Clicks and Cliques. Exploring the Soul of the Community

In the paper we analyze 26 communities across the United States with the objective to understand what attaches people to their community and how this attachment differs among communities. How different are attached people from unattached? What attaches people to their community? How different are the communities? What are key drivers behind emotional attachment? To address these questions, graphical, supervised and unsupervised learning tools were used and information from the Census Bureau and the Knight Foundation were combined. Using the same pre-processed variables as Knight (2010) most likely will drive the results towards the same conclusions than the Knight foundation, so this paper does not use those variables

The role of microstructure in fatigue crack initiation and propagation in 9-12Cr ferritic-martensitic steels

The present paper presents low-cycle fatigue results about cyclic behaviour, the evolution of the dislocation structure and the nucleation and propagation of microstructural cracks in commercial ferritic-martensitic steel AISI 410.Fil: Batista, Maria Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Hereñu, Silvina Andrea Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Alvarez, Iris. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentin

Specifically Adsorbed Ions in Hematite Flotation

Specifically adsorbed ions, such as calcium and magnesium in iron ore flotation, are ions that can chemically bind with the mineral surfaces and alter the surface properties. Calcium and magnesium are unavoidable in process water and their concentrations are increasing due to water recirculation and reagent additions. These ions are detrimental to the flotation process. Calcium has always been the main focus in research, yet we found that magnesium is more detrimental in flotation due to its smaller atomic size. Starch adsorption in iron ore flotation is key for the effective depression of hematite. It has been determined by flotation, zeta potential, and settling tests, that increasing calcium concentrations promote starch adsorption and reduce entrainment of hematite, whereas increasing magnesium concentrations greatly reduce the selectivity overall by promoting the adsorption of starch to everything in the slurry and resulting in lower selectivity

REVERSE CATIONIC FLOTATION OF HEMATITE

The reverse cationic flotation of hematite is the most common method to process hematite ores. The goal of this research is to understand the impact of fundamental water and surface effects to enable the optimization of the flotation process. At present, reverse cationic flotation is performed using a single chemical as both collector and frother. Excessive amounts of frother or collector should lead to diminished performance. This research investigates this phenomenon by replacing some of the collector with frothers. It was found that flotation recovery can be improved up to 2.5wt% via 10% replacement with methyl isobutyl carbinol (MIBC). Since most frothers are less expensive than the amine collector, there is a possibility of reducing cost of reagents and increasing profits in industry. There is a large body of literature on the impact of calcium on the flotation process. However, despite magnesium and calcium often being treated as interchangeable in literature and practice, magnesium’s smaller atomic size suggests that its behavior in flotation should be stronger. This research investigates the effect of calcium and magnesium in the adsorption of starch onto the hematite. We have found that initially both ions are beneficial to the process but as the magnesium concentrations increase, it becomes detrimental to flotation. These results make it clear that magnesium is not a one-for-one replacement of calcium in iron ore flotation, and should be accounted for and, if necessary, controlled separately. Lastly, the time it takes for the hematite to become fully hydrated may play a role in flotation. If the hydration of fresh surfaces takes place during the ½ to 2 hours that the xix hematite is expected to reside in the concentration process, then this could have a significant impact in flotation. In this research, the time scale of the hydration of pure hematite was determined to be on the order of 5 to 20 minutes, which tells us that in a plant-scale operation, it is very likely that the hematite is completely hydrated before it reaches flotation. These findings demonstrate improved understanding of reverse cationic flotation, which leads to a set of clear process recommendations

Mechanical topological insulator in zero dimensions

We study linear vibrational modes in finite isostatic Maxwell lattices, mechanical systems where the number of degrees of freedom matches the number of constraints. Recent progress in topological mechanics exploits the nontrivial topology of BDI class Hamiltonians in one dimenson and arising topological floppy modes at the edges. A finite frame, or zero-dimensional system, also exhibits a nonzero topological index according to the classification table. We construct mechanical insulating models in zero dimensions that complete the BDI classification in the available real space dimensions. We compute and interpret its nontrivial invariant Z2.N.L. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through The María de Maeztu Programme for Units of Excellence in R&D (Grant No. MDM-2014-0377). This work has been funded by MINECO Grant No. FIS2015-64886-C5-5-

Choroidal imaging by spectral domain-optical coherence tomography

AbstractDespite the fact that the choroid plays an important role in the structure and function of the eye, it has not been studied in detail in vivo. Improvements in optical coherence tomography (OCT) imaging technology allow the routine imaging of the choroid and deep optic nerve structures in most patients. As with any new technology, it needs validation in both healthy and diseased eyes. Reproducible measurements of choroidal and lamina cribrosa thickness are possible. Several variables such as age, axial length, and time of day, affect choroidal thickness and must be taken into account when interpreting data on choroidal thickness. Lamina cribrosa thickness appears to be affected by age as well but other factors need to be determined. Choroidal thickness may be used to differentiate between central serous chorioretinopathy (CSC), polypoidal choroidal vasculopathy (PCV) and exudative age-related macular degeneration (AMD). Enhanced depth imaging-optical coherence tomography (EDI-OCT) of the choroid may detect tumors not detectable by ultrasound. Studying the choroid may help us gain insight into the pathogenesis of several diseases such as AMD, CSC, glaucoma, posteriorly located choroidal tumors, and PCV among others

Deconstructing the Clinician: An Auto-Ethnographic Study

There is little research focused on uncovering bias in the music therapist. This study utilized autoethnography and was guided by a participatory action research (PAR) lens to explore a music therapist’s experience of and relation to internalized bias and interlocking systems of oppression, such as white supremacy, sexism and ableism. Autoethnography refers to a combination of autobiographical and ethnographic methods. PAR focuses on collective meaning making, redistributing harmful power dynamics, and societal change with a liberatory aim. While I (Nicole) was the primary participant and investigator in the research, Natalia was invited to the study as a co-investigator and participant. Natalia was asked to facilitate three music therapy sessions with myself as the client. We engaged in a reflexive process of collaboration with one another throughout the study. Data included recordings and transcripts of the music therapy sessions, our reflective writings, art, memories, and relevant literature. Data were analyzed through the continuous process of autoethnography. Findings are presented in narrative form, interwoven with writing from both Natalia and myself. This study may contribute to the growing body of research in the larger music therapy community regarding client experience, bias, and systems of oppression

Potential peptidic proteasome inhibitors by incorporation of an electrophilic trap based on amino acid derived α-substituted sulfonyl fluorides

Peptido sulfonyl fluoride derivatives were designed and synthesized containing a substituent on the alpha position (αPSFs) with respect to the sulfonyl fluoride electrophilic trap. The chemical reactivity of these α-substituted amino sulfonyl fluorides was studied and compared with the previously described β-substituted amino sulfonyl fluorides in order to get a deeper insight into the importance of the immediate structural environment of the sulfonyl fluoride moiety. Unfortunately, the poor solubility of the resulting αPSFs precluded a proper evaluation of their biological activity