oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
I codici Casin. 98 e 99: la tradizione omiletica a Montecassino all’epoca dell’abate Desiderio  [cached]
Roberta Casavecchia
Scrineum Rivista , 2012,
Abstract: The contribution focuses on the analysis of two 11th-century homiliaries (Casin. 98 and 99) produced at Montecassino under the abbot Desiderius (1058-1087), both especially well known for the high quality of their decoration (Casin. 99 also for the valuable information conveyed by its colophon). The article offers detailed descriptions of both codices, and a thorough identification of the texts they contain. The composition of the two collections, focusing on the main feasts of the two great liturgical cycles (Temporale and Santorale), is examined within the wider framework of the homiletic production in Beneventan script. Casin. 98 also contains a sermon by Peter Chrysologus, added at the beginning of the original codex, which raises questions about its possible identification with the Sermones Severiani which are mentioned in the book catalogue reported by the Chronica Monasterii Casinensis. Moreover, the loss of most of the leaves containing decorated initials allows to formulate an hypothesis of reconstruction of the original structure of the codex.
Study of Enzymolysis Kinetics with Four Kinds of Protein Feeds in Megalobrama amblycephala in vitro
Xianglin Cao,Jianjun Chen,Haijin Liu,Junli Wang,Guoxing Nie
Journal of Animal and Veterinary Advances , 2012, DOI: 10.3923/javaa.2012.1378.1384
Abstract: This research provides a comparative study on the ability of protein digestion and enzymolysis with 4 kinds of common feed ingredients in Megalobrama amblycephala in vitro. About 12 Megalobrama amblycephala with were temporarily fed a day for eliminating the contents of digestive canal. The intestine and hepatopancreas were took out for the preparation of the digestive (I ve juice sample) for digesting four kinds of common feed ingredients (fish meal, soybean meal, rapeseed meal and cottonseed meal) by enzymatic hydrolysis in vitro. The results showed that compared with the hepatopancreas, the intestine of Megalobrama amblycephala possessed better enzymolysis ability for protein in feed ingredients. Moreover, the enzymolysis ability of post intestine was the highest and the lowest in former intestine. The enzymolysis rate of fish meal (6.543 mg h-1) in intestine within 0-4 h was higher than that of other feeds also the enzymolysis rate of fish meal (1.781 mg h-1) was the highest in hepatopancreas than others (p<0.05).
Quartz Microbalance Sensor for the Detection of Acrylamide  [PDF]
Guido Kleefisch,Christian Kreutz,Joachim Bargon,Gabriele Silva,Christoph A. Schalley
Sensors , 2004, DOI: 10.3390/s40900136
Abstract: Several macrocycles of the Hunter-V?gtle type have been identified as superior host compounds for the detection of small amounts of acrylamide. When coated onto the surface of a quartz microbalance, these compounds serve as highly sensitive and selective sensor-active layers for their use in electronic noses. In this study, differently substituted macrocycles were investigated including an open-chain analogue and a catenane. Their structure and functional groups are correlated with their observed affinities to acrylamide and related acids and amides. The much smaller response of the open-chain compound and the almost absent sensor response of the catenane suggest that binding occurs within the cavity of the macrocycle. Theoretical calculations agree well with the experimental data even though they do not yet take into account the arrangement of the macrocycles in the sensor-active layer. The lower detection limit of acrylamide is 10 parts per billion (ppb), which is impressively low for this type of sensor. Other related compounds such as acrylic acid, propionamide, or propionic acid show no or significantly lower affinities to the macrocycles in these concentration ranges.
Application of Nanoparticles in Quartz Crystal Microbalance Biosensors  [PDF]
Somayeh Heydari, Gholam Hossein Haghayegh
Journal of Sensor Technology (JST) , 2014, DOI: 10.4236/jst.2014.42009
Abstract:
Nanoparticles are playing an increasingly important role in the development of biosensors. The sensitivity and performance of biosensors are being improved by using Nanoparticles for their construction. The use of these Nanoparticles has allowed the introduction of many new signal transduction technologies in biosensors. In this report, a comprehensive review of application of nanoparticles in Quartz Crystal Microbalance biosensors is presented. The main advantages of QCM in sensing fields include high sensitivity, high stability, fast response and low cost. In addition, it provides label-free detection capability for bio-sensing applications. Firstly, basic QCM’s design and characterization are described. Next, QCM biosensors based on modification of quartz substrate structure and their applications are digested. Nanoparticles and their utilizationin analysis are then illustrated. These include Nanoparticles in bio applications that cover Nanoparticles in Quartz Crystal Microbalance biosensors.
