A remark on the Discrete Fourier Transform statistical test

The study of randomness has always been a topic of significant relevance, and the importance of this topic in cryptography is undeniable. In this paper, we are going to provide a short introduction regarding pseudo-random number generators, their applications in cryptography and an analysis of the Discrete Fourier Transform statistical test. Our contribution is that of compiling the results of multiple runs on several popular pseudo-random number generators, and a Python implementation for computing the probability of a type II error. We intend to underline the weak points of the Discrete Fourier Transform test by showcasing results on large amounts of data, and showcase how testing bigger sequences of bits can help reduce the probability of type II errors

The challenges of proving solvency while preserving privacy.

The increasing popularity of blockchain technology has affected the way we view many fields related to computer science, with E-commerce being no exception. The distributed nature and transparency of blockchain-based systems is one of its main perks, but it also raises some issues when it comes to privacy. Zero-knowledge proofs are very powerful building blocks when it comes to building privacy-preserving protocols, so, naturally, they have attracted a lot of attention in the last years. Following the recent collapse of the very popular crypto exchange FTX, we believe it is important to analyse how such events can be prevented in the future. This paper aims to highlight solutions that use zero-knowledge to prove solvency

Low-lying levels in F-15 and the shell model potential for drip-line nuclei

Journals published by the American Physical Society can be found at http://publish.aps.org/The ground and first excited states in F-15 were studied in resonant elastic scattering using the thick (CH4) gas target method in inverse kinematics with a separated O-14 beam. An analysis of the excitation functions of the elastic scattering was carried out with the potential model. The quantum numbers 1/2(+) (ground state) and 5/2(+) (first excited state) were assigned to the lowest two states in F-15. Also, the widths and the proton decay energies of the unbound levels were obtained. The analysis of the data indicates that a large diffuseness is needed in the Woods-Saxon potential in order to describe single-particle features in drip-line nuclei

Stellar reaction rate for (22)Mg + p -> (23)Al from the asymptotic normalization coefficient in the mirror nuclear system (22)Ne + n -> (23)Ne

Journals published by the American Physical Society can be found at http://publish.aps.org/The production of (22)Na in ONe novae can be influenced by the (22)Mg(p,gamma)(23)Al reaction. To investigate this reaction rate at stellar energies, we have determined the asymptotic normalization coefficient (ANC) for (22)Mg + p -> (23)Al through measurements of the ANCs in the mirror nuclear system (22)Ne + n -> (23)Ne. The peripheral neutron-transfer reactions (13)C((12)C, (13)C)(12)C and (13)C((22)Ne, (23)Ne)(12)C were studied. The identical entrance and exit channels of the first reaction make it possible to extract independently the ground-state ANC in (13)C. Our experiment gives C(p1/2)(2) ((13)C) = 2.24 +/- 0.11 fm(-1), which agrees with the value obtained from several previous measurements. The weighted average for all the obtained C(p1/2)(2) is 2.31 +/- 0.08 fm(-1). This value is adopted to be used in obtaining the ANCs in 23Ne. The differential cross sections for the reaction (13)C((22)Ne, (23)Ne) (12)C leading to the J(pi) = 5/2(+) and 1/2(+) states in (23)Ne have been measured at 12 MeV/u. Optical model parameters for use in the DWBA calculations were obtained from measurements of the elastic scatterings (22)Ne + (13)C and (22)Ne + (12)C. The extracted ANC for the ground state in (23)Ne, C(d5/2)(2) = 0.86 +/- 0.08 +/- 0.12 fm(-1), is converted to its corresponding value in (23)Al using mirror symmetry to give C(d5/2)(2) ((23)Al) = (4.63 +/- 0.77) x 10(3) fm(-1). The astrophysical S factor S(0) for the (22)Mg(p, gamma) reactionwas determined to be 0.96 +/- 0.11 keVb. The consequences for nuclear astrophysics are discussed

Single and double proton emissions from the O-14+He-4 interaction

Journals published by the American Physical Society can be found at http://publish.aps.org/We observed single and double proton emissions in the O-14+He-4 interaction by the thick target inverse kinematic (TTIK) method at initial energy for O-14 at 32.7 MeV. We found that the protons mainly originate from the resonance excitation of states in Ne-18. The observed states in Ne-18 decay by protons mainly to proton unstable states in F-17. It was found that the decay of a state in Ne-18 at E-ex=8.45 MeV demonstrates the features of a decay by a correlated proton pair. The observed properties of the O-14+He-4 interaction make a previous interpretation for the rate of O-14(He-4, p)F-17 at astrophysical energies suspect. We show how the TTIK method should be modified to obtain the data of astrophysical interest

Experimental study of beta-delayed proton decay of (23)Al for nucleosynthesis in novae

Journals published by the American Physical Society can be found at http://publish.aps.org/The beta-delayed gamma and proton decay of (23)Al has been studied with an alternative detector setup at the focal plane of the momentum achromat recoil separator MARS at Texas AandM University. We could detect protons down to an energy of 200 keV and determine the corresponding branching ratios. Contrary to results of previous beta-decay studies, no strong proton intensity from the decay of the isobaric analog state (IAS) of the (23)Al ground state at E(x) = 7803 keV in (23)Mg was observed. Instead we assign the observed low-energy group E(p,c.m.) = 206 keV to the decay from a state that is 16 keV below the IAS. We measured both proton and gamma branches from the decay of this state at E(x) = 7787 keV in (23)Mg, which is a very rare case in the literature. Combining our data with its measured lifetime, we determine its resonance strength to be omega gamma = 1.4(-0.4)(+0.5) meV. The value is in agreement with older direct measurements, but disagrees with a recent direct measurement. This state is the most important resonance for the radiative proton capture (22)Na(p, gamma)(23)Mg in some astrophysical environments, such as novae

