The evolutionary success of a species is linked to its ability to communicate. Auditory, optic and olfactory systems are biological communication channels. Compared to the latter two, auditory ...systems are less impeded by physical obstructions. Successful species have effectively articulated this to their advantage. Decoding the acoustic dynamics of a landscape can ingeniously be crafted as a rapid tool to assess biological diversity. Here, we present results of the acoustic analysis carried out in three contrasting soundscapes in Kerala, India. Representative sound samples were recorded at Ernakulam, Kerala, India using Marantz PMD 661 III sonic recorder from 6.00 a.m. to 6.00 p.m. (IST) from an urban park Hill Palace Museum (L1), a sacred grove Iringole Kavu (L2), and a legally protected area Salim Ali Bird Sanctuary (L3). Acoustic characteristics of these sites expressed as Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), Acoustic Evenness Index (AEI), Bioacoustic Index (BI) and Normalized Difference Soundscape Index (NDSI) were related to corresponding avian diversity. The objective finding reveals the distinctiveness of sonic characteristics and the status of diversity in each soundscape. Rapid assessment of biodiversity using acoustic indices is a prospective option that can be adopted as a means to generate biodiversity indicators of Sustainable Develeopment Goals (SDGs).
Anthrophony is an important determinant of habitat quality in the Anthropocene. Acoustic adaptation of birds at lower levels of anthrophony is known. However, threshold anthrophony, beyond which ...biophony starts decreasing, is less explored. Here, we present empirical results of the relationship between anthrophony and biophony in four terrestrial soundscapes. The constancy of the predicted threshold vector normalised anthropogenic power spectral density (~ 0.40 Watts/Hz) at all the study sites is intriguing. We propose the threshold value of anthropogenic power spectral density as an indicator of the avian acoustic tolerance level in the study sites. The findings pave the way to determine permissible sound levels within protected landscapes and directly contribute to conservation planning.
Because of higher energy absorbing capacity of porous metals, these materials are used in car crash protection, armours, etc. However, to the best of our knowledge the porous metals are not used in ...solid particle erosion (SPE) resistant coatings. Nanotechnology allowed development of effective erosion resistant coatings by reducing the grain size of coatings to ≤ 10 nm. As a further development to it, here the porous metal layers, sandwiched between blocks of Ti/TiN multilayers to develop the next generation SPE resistant coatings. Two different ultra-thin Ti/TiN (bi-layer ~7.5 nm, 373 bilayers) multi-layered coatings (each ~9 μm) with dense (Ti/TIN-D) and porous (Ti/TIN-P) Ti layers (320 nm) were deposited on Ti6Al4V substrates using magnetron sputtering system. The erosion tests were conducted with respect to erodent speed (30 to 100 m/s), angle (30 to 90°), and temperature (25 to 700 °C). The average erosion resistance performance of Ti/TIN-P coating is 44 times better than Ti6Al4V substrate and 3.3 times better than Ti/TIN-D coating for 100 m/s erodent speed. Finite element simulations were used to understand the superior performance of Ti/TIN-P over Ti/TIN-D coating for different speeds (20 to 100 m/s). The simulation results are in agreement with the experimental results.
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•Energy absorption capacity of porous metals and nano-technology was used to develop the advanced solid particle erosion resistant coatings.•Two different ultra-thin multi-layered coatings with dense (Ti/TIN-D) and porous (Ti/TIN-P) Ti layers were deposited on Ti6Al4V substrates.•Erosion resistance (@ 100 m/s) of Ti/TIN-P coating is 44 and 3.3 times better than Ti6Al4V and Ti/TIN-D coating, respectively.•Finite element simulations were used to understand the erosion phenomena and the results are in agreement with the experiment.
Human and insect pollinator perceived floral colors of 81 species of angiosperms (flowering plants) from Trivandrum (Kerala, India) was represented using the CIE 1976 L*a*b* color space and color ...hexagon, respectively. The floral color difference among human perceived red, yellow, and blue‐hued flowers and that of each flower from its respective pure hue was calculated using the CIE ΔE 2000 formula. Human perceived floral color difference values were consistently higher than 3.5, indicating the uniqueness of floral colors. Flowers perceived red and yellow by humans were dominant and of comparable proportions. Insect pollinators perceive most of the flowers as blue‐green. Quantitative representation of human and pollinator perceived floral colors would be invaluable to understand the information broadcasted by flowers. It can form the basis of flower grading in the floriculture industry and underpin objectivity in evolving the framework for national pollinator strategies.
•Explicate surrogacy of acoustic indices for rapid assessment of avian diversity.•Compares pre and post flood avian diversity using acoustic indices.•Acoustic estimation of biodiversity act as a ...travellator to realize conservation goals.
