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Coiled tubing (CT) has been widely used for oil and gas exploitation, however corrosion of CT under high pressure and high temperature (HPHT) environment was often reported, also corrosion induced failures of CT welds were often observed to occur during service. Corrosion related behaviors of CT welds are not clear. Therefore, a study of the corrosion resistance of CT welds under HPHT environment is carried out. In order to efficiently evaluate the corrosion resistance of welds, some test samples were obtained by linear cutting out of a CT110 in service on the site. The water samples from gas field were used as the test reagent to simulate the actual corrosive medium. Based on the results of weight loss test under HPHT corrosive environment and tensile test under room conditions, the corrosion sensitivities of the welding seam and base material under various temperatures and partial pressures of CO2 as well as the mechanical properties of the corroded CT were compared and evaluated quantitatively, the corrosion morphologies and material products of the test samples were analyzed by scanning electron microscope (SEM). The test results showed that the corrosion rates of the welding seam in a HPHT caldron were 1.7, 2.0 and 1.2 times of the base metal’s when the total pressure is 4MPa, and the temperature is 30°C, 60°C and 90°C, respectively. The corrosion rates of the welding seam is 2.0, 2.1 and 2.0 times of the base metal’s when the partial pressure of CO2 is 0.1MPa, 0.2MPa and 0.3MPa, respectively. The yield strength of the weld seam after corrosion test was found to be reduced by 4.8% (the yield strength of the base metal was reduced by 4.0%) and its tensile strength was reduced by 8.2% (the base metal was reduced by 7.1%). This indicates that CT weld seam is more susceptible to corrosion than CT base material under service condition.

In this report, ZnO nanoparticles embedded cellulose acetate (CA) fibrous membrane with multifunctional properties have been prepared through electrospinning method. The morphology of the electrospun composite membrane was analyzed by scanning electron microscope (SEM). It was found that the polymer concentration in the solution has a significant effect on the morphology of the fibers. The optical property of the sample was tested using photo luminescence (PL) spectra. There is no significant change in the emission features of cellulose acetate with the addition of ZnO. The anti-bacterial property of the sample was studied using disk diffusion method. The wettability of the pure and composite fibrous membrane was also studied by measuring the contact angle of water on the membrane. It was observed that the embedded ZnO in the CA was responsible for the hydrophobic nature of the surface. � 2013 Elsevier Ltd. All rights reserved.

We describe low-cost fabrication, size control and characterization of borosilicate glass nanopores for sensing of single biomolecules. Nanopores with pore diameters down to ∼100nm were fabricated in borosilicate glass capillaries using table-top carbon-di-oxide laser assisted glass capillary puller. We further achieve controlled reduction in pore diameter by sculpting of glass capillaries under constant electron beam exposure of a scanning electron microscope. We confirm successful fabrication of sub-10nm pores by SEM imaging. We further show electrical characterization and low-noise behavior of these borosilicate nanopores and compare various geometries of pulled conical glass nanopores. We show, for the first time, a comprehensive characterization of glass nanopore conductance across a wide range (1M-1μM) of salt conditions. We show the conditions for the conical pore conductance model to fit to this extended salt range. We also experimentally show, for the first time, the role of buffer conditions in this wide salt range measurement. Finally, we demonstrate single molecule sensing capabilities of these devices with real-time translocation experiments of individual λ-DNA molecules. We observe distinct current blockage signatures of single and multiply folded DNA molecules as they undergo voltage-driven translocation through the glass nanopores. We find increased signal to noise for single molecule detection for higher trans-nanopore driving voltages.

Polycrystalline MgCuZn ferrites with chemical formula Mg 0.50-x Cu x Zn 0.50 Fe 2 O 4 ( x = 0.00, 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) were prepared by microwave sintering method. These powders were calcined, compacted and sintered at 950 °C for 30 min. Structural, microstructural and elemental analyses were carried out using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectrometry (EDS), respectively. The lattice parameter is found to increase with increasing copper content. A remarkable densification is observed with the addition of Cu ions in the ferrites. The sintered ferrite was characterized for initial permeability, dielectric constant and dielectric loss tangent and ac conductivity measurements. The temperature variation of the initial permeability of these samples was carried out from 30 °C to 200 °C. The dielectric constant, dielectric loss tangent and ac conductivity have been measured in the frequency range of 100 Hz to 1 MHz. Initial permeability and dielectric constant were found to increase and dielectric loss decreased with Cu substitution for Mg, up to x = 0.20. The ferrite powder prepared is suitable for the application in multilayer chip inductor due to its low-temperature sinterability, good magnetic properties and low loss at high frequency.

