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101.
Milan R. Rapaić Tomislav B. Šekara 《Electrical Engineering (Archiv fur Elektrotechnik)》2011,93(2):91-102
This paper addresses the problem of discretization of fractional differintegrators and fractional systems in general. Two
new discretization schemes are proposed—optimal direct method, and computationally inexpensive indirect method. The proposed
methods are highly flexible and suitable for obtaining both general purpose and specialized, application-specific approximations.
Both proposed methods outperform recently proposed approximations, as it is shown in several illustrative examples. 相似文献
102.
Inês J. Seabra Mara E. M. Braga Maria T. P. Batista Hermínio C. de Sousa 《Food and Bioprocess Technology》2010,3(5):674-683
Fractionated high pressure extractions from dry and in natura elderberry pomace were performed in order to obtain anthocyanin rich extracts. Experiments were carried out using CO2 supercritical fluid extraction followed by enhanced solvent extraction (ESE) with CO2/EtOH–H2O mixtures (1–100%, v/v), to obtain anthocyanin rich fractions in the second step, at 313 K and ~20 MPa. Higher extract yields, anthocyanin contents
and antioxidant activities occurred by the presence of water, both in the raw material and in the solvent mixture. The CO2 dissolved in the ESE solvent mixture favored either anthocyanin contents or antioxidant activities, which were not directly
related. Comparing to the literature data for elderberries and grapes, these fractions had higher anthocyanins contents. From
these results, an added economical value to this agroindustrial residue is proposed, using solvents and techniques “generally
regarded as safe” in the food and pharmaceutical industries. 相似文献
103.
Milan K. Jermář 《Water Resources Management》1989,3(4):299-313
This paper attempts to discover the real bottleneck of many irrigation projects: the complex of technical and nontechnical constraints which oppose the integrated and stable utilization of available soil and water resources. The efficiency of irrigation water use is the basic problem of intensive agriculture. Irrigation projects are, in the initial stage of operation, required to serve short-term objectives, such as to reach local self-sufficiency in food production. Their operation should, in the long run, nevertheless be based on a water-use concept and should reflect the desirable development of agriculture resulting from the need for further intensification and diversification of production. The establishment of the Water Management Strategy Plan for the Kirindi Oya Irrigation and Settlement Project in Sri Lanka is an example of the integrated approach to water resources development and management. This plan has been established on the basis of a multidisciplinary system analysis and simulation/optimization of the hydraulic and agricultural performance of the irrigation system. 相似文献
104.
The Extended Gate Field Effect Transistor (EGFET) is a device composed of a conventional ion-sensitive electrode and a MOSFET
device, which can be applied for the measurement of ion content in a solution. The EGFET is fabricated connecting the sensitive
membrane to a commercial MOSFET. We investigated the use of fluorine-doped tin oxide films (FTO) as sensitive membrane to
EGFET. The commercial FTO shows a low resistivity and a crystalline structure, both determined using conductivity set-up and
X-ray diffraction experiments, respectively. So far, it has been known that an amorphous structure is desirable to obtain
high sensitivity. Despite of the a crystalline structure, we have fabricated the FTO as EGFET for pH sensor and carried out
experiments in order to obtain the response of the device inserted into solutions with pH values from 2 up to 12. In this
range, we have quantified a sensitivity of 50 mV/pH, which may have large potential applications as pH and biosensors. In
addition, both the film and the structure of the sensor are cheaper and easier to make than in common techniques. 相似文献
105.
Milan Vatovec Paul L. Kelley Tarek Alkhrdaji Antonio Nanni 《Canadian Metallurgical Quarterly》2002,6(3):184-193
The concrete-repair fiber reinforced polymer technology emerged in the United States during the past 10 years. Since 1995, carbon fiber reinforced polymer (CFRP) has been applied to strengthen concrete decks of a troubled posttensioned garage in Atlanta. During the construction of the garage, design deficiencies were found. A remedial repair, involving heavily?reinforced, 7.6 cm (3 in.) thick Gunite (Shotcrete) beams, applied to the underside of the slab between drop panels in the east-west (E-W) direction, was developed in 1984. Since then, delamination of Gunite beams and other structural problems repeatedly occurred. Epoxy injection and other limited repairs were done over the years in an attempt to remediate the problems. In 2000, due to the growing delamination concerns, backed up with nondestructive impact-echo testing results, and due to the newest set of structural analyses that showed additional design deficiencies, Simpson Gumpertz & Heger developed a new and comprehensive remedial program. The first phase of this program included an in-depth mechanical in?situ load test program to study the strength and stiffness performance of the existing typical slab spans, including the effects of Gunite beams, the loss of Gunite beams due to delamination, and the CFRP?strengthing of spans. The tests showed that the CFRP repair of E-W spans with delaminated Gunite beams is warranted and that it performs well. The performance of the existing typical spans in the north-south direction was found to be acceptable without any repairs. Further monitoring of the performance of Gunite beams is required, and additional CFRP strengthening will be done periodically. In addition, structural deficiencies of the typical second-level end bays were repaired using additional steel framing supports. 相似文献
106.
