Relative Degrees Of Freedom Research Articles

Coevolution of superconductivity and Hall coefficient with anisotropic lattice shrinkage in compressed KCa2Fe4As4F2

Abstract The stability of superconductivity in superconductors is widely recognized to be determined by various factors, including charge, spin, orbit, lattice, and other related degrees of freedom. Here, we report our findings on the pressure-induced coevolution of superconductivity and Hall coefficient in KCa2Fe4As4F2, an iron-based superconductor possessing a hybrid crystal structure combining KFe2As2 and CaFeAsF. Our investigation, involving high-pressure resistance, Hall effect and x-ray diffraction (XRD) measurements, allows us to observe the connection of the superconductivity and Hall coefficient with the anisotropic lattice shrinkage. We find that its ambient-pressure tetragonal (T) phase presents a collapse starting at around 18 GPa, where the sign of the Hall coefficient (R H) changes from positive to negative. Upon further compression, both superconducting transition temperature (T c) and R H exhibit a monotonous decrease. At around 41 GPa, the superconductivity is completely suppressed (T c = 0), where the parameter a begins to decline again and the Hall coefficient remains nearly unchanged. Our experiment results clearly demonstrate that the pressure-induced anisotropic lattice collapse plays a crucial role in tuning the interplay among multiple degrees of freedom in the superconducting system and, correspondingly, the stability of the superconductivity.

Promoting fringe benefits as motivational strategy and staff productivity in Nigerian Universities

The trust of this paper is to unravel fringe benefits as a tool of motivation and staff productivity in educational zones. To fulfill the objective of this investigation, a single research query was posed, also a null hypothesis was generated. The study employed a survey research design, selecting a sample of 792 respondents from a population of 8,112 administrative staff through random sampling. Stratified random sampling was utilized in the selection process. Data collection relied on questionnaires as the primary instrument, which underwent face validation. The instruments’ reliability was assessed using Cronbachalpha reliability method, along with statistical analyses like Pearson product-moment correlation and multiple regression. The hypothesis was subjected to testing at 0.05 level of significance with relative degrees of freedom. The results of the findings revealed that, inclusiveness of fringe benefits in a place of work significantly relate to staff’ productivity. Based on the findings of the study, it was recommended among others that management of all educational zones should ensure that both administrative and academic staff should be motivated by paying their fringe benefit as at when due to enhance productivity and work relief

Personal Variables, Pastoral Counselling and Patients’ Psychosocial Adjustment in Government Hospitals in Cross River State, Nigeria

The study investigated the influence of Personal Variables, Pastoral Counselling on Psychosocial Adjustment of Patients in Government Hospitals in Cross River State, Nigeria. Three hypotheses directed the study and relevant literature was reviewed. The ex-post factor research design was used. The population consisted of 4,200 inpatients in Government Hospitals in Cross River State, Nigeria. 420 respondents were randomly selected as sample for the study. The questionnaires titled “Personal Variables, Pastoral Counselling and Patients’ Psychosocial Adjustment Questionnaire (PEVAQ) was used for data collection. The instrument was subjected to validation by experts in Measurement and Evaluation Pastoral Counsellors in the Faculty of Education, University of Calabar. The test-retest reliability method was used with sub-scale estimates of 71-80 were found to be high enough, hence the instrument was deemed reliable. Independent t-test was used to test the hypotheses at .05 level of significance with relative degree of freedom. The result showed that age, perception towards pastoral counselling, counselling except gender significantly influence patient’s psychosocial adjustment in Government Hospitals in Cross River State, Nigeria. It was concluded that personal variable, pastoral counselling influence patients’ psychosocial adjustment in the hospitals. It was therefore recommended among others that apart from administering drugs therapies on patient, their psychology, emotion, self-concept should be worked upon to boost their self-confidence, their resolve and their mentality to adjustment and recovery while on admission in the hospitals.

(Re)conceptualizing movement behavior in sport as a problem-solving activity.

