In the Philippines, about twenty (20) typhoons occur annually, causing heavy flooding which poses risks that lead to injuries and casualties despite preparedness measures. This study addresses the problem of hindered rescue efforts due to limited resources, dangerous access to flooded areas, and damaged communication infrastructures by introducing an innovative solution: an unmanned amphibious robot for search and monitoring tasks. The developed robot is capable of locating human presence and help needed while providing a live video feed. Evaluations demonstrated the capabilities of the robot to navigate both on land and water with respective speeds of 1.2 m/s and 0.205 m/s over a 120-m LoRa communication. The live video feed quality highlights the feasibility of a 4G LTE network for real-time display. The trained YOLOv5 model had high accuracy in detecting human presence and help needed over 3.5m and 7m distances with 90% and 93.33%, respectively. GPS coordinate reception yields good results in open areas only. There was also a seamless integration of data from the robot to the local website, offering accessible data. Limitations arose when live video feed streaming and YOLOv5 processing were performed simultaneously. This research contributes to aiding post-typhoon heavy flooding response by developing an unmanned amphibious robot, offering insights into its performance and potential for real-world applications in disaster response scenarios.

The emergence of new technologies focusing on “image analysis” contributes significantly to the assessment of fruit quality based on objective and non-destructive features. In this investigation, the ‘Mejhoul’ date fruit cultivar was subjected to freezing at -10°C and -18°C and stored for 6 months. Its quality was evaluated according to texture features extracted from images acquired using a digital camera and flatbed scanner. The extraction process was carried out according to an internal procedure using MaZda software. Then, the extracted features were used as inputs for pre-established algorithm groups within WEKA software to classify frozen date fruit after 0, 2, 4, and 6 months of storage. Accordingly, reducing these features using the “Best-First” method allowed for a selective ranking of about twenty accurate features that were submitted to four classifier groups of algorithms: Bayes, Functions, Lazy, and Trees.

The results allowed for the extraction of a hundred texture features that differ depending on “storage temperature” and “storage period”. Furthermore, high accuracy levels for the classification of ‘Mejhoul’ date fruit were obtained for each storage period based on the selected features, and slight differences were noted between the algorithms used. In future, physicochemical attributes will be added to the developed models to correlate with image features and predict the behaviour of date fruit under storage.

This study was conducted with the aim of identifying the most effective extraction technique and evaluating the suitability of the extracted oils for ingestion and other potential applications by extracting oils from cashew kernels using three different methods: cold press, mechanical, and Soxhlet extraction. The research focused on comparing the yield and physicochemical properties of the oils obtained through each of these methods. The cold press extraction was performed using a traditional local method, which has been passed down through generations; the mechanical extraction method was carried out using hydraulic presses, which apply significant pressure to the kernels; and the Soxhlet extraction was conducted using Soxhlet apparatus, a well-established method in which n-hexane is used as the solvent to facilitate the extraction process. The study found that the percentage of oil extracted from the cashew kernel was highest with the Soxhlet extraction method, yielding 40%, followed by the mechanical method with a 27% yield, and the cold press method with a 12% yield. Cashew kernel oil (CKO), as observed through physical analysis, is light yellow in color. The physical and chemical characterization of the oil revealed a pH of 5.65 for Soxhlet extraction, 5.4 for mechanical extraction, and 5.4 for cold press extraction. The acid value was found to be 8.25 mg KOH/g for Soxhlet extraction, 8.43 mg KOH/g for mechanical extraction, and 8.697 mg KOH/g for cold press extraction. The density of the oils was measured at 0.91g/cm³, 0.909g/cm³, and 0.907g/cm³, and the free fatty acid content was 4.125, 4.215, and 4.348 for the Soxhlet, mechanical, and cold press extractions, respectively. Given that cashew kernel oil is non-toxic, this suggests its potential for use in the food and cosmetic industries.

Microbiological contamination of surfaces in food production facilities and food-handling areas represents a major challenge in preventing cross-contamination and selecting biocidal products. Consequently, examining the microbiology purity of surfaces that come into contact with food requires a serious methodological approach.

This paper presents the method of determination of Proteus spp. from surface samples (5x5 cm²). The three levels of artificial soiled aluminium foil were prepared using bacterial suspensions of Proteus hauseri ATCC 13315. After the surface swabbing method for determination of Proteus spp. was applied. The swab was homogenized with Eugon LT 100 broth and 1 mL was transferred to enrichment broth. After incubation of the enrichment broth, streaking on the Brilliant green agar and SS agar was performed. The characteristic colonies were confirmed by biochemical reactions.

The number of positive findings of Proteus hauseri on the applied level of contamination was used for calculation by the PODLOD_ver12.xls ECEL program by Wirlich and Wilrich. This program estimates the probability of detection (POD) function and the limit of detection (LOD) of qualitative microbiological methods.

