History of Hand Grenades from a Weapon Science Perspective Example of Polish Hand Grenade Constructions 1919–1944

The article presents the history of creation and development of hand grenades as infantry weapons. The most interesting designs of Polish grenades from the interwar period and the German occupation are described. Both prototype designs from the time of occupation, which were the basis for mass production and on a nearly industrial scale, as well as self-made designs that did not meet the conditions for mass production and whose features, due to a very small number of surviving copies, are poorly known, are described.W artykule przedstawiono historię powstania i rozwoju granatów ręcznych jako broni piechoty. Opisano najciekawsze konstrukcje polskich granatów z okresu międzywojnia i okupacji niemieckiej. Odnotowano zarówno prototypowe konstrukcje z czasów okupacji, które stanowiły podstawę do produkcji seryjnej i na niemal przemysłową skalę, jak i projekty samodziałowe, które nie spełniały warunków seryjności produkcji i których cechy, z uwagi na bardzo nikłą liczbę zachowanych egzemplarzy, są mało znane

Development of low friction coatings for alsi milling

Aluminium silicon (AlSi) alloys play an essential role in many industries because of their good machinability characteristics. However, their low degree of plasticity promotes adhesion at the tool edge during machine cutting, leading to a built-up edge (BUE) which reduces tool lifetimes, and the silicon content leads to tool abrasion. Currently, cemented carbide mill inserts coated with titanium diboride (TiB₂)offer the prospects of machining an array of structural metallic alloys including AlSi. However, the brittle nature of TiB₂ leaves it prone to extensive surface damage, particularly during the running-in stage of machining when tool adaptation takes place. An additional coating addressing abrasive wear and preventing BUE could limit TiB₂damage. Fabricating coatings of TiB₂ using arc evaporation remains challenging as an extensive cathode fracture occurs. Thus, the present work aims to address the drawbacks associated with TiB₂ by the deposition of a thin lubricious coating on top of the TiB₂.Secondly, the development of a new cathode, which would allow the deposition of TiB₂ by arc evaporation is investigated. A hybrid Physical Vapor Deposition system combining Filtered Cathodic Vacuum Arc (FCVA) and Magnetron Sputtering was developed forth is study. Three lubricious coating systems of Ti-MoS₂, single layer DLC and DLC-WS₂ were investigated as a top layer. Ti-MoS₂ was optimised for dry machining applications, and a Ti:MoS₂ ratio around 0.39 was found to prevent Al from sticking to the tool edges. The DLC and DLC-WS₂ coatings were designed for machining with coolant. In comparison to the performance of a TiB₂ benchmark, the monolayer DLC coating improved the machining length by ~60% and a two-layer DLC-WS₂ coating decreased wear rate by ~75%, having a measured coefficient of friction of 0.05. The development of TiB₂ cathodes for FCVA required a modification of the chemical composition to improve it’s sinterability and prevent cathode fracture during arc operation. A TiB₂-TiSi₂ (5 wt%)cathode ensured the best balance between arc stability and cathode utilisation while TiB₂-C(1 wt%)has provided exceptional arc stability, although the cathode utilisation was less due to the constant generation of cathode flakes

Pyrotechnic Recognition

With the financial support of Internal Security Fund Police Programme European Commission Directorate General Home Affairs. This project has been founded with support from the European Commission. This publication reflects the views only of the authors, and European Commission cannot be held responsible for any use which may be made of the information contained therein

Lateralizacja i lokalizacja funkcji językowych w mózgu (przegląd najważniejszych zagadnień)

The article has the nature of a general overview (inter alia it furnishes an overview of publications in the field of neurolinguistics). The author seeks an answer to the following question: where (and) how the units of speech (of language and speech) are located in the brain. The work consists of a number of parts. In the first chapter the author focuses on the nervous system (the object of neurological research). In the second chapter the author focuses on the linguistic capacity (the object of linguistic research). Both chapters distinguish the units of the brain and speech to which researchers refer in their attempts to describe the relationship between language and the brain. The third chapter alludes to (and classifies) the most recent achievements in the field of neuroscience about the lateralisation and localisation of the linguistic functions in the brain. Eventually the units of human speech are ascribed to the selected areas in the brain. The final part of the work contains a comprehensive bibliography of the subject

Stiffness memory of EA.hy926 endothelial cells in response to chronic hyperglycemia

