Repairing peripheral nerve injury using tissue engineering techniques

Each year approximately 360,000 people in the United States suffer a peripheral nerve injury （PNI）, which is a leading source of lifelong disability （Kelsey et al., 1997; Noble et al., 1998）. The most frequent cause of PNIs is motor vehicle accidents, while gunshot wounds, stabbings, and birth trauma are also common factors. Patients suffering from disabilities as a result of their PNIs are also burdensome to the healthcare system, with aver- age hospital stays of 28 days each year （Kelsey et al., 1997; Noble et al., 1998）.

A Comparative Study of Dispersion Characteristics Determination of a Trapezoidally Corrugated Slow Wave Structure Using Different Techniques

The linear dispersion relation of a trapezoidally corrugated slow wave structure （TCSWS） is analyzed and presented. The size parameters of the TCSWS are chosen in such a way that they operate in the x-band frequency range. The dispersion relation is solved by utilizing the Rayleigh-Fourier method by expressing the radial function in terms of the Fourier series. A highly accurate synthetic technique is also applied to determine the complete dispersion characteristics from experimentally measured resonances （cold test）. Periodic structures resonate at specific frequencies when the terminals are shorted numerical calculation, synthetic technique and cold appropriately. The dispersion characteristics obtained from test are compared, and an excellent agreement is achieved.

Satellite Data Reduction Using Entropy-preserved Image Compression Technique

In this paper, three techniques, line run coding, quadtree DF (Depth-First) representation and H coding for compressing classified satellite cloud images with no distortion are presented. In these three codings, the first two were invented by other persons and the third one, by ourselves. As a result, the comparison among their compression rates is. given at the end of this paper. Further application of these image compression technique to satellite data and other meteorological data looks promising.

Atmospheric NO_2 Concentration Measurements Using Differential Absorption Lidar Technique

Using the Differential Absorption Lidar (DIAL) technique, two types of approaches, namely, reflection from retroreflector / topographic target and backscatter from atmosphere, are available for studying remotely the atmospheric NO, concentration. The Argon ion lidar system at the Indian Institute of Tropical Meteorology (IITM), Pune, India has been used for the measurements by following both the path-averaged and range-resolved approaches. For the former, a topographic target (hill) is used for determining path-averaged surface concentration. In the latter, spectral properties of atmospheric attenuation is used for making range-resolved measurements in the surface layer. The results of the observations collected by following both approaches are presented. The average surface NO2 concentration was found to vary between 0.01 and 0.105 ppm and the range-resolved measurements exhibited higher values suggesting treatment of the lidar data for scattering and extinction effects due to atmospheric aerosols and air molecules, and atmospheric turbulence. Certain modifications that are suggested to the experimental set-up, data acquisition and analysis to improve the measurements are briefly described.

Fabrication of Grain-oriented (Bi,Pb)_2Sr_2Ca_2Cu_3O_x Superconducting Tapes Using Magnetic Field and Vibration Technique

Highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes have been fabricated by means of magnetic-field and vibration technique. This method is an effective way of improving the degree of grain alignment and density of oxide core in tapes after heat treatment and pressing cycles.Jc of above 20% was increased than that without treatment.

SEPARATION OF OVERLAPPING INCISIONS OF A.C.OSCILLOPOLAROGRAM USING KALMAN'S FILTER TECHNIQUE

Kalman's Filter Technique for the separation of overlapping incisions of an a.c.oscillopolarogram is presented,the experimental verifications were carried out in various systems with the ions of Pb^(2+),Tl^+,In^(3+)and Cd^(2+).The results showed that the concentration of the depolarizer can be determined directly and easily with this technique in the presence of interference elements.

