Interfacial film properties of asphaltenes and resins have been studied by interfacial shear viscosity measurements. The results show that the structure of the asphaltene film at the interface ...between oil and water is changed from two-dimensional to three-dimensional network as the concentration of the asphaltene at the interface increased. The film can be divided into three types namely expanded liquid film, condensed liquid film and solid-like three-dimensional network film. Furthermore, the structures of the interfacial films formed by asphaltene molecules and asphaltene particles are different and the strengths of these films are also different. The adsorption and migration processes of asphaltene molecules and migration process of asphaltene particles at the interface are different.
Carbonaceous aerosols represent an important nexus between air pollution and climate change. Here we collected filter-based PM
samples during summer and autumn in 2015 at one urban and two rural ...sites in Guangzhou, a megacity in southern China, and got the light absorption by black carbon (BC) and brown carbon (BrC) resolved with a DRI Model 2015 multi-wavelength thermal/optical carbon analyzer apart from determining the organic carbon (OC) and elemental carbon (EC) contents. On average BrC contributed 12-15% of the measured absorption at 405nm (LA
) during summer and 15-19% during autumn with significant increase in the LA
by BrC at the rural sites. Carbonaceous aerosols, identified as total carbon (TC), yielded average mass absorption efficiency at 405nm (MAE
) that were approximately 45% higher in autumn than in summer, an 83% increase was noted in the average MAE
for OC, compared with an increase of only 14% in the average MAE
for EC. The LA
by BrC showed a good correlation (p<0.001) with the ratios of secondary OC to PM
in summer. However, this correlation was poor (p>0.1) in autumn, implying greater secondary formation of BrC in summer. The correlations between levoglucosan (a marker of biomass burning) and the LA
by BrC were significant during autumn but insignificant during summer, suggesting that the observed increase in the LA
by BrC during autumn in rural areas was largely related to biomass burning. The measurements of light absorption at 550nm presented in this study indicated that the use of the IMPROVE algorithm with an MAE value of 10m
/g for EC to approximate light absorption may be appropriate in areas not strongly affected by fossil fuel combustion; however, this practice would underestimate the absorption of light by PM
in areas heavily affected by vehicle exhausts and coal burning.
In order to reduce the energy consumption and working procedure for manufacturing thin-walled titanium alloy components, a hot stretch-creep forming (SCF) technique via resistance heating is proposed ...to form the hard-to-form material. Firstly, the principle of hot SCF was introduced that the technique can manufacture titanium alloy components precisely because the residual stress relaxes in the material during the dwelling time. Secondly, the hot SCF equipment via resistance heating was developed, which makes use of electrical current for heating the titanium materials to improve their ductility. Then based on a set of optimized process parameters, including forming temperature, stretch velocity, post stretch percentage and dwelling time, a comparative experment of single curvature Ti-6Al-4V alloy sheet components was conducted via this innovative technology to examine the hot SCF equipments and the effect of creep forming. Results show that the component precision of the hot SCF is more precise than that of the hot stretch forming (SF) due to the creep in the stress relaxation period. Comparing to the as-received material, the yield strength of the material suffered hot SF decreases a little; while the strength suffered hot SCF increases a little. This novel technique shows a promising future to manufacture titanium sheet or profile components precisely as a feasible and cost-effective way.
The influence of HPAM on interfacial properties and stability of the emulsions formed by formation water and asphaltene, resin, and crude model oils from Gudong crude oil was investigated by ...measurement of interfacial shear viscosity, interfacial tension, Zeta potential, and emulsion stability. HPAM may be adsorbed at the interface between the model oils and water, but the interfacial tension is not decreased. With increasing HPAM concentration, the interfacial shear viscosity, Zeta potential, and emulsion stability of the model oils system is increased. The o/w emulsion stability was enhanced with the polymer by steric and electrostatic stabilization.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
HSP40s are a subfamily of heat shock proteins (HSPs) and play important roles in regulation of cell proliferation, survival and apoptosis by serving as chaperones for HSP70s. Up to date hundreds of ...HSP40 proteins derived from various species ranging from
Escherichia coli to homo sapiens have been identified. Here we report the cloning and characterization of a novel human type C DnaJ homologue, HDJC9, containing a typical N-terminal J domain. HDJC9 is upregulated at both mRNA and protein levels upon various stress and mitogenic stimulations. HDJC9 is mainly localized in cell nuclei under normal culture conditions while it is transported into cytoplasm and plasma membrane upon heat shock stress through a non-classical and lipid-dependent pathway. HDJC9 can interact with HSP70s and activate the ATPase activity of HSP70s, both of which are dependent on the J domain. Our data suggest that HDJC9 is a novel cochaperone for HSP70s.
