6,368 research outputs found
Beam Imaging and Luminosity Calibration
We discuss a method to reconstruct two-dimensional proton bunch densities
using vertex distributions accumulated during LHC beam-beam scans. The -
correlations in the beam shapes are studied and an alternative luminosity
calibration technique is introduced. We demonstrate the method on simulated
beam-beam scans and estimate the uncertainty on the luminosity calibration
associated to the beam-shape reconstruction to be below 1\%.Comment: Figures added, typos correcte
Data-Driven Precision Luminosity Measurements with Z Bosons at the LHC and HL-LHC
A method to measure integrated luminosities at the LHC using Z bosons without
theoretical cross section input is discussed. The main uncertainties and the
prospects for precision luminosity measurements using this method are outlined.Comment: Minor revisio
Using small-angle X-ray scattering to investigate the compaction behaviour of a granulated clay
The compaction behaviour of a commercial granulated clay (magnesium aluminium smectite, gMgSm) was investigated using macroscopic pressure-density measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray microtomography (XμT) and small-angle X-ray scattering (SAXS). This material was studied as a potential compaction excipient for pharmaceutical tabletting, but also as a model system demonstrating the capabilities of SAXS for investigating compaction in other situations.
Bulk compaction measurements showed that the gMgSm was more difficult to compact than polymeric pharmaceutical excipients such as spheronised microcrystalline cellulose (sMCC), corresponding to harder granules. Moreover, in spite of using lubrication (magnesium stearate) on the tooling surfaces, rather high ejection forces were observed, which may cause problems during commercial tabletting, requiring further amelioration. Although the compacted gMgSm specimens were more porous, however, they still exhibited acceptable cohesive strengths, comparable to sMCC. Hence, there may be scope for using granular clay as one component of a tabletting formulation.
Following principles established in previous work, SAXS revealed information concerning the intragranular structure of the gMgSm and its response to compaction. The results showed that little compression of the intragranular morphology occurred below a relative density of 0 · 6, suggesting that granule rearrangements or fragmentation were the dominant mechanisms during this stage. By contrast, granule deformation became considerably more important at higher relative density, which also coincided with a significant increase in the cohesive strength of compacted specimens.
Spatially-resolved SAXS data was also used to investigate local variations in compaction behaviour within specimens of different shape. The results revealed the expected patterns of density variations within flat-faced cylindrical specimens. Significant variations in density, the magnitude of compressive strain and principal strain direction were also revealed in the vicinity of a debossed feature (a diametral notch) and within bi-convex specimens. The variations in compaction around the debossed notch, with a small region of high density below and low density along the flanks, appeared to be responsible for extensive cracking, which could also cause problems in commercial tabletting
Economic and Confessional Relationships in 18th Century Travel Writing from the Rhine
For the enlightened community in the 18th century in Germany, travel writing was an important medium for sharing “empiric” data and facts about the different parts of the “Holy Empire.” Starting with the publications of Friedrich Nicolay in 1783, observations on different religious behaviour was an important influence on the economy. For example, Catholicism was said to be a major factor for the economic backwardness of the South. For the majority of enlightened travellers of the 18th century, the industrial protestant regions like northern Germany, or at a European level the Netherlands and England, were the embodiment of the economic development of a modern state
- …
