bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some properties on $$\mathrm{IA_Z}$$-automorphisms of groups
Authors: Taheri Hamid , Moghaddam Mohammd Reza R. , Rostamyari Mohammad Amin 
Published: June 2019

AbstractLetGbe a group and$$\mathrm{IA}(G)$$IA(G)denote the group of all automorphisms ofG, which induce identity map on the abelianized group$$G_{ab}=G/G'$$Gab=G/G′. Also the group of those$$\mathrm{IA}$$IA-automorphisms which fix the centre element-wise is denoted by$$\mathrm{IA_Z}(G)$$IAZ(G). In the present article, among other results and under some condition we prove that the derived subgroups of finitep-groups, for which$$\mathrm{IA_Z}$$IAZ-automorphisms are the same as central automorphisms, are either cyclic or elementary abelian.
Charge Engineering of Mo2C@Defect-Rich N-Doped Carbon Nanosheets for Efficient Electrocatalytic H2 Evolution
Authors: Lei Chunsheng , Zhou Wen , Feng Qingguo , Lei Yongpeng , Zhang Yi , Chen Yin , Qin Jiaqian 
Published: June 2019

Abstract
Charge engineering of carbon materials with many defects shows great potential in electrocatalysis, and molybdenum carbide (Mo2C) is one of the noble-metal-free electrocatalysts with the most potential. Herein, we study the Mo2C on pyridinic nitrogen-doped defective carbon sheets (MoNCs) as catalysts for the hydrogen evolution reaction. Theoretical calculations imply that the introduction of Mo2C produces a graphene wave structure, which in some senses behaves like N doping to form localized charges. Being an active electrocatalyst, MoNCs demonstrate a Tafel slope as low as 60.6 mV dec−1 and high durability of up to 10 h in acidic media. Besides charge engineering, plentiful defects and hierarchical morphology also contribute to good performance. This work underlines the importance of charge engineering to boost catalytic performance.
Duration of preclinical, prodromal, and dementia stages of Alzheimer's disease in relation to age, sex, and APOE genotype
Authors: Vermunt Lisa , Sikkes Sietske A.M. , van den Hout Ardo , Handels Ron , Bos Isabelle , van der Flier Wiesje M. , Kern Silke , Ousset Pierre‐Jean , Maruff Paul , Skoog Ingmar , Verhey Frans R.J. , Freund‐Levi Yvonne , Tsolaki Magda , Wallin Åsa K. , Olde Rikkert Marcel , Soininen Hilkka , Spiru Luisa , Zetterberg Henrik , Blennow Kaj , Scheltens Philip , Muniz‐Terrera Graciela , Visser Pieter Jelle ,   for the Alzheimer Disease Neuroimaging Initiative,   AIBL Research Group,   ICTUS/DSA study groups
Published: June 2019

AbstractIntroductionWe estimated the age‐specific duration of the preclinical, prodromal, and dementia stages of Alzheimer's disease (AD) and the influence of sex, setting, apolipoprotein E (APOE) genotype, and cerebrospinal fluid tau on disease duration.MethodsWe performed multistate modeling in a combined sample of 6 cohorts (n = 3268) with death as the end stage and estimated the preclinical, prodromal, and dementia stage duration.ResultsThe overall AD duration varied between 24 years (age 60) and 15 years (age 80). For individuals presenting with preclinical AD, age 70, the estimated preclinical AD duration was 10 years, prodromal AD 4 years, and dementia 6 years. Male sex, clinical setting, APOE ε4 allele carriership, and abnormal cerebrospinal fluid tau were associated with a shorter duration, and these effects depended on disease stage.DiscussionEstimates of AD disease duration become more accurate if age, sex, setting, APOE, and cerebrospinal fluid tau are taken into account. This will be relevant for clinical practice and trial design.
The Departure from Equilibrium of Turbulent Boundary Layers
Authors: McDonald H. 
Published: June 2019

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.
On the Bifurcational Buckling of Elastic Beams, Plates and Shallow Shells
Authors: Pope G. G. 
Published: June 2019

