Ricci almost solitons

We introduce a natural extension of the concept of gradient Ricci soliton: the Ricci almost soliton. We provide existence and rigidity results, we deduce a-priori curvature estimates and isolation phenomena, and we investigate some topological properties. A number of differential identities involving the relevant geometric quantities are derived. Some basic tools from the weighted manifold theory such as general weighted volume comparisons and maximum principles at infinity for diffusion operators are discussed

Study of microring nonlinearities in silicon photonics for neuromorphic computing

We analyze a theoretical and experimental reservoir computing architecture based on an add-drop silicon micror- ing resonator. We test it with different datasets, including the recognition of flowers from the IRIS dataset.The information is transferred to the ring by means of a high power (>10 mW) pump signal which generates non- linearities affecting a low-power continuous wave signal acting as a probe. The experimental setup was also simulated employing a time domain model [1] of the non-linear response of the ring to assess the physical limit of the pump powe

New sp3 diphosphine-based rhodium catalysts for the asymmetric conjugate addition of aryl boronic acids to 3-azaarylpropenones

Different chiral diphosphine ligands were successfully applied to the rhodium catalyzed asymmetric conjugate addition of differently substituted boronic acids to 3-azaarylpropenones containing both pyridinyl and imidazolyl cores. Atropoisomeric (S)-TetraMe-BITIANP (L1) and (S)-BITIANP (L2), together with ligands bearing a mixed chirality as (S,S,Sax)-DIOPHEP (L3), (R,Rax)-ISAPHOS C1 (L4) and (S,Rax,Rax)-ISAPHOS C2 (L5), and the ones containing a stereogenic sp3 carbon ((R,R)-ZEDPHOS L6, (R,R)-EPHOS L8 and their derivatives L7 and L9) have been employed as source of chirality in rhodium complexes. Among this last class of diphosphines, the new phosphorus-based ligand called (R,R)-EPHOS (L8) has been synthesized and employed for the first time as a chiral ligand in rhodium complex for its catalytic activity. Computational studies suggested a cis coordination with a wide bite angle. When applied to the asymmetric conjugate addition of phenyl boronic acid to 3-azaarylpropenone 1, the catalytic system bearing L8 afforded the product 1a in a remarkable 94% e.e. in THF

Farinha de ossos como fonte de fósforo para a cultura da cana-de-açúcar forrageira

Phosphate fertilizers of organic origin may represent a viable alternative for the replacement of mineral fertilizers in the nutrition of crops such as forage sugarcane. This study aimed to investigate the effects of phosphate fertilization with bone meal and single superphosphate on the concentration of phosphorus (P) in the plant tissue, total soluble solids and yield aspects of forage sugarcane. A complete randomized block design was used, in a 2 × 5 factorial scheme, with four replicates. The treatments consisted of combining two phosphorus sources (single superphosphate and bone meal) and five P2O5 doses (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, 150 kg ha-1 and 200 kg ha-1). Sugarcane plants fertilized with the addition of bone meal showed an increase in height and number of nodes (13 % and 15 %, respectively), when compared to the mineral fertilization with single superphosphate. The sugarcane attributes, in response to the P2O5 doses, were described by quadratic functions. The dose of 95.80 kg ha-1 of P2O5 in the bone meal led to the highest concentration of P in the plant tissue (3.60 g kg-1). The comparison between the sources of P at the doses of 100 kg ha-1 and 150 kg ha-1 of P2O5 showed that the total soluble solids content was 8.62 % and 13.84 % higher, respectively, in plants fertilized with bone meal. KEYWORDS: Saccharum officinarum, organic fertilizer, phosphate, mineral plant nutrition.Adubos fosfatados de origem orgânica podem apresentar-se como alternativas viáveis para a substituição de adubos minerais na nutrição de culturas como a cana-de-açúcar forrageira. Objetivou-se investigar os efeitos da adubação fosfatada com farinha de ossos e superfosfato simples sobre a concentração de fósforo (P) no tecido vegetal, sólidos solúveis totais e aspectos produtivos da cana-de-açúcar forrageira. Utilizou-se o delineamento experimental de blocos casualizados, em esquema fatorial 2 × 5, com quatro repetições, sendo os tratamentos compostos pela combinação de duas fontes de fósforo (superfosfato simples e farinha de ossos) e cinco doses de P2O5 (0 kg ha-1, 50 kg ha-1, 100 kg ha-1, 150 kg ha-1 e 200 kg ha-1). A adubação com farinha de ossos incrementou a altura e o número de nós da cana-de-açúcar em 13 % e 15 %, respectivamente, quando comparada à adubação mineral com superfosfato simples. Os atributos da cana-de-açúcar, em resposta às doses de P2O5, foram descritos por funções quadráticas. A dose de 95,80 kg ha-1 de P2O5 na fonte farinha de ossos proporcionou a maior concentração de P no tecido vegetal (3,60 g kg-1). Comparando-se as fontes de P propostas nas doses de 100 kg ha-1 e 150 kg ha-1 de P2O5, observou-se que o teor de sólidos solúveis totais foi 8,62 % e 13,84 % maior, respectivamente, em plantas adubadas com farinha de osso. PALAVRAS-CHAVE: Saccharum officinarum, adubo orgânico, fosfato, nutrição mineral de plantas

