Facta Universitatis - Series: Physics, Chemistry and Technology最新文献_第7页

DETERMINATION OF PHYSICAL CHARACTERISTICS OF HORIZONTALLY POSITIONED SOLAR MODULE IN REAL CLIMATE CONDITIONS IN NIŠ, SERBIA 水平定位太阳能组件在塞尔维亚niŠ真实气候条件下的物理特性测定

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1601037P

L. Pantić, T. Pavlovic

{"title":"DETERMINATION OF PHYSICAL CHARACTERISTICS OF HORIZONTALLY POSITIONED SOLAR MODULE IN REAL CLIMATE CONDITIONS IN NIŠ, SERBIA","authors":"L. Pantić, T. Pavlovic","doi":"10.2298/FUPCT1601037P","DOIUrl":"https://doi.org/10.2298/FUPCT1601037P","url":null,"abstract":"The aim of this paper was to investigate the influence of solar radiation intensity, ambient temperature, wind speed and solar module temperature on the modules physical characteristics, in local climate conditions and for all seasons in Nis, Serbia. Twelve sunny days, for each month of the year, from the period September 2014 - June 2016 were selected. During each day meteorological parameters, solar module temperature and solar module output parameters were measured. The highest values of solar radiation intensity, ambient temperature and solar module temperature were measured in summer months, while the lowest values were in winter months. The maximal values of the output power were measured in summer months due to the high values of solar radiation intensity on the solar modules surface. A negative impact of high solar module temperature on the open circuit voltage, the output power, the fill factor and the efficiency was observed. In the winter months the local climatic conditions and air pollution have an adverse impact on the solar module efficiency and lead to a noticeable reduction of the efficiency.","PeriodicalId":12248,"journal":{"name":"Facta Universitatis - Series: Physics, Chemistry and Technology","volume":"18 1","pages":"37-51"},"PeriodicalIF":0.0,"publicationDate":"2016-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84980079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

DEVELOPMENT AND VALIDATION OF KINETIC SPECTROPHOTOMETRIC METHOD FOR HERBICIDE BROMFENOXIM DETERMINATION 动态分光光度法测定除草剂溴螨肟的建立与验证

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/fupct1602115p

T. E. Pecev-Marinkovic, M. Grahovac, S. Mitić, N. Pavlovic, D. I. Rasic-Misic, S. Miletić

引用次数: 0

THE RADIOACTIVITY OF BRICKS PRODUCED IN SERBIA 塞尔维亚生产的砖的放射性

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1601053M

V. Manić, G. Manic, D. Nikezic, D. Krstić

引用次数: 0

GROUP VELOCITY OF LIGHT IN LADDER-TYPE SPHERICAL QUANTUM DOT WITH HIDROGENIC IMPURITY 含含氢杂质的阶梯型球形量子点中光的群速度

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1601001P

V. Pavlovic, Ljiljana Stevanović

引用次数: 0

QUANTITATIVE STRUCTURE-GAS CHROMATOGRAPHIC RETENTION INDEX RELATIONSHIP OF LONG-CHAIN ESTERS: THE CASE OF SCANDIX PECTEN-VENERIS L. ESSENTIAL-OIL CONSTITUENTS 长链酯的定量结构-气相色谱保留指数关系:以麝香精油成分为例

