Značajke legura SnBi5Pbx dobivenih prskanjem

Sn-5wt.%Bi binary master alloy was prepared by melt spinning. Ternary alloys with different Pb contents of 0.5 to 2.5 wt.% were prepared by the same technique. All alloys were irradiated with 1.2 MGy g-radiation at room temperature. The internal friction, thermal diffusivity and Young`s modulus were measured at room temperature, before and after irradiation by applying the resonance technique. DTA thermograms and X-rays diffraction patterns were obtained for the tested alloys. The results show a remarkable dependence of the measured properties on both the Pb content and irradiation doze. The observed changes are attributed to the defects induced by irradiation and to the uncontrolled dispersion of Pb content in the matrix which leads to the composition inhomogeneity and density fluctuations.Pripremali smo osnovnu dvokomponentnu leguru Sn-5wt.%Bi kao i trokomponentne legure s dodacima Pb od 0.5 do 2.5 tež.% metodom prskanja na aluminijski valjak. Sve smo uzorke također ozračili na sobnoj temperaturi γ-zračenjem do doze 1.2 MGy. Mjerili smo unutarnje trenje, toplinsku difuznost i Youngov modul na sobnoj temperaturi, prije i nakon ozračivanja, rezonantnom metodom. Za ispitane uzorke dobili smo DTA termograme i rentgenske difrakcijske snimke. Ishodi mjerenja pokazuju jaku ovisnost mjerenih svojstava o sadržaju Pb i dozi ozračivanja. Opažene se promjene tumače defektima izazvanim zračenjem odnosno neupravljanom disperzijom Pb u matrici legure koji dovode do nejednolikosti sastava i promjenljivosti gustoće

Environmental isotope investigation of the river catchments

Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Značajke legura SnBi5Pbx dobivenih prskanjem

Sn-5wt.%Bi binary master alloy was prepared by melt spinning. Ternary alloys with different Pb contents of 0.5 to 2.5 wt.% were prepared by the same technique. All alloys were irradiated with 1.2 MGy g-radiation at room temperature. The internal friction, thermal diffusivity and Young`s modulus were measured at room temperature, before and after irradiation by applying the resonance technique. DTA thermograms and X-rays diffraction patterns were obtained for the tested alloys. The results show a remarkable dependence of the measured properties on both the Pb content and irradiation doze. The observed changes are attributed to the defects induced by irradiation and to the uncontrolled dispersion of Pb content in the matrix which leads to the composition inhomogeneity and density fluctuations.Pripremali smo osnovnu dvokomponentnu leguru Sn-5wt.%Bi kao i trokomponentne legure s dodacima Pb od 0.5 do 2.5 tež.% metodom prskanja na aluminijski valjak. Sve smo uzorke također ozračili na sobnoj temperaturi γ-zračenjem do doze 1.2 MGy. Mjerili smo unutarnje trenje, toplinsku difuznost i Youngov modul na sobnoj temperaturi, prije i nakon ozračivanja, rezonantnom metodom. Za ispitane uzorke dobili smo DTA termograme i rentgenske difrakcijske snimke. Ishodi mjerenja pokazuju jaku ovisnost mjerenih svojstava o sadržaju Pb i dozi ozračivanja. Opažene se promjene tumače defektima izazvanim zračenjem odnosno neupravljanom disperzijom Pb u matrici legure koji dovode do nejednolikosti sastava i promjenljivosti gustoće

Eagles Soar Past UMass-Lowell, 8-3

Eagles Soar Past UMass-Lowell, 8-3 Witkowski has career day at the plat

Sinusoidal coded model

This article discusses a usage of modified periodic harmonic analysis to prove the periodicity of experimental data for seasonal stable isotope variations in precipitation and stream water. A proof for sinusoidal coded model is based on a hypothesis concerning the importance of the first harmonic. The utility of proposed model was demonstrated on experimental data for oxygen isotope stream water content of the Velika Morava catchment over the period 2004-2007. This study suggests an applicability of sinusoidal coded model for more accurate estimation of mean residence time without a loss of theoretical or physical significance.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Tritium content in precipitation and atmospheric water vapour of the reactor hall in the Vinča institute of nuclear sciences

Tritium activity was determined in precipitation samples collected at two locations in Belgrade over the period 1998-2007: meteorological station Belgrade (Zeleno Brdo 44º47' N, 20º32' E, altitude 243.2m asl) and the station at the Vinča Institute of Nuclear Sciences. Tritium concentrations in precipitation ranged from 0.4 to 4.41 Bq l-1 (samples collected at Zeleno Brdo) and from 2.31 to 41.30 Bq l-1 (samples collected at VINS). Tritium content in atmospheric water vapour of the indoor reactor hall and inside of the reactor during the regular inspection of the fuel channels in the Vinča Institute of Nuclear Sciences in March and May 2006 was measured. The obtained results showed that the tritium content in HTO form varied from 1.56x102 Bq m-3 to 4.05x102 Bq m-3.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200

