Thermally induced behavior of the K-exchanged erionite. A further step in understanding the structural modifications of the erionite group upon heating

Fibrous erionite is a naturally occurring zeolite considered to be highly carcinogenic upon inhalation, even more than crocidolite. Since no iron is typically present in erionite, its toxicity has been attributed to ion-exchanged Fe participating in Fenton chemistry. Recently, a study aimed at investigating possible fiber inactivation routes surprisingly showed that, despite having completely occluded all available pores with K ions, the erionite-Na sample preserved the property to upload Fe (II) within the structure. In this work, the thermal behavior of the K-exchanged erionite-Na was investigated by TG/ DSC and in situ XRPD analyses in order to provide relevant information for modeling the thermally induced behavior of the erionite group. Rietveld refinement results evidenced a general trend of cell parameters and volume with temperature similar to that observed for erionite-K from Rome (Oregon, USA). However, the dependence of Tdehydrand Tbreakfrom Si/Si+Al ratio observed in zeolites (high Si content favours a lower Tdehydrand a higher Tbreak) is not observed, possibly due to the effect of the relevant amount of large K ions dispersed within the erionite cage, acting as reinforcing blocks for the framework. Heating produces a progressive emptying of the Ca sites, common effect previously observed in erionite samples showing different chemistry. In addition, K1 s.s. remains unchanged evidencing the absence of any “internal ion exchange” process, whereas s.s. at K2 increases in the range 438-573 K and then slowly decreases in the range 700-1218 K. Both Rietveld and DSC data suggest the motion of K ions from OW sites toward the walls of the erionite cavity during dehydration

Primary cosmic ray spectrum in the 10 to the 12th power - 10 to the 16th power eV energy range from the NUSEX experiment

A primary cosmic ray spectrum was derived which fits both experimental multiple muon rates and the all-nucleon flux derived from the single muon intensities underground. In the frame of the interaction model developed by Gaisser, Elbert and Stanev, it is possible to reproduce NUSEX muon data with a primary composition in which the iron spectrum is only slightly flatter than the proton one. This result rules out the popular idea that the primary composition varies drastically with increasing energy, leading to the dominance of heavier nuclei at energies 10 to the 15th power to 10 to the 16th power eV

Results from KLOE at DAFNE

The KLOE experiment at the Frascati φ factory, Daφne, has collected ~500 pb -1, i.e. 1.5 × 10^9 φ decays. At the φ factory it is possible to select pure KL and KS beams. Although the integrated luminosity is insufficient for precision tests of the CP, T symmetries in kaon decays, a wide number of topics in kaon and hadronic physics are accessible from the largest sample of φ decays at rest collected so far. The cross section σ(e+e- --> π+π-γ) below 1 GeV, relevant for the precise evaluation of the muon magnetic moment, has been measured with a statistical accuracy better than 1%. For the KS, we obtained the ratio of the branching fractions Γ(KS --> π+π-(γ))/Γ(KS --> π0π0) = (2.239 +/- 0.003stat +/- 0.015syst), fully inclusive of the ππγ final state. The analysis of the ~20,000 KS semileptonic decays KS --> πeν is being finalized providing precise measurements of both, the KS semileptonic branching ratio, and Re x+, i.e. the ΔS = ΔQ rule violation parameter. For the KL, we obtained the ratio Γ(KL --> γγ)/Γ(KL --> π0π0π0) = (2.80 +/- 0.02stat +/- 0.02syst) × 10-3, of interest to Chiral Perturbation Theory (ChPT), as well as preliminary results on the branching ratios to other decay modes. In particular, our measurements of the semileptonic decays of both, neutral, and charged kaons will improve the precision of the CKM matrix element |Vus|, clarifying the present disagreement between different experiments. The φ radiative decays, both in scalar and pseudo-scalar mesons, have been analyzed giving new measurements of the ɛ - ɛ' mixing angle, and of the φ --> a0(980)γ, φ --> f0(980)γ branching ratios

Preliminary Design of a Remotely Piloted Aircraft System for Crop-Spraying on Vineyards

This paper describes the preliminary design of an innovative concept rotary-wing Unmanned Aircraft System (UAS) for precision agriculture and aerial spraying applications. Aerial spraying of plant protection products and pesticides shows open challenges in terms of performance and regulatory requirements. In particular*the focus here is on highlighting the advantages of the proposed solution in performing precise and expeditious interventions, coping with the spray drift problem (i.e. minimization of drift). Flight performances and agronomists' requirements are combined to define the mission and the aerial vehicle and spray system design

Avaliação da fertilidade dos solos do Distrito Federal.

