Implementation of a low power 16-bit radix-4 pipelined SRT divider using a modified Split-Path Data Driven Dynamic Logic (SPDL) structure

In this paper a 16-bit radix-4 pipelined divider implemented in a modified version of SPD³L family structure (SPCD³L: Split-Path Clock-Data driven Dynamic Logic) is presented. Through the modification, the clock signal is also used to pre-charge some critical parts of the circuit. Performance of the circuit is evaluated at different simulation corners. The results show that, compared with Domino structure, the proposed circuit has lower power consumption and higher speed. Latency of the divider is equal to 10 half clock cycles. The design is simulated using HSPICE in a 1.8-V TSMC_180 nm CMOS process.     

Most-probable-number determination of salmonella levels in naturally contaminated raw almonds using two sample preparation methods

Pathogens occurring in particulate foods may be unevenly distributed, which may impact interpretation of most-probable-number (MPN) values. The MPN analysis of Salmonella in naturally contaminated raw almonds was conducted using two sample preparation methods. Raw almond kernels (3,698 samples) and inshell almonds (455 samples) were collected from almond processors throughout California during the 2006 and 2007 harvests, and 100-g samples were enriched for Salmonella. The prevalence of Salmonella on kernels and inshell almonds was 1.6 and 0.9%, respectively, in 2006, and 0.83 and 2.2%, respectively, in 2007. Almond kernel samples from 2006 were further enriched for Salmonella, and levels of the organism were determined for positive samples by three-tube MPN analysis (25 g, 2.5 g, 0.25 g). Almonds were either divided into subsamples prior to blending and enrichment (method A), or samples were blended in enrichment broth prior to preparation of subsamples (method B). Salmonella was not isolated (<1.2 MPN/100 g) upon retesting of 19 of 31 (method A) or 23 of 29 (method B) positive samples. When detected, levels were 1.4 to 15.5 MPN/100 g (average 2.3 MPN/100 g) or 1.4 to 18.3 MPN/100 g (average 2.1 MPN/100 g) using methods A or B, respectively. A total of 23 different Salmonella serovars were identified from the original almond samples. Salmonella Muenchen was the most frequently isolated serovar (15%) from the 53 Salmonella-positive samples, followed by Newport (12%), Enteritidis (10%), and Typhimurium (8%). No correlation was found between presence of Salmonella and E. coli levels, aerobic plate counts, or counts of yeasts or molds.     

Activities Study of Short-lived Radioisotopes with a Filippov-type Plasma Focus

Plasma focus devices are characterized by short-lived dense and hot plasma “pinch” due to the radial compression and electromagnetic acceleration. Through a short period of time, typically a few tens of nanoseconds, the pinched plasma goes through two phases of compression (thermal) and expansion (non-thermal or beam target) that provide necessary conditions for high nuclear reaction rates. If appropriate gas admixture at a desirable pressure is used, the processes can generate short-lived radioisotopes (SLRs) which the level of activities depends on the design and operational parameters. In this paper, the results of simulated theoretical works of two SLRs such as ¹⁰B (d, n) ¹¹C and ¹⁴N (d, n) ¹⁵O are presented using a Filippov-type plasma focus “Dena” as a breeder with the bank energy ranges from 20 to 90 kJ at the repetition rates from 1 to 10 Hz. The admixture gas pressure of ¹⁰B and ¹⁴ N were taken to be approximately 0.05 of initial working pressure at optimum neutron yield regime. The results obtained are discussed.     

Design and analysis of differential ring voltage controlled oscillator for wide tuning range and low power applications

Voltage-controlled oscillator (VCO) is the most basic component required for all wireless and communication systems. In this article, a four-stage differential ring VCO with two control voltages for wide tuning range is proposed. This VCO uses the dual-delay loop technique for high operation frequency. Also, a low-V_T NMOS transistor is used in series with pull down network of the proposed VCO delay cell to achieve low frequencies. Prelayout simulation of the proposed VCO is performed in 65-nm TSMC CMOS technology in Cadence software under 1.2-V supply voltage. The tuning range of the proposed VCO varies from 1 MHz to 13.8 GHz and has been improved by 19.77% compared to other works. The power consumption of this low power VCO is between 29.3 μW to 1.715 mW. The phase noise of the proposed circuit is −82.3 dBc/Hz at 1 MHz offset frequency and −106.9 dBc/Hz at 10 MHz offset frequency from 5.161 GHz center frequency, while its area is 102.457 μm² . This design demonstrates other benefits in low power consumption and area compared with other ring oscillators.     

