Physicochemical Assessment of the Biodegradability of Agricultural Nonwovens Made of PLA

Compostable biodegradable plastics are an ecological alternative to traditional products based on petroleum derivatives, whose post-use waste may pollute the natural environment. Modern polymer materials show the functional properties of plastics obtained by conventional methods, but they also may be degraded as a result of biochemical transformations in composting. This allows such materials to be included in the scheme of the currently implemented circular economy, which does not generate post-consumer waste. This paper presents methods for the assessment of the biodegradation process of selected agricultural nonwovens produced from commercial PLA 6252D polylactide, supplied by Nature Works® LLC, USA. The agricultural nonwovens tested, obtained by the spun-bond technique, were characterised by different degrees of crystallinity in the range from 11.1% to 31.4%. Biodegradation tests were carried out as simulated aerobic composting while maintaining constant environmental conditions in accordance with test procedures based on PN-EN/ISO standards using the method of sample mass loss determination. Gel chromatography (GPC/SEC) and FTIR spectroscopy were also applied to assess the degree of biodegradation. The aim of this study was to evaluate the effect of the crystallinity of nonwoven made of PLA 6252 D on its degradation in a compost environment.

Development of Structured Sunflower Oil Systems for Decreasing Trans and Saturated Fatty Acid Content in Bakery Creams

In this work, the design of low moisture (10%) oil/water emulsions based on sunflower oil were investigated, as well as their application in a bakery cream as a conventional fat replacer. The emulsions were dehydrated to reach 10% moisture content, achieving highly concentrated vegetable oil gel emulsions of different consistencies and qualities. Physical properties of the dried emulsions were evaluated by texture, microstructure, and oil loss determination. The reformulated bakery creams with the dried emulsions obtained from 47% oil showed better spreadability, viscosity, and viscoelasticity properties. A shortening replacement with the dried emulsion obtained from 70% initial oil caused a negative impact on the creams’ consistency, with lower viscosity and lower hysteresis area, revealing a weakness of structure. This research provided new knowledge about the structuration of vegetable oils through concentrated emulsions and their application as a source of healthy fat in creams for bakery applications.

PHARMACOGNOSTIC ANALYSIS AND ANALYSIS OF THE PHENOLIC COMPOUNDS OF THE AERIAL PARTS OF THE SPECIES CERASTIUM BULGARICUM UECHTR. SIN. CERASTIUM GRACILE DUFOUR

"The main objective of the paper was the pharmacognostic analysis of the microscopic and chemical species of the aerial part of the species Cerastium bulgaricum Uechtr. sin. Cerastium gracile Dufour, to establish the chemical composition and especially to identify active principles that scientifically substantiate the traditional use of the plant product. The microscopic analyses of the vegetative organs (stem and leaf) the species Cerastium bulgaricum Uechtr led to the conclusion that its histo-anatomical structure is specific to Caryophyllaceae. Following the global chemical analysis, active principles known in the literature for the antioxidant potential were identified. Following the preliminary quantitative determinations (drying loss, determination of soluble substances) results comparable to those in the literature on the content of volatile substances and soluble substances were obtained. The separation, identification and quantification of poliphenols compounds were made through high performance of liquid chromatography (HPLC), standardized method according to USP30-NF25 Monograph"

Tin Complexes Containing an Atenolol Moiety as Photostabilizers for Poly(Vinyl Chloride)

The lifetime of poly(vinyl chloride) (PVC) can be increased through the addition of additives to provide protection against irradiation. Therefore, several new tin complexes containing atenolol moieties were synthesized and their photostabilizing effect on PVC was investigated. Reacting atenolol with a number of tin reagents in boiling methanol provided high yields of tin complexes. PVC was then mixed with the tin complexes at a low concentration, producing polymeric thins films. The films were irradiated with ultraviolet light and the resulting damage was assessed using different analytical and surface morphology techniques. Infrared spectroscopy and weight loss determination indicated that the films incorporating tin complexes incurred less damage and less surface changes compared to the blank film. In particular, the triphenyltin complex was very effective in enhancing the photostability of PVC, and this is due to its high aromaticity (three phenyl rings) compared to other complexes. Such an additive acts as a hydrogen chloride scavenger, radical absorber, and hydroperoxide decomposer.

The novel design of an energy efficient superconductor-based series reactor for installation at a grid connected research site

This paper proposes the development of a superconducting series reactor (SSR) as an alternative to traditionally employed technologies and superconducting fault current limiters when managing fault levels on the electrical power grid. By utilizing superconducting tape, which has negligible resistance, in the construction of a series reactor, it is proposed that fault level mitigation could be achieved in a more energy efficient manner. Once constructed the SSR will be installed and tested at a grid-connected power engineering research site, and the proposed impact of this installation is firstly simulated using Reticmaster® power system simulation software. Design parameters for the prototype SSR are then calculated enabling the total cost of the modifications and prototype SSR to be determined. A desktop SSR was also constructed and tested as a pre-cursor to the prototype construction to confirm functionality and design and was found to be up to four times more energy efficient as the equivalent copper reactor. Finally, the calorimetric method of power loss determination was investigated and experimentally shown to be a viable alternative to the traditional electrical method of power loss determination. In the past, the relatively cheap cost of electricity in South Africa had favoured the installation of poor power efficiency devices that required a lower initial capital investment. With increasing energy costs and a focus on carbon emission reductions, the development of the SSR augurs a new era in power system engineering in which designs are proposed considering both total lifecycle costs and energy efficiency. Design proposal for the first superconducting power device in Africa Alternative to less efficient fault current management technologies currently employed Construction and testing of a desktop superconducting series reactor Verification of the calorimetric method for power loss determination.