bluuebunny/crossref_metadata_2025 huggingface dataset:
Ion charge state and energy distributions of laser produced plasma from pure metals and their alloy
Authors: Zhang J. J. , Zhao H. Y. , Wang G. C. , Sun L. T. , Zhang X. Z. , Li G. P. , Zhao H. W.
Published: December 2019

A high intensity highly charged laser ion source has been studied at the Institute of Modern Physics for the last few years. In order to investigate the processes of plasma heating and expansion of laser produced plasma, the charge state and energy distributions of the ions from pure copper, silver, and copper-silver alloy, in which the atom number ratio between copper and silver is 2:3, were measured with a 90° cylindrical electrostatic ion analyzer. It was shown that the yields of highly charged copper ions from the pure copper target are higher compared with those of the alloy target. In contrast, higher yields of highly charged silver ions were obtained from the copper-silver alloy target. Moreover, the ion energy distributions were derived from the time-of-flight spectra for the ions with different ion charge states and compared between the pure metal and alloy targets.
Asymmetric magnetic reconnection driven by ultraintense femtosecond lasers
Authors: Ping Yongli , Zhong Jiayong , Wang Xiaogang , Zhao Gang
Published: December 2019

Three-dimensional asymmetric magnetic reconnection (AMR) driven by ultraintense femtosecond (fs) lasers is investigated by relativistic particle-in-cell (PIC) simulation. The reconnection rate is found to be only one-third of that in the previous symmetric reconnection PIC simulations. Similar to the case of dayside reconnection at geomagnetopause, magnetic X- and velocity stagnation points are not colocated, with the X-point at the lower field side and the stagnation point at the higher field side. Moreover, the moving direction of the X-point as reconnection evolving with the laser irradiation is determined by δBH/δBL, and the moving of stagnation point is dominated by neHBL/neLBH, where δB and ne are the magnetic field disturbance and the electron density with the subscripts “H” for the higher field side and “L” for the lower field side, respectively. Then, the hosing instability triggered by AMR and the merging of two parallel currents resulting in the tilt of the electron beam generated by the weak laser are also investigated.
The Poisson–Boltzmann model for implicit solvation of electrolyte solutions: Quantum chemical implementation and assessment via Sechenov coefficients
Authors: Stein Christopher J. , Herbert John M. , Head-Gordon Martin
Published: December 2019

We present the theory and implementation of a Poisson–Boltzmann implicit solvation model for electrolyte solutions. This model can be combined with arbitrary electronic structure methods that provide an accurate charge density of the solute. A hierarchy of approximations for this model includes a linear approximation for weak electrostatic potentials, finite size of the mobile electrolyte ions, and a Stern-layer correction. Recasting the Poisson–Boltzmann equations into Euler–Lagrange equations then significantly simplifies the derivation of the free energy of solvation for these approximate models. The parameters of the model are either fit directly to experimental observables—e.g., the finite ion size—or optimized for agreement with experimental results. Experimental data for this optimization are available in the form of Sechenov coefficients that describe the linear dependence of the salting-out effect of solutes with respect to the electrolyte concentration. In the final part, we rationalize the qualitative disagreement of the finite ion size modification to the Poisson–Boltzmann model with experimental observations by taking into account the electrolyte concentration dependence of the Stern layer. A route toward a revised model that captures the experimental observations while including the finite ion size effects is then outlined. This implementation paves the way for the study of electrochemical and electrocatalytic processes of molecules and cluster models with accurate electronic structure methods.
Reactivity of platinum and rhodium nanoclusters supported by graphene
Authors: Kim Meeri
Published: December 2019

A new article investigates the reactivity and size dependence of platinum and rhodium nanoclusters in the catalyzed decomposition of methanol-d4.
Development of a physiotherapy-led bronchoscopy service: a regional hospital perspective
Authors: Lockstone Jane , Boden Ianthe , Zalucki Nadia , Darvas James , Parkes Scott
Published: December 2019

Extended scope of practice (ESoP) and advanced scope of practice (ASoP) physiotherapy roles have been in place in the UK for over 20 years. However, interest in these types of services appears to be only just evolving within Australia. Although ESoP and/or ASoP cardiorespiratory roles in intensive care units (ICU) may be perceived to be more achievable in large metropolitan teaching hospitals, at least 67% of Australian ICUs provide physiotherapy services. Very little has been published on the practicalities (e.g. training pathways, evidence for use and guidelines) of developing advanced or extended scope cardiorespiratory physiotherapy services within Australian ICUs. This report describes the development and implementation of a physiotherapy-led bronchoscopy service from a regional hospital perspective. What is known about the topic? Although ESoP and ASoP physiotherapy roles are well established in the UK, such services appear to be only just evolving in Australia. Clarity on the definitions of extended and advanced physiotherapy roles have been articulated by the Australian Physiotherapy Association. However, there is a paucity of evidence published on the practicalities of establishing advanced or extended scope cardiorespiratory physiotherapy services within Australian ICUs. What does this paper add? One of the main emerging areas of ESoP and/or ASoP in the cardiorespiratory field is the use of bronchoscopy by physiotherapists. This paper describes the framework, implementation, limitations and barriers of developing a physiotherapy-led bronchoscopy service from a regional hospital perspective. What are the implications for practitioners? This paper allows the potential for our credentialing and practice framework model to be transferred in other public hospitals commencing or considering implementing physiotherapy-led bronchoscopy services within their ICU.
Individual structural features constrain the mouse functional connectome
Authors: Melozzi Francesca , Bergmann Eyal , Harris Julie A. , Kahn Itamar , Jirsa Viktor , Bernard Christophe
Published: December 2019

