The present study reports the analysis of hourly equivalent noise levels of 100 sites in the NCT (National Capital Territory) of Delhi and correlates with the community perception that has not been ...reported so far. The study presents the environmental noise scenario of 100 sites in the NCT of Delhi, India, including 19 commercial, 9 industrial, 16 residential, 43 silence zones, 3 highway sites, and 10 intersection sites. The hourly equivalent noise levels of 100 sites were monitored at various timings between 9 AM and 8 PM to analyze the environmental noise pollution scenario in the city. Along with the hourly equivalent continuous sound levels (
L
Aeq, 1 h
); 10-percentile exceeded sound levels (
L
10
), Traffic Noise Index (TNI), Noise Climate (NC), and Noise Pollution Level (NPL) of these sites were also computed. The
L
Aeq, 1 h
levels varied from 66.5 to 84.7 dB(A), and majority of the sites (90.0% sites) exhibited
L
Aeq, 1 h
between 70 and 80 dB(A). A noise map was developed in addition to a socio-acoustic survey conducted to analyze the public perception toward noise pollution and associated health hazards. The study revealed that road traffic noise along with honking noise is the major dominant source of noise pollution. It shall be very helpful in recommending appropriate noise control strategies for abatement and control of environmental noise pollution in the city.
There are compelling evidences for the existence of a fourth degree of freedom of neutrinos, i.e., sterile neutrino. In the recent studies the role of sterile component of neutrinos has been found to ...be crucial, not only in particle physics, but also in astrophysics and cosmology. This has been proposed to be one of the potential candidates of dark matter. In this work we investigate the updated solar neutrino data available from all the relevant experiments including Borexino and KamLAND solar phase in a model independent way and obtain bounds on the sterile neutrino component present in the solar neutrino flux. The mystery of the missing neutrinos is further deepening as subsequent experiments are coming up with their results. The energy spectrum of solar neutrinos, as predicted by Standard Solar Models (SSM), is seen by neutrino experiments at different parts as they are sensitive to various neutrino energy ranges. It is interesting to note that more than 98% of the calculated standard model solar neutrino flux lies below 1 MeV. Therefore, the study of low energy neutrinos can give us better understanding and the possibility of knowing about the presence of antineutrino and sterile neutrino components in solar neutrino flux. As such, this work becomes interesting as we include the data from medium energy (~1 MeV) experiments, i.e., Borexino and KamLAND solar phase. In our study we retrieve the bounds existing in literature and rather provide more stringent limits on sterile neutrino ( ν s ) flux available in solar neutrino data.
Weeds are a major biotic constraint to the production of crops. Studies on the critical period of weed control (CPWC) consider the yield loss due to the presence of all weeds present in the crop ...cycle. The CPWC is the time interval between the critical timing of weed removal (CTWR) and the critical weed-free period (CWFP), and the weed presence before and after the extremes of CTWR and CWFP may not significantly reduce crop yield. The crop yield is taken into consideration and weed density or biomass of individual weeds (annual or perennial) is not so important while calculating the CPWC. Only weed density or biomass is considered for calculating weed control efficiency of a particular management practice for which the weed seed bank is also a criterion. However, weed biomass is the outcome after competition experienced by each weed species with the fellow crop and the weeds. Consequently, the weed pressure in the subsequent season will be the cumulative effect of the preceding season too, which is unaccounted for in CPWC. It is argued that in organic farming or low-input farming systems, where herbicides are not used, the concept of CPWC can be misleading and should be avoided. It is concluded that CTWR is more meaningful than the CPWC.
Glaucoma is a multifactorial neurodegenerative disease that leads to the progressive loss of retinal ganglion cells (RGCs) and their axons resulting in visual field damage and retinal and optic nerve ...head changes. Progression is generally slow but, in some patients, can lead to a ‘catastrophic’ reduction of visual function and in advanced cases may lead to blindness. Glaucoma is, in fact, the leading cause of irreversible blindness worldwide.
Finding a model of retinal ganglion cell (RGC) loss or experimental glaucoma which accurately mimics human disease has been a challenge for researchers. There have been many attempts to produce a model of studying RGC pathophysiology or death longitudinally to study pharmacological treatments or neuroprotective interventions. There are many methods, both acute and chronic, that have been used to induce retinal ganglion cell death. Some methods made a direct injury to the optic nerve which causes rapid RGC death, while others are models try to increase the IOP with mechanical damage or injection of different agents into the anterior chamber to block aqueous humour outflow.
