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Minimizing annual energy consumption using innovative cooling system architecture for diverse climatic conditions
No full textSeparate sensible and latent cooling (SSLC) is a promising technology for enhancing the energy efficiency of space cooling systems. In this paper, we propose an SSLC configuration consisting of an indirect evaporative cooling (IEC) device and vapor compression cycle (VCC) for handling space sensible load, and a desiccant wheel for handling space latent load. The performance of the proposed configuration is investigated using physics-based or empirical models for each component. A year-round simulation study of the proposed SSLC system is performed for 12 different cities with diverse climatic conditions. This study considers electrical, thermal, or solar energy for desiccant wheel regeneration. Parameters governing the system performance such as the air flowrate ratio in the IEC and the DW, DW regeneration air temperature, and supply temperature are studied. The proposed SSLC configuration is superior to the conventional system in all cities. The enhancement of seasonal coefficient of performance (sCOP) ranges between 50 and 261 %, 67 and 387 %, and 60 and 2072 % with yearly electrical energy savings of 33 and 72 %, 40 and 79 %, and 38 and 95 % for electrical, thermal, and solar energy for regeneration of DW, respectively
Fawzia El Abbassi : A TV Presenter and a Grandma
Get PDFFawzia El Abbassi was a famous TV presenter in the 20th century, but she was also Zozo my grandmother. She lived life with authenticity, kindness, love, warmth and grace... and this is what I wanted to share with the world
Facile sonochemically-assisted bioengineering of titanium dioxide nanoparticles and deciphering their potential in treating breast and lung cancers: biological, molecular, and computational-based investigations
Get PDFCombining sonochemistry with phytochemistry is a modern trend in the biosynthesis of metallic nanoparticles (NPs), which contributes to the sustainability of chemical processes and minimizes hazardous effects. Herein, titanium dioxide (TiO2) NPs were bioengineered using a novel and facile ultrasound-assisted approach utilizing the greenly extracted essential oil of Ocimum basilicum. FTIR and UV-Vis spectrophotometry were used to confirm the formation of TiO2 NPs. The X-ray diffraction (XRD) analysis showed the crystalline nature of TiO2 NPs. TEM analysis revealed the spherical morphology of the NPs with sizes ranging from 5.55 to 13.89 nm. Energy-dispersive X-ray (EDX) confirmed the purity of the greenly synthesized NPs. TiO2 NPs demonstrated outstanding antitumor activity against breast (MCF-7) and lung (A-549) cancer cells with estimated IC50 values of 1.73 and 4.79 μg mL−1. The TiO2 NPs were cytocompatible to normal cells (MCF-10A) with a selectivity index (SI) of 8.77 for breast and 3.17 for lung cancer. Biological assays revealed a promising potential for TiO2 NPs to induce apoptosis and arrest cells at the sub-G1 phase of the cell cycle phase in both cancer cell lines. Molecular investigations showed the ability of TiO2 NPs to increase apoptotic genes\u27 expression (Bak and Bax) and their profound ability to elevate the expression of apoptotic proteins (caspases 3 and 7). Molecular docking demonstrated strong binding interactions for TiO2 NPs with caspase 3 and EGFR-TK targets. In conclusion, the greenly synthesized TiO2 NPs exhibited potent antitumor activity and mitochondrion-based cell death against breast and lung cancer cell lines while maintaining cytocompatibility against normal cells
Transition metal chalcogenide nanoparticle embedded metal-organic framework nanosheets for high-performance H2O2 electrosynthesis
No full textThe rational design of high-performance two-electron oxygen reduction reaction (2e-ORR) electrocatalysts is of great significance for sustainable H2O2 production. Herein, we report the synthesis of a transition-metal chalcogenide@metal-organic framework (TMC@MOF) composite material as an efficient 2e-ORR electrocatalyst. Through a partial conversion route using NiFe-MOF nanosheets as precursors, the Ni ions are partially converted into NiS2 nanoparticles, which are embedded in the MOF skeleton with partially preserved crystalline structure and in situ generated mesopores. Experimental and theoretical results demonstrate that the interaction between NiS2 and retained MOFs regulates the electronic structure of Ni sites in NiS2 toward optimized adsorption of oxygen intermediates, enhancing the 2e-ORR selectivity. Additionally, the ultrasmall NiS2 nanoparticles (grain size \u3c 10 nm) expose abundant active sites, and the created mesopores facilitate the mass transfer. Collectively, excellent 2e-ORR performances are achieved with a high selectivity of 96% and a high H2O2 production rate of 4.2 mol gcat−1 h−1. The proposed partial sulfidation strategy paves the way for the design of advanced MOF-based composite materials for various applications
