Activated lignin‒chitosan extruded blends for efficient adsorption of methylene blue

This work investigates the production of activated lignin-chitosan extruded (ALiCE) pellets with controlled particle size distribution (almost spherical: dp ~500‒1000µm) for efficient methylene blue adsorption. The novel preparation method employed in this study successfully produced activated lignin-chitosan pellets. Structural and morphological characterizations were performed using BET, FTIR and SEM-EDX analyses. The influence of contact time, solution pH, ionic strength, initial adsorbate concentration and desorption studies was investigated. The experimental data fitted well with the Langmuir isotherm (R2 = 0.997), yielding a maximum adsorption capacity of 36.25mg/g. The kinetic data indicated that methylene blue (MB) adsorption onto ALiCE can be represented by the pseudo second-order-model with intraparticle processes initially controlling the process of MB adsorption. Overall, these results indicate that the novel ALiCE offers great potential for removing cationic organic pollutants from rivers and streams.

Efficient Blue Electroluminescence Using Quantum-Confined Two-Dimensional Perovskites

Solution-processed hybrid organic–inorganic lead halide perovskites are emerging as one of the most promising candidates for low-cost light-emitting diodes (LEDs). However, due to a small exciton binding energy, it is not yet possible to achieve an efficient electroluminescence within the blue wavelength region at room temperature, as is necessary for full-spectrum light sources. Here, we demonstrate efficient blue LEDs based on the colloidal, quantum-confined 2D perovskites, with precisely controlled stacking down to one-unit-cell thickness (n = 1). A variety of low-k organic host compounds are used to disperse the 2D perovskites, effectively creating a matrix of the dielectric quantum wells, which significantly boosts the exciton binding energy by the dielectric confinement effect. Through the Förster resonance energy transfer, the excitons down-convert and recombine radiatively in the 2D perovskites. We report room-temperature pure green (n = 7–10), sky blue (n = 5), pure blue (n = 3), and deep blue (n = 1) electroluminescence, with record-high external quantum efficiencies in the green-to-blue wavelength region.

Agreed-upon procedures report on the City of Blue Grass, Iowa for the period July 1, 2014 through June 30, 2015

Agreed-upon procedures report on the City of Blue Grass, Iowa for the period July 1, 2014 through June 30, 2015

Le Blue Straggler Stars e le popolazioni multiple in quattro ammassi globulari galattici

In questo elaborato viene presentato lo studio fotometrico di quattro ammassi globulari galattici. I target di questa Tesi fanno parte della HST UV Legacy Survey degli ammassi globulari galattici (Piotto et al. 2015). Nell'ambito di questa survey sono stati osservati, in modo omogeneo, 57 ammassi globulari galattici con il telescopio spaziale Hubble e la camera WFC3, in tre bande fotometriche ultraviolette e blu. Un dataset così composto è adatto a numerosi scopi, tra cui lo studio delle popolazioni calde come le BSS e delle popolazioni multiple. Sono stati selezionati quattro ammassi particolarmente popolosi e tra i più densi del campione, allo scopo di mettere a punto indicatori di evoluzione dinamica e comprendere il ruolo di quest'ultima sulle proprietà delle popolazioni multiple presenti nei sistemi selezionati. Lo studio dell'evoluzione dinamica è stato effettuato tramite la distribuzione radiale delle BSS (Blue Straggler Stars), che è stato dimostrato esserne un efficiente indicatore (Ferraro et al. 2012). I risultati ottenuti evidenziano chiaramente che tutti gli ammassi selezionati si trovano in fasi avanzate di evoluzione dinamica, come suggerito dall'alta densità che li caratterizza. Anche lo studio delle proprietà delle popolazioni multiple, ovvero sottopopolazioni con differenti abbondanze chimiche di elementi leggeri, la cui presenza è stata recentemente osservata negli ammassi globulari, è stato effettuato tramite lo studio della loro distribuzione radiale. Tra i quattro casi analizzati, soltanto M 15 ha mostrato una separazione significativa tra le distribuzioni radiali delle due popolazioni.

