Ambient Air Temperature Research Articles

Climate stabilizing value of oak shelterbelts in Zhytomyr Polissia

Woody forest plantations, including shelterbelts, are one of the stabilizers of the optimal ecological state of the environment in agricultural landscapes. Shelterbelts are able to sequester carbon from the atmosphere in their phytomass and generate oxygen for a long time. These processes contribute to the partial but permanent prevention of global climate change. According to the calculations, we determined the volume of tree trunks in the protective strips, the cross-sectional area of the trunk, and the phytomass of wood, bark, and crown in a completely dry state. Based on the research data, correlations were created between the main taxonomic indicators and phytomass fractions, which showed a close relationship between phytomass fractions and the height and diameter of tree trunks. In the course of the research, a regression equation was built between tree phytomass and biometric indicators such as trunk height and diameter. The amount of carbon sequestered by the oak shelterbelts was determined by determining the proportion of carbon in the phytomass in absolutely dry residue. The main soil and climatic indicators were established, which in most temporary test plots were characterized by pH=7.0 (neutral), the level of atmospheric air temperature under the forest protection strips was 2°C lower than in agroecosystems (field), and the soil temperature was 8°C lower than in the studied agroecosystems. Soil moisture was identical. According to the statistical analysis, the sample was homogeneous in terms of height, diameter, and age of the plantation. The obtained results allow for further analysis and construction of regression equations between tree phytomass and biometric parameters — height, diameter. It has been determined that an increase in tree diameter by 1.94% and height by 1.0% has a direct impact on the growth of phytomass of common oak wood. It has been established that the total phytomass of oak in linear plantations is 157.7 kg for a middle-aged tree and 275.9 kg for a mature tree. According to the established value of the conversion coefficient of the carbon-absorbing capacity of field protection strips of oak plantations, CO2 emissions into the atmosphere in the Zhytomyr Polissia zone are annually reduced by 5%. The obtained equation of the conversion coefficient, with a sufficiently high determination index, makes it possible to use the obtained dependence in further calculations.

Typical and extreme weather datasets for studying the resilience of buildings to climate change and heatwaves

We present unprecedented datasets of current and future projected weather files for building simulations in 15 major cities distributed across 10 climate zones worldwide. The datasets include ambient air temperature, relative humidity, atmospheric pressure, direct and diffuse solar irradiance, and wind speed at hourly resolution, which are essential climate elements needed to undertake building simulations. The datasets contain typical and extreme weather years in the EnergyPlus weather file (EPW) format and multiyear projections in comma-separated value (CSV) format for three periods: historical (2001–2020), future mid-term (2041–2060), and future long-term (2081–2100). The datasets were generated from projections of one regional climate model, which were bias-corrected using multiyear observational data for each city. The methodology used makes the datasets among the first to incorporate complex changes in the future climate for the frequency, duration, and magnitude of extreme temperatures. These datasets, created within the IEA EBC Annex 80 “Resilient Cooling for Buildings”, are ready to be used for different types of building adaptation and resilience studies to climate change and heatwaves.

Evaluating the effect of ambient air temperature on the sustainability aspect of naphtha‐based gas turbine power plant

AbstractThe exergy‐based sustainability indices have been a cause of concern for gas turbine power plant as its performance is very sensitive to air temperature. Hence, the present study evaluates the impact of atmospheric air temperature on exergy sustainability and ecological function of a naphtha‐based gas turbine power plant using EES. The outcome of the study shows that combustion chamber (CC_1) needs more attention compared with other components present, and it has least improvement potential as compared with other components. Further while carrying out parametric analysis with respect to ambient air, it was observed that for a 1.1°C increase in atmospheric air temperature a reduction in sustainability index about 0.66% was observed respectively, for GT_1. Thus, this study established that the power plant's exergy sustainability performance has a negative impact at high ambient air temperatures on exergy sustainability indices.

