Encoding Bandpass Signals Using Zero/Level Crossings: A Model-Based Approach

A new approach to representing a time-limited, and essentially bandpass signal x(t) , by a set of discrete frequency values is proposed. The set of discrete frequency values is the set of locations along the frequency axis at which (real and/or imaginary parts of) the Fourier transform of the signal x(t) cross certain levels (especially zero level). Analogously, invoking time-frequency duality, a set of time instants denoting the zero/level crossings of a waveform x(t) can be used to represent a bandlimited spectrum X(f) . The proposed signal representation is based on a simple bandpass signal model that exploits our prior knowledge of the bandwidth/timewidth of the signal. We call it a Sum-of-Sincs (SOS) model, where Sinc stands for the familiar sinx/x function. Given the discrete fequency/time locations, we can accurately reconstruct the signal x(t) or the spectrum X(f) by solving a simple eigenvalue or a least squares problem. Using this approach as the basis, we propose an analysis/synthesis algorithm to decompose and represent complex multicomponent signals like speech over the entire time-frequency region. The proposed signal representation is an alternative to standard analog to discrete conversion based on the sampling theorem, and in principle, possesses some of the desirable attributes of signal representation in natural sensory systems.     

Different applications of Scheffler reflector for renewable energy: a comprehensive review

A fixed focus on receiver maintains constant temperature of receiver and it is achieved by Scheffler reflector. It is a best example of solar energy application used for medium-temperature applications. The present review shows a complete review of Scheffler reflector in solar thermal applications like desalination, coffee-making machine, agricultural application, electricity generation, hot water, cooking and plaster of Paris production. The Scheffler reflector is a best solar energy application in future emerging technologies.     

Investigation on performance analysis of a novel design of the vacuum tube-assisted double basin solar still: an experimental approach

In this present work, the lower basin is connected to the conventional vacuum tubes, hence the temperature of water remains higher throughout the day and the distillate output also remains higher and always releases the latent heat of condensation to the upper basin for heating of water and enhancement of the distillate output. In this research paper, the double basin solar still with vacuum tubes fabricated wastested in climate conditions of Mehsana, (23.6000°N, 72.4000°E), Gujarat, with three different water depths 0.03, 0.04 and 0.05 m inside the lower basin and upper basin for one year time period of January 2012 to December 2012. It has been found that the double basin solar still with 0.03 m depth produced more compared with 0.04 kg and 0.05 m. It has also found that the average distillate output of the present system was found to be 8 with the monetary value of produced water being around 0.37 Rs/kg.     

Synthesis and characterization of gold-conjugated <Emphasis Type="Italic">Backhousia citriodora</Emphasis> nanoparticles and their anticancer activity against MCF-7 breast and HepG2 liver cancer cell lines

Environmentally benign-synthesized gold nanoparticles (Au-NPs) have received substantial attention owing to their biomedical applications, particularly in cancer therapy. In the current study, Backhousia citriodora (B. citriodora) leaf extract was applied as a reducing agent for one-pot synthesis of controlled size Au-NPs. The effect of various parameters such as reaction time, pH, and B. citriodora leaf boiling time on the synthesis of Au-NPs was studied. The characterization of the Au-NPs synthesized at 15.0-min incubation time showed colour change because of the surface plasma resonance band around 530.0 nm. TEM photographs showed spherical morphologies with an average size of 8.40 ± 0.084 nm and zeta potential value was ? 29.74 mV, indicating stability of the nanoparticles. The biomedical properties of Au-NPs and B. citriodora leaf extract showed strong DPPH radical scavenging. The in vitro anticancer activity determined using MTT assay exhibited that Au-NPs showed a significant dose-dependent reduction in the viability of the MCF-7 breast cancer cell line and the HepG2 liver cancer cell line with IC₅₀ values of 116.65 and 108.21 µg, respectively.     

