Negative Effect Of Temperature Research Articles

The Effect of a Hot Humid Climate on Corrosion of Reinforced Concrete

The expansion of economic cooperation with countries located in areas with hot, humid climates and the construction of reinforced concrete buildings and structures in coastal zones of non–freezing seas poses the task of assessing the impact of climate on the corrosive state of reinforced concrete structures, primarily carbonation of concrete and seawater aerosol containing chlorides. The effect of low negative temperature is not considered in this work. The data on the carbonation of concrete under conditions of increased insolation and the action of sea salt aerosol are summarized, mainly using the example of the hot humid climate of Cuba for further development of research, and subsequently the development of standards for protection against corrosion and carbonation of concrete and steel reinforcement in areas with a tropical climate. Based on the results of a survey of the condition of reinforced concrete structures and structures manufactured and erected in Cuba, as well as the results of observations, the results of an analysis of aggressive environmental factors of the Republic of Cuba affecting the corrosion of reinforced concrete structures, the results of studies of concrete carbonation and the effects of sea salt aerosol are presented. When designing and building structures on the seashore by domestic organizations in countries with hot, humid climates, the aggressive effects of seawater aerosol and accelerated carbonation of concrete, which reduce the durability of reinforced concrete structures, should be taken into account.

Analysis of the Effect of Negative Temperature on the Strength of Adhesive-Riveted Joints Made of Aluminum Alloys

Analysis of the Effect of Negative Temperature on the Strength of Adhesive-Riveted Joints Made of Aluminum Alloys

Response of aestivum and durum wheat varieties to elevated CO2 and temperature under OTC condition

An experiment was undertaken during rabi season of 2020-2021 and 2021-2022 at experimental field of Division of Environmental Science, ICAR-Indian Agriculture Research Institute (IARI), New Delhi inside Open Top Chambers (OTCs) to study the growth and physiological response of aestivum (HD 3226) and durum wheat (HI 8627) varieties to elevated temperature and CO2 concentration. Results showed that days to maturity hastened under elevated temperature condition. Photosynthesis rate, leaf area index and tiller number of wheat varieties reduced in elevated temperature treatment while elevated CO2 concentration of 550 ppm was able to partially compensate the reduction. In aestivum variety of wheat, transpiration rate significantly reduced in elevated CO2 plus high temperature interaction treatment than ambient while transpiration rate of durum variety remained unaffected. The negative effect of elevated temperature on aboveground biomass was more in aestivum variety than durum variety. Elevated CO2 concentration compensated reduction in aboveground biomass by 5.9% in HD 3226 (aestivum) and by 3.6% in HI 8627 (durum) varieties under elevated temperature condition. Hence elevated CO2 concentration will be able to partially compensate reduced crop growth in both aestivum and durum wheat varieties under high temperature condition.

Highly structured habitats mitigate size‐ and growth‐selective mortality of post‐settlement juvenile fish

AbstractThe role of vegetated habitats such as seagrass and macroalgal beds as nurseries is essential for the survival of larval and juvenile fish, although quantitative evaluation of the contribution of these habitats to nursery function is limited. Moreover, growth–survival relationships of larvae and juveniles associated with vegetated habitats have rarely been examined. To quantitatively and qualitatively evaluate the processes affecting juvenile survival in vegetated habitats, we investigated whether there is a correlation between the degree of selection for bigger and faster‐growing fish and mortality rates for three cohorts by birth date of post‐settlement black rockfish (Sebastes cheni) in a macroalgal bed. We also analyzed relationships between growth rate and experienced temperature by age class to examine the effects of temperature on growth. The latest cohort, which grew under lower vegetation coverage due to a seasonal increase in water temperature, showed higher mortality with evidence of strong selection for survival of bigger and faster‐growing fish. The growth–temperature relationships showed that positive effects of temperature on growth weakened after settlement. Therefore, we suggest that macroalgal coverage has a critical role in controlling the growth–mortality relationship of post‐settlement S. cheni. Furthermore, the negative effects of high temperature on juvenile survival through loss of vegetation may be greater than the positive effects on juvenile growth. These findings would contribute to the management of fisheries resources by increasing the understanding of relationships between survival mechanisms in fish early life stages and vegetation phenology of their habitat under the increasing effects of global warming.

