Physical Properties and Hygrothermal Behavior of Mycelium-Based Composites as Foam-Like Wall Insulation Material

This research aims to study mycelium-based composites (MBC) by assessing their performance as foam-like wall insulation material. Various substrates have been selected to get optimized performance of the composite. Results showed that a prolonged growing period arose a denser mycelium outer layer in MBC, which rendered better water resistance due to the hydrophobicity of mycelium. Thermal conductivity and mechanical properties are highly dependent on substrate choices than other parameters of MBC, which coincided with the literature. Additionally, influences of accelerated aging test and moisture buffer capacity of MBC were first studied in this research. The results indicated that MBC not only maintained good functional performance after the accelerated aging test (i.e. drying and wetting cycles) but also constituted good moisture buffer capacity. This means that MBC has key material essences to apply as internal wall insulation material and become one of the layers in vapor-permeable building envelope systems to passively regulate indoor relative humidity and thermal comfort.

Improving the method for determining the physiological and sanitary potential of Gherkin seeds

Gherkin seeds usually show irregular physiological quality. Seed production requires fast and reliable tests to evaluate seed quality. Germination test is considered a recognized analysis method; however, seed technology has pursuit the improvement of vigor tests aiming the evaluation of seed’s physiological potential. Thus, the objective of this work was to evaluate procedures to perform the test of accelerated aging and determine the physiological and sanitary potential of gherkin seeds. Four seed lots of cultivar Liso Calcuta were used in the study. To evaluate the initial physiological quality the water content was determined and germination and emergence tests, as well as indices of germination speed and emergence speed were used. The accelerated aging test was performed as traditionally and with saturated saline solution, with 48, 72 and 96 hours, at temperatures of 41oC and 45oC. After aging, the water content was determined, and seeds’ germination and sanity tests were performed. The experiment was set under a completely random design in factorial 4x3x2 (lots x aging periods x temperatures). The standard accelerated aging test and the test with saturated saline solution at 41oC for 96 hours were efficient to evaluate the vigor of gherkin seeds. Saturated saline solution provides uniform water absorption and deterioration in gherkin seeds, allowing to discriminate seed lots in different vigor levels. The salinity test after accelerated aging with saline solution reduces the incidence of some fungi.

Germination and vigour of seed of sorghum (Sorghum bicolor L. Moench) treated with Arsenicum album

Rosimar Maria Marques1; Bruno Reis1; Anielen C. Tormena Cavazin1; Flávia Carolina Moreira1; Monica G. Buchoski1; Hingrid Ariane Silva1; Mayara A. Lois1; Carlos Moacir Bonato1* 1Universidade Estadual de Maringá – UEM 1* Orientador – [email protected] Introduction: The accelerated aging test evaluates the behavior of seeds exposed to stress conditions based on the fact that the rate of deterioration is considerably increased by exposure to high temperature and relative humidity [1]. The knowledge acquired in homeopathic science is experimental research on healthy living organisms that are undergoing experimentation using homeopathic medicines [2]. The experimental research on homeopathic plants has been performed in Europe, Mexico, India and Brazil, proving that the principle of homeopathy, as set out in the animal kingdom has been found in plants [3]. This experiment aimed to evaluate the effect of the homeopathic Arsenicum album in decimal (x) and centesimal (cH) scale on the physiological variables of the germination and growth of sorghum (Sorghum bicolor L.) subjected to accelerated aging. Materials and methods: The experiment was conducted at the Laboratory of Plant Physiology and Homeopathy, Universidade Estadual de Maringá - UEM. Arsenicum album 6x and 2CH matrices were acquired in homeopathic pharmacy. From matrices were prepared further dynamizations in decimal (x) and centesimal (C) scale, according to the Brazilian Homeopathic Pharmacopoeia [4]. In the accelerated aging test were used samples of 200 seeds per treatment distributed evenly forming a single layer on the surfaces of metal wire suspended inside the plastic box containing inside 40ml of Arsenicum album (9, 12, 18, or 30x 24 and 9, 12, 18, 24 or 30C). The control consisted of distilled water. The boxes were placed in BOD-chamber adjusted to 42°C and relative humidity 100% for 96 hours. After this period, led to the germination test, using four replicates of 50 seeds, totalizing 52 experimental units which were placed on germination paper previously soaked with distilled water in an amount equivalent to 2.5 times the paper weight[5]. The rolls were arranged randomly in the BOD-chamber at 25°C±2. The interpretation of the test was performed after seven days [6]. Germination percentage (% PG) was determined according to the Rules for Seed Analysis [5]. The length of primary roots (PRL) and hypocotyl (LH) were only performed in normal seedlings. The total length of the radicle (TLR) was calculated as the sum of the lengths of hypocotyl and primary root. The experimental design was completely randomized. We adopted the double-blind procedure, avoiding possible interference from the researcher. Data were subjected to analysis of variance and means compared by Scott-Knott test (P ≤ 0.05). Results: Arsenicum album 9x, 9CH and 12CH reduced the percentage of germination (%PG) (Figure 1A). The highest values in the length of hypocotyl (LH) ​​were observed in 12 and 24x dilutions, followed by a reduction in intermediate and higher inhibition at 30x and 9x. The 18x does not differ from control. All centesimal dilution presented effect on the variable analyzed. There was an increase in hypocotyl length in the 12, 18 and 24 dilutions, and reduction in 9 and 30 cH dilutions (Figure 1B). The primary root length (PRL) of sorghum was increased in dilutions 18 and 30x. However, the centesimal dilutions were not different from control (Figure 1C). There was an increase in the total length of the seedlings (TLS) in the dilutions 18, 24 and 30x and reduction in 9x when compared to control. As for centesimal dilutions, there was an effect only in 18cH. The other centesimal dilutions were not different from control (Figure 1D). Conclusions: In general, homeopathic preparations did not affect the germination percentage except for 9x, and 9cH 12cH dilution. Furthermore, the dilutions reduced the effects on premature aging verified by high values ​​of growth variables. These results suggest that high dilution Arsenicum album can be an alternative to minimize the deleterious effect to high temperature.

