In order to extract hesperidin from Citrus aurantium L. through green and efficient ways, a novel method based on deep eutectic solvent (DES) assisted extraction has been developed. Compared to known alkali extraction and acid precipitation or organic solvent (ethanol, methanol) extraction, this new DES system of choline chloride/diethanolamine (DES-14) method exhibited excellent extraction efficiency for hesperidin. Under optimal conditions, the extraction yield of hesperidin reached 6.26 ± 0.05%. Further studies with infrared spectroscopy, 1H nuclear magnetic resonance, and density functional theory showed the DES-14 was formed mainly through the interaction of H-bond and van der Waals forces. In addition, scanning electron microscopy and density functional theory revealed the strong dissolving capacity, and the H-bond formation between DES-14 and hesperidin, as well as van der Waals forces all contributed to efficient extraction of hesperidin. The results provide a new strategy for efficient extraction and utilization of hesperidin in Citrus. L ways (DES developed ethanol, ethanol (ethanol methanol chloridediethanolamine chloride diethanolamine DES14 14 (DES-14 conditions 626 6 26 6.2 005 0 05 0.05% spectroscopy H resonance DES-1 Hbond bond addition capacity DES1 1 (DES-1 62 2 6. 00 0.05 DES- (DES- 0.0 0.

A model was composed that integrated demand for railway services, systemic capacity design of production factors, operating efficiency, and the financial viability of the designed railway operations of a dedicated rail freight project. The design model incorporated efficiency measures essential to successfully developing new railway systems. The investment in rail infrastructure concerning the geometric parameters and their effect on the project's viability was deduced. A relationship between the geometric layout of track alignment and the hauling process of freight was determined. Results from simulation work to ascertain the operating efficiency informed the design of train-crossing capacity. The effect of inefficiencies on the performance of the production factors and the influence thereof on the rail tariff and the internal rate of return was determined. The design model covered the range of demand from low volumes of dedicated freight to the advent of heavy-haul operations, and will find its application in cases of new green-field projects. The design parameters applied in sub-models were correlated with the results of field tests and individual new railway projects undertaken in Southern Africa. The results of the effect of systemic operating efficiency on the capacity of the rolling stock fleet were illustrated.

The study aims to optimize machining parameters for turning SAE 8822 Alloy steel under green machining (without coolant), using a CNC turning machine with a carbide tool. The controlled factors are spindle speed (A), feed rate (B), and depth of cut (C), with roughness (Ra) as the response variable. The experimental runs are conducted using an L9 Orthogonal Array (OA). Orthogonal arrays are used to efficiently explore the parameter space with a relatively small number of experimental runs while maintaining statistical validity. The impact of the machining parameters on the roughness is interpreted using Analysis of Variance (ANOVA). ANOVA is a statistical technique that helps identify the significance of each parameter and their interactions on the response variable. The result indicated that variation of A between 1500 rpm to 2000 rpm resulted in a significant increase in Ra. Similarly, the effect of B and C contributed towards huge variations in Ra. The optimal values of 1500 rpm for A, 0.5 mm/rev for B, and 1 mm for C are identified as the most favorable combination for achieving the desired Ra. Achieving a minimum Ra of 0.04 microns indicate a very high-quality surface, which may be desirable in precision engineering applications. The analysis shows that the C and B have the highest influence followed by A on Ra. 882 without coolant, coolant , coolant) tool (A) (B) C, (C) (Ra variable L OA. OA . (OA) validity ANOVA. (ANOVA) 150 200 Similarly 05 0 5 0. mmrev rev 004 04 0.0 highquality high quality surface applications 88 (A (B (C (OA (ANOVA 15 20 00 8 2

The problem of a particle subject to a time-dependent driving force plus a linear velocity-dependent friction can be addressed by utilizing the unilateral Fourier transform, despite the presence of derivatives of odd and even order in the differential equation. This technique yields a system of algebraic equations that combine the Fourier sine and cosine transforms. While this method is useless for solving the homogeneous equation, it can be effectively used to obtain an integral representation of the particular solution. Remarkably, this integral representation of the particular solution is expressed in terms of the Green function. This type of exactly solvable problem is relevant for students who are studying mathematical methods applied in the fields of physics and engineering at the undergraduate level, as it can serve as a useful illustration of how unilateral Fourier transforms can be employed to solve problems and to develop an understanding of Green functions, even in introductory calculus courses. timedependent time dependent velocitydependent velocity transform equation Remarkably function level functions courses

