Micro-channel fabrication on silicon wafer (100) using Rotary Ultrasonic Machining

Silicon - In the Present work Rotary Ultrasonic machining is used for fabrication of micro channel on Silicon wafer. Silicon wafer possesses a plethora of applications, from their use in...     

Performance Enhancement of 3 × 20 Gbit/s MDM-Based OFDM-FSO System

The investigation of high-speed optical orthogonal-frequency division multiplexed-free space optical system using mode division multiplexing of three spiral phased Hermite Gaussian modes has been discussed in this article. The investigation of the system is reported by considering the effect of beam divergence and weather conditions. Square root module technique has been applied at the receiver side and the system performance has been analyzed by using the enhanced detection technique. Results indicate augmentation in the range limit of the system along with improvements in terms of signal quality.

     

Mathematical models of the column flotation process a review

Mathematical modelling is a valuable quantitative instrument, which is being effectively employed to the column flotation process in order to predict its metallurgical performance. This paper presents an up-to-date assessment of the various mathematical models for column flotation currently available under the categories of kinetic models and non-kinetic models and also identifies a number of associated shortcomings.     

用一个时钟在FPGA中计算直方图

直方图对数字数据的分析通常是一种有用的工具。不过,要从一个直方图获得可靠的结果,必须获得大量数据,通常是要10万到100万个点。如果需要分析一个ADC的数字输出,可以采用一片FPGA(图1)。图中显示了直方图、RAM和脉冲发生器部分,用于捕捉和显示基于     

New poly(arylene ether)s containing phthalimidine group in the main chain

Five new poly(arylene ether)s containing phthalimidine group in the main chain and pendent trifluoromethyl group have been prepared by the reaction of 4,4′‐(bis‐4‐fluoro‐3‐trifluoromethylphenyl)benzene (BTF) with bisphenols. Different molar ratios of N‐phenyl‐3,3‐bis(4‐hydroxyphenyl)phthalimidine (PA) and 4,4′‐isopropylidenediphenol (BPA) have been used to generate different copolymers. The polymers obtained by step growth polymerization exhibited weight‐average molecular weight upto 134,000 g/mol with a polydispersity index of 2.1–2.4. The homopolymer from BTF and PA showed very high glass transition temperature of 258°C and outstanding thermal stability upto 536°C for 5% weight loss under nitrogen. The polymers were soluble in a wide range of organic solvents. Transparent thin films of these polymers exhibited tensile strengths upto 65 MPa and elongation at break upto 45% depending on the exact repeat unit structures. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Relaxing the constant molar overflow assumption in distillation optimization

The constant molar overflow (CMO) framework, while useful for shortcut distillation models, assumes that all components have the same latent heats of vaporization. A simple transformation, from molar flows to latent-heat flows, allows shortcut models to retain the mathematical simplicity of the CMO framework while accounting for different latent heats, resulting in the constant heat transport (CHT) framework for adiabatic distillation columns. Although several past works have already proposed this transformation in the literature, it has not been well utilized in recent times. In this article, we show the utility of this transformation in upgrading various applications such as identifying energy-efficient multicomponent distillation configurations based on heat duty rather than surrogate vapor flow. The method transforms the $V^{\min }$ diagram to a $Q^{\min }$ diagram. Furthermore, we derive new and insightful analytical results in distillation, such as cumulative latent-heat stage fractions having monotonic profiles within a distillation column under the CHT framework.