Miracle-dz/UniFAR-FTUs huggingface dataset:
Ideals and centralizing mappings in prime rings

Let R be a prime ring and U be a nonzero ideal of R. If T is a nontrivial automorphism or derivation of R such that uuT uTu is in the center of R and uT is in U for every u in U, then R is commutative. If R does not have characteristic equal to two, then U need only be a nonzero Jordan ideal. If R is a ring, a mapping T of R to itself is called centralizing on a subset S of R if ssT sTs is in the center of R for every s in S. There has been considerable interest in centralizing automorphisms and derivations defined on rings. Miers [4] has studied these mappings defined on C*-algebras. In [5] Posner proved that if a prime ring has a nontrivial centralizing derivation, then the ring must be commutative. The same result was obtained for centralizing automorphisms in [3]. In this paper it is shown that the automorphism or derivation need only be centralizing and invariant on a nonzero ideal in the prime ring in order to ensure that the ring is commutative. Also, if R is of characteristic not two, then the mapping need only be centralizing and invariant on a nonzero Jordan ideal. For derivations this gives a short proof of a result related to that of Awtar [1, Theorem 3]. Awtar proved that if R is a prime ring of characteristic not two with a nontrivial derivation and a nonzero Jordan ideal U such that the derivation is centralizing on U, then U is contained in the center of R. Jeffrey Bergen deserves many thanks for his suggestions concerning the results and proofs in this paper. From now on assume that R is a prime ring and let Z be the center of R. Let [x,)y] = xy yx and note the important identity [x, yz] = y[x, z] + [x, y]z. The following lemmas will be used in the proofs of the main results. LEMMA 1. If b[a, r] = 0 for all r in R, then b = 0 or a is in Z. PROOF. Assume that b[a, r] = 0 for all r in R. Replace r by xy to obtain b[a, xy] = bx[a, y] + b[a, x]y = bx[a, y] = 0 for all x and y in R. Since R is prime, b = O or [a, y] = 0 for all x in R. LEMMA 2. If D is a derivation of R such that uD = 0 for all u in a nonzero right ideal U of R, then rD = 0 for all r in R. PROOF. Let u be a nonzero element in U and x be an element in R. Then ux is in U and 0 = (ux)D = UDx + u(xD) = u(xD). Now replace x by sr to obtain 0 = u(sr)D = [u(sD)]r + us(rD) = us(rD) for all r and s in R. Since R is prime and u is nonzero, rD = 0 for all r in R. Received by the editors October 21, 1981 and, in revised form, January 12, 1982. 1980 Mathematics Subject Classification. Primary 16A70; Secondary 16A12, 16A68, 16A72.
On the pH response of fiber optic evanescent field absorption sensor having a U-shaped probe: An experimental analysis

Summary An investigation is made of the response of fiber optic evanescent field absorption sensors in respect of the concentration of dye as well as its pH value. Patent blue VF dye is chosen as the measurand sample, and it is found that the evanescent absorbance of the dye is a nonlinear function of dye concentration, which is in contradiction with the theory of Beer-Lambert law of absorption, which states that the absorbance of the sample is linearly related to the sample concentration. Further, it is also observed that the degree of nonlinearity is a function of the pH value of the measurand sample; it (the nonlinearity) decreases with the decrease in sample pH. The reason is attributed to the accumulation of positively charged chromophores on the bare silica surface of the fiber in the case of higher pH values. Justification of it is also made on the basis of the results obtained through free-beam method. A U-shaped sensor probe is used for the investigation because the sensitivity of the system improves due to the higher penetration depth achieved in this case; this is experimentally shown too.
The Integration of Mind into Physics

The proper goal of science is a unified theory of all of nature, including our thoughts. An adequate theory of this kind will resolve the quantum measurement problem, which is to reconcile the nonclassical character of the quantum world with the classical character of our perceptions of it. A framework for such a theory is described. It weds the opposing views of Bohr and Einstein. Bohr held that quantum theory provides rules that relate aspects of our knowledge, while Einstein claimed that basic theory should describe what could be reality itself, not merely our knowledge of it.
The conductive propagation of nuclear flames. I. Degenerate C+O and O+ Ne + Mg white dwarfs

