Far-Field Maximal Power Absorption of a Bulging Cylindrical Wave Energy Converter

The maximal power that is absorbed by a wave energy converter can be estimated from the far-field behavior of the waves that are radiated by the device. For realistic estimates, constraints must be used to enforce restrictions on the set of admissible motions when deriving the maximal absorption width. This work is dedicated to the numerical computation of the maximal absorption width under constraints for devices with several non-trivial degrees of freedom. In particular, the method is applied to a model of SBM Offshore’s S3 wave energy converter, a bulging horizontal cylinder. The results are compared with a more classical approach, which consists of computing the linear dynamic response of the wave energy converter interacting with the waves. The far-field maximal absorption width can be seen as an upper bound to evaluate what would be the power captured by a perfect control strategy. The method also shows that the absorption width of the S3 wave energy converter is larger for wavelengths that are smaller than the device length. In practice, this means that S3 wave energy converters will be longer than the maximal wavelength to be captured on the targeted production site.

Isolasi Dan Karakterisasi Senyawa Steroid Dari Ekstrak Biji Mahoni (Swietenia mahagoni Jacq.)

Mahogany seeds (Swietenia mahagoni Jacq.) Have many benefits as drugs such as febrifuge, diabetes (Diabetes Mellitus), high blood pressure, fat decay, colds, colitis, diarrhea, wounds, and ulcers. Swietenia mahagoni Jacq Contain steroid compounds. This study aims to determine the characterization of steroid compounds isolated from mahogany seed extract (Swietenia mahagoni Jacq.). Extracts were obtained from maceration processes using n-hexane, ethyl acetate, and ethanol 70% solvents with percent of rendament of 6.34%, 7.34%, and 8% respectively. The test results for the chemical content of ethyl acetate extract positively contained steroids. 5 grams of extract was carried out using conventional column chromatography to produce 6 fractions. Fraction 6 were selected and continued with preparative thin layer chromotography and produced 2 isolates. Isolates P2b which showed one tonggal stain on the TLC profile with a value of Rf 0.50 were continued to be analyzed by UV-Vis and FT-IR spectrophotometry.The results of UV-Vis spectrophotometric isolates P2b had maximal absorption at a wavelength of 253.50 nm. FT-IR data shows the presence of functional groups C-H, C-O, C = O, C = C, and O-H whichare thought to be steroid compounds.

Influence of oenological tannins on malvidin-3-O-monoglucoside copigmentation in a model wine solution

Aim: The aim of the study was to evaluate the effects of five different oenological tannins on the color of a malvidin-3-O-monoglucoside solution, and thereby assess the effectiveness of these tannins as copigments.Methods and results: Solutions containing malvidin-3-O-glucoside and different doses of copigments were prepared. The malvidin-3-O-glucoside concentration of the solutions, and color parameters, were measured after 1 and 7 days.Conclusions: On days 1 and 7, a decrease in lightness and hue, and an increase in chroma, absorption at 520 nm and wavelength of maximal absorption were observed in solutions containing the oenological tannins. A decrease in malvidin-3-O-glucoside concentration in the tannin-containing solutions compared with the control solution was detected on day 7. The extent of this decrease depended on the specific tannin. Some changes in color parameters on day 7 compared with day 1 were observed, which were probably due to the formation of new pigments. The total color difference between the different malvidin-3-O-glucoside solutions and a pure white solution was calculated to estimate the effectiveness of the different tannins as copigments.Significance and impact of the study: These results prove that supplementation with oenological tannins is a viable option for improving the color of red wines. A copigmentation index is proposed for measurement of the effectiveness of copigments.

Dual-Band Plasmonic Perfect Absorber Based on Graphene Metamaterials for Refractive Index Sensing Application

We demonstrate a dual-band plasmonic perfect absorber (PA) based on graphene metamaterials. Two absorption peaks (22.5 μm and 74.5 μm) with the maximal absorption of 99.4% and 99.9% have been achieved, respectively. We utilize this perfect absorber as a plasmonic sensor for refractive index (RI) sensing. It has the figure of merit (FOM) of 10.8 and 3.2, and sensitivities of about 5.6 and 17.2 μm/RIU, respectively. Hence, the designed dual-band PA-based RI sensor exhibits good sensing performance in the infrared regime, which offers great potential applications in various biomedical, tunable spectral detecting, environmental monitoring and medical diagnostics.

Utilization of rigid polyurethane foam waste in removal of uncontrolled releases of hazardous substances

In 2017 in Poland 12522 incidents involving hazardous substances were recorded, of which 23 have been classified as large and very large. Apart from the share of carbon monoxide, most of them concerned uncontrolled petroleum product releases. In the same year over 427 m3 of foaming agents were used. Consequently, an extremely important issue at the intervention level is the efficient and safe removal of the resulting pollution. Tests of maximal absorption proprieties with the use of the modified Westinghouse method executed on a wide range of industrially used diverse industrial toxic substances and various classes of waste of firefighting foam agents have demonstrated substantial usability of rigid polyurethane foam waste. The obtained maximal theoretical sorptivity were within the range of 1.87-5.11 kg.kg-1. It has also been proven that absorption proprieties in relation to waste firefighting foaming agents were reduced. However, the maximum absorption proprieties of the tested rigid polyurethane foam waste are much higher than those for standard mineral sorbents used in rescue operations, which indicates a high potential for their practical use for emergency services.

Immobilization of Laccase on Surface Modified Magnetic Silica Particles and its Use for the Papermaking Wastewater

Surface modified magnetic silica particles for the immobilization of laccase. The maximal absorption capacities of laccase were evaluated systemically. Compared with unmodified magnetic silica particles, the modified magnetic silica particles showed better absorption capacity of the laccase. The immobilized laccase has been used to treat pulp and paper making wastewater, and showed high efficacy on the removal of COD.

Synthesis and Properties of Novel Light-Emitting Materials Containing Triphenylamine, Olefinic Linkers and Bipyridine Units

Organic light-emitting materials D1~D3 containing triphenylamine donors, bipyridine acceptors and olefinic linkers were synthesized and characterized. The optical, electrochemical properties of materials were studied by UV-Vis spectra, fluorescence emission spectra and cyclic voltammetry method. The results show that the maximal absorption peaks of three compounds are in the range of 404nm~408nm and fluorescence emission peaks at the region of 534nm~557nm in dichloromethane solutions, respectively. Cyclic voltammetry measurement showed that these compounds had HOMO energy level in the range of-5.02eV~-5.16eV, which is proper for hole injection. The properties indicate that these compounds have potential for the application as light-emitting materials or hole-transporting materials.

Synthesis Technology of Amine Surfactant Modified Brewer's Grains for the Adsorption of Cr(VI)

The modified adsorbent was modified by amine reaction with brewer's grains that using epichlorohydrin as etherfying agent,N,N-Dimethyl formamide as dissolvent, triethylenete tramine as cross-linking agent.The simulation of Cr (VI) wastewater as treatment object, through the optimization of synthesis conditions of Cr (VI), the optimal synthesis process was obtained.The results showed, 4 g brewer's grains, add 15 ml epichlorohydrin and 15 ml N,N-Dimethyl formamide stirring 1h at 85 °C. Then added dropwise to 4mL triethylenete tramine, mixing reaction 1h at 85 °C. The maximal absorption rate got 99.81%.The modified brewer's grains of amine surfactant modified is a promising treatment of chromium wastewater biological materials.