Thermal Model in ANSYS for a Comparison Between two Configurations of a Concentrating Photovoltaic System

The theoretical analysis of different concentrating photovoltaic and thermal systems (CPV/T) is presented in this paper; it allows to evaluate the cooling fluid temperature in different working conditions. In particular, two CPV/T systems with different optics, line-focus and point-focus, are studied and compared theoretically by means of a model developed in ANSYS-CFX able to evaluate the theoretical temperature values of the fluid that flows in the cooling circuit, designed with the Solidworks software. The comparison in terms of the thermal performances between the point-focus and line-focus configurations of a CPV/T system has been realized considering different working conditions. As model input the uniform cell temperature has been set to different values, included between 323 K and 363 K, or determined experimentally referring to the point-focus configuration. In particular, the outlet temperatures of the cooling fluid, the fluid and cells temperatures difference at the outlet section, the time necessary to reach a steady-state condition, the fluid temperature trend in different parts of the tube and along the circuit, have been evaluated. Moreover, the fluid temperature trend has been studied varying the fluid velocity, its mass flow rate, and the insulation thickness. Finally, the point-focus CPV/T system thermal performances have been also evaluated adopting some experimental measurements as input data; the fluid temperature trend has been tested under a variable cell temperature during different hours of a sunny and a cloudy day.     

Correction to: RECODE: revision control for digital images

Multimedia Tools and Applications - The author regrets that the acknowledgment of the original publication contains an error. The correct acknowledgement is written below:     

Mesenchymal Stem Cell Treatment Perspectives in Peripheral Nerve Regeneration: Systematic Review

Traumatic peripheral nerve lesions affect hundreds of thousands of patients every year; their consequences are life-altering and often devastating and cause alterations in movement and sensitivity. Spontaneous peripheral nerve recovery is often inadequate. In this context, nowadays, cell therapy represents one of the most innovative approaches in the field of nerve repair therapies. The purpose of this systematic review is to discuss the features of different types of mesenchymal stem cells (MSCs) relevant for peripheral nerve regeneration after nerve injury. The published literature was reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A combination of the keywords “nerve regeneration”, “stem cells”, “peripheral nerve injury”, “rat”, and “human” were used. Additionally, a “MeSH” research was performed in PubMed using the terms “stem cells” and “nerve regeneration”. The characteristics of the most widely used MSCs, their paracrine potential, targeted stimulation, and differentiation potentials into Schwann-like and neuronal-like cells are described in this paper. Considering their ability to support and stimulate axonal growth, their remarkable paracrine activity, their presumed differentiation potential, their extremely low immunogenicity, and their high survival rate after transplantation, ADSCs appear to be the most suitable and promising MSCs for the recovery of peripheral nerve lesion. Clinical considerations are finally reported.     

Preparation and characterization of antistatic packaging for electronic components based on poly(lactic acid)/carbon black composites

Poly(lactic acid) (PLA) is a biodegradable aliphatic polymer obtained from renewable sources; its main application is in the packaging sector. Electronic components require the use of antistatic packaging that prevents damage and electric shock. As PLA has no conductive characteristics, it requires the addition of allotropic carbon forms such as conductive carbon black to make the polymer less resistive as the dissipative material and making it suitable for the manufacture of antistatic packaging. In this study, PLA was melt blended with 5, 10, and 15 wt % of carbon black. The composites were prepared using a high-speed mixer. Samples were characterized by Izod impact resistance tests, scanning electron microscopy, thermal properties, electrical characterization, and biodegradation tests in garden soil. The addition of carbon black in the PLA matrix increases the temperature of degradation and decreases the crystallinity degree and the impact resistance of the composites. However, carbon black is a great option to increase the electrical conductivity of PLA. The addition of carbon black in PLA makes the composite less resistive and suitable for use as antistatic packaging for the transportation and storage of electronic components. Furthermore, this composite does not cause damage to the environment as the carbon black does not interfere in the degradation mechanism of PLA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47273.     

