Synchronous derived clock and synthesis of low power sequential circuits

Based on analyzing significance of controlling clock in design of low power sequential circuits, this paper proposes a technique that the gating signal is derived from the master latch in a flip-flop to make the derived clock having no glitch and no skew. The design of a decimal counter with half-frequency division shows that by using the synchronous derived clock the counter has lower power dissipation as well as simpler combinational logic. Computer simulation shows 20% power saving.     

PHYSICAL-CHEMICAL APPROACHES FOR THE ENVIRONMENTALLY SOUND DISPOSAL OF AN OIL SHALE RETORT WATER

ABSTRACT

The extraction of shale oil produces relatively large volumes of polluted process water. These waters contain large concentrations of organic and inorganic pollutants as well as environmentally significant amounts of trace materials. These substances either individually or in combination can be highly toxic to environmental systems. This paper addresses a suggested cleanup sequence designed to remove specific pollutants and to detoxify these waters. Hot gas stripping, followed by activated carbon adsorption and reverse osmosis removed over 93 percent of the total organic carbon load while also reducing the.toxicity of the resultant effluent as measured by a standard technique. Depending upon the ultimate use of these waters, the suggested treatment sequence or its individual components could be employed at a pilot or commercial scale retorting facility.     

The protection of mild steel by zinc-rich paint in flowing aerated 0.5 M NaCl solution—III. The effect of zinc content

The effect of the rate of flow of 0.5 M NaCl solution on the corrosion rate of mild steel and steel painted with zinc-rich paints containing from 50 to 93 wt% zinc dust was investigated. The results showed that the zinc dust content necessary to ensure protection of mild steel over the full flow range up to a Reynolds number of 16,000 was 80 wt% in the dried film.     

NBTI and hot-carrier effects in accumulation-mode Pi-gate pMOSFETs

Negative bias temperature instability (NBTI) and hot-carrier induced device degradation in accumulation-mode Pi-gate pMOSFETs have been studied for different fin widths ranging from 20 to 40 nm. The NBTI induced device degradation is more significant in narrow devices. This result can be explained by enhanced diffusion of hydrogen at the corners in multiple-gate devices. Due to larger impact ionization, hot-carrier induced device degradation is more significant in wider devices. Finally, hot-carrier induced device degradation rate is highest under stress conditions where V_GS = V_TH.     

Characteristics of heat insulating clay bricks made from zeolite,waste steel slag and expanded perlite

In order to lessen the energy loss of buildings during the operation phase, and also considering the importance of sustainable construction, producing bricks having more desirable thermal characteristics has become essential. In this study, insulation bricks composed of expanded perlite (EP), natural zeolite, ground granulated blast furnace slag (GGBFS) and clay were fabricated. The effect of replacing clay with GGBFS, zeolite and EP in amounts up to 15%, 15%, and 50% respectively on the bricks' properties was investigated. Mix proportion parameters of bricks were analyzed using the Taguchi method. Various properties of bricks including density, weight loss, shrinkage, apparent porosity, water absorption, resistance to freezing and thawing, compressive strength, thermal conductivity, and microstructural analysis of fired bricks were examined and compared against standard requirements for bricks. Overall, the results showed that while satisfying the standard requirements, bricks containing the aforementioned additives had lower thermal conductivity compared to normal bricks, and therefore, they could be utilized as heat insulation materials.     

Toward an intelligent approach for predicting surface tension of binary mixtures containing ionic liquids

Knowledge of the surface tension of ionic liquids (ILs) and their related mixtures is of central importance and enables engineers to efficiently design new processes dealing with these fluids on an industrial scale. It’s obvious that experimental determination of surface tension of every conceivable IL and its mixture with other compounds would be a herculean task. Besides, experimental measurements are intrinsically laborious and expensive; therefore, accurate prediction of the property using a reliable technique would be overwhelmingly favorable. To do so, a modeling method based on artificial neural network (ANN) trained by Bayesian regulation back propagation training algorithm (trainbr) has been proposed to predict surface tension of the binary ILs mixtures. A total set of 748 data points of binary surface tension of IL systems within temperature range of 283.1-348.15 K was used to train and test the applied network. The obtained results indicated that the predictive values and experimental data are quite matching, representing reliability of the used ANN model for such purpose. Also, compared with other methods, such as SVM, GA-SVM, GA-LSSVM, CSA-LSSVM, GMDH-PNN and ANN trained with trainlm algorithm the proposed model was better in terms of accuracy.     

Low power DCVSL circuits employing AC power supply

In view of changing the type of energy conversion in CMOS circuits, this paper investigates low power CMOS circuit design, which adopts a gradually changing power clock. First, we discuss the algebraic expressions and the corresponding properties of clocked power signals. Then the design procedure is summed up for converting complementary CMOS logic gates employing DC power to the power-clocked CMOS gates employing AC power. On this basis, the design of differential cas-code voltage switch logic (DCVSL) circuits employing AC power clocks is proposed. The PSPICE simulations using a sinusoidal power-clock demonstrate that the designed power-clocked DCVSL circuit has a correct logic function and low power characteristics. Finally, an interface circuit to convert clocked signals into the standard logic levels of a CMOS circuit is proposed, and its validity is verified by computer simulations.     

New Class of Electrocatalysts Based on 2D Transition Metal Dichalcogenides in Ionic Liquid

The optimization of traditional electrocatalysts has reached a point where progress is impeded by fundamental physical factors including inherent scaling relations among thermokinetic characteristics of different elementary reaction steps, non‐Nernstian behavior, and electronic structure of the catalyst. This indicates that the currently utilized classes of electrocatalysts may not be adequate for future needs. This study reports on synthesis and characterization of a new class of materials based on 2D transition metal dichalcogenides including sulfides, selenides, and tellurides of group V and VI transition metals that exhibit excellent catalytic performance for both oxygen reduction and evolution reactions in an aprotic medium with Li salts. The reaction rates are much higher for these materials than previously reported catalysts for these reactions. The reasons for the high activity are found to be the metal edges with adiabatic electron transfer capability and a cocatalyst effect involving an ionic‐liquid electrolyte. These new materials are expected to have high activity for other core electrocatalytic reactions and open the way for advances in energy storage and catalysis.     

Frequency domain damage detection of plate and shell structures by finite element model updating

Plate- and shell-like elements are the main constituent of many engineering structures such as ships and airplanes. This paper develops a frequency domain model updating method using power spectral density function and seeks its viability in damage identification of plates and shells. The derivation of the sensitivity equation is exact and measured natural frequencies of few lower modes are used to overcome the drawbacks of incomplete measurement. The method is numerically examined in several damage cases. The robustness of method against measurement and mass modelling error is numerically assessed using Monte-Carlo analysis and numerically simulated error contaminated data. The method proves to be robust against both kind of errors and performs well, both in cases of plate and shell elements.