scholarly journals Thermal performance of cellulose acetate/tea polyphenol nanofibers

2015 ◽  
Vol 19 (4) ◽  
pp. 1327-1329
Author(s):  
Zhu-Xin Zhao ◽  
Shuang Tian ◽  
Li-Hong Chen ◽  
Meng-Di Wang ◽  
Ping Wang

In this paper, the cellulose acetate/tea polyphenol nanofibers are manufactured by electrostatic spinning technique. The surface morphology and thermal property of obtained nanofibers are characterized via scanning electron microscope, thermal gravity analysis, and differential scanning calorimetry. Different concentrations of cellulose acetate/dimethyl formamide solutions are prepared before sonicated tea polyphenol powder was added. The diameter of cellulose acetate/tea polyphenol nanofibers increases with the increase of the cellulose acetate component.

2019 ◽  
Vol 38 (2019) ◽  
pp. 541-546
Author(s):  
Jolanta Romanowska

AbstractThe paper presents results of calorimetric investigation of the Bi-Cu-Sn system by means of differential scanning calorimetry (DSC) at the temperature interval 25-1250∘C, Values of liquidus, solidus and invariant reactions temperatures, as well as melting enthalpies of the selected alloys were determined. Microstructure investigation of the alloys were performed by the use of a scanning electron microscope (SEM) equipped with an energy-dispersive spectrometer (EDS).


Author(s):  
Aslina Br. Ginting ◽  
Supardjo Supardjo ◽  
Yanlinastuti Yanlinastuti ◽  
Dian Anggraini ◽  
Boybul Boybul

Meningkatnya densitas uranium dari 2,96 gU/cm3 menjadi 5,2 gU/cm3 bahan bakar U3Si2/Al harus diikuti dengan penggunaan kelongsong yang kompatibel. Bahan bakar berdensitas tinggi mempunyai kekerasan yang tinggi, sehingga bila menggunakan paduan AlMg2 sebagai kelongsong dapat menyebabkan terjadi dogbone pada saat perolan. Selain fenomena dogbone, pada saat bahan bakar tersebut digunakan di reaktor dapat terjadi swelling karena meningkatnya hasil fisi maupun burn up. Oleh karena itu, perlu dicari pengganti bahan kelongsong untuk bahan bakar U3Si2/Al densitas tinggi. Pada penelitian ini telah dilakukan karakterisasi paduan AlMgSi sebagai kandidat pengganti kelongsong AlMg2. Karakterisasi yang dilakukan meliputi analisis termal, kekerasan, mikrostruktur dan laju korosi. Analisis termal dilakukan menggunakan DTA (Differential Thermal Analysis) dan DSC (Differential Scanning Calorimetry). Analisis kekerasan menggunakan alat uji kekerasan mikro, mikrostruktur menggunakan SEM (Scanning Electron Microscope) dan analisis laju korosi dilakukan dengan pemanasan pada temperatur 150 oC selama 77 jam di dalam autoclave. Hasil analisis menunjukkan bahwa kelongsong AlMgSi maupun AlMg2 mempunyai kompatibilitas panas dengan bahan bakar U3Si2/Al cukup stabil hingga temperatur 650 oC. Kelongsong AlMgSi mempunyai kekerasan sebesar 115 HVN dan kelongsong AlMg2 sebesar 70,1 HVN. Sementara itu, analisis mikrostruktur menunjukkan bahwa morfologi ikatan antarmuka (interface bonding) kelongsong AlMgSi lebih baik dari kelongsong AlMg2, demikian halnya dengan laju korosi bahwa kelongsong AlMgSi mempunyai laju korosi lebih kecil dibanding kelongsong AlMg2. Hasil karakterisasi termal, kekerasan, mikrostruktur dan laju korosi menunjukkan bahwa PEB U3Si2/Al densitas 5,2 gU/cm3 menggunakan kelongsong AlMgSi lebih baik dibanding PEB U3Si2/Al  densitas 5,2 gU/cm3  menggunakan kelongsong AlMg2.Kata kunci: U3Si2/Al, densitas 5,2 gU/cm3, kelongsong AlMgSi dan AlMg2.


2014 ◽  
Vol 915-916 ◽  
pp. 751-754
Author(s):  
Shao Hui Wang

The composites of PP/Talc modified by stearic acid were prepared and its effect on the properties of PP/Talc composites was investigated in this paper. The tensile strength and impact strength of PP/Talc composites increased about 15% and 30% compared with pure PP respectively. Based on surface analysis by scanning electron microscope (SEM), the Talcparticles buried well in PP matrix when the Talc was coated with the stearic acid. At the same time, it was found that Talc significantly increased the crystallization temperature and crystallization rate of PP by differential scanning calorimetry (DSC).


