutrino-oscillation experiment designed to measure the mixing angle θ13 using anti-neutrinos produced by the reactors of the Daya Bay Nuclear Power Plant (NPP) and the Ling Ao NPP. Eight anti-neutrino detectors (AD) consists of liquid scintillator and Photomultiplier Tubes (PMTs) will be used in the experiment. The readout signals of the PMTs which are reacted by the Neutrino need to be accurately measured for the goal of the Daya Bay experiment which needs a measurement of sin22θ13 to 0.01 or better. But ringing was found in the PMT test. This paper describes the ringing in the readout signals of the PMTs, and analyses the cause of the ringing.
Techniques for PAPR Reduction in OFDM Systems
Authors: Chen Lin , Hu Xue Long
Published: January 2012

Orthogonal Frequency Division Multiplexing (OFDM) has been focused on in high-data-rate wireless communication research. But the high Peak-to-Average Power Ratio (PAPR) is one of the main obstacles to limit wide applications of OFDM. In this paper, based on the definition of the PAPR in OFDM systems, these techniques on PAPR reduction are presented, including signal distortion, signal scrambling, and block coding. The advantages and disadvantages of these techniques are discussed in detail and some performances are achieved by Monte Carlo simulations.
Resource Optimization Scheme Based on ROI Distortion-Minimized for Mobile Image Transmission
Authors: Tang Zhen Hua , Qin Tuan Fa , Li Xiang Cheng
Published: January 2012

In this paper, we present an adaptive resource optimization scheme for image coding and transmission over wireless channel. In the proposed scheme, system resources related with source coder, channel coder, and transmission amplifier are optimization according to varying channel conditions and input image characteristics. The optimization target is to achieve the distortion minimization of the region of interest (ROI) in received images under the system constraints. Moreover, both unequal error protection (UEP) and unequal transmission power distribution (UTPD) are considered in the presented scheme. Simulation results show that our proposed scheme can significantly improve the quality of ROI in received images compared to equal transmission protection (ETP) scheme.
An Implementation of CANopen at Water Electrolysis Hydrogen Generation Station
Authors: Kuang Fu Hua , Xu Bu Gong
Published: January 2012

In this paper, the structure and characteristic of CANopen protocol is analyzed, and the implementation in a Water Electrolysis Hydrogen Generation Station (WEHGS) is described in detail, which includes the hardware interface design of CAN controller based on the ARM7 of LPC2292, and the software implementation. Finally, the practice proved that used CANopen in WEHGS is a good way with real time action, more reliability and low cost.
Electrostatic Precipitator Monitoring System Based on CAN Bus
Authors: Zhang Zi Sheng , Hao Qing , Cui Chao , Lian Ya Fei , Xiao Zhen Lei , Liu Zhi Qiang , Li Qing
Published: January 2012

The hardware and software design are introduced about electrostatic precipitator control system. And this monitoring and control system is based on CAN bus. In this system the basic data acquisition and control functions can be achieved. The work status of precipitator can be collected in real time and fed back to the computer control interface, in order to provide reliable data support for the fault diagnosis of the ESP, so information integration level can be improved and the monitoring system can be optimized. Simple structure, high reliability, communication speed are the characteristics, and it have a wide range of application prospects.
A Liquid Level Measuring Device for a Tank Based on Image Senor
Authors: Yu Chun He , Zhang Chao , Bai Ying , Huang Chuan
Published: January 2012

A non-contact liquid level measuring system is designed based on image processing technology, and it consists of three parts: a COMS camera, a laser source, and a PC. The work principle of the device is: the laser beam from the laser source is irradiated to the liquid at a certain angle, and the image of the tank’s interior is picked up by the CMOS camera; then the light spot on the liquid surface is extracted by the technology of image processing; Through the center of the light spot, the information about liquid-level can be obtained. The model of the measurement system is proposed in the paper, and the method of the calibration is given by using the least square algorithm. Experiments tests that the liquid level measuring device can be used in strict and adverse environment.
Computer Simulation of Pitting Machine Shaft of Litchi Fresh Fruit
Authors: Wang Xu Dong , Ling Xuan
Published: January 2012

