An efficient image encryption scheme using elementary cellular automata with novel permutation box

Multimedia Tools and Applications - Digital image communication over public networks requires a high level of security to protect picture elements that represent information. Security is an...     

Machine learning approach for automatic diagnosis of Chlorosis in Vigna mungo leaves

Multimedia Tools and Applications - Viral infection in crops is something that may lead to a huge loss in crop yield as there are no known recovery procedures. Also, at the onset of yellowing in a...     

Enhancement in the limit of detection of lab-on-chip microfluidic devices using functional nanomaterials

Technological developments in recent years have witnessed a paradigm shift towards lab-on-chip devices for various diagnostic applications. Lab-on-chip technology integrates several functions typically performed in a large-scale analytical laboratory on a small-scale platform. These devices are more than the miniaturized versions of conventional analytical and diagnostic techniques. The advances in fabrication techniques, material sciences, surface modification strategies, and their integration with microfluidics and chemical and biological-based detection mechanisms have enormously enhanced the capabilities of these devices. The minuscule sample and reagent requirements, capillary-driven pump-free flows, faster transport phenomena, and ease of integration with various signal readout mechanisms make these platforms apt for use in resource-limited settings, especially in developing and underdeveloped parts of the world. The microfluidic lab-on-a-chip technology offers a promising approach to developing cost-effective and sustainable point-of-care testing applications. Numerous merits of this technology have attracted the attention of researchers to develop low-cost and rapid diagnostic platforms in human healthcare, veterinary medicine, food quality testing, and environmental monitoring. However, one of the major challenges associated with these devices is their limited sensitivity or the limit of detection. The use of functional nanomaterials in lab-on-chip microfluidic devices can improve the limit of detection by enhancing the signal-to-noise ratio, increasing the capture efficiency, and providing capabilities for devising novel detection schemes. This review presents an overview of state-of-the-art techniques for integrating functional nanomaterials with microfluidic devices and discusses the potential applications of these devices in various fields.     

pH-Responsive and Reversible A-Motif-Based DNA Hydrogel: Synthesis and Biosensing Application**

Functional DNA hydrogels with various motifs and functional groups require perfect sequence design to avoid cross-bonding interference with themselves or other structural sequences. This work reports an A-motif functional DNA hydrogel that does not require any sequence design. A-motif DNA is a noncanonical parallel DNA duplex structure containing homopolymeric deoxyadenosines (poly-dA) strands that undergo conformation changes from single strands at neutral pH to a parallel duplex DNA helix at acidic pH. Despite this and other advantages over other DNA motifs like no cross-bonding interference with other structural sequences, the A-motif has not been explored much. We successfully synthesized a DNA hydrogel by using an A-motif as a reversible handle to polymerize a DNA three-way junction. The A-motif hydrogel was initially characterized by electrophoretic mobility shift assay, and dynamic light scattering, which showed the formation of higher-order structures. Further, we used imaging techniques like atomic force microscopy and scanning electron microscope to validating its hydrogel like highly branched morphology. pH-induced conformation transformation from monomers to gel is quick and reversible, and was analysed for multiple acid-base cycles. The sol-to-gel transitions and gelation properties were further examined in rheological studies. The use of the A-motif hydrogel in the visual detection of pathogenic target nucleic acid sequence was demonstrated for the first time in a capillary assay. Moreover, pH-induced hydrogel formation was observed in situ as a layer over the mammalian cells. The proposed A-motif DNA scaffold has enormous potential in designing stimuli-responsive nanostructures that can be used for many biological applications.     

TFET on Selective Buried Oxide (SELBOX) Substrate with Improved ION/IOFF Ratio and Reduced Ambipolar Current

Silicon - This paper proposes a new structure for tunnel field effect transistor on a selective buried oxide (SELBOX) substrate. An extensive simulation study and a comparative performance analysis...     

