Abiotic stresses such as salt and drought represent adverse environmental conditions that significantly damage plant growth and agricultural productivity. In this study, the mechanism of the plant ...growth‐promoting rhizo‐bacteria (PGPR)‐stimulated tolerance against abiotic stresses has been explored. Results suggest that PGPR strains, Arthrobacter protophormiae (SA3) and Dietzia natronolimnaea (STR1), can facilitate salt stress tolerance in wheat crop, while Bacillus subtilis (LDR2) can provide tolerance against drought stress in wheat. These PGPR strains enhance photosynthetic efficiency under salt and drought stress conditions. Moreover, all three PGPR strains increase indole‐3‐acetic acid (IAA) content of wheat under salt and drought stress conditions. The SA3 and LDR2 inoculations counteracted the increase of abscisic acid (ABA) and 1‐aminocyclopropane‐1‐carboxylate (ACC) under both salt and drought stress conditions, whereas STR1 had no significant impact on the ABA and ACC content. The impact of PGPR inoculations on these physiological parameters were further confirmed by gene expression analysis as we observed enhanced levels of the TaCTR1 gene in SA3‐, STR1‐ and LDR2‐treated wheat seedlings as compared to uninoculated drought and salt stressed plants. PGPR inoculations enhanced expression of TaDREB2 gene encoding for a transcription factor, which has been shown to be important for improving the tolerance of plants to abiotic stress conditions. Our study suggest that PGPR confer abiotic stress tolerance in wheat by enhancing IAA content, reducing ABA/ACC content, modulating expression of a regulatory component (CTR1) of ethylene signaling pathway and DREB2 transcription factor.
Globally there is profuse literature on the continuous developments of box type solar cookers and solar ovens. A lot of research work has been carried out in recent passed years in the world which ...clearly shown the utilization of solar energy towards the greatest needs of mankind obviously solar cooking, fuel saving, non-polluting environment and to save and produce electricity. In the present literature the efforts have been made to focus on diverse developments of box type solar cooker till now. An attempt has been made to optimize the various major parameters such as geometries of box-cooker, glazing system, cooking vessels design, heat storage, insulation, mirror boosters and financial feasibility of solar cooker box. All the discussed factors have been taken into account in the fabrication of a simple solar box cooker and a good improvement has been found in the performance of box cooker with efficient working in low ambient temperatures. A wiper type mechanism to remove vapor droplets from the bottom of glazing, during the cooking process has been introduced and discussed with a new designed cooking vessel. The investigational testing of the fabricated box cooker has been carried out under the climate conditions of Moradabad (latitude – 28°58′north and longitude – 78°47′east) Uttar Pradesh.
Rapid identification of anomalous methane sources in oil/gas fields could enable corrective action to fight climate change. The GHGSat‐D satellite instrument measuring atmospheric methane with ...50‐meter spatial resolution was launched in 2016 to demonstrate space‐based monitoring of methane point sources. Here we report the GHGSat‐D discovery of an anomalously large, persistent methane source (10–43 metric tons per hour, detected in over 50% of observations) at a gas compressor station in Central Asia, together with additional sources (4–32 metric tons per hour) nearby. The TROPOMI satellite instrument confirms the magnitude of these large emissions going back to at least November 2017. We estimate that these sources released 142 ± 34 metric kilotons of methane to the atmosphere from February 2018 through January 2019, comparable to the 4‐month total emission from the well‐documented Aliso Canyon blowout.
Plain Language Summary
Methane is a potent greenhouse gas that is emitted from a variety of natural processes and human activities. Reducing methane emissions from oil/gas production and transmission facilities is considered to be one of the most immediately actionable ways to abate climate change, because the captured methane can be sold. Studies of U.S. oil/gas fields have shown that a small number of high‐emitting facilities are responsible for the bulk of the total emission from oil/gas operations. So far, the only way to identify and quantify these sources has been through field studies involving aircraft and ground‐based observations, but these are expensive, and much of the world cannot be observed in this way. Here we use satellite instruments to identify and quantify anomalously large point sources from an oil/gas field in Central Asia. Our work shows how satellite instruments can be used to monitor methane emissions from individual point sources across the world. It points to an observing strategy where instruments with global coverage at coarse spatial resolution can first identify methane hot spots and then instruments with fine spatial resolution but limited coverage can zoom in to identify the facilities responsible for the hot spots.