Soil temperature and local initial conditions drive carbon and nitrogen build-up in young proglacial soils in the Tropical Andes and European Alps

Climate warming has accelerated the retreat of mountain glaciers worldwide, exposing new areas to weathering, vegetation colonization, and soil formation. In light of probable climate changes such as warming and new extremes, understanding the factors that control soil organic carbon (SOC) and nitrogen build-up is crucial to comprehend proglacial soils and ecosystem formation. To this end, we examine the evolution of SOC, nitrogen (total N and NH4+), and phosphorus (available P) along nine 120-year chronosequences of deglacierization distributed between the European Alps and Tropical Andes. Our dataset includes geochemical analyses of 188 soil samples, in situ soil temperature data for the period 2019–2022, and hydrographic variables. Although time controls proglacial soil development at all sites, our study highlights distinct pedogenesis dynamics between proglacial landscapes depending on the micro and macro environmental context. Differences in soil development were strongly driven by growing degree days (GDD), maximum soil temperature, and parent material. Notably, we identified a positive effect of GDD on SOC and N (total N and NH4+), while our results indicate a negative effect of maximum soil temperature on SOC and NH4+, suggesting that overly high temperatures reduce microbial mineralization and organic matter input to the soil matrix. We reported the presence of higher initial SOC, total N, and NH4+ in the Andean sites than in the Alps sites, suggesting enhanced soil development at the Andean locations. This comparative study suggests the relative importance of maximum temperature and initial site conditions (e.g., parent materials, glacier biomes) during proglacial pedogenesis. Our findings highlight that soil temperature modulates pedogenesis in a complex way and suggest avoiding simply associating greater soil development with higher soil temperature in proglacial landscapes.

Predicting the strengths of date fiber reinforced concrete subjected to elevated temperature using artificial neural network, and Weibull distribution

Date palm fiber (DPF) is normally used as fiber material in concrete. Though its addition to concrete leads to decline in durability and mechanical strengths performance. Additionally, due to its high ligno-cellulose content and organic nature, when used in concrete for high temperature application, the DPF can easily degrade causing reduction in strength and increase in weight loss. To reduce these effects, the DPF is treated using alkaline solutions. Furthermore, pozzolanic materials are normally added to the DPF composites to reduce the effects of the ligno-cellulose content. Therefore, in this study silica fume was used as supplementary cementitious material in DPF reinforced concrete (DPFRC) to reduce the negative effects of elevated temperature. Hence this study aimed at predicting the residual strengths of DPFRC enhanced/improved with silica fume subjected to elevated temperature using different models such as artificial neural network (ANN), multi-variable regression analysis (MRA) and Weibull distribution. The DPFRC is produced by adding DPF in proportions of 0%, 1%, 2% and 3% by mass. Silica fume was used as partial substitute to cement in dosages of 0%, 5%, 10% and 15% by volume. The DPFRC was then subjected to elevated temperatures between 200 and 800 °C. The weight loss, residual compressive strength and relative strengths were measured. The residual compressive strength and relative strength of the DPFRC declined with addition of DPF at any temperature. Silica fume enhanced the residual and relative strengths of the DPFRC when heated to a temperature up to 400 °C. To forecast residual compressive strength (RCS) and relative strength (RS), we provide two distinct ANN models. The first layer's inputs include DPF (%), silica fume (%), temperature (°C), and weight loss (%). The hidden layer is thought to have ten neurons. M-I is the scenario in which we use RCS as an output, whereas M-II is the scenario in which we use RS as an output. The ANN models were trained using the Levenberg–Marquardt backpropagation algorithm (LMBA). Both neural networking models exhibit a significant correlation between the predicted and actual values, as seen by their respective R = 0.99462 and R = 0.98917. The constructed neural models M-I and M-II are highly accurate at predicting RCS and RS values. MRA and Weibull distribution were used for prediction of the strengths of the DPFRC under high temperature. The developed MRA was found to have a good prediction accuracy. The residual compressive strength and relative strength followed the two-parameter Weibull distribution.

