Normal Frequency Research Articles

Q-balls meet fuzzballs: non-BPS microstate geometries

We construct a three-parameter family of non-extremal microstate geometries, or “microstrata”, that are dual to states and deformations of the D1-D5 CFT. These families are non-extremal analogues of superstrata. We find these microstrata by using a Q-ball-inspired Ansatz that reduces the equations of motion to solving for eleven functions of one variable. We then solve this system both perturbatively and numerically and the results match extremely well. We find that the solutions have normal mode frequencies that depend upon the amplitudes of the excitations. We also show that, at higher order in perturbations, some of the solutions, having started with normalizable modes, develop a “non-normalizable” part, suggesting that the microstrata represent states in a perturbed form of the D1-D5 CFT. This paper is intended as a “Proof of Concept” for the Q-ball-inspired approach, and we will describe how it opens the way to many interesting follow-up calculations both in supergravity and in the dual holographic field theory.

Spatial Relative Equilibria and Periodic Solutions of the Coulomb $$(n+1)$$-Body Problem

We study a classical model for the atom that considers the movement of n charged particles of charge \(-1\) (electrons) interacting with a fixed nucleus of charge \(\mu >0\). We show that two global branches of spatial relative equilibria bifurcate from the n-polygonal relative equilibrium for each critical value \(\mu =s_{k}\) for \(k\in [2,\ldots ,n/2]\). In these solutions, the n charges form n/h-groups of regular h-polygons in space, where h is the greatest common divisor of k and n. Furthermore, each spatial relative equilibrium has a global branch of relative periodic solutions for each normal frequency satisfying some nonresonant condition. We obtain computer-assisted proofs of existence of several spatial relative equilibria on global branches away from the n-polygonal relative equilibrium. Moreover, the nonresonant condition of the normal frequencies for some spatial relative equilibria is verified rigorously using computer-assisted proofs.

Why are large conformational changes well described by harmonic normal modes?

Low-frequency normal modes generated by elastic network models tend to correlate strongly with large conformational changes of proteins, despite their reliance on the harmonic approximation, which is only valid in close proximity of the native structure. We consider 12 variants of the torsional network model (TNM), an elastic network model in torsion angle space, that adopt different sets of torsion angles as degrees of freedom and reproduce with similar quality the thermal fluctuations of proteins but present drastic differences in their agreement with conformational changes. We show that these differences are related to the extent of the deviations from the harmonic approximation, assessed through an anharmonic energy function whose harmonic approximation coincides with the TNM. Our results indicate that mode anharmonicity is more strongly related to its collectivity, i.e., the number of atoms displaced by the mode, than to its amplitude; low-frequency modes can remain harmonic even at large amplitudes, provided they are sufficiently collective. Finally, we assess the potential benefits of different strategies to minimize the impact of anharmonicity. The reduction of the number of degrees of freedom or their regularization by a torsional harmonic potential significantly improves the collectivity and harmonicity of normal modes and the agreement with conformational changes. In contrast, the correction of normal mode frequencies to partially account for anharmonicity does not yield substantial benefits. The TNM program is freely available at https://github.com/ugobas/tnm.

Pedestrian-induced lateral vibration of footbridge based on binary coupled Kuramoto model

At present, inverted pendulum model (IPM) has been recognized by increasing researchers due to its capability to capture the characteristics of pedestrian lateral excitation. However, the IPM still has a downside that has been continuously questioned: the velocity proportional pedestrian load coefficient is inconsistent with the on-site observations in the case of pedestrian walking with normal frequency. This problem is most likely resulted from that the IPM ignores the synchronization effect. The IPM is derived from indoor single-person experiment and cannot consider the synchronization in the crowd. Synchronization effects are classified into two types： pedestrian–bridge and pedestrian–pedestrian synchronizations. Pedestrian–bridge synchronization is stimulated by bridge vibration, whereas pedestrian–pedestrian synchronization is stimulated by surrounding crowd. In this study, a novel model for pedestrian-induced lateral vibration of footbridge is proposed. It uses the IPM as the basis and adopts a binary coupled Kuramoto model that originally derived from the collective synchronization phenomena to overcome the limitation in IPM. This model can consider the pedestrian–bridge and pedestrian–pedestrian synchronizations, which provides a new way to reveal the mechanism of pedestrian-induced lateral vibration of footbridge. The proposed method is verified through a case study of the London Millennium Bridge, and some useful conclusions are obtained.

