Was put on this trail by a pottery specialist colleague...........
Only in the development/experimental phase but think of the possibilities if successful!
The Clepsydra Chronicle (Spring 2012)
http://www.datingceramic.manchester.ac.uk/
Welcome to the first edition of “The Clepsydra Chronicle”, a quarterly newsletter that will be reporting developments of research into rehydroxylation (RHX). The introduction of RHX as a potential dating technique in 2009 has generated a lot of interest, and this newsletter aims to cater to this demand by providing regular updates for interested parties.
RHX is a completely new and unique approach to dating archaeological ceramics. Nothing like this has been attempted before, so we are a long way from routinely providing dating services; although commercialization is our long term aim. We would like to begin by thanking all those who expressed an interest in becoming involved with RHX. The response to the 2009 paper in Proc. Roy. Soc. A was both delightful and overwhelming. Unfortunately, we were not able to respond to all individual enquiries but we hope that many of the questions sent to us will be addressed in this and future editions of the newsletter.
The origins of RHX lie in the construction industry and the underlying principles that are exploited in this technique have been known to engineers for some time. It was only since the discovery of the RHX power time law that it became possible to apply this knowledge as a dating method. The RHX process occurs at a rate that is proportional to the fourth root of time (t1/4)law and fulfils the criteria of a scientific dating technique for archaeological material, as it is intrinsic to the object, can be associated with a specific event in the object’s lifespan and is external to any anthropogenic activity.
Meet the team
Our current funding is split over three institutions, Universities of Manchester, Edinburgh and Bradford. The Manchester team is led by Dr Moira Wilson, a physicist with a research background in water movement in porous inorganic materials. Other team members are Dr Margaret Carter, a physical chemist specialising in the deterioration processes of the major materials of construction - concrete, steel, natural stone, cement and lime masonry mortars and Dr Sarah-Jane Clelland, an archaeological scientist with a research background in applying scientific methods of analysis to archaeological materials.
The Edinburgh team is led by Dr Andrea Hamilton, an engineer and surface scientist with a background in crystal growth inside porous materials, crystal engineering, X-ray and analytical techniques applied to archaeological artefacts and modelling water transport through porous materials and crack growth. She is particularly interested in the role of contaminants on the RHX process and numerical modelling.
The Bradford team is led by Dr Cathy Batt, an archaeological scientist with a focus on integrating scientific investigations into archaeological projects, and specific expertise in scientific dating and establishing multi-method site chronologies.
Progress report
Since publishing the dates from historically dated bricks and tiles in 2009 we have been applying for funding to make the transition from building materials to archaeological ceramics. The positive response to this first paper assured us that there was a demand for this type of research and in many ways this obvious interest carried us through. We have now secured NERC funding to explore the potential for developing RHX as a method that can be applied to all archaeological and historical fired clay material. In other words, we have two years to validate RHX as a dating technique. Despite the challenges that the step from modern bricks to archaeological material presents, some progress has already been made in. We have:
From the work carried out so far we have identified a selection of ceramic materials that will provide reproducible results. We are always interested in speaking to other laboratories that have well developed RHX data sets on any type of historical ceramic and would warmly welcome any interest in developing new research funding routes through collaboration.
Current goals
Our strategy for validating RHX as a dating technique is to attempt to date as many different types of archaeological materials as possible from a range of locations and depositional environments from across the globe. As the research is very much still in the development stage, we have been working to acquire access to material which is confidently and securely dated by, ideally, a selection of other well established methods. We have already secured samples from a variety of sites worldwide and over the next two years we intend to better understand the process of RHX, how it differs (or not) in archaeological fired-clay material to bricks and to generate enough data so that we can validate this as a reliable and widely applicable dating technique.
Bluffers guide to RHX
Rehydroxylation
This is a super-slow chemical reaction where atmospheric moisture is chemically recombined into fired ceramic material via a nano-scale process called single file diffusion. This leads to expansion and mass increase of the ceramic material.
Relative Humidity (RH)
This describes the amount of water vapour in a mixture of air and water vapour and is used when the rate of water evaporation is important. RH depends not only on the temperature but also on the pressure of the system under study. In nature the relative humidity in clouds is typically 101%.
Estimated Lifetime Temperature (ELT)
As rehydroxylation is a chemical process, the rate of reaction is temperature dependent. Therefore it is necessary to provide an estimate of the temperature that an individual object has been exposed to during its lifetime (i.e. since manufacture). We have developed a model based on climatic data that can calculate the ELT for most locations worldwide over the last 5000 years to within 0.1?C
Microbalance
This instrument is a gravimetric, dual sample water vapour sorption analyser. The technique involves very accurately measuring the weight
change of 0.5-5g samples after they have equilibrated at a range of relative humidities. The weights of one or two samples are constantly monitored and recorded as the relative humidity is held constant (or can be altered) by the blending of dry carrier gas with a saturated water vapour stream. It is a commonly used to determine the amount of water vapour which will be adsorbed by a material as a function of the relative humidity surrounding that sample.
Clepsydra
Clepsydra (literally "water thief") is the Greek word for water clock. This is a device for measuring time via the regulated flow of liquid into (inflow type) or out from (outflow type) a vessel where the amount is then measured. Along with the sundial, water clocks are probably amongst the oldest quantitative instruments. There is evidence that they were used in Egypt and the Mesopotamian region from the second millennium BC.
In the next edition of “The Clepsydra Chronicle” we will be addressing some of the frequently asked questions about rehydroxylation.
Please send any correspondence to rhxdating@gmail.com
Only in the development/experimental phase but think of the possibilities if successful!