The use of the term problem-solving in relation to movement behavior is an often-broached topic within kinesiology. Here we present a clear rationale for the concept of problem-solving, specifically pertaining to the skilled organization of movement behaviors in sport performance, and the respective processes that underpin it, conceptualized within an ecological dynamics framework. The movement behavior that emerges in sport can be viewed as a problem-solving activity for the athlete, where integrated movement solutions are underpinned by intertwined processes of perception, cognition, and action. This movement problem-solving process becomes functionally aligned with sport performance challenges through a tight coupling to relevant information sources in the environment, which specify affordances offered to the athlete. This ecological perspective can shape our lens on how movements are coordinated and controlled in the context of sport, influencing practical approaches utilized towards facilitating dexterity of athletes. These ideas imply how coaches could set alive movement problems for athletes to solve within practice environments, where they would be required to continuously (re)organize movement system degrees of freedom in relation to dynamic and emergent opportunities, across diverse, complex problems. Through these experiences, athletes could become attuned, intentional, and adaptable, capable of (re)organizing a behavioral fit to performance problems in context-essentially allowing them to become one with the movement problem.

Stiffness performance analysis of a 3-PRPS kinematically redundant parallel mechanism

The stiffness performance of a spatial kinematically redundant parallel mechanism (KRPM) with three relative degree-of-freedom (RDOF) is analyzed. Firstly, the composition principle of the KRPM is introduced, the RDOF is analyzed, the kinematics model is established, and the overall Jacobian matrix is established based on the screw theory. Secondly, the workspace of the KRPM is drawn, and the theoretical stiffness model is established considering the internal restraint force and the external load. The stiffness variation in the workspace is drawn, and the effectiveness of the theoretical stiffness model is verified through finite element analysis. Finally, according to the theoretical stiffness model, four task-based stiffness performance evaluation indexes are obtained, and they are optimized based on the NSGA-II multi-objective genetic algorithm. The results show that adding and adjusting redundant actuators in a parallel mechanism can effectively improve the stiffness performance of the mechanism. In the meantime, different stiffness optimization schemes can be proposed for different task paths based on the NSGA-II genetic algorithm.

Value orientation, Parental attitude and examination malpractice

The purpose of this study was to investigate on value orientation, parental attitude and attitude to examination malpractice among senior secondary school students in Southern Educational Zone of Cross River State. To achieve the purpose of this study, two null hypotheses were generated to direct the study. Literature review was done according to the variables under study. Ex-post factor research design was adopted for the study. A sample of one thousand (1000) students was randomly selected. The selection was done through the simple random sampling technique. The questionnaire was the main instrument used for data collection. The instrument was both face and content validated by the supervisors and experts in measurement and evaluation in the Faculty of Education, University of Calabar, Calabar. The reliability estimates of the instruments established through split-halg reliability method. The reliability co-efficient ranges from 0.70-1.83. Pearson product moment correlation analysis and one-way analysis of variance!(ANOVA)!were the statistical analysis techniques adopted to test the hypotheses under study. All hypotheses were subjected to testing at 0.05 level of significance with relative degrees of freedom. The results of the analysis revealed that, parental socio-economic status, parental occupation, parental educational level, family size, value orientation and parental attitude significantly influence students’ attitude towards examination malpractice in southern educational zone of Cross River State. Based on the results and findings of the study, it was recommended that Action arising from the results of the study could include the following to minimize examination!malpractice. the results of the study should be presented to the Department and Faculty. The counselors to Guidance and Counselling Units should discuss results at seminars organized by the!authority and regularly organise parents teachers association (PTA)!meeting!where school/examination related problems could be discussed. This is to create awareness for parents, counselors teachers, school and other stakeholders in education on the prevailing incidence of examination malpractice status. Teachers and consumers should help students to develop a sensitive self-concept and value orientation of themselves to abhor examination malpractice. !!Government, School Educational Board and non-governmental organizations should assist in providing schools with necessary learning facilities to improve upon the present teaching/learning situation. This will go a long way to helping the less privileged students. Teachers and counselors should identify strategies of reducing test anxiety by giving frequent tests to students as this may reduce malpractice behaviours during examination. Parents should not encourage malpractice behaviour among students by sponsoring them financially.!School authorities should ensure that teachers perform their duties effectively to avoid students’ involvement in examination malpractice. Dedicated teachers/students on examination ethics mattess should be identified and re-warded accordingly.There is need to re-emphasis continuous assessment in our secondary schools as it is predicated on the belief that several samples of an individual test records will give a better aggregate of individual students than a one sample or a few samples only would give. Besides, continuous assessment helps to check the incidence of examination malpractice, tremendous anxiety and nesvousness in students during examinations.!! Examination ethics code of conduct should be produced and distributed in schools and education offices. This should spell out duties and responsibilities as well as penalties needed for the conduct of examination in our secondary schools. Examination ethics clubs should also be formed in our secondary schools.