Benchmark ab initio proton affinity and gas-phase basicity of α-alanine based on coupled-cluster theory and statistical mechanics.

We determine the proton affinity (PA) and gas-phase basicity (GB) of amino acid α-alanine at a chemically accurate level by performing explicitly-correlated CCSD(T)-F12b/aug-cc-pVDZ geometry optimizations and normal mode vibrational frequency calculations as well as CCSD(T)-F12b/aug-cc-pVTZ energy computations at the possible neutral and protonated geometries. Temperature effects at 298.15 K considering translational, rotational, and vibrational enthalpy and entropy corrections are obtained via standard statistical mechanics utilizing the molecular geometries and the harmonic vibrational energy levels. Both the amino nitrogen (N) and the carbonyl oxygen (O) atoms are proven to be potential protonation sites and a systematic conformational search reveals 3 N- and 9 O-protonated conformers in the 0.00-7.88 and 25.43-30.43 kcal/mol energy ranges at 0K, respectively. The final computed PA and GB values at (0)298.15 K in case of N-protonation are (214.47)216.80 and 207.07 kcal/mol, respectively, whereas the corresponding values for O-protonation are (189.04)190.63 and 182.31 kcal/mol. The results of the benchmark high-level coupled-cluster computations are utilized to assess the accuracy of several lower-level cost-effective methods such as MP2 and density functional theory with various functionals (SOGGA11-X, M06-2X, PBE0, B3LYP, M06, TPSS).

Quasi-periodic solutions for the generalized Benjamin–Bona–Mahony​ equation

A generalized Benjamin–Bona–Mahony (gBBM) equation ut−uxxt+ux+u4ux=0,subject to the periodic boundary condition is studied in this paper. Based on a new infinite dimensional Kolmogorov–Arnold–Moser (KAM) theorem with normal frequencies of finite limit-points, it is shown that the above gBBM equation admits plenty of time-quasi-periodic solutions with two frequencies of high modes.

Frictional behavior of granular materials exposed to dynamic normal load

Understanding the frictional characteristics of granular materials (e.g., fault gouge and sand foundations) exposed to dynamic normal load are important for investigations of engineering geology disasters and safety assessment. Direct shear tests on granular materials under dynamic normal load were performed in the laboratory using a dynamic shear box device. Experimental results showed that the shear strength and normal displacement varied with variations of normal load, identified by a phase shift and normal stress loading peak. The peak shear stress decreased with increasing normal load frequency and shear velocity, in particular, the peak shear stress changed nonlinearly with the increase of normal load amplitude, characterized by a critical point. The influence of normal load amplitude on the shear strength and normal displacement was analyzed in detail. Furthermore, the results showed that dynamic normal load can both enhance and reduce the shear strength on granular material, and the frictional behaviors were velocity-amplitude-frequency dependent, which can be well interpreted by the Rate and State Friction constitutive law. These findings provide guidance in the design of geotechnical engineering projects when dynamic normal loads are encountered (e.g., blasting, earthquakes, earth tides and reservoir effects).

Analysis of cyclic shear characteristics of reinforced soil interfaces under cyclic loading and unloading

The cyclic properties of geosynthetic soil interface are crucial for reinforced soil structures subject to seismic loading. A series of cyclic direct tests under cyclic normal loading was conducted on geogrid-gravel interface. The relationship among the amplitudes of cyclic normal loading and shear displacement and frequencies in the horizontal and vertical directions with interface shear strength and volume change was investigated. Test results showed that the relative time shift, shear stiffness, and enhance coefficient increased with increasing amplitude of cyclic normal loading. The interface exhibited shear hardening and softening with increasing amplitude of shear displacement. The vertical displacement decreased with increasing amplitude of cyclic normal loading but increased with increasing amplitude of shear displacement. Furthermore, three patterns were analysed for different frequencies in two loading directions. The value of vertical displacement was largest when the normal loading impact frequency was larger than the cyclic horizontal shear frequency, and smallest at equal frequencies in two loading directions. The shear stiffness was positively correlated with the amplitude of cyclic normal loading. However, it was negatively correlated with the amplitude of shear displacement. The value of the damping ratio was smallest under constant normal loading at a shear displacement amplitude of 0.5 mm.