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1602097M

M. Mladenović, N. Radulović

引用次数: 1

ISOLATION AND IDENTIFICATION OF SECONDARY METABOLITES OF UMBILICARIA CRUSTULOSA (ACH.) FREY 脐带次生代谢产物的分离与鉴定弗雷

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1602125Z

I. Zlatanović, G. Petrovic, O. Jovanovic, Ivana Zrnzević, S. Stojanovic

{"title":"ISOLATION AND IDENTIFICATION OF SECONDARY METABOLITES OF UMBILICARIA CRUSTULOSA (ACH.) FREY","authors":"I. Zlatanović, G. Petrovic, O. Jovanovic, Ivana Zrnzević, S. Stojanovic","doi":"10.2298/FUPCT1602125Z","DOIUrl":"https://doi.org/10.2298/FUPCT1602125Z","url":null,"abstract":"Herein, we have studied secondary metabolites of Umbilicaria crustulosa (Ach.) Frey. By using preparative HPLC, four compounds were isolated from the U. crustulosa methanol extract. The structure of isolated lichen substances was determined on the basis of their 1H, 13C and 2D NMR spectra as follows: methyl orsellinate, lecanoric acid, methyl lecanorate and gyrophoric acid. In addition to methanol, the composition of acetone and ethanol extracts were also studied (analytical HPLC). Relative distributions (%) of the detected constituents were as follows (in methanol/acetone/ethanol extracts): methyl orsellinate (5.7/1.5/0.9), lecanoric acid (17.9/5.7/6.7), crustinic acid (8.0/2.8/2.5), methyl lecanorate (4.8/0/0) and gyrophoric acid (59.2/78.0/85.7). A significant difference in the chemical profiles of the studied extracts was in the presence/absence of methyl esters of lichen acids. Nonetheless, the chemical composition of the ethanol extracts (no ethyl esters were detected) and the fact that treatment of acetone and ethanol extracts with methanol does not lead to changes in their composition suggests that methyl esters were not artifacts of the isolation procedure. The lower content of methyl orsellinate and the absence of methyl lecanorate from acetone and ethanol extracts may be the result of different solubilities of these compounds in methanol, ethanol and acetone.","PeriodicalId":12248,"journal":{"name":"Facta Universitatis - Series: Physics, Chemistry and Technology","volume":"11 1","pages":"125-133"},"PeriodicalIF":0.0,"publicationDate":"2016-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84338091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

DETERMINATION OF RIBOFLAVIN CONTENT IN INFANT FORMULAS FROM SERBIA BY LIQUID CHROMATOGRAPHY WITH FLUORESCENCE DETECTION 荧光液相色谱法测定塞尔维亚婴幼儿配方奶粉中核黄素的含量

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1602089D

Marko Denić, S. Sunarić, G. Kocic

{"title":"DETERMINATION OF RIBOFLAVIN CONTENT IN INFANT FORMULAS FROM SERBIA BY LIQUID CHROMATOGRAPHY WITH FLUORESCENCE DETECTION","authors":"Marko Denić, S. Sunarić, G. Kocic","doi":"10.2298/FUPCT1602089D","DOIUrl":"https://doi.org/10.2298/FUPCT1602089D","url":null,"abstract":"Breastfeeding is considered as the best feeding choice for newborns. As some infants could not be fed by their mothers, infant formulas remain an alternative to breast-milk and thus, play an important role in infant’s diet. During the years, infant formula manufacturers have made changes to formulas in order to closely match human milk composition. However, the control of the infant formula quality is mandatory in order to ensure that infants everywhere are well nourished. Riboflavin, or vitamin B 2 , is essential for normal infant growth, so infant formulas had to contain the required levels of this vitamin. Therefore, in this work, it was developed and validated a simple and accurate HPLC-FLD method for assessment of vitamin B 2 content in infant formulas (linearity range=0.02−2.0 µg/mL; LOQ=0.033 µg/mL; accuracy>96%, respectively). The main advantages of herein described protocol are the use of small volumes of toxic solvents and reagents, simple sample pre-treatment (without enzymatic digestion) and short time of analysis. Ten best-selling infant formulas on Serbian market were assayed for riboflavin content employing the described method. Significant differences were found in the vitamin B 2 levels (from 68.60 to 131.18 µg per 100 mL of prepared milk) in formulas produced by different manufacturers. The values obtained for riboflavin content in all samples mainly correspond to the declared amounts by manufacturer. The conducted quality monitoring revealed that infant formulas from Serbia comply with the nutritional needs of infants with regard to vitamin B 2 .","PeriodicalId":12248,"journal":{"name":"Facta Universitatis - Series: Physics, Chemistry and Technology","volume":"2 1","pages":"89-96"},"PeriodicalIF":0.0,"publicationDate":"2016-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76482320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

