Interrogation Method Research Articles

Deep learning classification and regression models for temperature values on a simulated fibre specklegram sensor

Fiber optic specklegram sensors use the modal interference pattern (or specklegram) to determine the magnitude of a disturbance. The most used interrogation methods for these sensors have focused on point measurements of intensity or correlations between specklegrams, with limitations in sensitivity and useful measurement range. To investigate alternative methods of specklegram interrogation that improve the performance of the fiber specklegram sensors, we implemented and compared two deep learning models: a classification model and a regression model. To test and train the models, we use physical-optical models and simulations by the finite element method to create a database of specklegram images, covering the temperature range between 0 °C and 100 °C. With the prediction tests, we showed that both models can cover the entire proposed temperature range and achieve an accuracy of 99.5%, for the classification model, and a mean absolute error of 2.3 °C, in the regression model. We believe that these results show that the strategies implemented can improve the metrological capabilities of this type of sensor.

Comparative study of the highly sensitive plasmonic sensor based on a D-Shaped photonic crystal fiber with silver or gold layers

A highly sensitive D-shaped photonic crystal fiber sensor with circular lattice is proposed for external plasmonic sensing. The proposed design of plasmonic material in a D-shaped form effectively facilitates the excitation of surface plasmons and enhances the sensor performance. As a comparative study, two different plasmonic materials, gold and silver, are applied D-shapely on the fiber and the proposed sensor performance is numerically investigated and evaluated. Moreover, the optimized structural parameters such as air-hole diameters and the thickness of silver and gold layers are selected via simulation results which cause the highest sensitivity of 40000 nm/RIU for the gold coated fiber using the wavelength interrogation method. Furthermore, the maximum figure of merit can reach 621.50 Analytes with the refractive indices ranging from 1.34 to 1.39 can be detected by double-loss peak that is a more reliable method of simultaneous detection and verification of sensing characteristics. Due to its promising results, the proposed sensor can be widely useful in the area of chemical and biological sensing.

Isotope-Sensitive Imaging of Special Nuclear Materials Using Computer Tomography Based on Scattering Nuclear Resonance Fluorescence

The characterization and radiography of special nuclear materials (SNMs) such as plutonium and uranium is essential in various scenarios in the context of nonproliferation and national security. However, existing techniques are not sufficient in and of themselves for rapid isotope-sensitive interrogation of SNMs. In the present study, we propose an interrogation method, called scattering-nuclear-resonance-fluorescence-based computer tomography (SNRF CT), to reveal concealed SNMs with simultaneous measurements of the isotopic composition and tomographic distribution. Monte Carlo simulations show that three NRF signatures at 1802, 1846, and 1862 keV from a uranium target composed of ${ }^{235}\mathrm{U}$ and ${ }^{238}\mathrm{U}$, irradiated by a quasimonochromatic $\ensuremath{\gamma}$-ray beam of high intensity, can be identified. For different target configurations, sinograms of the SNRF signatures are obtained, and the tomographic distributions are reconstructed with appreciable image contrast and spatial precision. It is found that the tomographic patterns of ${ }^{235}\mathrm{U}$ and ${ }^{238}\mathrm{U}$ hidden in a 30-mm-diameter iron rod can be clearly visualized. Compared with transmission NRF CT (TNRF CT), SNRF CT has the advantage that it does not need a witness target or calibration of the notch-refill effect. Furthermore, the imaging time for SNRF CT is 20 times shorter than that for TNRF CT, assuming a low missed-detection rate of ${10}^{\ensuremath{-}4}$. We conclude that, using an intense $\ensuremath{\gamma}$-ray beam, the proposed SNRF CT technique is capable of simultaneous identification and tomographic imaging of the isotopic content of SNMs in a realistic measurement time. This imaging method could be extended to other applications in spent-fuel management and screening of cargo for explosives, drugs, and toxic chemicals.

