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Centre filling of a cylindrical silo results in a peaked grain pile with a high concentration of fines in the bulk core restricting airflow. Fines are also known to have higher mycotoxin levels than whole grain. Coring is recommended to minimise fines and to increase localised airflow through the top grain regions. However, the proportion of coring is not a generalised factor when silo dimensions and fan capacities are considered. Also, the coring proportion used should be minimised to maximise storage capacity and provide good economic returns. A study of sequential coring was conducted using a computational fluid dynamics method to predict the optimised coring volume for a 1000 t silo fitted with 3 kW and 5 kW fans. Each configuration following coring was validated using airflow data measured on the top grain surface of the 12.8 m diameter on-farm silo. Results showed that the model predicted standard errors of 0.0009–0.0024 m s−1 for 16 t, 32 t, 48 t, 80 t, and 158 t coring cases. When fully loaded, around 9% (80 t) of the total mass was required to be unloaded to exhibit the desired airflow in the top-grain region using a 3 kW fan. However, the unloaded mass decreased to 2% (16 t) for the same effect with a 5 kW fan. Thus, a 5 kW fan was recommended as it decreased the proportion of dead zones in the lower bulk region by 65% in a typical 1000 t silo. Refereed/Peer-reviewed

The change in optical properties on exposure to radiation has been studied for polyvinyl alcohol, 2, 3, 5-triphenyl tetrazolium chloride salt dyed films. The comparative results between the two different dyes namely methyl orange and di-methyl yellow have been studied for the change in color for the application of dosimeter. The film samples exposed at different doses from 0 to 30 kGy by exposing gamma rays using 60Cobalt gamma source at 0.95 kGy/hour. The visual color change from yellow to red for films containing methyl orange dye whereas change in color from greenish-yellow to red for films containing di-methyl yellow dye have been observed after gamma irradiation and confirmed using various characterization techniques. Colorimetric analysis shows differentiation between the visual color change by comparing colorimetric coordinates like L* a* and b* to each other. Whereas the change in absorption band by UV–Visible spectrophotometer shows an increase in the absorption with an increase in the doses. The FT-IR analysis reveals the change in structural groups. The reproducibility and post-stability studies established and further considered to be used as a routine dosimeter.

The influence of irradiation on optical and structural properties of the gel dosimeter composed of polyvinyl alcohol based BR 29 dyed gel. The comparative results between the gel with and without silver nitrate have been studied. The gel samples subjected to gamma irradiation at dose 1–5, 10, 15, 20, 25 and 30 kGy in a controlled manner using 60Cobalt gamma source at 0.95 kGy/h. The color change from red to pale yellow to colorless has been observed after gamma irradiation which have been confirmed by measuring the absorbance. Addition of silver nitrate to the gel solution enhances the intensity of absorbance, it specifically slowdowns the fading of color. UV–Vis spectrophotometer shows the decrease in absorbance with an increase in absorbed dose. The crosslinking network formed has been confirmed by swelling percentage and gel content. The percentage of swelling increases with the time duration but declines with the increase in the irradiation dose. The corresponding progress in gel content of the samples indicates the crosslinking pattern of the gel from 20 kGy and attains equilibrium at 30 kGy. The proper formation of gel have been found to be between 20 and 30 kGy. The FT-IR analysis reveals the modification in the functional groups. The bound water and the free water content have been carried out using TGA and DSC.

The Indian Shield is cross-cut by a number of distinct Paleoproterozoic mafic dyke swarms. The density of dykes in the Dharwar and Bastar Cratons is amongst the highest on Earth. Globally, boninitic dyke swarms are rare compared to tholeiitic dyke swarms and yet they are common within the Southern Indian Shield. Geochronology and geochemistry are used to constrain the petrogenesis and relationship of the boninitic dykes (SiO2 = 51.5 to 55.7 wt%, MgO = 5.8 to 18.7 wt%, and TiO2 = 0.30 wt% to 0.77 wt%) from the central Bastar Craton (Bhanupratappur) and the NE Dharwar Craton (Karimnagar). A single U-Pb baddeleyite age from a boninitic dyke near Bhanupratappur yielded a weighted-mean 207Pb/206Pb age of 2365.6 ± 0.9 Ma that is within error of boninitic dykes from the Dharwar Craton near Karimnagar (2368.5 ± 2.6 Ma) and farther south near Bangalore (2365.4 ± 1.0 Ma to 2368.6 ± 1.3 Ma). Rhyolite-MELTS modeling indicates that fractional crystallization is the likely cause of major element variability of the boninitic dykes from Bhanupratappur whereas trace element modeling indicates that the primary melt may be derived from a pyroxenite mantle source near the spinel-garnet transition zone. The Nd isotopes (eNd(t) = −6.4 to +4.5) of the Bhanupratappur dykes are more variable than the Karimnagar dykes (eNd(t) = −0.7 to +0.6) but they overlap. The variability of Sr-Nd isotopes may be related to crustal contamination during emplacement or is indicative of an isotopically heterogeneous mantle source. The chemical and temporal similarities of the Bhanupratappur dykes with the dykes of the Dharwar Craton (Karimnagar, Penukonda, Chennekottapalle) indicate they are members of the same giant radiating dyke swarm. Moreover, our results suggest that the Bastar and Dharwar Cratons were adjacent but likely had a different configuration at 2.37 Ga than the present day. It is possible that the 2.37Ga dyke swarm was related to a mantle plume that assisted in the break-up of an unknown or poorly constrained supercontinent.

