Filatura del algodón : manual teórico-práctico

Las il. y las h. de grab. son dib. de maquinaria

Industry 4.0 and sustainability: Towards conceptualization and theory

Both Industry 4.0 and sustainability have gained momentum in the academic, managerial and policy debate. Despite the relevance of the topics, the relation between Industry 4.0 and sustainability \u2013 revealed by many authors \u2013 is still unclear; literature is fragmented. This paper seeks to overcome this limit by developing a systematic literature review of 117 peer-reviewed journal articles. After descriptive and content analyses, the work presents a conceptualization and theoretical framework. The paper contributes to both theory and practice by advancing current understanding of Industry 4.0 and sustainability, especially the impact of Industry 4.0 technologies on sustainability practices and performance

Carducci e «La guerra»

Chi ritorni a sfogliare l’ultima raccolta di Carducci può imbattersi, come a me è avvenuto quasi per caso, in un verso (e mezzo) davvero, per me, fulminante: «(Colà dove mummie) / Dormono inutili Faraoni...». La poesia, ahimè, che è La guerra (1891), di fulminante non ha invece nulla, e non mi meraviglio di non averci fatto caso ai tempi in cui leggevo Carducci con partecipazione, né di non averla citata nel mio manuale di metrica.Qui (essendo la metrica altra cosa dalla poesia) avrebbe potuto trovare un posto come ode alcaica il cui decasillabo non ha mai l’accento sulla sesta sillaba, come, nelle stesse Rime e ritmi di cui fa parte, la prima e la terza parte di Cadore, diversamente dall’odicina Nel chiostro del Santo, il cui decasillabo ha sempre terza e sesta toniche: forse perché la prima soluzione era sentita come più solenne? Si può solo dire che quando Carducci riesce nella migliore delle alcaiche, Alla stazione, a mettere in tensione e a rendere poeticamente necessario un linguaggio tra arcaico e straniato, il decasillabo ha sempre terza e sesta toniche («Tu pur pensosa, Lidia, la tessera / al secco taglio dài de la guardia, / e al tempo incalzante i begli anni / dài, gl’istanti gioiti e i ricordi»). Una semplice occhiata ai manoscritti mostra però il fatto curioso che a Carducci per il quarto verso tendeva a scappare l’endecasillabo: nella prima versione delle prime due strofe, «E l’uomo surse sbadigliando guerra » (destossi annotato sopra surse), «E truce rise sul percosso Abele»; e in un’ulteriore strofa che si trova nel primo foglietto manoscritto, e di cui non si rimpiangerà che non sia poi rimasto quasi nulla, un assai dubbio «Ad acuire la lucente selce» (ma si sa che i poeti dell’Ottocento per il sillabismo interno di parola – dieresi e sineresi – non esitavano quasi di fronte a niente)

Perturbation Theory for Metastable States of the Dirac Equation with Quadratic Vector Interaction

The spectral problem of the Dirac equation in an external quadratic vector potential is considered using the methods of the perturbation theory. The problem is singular and the perturbation series is asymptotic, so that the methods for dealing with divergent series must be used. Among these, the Distributional Borel Sum appears to be the most well suited tool to give answers and to describe the spectral properties of the system. A detailed investigation is made in one and in three space dimensions with a central potential. We present numerical results for the Dirac equation in one space dimension: these are obtained by determining the perturbation expansion and using the Pad\'e approximants for calculating the distributional Borel transform. A complete agreement is found with previous non-perturbative results obtained by the numerical solution of the singular boundary value problem and the determination of the density of the states from the continuous spectrum.Comment: 10 pages, 1 figur

Combined use of lung ultrasound, B-type natriuretic peptide, and echocardiography for outcome prediction in patients with acute HFrEF and HFpEF

Background: Lung ultrasound (LUS) can be used to assess pulmonary congestion by imaging B-lines (‘comets’) for patients with acute heart failure (AHF). Objectives: Investigate relationship of B-lines, plasma concentrations of B-type natriuretic peptide (BNP), and echocardiographic left ventricular (LV) function measured at admission and discharge and their relationship to prognosis for AHF with preserved (HFpEF) or reduced (HFrEF) LV ejection fraction. Methods: Patients with AHF had the above tests done at admission and discharge. The primary outcome was re-hospitalization for heart failure or death at 6 months. Results: Of 162 patients enrolled, 95 had HFrEF and 67 had HFpEF, median age was 80 [77–85] years, and 85 (52%) were women. The number of B-lines at admission (median 31 [27–36]) correlated with respiratory rate (r = 0.75; p < 0.001), BNP (r = 0.43; p < 0.001), clinical congestion score (r = 0.25; p = 0.001), and systolic pulmonary artery pressure (r = 0.42; p < 0.001). At discharge, B-lines were also correlated with BNP (r = 0.69; p < 0.001) and congestion score (r = 0.57; p < 0.001). B-line count at discharge predicted outcome (AUC 0.83 [0.77–0.90]; univariate HR 1.12 [1.09–1.16]; p < 0.001; multivariable HR 1.16 [1.11–1.21]; p < 0.001). Results were similar for HFpEF and HFrEF. Conclusions: LUS appears a useful method to assess severity and monitor the resolution of lung congestion. At hospital admission, B-lines are strongly related to respiratory rate, which may be a key component of the sensation of dyspnea. Measurement of lung congestion at discharge provides prognostic information for patients with either HFpEF or HFrEF

Gradient catastrophe and flutter in vortex filament dynamics

Gradient catastrophe and flutter instability in the motion of vortex filament within the localized induction approximation are analyzed. It is shown that the origin if this phenomenon is in the gradient catastrophe for the dispersionless Da Rios system which describes motion of filament with slow varying curvature and torsion. Geometrically this catastrophe manifests as a rapid oscillation of a filament curve in a point that resembles the flutter of airfoils. Analytically it is the elliptic umbilic singularity in the terminology of the catastrophe theory. It is demonstrated that its double scaling regularization is governed by the Painlev\'e-I equation.Comment: 11 pages, 3 figures, typos corrected, references adde

Surgical treatment of central grade 1 chondrosarcoma of the appendicular skeleton.

Diagnosis and treatment of low-grade chondrosarcoma remain controversial. We performed a review of a single-center series with the aims of assessing the oncologic outcome of these patients, verifying if intralesional curettage can be adequate treatment, and defining clinical criteria to support the surgeon and the oncologist in decision-making for surgery and subsequent follow-up