The paper determines the physical properties - speed, width, and density structure - of conductive burning fronts in degenerate carbon-oxygen (C + O) and oxygen-neon-magnesium (O + Ne + Mg) compositions for a grid of initial densities and compositions. The dependence of the physical properties of the flame on the assumed values of nuclear reaction rates, the nuclear reaction network employed, the thermal conductivity, and the choice of coordinate system are investigated. The occurrence of accretion-induced collapse of a white dwarf is found to be critically dependent on the velocity of the nuclear conductive burning front and the growth rate of hydrodynamic instabilities. Treating the expanding area of the turbulent burning region as a fractal whose tile size is identical to the minimum unstable Rayleigh-Taylor wavelength, it is found, for all reasonable values of the fractal dimension, that for initial C + O or O + Ne + Mg densities above about 9 x 10 exp 9 g/cu cm the white dwarf should collapse to a neutron star. 97 refs.
Conceptual framework for a positive psychology coaching practice

The complementary nature of positive psychology and coaching psychology has long been recognised by both researchers and practitioners. The last decade saw a tenfold increase of articles relating to positive psychology coaching and even more literature attempting to apply some of the findings from positive psychology in a coaching practice. However, despite the interest and the complexity of both fields, there is a lack of systematic approach to this new practice. The current paper introduces the Conceptual Framework for Positive Psychology Coaching Practice, the aim of which is to offer advice to both practitioners and researchers of the elements necessary to exist, in order to practise positive psychology coaching, as well as inform the policy and curriculum of programmes teaching positive psychology coaching in third level education.
On the Design of Perforated Facings for Acoustic Materials

An approximate analysis of the acoustic behavior of perforated facings for absorptive materials is outlined and is reduced to a design chart. Only the mass reactances of the holes and of the facing material are included in the analysis. This simplified picture is adequate for many practical problems, but breaks down for certain conditions which are discussed. If the acoustic impedance of the unfaced material is known, absorption coefficients for the material with perforated facing can be read directly from the chart.
Chained cross-training of workers for robust performance

Training workers to perform multiple tasks can improve workforce agility for dealing with variations in workload. However, cross-training can be costly, time consuming to implement, is limited by worker learning capacity, and can lead to ambiguity about work responsibilities. Therefore, it is important to implement cross-training in the most efficient way and especially, due to the training time required, in a way that is robust to system changes. We use queueing and simulation analysis to investigate cross-training in the context of maintenance in a manufacturing plant. The tasks are independent and can be represented as a set of parallel queues that are served by dedicated and cross-trained workers. We propose a cross-training strategy called chaining, in which a few workers are strategically cross-trained, and show that it yields most of the benefits of cross-training all workers, with much less effort. Most importantly, we demonstrate that cross-training workers to form a “complete chain” is extremely robust in the following ways: (i) it is insensitive to the variety of ways a complete chain can be formed; (ii) it performs well even if there are major changes to or uncertainty in system parameters (such as mean task arrival rates); and (iii) performance is insensitive to control decisions that, without complete chaining, can significantly harm performance.
EfShard: Toward Efficient State Sharding Blockchain via Flexible and Timely State Allocation

State sharding is a promising approach to address the scalability issue in the blockchain system. However, the previous sharding schemes using the fixed data partitioning mechanism bring high proportion of costly cross-shard transactions and cannot effectively handle the workload imbalance that occurs in practice, which slows down the performance. To address these issues, we propose EfShard, an efficient state sharding blockchain system that enables allocating states flexibly and timely across shards according to recent transactions. Firstly, we propose a hierarchical state partition to enable flexible mapping of states to shards. Second, we design a new state transfer protocol to efficiently migrate states across shards while guaranteeing consistency and liveness. Then, we provide a greedy-based state allocation algorithm to decide when and how to migrate states. The allocation mechanism groups highly correlated state data into the same shard to reduce the proportion of cross-shard transactions and distributes state data to shards with relatively low load to balance workload, thus improving the performance. In the end, we conduct extensive experiments to evaluate EfShard and the results demonstrate that EfShard outperforms state-of-the-art approaches in terms of transaction throughput, confirmation latency, workload balance, and queue size of transaction pool.
A Guided Tour through Excursions

