Parâmetros de consistência dos solos: seu estudo e avaliação ao longo de perfis pedológicos para aplicação na engenharia rodoviária.

Foram estudados os limites de consistencia dos solos ao longo de perfis pedologicos para aplicacao na engenharia rodoviaria. As amostras foram coletadas de horizontes superficiais e subsuperficiais em dez perfis de diferentes classes de solos. As analises das amostras foram efetuadas em laboratorio seguindo a rotina usada em pedologia. Foram determinados tambem, para cada horizonte considerado, os limites de liquidez(LL), plasticidade(LP) e contracao(LC); o indice de plasticidade(IP), e o grau de contracao(GC). A analise dos dados de laboratorio, aliada as observacoes de campo, demonstrou haver uma correlacao empirica, entre as razoes "% de argila/IP" ou "IP//% de argila" e as propriedades dos solos considerados quanto a conservacao das estradas, no caso dossolos com mais de 35% de argila no horizonte B. Essas relacoes poderiam funcionar como indicadores das qualidades desses solos para a implantacao de rodovias. Obteve-se tambem uma certa evidencia neste sentido, para esses mesmos solos, atraves de graficos elaborados para cada perfil.bitstream/item/62536/1/CNPS-BOL.-PESQ.-13-82.pd

Synthesis, Photochemical, and Redox Properties of Gold(I) and Gold(III) Pincer Complexes Incorporating a 2,2′:6′,2″-Terpyridine Ligand Framework

Reaction of [Au(C6F5)(tht)] (tht = tetrahydrothiophene) with 2,2′:6′,2″-terpyridine (terpy) leads to complex [Au(C6F5)(η1-terpy)] (1). The chemical oxidation of complex (1) with 2 equiv of [N(C6H4Br-4)3](PF6) or using electrosynthetic techniques affords the Au(III) complex [Au(C6F5)(η3-terpy)](PF6)2 (2). The X-ray diffraction study of complex 2 reveals that the terpyridine acts as tridentate chelate ligand, which leads to a slightly distorted square-planar geometry. Complex 1 displays fluorescence in the solid state at 77 K due to a metal (gold) to ligand (terpy) charge transfer transition, whereas complex 2 displays fluorescence in acetonitrile due to excimer or exciplex formation. Time-dependent density functional theory calculations match the experimental absorption spectra of the synthesized complexes. In order to further probe the frontier orbitals of both complexes and study their redox behavior, each compound was separately characterized using cyclic voltammetry. The bulk electrolysis of a solution of complex 1 was analyzed by spectroscopic methods confirming the electrochemical synthesis of complex 2

Infected Vertebroplasty Due to Uncommon Bacteria Solved Surgically: A Rare and Threatening Life Complication of a Common Procedure

Case report. OBJECTIVE: The aim of this work is to describe a case of infected vertebroplasty due to uncommon bacteria solved surgically with 2 years of follow-up and to discuss 6 other cases found in literature. SUMMARY OF BACKGROUND DATA: Vertebroplasty is a well-known and useful technique for the treatment of painful osteoporotic vertebral fractures. Complications, such as cord or root compression or pulmonary embolisms, are infrequent and are mainly related with the frequent escape of cement throughout the vertebral veins. Infection is even more rare, but when it occurs is difficult to manage and can be a life-threatening complication. METHODS: A 63-year-old-man had a spondylitis of L2 after vertebroplasty. The patient was initially managed with antibiotics without clinical improvement. Surgical treatment by anterior debridement and anterior and posterior stabilization was done. The bacteria isolated from the intraoperative cultures were Serratia marcescens, Stenotrophomonas maltophilia, and Burkholderia cepacia. After surgery, the patient was treated with antibiotics for 3 month. RESULTS: After 2 years of follow-up, the patient was free of pain, without signs of infection, and a correct fusion was achieved. CONCLUSION: When facing an infected vertebroplasty, initial conservative treatment with needle biopsy culture and antibiotic administration are a rational option to start. If this treatment fails, surgical debridement is then indicated in order to remove the infected tissue and the acrylic cement and to stabilize the spine. Although this can be an effective treatment, it could be a difficult and hazardous surgical procedure