O SNLCS tem procurado ampliar o alcance e a utilização prática, dos dados obtidos através dos levantamentos de solos que realiza. Prosseguindo as pesquisas que objetivam a elaboração do mapa de solos do Brasil a nível de reconhecimento, esta entidade vem complementando seus trabalhos com mapas de aptidão agrícola das terras, em relação com diferentes tipos de manejo e culturas. Dentro dos parâmetros usados para definir a aptidão agrícola dos solos, a fertilidade e o mais facilmente controlável e aquele cuja alteração modifica mais sensivelmente a produtividade das terras. Por outro lado, os mapas de aptidão, pela sua natureza, não mostram claramente as limitações de uso devido unicamente ao nível de fertilidade das terras. Tal informação é de grande importância ao estudo de viabilidade econômica de projetos agropecuários, por permitir estimar a necessidade de fertilizantes e corretivos para determinada área. A análise conjunta dos mapas de classificação e aptidão agrícola e ainda de uma avaliação da fertilidade dos solos, daria aos usuários dos trabalhos de levantamento uma visão mais completa dos recursos disponíveis, facilitando as decisões quanto ao tipo de exploração agrícola e ao sistema de manejo mais adequado em cada caso. O presente projeto propõe a complementação de cada trabalho de levantamento com uma avaliação e quantificação da fertilidade, cuja precisão e confiabilidade serão tanto maiores quanto maior for o nível de detalhe do levantamento de solos em que seja baseado.bitstream/item/62835/1/CNPS-BOL.-TEC.-74-80.pdf; bitstream/item/125962/1/Avaliacao-da-Fertilidade-dos-Solos-do-Distrito-Federal.pdfAcompanha 1 mapa, color. Escala 1:100.000

Kaon physics with the KLOE detector

In this paper we discuss the recent finalized analyses by the KLOE experiment at DA$\Phi$NE: the CPT and Lorentz invariance test with entangled $K^0 \bar{K}^0$ pairs, and the precision measurement of the branching fraction of the decay ${ K^+} \rightarrow \pi^+\pi^-\pi^+(\gamma)$. We also present the status of an ongoing analysis aiming to precisely measure the $K^{\pm}$ mass

High-statistics study of the low-energy cosmic-muons angular distribution - Results from MICRO

We present results from MICRO, a muon telescope with good angular resolution, which has collected more than 31·106 cosmic muons. Upper limits are given for the flux coming from point sources and for the periodic component from Cygnus X3

In Vitro Production of Calcified Bone Matrix onto Wool Keratin Scaffolds via Osteogenic Factors and Electromagnetic Stimulus

Pulsed electromagnetic field (PEMF) has drawn attention as a potential tool to improve the ability of bone biomaterials to integrate into the surrounding tissue. We investigated the effects of PEMF (frequency, 75 Hz; magnetic induction amplitude, 2 mT; pulse duration, 1.3 ms) on human osteoblast-like cells (SAOS-2) seeded onto wool keratin scaffolds in terms of proliferation, differentiation, and production of the calcified bone extracellular matrix. The wool keratin scaffold offered a 3D porous architecture for cell guesting and nutrient diffusion, suggesting its possible use as a filler to repair bone defects. Here, the combined approach of applying a daily PEMF exposure with additional osteogenic factors stimulated the cells to increase both the deposition of bone-related proteins and calcified matrix onto the wool keratin scaffolds. Also, the presence of SAOS-2 cells, or PEMF, or osteogenic factors did not influence the compression behavior or the resilience of keratin scaffolds in wet conditions. Besides, ageing tests revealed that wool keratin scaffolds were very stable and showed a lower degradation rate compared to commercial collagen sponges. It is for these reasons that this tissue engineering strategy, which improves the osteointegration properties of the wool keratin scaffold, may have a promising application for long term support of bone formation in vivo