Evaluating and comparing the efficacy of histopathology to TVS/TAS in diagnosing the abnormal uterine bleeding: A prospective clinical study

Background: AUB (Abnormal Uterine Bleeding) is any bleeding outside normal frequency, regularity, duration, and volume. Abnormal bleeding in menstruation is depicted using terms such as oligomenorrhea, Polymenorrhea, Metorrhagia, and menorrhagia.Objectives: The present clinical study was conducted to assess the efficacy of histopathological findings and TVS/TAS in subjects with AUB.Methods: In the present prospective clinical study, 102 subjects within the age of 21-85 years with abnormal uterine bleeding. All subjects underwent hysteroscopy and premenstrual dilatation and curettage despite sonography findings and baseline investigations. The obtained endometrial tissue was assessed via histopathological examination.Result: Cervical carcinoma, Endometrial carcinoma, Cervical polyp, Endometrial polyp, Adenomyosis, and Myoma as seen in 3.92% (n = 4), 12.74% (n = 13), 2.94% (n = 3), 32.35% (n = 33), 51.96% (n = 53), and 54.90% (n = 56) study subjects respectively. Tissue findings in the study were assessed as Cervical Carcinoma, Endometrial Carcinoma, Endometrial polyp, Endometritis, Atrophic endometrium, Mixed, Secretary, Proliferative phase, Endometrial hyperplasia, and normal epithelium was seen in 1.96% (n = 2), 10.78% (n = 11), 5.88% (n = 6), 0.98% (n = 1), 2.94% (n = 3), 3.92% (n = 4), 15.68% (n = 16), 11.76% (n = 12), 25.49% (n = 26), and 20.58% (n = 21) subjects respectively.Conclusion: The present study concludes that transvaginal/transabdominal ultrasounds are an economical and primary assessment tool for screening of AUB, and must be included in routine assessment and examination. Although, the diagnosis and management of AUB are confusing among non-gravid females, however, histopathologic assessment is the gold standard in such cases.

Association of Mucoid Degeneration of the ACL with Medial Tibiofemoral Osteoarthritis Progression at MR Imaging

Abstract Background Using MRI, ACL mucoid degeneration is defined as a thickened ACL with increased signal intensity on all MR pulse sequences, with discrete fibers easily distinguished on fatsaturated T2-weighted or fat-saturated proton-density (PD)-weighted images but poorly differentiated on T1-weighted or non-fat-saturated PD-weighted images. Objective To assess the prevalence of ACL mucoid degeneration in a population of patients referred for routine knee MRI, and its association with age and structural joint damage. Patients and Methods Our study is a retrospective study conducted at the radiology department of Ain Shams University hospitals and Ain Shams University Specialized Hospital including 81 cases of knees with ACL mucoid degeneration by MRI and no sex predilection. Cases and controls were scored with respect to independent articular features: cartilage signal and morphology, subarticular bone marrow abnormality, subarticular cysts, subarticular bone attrition, marginal osteophytes and medial meniscal integrity. Results Patients with ACL mucoid degeneration were older than patients with a normal ACL, without statistically significant sex difference. Knees with ACL mucoid degeneration had statistically significant medial meniscal injuries and cartilage damage involving the central and posterior MTFC compared to control knees with a normal ACL frequency matched for age, sex and MR field strength. Conclusion Our study proved that there is a strong association between ACL mucoid degeneration and cartilage damage in MTFC.