Surface plasmon resonance chemical sensor composed of a microstructured optical fiber for the detection of an ultra-wide refractive index range and gas-liquid pollutants

A surface plasmon resonance (SPR) chemical sensor comprising microstructured optical fiber (MOF) is designed for refractive index (RI) sensing in the visible to near-infrared (0.42-1.60 µm) region (NIR) as well as detection of gas-liquid pollutants. To realize mode coupling and facilitate manufacturing, gold with inert and plasmonic properties and an analyte sensing layer are introduced to the external surface of the MOF. The sensor is analyzed by the full-vector finite element method (FEM) and the wavelength and amplitude interrogation methods are adopted to evaluate the sensing characteristics. Our analysis reveals a maximum wavelength sensitivity (WS) of 15,000 nm/RIU, amplitude sensitivity (AS) of 1,603.37 RIU-1, and resolution (R) of 6.67×10−6 RIU in the determination of analyte RIs spanning an ultra-wide range between 1.00 and 1.45. Furthermore, the figure of merit (FOM) and signal-to-noise ratio (SNR) of the sensor are 295.01 RIU−1 and 2.95, respectively. On account of its simple structure, low cost, and industrial compatibility, this multi-functional sensor has tremendous potential in the chemical industry, environmental monitoring, and safety control such as harmful gas monitoring, industrial wastewater and domestic sewage detection.

A new one-dimensional photonic crystal magnetic sensor based on magnetic fluid film with excellent sensing ability and figure of merit

A magnetic sensor based on a one-dimensional (1D) photonic crystal was proposed. The transmission characteristics of the 1D photonic crystal magnetic sensor were analyzed using the theory of rigorous coupled wave analysis (RCWA). The variation pattern of magnetic fluid films refractive index with magnetic field and the effect of structural parameters on sensitivity and figure of merit (FOM) were investigated. Based on the wavelength interrogation method, the resonance wavelength is red-shifted with the change of the magnetic field for certain structural parameters. The results show that the structure has a highly linear response within the external magnetic field variation range from 30 Oe to 90 Oe, and its sensitivity and FOM can reach 0.817 nm/Oe and 17.439 Oe−1. Due to the advantages of 1D photonic crystal structure has harp peak, highly linear response, and low transmission loss. The structure has a large potential for applications in complex environments and real-time monitoring.

An Overview of Strategies for Detecting Genotype-Phenotype Associations Across Ancestrally Diverse Populations.

Genome-wide association studies (GWAS) have been very successful at identifying genetic variants influencing a large number of traits. Although the great majority of these studies have been performed in European-descent individuals, it has been recognised that including populations with differing ancestries enhances the potential for identifying causal SNPs due to their differing patterns of linkage disequilibrium. However, when individuals from distinct ethnicities are included in a GWAS, it is necessary to implement a number of control steps to ensure that the identified associations are real genotype-phenotype relationships. In this Review, we discuss the analyses that are required when performing multi-ethnic studies, including methods for determining ancestry at the global and local level for sample exclusion, controlling for ancestry in association testing, and post-GWAS interrogation methods such as genomic control and meta-analysis. We hope that this overview provides a primer for those researchers interested in including distinct populations in their studies.

High-performance coherent population trapping clock based on laser-cooled atoms

We present a coherent population trapping clock system based on laser-cooled 87Rb atoms. The clock consists of a frequency-stabilized CPT interrogation laser and a cooling laser as well as a compact magneto-optical trap, a high-performance microwave synthesizer, and a signal detection system. The resonance signal in the continuous wave regime exhibits an absorption contrast of ∼ 50%. In the Ramsey interrogation method, the linewidth of the central fringe is 31.25 Hz. The system achieves fractional frequency stability of , which goes down to 1.8 × 10−13 at 20000 s. The results validate that cold atom interrogation can improve the long-term frequency stability of coherent population trapping clocks and holds the potential for developing compact/miniature cold atoms clocks.

