Gas detection using large-size graphene with defects

2014 ◽  
Vol 116 (19) ◽  
pp. 193704 ◽  
Author(s):  
Shiu-Ming Huang ◽  
Yu-Fang Fan ◽  
Pushpendra Kumar
Keyword(s):  
Gas Detection ◽  
Large Size

New system for detecting, mapping, monitoring, quantifying and reporting fugitive gas emissions

2017 ◽  
Vol 57 (2) ◽  
pp. 561
Author(s):  
Tracy R. Tsai ◽  
Kendrick Du ◽  
Bill Stavropoulos
Keyword(s):  
Scale Up ◽  
Gas Detection ◽  
Barnett Shale ◽  
Fugitive Emissions ◽  
Coal Seam Gas ◽  
Large Size ◽  
Close Proximity ◽  
New System ◽  
Detection Technologies ◽  
Methane Detection

Coal seam gas (CSG) is an abundant energy source that’s been portrayed as having a lower Greenhouse Gas footprint than coal, but there have been concerns that fugitive emissions may be larger than estimated. Fugitive emissions associated with CSG development are engineered release points (valves and vents etc.) and unintentional equipment leaks. Various gas detection technologies are utilised across the industry that are effective at detecting large emissions sources in close proximity, but they are difficult to scale up to the large size needed for the CSG industry. We’ll present a summary of a trial utilising a new mobile methane detection and emission quantification system: the Picarro EQ (Emissions Quantification). After driving this instrument around CSG infrastructure, Picarro’s cloud-based analytics generate a map of methane measurements and emissions with wind indicators pointing to likely sources. Since all measurements are on a secure cloud-based service, any authorised operator can log into it to run reports and analytics. This system has been used to make measurements in the Barnett Shale, United States. We present results and demonstrate its usage within an operational CSG area to quantify and identify emissions from CSG infrastructure.

Characterization of Difference Size of IDE Pattern for Formaldehyde Detection Sensor

2015 ◽  
Vol 754-755 ◽  
pp. 917-922 ◽  
Author(s):  
M. Zaki ◽  
Uda Hashim ◽  
Mohd Khairuddin Md Arshad ◽  
M.F.M. Fathil ◽  
A.H. Azman ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Low Cost ◽  
Electrical Characterization ◽  
Gas Detection ◽  
Si Substrate ◽  
Hard Mask ◽  
Large Size ◽  
Mask Design ◽  
The Ideal

This paper studies the effect of different gap sizes of IDE pattern on the surface morphology and electrical properties for the formaldehyde detection sensor. Two types of IDE chrome mask are designed to determine the ideal IDE pattern for formaldehyde gas detection by using conventional lithography. In the first method, IDE is transferred onto SiO2layer. In order to ensure that the perfect pattern with minimum defect structure is obtained, the process parameters should be optimized and controlled. In the second method, the aluminium is deposited directly on SiO2/Si substrate by using IDE hard mask design plate. The fabricated IDE pattern is further validated through morphological and electrical characterization. The average gap size of IDE sensor is approximately 100 μm and 400 μm for IDE chrome and IDE hard mask respectively. The latter method is preferable since for formaldehyde gas sensing large size is needed and moreover the process is simple and requires low cost. Characterization of difference IDE pattern is demonstrated by various measurements.

Coherency loss in γ' precipitates in nickel-base superalloy

1983 ◽  
Vol 41 ◽  
pp. 244-245
Author(s):  
R. A. Ricks ◽  
Angus J. Porter
Keyword(s):  
Lattice Mismatch ◽  
Lattice Parameter ◽  
Nickel Base Superalloy ◽  
Large Size ◽  
The Matrix ◽  
Nimonic 80A ◽  
Interfacial Dislocations ◽  
Nickel Base ◽  
Coherency Loss ◽  
Nimonic 115

During a recent investigation concerning the growth of γ' precipitates in nickel-base superalloys it was observed that the sign of the lattice mismatch between the coherent particles and the matrix (γ) was important in determining the ease with which matrix dislocations could be incorporated into the interface to relieve coherency strains. Thus alloys with a negative misfit (ie. the γ' lattice parameter was smaller than the matrix) could lose coherency easily and γ/γ' interfaces would exhibit regularly spaced networks of dislocations, as shown in figure 1 for the case of Nimonic 115 (misfit = -0.15%). In contrast, γ' particles in alloys with a positive misfit could grow to a large size and not show any such dislocation arrangements in the interface, thus indicating that coherency had not been lost. Figure 2 depicts a large γ' precipitate in Nimonic 80A (misfit = +0.32%) showing few interfacial dislocations.

Automatic analysis of Kikuchi diffraction patterns

1994 ◽  
Vol 52 ◽  
pp. 900-901
Author(s):  
H. Weiland ◽  
D. P. Field
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Spatial Resolution ◽  
Relevant Information ◽  
Crystalline Materials ◽  
Large Size ◽  
Transmission Electron ◽  
New Type ◽  
Diffraction Patterns ◽  
Orientation Determination

Recent advances in the automatic indexing of backscatter Kikuchi diffraction patterns on the scanning electron microscope (SEM) has resulted in the development of a new type of microscopy. The ability to obtain statistically relevant information on the spatial distribution of crystallite orientations is giving rise to new insight into polycrystalline microstructures and their relation to materials properties. A limitation of the technique in the SEM is that the spatial resolution of the measurement is restricted by the relatively large size of the electron beam in relation to various microstructural features. Typically the spatial resolution in the SEM is limited to about half a micron or greater. Heavily worked structures exhibit microstructural features much finer than this and require resolution on the order of nanometers for accurate characterization. Transmission electron microscope (TEM) techniques offer sufficient resolution to investigate heavily worked crystalline materials.Crystal lattice orientation determination from Kikuchi diffraction patterns in the TEM (Figure 1) requires knowledge of the relative positions of at least three non-parallel Kikuchi line pairs in relation to the crystallite and the electron beam.