The present work deals with a comparative study concerning the combined influence of ER fluid lubrication and surface texturing on the performance of two-lobe/circular non-recessed hybrid journal bearings compensated with various types of flow control devices respectively. In order to describe the behavior of electro-rheological lubricant, Continuous Bingham model has been used. Further, the solution of modified Reynolds equation has been obtained with the help of FEM approach. The comparative study revealed that the ER fluid lubricated CFV compensated two-lobe (δ = 1.1) non-recessed journal bearings gives superior performance vis-a-vis other compensating elements like capillary, orifice and slot-entry. Besides this, it has been noticed that the textured non-recessed journal bearings (two-lobe/circular) improves the bearing performance significantly for capillary, orifice and slot-entry restrictor except CFV restrictor. The numerically simulated results presented in this paper may help in proper selection of restrictor, lubricant and bearing configuration so as to get the desired performance.

Modelling airflow in large stored grain silos has been dealt with superficial velocities and with uniform airflow resistance across the bulk. However, superficial velocities are always lower than physical velocities in an isotropic medium. Besides, due to varying grain properties, there is a high potential of variation in airflow resistances along the vertical and horizontal directions. Thus, a 3D CFD model was developed considering physical velocity in an anisotropic porous media to predict airflow and static pressure distribution from a V-shaped aeration floor. Varying airflow resistances along the horizontal direction of an element were incorporated into the model to account for the variation in grain properties. Mesh independency tests were conducted for achieving numerical stability during the steady-state simulation. The model was validated using the static pressure taps and airflow data measured in an on-farm grain storage silo. A 0.35 m mesh size was optimized using the static pressure and airflow data in the silo model. Least error for static pressure and airflow predictions were observed when horizontal airflow resistance was 50% of the vertical airflow resistance. Furthermore, the model predicted that 14.3% of the total grain volume exhibited a low airflow rate below the recommended value of 2 L s−1 t−1 including a significant proportion of the top grain volume above the eave height. Due to 85% of the non-perforated section on the silo floor, 12.6% of the lower grain volume up to a maximum height of 4.4 m above the floor exhibited the low airflow regime. As physical experimentations are tedious, the proposed physical velocity based model could be extended for simulating different options for minimizing dead zone proportions for better grain storage management Refereed/Peer-reviewed

We experimentally find a practical stimulated Brillouin scattering (SBS) threshold for broadband high-performance fiber optical parametric devices relying on dispersion-stable GeO2-doped silica highly nonlinear fibers. We demonstrate that SBS limits the nonlinear phase shift in such fibers to ~0.3 rad per pump unless the SBS is mitigated in some way. We consequently derive corresponding limits on signal gain and conversion efficiency and find the required SBS mitigation factor for a range of fiber optic parametric devices’ applications. Finally, we examine the level of SBS mitigation using air gaps and fiber tapers for implementation in polarization-insensitive fiber optic parametric devices employing bidirectional loops. We observe that an air gap or fiber taper are not very efficient for SBS mitigation as they provided an increase in SBS threshold up to 0.7 dB attributed primarily to their excess loss.

Rutile TiO2 nanoparticle with high dielectric constant has already become an automatic choice as a favorable nanofiller for efficacious transformer oil (TO) nanofluids (NFs) development, thanks to their large surface area and splendid electron trapping capacity. In this work, the role of phase and morphology of TiO2 on the properties of TO has been deciphered for the first time. For this, solvothermally prepared ultra-thin, square nanosheets of purely anatase phase TiO2 (a-TiO2) with 50–70 nm dimensions are used for NF preparation in two types of commercial mineral oil. The dielectric breakdown strength and thermo-physical properties of the resultant TO NFs have been investigated thereafter. A significant enhancement (27–30%) in breakdown voltage (BDV) at very low filler fraction (0.005 wt%) due to accelerated charge scavenging capability by virtue of the inherent surface oxygen vacancies, high electronegativity and slightly higher band-gap than rutile phase is observed. Additionally, the thermal conductivity of TO is seen to rise by 13–23% (±5%) at 50C which is facilitated by long phonon lifetime mediated inter-sheet transfer of heat. Further, the electronegativity induced strong repulsive forces among the dispersed nanofillers at ultra-low concentrations leads to a surfactant-free stable liquid insulation over a prolonged time. Besides, the acidity and viscosity, the increment of which with filler fraction causes a serious drawback for NFs, are below par the alarming level of TO due to low filler fraction of a-TiO2. All the above beneficial features along with improved flash and pour points makes the synthesized 2D a-TiO2 a budding candidate for efficient NF development at very low filler fraction without any usage of surfactant.

