Leaks of CP violation in the real two-Higgs doublet model

We discuss the $Z_2$ symmetric two Higgs doublet model with a real soft breaking term (real 2HDM). We explain in detail why it is not tenable to assume CP conservation in the scalar sector to keep the dimension two term real, while CP is violated by the dimension four Yukawa couplings. We propose the calculation of the infinite tadpole of the (would-be) pseudoscalar neutral scalar. We construct a simple toy model with the same flaws, where the unrenormalizable infinity is easier to calculate. We then turn our attention to the same tadpole in the real 2HDM. We spearhead this effort focusing on diagrams involving solely bare quantities. This involves hundreds of Feynman three-loop diagrams that could feed the CP violation from the quark into the scalar sector, and is only possible with state of the art automatic computation tools. Remarkably, some intermediate results agree when using three independent derivations, including the peculiar cancellation of the leading pole divergence due to a subtle interplay between masses and the Jarlskog invariant, which we calculate analytically. The calculation is not complete however, since the full two-loop renormalization of the real 2HDM is not yet available in the literature. Still, we argue convincingly that there is an irremovable infinity.Comment: 12 pages, matches published versio

Leaks of CP violation in the real two-Higgs-doublet model

We discuss the Z$_{2}$ symmetric two-Higgs-doublet model with a real soft-breaking term (real 2HDM). We explain in detail why it is not tenable to assume CP conservation in the scalar sector to keep the dimension two term real, while CP is violated by the dimension four Yukawa couplings. We propose the calculation of the infinite tadpole of the (would-be) pseudoscalar neutral scalar. We construct a simple toy model with the same flaws, where the unrenormalizable infinity is easier to calculate. We then consider the same tadpole in the real 2HDM. We spearhead this effort focusing on diagrams involving solely bare quantities. This involves hundreds of Feynman three-loop diagrams that could feed the CP violation from the quark into the scalar sector, and is only possible with state of the art automatic computation tools. Remarkably, some intermediate results agree when using three independent derivations, including the peculiar cancellation of the leading pole divergence due to a subtle interplay between masses and the Jarlskog invariant, which we calculate analytically. The calculation is not complete however, since the full two-loop renormalization of the real 2HDM is not yet available in the literature. Still, we argue convincingly that there is an irremovable infinity

The effect of changes in depth of cut on surface roughness in machining of AISI 316 stainless steel

Currently, process optimization is an important part of design of CNC toolpath, allowing overall process improvement in accordance to a range of criteria. Available CAE software for CNC toolpath optimization works only by changing the feed rate value specified in the base toolpath. The authors are planning to devise a solution allowing for optimization of other process parameters, including depth of cut. In some cases, it would be important for surface roughness to remain unaltered after optimization by means of increasing depth of cut. In this work, the effect of depth of cut on surface roughness was investigated. Depth of cut was altered for the roughing pass, while technological parameters for the finish pass remained constant. Roughness measurements were performed on-machine after rough turning and finish turning. The authors have found that depth of cut has a noticeable effect on investigated roughness parameters, both in the case of rough turning and subsequent finish turning operations

The environmental impact of machining processes

This paper will examine issues of negative effects of the machining process on the environment. Basic concepts associated with the use of technological machines and the main machining process were discussed. A detrimental effect of chosen factors involved in the process of cutting (so as for example the noise or lubricants) to the natural environment was discussed. Possibilities of environmental effects minimization by applying of new solutions, in accordance with the convention of the best available technique (BAT) were described.W artykule poruszona została problematyka negatywnych efektów oddziaływania obróbki skrawaniem na człowieka i środowisko naturalne. Omówiono podstawowe pojęcia związane z eksploatacją maszyn technologicznych i obróbką skrawaniem. Przeanalizowany został szkodliwy wpływ wybranych czynników występujących w procesie skrawania (takich jak na przykład hałas czy stosowanie cieczy obróbkowej) na środowisko naturalne i człowieka. Zaprezentowane zostały możliwości minimalizacji negatywnych dla środowiska skutków poprzez zastosowanie nowych rozwiązań, zgodnych z konwencją najlepszej dostępnej techniki (Best Available Technique)

