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排序方式: 共有250条查询结果,搜索用时 312 毫秒
81.
Mina Kargozari Sohrab Moini Afshin Akhondzadeh Basti Zahra Emam-Djomeh Hassan Gandomi Isabel Revilla Martin Mehran Ghasemlou Ángel A. Carbonell-Barrachina 《Meat science》2014
The effect of adding autochthonous starter cultures isolated from Siahmazgi cheese, on the physicochemical parameters and microbial counts of sucuk was investigated during the ripening period. SPME–GC/MS was used in volatile compound analysis and a trained group of panelists carried out sensory analysis of the final product. After preliminary screening, three strains of Lactobacillus plantarum, which possess desirable technological properties, were used to prepare three starter cultures: LBP7, LBP10 and LBP14. The addition of LBP7 and LBP14 starter cultures had a significant effect (P < 0.05) on lightness, leading to higher L values compared to control sausages during the ripening period. Both LBP7 and LBP14 sausages showed higher counts of lactic acid bacteria, lower growth of Enterobacteriaceae and Gram-positive catalase-positive cocci and greatly lowered the pH value compared to control sausages throughout the ripening process. At the end of the ripening process, lactic acid bacteria counts were affected (P < 0.05) by the addition of starter culture since higher counts were observed in sausages prepared with LBP7 (9.14 log CFU/g) and LBP14 (8.96 log CFU/g) batches. The decrease of water activity during the ripening of sausages was not affected by the various starters. The texture profiles of all sausages were similar except for LBP10, which showed lower hardness and gumminess during ripening. Under the conditions of the study, volatile compounds were mainly from spices, and no marked differences were found among inoculated sausages. However, sensory evaluation revealed that most of the sensory attributes were scored higher for inoculated sausages than for the control ones. Therefore, LBP7 and LBP14 could be promising candidates for inclusion as starter cultures for the manufacture of sucuk. 相似文献
82.
A modified version of Kale's heat transfer correlation for viscoelastic turbulent pipe flows in terms of drag reduction ratio and Weissenberg number is presented. The proposed correlation is validated with experimental data of Kwack and this study for Separan AP-273 and Polyox WSR-301 with concentrations ranging from 10 to 1000 ppm in thermally fully developed flow in pipes with diameters of 1·11 and 1·88 cm I.D. under constant wall heat flux. The agreement between the experimental data and the predictions is within a maximum deviation of 30%. 相似文献
83.
In modern structural constructions, concrete-filled steel tubular (CFT) columns have gradually become a central element in structural systems like tall buildings, bridges and so forth. The effective parameters on load carrying capacity of CFT columns are the bond between the steel and internal concrete, local buckling strength of steel tube, creep of concrete and loading conditions of column at connections. Considering these effective parameters, a novel section is suggested which can be used for columns of tall buildings and bridges with large spans. The main characteristic of the suggested steel section is internal longitudinal symmetric stiffeners. In the present study, a comparative investigation into the behavior of this novel section (with circular and octagonal shapes) and the most common used sections of CFT columns has been carried out under axial and cyclic loading. Having verified the finite element modeling, several different analyses have been undertaken. The results of the analyses clearly exhibit the increase in strength and ductility of the suggested novel section under axial and cyclic loading and therefore, its application is recommended in construction practice. 相似文献
84.
Mohammad Hossein Ahmadi Afshin Tatar Parinaz Seifaddini Mahyar Ghazvini Roghayeh Ghasempour Mikhail A. Sheremet 《Numerical Heat Transfer, Part A: Applications》2013,63(6):1301-1322
AbstractThermal conductivity and dynamic viscosity play key role in heat transfer capacity of nanofluids. In the present study, thermal conductivity and dynamic viscosity of Fe2O3/water are modeled by applying various artificial neural network algorithms. The applied algorithms are MLP, GA-RBF, LSSVM, and CHPSO ANFIS algorithms. The data for modeling procedure are extracted from several experimental studies. Obtained results by the different algorithms are compared and it was concluded that the highest R-squared values belonged to GA-RBF algorithm which were equal to 0.9962 and 0.9982 for thermal conductivity ratio and dynamic viscosity, respectively. 相似文献
85.