Abstract Climate change is humanity’s 21st century biggest challenge. Due to the higher rates of soil sealing, its effects and consequences are expected to be more severe in cities. To mitigate climate change effects or adapt cities to them, several approaches can be adopted, namely by adopting nature-based solutions, such as blue and green infrastructures. During the course of Study and Behaviour of Soils, of the undergraduate degree in Sustainable City Management, taught at the Institute of Engineering of the Polytechnic Institute of Coimbra (ISEC-IPC), students are faced with the need to present solutions to solve an urban problem by implementing a green solution. Students are involved in a co-creation process to carry out this academic activity. This project-based learning methodology is seen as an active learning process, and its three stages are fully described in this paper. Students’ perceptions, academic results and assiduity are compared and contrasted to enhance the benefits of such an approach in geotechnical education. Results show that not only are students more willing to participate in class, reducing absenteeism, but students’ final project results increased when compared with a more traditional pedagogical approach. Also, based on the survey, it is possible to conclude that the co-creation approach allows the development of transversal skills and competencies, and such a learning process should be implemented more often during the undergraduate degree. humanitys humanity s st challenge sealing them adopted naturebased nature infrastructures Soils Management ISECIPC, ISECIPC ISEC IPC , (ISEC-IPC) solution cocreation co creation activity projectbased paper perceptions education class absenteeism Also survey competencies (ISEC-IPC

Abstract Composites are the recent ever-growing trend in the materials field of engineering. They have numerous applications in aerospace and automobile which make composites an inevitable research area. Currently, the research flow pattern centres around making sustainable green composites with accessible and overabundance of assets to contribute towards eco-friendly surroundings and waste management. In this paper, an attempt is made to reinforce natural fibres in polymer composite instead of synthetic fibres which are mostly non-biodegradable. Composite specimens are made with chemically treated cellulose microfibrils as reinforcements and epoxy as a matrix. Fatigue analysis of specimens prepared is carried out using ANSYS. The number of samples is decided based on the Box Behnken design (BBD), a design of experiments (DOE) method. The influences of parameters such as NaOH %, fibre diameter and Wt. % of Fibre on composite’s fatigue behaviour are investigated using analysis of variance (ANOVA). Optimised values of the input parameters are found to be 18.08 NaOH %, 250 µm fibre diameter and 3.778 Wt. % of Fibre which yields 1.3 x 106 cycles. evergrowing ever growing engineering area Currently ecofriendly eco friendly management paper nonbiodegradable. nonbiodegradable non biodegradable. biodegradable non-biodegradable matrix ANSYS BBD, BBD , (BBD) DOE (DOE method Wt s ANOVA. ANOVA . (ANOVA) 1808 18 08 18.0 25 3778 3 778 3.77 13 1 1. 10 cycles (BBD (ANOVA 180 0 18. 2 377 77 3.7 37 7 3.

In the quest for sufficient and comfortable housing in South Africa, attention to building orientation and thermal transmittance principles has significantly improved thermal performance in local houses. Thermal simulation and monitoring of houses in the Joe Slovo Phase Three development in Cape Town confirms improved performance by solar radiation blockage and shading. This paper simulates the thermal performance of a housing unit in this development. The house was instrumented with thermocouples, and monitored from March to December 2013 by Sustainable Energy Africa in collaboration with the National Department of Human Settlements. Sustainable Energy Africa reported significant improvement when compared to a nearby traditional Reconstruction and Development Programme house that had been monitored during the same period. With the benefit of the monitored thermal data, complete drawings, and specification details of the Joe Slovo Phase Three unit, the current research modelled and calibrated a simulation model in DesignBuilder. DesignBuilder was selected given its accreditation status for Green Star Rating of buildings in South Africa. An additional motivation for investigating this unit was the availability of recorded weather data from the nearby Cape Town International Airport, captured in the DesignBuilder climate data base for 2013, which was assumed relevant in lieu of complete weather station data measured at the location of the housing unit. The study aimed to simulate the monitored temperatures in the house with acceptable agreement, and to investigate further potential improvement in occupant thermal comfort by alternative 3D-printed concrete walling developed by the authors. Systematic finite element analysis (FEA) iteratively solved cavity radiation and convection in wall cavities to calibrate thermal transmittance parameters for DesignBuilder. The FEA results acceptably simulated temperatures monitored in this physical wall experiment. The calibrated DesignBuilder model simulated the indoor temperatures of the monitored house with acceptable agreement, and predicted significant improvement in occupant thermal comfort if the walls were 3D-printed with a particular cross-sectional design.

