312 research outputs found
Impact of Harsh Environmental Conditions on Nodule Formation and Dinitrogen Fixation of Legumes
Strongyloides stercoralis hyperinfection in a post-renal transplant patient
Strongyloides stercoralis is an intestinal nematode that is able to infect the host tissue and persist asymptomatic for many years through autoinfection. It causes life-threatening hyperinfection in immunocompromised hosts. This report describes a rare case of strongyloidiasis in a 40-year-old male following renal transplant, which was diagnosed by colonoscopic biopsy. The literature on the subject is also reviewed
A new approach for enhancing LSB steganography using bidirectional coding scheme
This paper proposes a new algorithm for embedding private information within a cover image. Unlike all other already existing algorithms, this one tends to employ the data of the carrier image more efficiently such that the image looks less distorted. As a consequence, the private data is maintained unperceived and the sent information stays unsuspicious. This task is achieved by dividing the least significant bit plane of the cover image into fixed size blocks, and then embedding the required top-secret message within each block using one of two opposite ways depending on the extent of similarity of each block with the private information needed to be hidden. This technique will contribute to lessen the number of bits needed to be changed in the cover image to accommodate the private data, and hence will substantially reduce the  amount of distortion in the stego-image when compared to the classic LSB image steganography algorithms
Development of an ANN Model for RGB Color Classification using the Dataset Extracted from a Fabricated Colorimeter
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Codes of red, green, and blue data (RGB) extracted from a lab-fabricated colorimeter device were used to build a proposed classifier with the objective of classifying colors of objects based on defined categories of fundamental colors. Primary, secondary, and tertiary colors namely red, green, orange, yellow, pink, purple, blue, brown, grey, white, and black, were employed in machine learning (ML) by applying an artificial neural network (ANN) algorithm using Python. The classifier, which was based on the ANN algorithm, required a definition of the mentioned eleven colors in the form of RGB codes in order to acquire the capability of classification. The software's capacity to forecast the color of the code that belongs to an object under detection is one of the results of the proposed classifier. The work demanded the collection of about 5000 color codes which in turn were subjected to algorithms for training and testing. The open-source platform TensorFlow for ML and the open-source neural network library Keras were used to construct the algorithm for the study. The results showed an acceptable efficiency of the built classifier represented by an accuracy of 90% which can be considered applicable, especially after some improvements in the future to makes it more effective as a trusted colorimeter.
Inexpensive organic dyes-sensitized zinc oxide nanoparticles photoanode for solar cells devices
Zinc oxide nanoparticles (ZnO NPs) were synthesized using a hydrothermal route.
The prepared ZnO NPs were characterized by x-ray diffraction (XRD), high-resolution transmission
electron microscopy (HR-TEM), UV–vis spectroscopy, and photoluminescence (PL)
spectroscopy. The XRD patterns confirmed the standard hexagonal wurtzite structure of
ZnO NPs, and the calculated value of the average particle size was 23.34 nm. HR-TEM micrographs
of ZnO NPs showed semispherical particle morphologies and their sizes lie between 10
and 40 nm. The estimated average size distribution of ZnO NPs was 21.35 6.01 nm. UV–vis
spectrum of ZnO NPs revealed the highest absorption band at 360.5 nm, and the Eg was
3.70 0.01 eV. The PL spectrum emission was deconvoluted by eight peaks into two regions
[near-ultraviolet (NUV) and visible that caused from the defects]. Two groups of dye-sensitized
solar cells (DSSCs) thin film devices based on ZnO NPs were sensitized in different concentration
solutions of 0.1, 0.32, and 0.5 mM of eosin B (EB) and eosin Y (EY) dyes. The sensitized
DSSCs device with 0.32-mM dye of EY displayed higher efficiency and its performance parameters
are much better among all other fabricated DSSCs devices. The short current density (Jsc)
increased from 1.59 to 4:97 mA∕cm2 and the Voc enhanced from 0.36 to 0.46 V. The conversion
efficiency from light to electricity showed a significant improvement from 0.29% to 0.94%. The
transient open circuit photovoltage decay (TOCPVD) was measured to estimate the apparent
electron lifetime or response time (Ï„n) or the electron recombination rate (krec), using the double
exponential function for first time to fit the experiment data of TOCPVD. The results revealed
that the EY dye can be used as an efficient and an inexpensive dye for DSSCs.This research activity carried out between Gaza and Cairo-Egypt was financially supported
by Qatar Charity IBHATH Project grant funded by the Gulf Cooperation Council for the
Reconstruction of Gaza through the Islamic Development Bank.Zinc oxide nanoparticles (ZnO NPs) were synthesized using a hydrothermal route.
