280 research outputs found
Boulton and Fothergill silver.
PhDThis thesis is about the silver business of Matthew Boulton and John
Fothergill at their Soho Manufactory near Birmingham. Their
partnership lasted from 1762 until 1782.
A rounded discussion of the topic is attempted. Within the contexts
of industry elsewhere and Soho's other activities, successive chapters
cover the early development, marketing, production, design, and later
decline of the partners' silver.
Silver plate was prestigious and, untypically for Boulton, he
concentrated on sales to the public rather than trade customers. To
attract orders he made modest charges. This was viable where mainly
machinery was used to make plate, even though sales were not high,
since the expense of machinery was substantially covered by the larger
sales of non-silver items. However, where Boulton relied to a
greater degree upon hand methods, he lacked technical means to
compensate for low profit-margins. Moreover, inefficiency and the
firm's lack of capital which led to substantial bankers' interest
charges on payment for bullion, particularly when customers paid late,
caused losses. These problems applied particularly to silver plate
and were mainly responsible for the decision to reduce production
drastically; however, the manufacture of a large range of small items
remained relatively consistent.
The thesis includes appendices. Some contain new information about
annual totals for the following aspects of the business: the volume of
assay silver; each type of article; pieces sold on commission; and
sterling silver supplies. Other appendices provide details about the
partners' silversmiths and extracts from a Soho inventory.
This thesis involves a more detailed use of sources than previous
studies of the topic. Apart from the silver itself (which is
selectively illustrated), the Matthew Boulton Papers and statistics
derived from The Birmingham Assay office provide the main sources.
Manuscripts covering silver production elsewhere provide contextual
material for understanding the partners' silver business
Proteomics goes forensic: detection and mapping of blood signatures in fingermarks
A bottom up in situ proteomic method has been developed enabling the mapping of multiple blood signatures on the intact ridges of blood fingermarks byMatrix Assisted Laser Desorption Mass Spectrometry Imaging (MALDI-MSI). This method, at a proof of concept stage, builds upon recently published work demonstrating the opportunity to profile and identify multiple blood signatures in bloodstains via a bottom up proteomic approach. The present protocol addresses the limitation of the previously developed profiling method with respect to destructivity;
destructivity should be avoided for evidence such as blood fingermarks, where the ridge detail must be preserved in order to provide the associative link between the biometric information and the events of bloodshed. Using a blood mark reference model, trypsin concentration and spraying conditions have been optimised within the technical constraints of the depositor eventually employed; the application of MALDI-MSI and Ion Mobility MS have enabled the detection, confirmation and visualisation of blood signatures directly onto the ridge pattern.
These results are to be considered a first insight into a method eventually informing investigations (and judicial debates) of violent crimes in which the reliable and non-destructive detection and mapping of blood in fingermarks is paramount to reconstruct the events of bloodshed
Glass Transition in a 2D Lattice Model
The dynamics of compaction of hard cross-shaped pentamers on the 2D square
lattice is investigated. The addition of new particles is controlled by
diffusive relaxation. It is shown that the filling process terminates at a
glassy phase with a limiting coverage density \rho_{rcp}=0.171626(3), lower
than the density of closest packing \rho_{cp}=0.2, and the long time filling
rate vanishes like (\rho_{rcp}-\rho(t))^2. For the entire density regime the
particles form an amorphous phase, devoid of any crystalline order. Therefore,
the model supports a stable random packing state, as opposed to the hard disks
system. Our results may be relevant to recent experiments studying the
clustering of proteins on bilayer lipid membranes
An electrochemical system for efficiently harvesting low-grade heat energy
Efficient and low-cost thermal energy-harvesting systems are needed to utilize the tremendous low-grade heat sources. Although thermoelectric devices are attractive, its efficiency is limited by the relatively low figure-of-merit and low-temperature differential. An alternative approach is to explore thermodynamic cycles. Thermogalvanic effect, the dependence of electrode potential on temperature, can construct such cycles. In one cycle, an electrochemical cell is charged at a temperature and then discharged at a different temperature with higher cell voltage, thereby converting heat to electricity. Here we report an electrochemical system using a copper hexacyanoferrate cathode and a Cu/Cu2+ anode to convert heat into electricity. The electrode materials have low polarization, high charge capacity, moderate temperature coefficients and low specific heat. These features lead to a high heat-to-electricity energy conversion efficiency of 5.7% when cycled between 10 and 60 degrees C, opening a promising way to utilize low-grade heat.open121
Solid-phase synthesis of Rhodamine-110 fluorogenic substrates and their application in forensic analysis
Surface Pressure of Liquid Interfaces Laden with Micron-Sized Particles
We consider the surface pressure of a colloid-laden liquid interface. As
micron-sized particles of suitable wettability can be irreversibly bound to the
liquid interface on experimental timescales, we use the canonical ensemble to
derive an expression for the surface pressure of a colloid-laden interface. We
use this expression to show that adsorption of particles with only hard-core
interactions has a negligible effect on surface pressures from typical
Langmuir-trough measurements. Moreover, we show that Langmuir-trough
measurements cannot be used to extract typical interparticle potentials.
