Measurement and Analysis of Axial End Forces in a Full-Length Prototype of LHC Main Dipole Magnets

A full-length, twin aperture prototype (MBP2N1) dipole magnet for the LHC project was assembled at CERN with collared coils delivered by industry. The design of this prototype is close to that foreseen for the dipole series manufacture as far the coil geometry and that of the yoke components are concerned. The bolts that transfer the axial magnetic forces from the coil ends to the cold mass end plates were instrumented to verify the axial coil support. These axial forces were initially measured after partial assembly, during a standard and an accelerated cool down Introduction to 1.9 K, and during magnet excitation up to 9.2 T. High force levels were observed, triggering a comparison with analytical models and measurements routinely made on 1-m single aperture dipole models. The prototype magnet was re-assembled with lower initial axial force settings and with additional instrumentation, to monitor these forces during the entire assembly process, and re-tested, to possibly correlate axial forces with training behaviour. This paper reports about the experimental observations and provides models towards their understandin

State of the Short Dipole Model Program for the LHC

Superconducting single and twin aperture 1-m long dipole magnets are currently being fabricated at CERN at a rate of about one per month in the framework of the short dipole model program for the LHC. The program allows to study performance improvements coming from refinements in design, components and assembly options and to accumulate statistics based on a small-scale production. The experience thus gained provides in turn feedback into the long magnet program in industry. In recent models initial quenching fields above 9 T have been obtained and after a short training the conductor limit at 2 K is reached, resulting in a central bore field exceeding 10 T. The paper describes the features of recent single aperture models, the results obtained during cold tests and the plans to ensure the continuation of a vigorous model program providing input for the fabrication of the main LHC dipoles

Present State of the Single and Twin Aperture Short Dipole Model Program for the LHC

The LHC model program for main dipoles is based on the design, fabrication and testing at CERN of a number of single and twin aperture 1m long magnets. So far, a number of single aperture models, each with specific characteristics, were tested at 2 K at a rate of about one per month. These magnets are the main tool used to check coil performance as a function of design and assembly options in view of optimizing and finalizing choices of components and procedures. Initial quenching field levels of 8.8 T were obtained and the short sample limit of the cable at 1.9 K was reached corresponding to a central bore field of 10 T. A few twin aperture dipole models were also built and tested, using the same structural components as for the long magnets which are now being built in industry. The paper discusses the main characteristics of the models built so far, the instrumentation developed to date and the experience obtained. Finally it describes the plans aimed at continuing a vigorous program to provide input to the long magnet program in industry

Fusicoccin Counteracts the Toxic Effect of Cadmium on the Growth of Maize Coleoptile Segments

The effects of cadmium (Cd; 0.1–1000 μM) and fusicoccin (FC) on growth, Cd2+ content, and membrane potential (Em) in maize coleoptile segments were studied. In addition, the Em changes and accumulation of Cd and calcium (Ca) in coleoptile segments treated with Cd2+ combined with 1 μM FC or 30 mM tetraethylammonium (TEA) chloride (K+-channel blocker) were also determined. In this study, the effects of Ca2+-channel blockers [lanthanum (La) and verapamil (Ver)] on growth and content of Cd2+ and Ca2+ in coleoptile segments were also investigated. It was found that Cd at high concentrations (100 and 1000 μM) significantly inhibited endogenous growth of coleoptile segments and simultaneously measured proton extrusion. FC combined with Cd2+ counteracted the toxic effect of Cd2+ on endogenous growth and significantly decreased Cd2+ content (not the case for Cd2+ at the highest concentration) in coleoptile segments. Addition of Cd to the control medium caused depolarization of Em, the extent of which was dependent on Cd concentration and time of treatment with Cd2+. Hyperpolarization of Em induced by FC was suppressed in the presence of Cd2+ at 1000 μM but not Cd2+ at 100 μM. It was also found that treatment of maize coleoptile segments with 30 mM TEA chloride caused hyperpolarization of Em and decreased Cd2+ content in coleoptile segments, suggesting that, in the same way as for FC, accumulation of Cd2+ was dependent on plasma membrane (PM) hyperpolarization. Similar to FC, TEA chloride also decreased Ca2+ content in coleoptile segments. La and Ver combined with Cd2+ (100 μM) significantly decreased Cd content in maize coleoptile segments, but only La completely abolished the toxic effect of Cd2+ on endogenous growth and growth in the presence of FC. Taken together, these results suggest that the mechanism by which FC counteracts the toxic effect of Cd2+ (except at 1000 μM Cd2+) on the growth of maize coleoptile segments involves both stimulation of PM H+-ATPase activity by FC as well as Cd2+-permeable, voltage-dependent Ca channels, which are blocked by FC and TEA chloride-induced PM hyperpolarization

