A novel low-latency DRAM based on the bitline-discharge rate

As well known by computer architects, the performance gap between the processor and the memory has been increasing over the years. This causes what is known as the memory wall. In order to alleviate the problem, a novel fast readout scheme is proposed in this article for the single-transistor single-capacitor dynamic random-access memory (1T-1C DRAM) cells. The proposed scheme works in the current domain in which the difference between the discharging rates of the bitline in the cases of ‘1’ and ‘0’ readings is detected. The proposed scheme is analysed quantitatively and compared with the conventional readout scheme. It is verified by simulation adopting the 45 nm CMOS Berkley predictive-technology model (BPTM) and shows 44 and 7.7% reductions in the average read-access and cycle times, respectively, as compared to the conventional readout scheme. It is also shown that the power is saved according to the proposed scheme if the probability of occurrence of ‘0’ storage exceeds 66.7%. This minimum value can be alleviated, however, at the expense of a smaller saving in the average read-access time. The impacts of process variations and technology scaling are also taken into account.     

Optimal throughput performance in full-duplex relay assisted cognitive networks

Wireless Networks - In this paper, we study a full-duplex cooperative cognitive radio network with multiple full-duplex secondary users acting as potential relays for transmitting the packets of a...     

The electroremoval of copper from dilute waste solutions using Swiss-roll electrode cell

Copper is usually present in concentrations less than 5 g/L⁻¹ in dilute waste solutions. The low concentrations make these solutions unsuitable for the electro-flow owinning processes via conventional electrolysis cells. Unconventional, two-and three-dimensional electrode cells with relatively large cathodic area are essential for such treatment. Different types of cells are mentioned in the literature. Among these cells, the two-dimensional Swiss-roll cell (SR) is considered in this study. The effects of cathodic current densities, initial copper concentrations, free sulfuric acid concentration, the presence of iron and zinc cations, and the rate of flow of the solution on both the cathodic current efficiency and power consumption were studied. Copper was removed from synthetic and industrial mixtures of Cu/Fe/Zn sulfate solutions to less than 5 ppm with power consumptions of 10.326 kWh/kg⁻¹ and 8.61 kWh/kg⁻¹, respectively. The correlation between the SR cell and packed-column cell on such treatment was also considered.     

Recycling of pharmaceutical waste gelatin for controlled‐release applications. I. A 2,4‐dicholorphenoxy acetic acid based system

Gelatin is a natural macromolecular protein. It contains a wide variety of amino acids in its polymer structure, and it is colorless to yellowish, water‐soluble, and tasteless. It is used as a dispersing agent, sizing medium, and coating for photographic films and in pharmaceutical formulations. In this study, biodegradable mulching, based on waste gelatin from pharmaceutical gelatin scraps (derived from pharmaceutical soft gelatin capsule production), was formulated via the casting of water solutions or suspensions into flexible and consistent films. Gelatin was blended with synthetic materials such as poly(vinyl alcohol) and other natural wastes such as sugar cane bagasse and sawdust. To all formulations, 2,4‐dichlorophenoxy acetic acid (2,4‐D) was added as a herbicide. The morphology and mechanical properties of the samples were investigated with scanning electron microscopy and tensile testing, respectively. The results showed that the produced films had controlled‐release properties. The effects of various additives and crosslinking on the films and the release of the herbicide 2,4‐D from the films were also investigated. The introduction of synthetic and natural additives reduced the release rate of 2,4‐D. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2313–2319, 2004     

Instant synthesis of mesoporous monolithic materials with controllable geometry,dimension and stability: a review

The development of the nanoscale structures and their integration into components, systems, and natural architectures (such as monoliths), and large-scale devices, is one of the most promising areas in the emerging field of nanotechnology. We believe that it is time to write a review that focused on the rapid synthesis and the functional properties of HOM mesoporous monoliths. Thus, we here introduce comprehensive and up-to-date reports on the instant synthesis (within minutes) of a range of mesoporous silica monoliths (HOM-type, High-Order-Monolith) by means of a direct-templating method of lyotropic and microemulsion liquid crystalline phases. A number of nonionic n-alkyl-oligo(ethylene oxide), namely, Brij-type (C _x EO _y ), and Triton- and Tween-type and cationic alkyl trimethylammonium bromide or chloride (C _n TMA-B or -C, where n = 12, 14, 16 and 18) surfactants were used as soft templates. A variety of 1D, 2D and 3D mesostructure geometries were successfully fabricated by using this simple, fast and yet reproducible design strategy. This is the first and detailed review of using rapid synthesis to fabricate disordered and ordered silica/surfactant mesophases with supermicro- and meso-pore engineering systems. In this review, we also addressed the prominent factors affected the formation of the large-scale ordered and worm-like structures (HOM): (1) the phase composition of domains, (2) the extent of solubilization of hydrocarbons, and (3) the nature of surfactant molecules (corona/core features). Significantly, due to large morphological particle sizes, these HOM monolithic structures exhibited considerable structural stability against longer hydrothermal treatment times. Such retention is crucial in industrial applications.     