Experimental study on frost heave characteristics and micro-mechanism of fine-grained soil under dynamic load for heavy-haul railway subgrades in seasonally frozen regions

In seasonally frozen regions, there is frequent uneven frost heave of heavy haul railway subgrades, which reduces the smoothness of the track and affects the operational safety of trains. To clarify the frost heave characteristics and micro-mechanism of subgrade filling under the action of unidirectional freezing and dynamic loading, unidirectional freezing tests were performed on a fine-grained subgrade filling under open conditions, and the frost heave characteristics under different initial water contents and dynamic loads were analyzed. The particle image velocimetry (PIV) technique was applied to analyze the development of local deformation at different locations in the samples. Scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP) were performed on the samples before and after freezing to reveal the development mechanism of the microstructure. The test results showed that with the increase in the initial water content and load amplitude, the frost heave increased, while the water replenishment and frost depth decreased. Combined with the PIV results, it was found that the soil in the frozen and unfrozen areas exhibited frost heave and compressive deformation, respectively, during the freezing process, further revealing the local deformation law of the soil. The samples mainly contained small pores and micropores before freezing and small pores and medium pores after freezing, indicating that the effect of freezing and swelling had the greatest influence on the small and medium pores inside the soil. The higher the initial water content, the higher the porosity of the sample after freezing; with the increase in the load amplitude, the porosity of the frozen samples decreased. The negative temperature effect of the change in phase from water to ice drove the particle movement, thereby increasing the inter-particle pore space, leading to a macroscopic frost heave deformation of the soil samples. Our results can serve as a basis in the maintenance and safety of railway subgrades in cold regions.

Effect of Negative Temperatures on the Strength and Deformability of a Reinforced Concrete Element

One of the main components of the economic development of the Russian Federation is the current trend in the development of the territories of the Far North and the Arctic. The need for such development is enshrined at the state level in various programs. Experiments on the study of the effect of negative temperatures on the operation of reinforcing steel show that with decreasing temperature, an increase in strength and modulus of elasticity is observed. At the same time, there are no unified recommendations on the deformation and strength properties of reinforcement for calculating reinforced concrete structures under conditions of low and ultra-low negative temperatures. RF standards do not take into account the influence of climatic (up to -70°C) and technological (up to -196°C) negative temperatures on the deformation and strength characteristics of reinforcing steel.The purpose of this work was to experimentally study the effect of negative temperatures (up to -196°C) on the deformation-strength properties of reinforcement, concrete and reinforced concrete rod elements. Concrete prisms 10x10x40 cm, samples of reinforcement of a periodic profile of class A400 and reinforced concrete prismatic rods with a section size of 12x18 cm and a reinforcement percentage of 1.45% were taken as prototypes. At the same time, the negative temperature of the tests varied. As a result of the studies carried out with centrally stretched reinforced concrete elements, it was found that lowering the temperature to -165°С leads to an in-crease in the cracking force by 162%; strength by 85%. Empirical dependencies are proposed to determine the deformation-strength characteristics of reinforcing steel, depending on the negative temperature.

Modelling the kinetics of Staphylococcus aureus in goat's raw milk under different sub-pasteurisation temperatures

In this study, the heat resistance of S. aureus in goats’ raw milk subjected to thermisation temperatures was characterised through tests at various temperatures and modelling the survival curves using the Weibull model, through a two-step and an omnibus approach, which can model a full dataset covering all experimental conditions in one step. The fitting capacity of the secondary models obtained from the two-step approach was reasonable (adj. R2 > 0.639) and both demonstrated the negative linear effects of temperature on χ (p = 0.0004) and β (p = 0.017). The fitting capacity of the omnibus model was more satisfactory (adj. R2 = 0.996) and also hinted at the negative linear effect of temperature on χ (p < 0.0001), with the added advantage that, in this model, random effects can be used to account for the variability in the parameters. Our study estimated the significant inactivation parameters and established a model capable of predicting S. aureus behaviour at various temperatures. This information is useful to create time-temperature tables to reach target log reductions of S. aureus in goats’ raw milk to be used by artisanal cheesemakers; hence providing an opportunity to increase the microbiological safety of cheeses made from unpasteurised milk.

Influence of Increase in Phosphorus Supply on Agronomic, Phenological, and Physiological Performance of Two Common Bean Breeding Lines Grown in Acidic Soil under High Temperature Stress Conditions.

