The previous article described a new approach methodology1 for work on the development of technology for the use of the SCR CRABE SCUBA2 type diving apparatus. However, after its publication numerous questions emerged regarding the genesis of the research undertaken, also from foreign partners using the same rebreather. The work on changing the technology of use was preceded by analyses, which were available only to people involved in the decision-making process. Demonstrating all the details of the decision-making process may be tedious, but failing to present them at all might raise justified doubts about the advisability of conducting a long-term research cycle.
This article only presents preliminary analyses. The necessity to perform them resulted from the specific requirements for military technologies3 which, as broadly as possible, should be knowledge-based. The knowledge-based approach by its very nature allows continuous improvement of the adequacy of the predictions made, the estimation of the level of risk when diagnosing deviations from the repeatability or precision of the model, and the possibility of adapting the technology to the changing requirements of the user resulting from tactical considerations of its use.
In the article the author describes the Polish specificity of deep dives used in underwater deep-sea works. The article briefly discusses the methods of deep diving used in the world to proceed to underwater works in the Polish offshore zone of 50-90m depth (according to the Act; deep water works are works below a depth of 50m). When discussing these methods, the author describes the technical-organisational and formal conditions and the type of conducted works. It then presents the methodology for evaluating the effectiveness of the main element of deep-sea works, i.e. diving. It provides information on deepsea underwater works on the Baltic Sea carried out by the Department of Underwater Works Technology of the Naval Academy in cooperation with the Polish Navy until 2001 and civil companies to date. On the basis of his own data from underwater deep-sea works, the author presents the methodology of evaluation of their effectiveness from the point of view of deep dives. In his conclusions, he puts forward recommendations for improving the efficiency of such works.
Patent foramen ovale (PFO) is a condition present in 25% of the adult population. It is a remnant of fetal foramen ovale which allows blood to pass from the right to the left atrium, bypassing the fetal lungs. In majority adults it does not have any clinical significance, but in some people it may allow shunting of venous blood into the left atrium (right – left – shunt or RLS), circumventing the lung filter, especially during sneezing, cough, lifting heavy equipment. Is such case, PFO may be a route for venous emboli or gas bubbles from veins to the arterial system. It is known as a paradoxical embolism and may be cause of ischaemic stroke or neurologic decompression sickness (DCI), inner-ear DCI and cutis marmorata. Transesophageal echocardiography is considered as a reference standard in detection of intracardial shunts. Its sensitivity and specificity ranges between 94%-100%. However, TEE is an invasive examination with potentially serious side effects. An alternative examination in RLS detection is contrast enhanced Transcranial Doppler (the bubble study or c-TCD). In comparison to TEE, Transcranial Doppler is not invasive, relatively not expensive and save technique. With its high sensitivity and specificity in detection of PFO, 97% and 93% respectively, it may improve detection of RLS and allow to conduct screening examination for PFO in divers.
Esin Eren, Furkan Yıldırım, Ozlem Giray and Necat Yilmaz
Hyperbaric oxygen (HBO) treatment is generally a relatively safe therapy for various conditions. However, there are some adverse side effects. For example HBO tratment has been reported to increase the production of free oxygen radicals(FRs). Furthermore, to our knowledge, no previous clinical research has been carried out to study the involvement of platelet-activating factor(PAF)as the lipid oxidative stressor in patients undergoing HBO treatment. A total of 45 patients included in this study were first given clinical assessment and laboratory measurements before starting HBO treatment and were named group baseline. After the HBO treatment, the same clinical and laboratory measurements from the same patients were repeated and this was named group sesion >20.As expected, long-term HBO treatment had no effect on oxLDL (oxidized low-density lipoprotein), a lipid oxidative stress(OS) marker. However, the mean PAF values in the second group showed a statistically significant increase compared to their pretreatment values, (P <0. 002).As this is a preliminary study, there is a need for more detailed investigations that demonstrate the association of HBO treatment with the lipid inflammatory response. Therefore, there is need for further clinical study for OS markers such as oxLDL in HBO treatment. Clinical prospective studies are required to confirm our laboratory findings.
