Status Report on the Hydrodynamic Simulations of a Tapered Plasma Lens for Optical Matching at the ILC e+e^+ Source

The International Linear Collider is a planned electron-positron linear collider with its positron source producing positrons by aiming undulator radiation onto a rotating target. The resulting, highly divergent positron beam requires immediate optical matching to improve the luminosity and therefore the success of the intended collision experiments. Here, optical matching refers to the process of capturing particles and making them available for downstream beamline elements like accelerators. In the past, this has been done with sophisticated coils, but more recently the usage of a current-carrying plasma, a so-called plasma lens, has been proposed as an alternative. For the International Linear Collider idealised particle tracking simulations have already been done with the purpose of finding the optimal plasma lens design with respect to the captured positron yield. The proposed design is characterised by a linearly widened radius in beam direction. Now further research and development of this design is required, including both experiments with a prototype set-up as well as corresponding simulations modelling the hydrodynamics of the current-carrying plasma and the resulting magnetic field. The accuracy of the latter will benefit greatly from the former. In this work, first preliminary hydrodynamic simulations instil confidence into further endeavours.Comment: Talk presented at the International Workshop on Future Linear Colliders (LCWS 2023), 15-19 May 2023. C23-05-15.

Fly ashes from the combustion of lignite as additive to the cement slurry used in the work of filling voids in the rock mass

W Polsce podstawowym źródłem energii elektrycznej i cieplnej jest nadal węgiel kamienny i brunatny. Podczas procesu spalania węgli powstają duże ilości produktów ubocznych, m.in.: popioły lotne, żużle paleniskowe oraz dostające się do atmosfery szkodliwe związki chemiczne w postaci gazu (CO2, NOx, związki siarki). Popioły lotne, z uwagi na swoją dużą miałkość (zbliżoną do cementu), skład chemiczny i fazowy oraz reaktywność, znalazły szerokie zastosowanie w rozwiązaniach technologicznych, m.in.: w produkcji cementu zwykłego, masywnego, hydrotechnicznego oraz cementów nowej generacji. Stosowanie odpowiedniego dodatku popiołów lotnych ma pozytywny wpływ na właściwości świeżego i stwardniałego betonu, a także umożliwia proekologiczne i ekonomiczne wytworzenie mieszanki cementowej. Eksploatacja bogactw naturalnych Ziemi związana jest z wykonywaniem na różnych głębokościach wyrobisk górniczych. Po pewnym czasie pułap wyrobiska ulega załamaniu, co pociąga za sobą obsunięcie się górnych warstw i wytworzenie się na powierzchni ziemi zagłębienia, tzw. niecki lub zapadliska. Taki rozwój sytuacji, wymusza potrzebę wzmacniania podłoża oraz uszczelniania górotworu. Aby zminimalizować ryzyko związane z problemami geotechnicznymi na terenach pogórniczych, należy stosować takie rozwiązania inżynierskie, które w sposób uniwersalny, ekonomiczny oraz wydajny poprawią nośność gruntów. Prowadzi to do rozwoju badań nad nowymi recepturami cementu stosowanego podczas prac geoinżynieryjnych, zwłaszcza na terenach górniczych. Co więcej, wymagania ekonomiczne zmuszają inżynierów do stosowania tańszych rozwiązań techniczno- technologicznych przy jednoczesnym zachowaniu właściwości wytrzymałościowych. Przykładem takiego rozwiązania jest użycie odpowiednich dodatków do receptur zaczynów uszczelniających, które zmniejszają całkowity jednostkowy koszt zabiegu.The main energy source in Poland is still hard coal and lignite. The coal combustion process produces large quantities of by-products, e.g. fly ashes, slag furnace and harmful chemical gases (CO2, NOx, sulfur compounds) which enter the atmosphere. Fly ashes, due to their being fine grained (cement-like), chemical and phase compound and reactivity, have also been widely used in various technological solutions e.g. in the production of ordinary cement, hydro-technical cement and the new generation of cements. The adequate amount of fly ashes additive has a positive effect on fresh and hardened cement slurry properties. What is more, it allows for the pro-ecological and economic production of cement mix The exploitation of natural resources is connected with performance mining excavations at different depths. After a certain period of time, those voids break down which, in turn, leads to the slip of upper layers and the so-called landslides forming on the surface. This situation imposes the necessity of basis and sealing rock mass reinforcement. To minimize the risk connected to geotechnical problems on the mining areas, there is a need to use engineering solutions which could improve soil bearing in a universal, economical and efficient way. This leads to the development of new cement slurry recipes used during geoengineering works, especially in the mining areas. Moreover, economic requirements are forcing engineers to use less expensive technical and technological solutions simultaneously maintaining strength properties. An example of such a solution is to use suitable additives to cement slurry which could reduce the total unit cost of the treatment