In the present work, a comparative study between textured surface and non-textured surface non-recessed hybrid journal bearing configurations is presented. To obtain the performance characteristics parameters of non-recessed hybrid journal bearing, the Reynolds equation, which governs the flow of lubricant in the clearance space, is solved using FEM and the performance parameters are computed. The shear stress–strain relation of lubricant is modeled with the help of a power-law fluid model. The numerically simulated results show that the textured non-recessed hybrid journal bearing provides improved stability parameter than that of journal bearing with non-texturing.

Fungi are one of the serious causes of spoilage in stored grain including wheat. Aspergillus spp. is one of the most common storage fungi that spoils stored wheat. The damage caused by fungi adversely affects the quality of wheat and reduces its nutritional composition. Present methods of analysing chemical composition of wheat and other cereals using wet chemistry are destructive and use bulk grain and thus rely on bulk analysis. Grains, similar to other biological materials, are highly non-homogenous, hence, bulk analysis which causes damage to intrinsic structure of kernels, cannot be used for characterization of single kernels and studying the compositional distribution within a single kernel. In the present work, synchrotron based high resolution infrared imaging was used to study the compositional changes in stored wheat due to fungal damage. Clear differences between healthy and damaged wheat endosperm spectra were observed at peaks around 1740, 1595, and 1250 cm-1. The difference in the absorption of infrared radiation was likely caused due to reduced lipid (1740 cm-1), lignin (1595 cm-1) and cellulose (1250 cm-1) content in damaged wheat endosperm. Refereed/Peer-reviewed

Healthy wheat kernels and wheat kernels damaged by the feeding of the insects, rice weevil (Sitophilus oryzae), lesser grain borer (Rhyzopertha dominica), rusty grain beetle (Cryptolestes ferrugineus), and red flour beetle (Tribolium castaneum) were scanned using a near-infrared (NIR) hyperspectral imaging system (700-1100 nm wavelength range) and a colour imaging system. Dimensionality of hyperspectral data was reduced and statistical and histogram features were extracted from NIR images of significant wavelengths and given as input to three statistical discriminant classifiers (linear, quadratric, and Mahalanobis) and a back propagation neural network (BPNN) classifier. A total of 230 features (colour, textural, and morphological) were extracted from the colour images and the most contributing features were selected and used as input to the statistical and BPNN classifiers The quadratic discriminant analysis (QDA) classifier gave the highest accuracy and correctly identified 96.4% healthy and 91.0-1000% insect-damaged wheat kernels using the top 10 features from 230 colour image features combined with hyperspectral image features. Refereed/Peer-reviewed

Although micrometeorological data are available for numerous low-elevation locations, data from mid- and upper-elevational sites on mountains are sparse. As part of a study on winter water relations in conifers, we instrumented forested sites at two elevations (640 and 715 m) on Mt. Ascutney, Vermont, USA to gain information on the within-canopy micrometeorology of the forest and possibly support or refute hypotheses about factors controlling trees growing at the edges of their elevational range. Here, we report on micrometeorological data collected within the canopy at two middle elevation sites in 1997, 1998 and 1999. Mean air temperatures were generally colder at the higher elevation site than the lower site in any given month of the study. Smaller standard deviations in soil temperatures compared to air temperatures suggest that soil temperatures were significantly damped relative to air temperatures. The adiabatic lapse rate between a nearby low-elevation monitoring station and each study site was roughly half of published annual values for the region. Relatively moderate wind speeds suggest strong damping effects by the forest canopy. Solar radiation maxima suggest that even in a closed-canopy, strong solar radiation can penetrate small areas.

The tactical missiles that use homing guidance in the terminal phase require the onboard seeker to acquire the target in midcourse. If, to save power and weight, a short-range seeker is used, it may hit the allowable angular deflection limit during target acquisition in certain engagements. Such an occurrence can be prevented by turning the body of the missile in the direction of the seeker deflection. But this implies having an autopilot that can track two inputs; the lateral acceleration (latax) and the attitude simultaneously. In this paper, such an autopilot is design for a dual controlled missile. The control configuration is chosen such that only the sensed outputs are used. A new design technique is used to compute the matrix of static output feedback gains that offers satisfactory performance.