TEST STUDY OF DETECTING OIL AND GAS BY USING REMOTE SENSING TECHNIQUE

Ⅰ The Indexes of Detecting Oil and Gas Resources The deeply buried reservoir which in a dynamic equilibrium state has a great pressure inside, and between it and earth surface there is a great difference of pressure. Therefore the hydrocarbon must spread and move vertically to the surface along the pressure gradient orientation. Hydrocarbons in the reservoir along some small rifts, cracks, joints and cleavages penetrate the overlying strata and seepage onto the surface. Thus the hydrocarbons become unvisble oil and gas signs. This process is called the phenomena of hydrocarbon microseepage of reservoir. Hydrocarbons microseepage in the process

Lorentz Force Electrical Impedance Detection Using Step Frequency Technique

Lorentz force electrical impedance tomography（LFEIT） inherits the merit of high resolution by ultrasound stimulation and the merit of high contrast through electromagnetic field detection. To reduce the instantaneous peak power of the stimulating signal to the transducer, the sinusoidal pulse and step-frequency technique is investigated in LFEIT. The theory of application of step-frequency technique in LFEIT is formulated with the direct demodulation method and the in-phase quadrature demodulation method. Compared with the in-phase quadrature demodulation method, the direct demodulation method has simple experimental setup but could only detect half of the range. Experiments carried out with copper foils confirmed that LFEIT using the step-frequency technique could detect the electrical conductivity variations precisely, which suggests an alternative method of realization of LFEIT.

The Potential of Activated Carbon in the Treatment of Water for Human Consumption, a Study of the State of the Art and Its Techniques Used for Its Development

This review article addresses the use of biological activated carbon in water treatment and its techniques for its development, with the premise of analyzing the potential of Activated Carbon (AC) in the treatment of water for human consumption. For this end, it aims to identify the techniques used for the production of AC, use and its benefits, production from vegetable waste for water treatment. Activated carbon has the ability to selectively collect gases, liquids and impurities inside its pores, which is the reason it is widely used in filtration systems and for that the treatment of water, the coal fulfills the function of adsorbent, retaining in its pores certain types of impurities: large particles that cause undesirable color, taste or odor in the water. In the treatment of effluents, coal is used for clarification, deodorization and purification of effluents.

Use of biologically synthesized antimicrobial nanoparticles for improving peritoneal dialysis technique： a translational research perspective

Peritoneal dialysis （PD） is a well-established renal replacement therapy （RRT） for end-stage renal failure （ESRF） and offers certain clear advantages over hemodialysis. However, PD is often associated with a high risk of infection of the intraperitoneal cavity, subcutaneous tunnel and catheter exit site, which may subsequently form microbial biofilms.

A new differential absorption lidar for NO_2 measurements using Raman-shifted technique

Based on Raman-shifted wavelengths of D2 and CHr pumped by third harmonic of Nd:YAG laser, a differential absorption lidar was presented in this paper and had been constructed for probing environmental NO2 concentration. NO2 experimental measurements were carried out at Anhui Institute of Optics and Fine Mechanics in Hefei. Some NO2 measurement results were given and discussed.

Arbitrary and reconfigurable optical vortex generation:a high-efficiency technique using director-varying liquid crystal fork gratings

A high-efficiency technique for optical vortex(OV) generation is proposed and demonstrated. The technique is based on liquid crystal fork gratings with space-variant azimuthal orientations, which are locally controlled via polarization-sensitive alignment layers. Thanks to the optical rewritability of the alignment agent and the dynamic image generation of the digital micro-mirror device, fork gratings can be instantly and arbitrarily reconfigured.Corresponding optical vortices carrying arbitrary azimuthal and radial indices are demonstrated with a conversion efficiency of 98.5%, exhibiting features of polarization control and electrical switching. The technique may pave a bright road toward OV generation, manipulation, and detection.