Aiming at obtaining lantern shape litchi flesh, a pitting machine was devised and made. Cutter shaft is one of the most important part of the machine and its reciprocating motion cause impact load on the machine. Unilateral load on the surface of the groove result in excessive wear of the cutter shaft. In view of the above problem, dynamic characteristics and the optimum design model of the cutter shaft are established. Used nonlinear optimization toolbox of MATLAB, the best structure parameters of the cutter shaft were calculated. The results are: (1) minimum mass of the shaft is 0.6421 kg ,which is lighter 10.07% than before;（2） the best spiral angle of the groove is 38.38°. 3D parameterized models of the cutter shaft were built and their kinematics simulation were made by using Pro/ENGINEER software. The simulation and test results show that the more rotate speed and spiral angle of the groove are, the higher press on the surface of the groove bears. The above results provide basis for improved design of the pitting machine for litchi fruit.
Study on 3D Modeling for History Building and Precision Analyzing
Authors: Zhang Hong Fei , Cheng Xiao Jun , Shi Yin Tao
Published: January 2012

Taking a certain history building as an example, we introduce a real 3D digital method for Large-Scale history building using 3D laser scanner and total station, and analyze the precision of coordinate conversion model and established 3D model. Firstly, the building are separated into many stations which are scanned separately in order to get the points cloud of each station, at the same time, the coordinates of targets and feature points of each station are obtained with laser scanner and total station respectively; next step, we convert the points cloud of every station with conversion program developed by Matlab so that the data are under the uniform reference frame with the collected homonymy targets; finally, the points cloud which have been registered are meshed in order to build real 3D digital history building model, meanwhile we analyze the precision of conversion model and the real 3D model. The result shows that this method is fast, efficient, and the prospective model has high precision.
Research on the Multi-Spectrum Imaging System Based on Vision Technology
Authors: Jin Xuan Hong , Zhou Zheng Yang , Xu Ran
Published: January 2012

This paper introduces an acquiring and processing system of a new type of optical spectrometer based on vision technology. It mainly introduces the hardware structure to acquire the spectrums dispersed by the spectrometer, and the multi-spectrum image processing software as well. Of the different spectrum wavelengths ranges from 400nm to 740nm, the system can create both the color image and the 68 channels gray scale image. Virtual instruments technology is introduced into this system and it makes programming easier and faster by combining virtual instrument and vision technology. The programming of the image processing software uses LabVIEW platform.
Approach to Detect Air Tightness of Engine Cylinder by Vibration Analysis
Authors: Qiao Xin Yong , Xie Xiao Yang , Liu Jian Min , Zhang Xiao Ming
Published: January 2012

Cylinder compression pressure reflects the air tightness of engine. A method for measuring the compression pressure of cylinder indirectly through measuring the vibration signal of cylinder head was studied and then to detect the air tightness. The air pressure signal in cylinder and vibration signals of cylinder head were measured at the same time when the diesel engine was driven by the motor. According to port timing, the vibration signal excited by cylinder pressure was separated using time domain analysis. A RBF neural network model was set up to build the relation between compression pressure and cylinder head vibration. So the air tightness of cylinder can be detected after calculating the compression pressure by use of neural network.
A Transmission Control System's Research for a Nursing Bed with Four Transmissions Driven by a Single Motor
Authors: Li Zhi Xiang , Zheng Jing
Published: January 2012

This paper introduces a kind of multi-function nursing bed control system which has won Chinese invention patent. This system takes AT89C51 as a core, uses a unique control mode for a single electrical machinery driven four transmissions, and adopts a modular control technology which respectively controls the movements of four lead screws through electrical machinery’s positive or negative rotation, and electromagnetic clutch’s connection or disconnection to decide the power transmission direction, so as to realize the different postures of the nursing bed, and meet the demands of patient care.
Research on Simulation Model and Application for Flexible Manufacturing System of Hot Stamping
Authors: Song Ke Wei , Zhang Yi Sheng
Published: January 2012

