The Ripple effect in supply chains: trade-off ‘efficiency-flexibility-resilience’ in disruption management

This study aims at presenting the Ripple effect in supply chains. It develops different dimensions of the Ripple effect and summarises recent developments in the field of supply chain (SC) disruption management from a multi-disciplinary perspective. It structures and classifies existing research streams and applications areas of different quantitative methods to the Ripple effect analysis as well as identifying gaps in current research and delineating future research avenues. The analysis shows that different frameworks already exist implicitly for tackling the Ripple effect in the SC dynamics, control and disruption management domain. However, quantitative analysis tools are still rarely applied in praxis. We conclude that the Ripple effect can be the phenomenon that is able to consolidate research in SC disruption management and recovery similar to the bullwhip effect regarding demand and lead time fluctuations. This may build the agenda for future research on SC dynamics, control, continuity and disruption management, making supply chains more robust, adaptable and profitable.     

The ‘Goldilocks’ effect: preservation bias in vertebrate track assemblages

Finite-element analysis was used to investigate the extent of bias in the ichnological fossil record attributable to body mass. Virtual tracks were simulated for four dinosaur taxa of different sizes (Struthiomimus, Tyrannosaurus, Brachiosaurus and Edmontosaurus), in a range of substrate conditions. Outlines of autopodia were generated based upon osteology and published soft-tissue reconstructions. Loads were applied vertically to the feet equivalent to the weight of the animal, and distributed accordingly to fore- and hindlimbs where relevant. Ideal, semi-infinite elastic–plastic substrates displayed a ‘Goldilocks’ quality where only a narrow range of loads could produce tracks, given that small animals failed to indent the substrate, and larger animals would be unable to traverse the area without becoming mired. If a firm subsurface layer is assumed, a more complete assemblage is possible, though there is a strong bias towards larger, heavier animals. The depths of fossil tracks within an assemblage may indicate thicknesses of mechanically distinct substrate layers at the time of track formation, even when the lithified strata appear compositionally homogeneous. This work increases the effectiveness of using vertebrate tracks as palaeoenvironmental indicators in terms of inferring substrate conditions at the time of track formation. Additionally, simulated undertracks are examined, and it is shown that complex deformation beneath the foot may not be indicative of limb kinematics as has been previously interpreted, but instead ridges and undulations at the base of a track may be a function of sediment displacement vectors and pedal morphology.     

Innovation in multinational firms: Does cultural fit enhance performance?

Abstract and Key Results

The magnetoelectric effect in nickel–GaAs–nickel structures

Technical Physics Letters - We have experimentally studied the magnetoelectric (ME) effect in structures obtained by the electrolytic deposition of nickel onto gallium arsenide substrates. It is...     

The effect of strontium oxide in glass–ionomer cements

The reaction of strontium oxide powder with poly(acrylic acid) has been studied both alone and within glass–ionomer cements. Reaction was found to be slow and the strontium-carboxylate structure was found to be partially covalent in character, as determined by Fourier transform infrared spectroscopy (FTIR). These are similar to the structures formed by calcium in glass–ionomer cements, but are different from typical monomeric strontium carboxylates, which tend to be purely ionic. Strontium oxide powder introduced in two types of glass–ionomer cements, slowed down the setting reaction at both 21 °C and 37 °C, but at low levels (5 wt %), increased the compressive strength in both cement formulations studied. However, at higher levels, it was found to decrease the compressive strength. This study confirms the view that strontium is a cement-forming ion; but concludes that, except at very low levels, strontium oxide powder does not improve the properties of glass–ionomer cements.     

The Stiles–Crawford effect: a theoretical revisit

Abstract

In 1973, Snyder and Pask published an explanation of the Stiles–Crawford effect based on optical-waveguide theory, but used only one set of experimental data for comparison. Since then there have been many new experiments and comments on the theory. In this paper we examine the assumptions made in the original theory, introduce some refinements, address some of the comments and examine how well the theory explains the experimental results obtained since 1973. We conclude that the waveguide theory, with some minor improvements, provides the theoretical basis for understanding the Stiles–Crawford effect.     

