Search Results (28)

Sustainability in higher education plays a crucial role in shaping future professionals with an eco-conscious mindset. This study focuses on developing and simulating a portable solar food dehydrator as a practical application of sustainability principles in technology education. By integrating sustainability into the curriculum, this research enhances students’ technical skills while promoting the use of renewable energy and effective food preservation methods. Furthermore, the project aligns with green campus initiatives by encouraging energy-efficient practices and reducing food waste. This study emphasizes the significance of education for sustainable development by offering learners hands-on experience in designing eco-friendly solutions, promoting innovation, and equipping them to contribute to a more sustainable future. A food dehydrator is a device that removes moisture from food to aid in its preservation, utilizing a heat source and airflow to reduce its water content. The researchers used two methods to dehydrate food: direct sunlight (sun drying) and indirect sunlight (solar drying). The study used a developmental research design. Simulations revealed that, with solar-powered electricity, the longer the drying time, the greater the reduction in the moisture content. This was evident in the eighth experiment, which was conducted on fruits and vegetables. While drying with direct sunlight, the same trends, albeit to a lesser extent, were observed in the reduction in the moisture content of the fruits and vegetables. These insights can inform future design improvements, making the products more visually appealing and distinctive, thereby enhancing their attractiveness and novelty. Full article

This study aims to create environmentally comfortable building designs in hot and dry steppe climates using more effective approaches. The purpose of this study is to assess the relationship between mean radiant temperature (MRT) and indoor air temperature (Tia), taking into account the orientation of buildings, for better building thermal performance. For this purpose, residential buildings with different orientations were selected in the study region ‘Garmian—northern Iraq’, and their thermal performance was evaluated. The results show how MRT contributes to the buildings’ thermal comfort. The outcomes of this research provide innovative empirical quantification of the correlation of MRT-Tia, as the regression coefficient (β) represents the rate of change in Tia per unit increase in MRT and ranges by orientation in the study area. The findings demonstrate that north-facing buildings buffer radiant heat gain (β~0.52), resulting in a 0.5 °C increase in indoor air temperature for each 1 °C rise in MRT. Moreover, west orientation delivers promising winter passive heating (MRT up to 22 °C and indoor air temperature up to 22.8 °C with a β of ~0.82). However, south-facing buildings perform poorly in the winter, with low MRT and a weak β (~0.44), contrasting with passive solar design strategies that favor south-facing buildings in the northern hemisphere. Furthermore, in the summer, the MRT is always higher than Tia, while it is lower in winter, indicating poor envelope and fenestration thermal insulation properties, which lead to excessive energy usage to maintain thermal comfort. Finally, the study suggests the novel quantified MRT-Tia mathematical correlation responds to the orientations for such climates, offering both diagnostic and predictive tools for thermal comfort performance optimization. This study is the first to empirically quantify orientation-specific MRT–Tia relationships in BSh climates, offering a novel diagnostic tool for sustainable building design. This study involved field observations in 36 residential row houses across four orientations. Key environmental and personal variables measured included mean radiant temperature (MRT), indoor air temperature (Tia), air velocity, relative humidity, metabolic rate, and clothing insulation. Full article

Oranges are popular worldwide, due not only to their refreshing taste but also to their high content of bioactive compounds. The main phytochemicals in oranges are phenolic compounds, vitamins, and carotenoids, which contribute to their antioxidant and anti-cancer activities. Various drying methods are used to remove the high moisture content in orange products to extend their shelf life. This review summarizes and compares the effects of different drying methods such as hot air drying, freeze drying, vacuum drying, spray drying, microwave drying, solar drying and innovative pretreatment on the physicochemical quality of orange products including slices, peels, and by-products. It lists the key parameters, advantages, and disadvantages of drying methods, as well as a decision tree for “product type-constraints-recommended drying method with pretreatment”. For example, the results indicate that vacuum microwave drying is effective in drying orange slices, and control techniques are employed to assist the drying process. Freeze drying preserves more phytochemicals in orange peels and their by-products, which results in higher antioxidant activity. Pretreatments like pulsed electric field and ozone enhance drying efficiency and phytochemical retention. Different drying methods are adopted to treat different by-products. This work can be used as a guide for selecting the optimal drying technique to balance efficiency, nutritional quality, and industrial scalability for different orange products. Full article

