144 research outputs found
Comparison of emulsifying properties of milk fat globule membrane materials isolated from different dairy by-products
Emulsifying properties of milk fat globule membrane (MFGM) materials isolated from reconstituted buttermilk (BM; i.e., BM-MFGM) and BM whey (i.e., whey-MFGM), individually or in mixtures with BM powder (BMP) were compared with those of a commercial dairy ingredient (Lacprodan PL-20; Aria Foods Ingredients Group P/S, Viby, Denmark), a material rich in milk polar lipids and proteins. The particle size distribution, viscosity, interfacial protein, and polar lipids load of oil-in-water emulsions prepared using soybean oil were examined. Pronounced droplet aggregation was observed with emulsions stabilized with whey-MFGM or with a mixture of whey-MFGM and BMP. No aggregation was observed for emulsions stabilized with BM-MFGM, Lacprodan PL-20, or a mixture of BM-MFGM and BMP. The surface protein load and polar lipids load were lowest in emulsions with BM-MFGM. The highest protein load and polar lipids load were observed for emulsions made with a mixture of whey-MFGM and BMP. The differences in composition of MFGM materials, such as in whey proteins, caseins, MFGM-specific proteins, polar lipids, minerals, and especially their possible interactions determine their emulsifying properties
VỀ CHỈ SỐ CHÍNH QUY CASTELNUOVO-MUMFORD CỦA VÀNH TỌA ĐỘ CỦA TẬP n + 3 ĐIỂM BÉO KHÔNG SUY BIẾN TRONG KHÔNG GIAN XẠ ẢNH Pn
In this paper we calculate the Castelnuovo-Mumford regularity index of the coordinate ring of n + 3 a set of non-degenerate fat points in Pn for almost all of cases.Trong bài báo này chúng tôi tính chỉ số chính quy Castelnuovo-Mumford của vành tọa độ của tập n + 3 điểm béo không suy biến trong Pn cho hầu hết các trường hợp của tập điểm
Chemical diversity of the Melaleuca cajuputi leaf oils from six locations in southern Vietnam
Melaleuca cajuputi Powell, a member of Myrtaceae family, is a popular and valuable plant in Vietnam, especially in the southern region. In this study, gas chromatography-mass spectrometry was used to determine the diversity in chemical composition of M. cajuputi leaf oil collected from six sites in the South of Vietnam. A total of sixty compounds has been identified from the essential oils of M. cajuputi leaf, such as α-thujene, α-pinene, benzaldehyde, β-pinene, β-myrcene, α-phellandrene, α-terpinene, benzene, 1-methyl-2-(1- methylethyl), 1,8-cineole, γ-terpinene, etc. Among those, five compounds were found in all six samples including α-thujene, α-pinene, α-phellandrene, γ-terpinene, and α-terpinolene, whereas other compounds were only present in some samples with varying amounts. Principal Component Analysis (PCA) has been performed to examine the similarities in the composition of leaf oils among the collection sites using XLSTAT software. The results from PCA suggested that six samples of leaf oil could be classified into 2 chemotypes with different chemical constituents. Note that 1,8-cineole only occurred in chemotype group 1 whereas it was omitted in chemotype group 2. This finding explains the diversity of bioactivity of M. cajuputi collected from different regions and provide more information on M. cajuputi for further application in medicine and food industry
Stress singularities and the formation of birefringent strands in stagnation flows of dilute polymer solutions
We consider stagnation point flow away from a wall for creeping flow of
dilute polymer solutions. For a simplified flow geometry, we explicitly show
that a narrow region of strong polymer extension (a birefringent strand) forms
downstream of the stagnation point in the UCM model and extensions, like the
FENE-P model. These strands are associated with the existence of an essential
singularity in the stresses, which is induced by the fact that the stagnation
point makes the convective term in the constitutive equation into a singular
point. We argue that the mechanism is quite general, so that all flows that
have a separatrix going away from the stagnation point exhibit some singular
behaviour. These findings are the counterpart for wall stagnation points of the
recently discovered singular behaviour in purely elongational flows: the
underlying mechanism is the same while the different nature of the singular
stress behaviour reflects the different form of the velocity expansion close to
the stagnation point.Comment: 15 pages, 6 figure
Corona based air-flow using parallel discharge electrodes
A novel air-flow generator based on the effect of ion wind has been developed by the simultaneous generation of both positive and negative ions using two electrodes of opposite polarity placed in parallel. Unlike the conventional unipolar-generators, this bipolar configuration creates an ion wind, which moves away from both electrodes and yields a very low net charge on the device. The electro-hydrodynamic behavior of air-flow has been experimentally and numerically studied. The velocity of ion wind reaches values up to 1.25 m/s using low discharge current 5 mu-A with the kinetic conversion efficiency of 0.65% and the released net charge of �30 fA, 8 orders of magnitude smaller compared with the discharge current. Due to easy scalability and low net charge, the present configuration is beneficial to applications with space constraints and/or where neutralized discharge process is required, such as inertial fluidic units, circulatory flow heat transfer, electrospun polymer nanofiber to overcome the intrinsically instability of the process, or the formation of low charged aerosol
A circulatory ionic wind for inertial sensing application
A novel gyroscope using circulatory electro-hydrodynamics flow in a confined space is presented for the first time. The configuration of the new gyroscope includes three point-ring corona discharge actuators that generate ion flows in three separated sub-channels. The three ion flows then merge together when going through a nozzle of the main chamber entrance and create a jet flow. In the new configuration, the residual charge of ion wind flow is removed by a master-ring electrode located at one end of the main chamber. Under the effect of the angular speed of gyroscope, the jet flow is deflected and this deflection is sensed using hotwires. The results, which are consistently acquired by both the numerical simulation and experiment on our prototypes, demonstrate the repeatability and stability of the new approach. Since the ion wind can be generated by a minimum power, the present configuration-based device does not require any vibrating component. Thus, the device is robust, cost, and energy-effective
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