Temporal dynamics of drinking water sodium levels in coastal areas, Cyprus 2009–2020

Around the world, groundwater salinity levels are increasing in coastal areas, as a result of its systematic overexploitation for domestic, agricultural and industrial demand and potentially due to climate change manifestations (such as, sea level rise). We hypothesized that the groundwater quality of many Mediterranean coastal areas is already being perturbed, especially for water salinity, depending on the groundwater distance from the seafront. The objectives of this study were: i) to evaluate the magnitude and temporal variance of drinking water sodium (Na) as a metric of salt intake used for public health purposes using drinking water data in Cyprus; and ii) to examine the degree of Na enrichment in drinking water as defined by the seawater coastline distance of each sampling point. Open access governmental data of drinking water Na (n = 3304), daily max ambient air temperature and total rainfall were obtained for the period of 2009–2020 from governmental repositories. Linear mixed-effect regression models of drinking water Na with unsupervised covariance matrix were used. After adjusting for temperature and rainfall data, there was a significant annual increase in drinking water Na levels over time (beta = 0.01; 95 % CI: 0.00, 0.02; p = 0.02) for the coastal areas (<10 km from coastline, cutoff used by the EU Environment Agency), but this was not the case for non-coastal areas (>10 km distance from coastline). The distance of each sampling point from the coastline in Cyprus was negatively associated with drinking water Na in coastal areas (beta = −0.04, 95%CI: −0.06, −0.01; p = 0.002); this was not the case for non-coastal areas. More research is warranted to better understand the impacts of global environmental change on water quality in association with the burden of disease in coastal areas.

Urban air PCDD/Fs: Atmospheric concentrations, temporal changes, gas/particle partitioning, possible sources and cancer risks

Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) are pollutants of concern due to their toxic effects. No active sampling study on PCDD/Fs has been conducted in Bursa. This study aimed to fill this gap by measuring PCDD/F levels in the region. Accordingly, the samples were collected from an urban area in Bursa, covering four seasons between June 2022 and April 2023. The total (gas+particulate) ambient air concentrations were between 312.23 and 829.80 fg/m3 (mean: 555.05 ± 173.62 fg/m3). In terms of toxic equivalents (TEQ), the average concentration was 43.29 ± 9.18 fg WHOTEQ/m3. Based on the concentration values obtained, cancer and non-carcinogenic risk values of PCDD/Fs were calculated for three different age groups. The results indicated negligible health risks for all age groups. In addition, a seasonal assessment was also made and it was observed that PCDD/F concentration values varied with the ambient air temperatures. In general, higher values were measured in colder months compared to warmer months. This was probably due to the additional sources and adverse meteorological conditions. Moreover, the gas/particle partitioning of PCDD/Fs was investigated in detail. The average gas and particulate phase concentrations for PCDD/Fs were 101.81 ± 20.77 and 453.24 ± 172.50, respectively. It was found that an equilibrium state was not reached in the gas/particle partitioning. Two different gas/particle partition models based on adsorption and absorption mechanisms were compared, and the absorption model gave more consistent predictions. The Principal Component Analysis (PCA) was employed to identify the possible PCDD/F sources. The results indicated that the region was influenced by vehicle emissions, residential heating, organized industrial zones and metal recycling facilities. In addition, 72-hour backward air mass trajectory analyses were performed to understand the long-range transported air masses. However, it was found that the transported air masses did not significantly affect the concentration values measured in the sampling site.

Utilizing Reversed Brayton Cycle for Enhanced Cooling Tower Technology

This study demonstrates an enhanced cooling tower technology (ECTT) under which the ambient air is precooled and dehumidified to improve the cooling tower efficiency. The reverse Brayton cycle, comprising a compressor, an air cooler, an expander, and a heat and mass exchanger, is used to precondition the ambient air before entering the cooling tower. A plant-scale thermodynamic model is constructed for ECTT, and the system parameters are optimized through genetic algorithm based on the maximum power gained from the system, including the effects of reducing the makeup water for the cooling tower. Compared to conventional cooling towers, the ECTT achieved sub-wet bulb cooling of water, which is 9.5 °C below the wet bulb temperature of ambient air, reduces steam condensation temperature by 34%, and increases steam turbine power output by 4.3%. It also reduces evaporative losses in the cooling tower and reduces the makeup water by 36%. With cooling tower exhaust recirculated in a closed loop, makeup water requirements are further reduced with additional gains in power output.

