Grzegorz Gralewicz

Investigations of Single and Multilayer Structures Using Lock-In Thermography—Possible Applications

This paper presents a study of the possibilities of evaluating thermal parameters of single and multilayer structures using dynamic thermography. It also discusses potential uses of lock-in thermography. It presents a simulation of a periodic excitation of a multilayer composite material. In practice, the described methods can be employed in various applications, for example, in multilayer nonwoven microelectronic components manufactured from hemp fibers, chemical fibers, with an addition of electrically conducting fibers, and in medicine and biology. This paper describes tests conducted with lock-in thermography on carbon fibre reinforced composites with implanted delamination defects. Lock-in thermography is a versatile tool for non-destructive evaluation (NDE). Lock-in thermography is a fast, remote and non-destructive procedure. Hence, it has been used to detect delaminations in the composite structure of aircraft. This method directly contributes to an improvement in safety.

Comparison of Fourier and wavelet analyses for defect detection in lock-in and pulse phase thermography

This paper demonstrates how the wavelet analysis can be used as an alternative tool to fast Fourier transform in case of lock-in thermography (giving similar qualitative results) and pulse phase thermography method (where the time information is of consideration) in order to improve its analysis capabilities for the price of higher computational cost. Besides of theoretical information about application of those transforms, for both of them qualitative experimental results are shown. This paper presents the chosen results of experiments realized at the Institute of Electronics, Technical University of Lodz.

Towards a conceptual framework of OSH risk management in smart working environments based on smart PPE, ambient intelligence and the Internet of Things technologies.

Recent developments in domains of ambient intelligence (AmI), Internet of Things, cyber-physical systems (CPS), ubiquitous/pervasive computing, etc., have led to numerous attempts to apply ICT solutions in the occupational safety and health (OSH) area. A literature review reveals a wide range of examples of smart materials, smart personal protective equipment and other AmI applications that have been developed to improve workers’ safety and health. Because the use of these solutions modifies work methods, increases complexity of production processes and introduces high dynamism into thus created smart working environments (SWE), a new conceptual framework for dynamic OSH management in SWE is called for. A proposed framework is based on a new paradigm of OSH risk management consisting of real-time risk assessment and the capacity to monitor the risk level of each worker individually. A rationale for context-based reasoning in SWE and a respective model of the SWE-dedicated CPS are also proposed.

Active Thermography in Qualitative Evaluation of Protective Materials

This is a study of the possibilities of a qualitative evaluation of protective materials with active thermography. It presents a simulation of a periodic excitation of a multilayer composite material. Tests were conducted with lock-in thermography on Kevlar® composite consisting of 16 layers of Kevlar® fabric reinforced with formaldehyde resin with implanted delamination defects. Lock-in thermography is a versatile tool for nondestructive evaluation. It is a fast, remote and nondestructive procedure. Hence, it was used to detect delaminations in the composite structure of materials used in the production of components designed for personal protection. This method directly contributes to an improvement in safety.

Quantitative thermographic analysis of viscoelastic substances in an experimental study in rabbits.