Whole brain dynamics intuitively depend upon the internal wiring of the brain; but to which extent the individual structural connectome constrains the corresponding functional connectome is unknown, even though its importance is uncontested. After acquiring structural data from individual mice, we virtualized their brain networks and simulated in silico functional MRI data. Theoretical results were validated against empirical awake functional MRI data obtained from the same mice. We demonstrate that individual structural connectomes predict the functional organization of individual brains. Using a virtual mouse brain derived from the Allen Mouse Brain Connectivity Atlas, we further show that the dominant predictors of individual structure–function relations are the asymmetry and the weights of the structural links. Model predictions were validated experimentally using tracer injections, identifying which missing connections (not measurable with diffusion MRI) are important for whole brain dynamics in the mouse. Individual variations thus define a specific structural fingerprint with direct impact upon the functional organization of individual brains, a key feature for personalized medicine.
Anisotropic diffusion creep in postperovskite provides a new model for deformation at the core−mantle boundary
Authors: Dobson David P. , Lindsay-Scott Alexander , Hunt Simon A. , Bailey Edward , Wood Ian G. , Brodholt John P. , Vocadlo Lidunka , Wheeler John
Published: December 2019

Significance

Earth’s core−mantle region is an important, but poorly understood, region which drives mantle convection (and hence surface processes) by heat transfer from the core to the mantle. Seismic observations show the complexity of the region, but current geodynamic modeling of lowermost mantle flow is hindered by an incomplete understanding of the rheology of the main mineral, postperovskite. Here we show that postperovskite is strongly anisotropic in diffusion creep and hence will show nonlinear behaviors during deformation, including strain weakening and localization. This will help to explain much of the observed seismic complexity of the core−mantle boundary region.
Ultraviolet light effect on characteristics of PbZrxTi1-xO3 (PZT) film during poling process
Authors: Cheng Chin-Chi
Published: December 2019

Poling process is one of the widely used strategies to enhance the film properties during the manufacturing processes of ceramic film. A lab-made PbZrxTi1-xO3 (PZT) film by spin-coating on Ti substrate is presented. After heating treatments, the fabricated
film was passed corona poling under ultraviolent (UV) light of various power. The characteristics of the PZT film have been evaluated by several instruments, such as X-ray diffractometer (XRD), scanning electron microscopy (SEM) and impedance analyzer. The results indicated that UV light would
affect the orientation of crystallization, microstructure and grain size of PZT film surface during poling process under room temperature.
Influence of Zr/Sn ratio on the Transverse Piezoelectric Coefficient [Inline formula] in Lanthanum-Doped Lead Zirconate Titanate Stannate Thin Films
Authors: Priya S. Laxmi , Kumar V. , Kanno Isaku
Published: December 2019

In this study, we report the effect of Zr/Sn ratio on the Antiferroelectric (AFE) → Ferroelectric (FE) phase transition and transverse piezoelectric characteristics on AFE thin films of compositions having the general formula Pb0.97La0.02(Zr1-x+ySnxTiy)O3,
where y = 0.10 and 0.10 ≤ x ≤ 0.15 along the phase boundary in the ternary system Pb(Zr0.50Ti0.50)O3-Pb(Zr0.50Sn0.50)O3-PbZrO3. Thin films having a thickness
of 2.0 µm were fabricated on platinised silicon substrates by sol–gel method. Data obtained from dielectric, ferroelectric and structural studies have been combined to explain the mechanism of AFE → FE switching.
Effects of Area Ratio on the Characteristics of Metal-Ferroelectric-Metal-Insulator-Semiconductor Field-Effect-Transistors (MFMIS FETs)
Authors: Sun Jing , Li Yanping , Cao Lei , Liu Jiaoyun , Shi Xiaorong , Tian Li
Published: December 2019

The switching physics of ferroelectric, series capacitance theory and Pao and Sah’s double integral are used for describing the polarization-voltage (P-V) characteristic of ferroelectric layer, capacitance-voltage (C-V) characteristic of MFMIS capacitor,
and drain current-gate voltage (ID-VGS) and drain current-drain voltage (ID-VDS) characteristics of MFMIS FET. The effects of the area ratio on the P-V, C-V, ID-VGS,
and ID-VDS characteristics are discussed. The results indicate that with the increase of the area ratio, the P-V characteristic, memory windows of C-V and ID-VGS characteristics become saturated,
while the drain current ON/OFF ratio and applied voltage for saturated memory window decrease.
Regulated resurfacing of a somatostatin receptor storage compartment fine-tunes pituitary secretion
Authors: Alshafie Walaa , Francis Vincent , Bednarz Klaudia , Pan Yingzhou Edward , Stroh Thomas , McPherson Peter S.
Published: December 2019

The surfacing of the glucose transporter GLUT4 driven by insulin receptor activation provides the prototypic example of a homeostasis response dependent on mobilization of an intracellular storage compartment. Here, we generalize this concept to a G protein–coupled receptor, somatostatin receptor subtype 2 (SSTR2), in pituitary cells. Following internalization in corticotropes, SSTR2 moves to a juxtanuclear syntaxin-6–positive compartment, where it remains until the corticotropes are stimulated with corticotropin releasing factor (CRF), whereupon SSTR2 exits the compartment on syntaxin-6–positive vesicular/tubular carriers that depend on Rab10 for their fusion with the plasma membrane. As SSTR2 activation antagonizes CRF-mediated hormone release, this storage/resurfacing mechanism may allow for a physiological homeostatic feedback system. In fact, we find that SSTR2 moves from an intracellular compartment to the cell surface in pituitary gland somatotropes, concomitant with increasing levels of serum growth hormone (GH) during natural GH cycles. Our data thus provide a mechanism by which signaling-mediated plasma membrane resurfacing of SSTR2 can fine-tune pituitary hormone release.
OCCURRENCE OF γ-GLOBULIN COMPLEXES IN SERUM AND JOINT FLUID OF RHEUMATOID ARTHRITIS PATIENTS: USE OF MONOCLONAL RHEUMATOID FACTORS AS REAGENTS FOR THEIR DEMONSTRATION
Authors: Winchester R. J. , Kunkel H. G. , Agnello V.
Published: December 2019