Analysis and Fate of Lipophilic Extractives in Sulphite Pulps

Abstract

One of the major requirements of sulphite pulps, particularly those used in the manufacture of dissolving grades, is that their extractives content must not exceed certain levels, as specified by the customer. Since these levels are generally very low, the accuracy and reproducibility of extractives measurements can be poor, which in turn can lead to disagreements between pulp suppliers and their customers. In an effort to improve the reliability of extractives measurements, we have evaluated several methods for the determination of lipophilic extractives in sulphite pulps, using Soxhlet and Soxtec solvent extraction and various modes of drying the extracts including hot plate, infrared lamp, and freeze drying. Analysis of the extracts by size exclusion chromatography showed that a significant portion of the extracts was polymerized during the production process. Lipophilic extractives from ammonium sulphite pulps contain more polymerized matter than the extractives from the magnesium process.     

Polyethyleneimine-containing sol-gels as novel sorbents for the removal of cadmium from aqueous solutions

The removal of cadmium ions from aqueous solutions is described using polyethyleneimine (PEI) entrapped in sol-gel matrices. The process is optimized with respect to operating conditions and both sorption and desorption are considered. The sorption process followed the Langmuir isotherm, and the corresponding Langmuir constants q_max and K_dwere found to be 80.64 mg Cd2⁺/g PEI and 236.36 mg/L, respectively, using the immobilized PEI polymer. More than 90% of the cadmium could be recovered in 2 h using 2 M NaCl solutions. This technique has potential applications in the recovery of cadmium in aqueous waste streams.     

Biodegradable membrane based on polycaprolactone/polybutylene succinate: Characterization and performance evaluation in wastewater treatment

Biodegradable membranes with different compositions of polycaprolactone (PCL) and polybutylene succinate (PBS) are prepared via immersion precipitation. The morphology, hydrophilicity, chemical structure, crystalline structure, mechanical properties, and biodegradability of the membranes are studied to assess the effect of PBS concentration in the polymer blend on membrane properties. Furthermore, the performance of the obtained membranes is assessed through the treatment of wastewater sampled from the chips and snacks factory. Also, membranes' antifouling properties are assessed by filtration of a model foulant. The investigations revealed that the addition of PBS to PCL increases the membrane hydrophilicity and biodegradability. Regarding the results, the PCL membrane blended with 30 wt% PBS has 106%, 26%, and 37% higher pure water flux, flux recovery ratio, and permeate flux, in addition to the higher rejection of pollution indices, in comparison with the PCL membrane.     

Early Development of Neurophysiological Processes Involved in Normal Reading and Reading Disability: A Magnetic Source Imaging Study.

This longitudinal study examined the development of the brain mechanism involved in phonological decoding in beginning readers using magnetic source imaging. Kindergarten students were assigned to 2 groups: those who showed mastery of skills that are important predictors of proficient reading (low-risk group) and those who initially did not show mastery but later benefited from systematic reading instruction and developed average-range reading skills at the end of Grade 1 (high-risk responders). Spatiotemporal profiles of brain activity were obtained during performance of letter-sound and pseudoword naming tasks before and after Grade 1 instruction. With few exceptions, low-risk children showed early development of brain activation profiles that are typical of older skilled readers. Provided that temporoparietal and visual association areas were recruited into the brain mechanism that supported reading, the majority of high-risk responder children benefited from systematic reading instruction and developed adequate reading abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of intravenous immunoglobulins on T-cell mediated, concanavalin A-induced hepatitis in mice

Concanavalin A (ConA) activates T lymphocytes and causes T-cell mediated hepatic injury in mice. The intravenous administration of human immunoglobulins has beneficial effects in T-cell mediated diseases such as experimental autoimmune encephalomyelitis and adjuvant arthritis. In the present study, we examined the effects of intravenous immunoglobulins in a mouse model of T-cell mediated, acute liver injury induced by concanavalin A. Balb/c mice were inoculated with 12 mg/kg concanavalin A with or without intravenous immunoglobulins at doses of 0.4, 0.6, 0.8 g/kg body wt. The serum levels of liver enzymes, tumor necrosis factor-alpha, interferon-gamma and interleukin-6 were assayed 2, 6 and 24 h after concanavalin A administration. Intravenous immunoglobulins did not prevent concanavalin A-induced hepatitis, as manifested by elevation of serum aminotransferases and histopathological evaluation. The serum levels of tumor necrosis factor-alpha in mice pretreated with immunoglobulins, measured 2 h after ConA treatment were reduced, while interferon-gamma levels measured 6 h after ConA inoculation were 5-fold higher than control levels. There was no effect of intravenous immunoglobulins on the release of interleukin 6. In conclusion, these results indicate that intravenous immunoglobulin is not effective in preventing T-cell mediated concanavalin A-induced hepatitis. The increased secretion of interferon-gamma and the incomplete suppression of tumor necrosis factor-alpha release may explain the lack of efficacy of intravenous immunoglobulin in this experimental model.