Techno-economic assessment of biogas-fed CHP hybrid systems in a real wastewater treatment plant

The integration of solid oxide fuel cell (SOFC) systems and micro gas turbines in a reference wastewater treatment plant is proposed. The main scope is to utilize the available biogas in a real wastewater treat- ment plant (WWTP) to feed both the SOFCs and micro gas turbines (MGTs) to produce electrical power while covering the digester thermal demand of the plant. To do so, two cases namely SOFC-WWTP (in which the SOFC system is the only CHP unit), and SOFC-MGT-WWTP (integration of both SOFCs and microturbine systems) are proposed. Results show that use of microturbines along with the SOFC systems can increase the share of electricity covered by self-generation within the WWTP by up to 15% while keeping stable the coverage of the thermal load. Also, the energy efficiency of the novel system (SOFC- MGT-WWTP) is calculated to be 7% more than that of the SOFC-WWTP. Economic analysis results reveal that using microturbines, the payback time for whole the system could be reduced about 4 years. Also, for the short term scenario, the levelized cost of electricity for the SOFC-MGT-WWTP system is found to be 0.118 $/kWh which is about 12% less than that for the SOFC-WWTP system. However, for the long term scenario, the difference becomes remarkably les

Two Randomized Trials Provide No Consistent Evidence for Nonmusical Cognitive Benefits of Brief Preschool Music Enrichment

Young children regularly engage in musical activities, but the effects of early music education on children’s cognitive development are unknown. While some studies have found associations between musical training in childhood and later nonmusical cognitive outcomes, few randomized controlled trials (RCTs) have been employed to assess causal effects of music lessons on child cognition and no clear pattern of results has emerged. We conducted two RCTs  with preschool children investigating the cognitive effects of a brief series of music classes, as  compared to a similar but non-musical form of arts instruction (visual arts classes, Experiment 1) or to a no-treatment control (Experiment 2). Consistent with typical preschool arts enrichment programs, parents attended classes with their children, participating in a variety of developmentally appropriate arts activities. After six weeks of class, we assessed children’s skills  in four distinct cognitive areas in which older arts-trained students have been reported to excel: spatial-navigational reasoning, visual form analysis, numerical discrimination, and receptive vocabulary. We initially found that children from the music class showed greater spatial-navigational ability than did children from the visual arts class, while children from the visual arts class showed greater visual form analysis ability than children from the music class (Experiment 1). However, a partial replication attempt comparing music training to a no-treatment control failed to confirm these findings (Experiment 2), and the combined results of  the two experiments were negative: overall, children provided with music classes performed no better than those with visual arts or no classes on any assessment. Our findings underscore the need for replication in RCTs, and suggest caution in interpreting the positive findings from past studies of cognitive effects of music instruction.Psycholog

Effect of syngas composition on the combustion and emissions characteristics of a syngas/diesel RCCI engine

Reactivity controlled compression ignition (RCCI) strategy uses two different fuels with different reactivities which provides more control over the combustion process and has the potential to dramatically lower combustion temperature and NOX and PM emissions. The objective of the present study is to numerically investigate the impact of syngas composition on the combustion and emissions characteristics of an RCCI engine operating with syngas/diesel at constant energy per cycle. For this purpose, different syngas compositions produced through gasification process have been chosen for comparison with the simulated syngas (mixture of hydrogen and carbon monoxide). The results obtained indicate that using syngas results in more soot, CO and UHC emissions compared with simulated syngas. Even though more NOX reduction can be achieved while operating with syngas, the engine could suffer from poor combustion and misfire at low loads due to the presence of nitrogen in the mixture. In terms of exergy, both syngas mixtures lead to more exergy destruction by the increase of syngas substitution. Nevertheless, the magnitude of exergy destruction for simulated syngas is less than the normal syngas

Marine environmental parameters influencing the distribution of Avicenna marina forests using logistic regression (Case Study: Hormozgan province)

This study predicates the prone areas for developing Avicenna Marina forests along the coastal areas of Hormozgan province by studying the oceanography features influencing these forests and using logistic regression models. Tidal areas, flooding level, salinity of water and waves were recognized as influencing variables. The prediction of prone areas was based on using logistic regression model and the validity of the model was studied by ROC test and Pseudo-R 2 .The results of this study indicates that; firstly the maximum wave height, the average maximum flooding level and the level of sanity of water are significantly associated with the presence of Mangrove and the high level of parameters of ROC and Pseudo-R 2 confirm the validity of the model. Secondly the maximum wave height was introduced as the main marine parameter influencing the Mangrove communities. Finally the eastern part of the Persian Gulf coast and the west coast of Oman were found as the most suitable areas for developing Mangrove forest

Surface acoustic wave attenuation by a two-dimensional electron gas in a strong magnetic field

The propagation of a surface acoustic wave (SAW) on GaAs/AlGaAs heterostructures is studied in the case where the two-dimensional electron gas (2DEG) is subject to a strong magnetic field and a smooth random potential with correlation length Lambda and amplitude Delta. The electron wave functions are described in a quasiclassical picture using results of percolation theory for two-dimensional systems. In accordance with the experimental situation, Lambda is assumed to be much smaller than the sound wavelength 2*pi/q. This restricts the absorption of surface phonons at a filling factor \bar{\nu} approx 1/2 to electrons occupying extended trajectories of fractal structure. Both piezoelectric and deformation potential interactions of surface acoustic phonons with electrons are considered and the corresponding interaction vertices are derived. These vertices are found to differ from those valid for three-dimensional bulk phonon systems with respect to the phonon wave vector dependence. We derive the appropriate dielectric function varepsilon(omega,q) to describe the effect of screening on the electron-phonon coupling. In the low temperature, high frequency regime T << Delta (omega_q*Lambda /v_D)^{alpha/2/nu}, where omega_q is the SAW frequency and v_D is the electron drift velocity, both the attenuation coefficient Gamma and varepsilon(omega,q) are independent of temperature. The classical percolation indices give alpha/2/nu=3/7. The width of the region where a strong absorption of the SAW occurs is found to be given by the scaling law |Delta \bar{\nu}| approx (omega_q*Lambda/v_D)^{alpha/2/nu}. The dependence of the electron-phonon coupling and the screening due to the 2DEG on the filling factor leads to a double-peak structure for Gamma(\bar{\nu}).Comment: 17 pages, 3 Postscript figures, minor changes mad

