Carlo Santulli | Università degli studi di Camerino UNICAM (original) (raw)

Papers by Carlo Santulli

The substitution of synthetic fillers, such as carbon black, with biobased ones in natural rubber... more The substitution of synthetic fillers, such as carbon black, with biobased ones in natural rubber (NR) is a trend of interest in view of increased sustainability and exploitation of agroforest waste in the materials sector. In this work, NR was filled with short fibers extracted from Sansevieria cylindrica (SC) leaves of various length (10, 20, 30, or 40 mm) and in different amounts (3, 6, or 10 g per 100 g NR). The 12 different composite combinations obtained are compared among them and with the unfilled NR, as regards properties, such as density, tensile performance, and tear strength. Density was gradually increased by filling the matrix by higher amounts of SC fibers. The introduction of up to 30 g SC fibers enabled strengthening and stiffening the pure matrix, while some decline was indicated by increasing SC fibers content to 40 g. In absolute terms, though, the best tensile performance was offered by the combination including 20 g of 6-mm-long SC fibers, namely resulting in 10.44 MPa tensile strength, 627.6% elongation at break, and 2.36 MPa Young's modulus. The superiority of this combination is confirmed when dealing with tear strength, which was always improved by the introduction of SC yet reached 34.99 N/mm for the composite with 20 g of 6-mm-long fibers. Morphological fracture observation using scanning electron microscope indicated the likeliness of pullout by interference caused when an excessive amount of SC fibers is introduced, showing rather clean fiber surface when separating from the matrix. In general terms, SC/NR composites showed improvement over the pure matrix, yet some interfacial issues need to be addressed by better compatibilization of the natural fibers.

The importance of environmental education is widely recognized worldwide: an important objective ... more 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.

23. Journal of Education and Practice , 2018

A possibility increasingly experimented in the field of design to improve end-of-life sustainabil... more A possibility increasingly experimented in the field of design to improve end-of-life sustainability is integration of agro-waste into materials. Design can "upcycle" waste, offering perceptive and aesthetical acceptance to objects produced from it. On-field experimentations can foster awareness over the possibility to modify objects lifecycle, avoiding a "use-and-throw" perspective, and exploring the identity of materials in their prospected field of application. This will be aimed at creating a bond between user and objects, based both on function and on affection, also considering the modifications the material can undergo over time, making it adapted to different uses. This practice can have a significant educational value: in particular, this study moves from an experimentation carried out at July and September 2017 by design and materials engineering researchers, with several groups of 15 children, age 8-11, at Museo dei Bambini-Explora in Rome, investigating their "experience" and "creativity" on the topic. Conclusions are also drawn on possible modifications of the step-like procedure to introduce students of all ages to the knowledge of experimental method through the production of DIY bioplastics from waste. This "trial and error" procedure allows reflecting from a play-like point of view on aspects essential for the success of this operation, such as mode of coloration, effect of texture, possibility of obtaining curved or complex shapes, mechanical workability, optimal cooking and aromatization. The consequence of the exercise is customizing materials obtained from waste, with the idea of teaching how an expressive and functional success of the objects produced can make these "resilient" over time, therefore inherently sustainable. This would lead, through a combined and simple teaching of elements of experimental procedure and sustainability, to an awareness of their respective importance in design. The tool for this result is the development of DIY materials. The significance of this experience, which could be applied also in other age ranges, appeared to be to communicate the role of design to improve the perception of materials by transforming them into valuable objects. This proved to be better explained in the challenging case of waste, hence a substance bearing no longer any emotional or functional relation with us, with which this "bond" needs to be rebuilt through an experiential path.

Journal of Education and Practice, 2020

The importance of environmental education is widely recognized worldwide: an important objective ... more 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.

Emerging Science Journal, 2020

A thermoplastic starch (TPS) was produced, starting with potato starch, glycerol and acetic acid,... more A thermoplastic starch (TPS) was produced, starting with potato starch, glycerol and acetic acid, to shape it in films of thickness around 100 microns. To TPS iron waste filing particles, in the amount of 12% the weight of starch, were introduced in different modalities: as received, reduced in size by the use of a mortar, after treatment with hydrochloric acid, and after treatment and removal of hydrochloric acid. Morphological studies were carried out by optical and scanning electron microscopy and illustrated that the dispersion of iron filings was not optimal, though some improvement was observed by a reduced dimension of the particles. Tensile tests indicated the considerable improvement of stiffness offered by the insertion of iron particles to TPS, although the ultimate strain was reduced to less than 10%. Thermal characterization using thermogravimetry allowed revealing the three typical peaks for potato starch degradation, with only a slight decrease due to iron introduction. EDS allowed evaluating the presence of impurities in the iron filings and evidenced that the presence of iron was more effective on the surface than in the rest of the film. As a final consideration, An improvement in electrical conductivity by over an order of magnitude was obtained by the TPS+Fe+HCl film with respect to pure TPS.

