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1.
Basic insulating refractories were fabricated by the pressing route using dead-burned magnesia, pure calcined alumina, expanded perlite, and calcined waste serpentine as starting raw materials in four compositions from F1 to F4. Periclase and forsterite were major phases in F1 and F2 compositions, while spinel was also detected in the XRD patterns of F3 and F4 samples. Quantitative phase analysis showed that F4 sample sintered at 1450?°C has the highest forsterite content among all other samples. On the other hand, it has lower thermal conductivity compared to F1 to F3, and even lower than aluminosilicate IFBs with the same bulk density. It is concluded that forsterite is a highly insulating material, compared to periclase, corundum, periclase-spinel, aluminosilicates, such as mullite, etc. 相似文献
2.
Mehran Afkhami Mahmood Shariat Nemat Jaafarzadeh Hossein Ghadiri & Ramin Nabizadeh 《Water and Environment Journal》2007,21(3):192-199
To achieve water quality goals in a river basin, a water quality management model (WQMM) has been developed through the geographic information system (GIS) approach and a mathematical water quality model. The developed model has been applied to the Karun and Dez Rivers, where water quality has decreased due to heavy pollutant loads from Khuzestan province cities and surrounding areas. Pollution sources, land use, geographic features and measured water quality data of the river basin were incorporated into the Arc‐View GIS database. With the database, the management model calculated management type and management cost for each management project in the river basin. Until now, river management policy for polluted rivers in Iran first penalizes pollution sources and then constructs treatment plants for the pollution sources whose wastewater is released untreated and for which the wastewater quality goal of the Iranian Department of Environment is not met. Different management projects with a time programme were proposed and they were compared with the results of the river quality without any management approach. It became clear that the results based on the management approach were much better than those for the unmanaged condition from the viewpoint of the achievement of water quality goals and cost optimization. 相似文献
3.
Nemat Tahmasebi Samira Mirzavand Alireza Hakimyfard Shahram Barzegar 《Advanced Powder Technology》2019,30(2):257-265
In this paper, a simple one-pot thermal decomposition method was successfully used to synthesize a novel Cs3PW12O40/WO3 composite for the first time. The synthesized composite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), FTIR, diffuse reflectance spectroscopy (DRS) and N2 adsorption-desorption techniques. The photocatalytic activity to degrade RhB molecules over Cs3PW12O40/WO3 composite was evaluated under xenon light irradiation. The results indicated the complete degradation of RhB molecules over Cs3PW12O40/WO3 composite after 30?min irradiation. However, the photocatalytic degradation of RhB over WO3 and Cs3PW12O40 after 80?min light irradiation are nearly 52%, and 68%, respectively. The enhanced photocatalytic activity of Cs3PW12O40/WO3 composite compared with WO3, and Cs3PW12O40 was ascribed to the strong interaction between WO3 and Cs3PW12O40, which effectively reduces the recombination of photogenerated electron-hole pairs. Based on experimental results, the possible mechanism of photocatalytic reactions on the Cs3PW12O40/WO3 composite photocatalyst was investigated, and the hydroxyl radical (OH) and superoxide radical (O2?) were determined as the main active species in the photocatalytic degradation of RhB over Cs3PW12O40/WO3 composite. 相似文献
4.
Pourramezan Mohammad-Reza Rohani Abbas Keramat Siavash Nemat Zarein Mohammad 《Neural computing & applications》2022,34(7):5465-5477
Neural Computing and Applications - Evaluating the condition of the lubricant plays an influential role in the maintenance engineering of mechanical systems. This study has several objectives and... 相似文献
5.
Horio T Kimura N Basaki A Tanaka Y Noguchi T Akashi T Tanaka K 《Yeast (Chichester, England)》2002,19(15):1335-1350
The structure and localization of the microtubule organization centres (MTOCs) of the fission yeast Schizosaccharomyces japonicus var. japonicus were examined by fluorescence microscopy and electron microscopy. Spindle pole bodies (SPBs), which are the fungal equivalent of centrosomes, of Sz. japonicus were visualized by immunofluorescent staining using a monoclonal anti-gamma-tubulin antibody. The behaviour of the SPBs during the cell cycle mostly coincided with previous reports on the most widely used fission yeast Schizosaccharomyces pombe. We cloned the gamma-tubulin gene from Sz. japonicus by PCR using redundant sets of primers corresponding to conserved regions of known gamma-tubulins. The predicted amino acid sequence of Sz. japonicus gamma-tubulin was most similar to the Sz. pombe gamma-tubulin. Under the electron microscope, the SPBs of Sz. japonicus were detected as electron-dense multilayered structures located just outside the nuclear envelope. The SPBs of Sz. japonicus were composed of three electron-dense layers and were surrounded by fuzzy material. Each layer showed structural changes according to the progression of the cell cycle. In mitotic cells, the SPBs were located on the fenestrae of the nuclear envelopes through which the mitotic spindle microtubules ran into the nucleoplasm. Our results show that Sz. japonicus is a very potent and attractive organism for the investigation of the microtubule nucleation system and morphogenesis in yeasts. The Accession No. for the nucleotide sequence of the Sz. japonicus gtb1(+) gene is AF159163. 相似文献
6.