Polyacrylamide‐grafted carboxymethyl cellulose: Smart pH‐sensitive hydrogel for protein concentration

A novel application, utilizing polyacrylamide‐g‐carboxymethyl cellulose (CMC‐g‐PAM) in concentrating dilute solutions of Bovine serum albumin (BSA), was investigated. The grafting reaction parameters were investigated and the hydrogel smartness was verified. FT‐IR proved that the grafting reaction occurred between the hydroxyl group located in anhydroglucose C₂ position of CMC and the π‐bond of PAM and SEM confirmed a changed morphology to a fibrillar structure. The pH sensitivity was proved; as the grafted polymer attained its maximum swelling at pH 7.2 while the minimum swelling was observed under acidic conditions (pH 1‐3). The rate of water uptake in the grafted polymer hydrogel was higher than that of the homopolymer hydrogel and the swelling behaviors of both hydrogels obeyed second‐order kinetics. The tested hydrogel showed a high potency towards concentrating BSA solutions with a concentration factor of 1 to 4.5 times and recovery of 60–90%. The concentration factor increased linearly with increasing both the polymer concentration and the process time and decreased with the increase in the protein concentration. The grafted polymer had stable efficiency in the concentration process for 20 cycles. The obtained results have recommended the employment of the prepared CMC‐g‐PAM hydrogel in the down stream protein concentration process in the industrial scale. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Synthesis,Characterization, and Evaluation of Ethoxylated Lauryl-Myrisityl Alcohol Nonionic Surfactants as Wetting Agents,Anti-Foamers,and Minimum Film Forming Temperature Reducers in Emulsion Polymer Lattices

Two nonionic FAEO (fatty alcohol ethoxylated) surfactants with varying solubility were obtained by the reaction of lauryl-myrisityl alcohol (LMA) with ethylene oxide to yield lauryl-myristyl/alcohol ethoxylated with 3 and 31 mol of ethylene oxide by changing the length of polyethylene glycol segment. The prepared surfactants, designated as LMAEO-3 and LMAEO-31, were characterized for their structures using spectroscopic measurements; in addition, their surface properties were investigated. The results indicated that LMAEO-31 exhibits excellent surface activity. Evaluation of the surfactants as wetting agents, anti-foamers, and minimum film forming temperature (MFFT) reducer in emulsion polymer lattices achieved promising results indicating high performance in the mentioned industrial applications.     

Microwave-Assisted Synthesis of the Flexible Iron-based MIL-88B Metal–Organic Framework for Advanced Energetic Systems

The 3D metal–organic framework (MOF), MIL-88B, built from the trivalent metal ions and the ditopic 1,4-Benzene dicarboxylic acid linker (H₂BDC), distinguishes itself from the other MOFs for its flexibility and high thermal stability. MIL-88B was synthesized by a rapid microwave-assisted solvothermal method at high power (850 W). The iron-based MIL-88B [Fe₃.O.Cl.(O₂C–C₆H₄–CO₂)₃] exposed oxygen and iron content of 29% and 24%, respectively, which offers unique properties as an oxygen-rich catalyst for energetic systems. Upon dispersion in an organic solvent and integration into ammonium perchlorate (AP) (the universal oxidizer for energetic systems), the dispersion of the MOF particles into the AP energetic matrix was uniform (investigated via elemental mapping using an EDX detector). Therefore, MIL-88B(Fe) could probe AP decomposition with the exclusive formation of mono-dispersed Fe₂O₃ nanocatalyst during the AP decomposition. The evolved nanocatalyst can offer superior combustion characteristics. XRD pattern for the MIL-88B(Fe) framework TGA residuals confirmed the formation of α-Fe₂O₃ nanocatalyst as a final product. The catalytic efficiency of MIL-88B(Fe) on AP thermal behavior was assessed via DSC and TGA. AP solely demonstrated a decomposition enthalpy of 733 J g^?1, while AP/MIL-88B(Fe) showed a 66% higher decomposition enthalpy of 1218 J g^?1; the main exothermic decomposition temperature was decreased by 71 °C. Besides, MIL-88B(Fe) resulted in a decrease in AP decomposition activation energy by 23% and 25% using Kissinger and Kissinger–Akahira–Sunose (KAS) models, respectively.

     

The Impact of Metastable Intermolrecular Nanocomposite Particles on Kinetic Decomposition of Heterocyclic Nitramines Using Advanced Solid‐Phase Decomposition Models

Journal of Inorganic and Organometallic Polymers and Materials - Surface oxygen of oxide catalyst has low coordination number; they are negatively charged. Surface oxygen can act active site for...