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  • Author: Krzysztof Kowalski x
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Open access

Izabella Krucińska, Ewa Skrzetuska and Krzysztof Kowalski

Abstract

In this study, the new tool for measuring thermal insulating power of garments for premature babies under coupled heat and moisture transport was developed. The thermal mannequin corresponds to the body weight and size of a premature baby born in the thirty fourth week of pregnancy. The mannequin surface temperature can be set at various levels, while the heat loss is measured in W/m2. The mannequin is divided into eleven independent heating zones and seven independent zones of moisture evolution. The study also presents the test results of heat insulating power obtained for the newly developed garment set with commercially available garment set for babies, conducted under different climatic conditions. The results exhibit the advantage of the new material construction of the garment over the commercially available one.

Open access

Witold Woźniak, Krzysztof Mlosek, Tomasz Miłek, Marcin Kowalski and Piotr Ciostek

The Association of Surgery and Sclerotherapy in the Treatment of Severe Chronic Venous Insufficiency

The aim of the study was to evaluate the efficacy of surgery in combination with sclerotherapy in the treatment of severe chronic venous insufficiency.

Material and methods. During the period between 2007 and 2009, 38 patients with symptoms of advanced chronic venous insufficiency - C4, C5 and C6, according to the CEAP classification- were subject to surgery in combination with sclerotherapy. The study group comprised 24 (63%) female and 14 (37%) male patients, aged between 42 and 95 years. Twenty-three patients were diagnosed with saphenous vein insufficiency, 14 with small saphenous vein insufficiency, and one with femoro-popliteal venous insufficiency. Based on the VCSS scale, disease symptoms were evaluated before the operation and six months after the surgical intervention. In cases of saphenous or small saphenous vein insufficiency, the patients underwent crossectomy, followed by ligation of the saphenous-femoral and small saphenous-popliteal ostia. The distal segment of the vein was obliterated using a 3% polidocanol foam solution. Control ultrasonography was performed 1, 3, 6 and 12 months after the procedure. Patients with crural ulcerations that did not heal by three months postoperatively were subject to additional epidermal grafts.

Results. Statistical analysis of the VSCC point scale before and after the operation demonstrated a significant reduction in the following parameters: pain, presence of varices, edema, ulcerations, and use of compression therapy. Analysis showed an effective elimination of the main venous trunks. Among patients with venous ulcerations, spontaneous healing was observed during the nine months after the procedure was observed in 17 (94%) patients. In one patient, the ulceration was reduced by 30-40%. Neurological, ophthalmological and thromboembolic complications of the deep venous system were not observed.

Conclusions. 1. The combination of surgery and sclerotherapy in the treatment of advanced chronic venous insufficiency is a method worthy of recommendation. 2. The method is effective with a low risk of complications, thus significantly shortening hospitalization and absence from work. 3. An evaluation of the disease stage based on the VCSS scale, before and after the operation, demonstrated a significant improvement.

Open access

Krzysztof Maćkała, Marek Fostiak and Kacper Kowalski

Abstract

The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1- repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01).

Open access

Krzysztof Kowalski, Lech Nowak, Łukasz Knypiński and Paweł Idziak

Abstract

The paper considers the influence of core saturation on the dynamics of magnetostrictive fast-acting actuator. The field-circuit mathematical model of the dynamic operation of the capacitor-actuator system is applied. Two kinds of magnetostrictive core nonlinearity are taken into account. It has been proved that the saturation of the B-H curve practically does not affect the current, and capacitor voltage waveforms, but significantly affects a core elongation waveform. The computed results are compared with experimental ones.

Open access

Pawel Lochynski, Maciej Kowalski, Bogdan Szczygiel and Krzysztof Kuczewski

Abstract

The influence of organic additives on the process of surface electropolishing of AISI 304 type steel was determined. Additives were selected in initial potentiodynamic tests pursuant to the plateau analysis on the current/potential curves. The assessment of the operational effectiveness of additives consisted in determining the relationship between surface gloss after electropolishing and the mass loss of the sample and in determining surface roughness. The applied electropolishing bath consisted of a mixture of concentrated acids: H3PO4 and H2SO4, and the following organic additives were used: triethylamine, ethanolamine, diethanolamine, triethanolamine, diethylene glycol monobutyl ether and glycerol. The best electropolishing result, i.e. low roughness and high gloss of stainless steel surface with a relatively low mass loss of the sample at the same time were obtained for baths containing triethanolamine.

Open access

Kazimierz Ćmielewski, Janusz Kuchmister, Piotr Gołuch, Izabela Wilczyńska and Krzysztof Kowalski

Abstract

The correctness of the geodetic service of an engineering object not seldom requires designing, alignment or renewing of geodetic situational control points. Building robots often cause that fixed situational control points are partly or completely inaccessible. For setting the position of these control points, there is worked out the methodology using the optoelectronic method. The prepared set of tools realizes the method’s assumptions and enables to determine the sides and control points based on the set of laser planes. In this article there is presented the innovative set of geodetic equipment for fixing horizontal control points. The presented set has been experimentally tested under laboratory conditions taking its functionality, operation range and applied accuracy into account. The measurement accuracy of the set of tools, resulting from identification of the energetic centres of laser planes’ edges, visualizing the sides of geodetic control networks, is within the range of ±0.02mm - ±0.05mm. There were also discussed exemplary versions of shapes and structures of horizontal geodetic control networks (regular and irregular), which are possible to be fixed with the use of the constructed set of tools.