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31.
A new method suitable for the on-line monitoring of adsorption column saturation/regeneration cycles was developed based on the discovery that the electrical resistance of adsorbents changes dramatically upon adsorption and returns to its original value upon desorption, and that this change can be measured reliably. The phenomenon was demonstrated on four different adsorbent/adsorbate systems, on both single particles and in a packed bed between parallel plates. The observed phenomenon was studied on the carbon/CO2 system in more detail, because of the availability of extensive literature data. It was found that the resistance change in this system correlated with the amount of CO2 adsorbed. The correlation was used to construct an adsorption isotherm based on resistance change data.  相似文献   
32.
We have prepared Nb thin films with e-beam evaporation under UHV conditions. Al thin films were deposited by resistive heating in the UHV chamber. The preparation of these films and the tri-layers of Nb/AlOx/Nb were intended for their use in Josephson junctions. The surface studies of these films were undertaken by using scanning electron microscope and atomic force microscope in the non-contact mode, whilst the interface analysis was carried out by depth profiling using scanning Auger microprobe. These studies have revealed that Nb films grown on AlOx are smoother than the ones grown on Si. Further, it is seen that Al diffuses into Nb on both sides and that the interface is very broad. This intermixing of various materials results in the failure of the tri-layers when subjected to application in SQUIDs.  相似文献   
33.
Innovative powder preparation and post-processing techniques can be employed to obtain high density ceramic parts by means of indirect selective laser sintering. Thermally induced phase separation (TIPS) was used to produce polymer and polymer–ceramic composite particles. The effect of polymer concentration, cooling rate, stirring and alumina particles on polymer and polymer–ceramic composite particles was investigated. Homogeneous spherical alumina–polypropylene (PP) composite powder was synthesized by TIPS for selective laser sintering (SLS). Green Al2O3–PP component parts with a density of 34% could be produced by conventional SLS of the polymer under optimized laser power, scan speed, scan spacing and powder preheating temperature. Various post-processing techniques like pressure infiltration (PI), warm isostatic pressing (WIPing) or a combination of both were applied to increase the green density of the Al2O3–PP SLM parts. Infiltrating the open porosity green SLS parts with a 30 vol% alumina-powder based ethanol suspension allowed to increase the sintered density, i.e. after polymer debinding and pressureless sintering in air at 1600 °C, from 38 to 64% of the theoretical density (TD). WIPing of the SLS and SLS/infiltrated green parts at 135 °C and 64 MPa allowed raising the green density up to 93 and 83% TD and a sintered density up to 89 and 88% TD, respectively.  相似文献   
34.
Functional and nutraceutical foods have captured the global market owing to trends and perceptions of consumers on the natural products and diet-health linkages. Health promoting potential of such foods has been attributed to the presence of essential bioactive moieties. Wheat, being staple food in many parts of the world, gained substantial attention of researchers particularly for the extraction of various functional components. Among these, fructan oligosaccharides in nature bestow quality of baked products and provide protection against various physiological disorders. Addition of fructan in various baked products enhances softness and color, especially in bread, and also imparts textural improvement. Moreover, fructans boost mineral absorption, hypocholesterolemic, and hypoglycemic perspectives, bifidogenic nature and controlling cancer insurgence. The benefits allied with fructan are mainly dose and time dependent. In this context, its industrial applications for vulnerable groups are increasing worldwide.  相似文献   
35.
Substantial efforts are underway to improve the recovery factor from existing oil reserves to meet the ever-growing global oil demand. Surfactants are known to increase oil recovery through reducing interfacial tension (IFT) and/or altering the rock wettability. The selection of surfactants for high-salinity high-temperature oil fields is a challenging task owing to poor thermal stability, precipitation, and adsorption of surfactants on reservoir rocks. Sulfobetaine-based polyoxyethylene zwitterionic surfactants have shown excellent thermal and surface properties. However, their solubility in high-salinity brines becomes poor particularly with a long hydrophobic tail (>C17). Recently, we synthesized such types of surfactants by incorporating ethylene oxide (EO) units into the hydrophobic tail, which improved the solubility in formation water (213,734 ppm) and seawater (SW) (57,643 ppm). In this work, we investigated the IFT, thermal stability, rheological behavior, and foaming properties of two polyoxyethylene zwitterionic surfactants having different degrees of ethoxylation. Aging experiments exhibited excellent thermal stability and no change in the chemical structure was detected. The surfactant with lesser EO units (EASB-1a) showed a lower IFT compared to the surfactant with higher EO units (EASB-1b). Rheological studies revealed that the addition of both surfactants reduced the viscosity of the acrylamide copolymer. However, the effect of EASB-1a was more prominent compared to that of EASB-1b. The surfactant with a higher degree of ethoxylation showed lower adsorption compared to the surfactant with a lesser degree of ethoxylation. Both surfactants showed excellent foamability and foam stability compared to the commercial surfactants. Excellent thermal stability, water solubility under harsh reservoir conditions, foaming properties, and lower adsorption make them a suitable choice for high-temperature, high-salinity reservoirs.  相似文献   
36.