SummaryThe buckling behaviour of elastic beams, plates and shallow shells must often be investigated by calculating the slope at the instant of buckling of a curve relating the applied loading and the deformation parallel to the undeformed middle surface. This paper demonstrates the circumstances under which this slope can be calculated exactly without taking into account changes in the mode shape as the buckle amplitude increases.
Establishment of the Bow-Wave in the Supersonic Flow of Carbon Dioxide Past a Sphere
Authors: Zienkiewicz H. K. , Malloch I. D. 
Published: June 2019

SummaryAn experimental study of bow-wave trajectories for a sphere in CO2 has been made in a shock tube, using a drum-camera-schlieren technique, for incident shock Mach numbers of 2·4, 2·8 and 4·0. Results show that vibrational relaxation has only a slight effect on the bow-wave formation time but significantly affects the stand-off distance in steady flow.
The Bending of Symmetrically Loaded Circular Plates of Variable Thickness under Uniform Compression
Authors: Dhaliwal R. S. 
Published: June 2019

SummaryThe solution has been obtained for the problem of a uniformly compressed and symmetrically loaded circular ring plate of linearly varying thickness. Four particular cases have been discussed and numerical values of the maximum deflection have been obtained for various sizes of the hole of the ring.
Theoretical Analysis of an Internally-Braced, Two-Dimensional Air Strut which is Partially Buckled
Authors: Newman B. G. , Jones D. 
Published: June 2019

SummaryA theoretical analysis is presented for a two-dimensional air strut with walls consisting of thin membranes which are joined by many inextensible strings. The strut is deflected through large angles so than an appreciable portion of each membrane is buckled and lies along the solid plates which form the ends of the strut. Numerical solutions are obtained for two cases and, in particular, the resultant force on each end plate is determined.
Supersonic Flow Past a Wedge with a Flame at its Apex
Authors: Foster R. , Clarke J. F. 
Published: June 2019

SummaryThe wholly supersonic flow past a two-dimensional wedge is analysed on the assumption that release of chemical energy into the stream can be accomplished across a thin discontinuous plane flame front attached to the apex. Forces experienced by the wedge are calculated and representative flow patterns exhibited. Some typical interactions between the flame and shocks or centred simple waves are discussed, with emphasis on the use of pressure-flow-deflection diagrams to obtain results.
Some Finite Two-Dimensional Contractions
Authors: Mills R. D. 
Published: June 2019

SummaryGeneral solutions for two-dimensional incompressible potential flow occurring between two equipotential planes perpendicular to the x-axis are given. The first form is the two-dimensional analogue of Thwaites’s solution for axisymmetric flow and allows the calculation of the flow when the axial velocity distribution is specified as a Fourier cosine series in x. The second form of solution, obtained by “inverting” the first form, allows the calculation of the flow when the shape of the “boundary streamline” is specified by a similar series in the velocity potential ϕ.It is shown how the second form of solution may be utilised to design contracting channels between equipotential planes. The computation of the contraction shapes and velocities is straightforward. In particular, contractions are derived from smoothing conditions similar to those used by Thwaites, and from a flow having a single (ϕ, y) step-discontinuity. It is shown in the Appendix that the latter flow possesses a closed form representation in terms of elliptic functions.
A Note on a Non-Linear Theory on Bending of Orthotropic Sandwich Plates
Authors: Ueng Charles E. S. , Lin Y. J. 
Published: June 2019

SummaryThe derivation of a non-linear theory on bending of orthotropic sandwich plates is carried out by the principle of complementary energy from elasticity. The governing differential equations and natural boundary conditions are obtained. The assumptions used are, namely, the facings are orthotropic thin elastic plates with negligible bending rigidities and are made of the same material; the orthotropic core can take the transverse shear only; and the transverse shortening of the core may be ignored. The geometrical non-linearities are equivalent to von Kármán’s theory for single-layered plates. Through the introduction of a “shear function”, the number of differential equations is reduced to three and the equations are in rather simple form. It appears that the equations obtained here would require, comparatively, the least amount of work for analysing the finite deflection sandwich plate problems having a wide range of properties of practical interest.
An Experimental Investigation of a Low-Speed Circulation-Controlled Aerofoil
Authors: Kind R. J. , Maull D. J. 
Published: June 2019

