Half-Rate Duobinary Transmitter Architecture for Chip-to-Chip Interconnect Applications

For a high speed duobinary transmitter clock frequency defines the transmission limit. A conventional duobinary transmitter needs a clock frequency equal to the data rate. In this work we propose a duobinary transmitter that uses a clock frequency half of the output data rate and hence achieves double the transmission rate for a given clock frequency as compared to a conventional duobinary transmitter. In the proposed transmitter the duobinary precoder is integrated into the last stage of a tree structured serializer to combine two NRZ data streams at half the transmission data rate. Two modes for the precoder have been incorporated into the design. The first mode is applicable for data transmission over copper whereas the second mode is suitable for wavelength division multiplexed optical transmission. A DLL based clock multiplier unit is employed to produce the high frequency clock with 50% duty cycle needed for the precoding operation. It incorporates a clock generation logic with integrated duty cycle control. A charge pump with dynamic current matching and a high resolution PFD are employed to reduce static phase error in locking and hence achieves improved jitter performance. A new delay cell along with automatic mode selection is proposed. To cover a wide range of data rate, the DLL is designed for a wide locking range and maintains almost 50% duty cycle. The design is implemented in 1.8-V, 0.18 μm Digital CMOS technology with an f _T of 27 GHz. Simulations shows that, the duobinary transmitter circuit works up-to 10 Gb/s and consumes 60 mW of power.     

Synthesis and characterization of organo‐soluble poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains

Poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains were synthesized by polycondensation of each of the two bisphenol monomers viz, 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane and 1,1‐bis(4‐hydroxyphenyl)‐3‐pentadecyl cyclohexane with activated aromatic dihalides namely, 4,4′‐difluorobenzophenone, and 1,3‐bis(4‐fluorobenzoyl)benzene in a solvent mixture of N,N‐dimethylacetamide and toluene, in the presence of anhydrous potassium carbonate. Polymers were isolated as white fibrous materials with inherent viscosities and number average molecular weights in the range 0.70–1.27 dL g^?1 and 76,620–1,36,720, respectively. Poly(ether ether ketone)s and poly(ether ether ketone ketone)s were found to be soluble at room temperature in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, and pyridine and could be cast into tough, transparent, and flexible films from their solutions in chloroform. Wide angle X‐ray diffraction patterns exhibited a broad halo at around 2θ = ～ 19° indicating that the polymers containing pentadecyl chains were amorphous in nature. In the small‐angle region, diffuse reflections of a typically layered structures resulting from the packing of pentadecyl side chains were observed. The temperature at 10% weight loss, obtained from TG curves, for poly(ether ether ketone)s and poly(ether ether ketone ketone)s were in the range 416–459°C, indicating their good thermal stability. A substantial drop in glass transition temperatures (68–78°C) was observed for poly(ether ether ketone)s and poly(ether ether ketone ketone)s due to “internal plasticization” effect of flexible pendant pentadecyl chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Porous Hybrid Network of Graphene and Metal Oxide Nanosheets as Useful Matrix for Improving the Electrode Performance of Layered Double Hydroxides

Mesoporous hybrid network of reduced graphene oxide (rG‐O) and layered MnO₂ nanosheets could act as an efficient immobilization matrix for improving the electrochemical activity of layered double hydroxide (LDH). The control of MnO₂/rG‐O ratio is crucial in optimizing the porous structure and electrical conductivity of the resulting hybrid structure. The immobilization of Co‐Al‐LDH on hybrid MnO₂/rG‐O network is more effective in enhancing its electrode activity compared with that of on pure rG‐O network. The Co‐Al‐LDH?rG‐O?MnO₂ nanohybrid deliveres a greater specific capacitance than does MnO₂‐free Co‐Al‐LDH?rG‐O nanohybrid. The beneficial effect of MnO₂ incorporation on the electrode performance of nanohybrid is more prominent for higher current density and faster scan rate, underscoring the significant enhancement of the electron transport of Co‐Al‐LDH?rG‐O. This is supported by electrochemical impedance spectroscopy. The present study clearly demonstrates the usefulness of the porously assembled hybrid network of graphene and metal oxide nanosheets as an effective platform for exploring efficient LDH‐based functional materials.     

