Institute of Engineering Science

The asteroid impact near the Russian city of Chelyabinsk on 15 February 2013 was the largest airburst on Earth since the 1908 Tunguska event, causing a natural disaster in an area with a population exceeding one million. Because it occurred in an era with modern consumer electronics, field sensors, and laboratory techniques, unprecedented measurements were made of the impact event and the meteoroid that caused it. Here, we document the account of what happened, as understood now, using comprehensive data obtained from astronomy, planetary science, geophysics, meteorology, meteoritics, and cosmochemistry and from social science surveys. A good understanding of the Chelyabinsk incident provides an opportunity to calibrate the event, with implications for the study of near-Earth objects and developing hazard mitigation strategies for planetary protection.

A home-based intelligent energy conservation system needs to know what appliances (or loads) are being used in the home and when they are being used in order to provide intelligent feedback or to make intelligent decisions. This analysis task is known as load disaggregation or non-intrusive load monitoring (NILM). The datasets used for NILM research generally contain real power readings, with the data often being too coarse for more sophisticated analysis algorithms, and often covering too short a time period. We present the Almanac of Minutely Power dataset (AMPds) for load disaggregation research; it contains one year of data that includes 11 measurements at one minute intervals for 21 sub-meters. AMPds also includes natural gas and water consumption data. Finally, we use AMPds to present findings from our own load disaggregation algorithm to show that current, rather than real power, is a more effective measure for NILM.

Modern agricultural practices have triggered the process of agricultural pollution. This process can cause the degradation of eco-systems, land, and environment owing to the modern-day by-products of agriculture. The substantial use of chemical fertilizers, pesticides, and, contaminated water for irrigation cause further damage to agriculture. The current scenario of the agriculture and food sector has therefore become unsustainable. Nanotechnology has provided innovative and resourceful frontiers to the agriculture sector by contributing practical applications in conventional agricultural ways and practices. There is a large possibility that agri-nanotechnology can have a significant impact on the sustainable agriculture and crop growth. Recent research has shown the potential of nanotechnology in improving the agriculture sector by enhancing the efficiency of agricultural inputs and providing solutions to agricultural problems for improving food productivity and security. The prospective use of nanoscale agrochemicals such as nanofertilizers, nanopesticides, nanosensors, and nanoformulations in agriculture has transformed traditional agro-practices, making them more sustainable and efficient. However, the application of these nano-products in real field situations raises concern about nanomaterial safety, exposure levels, and toxicological repercussions to the environment and human health. The present review gives an insight into recent advancements in nanotechnology-based agrochemicals that have revolutionized the agriculture sector. Further, the implementation barriers related to the nanomaterial use in agriculture, their commercialization potential, and the need for policy regulations to assess possible nano-agricultural risks are also discussed.

Global warming is considered one of the world's leading challenges in the 21st century as it causes severe concerns such as climate change, extreme weather events, ocean warming, sea-level rise, declining Arctic sea ice, and acidification of oceans.

Summary We consider the problem of testing a given time-series for stationarity. The approach is based on evolutionary spectral analysis, and the proposed method consists essentially in testing the “homogeneity” of a set of evolutionary spectra evaluated at different instants of time. Using a logarithmic transformation, we show that the mechanics of the test are formally equivalent to a two-factor analysis of variance procedure when the residual variance is known, a priori. In addition to testing stationarity, the analysis provides also a method for testing whether the observed series fits a “uniformly modulated” model, and a test for “randomness” (constancy of spectra).

Reduced graphene oxide (rGO) can improve the thermoelectric properties of polyaniline (PANI) by varying its concentration in composites of rGO nanosheets and PANI.

Arsenic is a toxic element and has been responsible for many accidental, occupational, deliberate, and therapeutic poisonings since its discovery in 1250. It occurs in natural waters as the arsenite (As3+) and arsenate (As5+) ions. The solubility of arsenite and arsenate compounds is relatively high so that these ions are readily transported through aqueous routes into the environment. Arsenic can be transferred from soils to crops and accumulates in various food crops and aquatic plants. The fascinating chemistry and toxicity potential make arsenic and its compounds of particular scientific interest and environmental concern. The conventional removal of heavy metals from wastewater, natural waters, and drinking water has only limited effects on arsenic removal. In this review, the main engineering and medical applications, salient health and environmental concerns, novel research on treatment for arsenic poisoning, and removal technologies for arsenic and their derivatives are discussed and enumerated with a view to pursue valuable applied research in order to protect the environment from arsenic toxicity.

