12 research outputs found
2C y los territorios de la arquitectura de la razon
No full textNelle pagine della Rivista 2C Construccion de la ciudad Carlos Marti Aris propone una costellazione semantica imperniata sui concetti di Realismo, Classicismo e Razionalità: una costellazoine ceh riprende dal dibattito italiano e dalla posizione di Rossi e che trasferisce nel dibattito spagnolo in un passaggio cruciale della fine del XX secoloIn the pages of the magazine 2C Construccion de la ciudad Carlos Marti Aris proposes a semantic constellation hinging on the concepts of Realism, Classicism and Rationality: a constellation that takes from the Italian debate and Rossi's position and transfers it to the Spanish debate in a crucial passage at the end of the 20th centur
CO2 transoral microsurgery for supraglottic squamous cell carcinoma
No full textThe present study analyzed the results of the endoscopic approach to T1, T2 and selected T3 supraglottic carcinoma with the aim of reviewing functional and oncologic outcomes after different types of endoscopic supraglottic laryngectomies. This is a retrospective clinical study of 42 consecutive patients (mean age of 61.8 years, 33 males, 9 females) treated by the senior author for supraglottic squamous cell carcinoma with a transoral CO2 laser approach and reviewed from November 2010 to September 2017. Surgical procedures were classified according to the European Laryngological Society. In addition to the standardized transoral supraglottic laryngectomies, we introduced a modified type IVb by sparing the inferior third of the arytenoid if not directly involved in the tumor. Swallowing was evaluated with the Swallowing Performance Status Scale reported by the Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology. Survival probabilities were estimated using Kaplan-Meier curves. Two type I, 2 type IIa, 2 type IIb, 3 type IIIa, 12 type IIIb, 13 type IVa, 3 type modified IVb, and 5 type IVb supraglottic laryngectomies were performed. Twenty-one patients (50%) underwent primary neck dissection. The pathologic TNM classification according to the 8th edition of the American Joint Committee on Cancer system was as follows: 9 pT1cN0, 2 pT1N0, 1 pT1N1, 7 pT2cN0, 1 rypT2cN0, 9 pT2N0, 4 pT2N1, 2 ypT2N1, 2 pT3cN0, 2 rypT3cN0, 1 pT3N1, and 2 pT3N2b. Mean follow-up was 3.4 years (range of 9 months to 6 years). According to the Kaplan–Meier analysis, 5-year disease-specific survival, local-relapse-free survival, nodal-relapse-free survival, overall laryngeal preservation and overall survival of patients without previous head and neck radiotherapy/open surgery were 100%, 95.2%, 87.8%, 100%, and 64.6%, respectively. Patients who underwent type I, IIa, and IIb resections (n = 6) started oral feeding the day after surgery, patients who underwent type III-IVb modified resections (n = 31) started oral feeding 3–4 days after surgery, and patients who underwent standard type 4b resections (n = 5) started oral feeding 7 days after surgery. Three months after surgery, patients without a clinical history of previous head and neck radiotherapy/open surgery who underwent type III, IVa, and modified IVb resections showed significantly better swallowing compared to patients who underwent standard type IVb resection: grade 4–6 impairment of swallowing in 8 and 66.7% of cases, respectively (p = 0.006072); patients with a clinical history of previous head and neck radiotherapy/open surgery who underwent type III, IVa, and modified IVb resections showed not statistically significant better swallowing compared to patients who underwent standard type IVb resection: grade 4–6 impairment of swallowing at 3 months in 16.7% and 50% of cases, respectively (p = 0.23568). Transoral CO2 laser supraglottic laryngectomy is an oncologic sound alternative to traditional open neck surgery and chemo-radiotherapy. Recovery of swallowing is significantly worsened after total resection of the arytenoid. Modified type IVb procedure leaving intact, when possible, the inferior third of the arytenoid and consequently the glottic competence, improves functional outcome
Il passato degli 'antichi'
No full textAlcuni esempi di come gli antichi pensavano e concettualizzavano l'antico, da Platone a Senec
3D printing of potassium sodium niobate by binder jetting: Printing parameters optimisation and correlation to final porosity
No full textBinder Jetting (BJT) is a non-fusion-based Additive Manufacturing (AM) technique. It consists of the selective deposition of a liquid binder to join powder particles, thereby enabling the creation of near-net-shaped parts. In this study, the main printing parameters correlated to the binder distribution and infiltration (binder saturation, binder set time, drying time, and target bed temperature) were optimised to improve the precision of green parts printed with potassium sodium niobate (KNN) powder. The optimisation procedure was conducted using the Taguchi statistical method. An L9 orthogonal array with four factors of control at three levels each was employed. The analysis showed that the drying time had the greatest influence on the precision of green parts, followed by binder saturation and target bed temperature. Binder set time did not seem to affect the results. Dimensional analysis, microstructural and piezoelectric characterisation of parts densified by pressureless sintering were conducted. The