Micro-environment inside disposable medical protective clothing and its improvement

Disposable medical protective clothing (DMPC) can cause severe discomfort and even safety problems to wearers, especially during summertime in warm climates. This study investigated the micro-environment (air temperature (TDMPC) and relative humidity (RHDMPC)) in the space between the DMPC and the body, as well as the physiological and subjective sensations of wearers under typical conditions in a controlled climate chamber. Three types of clothes drying and cooling (CDC) techniques, including desiccant (CDC1), phase change material (CDC2), and the combination of both (CDC3), were then evaluated. Under typical conditions in hot and humid regions (30 °C, 70 %), TDMPC stabilized at about 33.5 °C in 40 min and RHDMPC stabilized in the range of 85–100 % after 80 min. When the ambient air temperature increased to 36 °C, the TDMPC increased to about 36.5 °C during activities such as sitting and standing-talking, while the forehead temperature of DMPC wearers reached 38.0 °C in 40–60 min and continued to rise. It implies that 40 min should be the maximum recommended working period for DMPC wearers at such ambient temperature and activity level. The proposed CDC3 reduced TDMPC by 1.2–1.8 °C during the experiment. The use of CDC3 effectively reduced the participants' thermal sensation vote from “2” or “3” (“hot” or “very hot”) to below “1” (warm) and the sweating sensation vote from “3” or “4” (“slight sweat” to “skin became clammy”) to below “2” (“no sweat but sticky skin”) under low and moderate activity levels.

Surface-Assisted Selective Air Oxidation of Phosphines Adsorbed on Activated Carbon.

Trialkyl- and triarylphosphines readily adsorb onto the surface of porous activated carbon (AC) even in the absence of solvents through van der Waals interactions between the lone electron pair and the AC surface. This process has been proven by solid-state NMR techniques. Subsequently, it is demonstrated that the AC enables the fast and selective oxidation of adsorbed phosphines to phosphine oxides at ambient temperature in air. In solution, trialkylphosphines are oxidized to a variety of P(V) species when exposed to the atmosphere, while neat or dissolved triarylphosphines cannot be oxidized with air. When the trialkyl- and triarylphosphines PnBu3 (1), PEt3, (2), PnOct3 (3), PMetBu2 (4), PCy3 (5), and PPh3 (6) are adsorbed in a mono- or submonolayer on the surface of AC, in the absence of a solvent and at ambient temperature, they are quantitatively oxidized to the adsorbed phosphine oxides, 1ox-6ox, once air is admitted. No formation of any unwanted P(V) side products or water adducts is observed. The phosphine oxides can then be recovered in good yields by washing them off of the AC. The oxidation is likely facilitated by a radical activation of molecular oxygen due to delocalized electrons on the aromatic surface coating of AC, as proven by ESR. This easy and inexpensive oxidation method renders hydrogen peroxide or other oxidizers unnecessary and is broadly applicable to sterically hindered and even to air-stable triarylphosphines. Phosphines adsorbed at lower surface coverages on AC oxidize at a faster rate. All oxidation reactions were monitored by solution- and solid-state NMR spectroscopy.

One-pot synthesis of a porphyrin functionalized metal-organic frameworks as a recyclable visible-light-driven photosensitizer for efficient detoxification of a sulfur mustard simulant in air