γG globulin complexed in an unusual form has been demonstrated in the serum of many patients with rheumatoid arthritis. Such complexes have been detected and isolated principally through precipitation reactions with monoclonal γM rheumatoid factors. These monoclonal rheumatoid factors exhibited a greater sensitivity to react with small complexes or aggregates of γ-globulin than polyclonal rheumatoid factor from rheumatoid arthritis sera or isolated C1q. The serum complexes consisted in large part of high molecular weight but acid-dissociable 7S γG globulin molecules They however differed from the complexes in the joint fluid by not yielding precipitates with C1q and were not found in association with evidence of marked serum complement fixation or activation. A small number of systemic lupus erythematosus sera, primarily those forming cryoprecipitates, also gave reactions with monoclonal rheumatoid factor. Sera from patients with a variety of nonrheumatic diseases gave a low incidence of reactions. The exact nature of the complexes in the rheumatoid arthritis sera remains somewhat in doubt although γG rheumatoid factors appear partly involved.
ON THE CAUSE OF THE HEART BEAT
Authors: Porter W. T.
Published: December 2019

Vol. II, page 391. The last word of the first paragraph should be "wall," instead of "septum."
Gene therapy for severe combined immunodeficiencies and beyond
Authors: Fischer Alain , Hacein-Bey-Abina Salima
Published: December 2019

Ex vivo retrovirally mediated gene therapy has been shown within the last 20 yr to correct the T cell immunodeficiency caused by γc-deficiency (SCID X1) and adenosine deaminase (ADA) deficiency. The rationale was brought up by the observation of the revertant of SCIDX1 and ADA deficiency as a kind of natural gene therapy. Nevertheless, the first attempts of gene therapy for SCID X1 were associated with insertional mutagenesis causing leukemia, because the viral enhancer induced transactivation of oncogenes. Removal of this element and use of a promoter instead led to safer but still efficacious gene therapy. It was observed that a fully diversified T cell repertoire could be generated by a limited set (<1,000) of progenitor cells. Further advances in gene transfer technology, including the use of lentiviral vectors, has led to success in the treatment of Wiskott–Aldrich syndrome, while further applications are pending. Genome editing of the mutated gene may be envisaged as an alternative strategy to treat SCID diseases.
Human tau pathology transmits glial tau aggregates in the absence of neuronal tau
Authors: Narasimhan Sneha , Changolkar Lakshmi , Riddle Dawn M. , Kats Alexandra , Stieber Anna , Weitzman Sarah A. , Zhang Bin , Li Zhiyong , Roberson Erik D. , Trojanowski John Q. , Lee Virginia M.Y.
Published: December 2019

Tauopathies are characterized by abnormal accumulation of tau protein in neurons and glia. In Alzheimer’s disease (AD), tau aggregates in neurons, while in corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP), tau also aggregates in astrocytes and oligodendrocytes. We previously demonstrated that human CBD and PSP tauopathy lysates (CBD-tau and PSP-tau) contain distinct tau strains that propagate neuronal and glial tau aggregates in nontransgenic (nonTg) mouse brain. Yet the mechanism of glial tau transmission is unknown. Here, we developed a novel mouse model to knock down tau in neurons to test for glial tau transmission. While oligodendroglial tau pathology propagated across the mouse brain in the absence of neuronal tau pathology, astrocytic tau pathology did not. Oligodendroglial tau aggregates propagated along white matter tracts independently of neuronal axons, and resulted in oligodendrocyte cell loss. Thus, glial tau pathology has significant functional consequences independent of neuronal tau pathology.
THE RELATION OF THE SPINAL CORD TO THE SPONTANEOUS LIBERATION OF EPINEPHRIN FROM THE ADRENALS
Authors: Stewart G. N. , Rogoff J. M.
Published: December 2019

On page 616, Vol. XXVI, No. 5, November 1, 1917, foot-note 2, for Marine, D., and Rogoff, J. M., J. Pharm. and Exp. Therap., 1916-17, ix, 1, read Stewart, G. N., and Rogoff, J. M., J. Pharm. and Exp. Therap., 1917, x, 1.

On page 627, foot-note 4, for Stewart and Rogoff, J. Pharm. and Exp. Therap., 1916-17, ix, 479, read Stewart and Rogoff, J. Pharm. and Exp. Therap., 1916, viii, 479.
STUDIES ON THE TREATMENT OF HUMAN TRYPANOSOMIASIS WITH TRYPARSAMIDE (THE SODIUM SALT OF N-PHENYLGLYCINEAMIDE-p-ARSONIC ACID)
Authors: Pearce Louise
Published: December 2019

On page 1, Supplement No. 1, lines 1 and 2, for November 1, 1921, Vol. xxxiv, No. 5, read December 1, 1921, Vol. xxxiv, No. 6.
STUDIES ON PNEUMOCOCCUS GROWTH INHIBITION
Authors: Robertson Oswald H. , Sia Richard H. P.
Published: December 2019

In Vol. xxxix, No. 2, page 226, line 12, for 0.1 cc. contained 5,000 leucocytes read 0.1 cc. contained the calculated number of leucocytes for one tube.
ALLERGIC IRRITABILITY
Authors: Lewis Paul A. , Loomis Dorothy
Published: December 2019

1. The allergic irritability of the guinea pig (capacity of the animal to react to antigenic substances) is increased by infection with Bacillus abortus and a streptococcus, by the dead tubercle bacillus, and by intensive treatment with trypan blue, respectively. The effect of these influences, while definite, is less pronounced than that previously found for infection with the tubercle bacillus. The production of anti-sheep hemolytic amboceptor was used as the test reaction in these cases.

