Host preferences of some acridids (Insecta: Orthoptera) in relation to some biochemical parameters

Biochemical analysis of host plants of 6 species of acridids for their total protein, carbohydrates, phenols, free aminoacids, water and nitrogen content revealed significant correlation in regard to their host preferences, wherein the leaf water-nitrogen index as well as the total phenol composition appeared to play an important role

A variable star population in the open cluster NGC\,6819 observed by the Kepler spacecraft

We present the list of variable stars we found in the \kep\ superstamp data covering approximately nine arcminutes from the central region of NGC6819. This is a continuation of our work presented by Sanjayan et al.(2022a). We classified the variable stars based on the variability type and we established their cluster membership based on the available Gaia Data Release 3 astrometry. Our search revealed 385 variable stars but only 128 were found to be cluster members. In the case of eclipsing and contact binaries we calculated the mid-times of eclipses and derived ephemerides. We searched for eclipse timing variation using the observed minus calculated diagrams. Only five objects show significant orbital period variation. We used isochrones calculated within the MESA Isochrones and Stellar Tracks project and derived the average age (2.54 Gyr), average distance (2.3 kpc) and iron content [Fe/H] = -0.01(2), of NGC6819. We confirm this distance by the one derived from Gaia astrometry of the cluster members with membership probabilities greater than 0.9

Infrared thermochromic antenna composite for self-adaptive thermoregulation

Self-adaptive thermoregulation, the mechanism living organisms use to balance their temperature, holds great promise for decarbonizing cooling and heating processes. The functionality can be effectively emulated by engineering the thermal emissivity of materials to adapt to background temperature variations. Yet, solutions that marry large emissivity switching (${\Delta}\epsilon$) with scalability, cost-effectiveness and design freedom are still lacking. Here, we fill this gap by introducing infrared dipole antennas made of tunable thermochromic materials. We demonstrate that non-spherical antennas (rods, stars and flakes) made of vanadium-dioxide can exhibit a massive (~200-fold) increase in their absorption cross-section as temperature rises. Embedding these antennas in polymer films, or simply spraying them directly, creates free-form thermoregulation composites, featuring an outstanding ${\Delta}\epsilon\sim0.6$ in spectral ranges that can be tuned at will. Our research paves the way for versatile self-adaptive heat management solutions (coatings, fibers, membranes and films) that could find application in radiative-cooling, heat-sensing, thermal-camouflage, and other

An investigation of the mechanisms for strength gain or loss of geopolymer mortar after exposure to elevated temperature

When fly ash-based geopolymer mortars were exposed to a temperature of 800 °C, it was found that the strength after the exposure sometimes decreased, but at other times increased. This paper shows that ductility of the mortars has a major correlation to this strength gain/loss behaviour. Specimens prepared with two different fly ashes, with strengths ranging from 5 to 60 MPa, were investigated. Results indicate that the strength losses decrease with increasing ductility, with even strength gains at high levels of ductility. This correlation is attributed to the fact that mortars with high ductility have high capacity to accommodate thermal incompatibilities. It is believed that the two opposing processes occur in mortars: (1) further geopolymerisation and/or sintering at elevated temperatures leading to strength gain; (2) the damage to the mortar because of thermal incompatibility arising from non-uniform temperature distribution. The strength gain or loss occurs depending on the dominant process

A multifaceted ferrocene interlayer for highly stable and efficient lithium doped spiro‐OMeTAD‐based perovskite solar cells

Over the last decade, 2,2″,7,7″-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD) has remained the hole transporting layer (HTL) of choice for producing high efficiency perovskite solar cells (PSCs). However, PSCs incorporating spiro-OMeTAD suffer significantly from dopant induced instability and non-ideal band alignments. Herein, a new approach is presented for tackling these issues using the functionality of organometallocenes to bind to Li+ dopant ions, rendering them immobile and reducing their impact on the degradation of PSCs. Consequently, significant improvements are observed in device stability under elevated temperature and humidity, conditions in which ion migration occurs most readily. Remarkably, PSCs prepared with ferrocene retain 70% of the initial power conversion efficiency (PCE) after a period of 1250 h as compared to only 8% in the control. Synergistically, it is also identified that ferrocene improves the hole extraction yield at the HTL interface and reduces interfacial recombination enabling PCEs to reach 23.45%. This work offers a pathway for producing highly efficient spiro-OMeTAD devices with conventional dopants via addressing the key challenge of dopant induced instability in leading PSCs