Herein, we report a facile one-pot in situ self-assembly approach that enables a porphyrin photosensitizer, [5,10,15,20-tetrakis(4-methoxycarbonylphenyl)porphyrin]-Zn(II) (ZnTPP), to be enshrouded by a zeolitic imidazolate framework-8 (ZIF-8) to afford a novel visible-light-driven heterogeneous photosensitizer, ZnTPP@ZIF-8 composite. The ZnTTP photosensitizer was well dispersed and fully confined within the ZIF-8 crystals and the framework intactness and porosity were well maintained. The as-prepared ZnTPP@ZIF-8 composite integrates the advantages of ZIF-8 MOFs and ZnTTP photosensitizer. It not only can effectively produce both singlet oxygen (1O2) and superoxide ion (∙O2−) under visible light irradiation, but also exhibit high surface area and excellent stability. The structure characterization of ZnTPP@ZIF-8 composite was first carried out, and then this material can be used as a heterogeneous photosensitizer for the rapid and highly selective detoxification of a sulfur mustard simulant (2-chloroethyl ethyl sulfide) into the corresponding much less toxic sulfoxide product with a half-life of only 1.5 min under visible light irradiation at room temperature in air atmosphere. This catalyst can be readily recycled and reused at least six times without obvious loss of catalytic activity. This study will provide us a new strategy for the facile, rapid and environmentally friendly preparation of photosensitizer@MOFs composites and the rapid detoxification of sulfur mustard under ambient conditions in the future.

Ovarian PERK/NRF2/CX43/StAR/progesterone pathway activation mediates female reproductive dysfunction induced by cold exposure

Ambient air temperature is a key factor affecting human health. Female reproductive disorders are representative health risk events under low temperature. However, the mechanism involving in cold-induced female reproductive disorders remains largely unknown. Female mice were intermittently exposed to cold conditions (4 °C) to address the health risk of low temperature on female reproductive system. Primary granulosa cells (GCs) were prepared and cultured under low temperature (35 °C) or exposed to β3-adrenoreceptor agonist, isoproterenol, to mimic the condition of cold exposure. Western-blot, RT-PCR, co-IP, ELISA, pharmacological inhibition or siRNA-mediated knockdown of target gene were performed to investigate the possible role of hormones, gap conjunction proteins, and ER stress sensor protein in regulating female reproductive disorders under cold exposure. Cold exposure induced estrous cycle disorder and follicular dysplasia in female mice, accompanying with abnormal upregulation of progesterone and its synthetic rate-limiting enzyme, StAR, in the ovarian granulosa cells. Under the same conditions, an increase in connexin 43 (CX43) expressions in the GCs was also observed, which contributed to elevated progesterone levels in the ovary. Moreover, ER stress sensor protein, PERK, was activated in the ovarian GCs after cold exposure, leading to the upregulation of downstream NRF2-dependent CX43 transcription and aberrant increase in progesterone synthesis. Most importantly, blocking PERK expression in vivo significantly inhibited NRF2/CX43/StAR/progesterone pathway activation in the ovary and efficiently rescued the prolongation of estrous cycle and the increase in follicular atresia of the female mice induced by cold stress. We have elucidated the mechanism of ovarian PERK/NRF2/CX43/StAR/progesterone pathway activation in mediating female reproductive disorder under cold exposure. Targeting PERK might be helpful for maintaining female reproductive health under cold conditions.

Effect of activator concentration on setting time, workability and compressive strength of sustainable concrete with alkali-activated slag binder

The global need to reduce carbon dioxide (CO2) emissions prompted studies on sustainable alternatives to conventional concrete made with ordinary Portland cement (OPC) binders. Alkali-activated ground granulated blast furnace slag (GGBS) is a promising sustainable to OPC in terms of the impact on the environment and reduction of CO2 emissions. Concretes and mortars made with alkali-activated binders demonstrate promising fresh and mechanical properties. This article presents the findings of an experimental study investigating the fresh and mechanical properties of mortar using alkali-activated GGBS binder. The activators used were sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solution with 6 M, 8 M, 10 M, and 12 M molarities. The study assessed their initial setting time, workability, and 28-day compressive strength. The study evaluated the effect of partial replacement of GGBS with 5 % silica fume. The compressive strength was determined after 28 days of curing in three different environments: 1) ambient air temperature, 2) water submersion, and 3) water immersion for 7 days followed by 21 air curing in ambient temperature. The results showed an increase in compressive strength with higher NaOH concentration but a corresponding decrease in initial setting time and flowability. Depending on the curing method, efflorescence, and blue-green pigmentation were seen during the physical assessment of the samples. The highest 28-day compressive strength was 67.5 MPa when the NaOH activator molarity was 10 mol/L which represents an optimum concentration for strength development. Replacing 5 % of the GGBS binder with silica fume resulted in a decrease in the 28-day compressive strength and workability without affecting the initial setting time.