The effect of meta-halloysite on alkali–aggregate reaction in concrete

Damage to concrete structures may occur as a result of internal effects. Alkali silica reaction (ASR) is a long term reaction between alkalis and reactive aggregate present in the concrete. The reaction product is sodium–potasium–calcium silica gel, able to absorb water, resulting in the expansion and cracking of concrete. The key problem is to find the right method for mitigating the internal damage. This paper presents the results of an investigation into the effectiveness of calcined halloysite (meta-halloysite) in improving the resistance to alkali-silica reaction (ASR). The pozzolanic reactivity of meta-halloysite was also evaluated using Thermo-Gravimetric Analysis. Microstructures of mortar bars were observed by Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (EDS) to investigate the location and chemical composition of ASR gel. The results from this study showed satisfactory level of pozzolanic reactivity when cement was partially replaced by meta-halloysite. It was demonstrated that a 20% addition of meta-halloysite are able to mitigate ASR and lower expansion of mortar bars with reactive aggregate to a safe level of not more than 0.1% at 14 days. Microstructural observations of the specimens containing meta-halloysite indicated the presence of a calcium–alkali–silicate–hydrate gel. But fewer reaction products and with different composition than those forming in the pastes without mineral additives are present.     

Excess energy in quenchedβ-Cu-Zn-Al alloys: relation to the martensitic transformation

The disorder-induced excess energy,L , of a-Cu_1– x)(ZnAl) _x (0.30 x 0.35) alloy, which shows a martensitic transformation at low temperature, after quenching from different initial temperatures,T _i, is calculated. Ordering-energi-es for the different nearest and next-nearest neighbour atom pairs, obtained by fitting mean field expressions of order-disorder critical temperatures to experimental data, are used. The excess energy is related to the changes of the latent heat of the martensitic transformation,L, observed just after quenching from T_i. It was found that the shift in latent heat correlates linearly with the calculated excess energy of the-phase. Calorimetric measurements justify the results.     

The “Paramagnetic” Meissner Effect in Superconductors

There are a number of publications concerning the observation of a paramagnetic signal in HTSC ceramic samples during field-cooling procedures. Some authors assume that this signal is connected with spontaneous currents and discuss the possibility of the existence of -junctions in Josephson media. In this work, it is shown that the paramagnetic signal could appear in the case of capture and compression of the magnetic flux in a sample during field-cooling procedures. The results of numerical calculation of the magnetic moment for different configurations of the sample and flux compression are presented. The unusual behavior of longtime relaxation of the magnetic moment in experiments on capture of magnetic flux is discussed.     

The effect of mica surface “dehydroxylation” on particulate palladium vapor deposits

Electron energy loss spectroscopy (ELS) and palladium nucleation were used to study the influence of pre-and post-cleavage annealing on some surface properties of muscovite mica. Two ELS features at 28 eV and 16 eV indicate OH molecules on the mica surface and in the near-surface bulk respectively. On post-cleavage heating of the mica to temperatures above 400°C the two surface losses disappear, causing the simultaneous liberation of water, which is explained by a dehydration of the AlO(OH) layer of the mica lattice. The palladium nucleation and growth behavior is strongly influenced by the state of “dehydroxylation” of the mica surface. On “dehydroxylated” mica the particle number density of palladium is increased and the mean particle size decreased owing in principle to stronger interaction between the mica substrate and the palladium deposit.     

