scholarly journals Karakterisasi Mineral Magnetik Sedimen Sungai Citarum Hilir Melalui Analisa Sifat Magnetik, Mineralogi serta Morfologi Magnetik

POSITRON ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 52
Author(s):  
Kartika Hajar Kirana ◽  
Mechdi Ghazali ◽  
Luh Ayu Eka Safitri Septiana ◽  
Dini Fitriani ◽  
Eleonora Agustine ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Total Dissolve Solid ◽  
X Ray ◽  
Scanning Electron

Sungai Citarum merupakan sungai utama yang ada di Provinsi Jawa Barat yang sangat penting bagi kehidupan sosial dan ekonomi. Di bagian hilir, Sungai Citarum ini banyak melewati daerah pemukiman padat penduduk, daerah industri, dan bahkan pesawahan. Oleh karena itu, perlu kajian mengenai kondisi Sungai Citarum salah satunya dengan mengidentifikasi parameter electrical conductivity (EC), total dissolve solid (TDS), pH dan suhu serta karakteristik mineral magnetik pada sedimen melalui analisis sifat magnetik, mineralogi dan morfologi magnetiknya. Pengukuran parameter EC, TDS, pH dan suhu dilakukan secara in situ pada sampel air Sungai Citarum, pengukuran sifat magnetik dilakukan pada sampel sedimen yang telah dipreprasi, sedangkan pengukuran mineralogi dan morfologi dilakukan pada sampel sedimen yang telah diekstraksi. Sifat magnetik sedimen diketahui dari nilai suseptibilitas magnetik dual frekuensi yang diukur menggunakan Bartington Magnetik Susceptibilitymeter, sedangkan mineralogi dan morfologi magnetik diketahui berdasarkan hasil pengukuran scanning electron microscope–energy disperdsive x-ray (SEM-EDS) dan x-ray diffractometer (XRD). Hasil pengukuran secara in situ pada sampel air menunjukkan bahwa rentang nilai EC, TDS, pH dan suhu berturut-turut adalah (200–4120) mS/cm, (100–2060) ppt, 7,34–9,22, dan (26,8–32,6) oC. Sedangkan, hasil pengukuran sifat magnetik menunjukkan bahwa sampel sedimen Sungai Citarum bagian hilir memiliki nilai suseptibilitas magnetik frekuensi rendah (cLF) dengan rentang (65,00–173,80) x 10-8 m3/kg, sedangkan rentang nilai suseptibilitas magnetik frekuensi tinggi (cHF) adalah (64,90–165,70) x 10-8 m3/kg. Dari kedua pengukuran cLF dan cHF diperoleh rentang nilai cFD (%) sebesar 0,15–4,66. Selanjutnya, hasil analisis morfologi dari citra SEM-EDS dan analisis mineralogi berdasarkan pengukuran XRD menunjukkan dominasi jenis mineral magnetik pada sampel sedimen adalah magnetit. Mineral magnetit ini memiliki morfologi berbentuk oktahedral sebagai representasi mineral magnetik alami dan ada pula yang berbentuk spherule sebagai representasi mineral magnetik karena adanya proses oksidasi akibat kehadiran material antropogenik pada sedimen Sungai Citarum bagian hilir.

Effect of Briquetting Pressure on the Performance of In Situ Formed Sialon in Al2O3-C Refractory Bricks

2014 ◽  
Vol 881-883 ◽  
pp. 1049-1052 ◽  
Author(s):  
Nai Peng ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Z Value ◽  
Refractory Bricks ◽  
Scanning Electron

In this paper, the effects of briquetting pressure on the performance of in-situ formed Sialon in Al2O3-C refractory bricks are investigated. The phase compositions and microstructure of the Al2O3-C refractory were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM).The results show the briquetting pressure hardly has effect on the phase of the sintered specimens, two new phases of Sialon with a Z value of 2 and SiC formed. The micrographs of Sialon crystals have the shape of both column and tabular column, but with a cone tip in the specimens sintered at 200MPa and 300MPa and smooth tip in specimens sintered at 400MPa and 500MPa.

scholarly journals Construction of in situ degradation bacteria of corn straw and analysis of its degradation efficiency

2020 ◽  
Vol 70 (1) ◽  
Author(s):  
Xiujie Gong ◽  
Hongtao Zou ◽  
Chunrong Qian ◽  
Yang Yu ◽  
Yubo Hao ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Degradation Efficiency ◽  
Corn Straw ◽  
X Ray ◽  
In Situ Degradation ◽  
Infrared Spectrometer ◽  
Scanning Electron