Implementation and validation of boundary conditions between a chemical reactor and ambient air

This work is dedicated to the development and validation of boundary conditions for a hot object cooled in a colder environment due to natural convection, radiation and evaporation. The main background of this research is to present boundary conditions for a hot reactor in cold ambient air, where the reactor walls are not thermally insulated. Water cooling in a standard small paper cup (coffee cup) was selected as a validation test. The experimental data comprise time histories of the cup’s side wall temperature measured using three thermoelements. The initial water temperature was set to 94 °C. The ambient air temperature was fixed at 25 °C and the air humidity at 20%. The computational model is based on unsteady laminar flow Navier–Stokes equations coupled with the heat transfer equation. The water density and all water transport properties (i.e., thermal conductivity, molecular viscosity, and specific heat capacity) are temperature-dependent. Numerical simulations in two-dimensional (2D) axisymmetry aligned well with the results from experiments. Including evaporative cooling on the top water surface proved essential to accurately determine the temperature profile. The boundary conditions are implemented into the Ansys Fluent 2022R2 computational fluid dynamics (CFD) commercial solver using user-defined functions (UDFs). The model equations can be used as a boundary condition for fixed beds and adsorption columns to improve the prediction of thermal profiles in both lab-scale and industrial-scale units.

Mega-train turbine performance improvement through intake air cooling system dimensioning and design

Gas turbines are a well-known rotating machines used in a variety of industrial sectors. However, the aforementioned turbines are highly sensitive to climatic changes such as variations in temperature and humidity, which can significantly affect their performance. Focusing on the being cited limitations, and aiming at the improvement of the system performances, it is important to control the ambient air temperature. In this context, the current study analyzes the design of an enhanced air-cooling system by putting forth a novel and practical method for raising output while lowering investment costs and ensuring steady and dependable operation. Firstly, the thermodynamic analysis of the realistic MS-7001 is carried out. Then, the feasibility of an air-cooling system for the MS-7001 turbine used at the Natural Gas Liquefaction complex – Skikda is conducted before starting the prototyping process. The proposed system uses a water evaporative cooler as a pre-cooler to reduce the temperature by around 12°C, while, increasing the relative humidity to around 90%, In order to ensure the thermal effectiveness of the system, a compressed air injection station is used for the production of a cold air at high pressure. CFD analysis results and conducted experiments on the proposed prototype have confirmed that it is effective and can be adapted to both wet and dry climates, even under hard variations. The adopted technique enhances the system efficiency and makes it possible to maintain the nominal operating point of gas turbines independently of external variations of atmospheric condition, without modifying their composition, which minimizes investment, development and maintenance costs.

Changes in Surface Runoff and Temporal Dispersion in a Restored Montane Watershed on the Qinghai–Tibetan Plateau