highest average relative density exceeded 80% for the specimens printed with the lower binder saturation. Piezoelectric properties exhibit more complex behaviour. The prolonged infiltration of larger binder volumes is correlated to higher g33, thus FOMh and FOM33, and lower values for ε33^T. On the other hand, d33 does not display a specific dependence on density or printing parameters. The results of this study indicate that BJT can be used to fabricate high-precision KNN components with good piezoelectric properties. The optimisation of printing parameters is essential to achieve the desired results.Binder Jetting (BJT) is a non-fusion-based Additive Manufacturing (AM) technique. It consists of the selective deposition of a liquid binder to join powder particles, thereby enabling the creation of near-net-shaped parts. In this study, the main printing parameters correlated to the binder distribution and infiltration (binder saturation, binder set time, drying time, and target bed temperature) were optimised to improve the precision of green parts printed with potassium sodium niobate (KNN) powder. The optimisation procedure was conducted using the Taguchi statistical method. An L9 orthogonal array with four factors of control at three levels each was employed. The analysis showed that the drying time had the greatest influence on the precision of green parts, followed by binder saturation and target bed temperature. Binder set time did not seem to affect the results. Dimensional analysis, microstructural and piezoelectric characterisation of parts densified by pressureless sinterin..
Additive manufacturing of lead-free KNN by binder jetting
No full textAdditive manufacturing of lead-free piezoceramics is of great interest, given the large request of application-oriented designs with optimal performances and reduced material consumption. Binder Jetting (BJ) is an additive manufacturing technique potentially suited to the production of ceramic components, however the number of feasibility studies on BJ of piezoceramics is extremely limited and totally lacking in the case of sodium-potassium niobate (KNN). In this work, as-synthesised powders are employed in the BJ 3D printing process. Microstructural properties, such as porosity, grain size distributions, and phase composition are studied by SEM, XRD and MIP (Mercury Intrusion Porosimetry) and compared to die-pressed pellets. Analyses reveal considerable residual porosity (~40%) regardless of the printing parameters, with a weak preferential orientation parallel to the printing plane. The piezoelectric characterization demonstrates an outstanding d33 value of 80–90 pC N−1. Finally, Figures of Merits for the employment as porous piezoceramics in the direct mode are presented
Spray drying granulation of potassium sodium niobate (KNN) for binder jetting: Feedstock preparation and influence on sintered material properties
No full textBinder jetting of potassium sodium niobate (K0.5Na0.5NbO3) offers potential for generating shape-dependent responses with high industrial output. However, the printing stage relies heavily on the properties of the dry feedstock, making its performance optimization crucial. In this regard, morphological functionalization through granulation can be a useful methodology. This study characterizes two powders in dry and wet states to develop colloidal suspensions for spray drying granulation. Particle size, shape, and ζ-potential are measured to stabilize them in an aqueous slurry. Granule morphology and flowability are assessed and compared with the original feedstock. Disk-shaped specimens are then printed and sintered. Spray drying granulation successfully produces spherical and fine feedstocks compatible with the typical layer thickness (50 μm) of binder jetting. Densified parts displayed significant residual porosity (20–40 %) along the building direction, affecting piezoelectric performance: strain coefficients were reduced, but increased voltage coefficients yielded high figures-of-merit
Hermeneutics and Epistemology
No full textIn a collection of essays published in the 1970s under the title Vernunft in die Zeitalter der Wissenschaft, Gadamer confronts developments in analytical epistemology, arguing about epistemology from a hermeneutical point of view. Relations between the two traditions remain difficult. Paolo Parrini was among the few who opened to a real dialogue, neither superficial nor formal. He considered the hermeneutical tradition from an epistemological point of view, finding many connections via a third view between metaphysical realism and strong relativism. This theoretically dense and challenging perspective was expressed in two essays – “Ermeneutica ed epistemologia” (1998) and “Ermeneutica ed epistemologia 2: Heidegger, Kant e la verità” (2011). Parrini focused on the concept of Offenheit der Erfahrung in Gadamer’s Wahrheit und Methode and, later, on Heidegger’s theory of truth as alètheia. In this paper the author argues that original results of Parrini’s research confirm the fruitfulness of the encounter between hermeneutics and epistemology. He tries at the same time to identify some friction points and theoretical constraints, for further comparative development, in theory of language and theory of history, on which Gadamer’s ontological hermeneutics lies. The first tends to eliminate any distance between experience and