2. The allergic irritability of the guinea pig with reference to anti-typhoid agglutinin is increased by infection with the tubercle bacillus.

3. The allergic irritability of the rabbit with reference to anti-sheep hemolytic amboceptor is increased by an infection of suitable severity with the tubercle bacillus.

4. In the guinea pig the curve of antibody production is complex. Its peculiarities are developed during the production of antityphoid agglutinins as well as that of anti-sheep hemolytic amboceptor. In the latter case injections of antigen subsequent to the first give rise to a curve of production unchanged in form but somewhat affected in the time relations.

5. The effects of infection with Bacillus tuberculosis on allergic irritability with reference to anti-sheep hemolytic amboceptor are operative throughout a course of immunizing treatments. The successive increases due to the cumulative effect of repeated doses of the antigen are developed on a higher level. The end-result is that the animal with increased irritability furnishes more antibody not only in response to the initial injection of antigen as previously described, but an absolute increase over the amount attainable by a comparable number of treatments in series. That portion of the final result contributed by the increase in allergic irritability appears to be no less, and may even in instances be somewhat more than that due to the earlier doses of the specific antigen.
MICROBIC VIRULENCE AND HOST SUSCEPTIBILITY IN PARATYPHOID-ENTERITIDIS INFECTION OF WHITE MICE
Authors: Pritchett Ida W.
Published: December 2019

In Vol. xliii, No. 2, through an unfortunate oversight, the scale along the ordinate was omitted from Text-fig. 1, between pages 146 and 147, as originally printed. The accompanying slip is arranged to be pasted along the left side of Text-fig. 1. The arrow at the top of the slip should be so placed as to be a continuation of the upper border of the chart.

From the scale given in this slip the relative values of the curves shown in Text-fig. 2 (page 148) can be easily determined, since this is merely an enlarged and somewhat compressed portion from the larger text-figure.

See PDF for Structure
THE ETIOLOGY OF TRACHOMA
Authors: Noguchi Hideyo
Published: December 2019

In Supplement No. 2, issued with the August, 1928, number of The Journal of Experimental Medicine, on page 27, at the beginning of line 19, for the number 70 read 120.
REACTIONS OF RABBITS TO NON-HEMOLYTIC STREPTOCOCCI
Authors: Derick C. L. , Hitchcock C. H. , Swift Homer F.
Published: December 2019

On page 6, Vol. 52, No. 1, July 1, 1930, in the second explanatory note at the foot of Table I, the plus sign should be a minus sign; i.e., for + = negative reaction read – = negative reaction.
RESISTANCE TO PNEUMOCOCCUS INFECTION IN RABBITS FOLLOWING IMMUNIZING INJECTIONS OF HEAT-KILLED PNEUMOCOCCUS SUSPENSIONS
Authors: Stillman Ernest G. , Goodner Kenneth
Published: December 2019

On pages 202 and 205, Vol. 58, No. 2, August 1, 1933, the cuts for Text-figs. 2 and 3 should be interchanged. The cut on page 202 is Text-fig. 3, and should appear on page 205. The cut on page 205 is Text-fig. 2, and should appear on page 202. The legends should remain on the pages where they now appear.
A QUANTITATIVE THEORY OF THE PRECIPITIN REACTION
Authors: Heidelberger Michael , Kendall Forrest E.
Published: December 2019

Page 702, at the bottom of the 3rd column of Table II, for 0.36, read 0.26. This change necessitates the following correction also.

Page 707, 3rd line from the top, for the entire amount, read much.

Page 715, 9th line from the top, for actually occurs, read occurs to a great extent. 12th line from the top, for was 0.36 mg., and precisely this amount was, read was 0.36 mg. without deducting about 0.1 mg. for solubility, whereas 0.26 mg. was.
ON GROUP SPECIFIC A SUBSTANCES
Authors: Landsteiner K. , Chase M. W.
Published: December 2019

Page 816, 4th paragraph, first sentence, the words, "and the acetyl polysaccharide of Pneumococcus I which likewise reacts with A immune sera (13)," should be omitted.
INFLUENCE OF HOST FACTORS ON NEUROINVASIVENESS OF VESICULAR STOMATITIS VIRUS
Authors: Sabin Albert B. , Olitsky Peter K.
Published: December 2019

In Vol. 67, No. 2, February 1, 1938, page 237, Table IV, in the heading of the first column, for 10–6 read 106.
SOME CONSTITUENTS OF ELEMENTARY BODIES OF VACCINIA
Authors: Smadel Joseph E. , Lavin George I. , Dubos René J.
Published: December 2019

Page 388, for the two sentences beginning with line 10, the following sentences should be substituted.