Targeting Policies for Multidimensional Poverty and Social Fragility Relief Among Migrants in Italy, Using F-FOD Analysis

In this paper, we apply the novel Fuzzy First-Order Dominance (F-FOD) methodology to rank migrant subpopulations in Lombardy (Italy), in terms of multidimensional poverty and social fragility, for the year 2014, with the purpose to possibly provide useful support to policy-makers, in targeting relief interventions from poverty and discomfort. The F-FOD methodology allows for the direct comparison of different distributions of poverty and fragility, assessed by means of suitable ordinal multi-indicator systems, so extending to this more complex setting, the usual univariate first-order dominance criterion. It also provides complimentary “incomparability” scores, to assess to what extent the final rankings are reliable or instead forcing. It turns out that the levels of poverty and fragility of migrant subpopulations are quite different and, in particular, that the time since migrations has a key impact, on the identification of most critical cases, which typically involve recently migrated people. Evidence also emerges that the temporal poverty/fragility trajectories of migrants, distinguished by country of origin, follow different paths, suggesting how policy interventions must be properly, and differently, tuned to be effective

Addressing experimental self-generation of frequency combs in III-V/SiN hybrid integrated tunable lasers

We present experimental results featuring the self-generation of optical frequency combs in a III-V/SiN hybrid integrated laser with a frequency selective mirror. We model the laser through a set of time-delayed algebraic equations accounting for longitudinal mode competition, non-zero alpha factor and the narrowband SiN mirror. We are able to produce frequency combs matching the experimental case in terms of bandwidth, free-spectral range and optical frequency spectrum. Supported by our model, we demonstrate that the optical frequency combs occur when the laser becomes CW unstable due to the resonance between the relaxation oscillation frequency and the frequency separation between cavity modes, and efficient four-wave mixing allows for the locking mechanism between optical lines. The comb is characterized by both amplitude and frequency modulatio

Low Energy Houses Heated By Biomass Boilers: Optimization Of The Heating System Control Strategy By Means Of Dynamic Simulation

The aim of this work is to analyze the energetic performance of a low energy house, situated in the region of Lower Austria (48° 11’ N, 15° 5’ E), by means of dynamic building simulation and on-site monitoring. According to the Austrian regulations, the annual heat demand of a low energy house is below 50 kWh•m2•yr-1. The building under study is a pre-fabricated house manufactured by an Austrian company. It has highly insulated walls made of lightweight materials and triple glazed windows. Indoor air quality is ensured by a ventilation system equipped with a heat recovery unit. The living space is heated by a 6 kW pellet boiler supplying hot water to a floor heating system. The house, inhabited by two people, is currently monitored in the frame of the BioMaxEff project, a European project aiming at the demonstration of biomass boilers in real life conditions. Parameters describing the boiler operation (water flow rate, inlet and outlet water temperature, pellet consumption etc.) as well as outdoor and indoor temperatures are registered continuously during the whole heating season. A coupled simulation of the building and its energy systems has been performed in a dynamic simulation environment (TRNSYS). First, the building envelope and the internal heat gains have been analyzed to calculate the annual heat demand, the annual peak load and the duration of the heating season. Second, the heating system has been added to simulation, including all its components and its control unit. The boiler has been simulated with the “Type 869” boiler model, which describes accurately the performance of pellet boilers. The model has been calibrated and validated with reference to laboratory data and successively integrated in the TRNSYS simulation. A new TRNSYS component has been programmed to simulate the heating system control unit, according to the specifications of the manufacturing company. Interviews with the house owner informed about the settings of the control strategy. Simulation results reveal that the boiler is slightly undersized and cannot completely fulfil the heat demand of the house. Moreover, the settings imposed in the heating system control unit are not adequate to maintain a comfortable indoor temperature during the whole day. These results have been confirmed by the data registered during on-site monitoring. To conclude the study, some improvements of the system control strategy have been proposed. In particular we suggest to adjust the system’s heating curve and the night setback temperature. By taking advantage of the thermal inertia of the floor heating system, the new control strategy improves the indoor comfort

Constraints on mediator-based dark matter and scalar dark energy models using √s = 13 TeV pp collision data collected by the ATLAS detector

Constraints on selected mediator-based dark matter models and a scalar dark energy model using up to 37 fb−1√s = 13 TeV pp collision data collected by the ATLAS detector at the LHC during 2015-2016 are summarised in this paper. The results of experimental searches in a variety of final states are interpreted in terms of a set of spin-1 and spin-0 single-mediator dark matter simplified models and a second set of models involving an extended Higgs sector plus an additional vector or pseudo-scalar mediator. The searches considered in this paper constrain spin-1 leptophobic and leptophilic mediators, spin-0 colour-neutral and colour-charged mediators and vector or pseudo-scalar mediators embedded in extended Higgs sector models. In this case, also √s = 8 TeV pp collision data are used for the interpretation of the results. The results are also interpreted for the first time in terms of light scalar particles that could contribute to the accelerating expansion of the universe (dark energy)