In order to maintain the synchronization between the development of total control system of product line and the manufacturing of hardware devices, virtual designs and simulation technologies have been utilized and virtual product line has been built, which was used for developing the total control system that was based on EtherCAT technology and was for distributed processing. First, according to the characteristics and structures of hardware devices, mathematical models were built up. Then, device simulation system and total control system according to the mathematical models of devices have been developed, and also discussions have been made on the synchronous control of product line and the dynamic setup of working procedures in the total control system. Finally, the characteristics of the system have been tested and analyzed in the following two aspects: data acquisition and system response.
Powder Particle Size Measurement with Digital Image Processing Using Matlab
Authors: Wu Li Cai , Yu Chuang
Published: January 2012

The application of powder particle size measurement in engineering field are introduced, the major powder particle size research methods are also included. Furthermore we analyzed the characteristics of these methods. Based on these, we proposed a method, which makes full use of Matlab to process and analyze the SEM image of powders to get powder particle size and the distribution, and the method achieve a good effect. Finally, In order to verify the processing method, the authors performed an example of the approach. Based on the results, it can be confirmed, therefore, the method using MATLAB is convenient to analyze the powder particle size.
Effects of Initial Axial Stress on the Vibration of Double-Walled Carbon Nanotubes under Temperature Field
Authors: Yan Yan , Wang Wen Quan , Zhang Li Xiang
Published: January 2012

The paper studies the linear vibrating mechanical behaviors of double-walled carbon nanotubes (DWCNTs) with the initial axial stress under the temperature field. The DWCNTs are modeled as double elastic shells coupled together through vdW interaction between inner and outer nanotubes. Based on the model, the relation between the amplitudes and the frequencies of the tubes is achieved. The results show that the initial axial stress could crucially affect the existence of the natural and intertube frequencies. Meanwhile, it is also concluded that the temperature change is significant for natural frequency, but weakly affects intertube frequency and amplitude ratios.
New Method of Dynamical Reanalysis for Large Modification of Structural Topology Based on Reduced Model
Authors: He Jian Jun , Jiang Jie Sheng
Published: January 2012

The paper presents a new improved method for structural dynamic reanalysis with large change in structure topology possessing added degrees of freedom (DOF). The method，which is based on twice reduced model of original and topological structures, combines independent mass orthogonality and Rayleigh-Ritz analysis. Two numerical examples were used to show that the presented method can provide efficient and high quality approximation result for eigenvalues reanalysis when large modifications of the structural topology are made.
Static Interval Optimization for Structures with Interval Parameters and Interval Loading
Authors: Zhang Shu Guang , Chen Su Huan
Published: January 2012

A static interval optimization method for structures was developed. The matrices of structures with interval parameters are given. Combining the interval extension of functions with the perturbation theory of static analysis, the method for interval static analysis of the structure with interval parameters and interval loading was derived. The Interval optimization problem was transformed into a corresponding deterministic one. Because the mid-values and the uncertainties of the interval parameters can be selected as the design variables, more information of the optimization results can be obtained by the present method than that obtained by the deterministic one. The numerical results show that the present method is valid.
Application of Optimized GM (1,1) in the Machine Tool Thermal Error Modeling
Authors: Yu Bo
Published: January 2012

Considering the prediction of thermal machine tool error data this paper proposes using GM (1,1) model of gray system to predict machine tool thermal error data. Through comparing with the calculated result between traditional GM(1,1) model and the optimized GM(1,1) model, more satisfactory results can be achieved, and indicating that this model can predict the distribution of machine tool thermal error data more accurately. So the optimized GM (1,1) model can be used to provide a more reliable methodology in controlling the digital machine tool.
Equivalent Profile of High-Speed Mill Considering Gyroscopic Effect
Authors: Zhou Hong Liang , Tang Wei Xiao , Song Qing Hua
Published: January 2012

