Narrow Results

Jet substructure in heavy-ion collisions is a rapidly evolving area with lots of intriguing new measurements. This contribution presents a selection of recent jet-substructure measurements from experiments at the LHC, in particular, soft-drop groomed radii of jets and reclustered large-radius jets from ATLAS, jet axis difference and generalized jet angularities from ALICE, as well as dijet shapes and b-jet shapes from the CMS experiment.

The submesh allocation problem is to recognize and locate a free submesh that can accommodate a request for a submesh of a specified size. An efficient submesh allocation strategy is required for achieving high performance on mesh multicomputers. In this paper, we propose a new best fit submesh allocation strategy. The proposed strategy maintains and uses a free submesh list to get global information for free submeshes. For an allocation request, the strategy tries to allocate a best fit submesh which causes the least amount of potential fragmentation so as to preserve the large free submeshes to be as many as possible and to prevent processor fragmentation for later requests. For this purpose, we introduce a novel function for quantifying the degree of potential fragmentation of submeshes. The proposed strategy has the complete submesh recognition capability. Extensive simulation is carried out to compare it with the previous strategies, and experimental results indicate that it exhibits the best performance along with an about 30% average improvement over the previous best strategy.

Melting and fragmentation behaviors of Ni₄₂₉ cluster have been studied with molecular-dynamics simulations using a size-dependent empirical model potential energy function. To monitor thermal behaviors of the cluster, we calculated some physical quantities such as average potential energy per atom, specific heat, radial atomic distribution, bond length distribution, average interatomic distance, nearest neighbor distance and average coordination number as a function of temperature. The roles of the surface and core atoms in the melting and fragmentation process of the cluster are also investigated by considering the surface and the bulk coordination numbers of the cluster.

We perform extensive molecular dynamics simulations to study the mass size distribution of a two-dimensional fragmentation process. Our model consists of a large number of particles interacting through the Lennard–Jones potential. The fragmentation is induced by suddenly imposing a radial component on the particles' velocities, in order to mimic an explosion phenomenon. We then investigate the effect of the input energy on the resulting mass distribution of fragments.

Time evolution of number of cities, population of cities, world population, and size distribution of present languages are studied in terms of a new model, where population of each city increases by a random rate and decreases by a random division. World population and size distribution of languages come out in good agreement with the available empirical data.

A study of the distribution of the value of traded goods under the Harmonized System is presented. The ramifications of this classification system are found to exhibit an approximate power law decay, indicating complexity and self-organization in the nomenclature of traded merchandises. For almost all countries with available data, log-values of annually imported and exported goods are well described by three-parameter Weibull distributions. This distribution commonly appears in particles size distributions, suggesting a connection between random fragmentation processes and the mechanisms behind the international trade of merchandises. Analysis of the resulting values for the fitting parameters from 1995 to 2018 shows a nearly constant linear relationship between the parameters of the Weibull distributions, so that, for each country, the distribution of log-values can be approximately characterized by a single shape parameter $\beta$. The empirical findings of this paper suggest that specialization on trading a constant set of goods prevents the values of all traded merchandises from growing/decreasing simultaneously.

This paper describes a two-dimensional computer simulation of solid fracture that allows the body and the fragments to be followed well beyond the point of simple crack formation. The model is based on discrete particle computer simulations used for studying granular flows. Here, macroscopic polygonal solid are constructed by “gluing” together small elements. Depending on the stress conditions the glued bonds between the elements can respond elastically, undergo plastic failure or break, allowing cracks to propagate across the macroscopic particle along the boundaries between their microscopic constituents. In essence, this process creates a simulated material upon which breakage occurs. Several element shapes have been studied.

This paper uses the model described in Ref. 1 to simulate fracture in many simple systems with the goal of evaluating the advantages and deficiencies of the model. The examples include compressive failure of a rectangular sample, four-point shear failure of a beam and the impact of particles with a plate and binary impacts of particles. Where possible, the simulated results seem to be in good agreement with typical experimental results. Finally, a simulation of ball-milling, which involves the flow and fracture of many particles is shown to demonstrate the overall utility of the model.