Microalgae growth for nutrient recovery from sludge liquor and production of renewable bioenergy

Proof-of-concept has been demonstrated for a process that will utilize nutrients from sludge liquor, natural light, and CO2 from biogas to grow microalgae at wastewater treatment plants. This process will reduce the impact of returning side-streams to the head of the plant. The produced algae will be fed to anaerobic digesters for increased biogas production. Dewatering of anaerobically digested sludge in centrifuges produces reject water with extremely low transmittance of light. A pretreatment procedure was developed that improved light transmittance for reject water from the FREVAR, Norway, wastewater treatment plant from 0.1% T to 77% T (670 nm, 1 cm path). Chlorella sp. microalgae were found to be suitable for growth in this pre-treated reject water. Typical nitrogen removal was 80-90 g N/kg TSS of produced microalgae. The microalgae were successfully harvested by chemically assisted flocculation followed by straining through a 33 microm sieve cloth, achieving up to 99% recovery. Harvested algae were anaerobically co-digested with wastewater sludge. The specific methane gas production (mL CH4/g VS fed) for the algae varied from less than 65% to 90% of the specific methane gas production for the wastewater sludge, depending on digester temperature, retention time and pre-treatment of the algae biomass.     

Flow structure and scour around circular compound bridge piers – A review

Large amount of literature is presently available on the topic of scour around uniform piers and its control. However, relatively fewer studies have been carried out so far on the topic of flow field and scour around compound piers. The state of art on the topic of flow structure and scour around circular compound piers is presented herein. The available literature reveals that variations in foundation and pier geometry significantly affect the maximum depth of scour and its temporal variation. In case of compound piers the scour depth is highly sensitive to the change in elevation of the top surface of the foundation well. As compared to uniform piers, a reduction is observed in maximum depth of scour around compound pier when the top surface of the well is kept below the general level of river bed. These observations however are yet to be quantified. Results from an experimental study on flow field around the compound piers are also presented.     

Uncertainty Assessment in Cognitive Load for Multiple Object Tracking Based on EEG

Cognitive load varies the attention level, which has serious consequences in complex dynamic situations. Assessment of uncertainty in cognitive load during multiple object tracking task is necessary, as it is used to improve the cognitive capabilities. The present research work investigates the uncertainty in cognitive load of multiple object tracking task using electroencephalograph (EEG) on 25 football players. A d2 test of neuropsychological measure of attention was employed before starting the experiment. Each player participated in four levels of the task with variation in the cognitive load, which varies in terms of the targets from 2 to 5. Percentage changes in the power spectral density were estimated for the cognitive levels. Results show that the percentage changes were much more in high cognitive load than in low cognitive load. Significant changes (p < 0.05) were observed in level 1 (− 11.07 to 1.91%), level 2 (− 3.13 to − 14.51%), level 3 (− 6.33 to − 19.46%) and level 4 (− 8.10 to − 20.88%). Variation in the EEG data in terms of the combined uncertainty corresponds very well with low to high cognitive loads. The fourth level of the task with high cognitive load has more uncertainty than the low cognitive load levels. The results are useful for assessing the cognitive state of the player, which is valuable for the design of the effective training model.     

Robust object tracking with crow search optimized multi-cue particle filter

Pattern Analysis and Applications - Particle filter is used extensively for estimation of target nonlinear and non-Gaussian state. However, its performance suffers due to its inherent problem of...     

Lanthanide Doped Near Infrared Active Upconversion Nanophosphors: Fundamental Concepts,Synthesis Strategies,and Technological Applications

Near infrared (NIR) light utilization in a range of current technologies has gained huge significance due to its abundance in nature and nondestructive properties. NIR active lanthanide (Ln) doped upconversion nanomaterials synthesized in controlled shape, size, and surface functionality can be combined with various pertinent materials for extensive applications in diverse fields. Upconversion nanophosphors (UCNP) possess unique abilities, such as deep tissue penetration, enhanced photostability, low toxicity, sharp emission peaks, long anti‐Stokes shift, etc., which have bestowed them with prodigious advantages over other conventional luminescent materials. As new generation fluorophores, UCNP have found a wide range of applications in various fields. In this Review, a comprehensive overview of lanthanide doped NIR active UCNP is provided by discussing the fundamental concepts including the different mechanisms proposed for explaining the upconversion processes, followed by the different strategies employed for the synthesis of these materials, and finally the technological applications of UCNP, mainly in the fields of bioimaging, drug delivery, sensing, and photocatalysis by highlighting the recent works in these areas. In addition, a brief note on the applications of UCNP in other fields is also provided along with the summary and future perspectives of these materials.