Multiobjective multiproduct parcel distribution timetabling: a real‐world application

Multiobjective multiproduct parcel distribution timetabling problem is concerned with generating effective timetables for parcel distribution companies that provide interdependent services (products) and have more than one objective. A parcel distribution timetabling problem is inherently multiobjective because of the multitude of criteria that can measure the performance of a timetable. This paper provides the mathematical formulation of the problem and applies the model to a real‐world case study. The application shows that without a common ground with the practitioners, it would be impossible to define the actual requirements and objectives of the company; problem definition is as important as model construction and solution method.     

Electrical conductivity of 1 : 1 and 2 : 1 clay minerals

The A.C. impedance plots were used as tools to analyze the electrical response of two varieties of Tunisian halloysite 1: 1 and illitic samples 2: 1 as a function of frequency at different temperatures (80–800°C). The real and imaginary parts of the complex impedance trace semicircles in the complex plane. Except for the illite, It-1, the second sample analyzed in this study, these plots give evidence for the presence of both bulk and grain boundary effect, above 600°C onwards. The bulk resistance of the materials decreases with the rise in temperature. Impedance Spectroscopy data reveal a non-Debye type of dielectric relaxation. The Nyquist plots show the negative temperature coefficient of resistance of both pure Tunisian illite and halloysite samples. The results of bulk electrical conductivity and its activation energy are presented for the two mineral clay samples. For illite It-1, the activation energy values estimated from the AC conductivity pattern and modulus pattern are very similar and suggest a possibility of a long-range mobility of charge carriers (ions) via hopping mechanism of electrical transport processes at higher temperature. On the other hand, for the halloysite sample provided from kasserine, (Ha-Kass), the modulus analysis admit that the electrical transport processes of the material are very likely of electronic nature. Relaxation frequencies follow an Arrhenius behavior with the activation energy values not comparable to those found for the electrical conductivity.     

Beneficial Effects of Silicon (Si) on Sea Barley (Hordeum marinum Huds.) under Salt Stress

Silicon - Silicon (Si) plays an important role in providing beneficial effects on plant growth and yield, especially under stressful environments such as salinity. The objective of this work is to...     

Branch and bound algorithms for rate-distortion optimized media streaming

We consider the problem of rate-distortion optimized streaming of packetized multimedia data over a single quality-of-service network using feedback and retransmissions. For a single data unit, we prove that the problem is NP-hard and provide efficient branch and bound algorithms that are much faster than the previously best solution based on dynamic programming. For a group of interdependent data units, we show how to compute optimal solutions with branch and bound algorithms. The branch and bound algorithms for a group of data units are much slower than the current state of the art, a heuristic technique known as sensitivity adaptation. However, in many real-world situations, they provide a significantly better rate-distortion performance.     

Priming of Cardiopulmonary Bypass with Human Albumin Decreases Endothelial Dysfunction after Pulmonary Ischemia–Reperfusion in an Animal Model

The routine use of mechanical circulatory support during lung transplantation (LTx) is still controversial. The use of prophylactic human albumin (HA) or hypertonic sodium lactate (HSL) prime in mechanical circulatory support during LTx could prevent ischemia–reperfusion (IR) injuries and pulmonary endothelial dysfunction and thus prevent the development of pulmonary graft dysfunction. The objective was to investigate the impact of cardiopulmonary bypass (CPB) priming with HA and HSL compared to a CPB prime with Gelofusine (GF) on pulmonary endothelial dysfunction in a lung IR rat model. Rats were assigned to four groups: IR-CPB-GF group, IR-CPB-HA group, IR-CPB-HSL group and a sham group. The study of pulmonary vascular reactivity by wire myograph was the primary outcome. Glycocalyx degradation (syndecan-1 and heparan) was also assessed by ELISA and electron microscopy, systemic and pulmonary inflammation by ELISA (IL-1β, IL-10, and TNF-α) and immunohistochemistry. Clinical parameters were evaluated. We employed a CPB model with three different primings, permitting femoral–femoral assistance with left pulmonary hilum ischemia for IR. Pulmonary endothelium-dependent relaxation to acetylcholine was significantly decreased in the IR-CPB-GF group (11.9 ± 6.2%) compared to the IR-CPB-HA group (52.8 ± 5.2%, p < 0.0001), the IR-CPB-HSL group (57.7 ± 6.3%, p < 0.0001) and the sham group (80.8 ± 6.5%, p < 0.0001). We did not observe any difference between the groups concerning glycocalyx degradation, and systemic or tissular inflammation. The IR-CPB-HSL group needed more vascular filling and developed significantly more pulmonary edema than the IR-CPB-GF group and the IR-CPB-HA group. Using HA as a prime in CPB during Ltx could decrease pulmonary endothelial dysfunction’s IR-mediated effects. No effects of HA were found on inflammation.     

