Evaluation of thermal/acoustic performance to confirm the possibility of coffee waste in building materials in using bio-based microencapsulated PCM.

As the demand for coffee has increased, by-product disposal has become a challenge to solve. Many studies are being conducted on how to use coffee waste as building materials to recycle it. In this study, the thermal performance and acoustic performance of a composite developed using bio-based microencapsulated phase change material (MPCM) and coffee waste were evaluated, and the composite was applied as building material. The coffee waste was successfully degreased with ethanol to produce composites, and removal of contaminants and oils was confirmed via scanning electron microscopy. In the phase change process of MPCM, an appropriate amount of thermal energy is absorbed and stored, and the temperature is maintained. MPCM was used in the mixture and the improved thermal performance was evaluated via differential scanning calorimetry analysis, revealing a latent heat of 3.8 J/g for MPCM content of 10%. Further, thermal imaging cameras revealed that an increase in the proportion of MPCM leads to a slower decrease in temperature because of the heat preserved by MPCM over time. In an acoustic performance evaluation, impedance tube test results showed different aspects depending on low, mid, and high-frequency bands. Specifically, at medium frequencies, which correspond to the range of noise generated in cafes, specimens fabricated using MPCM were confirmed to exhibit a higher sound absorption coefficient and an improved acoustic performance. Hence, the composite can be considered an eco-friendly building material with promising thermal and acoustic performance.

Reactive oxygen species mediated-antifungal activity of cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils and their constituents against two phytopathogenic fungi.

To find new and safe type of control agents against phytopathogenic fungi, the fumigant antifungal activity of 10 plant essential oils and constituents identified in cinnamon bark (Cinnamomum verum) and lemongrass (Cymbopogon citratus) essential oils was investigated against two phytopathogenic fungi, Raffaelea quercus-mongolicae and Rhizoctonia solani. Among plant essential oils, cinnamon bark and lemongrass essential oils showed 100% inhibition of R. quercus-mongolicae and R. solani at 5 mg/paper disc, respectively. Among test constituents, salicylaldehyde, eugenol, and hydrocinnamaldehyde showed 100% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geraniol, geranial, trans-cinnamaldehyde, methyl cinnamate, isoeugenol, and methyl eugenol exhibited >80% inhibition of growth of R. quercus-mongolicae at 2.5 mg/paper disc. Neral, geranial, trans-cinnamaldehyde, hydrocinnamaldehyde, and salicylaldehyde showed 100% inhibition of growth of R. solani at 2.5 mg/paper disc. A fumigant antifungal bioassay of artificial blends of the constituents identified in cinnamon bark and lemongrass essential oils indicated that trans-cinnamaldehyde and geranial were major contributors to the fumigant antifungal activity of the artificial blend. Confocal laser scanning microscopy images of fungi treated with cinnamon bark and lemongrass essential oils, trans-cinnamaldehyde, neral, and geranial revealed the reactive oxygen species (ROS) generation and cell membrane disruption.

Circular reutilization of coffee waste for sound absorbing panels: A perspective on material recycling.

The increase in coffee consumption has led to increased production of coffee waste. Methods to recycle coffee waste are constantly being researched. Coffee powder is a porous material that can effectively be used to absorb sound. In this study, sound-absorbing panels were developed using coffee waste combined with resin. A sound absorption characterization of the new material was performed. Then, the noise reduction potential using coffee-waste sound absorbers was investigated in cafés. A café has several noise sources, such as coffee machines, music, and the voices of people. The noise reduction effect was evaluated using the ODEON simulation software together with the improvement in both the clarity and reverberation time in a case study café. In the investigated room, the acoustic definition (D50) increased up to 0.8, while the reverberation time (RT) reduced to 0.6 s. The results of this study demonstrate that the noise generated in the café was reduced by recycling the coffee waste produced as a by-product in the same building. Finally, this study presents a new construction material manufactured through coffee waste that is in turn applied to cafés where the coffee waste itself is produced.

Fumigant Antifungal Activity via Reactive Oxygen Species of Thymus vulgaris and Satureja hortensis Essential Oils and Constituents against Raffaelea quercus-mongolicae and Rhizoctonia solani.

In this study, the fumigant antifungal activity of 10 Lamiaceae plant essential oils was evaluated against two phytopathogenic fungi, Raffaelea quercus-mongolicae, and Rhizoctonia solani. Among the tested essential oils, thyme white (Thymus vulgaris) and summer savory (Satureja hortensis) essential oils exhibited the strongest fumigant antifungal activity against the phytopathogenic fungi. We analyzed the chemical composition of two active essential oils and tested the fumigant antifungal activities of the identified compounds. Among the tested compounds, thymol and carvacrol had potent fumigant antifungal activity. We observed reactive oxygen species (ROS) generation in two fungi treated with thymol and carvacrol. Confocal laser scanning microscopy images of fungi stained with propidium iodide showed that thymol and carvacrol disrupted fungal cell membranes. Our results indicated that ROS generated by thymol and carvacrol damaged the cell membrane of R. querqus-mongolicae and R. solani, causing cell death.

Insecticidal Activity of Lamiaceae Plant Essential Oils and Their Constituents Against Blattella germanica L. Adult.

The insecticidal activities of 13 Lamiaceae plant oils and their components against adult German cockroaches, Blattella germanica L. (Blattodea: Blattellidae), were evaluated using fumigant and contact bioassay. Among the tested oils, basil, pennyroyal, and spearmint showed the strongest insecticidal activities against adult B. germanica. Insecticidal activity of pennyroyal was 100% against male B. germanica at 1.25 mg concentration in fumigant bioassay. Basil and spearmint revealed 100% and 100% insecticidal activity against male B. germanica at 5 mg concentration, but their activities reduced to 80% and 25% at 2.5 mg concentration, respectively. In contact, toxicity bioassay, basil, pennyroyal, and spearmint oils exhibited 100%, 100%, and 98% mortality against female B. germanica at 1 mg/♀, respectively. Among the constituents identified in basil, pennyroyal, and spearmint oils, insecticidal activity of pulegone was the strongest against male and female B. germanica.