(l.i) what happens after Tn is independent of what happened before; (l.ii) the evolution of the game from Tn on, {ST +k'. k^ 0}, is just like the evolution of the original game {Sk: k ^ 0}. The whole game starts afresh at time Tn! Thus if we define the nth excursion ^ " b y Zn = {Sk:Tn_x^k^Tn}, nsN, (1 .i) can be re-expressed as saying £15. , £n are independent of£n+1, £n+2,. ; because of (l.ii), £n+1 has the same distribution as £v Hence
Stability of polymeric thin film transistors for x-ray imaging applications

The effects of x-ray irradiation on the electrical performance of organic thin film transistors (OTFTs) have been examined up to equivalent lifetime doses for medical digital x-ray imaging backplanes. Transistor performance metrics have been assessed before and after exposures up to 500Gy for bottom-gate, bottom-contact OTFTs of p-channel polytriarylamine and polyfluorene semiconductors. There is no discernible degradation in device performance for either material and no indication of the creation of additional trap states. In situ measurements indicate that x-ray exposure tends to reverse undesirable shifts in the threshold voltage due to prolonged atmospheric exposure and bias stress.
Cardiac arrest and pulmonary hypertension in scurvy: a case report

We report a case of a six-year-old boy who presented after a cardiac arrest, likely due to a pulmonary hypertensive crisis in the setting of vitamin C deficiency. After initially presenting with subacute multifocal bone lesions of unknown etiology, he experienced a pulseless electrical activity cardiac arrest while undergoing a diagnostic procedure under sedation. During his post-arrest convalescence, he developed persistent tachycardia and peripheral edema. An echocardiogram revealed findings consistent with significant pulmonary arterial hypertension, which was found to be responsive to inhaled nitric oxide. Laboratory investigation revealed undetectable levels of vitamin C, resulting in disclosure of a history of severe restrictive eating behavior. With ascorbate supplementation, the patient’s pulmonary vasodilators were weaned and discontinued. Given his complete recovery, we suspect that the cardiac arrest and pulmonary hypertension were the consequence of a rare, but reversible, complication of scurvy.
Two dimensional trans-rectal ultrasonographic studies in early pregnant murrah buffaloes

Two dimensional ultrasonographic studies were conducted in six pregnant Murrah buffaloes using 5.0-7.5 MHz frequency rectal probe twice a week from day 18 to 60 days followed by weekly interval up to 90 days postin semination. Two dimensional images of antenatal fetal organs particularly fetal stomach, eye, limbs, heart, umbilical cord, thorax, liver and placentomes were imaged and variat ions in size of placentome, stomach and crown rump length were measured. Fetal heart beat was measured from day 26 to 90 which decreased with advancement of gestation. From the present study it may be concluded that early pregnancy can be diagnosed ultrasonogra phicallythrough trans-rectal approach by day 26 post insemination.
Health benefit and economic impact of utilising ECMO in COVID-19 patients: patient or cost first

%) and other causes (30.1%). The “other” category was defined as conditions, such as cancer or sepsis, which would eventually require secondary ECMO therapy. The authors found that the median total healthcare cost of patients on ECMO support was United States Dollars (USD) 46,308.0 [interquartile range (IQR): 25,727.0–86,924.8]. This was demonstrated by the median ECMO support and hospital stay duration of ECMO survivors between 3 (IQR: 1–7) and 25 (IQR: 15–31) days. With a total healthcare cost increase of USD 1000, these patients were also found to have an increased three-year all-cause mortality when compared to patients who did not accrue such costs. Interestingly, they did not find the mortality rates to be significantly different between the cardiac and respiratory indication cohorts (P=0.926). However, a 1.94-fold higher mortality rate was
PHOTOMETRIC PROPERTIES OF HD 200925.