Richard A. Brown Jon E. Evans Nathan A. Smith Afshin Tarat Daniel R. Jones Chris J. Barnett Thierry G. G. Maffeis 《Journal of Materials Science》2013,48(14):4908-4913
If the silicon industry is to successfully integrate ZnO nanowires (NWs) into existing devices to fully utilise the piezoelectric or optical properties of ZnO NWs, then a detailed understanding of the effect of metal interconnects on the morphology of the NWs during growth needs to be obtained. In this study, ZnO NWs were hydrothermally grown at 90 °C on Au, Ni and a Si substrate control to mimic the typical surfaces of a MetalMUMPs MEMS chip. The growth rate was significantly affected by the metal film below the ZnO seed layer, which was mainly attributed to changes in the roughness and grain size of the seed layer deposited, with the growth rate decreasing with increasing roughness. The growth rate on Si and Au surfaces also increased when isolated from the Ni samples, suggesting that Ni cations released in the solution could also inhibit growth by electrostatically attaching to the NWs surface and acting as a barrier to the incorporation of zinc ions. Furthermore, photoluminescence studies show the addition of metal layers to the substrate reduces the optical quality of the produced ZnO NWs. 相似文献
86.
Since the early 90s the lean manufacturing system has become popular for industries. Following that, agility in production has received great attention. Exploration of any new techniques for bringing these strategic concepts closer to each other has become advantageous for pioneer industries. Accordingly, the new paradigm of individual control, with the progressive interpretation of ‘autonomy’, can contribute to the objectives of the lean and the agile concepts in production and logistics environments. To explain the contributions of the addressed thesis the study describes it in theoretical and empirical forms. The compatibility of these leading-edge concepts to realise the notion of continuous material flow through supply chains and production floors is examined. Simultaneously, the factors of efficiency, effectiveness and responsiveness are considered. This study covers a quick review on the lean and agility techniques and highlights some specific contributions of autonomous control to their targets. The purpose is to clarify the role of the autonomy in compliance with the lean and agility goals. This is inspected through development of a discrete event simulation with some scenarios in a supply network. 相似文献
87.
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89.
Photocatalytic oxidative paints (e.g., a paint containing nano‐TiO2) are used to break down volatile organic compounds to CO2 by photooxidation reactions. In this research, a photocatalytic oxidative pseudo‐paint was made with acrylic–styrene copolymer latex, TiO2 pigment, calcium carbonate extender, and TiO2 nanoparticles as a photocatalyst. To investigate the effects of the pigment, extender, and nanoparticles on the mechanical properties of the samples and their relationship to their photocatalytic activity, different contents of the particles were dispersed in the paint formulation. The tensile strengths (TSs) of the samples were measured as the mechanical properties. The samples were characterized by scanning electron microscopy analysis. We found that up to 3% nano‐TiO2 enhanced the mechanical properties of the pigmented resin, whereas beyond this, TS decreased. In samples containing 3% nanoparticles, the incorporation of 15% TiO2 pigment caused optimized mechanical properties, and beyond that, TS decreased because of particle agglomeration. In the absence of nanoparticles, the samples showed improvements in the mechanical properties with up to a 40% loading of pigment. The results reveal that the samples containing nano‐TiO2 and pigment showed the same trend for the mechanical and photocatalytic properties before the critical pigment volume concentration (CPVC). However, when the extender was incorporated or TiO2 particles were loaded beyond CPVC, the mechanical and photocatalytic properties correlation was compromised, and they were not directly correlated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42885. 相似文献
90.
Zareian M Ebrahimpour A Bakar FA Mohamed AK Forghani B Ab-Kadir MS Saari N 《International journal of molecular sciences》2012,13(5):5482-5497
l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound. 相似文献