Search results for "Limite"

Analysis and design of elastic plastic structures subjected to dynamic loads

In the last decades, the concept of “optimization” has reached considerable value in many different fields of scientific research and, in particular, it has assumed great importance in the field of structural mechanics. The present study describes and shows the scientific path followed in the three years of doctoral studies. The state of the art concerning the optimization of elastic plastic structures subjected to quasi-static loads was already well established at the beginning of the Ph.D. course. Actually, it was already faced the study of structures subjected to quasi-static cyclic loads able to ensure different structural behaviors in relation to different intensity levels of the appli…

Minimum volume design of structures with constraints on ductility and stability

2014

Abstract A minimum volume design problem of elastic perfectly plastic frame structures subjected to different combinations of fixed and seismic loads is presented, in which the design variables are considered as appertaining alternatively to a continuous assigned range as well as to appropriate discrete sets. The structure is designed so as to behave elastically for the applied fixed loads, to shakedown in presence of serviceability seismic conditions and to prevent the instantaneous collapse for suitably chosen combinations of fixed and high seismic loadings. In order to avoid further undesired collapse modes, the P-Delta effects are considered and the structure is also constrained to prev…

TWO NEW FAMILIES OF PLATICURTIC CURVES FOR LIMITED INTERVALS

2006

Mediterranean diet and adiposity in children and adolescents: A systematic review

2021

Our aim was to summarize, through a systematic review, the current evidence from dietary intervention and observational studies on the impact of adherence to the Mediterranean diet on adiposity markers and obesity in children and adolescents. We searched Medline up to June 1, 2021 for the identification of intervention and observational studies meeting the inclusion criteria, following the PRISMA statement. We included 55 articles: 8 intervention studies and 47 observational studies. Three trials report a beneficial effect of the dietary intervention, whereas two did not, and three did not compare with a control. All observational studies were cross-sectional, and only five studies also inc…

Opinia prawna na temat beneficjenta rzeczywistego w przypadku spółki kapitałowej, której jedynym (100%) udziałowcem czy akcjonariuszem jest zakon, bą…

2020

Celem niniejszej opinii prawnej jest udzielenie odpowiedzi na pytanie: Kto jest beneficjentem rzeczywistym w przypadku spółki kapitałowej, której jedynym (100%) udziałowcem czy akcjonariuszem jest zakon bądź jego jednostka organizacyjna (prowincja zakonna, opactwo, klasztor niezależny, dom zakonny)? Przeprowadzone analizy przepisów prawa polskiego i prawa kanonicznego prowadzą do wniosku, że w przypadku spółki kapitałowej, której jedynym (100%) udziałowcem czy akcjonariuszem jest zakon bądź jego jednostka organizacyjna (prowincja zakonna, opactwo, klasztor niezależny, dom zakonny) beneficjentem rzeczywistym jest właściwy wyższy przełożony tego zakonu oraz członkowie jego rady. Osoby te speł…

Collective coordinate approach for the dynamics of light pulses in fiber ring lasers

2014

We present an efficient variational approach for fiber lasers in which light pulses may execute complex dynamics, and we establish its validity by comparison with the numerical approach based on the generalized nonlinear Schroedinger equation.

Nonlinear pulse shaping and polarization dynamics in mode-locked fiber lasers

2014

International audience; We review our recent progress on the study of new nonlinear mechanisms of pulse shaping in passively mode-locked fiber lasers. These include a mode-locking regime featuring pulses with a triangular distribution of the intensity, and spectral compression arising from nonlinear pulse propagation. We also report on our recent experimental studies unveiling new types of vector solitons with processing states of polarization for multi-pulse and tightly bound-state soliton (soliton molecule) operations in a carbon nanotube (CNT) mode-locked fiber laser with anomalous dispersion cavity.

Self-similarity in ultrafast nonlinear optics

2007

International audience; Recent developments in nonlinear optics have led to the discovery of a new class of ultrashort pulse, the `optical similariton'. Optical similaritons arise when the interaction of nonlinearity, dispersion and gain in a high-power fibre amplifier causes the shape of an arbitrary input pulse to converge asymptotically to a pulse whose shape is self-similar. In comparison with optical solitons, which rely on a delicate balance of nonlinearity and anomalous dispersion and which can become unstable with increasing intensity, similaritons are more robust at high pulse powers. The simplicity and widespread availability of the components needed to build a self-similar amplif…

Analytical Evaluation of the Temporal Focal Shift for Arbitrary Pulse Shapes

2004

In this letter, we analyze the propagation of linearly chirped arbitrary-shaped light pulses through a parabolic dispersive medium to derive an analytical formula of assessing the location of the transverse plane where the pulse root-mean-square width is minimum. Closed form expressions for compressed pulses, which are independent of the input pulse shape, are demonstrated. In this way, we demonstrate that both the relative temporal focal shift and the minimum pulsewidth are solely determined by two factors, the temporal equivalent of the Fresnel number of the geometry and the pulse quality factor, i.e., the temporal analogue of the spatial M/sup 2/ beam quality factor. Some examples are di…

Thermal solitons along wires with flux-limited lateral exchange

2021

We obtain some exact solutions in the context of solitons, for heat conduction with inertia along a cylinder whose heat exchange with the environment is a non-linear function of the difference of temperatures of the cylinder and the environment, due to a flux-limiter behavior of the exchange. We study the consequences of heat transfer and information transfer along the wire, and we compare the situation with analogous solitons found in nonlinear lateral radiative exchange studied in some previous papers. We also find further exact solutions in terms of Weierstrass elliptic functions for the sake of completeness.