Signal Integrity: Fault Modeling and Testing in High-Speed SoCs

As we approach 100 nm technology the interconnect issues are becoming one of the main concerns in the testing of gigahertz system-on-chips. Voltage distortion (noise) and delay violations (skew) contribute to the signal integrity loss and ultimately functional error, performance degradation and reliability problems. In this paper, we first define a model for integrity faults on the high-speed interconnects. Then, we present a BIST-based test methodology that includes two special cells to detect and measure noise and skew occurring on the interconnects of the gigahertz system-on-chips. Using an inexpensive test architecture the integrity information accumulated by these special cells can be scanned out for final test and reliability analysis.     

Optimization of triangular microchannel heat sinks using constructal theory

The present paper examines the optimization of triangular microchannel heat sinks. The impact of volume fraction of solid material and pressure drop on the maximum temperature of the microchannel heat sinks are investigated and their optimum operating conditions are compared. From the results, it is seen that increasing the side angle of the triangular microchannel, improves its performance. Furthermore, there is an appropriate agreement between the analytical and numerical results. Finally, the effect of degrees of freedom on the performance of microchannels is investigated. To accomplish this end, the triangular microchannels with the side angle of 60 degree have been chosen as it has the best performance compared to other microchannels. It is observed that the minimized maximum temperatures of optimized microchannel heat sinks with three degrees of freedom are 10% lower than the ones with two degrees of freedom.

     

Modeling of Mechanical Characteristics in Hot Deformation of 4130 Steel

In this investigation, hot compression tests were performed at 900 °C ? 1100 °C and strain rate of 0.001 ? 0.1 s^?1 to study hot deformation behavior and flow stress model of 4130 steel. Based on the classical stress–dislocation relations and the kinematics of the dynamic recrystallization, the flow stress constitutive equations of the work hardening‐dynamical recovery period and dynamical recrystallization period were established for 4130 steel, respectively. The validity of the model was demonstrated by comparing the experimental data with the numerical results. The agreement of this comparison is quite reasonable.     

Biologically‐synthesised ZnO/CuO/Ag nanocomposite using propolis extract and coated on the gauze for wound healing applications

Wound healing has long been recognised as a major clinical challenge for which stablishing more effective wound therapies is necessary. The generation of metallic nanocomposites using biological compounds is emerging as a new promising strategy for this purpose. In this study, four metallic nanoparticles (NPs) with propolis extract (Ext) and one without propolis including ZnO/Ext, ZnO/Ag/Ext, ZnO/CuO/Ext, ZnO/Ag/CuO/Ext and ZnO/W were prepared by microwave method and assessed for their wound healing activity on excision experimental model of wounds in rats. The developed nanocomposites have been characterised by physico‐chemical methods such as X‐ray diffraction, scanning electron microscopy, diffuse reflectance UV–vis spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and Brunauer–Emmett–Teller analyses. The wounded animals treated with the NPs/Ext in five groups for 18 days. Every 6 days, for measuring wound closure rate, three samples of each group were examined for histopathological analysis. The prepared tissue sections were investigated by haematoxylin and Eosin stainings for the formation of epidermis, dermis and muscular and Masson''s trichrome staining for the formation of collagen fibres. These findings toughly support the probability of using this new ZnO/Ag/Ext materials dressing for a wound care performance with significant effect compared to other NPs.Inspec keywords: nanomedicine, X‐ray diffraction, II‐VI semiconductors, visible spectra, ultraviolet spectra, nanocomposites, biomedical materials, proteins, wounds, nanoparticles, scanning electron microscopy, nanofabrication, skin, zinc compounds, silver, antibacterial activity, Fourier transform infrared spectra, copper compounds, molecular biophysicsOther keywords: propolis, wound healing applications, effective wound, metallic nanocomposites, biological compounds, metallic nanoparticles, microwave method, wound healing activity, physico‐chemical methods, Fourier transform infrared spectroscopy, diffuse reflectance UV‐vis spectroscopy, Brunauer‐Emmett‐Teller analyses, wounded animals, wound closure rate, wound care performance, histopathological analysis, scanning electron microscopy, X‐ray diffraction, thermogravimetric analysis, haematoxylin, Eosin stainings, Masson trichrome, epidermis, muscular trichrome, collagen fibres, time 18.0 d, time 6.0 d, ZnO‐CuO‐Ag     

Hot Deformation Characteristics of 34CrMo4 Steel

The 34CrMo4(AISI 4130)steel is extensively utilized in the compressed natural gas cylinders.Due to the importance of thermomechanical processing in the production of these cylinders,the dynamic recrystallization(DRX)characteristics of 34CrMo4 steel were investigated.The effect of hot deformation parameters such as temperature and strain rate on the dynamic restoration processes of a 34CrMo4 alloy was studied.Hot compression tests were performed in the temperature range of 900 to 1100 ℃ and the strain rate r...     

Incorporation of graphene oxide and calcium phosphate in the PCL/PHBV core-shell nanofibers as bone tissue scaffold

Bone tissue scaffolds should have both desired mechanical stability and cell activities including biocompatibility, cell differentiation, and maturation. Also, suitable mineralization is another key factor for these materials. Hence, in current work, in order to achieve a scaffold with desired mechanical and bioactivity properties, core-shell nanofibers based on the polycaprolactone and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with different concentration of graphene oxide (GO) (0.5, 1, and 1.5 wt%) and calcium phosphate (CP) (1 and 3 wt%) were prepared to utilize as bone scaffold. Microstructure of nanofibers observed by field emission scanning electron microscope (FE-SEM) and results exhibited that the most of nanofibers had 270–500 nm diameter. Attenuated total reflectance Fourier transform infrared spectroscopy and energy dispersive X-ray evaluations verified appearance of GO and CP into the electrospun scaffolds (ES). Transmission electron microscopy analysis endorsed core-shell structure of nanofibers. X-ray diffraction study moreover determination of semicrystalline structure, verified presence of GO and CaPO₄ into the nanofibers. Water contact angle demonstrates that, ES2 and ES3 situated in suitable domain of hydrophilicity. Tensile analysis determined that, ES2, ES3, and ES4 had the highest mechanical properties for use as bone scaffold. Cell viability assessment confirmed biocompatibility of scaffold during 7 days. Alkaline phosphatase and alizarin red staining exhibited maturating and differentiating of osteocytes after 21 days seeding on the scaffolds.     

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.     

Synthesis and characterization of a novel pH-responsive nanocomposite hydrogel based on chitosan for targeted drug release

Over the last decade, nanocomposite hydrogels have been provided a new approach for the biomedical field. In this work, a novel pH-responsive nanocomposite hydrogel was fabricated using simultaneous in situ formation of magnetite iron oxide nanoparticles and hydrogel networks of poly(acrylic acid) grafted onto chitosan. The effects of various types of precursor molecules, pH, salt, and loading pressure were examined on the swelling properties of resulting nanocomposite hydrogels. The synthesized nanocomposite hydrogel was well characterized using different instruments. In vitro drug releasing behavior of doxorubicin was studied at pH 5.4 and 7.4. The drug release mechanism was investigated through different kinetic models. These experimental results open a new opportunity to make pH-responsive nanocomposite hydrogel devices for controlled delivery of drug.