49P Identifying and validating networks of oncology biomarkers mined from the scientific literature

Biomarkers are indicators of a biological state and have a pivotal role in estimations of disease risk, early detection, assessment of progression and outcomes prediction. Studies of cancer biomarkers are published daily, some are well characterized, while others are of growing interest. Managing this flow of information is challenging for scientists and clinicians. We sought to validate an AI-driven literature interrogation method and a publicly available tool to help researchers identify these emergent biomarkers.

KOREAN COMMUNICATION BEHAVIOR AND ITS PECULIARITIES

This article focuses on the Korean people's communication skills and their peculiarities. It also provides information on Korean communication methods and application units. There is also talk of interrogation methods.

Highly-sensitive Refractometer Based on a D-shaped Fiber Bragg Grating Integrated into A Loop-mirror Optical Fiber Laser

In this paper, we report a new type of refractometer based on a D-shaped fiber Bragg grating (FBG) integrated in a loop-mirror optical fiber laser. This proposed sensor is used in wavelength interrogation method, in which the D-shaped FBG is applied as a refractive index (RI) sensing probe and a mirror to select mode of laser. The D-shaped FBG is prepared by the removal of a portion of the fiber cladding covering the FBG by means of side-polishing technique. The D-shaped FBG sensing probe integrated in a loop-mirror optical fiber laser with saturated pump technique, the characteristics of sensing signals have been improved to obtain stable intensity, narrower bandwidth and higher optical signal-to-noise ratio compare to normal reflection configuration. The limit of detection (LOD) of this sensor can be achieved to 2.95 x 10-4 RIU in the refractive index (RI) range of 1.42-1.44. Accordingly, we believe that the proposed refractometer has a huge potential for applications in biochemical-sensing technique.

Design of surface plasmon resonance based both side polished photonic crystal fiber for highly efficient refractive index sensor

In this paper, both sides flat photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensor has been proposed. In this external sensing mechanism based sensor, we have used gold as plasmonic material with an adhesive TiO2 layer over it, enhancing the interaction between analyte channel and gold metal. Using the wavelength interrogation and amplitude interrogation method, the maximum wavelength and amplitude sensitivities are obtained 22,800 nm/RIU and 947 RIU−1, respectively, for analyte range 1.30–1.40 with a maximum wavelength resolution of 4.38 × 10−6. With Full-width half maxima (FWHM) around 45 nm, the sensor provides a high figure of merit (FOM) 507 RIU−1. The proposed sensor can be fabricated from newly available technologies such as the sol-gel method, stack and draw method for several practical applications in the bio-medical field, bio-chemical field to provide higher and accurate sensing results. The presented sensor has also played a vital role in cancer cell detection with higher sensing performance.

Measurement of Strial Blood Flow in Mouse Cochlea Utilizing an Open Vessel-Window and Intravital Fluorescence Microscopy.

Transduction of sound is metabolically demanding, and the normal function of the microvasculature in the lateral wall is critical for maintaining endocochlear potential, ion transport, and fluid balance. Different forms of hearing disorders are reported to involve abnormal microcirculation in the cochlea. Investigation of how cochlear blood flow (CoBF) pathology affects hearing function is challenging due to the lack of feasible interrogation methods and the difficulty in accessing the inner ear. An open vessel-window in the lateral cochlear wall, combined with fluorescence intravital microscopy, has been used for studying CoBF changes in vivo, but mostly in guinea pig and only recently in the mouse. This paper and the associated video describe the open vessel-window method for visualizing blood flow in the mouse cochlea. Details include 1) preparation of the fluorescent-labeled blood cell suspension from mice; 2) construction of an open vessel-window for intravital microscopy in an anesthetized mouse, and 3) measurement of blood flow velocity and volume using an offline recording of the imaging. The method is presented in video format to show how to use the open window approach in mouse to investigate structural and functional changes in the cochlear microcirculation under normal and pathological conditions.