High-speed milling (HSM) has advantages in high productivity high precision and low production cost. Thus it can be widely used in the manufacture industry. However, when the speed of spindle-tool reaches a higher speed range, the gyroscopic effect will become an important part of its stable milling. In this paper, a dynamics model of HSM system was proposed considering the influence of gyroscopic moment due to high rotating speed of end milling, and solution it. Then, the natural frequencies of end-milling model were researched by using analyse software. And analysis the stability of end-milling that considered gyroscopic effects under different speeds, obtain the Campbell Diagram. Get the trajectory of one point in end face milling. Then draw the fitting trajectory and ideal trajectory of the point in milling. Compare the actual trajectory, fitting trajectory and the ideal trajectory. So it can provide a basis for stability prediction of high speed milling.
Synthesis of 5-Benzoylacenaphthene in the Presence of [Bmim] Cl/AlCl3 Ionic Liquid
Authors: Zhu Shu Yun , Jiang De Li , Fang Yu , Xie Ji Min , Chen Min
Published: January 2012

Acylation of acenaphthene with benzoyl chloride to 5-benzoylacenaphthene catalyzed by [Bmin]Cl/AlCl3 ([Bmin]+ = 1-butyl-3-methylimidazolium cation) ionic liquid was investigated. Pure 5-benzoylacenaphthene was obtained and the structure of 5-benzoylacenaphthene was identified by GC/MS, FT-IR and 1H NMR spectra. The yield of 5-benzoylacenaphthene was up to 85.2 % and the selectivity towards 5-benzoylacenaphthene was up to 89.6 %. The [Bmim]C1/A1C13 ionic liquid catalyst shows well catalytic activity after running for 5 times. The facile product separation and the recycling performance of the ionic liquid catalyst is expected to contribute to the development of clean and environmentally friendly strategy for the synthesis of 5-benzoylacenaphthene.
Experimental Investigation of Vibration and Noise Control of Reciprocating Compressors
Authors: Long Jiang Qi , Zhou Si Jia , Yu Ping
Published: January 2012

The reciprocating compressor contains crank-rod mechanism whose unbalanced inertia force mainly accounts for mechanical noise and vibration during the working process. Through the analysis of fit between the diameter of the compressor piston and the crank eccentricity, influence of imbalance force on the compressor vibration and noise is obtained under no change in other parts. The tests of vibration and noise are followed for the purpose of verification. The results show that the vibration and noise control will be better if a small piston diameter and a big crank eccentricity are utilized.
Design of Small and Medium Power Smart Frequency Conversion Electric Actuator
Authors: Yang Yang , Bian Jian Yong , Zhu Cai Lian , Yang Run Feng
Published: January 2012

In order to solve the domestic intelligent electric actuator being low accuracy, poor and simple network communication function, this paper presents the development of small and medium power intelligent electric actuators based on TMS320F2812 DSP chip. This intelligent electric actuator has a few functions including network communication, high precise positioning, configuration, control and display self-checking. This type of actuator has compact structure and high intelligence. The advanced frequency conversion control method of vector magnetic beam is adopted in the process module of the actuator. Overall performance of the electric actuator is close to the international level.
Machine Performance Degradation Recognition Using Locality Preserving Projections and Clustering Approach
Authors: Yu Jian Bo , Liu Jian Ping , Liu Mei Fang , Yin Ji Ting , Wang Yong Guo
Published: January 2012

The sensitivity of various features that are characteristics of machine performance may vary significantly under different working conditions. Thus it is critical to devise a systematic feature extraction (FE) approach that provides a useful and automatic guidance on using the most effective features for machine performance recognition without human intervention. This paper proposes a locality preserving projection (LPP)-based FE approach for machine performance degradation recognition. Different from principal component analysis (PCA) that aims to discover the global structure of the Euclidean space, LPP is capable to discover local structure of the data manifold. This may enable LPP to find more meaningful low-dimensional information hidden in the high-dimensional observations compared with PCA. This experimental result on a bearing test-bed shows that LPP-based FE improves the performance of recognizers for identifying performance degradation of bearings.
Production of TNF-α in Macrophages Activated by T Cells, Compared with Lipopolysaccharide, Uses Distinct IL-10–Dependent Regulatory Mechanism
Authors: Agbanoma Gideon , Li Ching , Ennis Darren , Palfreeman Andrew C. , Williams Lynn M. , Brennan Fionula M.
Published: January 2012

