scholarly journals Salinity Sensing Characteristics Based on Optical Microfiber Coupler Interferometer

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 77 ◽  
Author(s):  
Lingjun Zhou ◽  
Yang Yu ◽  
Huimin Huang ◽  
Yuyu Tao ◽  
Kui Wen ◽  
...  
Keyword(s):  
Sea Water ◽  
Technical Solution ◽  
Structure Parameters ◽  
Sensor Signal ◽  
Device Structure ◽  
Response Sensitivity ◽  
Reading Error ◽  
Seawater Salinity ◽  
Optical Microfiber ◽  
Sensing Characteristics

In this paper, we report a novel and compact sensor based on an optic microfiber coupler interferometer (OMCI) for seawater salinity application. The OMCI device is fabricated by connecting Faraday rotating mirrors to the two out-ports of the microfiber coupler, respectively. The sensor signal processing is based on a wavelength demodulation technique. We theoretically analyze the sensing characteristics with different device structure parameters. Besides, the results show that the date reading error decreases with the thinner waist region and longer arm difference. Through the experiment, the reflection spectra red-shifted as the sea water salinity increased; the highest response sensitivity of the OMCI salinity sensor reached 303.7 pm/‰ for a range of 16.6–23.8‰, and the resolution was less than 0.03‰. This study provides a new technical solution for the development of practical optical fiber seawater salinity sensors.

Improving the water transpiration in a solar steam generation device

2019 ◽  
Vol 20 (1) ◽  
pp. 59-64
Author(s):  
Yuan Meng ◽  
Haibo Li
Keyword(s):  
Thermal Evaporation ◽  
Sea Water ◽  
Bulk Water ◽  
Solar Irradiation ◽  
Steam Generation ◽  
Device Structure ◽  
Water Transportation ◽  
Speed Up ◽  
Solar Steam Generation ◽  
Water Transpiration

Abstract Solar steam generation (SSG) has been proposed as one of the most advanced techniques to trigger solar energy desalination of sea water. Although many efforts have been dedicated to develop SSG devices, the efficiency remains relatively low. Previous work was mainly focused on thermal insulation film and light absorption. Attention has seldom been concentrated on device structure. Inspired by the manner of water transportation within flowers, we designed an artificial SSG unit which can effectively speed up the water transpiration from the bulk to the surface. Another advantage of such a device is that steam generation is separated from the bulk salty solution and thereby the solar thermal evaporation can be improved greatly. As demonstrated via the desalination experiment, the mass change and evaporation rate under 1 solar irradiation can reach as high as 2.51 kg/m2 and 1.26 kg/m2·h−1, respectively. Meanwhile, the evaporation efficiency is 74%. These values are much higher than those of traditional SSG devices and bulk water.

Comparison of Hydrogen Sensing Characteristics of CrNbO4 Prepared by Solid-State Route and Solution Combustion Synthesis (SCS)

2012 ◽  
Vol 710 ◽  
pp. 715-720 ◽  
Author(s):  
A. Sree Rama Murthy ◽  
K.I. Gnanasekar ◽  
V. Jayaraman ◽  
A.M. Umarji ◽  
T. Gnanasekaran
Keyword(s):  
Electrical Conductivity ◽  
Solid State ◽  
Combustion Synthesis ◽  
Solution Combustion Synthesis ◽  
Sensor Signal ◽  
Prepared Compound ◽  
Solution Combustion ◽  
Hydrogen Sensing ◽  
Solid State Route ◽  
Sensing Characteristics

Solution combustion synthesis is adopted for the preparation of CrNbO4. Its electrical conductivity is found to be less than that of the solid state synthesized compound. Hydrogen sensing property of solution-synthesized compound is comparable to that of solid-state prepared compound up to about 400 vppm of H2. However, the sensor signal saturates beyond 2500 vppm of H2. Hydrogen sensing property is compared between the combustion derived and solid state prepared compounds.

scholarly journals An Experimental Investigation the Optimum of Salinity and Ph of Sea-Water to Improve Oil Recovery from Sandstone Reservoir as A Secondary Recovery Process

