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991.
Hye‐Yeon Song Wan‐Shin Jo Nak‐Bum Song Sea C. Min Kyung Bin Song 《Journal of food science》2013,78(6):C817-C822
Fresh‐cut apples are easily susceptible to browning and microbial spoilage. In this study, an edible coating prepared from Aloe vera gel containing antibrowning solution was applied to preserve the quality of fresh‐cut apples during storage. Fresh‐cut apples were treated with both an Aloe vera gel and an Aloe vera gel containing 0.5% cysteine and then stored at 4 °C for 16 d. The color, firmness, weight loss, soluble solid content, titratable acidity, microbial analysis, and sensory evaluation were analyzed during storage. Fresh‐cut apples coated with the Aloe vera gel showed delayed browning and reduced weight loss and softening compared to the control. The Aloe vera gel coating was also effective in reducing the populations of the total aerobic bacteria and yeast and molds. In particular, Aloe vera gel containing 0.5% cysteine was most effective in delaying browning and the reduction of microbial populations among the treatments. These results suggest that an Aloe vera gel coating can be used for maintaining the quality of fresh‐cut apples. 相似文献
992.
Rogério M. ribas Carlos H. Ataíde João J. R. Damasceno 《Particulate Science and Technology》2013,31(2):174-180
Brazil is the world's second largest producer of dicalcium phosphate, which is the main source of dietary phosphorus that complements the mineral salts contained in cattle, pig and poultry feed. The natural sources of dicalcium phosphate are not homogeneous and a final product classification process is required to ensure compliance with the physical specifications of the product shipped to clients. The objective of this work is to study a classification system for dicalcium phosphate using fluidization. A statistical analysis of the main experimental results using factorial planning and multiple regressions yielded parameters for the individual variables and the interactions among them. The model is validated by means of eight experiments performed in a pilot fluidized bed. The separation and recovery efficiencies obtained with the pilot system demonstrate the excellent technological application of the proposed dicalcium phosphate classification. 相似文献
993.
Aging behavior of Mg-3.6Y-0.5Zr and Mg-2.TNd-0.5Zr alloys was investigated by microhardness measurement and transmission electron microscopy.In the case of Mg-Y-Zr alloy,the presence ofβ″phase,a major strength- ener,having base centered orthorhombic structure with its lattice constants of a-(β″)=0.64 nm,b-(β″)=2.22 nm, and c-(β″)=0.52 nm was identified.In the case of Mg-Nd-Zr alloy aged at 250℃,the presence ofβ″andβ′phases was identified.The crystal structure ofβ″phase was found to be DO-(19) and its orientation relationships with Mg matrix were [0001]-(β″)//[0001]-(Mg) and [01(?)0]-(β″)//[01(?)0]-(Mg).Theβ′phase had face centered cubic structure and its orientation relationships with Mg matrix were [011]-(β′)//[0001]-(Mg) and [(?)1(?)]β′//[(?)110])-(Mg). The Mg-2.TNd-0.5Zr alloy showed higher hardness compared with Mg-3.6Y-0.5Zr alloy. 相似文献
994.
João P. Lopes Silvana S.S. Cardoso Alírio E. Rodrigues 《American Institute of Chemical Engineers》2012,58(6):1880-1892
A new approximate solution which bridges the gap between the classical theories of Graetz and Lévêque for heat/mass transfer in channel flow is presented. The results include expressions, uniformly valid in the axial direction, for the mixing‐cup concentration (or temperature) profile 〈c〉 when transport towards the wall is slow (Dirichlet limit), and for the Sherwood number Sh when the wall flux can be considered uniform (Neumann limit). The technique employed provides insight into the mathematical structure of both quantities 〈c〉 (or conversion XR) and Sh identifying explicitly the contributions from fully developed and developing behaviors, while maintaining accuracy in the transition region. Criteria to bound the different convection‐diffusion regimes are suggested, which critically systematize previous results. These results are important for model selection in the design and simulation, among others, of heat exchangers and wall‐coated microreactors where fast heterogeneous reactions occur. © 2011 American Institute of Chemical Engineers AIChE J, 58: 1880–1892, 2012 相似文献
995.
