Estimation of carbon sequestration in vineyards in the island of Crete, Greece

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Climate change consists of a serious global environmental problem and many efforts are focused on its mitigation either by reducing the anthropogenic carbon emissions or by absorbing atmospheric carbon. Agricultural crops usually absorb carbon via photosynthesis acting as carbon sinks. Viticulture is well developed in Crete, Greece since ancient times and the island nowadays produces several well-known grapes and wines. The carbon uptake in Cretan vineyards in Crete has been evaluated. The carbon sequestration rate in vineyards from existing studies in several countries has been used for the evaluation. These studies indicate that carbon uptake in vineyards varies in a wide range of values at 69 – 900 g C m-2 yr-1.  The total surface area of vineyards in Crete is 22,184 ha while their annual carbon sequestration has been estimated at 55,460 t C corresponding at an annual carbon sequestration per capita 0.36 t CO2. Although our results should be considered as indicative, they show that carbon sequestration in Cretan vineyards is not negligible and it should be considered in policy development regarding decarbonization in the island. Our results could be useful to policy makers and to stakeholders of the viticulture industry in the island.

Decarbonization of the Cheese Making Industry on the Island of Crete, Greece

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Cheese making is a well-developed activity in the island of Crete, Greece since a long time ago. It is mainly based on local sheep’ and goats’ milk while the small-scale cheese making plants in Crete use conventional energy sources to meet their heat and electricity demand. However, solar energy and solid biomass are abundant in the island and they are currently used for heat and power generation. Elimination of carbon emissions in cheese making plants in Crete can be achieved with the replacement of grid electricity and fossil fuels used with local renewable energies such as solar energy and solid biomass. It has been estimated that complete elimination of the operational carbon emissions due to energy use in a small-size cheese making plant in Crete with annual capacity 120 tons cheese can be achieved with the installation of a solar photovoltaic system at 88 kWp for electricity generation and the annual use of 62.86 tons of olive kernel wood for heat production. Additionally, solar thermal systems and high efficiency heat pumps can be used for heat and cooling production. The abovementioned sustainable energy sources and technologies are mature, reliable, cost-efficient and they are currently used in Crete in various sectors. The results of the present study could be useful to all stakeholders of the cheese making industry in the island.

Hydrometallurgical Recovery of Rare Earth Elements from Metallurgical Slags (2020–2026): A Critical Review

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Metallurgical slags generated from ironmaking, steelmaking, ferroalloy production, and molten salt electrolysis are increasingly recognized as secondary resources for critical raw materials, particularly rare earth elements (REEs) such as scandium, yttrium, and light REEs, which are incorporated into complex silicate, aluminate, and fluoride phases formed at high temperatures. This review critically evaluates hydrometallurgical routes for REE recovery across a wide range of slag systems, including blast furnace, basic oxygen furnace, electric arc furnace, bauxite residue–derived, FCC catalyst, and molten salt electrolytic slags, covering direct leaching approaches (acidic, alkaline, and ammoniacal), hybrid roast–leach processes (sulfation, chlorination, and alkali roasting), and downstream separation techniques such as selective precipitation and solvent extraction. Particular emphasis is placed on the role of slag mineralogy, phase assemblage, and glassy matrices in controlling leaching kinetics, selectivity, and impurity co-dissolution, with silicate-rich slags identified as the most challenging systems due to their polymerized structure, which limits reagent accessibility and often requires thermal pretreatment to achieve recoveries above 80–90%, typically at high reagent consumption (>50–300 kg/t). Comparative evaluation reveals that reported performance is frequently dominated by recovery metrics, while key parameters such as selectivity, reagent intensity, and process integration remain underreported, such that high extraction efficiencies do not necessarily translate into industrial feasibility. The main limitations across existing approaches include silica gel formation, extensive co-dissolution of matrix elements, and the generation of secondary residues, all of which negatively impact process stability and economic viability; moreover, most reported systems remain constrained by poor selectivity, high reagent intensity, and lack of continuous pilot-scale validation, limiting their industrial transferability. Future progress, therefore, depends on shifting from isolated process optimization to integrated, mineralogy-driven process design, supported by reduced reagent consumption, simplified separation flowsheets, and validation under industrially relevant conditions, positioning metallurgical slags as strategic secondary resources capable of supporting diversified and resilient REE supply chains within circular economy systems.

