Highly improved the performance of film-based fluorescent sensor via nanomesh scaffold strategy

Public safety and environmental monitoring is of great significance to maintain human health. Therefore, a simple and effective strategy for preparing the substrate layer of film-based fluorescent sensor is developed...

Influence of Degradation Product Thickness on the Elastic Stiffness of Porous Absorbable Scaffolds Made from an Bioabsorbable Zn–Mg Alloy

For orthopaedic applications, additive manufactured (AM) porous scaffolds made of absorbable metals such as magnesium, zinc or iron are of particular interest. They do not only offer the potential to design and fabricate bio-mimetic or rather bone-equivalent mechanical properties, they also do not need to be removed in further surgery. Located in a physiological environment, scaffolds made of absorbable metals show a decreasing Young’s modulus over time, due to product dissolution. For magnesium-based scaffolds during the first days an increase of the smeared Young’s modulus can be observed, which is mainly attributed to a forming substrate layer of degradation products on the strut surfaces. In this study, the influence of degradation products on the stiffness properties of metallic scaffolds is investigated. For this, analytical calculations and finite-element simulations are performed to study the influence of the substrate layer thickness and Young’s modulus for single struts and for a new scaffold geometry with adapted polar cubic face-centered unit cells with vertical struts (f2cc,z). The finite-element model is further validated by compression tests on AM scaffolds made from Zn1Mg (1 wt% Mg). The results show that even low thicknesses and Young’s moduli of the substrate layer significantly increases the smeared Young’s modulus under axial compression.

NEW DESIGN OF MICRO-STRIP PATCH ANTENNA FOR WI-FI APPLICATIONS

In this research, a new design of a semi-star patch antenna is simulated for Wi-Fi applications. The antenna is operated at 2.4GHz, which is modified by inserting rectangular slots in the ground layer. Copper is used for the patch and ground layers, while FR-4 epoxy is used for the substrate layer. FR-4 epoxy has a Ԑr=4.3 and a loss tangent (tanδ) of 0.025. The antenna size is (45x48x1.6) mm³. The proposed antenna provides a reflection coefficient of -41.5 dB and a gain of 2.8 dB at the operating frequency. The proposed antenna is simulated by CST STUDIO SUITE 2019.

Influence of Degradation Products on the Elastic Stiffness Properties of Porous Absorbable Scaffolds Made From Bioabsorbable Metals

For orthopaedic applications, additive manufactured (AM) porous scaffolds made of absorbable metals like magnesium, zinc or iron are of particular interest. They do not only offer the potential to design and fabricate bio-mimetic or rather bone equivalent mechanical properties, they also do not need to be removed in further surgery. Located in a physiological environment, scaffolds made of absorbable metals show a decreasing Young’s modulus over time, due to product dissolution. For WE43 scaffolds, during the first days an increase of the smeared Young's modulus can be observed, which is mainly attributed to a forming substrate layer of degradation products on the struts surfaces. In this study the influence of degradation products on the stiffness properties of metallic scaffolds is investigated. For this, analytical calculations and finite element simulations are performed to study the influence of the substrate layer thickness and Young's modulus for single struts and for a new scaffold geometry with adapted polar f2cc,z unit cells. The finite element model is further validated by compression tests on AM scaffolds made from Zn1Mg. The results show, that even low thicknesses and Young's moduli of the substrate layer increases significantly the smeared Young's modulus under axial compression.

Modifications of Phytoseiidae mite breeding methods to suppress spider mite

Populations of mites from the Tetranychidae family are characterized as high-resistant to acaricides, which, in turn, leads to an increase in the pesticide load on the agrocenoses ecosystem. Carnivorous arthropods from the Phytoseiidae family can be used as an alternative pest control. Our research aimed at improving the methods of breeding, storage and use of predatory mites against Tetrahychus urticae Koch. In 2015–2018, work was being undertaken to define the optimum thickness of the substrate layer (2.0, 4.0 and 6.0 cm) for breeding the food object – Acaris farus Oud. We also assessed the effect of the fodder substrate composition (wheat bran – control, wheat bran + soybean meal – experimental variant) on the population density of Amblyseius andersoni Chant. In 2016–2019, experiments on the storage of Neoseiulus barkeri Hughes, Neoseiulus cucumeris Oud. and Amblyseius swirskii Athias-Henriot at 4 °C (control – no storage) were carried out. In 2018–2019, to control Tetrahychus urticae Koch. in the soybean field, a mixture of N. cucumeris and A. andersoni was used according to the method of introduction into natural foci of prey. The optimum thickness of the substrate layer was found to be 4 cm. In this case, it was possible to obtain 6,983 mites in 1 cm3 for 7 days. Soybean meal addition increased the number of A. andersoni by 22.3 % compared to control (263 ind. vs 204 ind. per cm3). 30–45 days – an effective storage period for N. barkeri, 30 days – for N. cucumeris, no more than 10 days – for A. swirskii. On average, in 2018–2019, N. cucumeris and A. andersoni mixture reduced the number of T. urticae. The number of spider mites in the control variant was 14.6, in the experimental one – 5.3 ind./leaf. No predatory activity was observed on eggs. To prevent the development of spider mites, it is necessary to use N. cucumeris and A. andersoni at least twice with an interval of 5–7 days.