Many common bean (Phaseolus vulgaris L.) plants cultivated in areas of the world with acidic soils exhibit difficulties adapting to low phosphorus (P) availability, along with aluminum (Al) toxicity, causing yield loss. The objective of this study was to evaluate the influence of an increase in P supply level on the agronomic, phenological, and physiological performance of two common bean breeding lines grown in acidic soil, with low fertility and under high temperature conditions, in a screenhouse. A randomized complete block (RCB) design was used under a factorial arrangement (five levels of P × 2 genotypes) for a total of 10 treatments with four replications. The factors considered in the experiment were: (i) five P supply levels (kg ha-1): four levels of P0, P15, P30, and P45 through the application of rock phosphate (RP), and one P level supplied through the application of organic matter (PSOM) corresponding to 25 kg P ha-1 (P25); and (ii) two advanced bean lines (BFS 10 and SEF10). Both bean lines were grown under the combined stress conditions of high temperatures (day and night maximum temperatures of 42.5 °C/31.1 °C, respectively) and acidic soil. By increasing the supply of P, a significant effect was found, indicating an increase in the growth and development of different vegetative organs, as well as physiological efficiency in photosynthesis and photosynthate remobilization, which resulted in higher grain yield in both bean lines evaluated (BFS 10 and SEF10). The adaptive responses of the two bean lines were found to be related to phenological adjustments (days to flowering and physiological maturity; stomatal development), as well as to heat dissipation strategies in the form of heat (NPQ) or unregulated energy (qN) that contributed to greater agronomic performance. We found that, to some extent, increased P supply alleviated the negative effects of high temperature on the growth and development of the reproductive organs of bean lines. Both bean lines (BFS 10 and SEF 10) showed adaptive attributes suited to the combined stress conditions of high temperature and acidic soil, and these two lines can serve as useful parents in a bean breeding program to develop multiple stress tolerant cultivars.

Solar Panel Study in the Desert Climate of Abu Dhabi, United Arab Emirates

The negative effects of climate change and global warming are no longer a futuristic issue to deal with. This is the result of the continued and extensive use of fossil fuels and subsequent greenhouse gasses emissions such as CO2. Earth has been warming at an alarmingly fast pace the last 40 years due to greenhouse gas emission and the trapping of heat in the atmosphere. To slow down and eliminate this unnatural warming rate a reduction in greenhouse gas emissions is essential. This is accomplished by an increase in the deployment and use of clean renewable energy. Solar energy continues to play a significant role in the clean energy shift due to the abundance and unlimited supply of energy provided by the sun. The use of solar energy is on an exponential rise thanks to recent government policies to reduce emissions. For example, solar energy production in the United Arab Emirates (UAE) from 2009-2019 shows an exponential rise starting in 2016 reaching almost 3500 GWh of production in 2019 [1]. The UAE is also home to the Mohammed Bin Rashid Al Maktoum solar park. The largest single site solar park the world. This project will help reduce more than 6.5 million tons of emissions and will have capacity of 5000 megawatts [2].The United Arab Emirates is an ideal region for solar due the amount of sunshine and with very few cloudy/rainy days. However, desert climates have their own unique challenges, such as extreme heat and soling. Temperatures can reach above 40 in summer months in the UAE with high humidity and effect of soiling from dust is not very well understood [3]. Also, what is important is finding the optimal angle and direction of roof top solar panels to maximize the power and limit these negative effects.In this work, we studied a real solar panel on the rooftop in Abu Dhabi. The solar panel was bought from a local vendor in the UAE. The solar panel is polysilicon with specs: 10W, Vmp 18V, Imp 0.56A, Voc 24.4V and ISC 0.69A under AM1.5G at 25°C. We placed the panel on a roof top in Abu Dhabi at Khalifa University. To find the optimal angle and location we tested the panels at 12noon to maximum sun power. We first fixed the angle around 22° based on literature, and then modified the direction from north, south, west and east to find which direction gave the peak. We found that south gave the highest power from the rest (10.32W). Then we changed from angle from this data from 0°-90° in steps of 10°. The data showed the maximum power is when panel is facing south with angle between 25°-30°. The optimum placement of solar panels is key in helping to mitigate the negative desert effects such at heat and soiling. In addition, to this study, we also studied the panel for a continuous period to see effects of soling and longer-term heat exposure. More on this data will be added to in the poster to be presented.In summary, the use for solar panels is key to help prevent the negative effect of climate change. In desert like conditions, while there is plenty of sunshine, the negative effects of soling and temperature is not fully studied yet. Finding the optimum, angle and direction is key it get the peak performance of the panel and helping to mitigate some of these negative effects. Also studying the long-term effects of the temperature and soiling is important. Finally, knowing the negative effects can help researchers find new materials and solutions for solar cells for desert like environments.[1] E. Agency, "Renewables Information," July 2021. [Online].[2] T. National, "Road to Net Zero," 09 May 2019. [Online][3] O. Albadwawi et al., "Quantification of spectral losses of Natural soiling and detailed microstructural analysis of Dust collected from Different locations in Dubai, UAE," 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC), 2019, pp. 3115-3118, doi: 10.1109/PVSC40753.2019.8980937. Figure 1