Biodiversity assessment, in the aftermath of a natural disaster, remains a challenge. Sonic (acoustic) analysis is increasingly gaining acceptance as a means of rapid assessment of biodiversity. However, its utility in the immediate aftermath of natural disasters is unreported. We compare pre-flood, flood-period and post-flood acoustic indices of Salim Ali Bird Sanctuary, Kerala, India, to illustrate their utility in assessing avian biodiversity. The temporal dynamics of acoustic indices capture the spectre of floods on avian diversity and its resurgence with time in the sanctuary.
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The present work reports the fabrication of superhydrophobic oxide layer on commercially pure zirconium samples. A two-step process, plasma electrolytic oxidation process (PEO) followed by stearic ...acid treatment was employed to fabricate the superhydrophobic layer on Zr substrate. The PEO process was carried out in sodium aluminate electrolyte for 6 min. After that, the PEO coated specimens were immersed in the 0.01 M ethanolic solution of stearic acid. The oxide layer developed by the PEO process was modified using stearic acid by simple immersion technique. The effects of hydrophobic treatment time on the contact angle (CA) values of the samples were investigated. The contact angle measurement reveals a tremendous increase in the CA of the stearic acid solution treated specimens. The corrosion analysis by potentiodynamic polarization test reveals that the protection efficiency of the coating has been significantly improved by the hydrophobic treatment and the lowest corrosion current (icorr) value was obtained for the specimen, treated with stearic acid for 5 h and, that is 2 orders of magnitude lesser than the base coating.
Video journals for science communication Kumar, V. Saroj; Sooraj, N. P.; Sajeev, C. R. ...
Current science (Bangalore),
07/2020, Letnik:
119, Številka:
1
Journal Article
This paper reports the dissimilar floral spectral reflection of invasive and non-invasive angiosperms. Hyper spectral floral reflectance of 22 non-invasive and 8 invasive, co-habiting and ...co-flowering angiosperm from Trivandrum, India were measured from 350 to 700 nm. using hand-held spectroradiometer. The ultraviolet, blue and green portions of the electromagnetic spectrum was converted to corresponding photoreceptor excitation values, and insect pollinator (bee) perceived colours respectively. The colour distance between invasive and non-invasive flowers was calculated. Spectral similarity and principal component analysis carried out on photoreceptor excitation values in the ultraviolet, blue and green region reveal the markedly different floral colour perception rendered by invasive species from that of their co-flowering, non-invasive counterparts. Floral spectral reflection in the ultraviolet and blue region was the least similar.
•Invasive and non-invasive angiosperms exhibit dissimilar floral spectral reflectance.•Floral spectral reflection in the ultraviolet and blue region was the least similar.•Invasive and non-invasive species render different floral colour perception to insect pollinators.•Dissimilar spectral reflectance is a probable invasion strategy.
Business-as-usual is no more an option on the table for biodiversity conservation. Disruptive transformation at both policy and polity levels are pressing needs. The possibilities presented by the ...current wave of information and communication technology can act as travelators to meet the conservation targets. Here, we introduce twin concepts of biodiversity clock and conservation triangle that posit as convergence plane to seamlessly consolidate ongoing discrete efforts and convey real-time biodiversity information in a lucid schematic form. In its present form, the biodiversity clock depicts 12 ecological and 6 biophysical components. The universal consistency in clock-reading facilitates the biodiversity clock to be read and interpreted identically across the world. A ternary plot of the International Union of Conservation of Nature (IUCN) species conservation status is presented as the conservation triangle. Together, the biodiversity clock and the conservation triangle are invaluable in strategizing biodiversity conservation, post-2020. Leveraged smartly, they make possible pre-emptive intervention for biodiversity conservation.
This paper presents the results of floral spectral studies on 1275 flowers from India, Brazil, Israel, Germany, and Norway. Floral spectral reflectance from 400 to 700 nm (nm) was used to ...quantitatively represent ‘human-perceived’ color of flowers in Red, Green, Blue color space. Floral spectral reflectance from 350 to 600 nm was used to discern and objectively represent ‘insect pollinator-perceived’ flower colors in color hexagon. We leverage the advantage offered by ‘quantified human perception’ provided by ‘human-perceived’ floral colors to represent the distribution of floral hues and uncover the relationship between the composition of incoming solar radiation and predominant ‘human-perceived’ floral colors at the tropics and the higher latitudes. Further, the observed species-level mutual exclusivity of ‘insect pollinator-perceived’ floral colors is stated as chromatic exclusivity hypothesis. We compare ‘human-perceived’ and ‘insect pollinator-perceived’ floral colors at Trivandrum (India) and provide a physical explanation for short and long ‘wavelength triads’ of insect pollinator and human visual sensitivity respectively.
•Objective representation of human and insect pollinator perceived floral colors.•Reports the mutual exclusivity of insect pollinator-perceived floral colors.•The composition of the incoming solar spectrum determines the floral colors.•Floral radiometry will complement the development of national pollinator strategies.
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