Study on the Relativity between Intrinsic Coercivity and Microstructure of the Nd-Fe-B Magnet Treated by the Optimized Aging Process

2014 ◽  
Vol 1002 ◽  
pp. 73-76 ◽  
Author(s):  
Xia Ding ◽  
Xiao Li Wang ◽  
Cong Hui Si ◽  
Li Na Zhao ◽  
Kai Hong Ding ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Process Optimization ◽  
Aging Process ◽  
Thermal Field ◽  
Aging Treatment ◽  
Optical Microscope ◽  
Intrinsic Coercivity ◽  
Energy Disperse Spectroscopy ◽  
Scanning Electron

In order to increase the intrinsic coercivity of the Nd-Fe-B magnets, the aging process optimization had been carried out. The results showed that more than 17 kOe intrinsic coercivity could be obtained by the aging process optimization. The microstructures and the fractures of the Nd-Fe-B magnets treated by the optimized aging process were also investigated by optical microscope, thermal field emission scanning electron microscopy and energy disperse spectroscopy. It was showed that the thin, continuous and smooth Nd-rich layer along the boundaries of the main crystal phase Nd2Fe14B could be formed by the optimized aging treatment and it resulted in the increase of the intrinsic coercivity of the Nd-Fe-B magnets.

scholarly journals Characterization of a Mahamayuri Vidyarajni Sutra excavated in Lu’an, China

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Liu Liu ◽  
Decai Gong ◽  
Zhengquan Yao ◽  
Liangjie Xu ◽  
Zhanyun Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tang Dynasty ◽  
Optical Microscope ◽  
Lead White ◽  
Scientific Methods ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Scanning Electron

Abstract Historically, sutras played an important role in spreading Buddhist faith and doctrine, and today these remain important records of Buddhist thought and culture. A Mahamayuri Vidyarajni Sutra with polychrome paintings was found inside the cavity on top of the Nanmen Buddhist pagoda, built in the early Tang dynasty (618–627 CE) and located in Anhui Province, China. Textile was found on the preface which is strongly degraded and fragile. Unfortunately, the whole sutra is under severe degradation and is incomplete. Technical analysis based on scientific methods will benefits the conservation of the sutra. Optical microscopy (OM), micro-Raman spectroscopy combined with optical microscope (Raman), scanning electron microscopy in combination with energy dispersive X-ray analysis (SEM–EDS) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterize the pigment and gilded material, as well as the paper fiber and textile. Pigments such as cinnabar, minium, paratacamite, azurite, lead white were found. Gilded material was identified as gold. A five-heddle warp satin, made of silk, was found as the textile on the preface of the sutra. The sutra’s preface and inner pages were made of paper comprised of bamboo and bark. As a magnificent yet recondite treasure of Buddhism, the sutra was analyzed for a better understanding of the material. A conservation project of the sutra will be scheduled accordingly.

scholarly journals THE MICROSTRUCTURAL PROPERTIES OF PLASTER COMPOSITE PRODUCED DURING PRE-REPUBLIC AND EARLY REPUBLIC PERIODS IN DEMIRCI

2020 ◽  
Vol 4 (12) ◽  
pp. 8-12
Author(s):  
SadıkAlper Yıldızel
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Early Republic ◽  
Building Materials ◽  
Optical Microscope ◽  
Microstructural Properties ◽  
Micro Structure ◽  
Existing Structures ◽  
Composite Production ◽  
Scanning Electron

Structural plaster properties of the residence type buildings that were constructed during prerepublic and early republic periods in Demirci were investigated within the scope of this study. Samples taken from the existing structures were dried in laboratory conditions and made ready for micro-structure examination. Proper samples were examined with scanning electron microscopy (SEM) with the sensitivity of 5 nm and a magnification of 20.000 times, and the optical microscope (magnification: 250 x). In the light of obtained results, it has been determined that the microstructure of the composite used in the Demirci county in the preRepublican period and early republic period is similar to the resultant of mixes produced with the modern fiber added composite production technology. It is thought that this study will contribute to the study of the production of the related building materials to be improved in the future within the limits of the district.

Microstructure and Properties of Boronized Layer Produced by Borosulphurizing Method

2012 ◽  
Vol 562-564 ◽  
pp. 204-207
Author(s):  
Dong Wang ◽  
Hui Qin Li ◽  
Han Yu Zhao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Optical Microscope ◽  
Boride Layer ◽  
Microstructure And Properties ◽  
Scanning Electron ◽  
Microhardness Tester

In this study, 45 carbon steel was boronized and borosulphurized at 950°C for 2, 3， 4, 5, 6 and 8 h, respectively. The samples were characterized by scanning electron microscopy, optical microscope, microhardness tester and ring-on-block wear tester. It is found that the surface of borosulphurized samples was dense, compact and relatively smooth; Although the boride layers produced by boro- sulphurizing at 950°C showed a lower microhardness value compared with that produced by boronizing, the wear resistance of the borosulphurized carbon steel is higher than that of boronized sample due to formation of FeS phase in the boride layer.

