Potential of a hybrid wind-diesel-compressed air system for nordic remote canadian areas

In Canada, off-grid power production is significant, with more than 200,000 people living in about 300 remote communities scattered across Yukon, the Northwest Territories, Nunavut, and other islands. Most of these isolated sites rely on diesel to generate electricity. The operation of these remote isolated grids run on a deficit in the order of hundreds of millions of dollars yearly and must therefore be subsidized by the government. Low and high penetration wind–diesel hybrid systems (WDS) have been experimented to reduce diesel consumption. In a previous article, we explored the re-engineering of current diesel power plants with the introduction of high penetration wind systems using compressed air energy storage (CAES). This is a viable alternative to increase the overall percentage of renewable energy and reduce the cost of electricity, to increase the diesel engine lifetime and efficiency and to decrease their fuel consumption and GHG emissions. In this paper, we present the operative principle of this hybrid system, its economic benefits and advantages. Finally, we apply this concept in the case of a Canadian Nordic village to demonstrate the real energetic, ecological and economic potential of this system

Modeling and characterization of cladding-pumped erbium-ytterbium co-doped fibers for amplification in communication systems

Cladding-pumped optical fiber amplifiers are of increased interest in the context of space-division multiplexing but are known to suffer from low power efficiency. In this context, ytterbium (Yb) co-doping can be an attractive solution to improve the performance of erbium (Er) doped fiber amplifiers. We present a detailed direct comparison between Er/Yb-co-doping and Er-doping using numerical simulations validated by experimental results. Two double-cladding fibers, one doped with Er only and the other one co-doped with Er and Yb, were designed, fabricated and characterized. Using the experimentally extracted parameters, we simulate multi-core fiber amplifiers and investigate the interest of Er/Yb-co-doping. We calculate the minimum gain of the amplifiers over a 35-nm spectral window considering various scenarios

Demonstration of an erbium-doped fiber with annular doping for low gain compression in cladding-pumped amplifiers

We present the design and characterization of a cladding-pumped amplifier with erbium doping located in an annular region near the core. This erbium-doped fiber is proposed to reduce gain saturation, leading to smaller gain compression when compared to uniform core doping. Through numerical simulations, we first compare the performance of three fibers with different erbium doping profiles in the core or the cladding. When the doped fibers are operated at the optimum length, results show that the smaller overlap of the signal mode field with the annular erbium doping region leads to higher gain and lower saturation of the amplifier. A single-core erbium-doped fiber with an annular doping and a D-shaped cladding was fabricated. Measurements demonstrate less than 4 dB of gain compression over the C-band for input power ranging from −40 dBm to 3 dBm. Small gain compression EDFAs are of interest for applications that require input channel reconfiguration. Higher gain and saturation output power are also key issues in cladding-pumped multi-core amplifiers

Biopolymer-based membranes associated with osteogenic growth peptide for guided bone regeneration

Barrier membranes for guided bone regeneration (GBR) mainly promote mechanical maintenance of bone defect space and induce osteopromotion. Additionally, biopolymer-based membranes may provide greater bioactivity and biocompatibility due to their similarity to extracellular matrix (ECM).In this study, biopolymers-based membranes from bacterial cellulose (BC) and collagen (COL) associated with osteogenic growth peptide (OGP(10–14)) were evaluated to determine in vitro osteoinductive potential in early osteogenesis; moreover, histological study was performed to evaluate the BC–COL OGP(10–14) membranes on bone healing after GBR in noncritical defects in rat femur. The results showed that the BC–COL and BC–COL OGP(10–14) membranes promoted cell proliferation and alkaline phosphatase activity in osteoblastic cell cultures. However, ECMmineralization was similar between cultures grown on BC OGP(10–14) and BC–COL OGP(10–14) membranes. In vivo results showed that all the membranes tested, including the peptide-free BC membrane, promoted better bone regeneration than control group. Furthermore, the BC–COL OGP(10–14) membranes induced higher radiographic density in the repaired bone than the other groups at 1, 4 and 16 weeks. Histomorpho-metric analyses revealed that the BC–COL OGP(10–14) induced higher percentage of bone tissue in the repaired area at 2 and 4 weeks than others membranes. In general, these biopolymer-based membranes might be potential candidates for bone regeneration applications

