scholarly journals Z ECHO NMR POWDER SPECTRUM OF THREE-LEVEL SYSTEMS

1991 ◽  
Vol 40 (10) ◽  
pp. 1717
Author(s):  
LI GENG-YING ◽  
WU XUE-WEN
Keyword(s):  
Powder Spectrum

The variability of the infrared powder spectrum of amorphous SiO2

1989 ◽  
Vol 107 (2-3) ◽  
pp. 187-192 ◽  
Author(s):  
M. Ocaña ◽  
V. Fornés ◽  
C.J. Serna
Keyword(s):  
Powder Spectrum ◽  
Amorphous Sio2

X-band ESR powder spectrum and related magneto-microwave effects of CuF2.2H2O

Physica B+C ◽  
1978 ◽  
Vol 95 (3) ◽  
pp. 364-368
Author(s):  
Yves Servant ◽  
Jean-Claude Bissey ◽  
Slimane Gharbage
Keyword(s):  
Powder Spectrum ◽  
X Band ◽  
Microwave Effects

scholarly journals Mechanism of Trees / Bushes Like Pattern in Chemical System

2009 ◽  
Vol 6 (3) ◽  
pp. 819-829
Author(s):  
P. K. Srivastava ◽  
Narendra Yadav
Keyword(s):  
Pattern Formation ◽  
Ir Spectra ◽  
Succinic Acid ◽  
Ammonium Sulphate ◽  
Cyclic Compound ◽  
Chemical System ◽  
Powder Spectrum ◽  
Initial Concentration ◽  
X Ray ◽  
Type Pattern

Trees / bushes like pattern have been investigated in succinic acid + ethylacetoacetate + BrO3−+ Fe (phen)3+2+ Ce+4+ H2SO4system at 30 °C in a petridish after 6 hours. These patterns are dependent on initial concentration of reactants and temperature. The system first shows fast appearing / disappearing blue and red pattern then bifurcate into concentric waves and finally shows a tree / bushes type pattern which grows in length and breadth against time. Microphotographs of trees / bushes pattern, succinic acid and ceric ammonium sulphate shows that a new compound has been formed which is responsible for this pattern. It is further confirmed by X-ray powder spectrum of trees / bushes pattern material and succinic acid. IR spectra of pattern material show that presence of cyclic compound in which Ce+4ion coordinated by hydroxyethylacetoacetate. A tentative mechanism of pattern formation is proposed.

REDUCTION BY HYDROGEN OF VANADIUM IN PHOSPHATE AND VANADATE LEAD APATITES: AN ESR STUDY

2007 ◽  
Vol 21 (22) ◽  
pp. 1489-1500 ◽  
Author(s):  
M. IKRAM ◽  
H. AHMED ◽  
PIETRO MENDES ◽  
F. A. MIR ◽  
A. BASHIR ◽  
...  
Keyword(s):  
Solid Solution ◽  
Computer Simulations ◽  
Esr Spectroscopy ◽  
Esr Spectra ◽  
Hydrogen Gas ◽  
Charge Carriers ◽  
Spin Hamiltonian ◽  
Powder Spectrum ◽  
Hamiltonian Parameters ◽  
Vanadium Ions

A solid solution of phosphate and vanadate lead apatites Pb 10( PO 4)6-x( VO 4)x( OH )2 (x = 0.5, 1.0, 2.0, 3.0, and 6.0) were reduced with hydrogen gas at temperature 300°C for one hour. All these compounds were investigated by XRD and ESR spectroscopy. Only one reduced oxidation state, V 4+, was detected. Two types of species-like isolated vanadium (+ 4) and clusters of V 4+ were observed. The EPR powder spectrum computer simulations were performed using the program Simfonia from Bruker. Spin Hamiltonian parameters were also calculated. As the concentrations of vanadium ions increase to 2.0, the intensity of the ESR lines increases, and x = 3.0 the intensity of the ESR line decreases sharply. After this concentration, i.e. x > 3.0, there is again an increase in the intensity. The variation of the line shape and intensity of the ESR spectra can be attributed to increases in the hopping rate of the charge carriers (polarons) in different apatite compositions.