Photometric observations have been carried out over ninety percent of the pulsation cycle for the variable star HD 200925. The observations were obtained using a single-channel photometer, and a photomultiplier attached to a 61-cm reflecting telescope. The instrumental indices were reduced to the standard Stromgren and beta-systems of 13 standard stars. The photometric data show that HD 200925 is multiperiodic. A reddening value of 0.040 mag was derived as the average of the variable and comparison star observations. Analysis of the intrinsic (b-y) and cl values for one primary pulsation cycle indicated a mean effective temperature of 7470 K, and a mean surface gravity of 3.87 log g. HD 200925 is found to have a somewhat higher (+0.33) Fe/H abundance ratio than stars in the Hyades. The observed magnitude and color variations of HD 200925 are reproduced in graphic form.
A Variational Formulation for Multicriteria Structural Optimization

ABSTRACT Multicriterion structural optimization problems stated as minimization of the maximum of a set of weighted criteria are considered. Interpretation of the min-max problem as a simple minimization problem for an upper bound on the criteria leads to a formulation that is convenient for analysis of problems with global as well as local objectives. The method is demonstrated on multipurpose design of a vibrating cantilever, on design of a
Terminal viscous and elastic properties of linear ethene∕α-olefin copolymers

Several linear ethene∕α-olefin copolymers with butene, hexene, octene, dodecene, octadecene, and hexacosene as comonomers were characterized in linear-viscoelastic shear flow. Creep and creep recovery measurements were used to obtain the zero shear-rate viscosity η0 and the steady-state elastic recovery compliance Je0. The correlation between the zero shear-rate viscosity and the weight average molar mass η0(Mw) established for metallocene catalyzed high density polyethylene (mHDPE) was found to be obeyed by all samples containing comonomer contents up to 29wt%. For the linear steady-state elastic compliance Je0 an increase with growing molar mass Mw or comonomer content wc was observed.
Effective collision strengths for transitions among the 3s2, 3s3p and 3p2 configurations of Fe XV

Effective collision strengths for transitions among the ten energetically lowest fine-structure levels belonging to the (1s22s22p6)3s2, 3s3p and 3p2 configurations of Fe XV have been calculated in the electron temperature range of 105-107 K, using the recent Dirac atomic R-matrix code of Norrington and Grant. The results are compared with the other recently available independent Breit-Pauli R-matrix calculations of Eissner et al (Eissner W, Galavis M E, Mendoza C and Zeippen C J 1999 Astron. Astrophys. Suppl. 137 165) and Griffin et al (Griffin D C, Badnell N R, Pindzola M S and Shaw J A 1999 J. Phys. B: At. Mol. Opt. Phys. 32 2139, 4129). Large differences are observed for many transitions over almost the entire temperature range. These differences are analysed and discussed, and the accuracy of the calculations is assessed.
Convergence of the finite volume method for multidimensional conservation laws

We establish the convergence of the finite volume method applied to multidimensional hyperbolic conservation laws and based on monotone numerical flux-functions. Our technique applies with a fairly unrestrictive assumption on the triangulations (“flat elements” are allowed) and to Lipschitz continuous flux-functions. We treat the initial and boundary value problem and obtain the strong convergence of the scheme to the unique entropy discontinuous solution in the sense of Kruzkov. The proof of convergence is based on a convergence framework [Coquel and LeFloch, Math. Comp., 57 (1991), pp. 169–210 and J. Numer. Anal. , 30 (1993), pp. 675–700]. From a convex decomposition of the scheme, we derive a new estimate for the rate of entropy dissipation and a new formulation of the discrete entropy inequalities. These estimates are shown to be sufficient for the passage to the limit in the discrete equation. Convergence follows from DiPerna’s uniqueness result in the class of entropy measure-valued solutions.
COVID-19 Associated Neurological Manifestation