Several models of chronic glaucoma, primarily in non‐human primates and rodents, in which IOP is elevated has been described. However, most of these animal models due to the opacification of the ocular medias as a result of the inflammation or intraocular pression increase only allow to perform a single time point for many different time ex vivo analysis of the RGCs. So, longitudinal changes in the number of RGCs in the same animal can only be performed in vivo. This is an important way to remove the between‐subject variability, but any aging effects will be compounded to those due to disease progression.
A novel glaucoma model using a cross‐linking polymer result in a consistent and sustained elevation of IOP with preservation of optical media clarity for long term.
This model is based on in situ temperature sensitive cross‐linking of a mixture of two components (hyaluronic acid functionalized with vinyl sulfone (HA‐VS) and thiol groups (HA‐SH)). When the mixture is injected into the anterior chamber, the higher temperature of aqueous humour compared to air causes the gel to solidify within the anterior chamber angle thereby blocking aqueous outflow through the trabecular meshwork and increasing the IOP. Furthermore, the hydrogel is localized to the anterior chamber angle with no noticeable media opacities, thereby allowing repeated in vivo imaging.
It has been shown that the increased IOP and the optical media clarity produced in this animal model of glaucoma allows for in vivo study with the Confocal Scanning Laser Ophthalmoscope of the density and structural loss of RGCs, as well as functional loss of RGCs with electroretinography for more than 4 weeks after the hydrogel injection.
We discuss the continuous and infinitesimal gauge, supergauge, reparameterization, nilpotent Becchi-Rouet-Stora-Tyutin (BRST), and anti-BRST symmetries and derive corresponding nilpotent charges for ...the one 0+1-dimensional (1D) massive model of a spinning relativistic particle. We exploit the theoretical potential and power of the BRST and supervariable approaches to derive the (anti-)BRST symmetries and coupled (but equivalent) Lagrangians for this system. In particular, we capture the off-shell nilpotency and absolute anticommutativity of the conserved (anti-)BRST charges within the framework of the newly proposed (anti-)chiral supervariable approach (ACSA) to BRST formalism where only the (anti-)chiral supervariables (and their suitable super expansions) are taken into account along the Grassmannian direction(s). One of the novel observations of our present investigation is the derivation of the Curci-Ferrari- (CF-) type restriction by the requirement of the absolute anticommutativity of the (anti-)BRST charges in the ordinary space. We obtain the same restriction within the framework of ACSA to BRST formalism by (i) the symmetry invariance of the coupled Lagrangians and (ii) the proof of the absolute anticommutativity of the conserved and nilpotent (anti-)BRST charges. The observation of the anticommutativity property of the (anti-)BRST charges is a novel result in view of the fact that we have taken into account only the (anti-)chiral super expansions.
► Hybrid rice has the potential to grow in dry-seeded conditions if seeds can be planted at low seedling rates. ► Herbicide-treated plots had fewer rice plants than the weedy and weed-free plots when ...rain occurred before crop emergence. ► Herbicide treatment provided 81–93% better weed control than the weedy treatment, which resulted in 54–125% yield advantages over the weedy treatment. ► Study suggests that hybrids can be grown at low seeding rates or at 20-cm plant-to-plant spacing, provided that there is no herbicide phytotoxicity on crop emergence and rice plant density is uniform.
Farmers in many Asian countries are moving from puddled-transplanted rice to dry-seeded rice systems as they respond to increased costs or decreased availability of labor or water. Hybrid rice has the potential to grow in dry-seeded conditions and can perform well even if seeds can be planted at low seedling rates. A field study was conducted in the wet season of 2011 and dry season of 2012 to evaluate the effect of plant-to-plant spacing (10 or 20cm), the number of rice seeds planted per spacing (2 or 3), and weed control methods (42 days weedy, weed-free, and oxadiazon followed by penoxsulam+cyhalofop) on the growth and yield of rice under a dry-seeded rice system. The crop was planted at 20-cm row spacing. Herbicide-treated plots had fewer rice plants than the 42 days weedy and weed-free plots when rain occurred before crop emergence. However, the herbicide treatment provided 81–93% better weed control than the 42 days weedy treatment, which resulted in 54–125% yield advantages over no weeding for 42 days. Grain yield in the herbicide-treated plots was only 75–88% of the grain yield in the weed-free plots, suggesting further scope to improve rice yield in dry-seeded systems. Grain yield was similar across plant-to-plant spacing and the number of seeds planted per spacing. Our study suggests that hybrids can be grown at low seeding rates or at 20-cm plant-to-plant spacing, provided that there is no herbicide phytotoxicity on crop emergence and rice plant density is uniform. These results may help manufacturers in designing sowing drills with precise seed-metering systems for dry-seeded rice systems in Asia.