Jerzy K. Garbacz, Karol Karpiński and Mariusz Kozakiewicz
Continuing the discussion on the description of adsorbate-adsorbate association on homogeneous surfaces of solids, an attempt was made to formulate an analytical form of adsorption equation for a multilayer adsorption phase. The validity of Berezin’s and Kiselev’s assumptions concerning the independence of adsorption in further layers from the model of the phenomenon in the first of them was discussed. The fundamental validity of this assumption has been demonstrated, simultaneously ridding it of its arbitrary character. The main aim of the study was to demonstrate the possibility of formulating a description assuming molecule association in the entire adsorption phase (and not only in the first layer). Theoretical considerations are confined to the case of dimerisation in the concentration range thus warranting the approximation characteristic of the Berezin and Kiselev model. The obtained final adsorption equation exhibits physically acceptable boundary properties; with adequate assumptions it amounts to the Brunauer, Emmett and Teller equation, the equation formulated earlier by one of the authors of this paper or the Langmuir equation.
This article is a brief description of a new methodology1 for utilising the Nx – SCR CRABE SCUBA rebreather 2. This new approach differs from that described in a previous article [1,2]. The new methodology is based on a Polish theory3 mainly consisting of deterministic methods4 of modelling semi-closed circuit rebreathers. Further research5 can henceforth be carried out in a more reliable and efficient manner than ever before.
The search and detection of objects under water is carried out by groups of specialised divers. However, their time underwater and their ability to penetrate the depths are limited. For these reasons, the use of unmanned underwater vehicles equipped with technical observation equipment, including TV cameras, is becoming increasingly popular for these tasks. Video images from cameras installed on vehicles are used to identify and classify underwater objects. The process of recognition and identification of objects is tedious and difficult and requires the analysis of numerous sequences of images, and so it is desirable to automate this process. In response to these needs, this article presents the concept of identification of underwater objects based on visual images from an underwater body of water sent from an unmanned underwater vehicle to a base vessel. The methods of initial processing of the observed images from an underwater area as well as the method of searching for selected objects in these images and their identification with the use of the Hough transform will be described. Furthermore, the paper presents the results of the preliminary processing and identification of the observed images following a deconvolution operation.
This material is a continuation of the article published in the PHR no. 3(52)2015 concerning the methodology of selecting underwater exploration strategies for process development purposes. The article proposes to use one of the methods of decision optimization for the selection of the appropriate course of action in such cases.
Dorota Niewiedział, Maria Miłkowska, Piotr Siermontowski, Zbigniew Dąbrowiecki, Dorota Kaczerska, Dariusz Juszczak and Romuald Olszański
The aim of the article is a review of psychological literature relating to the problem of anxiety in divers, where an emphasis is placed on the degree of mental adaptation of the individual to the underwater environment, primarily highlighting the trait of anxiety and the neuroticism of a person involved in a specific type of diving. The article presents selected reports from all over the world regarding research on anxiety in divers. Treating a high level of the indicator of anxiety as a predictor of panic anxiety reveals the importance of this trait in predicting the risk of an occurrence of diving accidents during the operation under water. In the own research presented in the article, the results on the levels of anxiety as a trait and a state in divers taking part in hyperbaric exposures indicate the fact that the majority of the examined divers have low levels of anxiety both as a trait and a state, which most probably indicates the good psychological condition of the examined divers.
The analysis of Berezin and Kiselev’s concept assuming linear association of molecules in a localised adsorption monolayer on the homogeneous surface of a solid adsorbent was carried out. An inconsistency due to the lack of consideration of equilibrium concentration of free adsorption sites in the formulation of the expression for the association constant has been pointed out. It was shown that the correct form of this function leads to the final adsorption equation being identical to the specific case of the Fowler-Guggenheim equation. The obtained result has been generalised to cases of branched adsorbateadsorbate associations. A new adsorption equation limiting the association to at most the dimers has been introduced. Critical conditions for the two-dimensional condensation of the adsorption layer were determined. By applying the formalism of canonical ensemble, full equivalence of the phenomenological and statistical methods was demonstrated in the description of the intermolecular interactions in the localised adsorption monolayer.