1,721,365 research outputs found
sj-docx-1-wmr-10.1177_0734242X221124069 – Supplemental material for Identification and selection of suitable landfill sites using GIS-based multi-criteria decision analysis in the Peshawar District, Pakistan
No full textSupplemental material, sj-docx-1-wmr-10.1177_0734242X221124069 for Identification and selection of suitable landfill sites using GIS-based multi-criteria decision analysis in the Peshawar District, Pakistan by Iftikhar Ali, Aneeza Islam, Syeda Maria Ali and Syed Adnan in Waste Management & Research</p
High-throughput NMR-based metabolomics: a robust toolbox for searching human disease biomarkers / Syed Adnan Ali Shah
Get PDFMetabolomics deals with the whole ensemble of metabolites (the metabolome). It is a holistic approach to studying systematic metabolic changes in biospecimens such as cells, tissue, organs, or organisms. It is a valuable tool that uniquely connects all "omics" techniques and best represents the phenotype. As one of the -omic sciences, it relates to biology, physiology, pathology and medicine, but metabolites are chemical entities, small organic molecules or inorganic ions. Therefore, their proper identification and quantitation in complex biological matrices require a solid chemical ground [1]. Metabolomics monitors the global outcome of all exogenous and endogenous factors without making assumptions about the effect of any single contribution to that outcome. It makes metabolomics a perfect technique for investigating and understanding the molecular mechanisms of human health and disease
An analysis of the AAḃ asymmetric encryption scheme on embedded devices for IoT environment / Syed Farid Syed Adnan
Get PDFLightweight cryptography offers energy-efficient cryptographic capabilities on low powered devices such as those commonly found in the Internet of Things (IoT). One such lightweight scheme is the AA-Beta (AAḃ) asymmetric cryptographic scheme whose algorithm consists of only basic arithmetic operations of addition and subtraction for both the encryption and decryption processes. These features resulted in faster runtime compared to the more established RS A asymmetric encryption scheme, making AAp a potential alternative for IoT security. At the time of writing this thesis, AAḃ algorithm still exists as a mathematical concept and proven in a mathematical based software. To date, this research found no known practical implementation of the AAḃ algorithm to prove or to validate its efficiency on a real-world computing platform. There has been no analysis of the AAḃ performance on any resource-constrained platform although previous mathematical simulations showed that it would perform well in resource-constrained platforms. It is also not known how the algorithm would perform against the widely used RSA on resource-constrained platforms. This thesis seeks to study the AAḃ design philosophy and the specifications of the AAḃ asymmetric encryption scheme, develop the AAḃ encryption scheme and evaluate the computational speed, power consumption and feasibility of AAḃ encryption scheme on an embedded system in the practical domain. The results from the study are being compared to the mathematical simulation, and experimentally, to the RSA. This investigation takes the form of an IoT environment, beginning with an in-depth examination of the AAḃ encryption scheme design, and continuing into the development and real-world application of AAḃ from its mathematical origin. The experimental analysis focused on the AAḃ algorithm's performance on embedded platforms, namely, the Raspberry Pi microcomputer and microcontroller (ARM Cortex-M7) platforms. A feasibility assessment for an AAḃ cryptosystem for sensor nodes including a client to server testbed with wireless communications was carried out in the final stage. In this research work, the performance analysis of the AAḃ scheme produced remarkable timing improvements for the encryption and decryption of messages when compared to previous trials on a numeric computing environment. The research goes on to compare the energy consumptions for encryption and decryption using the AAḃ AAp scheme with similar processes using the Textbook RSA scheme on the aforesaid embedded platforms. The AAḃ encryption process demonstrates a significantly lower energy consumption compared to RSA, where as much as three times less energy was used by AAḃ when encrypting messages while considerable energy savings were also seen during AAḃ message decryption on the Raspberry Pi 2 and ARM Cortex-M7 device. A conclusion can thus be made that the AAḃ encryption scheme is a cryptographic scheme with a great potential for deployment on low-powered devices especially at the encryption side, offering fast and energy-efficient asymmetric cryptographic capabilities to all devices
Synthesis and characterization of lisicon structured solid electrolytes for potential application in solid state electrochemical cells / Syed Bahari Ramadzan bin Syed Adnan
