石膏板干墙系统与建筑防火

<正>轻钢龙骨石膏板隔墙和吊顶系统,统称石膏板干墙系统,凭借着其安装快速简便、可灵活造型、轻质、美观等特性已成为室内装修不可缺少的系统。其实,干墙系统除了这些优秀的装饰特性外还具备很强的建筑构件必备的保温隔热、隔声、吸声和防火等功能。     

Wild Brazilian Mustard (Brassica juncea L.) Seed Oil Methyl Esters as Biodiesel Fuel

Wild mustard (Brassica juncea L.) oil is evaluated as a feedstock for biodiesel production. Biodiesel was obtained in 94 wt.% yield by a standard transesterification procedure with methanol and sodium methoxide catalyst. Wild mustard oil had a high content of erucic (13(Z)-docosenoic; 45.7 wt.%) acid, with linoleic (9(Z),12(Z)-octadecadienoic; 14.2 wt.%) and linolenic (9(Z),12(Z),15(Z)-octadecatrienoic; 13.0 wt.%) acids comprising most of the remaining fatty acid profile. The cetane number, kinematic viscosity, and oxidative stability (Rancimat method) of the methyl esters was 61.1, 5.33 mm² s⁻¹ (40 °C) and 4.8 h (110 °C), respectively. The cloud, pour and cold filter plugging points were 4, −21 and −3 °C, respectively. Other properties such as acid value, lubricity, free and total glycerol content, iodine value, Gardner color, specific gravity, as well as sulfur and phosphorous contents were also determined and are discussed in light of biodiesel standards ASTM D6751 and EN 14214. Also reported are the properties and composition of wild mustard oil, along with identification of wild mustard collected in Brazil as Brassica juncea L. (2n = 36) as opposed to the currently accepted Sinapis arvensis L. (2n = 18) classification. In summary, wild mustard oil appears to be an acceptable feedstock for biodiesel production. Disclaimer: Product names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

A novel method for vehicle detection in high-resolution aerial remote sensing images using YOLT approach

Multimedia Tools and Applications - Owing to the innovative challenge stood by an intergovernmental military alliance, we have proposed a model to find novel solutions in the areas of data...     

Effect of Co γ-ray irradiation on electrical properties of GaAs epilayer and GaAs p-i-n diode

GaAs epilayers and p-i-n diodes structures grown using metal-organic vapor phase epitaxy were irradiated at room temperatures by ⁶⁰Co γ-ray radiation with varying the dose up to 50 kGy. The carrier concentration and mobility on GaAs epilayer decreases while leakage current of p-i-n diode increases at higher radiation dose (10-50 kGy). However at lower dose (<6 kGy) carrier mobility remain same but leakage current still shows significant increase. Furthermore carrier mobility of irradiated GaAs epilayers recovers partially (68%) after annealing at 300 °C while leakage current of p-i-n diode does not show any noticeable recovery. These effects are mainly due to the creation of more deep levels compared to shallow levels as determined from photoluminescence, Hall, current-voltage and electrochemical capacitance voltage analysis.     

Comparison of appearance,microstructure and tensile properties during friction stir welding processes of Al–Si alloys

The scope of this paper is to evaluate and discuss the flow phenomena of Al–2Si and Al–12Si alloys, which were joined through friction stir welding processes. The feed rate of 50mm/min and tool rotation of 600, 900, and 1200 rpm were selected for the processes. There was much change in the surface morphology with smoothness for Al–2Si alloy and roughness for Al–12 Si alloys. The microstructure studies on the weld zone were performed. The mechanical properties like tensile strength and hardness are discussed in detail.     

Porochemothermoelastic Solution for an Inclined Borehole in a Transversely Isotropic Formation

A generalized anisotropic poromechanics formulation for chemically active poroelastic media under nonisothermal conditions, termed as porochemothermoelastic, is presented. The pore fluid is modeled as a two-species constituent comprised of the solute and the solvent. Governing equations are developed and applied to obtain the analytical solution for an inclined borehole in chemically active transversely isotropic formation subjected to a three-dimensional state of stress and nonisothermal conditions. Numerical examples are presented to demonstrate the thermochemical effects on stress and pore pressure distributions in the vicinity of the borehole and their potential impacts on borehole stability.     

The corrosion of INCONEL alloy 740 in simulated environments for pulverized coal-fired boiler

The corrosion of a new nickel base superalloy, INCONEL alloy 740, has been studied at 550 and 700 °C on exposure to the synthetic coal ash/flue gas environments by means of XRD, SEM, and EDX. Low temperature hot corrosion of the new alloy occurred at two temperatures. The corrosion started to form the thin Cr₂O₃ scale on the alloy at 550 °C and developed as pitting attack resulted from sulfidation. The frontal attack at 700 °C consisted of two successive stages in which the corrosion mechanism started from the sulfidation and ended up in the fluxing of oxide. The compact and protective Cr₂O₃ scale formed and the internal sulfidation took place during the initial stage. The severe hot corrosion occurred due to the presence of the molten CoSO₄ during the propagation stage. The loose and porous outer layer and the compact inner layer consisted of spinels and oxides, respectively. The sulfides of Cr, Ti, and Nb formed on the front of oxide scale and in Cr-depletion zone. The rapid degradation of corrosion resistance of the alloy can be attributed to the dissolution of both cobalt and cobalt oxide on the surface. The alloy of 25% Cr exhibited better resistance to coal ash/flue gas corrosion as compared to the alloy of 23% Cr in the present case.     

Chemorheological analysis of unsaturated polyester-styrene copolymerization

An important feature of free radical crosslinking copolymerization of unsaturated polyester resin (UP) - styrene is the formation of a heterogeneous structure through intra-molecular reactions and phase separation. Such structure formation affects not only the cure behavior, but also the rheological changes. The chemorheology and the effect of shear on the structure formation, as well as the rheological changes, were investigated using rheometry, electron spin resonance spectroscopy, and dynamic light scattering goniometry. Based on experimental results, a conceptual model and a simple mathematical formulation are proposed to explain the shear effect on resin viscosity changes. Predictions obtained from the mathematical model are compared with experimental results.     

Electrochemical impedance spectroscopy (EIS) study of nano-alumina modified alkyd based waterborne coatings

A nano-composite coating was formed by dispersing nano-Al₂O₃ as pigments in different concentrations, to a specially developed alkyd based waterborne coating. The nano-Al₂O₃ based composite coatings were applied on mild steel substrate by dipping. The dispersion of particles in coating system was investigated by using SEM and AFM techniques. The effect of addition of these nano-pigments on the electrochemical behavior of the coating was investigated in 3.5% NaCl solution, using electrochemical impedance spectroscopy (EIS). It was found that coating modified with higher concentration of nano-Al₂O₃ particles showed comparatively better performance as it was evident from pore resistance (R_p) and coating capacitance (C_c) values after 30 days of exposure. In general, the study showed an improvement in the corrosion resistance of the nano-particle modified coatings as compared to the neat coating, confirming the positive effect of nano-particle addition in coatings.     

Coupled-cavity analysis of the resonant loop mirror: closed-form expressions and simulations for enhanced performance lasing

A coupled-cavity analysis of the resonant loop mirror with a signal flow graph technique is presented. Use of this technique has resulted in simple closed-form expressions for reflectance, transmittance, critical coupling, bandwidth, finesse, gain threshold, and mode splitting. Application of this device to enhance the single longitudinal mode operation of a fiber laser is also proposed. Detailed simulation results show a dramatic reduction in bandwidth and a threefold enhancement of the free spectral range by use of the vernier effect. The formulas and results obtained would also be useful in laser sensors and filters.