Nitrification-denitrification in WSP: a mechanism for permanent nitrogen removal in maturation ponds

A pilot-scale primary maturation pond was spiked with 15N-labelled ammonia (15NH4Cl) and 15N labelled nitrite (Na15NO2), in order to improve current understanding of the dynamics of inorganic nitrogen transformations and removal in WSP systems. Stable isotope analysis of δ15N showed that nitrification could be considered as an intermediate step in WSP, which is masked by simultaneous denitrification, under conditions of low algal activity. Molecular microbiology analysis showed that denitrification can be considered a feasible mechanism for permanent nitrogen removal in WSP, which may be supported either by ammonia-oxidising bacteria (AOB) or by methanotrophs, in addition to nitrite-oxidising bacteria (NOB). However, the relative supremacy of the denitrification process over other nitrogen removal mechanisms (e.g., biological uptake) depends upon phytoplanktonic activity

Aligning physical elements with persons' attitude: an approach using Rasch measurement theory

Affective engineering uses mathematical models to convert the information obtained from persons' attitude to physical elements into an ergonomic design. However, applications in the domain have not in many cases met measurement assumptions. This paper proposes a novel approach based on Rasch measurement theory to overcome the problem. The research demonstrates that if data fit the model, further variables can be added to a scale. An empirical study was designed to determine the range of compliance where consumers could obtain an impression of a moisturizer cream when touching some product containers. Persons, variables and stimulus objects were parameterised independently on a linear continuum. The results showed that a calibrated scale preserves comparability although incorporating further variables

Zoneamento climático da Heveicultura no Brasil.

Para o zoneamento da aptidão climática da heveicultura no Brasil, considerou-se as exigências climáticas da espécie a ser cultivada e da principal doença que afeta a cultura. Neste trabalho, utilizou-se a temperatura média anual do ar, a deficiência hídrica no solo e a temperatura média do mês mais frio, como condicionantes do desempenho da cultura e da ocorrência de surtos epidêmicos do Microcyclus ulei (P. Henn) V. Arx., principal patógeno da seringueira no Brasil e causador do "mal-das-folhas". Considerando esses fatores, elaborou-se uma carta de aptidão climática da heveicultura no Brasil, baseada em isolinhas de temperatura, precipitação, e de outros fatores de interesse, estabelecendo-se, assim, as regiões brasileiras com condições climáticas aptas, restritas, marginais e inaptas para o cultivo comercial da seringueira.bitstream/CNPM/1254/1/d24_heveic_fin.pd

Lifetimes of ultralong-range strontium Rydberg molecules in a dense BEC

The lifetimes and decay channels of ultralong-range Rydberg molecules created in a dense BEC are examined by monitoring the time evolution of the Rydberg population using field ionization. Studies of molecules with values of principal quantum number, $n$, in the range $n=49$ to $n=72$ that contain tens to hundreds of ground state atoms within the Rydberg electron orbit show that their presence leads to marked changes in the field ionization characteristics. The Rydberg molecules have lifetimes of $\sim1-5\,\mu$s, their destruction being attributed to two main processes: formation of Sr$^+_2$ ions through associative ionization, and dissociation induced through $L$-changing collisions. The observed loss rates are consistent with a reaction model that emphasizes the interaction between the Rydberg core ion and its nearest neighbor ground-state atom. The measured lifetimes place strict limits on the time scales over which studies involving Rydberg species in cold, dense atomic gases can be undertaken and limit the coherence times for such measurements.Comment: 9 pages, 8 figure

Creation of Rydberg Polarons in a Bose Gas

We report spectroscopic observation of Rydberg polarons in an atomic Bose gas. Polarons are created by excitation of Rydberg atoms as impurities in a strontium Bose-Einstein condensate. They are distinguished from previously studied polarons by macroscopic occupation of bound molecular states that arise from scattering of the weakly bound Rydberg electron from ground-state atoms. The absence of a $p$-wave resonance in the low-energy electron-atom scattering in Sr introduces a universal behavior in the Rydberg spectral lineshape and in scaling of the spectral width (narrowing) with the Rydberg principal quantum number, $n$. Spectral features are described with a functional determinant approach (FDA) that solves an extended Fr\"{o}hlich Hamiltonian for a mobile impurity in a Bose gas. Excited states of polyatomic Rydberg molecules (trimers, tetrameters, and pentamers) are experimentally resolved and accurately reproduced with FDA.Comment: 5 pages, 3 figure

Theory of excitation of Rydberg polarons in an atomic quantum gas

We present a quantum many-body description of the excitation spectrum of Rydberg polarons in a Bose gas. The many-body Hamiltonian is solved with functional determinant theory, and we extend this technique to describe Rydberg polarons of finite mass. Mean-field and classical descriptions of the spectrum are derived as approximations of the many-body theory. The various approaches are applied to experimental observations of polarons created by excitation of Rydberg atoms in a strontium Bose-Einstein condensate.Comment: 14 pages, 9 figures. arXiv admin note: substantial text overlap with arXiv:1706.0371

Revision of the species of Melipona of the fuliginosa group (Hymenoptera, Apoidea, Apidae, Meliponini)

Três espécies são reconhecidas: Melipona (Michmelia) fuliginosa Lepeletier, 1836, de larga distribuição, do Suriname e Guiana Francesa até o sudeste do Brasil e noroeste da Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidado), endêmica do oeste da Amazônia, e M. (Michmelia) fallax sp. nov., do noroeste do Equador até a América Central. Melipona fuliginosa distingue-se pela pilosidade dos tergos metassomáticos II-V, tanto do macho como da operária, densa e plumosa, e pelo primeiro tarsômero da perna III do macho mais largo que longo. Em M. titania e M. fallax sp. nov., a pilosidade dos tergos II-V é escassa e simples, não-plumosa, e o primeiro tarsômero tão longo quanto largo ou mais longo que largo. Operárias de Melipona titania e M. fallax sp. nov. separam-se pela forma do penicilo, que é fortemente sinuoso em M. titania, e nos machos de M. fallax sp. nov. as órbitas internas dos olhos são paralelas, enquanto em M. titania as órbitas são convergentes embaixo. Novos registros geográficos, dados bionômicos e uma chave para identificação das espécies são apresentados. Adicionalmente, são feitos comentários sobre o padrão biogeográfico e sobre as glândulas tergais das rainhas.Three species are recognized: Melipona (Michmelia) fuliginosa Lepeletier, 1836, widely distributed, from Suriname and French Guiana to southeastern Brazil and northwestern Argentina, M. (Michmelia) titania Gribodo, 1893 (revalidated), endemic to western Amazon and M. (Michmelia) fallax sp. nov., from northwestern Ecuador to Central America. Melipona fuliginosa differs from the other species by the pilosity of metasomal terga II-V, dense and plumose, in both male and workers, and the first tarsomere of leg III of the male wider than long. In M. titania and M. fallax sp. nov., the pilosity of terga II-V is scarce and simple, non-plumose, and the first tarsomere of leg III of the male is as long as wide or longer. Workers of Melipona titania and M. fallax sp. nov. differ by the shape of the penicillum, which is strongly sinuous in M. titania, and in the males of M. fallax sp. nov. the internal orbits of the eyes are parallel, while in M. titania the orbits are convergent below. New geographic records, bionomic data and an identification key for the species are presented. In addition, comments are given on geographic patterns and tergal glands of the queens