A stochastic joint replenishment problem considering transportation and warehouse constraints with gainsharing by Shapley Value allocation

The purpose of this paper is to introduce a heuristic approach that uses a capacitated inventory model as means for identifying a collaborative agreement between different buyers jointly replenishing multiple items from multiple vendors, thus attaining economies of scale while reducing by sharing fixed procurement and operational costs. The proposed approach is denominated Stochastic Collaborative Joint Replenishment Problem (S-CJRP) and consists of two stages. The first stage determines a cost-efficient replenishment frequency for each collaborating company in all possible coalition arrangements. To accomplish the former, an extension of the known Joint Replenishment Problem (JRP) considering real-life capacity constraints, such as stochastic demand assuming normal distribution, finite storage and transport, is solved via genetic algorithms delivering a suitable coalition. In a second stage, the Shapley Value function is established to assess and allocate the potential gains achieved by colluding in the first stage, determining a fair share distribution among players that increases the viability of such coalition. Several scenarios from a simulated numerical study illustrate average cost savings of 32.3%. 28.2% and 32.7% for 3, 4 and 5 players, respectively, considering up to 30 items for the proposed collaboration, in all cases consistently exhibiting cost reduction and increasing the proposal feasibility.     

Physicochemical characterisation and in vitro Starch digestion of Avocado Seed Flour (Persea americana V. Hass) and its starch and fibrous fractions

The avocado seed is considered a by-product of their pulp exploitation and today it does not present relevant food or industrial applications. In this study, we evaluate the potential use of its flour, their isolated starch and fibre fractions. After processing, the flour yielded 46.28%, and showed 6.7% of protein and low fat and ash contents (3.4, and 2.71% respectively). The starch yielded 27.28% with low-fibre content that influenced its viscosity properties; as well as their water absorption index (WAI), water solubility index (WSI) and oil absorption index (OAI), that were 2.43%, 11.22% and 0.16% respectively. The in vitro starch digestion of the different obtained fractions showed higher amounts of rapidly digestible starch (56.8%–75.36%, flour and starch respectively). The functional properties of the materials were correlated with strong molecular interactions with their apparently unique amylose structure; for this, this by-product may have different potential for food applications.     

Boundary element study on the optical method of caustic for measuring fast crack propagation toughness K ID

The dynamic stress field near the tip of a crack tip which is accelerated and decelerated in an elastic plate with finite width under impact loading is analyzed by the boundary element method, and a simulation of measuring fast crack propagation toughness K _ID by the caustic method is performed. The results of the simulation agree qualitatively with the experimental results by Arakawa and Takahashi, and indicate the dependence of the measured K _ID not only on crack acceleration but also plate width. The dependence of measured K _ID on crack acceleration may result from the fact that under the condition of high loading rate or abrupt change in crack velocity, the transient stress field near the initial curve of caustic can not be represented fully by the dynamic stress intensity factor K _I(t, v), as suggested by Rosakis et al. The dependence of measured K _ID on plate width may be attributable to the fact that the transient stress field near the initial curve is affected directly by the reflected stess wave and also indirectly through crack acceleration which depends on the reflected stress wave. The possible dependence of the measured K _ID on loading rate, loading history, crack propagation history is also discussed.     

Capturing “Extraordinary” Soft‐Assembled Charge‐Like Polypeptides as a Strategy for Nanocarrier Design

The rational design of nanomedicines is a challenging task given the complex architectures required for the construction of nanosized carriers with embedded therapeutic properties and the complex interface of these materials with the biological environment. Herein, an unexpected charge‐like attraction mechanism of self‐assembly for star‐shaped polyglutamates in nonsalty aqueous solutions is identified, which matches the ubiquitous “ordinary–extraordinary” phenomenon previously described by physicists. For the first time, a bottom‐up methodology for the stabilization of these nanosized soft‐assembled star‐shaped polyglutamates is also described, enabling the translation of theoretical research into nanomaterials with applicability within the drug‐delivery field. Covalent capture of these labile assemblies provides access to unprecedented architectures to be used as nanocarriers. The enhanced in vitro and in vivo properties of these novel nanoconstructs as drug‐delivery systems highlight the potential of this approach for tumor‐localized as well as lymphotropic delivery.     

The effect of azimuthal temperature distribution on the ballooning and rupture behavior of Zircaloy-4 cladding tube under transient-heating conditions

For the purpose of investigating the effect of azimuthal temperature distribution on the ballooning and rupture behavior of Zircaloy-4 (Zry-4) cladding tube, laboratory-scale experiments on non-irradiated Zry-4 cladding tube specimens were performed under transient-heating conditions which simulate loss-of-coolant accident (LOCA) conditions by using an external heating method, and the data obtained were compared to those from a previous study, where an internal heating method was used. The maximum circumferential strains of the cladding tube specimens were firstly divided by the engineering hoop stress. The divided maximum circumferential strains, ks, of the previous study, which used the internal heating method, were then corrected based on the azimuthal temperature difference (ATD) in the cladding tube specimen. The ks for the external heating method which was used in this study agreed fairly well with the corrected ks obtained in the previous study which employed the internal heating method in the burst temperature range below ～1200 K. Also, the area of rupture opening tended to increase with increasing of the value which is defined as the engineering hoop stress multiplied by the maximum circumferential strain. From the results obtained in this study, it was suggested that the maximum circumferential strain and the size of rupture opening of a cladding tube under LOCA-simulated conditions can be estimated mainly by using the engineering hoop stress, the maximum circumferential strain, and ATD in the cladding tube specimen, irrespective of heating methods.     