Surface runoff is a major component of the hydrological cycle, and it is essential for supporting the ecosystem services provided by grassland and forest ecosystems. It is of practical importance to understand the mechanisms and the dynamic processes of runoff in a river’s basin, and in this study, we focused on the restored montane Pailugou Basin in the Qilian Mountains, Gansu Province, China, since its water status is extremely important for the large arid area and local economies therein. Our purpose was to determine the annual variation in the surface runoff in the Pailugou Basin because it is important to understand the influence of climate fluctuations on surface water resources and the economy of the basin. In addition, little is known about the annual variations in precipitation and runoff in this region of the world. Daily atmospheric precipitation, air temperature and runoff data from 2000 to 2019 were analyzed by the calculation of the uneven annual distribution of surface runoff, the calculation of the complete adjustment coefficient, and the vector accumulation expressed by the concentration degree. We also used the cumulative anomaly approach to determine the interannual variation trend of runoff, while the change trend was quantified by the sliding average method. Finally, we used the Mann–Kendall mutation test method and regression analysis to establish the time-series trend for precipitation and runoff and to determine the period of abrupt runoff changes. The results indicated concentrated and positive distributions of surface runoff on an annual basis, with a small degree of dispersion, and an explicit concentration of extreme flows. The relative variation ranges exhibited a decreasing trend, and the distribution of the surface runoff gradually was uniform over the year. The runoff was highest from July to September (85% of the annual total). We also determined that annual surface runoff in the basin fluctuated over the 20-year period but showed an overall increasing trend, increasing by 3.94 × 105 m3, with an average increase rate of 0.42 × 105 m3 every ten years. From 2005 to 2014, the annual runoff and the proportion of runoff in the flood season (July to September) to the annual runoff fluctuated greatly. The correlation between the runoff and precipitation was significant (r = 0.839, p &lt; 0.05), whereas the correlation between air temperature and surface runoff was low (r = 0.421, p &lt; 0.05).

Population ecology of the intertidal xanthid crab Leptodius exaratus (H. Milne Edwards, 1834) (Decapoda: Brachyura: Xanthidae) on rocky shores in Kuwait, Arabian (Persian) Gulf

Abstract Leptodius exaratus (H. Milne Edwards, 1834) is an exploited species that has been used as bait for recreational fishing in Kuwait. The biological and ecological aspects of the species required to manage this practice are limited. We investigated the life history and population ecology of L. exaratus in the northwestern Arabian (Persian) Gulf. The spawning season of the crab in Kuwait starts in the late spring and continues through the summer and ends in September. Fecundity is highly correlated to female body size and ranges 2,533–11,991 eggs clutch–1, with a mean number of 7,055 eggs clutch–1. Juveniles are generally recruited between July and September, with lower minor recruitment levels occurring in October and November. Growth is highly seasonal, being slow during the cold season (October-February) and high during the warmer season (March and September), with a higher growth rate in males than in females. The seasonality of growth and reproduction of L. exaratus in the region is strongly related to ambient air and water temperatures. Sexual dimorphism is highly significant between males and females with males, reaching reproductive maturity at 17.43 ± 0.53 mm carapace width (CW) and females at 9.58 ± 1.21 mm CW. The overall sex ratio for the species is 0.8:1 (males:females). Furthermore, the life span of 3–4 yr and an overall mortality slightly higher in males than in females. The results of our study could be used to determine fishery management strategies such as minimum catch sizes and closures periods. The results on life history and dynamics of the complex life cycle of L. exaratus contribute to conservation and sustainable exploitation of the species in Kuwait.

The Impact of System Sizing and Water Temperature on the Thermal Characteristics of Floating Photovoltaic Systems

Accurately calculating the annual yield of floating PV (FPV) systems necessitates incorporating appropriate FPV-specific heat loss coefficients into the calculation, including both wind-dependent and wind-independent factors. The thermal behavior of several FPV systems has been investigated within this study, through the analysis of heat loss coefficients across various system sizes and configurations. Over a one-year period, data were collected from two measurement sites with three distinct systems: two ~50 kWp demonstrator-scale setups of Solarisfloat (azimuthal tracking) and Solar Float (East-West orientation) and a 2 MWp commercial-scale East–West system by Groenleven. The Solarisfloat demonstrator revealed a wind-dependent heat loss coefficient of 3.2 W/m3Ks. In comparison, the Solar Float demonstrator system displayed elevated wind-dependent heat loss coefficients, measuring 4.0 W/m3Ks for the east-facing module and 5.1 W/m3Ks for the west-facing module. The Groenleven system, which shares design similarities with Solar Float, showed lower wind-dependent heat loss coefficients of 2.7 W/m3Ks for the east-facing module and 2.8 W/m3Ks for the west-facing module. A notable discrepancy in the wind-dependent coefficients, particularly evident under a north wind direction, indicates a more efficient convective cooling effect by the wind on the demonstrator scale system of Solar Float. This could possibly be attributed to improved wind flow beneath its PV modules, setting it apart from the Groenleven system. Additionally, a thermal model founded on a ‘balance-of-energy’ methodology, integrating water temperature as a variable was introduced. The heat loss coefficient, dependent on the surface water temperature, fluctuated around zero, depending on whether the water temperature surpassed or fell below the ambient air temperature. It can be concluded that it is not of added value to introduce this floating specific heat loss coefficient parameter, as this parameter can be integrated in the wind speed independent Uc parameter.