The effect of displacement at failure on the results of FEM numerical simulation

W artykule przedstawiono wpływ parametru przemieszczenia niszczącego Uf na wyniki symulacji numerycznej procesu skrawania w programie Abaqus/CAE. W symulacji wykorzystano model konstytutywny Johnsona-Cooka, opracowany dla stopu tytanu Ti6Al4V. Omówiono warunki brzegowe oraz wpływ zmiękczenia termicznego stopu tytanu przy różnych prędkościach skrawania na wyniki symulacji MES. Wykazano znaczący wpływ przemieszczenia niszczącego Uf na przebieg dekohezji i kształtowanie wióra.In the article the effect of displacement at failure Uf on the simulation results of machining process conducted in Abaqus/CAE program is presented. A Johnson-Cook constitutive model with parameters adequate for Ti6Al4V titanium alloy was used in the simulation. Boundary conditions and the effects of thermal softening at different cutting speeds on the simulation results were described. The results shows a substantial effect of displacement at failure value on decohesion and chip formation

Optimization of CNC face milling process of Al-6061-T6 aluminum alloy

In modern machining industry, the use of computer software is an integral element in the design of technological processes. This work aims to present possibilities for optimization of milling operations with the use of commercial software designed especially for that use. A face milling operation of an aluminium flange was chosen for this study. Several different optimization strategies were described and their results shown, analysed and discussed. The effect of variable radial depth of cut on cutting force values in milling processes was reflected upon. Additionally, further research involving comparison of experiment results with simulation was proposed. It was proven that correct optimization strategy can reduce machining time for the analysed face milling operation about 37% without exceeding imposed process parameter constraints

Win–win for everyone? Reflecting on nature-based solutions for flood risk management from an environmental justice perspective

Nature-based solutions (NbS) are often framed positively in terms of win–win options or no-regret measures. However, are NbS equally beneficial for everyone? Are burdens and benefits of NbS really equally distributed and projects embraced by everyone? Is the process leading to the implementation of NbS always fair and inclusive? This chapter provides a broad overview of different environmental justice issues, critically reflecting on NbS through recognition justice, procedural justice, and distributive justice. Whereas the current critical literature focuses particularly on urban NbS, this chapter focuses on the wider translocal consequences of NbS projects. The theoretical reflections are illustrated with case studies of NbS from various countries: the recognition of marginalised women in Vietnam in mangrove restoration projects, the challenges when introducing procedural justice in implementing NbS in Serbia, the legal injustices locals are faced in the Czech Republic when they want to implement NbS, the trade-off between public collective and individual economic interest when implementing a sand nourishment project in the Netherlands, and the development of a beneficiary-pays based upstream–downstream compensation scheme in Austria

Minimum ion-beam exposure-dose determination for chemically amplified resist from printed dot matrices

Matrices of 90 nm dots have been printed into high-sensitivity positive resist (UVII HS, Shipley) with an ion projection system (IMS Vienna) to investigate the influence of shot noise on the printing probability of dots. Dot defect probability increases with diminishing ion dose following a Poisson distribution which demonstrates that shot noise is the dominating effect. The minimum ion numbers per dot to generate 50% defect probability are Ncrit=115 for standard resist treatment. This corresponds to N=165 for smaller defect probabilities of 10-4. Resist sensitivity was decreased with postexposure bake temperatures of 110 degrees C instead of 140 degrees C to improve the resolution capability of the resist. Under these conditions, and an additional resist top coat, Ncrit=130 ions per dot have been measured. The article demonstrates that ion projection lithography is not limited by shot noise at minimum resolution elements of 90 nm diam. The corresponding exposure doses are 0.3 mu C/cm2