The effect of water soluble carbon nano-dots (wsCND) on the growth of root and shoot of wheat plants under light and dark conditions has been studied. The wsCND enhances the growth of root and shoot both in light and dark conditions. The effect of wsCND on the growth of root was relatively more compared to that of shoot. Scanning electron and Fluorescence microscopic analysis show that wsCNDs enter inside the plant. Raman spectroscopy also confirms this. The present study shows that wsCNDs are non-toxic to the wheat plant and can be used to enhance the production of this cereal crop.

OBJECTIVE: Diabetic retinopathy (DR) is characterized by the progressive deterioration of retina with the appearance of different types of lesions that include microaneurysms, hemorrhages, exudates, etc. Detection of these lesions plays a significant role for early diagnosis of DR. METHODS: To this aim, this paper proposes a novel and automated lesion detection scheme, which consists of the four main steps: vessel extraction and optic disc removal, preprocessing, candidate lesion detection, and postprocessing. The optic disc and the blood vessels are suppressed first to facilitate further processing. Curvelet-based edge enhancement is done to separate out the dark lesions from the poorly illuminated retinal background, while the contrast between the bright lesions and the background is enhanced through an optimally designed wideband bandpass filter. The mutual information of the maximum matched filter response and the maximum Laplacian of Gaussian response are then jointly maximized. Differential evolution algorithm is used to determine the optimal values for the parameters of the fuzzy functions that determine the thresholds of segmenting the candidate regions. Morphology-based postprocessing is finally applied to exclude the falsely detected candidate pixels. RESULTS AND CONCLUSIONS: Extensive simulations on different publicly available databases highlight an improved performance over the existing methods with an average accuracy of and robustness in detecting the various types of DR lesions irrespective of their intrinsic properties.

A {010} and {110} facet-dominated BiVO₄/Fe-based LDH core/shell nanostructure was fabricated by an interface engineering strategy and it boosted photoelectrochemical oxygen evolution performance due to enhanced light absorption and increased interfacial charge transfer.

Reduced graphene oxide (rGO) generates reactive oxygen species (ROS) under visible light in air<italic>via</italic>a singlet oxygen–superoxide anion radical pathway that readily kills<italic>Enterobacter</italic>sp.

Untreated HIV-1 infection progresses through acute and asymptomatic stages to AIDS. Although each of the three stages has well-known clinical, virologic, and immunologic characteristics, much less is known of the molecular mechanisms underlying each stage. In this study, we report lymphatic tissue microarray analyses, revealing for the first time stage-specific patterns of gene expression during HIV-1 infection. We show that although there is a common set of key genes with altered expression throughout all stages, each stage has a unique gene expression signature. The acute stage is most notably characterized by increased expression of hundreds of genes involved in immune activation, innate immune defenses (e.g., RIG-1, MDA-5, TLR7 and TLR8, PKR, APOBEC3B, 3F, 3G), adaptive immunity, and in the proapoptotic Fas-Fas ligand pathway. Yet, quite strikingly, the expression of nearly all acute stage genes return to baseline levels in the asymptomatic stage, accompanying partial control of infection. This transition from acute to asymptomatic stage is tied to increased expression of a diverse array of immunosuppressive genes (e.g., CLEC12B, ILT4, galectin-3, CD160, BCMA, FGL2, LAG3, GPNMB). In the AIDS stage, decreased expression of numerous genes involved in T cell signaling identifies genes contributing to T cell dysfunction. These common and stage-specific gene expression signatures identify potential molecular mechanisms underlying the host response and the slow, natural course of HIV-1 infection.

The influence of copper oxide nanoparticles on the polymorphism of PVDF is systematically investigated. Strong interfacial interactions between the negative nanoparticle surface and positive –CH₂dipoles of PVDF enhance the electroactive β-phase.

Tin dioxide (SnO₂) is a material of ever increasing scientific attention as a result of its many constructive and varied physical properties: different morphological structures of SnO2 nanocrystals modulate the performance of diverse applications.