Scanning Electron Microscope (SEM) as one of the major research and industrial equipment for imaging of micro-scale samples and surfaces has gained extensive attention from its emerge. However, the acquired micrographs still remain two-dimensional (2D). In the current work a novel and highly accurate approach is proposed to recover the hidden third-dimension by use of multi-view image acquisition of the microscopic samples combined with pre/post-processing steps including sparse feature-based stereo rectification, nonlocal-based optical flow estimation for dense matching and finally depth estimation. Employing the proposed approach, three-dimensional (3D) reconstructions of highly complex microscopic samples were achieved to facilitate the interpretation of topology and geometry of surface/shape attributes of the samples. As a byproduct of the proposed approach, high-definition 3D printed models of the samples can be generated as a tangible means of physical understanding. Extensive comparisons with the state-of-the-art reveal the strength and superiority of the proposed method in uncovering the details of the highly complex microscopic samples.

The objective of this study was to improve the stability and water-solubility of patchouli alcohol by complexing with β-cyclodextrin (β-CD). The interactions between patchouli alcohol and β-CD were characterized by differential scanning calorimetry (DSC), Fourier transformation-infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and Scanning electron microscope (SEM), respectively. According to molecular modeling method, the enthalpy formation of host-guest illustrated the predominant configuration and the lowest value ΔbGo was -10.8174±1.9235 kcal/mol, suggesting the complex could reduce the energy of the system. The characterization analysis confirmed the formation of PA-CD inclusion complex, and the results indicated the advantage of the inclusion complex in stability and dissolution rates. These results identified PA-CD inclusion complex an effective way for the storage of PA, and better inclusion method still needed to be studied.

Intrinsic stresses in bondpads may lead to early failure of IC's. In order to determine the intrinsic stresses in semiconductor structures, a new procedure is set up. This procedure is a combined experimental/numerical approach which consists of the following steps: First, a conductive gold layer (20 nm thickness) is deposited on the power line surface; subsequently markers (small holes) for Digital Image Correlation (DIC) purposes are added using a focused ion beam (FIB). Next, a scanning electron microscope (SEM) is used to image the original ('before') surface. The FIB is then used to mill a slot into the surface to release the intrinsic stresses, which results in contraction of the surface. Finally, a SEM image is made of the contracted ('after') surface. DIC is used to determine in-plane displacements due to FIB milling. DIC performance was verified by the traditional strain gauge approach. An inverse Finite Element (FE) modelling approach is used to determine the before mentioned stresses. The slot displacements found with DIC are inserted into an FE model of the product. Stresses which now emerge from closing the (virtual) FIB slot correspond to the intrinsic stresses which were originally present in the product. Favorable positions for FIB milling are near the edge of the structure and displacements are determined to be in the nanometer range. This indicates a presence of substantial (50-250 MPa) compressive stresses. Displacements near the center of the structure appear to be smaller than DIC resolution. ©2010 IEEE.

We have developed a scanning tunneling microscope capable of detecting high frequency (1.8–12.5 MHz) acoustic waves. Acoustic pulses arriving at a conducting surface are detected as a high frequency perturbation of the tunneling current. Near and below the rolloff frequency of the current to voltage amplifier, the instantaneous displacement of the surface can be reconstructed. For higher frequencies, the nonlinear (rectifying) properties of the tunneling behavior allow the detection of the envelope (and hence the time of arrival and total amplitude) of the acoustic burst. The technique’s sensitivity is comparable to that of optical detection schemes but offers much better lateral resolution.

International audience; Nanometric spheres of an azopolymer are obtained by micellization from a solution. We observe photoinduced deformation of the individual nanospheres under white light illumination. The diameter expands up to 35% parallel to the substrate surface. The magnitude of the force that is necessary to produce the same effect is estimated.

Low power transferred arc plasma (TAP) processing is a simple and cost-effective method for large amount of ceramic processing in a very short period of time duration. In the present work, lanthanum zirconate (La2Zr2O7) was synthesized by transferred arc plasma (TAP) melting technique followed by mechanical milling. The mixture of La2O3 and ZrO2 powders with 1:2 mole ratio were ball milled for four hours and melted for three minutes in transferred arc plasma torch at 10 kW input power with 10 lpm of argon flow rate. The phase and microstructure formation of the processed samples were analyzed by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) images.