The prepared ZnO NPs were characterized by x-ray diffraction (XRD), high-resolution transmission
electron microscopy (HR-TEM), UV–vis spectroscopy, and photoluminescence (PL)
spectroscopy. The XRD patterns confirmed the standard hexagonal wurtzite structure of
ZnO NPs, and the calculated value of the average particle size was 23.34 nm. HR-TEM micrographs
of ZnO NPs showed semispherical particle morphologies and their sizes lie between 10
and 40 nm. The estimated average size distribution of ZnO NPs was 21.35 6.01 nm. UV–vis
spectrum of ZnO NPs revealed the highest absorption band at 360.5 nm, and the Eg was
3.70 0.01 eV. The PL spectrum emission was deconvoluted by eight peaks into two regions
[near-ultraviolet (NUV) and visible that caused from the defects]. Two groups of dye-sensitized
solar cells (DSSCs) thin film devices based on ZnO NPs were sensitized in different concentration
solutions of 0.1, 0.32, and 0.5 mM of eosin B (EB) and eosin Y (EY) dyes. The sensitized
DSSCs device with 0.32-mM dye of EY displayed higher efficiency and its performance parameters
are much better among all other fabricated DSSCs devices. The short current density (Jsc)
increased from 1.59 to 4:97 mA∕cm2 and the Voc enhanced from 0.36 to 0.46 V. The conversion
efficiency from light to electricity showed a significant improvement from 0.29% to 0.94%. The
transient open circuit photovoltage decay (TOCPVD) was measured to estimate the apparent
electron lifetime or response time (Ï„n) or the electron recombination rate (krec), using the double
exponential function for first time to fit the experiment data of TOCPVD. The results revealed
that the EY dye can be used as an efficient and an inexpensive dye for DSSCs
X-Ray Spectral Study of AGN Sources Content in Some Deep Extragalactic XMM-Newton Fields
We undertake a spectral study of a sample of bright X-ray sources taken from
six XMM-Newton fields at high galactic latitudes, where AGN are the most
populous class. These six fields were chosen such that the observation had an
exposure time more than 60 ksec, had data from the EPIC-pn detector in the
full-Frame mode and lying at high galactic latitude . The analysis
started by fitting the spectra of all sources with an absorbed power-law model,
and then we fitted all the spectra with an absorbed power-law with a low energy
black-body component model.The sources for which we added a black body gave an
F-test probability of 0.01 or less (i.e. at 99% confidence level), were
recognized as sources that display soft excess. We perform a comparative
analysis of soft excess spectral parameters with respect to the underlying
power-law one for sources that satisfy this criterion. Those sources, that do
not show evidence for a soft excess, based on the F-test probability at a 99%
confidence level, were also fitted with the absorbed power-law with a low
energy black-body component model with the black-body temperature fixed at 0.1
and 0.2 keV. We establish upper limits on the soft excess flux for those
sources at these two temperatures. Finally we have made use of Aladdin
interactive sky atlas and matching with NASA/IPAC Extragalactic Database (NED)
to identify the X-ray sources in our sample. For those sources which are
identified in the NED catalogue, we make a comparative study of the soft excess
phenomenon for different types of systems
Influence of Metal Ion Doping of Zinc Oxide Photoanode on the Efficiency of Dye Sensitized Solar Cell
Doping zinc oxide nanoparticles (ZnO NPs) and doped with Niobium (Nb5+) and Aluminium (Al3+) ions were synthesized to use as a photoanode for the Dye Sensitized Solar Cells (DSSCs). The structural of the synthetized samples were examined via X-ray diffraction (XRD).
The XRD patterns for all samples confirmed the hexagonal wurtzite structure. The DSSCs based on the undoped and doped ZnO NPs were fabricated and assembled. Scanning electron microscopic
(SEM) images were measured for all fabricated devices. The doping Nb5+ and Al3+ ions influenced the performance of the DSSCs. ZnO NPs doped Nb5+ led to higher surface area and hence more dye loading and retard the recombination of charges, which enhanced the open circuit voltage
Production and Estimation of Keratinase by Immobilized and Free Bacillus licheniformis (St. 24)
Abstract Alginate immobilized Bacillus licheniformis (St. 24) were isolated from chicken feather wastes recorded higher keratinase production than free bacterial suspension. 2-3% alginate concentration, medium pellet size, and in addition of keratin powder as adjuvant were optimum for keratinase production by the immobilized bacteria. Encapsulated B. licheniformis st. 24 was successfully produced keratinase for three repeated batch fermentation cycles each 24 hour incubation period. Immobilization of the whole cells proved to be useful for continuous production of keratinase and feather degradation
Effects of sand and gating architecture on the performance of foot valve lever casting components used in pump industries
Funding Information: The authors thank Kalasalingam Academy of Research and Education, Krishnankoil for providing the facilities for various tests and characterizations. The King Saud University authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project no. RG-148. This Research was funded by King Mongkut's University of Technology North Bangkok has received funding support from the National Science, Research and Innovation Fund (NSRF) (Grant No. KMUTNB-MHESI-64-16.1). Publisher Copyright: © 2021 The Author(s)This work addresses manufacture, testing and simulation of foot valve lever (FVL) for monoblock pump industry, using a cost-effective casting design process. The impact of different types of sands, such as air-set, dry and sodium silicate as well as gating designs, namely H-, U- and O-type, were studied with respect to surface roughness and porosity. The mold pattern was produced using additive manufacturing (AM) technology. Both experimental and numerical investigations were performed on the temperature distribution of molten metal at random locations for the different gating configurations or designs, considering mold filling and solidification. It was evident from the experimental investigation that contribution of air-set sand and O-type gating architecture showed limited consistency effects. Importantly, gating architecture was the most influential parameter to determine all specified quality outcomes, independent of sand mold. An order of O < H < U-type was obtained from the gating designs for minimal surface roughness and percentage of porosity. Furthermore, the microstructure analysis depicted only an irregular defect with minimum quantity at both surface and cross-section of O-type at two different locations. Optimum pouring temperatures of 740, 750 and 790 °C were obtained for mold filling of all 24 components of H-, O- and U-type of gating designs, respectively. The varying solidification temperature was observed from real time thermocouple reading, which was in close agreement with the numerical simulation. Evidently, O-type of gating design exhibited best performance for large-scale development of the FVL in terms of surface roughness, porosity and cooling effects.Peer reviewe
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