Lightweight, Compact, and High-Sensitivity Passive Fourier Transform Infrared Spectroscopy-Based Gas Detection System.

Potential-induced degradation of n-type front-emitter crystalline silicon photovoltaic modules — Comparison between indoor and outdoor test results

This study is in regard to the gas detection system and gas detection method utilizing smart phone. This study includes; 1) the sensor module attached to the smart phone to detect and measure flammable gas or toxic gas; and 2) gas detection APP which is installed inside the smart phone and recognizes the user information and location information automatically by reading RFID tag indicating the user or the location to detect gas through the contact area where RFID and blue tooth reader is installed inside of the above mentioned smart phone, and then measures the combustible gas or toxic gas by operating above mentioned sensor module and obtains the data thus measured, and above mentioned smart phone is characterized by its transmission of the above mentioned user information, location information and measured data which are obtained by above mentioned gas detecting APP to operation server via communication network. With this, reliability for the location detecting gas by the user, the result of the measurement, etc. can be secured. Furthermore, this provides the effect of preventing artificial manipulation at the time of input which is associated with the identification of the user to be measured by utilizing removable sensor module and application or the mistake resulted from wrong input by the user. In addition, by transmitting the measured data from the sensor module carrying out gas detection to operation server, this provides the effect of making it possible to process the data thus collected to a specialized data for combustible gas or toxic gas.

Operating FPSO's in severe weather conditions probably constitutes one of the most challenging aspects facing today's Offshore Oil Industry. Part of the challenge resides in achieving an optimal availability and reliability of the Gas Detection Systems. The proposed paper describes the approach and methodology adopted in response to specific challenges encountered while commissioning the Gas Detection System onboard an FPSO operating offshore the East Coast of Canada. Its contents will hopefully fit the Conference theme of "Delivering Sustainable HSE Performance Improvement Through Sharing". The subject Gas Detection System was being commissioned in preparation for first hydrocarbons in the thick of winter, and prevailing weather conditions exacerbated the situation, resulting in a significant number of gas detectors' faults being recorded. An action plan was put in place to identify the underlying causes and come up with the necessary improvements and enhancements to raise the system's performance to an acceptable level. Three major initiatives were undertaken to achieve the set objectives prior to production operations starting, and to maintain them through the life cycle of the facility. These initiatives were: A comprehensive internal operability review to determine the overall reliability for detecting gas within a given fire zone, and confirm all hardware and software is operational and within design parameters. An external review study by a specialist consultant to assess the detectors performance against the performance target using 3D modelling and mapping techniques. he development of an in house tracking mechanism to monitor both real time and retrospectively the performance of all gas detection devices on the FPSO. In conclusion, the above highlighted initiatives successfully allowed the FPSO Operator to demonstrate, and continue demonstrating an acceptable level of reliability and availability of the gas detection system, at all times during production operations.

In today's information age, digital signal processing technology with a new form of technology has been applied to various fields of society, and with its own significant advantages, in each field has played a powerful role. In order to ensure the air quality of living and working environment, the primary task is to analyze the main pollutants in the air. In addition to traditional chemical monitoring methods, digital signal processing methods are more common to detect pollutants, but filtering technology is needed to overcome the noise interference in the detection process. In this paper, the digital filter technology in digital signal processing is described in detail, and the model of digital signal in gas detection principle is simply abstracted, and the main application of digital signal processing technology in gas detection is described at last. At the same time, the paper analyzes the application of digital signal processing technology in gas detection, hoping to provide some help to the application of this technology and the good detection and treatment of gas pollution. Finally, a signal processing device for differential gas detection and its gas detection system are introduced.

In recent years the complexity and cost of Fire and Gas detection systems have increased rapidly with no measurable reduction in fatality rates or other losses. A principal reason for this disappointing outcome despite substantial investment is that systems designs have lost the focus of what they are trying to achieve. Another reason worth exploring is that investment in other areas may result in greater benefits. For instance, diverting funds to preventing lifting accidents, helicopter failures and materials handling incidents, could result in greater OVERALL benefit since these account for a larger proportion of risks. Nevertheless, Fire and Gas detections systems have a major role to play in preventing escalation, and this paper shows how they can be made more efficient in both cost and performance by combining four methods: targeting perceived hazards,integration from concept stage with other safety designs,control of design with effective performance specification, andcontrol of modifications throughout the system's life.

