Enhanced Sensitivity of the Pirani Vacuum Gauge by the AC Driving Method

2005 ◽  
Vol 277-279 ◽  
pp. 990-994
Author(s):  
Dae Jin Seong ◽  
Yong Hyeon Shin ◽  
Kwang Hwa Chung ◽  
D.H. Kim ◽  
Je Sik Shin ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Heat Conductivity ◽  
High Sensitivity ◽  
Log P ◽  
Vacuum Gauge ◽  
Enhanced Sensitivity ◽  
Yield Information ◽  
Method Yield ◽  
Pirani Gauge ◽  
Temperature Amplitude

We improved the sensitivity of existing commercial Pirani-vacuum gauges employing the AC method in the vacuum range above 1 Torr. The signals obtained through the use of the AC method yield information related to the specific heat and heat conductivity of gas. The output signal is obtained by two components: the oscillating temperature amplitude, and its phase. The amplitude increases with the decrease of pressure in the vacuum range from the atmosphere to about 1 Torr, which arises from the decrease of the heat capacity with the decrease of gas density. In contrast, the phase decreases monotonically as pressure decreases and the slop of a dΘ/d(log P) is large at higher than 1 Torr. This provides a good advantage for developing a new Pirani gauge with high sensitivity.

scholarly journals Temperature Dependence of Thermophysical Properties of Full-Scale Corium of Fast Energy Reactor

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Mazhyn K. Skakov ◽  
Nurzhan Ye. Mukhamedov ◽  
Alexander D. Vurim ◽  
Ilya I. Deryavko
Keyword(s):  
Heat Capacity ◽  
Thermal Diffusivity ◽  
Fast Reactor ◽  
Thermophysical Properties ◽  
Heat Conductivity ◽  
Nuclear Reactor ◽  
Reactor Vessel ◽  
Full Scale ◽  
Temperature Fields ◽  
First Time

For the first time the paper determines thermophysical properties (specific heat capacity, thermal diffusivity, and heat conductivity) of the full-scale corium of the fast energy nuclear reactor within the temperature range from ~30°С to ~400°С. Obtained data are to be used in temperature fields calculations during modeling the processes of corium melt retention inside of the fast reactor vessel.

Singular pole and enhanced sensitivity of PT-symmetric layered structure with resonators

2018 ◽  
Vol 84 (1) ◽  
pp. 10503 ◽  
Author(s):  
Rong-kun Ma ◽  
Jing Xia ◽  
Yun-tuan Fang
Keyword(s):  
Optical Properties ◽  
High Sensitivity ◽  
Refraction Index ◽  
Symmetric System ◽  
Scatter Matrix ◽  
Enhanced Sensitivity ◽  
Symmetric Structure ◽  
Single Cavity ◽  
Total Gain ◽  
Scatter Matrix Method

In order to achieve enhanced transmittance of parity-time (PT)-symmetric system, we design a layered PT-symmetric structure including resonators. We use the scatter matrix method to study the optical properties of the designed structure under the modulation of resonators. The structure system takes on a singular pole effect, i.e., the huge reflectance and transmittance occur at a special wavelength and period number. The field distribution reveals that the singular pole results from the coupling resonance of single cavity and the whole structure. Because of the coupling resonance, the total gain in layer A is much larger than the total loss in layer C. The reflectance and transmittance at the singular pole take on a high sensitivity on the refraction index of the resonators.

scholarly journals New Spectrofluorimetric Method with Enhanced Sensitivity for Determination of Paroxetine in Dosage Forms and Plasma

2008 ◽  
Vol 3 ◽  
pp. ACI.S1053 ◽  
Author(s):  
Ibrahim A. Darwish ◽  
Sawsan M. Amer ◽  
Heba H. Abdine ◽  
Lama I. Al-Rayes
Keyword(s):  
High Sensitivity ◽  
Dosage Forms ◽  
Official Method ◽  
Factors Affecting ◽  
Pharmaceutical Tablets ◽  
Enhanced Sensitivity ◽  
Spectrofluorimetric Method ◽  
Relative Standard ◽  
Optimized Conditions

New simple spectrofluorimetric method with enhanced sensitivity has been developed and validated for the determination of the antidepressant paroxetine (PXT) in its dosage forms and plasma. The method was based on nucleophilic substitution reaction of PXT with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in an alkaline medium (pH 8) to form a highly fluorescent derivative that was measured at 545 nm after excitation at 490 nm. The factors affecting the reaction was carefully studied and optimized. The kinetics of the reaction was investigated, and the reaction mechanism was presented. Under the optimized conditions, linear relationship with good correlation coefficient (0.9993) was found between the fluorescence intensity and PXT concentration in the range of 80-800 ng ml-1. The limits of detection and quantitation for the method were 25 and 77 ng ml-1, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 3%. The proposed method was successfully applied to the determination of PXT in its pharmaceutical tablets with good accuracy; the recovery values were 100.2 ± 1.61%. The results obtained by the proposed method were comparable with those obtained by the official method. The proposed method is superior to the previously reported spectrofluorimetric method for determination of PXT in terms of its higher sensitivity and wider linear range. The high sensitivity of the method allowed its successful application to the analysis of PXT in spiked human plasma. The proposed method is practical and valuable for its routine application in quality control and clinical laboratories for analysis of PXT.