Lithium attenuated the depressant and anxiogenic effect of juvenile social stress through mitigating the negative impact of interlukin-1β and nitric oxide on hypothala...

Abstract—The neuroimmune-endocrine dysfunction has been accepted as one of fundamental mechanisms contributing to the pathophysiology of psychiatric disorders including depression and anxiety. In this study, we aimed to evaluate the involvement of hypothalamic–pituitary–adre nal (HPA) axis, interleukin-1b, and nitrergic system in mediating the negative behavioral impacts of juvenile social isolation stress (SIS) in male mice. We also investigated the possible protective effects of lithium on behavioral and neurochemical changes in socially isolated animals. Results showed that experiencing 4-weeks of juvenile SIS provoked depressive and anxiety-like behaviors that were associated with hyper responsiveness of HPA axis, upregulation of interleukin-1b, and nitric oxide (NO) overproduction in the pre-frontal cortex and hippocampus. Administration of lithium (10 mg/kg) significantly attenuated the depressant and anxiogenic effects of SIS in behavioral tests. Lithium also restored the negative effects of SIS on cortical and hippocampal interleukin-1b and NO as well as HPA axis deregulation. Unlike the neutralizing effects of L-arginine (NO precursor), administration of L-NAME (3 mg/kg) and aminoguanidine (20 mg/kg) potentiated the positive effects of lithium on the behavioral and neurochemical profile of isolated mice. In conclusion, our results revealed that juvenile SIS-induced behavioral deficits are associated with abnormalities in HPA-immune function. Also, we suggest that alleviating effects of lithium on behavioral profile of isolated mice may be partly mediated by mitigating the negative impact of NO on HPA-immune function. � 2015 IBRO. Published by Elsevier Ltd. All rights reserve

Metformin attenuates streptozotocin-induced diabetic nephropathy in rats through activation of AMPK signaling pathway

Background: Nephropathy is the main problem of diabetes and can be classified into several phases according to the presence of albuminuria. Adenosine monophosphate-activated protein kinase (AMPK) operates as a sensor of energy charge. Objectives: The aim of our study was to evaluate the reno-protective properties of AMPK signaling pathway against streptozotocin (STZ)-induced nephropathy in the rat. Materials and Methods: Forty male Wistar rats were randomly distributed into four groups. Group 1 was normal rats (N group); group 2 was diabetic rats (D group); group 3 received diabetic rats + metformin (DM group), and group 4 received giabetic rats + metformin + dorsomorphin (DMD group). Serum albumin, uric acid, total protein and creatinine for estimation of renal injury were measured. Finally, the histological study was evaluated. Results: Reduction of body weight, albumin and total protein in the diabetic rat was reversed by metformin administration. Our results showed that serum uric acid and creatinine were significantly increased in diabetic rats and decreased after treatment with metformin in diabetic rats. AMPK improved the histopathology and morphological changes in STZ-induced diabetic rats. Administration of dorsomorphin (AMPK inhibitor) with metformin can reverse the beneficial effects of AMPK. Conclusions: AMPK signaling pathway ameliorates diabetic nephropathy by modifications of serum albumin, uric acid, total protein, creatinine and attenuation of kidney damage

Quantum Hall Effect in Three Dimensional Layered Systems

Using a mapping of a layered three-dimensional system with significant inter-layer tunneling onto a spin-Hamiltonian, the phase diagram in the strong magnetic field limit is obtained in the semi-classical approximation. This phase diagram, which exhibit a metallic phase for a finite range of energies and magnetic fields, and the calculated associated critical exponent, $\nu=4/3$, agree excellently with existing numerical calculations. The implication of this work for the quantum Hall effect in three dimensions is discussed.Comment: 4 pages + 4 figure

Commercial shellfish skin prick test extracts show critical variability in allergen repertoire

[Extract] Crustacean and mollusc (shellfish) allergy affects up to 3% of the general population, is usually lifelong and commonly triggers anaphylaxis.1 Allergen repertoire diversity among hundreds of edible shellfish species worldwide is poorly reflected in available in vivo and in vitro diagnostic tools for shellfish allergy. Skin prick testing (SPT) is often the preferred first-line diagnostic approach. However, widely utilized commercial SPT extracts are generally not standardized, limiting the diagnostic value of results.2 Asero et al. reported a heterogeneous abundance of three shellfish allergens in five commercial crustacean SPT extracts, resulting in 32 clinical profiles among 157 shrimp-allergic patients.3 In 2019, we demonstrated considerable variability in allergen repertoire and IgE-binding for 27 commercial fish SPT extracts.4 We now report an even greater, critical variability for 11 commercial crustacean and five mollusc SPT extracts, utilizing biochemical and immunological methods and mass spectrometry (see Appendix S1 for methodology and TableS1 for allergen extract details)