Infrared Radiation Changes Research Articles

Thermography as Method of Paraclinic Diagnosis in Diabetic Polyneuropathy

The concept of polyneuropathy comprises the etiological diversity of neurological syndromes characterized by the formation of bilateral and symmetrical lesions of limb peripheral nerves; symmetrical distal sensory-motor polyneuropathy is the most common form of diabetic neuropathy; it is the most frequent chronic complication of diabetes and more than half of the patients make this complication throughout their lives, both pathogenetic mechanisms and epidemiology, its diagnosis and treatment generate many controversy and challenges for both researchers and practitioners. The study batch consisted of 40 diabetic patients admitted to the Neurology Clinic of the Clinical Recovery Hospital and the Diabetes Clinic between January 2014 and December 2018 who were diagnosed according to clinical and electrophysiological criteria, the etiology of which was type II diabetes with a history of more than 5 years of development and who were examined the lower limb skin according to the local protocol. Thermography is already used as a diagnostic and monitoring tool for patients suffering from neuropathies, especially in the case of complex regional pain syndrome (sympathetic reflex dystrophy) and in our case of diabetic polyneuropathy. This non-invasive exploration has great potential for future research on its use in the diagnosis of other neurological diseases involving the peripheral nervous system. Medical imaging analysis provides a useful way to diagnose and monitor multiple physical illnesses; infrared imaging provides information about infrared energy from the surface of the skin. Emission of infrared radiation changes after nerve damage and vascular occlusions.

Daily Activity Recognition Using Pyroelectric Infrared Sensors and Reference Structures

Pyroelectric infrared (PIR) sensor is widely used as motion detector, due to its sensitivity to the infrared radiation changes (IRC) induced by human motion. In particular, it is also possible to determine the human activity patterns based on the IRC signal by improving the feature-specific sensitivity of the PIR sensors. In this paper, the feature-specific sensitivity is enhanced by visibility modulation at the geometric sensing layer. At the cooperative sensing layer, a novel stereo configuration is used in developing the infrared sensing system, which aims to handle the difficulties caused by occlusion and limited coverage area. The experimental results demonstrate the effectiveness of the developed system in daily activity recognition.

Switchable Plasmonic Metasurface Utilizing the Electro-Optic Kerr Effect of a Blue Phase Liquid Crystal

A switchable metasurface composed of plasmonic split ring resonators and a polymer-stabilized liquid crystal blue phase is developed. Owing to field-induced birefringence (electro-optic Kerr effect), the state of polarization of the incident near infrared radiation changes, when a voltage is applied to the liquid crystal. Thus, different resonant modes of the split ring resonators can be addressed and the transmission spectrum changes accordingly. In comparison with other liquid crystal phases, blue phases have several advantages. For example, they are optically isotropic in the field-off state, so that no alignment layer is required. The results of the present study indicate that the advantages of these mesophases can be utilized for switchable metasurfaces.

TRANSIENTS PROCESSES UNDER DRYING WITH CONVECTION AND INFRARED RADIATION

Based on the theory of the A.V. Lykov for heat and mass transfer the mathematical model of propagation of heat and moisture in a flat sample, which is blown by the air flow and is exposed to infrared radiation. The model is based on the following views: the density of heat loss is determined by the heat transfer by convection and heat exchange by radiation, and the intensity of the mass exchange surface with the environment depends on the difference in partial pressure of water vapor through the thickness of the boundary layer (the boundary condition of mass transfer in the form of Dalton); temperature field inside the material is determined by the heat transfer due to the phenomenon of thermal conductivity, and the presence of internal heat sources caused by the absorption of penetrating electromagnetic radiation and the processes of evaporation (condensation); the transfer of moisture inside the material is partly liquid and partly in vapor form, and is caused by moisture content gradients (diffusion) and temperature (thermal diffusion). The results of analytical calculation of steady-state fields of temperature and moisture content for cases of convective drying and infrared drying, and the results of numerical calculation of the same field in transient conditions are presented. Numerical experiment allows us to estimate the duration of the transition process, as well as the behavior of the differential moisture content between the borders of the plate, with the increase which increases the probability of failure of the sample from mechanical deformation. It is shown that for convective drying of such a danger occurs in the transitional regime, and for infrared drying – mode steady-state. To reduce internal mechanical stresses when drying by convection, avoid sudden temperature changes of the air flow; the time during which there is an increase in air temperature, should be around the time of the transition process. When drying with infrared rays, if the differences of moisture content in the steady state are invalid for their reduction can be used or drying in the oscillating radiation, or drying under the combined effect of the sample electromagnetic waves with large and small penetration depth. The distinction in the nature of transients, infrared drying and drying with hot air can be explained using the formula of Dalton, which is part of the used mathematical model and determining the intensity of the problem through the boundary layer. Due to the great inertia of thermal processes, even in the case where the intensity of the infrared radiation changes rapidly in time (for example at the initial time gap of the first kind), the surface temperature of the material, and with it the intensity of drying, continue to be continuous functions; on the contrary, an abrupt change in air temperature in convective drier automatically leads to a gap function of the flux density of moisture on the surface.Forcitation:Afanas'ev A.M., Nikishova A.V., Siplivy B.N. Transients processes under drying with convection and infrared radiation. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 94-101

A Novel Infrared Motion Sensing System for Compressive Classification of Physical Activity

Infrared radiation changes (IRCs) induced by human activity can provide important information about activity patterns. This paper presents an IRC-based compressive classification method for recognizing the physical activities of interest in home-based assisted living. To fully capture the IRC compressively, a multi-view infrared motion sensing system is developed, which consists of three IRC sensing modules, that is, one module on the ceiling and two modules on opposite tripods facing each other. A pilot study is conducted in the context of classifying six typical physical activities with the incorporation of the classification techniques, including hidden Markov model and support vector machine, which demonstrates the effectiveness of our system.