Using Feedback In Teaching Writing Descriptive Text

This study is to see the improvement of student's writing skill on descriptive text for seventh grade students of SMP 14 Kota Serang by using peer feedback technique. The subject of this research is the students of seventh grade of SMP 14 Kota Serang which consist of 30 students. This research is applied by a quasi-experimental design and quantitative research method. The instrument used in this research was tests (pre-test and post-test) which is conducted based on the main problems: 1) How is the students writing ability on descriptive text at the seventh grade of SMP 14 Kota serang? 2) How is the effectiveness of peer feedback in teaching writing descriptive text at the seventh grade of SMP 14 Kota serang?. The research finding of the last result showed that “to” from the calculation is higher than t table both at significance level 5% and 1%. Significance 5% t observation= 7.14 and t table= 1.67 or 7.14 >1.67 which its significance 1% t observation=7.14 and t table= 2.39 or 7.14 >2.39. In addition, the result of observations showed that the students more motivated in learning English, especially for writing subject. Based on the result above, it can be concluded that peer feedback can be used in teaching writing descriptive text. The result of this research shows that the students' writing on descriptive text who use peer feedback achieve better performance than those who do not use it. &nbsp

Protolytic equilibria and stability of quercetin in aqueous solutions

The protonation constant of carbonyl group and dissociation constants of -OH groups of quercetin were determined from the changes in UV and IR spectra of aqueous solutions of various acidities. The distribution diagram of ionic species was calculated. Besides, the stability of quercetin was investigated as the function of pH and concentration. The analysis of kinetic curves indicated that a noncatalyzed conversion took place together with the autocatalyzed degradation of quercetin.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Perbandingan Analisis Sentimen Mengenai BPJS pada Media Sosial Twitter Menggunakan Naïve Bayes Classifier (NBC) dan Support Vector Machine (SVM)

Seiring dengan perkembangan teknologi, masyarakat saat ini dapat mengungkapkan perasaan, pendapat, atau pandangannya kepada publik melalui jejaring sosial. Salah satu media sosial terpopuler saat ini adalah Twitter yang diluncurkan oleh Jack Dorsey pada tanggal 15 Juli 2006. Media sosial ini merupakan salah satu media sosial utama yang digunakan masyarakat Indonesia untuk memberikan opini kepada pengguna internet. Karena jumlah pengguna Twitter yang cukup besar, hal ini sering digunakan oleh pemerintah, pelaku bisnis, maupun masyarakat untuk melihat pendapat pengguna tentang suatu produk atau layanan. Karena sebagian besar masyarakat Indonesia menggunakan BPJS, maka hal ini menyebabkan banyak pengguna media sosial seperti Twitter mengunggah ulasan mereka terkait kinerja BPJS. Hal ini dikarenakan hasil penelitian diperoleh langsung dari opini publik atas apa yang mereka alami, maka hasil tersebut dapat digunakan sebagai pengoptimalisasian program kerja, dan peningkatan kualitas pelayanan bagi perusahaan tersebut. Penelitian ini menggunakan dua metode untuk membandingkan tingkat akurasi antara metode Naïve Bayes Classifier dan Support Vector Machine menggunakan data Twitter berupa tweet umum mengenai kinerja BPJS dengan kata kunci “BPJS”, “Badan Penyelenggara Jaminan Sosial”, “Klaim” sejak Januari 2019 sampai Desember 2021. Hasil penelitian menunjukkan bahwa metode Support Vector Machine Kernel RBF dengan parameter C = 1000 dan γ = 100 memiliki performa ketepatan klasifikasi yang paling baik dibanding Naïve Bayes Classifier dan Support Vector Machine Kernel Linear. Dengan hasil rata-rata ketepatan klasifikasi SVM Kernel RBF, SVM Kernel Linear, dan Naïve Bayes Classifier masing-masing sebesar 97,1%, 92,5%, dan 86,7%

Chemical characterization of potable mineral waters

This article discusses chemical characteristics of Serbian natural mineral watersin comparison to worldwide-recognized waters. The attempt has been made to range mineral waters in respect to the calculated statistical line of mineralization. A moving average method was adopted for the calculation of statistical representative points for the main ions content of mineral waters. Proposed mode for characterization specifies the pathway from low to high mineralized water accompanied with the changes in water chemical composition.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200