Over the past three decades, gas leakage is a major problem in the households, hotels, street shops, industries, apartments etc. The number of deaths due to the explosion of gas cylinders has been increased in recent years. The main idea of this paper is to compare different articles worked on the gas detection, to save people lives and their property from the fire accidents. There are several methods to stop the accidents due to the gas leakage that is to install the gas leakage detection system which can automatically detects the gas and helps to stop the gas leakage. The gas detection system detects the LPG, using gas sensors and to monitor temperature in different places. The gas detection system is built using Gas Sensor, Arduino Uno and some output devices. Due to this gas leaking the houses, apartments, industries, big buildings will be in risk because of the fire exposures. Mainly, the gas detection system is used for sending SMS to the user or authorized person that he can take immediate actions like turning off the gas valve from the cylinder and call to the fire station while fire is exposing. When the gas is leaking the buzzer gives a beeping sound that indicates the fire is detected. This system opens the windows, doors automatically when the gas is leaking and then GSM alerts the users that the gas is leaking by sending a notification to their mobile. Mostly fire accidents occurred because of the poor quality of rubber tube in gas cylinders. The gas supply from regulator to the burner may be on even the regulator is in off condition due to blocks in burner or leakage of gas pipes. When the gas leakage goes high it turns ON the LED to indicate and makes an alarm with the help of buzzer. Most of the system used 16×2 LCD display for this problem. An LCD displays the gas leakage result. This paper discussed about the future problems due to the gas leaking and the development in gas leakage.

Over the past two decades Rel-Tek developed and supplied permissible gas detection systems (GDS) for two large salt mines—Morton Salt, Weeks Island Facility, New Iberia, Louisiana, USA and Compass Minerals (formerly North American Salt) Franklin, Louisiana, USA. Both underground mines were deemed hazardous (i.e. containing methane gas) by MSHA (US Dept of Labor, Mine Safety and Health Administration) so all of the electrical gas detection equipment required protection against methane gas ignitions throughout the mine. This required a combination of MSHA-approved Explosion Proof (XP) and Intrinsically Safe (IS) products. A two-stage Blast Timer software feature was included to aid in production management. Data and alarm logging provides historical records, printable off line. Multiple Touch screen display terminals distribute information throughout the operation. The GDS is modularly expandable to suit virtually any mine configuration, and is particularly applicable to Chinese coal mines where they are fully hazardous, from the portable to the face.

In this paper, two methods for directly identifying inertial parameters of manipulator are proposed, which solves the problem that inertial parameters are difficult to identify due to coupling. First, a Model Identification Method (MIM) is proposed based on multibody dynamics. MIM realizes the decoupling of inertial parameters by the mathematical description of graph theory, and has extremely high identification accuracy. Since complex modeling and calculation will affect the real-time performance of the algorithm, MIM is suitable for offline identification. Second, a numerical identification method (NIM) is proposed based on neural networks. NIM avoids complex mechanical modeling process and obtains the approximate value of inertial parameters by numerical fitting method. Compared with MIM, the identification results lose some accuracy. However, NIM has excellent real-time performance and is suitable for online identification. Finally, the effectiveness of the method is verified by simulation experiments. MIM and NIM have complementary characteristics and different application scenarios, which can meet the vast majority of identification needs. The obtained results shed light on achieving precise control of manipulators.

In order to solve the problem that the deep neural network model is large in scale, the calculation time is too long, and the real-time performance is severely limited when combined with embedded devices, so studied the intelligent follower robot system based on YOLO-LITE algorithm combined with Raspberry Pi 3B+. The system mainly includes camera processing, target detection and other modules. Obtained the internal and external parameters of the camera through calibration, and according to these parameters to correct the binocular camera. Recognized and located the target in each frame of image, calculated the distance from the camera to the target and the center location error, and driven the car to move. The experimental results show that the following car has excellent real-time performance, the average detection frame rate can reach 20Fps, and the average detection accuracy can reach more than 80%.