Green information technology (IT) adoption is an important topic in the fields of information systems, business sustainability, and corporate social responsibility. This case study applies the green IT adoption model (GITAM) to perform a systematic and qualitative readiness assessment at a major South African IT services vendor. Thematic data analysis was used to analyse the data collected from managers and specialist IT staff. The assessment revealed that the main organisational adoption readiness barriers were the lack of a formal green IT policy, an unclearly defined green IT governance framework, and a lack of green performance management. The main drivers of adoption were economic imperatives and regulatory and ethical requirements. Interestingly, a contextual variable - an exogenous shock caused by COVID-19 and the robustness of the organisation's crisis response during the pandemic -rapidly increased the rate of green IT adoption at the firm.

Aanneming van groen inligtingstegnologie (IT) is 'n belangrike onderwerp op die gebied van inligtingstelsels, besigheidsvolhoubaarheid en korporatiewe sosiale verantwoordelikheid. Hierdie gevallestudie pas die groen IT-aannemingsmodel (GITAM) toe om 'n sistematiese en kwalitatiewe gereedheidsbeoordeling by 'n groot Suid-Afrikaanse IT-diensverskafferorganisasie uit te voer. Tematiese data-analise is gebruik om die data wat van bestuurders en spesialis IT-personeel ingesamel is, te ontleed. Die assessering het aan die lig gebring dat die vernaamste hindernisse vir organisatoriese aanvaardingsgereedheid die gebrek aan 'n formele groen IT-beleid, 'n onduidelik gedefinieerde groen IT-bestuursraamwerk en 'n gebrek aan groen prestasiebestuur was. Die belangrikste dryfvere van aanneming was ekonomiese imperatiewe en regulatoriese en etiese vereistes. Interessant genoeg het 'n kontekstuele veranderlike - 'n eksogene skok veroorsaak deur COVID-19 en die robuustheid van die organisasie se krisisreaksie tydens die pandemie -die tempo van groen IT-aanneming by die firma vinnig laat toeneem.

Resumen Este trabajo combina la ingeniería aplicada y los servicios ambientales para el bienestar del municipio de Guadalupe en el estado de Nuevo León. El norponiente del río y cerro de la Silla es zona con riesgos geológicos e hidrometeorológicos, ahí la población está vulnerable en cada evento meteorológico y recursivamente los daños ascienden a millones de pesos (mdp). Existen dos herramientas para prevenir y compensar los daños en 24 colonias distribuidas en 6 cuencas hidrológicas superficiales con encharcamientos y susceptibles de riesgo geológico reportados en el Atlas de Riesgos Estatal. Se identificaron algunas zonas para mejorar, regenerar y ampliar el espacio público en parques, cañadas, glorietas, y camellones. El método de línea clave o key line es un diseño hidrológico del terreno para controlar el escurrimiento del agua, la distribución de la infraestructura y los patrones de las áreas verdes en las colonias. A cada espacio público se le calculó el valor económico de los servicios ambientales en la superficie con riesgos geológicos e hidrometeorológicos. El valor estimado de los servicios ambientales es para 21 aspectos de lo urbano y natural. Los servicios incluyen la protección a las inundaciones, la cobertura y erosión del suelo, la estabilidad y contención del macizo rocoso, entre otros. Mantener un ordenamiento con ingeniería de los espacios públicos garantiza la prevención ante algún agente perturbador producido por la naturaleza o inducido. De esta investigación, la mitigación del riesgo en los espacios públicos puede producir servicios ambientales por $28.7 mdp para zonas susceptibles con riesgo geológico y $23.8 mdp para la protección a inundaciones. Valorar los beneficios de los espacios urbanos junto con los servicios en geología e hidrometeorología pueden ser útiles para evaluar los desastres naturales y en la toma de las decisiones para proteger a la población.

