scholarly journals Tannins Extraction of Tea Leaves by Ultrasonic Method: Comparison with The Conventional Method

2020 ◽  
Vol 8 (1) ◽  
pp. 84-95
Author(s):  
Herliati Rahman ◽  
Shafira Fildza Arini ◽  
Vredyta Utomo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Conventional Method ◽  
Camellia Sinensis ◽  
Ultrasonic Method ◽  
Method Comparison ◽  
Tea Leaves ◽  
Scanning Electron

Tanin merupakan senyawa polifenol yang berasal dari tumbuhan yang terdapat pada daun teh (Camellia sinensis). Umumnya tanin dipisahkan dari daun teh menggunakan ekstraksi pelarut. Sayangnya metode tersebut memberikan hasil yang kurang memuaskan, sehingga perlu dilakukan cara lain untuk mengatasi hal tersebut yaitu dengan metode ekstraksi ultrasonik. Penelitian ini bertujuan untuk mempelajari pengaruh ultrasonik terhadap peningkatan yield tanin hasil ekstraksi. Parameter yang diamati pada penelitian ini diantaranya waktu ekstraksi dan jenis daun teh yang digunakan dari tiga daerah dengan ketinggian dari permukaan laut yang berbeda, yaitu Ciwidey Bandung, Pagar Alam, dan Puncak Bogor. Variasi waktu ekstraksi yang digunakan adalah 4, 6, dan 8 jam dimana frekuensi ultrasonik pada 75 kHz dengan pelarut ethanol 70%. Produk yang mengandung tanin dianalisis secara kualitatif dan kuantitatif. Kadar tanin secara kualitatif diuji menggunakan FeCl3 dan Gelatin sedangkan analisis kuantitatif menggunakan spektrofotometer UV-vis Shimadzu UV 1800. Selain itu, karakterisasi Scanning Electron Microscopy (SEM) memberikan validasi bahwa metode ultrasonik berpengaruh terhadap peningkatan rendemen tanin. Hasil tertinggi diperoleh pada teh jenis Pagar Alam dengan waktu ekstraksi 8 jam, yaitu 23,1% yield dimana lebih tinggi 3% dibandingkan dengan metode konvensional.

scholarly journals Green Synthesis, Characterization, and Evaluation of the Antimicrobial Activity of Camellia sinensis Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Toga Khalid Mohamed ◽  
Marivt Osman Widdatallah ◽  
Maida Musa Ali ◽  
Afraa Mubarak Alhaj ◽  
DhiaEldin AbdElmagied Elhag
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Camellia Sinensis ◽  
Multiple Drug Resistance ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Scanning Electron

An extremely worrying and alarming increase in the level of multiple drug resistance is reported in Sudan, in which bacterial strains are becoming resistant to many commonly available antibiotics. Eventually, it is becoming extremely difficult to treat debilitating infections. In search of promising solutions to this arising crisis, Camellia sinensis silver nanoparticles were synthesized using the green synthesis method. The synthesis of the Camellia sinensis silver nanoparticles is confirmed using analytical methods as ultraviolet-visible spectroscopy, X-ray diffractometer, and scanning electron microscopy. Using the ultraviolet-visible spectroscopy, an absorption band of 412 nm was observed. Furthermore, scanning electron microscopy revealed the presence of silver nanoparticles which fell within the range of 1–100 nm, and X-ray diffractometer analysis showed three intense peaks with a maximum intense peak at 24.3 theta. Nanoparticles distribution between 12 nm and 64 nm was observed with an average diameter of 18.115 nm. It also revealed orthorhombic-shaped nanoparticles. The synthesized nanoparticles showed antimicrobial activity against Staphylococcus aureus with a zone of inhibition of 7 mm, but none was detected against Escherichia coli. The obtained physicochemical properties were correlated with the antibacterial activity of the silver nanoparticles.

scholarly journals PENGARUH SUHU SINTERING TERHADAP KEKERASAN PADUAN MIKRO Fe-Cr HASIL METODE ULTRASONIK

2018 ◽  
Vol 3 (2) ◽  
pp. 89-97
Author(s):  
Kusdi Prijono ◽  
Amin Suhadi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fuel Cell ◽  
Ultrasonic Method ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Alloy Particles ◽  
Scanning Electron