Analytic-normal-mode frequencies for N identical particles: The microscopic dynamics underlying the emergence and stability of excitation gaps from BCS to unitarity

The frequencies of the analytic normal modes for N identical particles are studied as a function of system parameters from the weakly interacting BCS regime to the strongly interacting unitary regime. The normal modes were obtained previously from a first-order L=0 group theoretic solution of a three-dimensional Hamiltonian with a general two-body interaction for confined, identical particles. In a precursor to this study, the collective behavior of these normal modes was investigated as a function of N from few-body systems to many-body systems analyzing the contribution of individual particles to the collective macroscopic motions. A specific case, the Hamiltonian for Fermi gases in the unitary regime was studied in more detail. This regime is known to support collective behavior in the form of superfluidity and has previously been successfully described using normal modes. Two phenomena that could sustain the emergence and stability of superfluid behavior were revealed, including the behavior of the normal mode frequencies as N increases. In this paper, I focus on a more detailed analysis of these analytic frequencies, extending my investigation to include Hamiltonians with a range of interparticle interaction strengths from the BCS regime to the unitary regime and analyzing the microscopic dynamics that lead to large gaps at unitarity. The results of the current study suggest that in regimes where higher-order effects are small, normal modes an be used to describe the physics of superfluidity from the weakly interacting BCS regime with the emergence of small excitation gaps to unitarity with its large gaps, and can offer insight into a possible microscopic understanding of the behavior at unitarity. This approach could thus offer an alternative to the two-body pairing models commonly used to describe superfluidity along this transition.

Клиническое значение морфологии сперматозоидов в выборе метода лечения мужского бесплодия

Introduction. Sperm morphology is one of the most common tests in fertility practice. The interlaboratory variability is the main drawback of the method. The clinical significance of sperm morphology in assisted reproductive technologies is controversial. The aim of the review is to address this question. Materials and methods. The search of relevant publications was carried out in PubMed and e-Library databases using the keywords «male infertility», «sperm morphology», «teratozoospermia», «IUI», «IVF», «ICSI». Conference abstracts and dissertations were excluded from analysis and 56 publications were included in this literature review. Results. The small numbers of studies were evaluated to the effect of teratozoospermia on the likelihood of natural pregnancy. The pregnancy rate was higher in the group of couples with normozoospermia. In the couples with severe teratozoospermia pregnancies rate was also detected. The most studies did not reveal a statistically significant effect of tertozoospermia on the frequency of pregnancy during intrauterine insemination. The data about the influence of sperm morphology on in vitro fertilization are contradictory. Early studies showed a positive correlation between normal sperm morphology and frequency of conception, but these results were not confirmed in further studies. The most studies have not been revealed the correlation between normal sperm morphology male fertility status, clinical and live birth rate. Discussion. To date the spermatozoa mofophology studying remains the «starting point» ofa man's examination for infertility. However, the data available do not confirm its role in choosing the method ofassisted reproductive technologies or predicting their results. Conclusions. To date the role of sperm morphology on conceive and pregnancy frequencies in ART use is controversal. The data available does not confirm the value of this test as a proxy of higher pregnancy and birth of healthy child probability. The further studies are required to address this question.

Effect of Zone and Climate on Yields, Quality and Ripening Characteristics of Montecristo Bananas Grown in Puerto Rico

A study was conducted to determine the effect of zone and climate on yields, ripening characteristics and quality of Montecristo bananas. Experimental plots were established at the Fortuna Substation on the southern coast of Puerto Rico at sea level, and the Adjuntas Substation located in the humid mountainous area at an elevation of 1,800 feet. In plots planted monthly throughout the year, the interval from planting to flowering ranged at the Adjuntas Substation from 371 to 448 days and from 319 to 388 days at the Fortuna Substation. At Fortuna, the length of the flowering period ranged from 120 to 147 days, while at Adjuntas it ranged from 107 to 200 days. A direct relationship was observed at Adjuntas between the length of the flowering period and time of planting. The flowering pattern of the combined monthly plots was different for the two zones. Two flowering cycles were observed at Adjuntas, with the highest percentage of plants flowering from June to December. Although three flowering cycles were observed at Fortuna, the distribution was similar to a normal frequency distribution. Bunch development was much slower at Adjuntas than at Fortuna. The age for harvesting at a given stage of development varied with the time of flowering, but this relationship was more marked at Adjuntas than at Fortuna. The fruit harvested at Adjuntas was quite different in characteristics from the fruit harvested at Fortuna. The bunches were heavier and the fruit weighed more. The bunches also had more hands and more fruit than those harvested at Fortuna. At Adjuntas, the weight of the bunch remained fairly constant throughout the year, while at Adjuntas the weight of the bunch varied with the month of flowering. The weight of the fingers at both locations varied with the time of flowering while the number of fruit per bunch at Fortuna varied only slightly throughout the year. Because the seed material used in these studies was obtained from two farms in the Adjuntas region, another set of experiments was conducted to study the behavior of the Montecristo bananas produced from seed from the experimental plots from each Substation when planted on the other. The results from these experiment showed that the seed material used in our previous studies were of uniform character and that differences observed in flowering patterns, yields, fruit quality and other characteristics were due to the effect of ecological conditions and not to clonal variation. The fruit from both locations when processed into purees gave products of good quality. Fruit from Adjuntas produced purees of a more pronounced yellow color and the flavor was better than fruit from Fortuna. From the standpoint of fresh fruit quality, however, the fruit from Fortuna was better than the fruit from Adjuntas. The fruit from Fortuna had better ripening characteristics, ripening more evenly and with a more attractive yellow color, than the fruit from Adjuntas.