Techniques To Exploit Vulnerabilities: Persuasion And Education In Chinese Police Interrogations

AbstractDrawing upon in-depth interviews with frontline police officers, this article examines persuasion and education as a psychological interrogation method routinely applied in Chinese police questioning. It analyses the three tactics employed by the interrogators in inducing the suspect to confess, including utilization of suspects’ personal relationships, their hope for the uncertain future and memories of past experiences. These mechanisms correspond to the three forms of universal vulnerability shared by human beings, namely the individuals’ susceptibility to human dependency, the predicament of irreversibility and uncertainty about the future. This article analyses the ways in which vulnerability as a universal human condition can be exploited by state coercion, and how this coercion produces the moral vulnerability of police.

Demonstration of High-Resolution DFB Fiber Laser Acoustic Emission Sensing System for CFRP Laminates

This paper proposes an interrogation method to improve the resolution of DFB (distributed feedback) fiber laser acoustic emission (AE) sensing system. In this method, the coefficients of three ellipses formed by every two-channel interference fringe are estimated using bias-corrected ellipse-specific fitting (BCESF). The system parameters can be further corrected using the coefficients of the three ellipses. A resolution of 2×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> pm/ √Hz at 100 kHz, which is approximately 10 dB higher than the traditional method, is achieved using the system parameters correction. The carbon fiber reinforced plastic (CFRP) laminates tensile test shows that the improved DFB fiber laser AE sensing system exhibits better performance than the PZT sensor. The damage initiation, damage spread, and instability stages of CFRP laminates' failure process can be accurately recognized.

Perlindungan Tahanan Pada Kamp-Kamp Penahanan Amerika Serikat

On May, 19th 2006, UN Anti-Torture Committee delivered a report that suggest a closing of the Guantanamo detention camp. The government of the United States of America then look an action by establishing the Law on Interrogation. The law stipulates several principles such as interrogation method and trial on terrorism that somehow legalizes the use of any means of force in such process. Another possibility that is stipulated in the Law is a conviction even the evidence is not visible. Tje protection of prisoner in the United States of America’s detention camp is regulated by both International law and national law. The tortures in such camps that was conducted to obtain a certain information have violated human rights that have been govern by international law and United States of Amarica’s national law itself.

Surface Plasmon Resonance Sensor Based on Double-Sided Polished Microstructured Optical Fiber With Hollow Core

A surface plasmon resonance sensor based on double-sided polished microstructured optical fiber with hollow core is put forward for refractive index sensing. Two gold films parallel to each other attached to the polished surface act as microfluidic sensing channels for the analyte. The artificially introduced air hole can facilitate the phase matching between the core mode and the plasmon mode. The sensitivities of the proposed sensor are investigated by the wavelength, amplitude and phase interrogation methods when the analyte refractive index increases from 1.33 to 1.34. In contrast to the D-shaped design, the double-sided polished structure demonstrates narrower resonance spectral width and greater phase sensitivity. Moreover, the numerical results indicate that the proposed sensor shows a good stability in the fabrication tolerances of ±5% of the thickness of gold film and the depth of polishing, respectively.

A surface plasmon temperature sensor based on E7 liquid crystal using angle interrogation method

ABSTRACT A prism-based surface plasmon resonance (SPR) sensor supported water/gas-based liquid crystal (LC) E7 is presented. A gold layer was internally attached to the chamber filled with LC. The results demonstrated that LC's resonance angle increases with the increasing temperature, and the variation can be detected by the absorption and angle shift of the plasmonic dip. The modeling results presented that the refractive index increases with increasing temperature at the variation from 15°C to 85°C. The temperature sensitivity was started at 0.06 degrees/°C at 15°C and reached the maximum value from 35 to 50 degrees/°C. The liquid crystal type E7 experimental results were compared with simulation results from 15°C to 85°C of MLC-9200-000, MLC9200-100, MLC-6608, TL-216, and E44. The water/LC-based SPR shows angle shift and absorption shift compared to gas/LC-based SPR. The SPR curve's sharpness was enhanced, but low angle shift and no absorption shift were recognized.

