High Efficiency Time Redundant Hardened Latch for Reliable Circuit Design

In a modern high density VLSI design, with higher operating frequency and technology scaling, small critical charge in circuit nodes significantly increases susceptibility to radiation induced transient faults. In this paper, we propose a high efficiency hardened latch using the undesired delay of Schmitt trigger circuit and a special feedback loop to a comparator to build a low overhead time redundancy scheme. The proposed structure masks internal node transient faults also improves the recovery of the output node by transferring the faulty output in two different paths to the comparison circuit’s inputs. Experimental results, simulated in 45 nm CMOS technology, show an acceptable increase in the critical charge compared with the previous hardened latches, with a fair increase in power, delay and area. Monte Carlo simulations have also confirmed the proposed latch resistance to the process, voltage and temperature variations.     

Short-term and long-term effects on carbon storage of pulse feeding on acclimated or unacclimated activated sludge

This study was aimed to investigate the effect of different feeding patterns on the physiological state of the activated sludge and related microbial composition in an SBR (SRT of 2 days, acetate as the sole carbon source, aerobic conditions). The activated sludge was acclimated to two subsequent feeding patterns, namely to continuous feeding throughout the reaction phase and then to pulse feeding. FISH and microscopy staining procedure (Nile blue) were used to investigate the microbial composition, in combination with quantitative determination of storage. At steady state, storage was significant even under continuous feeding whereas pulse feeding brought a strong increase of both rate and yield of storage. Short-term and long-term effects were clearly distinguishable: the immediate adaptation of biomass coming from continuous feeding to a single spike accounted for a significant portion of the overall increase of both rate and yield of polymer storage that was obtained after long acclimation to pulse feeding. On the contrary, after either type of feeding, both cultures were mainly constituted from the members of Thauera/Azoarcus group. Thus, the same dominant group preferably consumed the acetate via storage or growth depending on acclimation conditions. Our study clearly showed that a progressive increase of storage capacity is not necessarily due to a shift of microbial composition.     

Halogenated volatile organic compounds from the use of chlorine-bleach-containing household products

Sodium hypochlorite (NaOCl) and many organic chemicals contained in household cleaning products may react to generate halogenated volatile organic compounds (VOCs). Halogenated VOC emissions from eight different chlorine bleach containing household products (pure and diluted) were investigated by headspace experiments. Chloroform and carbon tetrachloride were the leading compounds along with several halogenated compounds in the headspace of chlorine bleach products. One of the most surprising results was the presence of carbon tetrachloride (a probable human carcinogen and a powerful greenhouse gas that was banned for household use by the U.S. Food and Drug Administration) in very high concentrations (up to 101 mg m(-3)). By mixing surfactants or soap with NaOCl, it was shown that the formation of carbon tetrachloride and several other halogenated VOCs is possible. In addition to quantitatively determined halogenated VOCs (n = 15), several nitrogen-containing (n = 4), chlorinated (n = 10), oxygenated compounds (n = 22), and hydrocarbons (n = 14) were identified in the headspace of bleach products. Among these, 1,1-dichlorobutane and 2-chloro-2-nitropropane were the most abundant chlorinated VOCs, whereas trichloronitromethane and hexachloroethane were the most frequently detected ones. Indoor air halogenated VOC concentrations resulting from the use of four selected household products were also measured before, during, and 30 min after bathroom, kitchen, and floor cleaning applications. Chloroform (2.9-24.6 microg m(-3)) and carbon tetrachloride (0.25-459 microg m(-3)) concentrations significantly increased during the use of bleach containing products. During/ before concentration ratios ranged between 8 and 52 (25 +/- 14, average +/- SD) for chloroform and 1-1170 (146 +/- 367, average +/- SD) for carbon tetrachloride, respectively. These results indicated that the bleach use can be important in terms of inhalation exposure to carbon tetrachloride, chloroform and several other halogenated VOCs.     

Particle-phase dry deposition and air-soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in Izmir, Turkey

Ambient air and dry deposition samples were collected at suburban and urban sites in Izmir, Turkey. Atmospheric total (particle+gas) ∑(14)PAHs concentrations were 36±39 and 144±163 ng m(-3) for suburban and urban sites, respectively. Phenanthrene was the most abundant compound at all sites, and all samples were dominated by low molecular weight PAHs. Average particulate ∑(14)PAH dry deposition fluxes were 8160±5024 and 4286±2782 ng m(-2) day(-1) and overall average particulate dry deposition velocities were 1.5±2.4 and 1.0±2.3 cm s(-1) for suburban and urban sites, respectively. Soil samples were collected at suburban site. Average soil concentration for ∑(14)PAH was 55.9±14.4 ng g(-1) dry weight. Calculated gas-phase air-soil exchange fluxes indicated that fluorene, phenanthrene, anthracene, and carbazole were deposited to soil in winter while they were volatilized in summer. Other compounds (fluoranthene-benzo[g,h,i]perylene) were deposited to soil in both periods. Annual average fluxes of PAHs representing soil to air (i.e., gas volatilization) and air to soil transfer (i.e., gas absorption, dry deposition, and wet deposition) processes were also compared. All processes were comparable for Σ(14)PAHs however their input was dominated by gas absorption. Gas absorption dominated for lower molecular weight PAHs, however dry deposition dominated for higher molecular weight PAHs. The results have suggested that for fluorene, soil and air may be approaching a steady state condition. For the remaining compounds, there was a net accumulation into the soil.     

