Search Results

You are looking at 1 - 5 of 5 items for

  • Author: Paweł Szymański x
Clear All Modify Search
Open access

Dariusz Mikielewicz and Paweł Szymański

Abstract

The combat potential of future warships will be directly related to the use of modern electronic devices being parts of advanced systems, such as, for instance, radar systems, fire aiming systems, fire detection systems, electric drive systems, and even electronic and radio-electronic weaponry, railguns and lasers, installed on these warships. The capacity and functionality of these devices is continually increasing, at decreasing mass and dimensions, which results in higher power consumption. Heat collection becomes a growing problem in operation of these devices.

The paper presents a concept of the use of the CPL (Capillary Pumped Loop) cycle for passive heat collection from precise electronic devices used on warships. It also includes the description of the experimental rig and discussion of the results of laboratory tests performed on this rig and confirmed using the mathematical model developed by the authors.

Open access

Józef Jasiczak, Paweł Szymański and Piotr Nowotarski

Abstract

Article presents the results of the effect of humidity on early shrinkage of normal concrete with variable W/C ratio. As known for a long time, shrinkage is dependent of many factors. One of them is the W/C ratio and the quantity of water which is located in the concrete mix. In article there were discussed changes taking place in the concrete mix, the methods of research and the partial results obtained by the authors of the paper. Shrinkage is a phenomenon well known and studied by various research centers. The total amount of shrinkage may depend on various factors such as humidity, temperature, composition of the concrete mix, the W/C ratio, the size of the item. The study was conducted to determine the amount of shrinkage in its early stages. It is very important for concrete floors contractors, precast manufacturers to start at the right time finishing work and prevent the formation of shrinkage cracks.

Open access

Zbigniew Kwieciński, Federico Morelli, Marcin Antczak, Martin Hromada, Paweł Szymański, Marcin Tobolka, Łukasz Jankowiak and Piotr Tryjanowski

Abstract

To study the seasonal changes in avian communities, we collected data in an extensively used farmland in Western Poland during 2006-2013. Generalized additive mixed models were used in order to study the effects of seasonality and protected areas on the overall bird species richness. A similarity percentage analysis was also conducted in order to identify the species that contribute most strongly to dissimilarity among each bird according to the phenological season. Furthermore, the differences in bird communities were investigated applying the decomposition of the species richness in season, trend, and remainder components. Each season showed significant differences in bird species richness (seasonality effect). The effect of the protected areas was slightly positive on the overall species richness for all seasons. However, an overall negative trend was detected for the entire period of eight years. The bird community composition was different among seasons, showing differences in terms of dominant species. Greater differences were found between breeding and wintering seasons, in particular, the spatial pattern of sites with higher bird richness (hotspots) were different between breeding and wintering seasons. Our findings showed a negative trend in bird species richness verified in the Polish farmlands from 2006. This result mirrors the same negative trend already highlighted for Western Europe. The role of protected areas, even if slightly positive, was not enough to mitigate this decline process. Therefore, to effectively protect farmland birds, it is necessary to also consider inter-seasons variation, and for this, we suggest the use of medium-term temporal studies on bird communities’ trends.

Open access

Edyta Łukasik, Paweł Targosiński, Michał Szymański, Olga Letkiewicz-Ryłów, Piotr Styczeń and Michał Wychowański

Abstract

Introduction: Upper crossed syndrome is a postural syndrome, with myofascial and functional imbalance within the shoulder girdle and the cervical spine. The therapy usually includes myofascial techniques or massage. The aim of this work was to indicate which of these forms of therapy is more effective in terms of myofascial release.

Material and methods: The study group consisted of 18 individuals (12 females and 6 males) with upper crossed syndrome who were randomly assigned to one of the two groups. In group 1 (8 females, 1 male), rehabilitation protocol involved myofascial techniques, while in group 2 (4 females, 5 males), massage was performed. In both groups, the therapy consisted of five 30-minute daily sessions. Prior to the therapy, on the 1st and the 5th day of the therapy immediately after the intervention as well as 14 days after the therapy completion, suprasternale height was measured and the cervical spine mobility was examined.

Results: It was revealed that both forms of the therapy resulted in an increase in the range of motion of the cervical spine, particularly in the case of the right flexion and right rotation. Effects were still present two weeks after the therapy. After 5 days of rehabilitation, both forms of the therapy led to a significant increase in suprasternale height (p<0.05).

Conclusions: Both myofascial techniques and massage result in an increase in the cervical spine and chest mobility in the longitudinal dimension in persons with upper crossed syndrome.