High gradient magnetic separation of china clays

High gradient magnetic separation has proved to be a successful method for removing micron size colouring bodies from china clays. Clays from Chotanagpur, Bihar have been beneficiated to improve its brightness. The effect of field, flow rate and dispersing agents has been studied on both the run of mine (rom) clay and the washed clay. Significant improvement in the brightness of clay has been obtained.     

Highlights from the literature on risk assessment techniques adopted in the mining industry:A review of past contributions,recent developments and future scope

In this paper a comprehensive review is presented of risk assessment techniques adopted in the mining industry worldwide;those techniques applied in other hazardous industries and potential techniques which are robust,mature and holistic and can be implemented for the Indian mining industry in future to enhance workplace safety are also presented.Findings from the review are indicative of the fact that socio-technical complexity of industrial systems has increased.Recent developments in the area of risk management highlight the need for implementation of the latest robust techniques of risk assessment in the mining sector.In consideration of the present scenario,the development of a model for risk analysis having an interface between hazard identification and risk assessment,along with an interface between risk assessment and accident causation to predict if an accident will occur under given conditions,has become dire necessity.This will increase hazard awareness and enable mine management to select and prioritize problem areas and identify safety system weaknesses in both underground and surface mining.This will ultimately help decision makers,risk analysts and safety managers make a major contribution in the development of workplace safety with a near-to-zero accident rate.     

A sustainable multi-parametric sensors network topology for river water quality monitoring

Wireless Networks - The deterioration of water quality due to natural and man-made hazards has affected the life on the Earth. Hence, water quality needs to be monitored regularly. The traditional...     

Sponge microflowers of NiCo2O4: a versatile material for high performance supercapacitor

Journal of Porous Materials - We report the development of well optimised NiCo2O4 microflowers for high performance supercapacitor application. The efforts were made to optimise the electrode...     

Boosting the Performance of ZnO/CdS Core-Shell Nanorod Array-based Solar Cells by ZnS Surface Treatment

With a view to enhancing the efficiency of ZnO/CdS core-shell nanorod array-based semiconductor sensitized solar cells (SSSCs), ZnS surface treatment is envisioned. It is achieved through a thin layer of ZnS being deposited onto ZnO/CdS film by a successive ionic layer adsorption and reaction (SILAR) technique. To ascertain the optimum thickness of ZnS and to enhance the solar cell performance, we have varied the number of SILAR cycles of ZnS deposition. The optimized film is then considered for structural, morphological, and electrochemical studies. The analysis reveals the benefits of ZnS surface treatment on ZnO/CdS core-shell photoelectrodes in terms of an enhancement of solar cell performance of up to 1.54 % from 1.23 %.     

Internet Predictions

More than a dozen leading experts give their opinions on where the Internet is headed and where it will be in the next decade in terms of technology, policy, and applications. They cover topics ranging from the Internet of Things to climate change to the digital storage of the future.     

Fabrication,characterization and comparison of DSSC using anatase TiO2 synthesized by various methods

In this study, anatase TiO₂ nanoparticles were synthesized by three techniques, namely, sol–gel, acid-base co-catalyst and room temperature colloidal methods. The synthesized materials were characterized by X-ray diffraction, scanning electron microscopy, pore diameter, pore volume and surface area. The dye-sensitized solar cells were fabricated using the synthesized materials and characterized for incident photon to current conversion efficiency, photocurrent density to photo voltage measurement and electrochemical impedance analysis. Among the studied materials, TiO₂ synthesized by sol–gel method displayed highest photon to current conversion of 76.8% and a maximum solar cell efficiency of 7.85% with J_sc of 14.75 mA/cm², V_oc of 0.76 V and FF of 0.7. This is the first study to report a high power conversion efficiency of DSSC using a sol–gel synthesized titania and its comparison with other two synthesized materials. The high power conversion efficiency of the solar cell using TiO₂ synthesized by sol–gel method is attributed to its characteristic properties such high surface area, larger pore diameter and larger pore volume and highest dye loading capacity.