REAKTOR ◽  
2007 ◽  
Vol 11 (2) ◽  
pp. 71
Author(s):  
Bahruddin Bahruddin ◽  
Sumarno Sumarno ◽  
Gede Wibowo ◽  
Nonot Suwarno

Morfologi dan properti campuran (blend) karet alam jenis SIR-20/polypropylene (NR/PP) yang divulkanisasi dinamik dalam internal mixer telah dipelajari. Blend dibuat dengan rasio berat NR/PP 10/90, 20/80, 50/50, 60/40 dan 70/30 dan komposisi sulfur 3 dan 5 phr (per hundred rubber). Proses pencampuran dilakukan pada suhu 180 oC dan kecepatan rotor 60 rpm. Analisa morfologi menggunakan SEM (Scanning Electron Microscope) dan DSC (Differential Scanning Calorimetry). Properti mekanik yang diukur meliputi tensile strength, elongation at break, izod impact, tearing dan hardness, berdasarkan standar ASTM. Didapatkan bahwa peningkatan rasio NR/PP menghasilkan distribusi partikel NR yang makin merata dengan ukuran yang makin kecil. Morfologi blend menunjukkan sistem dua fasa dan vulkanisasi fasa NR terjadi secara parsial dalam matrik PP. Peningkatan rasio NR/PP dan komposisi sulfur dapat meningkatkan properti elongation at break, namun menurunkan properti tensile strength, izod impact, tearing dan hardness. Elongation at break tertinggi yang dapat diperoleh adalah 70% pada rasio blend NR/PP 70/30 dan komposisi sulfur 5 phr.


2012 ◽  
Vol 598 ◽  
pp. 561-564
Author(s):  
Zhi Ming Cao ◽  
Guo Xin Li ◽  
Yi Liang Peng ◽  
Da Wei Hu

Four zinc-rich coatings were applied onto steel substrate and then placed in neutral salt spray for 4000 h in order to study the anti-corrosion performance of the coatings. The results showed that the samples with two kinds of the coatings were more seriously eroded than the others. The reasons could be that the zinc particles were dispersed inhomogeneous in the binder and the zinc content was very lower than 96 wt. % obtained through the analysis of Scanning Electron Microscope and Differential Scanning Calorimetry.


2013 ◽  
Vol 834-836 ◽  
pp. 241-245
Author(s):  
Shuang Zhao ◽  
Ming Yue Zhang ◽  
Ya Nan Ren ◽  
Wei Yang ◽  
Si Zhu Wu

A molecular colloidal shear thickening fluid (STF), polyborondimethylsioxane (PBDMS) was synthesized, which differs from traditionally studied Silica/PEG system. Differential Scanning Calorimetry (DSC), the controlled stress rheometer.etc, were used to characterize the produced PBDMS. Scanning Electron Microscope (SEM) is the method to get the surface morphology of the Kevlar fabric impregnated by the fluid. Meanwhile the ballistic and stab tests of the composites materials were investigated.


2019 ◽  
Vol 22 (4) ◽  
pp. 277-282
Author(s):  
Salam A. Mohammed ◽  
Rahimi M. Yusop ◽  
Mohammed Abdulsattar Mohammed ◽  
Rasheed Abed Mohammed ◽  
Dina S. Ahmed ◽  
...  

Poly(vinyl chloride) photodecomposition films that contains melamine Schiff base (0.5% by weight) as photostabilizers upon preservation with an ultraviolet light (UV) was investigated. The photodecomposition rate constant was reduced significantly in existence of melamine Schiff base compared to PVC (blank). The Schiff base 1 was found to most effective additive in PVC photostabilization films. Photodecomposition rate content for PVC films containing Schiff base 1 was found to be 5 × 10-3 sec-1 compared to 8.7 × 10-3 sec-1 for blank film. Ultraviolet radiation aging behaviors of PVC films were studied through leaching test by measuring the degree of migration. The surface morphology of PVC films was inspected by scanning electron microscope.


1971 ◽  
Vol 49 (3) ◽  
pp. 371-372 ◽  
Author(s):  
Y. Hiratsuka

Two types of surface markings on the aeciospores of five pine stem rusts occurring in Canada were observed under a scanning electron microscope. Spores of four species, Endocronartium harknessii (J. P. Moore) Y. Hiratsuka (= Peridermium harknessii J. P. Moore), Cronartium coleosporioides Arth. (= P. stalactiforme Arth. & Kern), C. comptoniae Arth., and C. ribicola J. C. Fisch., had annulated processes with five to seven layers and each spore had a smooth area. The smooth area was at the same level as the top layer of the processes. Each species could be distinguished by the shape and size of its processes. Spores of Cronartium comandrae Pk. had no smooth areas and had obtuse or cuspidate processes with no annulations. Different ontogenies were apparent for the two types of spore surface markings.


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