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Open access

Zygmunt Kowalski, Agnieszka Makara and Marcin Banach

Obtaining protein hydrolysates with chemical and enzymatic methods

The goal of our research was to work up a method of hydrolisates protein production using as raw material fresh pork meat-bone tissue after dismantling the process of half carcasses. Actually this raw material was practically all utilized as waste. The results of laboratory research and an industrial test allowed to state that is possible to produce hydrolysates containing 8 - 10% of proteins, and the most advantageous parameters of the chemical process are: the reaction time ~105 min., temperature 120°C, pressure 3.0 bars. With the use of enzymes (Protamex and Flavourzyme), it is possible to obtain a non-gelling protein hydrolysate with a high degree of clarity and light cream colour. The best results were achieved with the following parameters: the meat-bone feedstock to the water ratio from 1:1 to 1:2, the temperature of 40 - 45°C, the time of the process 3 h, pH ~6.

Open access

Łukasz Zaworski, Dariusz Chaberski, Marcin Kowalski and Marek Zieliński

Quantization Error in Time-to-Digital Converters

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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

Marcin Banach, Zygmunt Kowalski, Zbigniew Wzorek and Katarzyna Gorazda

A chemical method of the production of "heavy" sodium tripolyphosphate with the high content of Form I or Form II

Sodium tripolyphosphate STPP is used in laundry detergent as a detergent "builder". The paper presents the chemical method of obtaining "heavy", i.e. with higher bulk density granulated sodium tripolyphosphate. The bulk density of sodium tripolyphosphate was increased by preparing a mixture of the dried sodium phosphates, the recycled subgrain of STPP and water in specific proportions and calcining this mixture for 1 hour at 400°C and 550°C (to obtain a proper STPP form) in the chamber kiln. This method allows producing the granular sodium tripolyphosphate with high bulk density (1.04-1.07 kg/dm3) and a high content of Form I or Form II, respectively.

Open access

Agnieszka D. Jastrzębska and Marcin Kowalski

Abstract

Purpose. The aim of the study was to establish the respiratory response to unloaded cycling at different cadences. Methods. Eleven healthy participants performed a maximal graded exercise test on a cycle ergometer to assess aerobic fitness (maximal oxygen consumption: 46.27 ± 5.41 ml · min-1 · kg-1) and eight 10-min unloaded pedaling (0 W) bouts at a constant cadence (from 40 to 110 rpm). Respiratory data were measured continuously during each effort and then averaged over 30 s. Blood samples were collected before and 2 min after each effort to monitor changes in acid-base balance. Results. The efforts were performed at an intensity of 16.5-37.5% VO2peak. Respiratory response was not differentiated in cadences of 40, 50, 60 rpm. From 70 rpm, an increase in cadence was significantly associated with increased minute ventilation (F = 168.11, p < 0.000) and oxygen consumption (F = 214.86 p < 0.000) and, from 80 rpm, respiratory frequency (F = 16.06, p < 0.001) and tidal volume (F = 54.67, p < 0.000). No significant changes in acid-base balance were observed as a result of difference cadences. Conclusions. Unloaded cycling at a cadence of 70 rpm or above has a significant effect on respiratory function and may be associated with the involvement of large muscle ergoreceptors (mechanoreceptors) stimulated by the frequency of muscle contractions.

Open access

Marcin Wolkiewicz, Grzegorz Tarchała and Czesław T. Kowalski

Abstract

This paper deals with detection of the stator windings shorted turns in an induction motor drive working under open (scalar) and closed loop (Direct Field Oriented DFO) control structures. In order to detect the early stage of stator winding fault, the analysis of symmetrical and principal components of stator voltages and currents is used. Experimental results obtained from a specially prepared induction motor are presented.