Abstract This work combines applied engineering and environmental services for the well-being of the municipality of Guadalupe in the state of Nuevo León. The northeast of the river and Cerro de la Silla is an area with geological and hydrometeorological risks, in there, the population is vulnerable to each meteorological event, and recursively, the damages arise to millions of pesos (mop.). Two tools prevent and compensate for damage in 24 neighborhoods distributed in 6 surface watershed basins with flooding and susceptible to geological risk reported on the State Risk Atlas. Some areas were identified to improve, regenerate and expand the public space of parks, gullies, traffic circles, and medians. The key line method is a hydrological design of the land to control runoff, the distribution of infrastructure, and the patterns of green areas of the neighborhoods. For each public space, the economic value of environmental services was calculated in areas with geological and hydrometeorological risks. The estimated value of environmental services is for 21 urban and natural aspects. The services include flood protection, soil cover and erosion, rock mass stability and containment, among others. Keeping the order of public spaces with engineering guarantees prevention against any disturbing agent produced by nature or induced. From this investigation, risk mitigation in public spaces can produce environmental services for $28.7 million pesos for susceptible areas with geological risk and $23.8 million pesos for flood protection. Assessing the benefits of urban spaces together with geology and hydrometeorology services can help evaluate natural disasters and for decision-making to protect the population.

Composites based on green high-density polyethylene (G-HDPE) and hydroxyapatite (HA) compatibilized with maleic anhydride grafted high-density polyethylene (HDPE-g-MAH) were developed in this work. The main objective was to evaluate the effects of HA and HDPE-g-MAH contents on the mechanical and thermal properties and hydrolytic degradation of composites through design of experiments and statistical analysis, as well as to evaluate the hemolytic stability. Hydroxyapatite acts as a reinforcing agent for the G-HDPE matrix while the HDPE-g-MAH acts as a compatibilizing agent, improving the dispersion of the HA particles in the polymer matrix and thus increasing the mechanical properties. The crystallization temperature and the degree of crystallinity of the polymer matrix were increased with the addition of HA, suggesting the filler acts as a heterogeneous nucleating agent. Hemolysis tests performed on a composite sample with best mechanical performance did not indicate significant hydrolytic degradation, which suggests this composite is a promising material to be used in bone tissue engineering, for application in implants and bone grafts. highdensity high density GHDPE G HDPE (G-HDPE (HA HDPEgMAH g MAH (HDPE-g-MAH work analysis stability engineering grafts

Abstract This article presents novel non-singular influence functions for homogeneous media. These solutions are displacement and stress fields of a three-dimensional, isotropic full-space under time-harmonic vertical and horizontal loads, which can be used within the framework of boundary element methods to solve elastodynamics problems in engineering practice. In order to account for sharply-varying contact tractions that may occur in such problems, the solutions in this article consider a biquadratic distribution of the loads within the loaded surface. In the present derivation, sets of Fourier transforms are used to uncouple the medium's equation of motion and enable the incorporation of boundary conditions directly as traction discontinuities. The article brings selected numerical results for various geometric and constitutive parameters. nonsingular non singular media threedimensional, threedimensional three dimensional, dimensional three-dimensional fullspace full space timeharmonic time harmonic practice sharplyvarying sharply varying surface derivation mediums medium s discontinuities parameters

Abstract A possible option to increase the value of low-density woods may be to combine species with different densities. The manufacture of boards involving joining and mixing wood with different properties is known as an engineering product. The present work aimed to design, produce, and evaluate a 16 mm-thick three-layer engineered floor using coconut palm (Cocos nucifera) or melina (Gmelina arborea) as substrate and reinforced with red oak (Quercus castanea) using three types of adhesives: urea formaldehyde, henkel loctite and soy furfural. The results, with both wood substrates, showed an average specific weight of 0.53 g cm-3 and an average moisture content of 9%. The flexural strength ranged from 12 MPa to 62 MPa and from 1346 MPa to 10 660 MPa in modulus of elasticity, the combination of oak-melina-oak with urea formaldehyde being the one that presented the best results. Brinell hardness exhibits strengths from 30 N mm-2 to 48 N mm-2 with the oak-palm-oak combination with loctite achieving the highest value. The shear resistance of the gluing line renged from 0.11 MPa to 3.46 MPa, with the oak-palm-oak with soya furfural, oak-palm-oak with urea formaldehyde, as well as oak-melina-oak urea formaldehyde combinations showing no statistical differences. In delamination, floors with urea formaldehyde and furfural soy are susceptible to delamination by direct contact with water and while being subjected to dry changes in relative humidity in the environment of 35% and 55%.