SummaryExperiments performed on a low-speed circulation-controlled aerofoil are described. The aerofoil was of elliptic section with the circulation controlled by means of a jet blowing around the blunt trailing edge. Results for the lift, drag and pitching moment on the aerofoil are presented as functions of the blowing momentum coefficient and the angle of incidence. The results are for a two-dimensional aerofoil. Possible applications of this type of aerofoil are briefly discussed.
Differential Eigenvalue Problems with Particular Reference to Rotor Blade Bending
Authors: Wadsworth M. , Wilde E. 
Published: June 2019

SummaryA differential equation which contains an eigenvalue is considered as a pair of simultaneous differential equations by augmenting the main equation with the equation λ′=0. This ensures the constancy of the eigenvalue λ. The differential eigenvalue problem is thus reduced to a pair of simultaneous non-linear differential equations with two-point boundary conditions. An iterative method for the solution of the two-point boundary value problem is described.To demonstrate the method, the normal modes and frequencies in flapping of a helicopter rotor blade are calculated. In the case considered the stiffness and mass/(unit length) of the blade have points of discontinuity. The method may also be applied when the blade parameters are given in the form of experimental data.
A Unified Approach to the Initial Buckling of Stiffened Panels in Compression
Authors: Wittrick W. H. 
Published: June 2019

SummaryThis paper provides the basis for a very general approach to the determination of initial buckling stresses of long stiffened panels in uniform longitudinal compression. The panels are assumed to consist of a series of long flat strips, rigidly connected together at their edges, as in panels with top-hat or Z-section stringers, or in sandwich panels with corrugated cores. Whatever the buckling mode, the individual flats are subjected, just after buckling, to sinusoidally varying systems of both out-of-plane and in-plane edge forces and moments, superimposed on the basic state of uniform compression. The stiffness matrices corresponding to these sinusoidal edge loads are derived, taking account of the destabilising effect of the basic longitudinal compressive stress, not only in the out-of-plane but also in the in-plane deformations. For the latter purpose a non-linear theory of elasticity is used. The application of these stiffness matrices to specific panels is briefly described. All possible modes are incorporated within one determinantal equation. For panels with identical stiffeners spaced at equal intervals, the order of the determinant is independent of the number of stiffeners.
An Analysis of the Large Deflections of Beams using the Rayleigh-Ritz Finite Element Method
Authors: Walker A. C. , Hall D. G. 
Published: June 2019

SummaryThe Rayleigh-Ritz finite element method is used to obtain an approximate solution of the exact non-linear energy functional describing the large deflection bending behaviour of a simply-supported inextensible uniform beam subjected to point loads. The solution of the non-linear algebraic equations resulting from the use of this method is effected, using three different techniques, and comparisons are made regarding the accuracy and computing effort involved in each. A description is given of an experimental investigation of the problem and comparison of the results with those of the numerical method, and of the available exact continuum analyses, indicates that the numerical method provides satisfactory predictions for the non-linear beam behaviour for deflections up to one quarter of the beam’s length.
The Effect of Shear Flexibility and Rotatory Inertia on the Natural Frequencies of Uniform Beams
Authors: Carr J. B. 
Published: June 2019

SummaryAn energy approach has been used to obtain approximations to the natural frequencies of uniform beams when the effects of shear flexibility and rotatory inertia are included. The characteristic functions of simple beams are used to describe the bending deflection and the necessity for an assumed shear deflection shape has been eliminated by the use of simple relationships which exist between the effects of shear flexibility and rotatory inertia. A comparison of the approximate frequencies with the exact frequencies shows good agreement even at the higher frequencies. The method has been applied to hinged-hinged, fixed-free, free-free, fixed-fixed, fixed-hinged and free-hinged beams.
Some Techniques of Experimentation with Tea in North-East India
Authors: Sen A. R. , Biswas Asim K. 
Published: June 2019