The Clepsydra Chronicle (Spring 2012)
http://www.datingceramic.manchester.ac.uk/
Welcome to the first edition of “The Clepsydra Chronicle”, a quarterly newsletter that will be reporting developments of research into rehydroxylation (RHX). The introduction of RHX as a potential dating technique in 2009 has generated a lot of interest, and this newsletter aims to cater to this demand by providing regular updates for interested parties.
RHX is a completely new and unique approach to dating archaeological ceramics. Nothing like this has been attempted before, so we are a long way from routinely providing dating services; although commercialization is our long term aim. We would like to begin by thanking all those who expressed an interest in becoming involved with RHX. The response to the 2009 paper in Proc. Roy. Soc. A was both delightful and overwhelming. Unfortunately, we were not able to respond to all individual enquiries but we hope that many of the questions sent to us will be addressed in this and future editions of the newsletter.
The origins of RHX lie in the construction industry and the underlying principles that are exploited in this technique have been known to engineers for some time. It was only since the discovery of the RHX power time law that it became possible to apply this knowledge as a dating method. The RHX process occurs at a rate that is proportional to the fourth root of time (t1/4)law and fulfils the criteria of a scientific dating technique for archaeological material, as it is intrinsic to the object, can be associated with a specific event in the object’s lifespan and is external to any anthropogenic activity.
Meet the team
Our current funding is split over three institutions, Universities of Manchester, Edinburgh and Bradford. The Manchester team is led by Dr Moira Wilson, a physicist with a research background in water movement in porous inorganic materials. Other team members are Dr Margaret Carter, a physical chemist specialising in the deterioration processes of the major materials of construction - concrete, steel, natural stone, cement and lime masonry mortars and Dr Sarah-Jane Clelland, an archaeological scientist with a research background in applying scientific methods of analysis to archaeological materials.
The Edinburgh team is led by Dr Andrea Hamilton, an engineer and surface scientist with a background in crystal growth inside porous materials, crystal engineering, X-ray and analytical techniques applied to archaeological artefacts and modelling water transport through porous materials and crack growth. She is particularly interested in the role of contaminants on the RHX process and numerical modelling.
The Bradford team is led by Dr Cathy Batt, an archaeological scientist with a focus on integrating scientific investigations into archaeological projects, and specific expertise in scientific dating and establishing multi-method site chronologies.
Progress report
Since publishing the dates from historically dated bricks and tiles in 2009 we have been applying for funding to make the transition from building materials to archaeological ceramics. The positive response to this first paper assured us that there was a demand for this type of research and in many ways this obvious interest carried us through. We have now secured NERC funding to explore the potential for developing RHX as a method that can be applied to all archaeological and historical fired clay material. In other words, we have two years to validate RHX as a dating technique. Despite the challenges that the step from modern bricks to archaeological material presents, some progress has already been made in. We have:
- identified a range of contaminants (organic and inorganic) present in ceramics which interfere with the rehydroxylation reaction..
- discovered that not all types of ceramic material behave in the same way. This implies that the experimental conditions will probably have to be tailored to each material and this area requires further investigation.
From the work carried out so far we have identified a selection of ceramic materials that will provide reproducible results. We are always interested in speaking to other laboratories that have well developed RHX data sets on any type of historical ceramic and would warmly welcome any interest in developing new research funding routes through collaboration.
Current goals
Our strategy for validating RHX as a dating technique is to attempt to date as many different types of archaeological materials as possible from a range of locations and depositional environments from across the globe. As the research is very much still in the development stage, we have been working to acquire access to material which is confidently and securely dated by, ideally, a selection of other well established methods. We have already secured samples from a variety of sites worldwide and over the next two years we intend to better understand the process of RHX, how it differs (or not) in archaeological fired-clay material to bricks and to generate enough data so that we can validate this as a reliable and widely applicable dating technique.
Bluffers guide to RHX
Rehydroxylation
This is a super-slow chemical reaction where atmospheric moisture is chemically recombined into fired ceramic material via a nano-scale process called single file diffusion. This leads to expansion and mass increase of the ceramic material.
Relative Humidity (RH)
This describes the amount of water vapour in a mixture of air and water vapour and is used when the rate of water evaporation is important. RH depends not only on the temperature but also on the pressure of the system under study. In nature the relative humidity in clouds is typically 101%.
Estimated Lifetime Temperature (ELT)
As rehydroxylation is a chemical process, the rate of reaction is temperature dependent. Therefore it is necessary to provide an estimate of the temperature that an individual object has been exposed to during its lifetime (i.e. since manufacture). We have developed a model based on climatic data that can calculate the ELT for most locations worldwide over the last 5000 years to within 0.1?C
Microbalance
This instrument is a gravimetric, dual sample water vapour sorption analyser. The technique involves very accurately measuring the weight
change of 0.5-5g samples after they have equilibrated at a range of relative humidities. The weights of one or two samples are constantly monitored and recorded as the relative humidity is held constant (or can be altered) by the blending of dry carrier gas with a saturated water vapour stream. It is a commonly used to determine the amount of water vapour which will be adsorbed by a material as a function of the relative humidity surrounding that sample.
Clepsydra
Clepsydra (literally "water thief") is the Greek word for water clock. This is a device for measuring time via the regulated flow of liquid into (inflow type) or out from (outflow type) a vessel where the amount is then measured. Along with the sundial, water clocks are probably amongst the oldest quantitative instruments. There is evidence that they were used in Egypt and the Mesopotamian region from the second millennium BC.
In the next edition of “The Clepsydra Chronicle” we will be addressing some of the frequently asked questions about rehydroxylation.
Please send any correspondence to rhxdating@gmail.com