The Kyoto protocol was negotiated as a global effort to reduce greenhouse gas (GHG) emissions. The future standing of companies will be seriously affected by the steps they take today in regards to the environment. Perhaps, if vigilant actions are not taken by a firm then it could easily be left behind in today's highly competitive world. This paper presents a novel optimization model for green supply chain management, which integrates environmental management and its impact into the supply chain while taking carbon emissions into account. The model, which we formulate as a mixed-integer program (MIP), can help to reveal an optimal strategy for companies to meet their carbon cap, while minimizing opportunity cost. We demonstrate the viability of the model via a computational study.

Probiotic strains of Lactobacillus have been studied for their inhibitory effects on Candida albicans. However, few studies have investigated the effect of these strains on biofilm formation, filamentation and C. albicans infection. The objective of this study was to evaluate the influence of Lactobacillus acidophilus ATCC 4356 on C. albicans ATCC 18804 using in vitro and in vivo models. In vitro analysis evaluated the effects of L. acidophilus on the biofilm formation and on the capacity of C. albicans filamentation. For in vivo study, Galleria mellonella was used as an infection model to evaluate the effects of L. acidophilus on candidiasis by survival analysis, quantification of C. albicans CFU/mL, and histological analysis. The direct effects of L. acidophilus cells on C. albicans, as well as the indirect effects using only a Lactobacillus culture filtrate, were evaluated in both tests. The in vitro results showed that both L. acidophilus cells and filtrate were able to inhibit C. albicans biofilm formation and filamentation. In the in vivo study, injection of L. acidophilus into G. mellonella larvae infected with C. albicans increased the survival of these animals. Furthermore, the number of C. albicans CFU/mL recovered from the larval hemolymph was lower in the group inoculated with L. acidophilus compared to the control group. In conclusion, L. acidophilus ATCC 4356 inhibited in vitro biofilm formation by C. albicans and protected G. mellonella against experimental candidiasis in vivo.

Abstract In the present work we have studied a prey–predator model with logistic growth of the prey in the absence of the predator. We have also considered the fear effect and have investigated the impact of fear of the predator on prey when the predator is provided additional food. Functional responses of the predator towards prey and additional food are derived in this text. Death rates of both prey and predator have been considered as stochastic parameters due to the effect of the fluctuating environment. Existence and uniqueness, boundedness and uniform continuity of the global positive solution of the proposed model have been established. The conditions for extinction and persistence of the system have been derived. In the investigation, it is found that environmental noise plays a vital role in extinction as well as in persistence. Our analytical derivations are justified through numerical simulations which show the reliability of the model from the ecological point of view. We have also investigated the impact of intense fear as well as the absence of fear on this model by numerical simulation. Several interesting numerical results have been obtained based on different fear functions.

Mesoporous and core–shell like (p)CuO–(n)ZnO nanocomposites were prepared using microstructural refinement and solid state reactions, which showed enhanced photochemical and electrochemical performances.

Poly(vinylidene fluoride) (PVDF) nanocomposites are recently gaining importance due to their unique dielectric and electroactive responses. In this study, GeO2 nanoparticles/PVDF and SiO2 nanoparticles/PVDF nanocomposite films were prepared by a simple solution casting technique. The surface morphology and structural properties of the as-prepared films were studied by X-ray diffraction, scanning electron microscopy, and FT-IR spectroscopy techniques. The studies reveal that the incorporation of GeO2 or SiO2 nanoparticles leads to an enhancement in the electroactive β phase fraction of PVDF due to the strong interactions between the negatively charged nanoparticle surface and polymer. Analysis of the thermal properties of the as-prepared samples also supports the increment of the β phase fraction in PVDF. Variation of dielectric constant, dielectric loss, and ac conductivity with frequency and loading fraction of the nanoparticles were also studied for all the as-prepared films. Dielectric constant of the nanocomposite films increases with increasing nanofiller concentration in PVDF. 15 mass% SiO2-loaded PVDF film shows the highest dielectric constant, which can be attributed to the smaller size of SiO2 nanoparticles and the homogeneous and discrete dispersion of SiO2 nanoparticles in PVDF matrix.

Our designed chemosensor, rhodamine-HBT-dyad (RHD), selectively detects two biologically important ions (Al³⁺ and Zn²⁺) at two different wavelengths (red and green, respectively) through FRET and ESIPT <italic>in vitro</italic> and <italic>in vivo</italic>.