Background: At the end of 2019, COVID-19 was first detected in Wuhan. In March 2020, COVID-19 became a pandemic globally. Saudi Arabia registered the first case of COVID-19 on March 2, 2020. This research aimed to identify the prevalence of different neurological manifestations of COVID-19 and to assess the relation of the severity, vaccination state, and continuity of symptoms to the occurrence of these symptoms. Methods: Cross-sectional retrospective study was done in Saudi Arabia. The study was conducted on previously diagnosed COVID-19 patients by random selection using a predesigned online questionnaire to collect data. Data was entered through Excel and analyzed through SPSS version 23. Results: The study showed that the most common neurological manifestations in COVID-19 patients are headache (75.8%), changes in sense of smell and taste (74.1%), muscle pain (66.2%), and mood disturbance (depression, anxiety) (49.7%). Whereas other neurological manifestations such as weakness of the limbs, loss of consciousness, seizure, confusion, and vision changes are significantly associated with older individuals, this may lead to increased mortality and morbidity in these patients. Conclusion: COVID-19 is associated with many neurological manifestations in the population of Saudi Arabia. The prevalence of neurological manifestations is similar to many previous studies, where acute neurological manifestations such as loss of consciousness and convulsions are seen more in older individuals which may lead to increased mortality and worse outcomes. Other self-limited symptoms such as headache and change in smell function i.e., anosmia or hyposmia were more pronounced in those <40 years. This mandates more attention to elderly patients with COVID-19, to early detect common neurological manifestations associated with it, and to apply preventive measures known to improve the outcome of these symptoms.
The Nonfinite Generation of Aut(G), G Free metabelian of Rank 3

The group of automorphisms of the free metabelian group of rank 3 is not finitely generated. Let H be a free solvable group of rank n > 2, Aut(H) the automorphism group of H, and Inn(H) the group of inner automorphisms of H. For n = 2, it was shown by the authors and E. Formanek [4, Theorem 1] that Aut(H)/Inn(H)GL2(Z), Z the ring of integers. One consequence of this fact is that Aut(H) is finitely generated (f.g.). The purpose of this paper is to prove the following contrasting theorem. THEOREM. If G is the free metabelian group of rank three, then Aut(G) is not finitely generated. This result may also be compared with a theorem of L. Auslander [1], which states that the automorphism group of a polycyclic group is finitely presented. If G' denotes the commutator subgroup of G, then the kernel of the natural homomorphism Aut(G) -4 Aut(G/G') is called the group of IA-automorphisms of G and will be denoted by IA(G). IA(G), which contains Inn(G), was shown by the authors [3] to be non-f.g. for G as in the Theorem. To prove that Aut(G) is not f.g. , we need to show that IA(G) is not f.g. as an Aut(G/G') -GL3(Z)-operator group. The question arises concerning Aut(H) where H is free metabelian of rank n > 3. The immediate feeling that Aut(H) is also non-f.g. may be incorrect. For definiteness let n = 4. Suppose G is free metabelian of rank 3, and consider Aut(G) as embedded in Aut(H) in an obvious manner. The nonfinite generatiion of Aut(G) comes from the existence of "nontame" automorphisms in Aut(G), i.e., automorphisms of G F/F" which are not induced by automorphisms of the free group F of rank three, and the necessity to include infinitely many nontame automorphisms in any generating set for Aut(G). However, the authors have discovered that many of the nontame automorphisms become tame when considered as elements in Aut(H). Whether this phenomenon is true for all nontame elements of Aut(G) is unknown as yet, but the question of the finite or nonfinite generation of Aut(H) must be considered a difficult open problem, with the interesting possibility of finite generation as the answer. Received by the editors December 31, 1980. 1980 Mathematics Subject Classification. Primary 20F28.
Formation of the Taylor cone on the surface of liquid metal in the presence of an electric field

The hydrodynamic evolution of the surface of a liquid metal in the presence of an electric field is investigated using both analytical and numerical techniques. It is established that a free liquid surface with axial symmetry evolves with time into a cone-like shape, with the cone angle equal to Taylor's static value of 98.6°. The mechanism behind such interesting flow behaviour is that the system of electrohydrodynamic (EHD) equations has a self-similar asymptotic solution that generalizes Taylor's static result. The asymptotic solutions are found and the time-dependent behaviours of basic physical quantities (electric field strength, fluid velocity and surface curvature) near the singularity are established. The results and the analytical and numerical techniques used are thought to be useful in the development of time-dependent models of operating liquid metal ion sources and EHD sprayers.