Exclusive measurement of coherent eta photoproduction from the deuteron

Coherent photoproduction of eta mesons from the deuteron has been measured from threshold up to incident photon energies of 750 MeV using the photon spectrometer TAPS at the tagged photon facility at the Mainz microtron MAMI. For the first time, differential coherent cross sections have been deduced from the coincident detection of the eta meson and the recoil deuteron. A missing energy analysis was used for the suppression of background events so that a very clean identification of coherent eta-photoproduction was achieved. The resulting cross sections agree with previous experimental results except for angles around 90 deg in the photon-deuteron cm-system where they are smaller. They are compared to various model calculations.Comment: 4 pages, 4 figure

5G Radio Resource Allocation for Communication and Computation Offloading

Edge computing is envisioned as a key enabler in future cellular networks by bringing the computing, networking and storage resources closer to the end users and enabling offloading for computation-intensive or latency-critical tasks coming from the emerging 5G/6G applications. Such technology also introduces additional challenges when it comes to deciding when to offload or not since the dynamic wireless environment plays a significant role in the overall communication and computation costs when offloading workload to the nearby edge nodes. In this paper, we focus on the communication cost in computation offloading via wireless channels, by formulating an α -fair utility-based radio resource allocation (RRA) problem tailored for offloading in a multi-user urban scenario where the uplink connection is the main focus. We begin by modeling the wireless channel with large- and small-scale fading at both lower and millimetre-wave frequencies, followed by data rate calculation based on 3GPP for a more realistic approach. Then, while assessing the fairness of the RRA, we simulate the resource allocation framework while taking into account both users who need to offload and users who are only interested in high downlink data rates. Simulation results show that the weighted proportional fairness method adapted for computation offloading can provide a good trade-off between fairness and performance compared to other benchmark schemes

Neutron polarizabilities investigated by quasi-free Compton scattering from the deuteron

Measuring Compton scattered photons and recoil neutrons in coincidence, quasi-free Compton scattering by the neutron has been investigated at MAMI (Mainz) at $theta^{lab}_\gamma=136^o$ in an energy range from 200 to 400 MeV. From the data a polarizability difference of $\alpha_n - \beta_n = 9.8 \pm 3.6(stat)^{+2.1}_{-1.1}(syst)\pm 2.2(model)$ in units of $10^{-4}fm^3$ has been determined. In combination with the polarizability sum $\alpha_n+\beta_n= 15.2\pm 0.5$ deduced from photo absorption data, the neutron electric and magnetic polarizabilities, $\alpha_n=12.5\pm 1.8(stat)^{+1.1}_{-0.6}(syst)\pm 1.1(model)$ and $\beta_n = 2.7\mp 1.8(stat)^{+0.6}_{-1.1}(syst)\mp 1.1(model)$, are obtained

Quasi-free Compton Scattering and the Polarizabilities of the Neutron

Differential cross sections for quasi-free Compton scattering from the proton and neutron bound in the deuteron have been measured using the Glasgow/Mainz tagging spectrometer at the Mainz MAMI accelerator together with the Mainz 48 cm $\oslash$ $\times$ 64 cm NaI(Tl) photon detector and the G\"ottingen SENECA recoil detector. The data cover photon energies ranging from 200 MeV to 400 MeV at $\theta^{LAB}_\gamma=136.2^\circ$. Liquid deuterium and hydrogen targets allowed direct comparison of free and quasi-free scattering from the proton. The neutron detection efficiency of the SENECA detector was measured via the reaction $p(\gamma,\pi^+ n)$. The "free" proton Compton scattering cross sections extracted from the bound proton data are in reasonable agreement with those for the free proton which gives confidence in the method to extract the differential cross section for free scattering from quasi-free data. Differential cross sections on the free neutron have been extracted and the difference of the electromagnetic polarizabilities of the neutron have been obtained to be $\alpha-\beta= 9.8\pm 3.6(stat){}^{2.1}_1.1(syst)\pm 2.2(model)$ in units $10^{-4}fm^3$. In combination with the polarizability sum $\alpha +\beta=15.2\pm 0.5$ deduced from photoabsorption data, the neutron electric and magnetic polarizabilities, $\alpha_n=12.5\pm 1.8(stat){}^{+1.1}_{-0.6}\pm 1.1(model)$ and $\beta_n=2.7\mp 1.8(stat){}^{+0.6}_{-1.1}(syst)\mp 1.1(model)$ are obtained. The backward spin polarizability of the neutron was determined to be $\gamma^{(n)}_\pi=(58.6\pm 4.0)\times 10^{-4}fm^4$