This paper proposes a push-pull dual active bridge (DAB) DC transformer (DCX) based on dual coupled inductors, which reduces the number of required magnetic components and achieves a symmetric ...structure. The zero-voltage-switching (ZVS) model considering switch junction capacitor charging and the inductor is established, and parameter design for achieving ZVS over the full load range under small voltage fluctuations is introduced.
Previously, bis(α-furancarboxylato)oxovanadium(IV)(BFOV) exhibited potent hypoglycemic activity in diabetic animals. We evaluated the effects of BFOV on lipolysis in isolated rat adipocytes and lipid ...metabolism in fat-fed/streptozotocin (STZ)-induced diabetic rats, an animal model of type 2 diabetes.
Antilipolytic action of BFOV was investigated by observing free fatty acids (FFA) release in isolated rat adipocytes treated with epinephrine and forskolin. Diabetic rats were induced by high-fat feeding plus STZ injection (25 mg/kg, i.p.). The rats were randomly divided into non-diabetic, diabetic, diabetic-BFOV (0.02, 0.06 and 0.2 mmol/kg) and diabetic-vanadyl sulfate group. All substances were given intragastrically to rats for 4 weeks. The concentrations of blood glucose, serum lipid and leptin, as well as body weight and food intake were determined.
FFA release from adipocytes treated with epinephrine was markedly inhibited by BFOV and vanadyl sulfate, with the IC
50 values of 0.30
±0.20 and 0.46
±
0.26 mmol/l, respectively, but not by insulin. Whereas, the inhibition of vanadyl compounds on FFA release triggered by forskolin in adipocytes were not observed. BFOV dose-dependently reduced serum triglycerides and FFA concentrations when compared with untreated diabetic rats (
P
<
0.05), while it did not influence cholesterol concentrations, similar to vanadyl sulfate. Serum leptin concentration was also decreased both in the BFOV- and vanadyl sulfate-treated diabetic group (
P
<
0.05). Moreover, BFOV markedly reduced blood glucose concentration and food intake (
P
<
0.05), but it did not change the body weight of diabetic rats.
BFOV has an antilipolytic action in adipocytes mediated by catecholamines. This action was distinct from that of insulin and also not related to inhibiting the activity of adenylate cyclase. In vivo, BFOV could improve dyslipidemia and leptin sensitivity in fat-fed/STZ-diabetic rats.
Rab GTPases are Ras-like small molecular weight GTP binding proteins that are involved in various steps along the exocytic and endocytic pathways. Here we report that Rab39, a novel Rab protein, is a ...Golgi-associated protein involved in endocytosis of HeLa cells. Full-length cDNA of Rab39 contains 1251
bp with an open reading frame (ORF) of 636
bp, which is predicted to encode a 211 aa protein. By blast analysis of Rab39 cDNA and protein sequence with homologues, we find that Rab39 may be a short variant of Rab34. Rab39 contains conserved motifs involved in phosphate/guanosine binding and a microbody C-terminal targeting signal. RT-PCR analysis indicates that Rab39 is mainly detected in epithelial cell lines, and Northern blot analysis shows that Rab39 is expressed ubiquitously in human tissues. By using FITC-BSA as an endocytic tracer, we show that Rab39 can facilitate endocytosis in HeLa cells when expressed either transiently or stably. Confocal microscopy examination of Rab39 subcellular localization suggests that Rab39 is associated with Golgi-associated organelles. Our findings demonstrate that Rab39 is a novel Rab GTPase involved in cellular endocytosis.
The presence of radio-frequency interference (RFI) contaminates data collected by synthetic aperture interferometric radiometers (SAIRs). The performances of current RFI detection methods are limited ...due to insufficient exploration of RFI characteristics. This paper proposes a new RFI source detection method based on a convolutional neural network (CNN) that exploits side-lobe characteristics of the array factor of SAIR systems. Based on the common characteristic observed in RFI images, namely the presence of hexagonal tailings extended from a local peak of the RFI source, this method incorporates the hexagonal tailing feature into the detection scope, thereby expanding the capability to identify RFI. By including the hexagonal tailing feature, the method enhances the comprehensiveness and accuracy of RFI detection. This inclusion leads to a more comprehensive and accurate detection range for RFI sources. Results using real SMOS satellite data demonstrate that the proposed method has improved detection performance compared with traditional approaches that are commonly used in RFI detection tasks for SAIRs.