This study addresses the problem of agricultural waste utilization and nutrition for older adults by developing a food product based on a circular design approach. Pineapple core was used to produce a clean-label dietary powder without chemical or enzymatic treatment, relying on repeated rinsing and hot-air drying. The development process followed a structured analysis of physical, chemical, and sensory properties. The powder contained 83.46 g/100 g dietary fiber, 0° Brix sugar, pH 4.72, low water activity (aw < 0.45), and no detectable heavy metals or microbial contamination. Sensory evaluation by expert panelists confirmed that the product was acceptable in appearance, aroma, and texture, particularly for older adults. These results demonstrate the feasibility and safety of valorizing agri-waste into functional ingredients. The process was guided by the Transformative Circular Product Blueprint, which integrates clean-label processing, IoT-enabled solar drying, and decentralized production. This model supports traceability, low energy use, and adaptation at the community scale. This study contributes to sustainable food innovation and aligns with Sustainable Development Goals (SDGs) 3 (Good Health and Well-being), 9 (Industry, Innovation and Infrastructure), and 12 (Responsible Consumption and Production). Full article

Grain drying technology is a core process for ensuring food quality, extending storage life, and improving processing adaptability. With the continuous growth of global food demand and the increasing requirements for food quality and energy efficiency, traditional drying technologies face multiple challenges. This paper reviews six major grain drying technologies, comprising hot air drying, microwave drying, infrared drying, freeze drying, vacuum drying, and solar drying. It provides an in-depth discussion of the working principles, advantages, and limitations of each technology, and analyzes their performance in practical applications. In response to challenges such as high energy consumption, uneven drying, and quality loss during the drying process, the paper also explores the research progress of several hybrid drying systems, such as microwave–hot air drying combined systems and solar–infrared drying systems. Although these emerging technologies show significant potential in improving drying efficiency, energy saving, and maintaining food quality, their high costs, scalability, and process stability still limit large-scale applications. Therefore, future research should focus on reducing energy consumption, improving drying precision, and optimizing drying system integration, particularly by introducing intelligent control systems. This would maximize the preservation of food quality while improving the system’s economic efficiency and sustainability, promoting innovation in food production and processing technologies, and further advancing global food security and sustainable agricultural development. Full article

Pisco is an emblematic spirit in Peru and Chile, made from fermented grapes, gaining growing scientific interest over the last two decades. This study aimed to map 20 years of research on Pisco through a systematic bibliometric review. A search was conducted in the Scopus database covering the period from 2004 to 2024, applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology for the transparent selection of scientific articles. The search strategy considered titles, abstracts, and keywords, using the terms “Pisco” and “schnapps”, excluding unrelated fields such as geology (basin, seismic, fossil). The initial search yielded 360 records. After removing non-original articles (books, book chapters, conference papers, and reviews), 101 articles remained. A further screening excluded irrelevant studies (e.g., those referring to the city of Pisco rather than the beverage), resulting in 78 articles included for final analysis. It was observed that 19% of the studies focus on the history, culture, and appellation of origin; 14% on environmental sustainability; 10% on innovation and quality; and 9% on the bioactive properties of by-products. Other areas include extraction technologies (9%), distillation process modeling (8%), and marketing and economics (8%), among others. Recent trends are related to clean production practices. Thus, Pisco by-products and their components can be exploited by applying technologies such as supercritical fluids, drying, and biofilms, while, for waste management, the processes of composting, solar photo-Fenton, and ozonation can be applied. Moreover, it is important to highlight that the valorization of Pisco by-products opens opportunities for translation into the market, particularly in developing cosmetics, nutritional supplements, and bio-packaging materials, contributing to sustainability and innovation in new industries. However, a more holistic view is still needed in Pisco research. These findings suggest that future research should prioritize the integration of consumer-based sensory evaluations and sustainable production innovations to optimize Pisco’s quality, enhance market acceptance, and promote environmentally responsible industry practices. Full article