2020 ◽  
Vol 1 (2) ◽  
pp. 83
Author(s):  
Madi Abdullah Naser ◽  
Mohammed A Samba ◽  
Yiqiang Li
Keyword(s):  
Oil Recovery ◽  
Sea Water ◽  
Recovery Process ◽  
Water Flooding ◽  
Core Flooding ◽  
Low Salinity ◽  
Seawater Salinity ◽  
Secondary Recovery ◽  
Two Parameters ◽  
The Impact

Laboratory tests and field applications shows that the salinity of water flooding could lead to significant reduction of residual oil saturation. There has been a growing interest with an increasing number of low-salinity water flooding studies. However, there are few quantitative studies on seawater composition change and it impact on increasing or improving oil recovery.  This study was conducted to investigate only two parameters of the seawater (Salinity and pH) to check their impact on oil recovery, and what is the optimum amount of salinity and ph that we can use to get the maximum oil recovery.  Several core flooding experiments were conducted using sandstone by inject seawater (high, low salinity and different pH). The results of this study has been shown that the oil recovery increases as the injected water salinity down to 6500 ppm and when the pH is around 7. This increase has been found to be supported by an increase in the permeability. We also noticed that the impact of ph on oil recovery is low when the pH is less than 7.

scholarly journals Evaluation of isotopes and elements in planktonic foraminifera from the Mediterranean Sea as recorders of seawater oxygen isotopes and salinity

2020 ◽  
Author(s):  
Linda K. Dämmer ◽  
Lennart de Nooijer ◽  
Erik van Sebille ◽  
Jan Haak ◽  
Gert-Jan Reichart
Keyword(s):  
Mediterranean Sea ◽  
Oxygen Isotopes ◽  
Environmental Variability ◽  
Sea Water ◽  
Numerical Models ◽  
Salinity Gradient ◽  
Western Mediterranean ◽  
Ocean Current ◽  
Seawater Salinity ◽  
The Mediterranean

Abstract. The Mediterranean Sea is characterized by a relatively strong west to east salinity gradient, which makes it an area suitable to test the effect of salinity on foraminiferal shell geochemistry. We collected living specimens of the planktonic foraminifer Globigerinoides ruber (white) to analyse the relation between element/Ca ratios, stable oxygen isotopes of their shells and surface seawater salinity, isotopic composition and temperature. The oxygen isotopes of sea surface water correlate with salinity in the Mediterranean also during winter, when sampled for this study. Sea water oxygen and hydrogen isotopes are positively correlated in both the eastern and western Mediterranean Sea, though especially in the eastern part the relationship differs from values reported previously for that area. The slope between salinity and seawater oxygen isotopes is lower than previously published. Still, despite the rather modest slope, seawater and foraminiferal carbonate oxygen isotopes are correlated in our dataset although with large residuals and high residual variability. This scatter can be due to either biological variability in vital effects or environmental variability. Numerical models backtracking particles show ocean current driven mixing of particles of different origin might dampen sensitivity and could result in an offset caused by horizontal transport. Results show that Na/Ca is positively correlated to salinity and independent of temperature. Foraminiferal Mg/Ca increases with temperature, as expected, and in line with earlier calibrations, also in the high salinity environment. By using living foraminifera during winter, the previously established Mg/Ca-temperature calibration is extended to temperatures below 18 °C, which is a fundamental prerequisite of using single foraminifera for reconstructing past seasonality.

scholarly journals Magnetic Field Sensing Characteristics Based on Optical Microfiber Coupler Interferometer and Magnetic Fluid

Photonics ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 364
Author(s):  
Shangpeng Qin ◽  
Junyang Lu ◽  
Minwei Li ◽  
Yang Yu ◽  
Junbo Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Low Cost ◽  
High Sensitivity ◽  
Intelligent Manufacturing ◽  
Response Characteristics ◽  
Application Potential ◽  
Optical Microfiber ◽  
Sensing Characteristics ◽  
Waist Radius