This paper describes an extension to a computer simulation of solid fracture. In the original model, rigid elements are assembled into a simulated solid by "gluing" the elements together with compliant boundaries which fracture when the tensile strength of the glued joints is exceeded. The current extension applies portions of the finite element technique to allow changes in the shapes of elements. This is implemented at the element level and no global stiffness matrix is assembled; instead, the elements interact across the same compliant boundaries used in the rigid element simulation. As a result, the simulated material can conform to any desired shape and thus can handle large elastic and plastic deformation. This model is intended to study the propagation of multitudinous cracks through simulated solids to aid the understanding of problems such as the impact-induced fragmentation of particles.

This paper describes an extension into three dimensions of an existing two-dimensional technique for simulating brittle solid fracture. The fracture occurs on a simulated solid created by "gluing" together space-filling polyhedral elements with compliant interelement joints. Such a material can be shown to have well-defined elastic properties. However, the "glue" can only support a specified tensile stress and breaks when that stress is exceeded. In this manner, a crack can propagate across the simulated material. A comparison with experiment shows that the simulation can accurately reproduce the size distributions for all fragments with linear dimensions greater than three element sizes.

We study the phenomena associated with the low-velocity impact of two solid discs of equal size using a cell model of brittle solids. The fragment ejection exhibits a jet-like structure the direction of which depends on the impact parameter. We obtain the velocity and the mass distribution of the debris. Varying the radius and the initial velocity of the colliding particles, the velocity components of the fragments show anomalous scaling. The mass distribution follows a power law in the region of intermediate masses.

The scaling law of Edwards et al., for cluster fragmentation of critical percolation clusters is not confirmed by analogous Monte Carlo simulations at the Curie point of the two-dimensional Ising model.

Globalization has its detractors as well as supporters. Concerns have been expressed about the greater ease of fragmenting the production process so that more parts can be outsourced to a variety of countries. Highly developed regions worry about the possibility of greater unemployment or lower unskilled wage rates. Less developed regions are concerned that they may not possess a comparative advantage in the service link activities that promote fragmentation. The paper discusses these issues, with special emphasis on India and China.

This paper is a non-technical survey of the literature on offshoring and outsourcing, with special focus on the relevance of this literature for Asia. We first see how and to what extent this new literature helps us understand firms' tradeoffs between outsourcing and integration, the variation in the mixes of organizational forms and the location of outsourced activities. We also explore what plausibly triggers offshoring and thereafter what determines its dynamics. Finally, we draw inferences from the existing theory and empirical work about the developmental impact of offshoring on Asia, with special attention to issues related to inequality and poverty.

A salient feature of the East Asian region is the persistent discrepancy between the progress in de facto and de jure economic integration. East Asia has long been said to be the champion of loose regional economic integration, with deepening intra-regional trade and investment linkages in the absence of any formal cooperative scheme. However, an oft-heard claim is that East Asia has been shifting recently towards an institution-based form of regional economic cooperation, primarily as a result of the 1997–98 financial crisis. Next to post-crisis financial cooperative schemes under the ASEAN+3, the surge of Regional Trade Agreements (RTAs) involving East Asian countries is thought by some to further substantiate this claim. The objective of the paper is twofold; first, to assess the validity of the aforementioned claim; and second, to examine the links between de facto and de jure economic integration in East Asia compared to other regions of the world. In the process, the sequencing between trade and monetary cooperation is also addressed. The paper starts by providing a candid assessment of the current state of play of economic cooperation in East Asia (de jure integration), both from the trade and the financial/monetary perspective, and highlights the limitations of the formal regional integration movement in East Asia to date. As a next step, it explores the changing nature of intra-regional trade and investment linkages, contrasts it to the situation in other parts of the world such as Europe and examines to what extent this new form of interdependence may be instrumental in making formal regional economic schemes more attractive. A major conclusion is that de facto trade integration may not automatically lead to deeper regional trade cooperation de jure and that its impact is likely to be stronger on monetary cooperation projects.

This paper examines the trade of machinery parts and components between Thailand and the other Mekong countries though gravity model, for the purpose of assessing the existing production networks in Mekong region by applying fragmentation theory. The findings are: First, the evolution of production networks between Thailand and Vietnam was identified in terms of their two-way trade integration. Second, the trade intensity between Thailand and Vietnam was explained by the fragmentation factors, i.e., their gaps in per capita GDP and the relatively lower service-link costs in Vietnam. Third, the trade less-integration of Thailand with Cambodia and Myanmar was explained by their higher service-link costs.

