Organofunctional silanes recently have emerged as outstanding, environmentally friendly corrosion protectors for metal substrates,
compared with conventional chromate treatments. A simple immersion technique is typically used to coat the metal surface with
silane films. However, the thickness and uniformity of the films are uncontrolled in this process. This paper proposes a new
deposition technique for the silane films on the metal surface, i.e., by electrodeposition. Hydrolyzed silanes are water-soluble,
ionized molecules, so they can be deposited on metals by electrodeposition. Various combinations of silane mixtures were tested
at different voltages, pH values, bath concentrations, and exposure times on panels of alloy aluminum and mirror-polished
ferro-plate. The surface structure was characterized by scanning electron microscopy (SEM) and ellipsometry. The resistance
of the film to corrosion was investigated by direct current (DC) polarization and electrochemical impedance spectroscopy (EIS)
techniques. Electrodeposition results in a more organized and uniform film with fewer pores, compared with immersed or dipped
films.
This paper was presented at the 2nd International Surface Engineering Congress sponsored by ASM International, on September
15–17, 2003, in Indianapolis, Indiana, and appears on pp. 320–26 of the Proceedings. 相似文献
Attenuated total reflectance–Fourier transform infrared spectroscopy, along with chemometrics, were used to detect and quantify soya bean oil (SO) and sugar (CS) adulteration in milk. Bovine milk was artificially adulterated with SO (0.2–2.0%; v/v) and CS (1–10%; w/v) separately. Spectra revealed significant differences in specific wavenumber regions (SO: 1450–1250 cm?1; CS: 1200–900 cm?1). Soya bean oil adulteration was best predicted in wavenumber range of 1262–1164 cm?1, using partial least square regression (coefficient of determination (R2: 0.90 and 0.88 for calibration and validation, respectively). Common sugar adulteration was best predicted in wavenumber range of 1010–910 cm?1 (R2: 0.99 for calibration and validation) using partial least square. 相似文献
Five commonly consumed pulses, Mah (Vigna mungo), Green mung (Vigna radiata), Arhar (Cajanas cajan), Masur (Lens esculantus), and Moth (Vigna aconitifolia), were studied for their total phenolic content and antioxidant activity after germination (12 and 24 h) and pressure cooking. Arhar had the highest total phenolic content (6.71 mg ferulic acid/g flour) whereas Moth had the least (1.54 mg/g). All pulses, except Moth, showed a significant decrease in total phenolic content after germination. The antioxidant activity of the pulses varied from 10.61 to 36.38% (DPPH radical scavenging activity), which significantly decreased with germination in all pulses except Moth. The total phenolic content highly correlated with the antioxidant activity in the pulses. Cooking lowered the total phenolic content by 10–45% and antioxidant activity by 27–68% in the control and germinated pulses. 相似文献
An indigenous and simple electronic control system for Langmuir-Blodgett (LB) film deposition set-up has been developed. This
set-up consists of a microstepping circuit to drive the stepper motors with precision and smooth motion, essential for controlled
movement of the barriers and substrate in the LB set-up. Linear variable differential transformer (LVDT)-based displacement
measuring device has been developed and used to measure the surface pressure of the monolayer material spread on the water
surface. A control program is written which incorporates all operational modes required to drive the set-up and to acquire
the datain situ using a set of user-friendly commands. This control set-up has been successfully used to plot the pressure-area isotherm
of various amphiphilic compounds such as ferric stearate, zinc arachidate etc. and for deposition of ordered LB films of ferric
stearate. 相似文献
Given the ubiquity of handwriting and mathematical content in human transactions, machine recognition of handwritten mathematical text and symbols has become a domain of great practical scope and significance. Recognition of mathematical expression (ME) has remained a challenging and emerging research domain, with mathematical symbol recognition (MSR) as a requisite step in the entire recognition process. Many variations in writing styles and existing dissimilarities among the wide range of symbols and recurring characters make the recognition tasks strenuous even for Optical Character Recognition. The past decade has witnessed the emergence of recognition techniques and the peaking interest of several researchers in this evolving domain. In light of the current research status associated with recognizing handwritten math symbols, a systematic review of the literature seems timely. This article seeks to provide a complete systematic analysis of recognition techniques, models, datasets, sub-stages, accuracy metrics, and accuracy details in an extracted form as described in the literature. A systematic literature review conducted in this study includes pragmatic studies until the year 2021, and the analysis reveals Support Vector Machine (SVM) to be the most dominating recognition technique and symbol recognition rate to be most frequently deployed accuracy measure and other interesting results in terms of segmentation, feature extraction and datasets involved are vividly represented. The statistics of mathematical symbols-related papers are shown, and open problems are identified for more advanced research. Our study focused on the key points of earlier research, present work, and the future direction of MSR.
Nanocrystalline lanthanum hexaboride (LaB(6)) films have been deposited on molybdenum foil by the pulsed laser deposition (PLD) technique. The as-deposited films were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The XRD pattern shows the cubic crystallinity of the LaB(6) film. The AFM studies reveal that the conical shaped LaB(6) nanostructures have height 60?nm, base 800?nm, and a typical radius of curvature ~20?nm. A comparison of force and in situ current imaging AFM studies reveals that current contrast does not originate from the surface topography of the LaB(6) film. Field emission studies have been performed in the planar diode configuration. A current density of 4.4 × 10(-2)?A?cm(-2) is drawn from the actual emitting area. The Fowler-Nordheim plot is found to be linear, in accordance with the quantum mechanical tunneling phenomenon. The field enhancement factor is estimated to be 3585, indicating that the field emission is from LaB(6) nanocrystallites present on the emitter surface, as confirmed by the AFM. The emission current-time plots show current stability to the extent of 5% fluctuation about the average current over a period of 3?h. 相似文献