Specifics of Construction of Measuring Transducers with Logometric Output Based on Interconnected Piezoresonators

The paper presents the results of simulation modeling of measuring devices. The simulation modeling is based on the use of coupled oscillations in systems with two degrees of freedom. Methods of controlling the parameters of the oscillatory system of the converter based on interconnected piezoresonators are considered. A comparative assessment of the metrological characteristics of possible variants of piezoresoanase sensors with logometric (differential) output is conducted.
 It is shown that when the Q-factor of the oscillatory system of the primary converter is affected, a higher sensitivity of the measuring process is provided by the control of the active resistance of the coupling element replacement circuit between the resonators. In this case, it is proposed to use the ratio of the oscillation amplitudes of one of the interconnected resonators measured at the frequencies of common-mode and antiphase oscillations in the system as the output signal of the sensor. When the frequency-setting parameters of the converter are affected, it is recommended to use the ratio of the oscillation amplitudes of two interconnected piezoresonators measured at one of the normal frequencies of synchronized oscillations in the system to generate the output signal.
 There are several advantages of measuring devices of this type, such as high sensitivity, simplicity of design, low cost, manufacturability, and operational applicability for harsh conditions.

Tight-binding model for torsional and compressional waves in high-quality coupled-resonator phononic metamaterials

A tight-binding theoretical model which describes the vibration properties of a new type of mechanical metamaterial, the coupled-resonator phononic metamaterial (CRPM), is developed. This metamaterial, composed of mechanical resonators coupled through finite phononic crystals, exhibits spectral properties analogue to those of crystalline atomic systems. The CRPMs obey a quantum tight-binding model when a normal mode frequency of the resonators lies within a bandgap of the finite phononic crystals. Analytical expressions for the dispersion relation and group velocity are obtained. The results suggest that almost any material described by the tight-binding model, of solid-state physics, can be emulated with CRPMs.

Effect of Bulky Anion around the Dication on the Electronic Structure and Normal Frequencies in 1,3-Bis(3-methylimidazolium-1-yl)propane Bis(trifluoromethanesulfonyl)imide Ionic Liquid.

A manifestation of hydrogen bonding between the dication and anions attributed to their relative position of the anions around the cation can influence both the conformational equilibrium and the physical properties of ionic liquids. With this view, we studied the electronic structure and normal frequencies using density functional theory calculations to analyze the hydrogen-bonding interactions in dicationic ionic liquids. The conformers are distinguished based on the hydrogen-bonding sites of the cation and anion. The weak hydrogen bonding between the dication and anions in dication ionic liquids can lead to greater conformational equilibrium compared to the monocation system. Consequences of these interactions for the vibrational spectrum are analyzed to provide an insight into the conformational equilibrium in dicationic ionic liquids at the molecular level.

Time-periodicities in holographic CFTs

Dynamics in AdS spacetimes is characterized by various time-periodicities. The most obvious of these is the time-periodic evolution of linearized fields, whose normal frequencies form integer-spaced ladders as a direct consequence of the structure of representations of the conformal group. There are also explicitly known time-periodic phenomena on much longer time scales inversely proportional to the coupling in the weakly nonlinear regime. We ask what would correspond to these long time periodicities in a holographic CFT, provided that such a CFT reproducing the AdS bulk dynamics in the large central charge limit has been found. The answer is a very large family of multiparticle operators whose conformal dimensions form simple ladders with spacing inversely proportional to the central charge. We give an explicit demonstration of these ideas in the context of a toy model holography involving a ϕ4 probe scalar field in AdS, but we expect the applicability of the underlying structure to be much more general.

