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71.
A promising line of research for radar systems attempts to optimize the detector thresholds so as to maximize the overall performance of a radar detector–tracker pair. In the present work, we attempt to move in a direction to fulfill this promise by considering a particular dynamic optimization scheme which relies on a non-simulation performance prediction (NSPP) methodology for the probabilistic data association filter (PDAF), namely, the modified Riccati equation (MRE). By using a suitable functional approximation, we propose a closed-form solution for the special case of a Neyman–Pearson (NP) detector. The proposed solution replaces previously proposed iterative solution formulations and results in dramatic improvement in computational complexity without sacrificed system performance. Moreover, it provides a theoretical lower bound on the detection signal-to-noise ratio (SNR) concerning when the whole tracking system should be switched to the track before detect (TBD) mode. 相似文献
72.
Zeynep Münteha Şahin Erdinç Doğancı S. Zeki Yıldız Murat Tuna Faruk Yılmaz Yusuf Yerli Mesut Görür 《Synthetic Metals》2010,160(17-18):1973-1980
Two-armed poly(?-caprolactone) (TAPCL) polymers were successfully synthesized via the ring opening polymerization (ROP) of ?-caprolactone (?-CL) using the Schiff's base complexes [Cu(SAEE)2] (1) and [Ni(SAEE)2] (2), which have two hydroxyl functional groups, as the two-site initiators and tin(II) 2-ethylhexanoate (Sn(Oct)2) as the catalyst in bulk at 115 °C. The Schiff's base complexes (1 and 2) were synthesized by utilizing the concentrated template synthesis method starting from salicyl aldehyde, 2-(2-aminoethoxy) ethanol and related metal acetate salts. The synthesized TAPCL polymers were characterized by GPC, FTIR, UV–vis, and electron paramagnetic resonance (EPR). The molecular weights of TAPCL polymers linearly increased with increasing molar ratio of the monomer to the initiator. The results obtained from FTIR, UV–vis, and EPR studies indicated that TAPCL polymers had the Schiff's base complexes at the junction point of PCL arms. The crystallization behavior of TAPCL was studied by using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Thermal behavior of TAPCL was also investigated by thermogravimetrical analysis (TGA). 相似文献
73.
An automated computer program isdeveloped for calculating areal average rainfall(AAR) value and its implementation is presentedfor the arid region representative country,Libya.The procedure is conceptually simple byconsideration of almost equilateral trianglesconnecting adjacent meteorological stations withthe assumption of linear rainfall change betweenstations. The applications of the methodologyhave been achieved for monthly, seasonal andannual rainfall amounts recorded at 29meteorological stations scattered over thenorthern part of Libya.It has been shown thatthe proposed methodology yields results that arecomparable with the commonly used AAR calculationmethods. 相似文献
74.
Depiction of precipitation change by elevation in an areaindicates the possibilities of orographic rainfall occurrencesin the mountainous regions. In general, precipitation increaseswith elevation but sometimes inverse cases occur locally due toorographic and meteorological features of the area. Inpractice, prior to any quantitative modeling, qualitativeassessments and interpretations help to have sound foundationsin search for a suitable model. In this article, standardizedpoint cumulative semivariogram (SPCSV) methodology is employedfor identification of the precipitation-elevationrelationship. According to relative positions of theprecipitation and elevation SPCSVs four different precipitationcategories are suggested. The application of the methodologyproposed is presented for the precipitation records from YuccaMountain, Nevada, U.S.A. 相似文献
75.
Ozan Gürbüz Duygu Göçmen Fatih Dagˇdelen Murat Gürsoy Sami Aydin İsmet Şahin Levent Büyükuysal Mehmet Usta 《Food chemistry》2007,100(2):518-525
Concentrations of trans-resveratrol, catechin and epicatechin were analyzed in musts and wines produced from seven red and four white grape cultivars from various wine growing regions of Turkey. Phenolics were quantified using an HPLC method optimized for the separation of wine phenolics. Wine samples contained higher phenolics levels than the corresponding musts. With the exception of Semillion, white wines and musts contained lower concentrations of phenolics than red wines and musts. However, the white cultivar Semillion had the highest concentrations of catechin and epicatechin among all wine and must samples. Semillion wine catechin and epicatechin were 13.7 and 11.8 mg/L, respectively. The highest level of trans-resveratrol among the white cultivars was found in Narince wine (1.93 mg/L). Within the red wine and must cultivars, Bo?azkere, Öküzgozü, and Cabernet contained the highest concentrations of flavan-3-ols and trans-resveratrol. Catechin was the major phenolic in all wines and most musts. Epicatechin was the major phenolic in 6 of the 11 must samples, but none of the wine samples. trans-Resveratrol was generally found in lowest concentrations in both wines and musts. 相似文献
76.
