Browse

51 - 60 of 118 items :

  • Hygiene and Environmental Medicine x
  • Engineering, other x
Clear All

Abstract

This is the second part of material concerned with the analysis of drive systems in remotely controlled underwater vehicles. The first part involved the problem of classification of unmanned underwater vehicles, mainly remotely controlled, as well as the nomenclature used in relation to various components of the discussed drive systems and thrusters. The functionality of particular drive systems was discussed along with the advantages and disadvantages of the analysed design technologies. This material presents the method of conducting an analysis of drive systems, its methodology and results.

Abstract

The purpose of the study was to determine the effect of composition of various breathing mixes on physical capacity of rats swimming in hyperbaric conditions. The said effect was determined on the basis of results of a swim test performed in a pressure chamber. The study was performed with the use of atmospheric air, a mixture of nitrogen and oxygen (N2/O2) at a ratio of 89.5/10 and 92/7.5, as well as a mixture of argon and oxygen at a ratio of 79.5/20 (Ar/O2). The tests were conducted at a pressure range between 0-4 atm. The results suggest that the physical capacity of the tested animals decreased along with pressure increase regardless of the breathing mix used. Due to the fact that the burdening of rats with physical effort in hyperbaric conditions intensifies the adverse effects of components of breathing mixes on their performance, it seems appropriate to continue the study of physiological responses to breathing mixtures of various compositions in human body subjected to physical effort while under water.

Abstract

The barofunction of paranasal sinuses is of great significance in terms of diving safety and comfort. The paper aimed at determining the changes in the aeration of maxillary sinuses as a result of diving activities on the basis of a radiological image. Inter alia, it was observed that individuals who frequently practise diving show persistent changes in the radiological image of sinuses, however, usually they do not influence the diving capacity.

Abstract

Changes observed in the core body temperature of divers are the result of a multifaceted response from the body to the change of the external environment. In response to repeated activities, there may be a chronic, physiological adaptation of the body’s response system. This is observed in the physiology of experienced divers while diving. The purpose of this study is to determine the immediate and delayed effects of hyperbaric exposure on core temperature, as well as its circadian changes in a group of three experienced divers. During compression at 30 and 60 meters, deep body temperature values tended to increase. Subsequently, deep body temperature values showed a tendency to decrease during decompression. All differences in core temperature values obtained by the group of divers at individual time points in this study were not statistically significant.

Abstract

The paper discusses the treatment results of ten patients with severe atopic dermatitis (AD) who did not respond to standard pharmacotherapy and underwent hyperbaric oxygen therapy (HBOT). Each patient was subject to 10 oxygen exposures at pO2 2.5 ATA (~ 250 kPa) with the duration time of 60 minutes. In the period of implementation of the hyperbaric procedures the general treatment plan was suspended for all patients while maintaining typical local treatment. Clinical evaluation was performed in the study group as well as determination of levels of immunoglobulins: IgA, IgG, IgM and IgE and C3 and C4 complement. All patients indicated clinical improvement and a decreased IgE immunoglobulin and complement C3 level upon the completion of the exposure cycle. Taking into account the authors’ own observations and data from literature, an overall improvement in the clinical status and a decrease in the level of immunoglobulin E and C3 complement following a cycle of exposures may be indicative of an immunomodulating HBOT effect on AD, whereas hyperbaric oxygenation may constitute a therapeutic option for some patients with AD, especially those exhibiting a poor response to standard treatment.

Abstract

In relation to EU countries, the level of safety on Polish waters is still low. The drowning rate in our country is two times higher. Since 2013, there has even been an increase in the number of drownings. Typically, following each incident, attention is focused on the quality of work of the rescue services, however, there are multiple factors to be considered when seeking where responsibility for this state of affairs actually lies. In contemplations, the main subjects of analysis were external threats (atmospheric conditions, legal conditions, trends in water recreation) and threats generated by various groups of waterrelated subjects (administrators, service providers, rescuers, cleaning and medical services, participants enjoying recreation on or in the water). The purpose of this article is to present the issues of water safety from the perspective of the responsibility of various subjects, which are active in this environment. The attractiveness of recreation in or on water results largely from the emotions caused by increased risk. Often the greater the danger, the greater the attraction. At the same time, it is accompanied by an increased sense of security, excessive self-confidence and excessive trust, which weakens the natural defense mechanism. Hence, so many accidents in the water are caused by the victims themselves. In the article we are looking for an answer to the question about the reasons for such a phenomenon.

Abstract

Allergic contact eczema is the most common occupational skin disease caused by allergens. Thus far, no research has been conducted in Poland in relation to the development of contact allergies amongst divers resulting from particular diving suit components. A group of 86 divers were examined using allergy patch tests. Standard products of contact allergy diagnostics were used containing 40 allergens.

Abstract

This series of articles on high risk projects looks at the example of the modernisation of hydrogen incinerators on a submarine. The article describes problems connected with the management of such a project.

Abstract

The authors examined 104 divers performing dives in water, 14 exposed to simulated conditions in decompression chambers and 11 control subjects. The average blood sugar reading before diving amounted to 100 mg% with readings of 101 mg% after diving, whereas in the control group these readings were 107 and 100 mg% respectively and in the group of simulated dives, 102 before and 106 mg% after the exposure. It was found that the diet applied ensured a sufficiently high level blood sugar level in the subjects to protect them against hypoglycaemia. Further research in decompression chambers is required.

Abstract

The problem of oxygen toxicity, and its effect on the nervous system, is an important topic with regard to the application of oxygen and breathing mixes in the pursuit of diving, as well as in the light of the striking synergy between the effects of oxygen and ionising radiation. Studies on the level of lipid peroxides were performed on rat brains. The animals were subjected to exhaustive physical strain in a pressure chamber and oxygen at the pressure between 0-3 atm for the period of 25-60 minutes. Parallel research was conducted on rested animals. Following the dissection, the brain was homogenised and the levels of lipid peroxides were determined using the Wollman method with TBA. In animals subjected to physical effort over the specified time, no deviations in the levels of lipid peroxides were observed in comparison to the control group. An increase in lipid peroxide level was noted in rats manifesting oxygen toxicity symptoms. On the basis of the above findings, the authors presume that the growth of lipid peroxides in the brain in cases subjected to hyperbaric oxygenation should be recognised as a far-reaching harmful effect of oxygen, occurring after enzymatic damage and the violation of cellular antioxidant protection. At low oxygen overpressures, no deviations in the levels of lipid peroxides were noted as compared to the control group.