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Objective: Establishing thermal comfort zones solely through natural ventilation in hot and humid climates is challenging. Continuous reliance on mechanical cooling can compromise indoor air quality, posing health risks to building occupants. The building's skin and windows play a crucial role in the heat exchange, cooling loads, energy demands, and the thermal comfort of the residents. This study aimed to minimize total annual discomfort hours and solar radiation heat gain from external windows while utilizing natural ventilation in a residential building in Asalouyeh City's hot humid cliamte. Additionally, the study examined the impact of transparent and opaque wall materials, as well as window shadings, on the optimal Window-to-Wall Ratio (WWR) to minimize solar gain and discomfort hours. Method: Data collection was performed using simulation in DesignBuilder software version 6.1.0.006. For each common and proposed configuration of building construction and different values for WWR (10%-90%), the annual Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD) were determined at 1-hour intervals in a sitting zone of the case study building. The indices were also determined for the thermal peak day at 30-minute intervals. The obtained values were compared with the comfort range recommended by ASHRAE Standard 55 (+0.5 < PMV < -0.5, 0 < PPD < 20%). The annual total hours during which achieving thermal comfort through natural ventilation is possible were calculated. Finally, the optimal window-to-wall ratio and opening areas in the optimal construction configuration were determined using the optimization method. Results: With a WWR of 30% (a common ratio in building construction), the total annual solar radiation heat gain decreased from 3574 kW to 270 kW with proposed materials. The zone lounge remained within the comfortable range for at least 737 hours throughout the year, thanks to natural cooling. Optimal WWR values included 10%, 16%, 18%, 20%, 22%, 24%, 26%, 32%, 34%, 36% in combination with open areas of 75%, 49%, 84%, 54%, 66%, 36%, 94%, 38%, 5%, 5% respectively. The optimal properties for transparent surfaces include aluminum thermal break window frames, a 1-meter overhang, and left and right side-fin shadings for windows made from lightweight concrete cast (Conductivity: 0.3800 W/m-K, Specific Heat: 1000.00 J/kg-K, Density: 1200.00 kg/m³, Thickness: 0.002 m), and low emissivity glass (SHGC: 0.15, LT: 0.15, U-Value: 2.555 W/m²-K). The conductivity, specific heat, density, and thickness of the outermost and innermost layers of the frame were 0.16 and 0.17 W/m-K, 880.00 and 900.00 J/kg-K, 2800.00 and 1390.00 kg/m³, 0.002 and 0.005 m, respectively. The study also introduced the thermal properties of non-transparent surfaces. Conclusion: Findings showed that the glass properties (Light Transmission and Thermal transmittance or U-Value) and Solar Heat Gain Coefficient (total solar transmission) are the most important factors in determining the optimal design compared to other parameters (including thermal insulation, R-value of non-transparent surfaces, shading devices). Although minimizing WWR is recommended for hot and humid climates, this ratio can be increased by choosing the appropriate glass. [ABSTRACT FROM AUTHOR]

Background: Amphibian skins possess various antibacterial compounds that are effective against some microbial pathogens and are mostly released in response to environmental stress. In fact, the skin of Rana ridibunda, a large green frog, is a rich source of antimicrobial compounds that can be developed for therapeutic use. In the present study, the skin extract of Iranian Rana ridibunda was evaluated for its antimicrobial, hemolytic and cytototoxic activities. Methods: The frog specimens were collected from Minoodasht located in Golesten province in Iran, during 2009. Subsequently, their skins were removed and the intended compounds were extracted. The crude extract was partially purified by gel filtration chromatography. The antimicrobial effects of skin extract were assessed against various microorganisms such as Escherchia coli, methicillin-resistant and -sensitive Staphyloccus aureus, vancomycin-resistant and -susceptible Enteroccus fecalis, Pseudomonas aeroginosa and Candida albicans. In addition, its minimum inhibition concentration, cytotoxic and hemolytic activities were determined. Results: The crude extract of Rana ridibunda skin had valuable antimicrobial effects against methicillin-resistant and -susceptible S. aureus in comparison with E.coli and vancomycin-resistant and -susceptible E. fecalis. Besides, no antimicrobial activities were seen against P. aeroginosa or C. albicans. Moreover, the hemolytic and cytotoxic activities of the skin extract were minimal. Conclusion: The antimicrobial activity of Iranian Rana ridibunda was comparable to those isolated from other Rana species. In conclusion, the skin extract of Rana ridibunda had the potential for a new therapeutic agent against the emerging drugresistant bacteria, particularly methicillin-resistant and -sensitive S. aureus. [ABSTRACT FROM AUTHOR]