Resumen Una opción para incrementar el valor de las maderas de baja densidad puede ser el combinarlas con especies de densidades más altas. A los productos que combinan madera de diferentes propiedades se les conoce como productos de ingeniería. El presente trabajo tuvo como objetivo diseñar, producir y evaluar, a través de sus propiedades físicomecánicas, un piso de ingeniería de 16 mm de espesor. Este producto se conformó de tres capas, utilizando palma de coco (Cocos nucifera) o melina (Gmelina arborea) como sustrato y encino rojo (Quercus castanea) como refuerzo. Se ensayaron tres tipos de adhesivos: urea formaldehido, henkel loctite y soya furfural. Con los dos sustratos utilizados, se obtuvo una densidad normal promedio de 0.53 g cm-3 a un contenido de humedad promedio de 9%. La resistencia a la flexión fluctuó entre 12 MPa y 62 MPa y el módulo de elasticidad entre 1346 MPa y 10 660 MPa. La combinación de encino-melinaencino con urea formaldehido fue la que presentó los mejores resultados. La dureza Brinell exhibió valores de 30 N mm-2 a 48 N mm-2 y la combinación encino-palma-encino con loctite fue la que arrojó el mayor valor. La resistencia al cortante de la línea de encolado fue de 0.11 MPa a 3.46 MPa. Las combinaciones encino-palma-encino soya furfural, encino-palma-encino urea formaldehido, así como encino-melina-encino urea formaldehido no presentaron diferencias estadísticas significativas en la resistencia de la línea adhesiva. Los pisos con urea formaldehido y con soya furfural fueron susceptibles a la delaminación al contacto directo con el agua y ante cambios de humedad relativa en el ambiente de 35% y 55%.

After usage, foundry chromite sand is recycled to reduce production costs and comply with environmental regulations. Thermal and mechanical reclamation are the most prominent methods of sand recycling. The sand reclamation techniques used in the foundry sector are typically not evaluated through the green alternative or environmental sustainability concept's lenses. When contrasting mechanical and thermal reclamation, operational costs are the main factor to be taken into account. Therefore, this study compares mechanical and thermal reclamation of chromite sand by replicating the industrial processes in simulated laboratory tests. The methodology is designed to quantify the production of fine particles during reclamation, which has an array of negative effects on the environment, human health, the economy, and society. The findings show that, in general, mechanical reclamation produced more fine particles than thermal reclamation. The disparity in terms of fine percentage between the two processes could occasionally be as high as 15%. Therefore, mechanical reclamation was a less effective procedure than thermal reclamation when considering environmental sustainability, especially the impact on human health, which goes against conventional wisdom in the foundry sector.

Na gebruik word gietery-chromietsand herwin om produksiekoste te verminder en om aan omgewingsregulasies te voldoen. Termiese en meganiese herwinning is die mees prominente metodes van sandherwinning. Die sandherwinningstegnieke wat in die gieterysektor gebruik word, word tipies nie deur die groen alternatiewe of omgewingsvolhoubaarheidskonsep se lense geévalueer nie. Wanneer meganiese en termiese herwinning gekontrasteer word, is bedryfskoste die hooffaktor wat in ag geneem moet word. Daarom vergelyk hierdie studie meganiese en termiese herwinning van chromietsand deur die industriéle prosesse in gesimuleerde laboratoriumtoetse te herhaal. Die metodologie is ontwerp om die produksie van fyn deeltjies tydens herwinning te kwantifiseer, wat 'n verskeidenheid negatiewe effekte op die omgewing, menslike gesondheid, die ekonomie en die samelewing het. Die bevindinge toon dat meganiese herwinning in die algemeen meer fyn deeltjies as termiese herwinning geproduseer het. Die verskil in terme van fyn persentasie tussen die twee prosesse kan soms so hoog as 15% wees. Daarom was meganiese herwinning 'n minder effektiewe prosedure as termiese herwinning wanneer omgewingsvolhoubaarheid oorweeg word, veral die impak op menslike gesondheid, wat in stryd is met die konvensionele wysheid in die gietery sektor.