A new adaptive fuzzy inference system for electricity consumption forecasting with hike in prices

Large increase or hike in energy prices has proven to impact electricity consumption in a way which cannot be drawn from historical data, especially when price elasticity of demand is not significant. This paper proposes an integrated adaptive fuzzy inference system (FIS) to estimate and forecast long-term electricity consumption when prices experience large increase. To this end, first a novel procedure for construction and adaptation of Takagi–Sugeno fuzzy inference system (TS-FIS) is suggested. Logarithmic linear regressions are estimated with historical data and used to construct an initial first-order TS-FIS. Then, in the adaptation phase, expert knowledge is used to define new fuzzy rules which form a new secondary FIS for electricity forecasting. To show the applicability and usefulness of the proposed model, it is applied for forecasting of annual electricity consumption in Iran where removing energy subsidies has resulted in a hike in electricity prices. Gross domestic product (GDP), population and electricity price are three inputs for the initial TS-FIS. A questionnaire survey was conducted to collect the expert estimation on possible change in electricity per capita, change in electricity intensity and the ratio of GDP elasticity to population elasticity when price hikes. Based on the information collected, a fuzzy rule base is formed and used to construct the secondary FIS which is used for electricity forecasting until 2016. Furthermore, the performance of the proposed model of this paper is compared with three other models namely ANFIS, ANN and one-stage regression in terms of their mean absolute percentage error. The comparison shows a superior performance for the proposed FIS model.     

Incorporation of Propionibacterium shermanii subsp. freudenreichii in probiotic dairy drink production: physicochemical,rheological, microbiological and sensorial properties

The aim of this study was to investigate the use of Propionibacterium shermanii subsp. freudenreichii as a combined culture with Lactobacillus acidophilus (AP), Bifidobacterium animalis subsp. lactis (BP), Lactobacillus casei (CP) and Lactobacillus rhamnosus (RP) in probiotic dairy drink production. Although Propionibacterium spp. is used for many purposes including biopreservative and adjunct culture, in this study, probiotic dairy drinks containing P. freudenreichii were evaluated in terms of their physicochemical, rheological, microbiological and sensory properties. The results of the study showed that P. freudenreichii can also be suitable for the production of probiotic drinks and that there are no adverse effects on the product characteristics.     

Wet and dry deposition of formaldehyde in Izmir, Turkey

Samples were collected between May 2003 and May 2004 in Izmir, Turkey to measure dry and wet deposition of formaldehyde (HCHO). Particle-phase HCHO fluxes measured with dry deposition plates ranged between 2 and 56 microg m(-2) day(-1) (average+/-SD, 17+/-12 microg m(-2) day(-1)). Particulate phase dry deposition velocities calculated using the particulate fluxes measured and ambient particulate concentrations ranged from 0.1 to 9.6 cm s(-1) (1.4+/-1.4 cm s(-1)). The particulate overall dry deposition velocity agreed well with those measured previously for other pollutants using the same method. Formaldehyde concentration measured in 27 rain samples collected at the sampling site ranged between 10 and 304 microg l(-1). The annual formaldehyde wet deposition was calculated as 31.4 mg m(-2) year(-1). The annual HCHO total deposition (wet+dry) was dominated by wet deposition (83.7%).     

Nickel removal characteristics of an immobilized macro fungus: equilibrium,kinetic and mechanism analysis of the biosorption

BACKGROUND: An immobilized new biosorbent was prepared from macro fungi Lactarius salmonicolor for the effective removal of nickel ions from aqueous media. Operating conditions were optimized as functions of initial pH, agitation time, sorbent amount and dynamic flow rate. Immobilization and biosorption mechanism were examined and the developed biosorbent was tested for the removal of nickel ions from real wastewater. RESULTS: Biosorption performance of the biomass continuously increased in the pH range 2.0–8.0. The coverage of the biosorbent surface by silica gel resulted in a significant increase in biosorption yield of nickel ions. The highest nickel loading capacity was obtained as 114.44 mg g^?1 using a relatively small amount of immobilized biosorbent. Biosorption equilibrium time was recorded as 5 min. Experimental data were analyzed by different isotherm and kinetic models. Infrared spectroscopy, scanning electron microscopy and X‐ray energy dispersive analysis confirmed the process. The sorbent exhibited relatively good recovery potential in dynamic flow mode studies. Biosorption capacity of immobilized biosorbent was noted as 14.90 mg g^?1 in real wastewater. CONCLUSION: Silica gel immobilized biomass of L. salmonicolor is to be a low cost and potential biosorbent with high biosorption capacity for the removal of contaminating nickel from aqueous media. © 2012 Society of Chemical Industry