Shape control and stability of multicore millimetre-sized capsules using a combined monoaxial dispersion electrospraying–ionotropic gelation technique

Multicore millimetre-sized fish oil-loaded alginate capsules were developed using a combined monoaxial dispersion electrospraying–ionotropic gelation technique and their stability was explored. By adjusting the preparation parameters, the capsule shapes could be irregular, spherical with a short-tail, spherical, fusiform, and fusiform with a long-tail. The continuous phase of the millimetre-sized capsules consisted of hydrophilic alginate calcium and water. Moreover, the water content increased from 17% to 69% with increased alginate concentration (2.5–30 mg mL⁻¹). The capsules prepared with alginate concentration of 10 mg mL⁻¹ or 20 mg mL⁻¹ show a similar loading ratio (about 5–8%) of fish oil during storage. Headspace solid-phase microextraction–gas chromatography mass spectroscopy (HS-SPME-GC-MS) results confirmed the capsules masked the fishy odour of fish oil. Moreover, fish oil slowly migrated from the inside to the outside of the capsules. This work presented a simple method to prepare multicore millimetre-sized capsules with controlled shapes and a basic understanding of the effect of encapsulation using alginate to mask the fish oil odour.     

突发事件下三级供应链联合契约协调

突发事件会对基于随机需求的市场产生巨大的波动，造成供应链系统的不稳定，打破原有的协调。为此，构建了突发事件下供应链协调的应对策略，建立了收益共享-两部收费（RS-TT）联合契约。研究表明：突发事件前，联合契约可以实现供应链的协调；突发事件后，原契约不会起协调作用。因此，对原契约及契约参数进行改进，并通过算例分析验证了改进后的契约可以使供应链达到全局最优的状态且具有抗突发事件性。     

Secrecy Outage Performance Analysis of DF Cognitive Relay Network With Co-channel Interference

Wireless Personal Communications - In this paper, we investigate the secrecy outage performance of the decode-and-forward cognitive relay network with the existence of the co-channel interference,...     

Mathematical programming-based approaches for multi-facility glass container production planning

This paper introduces a mathematical model (together with a relaxed version) and solution approaches for the multi-facility glass container production planning (MF-GCPP) problem. The glass container industry covers the production of glass packaging (bottle and jars), where a glass paste is continuously distributed to a set of parallel molding machines that shape the finished products. Each facility has a set of furnaces where the glass paste is produced in order to meet the demand. Furthermore, final product transfers between facilities are allowed to face demand. The objectives include meeting demand, minimizing inventory investment and transportation costs, as well as maximizing the utilization of the production facilities. A novel mixed integer programming formulation is introduced for MF-GCPP and solution approaches applying heuristics and meta-heuristics based on mathematical programming are developed. A multi-population genetic algorithm defines for each individual the partitions of the search space to be optimized by the MIP solver. A variant of the fix-and-optimize improvement heuristic is also introduced. The computational tests are carried on instances generated from real-world data provided by a glass container company. The results show that the proposed methods return competitive results for smaller instances, comparing to an exact solver method. In larger instances, the proposed methods are able to return high quality solutions.     

Local sparsity preserving projection and its application to biometric recognition

Multimedia Tools and Applications - Dimensionality reduction techniques based on sparse representation have drawn great attentions recently and they are successfully applied to biometric...     

Effect of sputter deposited Zn precursor film thickness and annealing time on the properties of Cu2ZnSnS4 thin films deposited by sequential reactive sputtering of metal targets

Cu₂ZnSnS₄ (CZTS) is made of earth abundant elements and also have suitable optical properties for solar cell applications. But, in phase diagram, CZTS exists in a narrow range of temperature and composition. Therefore, optimizing the elemental composition and annealing time is very important for obtaining phase pure CZTS. In this study, the effects of elemental composition and short annealing time on the structural and optical properties of reactively sputtered CZTS thin films are reported. Thin films were deposited by reactive sputtering of Cu: Sn (60:40 wt%), Sn and Zn targets sequentially in the presence of H₂S at room temperature. Amount of Zn precursor was varied by changing the sputter time for Zn. The films were rapidly annealed in inert atmosphere for varying time. The band gap of sample changed with change in the composition as well as annealing time. Sample with higher Zn content showed better crystallinity. With increase in the annealing time the crystallinity of samples improved. Sample annealed for 12 min at 550 °C was phase pure. Obtaining good quality film even for very short anneal time is the novelty of reactive sputtering method as all the elements are already mixed and short annealing is required only for crystal growth. Through detailed experiments, the optimum composition and annealing time required for the growth of phase pure CZTS has been established.     