Effect of different polysorbates on development of self-microemulsifying drug delivery systems using medium chain lipids

The primary objective of this study was to develop lipid-based self-microemulsifying drug delivery systems (SMEDDS) without using any organic cosolvents that would spontaneously form microemulsions upon dilution with water. Cosolvents were avoided to prevent possible precipitation of drug upon dilution and other stability issues. Different polysorbates, namely, Tween 20, Tween 40, Tween 60, and Tween 80, were used as surfactants, and Captex 355 EP/NF (glycerol tricaprylate/caprate) or its 1:1 mixture with Capmul MCM NF (glycerol monocaprylocaprate) were used as lipids. Captex 355-Tween-water ternary phase diagrams showed that oil-in-water microemulsions were formed only when the surfactant content was high (80–90%) and the lipid content low (10–20%). Thus, mixtures of Tweens with Captex 355 alone were not suitable to prepare SMEDDS with substantial lipid contents. However, when Captex 355 was replaced with the 1:1 mixture of Captex 355 and Capmul MCM, clear isotropic microemulsion regions in phase diagrams with sizes in the increasing order of Tween 20?相似文献   

Moisture Absorption Behavior of Treated and Untreated Eggshell Particulate Epoxy Composites

Weight gain and thickness swelling in bio-waste composites material leads to an adverse effect on properties. In the present investigation the effect of different environments (saline, mineral, kerosene, subzero temperature) on the physical properties of the composites which are fabricated with unboiled(untreated) and boiled(treated 200 °C) eggshell filler materials are studied. XRD, SEM and ultimate analysis of the unboiled and boiled eggshells are also studied. The composites of different weight percentage 4, 8 and 12 wt% of unboiled and boiled eggshell filler epoxy composites are fabricated by a hand lay-up technique. The 12 wt% of boiled eggshell particulates reinforced epoxy composites showed the highest weight gains when exposed to different environments. Least absorption rate observed was for 4 wt% eggshell filler composite in subzero temperature condition. The composites showed a peculiar environmental behavior when exposed to kerosene.

     

A method for the preliminary design of gears using a reduced number of American Gear Manufacturers Association (AGMA) correction factors

Typically, the preliminary design of mechanical components such as gears is carried out using standardized design processes such as those developed by the American Gear Manufacturers Association (AGMA). These design standards include a large number of ‘correction factors’ to account for various uncertainties. As the knowledge about these uncertainties increases, it becomes possible to include them systematically in the design procedure, thereby reducing the number of empirical correction factors. Robust design provides a way to design in the presence of various uncertainties. In this article, a design method is proposed to eliminate empirical correction factors and is demonstrated by eliminating two correction factors from the AGMA design standards for a spur gear, namely, the factor of safety in contact and the reliability factor by the formal introduction of uncertainty in the magnitude of load and material properties. The proposed method is illustrated with the design of an automotive gear with desired reliability, cost and robustness.     

Biogeography and geo-sciences based land cover feature extraction

This work proposes a biogeography and geo-sciences based soft computing technique which is an extension of original biogeography based feature extraction algorithm using the concept of entropy inspired from the geo-sciences phenomenon of mantle convection and dynamics of the earth. This algorithm uses surface entropy in the relevant band of multi-spectral images as the basis of calculating the habitat suitability index which in turn forms the basis of identifying different terrain features in the satellite image. The proposed work has been primarily developed for the purpose of finding the applications of geo-sciences in developing computationally intelligent models. This may lead to another concept of process randomization, generation of virtual scenarios, etc. which are important ingredients in battlefield assessment. The proposed feature extractor algorithm has been applied on the datasets of Alwar region in Rajasthan and Patalganga area in Shivalik ranges. The results indicate that our proposed geo-sciences based classifier is highly efficient in extracting land cover features. Further when integrated with hybrid bio-inspired intelligent classifier proposed in our previous work, it improves its classification efficiency and outperforms the earlier probabilistic classifiers, recent soft computing classifiers such as membrane computing, hybrid FPAB/BBO, extended non-linear BBO, etc. and the very recent hybrid ACO2/PSO/BBO classifier proposed by us 0080 and 0105. Our results conclude that the classifier based on our proposed model is the best known classifier developed till date. The proposed model is flexible and can adapt itself to suit to a large number of classification problems including mixed pixel resolution, face recognition, pattern recognition, etc. whereby entropy can be simply calculated in any other band or according to its standard definition and hence feature extraction can be made.     

THE EFFECT OF OSMOTIC PRESSURE ON THE PRODUCTION AND EXCRETION OF ETHANOL AND GLYCEROL BY A BREWING YEAST STRAIN*

When the cells of a lager brewing yeast Saccharomyces uvarum (carlsbergensis) were grown in minimal media containing sucrose and a non-metabolized sugar sorbitol, significant levels of intracellular ethanol were obtained. Intracellular ethanol concentration decreased as the osmotic pressure of the medium was lowered and the proportion of extracellular ethanol increased. A reduction in cell viability occurred when there were high levels of intracellular ethanol. The total amount of glycerol produced increased with increased osmotic pressure, but glycerol diffused out of the cells faster than ethanol.