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Fiber Bragg grating sensors demonstrate a great potential as a structural health monitoring tool for civil structures to ensure structural integrity, durability, and reliability. The advantages of applying fiber optic sensors to a tall building include their immunity to electromagnetic interference and their multiplexing ability to transfer optical signals over a long distance. In the work, fiber Bragg grating sensors, consisting of strain and temperature sensors, are applied to structural monitoring of an 18-floor tall building since the date of its construction. The strain transferring rate from host material to the fiber core is discussed and the calibration of packaged fiber Bragg grating sensor is presented. The main purposes of the investigation are monitoring temperature evolution history within concrete during the pouring and curing process, measuring variation of the main column strains on the underground floor while upper 18 floors were subsequently added on, and monitoring relative displacement between two foundation blocks. Fiber Bragg grating sensors have been installed and integrated continuously for more than five months. Monitoring results of temperature and strain are presented in the paper. Furthermore, temperature lag behavior between concrete and its surrounding air is investigated.

We reported the effect of the deposition time of barrier layers on optical and structural properties of high-efficiency green-light-emitting InGaN/GaN multiple quantum wells (MQWs) by photoluminescence (PL) and high-resolution x-ray diffraction techniques. The MQW samples on (0001)-plane sapphire substrates were prepared with a ramping method by metalorganic chemical deposition. It was found that the structural or interface quality of the MQW system improved as the deposition time of barrier layers increased from 10 to 14 min, but lattice relaxation was still observed. The relaxation degree decreases from 33% to 6% as the deposition time increases. Temperature-dependent PL measurements from 12 to 300 K indicated that the integrated PL intensities start to decay rapidly as temperature rises above 50 K for the sample with the shorter deposition time, and above 100 K for the sample with the longer deposition time. The luminescence thermal quenching of the two samples suggests the two nonradiative recombination centers based on a fit to Arrhenius plot of the normalized integrated PL intensity over the entire temperature range. The first centers at higher temperatures show less difference for the two samples. The second centers at lower temperatures can be attributed to the trapping of carriers at the rough interface for the sample with the shorter deposition time and to the thermal quenching of bound excitons for the sample with the longer deposition time, respectively. [ABSTRACT FROM AUTHOR]

The article presents a study on the purification and biochemical characterizations of an antimicrobial protein from the housefly larvae induced by the ultrasonic wave. It says that during the evolution, insects have developed an innate immune system which differs from the immune system of vertebrates. Their defense mechanism lasts only for a few days but it offers a powerful resistances to microbial infections. It says that Musca domestica adults and the larvae are constantly exposed to the threat of microbial from the environment yet it manages to survive and multiply. The study showed that the discovery of the 16 kDA antimicrobial protein from the housefly larvae adds an example to the increasing family of antimicrobial proteins.