77.
Equilibrium and kinetic isotherms and parameters for molecularly imprinted with sclareol poly(acrylonitrile‐co‐acrylic acid) matrix 下载免费PDF全文
Ştefan‐Ovidiu Dima 《Polymer Engineering and Science》2015,55(5):1152-1162
The present work continues the previous studies concerning the synthesis and characterization of molecularly imprinted polymers (MIPs) with sclareol as template and three poly(acrylonitrile‐co‐acrylic acid) (AN:AA) copolymers with different ratios between monomers as matrices. The previous studies of rheology, elemental analysis, infrared spectroscopy, size exclusion chromatography, thermogravimetry, differential scanning calorimetry, batch rebinding tests, and Scatchard analysis, which confirmed the molecular imprinting, are being completed with the current equilibrium and kinetic adsorption studies. For this purpose, eight adsorption isotherms and three kinetic adsorption models were applied to six sets of experimental data obtained after three sclareol‐imprinted adsorbents (MIPs) and three nonimprinted adsorbents (NIPs) were submitted to batch adsorption experiments. After ordering the adsorption models according to the “minimum sum of normalized errors (SNE)” criteria, it was concluded that the adsorption in sclareol imprinted AN:AA copolymers is characterized by low surface coverage, takes place on heterogeneous binding sites and is reversible, while for NIPs the results suggest a difficult adsorption and/or easiness of template extraction, and that NIPs have homogeneous, but nonimprinted micropores. For the kinetic experiments, the minimum SNE for MIPs points to the first order kinetic model, fact that suggests a physical adsorption of template molecules on the imprinted sites. POLYM. ENG. SCI., 55:1152–1162, 2015. © 2014 Society of Plastics Engineers 相似文献
78.
79.
The removal of Fe(III), Cu(II), and Cd(II) ions from aqueous solutions was investigated with a crossflow filtration technique. Alginic acid (AA)/cellulose composite membranes were used for retention. In the filtration of Fe(III) solutions, the effects of the crossflow velocity, applied pressure, AA content of the membranes, and pH on the retention percentage and the permeate flux were examined. The maximum retention percentage was found to be 89% for a 1 × 10?4M Fe(III) solution at the flow velocity of 100 mL/min and the pressure of 60 kPa with 0.50% (w/v) AA/cellulose composite membranes at pH 3. Aqueous solutions of Cu(II) and Cd(II) were filtered at the flow velocity of 100 mL/min and pressure of 10 kPa. The effects of the AA content of the membranes and pH of the waste medium on the retention percentage and the permeate flux were determined. For 1 × 10?4M Cu(II) and Cd(II) solutions, the maximum retention percentages were found to be 94 and 75%, respectively, at pH 7 with 0.50% (w/v) AA/cellulose composite membranes. When metal‐ion mixtures were used, the retention percentages of Fe(III), Cu(II), and Cd(II) were found to be 89, 48, and 10%, respectively, at pH 3 with 0.50% (w/v) AA/cellulose composite membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
80.
Şaban Uysal H. İsmet Uçan 《Journal of Inorganic and Organometallic Polymers and Materials》2010,20(4):720-726
In this study, by using previously reported monomer complexes [(2-(4-carboxybenzimino)-4,6-diamino-1,3,5-triazine)(salen/salophenFeIII)], [(2-(4-carboxybenzimino)-4,6-diamino-1,3,5-triazine)(salen/salophenCrIII)], [(2-(3,4-dihydroxybenzimino)-4,6-diamino-1,3,5-triazine)(salen/salophenFeIII)] and [(2-(3,4-dihydroxybenzimino)-4,6-diamino-1,3,5-triazine)(salen/salophenCrIII)] obtained by Uysal and Uçan (J Inc Phenom Macrocycl Chem, in press), sixteen new polimer Fe(III) and Cr(III) complexes involving tetradentate Schiff bases N,N′-bis (salicylidene)ethylenediamine-(salenH2) or bis(salicylidene)-o-phenylenediamine-(salophenH2) with 2-(4-carboxybenzimino)-4,6-diamino-1,3,5-triazine or 2-(3,4-dihydroxybenzimino)-4,6-diamino-1,3,5-triazine (Uysal and Uçan, J Inc Phenom Macrocycl Chem, in press) and terephthaldehyde or glutaraldehyde have been synthesized and characterized by means of elemental analysis, 1H N.M.R., FT-IR spectrscopy, MS, thermal analyses and magnetic susceptibility measurements. The complexes have also been characterized as low-spin distorted octahedral Fe(III) and Cr(III) bridged by catechol and/or COO? groups. 相似文献