Beyond biopolitics: the importance of the later work of Foucault to understand care practices of healthcare workers caring for undocumented migrants

BackgroundUndocumented migrants experience multiple institutional and legal barriers when trying to access healthcare services. Due to such limitations, healthcare workers often experience ethical dilemmas when caring for undocumented migrants. This article aims to understand how individual healthcare workers who regularly take care of undocumented migrants deal with these dilemmas in practice. So far, the role of healthcare workers in this context has mainly been theorized through the lens of biopolitics, conceiving of healthcare workers as merely obedient instruments of humanitarian government or gatekeeping.MethodsBased on semi-structured, in-depth interviews and ethnographic observations with healthcare workers in Belgium, we explore how they ascribe meaning, reflect upon and give shape to care practices in relation to undocumented migrants. We use Foucault’s later work on care of the self to interpret the accounts given by the healthcare workers.ResultsHealthcare workers in clinical roles exercise a certain degree of freedom in relation to the existing limitations to healthcare access of undocumented migrants. They developed techniques such as purposefully being inattentive to the undocumented status of the migrants. They also try to master their affective responses and transform their bodily attitude towards undocumented patients. They perform practical mental exercises to remind themselves of their role or position in the wider healthcare system and about their commitment to treat all patients equally. These techniques and exercises are inspired by colleagues who function as role models, inspiring them to relate in an ethical way to limitations in healthcare access. The developed care practices sometimes reproduce, sometimes transform the legal and institutional limitations to care for undocumented migrants.ConclusionsThe findings nuance the biopolitical analysis regarding the role of healthcare workers in healthcare delivery to undocumented migrants that has been dominant so far. Theoretically this article provides a reconceptualization of healthcare ethics as care of the self, an ethical practice that is somewhat independent of the traditional professional ethics.Trial Registration Medical ethics committee UZ Jette, Brussels, Belgium – Registration date: 18/05/2016 – Registration number: B.U.N. 143201628279.

Two particles with zero-range interaction in a magnetic field

Energy levels are investigated for two charged particles possessing an attractive, momentum-independent, zero-range interaction in a uniform magnetic field. A transcendental equation governs the spectrum, which is characterized by a collective Landau-level quantum number incorporating both center-of-mass and relative degrees of freedom. Results are obtained for a system of one charged and one neutral particle, with the interaction chosen to produce a bound state in vanishing magnetic field. Beyond deriving the weak-field expansion of the energy levels, we focus on non-perturbative aspects. In the strong-field limit, or equivalently for a system in the unitary limit, a single bound level with universal binding energy exists. By contrast, excited states are resonances that disappear into the continuum as the magnetic field is raised beyond critical values. A hyperbola is derived that approximates the number of bound levels as a function of the field strength remarkably well.

