Whitepaper on Super-weakly Interacting Massive Particles for Snowmass 2013

Super-weakly interacting massive particles produced in the late decays of weakly interacting massive particles (WIMPs) are generic in large regions of supersymmetric parameter space and other frameworks for physics beyond the standard model. If their masses are similar to that of the decaying WIMP, then they could naturally account for all of the cosmological dark matter abundance. Their astrophysical consequences and collider signatures are distinct and different from WIMP candidates. In particular, they could modify Big Bang Nucleosynthesis, distort the Cosmic Microwave Background, reduce galactic substructure and lower central densities of low-mass galaxies.Comment: 4 pages, 2 figures, white paper for Snowmass 201

Sterile neutrino dark matter bounds from galaxies of the Local Group

We show that the canonical oscillation-based (non-resonant) production of sterile neutrino dark matter is inconsistent at $>99$% confidence with observations of galaxies in the Local Group. We set lower limits on the non-resonant sterile neutrino mass of $2.5$ keV (equivalent to $0.7$ keV thermal mass) using phase-space densities derived for dwarf satellite galaxies of the Milky Way, as well as limits of $8.8$ keV (equivalent to $1.8$ keV thermal mass) based on subhalo counts of $N$-body simulations of M 31 analogues. Combined with improved upper mass limits derived from significantly deeper X-ray data of M 31 with full consideration for background variations, we show that there remains little room for non-resonant production if sterile neutrinos are to explain $100$% of the dark matter abundance. Resonant and non-oscillation sterile neutrino production remain viable mechanisms for generating sufficient dark matter sterile neutrinos.Comment: 10 pages, 4 figures, 2 tables. Submitted to PR

Improving the sustainability of food supply chains through circular economy practices – a qualitative mapping approach

Purpose: The purpose of this paper is to present a methodological approach to support qualitative analysis of waste flows in food supply chains. The methodological framework introduced allows the identification of circular food waste flows that can maximise the sustainability of food supply chains. Design/methodology/approach: Following a qualitative approach, circular economy perspectives are combined with core industrial ecology concepts in the specification of a standardised analytical method to map food waste flows and industrial synergies across a supply chain. Findings: The mapped waste flows and industrial linkages depict two time-related scenarios: (1) current scenarios showing the status quo of existing food waste flows, and (2) future scenarios pointing out circular flows along the supply chain. The future scenarios inform potential alternatives to take waste flows up the food waste hierarchy. Research limitations/implications: The qualitative approach does not allow generalisations of findings out of the scope of the study. The framework is intended for providing focussed analysis, case by case. Future research involving mixed methods where quantitative approaches complement the qualitative perspectives of the framework would expand the analytical perspective. Originality/value: The framework provides a relatively low-cost and pragmatic method to identify alternatives to minimise landfill disposals and improve the sustainability of food supply chains. Its phased methodology and standardised outcomes serve as a referential basis to inform not only comparative analysis, but also policymaking and strategic decisions aimed at transforming linear food supply chains into circular economy ecosystems

Charge-discharge characteristics of textile energy storage devices having different PEDOT:PSS ratios and conductive Yarns configuration

Conductive polymer PEDOT:PSS, sandwiched between two conductive yarns, has been proven to have capacitive behavior in our textile energy storage devices. Full understanding of its underlying mechanism is still intriguing. The effect of the PEDOT to PSS ratio and the configuration of the electrode yarns are the focus of this study. Three commercial PEDOT:PSS yarns, Clevios P-VP-AI-4083, Ossila AI 4083, and Orgacon ICP 1050, as well as stainless steel and silver-coated polybenzoxazole (Ag/PBO) yarns, in various combinations, were used as solid electrolytes and electrodes, respectively. Analyses with NMR, ICP-OES, TGA, and resistivity measurement were employed to characterize the PEDOT:PSS. The device charge-discharge performance was measured by the Arduino microcontroller. Clevios and Ossila were found to have identical characteristics with a similar ratio, that is, 1:5.26, hence a higher resistivity of 1000 Ω.cm, while Orgacon had a lower PEDOT to PSS ratio, that is, 1:4.65, with a lower resistivity of 0.25⁻1 Ω.cm. The thermal stability of PEDOT:PSS up to 250 °C was proven. Devices with PEDOT:PSS having lower conductivity, such as Clevios P-VP-AI-4083 or Ossila AI 4083, showed capacitive behavior. For a better charge-discharge profile, it is also suggested that the PEDOT to electrode resistance should be low. These results led to a conclusion that a larger ratio of PEDOT to PSS, having higher resistivity, is more desirable, but further research is needed

Deposition Mechanism and Properties of Thin Polydopamine Films for High Added Value Applications in Surface Science at the Nanoscale

Polydopamine films have been introduced by Messersmith et al. as a possible “versatile” surface functionalization method allowing to coat the surface of almost all known materials even superhydrophobic surfaces. These new kinds of coatings also confer a plethora of functionalities to the coated materials owing to the complex chemistry of the catechol quinone moieties present on the surface of polydopamine. These coatings may hence become an interesting alternative to established surface coatings like self-assembled monolayers and polyelectrolyte multilayered films. In this review, we describe the knowledge acquired in the last 3 years about the deposition mechanisms of polydopamine films, their properties, and various applications in surface science at the nanoscale.Fonds Europeen de Developpement Economique et Regional (Chaptochem Project 2009-02-039-35

Star Formation Under the Outflow: The Discovery of a Non-Thermal Jet from OMC-2 FIR 3 and its Relationship to the Deeply Embedded FIR 4 Protostar

We carried out multiwavelength (0.7-5 cm), multiepoch (1994-2015) Very Large Array (VLA) observations toward the region enclosing the bright far-IR sources FIR 3 (HOPS 370) and FIR 4 (HOPS 108) in OMC-2. We report the detection of 10 radio sources, seven of them identified as young stellar objects. We image a well-collimated radio jet with a thermal free-free core (VLA 11) associated with the Class I intermediate-mass protostar HOPS 370. The jet presents several knots (VLA 12N, 12C, 12S) of non-thermal radio emission (likely synchrotron from shock-accelerated relativistic electrons) at distances of ~7,500-12,500 au from the protostar, in a region where other shock tracers have been previously identified. These knots are moving away from the HOPS 370 protostar at ~ 100 km/s. The Class 0 protostar HOPS 108, which itself is detected as an independent, kinematically decoupled radio source, falls in the path of these non-thermal radio knots. These results favor the previously proposed scenario where the formation of HOPS 108 has been triggered by the impact of the HOPS 370 outflow with a dense clump. However, HOPS 108 presents a large proper motion velocity of ~ 30 km/s, similar to that of other runaway stars in Orion, whose origin would be puzzling within this scenario. Alternatively, an apparent proper motion could result because of changes in the position of the centroid of the source due to blending with nearby extended emission, variations in the source shape, and /or opacity effects.Comment: 16 pages, 4 figures, accepted for publication in The Astrophysical Journa