Joachim Schick Philippe Caullet Jean-Louis Paillaud Jo?l Patarin Stéphanie Freitag Claire Mangold-Callarec 《Journal of Porous Materials》2012,19(4):405-414
The phosphate adsorption kinetics are determined in batch-wise (noted B) and fixed-bed column (noted C) experiments on a Surfactant-Modified Zeolite (SMZ) and various Ca-zeolites. The influence of phosphate concentration (0.08 or 0.8?mmol/L), presence of NO3 ?, HCO3 ?, SO4 2? and Cl? competing anions (individual concentration?=?0.8?meq/L) and flow rate Q (1?C30?mL/min) is studied. Preliminary experiments lead to the selection of the most efficient Ca-LTA and SMZ samples for the subsequent studies. In B experiments, the nature of the used system does not influence the equilibrium removal rate R (??80%) but affects the adsorption kinetics. The equilibrium times are shorter on SMZ than on Ca-LTA, increasing with the phosphate concentration and the presence of competing anions, respectively in the ~0.5?C6 or ~3?C24?h ranges. In C experiments, the phosphate uptake performances on SMZ are higher than in the corresponding B experiments, with in particular higher final q/qm values. The deterioration of the performances on SMZ in presence of competing anions or with increase of Q is due to the effect of the slow phosphate ion-exchange kinetics and the short used contact time. For similar reasons, sorption on Ca-LTA is lower than on SMZ. For instance, with a 0.8?mmol/L phosphate concentration and a 10?mL/min flow rate, the time-decreasing R values become close to 50 and 10% after filtration of 10 bed-volumes respectively in presence of SMZ and Ca-LTA. Globally, SMZ is clearly more efficient than Ca-LTA, being furthermore a versatile and easily regenerable material. 相似文献
996.
Soline Boyer-Richard Cédric Robert Lionel Gérard Jan-Peter Richters Régis André Jo?l Bleuse Henri Mariette Jacky Even Jean-Marc Jancu 《Nanoscale research letters》2012,7(1):543
We perform accurate tight binding simulations to design type-II short-period CdSe/ZnTe superlattices suited for photovoltaic applications. Absorption calculations demonstrate a very good agreement with optical results with threshold strongly depending on the chemical species near interfaces. 相似文献
997.
When using the signal from the Global Positioning System (GPS) for precise estimation of a vehicle’s heading, the main challenge is finding the integer ambiguities in the carrier phase measurements. If the distance between the receiver’s antennas, also known as baseline length, is used in the process of solving that challenge, the resulting solution’s stability and precision can be enhanced, particularly for single-frequency L1 receivers. This paper presents a study of the overall influence of this baseline length in the precision and accuracy of the heading estimation, using raw measurements from two GPS single-frequency L1 receivers. Conclusions are presented based on the results from field trials for baselines up to 8 m. 相似文献
998.
Leonor Pereira Paula Martins-Lopes Cláudia Batista Geni C. Zanol Pedro Clímaco Jo?o Braz?o José E. Eiras-Dias Henrique Guedes-Pinto 《Food Analytical Methods》2012,5(6):1252-1259
Wine quality and market value greatly depend on the grapevine varietal composition, which may be characteristic of specific regions. In order to defend the distinct regions, Denominations of Origin were defined to protect against fraudulent practices. In this study, we evaluated the efficiency of two microsatellite-based systems (microsatellite (SSR) and intermicrosatellite (ISSR)) for must varietal composition determination and their potential role in certification purposes. Eleven Vitis vinifera L. varieties from leaf and monovarietal must DNA samples were screened with six SSR and 14 ISSR primers to discriminate polymorphisms. Principal coordinates analysis was performed with DCENTER on the resultant data using unweighted pair group mathematical average and revealed that ISSRs markers were not suitable for certification procedures, whereas nuclear SSR markers presented a complete correspondence between leaf and must samples, demonstrating that they were adequate for traceability purposes. 相似文献
999.
Rehabilitation/restoration systems involving bonded-in rods represent an efficient alternative method for the repair and/or reinforcement of structural timber members. However, in spite of their advantages, their use is still restrained by the lack of knowledge about their long-term performance. In order to correct this situation it is necessary to gain a greater understanding of their durability, creep and fatigue behaviour. However, reliable and realistic accelerated ageing tests do not yet exist, and the application of the existing European or American standards to epoxy bonded products are much too penalising, since they merely impose severe conditions that are not verified in service although these may be suitable for other adhesives. To address these concerns a test procedure to assess long-term behaviour of bonded-in rod connections was developed with the aim of providing a simple method for the selection of candidate repair system materials for specific applications. The data collected so far using the realistic performance assessment test (RPAT) appears to predict correctly the end-use performance for different adhesives as well as for different timbers. 相似文献
1000.