Background: Glycemic memory of endothelial cells is an effect of long-lasting hyperglycemia and is a cause of various diabetics complications, that arises despite of the treatment targeted towards returning low glucose level in blood system. On the other hand, endothelial dysfunction, which is believed to be a main cause of cardiovascular complications, is exhibited in the changes of mechanical properties of cells. Although formation of the glycemic memory was widely investigated, its impact on the mechanical properties of endothelial cells has not been studied yet. Methods: In this study, nanoindentaion with a tip of an atomic force microscope was used to probe the long-term changes (through 26 passages, c.a. 80 days) in mechanical properties of EA.hy926 endothelial cells cultured in hyperglycemic conditions. As a complementary method, alterations in the structure of actin cytoskeleton were visualized by fluorescent staining of F-actin. Results: We observed a gradual stiffening of the cells up to 20th passage for cells cultured in high glucose (25 mM). Fluorescence imaging has revealed that this behavior resulted from systematic remodeling of the actin cytoskeleton. In further passages, a drop in stiffness had occurred. The most interesting finding was recorded for cells transferred after 14 passages from high glucose to normal glucose conditions (5mM). After the transfer, the initial drop in stiffness was followed by a return of the cell stiffness to the value previously observed for cells cultured constantly in high glucose. Conclusions: Our results indicate that glycemic memory causes irreversible changes in stiffness of endothelial cells. The formation of the observed "stiffness memory" could be important in the context of vascular complications which develop despite the normalization of the glucose level

Nanomechanical sensing of the endothelial cell response to anti-inflammatory action of 1-methylnicotinamide chloride

There is increasing evidence that cell elastic properties should change considerably in response to chemical agents affecting the physiological state of the endothelium. In this work, a novel assay for testing prospective endothelium-targeted agents in vitro is presented. The proposed methodology is based on nanoindentation spectroscopy using an atomic force microscope tip, which allows for quantitative evaluation of cell stiffness. As an example, we chose a pyridine derivative, 1-methylnicotinamide chloride (MNA), known to have antithrombotic and anti-inflammatory properties, as reported in recent in vivo experiments. First, we determined a concentration range of MNA in which physiological parameters of the endothelial cells in vitro are not affected. Then, cell dysfunction was induced by incubation with tumor necrosis factor-alpha (TNF-α) and the cellular response to MNA treatment after TNF-α incubation was studied. In parallel to the nanoindentation spectroscopy, the endothelium phenotype was characterized using a fluorescence spectroscopy with F-actin labeling, and biochemical methods, such as secretion measurements of both nitric oxide (NO), and prostacyclin (PGI2) regulatory agents. We found that MNA could reverse the dysfunction of the endothelium caused by inflammation, if applied in the proper time and to the concentration scheme established in our investigations. A surprisingly close correlation was found between effective Young's modulus of the cells and actin polymerization/depolymerization processes in the endothelium cortical cytoskeleton, as well as NO and PGI_{2] levels. These results allow us to construct the physiological model of sequential intracellular pathways activated in the endothelium by MNA

Elasticity changes anti-correlate with NO production for human endothelial cells stimulated with TNF-α\alpha

Tumor necrosis factor alpha (TNF-$\alpha$) is a critical cytokine that is involved in systemic inflammatory response and contributes to the activation of the pro-inflammatory phenotype of the endothelium. In the present study, effects of TNF-$\alpha$ on morphology and elasticity of endothelium in relation to the production of NO and actin fiber reorganization were analyzed in human dermal microvascular endothelial cells. The cells were incubated in MCDB medium solution and stimulated with 10ng/ml of TNF-$\alpha$. Atomic force microscopy measurements have enabled characterization of cell morphology and elastic properties in physiological conditions. The spectrophotometric Griess method was applied to estimate nitric oxide (NO) production of the cells. We demonstrated that TNF-$\alpha$-induced changes in elasticity of endothelium anti-correlate with NO production and are associated with the reorganization of actin cytoskeleton

IR and Raman study of calcium aluminosilicate glasses of the composition xCaO ∙ xAI2O3 ∙ (100 - 2x)SiO2

Vibrational spectra are measured for calcium aluminosilicate glasses with the composition (in mol%) xCaO ∙ xAI2O3 ∙ (100 - 2x)SiO2. The OH bands show a systematic change with x in both MIR and NIR regions. The strongly asymmetric band at about 3550 cm-1 shifts to lower wave numbers with increasing x. In the same way the OH combination band at about 4500 cm-1 shifts to lower wave numbers. For the 3550 cm-1 band an extinction coefficient of about 60 1 ∙ mol-1 ∙ cm-1 is suggested for all the samples with x from 15 to 32. For the 4500 cm-1 band the extinction coefficient decreases from 1.0 to 0.49 1 ∙ mol-1 ∙ cm-1 with increasing x from 15 to 32. Systematic changes in the Raman and IR reflectance spectra reflect the substitution of Al3+ for Si4+ and a corresponding increase of Ca2+ in the network. Thus, the vibrational spectra can be related to a fully polymerized network without or with a small amount of nonbridging oxygens also for glasses with x ≥ 25