Finally, we argue that the dependence of measured surface pressure on surface
fraction can be explained by particle coordination number at low to
intermediate particle surface fractions. At high surface fractions, where the
particles are jammed and cannot easily rearrange, contact-line sliding and/or
deformations of the liquid interface at the length scale of the particles play
a pivotal role.Comment: 13 pages, 5 figure
Cellular Communication through Light
Information transfer is a fundamental of life. A few studies have reported that cells use photons (from an endogenous source) as information carriers. This study finds that cells can have an influence on other cells even when separated with a glass barrier, thereby disabling molecule diffusion through the cell-containing medium. As there is still very little known about the potential of photons for intercellular communication this study is designed to test for non-molecule-based triggering of two fundamental properties of life: cell division and energy uptake. The study was performed with a cellular organism, the ciliate Paramecium caudatum. Mutual exposure of cell populations occurred under conditions of darkness and separation with cuvettes (vials) allowing photon but not molecule transfer. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UV-light to longer waves. Even through glass, the cells affected cell division and energy uptake in neighboring cell populations. Depending on the cuvette material and the number of cells involved, these effects were positive or negative. Also, while paired populations with lower growth rates grew uncorrelated, growth of the better growing populations was correlated. As there were significant differences when separating the populations with glass or quartz, it is suggested that the cell populations use two (or more) frequencies for cellular information transfer, which influences at least energy uptake, cell division rate and growth correlation. Altogether the study strongly supports a cellular communication system, which is different from a molecule-receptor-based system and hints that photon-triggering is a fine tuning principle in cell chemistry
Stochastic light concentration from 3D to 2D reveals ultraweak chemi- and bioluminescence
For countless applications in science and technology, light must be concentrated, and concentration is classically achieved with reflective and refractive elements. However, there is so far no efficient way, with a 2D detector, to detect photons produced inside an extended volume with a broad or isotropic angular distribution. Here, with theory and experiment, we propose to stochastically transform and concentrate a volume into a smaller surface, using a high- albedo Ulbricht cavity and a small exit orifice through cavity walls. A 3D gas of photons produced inside the cavity is transformed with a 50% number efficiency into a 2D Lambertian emitting orifice with maximal radiance and a much smaller size. With high-albedo quartz-powder cavity walls ( P = 99.94%), the orifice area is 1/( 1 - P) approximate to 1600 times smaller than the walls' area. When coupled to a detectivity-optimized photon-counter ( D = 0.015 photon- 1 s1/ 2 cm) the detection limit is 110 photon s- 1 L- 1. Thanks to this unprecedented sensitivity, we could detect the luminescence produced by the non-catalytic disproportionation of hydrogen peroxide in pure water, which has not been observed so far. We could also detect the ultraweak bioluminescence produced by yeast cells at the onset of their growth. Our work opens new perspectives for studying ultraweak luminescence, and the concept of stochastic 3D/2D conjugation should help design novel light detection methods for large samples or diluted emitters
Thermo-Electrochemical Cells Based on Carbon Nanotube Electrodes by Electrophoretic Deposition
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