language; the second presents conflicting aspects about identity conditions of past events, as investigated in history. To become fully productive, the dialogue between epistemological and hermeneutical traditions will be able to face a deep revision about these topics.In a collection of essays published in the 1970s under the title Vernunft in die Zeitalter der Wissenschaft, Gadamer confronts developments in analytical epistemology, arguing about epistemology from a hermeneutical point of view. Relations between the two traditions remain difficult. Paolo Parrini was among the few who opened to a real dialogue, neither superficial nor formal. He considered the hermeneutical tradition from an epistemological point of view, finding many connections via a third view between metaphysical realism and strong relativism. This theoretically dense and challenging perspective was expressed in two essays – “Ermeneutica ed epistemologia” (1998) and “Ermeneutica ed epistemologia 2: Heidegger, Kant e la verità” (2011). Parrini focused on the concept of Offenheit der Erfahrung in Gadamer’s Wahrheit und Methode and, later, on Heidegger’s theory of truth as alètheia. In this paper the author argues that original results of Parrini’s research confirm the fruitfulness of the encounter between hermeneutics and epistemology. He tries at the same time to identify some friction points and theoretical constraints, for further comparative development, in theory of language and theory of history, on which Gadamer’s ontological hermeneutics lies. The first tends to eliminate any distance between experience and language; the second presents conflicting aspects about identity conditions of past events, as investigated in history. To become fully productive, the dialogue between epistemological and hermeneutical traditions will be able to face a deep revision about these topics
La casa, la calle y el territorio. Narraciones fotográficas de Guido Guidi
No full textGuido Guidi construye sus secuencias fotográficas como narraciones: sus imágenes pueden
ser interpretadas como testimonio de un paisaje contemporáneo solamente al considerar
también su connotación literaria: hay que reconocer las herramientas retoricas con las cuales
su autor las presenta y las vinculas entre ellas. El libro Cinque Paesaggi 1983-1993 (2013)
ofrece un ejemplo de esto: en sus páginas la figura de la casa es presentada como arquetipo
arquitectónico y se pone en relación dialéctica con la figura de la calle, contra un fondo natural
siempre presente. El arquitecto puede acoger las imágenes del fotógrafo como herramientas de
su trabajo solo si consigue comprenderlas más allá de su percepción inmediata.Guido Guidi builds his photographic sequences as literary narrations: an architect could
consider his images as evidence of the contemporary landscape only if he is aware of their
semantic connotations and could recognize the rhetorical tools by which the author displays and
interrelate his pieces. The book Cinque Paesaggi 1983-1993 (2013) offers a useful case study:
in its pages the figure of the house is presented as an architectural archetype in dialectical
relation with the figure of the road, both standing by an always persistent natural scenery.
Guidi’s images could be used by architects in their job only if they achieve to understand them
beyond their mere evidence
Theories of Interpretation and Wertfreiheit
No full textThis work stems from the need to deepen the reconstruction proposed for the headword “Avalutativity” in a large Dictionary of Hermeneutics (in preparation). The confrontation with the theme of “avalutativity” brings up very relevant and sometimes central questions in the 20th-century philosophical debate: from the relationship between language and experience to that between ontology and epistemology, and from the relationship between philosophy and science to accounts with the Kantian heritage. In order to address the philosophical complexity of the sources, the author develops an internal textual reconstruction of the topic, to get to the bottom of its autonomous theoretical depth
Additive Manufacturing of Piezoelectric Niobium-Doped Lead Zirconate Titanate (PZT-N) by Binder Jetting
No full textBinder jetting is an emerging indirect additive manufacturing technique for ceramic materials, which could be employed to produce application-oriented designed components impossible to achieve with traditional processes and featuring enhanced performances. In our study, niobium-doped lead zirconate titanate (PZT-N) powder, usually processed through the standard press-and-sinter route, was employed as the raw material. First, the powder was characterized in terms of granulometry and flowability to assess its suitability for the printing process. Then, shaping by binder jetting was studied, and the effect of three levels of binder saturation (75–90–105%) on the green bodies was assessed. Finally, the microstructure of the sintered samples was studied using SEM, to investigate the effect of thermal treatments on the grain size distribution and residual porosity (~40%). The piezoelectric properties were measured and compared to those of conventionally processed material. The piezoelectric charge and voltage constants (d33 and g33) were evaluated to determine the possible use of printed parts as porous piezoelectric components to be exploited in hydrophones in the direct mode
