Warnings:Violation symptoms indicating architecture erosion

As a software system evolves, its architecture tends to degrade, and gradually impedes software maintenance and evolution activities and negatively impacts the quality attributes of the system. The main root cause behind architecture erosion phenomenon derives from violation symptoms (i.e., various architecturally-relevant violations, such as violations of architecture pattern). Previous studies focus on detecting violations in software systems using architecture conformance checking approaches. However, code review comments are also rich sources that may contain extensive discussions regarding architecture violations, while there is a limited understanding of violation symptoms from the viewpoint of developers

Creating social value at the bottom of the pyramid:Elaborating resource orchestration via social intermediaries

Overcoming constrained resources and enabling social, environmental, and economic value creation for stakeholders remains a managerial challenge. Small enterprises in the bottom of the pyramid (BoP) context offer an opportunity to extract insights into orchestration of resources amidst such challenges. Extensive qualitative data collected via text analysis, field visits, and expert interviews with two social intermediaries and managers of eleven small enterprises operating in BoP markets were analyzed to understand how small enterprises engage with stakeholders to structure, bundle, and leverage resources, as well as how they address environmental contingencies and social challenges in poverty settings. The findings highlight that companies must move beyond an economic resource focus and engage a diverse stakeholder network, leveraging social intermediaries for resource orchestration throughout lifecycle stages. The emergent framework elaborates on Resource Orchestration Theory (ROT), with propositions related to resource management mechanisms, capabilities offered by social intermediaries, and contingencies for social value creation

Light-driven eco-evolutionary dynamics in a synthetic replicator system

Darwinian evolution involves the inheritance and selection of variations in reproducing entities. Selection can be based on, among others, interactions with the environment. Conversely, the replicating entities can also affect their environment generating a reciprocal feedback on evolutionary dynamics. The onset of such eco-evolutionary dynamics marks a stepping stone in the transition from chemistry to biology. Yet the bottom-up creation of a molecular system that exhibits eco-evolutionary dynamics has remained elusive. Here we describe the onset of such dynamics in a minimal system containing two synthetic self-replicators. The replicators are capable of binding and activating a co-factor, enabling them to change the oxidation state of their environment through photoredox catalysis. The replicator distribution adapts to this change and, depending on light intensity, one or the other replicator becomes dominant. This study shows how behaviour analogous to eco-evolutionary dynamics-which until now has been restricted to biology-can be created using an artificial minimal replicator system.</p

Heterogeneous nitration of nitrobenzene in microreactors: Process optimization and modelling

Aromatic nitration with mixed acid is an important step in the industrial synthesis of basic industrial chemicals, while the highly exothermic and heterogeneous nature of the reaction renders difficulties in achieving high safety and efficiency. In this work, a continuous flow microreactor system was developed for the nitration of nitrobenzene. Under the premise of high conversion and selectivity, the reaction time and temperature were reduced from more than 2 h and 80 ℃ in industrial operation to 10 min and 65 ℃ in microreactors, respectively. The reaction mechanism was verified that the reaction took place not only in the bulk aqueous phase but also at the phase interface. The kinetic parameters were then determined based on the assumption of pseudo-homogeneous reaction mixture. These findings may shed important insights into the high degree of controllability of nitration for a better process design and reactor optimization

Defect-healing of a laser-powder bed fusion Ti6Al4V alloy via electro-assisted micro-forging

In recent years, the concept of hybrid manufacturing has been proposed to heal the defects in additive manufactured (AM) materials, taking advantage of both the AM technique and additional secondary processes such as hot forging. However, the healing mechanism of defects, as well as the relationship between defects elimination and microstructure evolution need to be further studied. In this work, we designed laser-powder bed fusion (L-PBF) Ti6Al4V samples with high initial porosity, making it easier to trace the pores during the quasi in-situ X-ray tomography (XRT) observation. The samples were conducted hot forging by Gleeble-3800 system, which is named as electro-assisted micro-forging (EAMF) treatment, considering the characteristic of this process is to directly electrify the specimen to generate Joule heat. The results show that the porosity was effectively reduced by combining effects of electric current, heat energy and compressive stress during EAMF. Simultaneous enhancement of strength and ductility was realized. The defect-healing mechanism that comprising various stages was comprehensively disclosed. The competitive relationship between defect-healing and microstructure coarsening was revealed, which has a guiding effect on the subsequent optimization of process parameters.</p

Understanding the Surface Chemistry of SnO₂ Nanoparticles for High Performance and Stable Organic Solar Cells

In organic solar cells, the interfaces between the photoactive layer and the transport layers are critical in determining not only the efficiency but also their stability. When solution-processed metal oxides are employed as the electron transport layer, the presence of surface defects can downgrade the charge extraction, lowering the photovoltaic parameters. Thus, understanding the origin of these defects is essential to prevent their detrimental effects. Herein, it is shown that a widely reported and commercially available colloidal SnO2 dispersion leads to suboptimal interfaces with the organic layer, as evidenced by the s-shaped J–V curves and poor stability. By investigating the SnO2 surface chemistry, the presence of potassium ions as stabilizing ligands is identified. By removing them with a simple washing with deionized water, the s-shape is removed and the short-circuit current is improved. It is tested for two prototypical blends, TPD-3F:IT-4F and PM6:L8:BO, and for both the power conversion efficiency is improved up to 12.82% and 16.26%, from 11.06% and 15.17% obtained with the pristine SnO2, respectively. More strikingly, the stability is strongly correlated with the surface ions concentration, and these improved devices maintain ≈87% and ≈85% of their initial efficiency after 100 h of illumination for TPD-3F:IT-4F and PM6:L8:BO, respectively.</p

Cation delocalization and photo-isomerization enhance the uncaging quantum yield of a photocleavable protecting group

Photocleavable protecting groups (PPGs) enable the light-induced, spatiotemporal control over the release of a payload of interest. Two fundamental challenges in the design of new, effective PPGs are increasing the quantum yield (QY) of photolysis and red-shifting the absorption spectrum. Here we describe the combination of two photochemical strategies for PPG optimization in one molecule, resulting in significant improvements in both these crucial parameters. Furthermore, we for the first time identify the process of photo-isomerization to strongly influence the QY of photolysis of a PPG and identify the cis-isomer as the superior PPG. </p

Flexibility options in a decarbonising iron and steel industry

The decarbonisation of the iron and steel industry is expected to significantly increase its electricity consumption due to higher levels of electrification and the partial shift to hydrogen as iron reductant. With its batch processes, this industry offers large potential for the application of demand response strategies to achieve electricity cost savings. Previous research has primarily focused on investigating the demand response potential for currently operating manufacturing processes and partly for future low-carbon processes. This study aims to consolidate this knowledge and apply it to a modelling analysis that investigates the demand response potential of two new low-carbon technologies: the hydrogen-based direct reduction of iron with electric arc furnace technology (H2-DRI-EAF) and the blast furnace basic oxygen furnace technology retrofitted with carbon capture (BF-BOF-CCUS). A cost optimisation approach is applied to plant configurations with varying parameters relevant for flexibility, such as electrolyser and storage sizes, and in the context of future electricity prices. Multiple price profiles are selected to encompass uncertainties on the development of the power system. The potential for a H2-DRI-EAF plant is 3–27 times higher than for a BF-BOF-CCUS, with electricity costs savings potentials of 35% and 3%, respectively. The study finds that electricity prices have the most significant impact on the profitability of investing in electrolyser overcapacities, which enable operating costs reduction. Therefore, the profitability of these investments are strongly dependent on future power system configurations.</p