Particle cluster sizing in downer units: An applicable across downer scale methodology

Data analysis from downer requires a comprehensive methodology for setting the data baseline. This can be accomplished using solid mass balances as proposed by A. Lanza et al (1). This analysis involves an iterative calculation. Each signal baseline is defined as, X+ n sx where X is the signal average; sx is the signal standard deviation; and “n” is a baseline parameter (2). By using this methodology the noise resulting from secondary reflection is eliminated and all valuable data is kept in the time series. More than 500 experiments with more than 50 million data record were obtained using two independent gas-solid circulating fluidized bed downer units of 3 m height and different diameters (1 inch ID and 2 inch ID). The solid used was a FCC catalyst with a mean particle diameter of 84.42 µm and a particle density of 1,722 kg/m^3. Measurements were effected using a CREC-GS-Optiprobe, an optical sensor equipped with a GRIN lens. This lens forms a 118 ± 34 µm diameter highly irradiated volume, placed at 8.05 mm away from the sensor tip. CREC-GS-Optiprobes do not require calibration and offer minimum intrusion (3). Please click Additional Files below to see the full abstract

An effort to make sense of antisense transcription in bacteria

Analysis of bacterial transcriptomes have shown the existence of a genome-wide process of overlapping transcription due to the presence of antisense RNAs, as well as mRNAs that overlapped in their entire length or in some portion of the 5'- and 3'-UTR regions. The biological advantages of such overlapping transcription are unclear but may play important regulatory roles at the level of transcription, RNA stability and translation. In a recent report, the human pathogen Staphylococcus aureus is observed to generate genome-wide overlapping transcription in the same bacterial cells leading to a collection of short RNA fragments generated by the endoribonuclease III, RNase III. This processing appears most prominently in Gram-positive bacteria. The implications of both the use of pervasive overlapping transcription and the processing of these double stranded templates into short RNAs are explored and the consequences discussed

Computational fluid dynamics study of crec riser simulator: mixing patterns

The CREC Riser Simulator Reactor is a novel mini-fluidized reactor. This novel device was invented by de Lasa 1. The applications of this unit has shown to be of great value to establish catalyst performance and kinetic models for a diversity of gas phase catalytic reactions. This has been the case, given that the CREC Riser Simulator is excellent with respect to particle and fluid mixing2. This study establishes using CFD (Computational Fluid Dynamics), the CREC Riser Simulator mixing flow patterns. CFD simulations were developed using the COMSOL Multiphysics® module. Fig.1a reports the geometric characteristics of the CREC Riser Simulator including the impeller, the basket containing the catalyst and the external baffles.The proposed CFD model was validated using experimental data obtained in a basket as shown in Fig.1a. For instance, for an impeller speed of 4000 rpm, the outer annulus experimental gas velocity2 was ~0.9 m/s and the simulated CFD gas velocity2 was ~1.3 m/s. Please click Additional Files below to see the full abstract

Modeling of amphoteric heavy metals solubility in stabilized/solidified steel foundry dust

The influence of pH on the leaching of metals from waste materials can be described by geochemical and empirical models. These equations may be integrated into dynamic leaching models in order to describe the longterm behavior of waste-derived forms or they can be used to predict the concentration of metals in equilibrium leaching tests at a given pH. The aim of this work is to describe the equilibrium concentration of the main metals (Zn, Pb, and Cr) contained in untreated and stabilized/solidified (S/S) electric arc furnace dust (EAFD) using experimental data obtained from a pH-dependence leaching test (acid neutralization capacity, ANC). EAFD is a hazardous waste generated in steel factories. Steel foundry dust coming from an electric arc furnace was characterized by acid digestion, x-ray fluorescence (XRF), and x-ray diffraction (XRD). The waste mainly contains Zn and Fe, which were identified in zincite and zinc ferrite phases. Pb and Cr were also detected at lower concentrations. Cement/EAFD formulations ranging from 7 to 20% dry wt of cement were prepared and the ANC leaching test was performed. The amphoteric behavior of Zn, Pb, and Cr was described by the geochemical model Visual MINTEQ and by an empirical model developed for these metals. Zinc and lead solubilities were well described by both models; however, Visual MINTEQ failed to describe the chromium behavior quantitatively

Kerker Conditions Upon Lossless, Absorption, and Optical Gain Regimes

The directionality and polarization of light show peculiar properties when the scattering by a dielectric sphere can be described exclusively by electric and magnetic dipolar modes. Particularly, when these modes oscillate in-phase with equal amplitude, at the so-called first Kerker condition, the zero optical backscattering condition emerges for non-dissipating spheres. However, the role of absorption and optical gain in the first Kerker condition remains unexplored. In this work, we demonstrate that either absorption or optical gain precludes the first Kerker condition and, hence, the absence of backscattered radiation light, regardless of the size of the particle, incident wavelength, and incoming polarization. Finally, we derive the necessary prerequisites of the second Kerker condition of the zero forward light scattering, finding that optical gain is a compulsory requirement