Polymer Testing, 2014

ABSTRACT During the last decade, interest in using natural fibre reinforced composites has increa... more ABSTRACT During the last decade, interest in using natural fibre reinforced composites has increased due to their good specific mechanical properties. The results of an experimental study of the influence of temperature and impact velocity on the low velocity impact response of jute fiber reinforced unsaturated polyester (UP) composite laminates is presented. A series of low velocity impact tests were performed using an instrumented falling weight test system at three different temperatures (30, 50 and 75°C) and two impact velocities (1.5 and 2 m/s). The results indicate that jute/UP composites were able to withstand higher loads when tested at 30°C. The composites were subsequently subjected to three-point bending tests in order to investigate the flexural strength after impact (FAI) and it was found that FAI significantly decreased with increase in test temperature. Impact damage characterised by AE revealed delamination as a major failure mode.

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2014

ABSTRACT

Science and Engineering of Composite Materials, 2014

Damage following static indentation of jute/hemp (50 wt.% total fiber content) hybrid laminates w... more Damage following static indentation of jute/hemp (50 wt.% total fiber content) hybrid laminates was detected by a number of nondestructive testing (NDT) techniques, in particular, near (NIR) and short-wave (SWIR) infrared reflectography and transmittography, infrared thermography (IRT), digital speckle photography (DSP), and holographic interferometry (HI), to discover and evaluate real defects in a laminate with a complex structure. A comparative study between thermographic data acquired in the mid- (MWIR) and long-wave infrared (LWIR) spectrum bands, by pulsed (PT) and square pulse (SPT) thermography, is reported and analyzed. A thermal simulation by COMSOL

L'obiettivo di questo lavoro è l'investigazione delle attività dei catt... more L'obiettivo di questo lavoro è l'investigazione delle attività dei cattolici fiancheggiatori del fascismo e delle loro relazioni col Partito Popolare. I limiti temporali del lavoro sono l'inizio del dibattito sulla legge Acerbo (15 luglio 1923) ed il decreto di scioglimento del Partito Popolare (9 novembre 1926), che segna la fine del periodo aventiniano e che rende di fatto impossibile per i cattolici antifascisti continuare l'attività politica.

ABSTRACT Voids in composites have been a perennial problem, since the amount of porosities is dee... more ABSTRACT Voids in composites have been a perennial problem, since the amount of porosities is deemed to bear a strong relation with the degradation of service performance of laminates. On the other side, the effect of porosity on impact resistance of laminates is often dependant on their distribution in the material, especially with respect to the location and severity of impact damage in it. In this study, the influence of void content percentage on the residual flexural strength of CFRP laminates impacted at very low energy, in the region of 1 J, at different temperatures was investigated. Laminates were fabricated using 16 layers of Cycom 977-2 prepreg material in a [0/90/90/0]2S layup with different void contents in the range from 1 to 7% by varying cure conditions. Low velocity impact tests were conducted on three categories of laminates, defined as high pressure cured, low pressure debulked and low pressure non debulked respectively, each of these at ambient temperature (30 °C) and elevated temperatures of 50, 70 and 90 °C. Post-impact residual flexural strength of the laminates was measured by three-point bending tests followed in real time by acoustic emission (AE) monitoring. From the separation of frequency bands and of their amplitude levels, identification of the different failure modes, such as matrix cracking, delamination and fibre failure, was performed. The results indicated that in the case of very low impact energy high porosity laminates, such as non debulked ones, may possess slightly higher residual flexural strength and an enhanced delamination resistance with respect to debulked ones.

ABSTRACT In the present study, infrared vision and optical nondestructive testing (NDT) technique... more ABSTRACT In the present study, infrared vision and optical nondestructive testing (NDT) techniques were applied for the evaluation of emerging defects after artificially impacting composite materials reinforced with natural fibers. The samples were manufactured using wool felts and jute fibers inserted in an epoxy matrix. Infrared vision was applied by means of pulsed thermography (PT) and square pulsed thermography (SPT), evaluating two different thermal stimulation procedures; while the algorithms referred to as principal component thermography (PCT) and pulsed phase thermography (PPT) were used in order to enhance the information retrieval from the respective thermographic inspections. For comparison purposes, near-infrared reflectography (NIRR) and transmittography (NIRT), as well as laser speckle imaging techniques were also included. Additionally, ultraviolet (UV) imaging technique was used on the laminates both as complementary approach and as reference for future inspections. Two particular zones highlighted by the latter technique were characterized using an XRF spectrophotometer revealing a reverse concentration of the Al, Si and Cl elements. The results produced from the above comparative study confirmed the synergy of the applied techniques and further indicated that the methodology followed in the present research work can be considered as an innovative approach for the characterization of eco-friendly laminates after an impact loading.

