• Energy Research

The purpose of this research was to plan an approach to a project framework that integrated a model for sustainability and CSR, with the process groups of the Project Management Body of Knowledge (PMBOK®) standard, in its application to the training of a group of students in Project Design, Management, and Evaluation. The integration was justified by the scarce explicit references to sustainability and CSR found in traditional project management guidelines, norms, and standards. The new framework was used to structure a Sustainability Management Plan, which made it possible to incorporate sustainability criteria throughout the life cycle of the training project. The training proposal in Project Design, Management, and Evaluation was chosen, among several alternatives, by a multi-criteria selection process (fuzzy AHP) in the context of project scope management. The results reveal a great heterogeneity among the models and the lack of a base of key indicators in sustainability and CSR measurement tools as well as of explicit references to sustainability in project management standards. It is therefore necessary to develop a Sustainability Management Plan that can be introduced in the Project Management Plan and thus influence the strategic and operational guidelines of the Institution.

Agriculture is a critical domain, where technology can have a significant impact on increasing yields, improving crop quality, and reducing environmental impact. The use of renewable energy sources such as solar power in agriculture has gained momentum in recent years due to the potential to reduce the carbon footprint of farming operations. In addition to providing a source of clean energy, solar tracking systems can also be used for remote weather monitoring in the agricultural field. The ability to collect real-time data on weather parameters such as temperature, humidity, and rainfall can help farmers make informed decisions on irrigation, pest control, and other crop management practices. The main idea of this study is to present a system that can improve the efficiency of solar panels to provide constant power to the sensor in the agricultural field and transfer real-time data to the app. This research presents a mechanism to improve the arrangement of a photovoltaic (PV) array with solar power and to produce maximum energy. The proposed system changes its direction in two axes (azimuth and elevation) by detecting the difference between the position of the sun and the panel to track the sun using a light-dependent resistor. A testbed with a hardware experimental setup is designed to test the system’s capability to track according to the position of the sun effectively. In the end, real-time data are displayed using the Android app, and the weather data are transferred to the app using a GSM/WiFi module. This research improves the existing system, and results showed that the relative increase in power generation was up to 52%. Using intelligent artificial intelligence techniques with the QoS algorithm, the quality of service produced by the existing system is improved.