The former type has been found in preparations of a number of plant viruses (30) and of the agent of Rous' sarcoma (31). Although nucleoproteins have been reported in several types of bacteriophage (32), the importance of phosphorus-containing componds in one of these agents has been recently questioned (33).
THE KINETICS OF PENETRATION
Authors: Osterhout W. J. V.
Published: December 2019

On page 267, Vol. 13, No. 2, November 20, 1929, the bottom line should read

See PDF for Equation

On page 275, the fifth line should read

where PM + PAK = 1 this becomes

See PDF for Equation
THE DARK ADAPTATION OF THE EYE OF LIMULUS, AS MANIFESTED BY ITS ELECTRIC RESPONSE TO ILLUMINATION
Authors: Hartline H. Keffer
Published: December 2019

On page 387, Vol. 13, No. 3, January 20, 1930, the numbers in the last column of Table 1 should be divided by 10 to give the true values of k'.

In the next to the last line, under Table 1, for value of C = 0.337 read value of C = –0.337.
THE RESISTANCE OF DROSOPHILA TO ALCOHOL
Authors: Crozier W. J. , Pincus G. , Zahl P. A.
Published: December 2019

On page 536, in the heading of Table IV, after "with the standard deviations",insert "(σ1)".
THEORY AND MEASUREMENT OF VISUAL MECHANISMS
Authors: Crozier W. J. , Wolf Ernst
Published: December 2019

In Vol. 27, No. 5, May 20, 1944, page 403, in the eighth line from the bottom of the page, the comma after "intensity" should be a semicolon.

On page 413, in the second formula from the bottom of the page, for

See PDF for Equation

read

See PDF for Equation

On the same page, formula 2 should read

See PDF for Equation

On page 414, line 3, at the end of the line add "or" to read "of the level of I or of F."

On page 422, in the first line below the figure legend, for "illuminate" read "illuminated."

On page 430, line 22, for "lighteb dars" read "lighted bars."
CONTRIBUTION TO THE THEORY OF PERMEABILITY OF MEMBRANES FOR ELECTROLYTES
Authors: Michaelis L.
Published: December 2019

On page 39, Vol. viii, No. 2, September 18, 1925, multiply the right-hand side of formula (2) by the factor

See PDF for Equation.

On page 44, immediately after formula (1) the text should be continued as follows:

Let us suppose a membrane to be separated by two solutions of KCl of different concentrations K1 and K2 and these concentrations and the corresponding concentrations of K+ within the membrane, which are in equilibrium with the outside solutions, to be so high that the H+ ions may be neglected. When a small electric current flows across the system, practically the K+ ions alone are transferred and that in a reversible manner. Therefore the total P.D. is practically

See PDF for Equation

This P.D. is composed of two P.D.'s at the boundaries and the diffusion potential within the membrane. Suppose the immobility of the anions is not absolute but only relative as compared with the mobility of the cations, KCl would gradually penetrate into the membrane to equal concentration with the outside solution on either side and no boundary potential would be established. In this case the diffusion P.D. within the membrane is the only P.D., amounting to

See PDF for Equation

but, V being practically = 0, it would result that

See PDF for Equation

So the definitive result is the same as in the former case.

Now cancel the printed text as far as page 48, line 13 from the top of the page, but retain Fig. 1.

On page 50, line 19 from the top of the page, cancel the sentence beginning with the word But and ending with the words of the chain.
Characterization of solution-grown and sputtered Inx(O,S)y buffer layers in Cu(In,Ga)Se2 solar cells by analytical TEM
Authors: Jin Xiaowei , Schneider Reinhard , Popescu Radian , Hariskos Dimitrios , Witte Wolfram , Powalla Michael , Gerthsen Dagmar
Published: December 2019

Cu(In,Ga)Se2 thin-film solar cells were fabricated with In
x
(O,S)
y
as buffer material, where the buffer was deposited by either solution growth or radio-frequency sputtering. To elucidate the influence of the particular deposition technique on the properties of the In
x
(O,S)
y
layers, their structural peculiarities were characterized by high-resolution transmission electron microscopy (TEM) and nanobeam electron diffraction. Energy-dispersive x-ray spectroscopy in combination with scanning TEM was used for chemical analysis of the interfacial regions between Cu(In,Ga)Se2 absorber and In
x
(O,S)
y
layer as well as of the buffer itself. In general, the solution-grown and sputtered In
x
(O,S)
y
layers show a nanocrystalline structure. In both types of In
x
(O,S)
y
buffer layers, crystalline phases of tetragonal In2S3 and cubic In2O3 were detected. In addition, there are hints for the formation of a Cu-containing phase, e.g. hexagonal CuS in the sputtered In
x
(O,S)
y
layer. Moreover, there are also distinct differences in the chemical composition of the two analyzed In
x
(O,S)
y
layers, namely in the solution-grown In
x
(O,S)
y
buffer layer the oxygen content is considerably higher than in the sputtered In
x
(O,S)
y
layer.
Acoustic graphene network loaded with Helmholtz resonators: a first-principle modeling, Dirac cones, edge and interface waves
Authors: Zheng Li-Yang , Achilleos Vassos , Chen Ze-Guo , Richoux Olivier , Theocharis Georgios , Wu Ying , Mei Jun , Felix Simon , Tournat Vincent , Pagneux Vincent
Published: December 2019

In this work, we study the propagation of sound waves in a honeycomb waveguide network loaded with Helmholtz resonators (HRs). By using a plane wave approximation in each waveguide we obtain a first-principle modeling of the network, which is an exact mapping to the graphene tight-binding Hamiltonian. We show that additional Dirac points appear in the band diagram when HRs are introduced at the network nodes. It allows to break the inversion (sub-lattice) symmetry by tuning the resonators, leading to the appearence of edge modes that reflect the configuration of the zigzag boundaries. Besides, the dimerization of the resonators also permits the formation of interface modes located in the band gap, and these modes are found to be robust against symmetry preserving defects. Our results and the proposed networks reveal the additional degree of freedom bestowed by the local resonance in tuning the properties of not only acoustical graphene-like structures but also of more complex systems.
Quantum synchronisation enabled by dynamical symmetries and dissipation
Authors: Tindall J , Sánchez Muñoz C , Buča B , Jaksch D
Published: December 2019