Abstract Purpose The highly efficient degradation bacteria were selected from the humus from the very cold straw in China for many years to construct the in situ degradation bacteria, and the degradation efficiency of corn straw was determined by process optimization. Methods According to the main components of corn straw, through morphological, physiological, and biochemical screening, three highly efficient complementary degradation strains were selected to construct the compound flora, and the degradation efficiency was analyzed by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Result The corn straw selected in this paper is mainly composed of cellulose (31.99%), hemicellulose (25.33%), and lignin (14.67%). Through the determination of enzyme activity, strain Streptomyces sp. G1T has high decomposition ability to cellulose and hemicellulose but weak utilization ability to lignin; strain Streptomyces sp. G2T has the strongest decomposition ability to cellulose and hemicellulose among the three strains. The decomposition ability of strain Streptomyces sp. G3T to lignin was the strongest among the three strains. Therefore, by compounding the three strains, the decomposition ability has been greatly improved. The optimal process conditions obtained by single factor and response surface method are as follows: pH is 7, temperature is 30 °C, inoculation amount is 5%, rotational speed is 210 rpm, and the weight loss rate of straw is 60.55% after decomposing for 7 days. A large amount of degradation of corn straw can be seen by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Conclusion Streptomyces sp. G1T, Streptomyces sp. G2T, and Streptomyces sp. G3T screened from straw humus in very cold areas were used to construct in situ degradation bacteria, which had good straw degradation activity and had the potential to be used for straw treatment in cold areas after harvest. This characteristic makes the complex bacteria become a strong competitive candidate for industrial production, and it is also an effective biotechnology in line with the current recycling of resources.

Oxidation of Pure Aluminium Granules during In Situ Melting

2015 ◽  
Vol 1125 ◽  
pp. 28-32
Author(s):  
Aslinda Saleh ◽  
Mohd Hasbullah Idris
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Oxidation Behaviour ◽  
Pure Aluminium ◽  
Muffle Furnace ◽  
X Ray ◽  
Heating Duration ◽  
Scanning Electron

Oxidation behaviour of in-situ melted pure aluminium was investigated. The granules were heated in ceramic investment casting moulds between 700 and 850°C, for the duration of 30 and 60 min in air using high temperature muffle furnace. The product was visually inspected macroscopically for the geometry and appearance. Scanning electron microscope (SEM) together with energy dispersive x-ray spectroscopy (EDS) was employed to analyse the oxidation characteristics of the product. Macroscopically, the granules failed to melt and unable to produce a casting even when the temperature was increased to 850°C. The surface of the granule experienced oxidation and spalling. Both temperature and heating duration were found to influence geometry, appearance of the product and oxidation behaviour. The oxide layer encapsulated the granule during in-situ melting of Al granules was found to be Al2O3.

Investigate of Phase Compositions and Microstructure of MgO-C through In Situ Nitride

2014 ◽  
Vol 881-883 ◽  
pp. 914-917
Author(s):  
Xiao Jun Zhang ◽  
Nai Peng ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu ◽  
Wen Jie Yuan
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Scanning Electron

In this paper, the phase compositions and microstructure of MgO-C samples containing Si powder in N2sintered at 1350-1500°C were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The α-Si3N4, β-Si3N4, MgSiN2and SiC phases have formed together with MgO and C phases in the sintered samples. The morphologies of β-Si3N4crystals were almost in the shape of rod-like through the α-β phase transformation of Si3N4by Mg-Si-O-N and silicon liquid. The morphologies of α-Si3N4crystals were in the shape of equiaxed. The morphology of MgSiN2crystals was in the shape of polyhedron with the size of 5 μm.

scholarly journals In-Situ Biofabrication of Silver Nanoparticles in Ceiba pentandra Natural Fiber Using Entada spiralis Extract with Their Antibacterial and Catalytic Dye Reduction Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1104 ◽  
Author(s):  
Wan Khaima Azira Wan Mat Khalir ◽  
Kamyar Shameli ◽  
Seyed Davoud Jazayeri ◽  
Nor Azizi Othman ◽  
Nurfatehah Wahyuny Che Jusoh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Natural Fiber ◽  
Ag Nps ◽  
X Ray ◽  
Ceiba Pentandra ◽  
Dye Reduction ◽  
Scanning Electron