Immunoprobe localization in mammalian embryos

1990 ◽  
Vol 48 (3) ◽  
pp. 32-33
Author(s):  
Patricia G. Calarco ◽  
Margaret C. Siebert
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Thin Sections ◽  
Relative Lack ◽  
Large Size ◽  
Mammalian Embryos ◽  
Antigen Localization ◽  
Difficult Challenge ◽  
Lowicryl K4m ◽  
Fertilized Egg

Visualization of preimplantation mammalian embryos by electron microscopy is difficult due to the large size of the ircells, their relative lack of internal structure, and their highly hydrated cytoplasm. For example, the fertilized egg of the mouse is a single cell of approximately 75μ in diameter with little organized cytoskelet on and apaucity ofor ganelles such as endoplasmic reticulum (ER) and Golgi material. Thus, techniques that work well on tissues or cell lines are often not adaptable to embryos at either the LM or EM level.Over several years we have perfected techniques for visualization of mammalian embryos by LM and TEM, SEM and for the pre-embedding localization of antigens. Post-embedding antigenlocalization in thin sections of mouse oocytes and embryos has presented a more difficult challenge and has been explored in LR White, LR Gold, soft EPON (after etching of sections), and Lowicryl K4M. To date, antigen localization has only been achieved in Lowicryl-embedded material, although even with polymerization at-40°C, the small ER vesicles characteristic of embryos are unrecognizable.

Vibration Isolator System for Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 182-183
Author(s):  
K. Ohi ◽  
M. Mizuno ◽  
T. Kasai ◽  
Y. Ohkura ◽  
K. Mizuno ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnetic Fields ◽  
Environmental Conditions ◽  
Vibration Isolator ◽  
Air Conditioners ◽  
Vibration Isolators ◽  
Large Size ◽  
Electron Microscopes

In recent years, with electron microscopes coming into wider use, their installation environments do not necessarily give their performance full play. Their environmental conditions include air-conditioners, magnetic fields, and vibrations. We report a jointly developed entirely new vibration isolator which is effective against the vibrations transmitted from the floor.Conventionally, large-sized vibration isolators which need the digging of a pit have been used. These vibration isolators, however, are large present problems of installation and maintenance because of their large-size.Thus, we intended to make a vibration isolator which1) eliminates the need for changing the installation room2) eliminates the need of maintenance and3) are compact in size and easily installable.

Clinically Meaningful Change

Methodology ◽  
2019 ◽  
Vol 15 (3) ◽  
pp. 97-105
Author(s):  
Rodrigo Ferrer ◽  
Antonio Pardo
Keyword(s):  
Effect Size ◽  
False Negative ◽  
False Negative Rate ◽  
Point Of View ◽  
Skewed Distribution ◽  
Effect Sizes ◽  
False Negatives ◽  
Large Size ◽  
Before And After ◽  
Post Test

Abstract. In a recent paper, Ferrer and Pardo (2014) tested several distribution-based methods designed to assess when test scores obtained before and after an intervention reflect a statistically reliable change. However, we still do not know how these methods perform from the point of view of false negatives. For this purpose, we have simulated change scenarios (different effect sizes in a pre-post-test design) with distributions of different shapes and with different sample sizes. For each simulated scenario, we generated 1,000 samples. In each sample, we recorded the false-negative rate of the five distribution-based methods with the best performance from the point of view of the false positives. Our results have revealed unacceptable rates of false negatives even with effects of very large size, starting from 31.8% in an optimistic scenario (effect size of 2.0 and a normal distribution) to 99.9% in the worst scenario (effect size of 0.2 and a highly skewed distribution). Therefore, our results suggest that the widely used distribution-based methods must be applied with caution in a clinical context, because they need huge effect sizes to detect a true change. However, we made some considerations regarding the effect size and the cut-off points commonly used which allow us to be more precise in our estimates.

MANAGEMENT OF BLADDER STONE WITH HOLMIUM-YAG LASER AT KARDINAH HOSPITAL TEGAL

2020 ◽  
Vol 27 (1) ◽  
pp. 1-4
Author(s):  
Fatan Abshari ◽  
Zulfikar Ali
Keyword(s):  
General Hospital ◽  
Laser Energy ◽  
Major Complication ◽  
Mucosal Injury ◽  
Cross Sectional Study ◽  
Stone Size ◽  
Cross Sectional ◽  
Yag Laser ◽  
Bladder Stones ◽  
Large Size

Objective: Transurethral lithotripsy using Holmium-YAG laser has been reported to be beneficial in breaking up bladder stones with large size (>4cm in diameter) with lower risk of mucosal injury and hematuria. The aim of this study is to evaluate the utilization of Holmium-YAG laser for the management of bladder stones at Kardinah General Hospital, Tegal. Material & Methods: This is a cross-sectional study conducted from January 2017 to March 2017. Patient’s demography, which included age, sex, length of surgery, stone size, and laser’s energy count were recorded. Results: We included 120 patients in this study. Mean of patients age in this study was 51.93 years old with age range were 41-85 years old. Most of the patients were male (109 vs 11) with a mean size of stone 25.09 ± 3.04 mm. Length of surgery ranges from 15 to 75 minutes and mean energy of the laser 28.99 ± 19.34 kJ. There was 100% stone’s clearance following surgery with no major complication occurred. Conclusion: Holmium-YAG laser is effective in managing bladder stones at Kardinah General Hospital particularly for large size stones. Length of surgery and energy of laser used depend on the stone size in which bigger stone size is associated with longer surgery time and bigger laser energy needed.

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