Previously, we demonstrated that spontaneous TNF-α production by macrophages in rheumatoid arthritis (RA) synovial tissue is largely driven by contact-dependent activation with T cells in that tissue. Whereas abundant IL-10 is present in these RA synovial cultures, it does not adequately control the production of TNF-α. In this study, we have compared the mechanisms involved in IL-10–mediated TNF-α regulation in LPS-stimulated macrophages with macrophages stimulated with activated T cells. We confirm that in LPS-stimulated macrophages the 3′ enhancer region of tnf is essential for tnf transcription, and its regulation by IL-10 is dominated by a STAT3-dependent pathway. However, in contrast, we have found that tnf transcription in macrophages stimulated by activated T cells or by RA synovial T cells does not require the 3′ enhancer region of tnf, and that its regulation by IL-10 is subsequently altered and clearly is not mediated by a dominant STAT3 pathway. These observations have very important implications for our understanding as to how IL-10 regulates TNF-α production at sites of chronic inflammation, such as the synovial tissue of patients with RA. Furthermore, these distinct IL-10 mechanisms will have bearing upon the identification of potential therapeutic targets in RA synovial macrophages where the activation stimulus is clearly not LPS.
Comunicadores resonantes, comunicadores eficaces. Flujo y credibilidad del comunicador
Authors: García-Ureta Irene , Toral-Madariaga Gotzon , Murelaga-Ibarra Jon
Published: January 2012

Los estudios de comunicación están integrando los avances en la ciencia cognitiva, reconociéndose la importancia de entender los procesos subjetivos de recepción de la comunicación. Este trabajo argumenta la necesidad de estudiar también la psicología del comunicador. Presentamos la fundamentación teórica y los resultados de un modelo de formación de comunicadores audiovisuales basado en las teorías de la auto eficacia y del flujo. El programa busca mejorar la comunicación de los alumnos mediante técnicas de locución y habilidades psicológicas para evitar que una ansiedad excesiva interfiera en su expresividad. Se utiliza una metodología activa basada en la modelización, visualización, retroalimentación inmediata y refuerzo positivo. Un ANOVA con medidas repetidas muestra que el programa disminuye los niveles de ansiedad ante la locución, aumenta la autoeficacia percibida, promueve el estado psicológico óptimo para desenvolverse mejor ante las cámaras (flujo), y mejora la calidad de la locución del alumnado. Mediante análisis path se comprueba que los niveles de autoeficacia percibida y ansiedad predicen la experiencia de flujo durante la comunicación. Finalizado el programa, aquellos que experimentan un mayor nivel de flujo y disfrutan de la tarea consiguen una mayor calidad en su comunicación. Se concluye que los conceptos de auto eficacia y flujo permiten avanzar en el conocimiento de los factores que determinan la credibilidad del comunicador y su conexión con el público
Efficacy of Two Methods for Restorative Materials’ Removal in Primary Teeth
Authors: Bittar Daniela Gonçalves , Murakami Christiana , Hesse Daniela , Imparato José Carlos Pettorossi , Mendes Fausto Medeiros
Published: January 2012

Aim

This in vitro study aimed to compare the time required for removal, the presence of residues of restorative material, tooth structure loss and dental surface morphology after removal of composite resin and amalgam restorations from occlusal cavities in primary molars using conventional high-speed bur and CVDentus® ultrasonic diamond tips.

Materials and methods

A total of 37 primary molars were allocated into four groups: Group 1 (n=9)—amalgam restorations removed using high-speed bur; Group 2 (n=10)—amalgam restorations removed using ultrasonic tip; Group 3 (n=8)— composite resin restorations removed using high-speed bur; Group 4 (n=10)—composite resin restorations removed using ultrasonic tip. After being restored, teeth were sectioned and analyzed through stereoscopic microscope images before and after restoration removal. The structural loss was analyzed by software of image analysis, and an examiner assessed for the presence of residues. Scanning electron microscopy was used to evaluate the morphology. Time and structural loss values were compared using ANOVA, and the percentages of samples with residues using Fisher test.

Results

There was no statistically significant difference in the tooth structure loss among different methods and restorative materials, as well as in the presence of residues of restorative material. However, diamond burs were faster than the ultrasonic method for both materials. Differences in dental morphology were observed between the methods of restoration removal, but not related to the restorative material.