Physiological responses and lactational performances of late-lactation dairy goats under heat stress conditions

Eight Murciano-Granadina dairy goats in late lactation were exposed to different ambient conditions, using metabolic cages in a climatic chamber. The experimental design was a crossover (2 periods of 35 d and 4 goats each) and conditions were (1) thermal neutral (TN; 15 to 20°C day-night) and (2) heat stress (HS; 12-h day at 37°C and 12-h night at 30.5°C). Humidity was maintained at 40% and light-dark was constant (12–12 h). The forage:concentrate ratio was adjusted daily for maintaining similar value in TN and HS goats (70:30). Water was freely available at ambient temperature. Rectal temperature and respiratory rate (0800, 1200 and 1700 h) and milk yield were recorded daily, whereas milk composition, nonesterified fatty acids and haptoglobin in blood were analyzed weekly. At d 25, additional blood samples were taken for analysis of metabolites and indicators of the acid-base balance. Digestibility coefficients and N balance were determined (d 31 to 35) and body weight was recorded (d 35). Compared with TN goats, HS goats experienced greater rectal temperature (+0.58°C), respiratory rate (+48 breaths/min), water intake (+77%) and water evaporation (+207%). Intake of HS goats rapidly declined until d 7 (−40%), partially recovered from d 7 to 19, and steadied thereafter (−14%). No changes in digestibility or N balance were detected. Blood nonesterified fatty acids and haptoglobin peaked at d 7 in HS goats but did not vary thereafter. Although milk yield did not vary by treatment, milk of HS goats contained −12.5% protein and −11.5% casein than TN goats. Panting reduced concentration and pressure of CO₂ in the blood of HS goats, but they were able to maintain their blood pH similar to the TN group by lowering HCO₃⁻ and increasing Cl⁻ concentrations in their blood. In conclusion, HS dairy goats showed dramatic physiological changes during the first week of treatment and partially recovered thereafter. They were able to maintain milk yield by losing body mass, but milk protein content and protein yield were depressed. Further research is needed to assess the response of dairy goats to HS at earlier stages of lactation.     

Topotactic transformation of (T-T’) La1.8Nd0.2CuO4: Synthesis,structure, electrical properties and oxygen diffusion pathways simulation

The starting sample T-La_1.8Nd_0.2CuO₄ (SG: Bmab) has been synthesized by the conventional solid-state reaction at 900 °C. The T′-La_1.8Nd_0.2CuO₄ (SG: I4/mmm) sample has been obtained via a topotactic reduction reaction of T-La_1.8Nd_0.2CuO₄ (SG: Bmab) using CaH₂ (as reductor) followed by an oxidation at 400 °C in air. The temperature of the phase transition (T-T′) has been determined using the differential thermal analysis (DTA) and the temperature-dependent powder X-ray diffraction (TDXD). The crystal structures of the title compounds have been refined by using the Rietveld method and confirmed by the means of the charge distribution model (CHARDI). The electrical properties of the title compounds have been studied by impedance complex spectroscopy between 200 °C and 650 °C. This study shows two slopes in the Arrhenius plot with experimental activation energies 1.033 eV and 1.657 eV which correspond to the reduced phase and the T′ phase respectively. The simulation of oxygen diffusion in structures by using the Bond Valence Site Energy (BVSE) method shows three-dimensional pathways of oxygen diffusion. The calculated activation energies of the T′ and T structure are 1.619 and 2.369 eV, respectively.     

Effects of the position substrate upon the structural behaviour, electrical and optical properties of zinc-oxide films used in solar cells

The preparation by the rf sputtering technique and characterisation of ZnO thin films used as windows in solar cells are described. The electrical behaviour and structural spectra clearly show an important effect of the substrate position with respect to the target. In fact, among all the studied substrate positions, only the samples facing the target are randomly oriented having the mixed orientation (100), (002) and (101). All the others have the c(002)-axis orientation. The scanning electron-microscope observations confirm the X-ray analysis results. The last samples have a resistivity as low as 10⁻³ Ωcm while the randomly-oriented, ones have a large resisivity of about 10²−10³ Ωcm These latter show, in their transmittance characteristics, a slight shift towards higher wavelengths. However, no effect is noticed when the other samples are optically assessed. Consequently, the optical gap is found to be about 3.38 eV for the conducting films and 3.3 eV for the ones having a higher resistivity. The average transmittance in the visible range is around 85–90% for all the samples     

New stable adaptive fuzzy approach to control uncertain nonlinear SISO systems

This paper deals with the synthesis of a new robust adaptive fuzzy control for a class of nonlinear and disturbed single-input single-output (SISO) systems. To attenuate the effect of both of the approximation errors and the external disturbances to a prescribed level, two signals are added to the indirect adaptive fuzzy control law: the first deduced from a fuzzy system allows approximation errors and external disturbances to eliminated; the second signal deduced from the Riccati equation attenuates the effect of the residual errors to a prescribed level. To illustrate the efficiency of the proposed approach, a simulation example is presented.