81 research outputs found
On metal and ‘spoiled’ wine: analysing psimythion (synthetic cerussite) pellets (5th-3rd centuries BCE) and hypothesising gas-metal reactions over a fermenting liquid within a Greek pot
A Pb-based synthetic mineral referred to as psimythion (pl. psimythia) was manufactured in the Greek world at least since the 6th c BCE and routinely by the 4th c BCE. Theophrastus (On Stones, 56) describes its preparation from metallic Pb suspended over a fermenting liquid. Psimythion is considered the precursor of one of western art’s most prominent white pigments, i.e. lead white (basic lead carbonate or synthetic hydrocerussite). However, so far, and for that early period, published analyses of psimythia suggest that they consisted primarily of synthetic cerussite. In this paper, we set out to investigate how it was possible to manufacture pure cerussite, to the near exclusion of other phases. We examined the chemical and mineralogical composition (pXRF/XRD) of a small number of psimythion pellets found within ceramic pots (pyxis) from Athens and Boeotia (5th–4th c BCE) in the collection of the National Archaeological Museum (NAM), Athens. Analyses showed that the NAM pellets consisted primarily of Pb/cerussite with small amounts of Ca (some samples) and a host of metallic trace elements. We highlight the reference in the Theophrastus text to ‘spoiled wine’ (oxos), rather than ‘vinegar’, as has been previously assumed, the former including a strong biotic component. We carried out DNA sequencing of the pellets in an attempt to establish presence of microorganisms (Acetic Acid Bacteria). None was found. Subsequently, and as a working hypothesis, we propose a series of (biotic/abiotic) reactions which were likely to have taken place in the liquid and vapour phases and on the metal surface. The hypothesis aims to demonstrate that CO2 would be microbially induced and would increase, as a function of time, resulting in cerussite forming over and above hydrocerussite/other Pb-rich phases. Psimythion has for long been valued as a white pigment. What has perhaps been not adequately appreciated is the depth of empirical understanding from the part of psimythion manufacturers of the reactions between abiotic and biotic components within ‘oxos’/pot, as key drivers of minerals synthesis. Ultimately, psimythion manufacture may rest in understanding the nature of ‘oxos’, antiquity’s relatively little researched strongest acid
Bi-fractional transforms in phase space
The displacement operator is related to the displaced parity operator through a two dimensional
Fourier transform. Both operators are important operators in phase space
and the trace of both with respect to the density operator gives the Wigner functions
(displaced parity operator) and Weyl functions (displacement operator). The generalisation
of the parity-displacement operator relationship considered here is called
the bi-fractional displacement operator, O(α, β; θα, θβ). Additionally, the bi-fractional
displacement operators lead to the novel concept of bi-fractional coherent states.
The generalisation from Fourier transform to fractional Fourier transform can be
applied to other phase space functions. The case of the Wigner-Weyl function is considered
and a generalisation is given, which is called the bi-fractional Wigner functions,
H(α, β; θα, θβ). Furthermore, the Q−function and P−function are also generalised to
give the bi-fractional Q−functions and bi-fractional P−functions respectively. The
generalisation is likewise applied to the Moyal star product and Berezin formalism for
products of non-commutating operators. These are called the bi-fractional Moyal star
product and bi-fractional Berezin formalism.
Finally, analysis, applications and implications of these bi-fractional transforms
to the Heisenberg uncertainty principle, photon statistics and future applications are
discussed
Measurement of the mass difference m(D-s(+))-m(D+) at CDF II
We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)
Oil Man Goes Free After Serving 7 Months For Contempt
Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Harry F. Sinclair, The New York oil baron to whom Albert E. Fall, leased the Teapot Dome Navel reserve oil fields in Wyoming, and who has been a prisonersin the District of Columbia jail for almost seven months for contempt of court, is shown aabove as he left the jail a free man.
[Photograph 2012.201.B0241.0103]
Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Dr. Wilfred T. Grenfell. Deceased 10-9-40
Το νερό, η συλλογή και χρήση του στα πλυντήρια της Αγριλέζας, Λαυρίου, 4ος π.Χ. αιώνας. Μερικές νέες παρατηρήσεις και αποτελέσματα.
SEM and TEM examination of Byzantine and post-Byzantine metal threads in Greek Orthodox ecclesiastical textiles
No abstract available
The possibility of smelting iron-rich lateritic ores in the Hellenistic settlement of Petres, NW Greece
No abstract available
Water, its collection and usage in the washeries of 4th century Agrileza: some new observations and results
No abstract available
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