57 research outputs found
Gender, media, and mixed martial arts in Poland: the case of Joanna Jędrzejczyk
Recent growth in the media visibility of female combat sport athletes has offered a compelling site for research on gender and sport media, as women in deeply masculinized sports have been increasingly placed in the public spotlight. While scholars in the Anglophone West have offered analyses of the media framing of this phenomenon, little work has been done outside these cultural contexts. Thus, in this paper we offer a qualitative exploration of how Joanna Jędrzejczyk, a Polish champion of the Ultimate Fighting Championship, has been represented in Polish media. Our findings reveal a relatively de-gendered, widely celebratory account, primarily framed by nationalistic discourse–findings we ascribe to both the particularities of the sport of mixed martial arts as well as the historic nature of Jędrzejczyk’s success
Barium concentration in cast roe deer antlers related to air pollution caused by burning of barium-enriched coals in southern Poland
The Mathematical Model for the Secondary Breakup of Dropping Liquid
Investigating characteristics for the secondary breakup of dropping liquid is a fundamental scientific and practical problem in multiphase flow. For its solving, it is necessary to consider the features of both the main hydrodynamic and secondary processes during spray granulation and vibration separation of heterogeneous systems. A significant difficulty in modeling the secondary breakup process is that in most technological processes, the breakup of droplets and bubbles occurs through the simultaneous action of several dispersion mechanisms. In this case, the existing mathematical models based on criterion equations do not allow establishing the change over time of the process’s main characteristics. Therefore, the present article aims to solve an urgent scientific and practical problem of studying the nonstationary process of the secondary breakup of liquid droplets under the condition of the vibrational impact of oscillatory elements. Methods of mathematical modeling were used to achieve this goal. This modeling allows obtaining analytical expressions to describe the breakup characteristics. As a result of modeling, the droplet size’s critical value was evaluated depending on the oscillation frequency. Additionally, the analytical expression for the critical frequency was obtained. The proposed methodology was derived for a range of droplet diameters of 1.6–2.6 mm. The critical value of the diameter for unstable droplets was also determined, and the dependence for breakup time was established. Notably, for the critical diameter in a range of 1.90–2.05 mm, the breakup time was about 0.017 s. The reliability of the proposed methodology was confirmed experimentally by the dependencies between the Ohnesorge and Reynolds numbers for different prilling process modes
Changes of velocity of detonation of bulk emulsion explosives in relation to time based on emulinit 8l
Jako jeden z elementów podwyższonego bezpieczeństwa materiału wybuchowego emulsyjnego ładowanego mechanicznie
podaje się utratę jego właściwości wybuchowych po upływie pewnego czasu, niestety bez odniesienia się do konkretnych
badań. Producent określił ten czas na ok. 48 godzin od momentu jego wytworzenia i załadowania do otworów strzałowych.
W normalnych warunkach prowadzenia eksploatacji jest to czas w zupełności wystarczający do bezpiecznego prowadzenia
ruchu. Jednak w praktyce mogą pojawić się sytuacje wyjątkowe, niemożliwe do przewidzenia, w wyniku których nie dochodzi
do odpalenia załadowanego MW w przewidzianym terminie. Celem pracy było zweryfikowanie danych odnośnie zachowania
się stosowanych w kopalniach KGHM materiałów wybuchowych emulsyjnych ładowanych mechanicznie poprzez śledzenie
zmian prędkości detonacji w czasie. Przedmiotem badań był MWE typu Emulinit 8L produkowany przez NITROERG S.A.
z Bierunia. Rejestrację prowadzono przy wykorzystaniu aparatury MicroTrapTM VOD/Data Recorder, która pozwala na ciągły
pomiar prędkości detonacji materiałów wybuchowych.As one of the elements of enhanced safety of mechanically charged emulsion explosives, the loss of its explosive properties
after a certain period of time is given, but without reference to the particular research. The manufacturer described this time
for approximately 48 hours from the time of its charging to the blasting holes and sensitizing. Under regular conditions of
mining works, this time is absolutely sufficient for safe mining operations. However, in practice there may be some exceptional
situations, impossible to predict, that the charged explosive is not fired within the prescribed period of time. The aim of the
study was to verify the data regarding the behavior of mechanically loaded emulsion explosives used in KGHM’s mines by
tracking the changes of velocity of detonation over time. The subject of the research was Emulinit 8L emulsion explosive
manufactured by Nitroerg S.A. from Bieruń. The measurements were provided using MicroTrapTM VOD/Data Recorder,
which allows for continuous measurement of velocity of detonation of explosives
Impact of initiation method of bulk emulsion explosive on the velocity of detonation based on Emulinit 8L
W artykule przedstawiono wyniki badań wpływu zastosowanego środka inicjującego na prędkość detonacji materiału wybuchowego.
