The importance of light intensity in algal tests with coloured substances

Current algal test protocols do not distinguish between chemical toxicity and growth inhibition due to physical shading when coloured substances like dyes are evaluated. To eliminate the interfering physical effect, we investigated the importance of light intensity and culture volume in the algal growth inhibition tests with Desmodesmus subspicatus and three selected dyestuffs. A photon flux density above light saturation is needed to prevent inhibition of algal growth solely due to the light absorption by dyes. Furthermore, a smaller culture volume and moderate shaking of the test flasks is advantageous in that these conditions decrease the influence of the light absorption. At 120 microE s(-1) m(-2), the shading effect of three tested dyes could be eliminated, up to a concentration of 100 mg l(-1). In a mixture with a blue dyestuff, the model toxicant potassium dichromate showed nearly the same EC50 as if applied alone, indicating that the impact of the dye was negligible. Also a small culture volume decreases the inhibition of the average growth rate of Desmodesmus. Thus, by increasing the light intensity and optionally also reducing the culture volume, this method allows a more direct measure of a potential inherent chemical toxicity of coloured substances to algae. Additionally, high light intensities and lower culture volumes result in lower coefficients of variation, which improves the sensitivity of the test for the statistical calculation of toxicity data.     

Retrospective recall of sexual orientation identity development among gay, lesbian, and bisexual adults.

Although recent attention has focused on the likelihood that contemporary sexual minority youth (i.e., gay, lesbian, bisexual [GLB]) are “coming out” at younger ages, few studies have examined whether early sexual orientation identity development is also present in older GLB cohorts. We analyzed retrospective data on the timing of sexual orientation milestones in a sample of sexual minorities drawn from the California Quality of Life Surveys. Latent profile analysis of 1,260 GLB adults, ages 18–84 years, identified 3 trajectories of development: early (n = 951; milestones spanning ages 12–20), middle (n = 239; milestones spanning ages 18–31), and late (n = 70; milestones spanning ages 32–43). Motivated by previous research on variability in adolescent developmental trajectories, we identified 2 subgroups in post hoc analyses of the early profile group: child onset (n = 284; milestones spanning ages 8–18) and teen onset (n = 667; milestones spanning ages 14–22). Nearly all patterns of development were identity centered, with average age of self-identification as GLB preceding average age of first same-sex sexual activity. Overall, younger participants and the majority of older participants were classified to the early profile, suggesting that early development is common regardless of age cohort. The additional gender differences observed in the onset and pace of sexual orientation identity development warrant future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

An Effective Double Sampling Scheme for the c Control Chart

In the present paper is developed a statistical process control inspection procedure based on a new simple‐to‐implement and effective double sampling scheme for the c control chart, aimed at the minimization of the number of inspected observation units and warranting fixed levels for the type I and II error risks. In particular, the formulations of the false alarm risk α, the power P of the chart, and the expected number of inspected observation units for the developed inspection procedure are given, whereas a macro of Microsoft Excel is adopted to solve the tackled problem. In order to illustrate the application of the developed approach and to investigate on the influence of several operating parameters, numerical examples are carried out and the related considerations are given. Finally, by comparing the performance of the developed inspection procedure with that of the related classic c chart scheme, meaningful reduction of the number of the inspected observation units can be achieved by adopting the proposed approach. Copyright © 2013 John Wiley & Sons, Ltd.     

IEEE 802.11ac MIMO Transceiver Baseband Processing on a VLIW Processor

Wireless standards are evolving rapidly due to the exponential growth in the number of portable devices along with the applications with high data rate requirements. Adaptable software based signal processing implementations for these devices can make the deployment of the constantly evolving standards faster and less expensive. The flagship technology from the IEEE WLAN family, the IEEE 802.11ac, aims at achieving very high throughputs in local area connectivity scenarios. This article presents a software based implementation for the Multiple Input and Multiple Output (MIMO) transmitter and receiver baseband processing conforming to the IEEE 802.11ac standard which can achieve transmission bit rates beyond 1Gbps. This work focuses on the Physical layer frequency domain processing. Various configurations, including 2×2 and 4×4 MIMO are considered for the implementation. To utilize the available data and instruction level parallelism, a DSP core with vector extensions is selected as the implementation platform. Then, the feasibility of the presented software-based solution is assessed by studying the number of clock cycles and power consumption of the different scenarios implemented on this core. Such Software Defined Radio based approaches can potentially offer more flexibility, high energy efficiency, reduced design efforts and thus shorter time-to-market cycles in comparison with the conventional fixed-function hardware methods.     