Comparison of the Efficiency of Williamson and Anderson Turn Manoeuvre

The paper presents comparison of the ‘Person over board’ manoeuvres. The article was based on research con-ducted on a group of students of the Faculty of Navigation of Gdynia Maritime University. People involved in studies previously conducted on board training on school training ships: "Dar M?odzie?y" and "Horyzont II", but did not have experience as an officers. Research was carried on the Polaris Ships Bridge Simulator, located at the faculty of Navigation, of Gdynia Maritime University

Effect of the conditions of thermomechanical reclaiming of ground tire rubber on the properties of reclaimed rubber materials

Termomechaniczną regenerację miału gumowego (GTR) prowadzono przy użyciu współbieżnej wytłaczarki dwuślimakowej. Zastosowanie metody powierzchni odpowiedzi RSM (ang.: Response Surface Methodology) pozwoliło na scharakteryzowanie wpływu warunków termomechanicznej regeneracji odpadów gumowych (temperatury cylindra wytłaczarki, prędkości obrotowej ślimaków oraz wydajności wytłaczania) na przebieg procesu regeneracji (moment obrotowy) oraz właściwości otrzymanych regeneratów (zawartości ekstraktu acetonowego, zawartości frakcji zolowej, lepkości Mooneya, przyrostu momentów skrętnych, optymalnego czasu wulkanizacji). Stwierdzono, że najistotniejszym czynnikiem wpływającym na przebieg termomechanicznej regeneracji miału gumowego oraz na jakość otrzymanych regeneratów jest temperatura cylindra wytłaczarki.Thermomechanical reclaiming of ground tire rubber (GTR) was performed using a co-rotating twin screw extruder. Based on response surface methodology (RSM) the influence of reclaiming conditions (temperature of barrel, screw rotational speed, feed rate) on the processing (screw torque) and properties of reclaimed rubber (acetone extract content, sol fraction, Mooney viscosity, torque increment ΔM and optimal vulcanization time) were determined. It was found that barrel temperature is the main factor affecting the thermomechanical reclaiming process and quality of reclaimed rubber

Application of fluidal ashes as a component of cement slurry used in carbon dioxide injection wells - possibility analysis

One of the most important environmental issues bothering scientists nowadays are greenhouse gases, mainly carbon dioxide, and the possibility of limiting their emission and utilization. Many countries have been actively trying to limit the greenhouse gases emission, mainly carbon dioxide, and implement the Carbon Capture and Storage (CCS) technology for years. One of the essential aspects of geological injection is constant monitoring of carbon dioxide, especially its pressure and temperature. Those parameters have an impact on viscosity, density and phase alterations during the flow. It is of vital importance to maintain the supercritical state of the fluid because it is the most efficient way of CO2 storage. The negative impact of CO2 on the properties of the cement slurry may disturb the exploitation of the well and create considerable hazard for the geological storage of carbon dioxide. Therefore, the cement slurry should be appropriately selected and the role of CO2 in the development of technological properties of fresh and hardened cement slurry should be determined. The aim of this research is to select the most appropriate cement slurry composition exhibiting optimal properties with respect to the phase changes of carbon dioxide. The first part of the research consists in creating cement slurries of various compositions and investigating its thermal conductivity and sogginess under in-situ conditions. The second part concerns a possibility of utilization of fluidal ashes from combustion of lignite as a component of cement slurry

Determination of the wind speed limits causing the break away of the vessel from jetty p in naftoport : simulation study

The safety of the tanker during the loading operations carried out in the oil terminal is influenced by many factors. Based on the observations of port personnel and weather analyses in that area it was found that for Naftoport one of the most important factors affecting the security of the tanker is the wind, and more precisely – its direction and speed. Less important are accompanying waves and generated by it variable and periodic wind current. In this selected area of the Baltic Sea the direction and speed of wind change very dynamically depending on the activity of pressure patterns, which are very closely related to the occurrence of seasons. For the purpose of the article simulations were carried out of variable wind speeds, from directions causing the breakaway of the ship from the jetty, with an application of the model of the tanker in the least favourable load condition. The results obtained – the load in the mooring ropes from simulation tests were compared with the requirements of the OCIMF (Oil Companies International Marine Forum), determining the methodology of performing calculations of these forces for the selected type of tanker