Recent LHCb measurements of the $J/\psi$ meson production in jets are analyzed using fragmentation jet function formalism. It is shown that disagreement with theoretical predictions for distribution over the fraction of $J/\psi$ transverse momentum $z(J/\psi )$ in the cases of prompt production can be explained if one takes into account evolution of the fragmentation function and contributions from double parton scattering (DPS) mechanism or gluon fragmentation.

This work deals with the decay analysis of three compound nuclei ${}^{77}{\mathrm{\text{As}}}^{\ast }$, ${}^{83}{\mathrm{\text{Br}}}^{\ast }$ and ${}^{86}{\mathrm{\text{Sr}}}^{\ast }$ formed in proton-induced reactions $\mathrm{\text{p}}+{}^{76}\mathrm{\text{Ge}}$, $\mathrm{\text{p}}+{}^{82}\mathrm{\text{Se}}$ and $\mathrm{\text{p}}+{}^{85}\mathrm{\text{Rb}}$ at incident beam energies of 1–5 MeV using the Dynamical Cluster-decay Model (DCM). The motive is to explore the decay of compound systems formed via light charged particles as projectiles. The experimentally available data of n-evaporation for the aforementioned systems are addressed by optimizing the neck-length parameter $\mathrm{\Delta }R$, using spherical fragmentation approach. The comparative analysis of the decay structure of the chosen systems is carried out at a common incident beam energy $E_{\mathrm{\text{beam}}}\sim 3.6$ MeV. The effect of angular momentum $(\ell )$ and quadrupole $({\beta }_2)$-deformations is explored in reference to the decay structure/fragmentation of compound systems. In addition to this, the sensitivity of DCM-based cross-sections toward level density parameter (LDP) $a$ is also analyzed. The relative role of mass-dependent level density parameter $a(A)$ is also investigated for compound systems belonging to light and heavy mass region. Lastly, a theoretical systematics is explored where the proton beam in the reaction $\mathrm{\text{p}}+{}^{76}\mathrm{\text{Ge}}$ is replaced by a neutron beam forming the compound system ${}^{77}{\mathrm{\text{Ge}}}^{\ast }$, having the same $A$, but $Z$ one less than that of the compound system formed in the reaction using proton beam, and its effect on the decay characteristics such as preformation probability, penetration probability and barrier height is analyzed.

We present the results on fragmentation differences of quark and gluon jets obtained by CDF at . We compare the multiplicities and momentum distributions of charged particles in two data samples: dijet data and photon+jet data. These two samples have a different quark/gluon jet content, which allows a measurement of the inclusive properties of gluon and quark jets. The results are compared to the earlier measurements obtained at e+e- collisions and to the re-summed perturbative QCD calculations.

The fragmentation functions of D⁰, D^±, , D*^o, D*^± and at are measured with a data set of 102.7 fb^-1. Fragmentation model parametrizations (Peterson, Kartvelishvili, Collins-Spiller, Lund, and Bowler models) are compared to the data. The data at high x≃1 indicate a contribution of non-perturbative QCD processes.

A detailed study of fragmentation of vector mesons at the next-to-leading order (NLO) in QCD is given for e⁺e^- scattering. A model with broken SU(3) symmetry using three input fragmentation functions α(x, Q²), β(x, Q²) and γ(x, Q²) and a strangeness suppression parameter λ describes all the light quark fragmentation functions for the entire vector meson octet. At a starting low energy scale of for three light quarks (u, d, s) along with initial parametrization, the fragmentation functions are evolved through DGLAP evolution equations at NLO and the cross-section is calculated. The heavy quarks contribution are added in appropriate thresholds during evolution. The results obtained are fitted at the momentum scale of for LEP and SLD data. Good-quality fits are obtained for ρ, K*, ω and ϕ mesons, implying the consistency and efficiency of this model. Strangeness suppression in this model is understood both in terms of ratios of quark fragmentation functions alone as well as in terms of observables; the latter yield a suppression through the K*/ρ multiplicity ratio of about 0.23 while the x dependence of this suppression is also parametrized through the cross-section ratios.

We present a review of heavy flavor physics results from the CDF and DØ Collaborations operating at the Fermilab Tevatron Collider. A summary of results from Run 1 is included, but we concentrate on legacy results of charm and b physics from Run 2, including results up to Summer 2014.