Get PDFThe aim of this study is to obtain LISICON structured Li4SiO4 based solid electrolyte with adequate conductivity for application in electrochemical cells. The parent and
modified Li4SiO4 compounds were synthesized by sol gel method. The modified compounds were prepared by partial substitution using divalent ion (Li4-2xZnxSiO4), trivalent ion (Li4-3xCrxSiO4), tetravalent ion (Li4SnxSi1-xO4 and Li4ZrxSi1-xO4) and double partial substitution using trivalent and tetravalent ions (Li4-3xCrxZrySi1-yO4). The prepared samples were characterized using various techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscope, energy dispersive X-ray, laser particle analyser, differential scanning calorimetry, impedance spectroscopic, lithium transference number, linear sweep voltammetry and charge-discharge study. The XRD results showed that the Li4SiO4 system can be indexed to monoclinic structure in space group P21/m. The highest bulk, grain boundary and total conductivity of this compound at ambient temperature were 3.36 × 10-6, 1.58 × 10-6 and 1.51 × 10-6 S cm-1 respectively. The frequency dependence of conductivity followed Jonscher's universal power law, σac (ω) = σo + Aωs. The plot of pre-exponent, s versus temperature suggests
that the conduction mechanism in the system can be described using correlated barrier hopping model. The increase in dielectric constant and dielectric loss and peak shift of tan to higher frequencies with temperature indicated that the increase in conductivity with temperature was due to the increase in number and hopping rate of charge carriers with temperature. The effects of partial substitution to this parent compound have also
been investigated. The impedance spectroscopic analysis shows that the conductivity of the parent compound increases with different doping ions. The substitutions using divalent ions Zn2+, (Li3.88Zn0.06SiO4) showed increment of conductivity at ambient temperature. The value of bulk, grain boundary and total conductivity were 3.20 × 10-5 , 2.79 × 10-5 and 1.51 × 10-5 S cm-1 respectively. This effect was due to increase in number of vacant sites in the crystal lattice. Meanwhile, differential scanning calorimetry analysis showed increases in phase transition and melting temperature in this compound indicating the enhancement in thermal stability of the Li4SiO4 compound upon substitutions of Zn2+ to 2Li+ ions. The transference number corresponding to Li+ ion transport value was 0.82 which indicated that the majority of charge carrier in the compound was Li+ ions. The substitutions using Cr3+ into Li4SiO4 structure was confirmed by X-ray diffraction and Fourier transform infrared studies. This partial substitution also showed enhancement of conductivity at ambient temperature. The highest bulk, grain boundary and total conductivity were 7.93 × 10-5, 3.68 × 10-5 and 2.51 × 10-5 S cm-1 respectively for Li3.94Cr0.02SiO4 compound. The scanning electron microscope and particle size analysis showed that particle size decreases with Cr3+ ion doping. The average grain size decreases from 11.8 μm in Li4SiO4 sample to 0.59 μm in Li3.94Cr0.02SiO4 sample. Ionic transference number of Li+ ion determined by means of Bruce and Vincent technique was 0.79 for Li4SiO4 compound is increased to 0.95 for Li3.94Cr0.02SiO4 compound. Linear sweep voltammetry results showed that the doping by Cr3+ ion improved the limit of electrolyte decomposition from 2.73 V in Li4SiO4 to 4.51 V in Li3.94Cr0.02SiO4 versus Li/Li+ reference electrode. The partial substitutions on silicon ion by cation of larger size (Sn4+ and Zr4+) also enhanced the conductivity of Li4SiO4 compound by one order of magnitude. The highest bulk, grain boundary and total conductivity were 1.00 × 10-4, 4.42 × 10-5 and 3.07 × 10-5 S cm-1 respectively for Li4Sn0.02Si0.98O4 compound. Meanwhile, Li4Zr0.06Si0.94O4 compound showed maximum bulk, grain boundary and total conductivity values of 1.19 × 10-4, 4.75 × 10-5 and 3.41 × 10-5 S cm-1 respectively. The size of Sn4+ (0.069 nm) and Zr4+ (0.080 nm), are larger than that of Si4+ (0.041 nm) increased the size of Li+ migration channels which led to increase of ion mobility. The charge carrier concentration was found to be constant over the temperature range from 303 to 773 K while mobility of ion increased with temperature. This was due to increase in ion mobility. Linear sweep voltammetry results showed that Li4Sn0.02Si0.98O4 sample is electrochemically stable in the voltage range of -5.3 to 5.3 V versus Li/Li+ reference electrode. The average particle size for Li4Zr0.06Si0.98O4 was 1.198 μm, is smaller compared to the parent compound. Energy dispersive x-ray analysis also showed that the chemical compositions of the prepared Li4Zr0.06Si0.94O4 samples were very close to the desired compositions. The value of lithium transference number for Li4Zr0.06Si0.94O4 compound was 0.92. This value was higher compared to