Conclusion

Both conventional high-speed bur and ultrasonic diamond tip methods remove similar amounts of tooth structure, but the removal performed with diamond tips in ultrasonic devices is slower.

Clinical significance

This study shows that both ultrasonic and conventional high-speed bur methods for removing restorations generate similar loss of sound dental tissue, but the former is slower.

How to cite this article

Bittar DG, Murakami C, Hesse D, Imparato JCP, Mendes FM. Efficacy of Two Methods for Restorative Materials’ Removal in Primary Teeth. J Contemp Dent Pract 2011;12(5):372-378.
Long-term tropospheric trend of octafluorocyclobutane (c-C4F8 or PFC-318)
Authors: Oram D. E. , Mani F. S. , Laube J. C. , Newland M. J. , Reeves C. E. , Sturges W. T. , Penkett S. A. , Brenninkmeijer C. A. M. , Röckmann T. , Fraser P. J.
Published: January 2012

Abstract. Air samples collected at Cape Grim, Tasmania between 1978 and 2008 and during a series of more recent aircraft sampling programmes have been analysed to determine the atmospheric abundance and trend of octafluorocyclobutane (c-C4F8 or PFC-318). c-C4F8 has an atmospheric lifetime in excess of 3000 yr and a global warming potential (GWP) of 10 300 (100 yr time horizon), making it one of the most potent greenhouse gases detected in the atmosphere to date. The abundance of c-C4F8 in the Southern Hemisphere has risen from 0.35 ppt in 1978 to 1.2 ppt in 2010, and is currently increasing at a rate of around 0.03 ppt yr−1. It is the third most abundant perfluorocarbon (PFC) in the present day atmosphere, behind CF4 (~75 ppt) and C2F6 (~4 ppt). Although a number of potential sources of c-C4F8 have been reported, including the electronics and semi-conductor industries, there remains a large discrepancy in the atmospheric budget. Using a 2-D global model to derive top-down global emissions based on the Cape Grim measurements yields a recent (2007) emission rate of around 1.1 Gg yr−1 and a cumulative emission up to and including 2007 of 38.1 Gg. Emissions reported on the EDGAR emissions database for the period 1986–2005 represent less than 1% of the top-down emissions for the same period, which suggests there is a large unaccounted for source of this compound. It is also apparent that the magnitude of this source has varied considerably over the past 30 yr, declining sharply in the late 1980s before increasing again in the mid-1990s.
The contribution of natural and anthropogenic very short-lived species to stratospheric bromine
Authors: Hossaini R. , Chipperfield M. P. , Feng W. , Breider T. J. , Atlas E. , Montzka S. A. , Miller B. R. , Moore F. , Elkins J.
Published: January 2012

Abstract. We have used a global three-dimensional chemical transport model to quantify the impact of the very short-lived substances (VSLS) CHBr3, CH2Br2, CHBr2Cl, CHBrCl2, CH2BrCl and C2H5-Br on the bromine budget of the stratosphere. Atmospheric observations of these gases allow constraints on surface mixing ratios that, when incorporated into our model, contribute ~4.9–5.2 parts per trillion (ppt) of inorganic bromine (Bry) to the stratosphere. Of this total, ~76 % comes from naturally-emitted CHBr3 and CH2Br2. The remaining species individually contribute modest amounts. However, their accumulated total accounts for up to ~1.2 ppt of the supply and thus should not be ignored. We have compared modelled tropical profiles of a range of VSLS with observations from the recent 2009 NSF HIPPO-1 aircraft campaign. Modelled profiles agree reasonably well with observations from the surface to the lower tropical tropopause layer. We have also considered the poorly studied anthropogenic VSLS, C2H5Br, CH2BrCH2Br, n-C3H7Br and i-C3H7Br. We find the local atmospheric lifetime of these species in the tropical tropopause layer are ~183, 603, 39 and 49 days, respectively. These species, particularly C2H5Br and CH2BrCH2Br, would thus be important carriers of bromine to the stratosphere if emissions were to increase substantially. Our model shows ~70–73 % and ~80–85 % of bromine from these species in the tropical boundary layer can reach the lower stratosphere.
Inter-hemispheric asymmetry of dependence of the cusp location on dipole tilt during northward IMF conditions
Authors: Shi J. , Guo J. , Dunlop M. , Zhang T. , Liu Z. , Lucek E. , Fazakerley A. , Rème H. , Dandouras I.
Published: January 2012

