Shedding Light on Phase Stability and Surface Engineering of Formamidinium Lead Iodide (FaPbI3) Thin Films for Solar Cells

In this work, FAPbI3 thin films with different antisolvents (toluene, diethyl ether and chlorobenzene) were successfully elaborated by the spin coating technique to study the influence of the different antisolvents in the films. The crystal structure, surface morphology and optical properties were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) photoluminescence and UV–visible spectrometry. According to XRD, the crystalline structure of FAPbI3 was found in the orientation of the (110) plane, and it is observed that the type of antisolvent content in the absorber layer plays an important role in the growth and stabilization of the film. Here, chlorobenzene leads to a smooth and homogenous surface, a large grain size and a pinhole-free perovskite film. Additionally, the optical analysis revealed that the band gap is in the range from 1.55 to 1.57 eV. Furthermore, in an approximately 60% humidity environment and after two weeks, the stability and absorption of FaPbI3 showed low degradation.

Recurring exposure to low humidity induces transcriptional and protein level changes in the vocal folds of rabbits

Voice disorders are an important human health condition. Hydration is a commonly recommended preventive measure for voice disorders though it is unclear how vocal fold dehydration is harmful at the cellular level. Airway surface dehydration can result from exposure to low humidity air. Here we have induced airway surface dehydration in New Zealand White rabbits exposed to a recurring 8-h low humidity environment over 15 days. This model mimics an occupational exposure to a low humidity environment. Exposure to moderate humidity was the control condition. Full thickness soft-tissue samples, including the vocal folds and surrounding laryngeal tissue, were collected for molecular analysis. RT-qPCR demonstrated a significant upregulation of MUC4 (mucin 4) and SCL26A9 (chloride channel) and a large fold-change though statistically non-significant upregulation of SCNNA1 (epithelial sodium channel). Proteomic analysis demonstrated differential regulation of proteins clustering into prospective functional groups of muscle structure and function, oxidative stress response, and protein chaperonin stress response. Together, the data demonstrate that recurring exposure to low humidity is sufficient to induce both transcriptional and translational level changes in laryngeal tissue and suggest that low humidity exposure induces cellular stress at the level of the vocal folds.

Evaluation of Residents’ Comfort in High-Rise Residential Buildings in Dubai, United Arab Emirates

The global record of 1,700 % urban footprint growth in only 38 years made Dubai one of the fastest growing cities in the world. The density of the metropolis population is approximately 762.6 individuals/ km2, and high-rise residential buildings in Dubai have reached 581,166 units (79%) in 2020 and become a common residential type. The objective of this study is to provide basic data for the design of high-rise residential buildings in the future by evaluating the health of the residents of high-rise residential buildings in Dubai. As a methodology, the Todai Health Index, a structured health assessment tool, was used for high-rise residents’ survey. For the analysis, the health evaluation data from residents were used as the dependent variable, and the number of living floors as the architectural characteristic and the indoor temperature and humidity condition as the residential environments were analyzed as the independent variable. The result had shown that residence floor is irrelevant to overall health, changes in the health status compared to those in the previous year, and the occurrence of daily disease health evaluation by the Todai Health Index. It was statistically proven that the thermal environment has a significant correlation with the residence floor, but the effect of the thermal environment on health was not strong. However, the humidity environment has a very strong relationship with the health of residents. The humidity environment has a very close relationship not only with the occurrence of daily diseases of residents but also with the health evaluation analyzed by the Todai Health Index. There is a significant relationship between the humidity environment and both physical and mental health. It was analyzed that a slightly humid condition had a positive effect on health.

A fan-attached jacket worn in an environment exceeding body temperature suppresses an increase in core temperature

We examined whether blowing hot air above body temperature under work clothing may suppress core temperature. Nine Japanese men engaged in two 30-min bicycle ergometer sessions at a workload of 40% VO2max at 40 °C and 50% relative humidity. The experiment was conducted without wearing any cooling apparatus (CON), wearing a cooling vest that circulated 10.0 °C water (VEST), and wearing a fan-attached jacket that transferred ambient air underneath the jacket at a rate of 30 L/s (FAN). The VEST and FAN conditions suppressed the increases of rectal temperature (CON, VEST, FAN; 38.01 ± 0.19 °C, 37.72 ± 0.12 °C (p = 0.0076), 37.54 ± 0.19 °C (p = 0.0023), respectively), esophageal temperature (38.22 ± 0.30 °C, 37.55 ± 0.18 °C (p = 0.0039), 37.54 ± 0.21 °C (p = 0.0039), respectively), and heart rate (157.3 ± 9.8 bpm, 136.9 ± 8.9 bpm, (p = 0.0042), 137.5 ± 6.5 bpm (p = 0.0023), respectively). Two conditions also reduced the estimated amount of sweating and improved various subjective evaluations. Even in the 40 °C and 50% relative humidity environment, we may recommend wearing a fan-attached jacket because the heat dissipation through evaporation exceeded the heat convection from the hot ambient air.

Model of a digital device for assessing the state of xylem in tree trunks

For the development of systems for predicting the state of forests and trees, adequate models of the influence of temperature and humidity environment fluctuations on the kinetics of the wood microstructure are needed. Formalized modeling should be based on monitoring data obtained with controlled accuracy in real time. The aim of the work was to substantiate the layout of a device for measuring the potential difference in tree trunks to study their state. For the first time in the article, the recorder layout with the operating principle based on the phenomenon of thermally stimulated polarization of wood has substantiated. In addition, a formalized model has presented for processing the monitoring data of the studied potential difference in the framework of classical thermodynamics, which makes it possible to determine the parameters of the kinetics of the microstructure of wood in tree trunks at fluctuations of external factors. As a result of the research carried out, a model of a digital device for assessing the state of wood of tree trunks was developed. The proposed device for recording the response of the trunk wood on the fluctuations of external factors practically does not violate the unique microstructure of the biocomposite and has a controlled accuracy in real time.

Effect of Negative Bias Voltage on Tribological Properties under High Relative Humidity Environment and Corrosion Resistance of Boron Carbide Coatings

Humid air is a very important service environment, in which metal friction parts should be enhanced to offer excellent corrosion resistance and wear resistance. The B4C coating is an excellent candidate material to enhance the corrosion resistance and tribological behaviors. The purpose is to investigate the effect of negative bias voltages on the tribological properties of B4C coatings under a high relative humidity environment. Amorphous B4C coatings were successfully prepared by closed field unbalanced magnetron sputtering technology and its microstructure, hardness, elastic modulus, adhesive force and tribological properties were systematically studied. Results demonstrate that the B4C coatings deposited at each negative bias voltage have a columnar structure and the surface roughness remained unchanged (about 1.0 nm), while the thickness, hardness, elastic modulus and adhesion force increase first and then decrease with the negative bias voltage increasing. Among them, the B4C (−50 V) coating showed the best mechanical properties. It should be noted that the B4C (−50 V) coating with an excellent corrosion resistance also exhibits the lowest friction coefficient (~0.15) and wear resistance (7.2 × 10−7 mm3·N−1·m−1) under humid air (85% RH). This is mainly due to the tribochemical reaction of B4C during a sliding process to produce boric acid at the sliding interface. B4C coatings can provide an excellent corrosion resistance and high wear resistance due to their high chemical stability and high hardness.