Volumen 69 (2019): Edición 4 (December 2019)

Maintaining a stable carbon dioxide content below the established CTQ¹ requirements in the process of obtaining breathing gas for hyperbaric oxygen conditions is essential for the safety of underwater work. This article discusses the subject of validation of a selected measuring system for on-line control of the breathing gas production process and describes the application of multidimensional sensory systems to control critical parameters of the production process in production systems intended for intensive use away from supply facilities. In this case, the on-line contamination measurement option should be considered². Monitoring of the analysed process from the point of view of its ability to minimise its variability should be oriented towards measuring the input or process values in such a way as to prevent the occurrence of potential defects already at the production stage. The assessment of the CCS - Carbon Dioxide Control System³ selected for testing, designed to control the carbon dioxide content, was performed in DUWT PNA⁴ for the DGKN - 120 complex compressed air supply system⁵. The system evaluation was conducted using MSA⁶ procedures and methods of SPC⁷.

This paper characterises the concept of monolayer mobile gas adsorption on a homogeneous surface of a solid. The theoretical basis of the phenomenological variant of the description of adsorption equilibrium in the system in question are discussed. The essential features of the solutions to date are discussed, and the effect of the free surface of adsorbent on the form of the final adsorption equation is stressed.

An alternative concept of the free surface based on the modified two-dimensional analogue of Reiss, Frisch and Lebowitz equations is also presented. The obtained adsorption equation was tested for critical parameters of two-dimensional condensation of the adsorption layer, and then used to describe the experimental data available in literature. The verification carried out confirmed the correctness and usefulness of the proposed concept.

In the article the author presents the specificity of decompression of deep-sea dives in relation to methods used in underwater works, with particular emphasis on commercial diving in our country. In the 50 - 90 m depth zone in the Polish offshore area, decompression was used in underwater works (works below the depth of 50 m) based on tables designed for bell diving. The technical, organisational and formal conditions of these underwater works corresponded to the national diving potential. The implementation of decompression, particularly in deep-sea dives, provides the possibility of performing it in many different ways. They, in turn, are the result of experience, diving technique, organisation and specificity of underwater works.

The article presents the implementation of decompression from the executive side of underwater deep-sea works developed and carried out by the Department of Underwater Works Technology of the Naval Academy in cooperation with the Navy until 2001 and civil companies to date.

The prerequisite of development of pulmonary barotrauma [PB] is retention of the breathing mix in the lungs during a sudden decrease in external pressure or its administration into the airways under increased pressure or in a volume exceeding the maximum lung capacity. In such cases, the pulmonary parenchyma ruptures and air enters both the pleural cavity and/or the lumen of ruptured blood vessels located in the alveolar septa. The result is permanent disruption of the pulmonary parenchyma.

The aim of the study was to assess the influence of post-PB lesions on the heart muscle and the importance of hyperbaric treatment on the exacerbation of such lesions in the heart. The hearts of 35 rabbits were used in the study. In animals of the experimental group, PB was induced in the pressure chamber using the proprietary method described in previous publications. Part of the animals in this group were treated with air hyperbaria. The comparison group consisted of animals, which did not undergo PB during a simulated dive. All animals were weighed, observed for four weeks and then put to death following the experiment. In autopsy, among others, whole hearts were collected and weighed after fixation. Subsequently, the C/S ratio, i.e. the body to heart weight ratio, was calculated. The measurement results were subject to statistical analysis. A statistically significant increase in the C/S ratio was found, indicating an increase in the share of heart weight in the total body weight in the group of animals with PB not treated with air hyperbaria as compared to the control group.

The aim of the research was to evaluate the occurrence of arrhythmias and heart rate variability during diving in recreational divers. Continuous electrocardiographic (ECG) Holter monitoring was conducted in a group of 50 divers (age 36,8 ± 8,7). The recorded data included the duration of the dive, including a period of 60 minutes before the dive and 60 minutes after the dive. Moreover, divers filled in a questionnaire that had been prepared for the purpose of the study and the psychological tests State-Trait Anxiety Inventory (STAI). The ECG recordings were synchronised with dive computers to correlate the ECG changes with diving events and analysed for the heart rate, arrhythmias and conduction disorders. The average heart rate was the highest (M=107.34 beats/minute) before diving, and the lowest after diving (M = 102.00 beats/minute). Supraventricular arrhythmias were recorded in nineteen (38%) of the participants of the study. The number of arrhythmias during diving (M = 14,45) is significantly higher than before (M = 9,93, p < 0,01) and after dive (M = 6,02, p < 0,05). All results were obtained from the continuous ECG Holter monitoring. It seems that using continuous ECG monitoring in conditions similar to diving (physical and psychological stress), brings more benefits than traditional, resting electrocardiogram.

Harmful biological factors accumulated in the ambient atmosphere are a very important and increasingly recognised problem of both occupational medicine and public health. The quantitative and qualitative assessment of harmful biological agents in the working environment is a very important element of the exposure assessment and therefore of an assessment of workers’ health risks. In 2018, a pilot study on the microbiological quality of air was carried out at two facilities of the Polish Navy.

This article discusses the energy input and effort of swimmers during long-distance swimming, classifying them according to the definitions of work intensity. It also refers to the diver’s effort while performing tasks underwater.

This paper presents an in-depth (in comparison to the pilot studies conducted in 2017) analysis of the offering of the Piechcin recreational dive area. The intention was to check whether the current service offering translates into customer satisfaction, and the activities undertaken on site correlate with the reasons why divers choose this place. In addition, it was established whether the proposal to introduce additional facilities for visitors to the site would translate into their return to the location. The main obstacles to the lack of frequent implementation of dives in Piechcin and infrastructural problems of the reservoir were identified. Particular attention has been paid to the competences and creativity of the organiser of this form of recreation, since personal potential is often a determinant of the success of the business (including in particular ensuring the safety of visitors).