Abstract. A data set of the Cluster cusp crossings over a 5-year period is studied for the interhemispheric comparison of the dipole tilt angle effect on the latitude of the mid-altitude cusp. The result shows that the dipole tilt angle has a clear control of the cusp latitudinal location. Although, the northern cusp moves 0.054° ILAT for every 1° increase in the dipole tilt angle at the mean altitude of 5.2 RE, the southern cusp moves 0.051° ILAT for every 1° increase in the dipole tilt angle at the mean altitude of 6.6 RE. The northern cusp dependence agrees with the trend formed by other observations of different satellites for different altitudes, whereas the southern cusp does not. We therefore suggest that there is an inter-hemispheric difference in the dipole tilt angle dependence of cusp, latitudinal location, which has an impact on other observations of different satellites in different altitudes.
A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O2 airglow temperatures measurements
Authors: Taori A. , Jayaraman A. , Raghunath K. , Kamalakar V.
Published: January 2012

Abstract. The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation.
Exploring the "overflow tap" theory: linking forest soil CO2 fluxes and individual mycorrhizosphere components to photosynthesis
Authors: Heinemeyer A. , Wilkinson M. , Vargas R. , Subke J.-A. , Casella E. , Morison J. I. L. , Ineson P.
Published: January 2012

Abstract. Quantifying soil organic carbon stocks (SOC) and their dynamics accurately is crucial for better predictions of climate change feedbacks within the atmosphere-vegetation-soil system. However, the components, environmental responses and controls of the soil CO2 efflux (Rs) are still unclear and limited by field data availability. The objectives of this study were (1) to quantify the contribution of the various Rs components, specifically its mycorrhizal component, (2) to determine their temporal variability, and (3) to establish their environmental responses and dependence on gross primary productivity (GPP). In a temperate deciduous oak forest in south east England hourly soil and ecosystem CO2 fluxes over four years were measured using automated soil chambers and eddy covariance techniques. Mesh-bag and steel collar soil chamber treatments prevented root or both root and mycorrhizal hyphal in-growth, respectively, to allow separation of heterotrophic (Rh) and autotrophic (Ra) soil CO2 fluxes and the Ra components, roots (Rr) and mycorrhizal hyphae (Rm). Annual cumulative Rs values were very similar between years (740 ± 43 g C m−2 yr−1) with an average flux of 2.0 ± 0.3 μmol CO2 m−2 s−1, but Rs components varied. On average, annual Rr, Rm and Rh fluxes contributed 38, 18 and 44%, respectively, showing a large Ra contribution (56%) with a considerable Rm component varying seasonally. Soil temperature largely explained the daily variation of Rs (R2 = 0.81), mostly because of strong responses by Rh (R2 = 0.65) and less so for Rr (R2 = 0.41) and Rm (R2 = 0.18). Time series analysis revealed strong daily periodicities for Rs and Rr, whilst Rm was dominated by seasonal (~150 days), and Rh by annual periodicities. Wavelet coherence analysis revealed that Rr and Rm were related to short-term (daily) GPP changes, but for Rm there was a strong relationship with GPP over much longer (weekly to monthly) periods and notably during periods of low Rr. The need to include individual Rs components in C flux models is discussed, in particular, the need to represent the linkage between GPP and Ra components, in addition to temperature responses for each component. The potential consequences of these findings for understanding the limitations for long-term forest C sequestration are highlighted, as GPP via root-derived C including Rm seems to function as a C "overflow tap", with implications on the turnover of SOC.
Abundance and distribution of gaseous ammonia and particulate ammonium at Delhi (India)
Authors: Singh S. , Kulshrestha U. C.
Published: January 2012

