New Procedure to Obtain Specific and High Absorbent Silicon Nanotextures: Inverted Pyramids, Cubic Nano-Microholes, Spiroconical Nano-Microholes and Rhombohedral-Stared Nanosheet Bouquets (Nanobuckets)

The present work relates to a process for silicon surface texturing for preparing large-area, silicon nanotextures on silicon substrates at ambient temperature by assisted chemical etching. A novel strategy comprises of two fundamental steps (metal-assisted chemical etching (MACE) and solution post-treatment) of using the silver catalyst to obtain specific nano- or micro-textures. The strategy is based on metal-induced (Ag) local oxidation and dissolution of a silicon substrate in three different concentrations of aqueous fluoride solution with the post-treatment solution. The etching technique is dependent on the etching time and concentration of aqueous fluoride solution. Therefore, detailed scanning electron microscopy observations reveal specifics shapes as inverted pyramids, cubic nano-microholes, spiroconical nano-microholes and rhombohedral-stared nanosheet bouquets (called Nanobukets), obtained for the first time on a (100) silicon surface by this new variant of the MACE method named Double Etching Method (DEM). Silicon nanostructures are used in many nanotechnology applications such as nano-microelectronics, optoelectronics or biomedical applications. UV-Visible spectrometry measurements carried out made it possible to obtain the lowest reflectance and highest absorbance values who are 3% and 97%, respectively for the rhomboedral-stared nanosheet bouquets on (100) crystalline silicon substrates in the UV-visible-NIR wavelength range from 300 to 1200 nm.

A new three-step procedure for pancreatic head carcinoma with invasion of superior mesenteric artery

Pancreatic head carcinoma is characterized by high malignancy and a low survival rate and its mortality ranks fourth for malignant tumors with a 5-year survival rate of only 5%[1].Treatment of this cancer relies on surgical resection.However,the resection rate is only about 20%,because majority of the patients are classified as unresectable when diagnosed due to distant metastasis or

Preliminary Investigation on Establishing a New Resilient Modulus Test Approach for Reduced Size Asphalt Mixture Samples Smaller Than 100 mm Diameter

The performance evaluation of existing flexible pavements has become a priority issue for many highway maintenances engineers.To make appropriate rehabilitation and management decisions,the engineers most often rely on efficient methods for the determination of the strength of pavement layers.Resilient modulus is a very important parameter to be identified and used in pavement design.The resilient moduli of asphalt mixtures are typically measured using the indirect tension test procedure in compliance with the ASTM D4123 standard that is superseded by ASTM D7369.The standard requirement is that the prepared specimens for the tests should have a minimum height of the sample over its diameter ratio of 0.4.Generally,specimens used in the tests are either a nominal 100 mm or 150 mm in diameter with a minimum thickness over diameter ratio of 0.4.However,100 mm diameter core specimens taken from site wearing courses with thicknesses ranging from 40 mm to 50 mm most often do not fulfil the minimum ratio of 0.4 after they are trimmed for testing.Since there was no any option,part of the binder courses had to be trimmed to make up for the minimum ratio requirement.This tends to result in inaccurate assessment of the resilient modulus values of the samples.As such,a new procedure was explored to test specimens smaller than 100 mm in diameter.This may minimize the material volume requirement from the field and also for the fabrication of smaller samples in the laboratory.Based on the available thickness of wearing course or overlay,the appropriate sizes were determined.For a two-layer system a 56.3 mm diameter was deemed necessary while a 37.5 mm diameter was observed to be appropriate for a three-layer system.Such an approach for resilient modulus test using miniature specimens of 56.3 mm and 37.5 mm in diameter has a great potential for practical relevance for the industry.

A 6-b 600 MS/s SAR ADC with a new switching procedure of 2-b/stage and selflocking comparators

This paper presents a 6-b successive approximation register （SAR） ADC at the sampling rate of 600 MHz in a 65 nm CMOS process. To pursue high speed, this design employs the idea of the 2-b/stage. Based on this, the proposed structure with a new switching procedure is presented. Compared with traditional structures, it optimizes problems cause by mismatches of DACs and saves power. In addition, this paper takes advantage of dis- tributed comparator topology to improve the speed, while the proposed structure and self-locking technique lighten the kickback and offset caused by multiple comparators. The measurement results demonstrate that the signal-to- noise plus distortion ratio （SNDR） is 32.13 dB and the spurious-free dynamic range （SFDR） is 44.05 dB at 600 MS/s with 5.6 MHz input. By contrast, the SNDR/SFDR respectively drops to 28.46/39.20 dB with Nyquist input. Fabricated in a TSMC 65 nm process, the SAR ADC core occupies an area of 0.045 mm2 and consumes power of 5.01 mW on a supply voltage of 1.2 V resulting in a figure of merit of 252 fJ/conversion-step.

An integrated laboratory experiment of realistic diagenesis,perforation and sand production using a large artificial sandstone specimen

Sand production is,a challenging issue in petroleum industry,mainly associated with weak unconsolidated formations.A novel testing procedure and a new apparatus were developed to conduct an integrated experiment of diagenesis,perforation and sand production on a single large cylindrical artificial sandstone specimen,where solid and fluid pressures can be independently controlled such that realistic reservoir historical conditions can be well simulated in the laboratory.Fluid injection can be performed in both radial and vertical directions,where both single-and two-phase flows can be implemented for study of sand production behaviors at different reservoir’s maturity stages.The equipment consists of an intensive instrumentation system to monitor pressures,displacements and material states continuously.The produced sand particles were filtered and monitored in real-time for the study of time-dependent phenomena.The experimental results showed similar patterns to that observed in the field and provided valuable insight for the development of prediction methods for sand production of similar materials.