Embedding Spatial Software Visualization in the IDE: an Exploratory Study

Software visualization can be of great use for understanding and exploring a software system in an intuitive manner. Spatial representation of software is a promising approach of increasing interest. However, little is known about how developers interact with spatial visualizations that are embedded in the IDE. In this paper, we present a pilot study that explores the use of Software Cartography for program comprehension of an unknown system. We investigated whether developers establish a spatial memory of the system, whether clustering by topic offers a sound base layout, and how developers interact with maps. We report our results in the form of observations, hypotheses, and implications. Key findings are a) that developers made good use of the map to inspect search results and call graphs, and b) that developers found the base layout surprising and often confusing. We conclude with concrete advice for the design of embedded software maps.Comment: To appear in proceedings of SOFTVIS 2010 conferenc

Empowering Collections with Swarm Behavior

Often, when modelling a system there are properties and operations that are related to a group of objects rather than to a single object. In this paper we extend Java with Swarm Behavior, a new composition operator that associates behavior with a collection of instances. The lookup resolution of swarm behavior is based on the element type of a collection and is thus orthogonal to the collection hierarchy

Reduced Coulomb interaction in organic solar cells by the introduction of inorganic high-k nanostructured materials

In this article a concept is introduced, which allows for reduced Coulomb interaction in organic solar cells and as such for enhanced power conversion efficiencies. The concept is based on the introduction of electrically insulating, nanostructured high-k materials into the organic matrix, which do not contribute to the charge transport, however, effectively enhance the permittivity of the organic active layer and thereby reduce the Coulomb interaction. Using an analytical model it is demonstrated that even at a distance of 20 nm to the organic / inorganic interface of the nanostructure, the Coulomb interaction can be reduced by more than 15 %. The concept is implemented using P3HT:PCBM solar cells with integrated high-k nanoparticles (strontium titanate). It could be demonstrated that in comparison to a reference cell without integrated nanoparticles, the power conversion efficiencies could be improved by ~20 %.Comment: 11 pages, 7 figure

PENGARUH KONSENTRASI AGAR TERHADAP KARAKTERISTIK FISIKOKIMIA DAN ORGANOLEPTIK SELAI LEMBARAN APEL ANNA DAN ROSELLA

Anna apple and rosella jam is defined as jam which is made from sugar, Anna apple, and rosella. This product has a potential to be developed in slice form. The benefits of Anna apple and rosella jam slice are more practical to prepare, carry, stored, and minimize the risk of food contamination. Anna apple and rosella jam slice has compact texture, glossy and is not sticky on its package. Addition of hydrocolloid like agar is solution to get the desired slice jam characteristics. Use of agar can affect physicochemical and organoleptic Anna apple and rosella jam slice, therefore a research is needed to know the effects of agar’ s concentration. The methodology of this research was a randomized block design (RBD) with one factor, that is the concentration of agar (P), which consists of six levels 0.6% (P1); 0.7% (P2); 0.8% (P3); 0.9% (P4); 1.0% (P5); and 1.1% (P6) of Anna apple rosella pure. Repetition of the experiments were carried out four times. Agar concentration difference affected moisture content, pH, hardness, cohesiveness, adhesiveness, and organoleptic score (firmness). Higher concentration of agar caused a declined on moisture content and syneresis level, on the other hand hardness, adhesiveness, cohesiveness, and pH increased. Anna apple and rosella jam slice color was purplish red (L between 26.6-27.4; a* between 2.5-3.1; b* between 0.2-0.6; C between 2.5- 3.0; dan °h between 5.3-11.0°). Best concentration of agar was 1.0% which had moisture content 39.30%, pH 3.69, hardness score 965.221 g, cohesiveness 0.346, adhesiveness score -554.336 g.s, phenolic content 1183.6163 mg GAE/100 g, with sensory score of taste 4.9847, color 5.4659, and firmness 5.5306 with standard score 1-7