Sibling species as a result of microevolution (a case study of Lepidoptera)

This article is devoted to the problems of diagnosis and taxonomy of sibling species in Lepidoptera of different taxonomic groups. The most important advances in understanding the reality of species include: species are real and objectively exist; each species has specific spatial characteristics and its own biological time, which may not coincide with the physical one. The main criteria for the reality of a species include the following: a certain stability in space and time, isolation from the surrounding world, a certain opposition to the environment; material continuity over time; a certain degree of indivisibility; the presence of special, distinctive properties in relation to other similar systems; the presence of a certain number of degrees of freedom in relation to higher taxa; the presence of a given set of individuals of a lower order, a certain hierarchy of individuals; continuity in space and time. Through the construction of a natural system of phenotypes of the wing pattern, it is possible to build a system of groups of populations of a species and create a population taxonomy, while the phenotype should act as a reliable diagnostic feature of a specific population or groups of populations. In the landscape complex of Lepidoptera populations of a particular geographic region, as a rule, only one of the available forms is the most often found, which is also the most often collected and described as typical. All other forms are found in populations with a lower frequency, so they can be described as atypical, up to giving them the status of new species. This applies primarily to European populations of Lepidoptera, individuals of which were once accepted by taxonomists as typical and therefore received the status of nominative species and subspecies. Individuals from populations at the border of ranges, for example, from mountainous areas, are most often described as new taxa. Quite often, polytypical Lepidoptera species have a wide phenotypic diversity of the wing pattern, which makes rare forms in central populations often found in peripheral populations of the range. Therefore, the species of Lepidoptera should be considered in the light of a biological concept. Based on an integrated approach to studying the phenotypic variability of the wing pattern, it is possible to carry out taxonomic studies of Lepidoptera populations and the separation of sibling species.

A study of chi-square-type distribution with geometrically distributed degrees of freedom in relation to distributions of geometric random sums

AbstractThe purpose of this paper is to study a chi-square-type distribution who degrees of freedom are geometric random variables in connection with weak limiting distributions of geometric random sums of squares of independent, standard normal distributed random variables. Some characteristics of chi-square-type random variables with geometrically distributed degrees of freedom including probability density function, probability distribution function, mean and variance are calculated. Some asymptotic behaviors of chi-square-type random variables with geometrically distributed degrees of freedom are also established via weak limit theorems for normalized geometric random sums of squares of independent, standard normal distributed random variables. The rates of convergence in desired weak limit theorems also estimated through Trotter’s distance. The received results are extensions and generalizations of several known results.

A global–local strategy with the generalized finite element framework for continuum damage models

This paper presents a global–local strategy with the generalized finite element framework to simulate structural failure through nonlinear continuum damage models. The global problem is the scale of the structure which is discretized with relative coarse meshes while the local problem is a subdomain of interest of the global problem where refined meshes can be used to simulate localized crack growth. The proposed method uses the converged nonlinear local problem solution as enrichment functions for the global problem which is considered linear with no need for an iterative procedure to solve it. The strategy is validated and compared with reference solutions and experimental results with crack propagation in mode I and mixed-mode conditions in monotonic tests of quasi-brittle materials. The results show that the method has the capability to transfer the kinematic effects and the damage state variable that occurs in the local problem to accurately predict the global structural behavior under the damage process. The proposed strategy demonstrated the capability to accurately predict the experimental crack paths and load–displacement curves with a reduced number of iterations and degrees of freedom in relation to the conventional finite element and generalized finite element methods.

Internal oscillations of a dark-bright soliton in a harmonic potential

We investigate the dynamics of a dark-bright soliton in a harmonic potential using a mean-field approach via coupled nonlinear Schrödinger equations appropriate to multi-component Bose–Einstein condensates. We use a modified perturbed dynamical variational Lagrangian approximation, where the perturbation is due to the trap, taken as a Thomas–Fermi profile. The wave function ansatz is taken as the correct hyperbolic tangent and secant solutions in the scalar case for the dark and bright components of the soliton, respectively. We also solve the problem numerically with pseudo-spectral Runge–Kutta methods. We find, analytically and numerically, for weak trapping the internal modes are nearly independent of center of mass motion of the dark-bright soliton. In contrast, in tighter traps the internal modes couple strongly to the center of mass motion, showing that for dark-bright solitons in a harmonic potential the center of mass and relative degrees of freedom are not independent. This result is robust against noise in the initial condition and should, therefore, be experimentally observable.