Design of an automated cyanide gas detection and control system for a gold mine

CO concentration prediction in mid-infrared TDLAS systems via an EWT-SE-WTD enhanced BPNN model.

This paper proposes the design of a highly responsive, compact, non-contact methane telemetry sensor, employing the open-path tunable diode laser absorption spectroscopy (OP-TDLAS) technology. The sensor uses the dual-core structure of FPGA and ARM to achieve high-speed methane telemetry at 100 KHz repeated modulation frequency for the first time with a non-cooperate target, and a higher gas responsive time of 1.8 ms was achieved than previously reported. Moreover, the optical system (L × W × H: 68.8 × 52 × 62.7 mm) and the electronic system (L × W: 70 × 50 mm) make the sensor more compact. Methane gas samples of varying integral concentrations were examined at a distance of 20 m. The amplitude of the absorption peaks was subjected to a linear fit with the standard concentration values, resulting in a robust linear correlation coefficient (R2 = 0.998). Notably, despite the compact form factor of the methane sensor, it demonstrated commendable stability in gas concentration detection, offering a minimum detection limit of 43.14 ppm·m. Consequently, this highly responsive and compact methane sensor, with its open-path feature, is apt for integration into a variety of applications requiring such attributes. These include handheld telemetry devices, Unmanned Aerial Vehicle (UAV) gas detection systems, vehicle mounted gas detection, and laser gas radar.

In this work, we present a low cost multi gas detection system for simultaneous measurement of up to three gases. The main conclusions are based on the investigation of the concentrations of CO2 gas as well as of CH4 gas and of H2O vapor. It was found that the continuous heating of the IR source and the absolute values of thermopile voltages are not suitable parameters for the gas detection because of their high sensitivity to the influence of temperature and/or gas flow parameters. A sine like signal is preferential for our measurement system. The amplitude of the sine is very stable and is proportional only to the concentration of particular gas (according to the optical filter) and is not dependent on the concentration of other gases or on temperature. In this way, the CO2 gas concentration can be measured from 50 ppm to 400000 ppm with the same measurement setup. The lowest detectable concentration of CH4 was about 500 ppm.

This paper designs a TDLAS CO₂ gas detection system based on STM32H750. The system uses VCSEL laser as the core light source, and realizes the high precision and high sensitivity detection of CO₂ gas by combining hardware and software. The temperature control system developed in this paper can control the system temperature accurately, controlling the output wavelength of the laser and stabilizing the spectral line coefficient of the gas absorption line effectively. The accuracy and stability of the gas detection system are improved significantly.

The Staebler-Wronski effect in amorphous silicon based photovoltaic devices is responsible for degradation of their power conversion efficiency, within approximately the first one thousand hours of light soaking. Several experimental studies led to highlight the performance instability phenomena for the mentioned devices, underling that recovery and improvement of such performance are observable, by subjecting such devices (both of single-junction and tandem types) to DC reverse bias stresses under illumination, or to operation in the Maximum Power Point (MPP) under variable conditions of temperature and illumination. In this work, we present and discuss the results of novel recent outdoor tests on stabilized specimens (i.e., exposed to 1000 h extended light soaking, before our tests) of tandem amorphous/microcrystalline Si (a-Si/µc-Si) photovoltaic (PV) minimodules operating in their MPP, by analyzing the causes of the performance instability effects, systematically observed on a daily scale. During the mentioned tests, we have monitored the solar cell operating temperature and the incident solar spectrum at various times in different days to verify the effect of cell temperature and solar spectrum changes on the cell performances. The experimental results show a clear correlation between performance improvements of the photovoltaic modules and their thermal history during the outdoor tests, proving the interplay between defect build-up at a lower temperature and defect annealing at a higher temperature, taking place in the solar cells operated in MPP during conventional outdoor operation.