Methodology to evaluate design modifications intended to eliminate frosting and high discharge temperatures in air-source heat pumps (ASHPs) in cold climates

Air-source heat pumps (ASHPs) operating in cold climates experience problems with frosting and high refrigerant temperatures. These problems increase energy consumption, and their severity depends on the climatic conditions. In the present paper, a methodology for identifying the prevailing problem between frosting and high discharge temperatures is presented. Three performance indices, the frosting index (FI), the discharge index (DI), and the total loss index (TLI), are proposed to quantify the impacts of frosting and high discharge temperatures on the annual performance of ASHPs in different climatic conditions. The FI and DI show which problem (frosting or high discharge temperature) dominates, and the TLI indicates the combined effect of frosting and high discharge temperatures on the performance of an ASHP. A thermodynamic model of an ASHP coupled with the TRNSYS building simulation tool is used to estimate the performance of an ASHP and the proposed loss indices to estimate the impact of both frosting and high discharge temperatures for 45 cities in Canada. The results can be extended to other parts of the world that experience similar climatic conditions The results reveal that in cities in ASHRAE climatic zones 5 and 6 (classified as cold regions) where the ambient air temperatures are predominantly between −15 °C to 6 °C, ASHPs are heavily impacted by frosting. The problem of high discharge temperatures in ASHPs is predominant in cities in climate zones 7 and 8 (classified as very cold and subarctic regions) where the temperatures are frequently below −20 °C in winter. Among the cities considered, St. John, NL has the highest fraction of heating hours experiencing frosting (90 %), where the annual increase in energy consumption due to frosting is 13.5 % of the annual heating energy consumption. The highest annual increase in energy consumption due to high discharge temperatures is in Isachsen, NU (zone 8), where the increase is 30 % of the annual heating energy consumption.Based on the proposed indices, another index called the performance gain index (PGI) is created, which can be used as a first step to assess the energy-saving potential of design modifications applied to ASHPs to solve the problems of frosting and high discharge temperatures. The PGI will aid in developing climate specific ASHPs. One possible design modificationis the use of a two-stage ASHP with an economizer. It is observed that the two-stage ASHP with economizer can mitigate high discharge temperatures and improve performance in very cold and subarctic regions (zones 7 and 8). However, it is not as beneficial in zones 5 and 6, where the impact of high discharge temperatures on performance is minimal and frosting dominates. Finally, a case study, using the PGI to evaluate the economic and environmental effectiveness of a two-stage ASHP with economizer is presented for the city of Saskatoon.

Incidence and seasonality of Kawasaki disease in children in the Philippines, and its association with ambient air temperature.

Despite an unknown cause, Kawasaki disease (KD) is currently the primary leading cause of acquired heart disease in developed countries in children and has been increasing in recent years. Research efforts have explored environmental factors related to KD, but they are still unclear especially in the tropics. We aimed to describe the incidence of KD in children, assess its seasonality, and determine its association with ambient air temperature in the National Capital Region (NCR), Philippines from January 2009 to December 2019. Monthly number of KD cases from the Philippine Pediatric Society (PPS) disease registry was collected to determine the incidence of KD. A generalized linear model (GLM) with quasi-Poisson regression was utilized to assess the seasonality of KD and determine its association with ambient air temperature after adjusting for the relevant confounders. The majority of KD cases (68.52%) occurred in children less than five years old, with incidence rates ranging from 14.98 to 23.20 cases per 100,000 population, and a male-to-female ratio of 1.43:1. Seasonal variation followed a unimodal shape with a rate ratio of 1.13 from the average, peaking in March and reaching the lowest in September. After adjusting for seasonality and long-term trend, every one-degree Celsius increase in the monthly mean temperature significantly increased the risk of developing KD by 8.28% (95% CI: 2.12%, 14.80%). Season-specific analysis revealed a positive association during the dry season (RR: 1.06, 95% CI: 1.01, 1.11), whereas no evidence of association was found during the wet season (RR: 1.10, 95% CI: 0.95, 1.27). We have presented the incidence of KD in the Philippines which is relatively varied from its neighboring countries. The unimodal seasonality of KD and its linear association with temperature, independent of season and secular trend, especially during dry season, may provide insights into its etiology and may support enhanced KD detection efforts in the country.