In nature, instances of synchronisation abound across a diverse range of environments. In the quantum regime, however, synchronisation is typically observed by identifying an appropriate parameter regime in a specific system. In this work we show that this need not be the case, identifying conditions which, when satisfied, guarantee that the individual constituents of a generic open quantum system will undergo completely synchronous limit cycles which are, to first order, robust to symmetry-breaking perturbations. We then describe how these conditions can be satisfied by the interplay between several elements: interactions, local dephasing and the presence of a strong dynamical symmetry—an operator which guarantees long-time non-stationary dynamics. These elements cause the formation of entanglement and off-diagonal long-range order which drive the synchronised response of the system. To illustrate these ideas we present two central examples: a chain of quadratically dephased spin-1s and the many-body charge-dephased Hubbard model. In both cases perfect phase-locking occurs throughout the system, regardless of the specific microscopic parameters or initial states. Furthermore, when these systems are perturbed, their nonlinear responses elicit long-lived signatures of both phase and frequency-locking.
Mechanical and free vibration properties of clamshell particles/polyester composites
Authors: Mostafa Nawras H , Hunain Mustafa Baqir , Khafaji Salwan Obaid Waheed
Published: December 2019

In this work, an experimental investigation was implemented to identify the effect of adding clamshell powder (CSP) into the polyester matrix on the tensile and impact properties along with vibration characteristics of the particulate composites towards using eco-friendly reinforcement phase. Different weight ratios of clamshell powder, ranged from 0 to 20 wt%, were loaded into the polyester resin with particle sizes ranged from 25 to 75 μm. Tensile, Charpy impact and free vibration tests were performed to the specimens fabricated from the neat polyester and CSP-filled polyester. The results showed that the inclusion of CSP into the polyester matrix could improve the tensile modulus of the polyester up to 50% when the CSP weight ratio equals to 12%. Meanwhile, the strain-to-failure, tensile and impact strengths showed decreasing trends with increasing the CSP filler content owing to the weak adhesion (bonding) strength between CSP and the polyester matrix. Maximum improvements in the fundamental natural frequency and damping ratio of CSP-filled polyester were 24% (at 12 wt% of CSP) and 21% (at 8 wt% of CSP), respectively. Based on the results, the clamshell powder could be used as a very cheap bio-filler material within the polyester matrix if the high stiffness composites with improved damping properties are required.
Atomistic behavior of nanoporous carbon nanotube-aluminum composite under compressive loading
Authors: Suk Myung Eun
Published: December 2019

Metal matrix nanocomposites have been actively studied to discover the characteristics of a new class of materials. In the present study, metal matrix nanocomposites are investigated using molecular dynamics simulations of the compressive behavior of nanoporous carbon nanotube (CNT)-aluminum (Al) composites that have a density of approximately 77% to that of pure Al. The weight-reduced nanocomposites exhibited an enhanced Young’s modulus of 138%, and a compressive strength degraded by 13% compared with pure Al. Through stress decomposition into CNT and Al constituents, it was observed that the Young’s modulus was enhanced due to the high stiffness of the CNTs; further, the reduced strength was primarily due to the early failure strain. The effects of CNT volume fractions and sizes are further analyzed using the rule of mixture, which is modified by the interphase area definition. In addition, the atomistic details of the structure and stress revealed a buckling behavior in the CNT as well as a massive slip behavior in the Al matrix during plastic deformation. The results presented in this study will have implications in the design and development of metal matrix nanocomposites for applications in high-performance lightweight materials.
Multi-band Superconductivity in a misfit layered compound (SnSe)1.16(NbSe2)2
Authors: Bai Hua , Qiao Lei , Li Miaocong , Ma Jiang , Yang Xiaohui , Li Yupeng , Tao Qian , Xu Zhu-An
Published: December 2019

We report the discovery of superconductivity with T
c of about 5.3 K in a new misfit layered compound (SnSe)1.16(NbSe2)2. High resolution transmission electron microscopy and selected area electron diffraction of the single-crystalline samples clearly reveal the misfit layered structure. Based on the McMillan equation, the electron-phonon coupling constant λ

e – ph
is estimated to be about 0.96, which is close to strong coupling range. The estimated out-of-plane and in-plane upper critical magnetic fields are 8.9 T and 15.5 T respectively.

H

c
2

ab

(0) is 1.74 times the value of Pauli paramagnetic limit. Moreover, there is a positive curvature in the

H

c
2

(
T
)

curves near T

c
, indicating a feature of multi-band superconductivity. The temperature dependence of specific-heat in superconducting state can be fit by a two-band BCS model, which confirms further the multi-band superconductivity. The reduced charge transfer between the two subsystems may account for the enhanced T
c comparing with (SnSe)1.16(NbSe2).
Numerical investigation of graphene-based metamaterial microstrip radiating structure
Authors: Dhasarathan Vigneswaran , Bilakhiya Nizam , Parmar Juveriya , Ladumor Mayurkumar , Patel Shobhit K
Published: December 2019