scholarly journals Enhanced Sensitivity and Detection of Near-Infrared Refractive Index Sensor with Plasmonic Multilayers

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7056
Author(s):  
Tan Tai Nguyen ◽  
Nguyen Van Sau ◽  
Quang Minh Ngo ◽  
Gauthier Eppe ◽  
Ngoc Quyen Tran ◽  
...  
Keyword(s):  
Refractive Index ◽  
Near Infrared ◽  
High Sensitivity ◽  
Dielectric Films ◽  
Silver Layer ◽  
Refractive Index Sensor ◽  
Detection Accuracy ◽  
Spr Sensor ◽  
Enhanced Sensitivity ◽  
Sensor Sensitivity

In this work, the multilayer of the surface plasmon resonance (SPR) sensor was optimized to achieve the maximum sensor sensitivity. By optimizing the thickness of the silver layer (Ag) and dielectric films (TiO2 and AlAs), the optimum sensitivity of the SPR sensor could be obtained. The performance of the SPR sensor proposed was compared with control simulations utilizing zinc oxide (ZnO) and molybdenum oxide (MoO3). The numerical results indicate that the figure-of-merits (FOM) of the SPR sensor was achieved around 150/RIU, corresponding to the sensor sensitivity of 162.79°/RIU with the optimized thicknesses of the TiO2, Ag, and AlAs layers of 140 nm, 60 nm, and 25 nm, respectively. This refractive index sensor shows the FOM to have high detection accuracy and high sensitivity that lead to finding potential application in bio-chemical detection with a small volume of liquid used in biological diagnosis.

scholarly journals A Novel Sensor Prototype with Enhanced and Adaptive Sensitivity Based on Negative Stiffness Mechanism

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4644
Author(s):  
Lijun Liu ◽  
Yongzhong Nie ◽  
Ying Lei
Keyword(s):  
Low Frequency ◽  
High Sensitivity ◽  
Negative Stiffness ◽  
Micro Electro Mechanical Systems ◽  
Enhanced Sensitivity ◽  
Landslide Hazards ◽  
Negative Stiffness Mechanism ◽  
Low Sensitivity ◽  
Electric Filed ◽  
Design And Manufacture

Loess–mudstone/soil-rock interfacial landslide is one of the prominent landslide hazards that occurs in soil rock contacting zones. It is necessary to develop sensors with high sensitivity to weak and low frequency vibrations for the early warning of such interfacial landslides. In this paper, a novel monitoring sensor prototype with enhanced and adaptive sensitivity is developed for this purpose. The novelty of the sensitive sensor is based on the variable capacitances and negative stiffness mechanism due to the electric filed forces on the vibrating plate. Owing to the feedback control of adjustable electrostatic field by an embedded micro controller, the sensor has adaptive amplification characteristics with high sensitivity to weak and low frequency input and low sensitivity to high input. The design and manufacture of the proposed sensor prototype by Micro-Electro-Mechanical Systems (MEMS) with proper packaging are introduced. Post-signal processing is also presented. Some preliminary testing of the prototype and experimental monitoring of sand interfacial slide which mimics soil–rock interfacial landslide were performed to demonstrate the performance of the developed sensor prototype with adaptive amplification and enhanced sensitivity.

Graphene Oxide Functionalized with Silver Nanoparticles and ZnO Synergic Nanocomposite as an Efficient Electrochemical Sensor for Diclofenac Sodium

NANO ◽  
2021 ◽  
Author(s):  
Saira Naz ◽  
Amjad Nisar ◽  
Lizhi Qian ◽  
Shafqat Hussain ◽  
Shafqat Karim ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Diclofenac Sodium ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Cost Effective ◽  
Fast Response ◽  
Industrial Applications ◽  
Ag Nps ◽  
Enhanced Sensitivity

The development of a highly sensitive and selective electrocatalyst for the detection of diclofenac sodium (D.S.) has remained a great challenge. In this work, graphene oxide functionalized with silver nanoparticles and zinc oxide (Ag–ZnO–GO) electrocatalyst was developed and investigated for the detection of D.S. The Ag–ZnO–GO/glassy carbon electrode exhibits high sensitivity and fast response within 3[Formula: see text]s owing to the efficient oxidation of D.S. at a very low potential at 0.25[Formula: see text]V. Moreover, the electrode shows a low detection limit of 0.02[Formula: see text][Formula: see text]M ([Formula: see text]) and long-term stability. To explore the synergic effects, the measurements of D.S. using GO, ZnO and ZnO–GO modified electrodes were also performed. The results demonstrate that the Ag–ZnO–GO nanocomposite electrode exhibits enhanced sensitivity and selectivity compared to the other electrodes. In addition, the electrode reveals excellent results for D.S. detection in the real samples as well. The enhanced performance of the proposed electrode is attributed to the improved electron transfer ability and synergic effects of the plasmonic Ag NPs and ZnO–GO structure. It is expected that Ag–ZnO–GO composite is a promising candidate for the construction of cost-effective electrochemical biosensors for medical and industrial applications.

Sign in / Sign up

Export Citation Format

Share Document