Key Points
The GHGSat‐D satellite instrument with 50‐m resolution discovered very large methane point sources from oil/gas production in Central Asia
These large emissions were confirmed by the TROPOMI satellite instrument and extended over at least a year
Persistently large emissions from a gas compressor station (10–43 t hr−1 in >50% of observations) were observed over an 11‐month period
3-D modeling of coupled thermo-hydro-mechanical (THM) processes in enhanced geothermal systems using the control volume finite element code was done. In a first, a comparative analysis on the effects ...of coupled processes, operational parameters and reservoir parameters on heat extraction was conducted. We found that significant temperature drop and fluid overpressure occurred inside the reservoirs/fracture that affected the transport behavior of the fracture. The spatio-temporal variations of fracture aperture greatly impacted the thermal drawdown and consequently the net energy output. The results showed that maximum aperture evolution occurred near the injection zone instead of the production zone. Opening of the fracture reduced the injection pressure required to circulate a fixed mass of water. The thermal breakthrough and heat extraction strongly depend on the injection mass flow rate, well distances, reservoir permeability and geothermal gradients. High permeability caused higher water loss, leading to reduced heat extraction. From the results of TH vs THM process simulations, we conclude that appropriate coupling is vital and can impact the estimates of net heat extraction. This study can help in identifying the critical operational parameters, and process optimization for enhanced energy extraction from a geothermal system.
•THM modeling of deformation of rock matrix and joints with nonlinear stiffness.•Contraction of rock decreases flow impedance of fracture, leading to flow channeling and reduction of energy ...production.•Rapid pore pressure diffusion in rock matrix causes the deformation of reservoir at early-stages.•Thermal effects are more pronounced for higher permeability rocks.•Deformation of ground surface is an important effect resulting from geothermal energy production.
Hot water extraction and cold water injection into an underground geothermal reservoir cause mechanical deformation of rock matrix and rock joints/fractures. That leads to alteration of hydraulic transmissivity. To study the evolution of reservoir transmissivity we performed coupled Thermo-Hydro-Mechanical (THM) simulations using a robust code called Finite Element for Heat and Mass Transfer (FEHM) for a 3-D domain with a single fracture connecting the injection and production wells. Rock fracture was modeled as a thin equivalent porous medium. We established dynamic relations between the properties of the equivalent porous medium and fracture aperture. In this paper we discuss the alteration of fracture aperture due to heat extraction. The channeling of flow between injection and production wells by THM effects causes faster temperature drawdown and reduces energy production. The model also predicted fracture opening near injection well and closure at far field locations. We also simulated the aperture alteration for different joint stiffness, thermal expansion coefficients and rock matrix permeabilities. Increase in rock matrix permeability not only causes the leakage of injected water but also increases matrix contraction due to cooling and therefore the aperture growth. Additionally we reported the effect of thermo-poro-elastic deformation on the expansion and contraction of the formation for different reservoir properties. We established that in the early-stages the compaction/expansion of the formation was controlled by pore pressure change but in the late-stage it was controlled by thermal contraction.
The thermal Sunyaev-Zel'dovich (tSZ) effect induces a Compton-y distortion in cosmic microwave background (CMB) temperature maps that is sensitive to a line-of-sight integral of the ionized gas ...pressure. By correlating the positions of galaxies with maps of the Compton-y distortion, one can probe baryonic feedback processes and study the thermodynamic properties of a significant fraction of the gas in the Universe. Using a model fitting approach, we forecast how well future galaxy and CMB surveys will be able to measure these correlations, and show that powerful constraints on halo pressure profiles can be obtained. Our forecasts are focused on correlations between galaxies and halos identified by the upcoming Dark Energy Spectroscopic Instrument survey and tSZ maps from the Simons Observatory and CMB-S4 experiments, but have general applicability to other surveys, such as the Large Synoptic Survey Telescope. We include prescriptions for observational systematics, such as halo miscentering and halo mass bias, demonstrating several important degeneracies with pressure profile parameters. Assuming modest priors on these systematics, we find that measurements of halo-y and galaxy-y correlations with future surveys yield tight constraints on the pressure profiles of group-scale dark matter halos, and enable current feedback models to either be confirmed or ruled out.
