Reply to “Comment on ‘Piezonuclear decay of thorium’ [Phys. Lett. A 373 (2009) 1956]” [Phys. Lett. A 373 (2009) 3795]

In a paper appearing in this issue of Physics Letters A, Ericsson et al. raise some critical comments on the experiment [F. Cardone, R. Mignani, A. Petrucci, Phys. Lett. A 373 (2009) 1956] we carried out by cavitating a solution of thorium-228, which evidenced its anomalous decay behaviour, thus confirming the results previously obtained by Urutskoev et al. by explosion of titanium foils in solutions. In this Letter, we reply to these comments. In our opinion, the main shortcomings of the criticism by the Swedish authors are due to their omitting of inserting our experiment in the wider research stream of piezonuclear reactions, and to the statistical analysis they used, which does not comply with the rules generally accepted for samples with small numbers. However, apart from any possible theoretical speculation, there is the basic fact that two different experiments (ours and that by Urutskoev et al.), carried out independently and by different means, highlight an analogous anomaly in the decay of thorium subjected to pressure waves. Such a convergence of results shows that it is worth to further carry on experimental investigations, in order to get either a confirmation or a disproof of the induced-pressure anomalous behaviour of radioactive nuclides even different from thorium.     

Comment on: “Protective measurements and Bohm trajectories” [Phys. Lett. A 263 (1999) 137]

In the above Letter, it is claimed that Bohm's mechanics can be challenged by a simple gedanken experiment involving a protecting measurement. Here we show that this gedanken experiment can be justified without problem and without contradicting the axiom attributing a physical meaning to the Bohmian trajectory.     

Comment on: “Globally exponential synchronization in array of asymmetric coupled neural networks” [Phys. Lett. A 369 (2007) 444]

In this Letter, we indicate that the proposed sufficient condition in Letter [J.Q. Lu, W.C. Ho, M. Liu, Phys. Lett. A 369 (2007) 444] does not hold when coupling matrix G satisfies Assumption 3 in Letter [J.Q. Lu, W.C. Ho, M. Liu, Phys. Lett. A 369 (2007) 444]. Besides, there are some mistakes in deducing Theorem 1. The mistakes have been corrected and a correct version is given in this Letter.     

Comment on: “Quantum exam” [Phys. Lett. A 350 (2006) 174]

In the Letter [B.A. Nguyen, Phys. Lett. A 350 (2006) 174], a quantum exam protocol was presented. Here we show a cheating protocol, by which any student can get the other students' solution without being detected. Then we propose a possible modified protocol against this attacking strategy.     

Reply to: “Comment on: ‘Epidemic spreading on heterogeneous networks with identical infectivity’ [Phys. Lett. A 364 (2007) 189]” [Phys. Lett. A 372 (2008) 1722]

In a recent Letter [R. Yang, B.H. Wang, J. Ren, W.J. Bai, Z.W. Shi, W.X. Wang, T. Zhou, Phys. Lett. A 364 (2007) 189], we proposed a modified susceptible-infected-recovered (SIR) model, in which each node is assigned with an identical capability of active contact, A, at each time step. We found a threshold value λc=1/A in uncorrelated and unlocalized networks. A corresponding Comment, raised by Alberto d'Onofrio, claimed that (i) our model is not biologically relevant; (ii) our model does not have a threshold behavior for recovered population; (iii) the analytical result λc=1/A is incorrect being considered as a threshold for epidemic outbreak, because of an improper approximation of the initial configuration. In this Reply, I show that, by debating from point to point, our analysis and conclusion are solid and reasonable.     

Comment on: “Questions concerning the generalized Hartman effect” [Phys. Lett. A 375 (2011) 3259]

In this comment, we show that the arguments against the applicability of stationary phase method (SPM) for tunneling time calculations, presented in Letter “Questions concerning the generalized Hartman effect” are not valid for small wave packet energy widths.     

Comments on “Finite-time stabilization of three-dimensional chaotic systems based on CLF” [Phys. Lett. A 374 (2010) 3021]

In the Letter [W.G. Yu, Finite-time stabilization of three-dimensional chaotic systems based on CLF, Phys. Lett. A 374 (2010) 3021], Yu investigated the finite-time stabilization of three-dimensional chaotic systems based on CLF. However, there are some errors in that Letter.     

Erratum to: “Controlling complex dynamical networks with coupling delays to a desired orbit” [Phys. Lett. A 359 (2006) 42]

In this Letter, we indicate that the proposed sufficient condition in Letter [Z. Li, G. Feng, D., Hill, Phys. Lett. A 359 (2006) 42] does not hold, which cannot guarantee that the states of complex network with coupling delays globally exponentially synchronize with a desired orbit and it only applies to globally asymptotical synchronization with a desired orbit. For correcting the mistakes, a correct version of globally exponential synchronization is given and proved in this Letter.     

Comment on: “From classical to modern ether-drift experiments: the narrow window for a preferred frame” [Phys. Lett. A 333 (2004) 355]

In a recent article [M. Consoli, E. Costanzo, Phys. Lett. A 333 (2004) 355], M. Consoli and E. Costanzo have investigated classical and modern aether drift experiments and explored the narrow window for detection of a preferred reference frame. This Letter proposes an easy to perform variant of Fizeau's experiment, which may confirm or deny Consoli–Costanzo's claims.     

Comment on: “Dynamical analysis of Cohen-Grossberg neural networks with distributed delays” [Phys. Lett. A 364 (2007) 38]

It is pointed out that an unnatural assumption is made in the following Letter [Z. Mao, H. Zhao, Phys. Lett. A 364 (1) (2007) 38]. Therefore, the results of the Letter are not relevant to the real Cohen-Grossberg neural network model.     