Abstract Several studies have analyzed the integration of energy-saving strategies in buildings to mitigate their environmental impact. These studies focused mainly on a disaggregated analysis of such strategies and their effects on the building's energy consumption and thermal behavior, using energy engine simulation software (EnergyPlus, TRNSYS, and DOE2) or graphical interface software (DesignBuilder, eQuest, and ESP-r). However, buildings are complex systems whose energy behavior depends on the interaction of passive (e.g., location and construction materials) and dynamic (e.g., occupation) components. Therefore, this study proposes a composite indicator Building’s Energy Performance (BEP) as an alternative to deal with this complex and multidimensional phenomenon in a simplified way. This indicator considers energy efficiency and thermal comfort. The Electrical Engineering Building (EEB) of the Universidad Industrial de Santander was selected to verify the performance of the BEP indicator. In addition, a sensitivity analysis was performed for different mathematical aggregation methods and weighting values to test their suitability to reproduce the building behavior. Different simulation scenarios modeled with DesignBuilder software were proposed, in which the energy-saving strategies integrated with the building was individually analyzed. The results confirmed that the integration of the building's energy-saving strategies improved the BEP indicator by approximately 16%. It has also been possible to verify that the BEP indicator adequately reproduces the building’s energy behavior while guaranteeing comfort conditions. Finally, the Building Energy Performance indicator is expected to contribute to the integration of sustainability criteria in the design and remodeling stages of buildings.

Resumen Diversos estudios han analizado la integración de estrategias de ahorro energético en edificaciones para mitigar su impacto ambiental. Estos estudios se centraron en un análisis desagregado de estas estrategias y sus efectos sobre el consumo de energía y el comportamiento térmico del edificio utilizando motores de simulación energética (EnergyPlus, TRNSYS y DOE2) o software de interfaz gráfica (DesignBuilder, eQuest y ESP-r). Sin embargo, los edificios son sistemas complejos cuyo comportamiento energético depende de la interacción de componentes pasivos (p. ej., ubicación y materiales de construcción) y dinámicos (p. ej., ocupación). Por lo tanto, este artículo propone un indicador compuesto de desempeño energético de edificaciones (BEP) como una alternativa para enfrentar este fenómeno complejo y multidimensional de manera simplificada. Este indicador considera la eficiencia energética y el confort térmico. Para ello, se seleccionó un edificio real, el Edificio de Ingeniería Eléctrica (EEB) de la Universidad Industrial de Santander, con el fin de verificar el desempeño del indicador BEP. Además, se realizó un análisis de sensibilidad para diferentes métodos matemáticos de agregación y valores de ponderación para probar su idoneidad para reproducir el comportamiento del edificio. Se propusieron diferentes escenarios de simulación modelados mediante el software DesignBuilder, en los que se analizaron individualmente las estrategias de ahorro energético integradas con el edificio. Los resultados confirmaron que las estrategias de ahorro energético del edificio mejoraron el indicador en aproximadamente un 16 %. Asimismo, fue posible verificar que dicho indicador reproduce adecuadamente el comportamiento energético de la edificación mientras se garantiza condiciones de confort. Por último, se espera que el indicador contribuya en la integración de criterios de sostenibilidad en edificaciones durante las etapas de diseño y remodelación.

We describe literature-based research on the viability of whole-culm bamboo as a construction technology for South Africa. South Africa has one bamboo species considered suitable for construction, namely Bambusa balcooa, found in various parts of the country. Quantitative production figures are not currently available; however, local reports indicate that South Africa can expand its bamboo growth industry to meet any possible expected demand. Although the South African bamboo plant has not yet been evaluated in terms of its material properties, engineering design approaches and material properties from the literature indicate that this species is a viable construction material. The limitations for bamboo design and construction are not unique to South Africa but are common to countries involved in bamboo construction. Their experience in overcoming these limitations can be transferred to the use of bamboo in South Africa, making bamboo construction a potentially viable construction technology in South Africa. Significance: • Whole-culm bamboo can be used as a structural material in buildings and other specialised structures such as bridges, assembly halls, and the like. • South Africa has a bamboo species that should potentially be suitable for the construction of structures that lend themselves to this type of construction. • The information given here should allow designers, engineers and technologists to assess the viability of bamboo construction in South African situations.