The shape of the transverse momentum $(p_T)$ distribution of primary charged particles in minimum bias (nonsingle-diffractive) p–Pb collisions at $\sqrt{s_{NN}}=5.02\mathrm{\text{TeV}}$ is studied in the pseudorapidity regions: $\left|\eta \right|<0.3$, $0.3<\eta <0.8$ and $0.8<\eta <1.3$ and in the transverse momentum range $0.5<p_T<20\mathrm{\text{GeV}}/c$ using simulated data produced with the HIJING 1.0 code. These are compared with the ALICE data measured by the ALICE detector at the LHC. In the model, the central and forward $\eta$-regions differ more than in the ALICE data and due to this fact HIJING 1.0 cannot describe well the high $p_T$ region in the $p_T$ distributions. The comparison of results from simulation implies that the HIJING 1.0 considered narrower pseudorapidity distribution for the charged particles than it is in the ALICE data. It cannot take into account satisfactorily leading effect due to the asymmetric p–Pb fragmentation.

A combined analysis of both $e^{+}{e}^{-}$ (LEP, SLD) and $pp$ (RHIC-PHENIX and LHC-ALICE) hadroproduction processes are done for the first time for the vector meson nonet at the next-to-leading order (NLO) using a model with broken SU(3) symmetry. The transverse momentum ($p_T$) and rapidity ($y$) dependence of the differential cross-section for $\omega$ and $\varphi$ mesons of the $pp$ data are also discussed. The input universal quark (valence and singlet) fragmentation functions at a starting scale of $Q_0^2=1.5{\mathrm{\text{GeV}}}^2$, after evolution, have values that are consistent with the earlier analysis for $e^{+}{e}^{-}$ at NLO. However, the universal gluon fragmentation function is now well determined from this study with significantly smaller error bars, as the $pp$ hadroproduction cross-section is particularly sensitive to the gluon fragmentation since it occurs at the same order as the quark fragmentation, in contrast to the $e^{+}{e}^{-}$ hadroproduction process. Additional parameters involved in describing the strangeness and sea suppression and octet–singlet mixing are found to be close to the earlier analysis; in addition, a new relation between the gluon and sea suppression in $K^{\ast }$ and $\varphi$ hadroproduction has been observed.

Study of the mechanism of heavy quarkonia production is a powerful tool for a better understanding of the dynamics of strong interactions and probably to search for new physics. It is well-known that the fragmentation mechanism is dominant for heavy quarkonia production and forms the nonperturbative aspect of hadron production. Since the main contribution of $J∕\psi$ production in high energy processes results from the gluon fragmentation, through this work, we study the fragmentation mechanism of gluon into S-wave vector heavy charmonium $J∕\psi$ at lowest order perturbative QCD and extend our work to the noncommutative standard model. To investigate the effects of space–time noncommutativity, we employ the Seiberg–Witten maps. Our results show that the noncommutative effects are considerable, specifically when the gluon transverse momentum is small; $p_T<30$GeV.

Clusters of C₆₀ fullerenes are (multi)-ionised in collisions with O⁵⁺ projectiles at a collision energy of 100 keV. The dominant fragmentation channels are analysed by time-of-flight mass spectrometry for different cluster size distributions. Singly charged , ions are found to be the dominant fragments, in 25% connected with the loss of one or more C₂-units. This result is explained by the large charge mobility in fullerene clusters. Doubly charged fragments, in form of and , contribute to the observed spectrum with less than 5–10% only and are mainly attributed to the fragmentation of dimers. Singly charged small carbon clusters in the size range n = 7 to 19 are formed with low kinetic energies indicating the importance of thermal dissociation processes. The present experiments confirm earlier conclusions on the charge mobility in fullerene clusters.

Using vacuum ultraviolet radiation from a synchrotron source, threshold photoelectron photoion coincidence (TPEPICO) spectroscopy has been used to study the dissociative photoionisation of CHF₂–CH₃ in the photon energy from 11.8 eV to 24.8 eV. Combining with ab initio molecular orbital calculation, fragmentation process and fragmental mechanism of the valence states of parent ion are discussed. For single bond cleavage process, a statistical mechanism might govern the C–C bond cleavage, while the kinetic energy release derived from channel CHF₂–CH₃⁺ → CH₃–CHF⁺+ F + e^- shows evidence for impulsive mechanism. A two-step increase of signal CF₂–CH₃⁺/CHF₂–CH₂⁺ was observed. The two-step is due to the formation of ion CF₂–CH₃⁺/CHF₂–CH₂⁺ through two different dissociation channels. Both computed molecular orbital character and related G2 dissociation energy support the assumption.

