Hemifacial microsomia – a literature review

Hemifacial microsomia is a congenital syndrome of the I and II branchial arches caracterized by asymmetrical hypoplasia of the facial skeleton (mandible, maxilla, temporomandibular joint, zygoma, temporal bone), external and middle ear and facial soft tissues. The phenotype may be variable, including additional craniofacial and general anomalies. The treatment in most cases is long-lasting and interdisciplinary

Performance of TKX‐50 in thermobaric explosives

In this study, the behavior of the high-nitrogen compound TKX-50 in model thermobaric formulations was investigated. The addition of 10 % Al to TKX-50 reduces the heat of detonation by approximately 90 J/g. Despite this, Al reacts with the detonation products of TKX-50 in an exothermic manner, and the energy contribution was calculated to be approx. 375 J/g. In addition, the overpressure in the explosion chamber filled with argon after detonation of aluminized TKX-50 charges containing 27 % Al is approx. 20 % higher than in the case of neat TKX-50. Also the maximum temperature of the TKX-50/Al explosion products in the argon filled chamber is higher by 370 K than that of measured after detonating TKX only. What is more aluminum oxynitride with a low nitrogen content has been identified in the solid detonation products of aluminized TKX-50, but only for detonations in argon. Of course, charges made of TKX-50/Al mixture generate significantly higher overpressure and radiant temperature values in a confined space when they are detonated in an air atmosphere. It all means that burning aluminum in nitrogen provides little energy, and even if the concentration of nitrogen in the post-detonation products is much higher than that of oxygen, aluminum oxides are preferentially formed

Selected decision-making problems in management of logistics processes

W artykule przedstawiono główne problemy decyzyjne występujące w przedsiębiorstwach podczas zarządzania procesami logistycznymi. Przedmiotem analizy były rozbudowane łańcuchy dostaw złożone z wielu ogniw. Mnogość i złożoność wyzwań podejmowanych w ramach planowania i realizacji procesów logistycznych w takich łańcuchach dostaw stwarza konieczność informatycznego wspomagania działań w tym zakresie. W związku z tym w dalszej części artykułu przedstawiono wymagania wobec systemów informatycznych przeznaczonych do wspomagania zarządzania łańcuchami dostaw. Autorka dokonała również ramowej analizy oferty rynkowej takich systemów. W ostatniej części artykułu poruszono problematykę uwzględnienia zasad społecznej odpowiedzialności biznesu w procesie podejmowania decyzji w łańcuchach dostaw.The paper presents the main decision-making problems faced by companies in the management of logistics processes. The object of analysis is extended supply chains composed of many cells. The multitude and complexity of the challenges undertaken in the context of planning and implementation of logistics processes in these supply chains, creates the need for IT support of activities in this area. Consequently, the next part of article presents the requirements for IT systems dedicated to support supply chain management. The author has also made an analysis of market offers in this area. In last part of the article, the author describes problems connected with the necessity to consider the principles of corporate social responsibility in decision-making process in supply chains

Catalytic effect of nano Fe₂O₃ on burning rate of aluminized PBAN/AP/HMX composite propellant

W artykule przedstawiono wyniki badań heterogenicznego paliwa rakietowego PBAN/NH₄ClO₄/HMX/Al zawierającego nano i mikrocząstki Fe₂O₃ lub ferrocen w roli katalizatora. Nanoproszek Fe₂O₃ był otrzymywany przez redukcję azotanu żelaza za pomocą alkoholu poliwinylowego w warunkach niskotemperaturowej syntezy spaleniowej. Zbadano morfologię i mikrostrukturę składników. Przeprowadzono obliczenia termodynamiczne i zmierzono prędkość spalania w bombie Crawforda. Stwierdzono, że katalityczny wpływ nanoproszku Fe₂O₃ na liniową prędkość spalania jest porównywalny z wpływem ferrocenu.In the present work, aluminized PBAN/AP/HMX composite propellants containing nanometer and micrometer sized Fe₂O₃ as well as ferrocene as catalysts were tested. Fe₂O₃ nanopowders were prepared by the sol-gel auto-combustion method using polyvinyl alcohol as a gelating agent (and fuel) and iron nitrate as an oxidizer and a precursor of iron oxide. The morphology and microstructure of the components and propellant samples were determined. Thermodynamic calculations were performed and burning rates were measured using the Crawford strand burning technique. It was stated that the catalytic effect of the F₂O₃ nanopowder on the burning rate is comparable with that of ferrocene