Przedmiotem badań był materiał wybuchowy emulsyjny luzem Emulinit 8L produkowany przez firmę Nitroerg S.A.
z Bierunia. W ramach badań przeanalizowano przebiegi detonacji na całej długości ładunków MW dla wszystkich analizowanych
przypadków oraz charakterystykę rozbiegu materiału do prędkości maksymalnej.This paper presents the results of analysis of the impact of initiation method on the detonation velocity of explosives. The
subject of research was Emulinit 8L emulsion explosive manufactured by Nitroerg S.A. from Bieruń. Within the framework
of the presented research, detonation characteristics on the entire length of explosive’s samples as well as characteristics of
detonation run-up to maximum velocity were analyzed
Influence of Explosive Charge Diameter on the Detonation Velocity Based on Emulinit 7L and 8L Bulk Emulsion Explosives
One of the main parameters describing the properties of explosives is the velocity of detonation, which can be defined as the propagation speed of the chemical reaction zone in the detonating explosive. The detonation velocity of an explosive depends on many parameters, such as the material’s density or diameter and the shell of an explosive, plus the degree of crystal fragmentation, the initiation method and the content of particular components. The effectiveness of blasting work in underground mines depends primarily on the proper selection of the hole diameter, hole length, the distance between the holes and the delays of the detonators used. This article presents the results of studies investigating the influence of the diameter of a bulk emulsion explosive charge on the detonation velocity using a MicroTrapTM VOD/Data Recorder manufactured by MREL, Canada. The underground tests were developed in the “Polkowice-Sieroszowice” copper mine in Poland
Preparation of polymer materials containing titanium compounds
Titanium compounds in view of their physicochemical properties constitute interesting materials applied in chemical synthesis. They are used for preparation of antifungal agents as well as for production of self-cleaning coatings. Moreover, mentioned inorganic compounds are characterized by a capability of neutralizing of unpleasant odor. Those all characteristics make these substances useful in many fields. In the framework of presented research series of polymer materials modified with titanium and titanium oxide have been obtained by means of photopolymerization. In the further step, studies on such synthesized materials have been conducted with particular emphasis on determining a mechanical properties and wettability. Hardness of prepared polymers have been tested by means of Shore durometer. Based on the research it can be concluded that addition of titanium compounds to the polymer matrix resulted in the improvement of mechanical properties as well as in an increase of hydrophobicity. It is worth mentioning that it is possible to manipulate properties of the obtained compositions by the introduction of an appropriate amount of additive into their matrices
Synthesis of bees’ chitosan based hydrogels containing Aloe vera
Chitosan based hydrogels due to their specific properties and structure belong to the group of materials widely used in medicine. They are used as drug carriers with controlled release of active substances and in the preparation of innovative wound dressings. The main aim of the conducted research was the choice of the most favorable parameters for carrying the cross-linking reaction by means of UV radiation and microwaves. Subsequently, an adequate composition of the mixture containing chitosan and gelatin for further modification of such prepared the polymer matrix with Aloe vera extract was selected. Subsequently, an impact of introduction of Aloe vera extract into hydrogel on its physicochemical properties and structure was determined. The scope of the research included the measurement of swelling abilities of hydrogels in distilled water and selected simulated body fluids as well as incubation studies aimed at determination of tendency of prepared materials to degradation in previously mentioned fluids and their compatibility in relation to such environments. In order to characterize the chemical structure of the polymers and impact of incubation on this structure spectroscopic analysis was performed. Microscopic analysis was used to define the surface morphology of the hydrogels. Moreover, materials containing Aloe vera extract were subjected to the studies of release of additive from hydrogel matrix. Research was conducted both in acid and alkaline environment
Studies on superabsorbents modified with trehalose
Recently, trehalose becomes more and more popular compound. Increasing interest in this disaccharide results from the role as it starts to play in water economy of plants. In conditions of water shortage mentioned organic substance prevents their dehydration. Therefore, application of such interesting additive can contribute to the preparation of materials that can be applied in such areas as agriculture or cultivation of plants. It is also worth mentioning that properties of trehalose make this substance interesting from the medical point of view. Presented additive can have an impact on maintaining organs for transplantation in good condition. In presented research series of polymer superabsorbents modified with described disaccharide have been prepared. Obtained by means of photopolymerization materials differed in an amount of the additive. In the further step, physicochemical properties of superabsorbents have been determined. Following studies have been carried out: swelling studies and incubation studies in simulated body fluids aimed at determination of behavior of prepared materials in solutions similar to those one occurring in human body. Additionally, chemical structure of the hydrogels have been defined using spectroscopic technique. Based on the research it can be concluded that proposed materials are characterized by low sorption capacity and did not have significant impact on simulated body fluids. What is more, prepared hydrogels did not degrade significantly in the mentioned fluids - such conclusion is possible due to the fact that spectra of the tested materials before and after incubation studies obtained using FT-IR spectroscopy differed slightly from each other. Presented superabsorbents seem to be interesting materials that can be subjected to more advanced studies in view of their future medical application
- …