Algebraic solutions for the Fourier transform interrogator.

A new method for fast, high resolution interrogation of an array of photonic sensors is proposed. The technique is based on the integrated Fourier transform (FT) interrogator previously introduced by the authors. Compared to other interferometric interrogators, the FT-interrogator is very compact and has an unprecedented tolerance to variations in the nominal values of the sensors' resonance wavelength. In this paper, the output voltages of the interrogator are written as a polynomial function of complex variables whose modulus is unitary and whose argument encodes the resonance wavelength modulation of the photonic sensors. Two different methods are proposed to solve the system of polynomial equations. In both cases, the Gröbner basis of the polynomial ideal is computed using lexicographical monomial ordering, resulting in a system of polynomials whose complex variable contributions can be decoupled. Using an NVidia graphics processing card, the processing time for 1 026 000 systems of algebraic equations takes around 9 ms, which is more than two orders of magnitude faster than the interrogation method previously introduced by the authors. Such a performance allows for real time interrogation of high-speed sensors. Multiple solutions satisfy the algebraic system of equations, but, in general, only one of the solutions gives the actual resonance wavelength modulation of the sensors. Other solutions have been used for optimization, leading to a reduction in the cross-talk among the sensors. The dynamic strain resolution is 1.66 n ε/H z.

Boris Krajnc in drugi kemiki na dachauskih procesih

Boris Krajnc je bil prvi habilitirani učitelj ljubljanske univerze za področje biokemije - imenovanje v naziv docenta je datirano s 7. januarjem 1946. Vendar se je Krajnčeva življenjska pot zelo hitro končala, saj so ga 27. oktobra 1947 aretirali in 26. aprila 1948 na montiranem dachauskem procesu obsodili na smrt. Ustrelili naj bi ga 12. maja 1948, starega 34 let. Krajnčeva življenjska zgodba je tesno povezana z delom več slovenskih kemikov, ki so bili kot zaporniki v koncentracijskem taborišču Dachau izbrani za tehnično pomoč pri izvedbah poskusov na ljudeh ali pri delu v kliničnem laboratoriju. Na povojnih dachauskih procesih v Ljubljani je bilo skupaj obsojenih 8 kemikov, od teh jih je bilo 5 obsojenih na smrt in ustreljenih. V kasnejših presojah dachauskih procesov se je izkazalo, da so bile obtožnice skonstruirane, priznanja pa pridobljena s krutimi zasliševalskimi metodami, zato so bile vse sodbe razveljavljene. Po emigraciji encimatika Richarda Klemna ter pregonu Maksa Samca in Marte Blinc z univerze je bil Boris Krajnc tisti, ki naj bi skrbel za biokemijo na Tehniški fakulteti. Po njegovi smrti je nekaj let biokemijo predaval Krajnčev mlajši kolega Dušan Stucin z Medicinske fakultete, potem pa biokemije več let ni bilo v kemijskem kurikulumu.

Improved Pound-Drever-Hall Techniques for High Resolution Optical Fiber Grating Sensors

The interrogation technology plays a key role in high resolution fiber grating sensors. Due to the high sensitivity and quick response, the Pound-Drever-Hall (PDH) technique is one of the most successful interrogation methods in the high resolution fiber grating sensor systems. However, the traditional PDH technique can only interrogate one sensing element with limited measurement range, and can’t fully exploit the capability of optical fiber sensors. To break through this limitation, lots of efforts have been put to improve the PDH technique. This article reviews the recent improvements on PDH technique towards large measurement range and low probe power interrogation. Sideband interrogation method and high order PDH technique are proposed to expand the measurement range without tuning the laser frequency; In order to enable low probe power interrogation, which is essential in multiplexed sensing, coherent PDH and active PDH techniques are developed. Those improvements will promote the further development of PDH technique and provide powerful tools for high-resolution sensing applications.