Assessing the Effectiveness of Tradable Landuse Rights for Biodiversity Conservation: An Application to Canada's Boreal Mixedwood Forest

Ecological reserve networks are an important strategy for conserving biodiversity. One approach to selecting reserves is to use optimization algorithms that maximize an ecological objective function subject to a total reserve area constraint. Under this approach, economic factors such as potential land values and tenure arrangements are often ignored. Tradable landuse rights are proposed as an alternative economic mechanism for selecting reserves. Under this approach economic considerations determine the spatial distribution of development and reserves are allocated to sites with the lowest development value, minimizing the cost of the reserve network. The configuration of the reserve network as well as the biodiversity outcome is determined as a residual. However cost savings can be used to increase the total amount of area in reserve and improve biodiversity outcomes. The appropriateness of this approach for regional planning is discussed in light of key uncertainties associated with biodiversity protection. A comparison of biodiversity outcomes and costs under ecological versus economic approaches is undertaken for the Boreal Forest Natural Region of Alberta, Canada. We find a significant increase in total area protected and an increase in species representation under the TLR approach

Relationship between Grasshoppers and crops in an Agroecosystem of Tamil Nadu, India.

1. Grasshoppers were sampled in an agroecosystem of Tamil Nadu on major crops such as Oryza sativa, Arachis hypogaea, Phaseolus radiatus, Sorghum vulgare, as well as on fodder crops Coix lachryma and Panicum maximum for an entire year on a monthly basis with a view to analyse the association of plants and grasshoppers in an agroecosystem. - 2. Grasshoppers are less diverse in an agroecosystem in terms of their species composition. - 3. The total grasshopper population did not differ significantly with seasons on all the crops surveyed except A. hypogaea and P. radiatus. Also within a crop, the diversity of grasshopper species attacking it did not vary with season. - 4. The total yearly grasshopper faunal load in the agroecosystem was 1533.13. - 5. P. maximum supported maximum number of grasshoppers in the ecosystem. - 6. A bimodal distribution of diet breadth (Bi) values was observed for the grasshoppers with specialized species being more abundant on all the crops. - 7. The fraction of a plants faunal load made up of oligophagous grasshoppers showed good correlation with the fraction made up of specialist grasshoppers.StichwörterInsect-plant relations, Orthoptera, Grasshopper diversity, density, agro-ecosystem, diet breadth, faunal load.1. Grasshoppers were sampled in an agroecosystem of Tamil Nadu on major crops such as Oryza sativa, Arachis hypogaea, Phaseolus radiatus, Sorghum vulgare, as well as on fodder crops Coix lachryma and Panicum maximum for an entire year on a monthly basis with a view to analyse the association of plants and grasshoppers in an agroecosystem. - 2. Grasshoppers are less diverse in an agroecosystem in terms of their species composition. - 3. The total grasshopper population did not differ significantly with seasons on all the crops surveyed except A. hypogaea and P. radiatus. Also within a crop, the diversity of grasshopper species attacking it did not vary with season. - 4. The total yearly grasshopper faunal load in the agroecosystem was 1533.13. - 5. P. maximum supported maximum number of grasshoppers in the ecosystem. - 6. A bimodal distribution of diet breadth (Bi) values was observed for the grasshoppers with specialized species being more abundant on all the crops. - 7. The fraction of a plants faunal load made up of oligophagous grasshoppers showed good correlation with the fraction made up of specialist grasshoppers.KeywordsInsect-plant relations, Orthoptera, Grasshopper diversity, density, agro-ecosystem, diet breadth, faunal load