Expandable graphite embedded in flexible polymer surfaces for fire detection in multiple modes

AbstractFire detection sensors are a necessary facility to ensure fire safety. The long fire response time and the false fire alarms caused by a single fire response mode are urgent problems for fire detection sensors. Here, a strategy of embedding expandable graphite (EG) in the sample surface of a styrene‐butadiene‐styrene block copolymer/intumescent flame retardant is used to endow the sample with fire detection in multiple modes and early warning functions, thus shortening the fire warning time and preventing the false fire alarms. The EG improved the flame retardancy of the samples from failing to V‐0 in the vertical burning rating test. The EG also gave the samples the ability to sense tensile and bending deformation. The negative temperature effect of the EG resistance gave the sample an early warning capability for fires with warning temperatures as low as 200°C. The rapid expansion of EG exposed to flame into graphite worms was used for the rapid response of the sample to fire (response time &lt; 1 s). The Seebeck effect with response voltage of up to 0.3 V was used for fire detection of samples based on the temperature difference of EG on the sample surface caused by the flame. This study has potential application prospects for rapid fire warning in buildings.

Thermal dependence of Daphnia life history reveals asymmetries between key vital rates

Temperature variation affects virtually every aspect of ectotherms' ecological performance, such as their foraging rate, reproduction, and survival. Although these changes influence what happens at higher levels of organizations, such as populations and communities, qualitative changes in dynamics usually require some degree of asymmetry between key vital rates, i.e. that different vital rates, such as growth, development, fecundity and mortality rates, respond differently to temperature. In order to identify possible asymmetries among vital rates and/or life stages, we characterized the thermal response of individuals a clone of Daphnia sinensis, drawn from a high-mountain environment in Taiwan, and examined the temperature dependence of growth, maturation, reproduction, and mortality rates, as well as fitness measures (r and R0) at eight temperatures. Daphnia sinensis was able to maintain reproductive success over a broad range of temperatures, much wider than the one experienced in its environment. However, negative effects of temperature were perceptible at temperatures much lower than the highest one at which they can achieve reproductive success. Adult mortality greatly increased for temperatures above 23 °C, and other vital rates started to decelerate, resulting in a large drop in lifetime reproductive success. This finding implies that D. sinensis may be able to persist over a wide range of temperatures, but also that it may become more sensitive to the detrimental effect of species interactions at increased temperatures. Different vital rates responded relatively similarly at low temperatures, but the degree of asymmetry among these rates was much more pronounced at higher temperatures. In particular, rates associated with adult performance decelerated more strongly than juveniles’ rates. These findings indicate that elevated temperatures affect the balance between juvenile and adult performance, which is known to have a crucial role in Daphnia population dynamics. We discuss the implications of these results for the dynamics of structured populations.