Structural synthesis of a class of kinematically redundant parallel manipulators based on modified G–K criterion and RDOF criterion

Based on the modified Grübler–Kutzbach (G–K) criterion and relative degrees of freedom (RDOF) criterion, a novel method is proposed for structural synthesis of a class of kinematically redundant parallel manipulators (KR-PMs) with spherical joints attached to a moving platform. First, a formula that can be used to calculate the number of kinematic joints not limited to basic joints is proposed, which is affected by the number of links including fixed base, links with multi-node, compound hinges, and the INTERNAL independent loops in parallel manipulators. Furthermore, the sum degrees of all the kinematic joints possesses a direct relationship with the number of kinematic joints, the number of spherical joints, and the type combination of spherical joints attached to the moving platform. Then, the relationship between the mobility M and the RDOF with intermediate variables is derived based on modified G-K criterion and RDOF criterion, which is the base of the proposed synthesis procedure. Next, the proposed synthesis procedure is performed with the synthesis conditions RDOF = 3 or 4, and some typical KR-PMs are obtained. Finally, the condition for proper selection of actuators for KR-PM is revealed. And the reasons for large configuration randomness of the synthesized KR-PMs are discussed.

Coordination Failure and Opportunistic Behavior Results in Climate Chaos

<p><em>IT IS very much astonishing that no policy or management strategy is forthcoming towards the new theory of climate change. Up to 2030, the living conditions for people will change to the worse, as the social systems face much less degrees of freedom in relation to nature at large in terms of agriculture, potable water, forests, sea level rise, ocean acidification, etc.</em><em> </em><em>Climate change will enter a run away stage, from which there is no return—Hawking irreversibility. Natural science cannot explain this defeatism, but major model in the social sciences account for the collective action problematic. Only country resilience remains when coordination fails, but many countries are extremely vulnerable. Millions will die.</em></p>

Macroscopic superpositions require tremendous measurement devices

We consider fundamental limits on the detectable size of macroscopic quantum superpositions. We argue that a full quantum mechanical treatment of system plus measurement device is required, and that a (classical) reference frame for phase or direction needs to be established to certify the quantum state. When taking the size of such a classical reference frame into account, we show that to reliably distinguish a quantum superposition state from an incoherent mixture requires a measurement device that is quadratically bigger than the superposition state. Whereas for moderate system sizes such as generated in previous experiments this is not a stringent restriction, for macroscopic superpositions of the size of a cat the required effort quickly becomes intractable, requiring measurement devices of the size of the Earth. We illustrate our results using macroscopic superposition states of photons, spins, and position. Finally, we also show how this limitation can be circumvented by dealing with superpositions in relative degrees of freedom.

Kinematics analysis of a novel planar parallel manipulator with kinematic redundancy

In this paper, a novel planar parallel manipulator with kinematic redundancy is proposed. First, the Degrees of freedom (DOF) of the whole parallel manipulator and the Relative DOF (RDOF) between the moving platform and fixed base are studied. The results indicate that the proposed mechanism is kinematically redundant. Then, the kinematics, Jacobian matrices and workspace of this proposed parallel manipulator with kinematic redundancy are analyzed. Finally, the statics simulation of the proposed parallel manipulator is performed. The obtained stress and displacement distribution can be used to determine the easily destroyed place in the mechanism configurations.

The role of internal dynamics in the coherent evolution of indirect excitons

We study the time-dependent quantum scattering of a spatially indirect exciton by an external potential, taking fully into account the relative quantum dynamics of the electron-hole (e-h) pair. Exact calculations for an e-h wave packet show that transfer of energy between centre-of-mass (c.m.) and relative degrees of freedom may result in a genuine correction to the evolution during the scattering and eventually at asymptotic times. We show in experimentally relevant regimes and device configurations, that transmission resonances, tunnelling probabilities, diffraction patterns and wave packet fragmentation of indirect excitons are largely determined by the internal dynamics, and could not be reproduced by point-like dipole models or mean-field calculations.We show that a properly-designed local self-energy potential to be added to the c.m. Hamiltonian embeds the effects of the c.m.-internal motion correlation at a small fraction of the computation load needed for full-propagation calculations. The explicit form of this self-energy emphasises the dominant role of internal virtual transitions in determining scattering coefficients of indirect excitons.