Combustion synthesis of tungsten, tantalum, and molybdenum nanopowders

Refractory metal nanopowders have recently been of interest as starting materials for preparation of heavy alloys with exceptionally good mechanical properties resulting from their structure homogeneity at a nanoscopic level. In the light of recently published papers, the combustion synthesis seems to be a promising technique for the large-scale production of metal nanopowders. In this method, the self-sustaining internal combustion of energetic composites is used to produce useful materials. The energy released in the combustion wave, propagating through a pressed sample of the green mixture, causes a rapid increase in temperature which in turns enables the processes and reactions with high activation barriers to proceed. Unbalanced conditions and high time and space variability of temperature in combustion wave are conducive to the creation of compounds and structures that are difficult to produce using other methods. Thanks to this combustion synthesis there is a source of simple and complex metal oxides, ceramic materials, metals and intermetallic compounds as well as various composites of the substances, both in powdery and compact forms. The product form and its microstructure depends on the synthesis conditions, especially on the size and morphology of substrate particles, reactants ratio, the initial density, the presence and concentration of additives, temperature and external pressure [1–6]. Metal powders are typically produced by reduction of relevant oxides. Aluminum, magnesium, zinc, calcium, zirconium, titanium, silicon, carbon and their mixtures or compounds are used as reducers [11]. If the combustion temperature is excessively high (above 2000°C) coarse metal powders are usually produced. The initially formed crystallites are irregular in shape, they melt on the surface and agglomerate giving even bigger particles. To overcome this problem, alkali metal halide is included as an additional reactant in the system. The additive melts in the combustion wave, reduces the combustion temperature, aids in transportation of the main reactant species, which positively affects the size and shape of combustion product particles. In addition, molten salt prevents grain growth by forming a protective layer around the particles. The current paper reviews recently published works (mainly by H.H. Nersisyan et al. [7, 12–23]) on molten salt assisted combustion synthesis (SACR ) of tungsten, tantalum and molybdenum nanopowders. A detailed description of the synthesis method including its specific features, the experimental procedure, combustion parameters and macro-kinetic aspects of chemical reactions in the combustion wave, and characterization of the metal nanopowders are presented

The effect of Lecane inermis rotifers on filamentous bacteria in activated sludge from municipal wastewater treatment plant in Stalowa Wola.

Jednym z najpoważniejszych i najcięższych do usunięcia problemów występujących w oczyszczalniach ścieków, który w konsekwencji może doprowadzić do znacznego pogorszenia jakości odpływu jest zjawisko puchnięcia osadu czynnego, wywoływane przez nadmierny rozwój bakterii nitkowatych. Trwają poszukiwania skutecznych metod będących jednocześnie tanimi oraz przyjaznymi dla środowiska naturalnego sposobami zwalczania tego niekorzystnego procesu. Rezultaty wcześniejszych badań wykazały zdolność wrotków Lecane inermis do wyjadania bakterii nitkowatych występujących w osadzie czynnym. Przeprowadzony eksperyment miał na celu sprawdzenie w jaki sposób oddziałują one na bakterie nitkowate i czy mogą wpływać na ich liczebność. Doświadczenie przeprowadzono w 5 bioreaktorach BioFlo115, przeznaczonych do hodowli mikroorganizmów z wykorzystaniem osadu czynnego pochodzącego z miejskiej oczyszczalni ścieków zlokalizowanej w południowo-wschodniej części Polski. Do zbiorników 3 bioreaktorów introdukowano wrotki. Pozostałe 2 stanowiły kontrolę. Dodatkowo w końcowej fazie eksperymentu dwukrotnie zwiększono obciążenie badanego osadu. W celu zidentyfikowania zmian liczebnościowych i strukturalnych wykorzystano techniki barwienia metodą Gram’a i Neisser’a oraz technikę fluorescencyjnej hybrydyzacji „in situ” (FISH), która pozwala na szczegółowe badanie, budowy kłaczków i roli bakterii nitkowatych. Wyniki analizy mikroskopowej dowiodły, że wrotki Lecane inermis wykazują zdolność do kontrolowania zagęszczenia bakterii nitkowatych nie wpływając jednocześnie niekorzystnie na parametry fizyko-chemiczne osadu.One of the most serious and severe problems that appear in effluent treatment, which as a result can lead to considerable aggravation of sewage treatment quality, is the phenomenon sledge bulking, which is caused by the excessive growth of filamentous bacteria. Attempts are being made to find some effective methods which will simultaneously be cheap and ecofriendly in order to cope with this adverse process. The results of the previously conducted experiments proved that Lecane inermis rotifers absorb filamentous bacteria that appear in sediment sludge. The main aim of the conducted experiment was to find the way in which Lecane rotifers influence filamentous bacteria of sediment sludge and to check whether they may have influence upon the bacteria’s density. The experience was conducted in 5 bioreactors BioFlo115 (which are used to grow microorganisms) with the use of the sediment sludge taken from the effluent treatment located in the southeast part of Poland. The 3 containers were filled up with rotifers. The remaining 2 served as control. Additionally, during the last phase of the experiment, the encumbrance of the tested sludge was doubled. In order to identify the change in number and structure the dyeing techniques introduced by Gram and Neisser were used as well as the method of fluorescent crossing “in situ” (FISH), which enables detailed testing of the structure and the role of filamentous bacteria.Micro technique of analysing the sludge proved that Lecane rotifers are able to control the density of filamentous bacteria and simultaneously do not bear any harmful influence upon physicochemical parameters of the sludge