Microstructural Analysis and Compressive Strength of Fly Ash and Petroleum Sludge Ash Geopolymer Mortar under High Temperatures

The development of sustainable building materials and construction to decrease environmental pollution in both production and operational stages of the materials’ life cycle is appealing to great interest in the construction industries worldwide. This study evaluated the negative effect of temperature up to 1000 °C on the compressive strength and microstructure of fly ash and petroleum sludge ash (PSA) geopolymer mortar. A sodium silicate and sodium hydroxide mixture is used as an activator. The synthesized mortar was investigated using X-ray Diffraction (XRD), Fourier Transformation Infrared Spectroscopy (FTIR), Mercury Intrusion Porosimetry (MIP), and Field Emission Scanning Electron Microscopy (FESEM). As the temperature increased, the compressive strength of the geopolymer mortar decreased. The strength degradation is due to the damage to microstructure because of the temperature-induced dehydroxylation, dehydration thermal incompatibility between geopolymer aggregate and paste of geopolymer mortar at high temperatures. With an increase in temperature, the cumulative pore volume increased. The FESEM image showed the decomposition of the geopolymer matrix started at a temperature of 600 °C. Incorporating PSA in geopolymer mortar could result in an eco-friendly and sustainable environment that may reduce the problems associated with sludge disposal.

Quantum chemical mechanism on the depletion of C3O by oxygen atoms: barrierless to produce CO

ABSTRACT Accurate quantum chemical studies at the CCSD(T)/CBS//CCSD/cc-pVTZ level predicted the depletion reaction of C3O by both singlet and triplet O-atoms to be barrierless, leading to the astrophysically very abundant CO plus triplet CCO. The barrierless nature of the reaction fully complied with the long conjecture, whereas the product differed significantly. Our kinetic calculations indicated that the reaction possesses significant negative temperature effect below 30 K. The calculations should be useful for understanding the astrophysical recycling for both the carbon and oxygen species.

Assessment of Risks Associated with Extreme Climate Events in Small-Scale Bivalve Fisheries: Conceptual Maps for Decision-Making Based on a Review of Recent Studies

Extreme climate events, such as heatwaves and torrential rain, affect the physiology and functioning of marine species, especially in estuarine habitats, producing severe ecological and socioeconomic impacts when the affected species support important fisheries, such as artisanal shellfisheries. Studies of the impact of sudden decreases in salinity and increases in temperature were reviewed with the aim of producing comprehensive conceptual maps to aid the management of fisheries of the native clams Ruditapes decussatus and Venerupis corrugata, the introduced Ruditapes philippinarum, and the cockle Cerastoderma edule in Galicia (NW Spain). The maps show the effects on mortality, scope for growth, ability to burrow, changes in gonad development or predation risk. While V. corrugata will generally be more affected by low salinity (5 to 15) or high temperature (30 °C) during only two tidal cycles, C. edule populations may recover. Both species are also expected to become more vulnerable to predators. The clams R. philippinarum and R. decussatus will be more resistant, unless extreme events occur after massive spawning episodes; however, the presence of the intertidal seagrass Zostera noltei may buffer the negative effects of high sediment temperature on the growth of some species, such as R. decussatus. Finally, recommendations for assessing climate risk and designing management actions for shellfisheries are given.

Survival rates in the world's southernmost forest bird community.

The Magellanic sub-Antarctic Forest is home to the world's southernmost avian community and is the only Southern Hemisphere analogue to Northern Hemisphere temperate forests at this latitude. This region is considered among the few remaining pristine areas of the world, and shifts in environmental conditions are predominantly driven by climate variability. Thus, understanding climate-driven demographic processes is critical for addressing conservation issues in this system under future climate change scenarios. Here, we describe annual survival patterns and their association with climate variables using a 20-year mark-recapture data set of five forest bird species in the Cape Horn Biosphere Reserve. We develop a multispecies hierarchical survival model to jointly explore age-dependent survival probabilities at the community and species levels in a group of five forest passerines. At the community level, we assess the association of migratory behavior and body size with survival, and at the species level, we investigate the influence of local and regional climatic variables on temporal variations of survival. We found a positive effect of precipitation and a negative effect of El Niño Southern Oscillation on juvenile survival in the white-crested Elaenia and a consistent but uncertain negative effect of temperature on survival in juveniles and 80% of adults. We found only a weak association of climate variables with survival across species in the community and no temporal trends in survival for any of the species in either age class, highlighting apparent stability in these high austral latitude forests. Finally, our findings provide an important resource of survival probabilities, a necessary input for assessing potential impacts of global climate change in this unique region of the world.