that of the parent compound. A more significant enhancement occurred on double partial substitutions on Li+ and Si4+ sites by Cr3+ and Zr4+. The DC conductivity at ambient temperature rose to 1.88 × 10-4 S cm-1 in Li3.94Cr0.02Zr0.06Si0.94O4 compound with a maximum value in the order of 10-3 S cm-1 at 500oC. Apart from created vacant sites by Cr3+ doping, the doping by Zr4+ was believed to enlarge the Li+ migration channels of the sample. The lithium transference number also increased to 0.97 in this double substituted compound. Li3.94Cr0.02Zr0.06Si0.94O4 has a maximum discharge capacity of 103 mA h g-1 at constant current of 5 mA g-1 (0.05 C) between 3.0 and 4.2 V. This indicated that this ceramic electrolyte can be used in lithium cells
The study of radio frequency interference (RFI) for radio astronomy in some remote locations in Peninsular Malaysia / Syed Bahari Ramadzan bin Syed Adnan
Get PDFRadio Frequency Interference (RFI) is the main parameter to find the best site for radio astronomy research development. The increasing levels of RFI will pose a big problem for researchers in the radio astronomy field. The radio astronomers are encouraged to choose sites as free as possible from interference. In this research we aimed to survey the RFI at frequency 1 MHz-2000MHz to look the overview of the RFI profile and at frequency 1419 MHz-1421 MHz to monitor the RFI profile at Hydrogen line frequency (1420.4 MHz). We chose Peninsular Malaysia as the research area for RFI observation. We have used the Geographical Information System (GIS) software to find and create the lowest RFI mapping area in Peninsular Malaysia. Proper decision-making processes for selection of lowest RFI sites requires collection of information about various parameters like the density of Malaysian citizen‘s data, communication transmitter station‘s area data, road network, and land contour data. After recognizing a few suitable areas we will commence to the sites and construct the RFI observations. An RFI survey at that selection site will be done using an omni-directional discone antenna in wideband and narrowband methods. This method provides a basic way of determining the strength of the RFI at observation sites. Eventually, the best area base will be decided from the observations. The results of this experiment will support the development of the first radio telescope in Malaysia and provide the suitable area for radio astronomical observations in Peninsular Malaysia. From the GIS analysis, we have found three potential sites. They are Sekayu (Latitude: 04o57.967‘ N, Longitude: 102o57.332‘ E), Bertam (Latitude: 05o09.991‘ N, Longitude: 102o02.764‘ E) and Jelebu (Latitude: 03o 03.108‘ N, Longitude: 102 03.912‘ E). The RFI results showed that Sekayu is the best site for future radio astronomical observation in Peninsular Malaysia with average signals in wideband as -152.32 dBWm-2Hz-1 which is equivalent to 5.86 x 10-16 Jy and in narrowband as -153.93 dBWm-2Hz-1 which is equivalent to 4.04 x 10-16 Jy
Ancient and Nonuniform Loss of Olfactory Receptor Expression Renders the Shark Nose a De Facto Vomeronasal Organ
No full textCartilaginous fishes are renowned for a keen sense of smell, a reputation based on behavioral observations and supported by the presence of large and morphologically complex olfactory organs. At the molecular level, genes belonging to the four families coding for most olfactory chemosensory receptors in other vertebrates have been identified in a chimera and a shark, but it was unknown whether they actually code for olfactory receptors in these species. Here, we describe the evolutionary dynamics of these gene families in cartilaginous fishes using genomes of a chimera, a skate, a sawfish, and eight sharks. The number of putative OR, TAAR, and V1R/ORA receptors is very low and stable, whereas the number of putative V2R/OlfC receptors is higher and much more dynamic. In the catshark Scyliorhinus canicula, we show that many V2R/OlfC receptors are expressed in the olfactory epithelium in the sparsely distributed pattern characteristic for olfactory receptors. In contrast, the other three vertebrate olfactory receptor families are either not expressed (OR) or only represented with a single receptor (V1R/ORA and TAAR). The complete overlap of markers of microvillous olfactory sensory neurons with pan-neuronal marker HuC in the olfactory organ suggests the same cell-type specificity of V2R/OlfC expression as for bony fishes, that is, in microvillous neurons. The relatively low number of olfactory receptors in cartilaginous fishes compared with bony fishes could be the result of an ancient and constant selection in favor of a high olfactory sensitivity at the expense of a high discrimination capability
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
PLC and TRPC2 mediate amino acid detection in the main olfactory epithelium of an amphibian
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