Solution-Processed Cu2_2S Nanostructures for Solar Hydrogen Production

Cu$_2$S is a promising solar energy conversion material due to its suitable optical properties, high elemental earth abundance, and nontoxicity. In addition to the challenge of multiple stable secondary phases, the short minority carrier diffusion length poses an obstacle to its practical application. This work addresses the issue by synthesizing nanostructured Cu$_2$S thin films, which enables increased charge carrier collection. A simple solution-processing method involving the preparation of CuCl and CuCl$_2$ molecular inks in a thiol-amine solvent mixture followed by spin coating and low-temperature annealing was used to obtain phase-pure nanostructured (nanoplate and nanoparticle) Cu$_2$S thin films. The photocathode based on the nanoplate Cu$_2$S (FTO/Au/Cu$_2$S/CdS/TiO$_2$/RuO$_x$) reveals enhanced charge carrier collection and improved photoelectrochemical water-splitting performance compared to the photocathode based on the non-nanostructured Cu$_2$S thin film reported previously. A photocurrent density of 3.0 mA cm$^{–2}$ at −0.2 versus a reversible hydrogen electrode (V$_{RHE}$) with only 100 nm thickness of a nanoplate Cu$_2$S layer and an onset potential of 0.43 V$_{RHE}$ were obtained. This work provides a simple, cost-effective, and high-throughput method to prepare phase-pure nanostructured Cu$_2$S thin films for scalable solar hydrogen production

Demulsification mechanism of asphaltene-stabilized water-in-oil emulsions by a polymeric ethylene oxide-propylene oxide demulsifier

The demulsification mechanism of asphaltene-stabilized water-in-toluene emulsions by an ethylene-oxide-propylene oxide (EO-PO) based polymeric demulsifier was studied. Demulsification efficiency was determined by bottle tests and correlated to the physicochemical properties of asphaltene interfacial films after demulsifier addition. From bottle tests and droplet coalescence experiments, the demulsifier showed an optimal performance at 2.3 ppm (mass basis) in toluene. At high concentrations, the demulsification performance deteriorated due to the intrinsic stabilizing capacity of the demulsifier, which was attributed to steric repulsion between water droplets. Addition of demulsifier was shown to soften the asphaltene film (i.e., reduce the viscoelastic moduli of asphaltene films) under both shear and compressional interfacial deformations. Study of the macrostructures and the chemical composition of asphaltene film at the toluene-water interface after demulsifier addition demonstrated gradual penetration of the demulsifier into the asphaltene film. Demulsifier penetration in the asphaltene film changed the asphaltene interfacial mobility and morphology, as probed with Brewster angle and atomic force microscopy

Problematic Stabilizing Films in Petroleum Emulsions: Shear Rheological Response of Viscoelastic Asphaltene Films and the Effect on Drop Coalescence

Adsorption of asphaltenes at the water-oil interface contributes to the stability of petroleum emulsions by forming a networked film that can hinder drop-drop coalescence. The interfacial microstructure can either be liquid-like or solid-like, depending on (i) initial bulk concentration of asphaltenes, (ii) interfacial aging time, and (iii) solvent aromaticity. Two techniques--interfacial shear rheology and integrated thin film drainage apparatus--provided equivalent interface aging conditions, enabling direct correlation of the interfacial rheology and droplet stability. The shear rheological properties of the asphaltene film were found to be critical to the stability of contacting drops. With a viscous dominant interfacial microstructure, the coalescence time for two drops in intimate contact was rapid, on the order of seconds. However, as the elastic contribution develops and the film microstructure begins to be dominated by elasticity, the two drops in contact do not coalescence. Such step-change transition in coalescence is thought to be related to the high shear yield stress (~10(4) Pa), which is a function of the film shear yield point and the film thickness (as measured by quartz crystal microbalance), and the increased elastic stiffness of the film that prevents mobility and rupture of the asphaltene film, which when in a solid-like state provides an energy barrier against drop coalescence

Exacerbated fires in Mediterranean Europe due to anthropogenic warming projected with non-stationary climate-fire models

The observed trend towards warmer and drier conditions in southern Europe is projected to continue in the next decades, possibly leading to increased risk of large fires. However, an assessment of climate change impacts on fires at and above the 1.5 °C Paris target is still missing. Here, we estimate future summer burned area in Mediterranean Europe under 1.5, 2, and 3 °C global warming scenarios, accounting for possible modifications of climate-fire relationships under changed climatic conditions owing to productivity alterations. We found that such modifications could be beneficial, roughly halving the fire-intensifying signals. In any case, the burned area is robustly projected to increase. The higher the warming level is, the larger is the increase of burned area, ranging from ~40% to ~100% across the scenarios. Our results indicate that significant benefits would be obtained if warming were limited to well below 2 °C