On the Origin of the δk-Model and the Model of Plastic Strips

On the basis of a survey of works, we demonstrate the priority of the Lviv school of mechanics in the field of creation and development of the deformation theory of limiting equilibrium of bodies with cracks known as the _k -model. The theory is based on the criterion of crack opening displacement proposed by Leonov and Panasyuk and on the procedure of evaluation of this quantity by modeling the inelastic zones in front of the crack by cuts the edges of which are loaded by certain stresses ₀ whose physical meaning is determined by the properties of the material. This method (known as the model of plastic strips) is also used for the determination of the development of plastic zones at the crack tip for various configurations of plates and loads and also in twisted bodies. The results of numerical calculations agree with the experimental data.     

Initial Studies Concerning the Current Status and Problems on the Formulation and Revision of the National Standards for Electric Insulation Materials

IntroductionAfteritsaccessiontotheWTO,Chinamustestab-lishanoperationalmechanismforthestandardizationworktomeetthedemandsofdomesticandforeignmarkets,andgraduallyperfectastandardsystemthatmeettheneedsofnationaleconomyandsocialdevel-opment.AmongChina'sstandardsystems,thecurrentnationalstandardsforelectricalinsulationmaterialsonlyaccountforasmallpart,yettheyarewidelyusedinthefieldsofelectricalappliances,electricalengines,transformers,condensers,switches,powergeneration,powertransmission,power-tr…     

Effect of the length and the aggregate size of MWNTs on the improvement efficiency of the mechanical and electrical properties of nanocomposites—experimental investigation

An experimental investigation of the effect of nanotube length and aggregate size on the mechanical and electrical properties of the composites was reported. Three treatments, that affect mainly the length and aggregate size, were applied on the CVD MWNTs before they were added into a resin matrix. They had a very clear impact on the dielectric properties of the composites and on the improvement efficiency. There was an insulator-to-conductor transition with the as-prepared MWNTs at 0.5 wt%. Regarding the mechanical properties, the addition of MWNTs increased the Young's modulus and reduced the fracture strain. In that case, the pre-treatment on MWNTs, however, had a much more moderate effect on the improvement efficiency.     

Vortex rings and the superfluid λ-transition

A vortex-ring formulation of the₄He -transition provides a clear physical picture of the superfluid transition. The thermally excited rings are dipoles which orient in an applied flow field, and their net backflow cancels part of the applied flow, reducing the superfluid density. At the -point rings of infinite size drive the superfluid density to zero as a power law of the reduced temperature, with an exponent of 0.672. By fitting to the experimental superfluid amplitude the core energy of the smallest rings is found to be 6.1K at T and their diameter is 2.3 Å. It is proposed that these can be identified as the roton excitations of the Landau model. The vortex theory also yields new insights into topics such as boundary effects at a wall, finite-size effects, and the dynamics of the transition.     

How does the Earth system generate and maintain thermodynamic disequilibrium and what does it imply for the future of the planet?

The Earth's chemical composition far from chemical equilibrium is unique in our Solar System, and this uniqueness has been attributed to the presence of widespread life on the planet. Here, I show how this notion can be quantified using non-equilibrium thermodynamics. Generating and maintaining disequilibrium in a thermodynamic variable requires the extraction of power from another thermodynamic gradient, and the second law of thermodynamics imposes fundamental limits on how much power can be extracted. With this approach and associated limits, I show that the ability of abiotic processes to generate geochemical free energy that can be used to transform the surface-atmosphere environment is strongly limited to less than 1?TW. Photosynthetic life generates more than 200?TW by performing photochemistry, thereby substantiating the notion that a geochemical composition far from equilibrium can be a sign for strong biotic activity. Present-day free energy consumption by human activity in the form of industrial activity and human appropriated net primary productivity is of the order of 50?TW and therefore constitutes a considerable term in the free energy budget of the planet. When aiming to predict the future of the planet, we first note that since global changes are closely related to this consumption of free energy, and the demands for free energy by human activity are anticipated to increase substantially in the future, the central question in the context of predicting future global change is then how human free energy demands can increase sustainably without negatively impacting the ability of the Earth system to generate free energy. This question could be evaluated with climate models, and the potential deficiencies in these models to adequately represent the thermodynamics of the Earth system are discussed. Then, I illustrate the implications of this thermodynamic perspective by discussing the forms of renewable energy and planetary engineering that would enhance the overall free energy generation and, thereby 'empower' the future of the planet.     

