9 research outputs found
Testing of an anti-soiling coating for PV module cover glass
Soiling of solar module cover glass can significantly reduce the module power output. Coatings can be applied to the cover glass surface to reduce adhesion and make the surfaces easier to clean. These coatings should be resilient and resistant to environmental damage. A hydrophobic anti-soiling coating was exposed to a variety of environmental and abrasion stress tests. The hydrophobic performance of the coating was measured by monitoring the water contact angle and the water roll off angle after exposure to a range of environmental and mechanical stress tests. The coating was shown to be highly resistant to damp heat and thermal cycling. However, it was degraded by UV exposure and damaged during abrasion tests. The coating was also exposed to outdoor testing to compare the laboratory results with real performance degradation
Performance and durability of broadband antireflection coatings for thin film CdTe solar cells
Light reflection from the glass surface of a photovoltaic (PV) module is a significant source of energy
loss for all types of PV devices. The reflection at the glass and air interface accounts for 4% of the total
energy. Single layer antireflection coatings with sufficiently low refractive index have been used, such as
those using magnesium fluoride or porous silica, but these are only effective over a narrow range of
wavelengths. In this paper, the authors report on the design, deposition, and testing of multilayer
broadband antireflection coatings. These coatings reduce the weighted average reflection over the
wavelength range used by thin film CdTe devices to just 1.22%, resulting in a 3.6% relative increase in
device efficiency. The authors have used multilayer stacks consisting of silica and zirconia layers
deposited using reactive magnetron sputtering. Details of the stack design, sputter deposition process
parameters, and the optical and microstructural properties of the layers are provided. Antireflection
coatings on glass exposed to the outdoors must not degrade over the lifetime of the module. A
comprehensive set of accelerated environmental durability tests has been carried out in accordance with
IEC 61646 PV qualification tests. The durability tests confirmed no damage to the coatings or
performance drop as a result of thermal cycling or damp heat. All attempts to perform pull tests resulted
in either adhesive or substrate failure, with no damage to the coating itself. The coatings also passed acid
attack tests. Scratch resistance, abrasion resistance, and adhesion tests have also been conducted. The
optical performance of the coatings was monitored during these tests, and the coatings were visually
inspected for any sign of mechanical failure. These tests provide confidence that broadband
antireflection coatings are highly durable and will maintain their performance over the lifetime of the
solar module. All dielectric metal-oxide multilayer coatings have better optical performance and superior
durability compared with alternative single layer porous sol–gel coatings. Thin film CdTe devices are
particularly problematic because the antireflection coating is applied to one side of the glass, while
device layers are deposited directly on to the opposite glass surface in the superstrate configuration. In
thin film CdTe production, the glass is exposed to high temperature processes during the absorber deposition
and the cadmium chloride activation treatment. If glass precoated with a broadband antireflection
coating is to be used, then the coating must withstand temperatures of up to 550 C. Surprisingly, our
studies have shown that multilayer silica/zirconia antireflection coatings on soda lime glass remain unaffected
by temperatures reaching 600 C, at which point mild crazing is observed. This is an important
observation, demonstrating that low cost glass, which is preprocessed with a broadband antireflection
coating, is directly useable in thin film CdTe module production
SPH-FEM simulation of shaped-charge jet penetration into double hull: A comparison study for steel and SPS
This paper was accepted for publication in the journal Composite Structures and the definitive published version is available at http://dx.doi.org/10.1016/j.compstruct.2016.08.002A high-speed metal jet capable to cause severe damage to a double-hull structure can be produced after detonation of a shaped charge. A Smoothed Particle Hydrodynamics (SPH) method with a mesh-free and Lagrange formulations has natural advantages in solving extremely dynamic problems. Hence, it was used to simulate the formation process of a shaped-charge jet. A Finite Element Method (FEM) is suitable for a structural analysis and is highly efficient for simulations of a complex impact process in a relatively short time; therefore, it was applied to develop a double-hull model. In this paper, a hybrid algorithm fully utilizing advantages of both SPH and FEM is proposed to simulate a metal-jet penetration into a double hull made of different materials – steel and SPS (Sandwich Plate System). First, a SPH-FEM model of a sphere impacting a plate was developed, and its results were compared with experimental data to validate the suggested algorithm. Second, numerical models of steel/SPS double-hull subjected to a shaped-charge jet were developed and their results for jet formation, a penetration process and a damage response were analysed and compared. The obtained results show that the velocity of the metal jet tended to decrease from its tip to the tail during its formation process. The jet broke into separate fragments after the first steel shell was penetrated, causing the damage zone of the second shell that grew as a result of continuous impact by fragments. As for the SPS structure, its damage zone was smaller, and the jet trended to bend becoming thinner due to the resistance of the composite layer. It was found that the polyurethane layer could have a protective effect for the second shell
Single molecule mu-opioid receptor membrane-dynamics reveal agonist-specific dimer formation with super-resolved precision
G-protein-coupled receptors (GPCRs) are key signaling proteins that mostly function as monomers, but for several receptors constitutive dimer formation has been described and in some cases is essential for function. Using single-molecule microscopy combined with super-resolution techniques on intact cells, we describe here a dynamic monomer–dimer equilibrium of µ-opioid receptors (µORs), where dimer formation is driven by specific agonists. The agonist DAMGO, but not morphine, induces dimer formation in a process that correlates both temporally and in its agonist- and phosphorylation-dependence with β-arrestin2 binding to the receptors. This dimerization is independent from, but may precede, µOR internalization. These data suggest a new level of GPCR regulation that links dimer formation to specific agonists and their downstream signals
Single-molecule analysis reveals agonist-specific dimer formation of µ-opioid receptors
G-protein-coupled receptors (GPCRs) are key signaling proteins that mostly function as monomers, but for several receptors constitutive dimer formation has been described and in some cases is essential for function. Using single-molecule microscopy combined with super-resolution techniques on intact cells, we describe here a dynamic monomer-dimer equilibrium of µ-opioid receptors (µORs), where dimer formation is driven by specific agonists. The agonist DAMGO, but not morphine, induces dimer formation in a process that correlates both temporally and in its agonist- and phosphorylation-dependence with β-arrestin2 binding to the receptors. This dimerization is independent from, but may precede, µOR internalization. These data suggest a new level of GPCR regulation that links dimer formation to specific agonists and their downstream signals
Evaluation of tribothermal effectiveness of TiAlN-based bilayer coatings in cutting fiber-reinforced polymers
Guarding Traditions and Laws—Disciplining Bodies and Souls: Tradition, science, and religion in the age of Ottoman reform
Nutraceutical Potential of Apiaceae
Apiaceae family is large, with over 3.000 species worldwide cultivated for many purposes. Some plants in this family such as carrots, parsley, parsnip and celery are common vegetable crops, while other members like anise, caraway, coriander, cumin, fennel, lovage, angelica and dill are famous for their medicinal and aromatic properties. Usage of these plants is very popular in everyday diet because of their documented health benefits. Apiaceae are a very important source of phytochemicals – chemicals with biological activity. However, phytochemicals are non-nutritive plant chemicals, also called nutraceuticals. They are widely used for prevention, treatment or cure of conditions or diseases. Bioactive compounds with nutraceutical potential are polyphenolic compounds, polyacetylenes and terpenoids. The aim of this review is to represent selected plants of Apiaceae family currently used as nutraceuticals and describe their nutritional benefits