Structure of N-12 using C-11+p resonance scattering

Journals published by the American Physical Society can be found at http://publish.aps.org/The level structure of N-12 has been investigated from 2.2 to 11.0 MeV in excitation energy using a C-11+p resonance interaction with thick targets and inverse kinematics. Excitation functions were fitted using an R-matrix approach. Sixteen levels in N-12 were included in the analysis, several of them are new. Spin-parity assignments, excitation energies and widths are proposed for these levels

Mechanochemical and solution synthesis, X-ray structure and IR and 31P solid state NMR spectroscopic studies of copper(I) thiocyanate adducts with bulky monodentate tertiary phosphine ligands

A number of adducts of copper(I) thiocyanate with bulky tertiary phosphine ligands, and some nitrogen-base solvates, were synthesized and structurally and spectroscopically characterised. CuSCN : PCy3 (1 : 2), as crystallized from pyridine, is shown by a single crystal X-ray study to be a onedimensional polymer ...(Cy3P)2CuSCN(Cy3P)2CuSCN... (1) with the four-coordinate copper atoms linked end-on by S-SCN-N bridging thiocyanate groups. A second form (2), obtained from acetonitrile, was also identified and shown by IR and 31P CPMAS NMR spectroscopy to be mononuclear, with the magnitude of the dνCu parameter measured from the 31P CPMAS and the ν(CN) value from the IR clearly establishing this compound as three-coordinate [(Cy3P)2CuNCS]. Two further CuSCN/PCy3 compounds CuSCN : PCy3 (1 : 1) (3), and CuSCN : PCy3 : py (1 : 1 : 1) (4) were also characterized spectroscopically, with the dνCu parameters indicating three- and four-coordinate copper sites, respectively. Attempts to obtain a 1 : 2 adduct with tri-t-butylphosphine have yielded, from pyridine, the 1 : 1 adduct as a dimer [(But3P)(SCN-NCS)Cu(PBut3)] (5), while similar attempts with tri-o-tolylphosphine (from acetonitrile and pyridine (= L)) resulted in solvated 1 : 1 : 1 CuSCN : P(o-tol)3 : L forms as dimeric [{(o-tol)3P}LCu(SCN-NCS) CuL{P(o-tol)3}] (6 and 8). The solvent-free 1 : 1 CuSCN : P(o-tol)3 adduct (7), obtained by desolvation of 6, was characterized spectroscopically and dνCu measurements from the 31P CPMAS NMR data are consistent with the decrease in coordination number of the copper atom from four (for 6) (P,N(MeCN)Cu,S,N) to three (for 7) (PCuS,N) upon loss of the acetonitrile of solvation. These results are compared with those previously reported for mononuclear and binuclear PPh3 adducts which demonstrate a clear tendency for the copper centre to remain four-coordinate. The IR spectroscopic measurements on these compounds show that bands in the far-IR spectra provide a much more definitive criterion for distinguishing between bridging and terminal bonding than does an often-used empirical rule based on ν(CN) in the mid-IR, which leads to the wrong conclusion in some cases

Beta decay of proton-rich nucleus Al-23 and astrophysical consequences

Journals published by the American Physical Society can be found at http://publish.aps.org/We present the first study of the beta decay of Al-23 undertaken with pure samples. The study was motivated by nuclear astrophysics questions. Pure samples of Al-23 were obtained from the momentum achromat recoil separator (MARS) of Texas AandM University, collected on a fast tape-transport system, and moved to a shielded location where beta and beta-gamma coincidence measurements were made. We deduced beta branching ratios and log ft values for transitions to states in Mg-23, and from them determined unambiguously the spin and parity of the Al-23 ground state to be J(pi)=5/2(+). We discuss how this excludes the large increases in the radiative proton capture cross section for the reaction Mg-22(p,gamma)Al-23 at astrophysical energies, which were implied by claims that the spin and parity is J(pi)=1/2(+). The log ft for the Fermi transition to its isobaric analog state (IAS) in Mg-23 is also determined for the first time. This IAS and a state 16 keV below it are observed, well separated in the same experiment for the first time. We can now solve a number of inconsistencies in the literature, exclude strong isospin mixing claimed before, and obtain a new determination of the resonance strength. Both states are resonances in the Na-22(p,gamma)Mg-23 reaction at energies important in novae. The reactions Mg-22(p,gamma)Al-23 and Na-22(p,gamma)Mg-23 have both been suggested as possible candidates for diverting some of the flux in oxygen-neon novae explosions from the A=22 into the A=23 mass chain

First observation of alpha-cluster states in the (14)O+(4)He interaction

Journals published by the American Physical Society can be found at http://publish.aps.org/We measured (14)O+(4)He excitation functions for elastic scattering which demonstrate, for the first time, a well developed alpha-cluster structure in the proton rich nucleus, (18)Ne. We present the excitation energies and estimates of the spins for the dominant resonances using an R-matrix approach. A resonance at 9.2 MeV excitation energy in (18)Ne is particularly interesting. The spin-parity of the state is found to be 3(-) and the alpha particle reduced width for the state appears to be comparable to the single particle limit. We have found indications for unusually large size of the observed alpha-cluster configuration