Проявление линии Видома при микроволновых измерениях увлажненных перекисью водорода сорбентов

For deeply supercooled bulk water, anomalies of thermodynamic values are known near the Widom line, the locus of increased fluctuations of entropy and density. In this work, we measured the reflected power of microwave radiation at a frequency of 18 GHz from a silicate sorbent sample moistened with a hydrogen peroxide solution. In the experiment, we observed variations in the recorded reflected radiation power in the range –46 – –47 °С, determined by structural changes in the liquid. Thus, it is shown that fluctuations of water parameters near the Widom line are manifested in changes not only in thermodynamic, but also in electrophysical quantities.

Dynamic Measurement of Relative Complex Permittivity of Microwave Plasma at Atmospheric Pressure

Complex permittivity is one of the most important parameters to characterize the interaction between microwave and medium, especially for microwave-excited plasma. It is convenient to study plasma’s dielectric properties and microwave propagation characteristics by measuring its complex permittivity. A dynamic measurement method of equivalent relative complex permittivity of microwave-excited plasma at atmospheric pressure is proposed in this paper. Firstly, a cavity based on WR-430 at a frequency of 2.45 GHz was specially designed in COMSOL. Then, the samples with different real parts of complex permittivity and loss tangent were simulated in the designed cavity to obtain their corresponding S parameters, and they were used to train the BP neural network until the error was lower than 0.001. A two-port network was built to excite the plasma. The input power, reflected power, and transmitted power could be measured by the transmission reflection method. Finally, the measured power values were converted into S parameters and used as inputs in the BP neural network. The plasma’s real parts of complex permittivity and loss tangent were obtained by inversion. The variation of plasma complex permittivity conforms to the interaction principles between microwave and plasma, which verifies the accuracy of the method.

Fiber Bragg grating-based monitoring system for fiber to the home (FTTH) passive optical network

Fiber to the home (FTTH) passive optical network is one of the cost effective and effortlessly planning systems in the current era of communication systems. However, one of the substantial limitations of this optical communication network is the monitoring operation. It is essential to locate the fault branch in the network in order to take the required action to overcome the problem. Unfortunately, since the network is all passive, it is necessary to introduce a technique that should be passive and has the capacity to locate the fault location inside the network. In this paper, a methodology to localize the fault line was introduced, where a combination of Fiber Bragg Gratings was suggested, using this approach, the fault location can be easily determined among 36-branch, distributed in eight groups. Simulation results show that the broken line can be determined through monitoring the reflected signals from all the branches in the Central Office without paying any power to locate the leakage. In other words, it is easy to recognize the fault location by monitoring the power of the reflected signals, where after comprehensive simulations and power calculations, it was possible to put a threshold for that reflected power, hence, the fault branch, for any reason, may reflect power of less than that threshold, otherwise, the branch is not considered as broken.

Optimization of Fiber Bragg Gratings Inscribed in Thin Films Deposited on D-Shaped Optical Fibers

A fiber Bragg grating patterned on a SnO2 thin film deposited on the flat surface of a D-shaped polished optical fiber is studied in this work. The fabrication parameters of this structure were optimized to achieve a trade-off among reflected power, full width half maximum (FWHM), sensitivity to the surrounding refractive index (SRI), and figure of merit (FOM). In the first place, the influence of the thin film thickness, the cladding thickness between the core and the flat surface of the D-shaped fiber (neck), and the length of the D-shaped zone over the reflected power and the FWHM were assessed. Reflected peak powers in the range from −2 dB to −10 dB can be easily achieved with FWHM below 100 pm. In the second place, the sensitivity to the SRI, the FWHM, and the FOM were analyzed for variations of the SRI in the 1.33–1.4 range, the neck, and the thin-film thickness. The best sensitivities theoretically achieved for this device are next to 40 nm/RIU, while the best FOM has a value of 114 RIU−1.

Re-Situating Criminal Responsibility

Inspired by the work of Nicola Lacey as a leading critical criminal responsibility scholar, in my chapter, I offer a reflection on time and space and criminal responsibility. I introduce the notion of interstitial space as a useful analytical device to advance the field of critical scholarship on responsibility for crime. With a study of the intellectual sphere of comparative jurisprudence at around the turn of the twentieth century, which I suggest was an historical example of an interstitial space, I argue that such interstitial spaces form part of the story of the development of ideas of responsibility for crime. In comparative jurisprudence, national laws and legal systems were viewed from a transnational vantage point, and, as such, legal analysis was simultaneously embedded and disembedded, both tied to territorial space and free-floating. My examination of the first decades of the life of a key institutional text of comparative jurisprudence, the Journal of the Society of Comparative Legislation, shows that discussion of crime, punishment, and criminal justice encompassed an informative discussion of responsibility, with the light of comparative jurisprudence revealing the connection between criminal responsibility and broader ideas about ‘civilization’ and ‘progress’, which themselves reflected power relations between states.

Chalcogenide Glass-Capped Fiber-Optic Sensor for Real-Time Temperature Monitoring in Extreme Environments

We demonstrate a novel chalcogenide glass (ChG)-capped optical fiber temperature sensor capable of operating within harsh environment. The sensor architecture utilizes the heat-induced phase change (amorphous-to-crystalline) property of ChGs, which rapidly (80–100 ns) changes the optical properties of the material. The sensor response to temperature variation around the phase change of the ChG cap at the tip of the fiber provides abrupt changes in the reflected power intensity. This temperature is indicative of the temperature at the sensing node. We present the sensing performance of six different compositions of ChGs and a method to interpret the temperature profile between 440 °C and 600 °C in real-time using an array structure. The unique radiation-hardness property of ChGs makes the devices compatible with high-temperature and high-radiation environments, such as monitoring the cladding temperature of Light Water (LWR) or Sodium-cooled Fast (SFR) reactors.