PURPOSE: To measure the temperature parameters on the corneal surface during the delivery of standardized ultrasound energy assisted with ophthalmic viscosurgical devices (OVDs) or different temperatures of irrigating solutions in an experimental animal model. SETTING: Department of Ophthalmology and Visual Rehabilitation, Medical University of Lodz, and Central Institute for Labor Protection, National Research Institute, Warsaw, Poland. METHODS: Thirty rabbits (60 eyes) were randomly divided into 6 groups in which different OVD or balanced salt solutions (BSS) were used: group 1: Viscoat (sodium hyaluronate 3%–chondroitin sulfate); group 2: Provisc (sodium hyaluronate 1%); group 3: soft‐shell technique; group 4: Celoftal (hydroxypropyl methylcellulose 2%); group 5: BSS 22°C; and group 6: BSS 4°C. After the nucleus and lens cortex were removed, the anterior chamber was filled with OVD or BSS and a phaco tip was introduced into the pupillary plane and switched on. The same phaco tip parameters were used in all groups. For thermographic measurements (ie, maximal temperature [MT], dynamic rise in temperature [DRT], and time when the maximal level of temperature [TMLT] was achieved), a thermocamera was used. RESULTS: Mean preoperative temperature on the rabbit corneal surface was 22.76°C ± 1.48°C (SD). Working with a phaco tip increased the temperature in each group. A significantly higher MT was observed in group 5 (27.85°C ± 0.52°C), followed by group 2 (27.75°C ± 0.54°C), group 3 (27.74°C ± 0.46°C), and group 4 (27.25°C ± 0.60°C), than in group 6 (26.81°C ± 0.34°C) and group 1 (26.52°C ± 0.48°C) (P<.05). Significantly higher values of DRT and shorter TMLT values were observed in group 5 (1.16°C/s ± 0.42°C/s, 4 seconds) and group 6 (0.91°C/s ± 0.13°C/s, 5 seconds) than in groups 2, 3, 1, and 4 (0.09°C/s ± 0.07°C/s, 30 seconds; 0.08°C/s ± 0.04°C/s, 40 seconds; 0.07°C/s ± 0.03°C/s, 45 seconds; 0.06°C/s ± 0.02°C/s, 50 seconds, respectively) (P<.0001). CONCLUSIONS: Currently used OVDs potentially offer different levels of protection against the increase in temperature that occurs during phacoemulsification. Therefore, the surgeon should consider this aspect when choosing an OVD, particularly in difficult cases (ie, hard nucleus, shallow anterior chamber, endothelial abnormalities).

Light transmission through intraocular lenses with or without yellow chromophore (blue light filter) and its potential influence on functional vision in everyday environmental conditions

In this research the factors used to evaluate the light transmission through two types of acrylic hydrophobic intraocular lenses, one that contained yellow chromophore that blocks blue light transmission and the other which did not contain that filter, were defined according to various light condition, e.g., daylight and at night. The potential influence of light transmission trough intraocular lenses with or without yellow chromophore on functional vision in everyday environmental conditions was analysed.

Analysis of the selected optical parameters of filters protecting against hazardous infrared radiation.

The paper analyses the selected optical parameters of protective optic filters used for protection of the eyes against hazardous radiation within the visible (VIS) and near infrared (NIR) spectrum range. The indexes characterizing transmission and reflection of optic radiation incident on the filter are compared. As it follows from the completed analysis, the newly developed interference filters provide more effective blocking of infrared radiation in comparison with the currently used protective filters.

Changes of transmission characteristics for different optic radiation incidence angles in filters protecting against hazardous infrared radiation

Abstract The paper presents the fundamental information concerning the types of protective optical filters used for protection against hazardous radiation within the visible and near-infrared spectrum range. The changes of transmission characteristics for different optic radiation angles of incidence with metallic reflective filters and interference filters have been analyzed. The results demonstrate that such changes exert no effect on the level of protection provided by the filters.

Potential impact of colors of filters used in sunglasses on the melatonin suppression process

BACKGROUND In this article the methods for determining spectral transmittance of optical radiation in the visible waveband range through selected materials used as optical filters against solar glare were described. MATERIAL AND METHODS Transmittance coefficients specified for the fraction of light passing through tested filters, taking into account the mechanism of eye adaptation to daylight and night vision and the melatonin suppression process were compared for 4 dyed sunglass filters. RESULTS The values of transmittance coefficients specified for wavelength bands, 380-780 nm (for visible range) and 425-560 nm (for blue light range affecting the melatonin suppression process) were determined. CONCLUSIONS The use of sunglasses with different color filters modifies the spectral characteristics of transmittance (spectrum) of visible light reaching the eye (including blue radiation) in such a way that it may have a potential impact on the melatonin suppression process. Med Pr 2017;68(5):629-637.

Analysis of the selected mechanical parameters of coating of filters protecting against hazardous infrared radiation

This article presents a comparison of the test results of selected mechanical parameters (hardness, Young’s modulus, critical force for delamination) for protective filters intended for eye protection against harmful infrared radiation. Filters with reflective metallic films were studied, as well as interference filters developed at the Central Institute for Labour Protection – National Research Institute (CIOP-PIB). The test results of the selected mechanical parameters were compared with the test results, conducted in accordance with a standardised method, of simulating filter surface destruction that occurs during use.