Abstract. This study reports abundance and distribution of gaseous NH3 and particulate NH4+ at Delhi. Gaseous NH3 and particulate NH4+ concentrations were measured during pre monsoon, monsoon and postmonsoon seasons of the years 2010 and 2011. Average concentrations of gaseous NH3 during premonsoon, monsoon and post monsoon seasons were recorded as 26.4, 33.2 and 32.5 μg m−3, respectively. Gaseous NH3 concentrations were the highest during monsoon due to decay and decomposition of plants and other biogenic material under wet conditions which emit NH3. The results showed that particulate NH4+ was always lower than the gaseous NH3 during all the seasons. The concentrations of particulate NH4+ were recorded as 11.6, 22.9 and 8.5 μg m−3 during premonsoon, monsoon and postmonsoon seasons, respectively. The percent fraction of particulate NH4+ was noticed highest during monsoon season due to increased humidity levels. On anaverage, 33.3 % of total N-NHx was present as particulate NH4+. Higher concentrations of NH3 noticed during night time may be due to stable atmospheric conditions. Study highlighted that as compared to rural sites, urban sites showed higher concentrations of gaseous NH3 in India which may be due to higher population density, human activities and poor sanitation arrangements.
Pollen, vegetation change and climate at Lake Barombi Mbo (Cameroon) during the last ca. 33 000 cal yr BP: a numerical approach
Authors: Lebamba J. , Vincens A. , Maley J.
Published: January 2012

Abstract. This paper presents quantitative reconstructions of vegetation and climate along the pollen sequence of Lake Barombi Mbo, southwestern Cameroon (4°39'45.75" N, 9°23'51.63" E, 303 m a.s.l.) during the last 33 000 cal yr BP, improving previous empirical interpretations. The biomisation method was applied to reconstruct potential biomes and forest successional stages. Mean annual precipitation, mean annual potential evapotranspiration and an index of moisture availability were reconstructed using modern analogues and an artificial neural network technique. The results show a dense forested environment around Lake Barombi Mbo of mixed evergreen/semi-deciduous type during the most humid phases (highest precipitation and lowest evapotranspiration), but with a more pronounced semi-deciduous type from ca. 6500 cal yr BP to the present day, related to increased seasonality. This forest displays a mature character until ca. 2800 cal yr BP, then becomes of secondary type during the last millennium, probably due to increased human activity. Two episodes of forest fragmentation are shown, which are synchronous with the lowest reconstructed precipitation and highest potential evapotranspiration values. The first of these occurs during the LGM, and the second one from ca. 3000 to ca. 1200 cal yr BP, mainly linked to high precipitation seasonality. Savanna were, however, never extensive within the Barombi Mbo basin, existing instead inside the forest in form of savanna patches. The climate reconstructions at Lake Barombi Mbo suggest that the artificial neural networks technique would be more reliable in this region, although the annual precipitation values are likely under-estimated through the whole sequence.
Technical note: Late Pliocene age control and composite depths at ODP Site 982, revisited
Authors: Khélifi N. , Sarnthein M. , Naafs B. D. A.
Published: January 2012

Abstract. Ocean Drilling Program (ODP) Site 982 provided a key sediment section at Rockall Plateau for reconstructing northeast Atlantic paleoceanography and monitoring benthic δ18O stratigraphy over the late Pliocene to Quaternary onset of major Northern Hemisphere glaciation. A renewed hole-specific inspection of magnetostratigraphic reversals and the addition of epibenthic δ18O records for short Pliocene sections in holes 982A, B, and C, crossing core breaks in the δ18O record published for Hole 982B, now imply a major revision of composite core depths. After tuning to the orbitally tuned reference record LR04, the new composite δ18O record results in a hiatus, where the Kaena magnetic subchron might have been lost, and in a significant age reduction for all proxy records by 130 to 20 ky over the time span 3.2–2.7 million years ago (Ma). Our study demonstrates the general significance of reliable composite-depth scales and δ18O stratigraphies in ODP sediment records for generating ocean-wide correlations in paleoceanography. The new concept of age control makes the late Pliocene trends in SST (sea surface temperature) and atmospheric pCO2 at Site 982 more consistent with various paleoclimate trends published from elsewhere in the North Atlantic.