Spectroscopic Stability Studies of Pressure Sensitive Labels Facestock Made from Recycled Post-Consumer Waste and Agro-Industrial By-Products

To support circular economy and sustainability, the use of synthetic polymers should be minimized due to their excessive accumulation in the environment and low biodegradation rate which leads to a global waste problem. Thus, the quota of natural resources should be increased, as well as the use of agriculture and industrial waste or by-products as raw materials in industrial processes. Agro-industrial wastes were found to have high cellulose fiber potential which makes them an excellent resource for paper production. This study investigates the influence of artificial aging test on the stability of commercially available fiber based self-adhesive pressure sensitive labels (PSL), in which the facestock is made of 15% agro-industrial byproducts, 40% post-consumer recycled paper and 45% virgin wood pulp and compared to ones made of biobased polyethylene. The results showed that optical brighteners are present in the composition of fiber based PSL. Moreover, the fluorescence and UV-Visible spectroscopy results indicated that by the action of UV irradiation and temperature. The oxidation of cellulose was not found by FTIR spectroscopy, indicating its high stability.

Dynamic Mechanical Fatigue Behavior of Polymer Electrolyte Membranes for Fuel Cell Electric Vehicles Using a Gas Pressure-Loaded Blister

This study reports on an innovative press-loaded blister hybrid system equipped with gas-chromatography (PBS-GC) that is designed to evaluate the mechanical fatigue of two representative types of commercial Nafion membranes under relevant PEMFC operating conditions (e.g., simultaneously controlling temperature and humidity). The influences of various applied pressures (50 kPa, 100 kPa, etc.) and blistering gas types (hydrogen, oxygen, etc.) on the mechanical resistance loss are systematically investigated. The results evidently indicate that hydrogen gas is a more effective blistering gas for inducing dynamic mechanical losses of PEM. The changes in proton conductivity are also measured before and after hydrogen gas pressure-loaded blistering. After performing the mechanical aging test, a decrease in proton conductivity was confirmed, which was also interpreted using small angle X-ray scattering (SAXS) analysis. Finally, an accelerated dynamic mechanical aging test is performed using the homemade PBS-GC system, where the hydrogen permeability rate increases significantly when the membrane is pressure-loaded blistering for 10 min, suggesting notable mechanical fatigue of the PEM. In summary, this PBS-GC system developed in-house clearly demonstrates its capability of screening and characterizing various membrane candidates in a relatively short period of time (<1.5 h at 50 kPa versus 200 h).

Effect of Shell Temperature on Thermal Resistance and Junction Temperature for Power Diode

Accurate measurement of junction temperature can avoid thermal failure of diode. During aging test, junction temperature should be indirectly calculated by testing its thermal resistance. In this paper, junction-to-case thermal resistance (Rthjc) of XX diode is tested by T3ster based on transient dual interface method. Its Rthjc is about 1.23K/W at 25°C and contains PN junction thermal resistance, metal shell thermal resistance and Sn-based solder thermal resistance, respectively. These three types of thermal resistance decrease in order. Effect of shell temperature on junction temperature and Rthjc is then discussed. As shell temperature increases, temperature variation of PN junction before and after heating and corresponding thermal resistance Rthjc both increase.

Acid Aging of CFRP Composite Materials for Solar UAV Structure

The purpose of this investigation is to study the performance degradation mechanism of CRRP composite materials used in the structure of a solar UAV under acid rain environment and to provide references for the structural design of the solar UAV. An aging test was designed according to the actual working conditions of the solar unmanned aerial vehicle and was carried out by continuously immersing the composite material in both deionized water and an acidic solution with a pH of 2.0 at 60°C. The mechanical behavior of the composites was studied through a three-point bending test. The results showed that after 120 days of aging test, the composite material exhibits different characteristics in the two conditions. The composite material under the hygrothermal conditions finally reached the equilibrium moisture absorption content of 1.07%, and the flexural strength decreased by 8.77%. The composite material under acidic conditions deviated from the Fick behavior in the final stage of the test, and the final moisture content was 2.88%, and the bending strength decreased by 26.43%. Several typical empirical models were analyzed, and a hyperbolic tangent function empirical model with moisture content as the main variable was used to predict the CFRP flexural strength degradation process, and good results were obtained. The effect of aging conditions on the microstructure of composite materials was observed by SEM, and the aging mechanism of composite materials was analyzed. The corrosion of the polymer matrix and the debonding of the fiber/matrix interface are the root causes of the performance degradation of composite materials.