Structure and evolution of innovation research in the last 60 years: review and future trends in the field of business through the citations and co-citations analysis

The field of innovation studies has grown considerably in the last four decades, which has led to the emergence of new approaches and theoretical aspects that need to be examined and considered. Therefore, this paper aims to understand what are the main theoretical pillars that support the structure of innovation theories and fields, how it evolved over the years and what are the directions that lead to future trends in innovation research. The procedure consists in a mix-methods using the citation and co-citation analysis associated with bibliometric methods, Social Network Analysis, and a systematic review of the literature. The results were validated by Delphi with academic specialists in innovation. Considering publications between 1956 and 2016 divided into four 15-years timespan, the longitudinal analysis results indicate the evolution of the main streams of thoughts that support the current innovation research fields and depict a research orientation for future works that can be developed to generate relevant contributions for the theoretical development of the area. This paper differentiates itself bringing results based on a large database, by the research methods employed, and by the perspective adopted provides solid contributions to the understanding of the past, present, and future of the scientific research in innovation to business administration field.     

On the Impurity Parameters for Impurities Detected in the Eutectics Co?CC and Pt?CC and Their Role in the Estimate of the Uncertainty in the Eutectic Temperatures

In this paper, impurity parameters m _i and k _i have been calculated for a range of impurities I as detected in the eutectics Co?CC and Pt?CC, by means of the software package Thermo-Calc within the ternary phase spaces Co?CC-I and Pt?CC-I. The choice of the impurities is based upon a selection out of the results of impurity analyses performed for a representative set of samples for each of the eutectics in study. The analyses in question are glow discharge mass spectrometry (GDMS) or inductively coupled plasma mass spectrometry (ICP-mass). Tables and plots of the impurity parameters against the atomic number Z _i of the impurities will be presented, as well as plots demonstrating the validity of van??t Hoff??s law, the cornerstone to this study, for both eutectics. For the eutectics in question, the uncertainty u(T _E ? T _liq ) in the correction T _E ? T _liq will be derived, where T _E and T _liq refer to the transition temperature of the pure system and to the liquidus temperature in the limit of zero growth rate of the solid phase during solidification of the actual system, respectively. Uncertainty estimates based upon the current scheme SIE?COME, combining the sum of individual estimates (SIE) and the overall maximum estimate (OME) are compared with two alternative schemes proposed in this paper, designated as IE?CIRE, combining individual estimates (IE) and individual random estimates (IRE), and the hybrid scheme SIE?CIE?CIRE, combining SIE, IE, and IRE.     

On the Freezing and Melting Behavior of the Eutectic Pt?CC

The feasibility of referring to freezing as an alternative to melting for defining the eutectic transition temperature has been studied using two Pt?CC cells constructed at NIM, one of a sleeve type, and the other of a hybrid type, including support. Freezing and melting experiments have been done by varying the offset of the furnace temperature T _furn with respect to the nominal eutectic temperature T _E used to freeze the fixed point with offsets (T _furn?T _E)_freeze from ?5 K to ?40 K, followed by melting at a fixed offset (T _furn?T _E)_melt =?+?20 K. Plotting the liquidus temperatures T _liq,freeze and T _liq,melt obtained for freezing and melting against ${(T_{\rm E}-T_{\rm furn})^{1/2}_{\rm freeze}}$ resulted in linear relations for both cells, allowing extrapolation toward T _liq,freeze(0) and T _{liq, melt}(0). For the cells Pt?CC5# and Pt?CC6# under study: T _liq,melt(0)?T _liq,freeze(0) =?10 mK and 20 mK, respectively, with a standard uncertainty of 30 mK for both T _liq,melt(0) and T _liq,freeze(0). The coherence of the results obtained for melting and freezing indicates that freezing can be used, as an alternative to melting, to define the liquidus temperature T _liq(0) of the eutectic Pt?CC.     

Age and dose-limited PET-CT scan regime in lymphoma: between the devil and the deep blue sea?