A Systematic Approach for the Jacobian Analysis of Parallel Manipulators with Two End-Effectors

Parallel manipulators with two end-effectors (PM2Es) enable the design of gripping robots with high dynamic performance. The gripping action is enabled by internal, relative degrees of freedom (DoFs) between the two end-effectors. Many standard methods for the analysis and control of parallel manipulators rely on a Jacobian, where a complete Jacobian analysis includes constraint relations. These constraint relations have not been consistently included in previous analyses of PM2Es, while they are specifically relevant for PM2Es because constraints play an important role in the static force analysis of a PM2E. This is because wrenches applied by the actuators can be transferred to the end-effectors through internal constraints, an effect which is not captured by kinematic relations alone. This paper presents a systematic approach to perform the Jacobian analysis of PM2Es, which is based on screw theory, and that takes all constraint relations into account. The approach is applied to a PM2E with three legs and one internal closed-loop chain. An example mechanism was built to experimentally validate the resulting Jacobian analysis using a static force analysis.

ЦИРКАДИАННЫЕ РИТМЫ ГАЗОВОГО СОСТАВА КРОВИ У БОЛЬНЫХ ХРОНИЧЕСКОЙ ОБСТРУКТИВНОЙ БОЛЕЗНЬЮ ЛЕГКИХ

Chronobiological aspects of blood gas composition in 24 patients with COPD were studied. To achieve this goal, the gas composition of the arterialized capillary blood simultaneously with the investigation of respiratory function was studied with an interval of 6 hours over 2 days. In healthy individuals and patients with mild COPD two types of gas composition of blood biorhythm – daytime and nighttime – were found. In patients with moderate, severe and very severe disease 3 types of biorhythm of partial oxygen and carbon dioxide tension – morning time, noontime and evening time were registered. In healthy individuals and patients with mild COPD gas composition of blood was characterized by significant degrees of freedom in relation to functioning of the respiratory system, which indicated the stored processes of adaptation to changing conditions of the external and internal environment. In patients with moderate, severe and very severe COPD at the moment of acrophase of circadian rhythm of lung function maximum partial oxygen pressure in the arterialized capillary blood was observed. During the batiphaze of circadian rhythm of the respiratory system the highest values of the partial carbon dioxide tension were revealed. Thus, it was found out that with the growth of the severity of the disease in patients with COPD abnormal rhythms of blood gas composition are registered; the dependence of circadian rhythm of blood gas composition on the functioning of the respiratory apparatus increases.

Quark susceptibility in a generalized dynamical quasiparticle model

The quark susceptibility $\chi_q$ at zero and finite quark chemical potential provides a critical benchmark to determine the quark-gluon-plasma (QGP) degrees of freedom in relation to the results from lattice QCD (lQCD) in addition to the equation of state and transport coefficients. Here we extend the familiar dynamical-quasiparticle model (DQPM) to partonic propagators that explicitly depend on the three-momentum with respect to the partonic medium at rest in order to match perturbative QCD (pQCD) at high momenta. Within the extended dynamical-quasi-particle model (DQPM$^*$) we reproduce simultaneously the lQCD results for the quark number density and susceptibility and the QGP pressure at zero and finite (but small) chemical potential $\mu_q$. The shear viscosity $\eta$ and the electric conductivity $\sigma_e$ from the extended quasiparticle model (DQPM$^*$) also turn out in close agreement with lattice results for $\mu_q$ =0. The DQPM$^*$, furthermore, allows to evaluate the momentum $p$, temperature $T$ and chemical potential $\mu_q$ dependencies of the partonic degrees of freedom also for larger $\mu_q$ which are mandatory for transport studies of heavy-ion collisions in the regime 5 GeV $< \sqrt{s_{NN}} <$ 10 GeV.