optical detection Articles

  • Chemical sensing with nanowires using electrical and optical detection

    Chemical nanosensors based on inorganic nanowires hold promise for the extremely sensitive, direct detection of pollutants, toxins and biomolecules on platforms small enough to be integrated on optoelectronic chips or even deployed in living organisms. This paper discusses two approaches to nanowire-based chemical and biological detection. First we review the development of electrically-driven ...


    By Inderscience Publishers

  • Advances in Optical Techniques for Moisture and Hydrocarbon Detection

    Abstract Every year, the world uses in the region of 100 trillion scf (standard cubic feet) of natural gas (1). All of this gas requires treatment before it enters the pipeline, making natural gas processing a key global industry. Minimization of costs is achieved through optimization of these processes, requiring accurate online measurement of gas composition at multiple points in the ...


  • Assessment of detection limits of fiber-optic distributed temperature sensing for detection of illicit connections

    Distributed temperature sensing (DTS) with fiber-optic cables is a powerful tool to detect illicit connections in storm sewer systems. High-frequency temperature measurements along the in-sewer cable create a detailed representation of temperature anomalies due to illicit discharges. The detection limits of the monitoring equipment itself are well-known, but there is little information available ...


    By IWA Publishing

  • Optical encoders and LiDAR scanning

    Overview Modern technology is taken for granted; a driver only needs to type a destination into a SATNAV system and step-by-step instructions, journey distance and duration, driving conditions and hazards, as well as alternative routes, instantly appear. In order to work, highly accurate and up-to-date maps are required of an entire country's road ...


    By Renishaw plc

  • Rockfall precursor detection based on rock fracturing monitoring by means of optical fibre sensors

    The monitoring of the acoustic emissions (AEs) due to rock fracturing allows the detection of the rockfall precursor signals, leading to a strong improvement of the real time assessment of the induced risk. A network of piezoelectric sensors (PZTs) provides reliable AE data, as testified by a series of applications in non–destructive testing, but PZTs are strongly affected by lightings and ...


    By Inderscience Publishers

  • Spin–orbit coupling and optical detection of spin polarisation in triangular graphene quantum dots

    We present a theory of the effect of spin–orbit coupling on optical properties of triangular graphene quantum dots (TGQD). TGQDs with zigzag edges exhibit a degenerate band of states at the Fermi level. For the charge neutral TGQD, the shell is expected to be half–filled by spin polarised electrons leading to finite magnetisation. Using four–band tight–binding and effective Kane–Mele models, we ...


    By Inderscience Publishers

  • Detect Hydrogen Gas and Flames

    Under day-to-day conditions, people cannot see, smell, or taste the presence of hydrogen gas. Hydrogen, however, is very flammable and requires only a small amount of energy to ignite. In fact, if leaking from a pipe at a high enough pressure, hydrogen gas can self ignite without the aid of an external energy source. Working together, ...

  • Detection of moisture in ammonia gas

    Problem Statement As technologies advance, so does the request for ultra high purity ammonia. Ultra high purity (UHP) ammonia is used in the semiconductor industries, production of flat panel displays, and a number of other applications. Due to this rising interest in UHP ammonia, manufacturers are having to battle ammonia’s most prominent and damaging impurity--moisture. For ...


    By CIC Photonics, Inc.

  • Data Collection for Smart LDAR - Optical Imaging

    Abstract:  Use of infrared cameras to discover gaseous VOCs as part of a Fugitive Emissions Leak Detection And Repair (LDAR) regulatory compliance program is new to the chemical processing and oil ...


    By InspectionLogic Corporation

  • Oil & Gas Leakage Detection Contractors

    RADS (Remote Aerial Detection Systems) teamed with market leading vendors to supply state-of-the-art Intelligence Surveillance and Reconnaissance (ISR) and security equipment. RADS is a US-based top-tier Technology Integrator that serves international commercial and government customers across the world. Unlike the large US defense contractors, RADS is independent and can operate with agility ...


