A nonredundant ternary CAM circuit for network search engines

An optimized Ternary CAM concept is introduced for the hardware search engines in high-speed Internet routers. Our design employs w + 1 RAM bits to store a word of size w, whereas a conventional TCAM needs 2w RAM bits for the same word size. Based on this concept an 8-bit cluster is designed out of 9 SRAM bits, used as the basic building block of our Prefix-CAM (PCAM) structure. Four such clusters merge to store a 32-bit IPv4 prefix, thus, configuring a PCAM suitable for Internet packet forwarding. This PCAM module employs 48% less SRAM cells and a total of 22% less transistors plus 50% less address decode interconnects compared to a conventional TCAM, for equal storage size and equal functionality. We show that PCAM can be employed for multifield packet classification. Other factors, such as lookup speed and power dissipation, are not adversely affected.     

Effect of Deep Cryogenic Heat Treatment on the Wear Behavior of Carburized DIN 1.7131 Grade Steel

The effects of the deep cryogenic heat treatment on the microstructural changes,wear resistance,and hardness of carburized DIN 1.7131 grade steel were investigated.Results show that cryogenic heat treatment reduced the retained austenite and increased the carbide amount.In addition,after the cryogenic heat treatment,carbide shows a more uniform distribution,as compared to the conventionally treated ones.It was also clarified that the hardness of the cryogenically treated samples was improved,but the relative improvement decreases with the distance as the surface increases.It has been shown that the wear resistance improves due to the cryogenic heat treatment,and the predominant wear mechanism is a combination of the adhesive and tribo-chemical wear.     

Throughput increase in packet forwarding engines using adaptive block-selection scheme

We propose a new approach for using the block-selection scheme to increase the search throughput in a multi-block TCAM-based packet forwarding engine. While the existing methods try to counter and forcibly balance the inherent bias of the Internet traffic, our method takes advantage of it hence improving flexibility of table management and scalability towards high rates of change in traffic bias. This approach also offers higher throughput than the current art.     

Competitive Removal of Metals from Wastewater by Maghemite Nanoparticles: A Comparison Between Simulated Wastewater and AMD

Maghemite nanoparticles (γ-Fe₂O₃) produced using a recently developed, single-step method proved to be highly effective for selective removal of Cu, Ni, Mn, Cd(II), and Cr(VI) from acid mine drainage (AMD) and simulated wastewater. An average particle size of about 14 nm was estimated for the maghemite nano-particles using transmission electron microscopy. Their adsorption characteristics proved to be highly pH dependent, allowing facilitated selective adsorption of the studied metals, all of which followed the Langmuir adsorption model. In both simulated wastewater and AMD, Cr(VI) adsorption was best at 70 °C and pH = 2.6. Adsorption peaked at pH = 8.5 for Ni(II), 10 for Cd(II), 8.5 for Mn(II), and 6.5 for Cu(II).     

Effects of austenizing time on wear behavior of D6 tool steel after deep cryogenic treatment

 The effects of the prior austenite grain size in deep cryogenic treatment on the hardness, the structural change and the wear resistance of D6 tool steel were investigated. The wear resistance of the cryogenically treated samples was determined using the pin-on-disk wear machine. The microstructural characteristics and phases present in heat-treated samples were determined bye use of SEM and XRD techniques. The results showed that the retained austenite is completely transformed to martensite during the cryogenic treatment. Besides, there is an optimum grain size in which the maximum wear resistance and hardness are obtained.     

Prefix segregation scheme for a TCAM-based IP forwarding engine

A novel design for IP packet forwarding based on a new ternary content-addressable-memory configuration offers an efficient hardware solution for the longest-prefix matching problem in Internet routers. The architecture has lower update complexity, lower cost, and shorter search latency compared to the conventional TCAM structure.     

Effect of Carbide Distribution on Corrosion Behavior of the Deep Cryogenically Treated 1.2080 Steel

Deep cryogenic heat treatment is a supplementary process performed on steels specifically tool steels before tempering to improve the wear resistance and hardness of these materials. The carbide distribution changes via the electric current flow or the application of a magnetic field during the deep cryogenic heat treatment. Hence, the electric current and the magnetic field were applied to the samples to investigate the corrosion behavior of the deep cryogenically treated samples by electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The results showed that increasing the carbide percentage and achieving a more homogenous carbide distribution during the deep cryogenic heat treatment will remarkably decrease the corrosion resistance due to a decrease in the solutionized chromium atoms in the structure as well as the increase in the martensite-carbide grain boundaries (the galvanic cell areas). Moreover, it was clarified that the electric current flow and magnetic fields reduce the carbide percentage, which leads to an increase in the corrosion resistance of these samples in comparison with the deep cryogenically treated samples.