Allopurinol, oxypurinol, and thiopurinol expired drugs as corrosion inhibitors toward Al (111) surface: a DFT and FPMD simulation study
No full textBy means of density functional theory and first-principle molecular dynamics (FPMD) simulations, the corrosion inhibition potential of allopurinol (Allo), oxypurinol (Oxy), and thiopurinol (Thio) expired drugs toward the aluminium (Al) (111) surface was thoroughly examined. ESP maps and FMOs analysis indicated the electron-donating nature of the studied drugs. From global reactivity descriptors, the potential of the Allo, Oxy, and Thio drugs in gas and aqueous phases as corrosion inhibitors was confirmed. Thio drug showed lower IP and higher EA values than the other investigated drugs, illustrating its higher reactivity. Further, the lowest value of ƞ and the highest value of σ were found for the Thio drug, indicating its high potential as a corrosion inhibitor. Employing FPMD simulations, the most stable configurations of the drug∙∙∙Al (111) complexes were determined, and the corresponding interaction and binding energies were estimated. According to the energetic affirmations, the Thio drug demonstrated the largest affinity to inhibit the Al (111) surface with an interaction energy (Eint) value of − 25.12 kcal/mol. The findings of the charge transfer (Qt) were in line with the Eint, in which the Qt of the drug∙∙∙Al (111) complexes decreased in the order Thio∙∙∙ \u3e Allo∙∙∙ \u3e Oxy∙∙∙Al (111) with values of − 0.5119, − 0.2737, and − 0.2471 e, respectively. The obtained results would provide fundamental insights into the promising application of Allo, Oxy, and Thio expired drugs as corrosion inhibitors, especially for aluminium surface. Graphical abstract: (Figure presented.
Beyond Co-integration: New Tools for Inference on Co-movements
No full textMacroeconomic and aggregate financial series were shown empirically to share an unconventional form of cyclical and persistent dynamics, whose functional form was obtained from the solution of general-equilibrium models with heterogeneous firms. The econometric modeling of equations that link such series requires a new methodology, as existing parametric techniques can cause paradoxical regression results and omit predictabilities. We provide a solution to disentangle the genuine relation between variables (the parameters linking them) from the unconventional dynamics that drive them. As an application, we show that GBP-USD forward premia have no predictive power for excess returns over 1976-2015 (thus solving this forward-premium puzzle) once the unconventional dynamics of spot rates are modeled. Taking advantage of these dynamics, we uncover a trading strategy which consistently outperforms existing ones in the out-of-sample period 2015-2021, delivering almost treble their profits and yielding a Sharpe ratio of 85%. Hence, even in this heavily traded market, the efficient market hypothesis has been failing for over 45 years as persistent profit opportunities remained unexploited because of the unconventional dynamics of the spot rate
Experimental Insights into Friction Losses of Post-Tensioned Precast Full-Scale Girders
Get PDFThe use of post-tensioning in construction has revolutionized the construction industry and made way for several construction and structural applications that were unattainable before. One of the most important topics that are synonymous with the use of post-tensioning is the matter of accurately calculating the short-term and long-term losses that arise in pre-stress. One of the prominent types of losses is the friction losses that occur during the jacking of the concrete elements due to its impact on structural integrity and longevity.
The thesis examines this critical aspect of friction losses in post-tensioned concrete structures. The study focuses on full-scale, 30-meter precast girders, employing an experimental setup that involves the use of strain gauges embedded along the tendons within the concrete girders to measure and document the stress and strain behaviors during the jacking process. This analysis is motivated by the transformative effect of post-tensioning in the construction industry, which has enabled several new structural applications and spurred extensive research to refine and expand the understanding of post-tensioned systems. The research aims to bridge the gap between theoretical predictions and actual field results, providing a more accurate calculation of short-term losses due to pre-stress in such systems. Through this on-site investigation, the thesis provides empirical evidence highlighting that the friction losses occurring during the tensioning process are more pronounced and develop more rapidly than conventional models and standards predict.