  • Optical bioassay for measuring sublethal toxicity of insecticides in Daphnia pulex

    Many emerging contaminants tend to be biologically active at very low concentrations, occur in water as part of complex mixtures, and impact biota in ways that are not detected using traditional toxicity tests (e.g., median lethal concentration). To evaluate emerging contaminants, the authors developed a method for detecting sublethal behavioral effects by quantifying the swimming behavior of ...


    By John Wiley & Sons, Ltd.

  • Fibre optic sensors as a non–destructive tool for structural monitoring

    Structural monitoring is a diagnostic tool for detection of defects/damages and for scheduling maintenance operations. It is essential to determine the safety of the structures by Non–Destructive Testing (NDT) for evaluation of strength/integrity. This assessment is required for the repair, rehabilitation and life extension of the structure. Fibre Optic Sensors (FOS) are attractive sensing ...


    By Inderscience Publishers

  • Time-Domain Physical-Optics Simulation Technique for Electromagnetic Imaging by Subsurface Radar

    Abstract - This paper presents a 2-D scalar numerical time-domain (TD) model based on physical optics (PO) for simulation of electromagnetic phenomena. This TD-PO model should be applied for detection and location of objects hidden in opaque media by subsurface TD radar system. The proposed approach allows considering of basic physical principles, governing electromagnetic radiation and ...


    By Transient Technologies LLC

  • Estimation of stand productivity from multi-angular optical remote sensing

    Global modeling of gross primary production (GPP) is a critical component of climate change research. On local scales, GPP can be assessed from measuring CO2 exchange above the plant canopy using tower-based eddy covariance (EC) systems. The limited footprint inherent to this method however, restricts observations to relatively few discrete areas making continuous predictions of global CO2 fluxes ...


    By PP Systems

  • Optical DO Sensors Opening Doors to Online Aeration Control

    BACKGROUNDThe benefits of using online, automated control of aeration systems using dissolved oxygen (DO) sensors are well known in the industry and have been widely documented (e.g. Olsson et al, 2005). In most wastewater treatment facilities using activated sludge, the electricity provided to the aeration system is one of the most significant operating costs and a good control system can help ...

  • Electrical and optical properties of p–type conductive NiO–Pt thin films

    In this work, we deposited NiO–Pt composite films with varying Pt content in the range of 0-25.83 at.%. An ultra high electrical resistivity (ρ) is obtained and cannot be detected by four point probe measurement when the Pt content in NiO films is lower than 1.46 at.%. As the Pt content in the films rises to 4.65 at.%, the ρ value can be reduced to 33.40 Ω cm, and it decreases significantly to ...


    By Inderscience Publishers

  • Plasmonic colorimetry: visual detection of environmentally relevant species

    Colorimetric detection of chemical species based on specially tailored noble metal nanoparticles is garnering increasing interest in the scientific community. The aggregation/dispersion of unmodified or ligand–functionalised plasmonic nanostructures upon binding to an environmental pollutant results in a colorimetric response, which can be easily discerned with the naked eye. This review ...


    By Inderscience Publishers

  • Affinity–based biosensors for heavy metal detection

    In recent years, there has been a pressing need for fast and reliable methods for environmental monitoring. Among the various pollutants, the heavy metals are some of the most harmful because these substances are non–biodegradable and retained by the ecological system. Conventional analytical techniques for heavy metals imply high cost, trained personnel and the repute that they are mostly ...


    By Inderscience Publishers

  • HPLC separation and detection of bisphenol a (BPA) in plastics

    The BPA or bisphenol A (Figure 1) has become well know over the past year as concerns for its effect on human health and well being have been raised. The concerns over BPA began with baby bottles and spread to include other types of bottles. BPA is used in the production of two very common polymers PVC and Polycarbonate. PVC, Polyvinyl chloride, is used in many different products including ...


    By PerkinElmer, Inc.

  • Laser gas detection is now cheap, fast and reliable

    Laser based gas detectors are now being used in a wide variety of applications for process and quality monitoring, and safety and environmental compliance. The reasons are that laser detectors are more reliable and less expensive than alternative solutions. Laser detectors combine semiconductor tunable diode lasers (TDL) and optical fibres developed by the telecommunications industry with ...


    By Boreal Laser Inc.

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