Wzajemne zależności pomiedzy wpływem wapnia i kadmu na indukowany przez IAA wzrost elongacyjny segmentów koleoptyli kukurydzy

Stwierdzono, że komórki zwierzęce i roślinne mogą pobierać kadm poprzez interakcje z wapniem. Wysokie koncentracje wapnia obniżały toksyczne działanie Cd²⁺ na różne procesy fizjologiczne. Kurtyka i in. wykazali, że Cd²⁺ hamuje indukowany auksyną (IAA) wzrost elongacyjny segmentów koleoptyli kukurydzy. Jednakże pozostaje niewyjaśnione do tej pory, czy Ca²⁺ może obniżać toksyczne działanie kadmu na indukowany IAA wzrost elongacyjny. W związku z powyższym wydało się celowym określenie zależności pomiędzy koncentracją kadmu i wapnia w środowisku i ich wpływu na indukowany przez IAA wzrost segmentów koleoptyli kukurydzy. Badania prowadzono na 10 mm segmentach koleoptyli wycinanych z 4- dniowych etiolowanych siewek kukurydzy. Wzrost segmentów koleoptyli kukurydzy mierzono zgodnie z metodyką opisaną wcześniej przez Karcza i in. Stosowano dwa stężenia jonów Ca²⁺: 0,1 mmol・dm⁻³ i 1 mmol・dm⁻³. Stwierdzono, że wapń w stężeniu 1 mmol・dm⁻³ obniża toksyczne działanie kadmu na wzrost elongacyjny segmentów koleoptyli kukurydzy. Podczas gdy wapń podany w tym samym stężeniu w obecności IAA nie znosi toksycznego działania Cd²⁺ na wzrost segmentów koleoptyli.It has been suggested that cadmium uptake in animal and plant cells could be caused by interaction with calcium. It was also observed that higher calcium concentrations decrease the toxic effect of Cd²⁺ on different physiological processes. Kurtyka et al. showed that Cd²⁺ inhibited auxin (IAA) induced elongation growth of maize coleoptile sections. However, whether Ca²⁺ could decrease the toxic effect of cadmium on IAA-induced elongation growth remains unknown. To address this issue we investigated interrelation between calcium and cadmium in their effect on IAA-induced elongation growth. The experiments were carried out with 10 mm-long coleoptile segments cut from 4-day-old etiolated maize seedlings. The growth of coleoptile segments was measured in an agreement with methods described by Karcz et al. Two concentrations of CaCl₂ (0.1 mmol・dm⁻³ and 1 mmol・dm⁻³) and 0.1 mmol・dm⁻³ CdCl₂ were used. It was found that calcium at concentration of 1 mmol・dm⁻³ alleviates the toxic effect of cadmium on elongation growth of maize coleoptile sections. However, application of this calcium concentration in the presence of IAA did not diminish toxic action of Cd²⁺ on growth of coleoptile sections

Potential of biomass-to-fuel conversion technologies for power and means of transport

Reduction of CO2 emissions in Poland (excluding transport) should be related to a change in the structure of electricity production sources. Similar actions have been taken by many European countries. In 2017, in the European Union’s power industry, the largest emitters were dominated by coal-fired power plants in Germany (seven power plants). However, the leader of this ranking turned out to be the Belchatów power plant owned by the Polish Energy Group (PGE). Renewable energy is energy obtained from natural processes. It should be obtained in a way that would not cause a deficit of natural resources (renewed in a short time) to have a limited impact on the environment. The purpose of promoting and using renewable energy sources (RES) is to reduce the harmful effects of energy on the natural environment, primarily by limiting greenhouse gas emissions (water vapour, CO2, CH4, CFC, N2O, halon, ozone and industrial gases HFC, PFC, SF6). Biomass is the most widely used renewable energy source currently used. The study of the literature and comparison of the set parameters for different types of biomass in the given order shows that Virginia mallow has the highest usefulness for energy purposes. Considering the fact that both cashew and coconut (shells) cannot be grown due to the climate prevailing in Poland, Virginia mallow seems to be the best alternative for traditional fuels used in the energy sector in the analysed group. Virginia mallow has competitive properties to wood biomass and hard coal only significantly supercedes in terms of calorific value. The energy properties of Virginia mallow can additionally be improved as a result of the torrefaction process. In addition, in the literature on the subject, attention is paid to the fact that mallow may be grown on less-favoured soils and the process of its collection – in contrast to other such plants – does not require the use of specialized agricultural machinery