With the intensification of global climate change, buildings in hot climate zones face increasing challenges related to high energy consumption and thermal comfort. Building integrated photovoltaic (BIPV) façades, which combine power generation and energy saving potential, require further optimization in their climate-adaptive design. Most existing studies primarily focus on the photoelectric conversion efficiency of PV modules, yet there is a lack of systematic analysis of the coupled effects of temperature, humidity, and solar radiation intensity on PV performance. Moreover, the current literature rarely addresses the regional material degradation patterns, integrated cooling solutions, or intelligent control systems suitable for hot and humid climates. There is also a lack of practical, climate specific design guidelines that connect theoretical technologies with real world applications. This paper systematically reviews BIPV façade design strategies following a climate zoning framework, summarizing research progress from 2019 to 2025 in the areas of material innovation, thermal management, light regulation strategies, and parametric design. A climate responsive strategy is proposed to address the distinct challenges of humid hot and dry hot climates. Finally, this study discusses the barriers and challenges of BIPV system applications in hot climates and highlights future research directions. Unlike previous reviews, this paper offers a multi-dimensional synthesis that integrates climatic classification, material suitability, passive and active cooling strategies, and intelligent optimization technologies. It further provides regionally differentiated recommendations for façade design and outlines a unified framework to guide future research and practical deployment of BIPV systems in hot climates. Full article

A multifunctional paper-based composite of paper coated with a polypyrrole@lignocellulosic slurry (PPy@LS) and carboxymethyl cellulose (CMC) was developed. PPy@LS was prepared via the polymerization of pyrrole onto a lignocellulosic slurry derived from hemp stalks prepared using deep eutectic solvents. The PPy@LS slurry was mixed with the required amount of CMC and vacuum-filtered onto filter paper to fabricate the composite (PPy@LS/CMC). The resulting composite paper exhibited excellent multifunctional properties, including electrical conductivity, photothermal conversion, and antibacterial properties. These properties are stable against external environments, such as water and abrasion, due to the addition of CMC. The electrical conductivity of PPy@LS/CMC varied in the dry (1.6 × 10⁻⁴ S/cm) and wet (4.8 × 10⁻⁶ S/cm) states, suggesting its potential application in humidity sensing. Notably, the PPy@LS/CMC paper achieved significant photothermal activity under light irradiation, as demonstrated by the measured surface temperature exceeding 80 °C in 10 min. Moreover, the composite paper exhibited > 99.9% antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The combination of the inherent characteristics of filter paper along with the photothermal property of PPy enable the PPy@LS/CMC composite appropriate for solar interfacial evaporation application. These multifunctional composite papers with innovative combinations of properties have great potential for applications in smart packaging, humidity sensing, biomedicine, and solar-driven water purifications. Full article

Perovskite solar cells (PSCs) offer a number of key advantages over silicon solar cells. These include their low-cost materials, high efficiency, simplicity of fabrication, and inexpensive manufacturing techniques. To commercialize PSCs, there are many methods to develop the quality of the cells, one of them being printing techniques. Different printing techniques deposition have been developed for the perovskite solar cell, such as blade coating, slot die coating, inkjet printing, screen printing, spray coating, flexographic printing, and gravure printing. These techniques have a substantial impact on the performance of PSCs and controlling film formation to commercialize PSCs. This review summarizes a comprehensive overview of various deposition printing techniques used to fabricate PSCs during different years and different techniques, such as using different preparation methods, novel drying techniques, and ink engineering. In addition, the challenges that are faced by using these, such as material stability, reproducibility of printing processes, and cost-effectiveness techniques, are reviewed. Future research should focus on optimizing printing techniques to improve the stability and scalability of PSCs. Exploring novel perovskite materials, deposition techniques, and innovative fabrication methods may further enhance the PSCs and facilitate their commercialization. Full article