This article addresses the preparation of a concrete using recycled aggregates obtained from the rubble recovery of concrete and masonry works. The study showssome aspects such as : compressive strength at 3, 7, 14, 28, 56 and 91 days ; porosity, ultrasonic pulse speed and carbonation ; economic costs compared to aconventional concrete ; and a review of the public policies on sustainable construction and the use of rubble, in the city of Medellin, Colombia. For some mixes, thecompressive strength and the ultrasonic pulse speed measurements were approximately the 98% of that of the reference mix. Likewise, the mix prepared with 100%of recycled aggregates showed a difference in the carbonation deepness of only 0.7 mm compared with the mix of reference for a simulated age of 27 years. Theresults obtained with the replacement of natural coarse and fine aggregates in 25%, 50%, and 100%, and the advance in the political-administrative guidelines of thecity in the last eleven years, allow deducing the possibility of preparing structural and non-structural concretes for massive use in the construction area. Rev. ing. constr. [online]. 2015, vol. 30, n ° 2, pp. 99-108. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732015000200002 This article addresses the preparation of a concrete using recycled aggregates obtained from the rubble recovery of concrete and masonry works. The study showssome aspects such as: compressive strength at 3, 7, 14, 28, 56 and 91 days; porosity, ultrasonic pulse speed and carbonation; economic costs compared to aconventional concrete; and a review of the public policies on sustainable construction and the use of rubble, in the city of Medellin, Colombia. For some mixes, thecompressive strength and the ultrasonic pulse speed measurements were approximately the 98% of that of the reference mix. Likewise, the mix prepared with 100%of recycled aggregates showed a difference in the carbonation deepness of only 0.7 mm compared with the mix of reference for a simulated age of 27 years. Theresults obtained with the replacement of natural coarse and fine aggregates in 25%, 50%, and 100%, and the advance in the political-administrative guidelines of thecity in the last eleven years, allow deducing the possibility of preparing structural and non-structural concretes for massive use in the construction area. Rev. ing. constr. [online]. 2015, vol.30, n.2, pp. 99-108. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732015000200002 This article addresses the preparation of a concrete using recycled aggregates obtained from the rubble recovery of concrete and masonry works. The study shows aspects such as: compressive strength at 3, 7, 14, 28, 56 and 91 days; porosity, ultrasonic pulse speed and carbonation; economic costs compared to aconventional concrete; and a review of the public policies on sustainable construction and the use of rubble, in the city of Medellin, Colombia. For some mixes, the compressive strength and the ultrasonic pulse speed measurements were approximately 98% of that of the reference mix. Likewise, the mix prepared with 100%of recycled aggregates showed a difference in the carbonation deepness of only 0.7 mm compared with the mix of reference for a simulated age of 27 years. Theresults obtained with the replacement of natural coarse and fine aggregates in 25%, 50%, and 100%, and the advance in the political-administrative guidelines of the city in the last eleven years, allow deducing the possibility of preparing structural and non-structural concretes for massive use in the construction area. Rev. ing. construc. [online]. 2015, vol.30, no.2, pp. 99-108. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732015000200002 تتناول هذه المقالة تحضير الخرسانة باستخدام الركام المعاد تدويره الذي تم الحصول عليه من استعادة الأنقاض لأعمال الخرسانة والبناء. تظهر الدراسة جوانب مثل: قوة الانضغاط عند 3 و 7 و 14 و 28 و 56 و 91 يومًا ؛ المسامية وسرعة النبض بالموجات فوق الصوتية والكربنة ؛ التكاليف الاقتصادية مقارنة بالخرسانة التقليدية ؛ ومراجعة السياسات العامة بشأن البناء المستدام واستخدام الأنقاض، في مدينة ميديلين، كولومبيا. بالنسبة لبعض الخلطات، كانت مقاومة الانضغاط وقياسات سرعة النبض بالموجات فوق الصوتية حوالي 98 ٪ من تلك الخاصة بالمزيج المرجعي. وبالمثل، أظهر المزيج المحضر بنسبة 100 ٪من الركام المعاد تدويره فرقًا في عمق الكربنة يبلغ 0.7 مم فقط مقارنة بالمزيج المرجعي لعمر محاكاة يبلغ 27 عامًا. النتائج التي تم الحصول عليها مع استبدال الركام الخشن والغرامة الطبيعية في 25 ٪ و 50 ٪ و 100 ٪، والتقدم في المبادئ التوجيهية السياسية والإدارية للمدينة في السنوات الإحدى عشرة الماضية، تسمح باستنتاج إمكانية إعداد الخرسانة الهيكلية وغير الهيكلية للاستخدام المكثف في منطقة البناء. Rev. ing. construc. [online]. 2015, vol.30, no.2, pp. 99-108. ISSN 0718-5073. http://dx.doi.org/10.4067/S0718-50732015000200002

The objectives this study were to examine the integrated use of oil–coagulant for the direct extraction of coagulant from Moringa oleifera (MO) with 5% and 10% (NH4)2SO4 extractor solution to harvest Scenedesmus obliquus cultivated in urban wastewater and to analyze the oil extracted from MO and S. obliquus. An average content of 0.47 g of coagulant and 0.5 g of oil per gram of MO was obtained. Highly efficient algal harvest, 80.33% and 72.13%, was achieved at a dose of 0.38 g L−1 and pH 8–9 for 5% and 10% extractor solutions, respectively. For values above pH 9, the harvest efficiency decreases, producing a whitish water with 10% (NH4)2SO4 solution. The oil profile (MO and S. obliquus) showed contents of SFA of 36.24–36.54%, monounsaturated fatty acids of 32.78–36.13%, and polyunsaturated fatty acids of 27.63–30.67%. The biodiesel obtained by S. obliquus and MO has poor cold flow properties, indicating possible applications limited to warm climates. For both biodiesels, good fuel ignition was observed according to the high cetane number and positive correlation with SFA and negative correlation with the degree of saturation. This supports the use of MO as a potentially harmless bioflocculant for microalgal harvest in wastewater, contributing to its treatment, and a possible source of low-cost biodiesel.