Hydrogen Gas Sensor Based On Seven-core Fiber Interference And Pt-WO3 Film

Tungsten oxide (WO3) typically owns the characteristics of electrochemical, photo-chromic, and gas-chromic. The seven-core fiber (SCF) generates a strong interference signal that comprises super-modes. The thermo-optic and thermo-expansion characteristics of SCF were utilized with an aid of Pt-WO3 film that makes the sensor highly sensitive to the H2 gas environment. The sensor with spiral micro grooves by femtosecond-laser ablation considerably enhanced the H2 sensitivity from 3.28 nm% to 4.0 nm%, and obtained a response and recovery time \u3c 90 s

Inter-Cross De-Modulated Refractive Index And Temperature Sensor By An Etched Multi-Core Fiber Of A MZI Structure

We present a relative sensitivity of in-fiber inter-cross demodulation of a Mach-Zehnder interferometer (MZI) based on an etched multi-core fiber (eMCF). The sensor can measure the external refractive index (RI) and temperature with a large fringe visibility of 15 dB. It is tuned using a simple technique of slow chemical etching. When the outer cores of MCF will be exposed to the surrounding, a large difference of relative effective RI is observed, which enhances the sensitivity of the sensor. The sensor\u27s wavelength and intensity responses have displayed that it can function with three different inter-cross-demodulation phenomena. A superior RI sensitivity of 178.20 dB/RIU in the range of 1.334 to 1.370, and temperature sensitivity of 66.73 pm/°C in the range of 30 to 80 °C are obtained, with an adequate linear response. Besides, it can readily resolve the issues of cross-sensitivity. Moreover, it has many advantages including easy fabrication, compact size, multiplex, repeatable, stable, and can easily differentiate RI and temperature, which lack others

Gas Prices and Industrial Production Level: Empirical Evidence from Pakistan

Pakistan has a vast industrial base which contributes a large portion in economic growth and employs a large population directly and indirectly. The purpose of this research is to examine the shocks of natural gas prices on the industries that use extensive amount of natural gas in their production as raw material and heating source. The industries taken under study are cement, cotton cloth, cotton yarn, glass, nitrogen fertilizer, phosphorus fertilizer, paper and board, sheet iron and synthetic fiber and billet iron. Vector Auto regression (VAR) is applied to check the shocks using monthly data from January 2012 to September 2017, collected from Pakistan Bureau of Statistics (PBS). Impulse response function (IRF), Variance Decomposition and Granger Causality test were executed from VAR estimates to examine gas price shocks on industrial production level in short and long run. Results reveal that gas prices have shocks in short run on all major industries but in long run they seems to stabilize and the effect is minimized. The idea of the study is original and findings help investors, policymakers and regulatory authorities as lots of researches have been undertaken on oil prices shocks and industrial production, while none of research has been conducted on gas prices shocks and industrial production. Keywords: Gas Prices, Impulse Response Function, Industrial Production level    JEL Classifications: E30 L95 O13 O14 Q42 

Securing Cognitive Radio Networks using blockchains

Due to the increase in industrial applications of Internet of Things (IoT), number of internet connected devices have been increased accordingly. This has resulted in big challenges in terms of accessibility, scalability, connectivity and adaptability. IoT is capable of creating connections between devices on wireless medium but the utilization of scarce spectrum in efficient manner for the establishment of these connections is the biggest concern. To accommodate spectrum allocation problem different radio technologies are being utilized. One of the most efficient technique being used is cognitive radio, which dynamically allocate the unlicensed spectrum for IoT applications. Spectrum sensing being the fundamental component of Cognitive Radio Network (CRN) is threatened by security attacks. Process of spectrum sensing is disturbed by the malicious user (MU) which attacks the primary signal detection and affects the accuracy of sensing outcome. The presence of such MU in system, sending false sensing data can degrade the performance of cognitive radios. Therefore, in this article a blockchain based method is proposed for the MU detection in network. By using this method an MU can easily be discriminated from a reliable user through cryptographic keys. The efficiency of the proposed mechanism is analyzed through proper simulations using MATLAB. Consequently, this mechanism can be deployed for the validation of participating users in the process of spectrum sensing in CRN for IoTs.publishe

Temperature And Strain Sensing With Hybrid Interferometer

A hybrid interferometer for simultaneous measurement of strain and temperature is proposed and investigated experimentally. This hybrid design is composed of Fabry-Perot interferometer (FPI) and Michelson Interferometer (MI) cascaded with each other. It is developed by fusion splicing a single mode fiber (SMF), a multimode fiber (MMF), a dual side hole fiber (DSHF), a hollow core fiber (HCF) and a tapered-SMF. The tapered SMF was inserted into the HCF to form a reflection mirror for the FPI. The maximum temperature and strain sensitivity of the hybrid interferometer achieved through experiments is 11.6 pm/°C and 6.8 pm/mu varepsilon , respectively. The different sensitivities of FPI and MI to temperature and strain enable us to achieve simultaneous measurement. The proposed hybrid interferometer sensor has many attractive features such as, novel design, low cost, easy fabrication, compact size, and good sensitivity. Therefore, the proposed hybrid sensor could be widely deployed in plenty of applications, for instance, structural health monitoring, civil engineering, food manufacturing, chemical and medical fields