Assembled PTO based on an array of double-acting hydraulic cylinders for WECs: From Conceptual Design to an Adjusted Detailed Model

All Wave Energy Converters (WECs) based on wave activated bodies comprises a Power Take- Off (PTO) system among other subsystems like the reaction mechanism, the supervisor of the system and the electrical generator. One of the most applied PTO systems consists of oil high pressure hydraulic devices. These devices are able to apply high forces, to store large quantities of energy through accumulators and to provide smoother power output to the motor coupled to a generator. In these systems the poor efficiency and the oil leakages contaminating the environment are considered main drawbacks. Despite of this, they are widely used in several promising WECs with the aim of optimizing the harvested wave energy along the time. The initial challenge to absorb an oscillating movement of ±30º at 5rad/s as a maximum angular speed absorbing up to 16000Nm from a specific WEC, led to the development of a simplified hydraulic model before manufacturing a PTO prototype to be verified in a Test Bench (Figure 1). The experimental results of PTO under different conditions have been used to adjust a full detailed PTO Model using Mathworks® software platform. This work presents a patented oil high pressure hydraulic PTO prototype based on an array of four double-acting hydraulic cylinders. This prototype has been designed and completely modelled as a proof concept at 1:4 scale being able to apply a variable Coulomb type damping torque through the activation of each hydraulic cylinder independently and through the modification of geometrical parameters easily. The complete model of the PTO has been accurately tuned up through adjustment of model parameters using the results of the experimental tests. This will allow the study of control strategies to optimize the extracted wave energy from a specific WEC, like point-absorbers

Functioning in patients with schizophrenia: A systematic review of the literature using the International Classification of Functioning, Disability and Health (ICF) as a reference

Purpose: To identify and quantify the main concepts included in published studies focusing on individuals with schizophrenia using the International Classification of Functioning, Disability and Health (ICF). Methods: Searches (limited to those published from 2008 to 2012) were performed in MEDLINE, PsycINFO and CINAHL. Included studies described participants with schizophrenia, were original articles and included only subjects who were at least 18 years of age at study entry. All concepts underlying the measures and the text of the articles were extracted, and they were linked to ICF categories using standardized rules. Results: From the 3584 abstracts retrieved, 348 were randomly selected, and of these, 206 studies met the inclusion criteria. A total of 17,141 concepts were extracted, 84.8% of which could be linked to 491 ICF categories: 222 (45.21%) of the categories referred to Body Functions, 29 (5.91%) to Body Structures, 186 (37.88%) to Activities and Participation and 54 (11%) to Environmental Factors. Seventy second-level categories were reported in at least 5% of all studies: 30 of these categories referred to Body Functions, 2 to Body Structures, 34 to Activities and Participation and 4 to Environmental Factors. Conclusion: The study has allowed us to identify and quantify the main concepts included in studies focusing on people with schizophrenia using the ICF. The majority of the concepts refer to Body Functions and Activities and Participation, rather than to Body Structures and Environmental Factors

Temperature dependence of underdense nanostructure formation in tungsten under helium irradiation

Recently, tungsten has been found to form a highly underdense nanostructured morphology ("W fuzz") when bombarded by an intense flux of He ions, but only in the temperature window 900-2000 K. Using object kinetic Monte Carlo simulations (pseudo-3D simulations) parameterized from first principles, we show that this temperature dependence can be understood based on He and point defect clustering, cluster growth, and detrapping reactions. At low temperatures (2300 K), all He is detrapped from clusters, preventing the formation of the large clusters that lead to fuzz growth in the intermediate temperature range. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

Efficacy of edelfosine lipid nanoparticles in breast cancer cells

Breast cancer is a heterogeneous group of neoplasms predominantly originating in the terminal duct lobular units. It represents the leading cause of cancer death in women and the survival frequencies for patients at advanced stages of the disease remain low. New treatment options need to be researched to improve these rates. The anti-tumor ether lipid edelfosine (ET) is the prototype of a novel generation of promising anticancer drugs. However, it presents several drawbacks for its use in cancer therapy, including gastrointestinal and hemolytic toxicity and low oral bioavailability. To overcome these obstacles, ET was encapsulated in Precirol ATO 5 lipid nanoparticles (ET-LN), and its anti-tumor potential was in vitro tested in breast cancer. The formulated ET-LN were more effective in inhibiting cell proliferation and notably decreased cell viability, showing that the cytotoxic effect of ET was considerably enhanced when ET was encapsulated. In addition, ET and ET-LN were able to promote cell cycle arrest at G1 phase. Moreover, although both treatments provoked an apoptotic effect in a time-dependent manner, such anti-tumor effects were noticeably improved with ET-LN treatment. Therefore, our results indicate that encapsulating ET in LN played an essential role in improving the efficacy of the drug