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A light intensity-modulated optical fiber sensor for continuous level measurement is proposed and demonstrated. The sensor is constructed by vertically arranging groups of fibers on the oblique surface which reflects all the incident light when the fibers are in the air but a small proportion of light when the fibers are immersed in the liquid. In order to implement easy modulation and detection, the angle of oblique surface is specially designed to get the maximum intensity modulation according to Fresnel reflection. The fiber groups consist of emitting and receiving fibers, which are tightly fixed to make it easy to detect reflected light based on side coupling effect. The calculation model of the oblique structure and the light path simulation by finite element analysis are used to optimize the oblique angle and prove the feasibility of the sensor. Gradient level experiments and stability tests in the laboratory indicate that the sensor has high sensitivity of 0.21mW/cm, superior resolution and good stability. © 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.

The platinum resistance temperature sensors, which are widely applied in high speed trains, have the disadvantage of unreliable performance which usually causes train delay. This paper presents a reliable high-speed train axle temperature monitoring system based on fluorescent optical fiber temperature sensor, which has the advantages of accurate temperature measurement, good versatility, simple principle, and low cost. The fluorescent decay effect is used to measure the temperature, and the optical fiber is used to transfer the fluorescent signal in order to overcome the failure of insulation, water, and electromagnetic interference (EMI). The system shows high accuracy and reliability in the type test, and will be used on the track engineering vehicle to get a real test.

Candida albicans is the most prevalent opportunistic fungus of humans and animals. While most studies focus on human isolates, they rarely focus on poultry isolates. In this study, C. albicans strains were recovered from poultry in the southern Hebei Province (China) and identified. Molecular typing and analyses were performed to understand the molecular epidemiology and genetic relatedness of the strains. The fungi were isolated from live birds with presumed candidiasis or their corpses. The isolates were identified based on morphology, differential medium culture, and rDNA internal transcribed spacer sequencing. The identified C. albicans strains were analyzed by ABC genotyping and multilocus sequence typing. Clonal groups were identified using the eBURST (version 3.0) software, and an UPGMA phylogenetic tree was constructed using the MEGA (version 6.06) software. Overall, 72 isolates were divided into three genotypes (A, B, and C), 48 novel sequence types (STs), five groups with 10 singletons, and four clades. Results indicated that candidiasis is common in poultry in the southern Hebei Province, and that the genetic composition of the C. albicans poultry population from the area is relatively complicated. Based on the eBURST analysis for the STs in this study and others, we suggest that C. albicans poultry isolates were relatively independent but not completely separated from human isolates. The strains with the same or closely related genotypes but recovered from both birds and humans could have transferred and evolved between the two types of host.

This paper reports on a novel fiber-optic ice sensor featuring oblique fiber end-faces, not perpendicular to the fiber axis. The inclination angles of the end-faces were respectively 50° and 30° for the source and signal fiber bundles. Ice-growth curves obtained in an icing wind tunnel showed that with increasing ice thickness, the output voltage of this sensor would reduce rapidly for glazed ice, increase rapidly for rime ice, and make no remarkable change for mixed ice. This significant difference is caused by the different optical intensity distributions for different ice types and can be used to accurately identify the ice type for aerospace applications.

The current study was to prepare a mouse-derived antibody against the angiotensin II type 1 receptor (AT1-mAb) based on monoclonal antibody technology, to provide a foundation for research on AT1-AA-positive diseases. Balb/C mice were actively immunized with the second extracellular loop of the angiotensin II type 1 receptor (AT1R-ECII). Then, mouse spleen lymphocytes were fused with myeloma cells and monoclonal hybridomas that secreted AT1-mAb were generated and cultured, after which those in logarithmic-phase were injected into the abdominal cavity of mice to retrieve the ascites. Highly purified AT1-mAb was isolated from mouse ascites after injection with 1 × 107hybridomas. A greater amount of AT1-mAb was purified from mouse ascites compared to the cell supernatant of hybridomas. AT1-mAb purified from mouse ascites constricted the thoracic aorta of mice and increased the beat frequency of neonatal rat myocardial cells via the AT1R, identical to the effects of AT1-AA extracted from patients’ sera. Murine blood pressure increased after intravenous injection of AT1-mAb via the tail vein. High purity and good biological activity of AT1-mAb can be obtained from mouse ascites after intraperitoneal injection of monoclonal hybridomas that secrete AT1-mAb. These data provide a simple tool for studying AT1-AA-positive diseases.

In this paper, an efficient structure of online adjustable variable fractional-delay filter (VFDF) for digital time-delay beamformer (DTDBF) is presented. The proposed structure is based on the decomposition of sine function. The efficiency improvement is achieved by decomposing the VFDF into two sub-VFDFs with lower polynomial order and a complex phase shift which can be easily realized by CORDIC algorithm. A high precision programmable delay element for DTDBF is designed with an FPGA as an example, and the implementation results show that the proposed structure can save over 6% of the logic elements (LEs) compared with the existing structures.

We present a novel light leaking optical fiber liquid level sensor for aircraft fuel measuring systems that is based on the side-emitting optical fiber. In operation, the fiber is bent as a spiral and inserted into the liquid, then the conducting light in the fiber will be scattered and transformed to be cladding mode and radiation mode. The radiation mode power in the scattering light is determined by the ambient refractive index. Since more power is lost in liquids than in the air, the output power of the sensor will monotonically decrease while the liquid level increases. The fiber is bent as a spiral to increase the sensor’s sensitivity. A laboratory prototype with a range of 1 m, a radius of 14 mm, and a screw pitch of 15 mm has been built and successfully demonstrated in water level measurement. The sensor’s response to liquid level is presented and shown to be consistent with the theory.