The substitution of synthetic fillers, such as carbon black, with biobased ones in natural rubber... more The substitution of synthetic fillers, such as carbon black, with biobased ones in natural rubber (NR) is a trend of interest in view of increased sustainability and exploitation of agroforest waste in the materials sector. In this work, NR was filled with short fibers extracted from Sansevieria cylindrica (SC) leaves of various length (10, 20, 30, or 40 mm) and in different amounts (3, 6, or 10 g per 100 g NR). The 12 different composite combinations obtained are compared among them and with the unfilled NR, as regards properties, such as density, tensile performance, and tear strength. Density was gradually increased by filling the matrix by higher amounts of SC fibers. The introduction of up to 30 g SC fibers enabled strengthening and stiffening the pure matrix, while some decline was indicated by increasing SC fibers content to 40 g. In absolute terms, though, the best tensile performance was offered by the combination including 20 g of 6-mm-long SC fibers, namely resulting in 10.44 MPa tensile strength, 627.6% elongation at break, and 2.36 MPa Young's modulus. The superiority of this combination is confirmed when dealing with tear strength, which was always improved by the introduction of SC yet reached 34.99 N/mm for the composite with 20 g of 6-mm-long fibers. Morphological fracture observation using scanning electron microscope indicated the likeliness of pullout by interference caused when an excessive amount of SC fibers is introduced, showing rather clean fiber surface when separating from the matrix. In general terms, SC/NR composites showed improvement over the pure matrix, yet some interfacial issues need to be addressed by better compatibilization of the natural fibers.

The importance of environmental education is widely recognized worldwide: an important objective ... more 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.

23. Journal of Education and Practice , 2018

A possibility increasingly experimented in the field of design to improve end-of-life sustainabil... more A possibility increasingly experimented in the field of design to improve end-of-life sustainability is integration of agro-waste into materials. Design can "upcycle" waste, offering perceptive and aesthetical acceptance to objects produced from it. On-field experimentations can foster awareness over the possibility to modify objects lifecycle, avoiding a "use-and-throw" perspective, and exploring the identity of materials in their prospected field of application. This will be aimed at creating a bond between user and objects, based both on function and on affection, also considering the modifications the material can undergo over time, making it adapted to different uses. This practice can have a significant educational value: in particular, this study moves from an experimentation carried out at July and September 2017 by design and materials engineering researchers, with several groups of 15 children, age 8-11, at Museo dei Bambini-Explora in Rome, investigating their "experience" and "creativity" on the topic. Conclusions are also drawn on possible modifications of the step-like procedure to introduce students of all ages to the knowledge of experimental method through the production of DIY bioplastics from waste. This "trial and error" procedure allows reflecting from a play-like point of view on aspects essential for the success of this operation, such as mode of coloration, effect of texture, possibility of obtaining curved or complex shapes, mechanical workability, optimal cooking and aromatization. The consequence of the exercise is customizing materials obtained from waste, with the idea of teaching how an expressive and functional success of the objects produced can make these "resilient" over time, therefore inherently sustainable. This would lead, through a combined and simple teaching of elements of experimental procedure and sustainability, to an awareness of their respective importance in design. The tool for this result is the development of DIY materials. The significance of this experience, which could be applied also in other age ranges, appeared to be to communicate the role of design to improve the perception of materials by transforming them into valuable objects. This proved to be better explained in the challenging case of waste, hence a substance bearing no longer any emotional or functional relation with us, with which this "bond" needs to be rebuilt through an experiential path.

Journal of Education and Practice, 2020

The importance of environmental education is widely recognized worldwide: an important objective ... more 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.

Emerging Science Journal, 2020

A thermoplastic starch (TPS) was produced, starting with potato starch, glycerol and acetic acid,... more A thermoplastic starch (TPS) was produced, starting with potato starch, glycerol and acetic acid, to shape it in films of thickness around 100 microns. To TPS iron waste filing particles, in the amount of 12% the weight of starch, were introduced in different modalities: as received, reduced in size by the use of a mortar, after treatment with hydrochloric acid, and after treatment and removal of hydrochloric acid. Morphological studies were carried out by optical and scanning electron microscopy and illustrated that the dispersion of iron filings was not optimal, though some improvement was observed by a reduced dimension of the particles. Tensile tests indicated the considerable improvement of stiffness offered by the insertion of iron particles to TPS, although the ultimate strain was reduced to less than 10%. Thermal characterization using thermogravimetry allowed revealing the three typical peaks for potato starch degradation, with only a slight decrease due to iron introduction. EDS allowed evaluating the presence of impurities in the iron filings and evidenced that the presence of iron was more effective on the surface than in the rest of the film. As a final consideration, An improvement in electrical conductivity by over an order of magnitude was obtained by the TPS+Fe+HCl film with respect to pure TPS.