Arbuscular Mycorrhizal Fungi Improve the Performance of Tempranillo and Cabernet Sauvignon Facing Water Deficit under Current and Future Climatic Conditions.

Climate change (CC) threatens Mediterranean viticulture. Rhizospheric microorganisms may be crucial for the adaptation of plants to CC. Our objective was to assess whether the association of two grapevine varieties with arbuscular mycorrhizal fungi (AMF) increases grapevine's resilience to environmental conditions that combine elevated atmospheric CO2, increased air temperatures, and water deficit. Tempranillo (T) and Cabernet Sauvignon (CS) plants, grafted onto R110 rootstocks, either inoculated (+M) or not (-M) with AMF, were grown in temperature-gradient greenhouses under two environmental conditions: (i) current conditions (ca. 400 ppm air CO2 concentration plus ambient air temperature, CATA) and (ii) climate change conditions predicted by the year 2100 (700 ppm of CO2 plus ambient air temperature +4 °C, CETE). From veraison to maturity, for plants of each variety, inoculation treatment and environmental conditions were also subjected to two levels of water availability: full irrigation (WW) or drought cycles (D). Therefore, the number of treatments applied to each grapevine variety was eight, resulting from the combination of two inoculation treatments (+M and -M), two environmental conditions (CATA and CETE), and two water availabilities (WW and D). In both grapevine varieties, early drought decreased leaf conductance and transpiration under both CATA and CETE conditions and more markedly in +M plants. Photosynthesis did not decrease very much, so the instantaneous water use efficiency (WUE) increased, especially in drought +M plants under CETE conditions. The increase in WUE coincided with a lower intercellular-to-atmospheric CO2 concentration ratio and reduced plant hydraulic conductance. In the long term, mycorrhization induced changes in the stomatal anatomy under water deficit and CETE conditions: density increased in T and decreased in CS, with smaller stomata in the latter. Although some responses were genotype-dependent, the interaction of the rootstock with AMF appeared to be a key factor in the acclimation of the grapevine to water deficit under both current and future CO2 and temperature conditions.

Investigating urban canyons, façade albedo, and pedestrian thermal comfort using microclimate model calculations

Previous studies have shown a strong relationship between heat-related fatalities and ambient air temperature. This problem is expected to increase due to constant urbanization and the threat of global warming. Therefore, designing urban street canyons (USC) to be thermally comfortable is essential for a healthy urban life. This paper investigates the correlation between an urban street canyon’s aspect ratio and the albedo material of its surrounding buildings. The aim is to study which combination can successfully mitigate urban heat stress and create a thermally comfortable pedestrian microclimate. This research uses a comparative analysis that suggests the optimum albedo for different USC geometries. An ENVI-met model was used to simulate 9 scenarios for an idealized 2D USC with varying aspect ratios and albedo values. Air temperature, mean radiant temperature and Universal Thermal Climate Index (UTCI) were analyzed. Results show that a medium albedo value performs best thermally in all USCs. High albedo had 13.2% more combined thermal stress compared to medium albedo. However, high albedo performed much better in deep canyons than wider ones, with the average UTCI decreasing by about 4.8%-5.7% when used in deep canyons. Medium albedo should be exclusively used in wide canyons for minimal thermal stress. Practical application: This study provides a reference to the use of materials in urban street canyons of different aspect ratios to achieve good outdoor thermal comfort for pedestrians.