scholarly journals Deteksi Bubuk Kopi Luwak Murni dan Bubuk Kopi Luwak Campuran Dengan Teknologi Hidung Elektronik

2019 ◽  
Vol 4 (3) ◽  
pp. 105-114
Author(s):  
Mubarak Hulda ◽  
Fachruddin Fachruddin ◽  
Agus Arip Munawar
Keyword(s):  
Principal Component Analysis ◽  
Electronic Nose ◽  
Principal Component ◽  
Component Analysis ◽  
Powder Spectrum ◽  
Pca Method ◽  
Coffee Powder ◽  
Electronic Nose Technology ◽  
Spectrum Data

Abstrak. Kopi luwak merupakan kopi yang berasal dari hasil konsumsi hewan luwak (musang) yang  telah mengalami fermentasi di dalam pencernaan luwak selam 12 jam. Kopi luwak merupakan komoditi yang sangat diminati dan bernilai jual tinggi. Tujuan dari penelitian ini untuk membedakan bubuk kopi luwak murni dan bubuk kopi luwak campuran dengan memanfaatkan instrumen berbasis teknologi hidung elektronik (electronic nose). Penelitian ini menggunakan bubuk kopi luwak murni dan bubuk kopi arabika yang dicampurkan dengan perbandingan (50:50, 60:40. 70:30, 80:20 dan 90:10). Jumlah sampel yang digunakan pada penelitian ini adalah sebanyak 10 sampel. Pengukuran intensitas sinyal aroma bubuk kopi menggunakan sensor piezoelectric tranducers. Klasifikasi data spektrum bubuk kopi menggunakan metode Principal Component Analysis (PCA) dengan pretreatment nya adalah Gap Reduction. Hasil penelitian ini diperoleh yaitu: Hidung elektronik mulai merespon aroma bubuk kopi pada detik ke-5.64, dan dapat mengklasifikasikan bubuk kopi pada detik ke 11.09. Hidung elektronik yang dikombinasikan dengan metode principal component analysis (PCA) telah berhasil mendeteksi bubuk kopi luwak murni dan bubuk kopi luwak campuran dengan tingkat keberhasilan sebesar 100% (PC-1 sebesar 100% dan PC-2 sebesar 0%).Deteksi Murni Powder Kopi Luwak dan Campuran Kopi Luwak Bubuk Menggunakan Teknologi Hidung ElektronikAbstract. Civet coffee is coffee that comes from the consumption of civet animals (ferrets) that have undergone fermentation in the digestion of mongoose for 12 hours. Civet coffee is a commodity that is very popular and has a high selling value. The purpose of this study is to distinguish pure civet coffee powder and mixed civet coffee powder by using an instrument based on electronic nose technology. This study used pure civet coffee powder and arabica coffee powder mixed with comparisons (50:50, 60:40. 70:30, 80:20 and 90:10). The number of samples used in this study were 10 samples. The measurement of the intensity of coffee powder’s smell signals using piezoelectric tranducers. The classification of coffee powder spectrum data using the Principal Component Analysis (PCA) method with its pretreatment is Gap Reduction. The results of this study were obtained: The electronic nose starts responding to the smell of coffee powder at 5.85 seconds, and can classify coffee powder in 11.09 seconds. The electronic nose combined with the principal component analysis (PCA) method has succeeded in detecting pure civet coffee powder and mixed Civet coffee powder with a success rate of 100 % (PC-1 of 100% and PC-2 of 0%).     

A program for EPR powder spectrum simulation

1985 ◽  
Vol 64 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Dinesh Nettar ◽  
Joseph J Villafranca
Keyword(s):  
Powder Spectrum ◽  
Spectrum Simulation
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