701 research outputs found
L’approccio della Fratelli Guzzini ai materiali
L’articolo si focalizza sull’esperienza di un’azienda italiana, la Guzzini, esempio storico ed autorevole del design italiano, che ha legato la sua storia e la sua immagine all’utilizzo di un materiale in particolare, il PMMA. Il fine dello studio è quello di svelare una storia inedita di ricerca materica che ha visto la sostituzione di un materiale naturale come il corno con un materiale sintetico, usandolo come “surrogato” di proprietà ingegneristiche e qualità espressivo-sensoriali, entrambe fondamentali per il progetto. Con riferimenti all’evoluzione del sistema produttivo si è cercato di evidenziare come l’azienda sia riuscita a valorizzare proprietà e qualità successivamente riconosciute come distintive del materiale sintetico
EXTRACTION OF CELLULOSE FROM DIFFERENT WASTE MATERIALS AS A MEANS TO ILLUSTRATE THE RELEVANCE AND THE POSSIBILITIES OF THE PROCESS OF WASTE UPCYCLING
The aim of this work is illustrating a possible example for explaining the upcycling of waste, hence producing value from it, for possible future use e.g., as viscose in the fashion industry. This has been performed by comparing the results obtained from different cellulose waste, especially yield of the product and its apparent quality.
The first objective of the experiments is explaining the chemical procedure to recover cellulose waste for further use. After this, the cellulose extracted is characterized as concerns its morphological structure in terms of dimensions of the fibers obtained. Then, infrared analysis data are compared with those available from previously analyzed cellulose with known composition.
Through this experience, the students are introduced to the importance of upcycling in general terms, starting with examples of though they are also presented with the very variable quality of the product obtained from cellulose waste, so to be able to make considerations about the possibility to proceed with the experiment and eventually developing it to an industrial level
Effect of cochlear implant electrode insertion on middle-ear function as measured by intra-operative laser Doppler vibrometry
Hypothesis: The aim of this study was to investigate the impact of cochlear implant electrode insertion on middle-ear low frequency function in humans.Background: Preservation of residual low frequency hearing with addition of electrical speech processing can improve the speech perception abilities and hearing in noise of cochlear implant users. Preservation of low frequency hearing requires an intact middle-ear conductive mechanism in addition to intact inner-ear mechanisms. Little is known about the effect of a cochlear implant electrode on middle-ear function.Methods: Stapes displacement was measured in seven patients undergoing cochlear implantation. Measurements were carried out intra-operatively before and after electrode insertion. Each patient acted as his or her own control. Sound was delivered into the external auditory canal via a speaker and calibrated via a probe microphone. The speaker and probe microphone were integrated into an individually custom-made ear mould. Ossicular displacement in response to a multisine stimulus at 80 dB SPL was measured at the incudostapedial joint via the posterior tympanotomy, using an operating microscope mounted laser Doppler vibrometry system.Results: Insertion of a cochlear implant electrode into the scala tympani had a variable effect on stapes displacement. In three patients, there was little change in stapes displacement following electrode insertion. In two patients, there was a significant increase, while in a further two there was a significant reduction in stapes displacement. This variability may reflect alteration of cochlear impedance, possibly due to differing loss of perilymph associated with the electrode insertion.Conclusion: Insertion of a cochlear implant electrode produces a change in stapes displacement at low frequencies, which may have an effect on residual low frequency hearing thresholds
An Experience on Environmental Education based on Respect-Reduce-Reuse-Recycle in a Village Primary School in the Marche Region, in Italy
T
he importance of environmental educatio n is widely recognized worldwide: an important objective is that the
citizens are accustomed to apply the best available practices in their life , while ask ing the administration and the
government to gradually enforce measures lead ing to a reduction of the environmental impact and to a more
sustainable lifestyle. This requires a formation starting at an early age: however, in Italy the relevant indications from
the National Curriculum are still limited and do not suggest explicitly the performance of any pr actical activity ,
tailored on the specific school setting . This inadequacy of the Curriculum becomes particularly apparent in cases
where other concerns are present, for example the areas in the Marche region affected by the 2016 earthquake : here,
the need to resum e a day by day routine put a kind of \u201cdamper\u201d on other questions, such as environmental issues .