Comment on “Deterministic six states protocol for quantum communication” [Phys. Lett. A 358 (2006) 85]

In [J.S. Shaari, M. Lucamarini, M.R.B. Wahiddin, Phys. Lett. A 358 (2006) 85] the deterministic six states protocol (6DP) for quantum communication has been developed. This protocol is based on three mutually unbiased bases and four encoding operators. Information is transmitted between the users via two qubits from different bases. Three attacks have been studied; namely intercept-resend attack (IRA), double-CNOT attack (2CNOTA) and quantum man-in-the-middle attack. In this Letter, we show that the IRA and 2CNOTA are not properly addressed. For instance, we show that the probability of detecting Eve in the control mode of the IRA is 70% instead of 50% in the previous study. Moreover, in the 2CNOTA, Eve can only obtain 50% of the data not all of it as argued earlier.     

Comment on: “Dynamical analysis of Cohen-Grossberg neural networks with continuously distributed delays” [Phys. Lett. A 364 (2007) 38]

Recently, Mao and Zhao [Z. Mao, H. Zhao, Phys. Lett. A 364 (2007) 38] considered the existence and uniqueness of the equilibrium point of the Cohen-Grossberg neural network model with continuously distributed delays. Mao and Zhao established Theorem 1. In this Letter, we would like to point out that Theorem 1 given by Mao and Zhao is incorrect in general.     

Comment on: “Construction of bound entangled edge states with special ranks” [Phys. Lett. A 359 (2006) 603]

Recently, Clarisse [L. Clarisse, Phys. Lett. A 359 (2006) 603] and Ha [K.-C. Ha, Phys. Lett. A 361 (2007) 515] found examples of types (5,5) and (6,6) entangled states with positive partial transposes. In this Letter, we show that their examples have the Schmidt number as 2.     

Comment on “Propagation of flexural wave in periodic beam on elastic foundations” [Phys. Lett. A 376 (2012) 626]

In this comment, we argue that the concept of the pivotal frequency presented in Letter “Propagation of flexural wave in periodic beam on elastic foundations” is not proper and the applicability of the formula of the pivotal frequency is not valid for all conditions.     

Comment on: “A simple chaotic delay differential equation” [Phys. Lett. A 366 (2007) 397]

The purpose of this Letter is to give the reference for the model proposed in the discussion section of the above paper [J.C. Sprott, Phys. Lett. A 366 (2007) 397] and to show that chaotic behavior of this model has been studied in [A. Uçar, Int. J. Eng. Sci. 40 (2002) 251; A. Uçar, Chaos Solitons Fractals 16 (2003) 187].     

Comment on “Piezonuclear decay of thorium” [Phys. Lett. A 373 (2009) 1956]

Subjecting a solution of ²²⁸Th to ultrasound (20 kHz, 100 W), Cardone et al. [F. Cardone, R. Mignani, A. Petrucci, Phys. Lett. A 373 (2009) 1956] claim to observe an increase in the transformation or decay rate of ²²⁸Th by a factor of 10⁴. The evidence provided seems however far from conclusive and in part contradictory to the claims made. In fact, looking at the presented data we find it cannot be taken as justification to discard the null hypothesis, namely, that the data from exposed and non-exposed samples are drawn from the same distribution. We suggest a number of additional tests that should be made in order to improve the quality of the study and test the hypothesis of so-called piezonuclear reactions.     

Reply to: “Comment on: ‘Efficient high-capacity quantum secret sharing with two-photon entanglement’ [Phys. Lett. A 372 (2008) 1957]” [Phys. Lett. A 373 (2009) 396]

A corresponding Comment, raised by Yang and Wen, claimed that (i) our scheme cannot complete the task of secret sharing well even if the agents obtain the information about their measuring bases; (ii) they give a feasible improvement of our protocol. In this Reply, we show that their first judgment is wrong and their improvement is insecure.     

Comment on: “Efficient high-capacity quantum secret sharing with two-photon entanglement” [Phys. Lett. A 372 (2008) 1957]

In a recent Letter [F.G. Deng, X.H. Li, H.Y. Zhou, Phys. Lett. A 372 (2008) 1957], an efficient high-capacity quantum secret sharing scheme was proposed. However, in this comment, it is shown that the protocol does not complete the task of secret sharing well when the message sender uses the nonorthogonal entangled states as the quantum information carriers. Finally a feasible improvement of this quantum secret sharing protocol is proposed.     

Erratum to “Adaptive synchronization of the complex dynamical network with non-derivative and derivative coupling” [Phys. Lett. A 374 (2010) 1673]

We indicate that the proof of theorem is incorrect in Letter [Y. Xu, W. Zhou, J. Fang, W. Sun, Phys. Lett. A 374 (2010) 1673]. For correcting the mistakes, a correct version of the proof of theorem is given in this Letter.     

Comment on “Piezonuclear decay of thorium” [Phys. Lett. A 373 (2009) 1956]

Cardone et al. [F. Cardone, R. Mignani, A. Petrucci, Phys. Lett. A 373 (2009) 1956] claim that cavitation speeds up radioactive decay of ²²⁸Th dissolved in water. The experimental evidence they presented was criticized by Ericsson et al. [G. Ericsson, S. Pomp, H. Sjöstrand, E. Traneus, Phys. Lett. A 373 (2009) 3795]. This Comment focuses on a presumably-ignored trivial effect that might be responsible for the reported experimental results. It also contains suggestions for improving the quality of future investigations.