30 research outputs found
Le conoscenze in FÃsica all'inizio dei corsi universitari in Italia
The article reports the results of an investigation on Italian university students concerning physics knowledge related to common sense schemes at the beginning of the university courses. The results of the diagnosis were communicated both to the students and to the teachers of the courses. The communication enabled the teachers, in the didactical practice, to pinpoint and discuss with the students the discrepancies between the scientific newtonian scheme and common sense scheme. A posttest, given at the end of the course, gives the indication that this practice is effective in inducing a change in the students ideas, notwithstanding the fact that no complete understanding of the scientific viewpoint is teached by the majority of students
Asymmetric Fluid Criticality I: Scaling with Pressure Mixing
The thermodynamic behavior of a fluid near a vapor-liquid and, hence,
asymmetric critical point is discussed within a general ``complete'' scaling
theory incorporating pressure mixing in the nonlinear scaling fields as well as
corrections to scaling. This theory allows for a Yang-Yang anomaly in which
\mu_{\sigma}^{\prime\prime}(T), the second temperature derivative of the
chemical potential along the phase boundary, diverges like the specific heat
when T\to T_{\scriptsize c}; it also generates a leading singular term,
|t|^{2\beta}, in the coexistence curve diameter, where t\equiv
(T-T_{\scriptsize c}) /T_{\scriptsize c}. The behavior of various special loci,
such as the critical isochore, the critical isotherm, the k-inflection loci, on
which \chi^{(k)}\equiv \chi(\rho,T)/\rho^{k} (with \chi = \rho^{2}
k_{\scriptsize B}TK_{T}) and C_{V}^{(k)}\equiv C_{V}(\rho,T)/\rho^{k} are
maximal at fixed T, is carefully elucidated. These results are useful for
analyzing simulations and experiments, since particular, nonuniversal values of
k specify loci that approach the critical density most rapidly and reflect the
pressure-mixing coefficient. Concrete illustrations are presented for the
hard-core square-well fluid and for the restricted primitive model electrolyte.
For comparison, a discussion of the classical (or Landau) theory is presented
briefly and various interesting loci are determined explicitly and illustrated
quantitatively for a van der Waals fluid.Comment: 21 pages in two-column format including 8 figure
Master crossover functions for the one-component fluid "subclass"
Introducing three well-defined dimensionless numbers, we establish the link
between the scale dilatation method able to estimate master (i.e. unique)
singular behaviors of the one-component fluid "subclass" and the universal
crossover functions recently estimated [Garrabos and Bervillier, Phys. Rev. E
74, 021113 (2006)] from the bounded results of the massive renormalization
scheme applied to the..
Conjectures on exact solution of three - dimensional (3D) simple orthorhombic Ising lattices
We report the conjectures on the three-dimensional (3D) Ising model on simple
orthorhombic lattices, together with the details of calculations for a putative
exact solution. Two conjectures, an additional rotation in the fourth curled-up
dimension and the weight factors on the eigenvectors, are proposed to serve as
a boundary condition to deal with the topologic problem of the 3D Ising model.
The partition function of the 3D simple orthorhombic Ising model is evaluated
by spinor analysis, by employing these conjectures. Based on the validity of
the conjectures, the critical temperature of the simple orthorhombic Ising
lattices could be determined by the relation of KK* = KK' + KK'' + K'K'' or
sinh 2K sinh 2(K' + K'' + K'K''/K) = 1. For a simple cubic Ising lattice, the
critical point is putatively determined to locate exactly at the golden ratio
xc = exp(-2Kc) = (sq(5) - 1)/2, as derived from K* = 3K or sinh 2K sinh 6K = 1.
If the conjectures would be true, the specific heat of the simple orthorhombic
Ising system would show a logarithmic singularity at the critical point of the
phase transition. The spontaneous magnetization and the spin correlation
functions of the simple orthorhombic Ising ferromagnet are derived explicitly.
The putative critical exponents derived explicitly for the simple orthorhombic
Ising lattices are alpha = 0, beta = 3/8, gamma = 5/4, delta = 13/3, eta = 1/8
and nu = 2/3, showing the universality behavior and satisfying the scaling
laws. The cooperative phenomena near the critical point are studied and the
results obtained based on the conjectures are compared with those of the
approximation methods and the experimental findings. The 3D to 2D crossover
phenomenon differs with the 2D to 1D crossover phenomenon and there is a
gradual crossover of the exponents from the 3D values to the 2D ones.Comment: 176 pages, 4 figure
Una investigación sobre habilidades para el aprendizaje cientÃfico
We report on the natural sciences aspects (physics and biology) of arnore complete research on the prerequisites which university teachers expect from freshmen, and the actual capabilities of students at the end of their secondary school. This research has been done on 120 students of 15 classes in Rome (Ktaly). We have tested their ability of transposition among verbal, mathematical and graphical languages, sf reading non-elementary graphs, of utilizing empirical data. The conclusion is that at the end of their high school students are largely unprepared to cope with scientific studies, because of their low training to assume analytic attitudes and to operate in formalized manners
Una investigación sobre habilidades para el aprendizaje cientÃfico
We report on the natural sciences aspects (physics and biology) of arnore complete research on the prerequisites which university teachers expect from freshmen, and the actual capabilities of students at the end of their secondary school. This research has been done on 120 students of 15 classes in Rome (Ktaly). We have tested their ability of transposition among verbal, mathematical and graphical languages, sf reading non-elementary graphs, of utilizing empirical data. The conclusion is that at the end of their high school students are largely unprepared to cope with scientific studies, because of their low training to assume analytic attitudes and to operate in formalized manners
Enseñanza de las ciencias : revista de investigación y experiencias didácticas
Resumen basado en el de la publicaciónResumen en inglésSe informa sobre los aspectos de las ciencias naturales (fÃsica y biologÃa) de una completa investigación sobre los requisitos previos que los profesores universitarios esperan de los estudiantes de primer año, y las capacidades reales de los estudiantes al final de su escuela secundaria.
Esta investigación se ha realizado en 120 estudiantes de 15 clases en Roma (Italia). Se ha probado su capacidad de transposición entre los lenguajes verbales, matemáticos y gráficos, de lectura de gráficos no elementales y de la utilización de datos empÃricos.
La conclusión es que al final de la escuela secundaria, los estudiantes no están en gran medida preparados para hacer frente a los estudios cientÃficos, debido a su baja instrucción para asumir actitudes analÃticas y para operar de forma formalizada.ES
Le conoscenze in FÃsica all'inizio dei corsi universitari in Italia
The article reports the results of an investigation on Italian university students concerning physics knowledge related to common sense schemes at the beginning of the university courses. The results of the diagnosis were communicated both to the students and to the teachers of the courses. The communication enabled the teachers, in the didactical practice, to pinpoint and discuss with the students the discrepancies between the scientific newtonian scheme and common sense scheme. A posttest, given at the end of the course, gives the indication that this practice is effective in inducing a change in the students ideas, notwithstanding the fact that no complete understanding of the scientific viewpoint is teached by the majority of students