COOPERATIVE LEARNING IN TEACHING PHYSICS AND ART IN SECONDARY SCHOOLS 合作学习在中学物理和美术教学中的应用

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/fupct1601061m

D. Milićević, L. Pecić

{"title":"COOPERATIVE LEARNING IN TEACHING PHYSICS AND ART IN SECONDARY SCHOOLS","authors":"D. Milićević, L. Pecić","doi":"10.2298/fupct1601061m","DOIUrl":"https://doi.org/10.2298/fupct1601061m","url":null,"abstract":"Teaching physics in primary and secondary schools is realized through classic lecturing in classes of about 30 students, individual examinations, written tests and assignments and laboratory exercises. Knowledge is transferred from teachers to students mostly in its final form, which is not motivating for students or their teachers to develop and construct knowledge actively. A good way to overcome this problem is active teaching/ learning through application of cooperative form of learning, where the aim is that students study through interaction which they enter on the basis of their previous knowledge and skills and to become active creators of their knowledge. This study presents a research survey with the aim to establish effects of cooperative learning of physics and music as well as physics and art in secondary schools. The surveys we conducted show that this approach to teaching contributes to a higher level of understanding, better transfer of knowledge, better achievement and also to the inner motivation of both students and teachers. The obtained results indicate that cooperative learning can be applied to students of all ages, for all school subjects and within a large number of themes.","PeriodicalId":12248,"journal":{"name":"Facta Universitatis - Series: Physics, Chemistry and Technology","volume":"1 1","pages":"61-78"},"PeriodicalIF":0.0,"publicationDate":"2016-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86483681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Electro-acustic influence of the measuring system on the photoacoustic signal amplitude and phase in frequency domain 测量系统对频域光声信号幅值和相位的影响

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1601009A

S. Aleksić, D. Markushev, D. Pantic, M. Rabasovic, D. Markushev, D. Todorović

{"title":"Electro-acustic influence of the measuring system on the photoacoustic signal amplitude and phase in frequency domain","authors":"S. Aleksić, D. Markushev, D. Pantic, M. Rabasovic, D. Markushev, D. Todorović","doi":"10.2298/FUPCT1601009A","DOIUrl":"https://doi.org/10.2298/FUPCT1601009A","url":null,"abstract":"The paper discusses the most common impacts of the measuring system on the amplitude and phase of the photoacoustic signals in the frequency domain using the opencell experimental set-up. The highest signal distortions are detected at the ends of the observed modulation frequency range from 20 Hz to 20 kHz. The attenuation of the signal is observed at lower frequencies, caused by the electronic filtering of the microphone and sound card, with characteristic frequencies of 15 Hz and 25 Hz. At higher frequencies, the dominant signal distortions are caused by the microphone acoustic filtering, having characteristic frequencies around 9 kHz and 15 kHz. It has been found that the microphone incoherent noise, the so called flicker noise, is negligibly small in comparison to the signal and does not affect the signal shape. However, a coherent noise originating from the power modulation system of the light source significantly affects the shape of the signal in the range greater than 10 kHz. The effects of the coherent noise and measuring system influence are eliminated completely using the relevant signal correction procedure targeting the photoacoustic signal generated by the sample.","PeriodicalId":12248,"journal":{"name":"Facta Universitatis - Series: Physics, Chemistry and Technology","volume":"56 1","pages":"9-20"},"PeriodicalIF":0.0,"publicationDate":"2016-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83346897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

SINGLE-ELECTRON DESCRIPTION OF THE STRONG-FIELD ELECTRON DETACHMENT OF HYDROGEN NEGATIVE ION 氢负离子的强场电子分离的单电子描述

Facta Universitatis - Series: Physics, Chemistry and Technology Pub Date : 2016-11-29 DOI: 10.2298/FUPCT1601027M

Z. Milošević, S. Simonovic

引用次数: 0