In this study the authors speculate about hypothetical effective-dose (E) reduction through limiting post-chemotherapy PET-CT scanning to lymphoma sites previously identified on pre-treatment CT. E reductions/scan time savings are compared between post-treatment standard and theoretically limited PET-CT scans. The influence of patient age with E savings and associated clinical implication for 100 subjects are discussed. The greatest E theoretical savings of 52 and 32% for the CT contribution and combined PET-CT, respectively, were seen in patients <18 y old using limited scans in this study, with a potential mean time saving of 16 min per patient across the entire cohort. However, the limited PET-CT regime here missed a 1% rate of unexpected cancer that standard PET-CT recorded. The authors recommend performing larger scale multi-centre studies comparing PET-CT pre- and post-chemotherapy to establish full clinical efficacy of this method.     

Integrating the customers’ perceived risks and benefits into the triple-channel retailing

Multiple channel retailing and channel selection strategy have become key issues for many corporations to place themselves at the heart of a new era of retailing. This paper studies a triple-channel system in which a manufacturer operates a conventional channel, a direct online channel, as well as increases its online presence with an online shopping platform. It also takes the heterogeneity of consumers’ price sensitivity and channel preferences into account. It highlights that the perceived risks and perceived benefits are aggregated into an inhibitor or activator entering the customers’ acceptance of triple channels and further affecting their purchasing decisions. Three cases are discussed to investigate the demand distributions, the profit behaviours, the optimal pricing strategies and the channel selection strategies. Theoretical analysis is further validated by a case study with the aid of agent-based modelling. Sensitivity analysis demonstrates that two acceptance indices – respectively, regarded as the consumers’ willingness to tolerate the perceived risks of the online channel and approve the perceived benefits from the third-party online platform – significantly govern the total profit in two stylised scenarios. This study schematically characterises the structure of demand distributions, helps the corporation to discern consumers’ channel choices and then focus its marketing efforts towards more profitable customers and strategic channel structures. Furthermore, some implications are outlined for the optimal supply chain designation decision.     

To Contribute our wisdom to the standardization and future of the world

Justas the them e ofthis year’s W orldStandards D ay,“Standards for a SaferW orld”,the W orld Standards D ay thisyear is unusual because the role of stan-dards is becom ing m ore and m ore im por-tant and irreplaceable.Standard,one ofthe key w ays to build a safe w orld isfound by years’collaborative efforts ofexperts w orldw ide w ho are engaged instandardization w ork.W e believe thatthere should be no lim it for standard.Standard is the base of w ide cooperationand com m unication f…     

Laguerre–Gaussian modes and the Wigner transform

Recent developments in laser physics have called renewed attention to Laguerre–Gaussian (LG) beams of paraxial light. In this paper we consider the corresponding LG modes for the two-dimensional harmonic oscillator, which appear in the transversal plane at the laser beam's waist. We see how they arise as Wigner transforms of Hermite–Gaussian modes, and we proceed to find a closed form for their own Wigner transforms, providing an alternative to the methods of Simon and Agarwal. Our main observation is that the Wigner transform intertwines the creation and annihilation operators for the two classes of modes.     

Examining the effects of government intervention on the firm’s environmental and technological innovation capabilities and export performance

Considering our living environments directly affect the quality of our daily lives, many believe that the environment should only be safeguarded by the mighty hands of the government instead of leaving the environmental stewardship in the hands of profit-making private enterprises. As such, the government often intervenes with the way private enterprises conduct business through many different forms of environmental regulations and business incentives. However, the efficiency and effectiveness of such government intervention are still unknown and unclear at best. Many sceptics still think that economic growth and environmental protection are in conflict with each other and subsequently the firm’s environmental performance and export performance cannot be achieved simultaneously even with active government intervention over the firm’s environmental management. To clarify this misconception, this paper aims to examine whether government intervention leads to the affected firm’s both environmental and export performance (export sales performance). In addition, it investigates whether government intervention enhances the firm’s environmental and technological innovation capabilities and thus makes the firm more competitive in the global marketplace. In so doing, this paper verifies the ecological modernisation theory and institutional theory using the empirical analysis of the survey data obtained from the Korean manufacturing industry.     

Influence of High Pressure and Temperature on the Structure and Properties of the WC–6Co Hard Alloy

The results are presented of the barothermal treatment studies of a WC–6Co hard alloy at high pressure (7 GPa). It is shown that such a treatment of hard alloy leads to the deterioration of the basic physico-mechanical characteristics, specifically the strength at the contact, and the coercive force, which is stipulated by the increase of the defects amount in the structure of the carbide phase of the hard alloy.