Global patterns in urban green space are strongly linked to human development and population density

Urban green space is important for alleviating high temperatures, pollution, and flooding in cities. Furthermore, it is becoming increasingly clear that urban green space is important for the mental and physical health of humans residing in cities and that urban green space may harbor unique biodiversity. Understanding the extent and drivers of urban green space is thus important. While urban green space has been mapped and studied at local to national scales, the global patterns and drivers of urban green space remain unknown, potentially hampering effective planning and allocation of resources toward reaching sustainable development goals. Here, we quantified the effect of environmental and socio-economic drivers (temperature, precipitation, human development, and population density) on urban green space globally by focusing on national capital cities. We used satellite imagery to map urban green space using two measures: the Normalized Difference Vegetation Index (NDVI), and the fractional cover of “green” land cover classes. NDVI is useful as it includes all vegetated surfaces, also small ones like gardens. However, land cover classes allow the exclusion of certain classes such as sports fields or cropland. We used boosted regression trees to show that climatic variables accounted for 75 % of the relative influence in urban green space, with a positive effect of precipitation and a negative effect of temperature. Importantly, socioeconomic variables accounted for 25 % of the influence on global urban green space, with a positive effect of human development index (HDI) and a negative effect of population density. HDI in relation to urban green space has not previously been tested globally, and our study shows that significantly affects urban greenspace. The results demonstrate that cities where development status is low and population densities are high, typically in the Global South, have less urban green space than the climate would predict. The results therefore suggest that human wellbeing does not only benefit directly from increasing human development and decreasing population densities in urban areas, but that these effects may be compounded by also improving nature’s contribution to people.

Vacuum annealing effects on the microstructure and properties of HfO2-based bilayer antireflective coatings by magnetron sputtering

Hafnia (HfO2) retains thermal stability, mechanical resilience, and chemical resistivity, which makes it feasible in various high-tech applications in optics and integrated circuit technology. This work presents the effects of thermal annealing on the microstructure, optical performance, and wettability of HfO2/Al2O3 and HfO2/ZrO2 bilayer thin films prepared by magnetron sputtering. The films were deposited on silicon (Si) and glass substrates and then annealed at a certain temperature (300–500 °C) in the ambient vacuum condition for 5hrs. XRD results of as-deposited and annealed films revealed the polycrystalline nature of the monoclinic phase. The core level orbitals of Hf 4f, Zr 3d, and Al 2p spectra showed the formation of stoichiometric compositions of HfO2, ZrO2, and Al2O3 films and exhibited a slight shift in binding energy after annealing. The AFM and SEM analysis were utilized to inspect the roughness and surface morphology and correlated with the change in hydrophobicity to the self-cleaning nature of the prepared bilayer coatings. The observed upsurge in refractive indexes of the coatings is allied to the packing density that causes lattice contraction and enhances the attraction between dipoles. The negligible effect of negative temperature on the antireflection efficiency makes it suitable for future applications in optoelectronic, photovoltaic devices operated in a cold or humid environment.

Quantum correlations and thermal coherence in a two-superconducting charge qubit system

Superconducting charge qubits represent a cutting-edge technology in the field of quantum computing, offering a promising platform for quantum processing. This study delves into the behaviors of thermal coherence and quantum correlations within a two-superconducting charge qubit system coupled by a fixed capacitance. Specifically, we investigate the effects of thermal noise on entanglement (measured by concurrence), nonclassical correlations (quantified by local quantum uncertainty), and quantum coherence (measured by correlated coherence) within the two-superconducting charge qubit capacitively coupled. Our analysis takes into account the interplay between the equilibrium temperature of the reservoir and various system parameters. Our findings demonstrate that an increase in temperature leads to a decrease in coherence and quantum correlations within the considered system. However, the behavior of these quantum resources is heavily dependent on the system parameters, and a careful selection of these parameters can help mitigate the negative effects of absolute temperature. Additionally, we observe that local quantum uncertainty and correlated coherence are more resilient than thermal entanglement to rising temperatures. These results provide insight into how a two-superconducting charge qubit system can be optimized for achieving quantum advantages.