The findings from the experimental work and, eventually, the statistical processing of these obtained findings indicate that the friction losses measured were slightly greater than those forecasted by existing predictions, with a faster development of losses across the tendon\u27s profile at varying levels of stress. These discrepancies underline the need for revisions in current engineering codes of practice and standards. The thesis thoroughly compares the experimental data with theoretical values from established literature and standards. Additionally, the research conducts regression analysis on the perceived dataset in order to propose an alternative prediction model for the matter of prestress losses, ultimately offering crucial insights and recommendations for improving the predictive accuracy and reliability of construction engineering calculations concerning post-tensioned concrete girders.
Overall, the thesis not only advances the theoretical framework for understanding friction losses in post-tensioned structures but also contributes practical insights that can lead to more robust and reliable construction practices. This work underscores the importance of on-site validation of theoretical models and stresses the need for continuous adjustment of engineering codes to reflect real-world conditions more accurately
Tandem electroreduction of nitrate to green ammonia on recycled copper sheets from spent batteries: splicing surface roughness achieves high yield rate
No full textElectrochemical conversion of nitrate to ammonia (eNitRR) offers a sustainable alternative to ammonia production. However, the lack of efficient and high turnover electrocatalysts is hindering the eventual commercialization of eNitRR. Moreover, in order to improve the viability of eNitRR commercialization further, electrocatalysts should also be sourced from recycled or waste materials. Battery waste, in particular spent lithium-ion batteries, is a massive and versatile resource for valuable metals. Herein, we extracted Cu foil from spent Li-ion batteries and modified it via various treatments to control the surface roughness factor (RF). The electrocatalytic performance increased as the RF increases, resulting in a maximum NH3 faradaic efficiency (FE) of ∼97.6% and a yield rate (YR) of ∼2.162 mmol h−1 cm−2. As surface morphology and roughness can play an integrative role in the catalytic activity, different roughened surfaces were built using Python code. Molecular dynamics (MD) studies revealed that the Cu roughened surfaces have square sites and close-packed sites with Cu (100) and Cu (111) facets, respectively. Ab initio calculations illustrate that NO3− adsorption likely takes place on the Cu (100) facets and transforms into NO2−, at which point the reactant species transfer to a Cu (111) facet, where further protonation occurs until ammonia is produced. This tandem interaction was theorized to be the underlying mechanism behind the obtained superior catalytic performance
The atmospheres of massiveness: The politics and times of the maybe in Southern megaregions
No full textIn this introduction to the special issue on massive urbanisation, the collective that has prepared this issue reviews the thinking and experiences that have been important to them. The reflections centre on the use of ‘massive’ in Jamaican patois, where it has two countervailing meanings. On the one hand, it means an inordinate lack of sensitivity to the real conditions taking place, a sense of extreme self-inflation beyond reason. On the other, it means a collectivity coming into being without a set form, but reflective of a desire for collaboration and mutuality. Massive urbanisation thus means here both the voluminous expansion of speculative accumulation, extraction of land value, replication of vast inequities and disfunction, and the continuous emergence of new forms of urban inhabitation, a constant remaking of the social field by what has been called the urban majority. All of the contributions attempt to work with this sense of doubleness, amplifying the creation of particular atmospheres of the urban as a materiality of its heterogeneity
Practical strategies to achieve resilient health systems: results from a scoping review
No full textBackground: This paper presents the results of a systematic review to identify practical strategies to create the institutions, skills, values, and norms that will improve health systems resilience. Methods: A PRISMA 2020 compliant systematic review identified peer-reviewed and gray literature on practical strategies to make health systems more resilient. Investigators screened 970 papers to identify 65 English language papers published since 2015. Results: Practical strategies focus efforts on system changes to improve a health system’s resilience components of collective knowing, collective thinking, and collaborative doing. The most helpful studies identified potential lead organizations to serve as the stewards of resilience improvement, and these were commonly in national and local departments of public health. Papers on practical strategies suggested possible measurement tools to benchmark resilience components in efforts to focus on performance improvement and ways to sustain their use. Essential Public Health Function (EPHF) measurement and improvement tools are well-aligned to the resilience agenda. The field of health systems resilience lacks empirical trials linking resilience improvement interventions to outcomes. Conclusions: The rigorous assessment of practical strategies to improve resilience based on cycles of measurement should be a high priority