Retina is the interior part of human's eye, has a vital role in vision. The digital image captured by fundus camera is very useful to analyze the abnormalities in retina especially in retinal blood vessels. To get information of blood vessels through fundus retinal image, a precise and accurate vessels segmentation image is required. This segmented blood vessel image is most beneficial to detect retinal diseases. Many automated techniques are widely used for retinal vessels segmentation which is a primary element of computerized diagnostic systems for retinal diseases. The automatic vessels segmentation may lead to more challenging task in the presence of lesions and abnormalities. This paper briefly describes the various publicly available retinal image databases and various machine learning techniques. State of the art exhibited that researchers have proposed several vessel segmentation methods based on supervised and supervised techniques and evaluated their results mostly on publicly datasets such as digital retinal images for vessel extraction and structured analysis of the retina. A comprehensive review of existing supervised and unsupervised vessel segmentation techniques or algorithms is presented which describes the philosophy of each algorithm. This review will be useful for readers in their future research.  相似文献   
37.
38.
Mobile Networks and Applications - An effective measure of Key Performance Indicators (KPIs) is of great significance to enhance the capabilities of a decision support system (DSS) of any...  相似文献   
39.
Composites play important role in dental filling by controlling shrinkage along with correction in teeth's shape and position. Rehabilitation of severely worn dentition can be achieved using mechanically strong composites. This study aims to synthesize zirconia-based composites to be used as dental fillers. Effect of microwave powers (100–900?W) along with Fe3O4 doping are studied on the structural, mechanical and magnetic properties of stabilized zirconia. SEM and TEM reveal formation of spherical nanoparticles with diameter of ~30?nm. XRD results shows phase pure tetragonal zirconia (t-ZrO2) at microwave power of 500?W without any post heat treatment. Crystallite size calculated from XRD data (~23?nm) matches well with the previously reported value for stabilization of t-ZrO2. Microwave energy dissipation results in stresses causing volume shrinkage leading to monoclinic to tetragonal phase transformation with higher X-ray density and hardness of ~1347HV. VSM results show ferromagnetic response with low coercivity (600Oe) value and saturation magnetization (~2emu/g). It is worth mentioning here that this is one of its kind study reporting synthesis of room temperature stabilized Fe3O4 doped zirconia composites at microwave power of 500?W. Antibacterial studies reveal inhibition zone of ~32?mm against bacillus bacteria suggesting their potential use as dental filler.  相似文献   
40.
This research was aimed at processing of metallic fiber hybrid spun yarns consisting of polyester/stainless steel and viscose/stainless steel staple fibers to achieve better electrical conductivity. Conventional ring spinning machine and ring twister machine were used to produce the single and plied yarns respectively. The linear electrical resistance of yarns was analyzed with reference to the three levels of twist multiplier (TM) for same yarn count, three levels of yarn fineness (Ne) at the same TM level, and number of plies for the same final yarn count. These results showed that by increasing twist, the electrical conductivity of yarn was increased. However, yarn fineness was in inverse relation with the electrical conductivity of yarns. The effect of yarn plying and twisting to produce the Ne 10s yarn was also found critical in governing the electrical properties. The electrical conductivity of viscose and stainless steel hybrid yarn was found more sensitive to increase with an increase in relative humidity contrary to that of polyester and stainless steel hybrid yarns. The findings of the study are significant to produce the hybrid spun conductive yarns for their potential applications in a variety of tailor-made functional, protective and smart textiles.  相似文献   
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