Equilibrium as the common ground: Introducing embodied perception into structural design with graphic statics

The analogy between the human body and architectural structures dates all the way back to ancient times and has significantly shaped the design of buildings and structures. The article examines the body's historical influence on how structures are perceived and designed, demonstrating how the body shapes the “technical truth” dimension of structural design while oblivious to the importance of an “artistic truth” or perceptual dimension. This article aims to connect recent neuroscience findings and their implications for structural design through graphic statics and its design methods. Finally, this article proposes an equilibrium-based structural design approach for designing embodied structures based on graphic statics.     

The New Nino Capability Index for Dynamic Process Capability Analysis

The process capability analysis is a crucial activity to evaluate if the process outcome meets the design specifications. Classically, such analysis is performed by verifying the in‐control condition of the process and evaluating suitable capability indices, by assuming the process in‐control steady‐state condition. However, the in‐control period of the process characterizes only a part of the system functioning cycle, the one with the lower defective rate. In particular, the system functioning cycle is also characterized by the out‐of‐control period, during which a greater defective rate is produced, and such increasing is not considered by the widely adopted capability indices. As consequence, the classical approaches to perform the process capability analysis involves an overestimation of the process capability level. For this reason, in order to overcome the previously described limitation, in the present paper it is proposed a new capability index based on the real defective rate of the process. Thus, such new index is able to estimate the real process capability level. Finally, in order to compare the new index to the conventional C_p capability index, a numerical comparison study related to a process capability analysis is carried out, and the related practical considerations are given. Copyright © 2013 John Wiley & Sons, Ltd.     

The Impact of Water on CO Oxidation with Au/TiO<Subscript>2</Subscript> Catalysts: Poison or Promotor? A Study with an Au–TiO<Subscript>2</Subscript>/MCM-48 Model Catalyst

Abstract  

CO oxidation was studied with a model catalyst containing Au and TiO _x nanoaggregates confined in a siliceous MCM-48 host. With this material, which has a particular small ratio between the TiO _x and Au components, activities well comparable to those of unconfined Au/TiO₂ catalysts were obtained in particular when a thermal activation in inert gas at temperatures between 523 and 673 K was applied. When the subsequent catalytic tests were performed in a feed containing ca. 20 ppm H₂O, strong deactivation phenomena were observed which could be reverted by repeated thermal treatment and are most likely caused by carbonate deposition. This deactivation was strongly attenuated when the water content of the feed was decreased to ca. 6 ppm, which suggests that water plays an important role in the formation of the poisoning species. With unconfined Au/TiO₂ catalysts, a promoting role of water on the formation of catalyst poison was observed as well, but to a much lower extent. The effect may therefore have escaped undetected so far as a contribution to the well-known catalyst deactivation by carbonate species.     

The Effect of Sulphur and Water Treatments on the Performance of Pd/��-Zeolite Diesel Oxidation Catalysts

Sulphur, sulphur-water, and water pretreatments were done to find out the effect of these compounds on a diesel oxidation Pd/??-zeolite catalyst and ??-zeolite washcoat. After pretreatments, the samples were analysed by BET, XRF, TEM-SEM, and XPS. In addition, the activity of fresh and pretreated Pd/??-zeolite catalysts was studied utilizing the by Gasmet FT-IR in production gas analysis. Sulphur compounds (SO₂ or ?SO₄) were found to have a deactivating effect on the activity of the studied Pd/??-zeolite catalyst.