1,721,082 research outputs found
Bioconverter insects: A good example of circular economy, the study case of hermetia illucens
No full textThe production cycle based on extraction, transformation, production, consumption and waste has not been sustainable for years. The goal is to have production cycles capable of self-regeneration, and therefore to identify a new way of managing byproducts is needed, one that would turn them into a resource. In the production cycle of the food industry, losses and waste account for about 1,3 billion of tons a year, and thus around 1/3 of world production for human consumption. Insects can represent a valid solution to the reuse and valorization of food industry by-products. In environmental and economic fields, an innovative application is offered by the capacity of some insects to bioconvert waste material into valuable products. Bioconverter insects can valorize organic waste from the agrifood industry through bioconversion. This process allows to obtain numerous products of high biological and economic value: proteins and lipids of animal origin, chitin and residues from the bioconversion process (frass of insect and partially digested organic material, rich in in uric acid and chitin, comparable to soil conditioner for agriculture and therefore usable for crop fertilization). Proteins and lipids deriving from some insect species could be used for feed production, and lipids can be exploited for the production of biodiesel or could find application in cosmetics field. Moreover, insect's chitin and its derivative chitosan can find many possible applications in agricultural, biomedical, pharmaceutical and industrial fields as well as in wastewater treatment. The breeding of insects for animal feed and as an alternative source of energy could represent one of the solutions to be adopted in the future. To date, in Europe the larval biomass obtained from bioconversion process can be marketed for the feeding of game animals, reptiles, fur animals and other insectivorous species (EU Reg. 68/2013, EU Reg. 142/2011); they can also be transformed into processed animal proteins (PAP) and then in flours with high nutritional content, to replace or supplement the protein and lipid quotas present in conventional feeds. The specific conditions of processing, production, storage, transport and use of insect flour for aquaculture (fish farming) has been governed by the European Regulation 2017/893 that allows the use of proteins for fish feed derived only from seven species, including the dipteran Hermetia illlucens. In the present paper, we describe the sustainable use of H. illucens to bioconvert agrifood by-products and produce proteins, lipids, chitin and its derivatives; furthermore, we shall outline their applications in the view of a zero-waste circular economy
Biobased and biodegradable rigid and flexible polymeric packaging
No full textThe present chapter is dedicated to the potentialities and opportunities of biobased and biodegradable polymeric materials currently available on the market for producing packaging. After some definitions considering regulatory and standardization aspects, these materials are described and classified. Biopolyesters and biopolymers are mainly used for these products in the form of blends or biocomposites, often in combination with additives based on biobased molecules. For flexible packaging blown film extrusion or flat die extrusion of poly(lactic acid) (PLA) based materials or starch based materials are currently the main options on the market. For rigid packaging, obtained mainly by injection molding or thermoforming, PLA blends or composites are the more promising alternatives, because of their good balance of properties and cost. The control of their processability and final properties is thus fundamental
Chitin and lignin waste in the circular economy
No full textFood and packaging waste, produced by food industries and consumers, cause an increasing pollution if not correctly managed. Recycling opportunities must be exploited to maintain our health and wellbeing, preserving the planet' natural raw materials and biodiversity for the future generations. Thus, the necessity to transform the linear economy, cause of people inequality and waste, in a circular economy based on economic prosperity, cultural vitality, social equity and environmental sustainability. For a sustainable community development, it will be necessary to recycle the industrial and agricultural waste and redesign and manufacture new products taking into account their end of life management and considering, through Life Cycle Assessment investigations, to maintain a low consume of energy and water. Among the different waste materials recovered worldwide, chitin and lignin, obtainable from food and agroforestry by-products respectively, represent the greatest source of natural raw materials available at low cost and underutilized. By many studies it has been shown that both chitin, lignin and the relative complexes, may be electro-spun with other natural polysaccharides to obtain antibacterial, immunomodulant, antioxidant and skin-repairing non-woven tissues. These innovative tissues, embedded by selected active ingredients, may be used to make facial beauty masks and/or advanced medications
Surface energy inducing asymmetric phase distribution in films of a bynary polymeric blend
No full textThe phase morphology of blends of low density polyethylene (PE) with low molecular weight copolyamide (CPA) was investigated in films
having 50–100 mm thickness. Films were prepared by compression moulding between two surfaces with different polarity, namely teflon and
aluminium sheets, in a parallel plate heating press. The film surface characterization and surface energy deduction were performed by FT-IR/ATR
spectroscopy and contact angle measurements, respectively. Moreover, the morphology and phase distribution were investigated by scanning
electron microscopy both on the surfaces and on the cryogenic section of the films.