Modeling of a Time-Spreading OCDMA System Including Nonperfect Time Gating, Optical Thresholding, and Fully Asynchronous Signal/Interference Overlapping

We present an extended theoretical model for time-spreading optical code-division multiple-access (OCDMA) coherent systems. We have updated well-known model to evaluate multiuser interference to include arbitrary encoded/decoded chip shape, receiver transfer function, and optical thresholding before detection. Full asynchronous regime is also assumed to exploit statistical benefits over the dominant primary beat noise. The model provides clear improvements in terms of number of users and required intercodes crosstalk, leading to more feasible OCDMA systems.     

Nature in corrosion-erosion surface for [TiN/TiAlN]n nanometric multilayers growth on AISI 1045 steel

The aim of this work is to characterize the electrochemical behavior of [TiN/TiAlN]n multilayer coatings under corrosion-erosion condition. The multilayers with bilayer numbers (n) of 2, 6, 12, and 24 and/or bilayer period (Λ) of 1500 nm, 500 nm, 250 nm, 150 nm and 125 nm were deposited by magnetron sputtering technique on Si (100) and AISI 1045 steel substrates. Both, the TiN and the TiAlN structures for multilayer coatings were evaluated via X-ray diffraction analysis. Mechanical and tribological properties were evaluated via nanoindentation measurements and scratch test respectively. Silica particles were used as abrasive material on corrosion-erosion test in 0.5 M of H₂SO₄ solution at impact angles of 30° and 90° over surface. The electrochemical characterization was carried out using polarization resistance technique (Tafel), in order to observe changes in corrosion rate as a function of the bilayer number (n) or the bilayer period (Λ) and the impact angle. Corrosion rate values of 9115 μm y for uncoated steel substrate and 2615 μm y for substrate coated with n = 24 (Λ = 125 nm) under an impact angle of 30° were found. On the other hand, for an impact angle of 90° the corrosion rate exhibited 16401 μm y for uncoated steel substrate and 5331 μm y for substrate coated with n = 24 (Λ = 125 nm). This behavior was correlated with the curves of mass loss for both coated samples and the surface damage was analyzed via scanning electron microscopy images for the two different impact angles. These results indicate that TiN/TiAlN multilayer coatings deposited on AISI 1045 steel represent a practical solution for applications in corrosive-erosive environments.     

Effect of the Synthesis Method on Co-catalysts Based on MCM-41 for the Fischer–Tropsch Reaction

In this work, cobalt catalysts based on ordered mesoporous materials of the MCM-41 type were synthesized and characterized. The synthesis of the catalysts was performed by using different methods: impregnation; incorporation of the metal in the synthesis gel and ionic exchange of the metal by the template. Different characterization techniques were used (N₂ adsorption–desorption, XRD, TPR, SEM and XPS) to study the textural and structural properties of the samples and the metal-support interaction corresponding to each method of synthesis. These samples were tested in the CO Hydrogenation (Fischer–Tropsch Synthesis) by measuring the CO conversion and the selectivity to CO₂ and some groups of hydrocarbons chains. The results show that structural and textural properties as well as the metal-support interactions are affected by the synthesis method. According to this study, catalytic performance is related to the properties of the samples, observing that the metal support interaction highly affects the activity and selectivity of the catalysts.     

Carotenoid composition of kale as influenced by maturity,season and minimal processing

The principal carotenoids of kale were identified by chemical reactions, high‐performance liquid chromatography/mass spectrometry and high‐performance liquid chromatography/photodiode array detection and were quantified by the last technique. In kale taken from conventional farms, the β‐carotene and lutein contents were significantly higher in the mature leaves, violaxanthin was at an unusually high level in the young leaves, and neoxanthin had practically the same concentration at both stages of maturity. In samples taken from an organic farm, the carotenoid contents were essentially the same in the young and the mature leaves. Except for β‐carotene, which did not differ with season, the carotenoid concentrations of marketed minimally processed kale were found to be significantly higher in the summer than in the winter, reflecting seasonal rather than processing effects. In minimally processed kale monitored during 5 days of storage at 7–9 °C, β‐carotene, lutein, violaxanthin and neoxanthin were reduced by 14, 27, 20 and 31% respectively. Thus minimal processing, seasonal and maturity factors were found to have an influence on the carotenoid content of kale. Copyright © 2004 Society of Chemical Industry