The results of the detection of Protues hauseri in surface samples showed a LOD_{50% ⁼}48.957 [24.596; 97.446] CFU in 1 ml of swab rinse, and LOD_95%=211.589 [106.303; 421.155] CFU in 1 mL of swab rinse.

These results open a discussion about the performance of the applied method. Also, they provide ideas for further research related to the type of surface, the type of used swab sticks and the type of microorganisms tested.

The terahertz (THz) band, ranging from 0.1 to 10 THz, offers substantial bandwidths that are essential for meeting the ever-increasing demands for high data rates in future wireless communication systems. This paper presents a comprehensive comparative analysis of various multicarrier waveforms suitable for THz-band communications. We explore the performance, advantages, and limitations of several waveforms, including Orthogonal Frequency Division Multiplexing (OFDM), Filter Bank Multicarrier (FBMC), Universal Filtered Multicarrier (UFMC), and Generalized Frequency Division Multiplexing (GFDM).

The analysis covers key parameters such as spectral efficiency, peak-to-average power ratio (PAPR), robustness to phase noise, and computational complexity. Simulation results demonstrate that while OFDM offers simplicity and robustness to multipath fading, it suffers from high PAPR and phase noise sensitivity. FBMC and UFMC, with their enhanced spectral efficiency and reduced out-of-band emissions, show promise for THz-band applications but come at the cost of increased computational complexity. GFDM presents a flexible framework with a trade-off between complexity and performance, making it a potential candidate for diverse THz communication scenarios.

Our study concludes that no single waveform universally outperforms the others across all metrics. Therefore, the choice of multicarrier waveform for THz communications should be tailored to the specific requirements of the application, balancing performance criteria and implementation feasibility. Future research directions include the development of hybrid waveforms and adaptive techniques to dynamically optimize performance in varying THz communication environments.

Laminated composite structures are widely used for structural applications, owing to their tailorable mechanical response. These structures are made of tens or hundreds of plies of various materials, each having a unique orientation, called the layup. The layup is a primary parameter in the design of composite structures. The numerous design variables involved in defining the layup of laminated structures are decided based on expert intuition, often resulting in overweight designs, as analysing all possible combinations may be time-consuming and sometimes impossible. Many researchers have worked on optimising the fibre orientations; however, these were limited to the problems whose analytical equations were available. Analytical models representing the behaviour of complex problems are often unavailable, such as the wing of a typical unmanned aerial vehicle. Such structures can be efficiently modelled using numerical methods such as finite element (FE) modelling, and these FE models can be further used for optimisation. The Design Optimisation module of general-purpose ANSYS has the capability of optimising such problems. However, this module is designed for the optimisation of systems made from isotropic material. This paper presents a two-step strategy for the weight optimisation of an aircraft wing fully made of composite materials. A code was developed which can cater for the range of wing span, number of ribs, spar width, and location of spars. The optimisation design variables considered were the number of composite layers, layer orientation, and their stacking sequence. The number of layers in each structural component was optimised, followed by the optimisation of layer sequence and orientation of each lamina. The weight of the specific wing was reduced by 45%, and the maximum stress values also lowered from 421 MPa to 330 MPa, meeting the material strength limits. The method presented is easily implementable for a wide range of problems, materials, and loading conditions.

In this work, four different types of agricultural waste, specifically pomegranate peels, banana peels, cotton waste and corn leaves, as well as different combinations of the previous biomasses, were used in order to produce reduced graphene oxide (rGO). Reduced graphene is a one-atom-thick sheet of sp²-hybridized carbon atoms arranged in a honeycomb lattice form with a large surface area, high electrical conductivity, strong chemical stability and superior tensile strength. rGO was synthesized directly from agricultural waste via direct carbonization at 300^oC in a muffled furnace under atmospheric conditions for 15 minutes in the presence of ferrocene as an oxidizing catalyst. Ferrocene is an orange-coloured organometallic compound which creates extensive structural changes in carbon materials, promoting the oxidation of porous carbon to graphene-like formations. The treated material, after cooling to room temperature, was collected in the form of a dark brown and black powder. These powders were then put through further study and analyses. The materials’ morphology and structure were characterized via XRD, FT-IR, SEM and BET analyses. According to the above characterizations, rGO nanomaterials were successfully synthesized from different types of biomasses, each demonstrating the potential use of waste as raw feedstock for the production of useful materials with attractive properties and wide ranges of applications.

Acknowledgment: We acknowledge support for this work by the project “Advanced Nanostructured Materials for Sustainable Growth: Green Energy Production/Storage, Energy Saving and Environmental Remediation” (TAEDR-0535821), which is implemented under the action “Flagship actions in interdisciplinary scientific fields with a special focus on the productive fabric” (ID 16618), Greece 2.0 – National Recovery and Resilience Fund and funded by European Union NextGenerationEU.