Recent advancement in antenna technology is directed to achieve reconfiguration of radiating structure parameters. In this paper, we propose graphene-based reconfigurable and high gain microstrip radiating structure for multiband wireless communication applications. The circular copper patch is used as a radiating element of the radiating structure. Graphene layer with circular holes is applied to this microstrip based radiating structure to tune the radiating structure parameters. The radiating structure is stacked with superstrate layers to improve the gain of the design. Frequency reconfiguration and gain enhancement are achieved by varying the chemical potential of graphene. Radiating structure analysis in terms of the reflection coefficient, radiation pattern and gain polar plot is obtained. The proposed reconfigurable radiating structure can be used for L and S-band applications.
Effect of voltage and spray–off distance of electric-arc spray technique on surface properties of nickel–chrome (Ni–Cr) coating developed on 304L stainless steel
Authors: Inam A , Raza M A , Hafeez M A , Shah S B , Ishtiaq M , Hassan M H , Irfan M , Nasik A , Siddique I , Butt O M , Maqbool A , Haider W
Published: December 2019

Nickel–chrome coatings are widely used to improve surface properties and service life of engineering components made from different ferrous and non–ferrous alloys. Herein, an attempt has been made to investigate the impact of various voltages ranging from 26–30 V and spray–off distances ranging from 100–300 mm of electric-arc spray technique on the surface properties of Ni–Cr coating developed on 304L stainless steel. Thickness, porosity, surface morphology, surface roughness, and hardness of Ni–Cr coatings were determined to study the impact of deposition parameters. Coating deposition at 26 V exhibited the lowest porosity and the highest percentage of Cr nodules among all samples. The comparison study showed that coating deposit developed at 26 V and 100 mm spray–off distance has a maximum thickness, followed by coating developed at 30 V and 100 mm spray–off distance. This indicated that coating deposit developed at 100 mm spray–off distance results in thicker coatings. Maximum hardness was achieved at 30 V and 300 mm spray–off distance. The shorter spray–off distance revealed that coatings tend to be thicker and harder resulting in longer coating life.
Exploring configurations and properties of boron carbide by first principle
Authors: Liu Meiling , Liu Chao , Kumar Uppalapati Pramod , Chen Mingwei
Published: December 2019

Based on the first principle, the formation energy, phonon vibration, physical property of three common B4C models were extensively study. Through the calculation of thermodynamic formation energy, it is confirmed po model has the most stable energy configuration. Combined the simulated x-ray and experimental data, it is found that the experimental boron carbide is actually composed of a variety of configurations, the majority of which is po model. Via the analysis of phonon vibration, the highest phonon frequencies of the different configurations were identified as the result of stretching vibrations from the triatomic chain. The research of electrical properties of three B4C models clarify B4C is a semiconductor but will transform to conductor at specific high pressure. The calculation of the mechanical property states that B4C is hard material while the hardness will gradually decrease with pressure increases. Both the relationship of their electrical properties and mechanical properties with pressure illustrate that the po model has the fastest structural change and ch model has the slowest change.
A comparative investigation of hardness and compression strength of Nickel coated B4C reinforced 601AC/201AC selective layered functionally graded materials
Authors: Vijay S , CH Srinivasa Rao
Published: December 2019

High hardness and compression strength are the essential properties in many engineering applications. Requirement of light weight materials with high mechanical properties as a function of direction leads to the development of Aluminium based Functionally Graded Materials (FGM). Two different matrix metal blends 601AC and 201 AC are used for the comparison. Mechanical Alloying technique (MA) is used to blend the metal powders. The FGM specimens with 2 layers, 3 layers and 5 layers are fabricated using Powder Metallurgy (P/M) technique. B4C with Nickel coating and without Nickel coating is used as particulate. Two different average particle size of B4C (20 μm and 50 μm) was selected. The configurations used for the FGMs are 0%/5% for 2 layered specimen, 0%/5%/10% for 3 layered specimen and 0%/5%/10%/15%/20% for five layered specimen. Specimens are prepared according to ASTM B925-3 standard for micro-hardness test and compressive strength test. Graphs are plotted in terms of number of layers, particle size, sintering temperature, and coating condition. From the experiments it is observed that, number of layers influences the hardness and compressive strength. The average specimen hardness is enhanced from 55 HV for two layered FGM to 73 HV for three layered FGM. The compressive strength is increase from 613 MPa for three layered specimen without Nickel coated B4C to 732 Mpa for three layered specimen with Nickel coating. Best possible combination of all parameters is observed from the experiment is particle size of 20 μm, sintering temperature of 570 °C, and B4C particulate with Nickel coating. Compared to the hardness values for two different matrix materials 601AC/201AC, closure values are observed for the best possible combination of other variables. Where-as for the compressive strength 201AC matrix shows superior values compared to 601AC for the best possible combination of all the other variables.
Effect of Mn addition on magnetoelectric coupling behavior of BiFeO3-Pb/BaTiO3 multiferroics
Authors: Kumar Naveen , Bastola Narayan , Singh Arun Kumar , Kumar Sanjeev
Published: December 2019