Real-Time Process Monitoring Based on Multivariate Control Chart for Anomalies Driven by Frequency Signal via Sound and Electrocardiography Cases

Recent developments in network technologies have led to the application of cloud computing and big data analysis to industrial automation. However, the automation of process monitoring still has numerous issues that need to be addressed. Traditionally, offline statistical processes are generally used for process monitoring; thus, problems are often detected too late. This study focused on the construction of an automated process monitoring system based on sound and vibration frequency signals. First, empirical mode decomposition was combined with intrinsic mode functions to construct different sound frequency combinations and differentiate sound frequencies according to anomalies. Then, linear discriminant analysis (LDA) was adopted to classify abnormal and normal sound frequency signals, and a control line was constructed to monitor the sound frequency. In a case study, the proposed method was applied to detect abnormal sounds at high and low frequencies, and a detection accuracy of over 90% was realized. In another case study, the proposed method was applied to analyze electrocardiography signals and was similarly able to identify abnormal situations. Thus, the proposed method can be applied to real-time process monitoring and the detection of abnormalities with high accuracy in various situations.

Application of the Paracentrotus lividus sea-urchin embryo-larval bioassay to the marine pollution biomonitoring program in the Tunisian coast.

The pollution of the marine environment by treated and untreated effluents has increased due to human activities. Monitoring the marine ecosystem is nowadays a global concern. In this work, we evaluated the effect of contaminated and uncontaminated seawater, from different Tunisian coastal areas, on the fertilization, gastrulation, and embryo-larval development events of sea urchins (Paracentrotus lividus). The station of Salakta (SA) is considered as a control station, while the stations of Hamdoun Wadi (HW), Port of Monastir (PM), Karaia Monastir (KM), Teboulba (TE), and Khniss Lagoon (KL) are considered to be contaminated stations. The analysis of seawater physicochemical characteristics showed that levels of the total suspended matter (TSM), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), and nitrate (NO3-) were lower in the seawater of the reference site Salakta (SA) when compared to those of the contaminated seawater sites. In addition, a very strong variation in the levels of trace metals in seawaters sampled in the studied sites was noted. In fact, the highest concentrations of Pb and Cu were observed in Hamdoun Wadi (HW), port of Monastir (PM), and Karaia Monastir (KM), while the highest concentration of Zn was noted in the Teboulba lagoon (TE) and Khniss (LK). Alterations in physicochemical characteristics as well as elevated trace metal levels in the studied seawater samples were correlated with reduced fertility rate, gastrulation rate, and the frequency of normal sea urchin larvae. The total absence of normal sea urchin pluteus larvae in the sea waters of heavily polluted sites proves the great sensitivity of the larval frequency to mixed pollution. This work recommends the utility of urchin fertilization and gastrulation rates and normal pluteus larval frequencies as useful bioassays to monitor the exposure of marine ecosystems to mixed pollution.

Application of Modern Physics Findings in Medicine: Bio-Resonance Therapy

Nowadays, in addition to the main method of diagnosis and treatment, modern physics findings are utilized to a greater degree as a complementary and alternative method in medicine. Classical or conventional medical knowledge, in terms of disease and treatment, can be regarded as knowledge which usually has a specialized view towards diseases. According to physical theories, electromagnetic fields exist and interact with inside and outside the human body resulting in significant effects on physical and chemical processes therein. Bio resonance knowledge is a general physical method used to diagnose and treat many diseases in medicine. Bio resonance uses natural vibrations (resonance) that are present in all plant and animal bodies and cells. Each cell vibrates at a specific frequency, and if the cell becomes ill, it will have a different frequency than its normal frequency. Using this principle and its related technologies, devices and tools have been developed that have brought new approaches to the diagnosis and treatment of diseases, which are briefly mentioned in the present paper. This treatment is part of quantum medicine emerging as technologies that have come to the forefront of medical science. Quantum medicine is a combination of classical medicine, ancient Chinese and Japanese medical knowledge, herbal medicine and quantum physics theories.