The ionisation threshold of 12.02 ± 0.04 eV measured from the TPES and the appearance energies (AEs) identified from the ion yield curves are presented. New or refined upper limit values of enthalpy of formation at 298 K for ion CHF₂⁺, CF₂–CH₃⁺ and CHF–CH₃⁺ are derived.

We develop a method to describe the temporal evolution of an interacting system of bosons, for which the field operator expansion is truncated after a finite number M of modes, in a rigorously controlled manner. Using McLachlan's principle of least error, we find a self-consistent set of equations for the many-body state. As a particular benefit and in distinction to previously proposed approaches, the presently introduced method facilitates the dynamical increase of the number of orbitals during the temporal evolution, due to the fact that we can rigorously monitor the error made by increasing the truncation dimension M. The additional orbitals, determined by the condition of least error of the truncated evolution relative to the exact one, are obtained from an initial trial state by steepest constrained descent.

We study the electron-impact induced ionization of O₂ from threshold to 120 eV using the electron spectroscopy method. Our approach is simple in concept and embodies the ion source with a collision chamber and a mass spectrometer with a quadruple filter as a selector for the product ions. The combination of these two devices makes it possible to unequivocally collect all energetic fragment ions formed in ionization and dissociative processes and to detect them with known efficiency. The ion source allows varying and tuning the electron-impact ionization energy and the target-gas pressure. We demonstrate that for obtaining reliable results of cross-sections for inelastic processes and determining mechanisms for the formation of O${}^{+}{(}^{4}S,{}^{2}D,{}^{2}P)$ ions, it is crucial to control the electron-impact energy for production of ion and the pressure in the ion source. A comparison of our results with other experimental and theoretical data shows good agreement and proves the validity of our approach.

In the framework of the time-dependent density-functional theory, applied to valence electrons, coupled non-adiabatically to molecular dynamics of ions, the collision dynamics of cytosine impacted by proton is studied. We especially focus on the effect of the collision orientations on the damage of cytosine by choosing two collision orientations taking the oxygen atom on the double bond CO as the collision site with the incident energy of proton ranging from 150 eV to 1000 eV. First, two collision dynamical processes are explored by analyzing the molecular ionization, the ionic position and the kinetic energy, the energy loss of proton and the electronic density evolution. The results show that the damage process of cytosine induced by proton impact is mainly the capture of electrons by proton, the departments of ions and groups as well as the opening of ring. It is found that the orientation has little effect on the loss of the kinetic energy of proton, which is about 21.5$\%$ of the incident energy of proton. Although the scattering angle $𝜃$ has a polynomial relationship with $E_k$ in both cases, it is greatly affected by the orientation. When $E_k>200$ eV, the scattering angle of proton colliding with O along the $x$-axis is greater than that of proton colliding with O along the $y$-axis. The orientation also has a great effect on the mass distribution of the fragments and the fragmentation route. When proton moves along the $x$-axis, the fragmentation route is that O leaves the cytosine and the rest keeps on vibration, while products are not only related to the incident kinetic energy, but also show diversity when proton moves along the $y$-axis.

Knowledge bases contain specific and general knowledge. In relational database systems, specific knowledge is often represented as a set of relations. The conventional methodologies for centralized database design can be applied to develop a normalized, redundancy-free global schema. Distributed database design involves redundancy removal as well as the distribution design which allows replicated data segments. Thus, distribution design can be viewed as a process on a normalized global schema which produces a collection of fragments of relations from a global database. Clearly, not every fragment of data can be permitted as a relation. In this paper, we clarify and formally discuss three kinds of fragmentations of relational databases, and characterize their features as valid designs, and we introduce a hybrid knowledge fragmentation as the general case. For completeness of presentation, we first show an algorithm for the validity test of vertical fragmentations of normalized relations, and then extend it to the more general case of unbiased fragmentations.

Interaction diagrams are used in multi-agent systems to graphically describe agent computation threads and communications while fragmentations are the algebraic representations of interaction diagrams. The IDAF (Interaction Diagrams And Fragmentations) tool suite has been developed based on the formalism of interaction diagrams and fragmentations. The tool suite consists of ValidatoR, FormatteR, TranslatoR, GrapheR and TesteR. This paper describes the usage of the tool suite and demonstrates it in two different multi-agent systems.

