Ivory simulants

Manatees and dugongs - sometimes called sea cows - belong to the order Sirenia. They live in the seas around parts of Africa, Australia, Asia, North America, and in the Caribbean. They are not well known and are protected species, so it is very rare to encounter an item made from their bone. However, they should be mentioned because they are unique in that all their bones are compact and not hollow. This has made their bone more versatile for carving than bone from other species, and it has been used as an ivory simulant. 

Heat is used to darken amber, ivory, and jade to simulate age. Pieces of amber and tortoiseshell can be reconstmcted, ie, joined under heat and moderate pressure. By careful heating in oil, milky amber can be clarified when the gas and water within small bubbles diffuse out of the stone. If heating is rapid, the attractive sun-spangle cracking shown in Figure 1 results. 

Ivories of Unknown Provenance. The data for the Khorsabad ivories are consistent with the suggested age. These data do not, however, eliminate the possibility of artificial methods for simulating the patina and texture, generally acquired by long-term burial, by chemical extraction... 

Figure 27 Synthetic plastics imitated successfully exclusive natural materials a Bakelite ash tray with built-in match holder and striker in marble Roanoid, with marbleized, brass-tipped cigarette holder, 1930s. Carvacraft desk set in amber cast phenolic, 1948-51 double inkwell, notepad holder, blotter and paper knife with clear acrylic blade. Smiths Sectric alarm clock with marbleized urea-formaldehyde case, 1932. Ardath Tobacco cigarette box in ivory and black urea-formaldehyde with lid moulded to simulate a classical relief, 1935. Propelling pencil with black and orange mottle typical of vulcanite, 1930s (Photo Stephen Brayne, Collection Sylvia Katz)...

There exists a wealth of old, jet simulants. Several materials used to make jewellery were black, and further, almost anything could be dyed black. It was much harder to produce plastics in pale colours, or to bleach materials, to imitate a material such as ivory. There are also other coals which were worked in their own right and not necessarily intended as a simulant of jet, but which may be confused with jet. 

Bone is the most common simulant of ivory. In smaU items or as inlay it can be difBcult to tell which material has been used as both bone and ivory appear much the same colour and have many similar properties. However, bone contains none of the structural patterns of ivories, for example the engine turned pattern of elephant and mammoth ivory or the tapioca pattern of the secondary dentine in walrus ivory. Instead it has the black dots or lines of the Haversian canals (nutrient bearing canals) (Figs 4.2 and 4.3). 

Plastic. Modem plastic simulants are sometimes called faux ivory . Plastic has been used to simulate ivory for almost 100 years, indeed the early plastics such as casein and cellulose nitrate were some of... 

Imitation scrimshaw is made of plastic - for example, epoxy -which is moulded in a silicone rubber mould that is flexible. This enables it to be pealed off the moulded object, and eliminates the risk of marks from joins in the mould. The plastic is weighted to simulate ivory (Figs 3.10 and 3.11). 

Cameos made in separate sections or layers indicate a simulant. Doublets of ivory pictures on a coral bact round have been produced, but they are rare, and are recognisable under careful examination. 

Electrophoretic elution and "switch" monoclonal antibodies are combined in a new rapid recycle method an affinity-mediated membrane transport process reported by Dall-Bauman and Ivory (8). In this modeling paper, a "switch" monoclonal antibody incorporated into a supported liquid membrane is used to facilitate the transport of human growth hormone from a high-pH to a low-pH environment. Electrochemical effects, including Donnan equilibria between the membrane and external environments, and imposition of external electrical fields, significantly affected the flux of protein across the membrane. Experimental confirmation of the simulation results could introduce affinity-mediated transport as a powerful new biospecific separation method. 

Thome, B. and Ivory, C. F., Continuous fractionation of enantiomer pairs in free solution using an electrophoretic analog of simulated moving bed chromatography. Journal of Chromatography, A 2002, 953, 263-277. 

Ivory CF, Srivastava SK (2011) Direct current dielectrophoietic simulation of proteins using an array of circular insulating posts. Electrophoresis 32 2323-2330... 

Figure 15 FT-Raman spectra of fake ivory specimens (a) carved X ctorian bangle, (b) large bangle, (c) small bangle, (d) cal. The absence of the characteristic proteinaceous features in true ivory near 1650 and 1450 cm and the strong phosphate mode near 960 cm" should be noted. Also, the presence of the aromatic ring bands at 3060, 1600, and 1000 cm" in (b) and (d) indicate a polystyrene resin content, whereas the carbonyl stretching band at 1725 cm" in all fake specimens indicates the presence of poly(methyl methacrylate). In the cat specimen, the band at 1086 cm uniquely identifies a calcite additive in the specimens of imitation ivory studied. (Reproduced with permission from HGM Edwards, DW Farwell. Ivory and simulated ivory artifacts Fourier-transform Raman diagnostic study. Spectrochimica Acta, Part A, 51 2073-2081. 1995, Elsevier Science B.V.)...

HGM Edwards, DW Farwell. Ivory and simulated ivory artefacts an FT-Raman diagnostic study. Spectrochim Acta A 51 2073-2081, 1995. 

In a survey of usability evaluation methods. Ivory and Hearst (Ivory Hearst, 2001) identified 132 methods for usability evaluation, classifying them into five different classes (User) Testing Inspection Inquiry Analytical Modelling and Simulation. They concluded that automation of the evaluation process is greatly unexplored. Automating evaluation is a relevant issue since it will help reduce analysis costs by enabling a more systematic approach. 

Ivory s group published very interesting examples of micropreparative enantioseparations based on the FCCE principle very similar to that described in [15]. This group also developed an electrophoretic separation system shown in Fig. 6 [91, 92, 94] as an analogue of the simulated moving bed (SMB) system well known in chromatography [95]. 

Figure 3 Ivory cat, which was identified spectroscopically as a modern limitation composed of poly(methyl methacrylate) and polystyrene resins with added calcite to give the texture and density of ivory. Reproduced with permission from Edwards HGM and Farwell DW, Ivory and simulated ivory arte cts Fou-rier-transform Raman diagnostic study, Spectrochimica Acta, Part A, 51 2073-2081 1995, Elsevier Science B. V. (See Colour Plate 3).

Thome B, Ivory CF. Electrophoretic analog of simulated moving hed chromatography. J. Chromatogr. A 2002 953 263-277. 

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