In this paper, a novel and compact magnetic field sensor based on the combination of an optical microfiber coupler interferometer (OMCI) and magnetic fluid (MF) is proposed. The sensor is made up of an OMCI cover with polydimethylsiloxane (PDMS) and MF, and it uses MF as a material for adjusting the magnetic refractive index and magnetic field response. The sensing characteristics of the sensor are analyzed, and the experimental test is carried out. Under the condition of the same OMC waist length, the sensor sensitivity increases with the decrease of the OMC waist radius. The sensitivity of 54.71 and 48.21 pm/Oe was obtained when the OMC waist radius was set at 3.5 and 4 μm, respectively. In addition, we also tested the sensing response time and vector response characteristics of the sensor. At the same time, we discuss the demodulation idea about the cross-sensitivity of the magnetic field and temperature. The sensor has the advantages of high sensitivity, low cost, small size, optimized performance, and convenient integration. It has huge application potential in the fields of navigation and industrial intelligent manufacturing.

Investigation of Intersubband Transition in GaAs/AlGaAs Quantum Well Infrared Photodetectors

2007 ◽  
Vol 31 ◽  
pp. 105-107 ◽  
Author(s):  
D.S. Li ◽  
W.J. Fan ◽  
Y.X. Dang ◽  
B.S. Ma ◽  
D.H. Zhang ◽  
...  
Keyword(s):  
Quantum Well ◽  
Absorption Peak ◽  
Infrared Photodetectors ◽  
Structure Parameters ◽  
Intersubband Transition ◽  
Intersubband Transitions ◽  
Device Structure ◽  
Transition Energies ◽  
Quantum Well Infrared Photodetectors ◽  
Simulation Results

We report the design, characterization and fabrication of GaAs/AlGaAs quantum well infrared photodetectors (QWIPs) to achieve intersubband transitions at expected long wavelengths. With eight-band k·p model, we calculated the E2-E1 transition energies of GaAs/Al0.25Ga0.75As QWs with the different well widths. According to the calculation, we designed a QWIP with the estimated detection wavelength around 9 μm. The actual device structure parameters, such as well width and Al composition, were confirmed by the XRD measurements. The absorption peak at 9.46 μm and the peak responsivity at 8.7 μm are obtained, which are very close to the simulation results.

scholarly journals Design and Investigation of the High Performance Doping-Less TFET with Ge/Si0.6Ge0.4/Si Heterojunction

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 424 ◽  
Author(s):  
Tao Han ◽  
Hongxia Liu ◽  
Shupeng Chen ◽  
Shulong Wang ◽  
Wei Li
Keyword(s):  
Integrated Circuits ◽  
Field Effect ◽  
High Performance ◽  
Field Effect Transistor ◽  
Structure Parameters ◽  
Device Structure ◽  
Ultra Low Power ◽  
Order Of Magnitude ◽  
Effect Transistor ◽  
Channel Control

A high performance doping-less tunneling field effect transistor with Ge/Si0.6Ge0.4/Si heterojunction (H-DLTFET) is proposed in this paper. Compared to the conventional doping-less tunneling field effect transistor (DLTFET), the source and channel regions of H-DLTFET respectively use the germanium and Si0.6Ge0.4 materials to get the steeper energy band, which can also increase the electric field of source/channel tunneling junction. Meanwhile, the double-gate process is used to improve the gate-to-channel control. In addition, the effects of Ge content, electrode work functions, and device structure parameters on the performance of H-DLTFET are researched in detail, and then the above optimal device structure parameters can be obtained. Compared to the DLTFET, the simulation results show that the maximum on-state current, trans-conductance, and output current of H-DLTFET are all increased by one order of magnitude, whereas the off-state current is reduced by two orders of magnitude, so the switching ratio increase by three orders of magnitude. At the same time, the cut-off frequency and gain bandwidth product of H-DLTFET increase from 1.75 GHz and 0.23 GHz to 23.6 GHz and 4.69 GHz, respectively. Therefore, the H-DLTFET is more suitable for the ultra-low power integrated circuits.