It is believed of great interest to incorporate silver nanoparticles (Ag-NPs) into stable supported materials using biological methods to control the adverse properties of nanoscale particles. In this study, in-situ biofabrication of Ag-NPs using Entada spiralis (E. spiralis) aqueous extract in Ceiba pentandra (C. pentandra) fiber as supporting material was used in which, the E. spiralis extract acted as both reducing and stabilizing agents to incorporate Ag-NPs in the C. pentandra fiber. The properties of Ag-NPs incorporated in the C. pentandra fiber (C. pentandra/Ag-NPs) were characterized using UV-visible spectroscopy (UV-vis), X-ray Diffraction (XRD), Field Emission Transmission Electron Microscope (FETEM), Scanning Electron Microscope (Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), Brunauer-Emmett-Teller (BET), Thermogravimetric (TGA) and Fourier Transform Infrared (FTIR) analyses. The average size of Ag-NPs measured using FETEM image was 4.74 nm spherical in shape. The C. pentandra/Ag-NPs was easily separated after application, and could control the release of Ag-NPs to the environment due to its strong attachment in C. pentandra fiber. The C. pentandra/Ag-NPs exposed good qualitative and quantitative antibacterial activities against Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 25922) and Proteus vulgaris (ATCC 33420). The dye catalytic properties of C. pentandra/Ag-NPs revealed the dye reduction time in which it was completed within 4 min for 20 mg/L rhodamine B and 20 min for 20 mg/L methylene blue dye, respectively. Based on the results, it is evident that C. pentandra/Ag-NPs are potentially promising to be applied in wound healing, textile, wastewater treatment, food packaging, labeling and biomedical fields.

Effects of Sintering Temperature on Microstructure and Phase Formation of Nitrides Bonded MgAl2O4-Crefractory

2013 ◽  
Vol 634-638 ◽  
pp. 2354-2357
Author(s):  
Nai Peng ◽  
Cheng Ji Deng ◽  
Wen Jie Yuan ◽  
Hong Xi Zhu
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Phase Analysis ◽  
Crystal Morphology ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Large Size ◽  
Scanning Electron

The microstructure and phase analysis of in situ nitrides formation in MgAl2O4-C refractory were investigated with different temperature. The phase compositions and microstructure of the MgAl2O4-C refractory were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that sintering temperature has a significant influence on the microstructure and phase analysis of MgAl2O4 refractory. As the sintering temperatures are 1450°C and 1500°C, nitride that formed in samples is β-Sialon and the crystal morphology is columnar with short size. With the temperature rise to 1550°C and 1600°C, nitride formed in sample is AlON with the crystal morphology is tabular polymorph with large size.

scholarly journals Relationship between Chamosite Alteration and Fe-Plugging in Sandstone Pores during Acid In Situ Leaching of Uranium

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 497
Author(s):  
Lixin Zhao ◽  
Po Li
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Uranium Deposit ◽  
Northwest China ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Pore Plugging

Sandstone pore-plugging is a serious problem that bothers acid in situ leaching (ISL) uranium deposit, but currently, the mechanism of pore-plugging has not attracted much attention. In this study, using X-ray fluorescence, scanning electron microscope, optical microscope, and X-ray diffraction, we present both macro- and micro-evidence of pore-plugging occurred during acid in situ mining of sandstone uranium deposit at Yili Basin, NW (northwest) China. Our study reveals that in comparison with normal sandstones, the plugged sandstones are yellow in color and have relatively high contents of Fe and chamosite. The plugging in studied samples is mainly caused by precipitation of Fe(OH)3 at a pH of 2.0–4.0 for quantitative effect and by precipitation of gypsum (CaSO4·2H2O) as well. Alteration/dissolution of chamosite and to a lesser extent, Fe-bearing microcline and muscovite, may have contributed iron for Fe(OH)3 precipitation. It is suggested that adjustment of injection pH < 2.0 throughout the leaching passage would be an effective way to avoid/minimize this type of sandstone pore-plugging.

In Situ Thermal Oxidation Route to SnO2 Nanostructures

2013 ◽  
Vol 538 ◽  
pp. 150-153
Author(s):  
Tian Hong Guo ◽  
Juan Li ◽  
Yong Cai Zhang ◽  
Zhan Jun Yang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Thermal Oxidation ◽  
Field Emission ◽  
Heating Temperature ◽  
Sno2 Nanostructures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

An in situ thermal oxidation strategy was proposed for synthesizing different SnO2 nanostructures, using our homemade SnS2 nanoplates as a precursor. The characterization results from X-ray diffraction, energy dispersive X-ray spectroscopy, and field emission scanning electron microscope revealed that the heating temperature played an important role in the microstructure and composition of the resultant products. By heating the SnS2 nanoplates in air at 400, 600 and 800 °C for 5 h, nanoplates, a mixture of nanoplates and nanoparticles, and nanoparticles of SnO2 were synthesized, respectively. The residual S was about 2.2 mol % in the product synthesized at 400 °C, while no residual S was detected in the products synthesized at 600 and 800 °C.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

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