A two-component analysis of spectra to p_t = 12 GeV/c for identified pions and protons from 200 GeV Au–Au collisions is presented. The method is similar to an analysis of the n_ch dependence of p_t spectra from p–p collisions at 200 GeV, but applied to Au–Au centrality dependence. The soft-component reference is a Lévy distribution on transverse mass m_t. The hard-component reference is a Gaussian on transverse rapidity y_t with exponential (p_t power-law) tail. Deviations of data from the reference are described by hard-component ratio r_AA, which generalizes nuclear modification factor R_AA. The analysis suggests that centrality evolution of pion and proton spectra is dominated by changes in parton fragmentation. The structure of r_AA suggests that parton energy loss produces a negative boost Δy_t of a large fraction (but not all) of the minimum-bias fragment distribution, and that lower-energy partons suffer relatively less energy loss, possibly due to color screening. The analysis also suggests that the anomalous p/π ratio may be due to differences in the parton energy-loss process experienced by the two hadron species. This analysis provides no evidence for radial flow.

We investigate the charge-pickup cross section of 158A GeV ²⁰⁷Pb projectiles on Bi, Pb, Cu and Al targets using CR39 nuclear track detectors. The target-detector stacks were exposed at CERN SPS beam facility. Chemical etched detectors are scanned using optical microscope, and the data in the form of etched cone heights have been collected. We have identified the beam and fragment charge states in particular charge-pickup (Z = 83) by the Pb ions using the etched cone heights. Dependence of charge-pickup cross section of 158A GeV ²⁰⁷Pb projectiles on the target mass number is described and results are compared to similar measurements found in the literature.

The new experimental data on breakup of oxygen-16 nucleus on four doubly charged ($Z=+2$) fragments in ${}^{16}$O$+p$ interactions at 3.25 GeV/$c$ per nucleon are presented. The number of such interaction events (with the formation of four doubly charged fragments) with simultaneous production of ${\pi }^{+}+{\pi }^{-}+p_{\mathrm{\text{fr}}}$ with no recoil proton has proved to be equal to the number of events with simultaneous production of ${\pi }^{+}+{\pi }^{-}$ as well as $p_{\mathrm{\text{fr}}}+{\pi }^{-}$ in events with a recoil proton. For the first time, the experimental cross-section of the diffractive dissociation of the oxygen-16 nucleus on four $\alpha$-particles in ${}^{16}$O$+p$ interactions at 3.25 GeV/$c$ per nucleon has been determined to be $\sigma$ (diffr.)$=1.42\pm 0.25$ mb. The temperature of the diffractive breakup of oxygen nucleus on four $\alpha$-particles has been calculated to be $7.6\pm 0.7$ MeV within the framework of the statistical model of fast fragmentation of Feshbach–Huang–Goldhaber. Using the obtained slope of the integral distribution on the square of a transverse momentum of a recoil proton in the laboratory system for the events of diffractive breakup of an oxygen nucleus on four $\alpha$-particles, we have calculated the radius of a target proton to be $0.84\pm 0.05$ fm, which agrees very well with the corresponding radius, $0.831\pm 0.007\pm 0.012$ fm, determined a few years ago in the Jefferson Lab Proton Radius (PRad) experiment.

SINGAPORE – Human Heart Tissue Grown from Stem Cells Improves Drug Testing.

UNITED STATES – Bioengineered Human Livers Mimic Natural Development.

UNITED STATES – New Cellular Target May Put the Brakes on Cancer’s Ability to Spread.

UNITED STATES – Does Consuming Low-Fat Dairy Increase the Risk of Parkinson’s Disease?

UNITED STATES – Memory Loss and Other Cognitive Decline Linked to Blood Vessel Disease in the Brain.

AUSTRALIA – Fabricating High Performance Nanohybrid Catalysts.

TAIWAN – US FDA Approves Zhaohe Cao-based Botanical Drug as an Investigational New Drug for Cancer Therapy.

KOREA – Distinguished Professor Sang Yup Lee Elected to the NAS.