The copolyamide resulted to be the dispersed phase in all compositions (90/10, 95/5, 97.5/2.5 and 99/1 PE/CPA) and the shape, dimension and
distribution of the domains depending on temperature, pressure, time and nature of the surfaces used during the compression stage.
The experimental evidences were discussed with respect to the different surface energies of the type of moulding material during the film
preparation and related compatibility of the components
Recyclability of biodegradable polymer blends and biocomposites through reprocessing tests
No full textIn Europe post-consumer plastics packaging amounted in 2020 at about 18 Mt. Its management consists mainly of energy recovery (42%), recycling (35%) and landfill. The necessity of producing carbon neutral goods is addressing packaging companies towards biobased materials. In particular, biobased and compostable packaging is strategic because it provides the possibility of using carbon neutral materials that can be managed by composting (organic recycling) as they turn into waste. The european BIONTOP project (https://biontop.eu/) has developed home-compostable blends including biopolyesters and composites including bran, an underutilized agro-food by-product. Prototypes of trays, films and textiles developed during the project are currently under validation in the involved industries. Recycling these materials in the same or other applications can be relevant, because their life duration can be increased and the final composting postponed. To investigate their recyclability by grinding and melt processing, the materials were reprocessed several times by injection moulding and they were characterized in terms of melt index, thermo-mechanical properties and colour as a function of injection moulding cycles number. Thanks to the full analysis it was possible to assess the number of injection moulding cycles that materials could undergo without significant detrimental effect onto their properties. Hence, it can be deducted that biobased and biodegradable films could be ground and recycled for the same film production before being composted. On the other hand, biocomposites containing wheat bran are more susceptible to polymer degradation. Thus, they could be recycled only with a “downcycling” approach or adopting chain extenders as reactive additives to counterbalance the biopolyesters decrease in molecular weight
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
A New Carrier for Advanced Cosmeceuticals
Full text linkCosmetic products are generally formulated as emulsions, ointments, solutions or powders containing active ingredients. According to EU legislation, a cosmetic product is “any substance or preparation intended to be placed in contact with the various external parts of the human body with a view exclusively or mainly to cleaning, perfuming them, changing their appearance, and/or correcting body odors and/or protecting them or keeping them in good conditions„. However, science advancement in both active carriers and ingredients has streamlined the process through which many cosmetic products by their delivery systems can induce modifications on the skin physiology. This is the reason why Reed and Kligman redefined these products as “cosmeceuticals„, which refers to the combination of cosmetics and pharmaceuticals. Until recently, the term of cosmeceuticals has not had legal significance. The so-called cosmeceuticals, in fact, may induce modifications on the skin physiology, modifying, for example, transepidermal water loss, keratinocytes cohesion and turnover, modulating the inflammatory cascade, and/or altering the surface microbiota by the activity of the preservatives content. For these reasons, they are claimed to have medical or drug-like benefits. Naturally, their effectiveness on minor skin disorders or mild skin abnormalities has to be shown by in vitro and in vivo studies. On the other hand, their formulations contain emulsifiers, preservatives, and other chemicals which, by their cumulative use, may provoke side effects, such as allergic and/or sensitization phenomena. Moreover, many ingredients and packaging for such products are not biodegradable. In this study, we would like to introduce an innovative category of cosmeceuticals made by biodegradable nonwoven tissues. These cosmeceutical tissues, produced through the use of natural fibers, may bind different active ingredients and therefore become effective as antibacterial, anti-inflammatory, sun-protective, whitening, or anti-aging products, depending on the ingredient(s) used. Differently from the usual cosmetics, they do not contain preservatives, emulsifiers, colors, and other chemicals. They can be applied as dried tissue on wet skin, remaining in loco for around 30 min, slowly releasing the active ingredients entrapped into the fibers. It is interesting to underline that the tissue, acting as a carrier, has its own effectiveness via chitin and lignin polymers with an antibacterial and anti-inflammatory activity. When hydrolyzed by the human microbiota enzymes, they give rise to ingredients used as cell nourishment or energy. This paper will review part of the scientific research results, supporting this new category of biodegradable cosmetic products known as facial mask sheets
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