The Embedment of Conjugated MDMO−PPV Polymer in Microcavities of Porous Silicon at Excess Pressure from Solution

The results of a controlled embedment of the polymer Poly[2-methoxy-5-(3',7'-dimethyloctyloxy)- 1,4-phenylene vinylene] (MDMO?PPV) in microcavities that are based on porous silicon from a solution in toluene at an excess pressure in the range from 1 to 3 atm are presented. The behavior of polymer luminescence depending on the magnitude of the excess pressure and embedment time has been investigated. It has been shown that luminescence reaches saturation for a characteristic time of 100 min regardless of the excess-pressure value. It has been demonstrated that the results of the embedment have a high degree of reproducibility. The influence of the porosity of the upper layer of the microcavity on the efficiency of the polymer embedment has been discussed.     

The effect of pressure on spontaneous Rayleigh–Brillouin scattering spectrum in nitrogen

In order to study the effect of gas pressure on spontaneous Rayleigh–Brillouin scattering spectrum and verify the validity of Tenti S6 model at pressures up to 8 atm, the spontaneous Rayleigh–Brillouin scattering experiment in nitrogen was performed for a wavelength of 532 nm at the constant room temperature of 296 K and a 90° scattering angle. By comparing the experimental spectrum with the theoretical spectrum, the normalized root mean square deviation was calculated and found less than 2.2%. It is verified that Tenti S6 model can be applied to the spontaneous Rayleigh–Brillion scattering of nitrogen under higher pressures. The results of the experimental data analysis demonstrate that pressure has more effect on Brillouin peak intensity and has negligible effect on Brillouin frequency shift, and pressure retrieval based on spontaneous Rayleigh–Brillouin scattering profile is a promising method for remote of pressure, such as harsh environment applications. Some factors that caused experiment deviations are also discussed.     

The effect of deformation-induced-ferrite-transformation on nanometre-sized carbides in Ti–Mo ferritic steel

In this study, the effect of deformation-induced-ferrite-transformation (DIFT) rolling on precipitation in Ti–Mo ferrite matrix micro-alloyed steel was investigated by comparing to rolling in austenite non-recrystallisation region. The precipitate volume fraction and precipitation-starting time-temperature (PTT) curves under two kinds of process were calculated by thermodynamic and kinetic calculation, and the effects of non-recrystallisation rolling and DIFT rolling on the contribution of strengthening mechanisms were quantitatively analysed. The results showed that comparing with rolling in the austenite non-recrystallisation region, carbides in the steel by DIFT rolling were finer and more uniform. Moreover, DIFT rolling could enhance fine grain strengthening and precipitation strengthening simultaneously, and the increments of fine grain and precipitation strengthening were 34 and 63.7?MPa, respectively.     

The Portevin–Le Chatelier effect: a review of experimental findings

Abstract

The Portevin–Le Chatelier (PLC) effect manifests itself as an unstable plastic flow during tensile tests of some dilute alloys under certain regimes of strain rate and temperature. The plastic strain becomes localized in the form of bands which move along a specimen gauge in various ways as the PLC effect occurs. Because the localization of strain causes degradation of the inherent structural properties and surface quality of materials, understanding the effect is crucial for the effective use of alloys. The characteristic behaviors of localized strain bands and techniques commonly used to study the PLC effect are summarized in this review. A brief overview of experimental findings, the effect of material properties and test parameters on the PLC effect, and some discussion on the mechanisms of the effect are included. Tests for predicting the early failure of structural materials due to embrittlement induced by the PLC effect are also discussed.     

New Wines in New Bottles: The “Renaissance” of the Italian Wine Industry

Unexpected events such as crises challenge organizations and actors who must search for solutions and alternatives. Severe crises can be fatal, especially when they affect entire industries. The ability to identify a viable course to address contingencies brought about by a crisis is critical to determining outcomes. In this paper, we examine the systemic response to a crisis at different levels within an industry in order to obtain a better understanding of industry responses to crises. Through a historical case study of the Italian wine industry renaissance, we show how a sudden and devastating crisis was circumvented to spur a renewed industry imbued with better practices and knowledge. Our findings also show the key role of preconditions in sustaining the renaissance.