Microorganism study - Bacterial isolants from harsh environments Final report

Soil bacterial isolants from harsh environment

Vulnerability of CMOS image sensors in megajoule class laser harsh environment

CMOS image sensors (CIS) are promising candidates as part of optical imagers for the plasma diagnostics devoted to the study of fusion by inertial confinement. However, the harsh radiative environment of Megajoule Class Lasers threatens the performances of these optical sensors. In this paper, the vulnerability of CIS to the transient and mixed pulsed radiation environment associated with such facilities is investigated during an experiment at the OMEGA facility at the Laboratory for Laser Energetics (LLE), Rochester, NY, USA. The transient and permanent effects of the 14 MeV neutron pulse on CIS are presented. The behavior of the tested CIS shows that active pixel sensors (APS) exhibit a better hardness to this harsh environment than a CCD. A first order extrapolation of the reported results to the higher level of radiation expected for Megajoule Class Laser facilities (Laser Megajoule in France or National Ignition Facility in the USA) shows that temporarily saturated pixels due to transient neutron-induced single event effects will be the major issue for the development of radiation-tolerant plasma diagnostic instruments whereas the permanent degradation of the CIS related to displacement damage or total ionizing dose effects could be reduced by applying well known mitigation techniques

Localization for Anchoritic Sensor Networks

We introduce a class of anchoritic sensor networks, where communications between sensor nodes is undesirable or infeasible, e.g., due to harsh environment, energy constraints, or security considerations

A gas sensor system for harsh environment applications

A novel low power, miniature gas sensor measuring system is presented for application in harsh environmental conditions, i.e. to detect carbon monoxide and oxygen at temperatures of up to +225oC and high relative humidities up to 95%. The gas sensors are fabricated using SOI high temperature technology and two full custom ASICs are embedded into a high-temperature circuit board interfaced to a low-cost general purpose microcontroller. The sensor system has been developed for a CO concentration range of 0 to 300 ppm, O2 concentration range of 0 to 21%, and monitors the humidity and temperature of the gas, as well as operating temperatures of micro-heaters within the two MOX gas sensors. Feedback control is built into the program of the micro-controller to compensate for temperature dependence of gas sensors. Preliminary experiments show promising results for the intended application within domestic boilers

Embeddable Advanced Sensors for Harsh Environment Sensing Applications

Research and development in advanced sensors with embedded monitoring capability have experienced significant growth in recent years, fueled by their broad applications in real-time measurement of a wide variety of physical, chemical, and biological quantities. Compared with conventional sensors with bulky assemblies, recent progress in 3D manufacturing technologies (e.g., ultrafast laser micromachining and additive manufacturing) has opened up a new avenue in one-step fabrication of assembly-freemicro devices in various materials as well as the development of compact, customized, and intricate smart structures/components. The merits of these advanced manufacturing techniques enable the integration of embeddable advanced sensors into smart structures and components for improved robustness, enriched functionality, enhanced intelligence, and unprecedented performance

Dependable reconfigurable multi-sensor poles for security

Wireless sensor network poles for security monitoring under harsh environments require a very high dependability as they are safety-critical [1]. An example of a multi-sensor pole is shown. Crucial attribute in these systems for security, especially in harsh environment, is a high robustness and guaranteed availability during lifetime. This environment could include molest. In this paper, two approaches are used which are applied simultaneously but are developed in different projects. \u

Sensors for Harsh Environment: Radiation Resistant FBG Sensor System

This paper presents radiation resistant characteristics of fibre Bragg grating (FBG) sensors written in a photosensitive fiber and connected to a silica core radiation resistant optical fibre, aiming to develop a sensor system suitable for both sensing and data transmission in harsh environment. The silica core fluorine-down-doped clad optical fibre has been specifically designed and fabricated for this study using the modified chemical vapor deposition technique. Key waveguide parameters, including the width of the fluorine doped inner cladding have been optimized to obtain a low loss (<;0.2 dB/km) at the operating wavelength region of 1550 nm. The fibre fabrication process, mainly the deposition condition, has also been optimized to achieve smooth deposition and sintering of silica core layers, to minimize radiation induced absorption. As a result, radiation induced absorption of ~2.2 dB/km at 1550 nm under accumulated dose of 25 MRad at dose rate of 0.39 MRad/hr has been successfully achieved. To create an effective sensor system for harsh environmental conditions, this specialty fibre is connected to a number of FBGs (sensors) fabricated in photosensitive fibres prior to their extensive evaluations by being exposed to different accumulated dose of gamma radiation. Their corresponding Bragg wavelength shifts (BWS) and peak amplitudes were continuously monitored. It was found that the radiation induced BWS can be greatly reduced by shielding the sensors using stainless steel tubing. The temperature sensitivity and peak amplitude were found to be largely unchanged before and after exposure to Gamma radiation of 25 MRad which shows their potential use for temperature measurements in radiation environments with an uncertainty of around 0.1 °C

Alaskan Submarine Cables: A Struggle with a Harsh Environment

Reviews the laying, repair and maintenance of telegraph and cable systems, at one time 86 submarine cables, between Puget Sound and Alaska 1901-60. Failures due to entanglement by whales, bruising and mauling by anchors and fishing trawls and various destructive effects of geologic agents on the sea floor are noted. In straits on the continental shelf and upper continental slope, cable failures are attributed primarily to chafe by bottom currents and, off the mouths of major streams, to turbidity currents and gravitational slides. Cable repair data for 1903-58 are tabulated, showing reported causes. Some cables at depths of 1000-1500 fathoms on the continental margin cross at least 40 major canyons, but have never failed because of turbidity currents; this indicates a lapse of 2000, possibly 5000 yr since such currents occurred in this region.Les c&acirc;bles sous-marins en Alaska, une lutte contre un milieu difficile. A un moment donn&eacute;, le syst&egrave;me de communications de l'Alaska comprenait 86 c&acirc;bles t&eacute;l&eacute;graphiques sous-marins, s'&eacute;tendant du Puget Sound vers le nord &agrave; travers l'Alaska c&ocirc;tier, puis vers l'ouest jusqu'&agrave; l'arc des Al&eacute;outiennes. Les pannes de ces c&acirc;bles sont r&eacute;v&eacute;latrices des forces dynamiques naturelles qui affectent le fond des mers. Dans les d&eacute;troits du plateau continental et de la partie sup&eacute;rieure du talus continental, les bris s'expliquent par le frottement d&ucirc; aux courants profonds&nbsp;: &agrave; l'embouchure des grands cours d'eau, ils sont provoqu&eacute;s par les courants de turbidit&eacute; et les glissements sous-marins