SummaryAn attempt is made to investigate some techniques of experimentation, based on data from uniformity trials and experiments on tea conducted in different regions of north-east India. The study showed that:i.Adjustment of yield due to covariance generally ceased to be efficient after the first four years of experimentation in manurial trials and after two years in pruning trials. Adjustment based on average yield over a period of four to six years resulted in an increase in efficiency.ii.Among the ancillary variables of pretreatment yield and pruning weight, the former proved to be generally more efficient, but when cost of operation is taken into account the latter was economical and, therefore, preferable. The two variables together, in a multiple regression, did not show any extra gain. Use of the pretreatment late crop, from September to December, was generally more efficient than using the whole season's crop.iii.Coefficient of variation showed a declining tendency with age, the fall being more marked up to six years of age. This suggests that, for a given degree of precision, more replication would be required for experiments with young tea than with mature tea.iv.Increase in plot size, up to 48 bushes, resulted in an increase in information per replicate in Darjeeling, though plots of smaller size would be more economical.v.On the basis of five uniformity trials in the Assam valley, Darjeeling and Cachar district, it was observed that for the same values of cost components proportional to number of replications and total area under experiment, the optimum plot size in Darjeeling and Cachar was about half that for the Assam valley.vi.Long and narrow plots, oriented with their longer sides extending along the contour lines, within blocks of which the longer sides ran down the slope, proved more efficient than other alternatives in Darjeeling district.vii.Systematic plucking of 1 in 2 out of the totality of plucking rounds, for experiments running for two or more years, provided estimates of treatment contrasts within 5 per cent of the population mean (P = 0-05). For a higher margin of error, of 10 per cent of the mean, systematic pluckings of 1 in 3 or even 1 in 4 would suffice if the treatment comparisons were based on five or more years.
Effects of Time of Nitrogen Application on Yield of Maize in the Tropics
Authors: Fayemi Adeboyejo A. 
Published: June 2019

SummaryA four-year study from 1958 to 1962 showed that time of application of fertilizer nitrogen greatly influenced the yield of grain, the percentage of nitrogen and the crude protein of the grain under Nigerian conditions characteristic of the early maize cropping season from March to July. Split applications of nitrogen fertilizer significantly increased maize grain yield by 35 per cent when two equal doses were given one month and two months after planting; and by 31 per cent when four equal doses were supplied at planting and one month, two months and three months after seeding. Yield was significantly reduced when application was delayed two months after planting. High yields of maize were not obtained by supplying the whole of nitrogen fertilizer at one time, eidier at sowing or any time later during the growing season. However, applying all of the nitrogen fertilizer one month after planting significantly increased the percentage of nitrogen and of the crude protein content of the grain. The maize ear weight was favourably influenced by spreading the nitrogen application over the three-month period of the maize growth.
Studies On Browse Plants in Ghana II. Digestibility, (d) Digestibility Of Grewia Carpinifolia From The Accra Plains, Using Local Cattle As Experimental Animals
Authors: Mabey G. L. , Rose Innes R. 
Published: June 2019

SummaryDigestibility of the palatable indigenous shrub Grewia carpinifolia was investigated. Digestion coefficients (%) were—organic matter 70, dry matter 70, crude protein 78, crude fibre 54, nitrogenfree extract 81, ether extract 13 and ash 52. Calculated nutritive values were—starch equivalent 27.3 and digestible crude protein 5.0, giving a nutritive ratio of about 1 : 5. The material used was moderately young.
The Productivity Of Mashona Cattle in Rhodesia
Authors: Oliver J. 
Published: June 2019