Asbestos fiber identification in liver from cholangiocarcinoma patients living in an asbestos polluted area: a preliminary study

2019 ◽  
Vol 105 (5) ◽  
pp. 404-410 ◽  
Author(s):  
Federica Grosso ◽  
Alessandro Croce ◽  
Roberta Libener ◽  
Narciso Mariani ◽  
Massimo Pastormerlo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Asbestos Exposure ◽  
Optical Microscope ◽  
Variable Pressure ◽  
Chrysotile Asbestos ◽  
Neoplastic Tissue ◽  
Asbestos Fibers ◽  
Preliminary Study ◽  
Scanning Electron

Purpose: To assess whether asbestos fibers may be observed in liver tissue of patients with cholangiocarcinoma (CC) with environmental or working asbestos exposure. Methods: Detection of fibers was performed directly on histologic sections of liver from 7 patients with CC using optical microscope and variable pressure scanning electron microscopy equipped with energy-dispersive spectroscopy (VP-SEM/EDS). All patients were from Casale Monferrato, Italy, a highly asbestos-polluted town. Due to ethical constraints, observers were blinded to patients’ clinical features. Results: Fibers/bundles of fibers of chrysotile were detected in 5 out of 7 patients (71%). The boundary between healthy and neoplastic tissue or the fibrocollagen tissue produced by the neoplasia were identified as areas of fiber incorporation. Conclusions: This study is the first report about the detection of chrysotile asbestos fibers in the liver of patients with CC. Further studies on larger cohorts are needed to corroborate our preliminary findings.

A Simple Method for Controlling the Morphology of CuO Nanostructures by Droplet

2012 ◽  
Vol 535-537 ◽  
pp. 280-283 ◽  
Author(s):  
Hao Ran An ◽  
Feng Shi Cai ◽  
Xue Wei Wang ◽  
Zhi Hao Yuan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscope ◽  
Growth Mechanisms ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Hydrophobic Substrate ◽  
X Ray ◽  
Shape Selective ◽  
Scanning Electron

Different morphology CuO nanostructures, including platelets, flower-like were simply synthesized at 350 °C controlled by droplet on hydrophobic substrate. This is a simple method which does not require any template, catalyst, or surfactant but can control the morphology of CuO from platelets to flowerlike. The morphologies are strongly dependent on the volume of droplet. Scanning electron microscopy (SEM), Optical microscope and X-ray diffraction (XRD) were used to observe the morphology, crystallinity, and chemical composition of the CuO structures. Growth mechanisms for shape selective CuO synthesis were proposed based on these results.

Preparation and Characterization of Silica Nanotubes with Cellulose as Template

2016 ◽  
Vol 851 ◽  
pp. 61-65 ◽  
Author(s):  
Kun Li Cao ◽  
Yan Wu ◽  
Jun Wang ◽  
Xiao Yu Hui ◽  
Xiao Tang Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cellulose Nanocrystals ◽  
Thermal Field ◽  
Sol Gel ◽  
Silica Nanotubes ◽  
Environmental Friendly ◽  
Natural Cellulose ◽  
Scanning Electron

Cellulose is a kind of renewable biological template with complex microstructure. Surface sol-gel technology, a practical and environmental-friendly approach to produce silica nanotubes, was discussed in this paper. A series of characterization techniques, namely thermal field emission scanning electron microscopy (SEM), and Aztec X-act spectrometer were used to characterize these samples. The design of the nanotube structure was achieved by natural cellulose and cellulose nanocrystals (CNC), and this nanocopying methodology provided silica nanotubes of cellulose template in nanometer precision.

Glass Wool Prepared under Various Rotating Speed by Centrifugal-Spinneret-Blow Process

2012 ◽  
Vol 457-458 ◽  
pp. 1573-1576 ◽  
Author(s):  
Bin Bin Li ◽  
Zhao Feng Chen ◽  
Zhou Chen ◽  
Jin Lian Qiu ◽  
Yan Qing Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fiber Diameter ◽  
Optical Microscope ◽  
Glass Wool ◽  
Pronounced Effect ◽  
Rotating Speed ◽  
The Mean ◽  
Scanning Electron

In this paper, glass wool has been prepared under various rotating speed of centrifugal pan by centrifugal-spinneret-blow process. The fiber diameter of glass wool has been studied by scanning electron microscopy (SEM) and vertical optical microscope (VOM). With the increase of rotating speed from 1800 rpm to 2400 rpm, the mean fiber diameter decreased from 5.9 µm to 3.9 µm, indicating the distribution of glass wool becomes more uniformity. The results show that the rotating speed has a direct and pronounced effect on the fiber diameter and distribution. The higher the rotating speed is, the smaller the mean fiber diameter is, and the more uniformity the distribution of fiber diameter is.

scholarly journals Solidification, Microstructure and Mechanical Properties of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr Cast Alloy with Erbium Addition

2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Microstructure Analysis ◽  
Cooling Curve ◽  
Scanning Electron

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.

The Performance of a Thermal Field Emission Gun

1975 ◽  
Vol 33 ◽  
pp. 146-147
Author(s):  
Dennis M. Maher ◽  
David C. Joy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Field Emission ◽  
Thermal Field ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Magnetic Alignment ◽  
Stable Operation ◽  
Alignment System ◽  
Scanning Electron

Although the "cold" field emission gun has been used successfully for both transmission and scanning electron microscopy it requires ultra-high vacuum which is not obtained easily when such a gun is interfaced to a conventional microscope system. Recently, the "thermal" field emission gun (TFEG) in which the emitting tip is held at around 1700°K has been proposed as an alternative electron source for such applications. Under this condition the tip is cleaned continuously, and surface asperities are smoothed, therefore stable operation is possible in a high vacuum. In this paper we report on the build-up characteristics, current stability and brightness of a TFEG which has been interfaced to a JEOL JEM 100B microscope equipped with a scanning attachment. The gun consists of a (111) tungsten emitter set on a rhenium filament, three anodes and a two stage magnetic alignment system. The gun chamber is ion pumped to a pressure in the range 6xl0-8 to 2xl0-9 torr.

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