Vat Leaching and Box Leaching in Hydrometallurgy: Process Principles, Industrial Applications, and Future Perspectives

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Vat leaching and box leaching are proven percolation-based hydrometallurgical methods that provide a controlled alternative to traditional heap and tank leaching. Unlike heap leaching, which works under large-scale, low-control conditions, and tank leaching, which involves fine grinding and intensive agitation, vat and box leaching systems process crushed ores in confined reactors. This allows for better distribution of solutions, faster recovery rates, and a smaller environmental impact. These methods are widely used to extract gold, copper, uranium, and, more recently, rare earth elements from both primary ores and secondary resources. Their main benefits include greater control over leaching parameters (such as residence time, irrigation rate, and solution chemistry), reduced reagent losses, and improved handling of effluents and emissions. However, limitations such as low throughput, the need for prior crushing and sizing, potential channeling effects, and higher capital costs per unit capacity hinder wider adoption. This review explores the fundamental principles of fluid flow, mass transfer, and reaction kinetics in vat and box leaching systems, assesses their industrial use across different commodities, and discusses recent technological developments, including modular setups, hybrid flowsheets, and digital process monitoring. It also highlights key knowledge gaps related to scale-up, modeling multiphase flow in packed beds, and integrating sustainable resource recovery strategies, providing a guide for future research and industry implementation.

The Role of Technical Drawing in Enhancing Vocational Skills within Higher Education Programs (A Case Study of the Civil and Hydrotechnical Departments, Construction Faculty, Jawzjan University)

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Technical drawing is a fundamental component of engineering and technical education, serving as an essential foundation for engineers, architects, and vocational professionals. It plays a critical role in developing spatial thinking, graphical literacy, and vocational competencies required for effective learning and professional practice in technical fields. This study aims to examine the importance of technical drawing in higher education curricula and its role in enhancing vocational skills and spatial cognition among university students. The research is applied in purpose and adopts a descriptive–analytical design. The statistical population consists of 70 undergraduate students enrolled in 2025 from the Industrial Construction, Civil Engineering, and Hydrotechnical Construction departments of the Faculty of Construction at Jawzjan University. Data were collected through educational document analysis and structured questionnaires, and subsequently analyzed using descriptive statistics and graphical representations. The findings reveal that prior exposure to geometry, trigonometry, and other graphical subjects at the secondary school level, as well as achieving high scores in the national university entrance examination (Kankor), significantly influence students’ performance in technical drawing courses. Students with adequate graphical preparation demonstrate stronger learning outcomes, while those lacking such preparation face noticeable difficulties. Moreover, the results indicate that technical drawing education contributes substantially to the improvement of vocational skills, spatial thinking, and students’ engagement in practical activities. The study concludes that effective instruction in technical drawing plays a vital role in enhancing the quality of technical and vocational education. The integration of modern educational technologies, along with strengthening students’ foundational knowledge before entering higher education, significantly improves learning outcomes. Therefore, technical drawing should be regarded as a core subject in technical curricula and continuously updated to meet the demands of the contemporary technological era.

Hybrid Bootstrap–LSTM Model for Probabilistic Sea Level Rise Prediction

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Sea level rise poses increasing risks to coastal regions, highlighting the need for accurate and reliable forecasting methods. This study proposes a probabilistic sea level forecasting framework by integrating a Long Short-Term Memory (LSTM) model with the Moving Block Bootstrap (MBB) technique. The LSTM model is used to capture nonlinear temporal dependencies in sea level time-series data, while the bootstrap approach is employed to quantify prediction uncertainty through probabilistic forecasting. The LSTM model achieved high deterministic prediction accuracy with an MSE of 2.11 × 10!”, RMSE of 0.00459, MAE of 0.00356, and MAPE of 0.34%. The proposed hybrid MBB–LSTM model generates probabilistic forecasts with a 95% confidence interval, resulting in an MSE of 0.01155, RMSE of 0.10749, MAE of 0.08370, and MAPE of 8.99%. Forecast results indicate relatively stable sea level variability until 2026 with an estimated rising trend of approximately 7.44 mm per year. The proposed hybrid framework provides a more informative prediction approach by combining deep learning with bootstrap-based uncertainty estimation, which is valuable for coastal risk assessment and climate adaptation planning.

Changes in Prostate Specific Antigen and Acid Phosphatase of Benign Prostatic Hyperplasia Induced Male Albino Rats Fed with Cooked Phaseolus Vulgaris (Black Bean) Juice

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Benign prostatic hyperplasia (BPH) is a common non-malignant enlargement of the prostate gland in ageing males and is associated with hormonal imbalances, inflammation and biochemical alterations. It could be detected biochemically through prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) assay. Plant-based interventions have gained increasing attention due to their affordability, safety, and rich phytochemical composition. Phaseolus vulgaris (black bean) is a legume containing phenolics, flavonoids, and bioactive peptides with antioxidant and anti-inflammatory properties, but its effect on prostate biomarkers has not been clearly established. This study investigated the effect of cooked black bean juice on PSA and PAP levels in testosterone-propionate induced BPH male albino rats. Twenty-four adult rats (150–280 g) were divided into four groups after induction of BPH by subcutaneous testosterone propionate. Animals were treated with graded doses of cooked P. vulgaris juice (low, medium, and high), while the control group received no extract. Serum PSA (ng/mL) and PAP (IU/L) were analyzed before and after treatment. Results showed that induction of BPH significantly elevated PSA and PAP. Administration of cooked black bean juice produced significant reductions (p < 0.05) in both biomarkers across all treated groups. PAP decreased from 11.55 ± 0.76 to 7.62 ± 0.93 in the high-dose group, 11.42 ± 0.98 to 7.32 ± 0.66 in the medium-dose group, and 10.73 ± 1.49 to 7.15 ± 0.68 in the low-dose group. PSA declined correspondingly from 3.12 ± 0.46 to 1.79 ± 0.58, 3.04 ± 0.54 to 1.77 ± 0.69, and 2.94 ± 0.40 to 1.22 ± 0.48 respectively. A strong positive correlation existed between PSA and PAP (r = 0.97, p = 0.000), indicating that reductions in these markers were closely related. The study concludes that cooked P. vulgaris juice exerts beneficial effects on prostate biochemical indices in BPH and may serve as a natural therapeutic adjunct in prostate health management