This had an effect also i n children\u2019s life on this question, school needs to take a stand , which is the objective of this
study . This work concerns an approach to environmental education in a multi classes primary school context (age
6 10) in a small village school, located in the Central Apennine in Italy. This is performed through an experience
carried out by investigating the behavior towards waste p roduction of the community, as perceived by children at
school. It is therefore articulated through the application of 4R (Respect, which encompasses Reduce, Reuse and
Recycle) applying and extending the indications from the Italian National Curriculum. Th e project leads also to an
experience of self production of objects by the use of waste, to improve their awareness of the possibilities included
in their upcycling. Feedback on the experience is finally acquired from the children and discussed, especially in the
sense of creating future citizens with a more sensible and reasonable behavior towards the environment and leading
possibly to zero waste strategies in their family and work setting. The data were analy z ed using thematic analysis
and different them es about waste production were singled out
Use of Sea Waste to Enhance Sustainability in Composite Materials: A Review
The term “sea waste” generally refers to any solid, liquid, or gaseous material or substance that is discarded, disposed of, or abandoned in the ocean, sea, or any other body of salty water, such as a lagoon, etc. This includes waste generated by human activities on land that makes its way into the ocean, as well as waste generated by ships and other vessels at sea. Examples of sea waste include plastic debris, chemicals and toxic substances, oil spills, sewage, and other forms of pollution. These pollutants can harm marine ecosystems, endanger marine life, and impact human health and wellbeing. Efforts are being made by governments, organizations, researchers, and individuals to reduce the amount of sea waste generated, and to clean up existing waste in the ocean. Less attention is usually paid to waste materials of natural origin as they are considered (sometimes wrongly) to be less critical; an example is the tons of organic and inorganic material of natural origin that wash up on the beaches daily and must be landfilled or incinerated. The present paper intends to provide an updated review of research experiences and engineering solutions that are able to offer a second life to natural (biological) sea waste by incorporating it into the creation of new, more sustainable materials, and especially composites
An Experience on Environmental Education Based on Respect-Reduce-Reuse-Recycle in a Village Primary School in the Marche Region, in Italy
The importance of environmental education is widely recognized worldwide: an important objective is that the
citizens are accustomed to apply the best available practices in their life, while asking the administration and the
government to gradually enforce measures leading to a reduction of the environmental impact and to a more
sustainable lifestyle. This requires a formation starting at an early age: however, in Italy the relevant indications
from the National Curriculum are still limited and do not suggest explicitly the performance of any practical
activity, tailored on the specific school setting. This inadequacy of the Curriculum becomes particularly apparent
in cases where other concerns are present, for example the areas in the Marche region affected by the 2016
earthquake: here, the need to resume a day-by-day routine put a kind of “damper” on other questions, such as
environmental issues. This had an effect also in children’s life: on this question, school needs to take a stand, which
is the objective of this study. This work concerns an approach to environmental education in a multi-classes
primary school context (age 6-10) in a small village school, located in the Central Apennine in Italy. This is
performed through an experience carried out by investigating the behavior towards waste production of the
community, as perceived by children at school. It is therefore articulated through the application of 4R (Respect,
which encompasses Reduce, Reuse and Recycle) applying and extending the indications from the Italian National
Curriculum. The project leads also to an experience of self-production of objects by the use of waste, to improve
their awareness of the possibilities included in their upcycling. Feedback on the experience is finally acquired from
the children and discussed, especially in the sense of creating future citizens with a more sensible and reasonable
behavior towards the environment and leading possibly to zero-waste strategies in their family and work setting.
The data were analyzed using thematic analysis and different themes about waste production were singled out
Abrasive wear behavior of CNT-filled unidirectional kenaf-epoxy composites
Kenaf (Hibiscus Cannabinus) fibers have received significant attention for replacing the usage of synthetic fibers, especially glass fiber, in the fabrication of fiber-reinforced polymer (FRP) composites. The aim of this research was to study the change in wear behavior of kenaf-epoxy fiber composites by filling them with multiwall carbon nanotubes (MWCNT). In particular, the effect of untreated MWCNT (PMWCNT), acid-treated MWCNT (AMWCNT), and silane-treated MWCNT (SMWCNT) was studied, using three different MWCNT loadings, i.e., 0.5, 0.75, and 1 wt.%. The abrasive wear test was conducted to measure the wear properties of the composites. A thermal infrared camera was also used to measure the punctual contact temperature during the abrasive wear test, while the abraded surfaces were analyzed using the stereomicroscope. Starting from the considerable reduction of wear rate with the introduction of kenaf fibers, it was observed that PMWCNT provided some further, yet modest, reduction of wear rate only at the higher loadings. In contrast, the inclusion of AMWCNT proved to increase the specific wear rate of the epoxy-kenaf composites, an effect worsened at higher loadings. This may be due to the weakened interfacial bonding between the AMWCNT and epoxy. On the other hand, the presence of SMWCNT improved the interfacial bonding between CNT and epoxy, as shown by an increase in contact temperature. However, the increase in bonding strength was stipulated to have caused the rougher worn debris, thus inducing a three-body abrasive wear effect
Development of thermoplastic starch (TPS) including leather waste fragments
A thermoplastic starch (TPS) material is developed, based on corn starch plasticized with glycerol and citric acid in a 9:3:1 ratio and further bonded with isinglass and mono-and diglycerides of fatty acids (E471). In TPS, leather fragments, in the amount of 7.5 15 or 22.5 g/100 g of dry matter, were also introduced. The mixture was heated at a maximum temperature of 80 °C, then cast in an open mold to obtain films with thickness in the range 300 ± 50 microns. The leather fragments used were based on collagen obtained from production waste from shoemaking and tanned with tannins obtained from smoketree (Rhus cotinus), therefore free from chromium. Thermogravimetric (TGA) tests suggested that material degradation started at a temperature around 285 °C, revealing that the presence of leather fragments did not influence the occurrence of this process in TPS. Tensile tests indicated an increase in tensile properties (strength and Young's modulus) with increasing leather content, albeit coupled, especially at 22.5 wt%, with a more pronounced brittle behavior. Leather waste provided a sound interface with the bulk of the composite, as observed under scanning electron microscopy. The production process indicated a very limited degradation of the material after exposure to UV radiation for eight days, as demonstrated by the slight attenuation of amide I (collagen) and polysaccharide FTIR peaks. Reheating at 80 °C resulted in a weight loss not exceeding 3%
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