Overheating is a major problem in many modern buildings due to the utilization of lightweight constructions with low heat storing capacity. A possible answer to this problem is the emplacement of phase change materials (PCM), thereby increasing the thermal mass of a building. These materials change their state of aggregation within a defined temperature range. Useful PCM for buildings show a phase transition from solid to liquid and vice versa. The thermal mass of the materials is increased by the latent heat. A modified gypsum plaster and a salt mixture were chosen as two materials for the study of their impact on room temperature reduction. For realistic investigations, test rooms were erected where measurements were carried out under different conditions such as temporary air change, alternate internal heat gains or clouding. The experimental data was finally reproduced by dint of a mathematical model. 相似文献
107.
In this paper, we investigate the effect of employing a parametrized covariance function in a regression experiment on corresponding
optimum designs. We demonstrate these effects in the framework of a real example for measuring the lung’s retention of radioactive
particles. Also, two different covariance functions are considered, and it is shown that this choice can play a crucial role.
相似文献
108.
109.
Panagiotis Dallas Jiri Tucek Dalibor Jancik Milan Kolar Ales Panacek Radek Zboril 《Advanced functional materials》2010,20(14):2347-2354
A recently developed multi‐functional phosphotriazine‐based polymer is used as a matrix for embedding γ‐Fe2O3 nanoparticles as well as a suitable chemical template for surface modification with silver nanoparticles. For the primary magnetic modification, maghemite nanoparticles are surface modified with oleic acid in order to render them organophilic and to prevent the aggregation of the nanoparticles. This aggregation could occur as the polymer synthesis, based on reaction of phosphonitrilic chlorine and 1,4‐phenylenediamine, takes place in toluene. The surface active amine units of the polymer structure enable the reduction of silver cations to silver nanoparticles, which are well attached and finely dispersed on its surface. The developed nanocomposite represents one of the few magnetically controllable antibacterial agents based on silver nanoparticles. Magnetic measurements reveal the completely suppressed interactions among maghemite nanoparticles because of their perfect surface coating with an organic surfactant and fine dispersion inside the polymer matrix. This magnetic nanocomposite exhibits a high antibacterial and antifungal activity as proven by tests with nine bacterial strains and four candida (yeast genus) species. For the majority of the tested species, the minimum‐inhibition concentrations are below 100 mg L?1, which is comparable to their equivalent minimum‐inhibition concentrations in colloidal silver systems. 相似文献
110.
Sneh Punia Bangar Monica Trif Fatih Ozogul Manoj Kumar Vandana Chaudhary Milan Vukic Maharishi Tomar Sushil Changan 《Comprehensive Reviews in Food Science and Food Safety》2022,21(2):1958-1978
According to the Food and Agriculture Organization of United Nations reports, approximately half of the total harvested fruits and vegetables vanish before they reach the end consumer due to their perishable nature. Enzymatic browning is one of the most common problems faced by fruit and vegetable processing. The perishability of fruits and vegetables is contributed by the various browning enzymes (polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase) and ripening or cell wall degrading enzyme (pectin methyl-esterase). In contrast, antioxidant enzymes (superoxide dismutase and catalase) assist in reversing the damage caused by reactive oxygen species or free radicals. The cold plasma technique has emerged as a novel, economic, and environmentally friendly approach that reduces the expression of ripening and browning enzymes while increasing the activity of antioxidant enzymes; microorganisms are significantly inhibited, therefore improving the shelf life of fruits and vegetables. This review narrates the mechanism and principle involved in the use of cold plasma technique as a nonthermal agent and its application in impeding the activity of browning and ripening enzymes and increasing the expression of antioxidant enzymes for improving the shelf life and quality of fresh fruits and vegetables and preventing spoilage and pathogenic germs from growing. An overview of hurdles and sustainability advantages of cold plasma technology is presented. 相似文献