Recrystallization of CL-20 to ε-polymorphic form Chauhan, B S; Thakur, A; Soni, P K ...
IOP conference series. Materials Science and Engineering,
01/2021, Letnik:
1033, Številka:
1
Journal Article
Recenzirano
Odprti dostop
High explosive CL-20 (2,4,6,8,10,12 - Hexanitro - 2,4,6,8,10,12 - hexaazaisowurtzitane) exists in four polymorphic forms i.e. α, β, γ and ε polymorphs at ambient conditions and polymorph ζ exists ...only at high pressure (1.44 GPa). CL-20 is the only single compound having highest energy among all the organic substances. But polymorphic form α- of CL-20 is generally obtained during most of the synthetic processes which has low density and high sensitivity. Thus, there is requirement of further recrystallization to obtain most stable ε-polymorphic form. Owing to the highest density, superior thermal stability and better insensitivity of ε- polymorph over other three polymorphs (α-, β- and γ- form) which are highly sensitive towards impact, friction and shock, ε- CL-20 is most desirable for use in defence applications. The present work studies the effect of various variables which influence the crystallisation process like effect of moisture, nature of solvent/anti-solvent and time on the preparation of ε- form of CL-20. Ethyl acetate and n-butyl acetate as solvents and toluene as anti-solvent resulted in the formation of desired ε- polymorphic form successfully. Polymorphic form was confirmed by FTIR and XRD analysis. SEM analysis was carried out for the morphological analysis of prepared samples.
Chauhan BS, Migo T, Westerman PR & Johnson DE (2010). Post‐dispersal predation of weed seeds in rice fields. Weed Research 50, 553–560.
Summary
Post‐dispersal weed seed predation can cause a ...substantial reduction in the number of weed seeds entering the seed bank and, as a consequence, reduce the number of weeds growing in subsequent seasons. Investigations on seed predation on four tropical rice fields in the Philippines were conducted to determine (i) the magnitude of post‐dispersal seed predation after rice harvest, (ii) whether vertebrates or invertebrates are the main seed predators, (iii) whether seed predation is affected by crop residue, (iv) whether seed predation is affected by proximity to the field edge, and (v) whether predation differs among seeds of the grasses Digitaria ciliaris, Echinochloa colona and Eleusine indica. Seed removal rate over a 14‐day period ranged from 78% to 91% among fields, was slightly higher in the interior of the fields (89%) than in the field margins (85%) and slightly higher without residue cover (89%) than with (86%). Selective exclosures indicated that invertebrates, presumed to be mainly fire ants (Solenopsis geminata), were the main seed predators (96%) and vertebrates, presumed to be mainly rodents, secondary predators (38%). Seed removal of D. ciliaris was higher (93%) than of E. indica (88%) and E. colona (75%). Results suggest substantial seed predation could contribute to ecologically‐based weed management in rice. Further studies are required to determine season‐long seed predation rates and to confirm the identity of the predators involved. Ways to integrate these seed predators into prevailing cropping practices need to be developed.
The study focusses on two major aspects: measurement methodology and uncertainty in the realization and dissemination of unit watt in airborne sound and consideration in legal sound regulations for ...various noise sources. Although sound power level is the fundamental unit invariant of distance from the source, yet there is no direct method for its measurement. An National Metrology Institute (NMI) perspective for the realization, dissemination and application of acoustical quantities: sound pressure and sound power level for strengthening the measurement traceability chain in India and formulation of legal noise limits and regulations of various noise sources is described. The low frequency limitations may yield different results using different methods, which thus necessitates the use of a harmonized approach in realizing the sound power parameter for improving the traceability for the unit watt in airborne sound. The use of sound power level and sound pressure level for noise labeling of appliances and other noise sources in India is recommended.
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