Measurement of the echo reduction for underwater acoustic passive materials by using the time reversal technique

A measuring method of the echo reduction of passive materials by using the time reversal（TR） technique is presented. To measure the echo reduction of a sample with this approach, the received signals are firstly focused according to the TR theory. Then, the sample is removed and the TR processing is again employed to realize the focus of the received signal.Finally, the echo reduction of the sample is evaluated with these focusing signals. Besides, to calibrate the measured echo reduction via the TR technique, a standard sample is employed to measure a constant coefficient that only depends on the measurement environment. An aluminum plate sample and a steel plate sample with the same size of 1.1 mxl.O m x0.005 m axe tested in a wave guide tank. The experimental results show that the calibrated values are well consistent with theoretical results under the free field at the measured frequency range of0.5-20 kHz. The relative errors of all the measured values are less than 10% and the values of the expanded uncertainty are less than 1.5 dB. The TR processing focuses the energy in spatial domain and temporal domain, so it can be used to measure the echo reduction of passive materials in the environments with reflections induced by boundaries and low frequency sources.

Characterization of planar photonic crystals using surface coupling techniques at large wavelengths

We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectroscope. At large wavelengths, devices behave as homogeneous isotropic materials defined by an effective filling factor. The experimental results related to the PhC limited dimensions confirm this characterization.

Novel Technique for All-Optical Clock Extraction Using Fiber Bragg Gratings

We demonstrate a simple passive technique, using phase shifted fibre Bragg gratings, for extraction of optical clock signals from RZ optical data signals. The generation of an optical clock signal at 12.5 GHz from a 12.5 Gbs RZ optical data stream is experimentally demonstrated with simulation of optical clock extraction at 10 GHz from 40 Gbs OTDM data streams.

Modeling of the nonlinear acoustic field generated from a phased array using Gaussian superposition technique

The nonlinearity has significant effect on the ultrasonic therapy using phased ar- rays. A numerical approach is developed to calculate the nonlinear sound field generated from a phased array based on the Gaussian superposition technique. The parameters of the phased array elements are first estimated from the focal parameters using the inverse matrix algorithm; Then the elements are expressed as a set of Gaussian functions; Finally, the nonlinear sound field can be calculated using the Gaussian superposition technique. In the numerical simulation, a 64~ 1 phased array is used as the transmitter. In the linear case, the difference between the results of the Gaussian superposition technique and the Fresnel integral is less than 0.5%, which verifies the feasibility of the approach. In the nonlinear case, the nonlinear fields of single-focus modes and double-focus modes are calculated. The results reveal that the nonlinear effects can improve the focusing performance, and the nonlinear effects are related with the source pressures and the excitation frequencies.

On the QoS for ATM Networks Using a New Buffer Utilization Technique

A buffer sharing scheme need to meet many competing objectives like robustness to changes in traffic conditions, fairness, efficiency, implementation simplicity, etc. Of the existing techniques, Push Out (PO) is optimum in terms of overall cell loss performance, but its delay performance is worse than that of all other methods for the multiple space priority. Another scheme named Dynamic Threshold (DT) is robust and adaptive which has good delay performance. A hybrid technique named Dynamic Threshold wi...

An optical sensor for hydrogen sulfide detection in open path using WMS-2f/1f technique

An optical hydrogen sulfide(H_2S) sensor based on wavelength modulation spectroscopy with the second harmonic(2f) corrected by the first harmonic(1f) signal(WMS-2f/1f) is developed using a distributed feedback(DFB) laser emitting at 1.578 μm and a homemade gas cell with 1-m-long optical path length. The novel sensor is constructed by an electrical cabinet and an optical reflecting and receiving end. The DFB laser is employed for targeting a strong H_2S line at 6 336.62 cm^(-1) in the fundamental absorption band of H_2S. The sensor performance, including the minimum detection limit and the stability, can be improved by reducing the laser intensity drift and common mode noise by means of the WMS-2f/1f technique. The experimental results indicate that the linearity and response time of the sensor are 0.999 26 and 6 s(in concentration range of 15.2—45.6 mg/m^3), respectively. The maximum relative deviation for continuous detection(60 min) of 30.4 mg/m^3 H_2S is 0.48% and the minimum detection limit obtained by Allan variance is 79 μg/m^3 with optimal integration time of 32 s. The optical H_2S sensor can be applied to environmental monitoring and industrial production, and it has significance for real-time online detection in many fields.