Single Domain 10 nm Ferromagnetism Imprinted on Superparamagnetic Nanoparticles Using Chiral Molecules

The rapid growth in demand for data and the emerging applications of Big Data require the increase of memory capacity. Magnetic memory devices are among the leading technologies for meeting this demand; however, they rely on the use of ferromagnets that creates size reduction limitations and poses complex materials requirements. Usually magnetic memory sizes are limited to 30–50 nm. Reducing the size even further, to the ≈10–20 nm scale, destabilizes the magnetization and its magnetic orientation becomes susceptible to thermal fluctuations and stray magnetic fields. In the present work, it is shown that 10 nm single domain ferromagnetism can be achieved. Using asymmetric adsorption of chiral molecules, superparamagnetic iron oxide nanoparticles become ferromagnetic with an average coercive field of ≈80 Oe. The asymmetric adsorption of molecules stabilizes the magnetization direction at room temperature and the orientation is found to depend on the handedness of the chiral molecules. These studies point to a novel method for the miniaturization of ferromagnets (down to ≈10 nm) using established synthetic protocols.     

Enhanced activity of Pd/α-MnO2 for electrocatalytic oxygen evolution reaction

This work describes the application of α-MnO₂ and Pd/α-MnO₂ as electrocatalysts in the oxygen evolution reaction (OER). Characterization data revealed that the Pd²⁺ precursor has been oxidized during the synthesis, and the resulting Pd⁴⁺ ions have unprecedently replaced the lattice framework Mn³⁺ ions of α-MnO₂. Furthermore, formation of PdO nanoparticles was also observed. Lower OER overpotential at j = 10 mA cm^?2 (636 mV) was obtained for Pd/α-MnO₂ in relation to α-MnO₂ (700 mV), what is in alignment with the lower charge transfer resistance of Pd/α-MnO₂ (4.9 kΩ cm²) compared to α-MnO₂ (10.4 kΩ cm²). Lower Tafel slope (73 mV dec^?1) and higher TOF (2.87 × 10^?4 s^?1) at overpotential of 350 mV was obtained for Pd/α-MnO₂ in relation to α-MnO₂ (Tafel of 77 mV dec^?1 and TOF of 1.94 × 10^?4 s^?1), indicating a faster electron transfer kinetics promoted by Pd. Pd/α-MnO₂ was stable at j = 14 mA cm^?2 for 6 h.     

Wiederbefeuchtung bei der Pressfiltration

During press filtration, the filter cake experiences a plastic deformation. However, a filter cake expansion may occur once the pressing forces are released, which is confirmed by experiments with an aqueous coal suspension. Rewetting of the cake occurs when a liquid film is present during cake swelling, which deteriorates the cake dryness significantly. However, this can be prevented when the liquid film is successfully removed, and lower pressures suffice for mechanical cake drying.     

Asthma and Chronic Rhinosinusitis: How Similar Are They in Pathogenesis and Treatment Responses?

Severe asthma and rhinosinusitis represent frequent comorbidities, complicating the overall management of the disease. Both asthma and chronic rhinosinusitis (CRS) can be differentiated into endotypes: those with type 2 eosinophilic inflammation and those with a non-type 2 inflammation. A correct definition of phenotype/endotype for these diseases is crucial, taking into account the availability of novel biological therapies. Even though patients suffering from type 2 severe asthma—with or without CRS with nasal polyps—significantly benefit from treatment with biologics, the existence of different levels of patient response has been clearly demonstrated. In fact, in clinical practice, it is a common experience that patients reach a good clinical response for asthma symptoms, but not for CRS. At first glance, a reason for this could be that although asthma and CRS can coexist in the same patient, they can manifest with different degrees of severity; therefore, efficacy may not be equally achieved. Many questions regarding responders and nonresponders, predictors of response, and residual disease after blocking type 2 pathways are still unanswered. In this review, we discuss whether treatment with biological agents is equally effective in controlling both asthma and sinonasal symptoms in patients in which asthma and chronic rhinosinusitis with nasal polyps coexist.