Ultrasonic-Assisted Enzymolysis to Improve the Antioxidant Activities of Peanut (Arachin conarachin L.) Antioxidant Hydrolysate  [PDF]
Lina Yu,Jie Sun,Shaofang Liu,Jie Bi,Chushu Zhang,Qingli Yang
International Journal of Molecular Sciences , 2012, DOI: 10.3390/ijms13079051
Abstract: The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scavenging activity of peanut hydrolysate could reach 90.06% under the following optimum conditions: ultrasonic power of 150.0 w, reaction temperature of 62.0 °C, incubation time of 25.0 min, and initial pH value of 8.5. The DPPH free radical scavenging rate of peanut hydrolysate from ultrasonic-assisted enzymolysis improved comparing with that of peanut hydrolysate from protease hydrolysis alone. The peanut antioxidant hydrolysate was found to display eight improved kinds of antioxidant activities. In conclusion, the optimal ultrasonic-assisted enzymolysis technology conditions described in this paper, appear to be beneficial for preparing peanut antioxidant hydrolysate.
DETECTION OF AFLATOXIN USING QUARTZ CRYSTAL MICROBALANCE  [PDF]
IOANA DULAMA,ION V. POPESCU,GH. VALERICA CIMPOCA,CRISTIANA RADULESCU
Journal of Science and Arts , 2010,
Abstract: Aflatoxins are naturally occurring mycotoxins that are produced by many species of Aspergillus, a fungus, most notably Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are toxic and among the most carcinogenic substances known. They aren’t destroyed by thermal procedures. Quartz Crystal Microbalance is an ultrasensitive piezoelectric method for detection of aflatoxin in concentrations under the value 4 ng/ml (ppb) – current maximum permitted levels set by European Commission. In this method, the quartz crystal surface was coated with a self-assembled monolayer of ethanethiol. Aflatoxins B1 and M1 were diluted in methanol. To obtain the calibration curve, several samples with various concentration of aflatoxin were measured.
Noise Measurement Setup for Quartz Crystal Microbalance
P. Sedlak,J. Majzner,J. Sikula,K. Hajek
Radioengineering , 2012,
Abstract: Quartz crystal microbalance (QCM) is a high sensitive chemical sensor which has found widespread spectrum of applications. There are several mechanisms that are related to fluctuation phenomena. Since the aim of our research is oriented to study the sensitivity and influence of different kind of noises on sensor resolution, we modified an existing method to measure the small frequency fluctuation of QCM. The paper describes our measurement setup, in which a quartz crystal oscillator with coated active layers and a reference quartz oscillator are driven by two oscillator circuits. Each one regulates a frequency of a crystal at the minimum impedance which corresponds to the series resonance. A data-acquisition card triggers on the rise-edges of the output signal and stores these corresponding times on which the instantaneous frequency is estimated by own-written software. In comparison to other measurement setups, our approach can acquire immediate change of QCM frequency, thus, chemical processes can be even described on the basis of high-order statistics. The experiments were provided on quartz crystals with the sorption layer of polypyrrole, which is suitable for the construction of QCM humidity sensors.
Surface modification of nanogold particles in DNA detection with quartz crystal microbalance
LIU Tao,TANG Jian,HAN Meimei,JIANG Long,
LIUTao
,TANGJi'an,HANMeimei,JIANGLong

科学通报(英文版) , 2003,
Abstract: Nanogold particles in different sizes, from 5 to 60 nm, were utilized to modify the surface of the quartz crystal microbalance (QCM). It was found that the gold-particle size of the modified QCM affects both the amount of the immobilization of the probe on the surface of QCM and the hybridization rate of the target DNA. 20 nm was determined to be the optimal size for the surface modification and it can maximally increase the sensitivity of the DNA detection.
QUARTZ CRYSTAL MICROBALANCE: NANO-SENSOR FOR CYANIDE DETECTION  [PDF]
IOANA DANIELA DULAMA,ION V. POPESCU,CRISTIANA RADULESCU,IOAN ALIN BUCURICA
Journal of Science and Arts , 2012,
Abstract: The extremely high level of potassium cyanide toxicity makes its effects to be important even in low concentrations. Quartz crystal microbalance (QCM) allows the determination of these values due to the high sensitivity of resonant crystal frequency. The sensitivity of the method increases with the alkaline pH values and for this reason in this study it has used two sets of solutions with pH 9 and 12. The obtained experimental results lead to the conclusion that the QCM method can be successfully used to obtain an accurate quantitative and qualitative analysis of cyanides in drinking water in real time.
Electrochemical Quartz Crystal Microbalance Study on Electrodeposition of Pt on Au-QCM  [PDF]
Amar Prasad Yadav
Journal of Nepal Chemical Society , 2012, DOI: 10.3126/jncs.v30i0.9328
Abstract: Platinum was electrodeposited on an Au-QCM in 40 mM H2PtCl6 solution using an electrochemical quartz crystal microbalance. At 0.2 V vs. SHE, a 4-electron reduction of Pt-ion took place. On the other hand, at 0.6 V a mixture of 2-electron and 4-electron reduction took place. DOI: http://dx.doi.org/10.3126/jncs.v30i0.9328 Journal of Nepal Chemical Society Vol. 30, 2012 Page: 1-4 Uploaded date: 12/16/2013 ?
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.