The preparation of new nanocomposites by combining chitosan–lignin and three different nanoparticles (NPs) of ZnO, TiO₂ and Zn₂SnO₄ was the main interest of the present work. Lignin provides enhanced UV protection in commercial products at less than a 10% blend with other material. Also, chitosan is an abundant polymer that can be applied in many industries due to its biodegradability and biocompatibility properties. ZnO, TiO₂ and SnZnO nanoparticles present increased thermal stability and UV protection, antimicrobial and antioxidant properties. Therefore, in this study, biodegradable nanocomposite membranes were prepared from a combination of chitosan–lignin (at a 1/1 molar ratio) and 0.5, 1 and 1.5%wt of ZnO, TiO₂ and Zn₂SnO₄ via the sol-cast method. The successful integration of the nanoparticles into the polymer matrix was confirmed by Fourier transform infrared spectroscopy measurements. In addition, the size and the morphology of the nanoparticles and the homogeneity of the nanocomposites were investigated using a Scanning Electron Microscope. The crystallinity of the nanocomposite membranes was studied using X-Ray Diffraction. Moreover, the water sorption capacity, water content, contact angle, water and soil stability and mechanical properties of the prepared nanocomposite membranes were analyzed. In addition, and most importantly, the UV-blocking efficiency of the prepared membranes was measured using UV-vis spectroscopy. Finally, the antioxidant and antimicrobial properties of the nanocomposites loaded with the ZnO, TiO2, and Zn2SnO4 NPs were studied using assays. As a result, the nanocomposites showed promising features for the development of food packaging and UV-protective films and for the development of new and sustainable materials.

This study aimed to evaluate the capacity of spent brewer's yeast (BSY) to adsorb tannins and other phenolic compounds from an alkaline-extracted chestnut shell tannin solution (CS tannin extract). The alkaline extraction process used 5% NaOH (v/v), a method commonly employed to extract cellulosic material from chestnut shells (CSs). The findings of this research contribute to the development of more sustainable laboratory practices and enhance the economic viability of cellulosic material extraction from CS.

Various treatments—lyophilization, immobilization in calcium alginate beads, and both alkaline and acid treatments—were applied to BSY to determine which method resulted in the highest tannin adsorption capacity from the CS tannin extract. Kinetic and equilibrium adsorption studies were performed to identify the best adsorption approach. The tannin content was analyzed using the Folin–Ciocalteau method, with results expressed as milligrams of tannic acid equivalents (TAEs) per milliliter of extract solution. The adsorbent material was characterized before and after the experiments; the characterization methods included the determination of the point of zero charge (pH_PZC), Fourier Transform Infrared (FT-IR) Spectroscopy, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS).

Equilibrium was reached within 10 minutes, with the highest (p<0.05) biosorption capacity of tannins from the CS tannin extract observed in lyophilized BSY (35.51 ± 0.97 mg TAE per gram of BSY). The Sips models provided an adequate description of the adsorption process, indicating that tannin biosorption by BSY is driven by chemisorption. FTIR analysis identified various functional groups in BSY, with carboxyl, amino/hydroxyl, and amide groups playing a significant role in the biosorption process.

Overall, these findings suggest that BSY has potential as a delivery system for the valorization of tannins from treatment solutions.

A patch that can avoid wound infection and promote tissue remodeling is of great value for wound healing. Herein, a series of skin-repairing dressings consisting of dexpanthenol (Dex)-loaded polymer membranes were fabricated using chitosan (CS)/polyvinyl alcohol (PVA) crosslinked with vanillin (VA). CS is a natural polysaccharide; it is biocompatible and biodegradable, with enhanced bioadhesive and wound-healing properties. PVA is a synthetic polymer that presents nontoxicity, good biodegradability, biocompatibility, and good mechanical properties. Vanillin, a primary extract of vanilla bean, is widely used in pharmaceuticals, cosmetics, foods, and beverages; it has one aldehyde and one hydroxyl group in its structure, making it an active crosslinker. Dexpanthenol is well absorbed when applied topically to the skin and supports skin regeneration by enhancing epidermal differentiation and facilitating wound healing. The successful synthesis of the CS/PVA/VA-Dex membranes was confirmed by Fourier Transform Infrared spectroscopy, their crystallinity was analyzed by X-Ray Diffraction, and the surface morphology of the membranes was studied with Scanning Electron Microscopy. Additionally, their water sorption and water content capacity were investigated, and their stability in different conditions was measured. Moreover, the encapsulation efficiency and release rate of dexpanthenol from the prepared products were studied using UV-vis spectroscopy. Finally, the cytotoxicity, antibacterial properties, cell adhesion, and wound-healing capacity of all prepared wound-healing dressings were examined in vitro.