Polymer Testing, 2014

ABSTRACT During the last decade, interest in using natural fibre reinforced composites has increa... more ABSTRACT During the last decade, interest in using natural fibre reinforced composites has increased due to their good specific mechanical properties. The results of an experimental study of the influence of temperature and impact velocity on the low velocity impact response of jute fiber reinforced unsaturated polyester (UP) composite laminates is presented. A series of low velocity impact tests were performed using an instrumented falling weight test system at three different temperatures (30, 50 and 75°C) and two impact velocities (1.5 and 2 m/s). The results indicate that jute/UP composites were able to withstand higher loads when tested at 30°C. The composites were subsequently subjected to three-point bending tests in order to investigate the flexural strength after impact (FAI) and it was found that FAI significantly decreased with increase in test temperature. Impact damage characterised by AE revealed delamination as a major failure mode.

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2014

ABSTRACT

Science and Engineering of Composite Materials, 2014

Damage following static indentation of jute/hemp (50 wt.% total fiber content) hybrid laminates w... more Damage following static indentation of jute/hemp (50 wt.% total fiber content) hybrid laminates was detected by a number of nondestructive testing (NDT) techniques, in particular, near (NIR) and short-wave (SWIR) infrared reflectography and transmittography, infrared thermography (IRT), digital speckle photography (DSP), and holographic interferometry (HI), to discover and evaluate real defects in a laminate with a complex structure. A comparative study between thermographic data acquired in the mid- (MWIR) and long-wave infrared (LWIR) spectrum bands, by pulsed (PT) and square pulse (SPT) thermography, is reported and analyzed. A thermal simulation by COMSOL

L'obiettivo di questo lavoro è l'investigazione delle attività dei catt... more L'obiettivo di questo lavoro è l'investigazione delle attività dei cattolici fiancheggiatori del fascismo e delle loro relazioni col Partito Popolare. I limiti temporali del lavoro sono l'inizio del dibattito sulla legge Acerbo (15 luglio 1923) ed il decreto di scioglimento del Partito Popolare (9 novembre 1926), che segna la fine del periodo aventiniano e che rende di fatto impossibile per i cattolici antifascisti continuare l'attività politica.

ABSTRACT Voids in composites have been a perennial problem, since the amount of porosities is dee... more ABSTRACT Voids in composites have been a perennial problem, since the amount of porosities is deemed to bear a strong relation with the degradation of service performance of laminates. On the other side, the effect of porosity on impact resistance of laminates is often dependant on their distribution in the material, especially with respect to the location and severity of impact damage in it. In this study, the influence of void content percentage on the residual flexural strength of CFRP laminates impacted at very low energy, in the region of 1 J, at different temperatures was investigated. Laminates were fabricated using 16 layers of Cycom 977-2 prepreg material in a [0/90/90/0]2S layup with different void contents in the range from 1 to 7% by varying cure conditions. Low velocity impact tests were conducted on three categories of laminates, defined as high pressure cured, low pressure debulked and low pressure non debulked respectively, each of these at ambient temperature (30 °C) and elevated temperatures of 50, 70 and 90 °C. Post-impact residual flexural strength of the laminates was measured by three-point bending tests followed in real time by acoustic emission (AE) monitoring. From the separation of frequency bands and of their amplitude levels, identification of the different failure modes, such as matrix cracking, delamination and fibre failure, was performed. The results indicated that in the case of very low impact energy high porosity laminates, such as non debulked ones, may possess slightly higher residual flexural strength and an enhanced delamination resistance with respect to debulked ones.

ABSTRACT In the present study, infrared vision and optical nondestructive testing (NDT) technique... more ABSTRACT In the present study, infrared vision and optical nondestructive testing (NDT) techniques were applied for the evaluation of emerging defects after artificially impacting composite materials reinforced with natural fibers. The samples were manufactured using wool felts and jute fibers inserted in an epoxy matrix. Infrared vision was applied by means of pulsed thermography (PT) and square pulsed thermography (SPT), evaluating two different thermal stimulation procedures; while the algorithms referred to as principal component thermography (PCT) and pulsed phase thermography (PPT) were used in order to enhance the information retrieval from the respective thermographic inspections. For comparison purposes, near-infrared reflectography (NIRR) and transmittography (NIRT), as well as laser speckle imaging techniques were also included. Additionally, ultraviolet (UV) imaging technique was used on the laminates both as complementary approach and as reference for future inspections. Two particular zones highlighted by the latter technique were characterized using an XRF spectrophotometer revealing a reverse concentration of the Al, Si and Cl elements. The results produced from the above comparative study confirmed the synergy of the applied techniques and further indicated that the methodology followed in the present research work can be considered as an innovative approach for the characterization of eco-friendly laminates after an impact loading.