Nucleolus: the fascinating nuclear body

Nucleoli are the prominent contrasted structures of the cell nucleus. In the nucleolus, ribosomal RNAs are synthesized, processed and assembled with ribosomal proteins. RNA polymerase I synthesizes the ribosomal RNAs and this activity is cell cycle regulated. The nucleolus reveals the functional organization of the nucleus in which the compartmentation of the different steps of ribosome biogenesis is observed whereas the nucleolar machineries are in permanent exchange with the nucleoplasm and other nuclear bodies. After mitosis, nucleolar assembly is a time and space regulated process controlled by the cell cycle. In addition, by generating a large volume in the nucleus with apparently no RNA polymerase II activity, the nucleolus creates a domain of retention/sequestration of molecules normally active outside the nucleolus. Viruses interact with the nucleolus and recruit nucleolar proteins to facilitate virus replication. The nucleolus is also a sensor of stress due to the redistribution of the ribosomal proteins in the nucleoplasm by nucleolus disruption. The nucleolus plays several crucial functions in the nucleus: in addition to its function as ribosome factory of the cells it is a multifunctional nuclear domain, and nucleolar activity is linked with several pathologies. Perspectives on the evolution of this research area are proposed

The use of digital imaging technique to support mechanical behavior analysis for evaluation of the thermal shock ability of refractories

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Supplementary Material for: Unemployment and Substance Use in Young Adults: Does Educational Attainment Modify the Association?

We studied whether patterns of substance use in relation to unemployment vary depending on educational level. Data come from 1,126 community-based young adults in France (18-35 years of age in 2011) and their parents (TEMPO and GAZEL studies). Tobacco use (≥1 cigarette/day, 22.5% prevalence), nicotine dependence (Fagerström test ≥2, 7.1% prevalence), alcohol use (≥2 units/week, 25.3% prevalence), alcohol abuse (WHO AUDIT ≥7 in women and ≥8 in men, 10.8% prevalence), cannabis use (≥1 time, 16.5% prevalence), and cannabis abuse (CAST ≥2, 5.0% prevalence) were assessed by interview. We conducted logistic regression analyses controlled for inverse probability weights of unemployment, calculated based on demographics, negative life events, health, and juvenile and parental characteristics. Compared to participants who were always employed, those who were unemployed and had no higher education were more likely to smoke tobacco (OR: 2.76, 95% CI: 1.86-4.10), to be nicotine dependent (OR: 5.70, 95% CI: 3.03-10.73), to use cannabis (OR: 2.27, 95% CI: 1.42-3.64), and to abuse cannabis (OR: 3.38, 95% CI: 1.63-7.04). Those who were unemployed and had higher education were especially likely to abuse alcohol (OR: 1.89, 95% CI: 1.16-3.09). Increases in unemployment may impact population levels of substance use, particularly in young adults with low educational attainment

Properties and structural investigation of gallophosphate glasses by 71Ga and 31P nuclear magnetic resonance and vibrational spectroscopies

The structure and optical properties of new gallophosphate glasses in the pseudo-binary system xGa2O3 − (100 − x) NaPO3 (x = 0 to 30 mol%), have been investigated. The effect of the progressive addition of Ga2O3 on the local glass structure has been evaluated using Raman and infrared spectroscopies, and 71Ga and 31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. 71Ga MAS NMR spectra collected at ultrahigh magnetic field (21.1 T) and fast spinning rates (60 kHz) permit the quantification of gallium in 4-, 5- and 6-fold coordination as a function of the Ga2O3 concentration. At low concentrations of Ga2O3, high-coordinate gallium coordinates to oxygens associated with the phosphate chains, increasing the dimensionality and strengthening the glassy network. At moderate Ga loadings, tetrahedral Ga is incorporated into the phosphate chains, introducing additional branching sites which further enhances network connectivity. Higher Ga2O3 content results in the formation of Ga–O–Ga bonds, thereby inhibiting glass formation. 31P MAS NMR and Raman and infrared spectroscopies provide complementary information about the distribution and connectivity of the phosphate groups within the glass network, supporting a structural model which is correlated with the measured optical and thermal properties of the Ga2O3–NaPO3 glasses as a function of the Ga2O3 concentration