scholarly journals PREDIKSI SALINITAS AIR LAUT DENGAN DEEP NEURAL NETWORK

2019 ◽  
Vol 21 (2) ◽  
pp. 84-90
Author(s):  
Wiwien Widyastuti ◽  
J. B. Budi Darmawan
Keyword(s):  
Neural Network ◽  
Least Squares ◽  
Network Model ◽  
Deep Neural Network ◽  
Sea Water ◽  
Predictive Performance ◽  
Regression Method ◽  
Least Squares Regression ◽  
Data Set ◽  
Seawater Salinity

Research in the marine field is important to look at the state of the ocean's atmosphere and the biodiversity that can live in it. Based on the CalCOFI data set, seawater salinity correlates with the depth of the sea. Sea water salinity can be predicted based on its depth. The classic method that is often used is the least squares regression. Deep neural network is one of the machine learning methods that has been widely applied to regression problems. This study aims to find better predictive performance by comparing the least squares regression method and the deep neural network method. The research method is done first by making an equation model with the least squares regression method. Second, by training the deep neural network using the same data so that the network model is obtained. Furthermore, the results of both methods are compared by calculating MAE and MSE. The results showed that the network model with superior deep neural network was used to predict data outside the range of trained data compared to the least squares regression method.

scholarly journals The Influence of Track Structure Parameters on the Dynamic Response Sensitivity of Heavy Haul Train-LVT System

2021 ◽  
Vol 11 (24) ◽  
pp. 11830
Author(s):  
Zhi-Ping Zeng ◽  
Yan-Cai Xiao ◽  
Wei-Dong Wang ◽  
Xu-Dong Huang ◽  
Xiang-Gang Du ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Track Structure ◽  
Lateral Stiffness ◽  
Structure Parameters ◽  
Response Sensitivity ◽  
Vertical Stiffness ◽  
Rail System ◽  
Heavy Haul Train ◽  
Heavy Haul ◽  
Heavy Haul Railway

Background: In order to study the applicability of Low Vibration Track (LVT) in heavy-haul railway tunnels, this paper carried out research on the dynamic effects of LVT heavy-haul railway wheels and rails and provided a technical reference for the structural design of heavy-haul railway track structures. Methods: Based on system dynamics response sensitivity and vehicle-track coupling dynamics, the stability of the upper heavy-haul train, the track deformation tendency, and the dynamic response sensitivity of the vehicle-track system under the influence of random track irregularity and different track structure parameters were calculated, compared and analyzed. Results: Larger under-rail lateral and vertical structural stiffness can reduce the dynamic response of the rail system. The vertical and lateral stiffness under the block should be set within a reasonable range to achieve the purpose of reducing the dynamic response of the system, and beyond a certain range, the dynamic response of the rail system will increase significantly, which will affect the safety and stability of train operation. Conclusions: Considering the changes of track vehicle body stability coefficients, the change of deformation control coefficients, and the sensitivity indexes of dynamic performance coefficients to track structure stiffness change, the recommended values of the vertical stiffness under rail, the lateral stiffness under rail, the vertical stiffness under block, and the lateral stiffness under block are, respectively 160 kN/mm, 200 kN/mm, 100 kN/mm, and 200 kN/mm.

scholarly journals COMPARATIVE BEHAVIOUR OF CORROSION FOR CARBON STEEL IN NHATRANG BAY (VIETNAM) AND VLADIVOSTOK (RUSSIA) SEA WATER

2011 ◽  
Vol 14 (1) ◽  
pp. 65-77
Author(s):  
Xuan Ba Bui ◽  
Kharachenko U. V. ◽  
Beleneva I. A
Keyword(s):  
Carbon Steel ◽  
Mild Steel ◽  
Marine Environment ◽  
Russian Federation ◽  
Sea Water ◽  
East Sea ◽  
Natural Conditions ◽  
Seawater Salinity ◽  
Water Conditions ◽  
Comparative Results

Comparative results of corrosion testing for carbon steel in natural conditions of Nhatrang Bay (East Sea, Vietnam) and Vladivostok (Russian Federation) sea water are presented. It is concluded, that corrosion of carbon mild steel in marine environment of Nhatrang Bay at normal seawater salinity is 1.5 to 2.5 times higher than that in Vladivostoc sea water conditions.

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