SummaryThe productivity of a herd of Mashona cattle is described, where hand-feeding was practised in winter to prevent loss of body weight. Calves weighed about 50 lb at birth, and gained weight at the rate of 1.27 lb a day to six months of age, compared widi 1.56 and 0.87 lb a day for calves at two other sites. Young animals gained an average of ½ lb a day from weaning to maturity. Mashona steers responded to pen-feeding and produced carcasses which were satisfactory for the Smithfield market. The mature weight of breeding cows was just under 700 lb and the calving rate varied from 72 to 92 per cent. Cows which failed to calve and those whose calves were early-weaned gained almost 100 lb liveweight by the end of die grazing season. Early-weaned calves fed a complete diet were 40 lb heavier than their contemporaries at 28 weeks of age. The need to develop die breed is discussed.
Rainfall Conservation and The Yields Of Sorghum and Groundnuts in Northern Nigeria
Authors: Lawes D. A. 
Published: June 2019

SummaryThe use of cultivation techniques to conserve rainfall, by preventing runoff, and to improve the soil surface infiltration rate, has produced spectacular increases in the yield of cotton on the Loess Plain soils of Northern Nigeria, where yields of the order of 2000 lb seed cotton per acre can now be produced regularly irrespective of the rainfall pattern. As yields of this level had not been obtained previously, it has been concluded that lack of soil moisture and poor soil aeration have in the past set a ceiling to seed cotton yields. The effects of these cultivation treatments on the two other major crops of the area, sorghum and groundnuts, have now been examined, and results from a series of field experiments over six seasons indicate that adequate soil moisture is essential to the production of high yields, but that the other soil conditions which are alleviated by these cultivations are not so critical for these two crops as they are for cotton. Reasons are suggested why spectacular increases in yield in response to the treatments are not generally to be expected with sorghum and groundnuts.
Preparing Papers For Scientific Journals
Authors: Kirkman A. J. 
Published: June 2019

SummaryScientific papers must be accurate and readable. Writers must deliberately arrange their information in a way that will interest and be useful to readers, and write clearly and directly, in the simplest possible English. There is no need for scientific writing to be ponderously overformal. Key features of style are short sentences, a minimum of jargon, use of familiar words, active rather than passive constructions, and personal, direct statements.
Notes on the Text and Transmission of the Apocryphal Psalms 151, 154 (= Syr. II) and 155 (= Syr. III)
Authors: Strugnell John 
Published: June 2019

The Hebrew originals of the above-mentioned Psalms have been recently published by J. A. Sanders from a scroll containing approximately the last quarter of the Psalter which was found in the Eleventh Cave at Qumrân. In his preliminary notice on the unrolling of this scroll Sanders had already written:There are seven non-canonical compositions, aside from Ps 151, interspersed among the psalms. One of these is a prose account of the psalms and songs composed by David and the purposes for which he wrote them. The total number of musical compositions attributed to David is 4050.
Can God Create Men and Address them Too?
Authors: Neville Robert C. 
Published: June 2019

The philosophical problem of whether God can create free men has a special form for Christian theologians. Among the many kinds of freedom that might be claimed for men, theologians are most interested in the kind that involves the human response to God. For Christians the important response is to God's revelation in Christ. The form of the problem of creation and freedom of chief interest to Christian theologians, therefore, is whether these two doctrines are compatible:1. that God is the creator of everything finite and contingent, including men and their responses, and2. that through the gospel of Jesus Christ God addresses men who may respond freely.
Two Ontologies of Power: A Comparison of Santayana and Tillich
Authors: Comstock W. Richard 
Published: June 2019

The positions of George Santayana and Paul Tillich disclose remarkable strands of congruent concern and approach. In spite of obvious differences in temperament and philosophical heritage, both thinkers see their philosophies as the culmination of traditional perspectives in Western thought and also as modern criticisms of them. Neither thinker is interested in a radical originality of thought severed from its roots in the past. Both rather want to formulate a general philosophy of culture that is eclectic in the best sense of that abused word.Working independently of each other, both finally focus their
attention on a similar concern that they see operating in the tradition and which is considered by them to have a continuing importance in the present. This is the problem of power and the appropriate human response to its manifestations. The intriguing features of agreement and disagreement in this common exploration are examined in the present essay.