A digital frequency independent phase meter 总被引:1,自引:0,他引:1
A digital, frequency-independent phase meter is described. It makes use of pulses derived from the multiplication of the frequency of the reference input signal as its clock pulses instead of conventional crystal controlled clock generators. Advantages of the meter include simplicity and the elimination of gating error. The main source of error for this circuit is harmonic distortion of the input signals 相似文献
7.
A digital frequency meter using frequency multiplication is described. It can be used in utility power system control centers and other low-frequency applications where resolutions of the order of 1/100 Hz and almost instantaneous readouts are essential. Possible improvements of the circuit are suggested 相似文献
8.
Welding of high strength low alloy steels (HSLA) involves usage of low, even and high strength filler materials (electrodes) than the parent material depending on the application of the welded structures and the availability of the filler material. In the present investigation, the fatigue crack growth behaviour of weld metal (WM) and heat affected zone (HAZ) regions of under matched (UM), equal matched (EM) and over matched (OM) joints has been studied. The base material used in this investigation is HSLA-80 steel of weldable grade. Shielded metal arc welding (SMAW) process has been used to fabricate the butt joints. Centre cracked tension (CCT) specimen has been used to evaluate the fatigue crack growth behaviour of the welded joints. Fatigue crack growth experiments have been conducted using servo hydraulic controlled fatigue testing machine at constant amplitude loading (R=0). A method has been proposed to predict the fatigue life of HSLA steel welds using fracture mechanics approach by incorporatin 相似文献
9.
New poly(amide-imide)/amino functionalized Fe3O4 nanocomposites were successfully fabricated through solution intercalation technique. A poly(amide-imide) derived from an imide-containing diacid and ether linkage diamine was synthesized and characterized. Aiming to have better compatibility, the hydrophilic nature of Fe3O4@SiO2 was changed into organophilic using N-[3-(trimethoxysilyl)propyl]ethylenediamine. The amino-functionalized Fe3O4 showed well dispersion in the poly(amide-imide) matrix. Thermal gravimetric analysis results indicated that char yields of the nanocomposites were improved. Microscale combustion calorimetry results showed that poly(amide-imide) had good flame retardancy and amino-functionalized Fe3O4 has further improved this property of poly(amide-imide). 相似文献
10.
Y Yanagihara K Kajiwara Y Basaki K Ikizawa K Akiyama H Saito 《Canadian Metallurgical Quarterly》1997,108(2):295-301
OBJECTIVES: Tumors are thought to metastasize by a process involving tumor cell attachment to extracellular matrix, degradation of matrix components by tumor-associated proteases, and cellular movement into the area modified by protease activity. Type IV collagen comprises the major element tumor cells must degrade to gain access to the rest of the body. Renal cancer cell line progelatinase A (E.C. 3.4.24.24; 72-kDa type IV collagenase; MMP-2) mRNA expression was correlated with patient survival. METHODS: Total cellular mRNA was extracted from tumor cell lines derived from patients with metastatic renal cell carcinoma. The results of the densitometric analysis of Northern blots were correlated with patient survival. Formalin-fixed, paraffin-embedded tissue sections of primary renal cancers were examined for immunohistochemical expression of MMP-2. RESULTS: Cell lines established from 23 primary renal tumors and six metastatic sites in 26 patients with metastatic renal carcinoma were studied. Variable expression of progelatinase A, relative to A2058 melanoma cells (mean +/- SEM, 0.60 +/- 0.21; median, 0.082; range, 0 to 4.78), was found. There was a significant inverse association between patient survival and the log of the MMP-2 expression (P = 0.045 by the Cox proportional-hazards model). Using a cutoff value of 0.10, the closest round number to the median expression of MMP-2, a significant difference between survival of patients with lower and higher MMP-2 expression in their primary renal cell line was found (P = 0.0054). Cell lines with low, intermediate, and high expression of MMP-2 mRNA all had primary tumors with high tissue immunohistochemical expression of MMP-2. CONCLUSIONS: These studies demonstrate an inverse relationship between renal cancer cell line MMP-2 mRNA expression and patient survival. Immunohistochemical studies of the primary tumors from which the cell lines were derived uniformly showed high MMP-2 expression. Previous work suggests local renal factors upregulate cellular expression of MMP-2 in the primary tumor, and are not active at extrarenal sites. 相似文献