The solar drying of sewage sludge in greenhouses is one of the most used solutions in wastewater treatment plants (WWTPs). However, it presents challenges, particularly in terms of efficiency and drying time. In this context, the present study explores the drying performances of an innovative Combined Solar Greenhouse Dryer (CSGD) for sewage sludge. The system integrates rock bed storage (RBS), a solar air collector (SAC), and a solar greenhouse dryer (SGD). A numerical model, developed using TRNSYS software, predicts the drying kinetics of sewage sludge through hourly dynamic simulations based on the climatic conditions of Marrakesh, Morocco. Experimental validation confirmed the accuracy of the model. The results reveal that integrating the SAC with the SGD during the day and the RBS with the SGD at night significantly enhances the drying efficiency of the sewage sludge. During daylight hours, the SAC generates hot air, reaching maximum temperatures of 64 °C in January and 109 °C in July. Concurrently, the outlet air temperature of the RBS rises notably during the day, corresponding to the charging phase of the storage unit. Moreover, during the night, the RBS air temperature exceeds ambient temperatures by approximately 7–16 °C in January and 11–37 °C in July. This integration leads to a substantial reduction in drying time. The reduction in sewage sludge water content from 4 kg/kg of dry solid (20% dry solid content) to 0.24 kg/kg of dry solid (80% dry solid content) is related to a decrease in the drying time from 121 h to 79 h in cold periods and from 47 h to 27 h in warm periods. The drying process is significantly enhanced within the greenhouse, both during daylight and nocturnal periods. The CSGD system proves to be energy-efficient, offering an effective, high-performance solution for sewage sludge management, while also lowering operational costs for WWTPs. This innovative solar drying system combines a thermal storage bed and a solar collector to enhance drying efficiency, even in the absence of sunlight. Full article

This review article provides a comprehensive analysis of the technical advancements and research trends in solar drying technologies for agricultural products. The study encompasses various innovations in energy storage systems, including phase change materials (PCMs) and the use of computational fluid dynamics (CFD) for optimizing the drying process. Through a bibliometric analysis of 126 scientific papers published between 1984 and 2024, five major research clusters were identified: energy generation, heat transfer, thermal storage, simulation modeling, and the integration of hybrid systems. The results demonstrate a marked increase in scientific output over the past decade, emphasizing a growing interest in the sustainable use of solar energy for drying applications. Key findings highlight that while PCM-based storage solutions significantly enhance the thermal stability of dryers, the high implementation costs and technical complexities limit their adoption, especially in small-scale operations. Similarly, CFD models have proven effective in optimizing air and temperature distribution within dryers; however, their performance is hindered by real-world fluctuations in solar radiation and humidity levels. To address these limitations, future research should focus on the development of cost-effective PCM materials and the improvement of CFD models for dynamic environmental conditions. The review concludes by emphasizing the importance of interdisciplinary collaboration in the design and application of these technologies, recommending the inclusion of real-world case studies to better illustrate the practical implications and economic benefits of solar drying technologies for agricultural production. Full article

This paper presents the results of the technical validation of an innovative prototype for drying alfalfa bales. It is based on a 4.1 kW Heat Pump (HP) that uses an advanced technology (optimized for extracting the humidity from the air) and is directly powered by a 6.6 kW_p PV generator without grid or batteries support. The main technical challenges of this work were managing solar irradiance fluctuations due to cloud-passing and achieving good drying efficiency. The prototype has been validated for two consecutive drying campaigns in La Rioja (Spain). There were no abrupt stops generated by cloud-passing. The PR_PV, which evaluates the performance of the PV system only during the periods when the PV energy can be used by the HP unit, presented values of 0.82 and 0.85, comparable to a well-performing grid-connected PV system. Although the bales’ initial relative humidity (RH) ranged from 18 to 30%, all but one of them presented a final RH below 16%, which is the limit point to avoid fermentation. The drying times ranged from 1 to 5 h, and the specific energy consumption per liter of water extracted, from 0.7 to 1.46 kWh/L. These values are comparable to traditional diesel and grid-powered systems. It is worth noting that the agricultural drying market represented USD 1.7 billion in 2023. Full article