Characterization to Estimate the Size of Gold Nanoparticles Deposited in Pregnancy Tests Using Diffuse Reflectance Spectroscopy

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When using a pregnancy test, a urine sample is deposited in one side of the nitrocellulose strip, which moves by capillary action to the other side of the test, where there are immobilized particles or biomarkers that indicate a positive or negative test result. Based on the manufacturer’s data sheet, these are usually colloidal gold nanoparticles. This paper describes the results of a characterization study using diffuse reflectance spectroscopy on qualitative pregnancy tests. The importance of this study resides in the possibility of finding invalid tests or false negatives in the results, at the same time, the approximate size of the nanoparticles can be determined indirectly by analysing the spectra obtained experimentally.

Redesign of Interactive Exhibitions in Mundo Fútbol

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This research project was developed in collaboration with the interactive center Mundo Fútbol, a company dedicated to educational entertainment through interactive sports exhibits. The main objective was the redesign of three of its most representative interactive exhibits: Compare Your Jump, Test Your Power, and Measure Your Speed. These exhibits, which are central to the visitor experience, showed significant deficiencies in material durability, ease of use, maintenance, and visual appeal due to prolonged use and a lack of technical updates for over a decade.

The research was structured based on the Design Thinking methodology, which allowed for a deep understanding of the needs of both the users and the Mundo Fútbol staff responsible for the transportation, installation, and operation of the exhibitions. The process was carried out in five stages: empathize, define, ideate, prototype, and test, supported by complementary tools such as the Ishikawa diagram, SCAMPER, and brainstorming. These tools helped facilitate the identification of root problems and the generation of innovative solutions.

Each exhibit was addressed individually, with a detailed analysis of its operation, structure, components, user interaction, and usage conditions. As part of the redesign, structural, functional, and aesthetic improvements were proposed and modeled using SolidWorks software, producing technical drawings, 3D models, and photorealistic renders of the new proposals. Additionally, structural simulations with static load analysis were conducted using materials such as ABS plastic and ASTM A-36 steel, in order to validate the strength, safety, and efficiency of each design.

The results demonstrate significant improvements in ergonomics, structural resistance, ease of maintenance, and user experience, while also reducing setup times and transportation requirements. This research not only provides technical solutions tailored to Mundo Fútbol’s needs but also establishes a replicable methodology for the development of modern, sustainable, and user-centered interactive exhibits within the field of industrial design and engineering.

Sentiment Analysis Based on Questionnaires: A Case Study on the Use of Induction Stove

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Indonesia’s reliance on subsidized Liquefied Petroleum Gas (LPG) for household cooking places a significant burden on the national energy subsidy budget and increases dependence on imported fossil fuels. As part of the clean energy transition strategy, the Indonesian government has promoted the conversion from LPG stoves to electric induction stoves. However, public acceptance and actual post-use experiences at the household level remain diverse and insufficiently examined empirically. This study aims to analyze public sentiment toward induction stove use based on post-adoption user reviews to identify factors that encourage interest and reveal existing adoption barriers.

This study employs a machine learning–based sentiment analysis approach using primary data collected through open-ended questionnaires distributed to induction stove users. A total of 265 valid textual responses were analyzed. Text preprocessing was conducted using Python with the NLTK and Sastrawi libraries, including data cleaning, case folding, tokenization, stopword removal, stemming, and duplicate removal. Sentiment classification was performed using the Term Frequency–Inverse Document Frequency (TF-IDF) method and the Naive Bayes algorithm, while WordCloud visualization was applied to identify dominant keywords.

The results indicate a relatively balanced sentiment distribution, with positive sentiment accounting for 33.6%, neutral sentiment 32.5%, and negative sentiment 34.0%. Positive sentiment is mainly associated with energy efficiency, safety, and ease of use, whereas negative sentiment is driven by concerns regarding initial costs and electricity dependence. Neutral sentiment reflects an evaluative phase among users. These findings provide empirical insights to support user-oriented policies and strategies for accelerating the sustainable adoption of induction stove technology in Indonesia’s clean energy transition.