Open access

Sławomir Grzelak, Jarosław Czoków, Marcin Kowalski and Marek Zieliński

Abstract

The ultrasonic flowmeter which is described in this paper, measures the transit of time of an ultrasonic pulse. This device consists of two ultrasonic transducers and a high resolution time interval measurement module. An ultrasonic transducer emits a characteristic wave packet (transmit mode). When the transducer is in receive mode, a characteristic wave packet is formed and it is connected to the time interval measurement module inputs. The time interval measurement module allows registration of transit time differences of a few pulses in the packet. In practice, during a single measuring cycle a few time-stamps are registered. Moreover, the measurement process is also synchronous and, by applying the statistics, the time interval measurement uncertainty improves even in a single measurement. In this article, besides a detailed discussion on the principle of operation of the ultrasonic flowmeter implemented in the FPGA structure, also the test results are presented and discussed

Open access

Anna Seniczak, Stanisław Seniczak, Jarosław Kowalski, Radomir Graczyk and Marcin Mistrzak

Abstract

Mites, and among them especially the Oribatida, are very abundant in bogs, being good bioindicators of various changes, but little is known about their reaction to heavy industrial exploitation of bogs. This study aimed to compare the acarofauna of the edges of small pools located in 2 bogs of Orawa-Nowy-Targ Basin (Kotlina Orawsko-Nowotarska), namely Łysa Puścizna (LP) and Bór Podczerwony (BP), degraded to different degrees by peat exploitation. The area of bog LP has decreased since the end of the 19th century by 34%, while that of BP has decreased during this time drastically (by 68%). Water in both studied pools differed from that in natural bogs, reported in the literature, especially in pH, colour, and oxygen conditions (COD and BOD5), and these differences were more pronounced at BP. The abundance of mites was similar to that observed in natural bogs, and the Oribatida dominated among mites, constituting over 99% of them. The species diversity of Oribatida was low in both pools, but especially in pool BP. In both bogs the aquatic species were the most abundant due to the wet study season. The species structure of Oribatida differed, however, from that reported from natural bogs as well as from each other. At the less degraded bog LP the most abundant was Hydrozetes lacustris (D = 69%), while at bog BP, with worse water parameters, Trimalaconothrus maior highly dominated (D = 93%). This suggests that the latter species is very tolerant to water parameters, being a successful coloniser of degraded bogs.

Open access

Stanisław Kowalski, Marcin Lukasiewicz, Aleksandra Duda-Chodak and Gabriela Zięć

Abstract

The chemical structure of 5-hydroxymethyl-2-furfural (HMF), its physicochemical properties and reactions that lead to the synthesis of HMF were discussed. Special attention was paid to HMF formation in food during processing. The potential applications of this compound in industry were described as well. Moreover, this review outlines the most important sources of HMF in human diet and estimates the potential daily intake of HMF by consumers. The known and suggested metabolic pathways, as well as the impact of HMF and its metabolites on human health are also discussed.

Open access

Kamila Dziwota, Agnieszka Dudek, Anna Szpak, Karolina Ludwikowska, Damian Kowalski, Łukasz Drabarek†, Ewelina Dziwota and Marcin Olajossy

Abstract

The basic purpose of this article is to compare how people with low and high self-esteem rated particular values. Additionally, the authors look at gender differences concerning the attitudes toward certain values.

The study involved 268 individuals aged 19-24 (M= 21.71, SD= 1.54). The participants were surveyed using the Rosenberg Self-Esteem Scale (SES) and the Rokeach Value Survey (RVS). The results were considered significant at p<0.05. The findings demonstrated that people with lower self-esteem had higher opinion of values like Conformity, Pleasure, and Comfortable Life as well as some Instrumental Values (Self-Control and Politeness), when compared against the individuals with higher self-esteem. On the other hand, they were found to value Courage. There were no differences concerning the way individuals with high and low self-esteem rated Social Recognition, A Sense of Accomplishment and Self-Respect.

Also, the authors noticed that men were more likely to appreciate Hedonistic and Intellectual values, while women attached greater significance to Relational values. There were no gender differences concerning the rating of Aesthetic and Subjective values.