Thermo-coupled Temperature Sensors By Seven-core MCF Structures

In this paper, we present an enhanced sensitivity of temperature sensors based on thermo-coupled Multicore Fiber (MCF) structures. The sensors are all fabricated using a controlled arc power of a splicing device. Two different principles of a Mach-Zehnder interferometer (MZI) and Michelson interferometer (MI) have been observed experimentally. The MZI and MI structures exhibit temperature sensitivity as 136.67 pm/°C and 70.61 pm/°C, respectively, and found insensitive to the refractive index (RI). Also, its RI response can readily resolve the issues of cross-sensitivity

Comparison of haemoglobin level between high altitude people and low altitude people

Background: Hemoglobin is the iron holding and oxygen carrying protein found inside the red blood cells. Studies have been done on Hb level variations in gender, race and region but no comparative study on different altitude effects in Pakistan is reported. Comparison of Hemoglobin level between people living at high altitude and low altitude was done in this study. Samples from district Skardu Gilgit-Baltistan, Pakistan were used as high-altitude samples and samples from district Lahore, Pakistan were utilized as low altitude samples. Samples were obtained from those people who don’t have any haemoglobinopathies.Methods:  50 blood samples were collected for this study; 25 individuals were from low altitude level and 25 of high-altitude level. Estimation of hemoglobin concentration was done by Cyanmethemoglobin method to compare the individuals HB from low altitude with high altitude.Results: All the blood samples were properly analyzed, and the results extracted from the samples, living at low altitude were compared with those living at high altitude. Mean and standard deviation values were calculated, and they found to be different for both populations, people at high altitude and the people living at low altitude. 25 residents of high altitude showed following results of hemoglobin: mean=15.0 and SD=0.632. On the other hand, 25 individuals of low altitude revealed these results: mean=14.53 and SD=0.633.Conclusion: There was a significant difference in Hb level in blood at high altitude (7500 feet) and low altitude (711 feet from sea level) P=0.004.  Keywords: Hemoglobin, Standard Deviatio

Highly Sensitive Strain Sensor by Utilizing a Tunable Air Reflector and the Vernier Effect

A highly sensitive strain sensor based on tunable cascaded Fabry–Perot interferometers (FPIs) is proposed and experimentally demonstrated. Cascaded FPIs consist of a sensing FPI and a reference FPI, which effectively generate the Vernier effect (VE). The sensing FPI comprises a hollow core fiber (HCF) segment sandwiched between single-mode fibers (SMFs), and the reference FPI consists of a tunable air reflector, which is constituted by a computer-programable fiber holding block to adjust the desired cavity length. The simulation results predict the dispersion characteristics of modes carried by HCF. The sensor\u27s parameters are designed to correspond to a narrow bandwidth range, i.e., 1530 nm to 1610 nm. The experimental results demonstrate that the proposed sensor exhibits optimum strain sensitivity of 23.9 pm/με, 17.54 pm/με, and 14.11 pm/με cascaded with the reference FPI of 375 μm, 365 μm, and 355 μm in cavity length, which is 13.73, 10.08, and 8.10 times higher than the single sensing FPI with a strain sensitivity of 1.74 pm/με, respectively. The strain sensitivity of the sensor can be further enhanced by extending the source bandwidth. The proposed sensor exhibits ultra-low temperature sensitivity of 0.49 pm/°C for a temperature range of 25 °C to 135 °C, providing good isolation for eliminating temperature–strain cross-talk. The sensor is robust, cost-effective, easy to manufacture, repeatable, and shows a highly linear and stable response for strain sensing. Based on the sensor\u27s performance, it may be a good candidate for high-resolution strain sensing

A Design Of Taper-Like Etched Multicore Fiber Refractive Index-Insensitive A Temperature Highly Sensitive Mach-Zehnder Interferometer

We propose and demonstrate Mach-Zehnder interferometer (MZI), which is the refractive index (RI) insensitive and temperature highly sensitive based on etched multi-core fiber (MCF) structure. The MCF and Fiber Bragg Grating (FBG) are used as hybrid sensing elements. The fabrication of the interferometer is provided a new taper-like structure by etching the MCF to further expose the side cores to the surroundings. The interferometer has produced a sensitivity of 103.2pm/°C within the ambient temperature up-to 70°C. Moreover, the superior temperature sensitivity is 89.19pm/°C, 66.64pm/°C, 56.42pm/°C in the range of 24°C to 130°C, and RI-insensitive in the range of 1.34 to 1.38, for different waists of etched seven-core fiber interferometers (E7CFIs) \sim ~84.70\mu \text{m} , 93.10\mu \text{m} , 108.67\mu \text{m} , respectively. Compared with the conventional FBGs, the sensitivity of the interferometer is significantly improved by 8 times. E7CFI\u27s novel and advantageous features can easily be distinguished other devices. Besides, the proposed sensing architecture is compact, easy to fabricate, highly sensitive, easy to reproduce, and makes it an inexpensive fiber optic device