Effects of europium content on structures and luminescence properties of tunable light-emitting silicon oxynitride phosphors

A series of europium (Eu)-activated silicon oxynitride samples with various atomic ratios x of Eu/Si from 0.001 to 0.057 was prepared by employing the polymer-derived method with polycarbosilane and Eu acetylacetonate as starting materials. Chemical compositions, phase structures, morphologies, and luminescence properties of the samples were investigated. It was found that all samples contained a dominated β-Si₃N₄-like phase, and had emission spectra with two peaks. The emission colors of the samples under near-UV excitation were tunable from blue to white, and then to yellow as x in the samples increased from 0.009 to 0.030, and then to 0.057. The white emitting sample with x = 0.030 was in the β-Si₃N₄-like single phase with its particles being single-crystallized in two space groups P6₃ and P6₃/m. Eu²⁺ ions located at interstitial sites of lattices and were coordinated by nine N/O atoms with different average bond lengths for the two space groups. A discussion was given to attribute the difference in the lattice environments for Eu²⁺ ions in two space groups P6₃ and P6₃/m to the appearance of two emission peaks at the lower (597 nm) and higher (454 nm) energy levels for the sample with x = 0.030.     

Effects of freeze-thaw cycles of Pacific white shrimp (Litopenaeus vannamei) subjected to radio frequency tempering on melanosis and quality

This study was conducted to investigate the effects of different tempering methods and freeze-thaw cycles on melanosis and quality parameters of pacific white shrimp. Frozen pacific white shrimps tempered with radio frequency tempering (RFT) were compared to that in water tempering (WT) and refrigerator tempering (RT) in terms of temper loss, total volatile base nitrogen (TVBN), polyphenol oxidase (PPO) activity, melanosis, total sulfhydryl contents, differential scanning calorimetry (DSC), and texture properties after 0, 1, 3, 5 freeze-thaw cycles. Results showed that crushed ice was effective as an effective surrounding medium for six layers of frozen shrimp reaching −2 °C within 6 min in RFT. For quality attributes, the temper loss of samples tempered with radio frequency is lower than that of RT and WT after all freeze-thaw cycles, and RFT resulted in the lowest TVBN value (9.17 mgN/100 g) of shrimps after the 5th freeze-thaw cycle. The PPO activity and melanosis of samples increased as the number of freeze-thaw cycles increased, and RFT effectively inhibited the development of melanosis. After the 3rd freeze-thaw cycle, the enthalpy change (△H) and the sulfhydryl content (0.16 mmol/gprot) of radio frequency tempered samples was significantly higher (p < 0.05) than that of WT and RT. RFT retained the hardness and chewiness of shrimp samples in all freeze-thaw cycles. Therefore, RFT effectively inhibited melanosis and reduce protein oxidation in Pacific white shrimp during freeze-thaw cycles with its fast and uniform heating characteristics.     

Investigation of thermal and magnetic behaviour of mixed valence iron hydroxyphosphate from Fe3(PO4)2(OH)2 lipscombite systems

Iron hydroxyphosphates are promising candidates for applications as cathode materials for Li-ion batteries, for example and present low production cost and reduced toxicity. In this work, a new fast method is proposed for the synthesis of mixed valence iron hydroxyphosphate from Fe₃(PO₄)₂(OH)₂ lipscombite systems. The as-obtained products were characterized by X-ray diffraction, FT-IR spectroscopy, scanning electron microscopy, and magnetic measurements were carried out. Thermal treatment performed at 300 °C and 500 °C for 4 h indicate the formation of other lipscombite phases in accordance with thermogravimetric analysis where two weight loss steps were observed at ∼200 °C and ∼450 °C. A complex magnetic behaviour is observed with antiferromagnetic interactions at T_N ∼140 K for the pristine lipscombite Fe₃(PO₄)₂(OH)₂ compound related to the strong magnetic interactions in the 3D crystal structure with small values for Fe-Fe distances and super-exchange contribution through PO₄ tetrahedra.