Concrete is the most widely used construction material for strategic structures which are subjected to high rate of loading (impact and blast loading). Hence, the study of the concrete material becomes essential day by day for the structural engineers for the analysis and design of the concrete structures for safety and security purposes. This paper focuses on investigating the dynamic compressive response of the standard concrete (M35) and high-strength concrete (M60) under impact loading by using the newly developed split Hopkinson pressure bar setup (SHPB) apparatus. First, the calibration of SHPB performed at a 4.90ms${}^{-1}$ impact velocity generates almost similar incident and transmission trapezoidal profile waves with minor reflection showing accuracy. Second, the dynamic compression tests were performed on the standard concrete (SC) and high-strength concrete (HSC) specimens of 29.5mm in diameter and $\sim 30$mm in length with an aspect ratio of about 1($L/D\approx 1$) and a comparative study of strain rate effect and quasi-static compressive strength on the material properties has been investigated. The dynamic compression behavior of SC and HSC thus studied under varying strain rates has been presented in terms of the compressive strength, dynamic increase factor, stress–strain relationship, material failure, and fragmentation. Compressive strength increments of 114% and 41% were observed in SC and HSC as the loading condition changed from quasi-static to dynamic. In addition, the HSC described the $\sim 23$% and $\sim 18$% higher compressive strength corresponding to 290s${}^{-1}$ and 131s${}^{-1}$ strain rate as compared to SC describing that the HSC is more sensitive to the strain rate. The dynamic mechanical properties increased with an increase in the strain rate, and the DIFs were found to vary in the range of 1.42–2.14 and 1.07–1.41 for SC and HSC, respectively. The critical strain and ultimate strain were also found to be sensitive to strain rate and increased with increase in strain rate for both grades of concrete. Moreover, strain rates exert a noteworthy influence on fragmentation, leading to an increase in the percentage weight of fine fragments and a decrease in the percentage weight of large fragments as the strain rate increases. Additionally, there is an overall increase in the quantity of fragments for both SC and HSC specimens under these conditions. The flaky, elongated, angular, and irregular shape fragments were observed but their quantity and size varied significantly with strain rate.

Theoretical exploration of network structure significance requires a range of different networks for comparison. Here, we present a new method to construct networks in a spatial setting that uses spectral methods in combination with a probability distribution function. Nearly all previous algorithms for network construction have assumed randomized distribution of links or a distribution dependent on the degree of the nodes. We relax those assumptions. Our algorithm is capable of creating spectral networks along a gradient from random to highly clustered or diverse networks. Number of nodes and link density are specified from start and the structure is tuned by three parameters (γ, σ, κ). The structure is measured by fragmentation, degree assortativity, clustering and group betweenness of the networks. The parameter γ regulates the aggregation in the spatial node pattern and σ and κ regulates the probability of link forming.

This paper deals with the convergence of finite volume scheme (FVS) for solving coagulation and multiple fragmentation equations having locally bounded coagulation kernel but singularity near the origin due to fragmentation rates. Thanks to the Dunford–Pettis and De La Vall$é$e-Poussin theorems, we establish that numerical solution is converging to the weak solution of the continuous model using a weak $L^1$ compactness argument. A suitable stable condition on time step is taken to achieve the result. Furthermore, when kernels are in $W_{\mathrm{\text{loc}}}^{1,\infty }$ space, first-order error approximation is demonstrated for a uniform mesh. It is numerically validated by taking four test problems of coupled coagulation–fragmentation models.

Patent ownership Fragmentation following the U.S. pro-patent shifts has built overlapping intellectual property rights or patent thickets. This has made the use of others’ innovations costlier due to transaction costs, licensing fees, and hold-up. Using panel data on 2,441 public U.S. manufacturing firms for 1976–2002, I find that patent thickets lower firms’ expected profit and their market value. I also find that firms with a large patent portfolio experience a smaller effect, likely because stronger bargaining position lowers the hold-up likelihood. There is no systematic time effect from patent thickets on firms’ market value with a large patent portfolio size.

This paper investigates the pattern of globalizing corporate activities of Japanese manufacturing firms and their domestic operations and international trade. More specifically, we compare changes in domestic operations and international trade of firms expanding operations in East Asia with those of firms not expanding operations in two contrastive periods, 1998–2002 and 2002–2006. In addition, we conduct analyses incorporating the information on the globalizing behavior in the former period for the latter period and analyses focusing only on non-MNEs or MNEs in line with the literature. Our study demonstrates that Japanese manufacturing firms with expanding operations in East Asia are more likely to increase domestic employment and the number of domestic affiliates and establishments as well as to intensify export/import activities with the region, particularly in the latter period, by effectively utilizing the mechanics of production process-wise division of labor in East Asia.