Abbondanze chimiche delle Blue Straggler Stars dell'ammasso aperto NGC 188

My Thesis work is aimed at searching for evidence of CO-depletion in the atmosphere of these objects. To this end, I am analyzing high-resolution spectra recently acquired with the spectrograph HDS at the Subaru Telescope. The global sample is composed of 5 BSSs with hot WD companions, 3 additional binary BSSs with no a significant far-UV excess, and one "normal" stars (along the RGB star) needed for comparison. The analysis will provide us with the surface chemical abundances (especially of C and O) of the target stars. The final goal is to verify the expected {chemical signature} and put constraints on its characteristic time scale (for instance, a positive detection in the 5 BSSs with hot companions and a non-detection in the other 3 binary BSSs would imply that CO-depletion is a transient phenomenon, lasting approx 300 Myr only). The analysis will also provide us with the rotational velocities of each target, thus allowing to investigate their kinematical properties and shed new light on their evolutionary path.

Black and Blue: Exploring Racial Bias and Law Enforcement in the Killings of Unarmed Black Male Civilians

In late 2014, a series of highly publicized police killings of unarmed Black male civilians in the United States prompted large-scale social turmoil. In the current review, we dissect the psychological antecedents of these killings and explain how the nature of police work may attract officers with distinct characteristics that may make them especially well-primed for negative interactions with Black male civilians. We use media reports to contextualize the precipitating events of the social unrest as we ground our explanations in theory and empirical research from social psychology and industrial and organizational (I/O) psychology. To isolate some of the key mechanisms at play, we disentangle racial bias (e.g., stereotyping processes) from common characteristics of law enforcement agents (e.g., social dominance orientation), while also addressing the interaction between racial bias and policing. By separating the moving parts of the phenomenon, we provide a more fine-grained analysis of the factors that may have contributed to the killings. In doing so, we endeavor to more effectively identify and develop solutions to eradicate excessive use of force during interactions between “Black” (unarmed Black male civilians) and “Blue” (law enforcement).

The Ocean Economic Statistical System of China and Understanding of the Blue Economy

The ocean and its resources are increasingly seen as indispensable in addressing the multiple challenges the planet is facing in the decades to come. It has never been easy to quantify this particular sector of the economy, in any country, given the lack of a detailed, centralized data base with adequate specifics covering the necessary sectors, this article aims to compare the existing ocean economy statistical systems, especially Asia-Pacific, American and European countries, in order to overcome the deficiencies with regard to the diversity of definitions and statistical representations of ocean sectors, establish the standard statistical system and compile data for the global ocean economy.

Measurement of the Ocean Economy From National Income Accounts to the Sustainable Blue Economy

The widespread efforts to incorporate the economic values of oceans into national income accounts have reached a stage where coordination of national efforts is desirable. A symposium held in 2015 began this process by bringing together representatives from ten countries. The symposium concluded that a definition of core ocean industries was possible but beyond that core the definition of ocean industries is in flux. Better coordination of ocean income accounts will require addressing issues of aggregation, geography, partial ocean industries, confidential, and imputation is also needed. Beyond the standard national income accounts, a need to incorporate environmental resource and ecosystem service values to gain a complete picture of the economic role of the oceans was identified. The U.N. System of Environmental and Economic Accounts and the Experimental Ecosystem Service Accounts provide frameworks for this expansion. This will require the development of physical accounts of environmental assets linked to the economic accounts as well as the adaptation of transaction and welfare based economic valuation methods to environmental resources and ecosystem services. The future development of ocean economic data is most likely to require cooperative efforts at development of metadata standards and the use of multiple platforms of opportunity created by policy analysis, economic development, and conservation projects to both collect new economic data and to sustain ocean economy data collection into the future by building capacity in economic data collection and use..