AbstrakFe-Cr      merupakan  paduan yang memiliki ketahanan pada suhu tinggi dan kemampuan yang dapat digunakan sebagai interkonek pada sel bakar Solid Oxide Fuel Cell (SOFC). Pada penelitian ini telah dilakukan sintesis bongkah paduan Fe-Cr dengan menggunakan serbuk paduan mikro Fe-Cr hasil sintesis dengan metode ultrasonik. Metode ultrasonik dimanfaatkan untuk sintesis paduan mikro Fe-Cr melalui penggunaan gelombang suara ultrasonik. Langkah yang dilakukan adalah memadatkan partikel paduan mikro Fe-Cr dengan  kompaksi tanpa lubrikan, hasil kompaksi dimasukan kedalam kapsul kaca kuarsa selanjutnya dilakukan  proses variasi sintering 11000C, 12000C dan 13000C pada kondisi suhu maximal ditahan selama 1 jam , lalu didinginkan secara normal dalam tungku. Karakterisasi strukturmikro dilakukan dengan Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD) disertai analisis dengan metode MAUD (Material Analisys Using Diffraction ) dan pengukuran Nilai kekerasan sesungguhnya. Partikel paduan mikro Fe-Cr lebih stabil dan konsisten dalam pembentukan fasa bongkah paduan Fe-Cr melalui variasi sintering. Diperoleh bongkah paduan Fe-Cr homogen tanpa oksida.Kata kunci: Paduan mikro Fe-Cr, Ultrasonik, Kapsul Kuarsa, Sintering AbstractFe-Cr is an alloy that has a high temperature resistance and is potential to be used as an interconnect on Solid Oxide Fuel Cell (SOFC) fuel cells. In this research, Fe-Cr alloys have been synthesized using Super Fe-Cr micro alloy powder with ultrasonic method. The ultrasonic method is utilized for the synthesis of Fe-Cr micro alloys through the use of ultrasonic sound waves. The steps taken were the consolidation of the Fe-Cr micro alloy particles through compaction without lubricant, then in a quartz glass capsule a sintering process variation of 11000C, 12000C and 13000C at maximum temperature conditions retained for 1 hour, then cooled normally in the furnace. Characterization of microstructure was performed by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD) with analysis by MAUD method (Material Analisys Using Diffraction) and actual density measurement. The Fe-Cr micro alloy particles are more stable and consistent in the formation of the Fe-Cr alloy phase via sintering variations. The alloys of Fe-Cr are homogenous without oxide.Keyword : Micro-alloy Fe-Cr, Ultrasonic, Capsule Quartz, Sintering

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Spontaneous Cataract in Nude Athymic Mice

1977 ◽  
Vol 35 ◽  
pp. 512-513
Author(s):  
Ronald H. Bradley ◽  
R. S. Berk ◽  
L. D. Hazlett
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nude Mouse ◽  
Cellular Immunity ◽  
Phosphate Buffer ◽  
Osmium Tetroxide ◽  
Athymic Mice ◽  
Transmission Microscopy ◽  
Mouse Lens ◽  
Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

Scanning and Transmission Microscopy of Nematocyst Batteries in Epitheliomuscular Cells of Hydra

1971 ◽  
Vol 29 ◽  
pp. 410-411 ◽  
Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Osmium Tetroxide ◽  
External Surface ◽  
Three Dimensional ◽  
Surface Structures ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Scanning Electron

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).

Microbulldozing and Microchiseling

1969 ◽  
Vol 27 ◽  
pp. 134-135
Author(s):  
J.N. Ramsey ◽  
D.P. Cameron ◽  
F.W. Schneider
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Material Handling ◽  
Microprobe Analysis ◽  
Foreign Matter ◽  
Specific Location ◽  
Potential Problems ◽  
Knoop Indenter ◽  
Scanning Electron ◽  
Microhardness Tester

As computer components become smaller the analytical methods used to examine them and the material handling techniques must become more sensitive, and more sophisticated. We have used microbulldozing and microchiseling in conjunction with scanning electron microscopy, replica electron microscopy, and microprobe analysis for studying actual and potential problems with developmental and pilot line devices. Foreign matter, corrosion, etc, in specific locations are mechanically loosened from their substrates and removed by “extraction replication,” and examined in the appropriate instrument. The mechanical loosening is done in a controlled manner by using a microhardness tester—we use the attachment designed for our Reichert metallograph. The working tool is a pyramid shaped diamond (a Knoop indenter) which can be pushed into the specimen with a controlled pressure and in a specific location.

A New Image Processing Technique for STEM

1974 ◽  
Vol 32 ◽  
pp. 432-433
Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Elastic Scattering ◽  
Field Emission ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Energy Analyzer ◽  
Scanning Microscope ◽  
Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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