The design and performance of a shallow geothermal system is influenced by the geological and hydrogeological context, environmental conditions and thermal demand loads. In order to preserve the natural thermal resource, it is crucial to have a balance between the supply and the demand for the renewable energy. In this context, this article presents a case study where an innovative system is created for the storage of seasonal solar thermal energy underground, exploiting geotechnical micropiles technology. The new geoprobes system (energy micropile; EmP) consists of the installation of coaxial geothermal probes within existing micropiles realized for the seismic requalification of buildings. The underground geothermal system has been realized, starting from the basement of an existing holiday home Condominium, and was installed in dry subsoil, 20 m-deep below the parking floor. The building consists of 140 apartments, with a total area of 5553 m², and is located at an altitude of about 1490 m above sea level. Within the framework of a circular economy, energy saving and the use of renewable sources, the design of the geothermal system was based on geological, hydrogeological and thermophysical analytical studies, in situ measurements (e.g., Lefranc and Lugeon test during drilling; Rock Quality Designation index; thermal response tests; acquisition of temperature data along the borehole), numerical modelling and long-term simulations. Due to the strong energy imbalance of the demand from the building (heating only), and in order to optimize the underground annual balance, both solar thermal storage and geothermal heat extraction/injection to/from a field of 380 EmPs, with a relative distance varying from 1 to 2 m, were adopted. The integrated solution, resulting from this investigation, allowed us to overcome the standard barriers of similar geological settings, such as the lack of groundwater for shallow geothermal energy exploitation, the lack of space for borehole heat exchanger drilling, the waste of solar heat during the warm season, etc., and it can pave the way for similar renewable and low carbon emission hybrid applications as well as contribute to the creation of smart buildings/urban areas. Full article

The pyrolysis process is a thermochemical conversion reaction that encompasses an intricate array of simultaneous and competitive reactions occurring in oxygen-depleted conditions. The final products of biomass pyrolysis are bio-oil, biochar, and some gases, with their proportions determined by the pyrolysis reaction conditions and technological pathways. Typically, low-temperature slow pyrolysis (reaction temperature below 500 °C) primarily yields biochar, while high-temperature fast pyrolysis (reaction temperature 700–1100 °C) mainly produces combustible gases. In the case of medium-temperature rapid pyrolysis (reaction temperature around 500–650 °C), conducted at very high heating rates and short vapor residence times (usually less than 1 s), the maximum liquid yield can reach up to 85 wt% (on a wet basis) or achieve 70 wt% (on a dry basis), with bio-oil being the predominant product. By employing the pyrolysis technique, valuable utilization of tobacco stem waste enriched with lignin can be achieved, resulting in the production of desired pyrolysis products such as transportation fuels, bio-oil, and ethanol. The present review focuses on catalytic pyrolysis, encompassing catalytic hydropyrolysis and catalytic co-pyrolysis, and meticulously compares the impact of catalyst structure on product distribution. Initially, we provide a comprehensive overview of the recent pyrolysis mechanism of lignin and tobacco waste. Subsequently, an in-depth analysis is presented, elucidating how to effectively design the catalyst structure to facilitate the efficient conversion of lignin through pyrolysis. Lastly, we delve into other innovative pyrolysis methods, including microwave-assisted and solar-assisted pyrolysis. Full article

This article deals with the urban and architectural concept of a shelter for refugees (refugees from civil war-stricken Syria), located in a desert area, in a hot and dry climate. The aim of the research was to develop a design concept for a temporary shelter that would provide refugees with decent living conditions and, at the same time, meet the demands of sustainable development. The conceptual design of the shelter includes a complex of 100 residential units intended for 500 refugees, service buildings, and public spaces. The proposed urban layout can be expanded multiple times. At an architectural scale, the concept includes several variants of residential units. To implement this project, it is proposed to use an innovative, environmentally friendly 3D printing technology employing quartz sand and using solar energy. The implementation of this technology in the construction of shelters for refugees in sandy desert areas will solve many problems related to logistics, availability of building materials, and energy costs. The design solutions proposed in the article are the result of taking into account technological, functional, cultural, humanitarian, economic, climatic, and ecological aspects. Full article