The disintegrating old open cluster Czernik 3 Sharma, Saurabh; Ghosh, Arpan; Ojha, D K ...
Monthly notices of the Royal Astronomical Society,
10/2020, Letnik:
498, Številka:
2
Journal Article
Recenzirano
Odprti dostop
ABSTRACT
We have performed a detailed analysis of the Czernik 3 (Cz3) open cluster by using deep near-infrared photometry taken with TIRCAM2 on the 3.6 m Devasthal optical telescope along with the ...recently available high-quality proper motion data from the Gaia DR2 and deep photometric data from Pan-STARRS1. The cluster has a highly elongated morphology with fractal distribution of stars. The core and cluster radii of the cluster are estimated as 0.5 and 1.2 pc, respectively. We have identified 45 stars as cluster members using the Gaia proper motion data. The distance and age of the cluster are found to be 3.5 ± 0.9 kpc and $0.9^{+0.3}_{-0.1}$ Gyr, respectively. The slope of the mass function `Γ′ in the cluster region, in the mass range ∼0.95 <M/M⊙ < 2.2, is found to be −1.01 ± 0.43. The cluster shows the signatures of mass segregation and is dynamically relaxed (dynamical age = 10 Myr). This along with its small size, big tidal radius, low density/large separation of stars, and elongated and distorted morphology indicates that the Cz3 is a loosely bound disintegrating cluster under the influence of external tidal interactions.
The presence of a narrow genetic base is the major bottleneck in improvements in litchi to get desired objectives. Studies on the nature and extent of genetic diversity are directly related to yield ...and quality, which can be used in a breeding programme for genetic improvement. In the present study, 30 litchi genotypes were assessed with respect to variability, heritability and genetic advance based on 39 quantitative traits. Results revealed that phenotypic coefficients were lower than their corresponding genotypic coefficients suggesting an inherent relationship among them. High phenotypic and genotypic coefficients of variation were recorded for flavonoids in seeds (132.39 and 132.38%), flavonoids in the pericarp (116.89 and 116.86%), phenolics in the pericarp (97.84 and 97.83%), anthocyanin in the pericarp (55.73 and 55.54%), female flowers (53.08 and 52.98%), total chlorophyll (51.07 and 50.99%), phenolics in seeds (48.60 and 48.58%), number of fruits per cluster (44.94 and 44.73%), tree volume (38.80 and 38.70%) and panicle length (28.15 and 19.92%). Broad-sense heritability was more than 80% for all the traits except trunk girth, leaflet width, panicle length and titratable acidity. Heritability and genetic advance were found to be maximum for female flowers (%), phenolics and flavonoids content. A high coefficient of variation was observed for female flowers (%), number of fruits per cluster, phenolics and flavonoids. The grouping of genotype based on combined qualitative and quantitative traits presented more accurate results. This will help to select distant diverse genotypes in the hybridization programme in order to get more diverse progenies.
Gamma-ray bursts (GRBs) are flashes of high-energy radiation arising from energetic cosmic explosions. Bursts of long (greater than two seconds) duration are produced by the core-collapse of massive ...stars
, and those of short (less than two seconds) duration by the merger of compact objects, such as two neutron stars
. A third class of events with hybrid high-energy properties was identified
, but never conclusively linked to a stellar progenitor. The lack of bright supernovae rules out typical core-collapse explosions
, but their distance scales prevent sensitive searches for direct signatures of a progenitor system. Only tentative evidence for a kilonova has been presented
. Here we report observations of the exceptionally bright GRB 211211A, which classify it as a hybrid event and constrain its distance scale to only 346 megaparsecs. Our measurements indicate that its lower-energy (from ultraviolet to near-infrared) counterpart is powered by a luminous (approximately 10
erg per second) kilonova possibly formed in the ejecta of a compact object merger.
PDF