Recent measurements of charm production at HERA are presented. They include measurements of charm fragmentation fractions, of charm production in DIS and of inelastic and exclusive J/ψ photoproduction. Charm measurements have been combined and analysed in the framework of a QCD fit to inclusive and charm data.

In this paper, the brittle fragmentation of an expanding ring is numerically studied by a simple atomistic model. We investigate the statistical distribution of fragment spanned over a wide range of strain rates when damage related to broken bond reaches a steady state. It is shown that at low strain rate limited number of heavy fragments can be generated because of anisotropic behavior while for high strain rate fragment can be well fitted with Weibull distribution. The physical mechanism of fragmentation process reveals that damage accompanying with numerous microcracks is found to initiate in the inner regime of the expanding ring. Furthermore, we discuss the effect of random defect on the fragmentation process.

This paper examines various economic issues on offshoring (international outsourcing). It begins with a discussion of the factors that determine a firm's decision to offshore and illustrates, with simple models, the cost saving of offshoring certain stages of production and the advantages of specializing in some input production and engaging in input trade. The paper then examines the recent trend in offshoring with special emphases on the rise of IT offshoring and the characteristics of firms engaging in offshoring and exporting. The effect of offshoring and national welfare is then discussed in light of numerous results in recent empirical studies. Finally, after examining the current US programs to aid the displaced workers, the paper discusses various short-run and long-run policy proposals to alleviate the negative impacts of offshoring.

In this work, a multiscale cohesive zone model (MCZM) is developed to simulate the high-speed penetration induced dynamic fracture process such as fragmentation in crystalline solids. This model describes bulk material as a local quasi-continuum medium which follows the Cauchy–Born rule while cohesive zone element is governed by an interface depletion potential, such that the cohesive zone constitutive descriptions are genetically consistent with that of bulk element. This multiscale method proved to be effective in describing material inhomogeneities and it is constructed and implemented in a cohesive finite element Galerkin weak formulation. Numerical simulations of high-speed penetration with different shape of penetrators, i.e., square, circle and parabola nose penetrators are performed. Results show that the proposed MCZM can successfully capture spall fracture, the penetration process and different characteristics of fragmentation under different shape of penetrators.

Mass selected fullerene ions are exposed to synchrotron radiation in the 17–300 eV energy range. Selected absolute cross-sections for single and multiple ionization as well as fragmentation were measured for ions of C₆₀, C₇₀, C₈₀, C₈₂, and C₈₄. More recently, the first ever experiments with endohedral and fullerene ions have been conducted.

Fragmentation functions can be cleanly obtained from e⁺e⁻ annihilation. In the recent years various measurements related to unpolarized, polarized and transverse-momentum dependent fragmentation functions have become available from the Belle, BaBar and BESIII experiments. These fragmentation functions are absolutely essential in extracting the spin and flavor structure of the nucleon and will play an important role in fulfilling the scientific goals of the electron-ion collider.

Natural gas consists mainly of methane (CH₄) and ethane (CH₃CH₃) and other hydrocarbons in small quantities. Depending on the source it may also contain CO₂, nitrogen (N₂), hydrogen sulfide (H₂S) and helium (He). It is very abundant and its combustion contributes to the increase of the CO₂ content in the biosphere. Natural gas is a non-renewable fuel (Section 5.1). It is widely used to produce electricity, heat, chemicals including hydrogen, and hydrocarbons (liquid fuels) and as a fuel for motor vehicles…

We saw (Section 4.4) that CO₂ (carbon dioxide) reacts with quicklime (calcium oxide) in water at 25°C, under 1 atm generating calcium carbonate or limestone (CaCO₃). The process is a sequence of two reactions (4.14) and (6.1):

In this lecture we review the theoretical investigation of heavy ion collisions in order to obtain information on the nuclear equation-of-state (EOS). We discuss the present knowledge of the EOS, and stress, in particular, the large uncertainty about the density dependence of the symmetry energy. We develop the treatment of heavy ion collisions with transport theory and non-equilibrium effects. We then discuss investigations both of the high density EOS with intermediate energy collisions and of the low density EOS in the Fermi energy regime. At the high density we make connections with neutron stars. At low density we discuss the fragmentation process and, in particular, the role and treatment of fluctuations and the dynamical fragment formation.