Hybrid multiferroic materials exhibiting morphotropic phase boundary (MPB) with enhanced ferroelectric and ferromagnetic properties has shown great potential for future technologies. In this paper, we report structural, ferroelectric, piezoelectric, magnetic and magnetoelectric characteristics of 0.7BiFeO3–0.3Pb0.5Ba0.5TiO3 (BFPTBT-Pure) and 0.7BiFeO3–0.3Pb0.5Ba0.5TiO3 + Mn0.5% (BFPTBT-Mn5%) ceramic compositions synthesized via conventional solid state reaction route. The crystallinity of the compositions exhibits polymorphs of rhombohedral (R3c) and tetragonal (P4mm) symmetries forming morphotropic phase boundary (MPB). Highly dense SEM micrographs were observed with an average grain size 0.57 μm and 0.62μm for BFPTBT-Pure and BFPTBT-Mn5%, respectively. Mn doped ceramic sample. Improved ferroelectric behavior has been observed with Mn doping in the composition as the value of remnant polarization increases from 2.46 μC cm−2 to 7.63 μC cm−2 recorded at an applied frequency of 50 Hz. The piezoelectric coefficients for BFPTBT-Pure and BFPTBT-Mn5% were found to be 36pC/N and 57pC/N respectively. M-H hysteresis loops depicted that remnant magnetization increases with Mn addition in the sample. The Curie transition temperature (T

c
) was observed to be 447 °C and 467 °C for BFPTBT-Pure and BFPTBT-Mn5% ceramics, respectively. The magnetoelectric coupling was confirmed through the observation of magnetic field induced relative change in dielectric constant (Magnetocapacitance: MC). MC was found to be 9.49% and 11.81% for BFPTBT-Pure and BFPTBT-Mn5%, respectively.
Low velocity impact, compression after impact and morphological studies on flax fiber reinforced with basalt powder filled composites
Authors: Prasath K Arun , Arumugaprabu V , Amuthakkannan P , Manikandan V , Deepak Joel Johnson R
Published: December 2019

The objective of this research is to examine the low velocity impact (LVI) and effect of compression after impact (CAI) properties on flax fiber and basalt powder reinforced polyester composites. For this study the 10 layers of flax fiber, basalt powder by varying from 5% to 30% the composites were prepared. In the LVI analysis composite (10 layers of basalt/10% of basalt powder) shows better results about 1755 N of force and for CAI also same composite B experienced with less deformation and more residual energy to absorbing the force of about 2250 N. The addition of filler material up to certain limit will support the reinforcing fiber to achieve some enhanced property. The morphological changes and their properties were assessed using Fourier Transform Infrared Spectroscopy (FTIR) and x-ray diffraction Analysis (XRD) studies for particulate basalt powder. The presence of Pyroxene group of rocks in basalt powder responsible for stability in high temperatures seen using XRD analysis. The band width around 3390–3425 cm−1 shows the presence of hydroxyl group (OH) in the basalt powder. This proved that the materials are Polar Hydrophilic in nature examined with FTIR spectroscopy.
Effect of annealing temperature on the morphology, structure, and optical properties of nanostructured SnO(x) films
Authors: Timofeev Vyacheslav A , Mashanov Vladimir I , Nikiforov Alexandr I , Azarov Ivan A , Loshkarev Ivan D , Korolkov Ilya V , Gavrilova Tatyana A , Yesin M Yu , Chetyrin Igor A
Published: December 2019

Nanostructured SnO(x) films were obtained by molecular beam epitaxy (MBE). The morphology, structure, and optical properties of obtained films annealed in the temperature range of 200 °C–1000 °C were studied. The reflection high-energy electron diffraction during the film deposition by the MBE method and the x-ray phase analysis showed that the initial films are in the polycrystalline phase. A single orthorhombic SnO2 phase was obtained for the first time after annealing the SnO(x) film in the air at a temperature of about 500 °C. The sharp change in the optical constants near the temperature of 500 °C was established using ellipsometry. The pronounced absorption edge appears in the short-wave region at temperatures above 500 °C and it disappears at lower temperatures. The film thickness changed non-monotonically during the annealing in the air. At first, it grows from 45 nm to 65 nm (active oxidation to 500 °C), and then (above 600 °C) it begins to decrease. The annealing at temperatures of 500 °C–1000 °C leads to the film compaction, since the film thickness decreases to 50 nm, but the refractive index increases by 10%–15%. Optical constants track the progress of film phase and morphological changes.
US seeks to bar graduate students from unionizing
Authors: Gwynne Peter
Published: December 2019

Graduate students at private US universities who are paid for teaching and research will not be regarded as employees with the right to unionize under new plans set out by the country’s National Labor Relations Board (NLRB).
UK to fund design of 'commercially viable' power plant
Authors: Banks Michael
Published: December 2019

The UK government has announced £220m over the next four years towards the preliminary design of a commercially viable fusion power station.
Building an ethical consensus
Authors: Vidaurri Monica
Published: December 2019

With plans for a human mission to Mars under way, Monica Vidaurri warns that there can be no progress without first tackling the ethics of human space travel
Scientific fireworks
Authors: Crease Robert P
Published: December 2019

Next time you’re watching a firework display, remember these explosions played a key role in the early days of modern science, says Robert P Crease
A mutual appreciation
Authors: Jones Graham
Published: December 2019

Legendary director Douglas Trumbull talks to Graham Jones about what moviemakers and scientists can learn from each other
A scientist in Hollywood
Authors: Tesh Sarah
Published: December 2019

Mathematical physicist Spiros Michalakis talks to Sarah Tesh about his experience as a science adviser to Hollywood on films like Ant-Man and Captain Marvel
The fictional science of science fiction
Authors: Allain Rhett
Published: December 2019

As the name suggests, science-fiction movies are just that – fiction. Unfortunately, that sometimes means the science is too. Rhett Allain examines some concepts that sci-fi movies regularly get wrong
Putting physics in plain language
Authors: Keppel Cynthia (Thia) , Harris Margaret
Published: December 2019

Cynthia (Thia) Keppel received the American Physical Society’s Distinguished Lectureship Award on the Applications of Physics in 2019 for her pioneering work in proton therapy and for promoting applications of physics to experts and non-experts.