Novel Nanoscale Single-Metal Polarization-Sensitive Infrared Detectors

We report a vastly simplified approach to infrared (IR) detection based on a single-metal nanostructure. This integrated structure contains a dipole antenna and a thermocouple (TC). The antenna provides wavelength selectivity, and the TC provides the conversion from optical to electrical signals. Moreover, the same nanowire structure serves both as the receiving element (antenna) and as the rectifying element (TC), yielding a highly integrated detector system. This study exploits a newly discovered thermoelectric effect in single-metal nanostructures with cross-sectional discontinuities to affect the TC functionality. In order to optimize the IR response, devices with various antenna lengths are simulated and fabricated. Both simulations and experiments demonstrate that the locations of the hot and cold TC junctions reverse as the polarization of the incident IR radiation changes, which results in reversal of the output signal polarity. The fabrication complexity of these single-metal devices is greatly reduced compared to that of other IR detector approaches, and their unique polarization-dependent response makes them attractive for new classes of IR systems.

Experimental Study on Infrared Radiation Changes with the Fracture and Progressive Failure of the Submarine Soft Rock Roadway

Based on the submarine soft rock supporting engineering in Beizao Mine, the physical model tests of four kinds of supports were carried out including high strength (HS) roadway without support, HS soft rock roadway with U-shape steel support (U-S-S-S), low strength (LS) roadway with bolt support (B-S), and LS roadway with U-S-S. The thermal infrared (TIR) changes with the fracture and damage of roadway are investigated. It is discovered that the TIR radiation is the stronger in the stress concentrated area, strong friction and interaction range between U-steel support and roadway than that in the stress relaxed area and week friction. The TIR temperature (TIRT) of the fracture increased higher and changed rapidly than other parts. The TIR radiation of soft rock is influenced with seawater. The TIR-anomaly appears at the stress concentrated area, interaction ranges and fractures. The TIR omens occur when load is 65%~90% of the peak load.

Brain responses at birth predict language skills at 5 years of age: a longitudinal study

A new method of neuroimaging is proposed that is based on the recording of weak changes in infra-red radiation from the brain. Thermoencephaloscopy (TES) uses a combination of thermovision and digital image processing techniques and allows one to make a dynamic investigation of the thermal fields of the cerebral cortex through an unopened skull. Today the method is characterized by: (i) differential thermosensitivity of up to 0.002°C; (ii) instrumental temporal resolution 40 ms (25 thermomaps/s); (iii) time of the temperature measurement in the part of an object that correspondes to one pixel on digital thermomap is equal to 2.4 μs; (iv) instrumental spatial resolution of up to 70 μm/pixel; and (v) the thermomap size is 10880 pixels (128 × 85). TES allows detection of an appearance and study of topography and dynamics of the small (from 140 to 300 μm) and precisely localized zones of activation or deactivation of the cerebral cortex that are modally and regionally specific with respect to stimuli modality and parameters and to the state of an animal. Up to now such studies were performed with white rats, rabbits, cats, monkeys and humans under different kinds of sensory stimulation, motor tasks, conditioning (associative learning). Fast thermowaves spreading over the brain cortex along specific trajectories were revealed under sensory stimulation. The mechanisms of the recorded phenomena are discussed: (i) joule heating produced by ion currents through membranes of activated neurones; (ii) metabolic thermoproduction; (iii) thermal convection by the local cerebral blood flow; and (iv) thermodipole formation in the cortical foci with changed ICBF.

Thermoimaging of the brain

A new method of neuroimaging is proposed that is based on the recording of weak changes in infra-red radiation from the brain. Thermoencephaloscopy (TES) uses a combination of thermovision and digital image processing techniques and allows one to make a dynamic investigation of the thermal fields of the cerebral cortex through an unopened skull. Today the method is characterized by: (i) differential thermosensitivity of up to 0.002°C; (ii) instrumental temporal resolution 40 ms (25 thermomaps/s); (iii) time of the temperature measurement in the part of an object that correspondes to one pixel on digital thermomap is equal to 2.4 μs; (iv) instrumental spatial resolution of up to 70 μm/pixel; and (v) the thermomap size is 10880 pixels (128 × 85). TES allows detection of an appearance and study of topography and dynamics of the small (from 140 to 300 μm) and precisely localized zones of activation or deactivation of the cerebral cortex that are modally and regionally specific with respect to stimuli modality and parameters and to the state of an animal. Up to now such studies were performed with white rats, rabbits, cats, monkeys and humans under different kinds of sensory stimulation, motor tasks, conditioning (associative learning). Fast thermowaves spreading over the brain cortex along specific trajectories were revealed under sensory stimulation. The mechanisms of the recorded phenomena are discussed: (i) joule heating produced by ion currents through membranes of activated neurones; (ii) metabolic thermoproduction; (iii) thermal convection by the local cerebral blood flow; and (iv) thermodipole formation in the cortical foci with changed ICBF.