Correction to: A Regular Integral Equation Formalism for Solving the Standard Boussinesq’s Equations for Variable Water Depth

The author would like to correct an error in calculation of the Eq. (A.2.8) in Appendix A.2 of the original article. The correct equation is as follows:

Corrigendum: In the paper Contribution study of the thermodynamics properties of the ammonia-water mixtures, doi reference: 10.2298/TSCI110206083K

Simeon Oka, Editor-in-Chief of the journal Thermal Science request that it is necessary to correct Equation No. 6 in the paper CONTRIBUTION STUDY OF THE THERMODYNAMICS PROPERTIES OF THE AMMONIA-WATER MIXTURES by Sahraoui KHERRIS a, b*, Mohammed MAKHLOUF b, Djallel ZEBBAR a, and Omar SEBBANE c aInstitute of Sciences and Technology, University of Tissemsilt, Tissemilt, Sidi Bel Abbes, Algeria bReactifs Systems and Materials Laboratory, Djillali LIABES University, Algeria cMaterials and Renewable Energy Laboratory, Abou Bekr Belkaid University, Tlemcen, Algeria Original scientific paper DOI: 10.2298/TSCI110206083K published in the journal THERMAL SCIENCE: Year 2013, Vol. 17, No. 3, pp. 891-902 since due to typing error Equation No. 6, of this paper has not been correctly written.<br><br><font color="red"><b> Link to the corrected article <u><a href="http://dx.doi.org/10.2298/TSCI110206083K">10.2298/TSCI110206083K</a></b></u>

Scale effects on conventional and intercooled turbofan engine performance-CORRIGENDUM

In the article by Rolt(1), there was an error in Equation (2). The correct equation is republished here. 2$$\begin{equation} {W_c} = \ \frac{{{W_{\it cref}}\left( {{T_{\it grel}} - {T_{\it cref}}} \right){{({W_4}/{W_{\it 4ref}})}^{0.65}}}}{{\left( {{T_{\it gref}} - {T_c}} \right)}}\ \ \ \ \ \ \ \end{equation}$$

Unlocking Problem Solving Difficulties of Teacher Education Students

Problem-solving is often associated with word problems that do not focus only the content knowledge but also on the ability of students to analyze the problem and apply appropriate strategy to arrive at the correct answer. This research used descriptive design to analyze the problem-solving abilities of the Bachelor of Elementary Education III students of the Isabela State University- Cauayan Campus for the SY 2011- 2012. The research used a teacher-made test. Frequency and percentage were employed to analyze data regarding sources of the difficulty of the students. Results showed that some students had a difficulty in representing the problem. A student who successfully represented the problem managed to produce the correct equation and eventually solve the problem correctly. The difficulty of the students lies in representing the unknown quantities. A proportion of those who did not make any attempts to represent the problem and those who did not correctly represent the problem can also produce correct equation by using the word matching approach. However, this approach is not applicable when the problem is using a less inconsistent problem that can be seen in the number problem. Some students with difficulty in solving equations were very minimal. Keywords-Mathematics, difficulty, problem-solving test, Isabela, Philippines

Direct calculation of length contraction and clock retardation

For simple electromagnetic models of a rod and a clock, a change of shape of a rod and of the rate of clock when they are set in uniform motion is calculated exactly, employing the correct equation of motion of a charged particle in electromagnetic field and the universal boostability assumption. Thus it is demonstrated that, for the simple system considered, the length contraction and clock retardation can be interpreted as dynamical cause-and-effect phenomena, and not as kinematical effects as usually construed in conventional presentations of Special Relativity. It is argued that the perspective relativistic change of an object (corresponding to observations from two inertial frames), while certainly being an a causal effect, has a dynamical content in the sense that it is tantamount to an actual dynamical change of the object in one frame.

Modified Hamiltonian Formalism for Regge-Teitelboim Cosmology

The Ostrogradski approach for the Hamiltonian formalism of higher derivative theory is not satisfactory because the Lagrangian cannot be viewed as a function on the tangent bundle to coordinate manifold. In this paper, we have used an alternative approach which leads directly to the Lagrangian which, being a function on the tangent manifold, gives correct equation of motion; no new coordinate variables need to be added. This approach can be used directly to the singular (in Ostrogradski sense) Lagrangian. We have used this method for the Regge-Teitelboim (RT) minisuperspace cosmological model. We have obtained the Hamiltonian of the dynamical equation of the scale factor of RT model.

Nonlinear ion acoustic excitations in relativistic degenerate, astrophysical electron-positron-ion plasmas – CORRIGENDUM

A misprint occured in equation 26 in the original article (Ur-Rahman et al. 2013). The correct equation is provided below. \[ \zeta=\epsilon^{1/2}\left(x-\lambda t\right) \rm{, \ \ }\tau=\epsilon^{3/2}t\rm{.}% \] This misprint does not affect the calculations, the figures and the discussion presented in the original article.

Why Should Ensemble Spread Match the RMSE of the Ensemble Mean?

When evaluating the reliability of an ensemble prediction system, it is common to compare the root-mean-square error of the ensemble mean to the average ensemble spread. While this is indeed good practice, two different and inconsistent methodologies have been used over the last few years in the meteorology and hydrology literature to compute the average ensemble spread. In some cases, the square root of average ensemble variance is used, and in other cases, the average of ensemble standard deviation is computed instead. The second option is incorrect. To avoid the perpetuation of practices that are not supported by probability theory, the correct equation for computing the average ensemble spread is obtained and the impact of using the wrong equation is illustrated.