Helen Rendell | Loughborough University (original) (raw)

Papers by Helen Rendell

Radiation Measurements, 1997

Thermoluminescence (TL), radioluminescence (RL) and cathodoluminescence (CL) spectra are presente... more Thermoluminescence (TL), radioluminescence (RL) and cathodoluminescence (CL) spectra are presented for a range of alkali feldspar samples. These show that the spectra are complex, but contain a number of distinct emission bands. Intercomparison of the TL, RL and CL data for the ca 400 nm band shows that the peak wavelength may vary with type of stimulation. Activation energy data calculated over the temperature range 80-110°C, which are sample dependent, indicate that the trapped charge population at 550 nm has a lower thermal stability than those associated with 290 and 400 nm centres.

Geological Society, London, Special Publications, 2000

... Luminescence techniques have traditionally been applied to sediments from a range of aeolian ... more ... Luminescence techniques have traditionally been applied to sediments from a range of aeolian environments (eg Ollerhead et al. 1994; Clarke et al. 1996; Rendell &amp; Sheffer 1996; Clarke &amp; Rendell 1998; Wintle et al. ... &#x27; I &#x27; I &#x27; &amp; &#x27; I i oo ooO o~ oo o ~ o o 04 eO ~!sue;ul 0 0 ...

Journal of Archaeological Science, 1986

least, did not find it interesting as I was left wondering what had happened to the initial hypot... more least, did not find it interesting as I was left wondering what had happened to the initial hypothesis and why White did not even reference any of the recent material on hunter-gatherer site formation. The final chapter deals with "Suggestions for Future Research". White had stated that he would provide test implications for his other hypotheses in this chapter but these fail to materialize. His suggestions for future research are hardly radical: identification of more discrete occupation levels, more absolute dates, better sampling, more detailed bone reports, wear analysis, seasonality studies and research into interregional links and styled zones-in fact, he merely lists the things that palaeolithic archaeologists have been doing for some time. There are good things in this volume, however. White does focus on an interesting question and there clearly is potential for a topographic analysis of settlement sites. As he argues, we do need to ask more behavioural questions and come to terms with an archaeological database collected and classified for other typological ends. However, this is on the whole a poor example of the way to proceed employing an inadequate use of quantitative methods and an overly simplistic approach to hypothesis testing.

Abstract The estimation of water content since deposition presents a major source of uncertainty ... more Abstract The estimation of water content since deposition presents a major source of uncertainty in the thermoluminescence dating of sediments. In the case of loess, information on dry density, porosity, pore size distribution, microstructures and behaviour during laboratory compaction tests may be used to obtain estimates of water content during burial. The results of laboratory studies of loesses from northern Pakistan are presented and their implications for the TL dating of loesses from different stratigraphic horizons are explored.

For the last half-century, the story of very early hominids, and their stone industries, has been... more For the last half-century, the story of very early hominids, and their stone industries, has been almost exclusively ‘in Africa’. This first report of a very early industry takes the story ‘out of Africa’ and into the Indian sub-continent – that is, in a geographical direction towards the early industries of eastern Asia.

Desertification in Europe, 1986

Severe soil erosion and landsliding affect 17% of the land area of Italy. The semi-arid zones of ... more Severe soil erosion and landsliding affect 17% of the land area of Italy. The semi-arid zones of the south of Italy and the islands of Sicily and Sardinia are particularly prone to erosion by virtue of a combination of climatic factors and high relative relief. Such areas are also prone to hazards such as forest fires. Soil conservation projects have achieved some success, but in some areas problems of erosion are being exacerbated by changes in agricultural land use.

Nuclear Tracks and …, 1985

Obsidian is an efficient TL phosphor that has been used as a dosimeter and for cross-calibration ... more Obsidian is an efficient TL phosphor that has been used as a dosimeter and for cross-calibration of laboratory radiation sources. In previous studies detection has been via broad band optical filters in the blue-ultraviolet part of the spectrum. In contrast, the present work has covered the wavelength range 250-800 nm and has recorded the TL emission spectra. This has shown that photon emission in the blue region accounts for only a few percent of the total number of photons emitted. The various obsidian samples exhibit differences in spectra and sensitivity to radiation dose, suggesting that the TL spectrum is potentially a powerful tool for discriminating between obsidians from different localities. The spectral characteristics of "'Obsidian Creek" obsidian from Canada bring into question its use for cross-calibration of sources. Intercalibration of ~Sr laboratory sodrces was reproducible to _+ 2% using a particular optical filter in a standard TL apparatus. However, on changing the filter from a Schott UGI 1 to a Coming 5-58 the ratios of the signals generated by the sofirces differed by up to 20%. This was observed even when an identical 9°Sr beta source geometry and packaging were used. Such discrepancies are discussed with reference to the TL emission spectra for the obsidian.

International Journal of Radiation Applications and Instrumentation. Part D. Nuclear Tracks and Radiation Measurements, 1988

Radiation …, 1983

... JH BLANKE, EW PRICE, HM RENDELL, J. TERRY and PD TOWNSEND University of Sussex, Fulmer, Brigh... more ... JH BLANKE, EW PRICE, HM RENDELL, J. TERRY and PD TOWNSEND University of Sussex, Fulmer, Brighton, Sussex, BNI 9QH7 UK and A. G. WINTLE Godwin Laboratory, University of Cambridge, Cumbs., CB2 3RS, UK ...

Radiation Measurements, 1994

The intrinsic defect structure of quartz is sensitive to heat treatments, and this is reflected i... more The intrinsic defect structure of quartz is sensitive to heat treatments, and this is reflected in changes in TL sensitivity and also the relative intensity of the component glow peaks. It is also known that even for the same crystal, there can be changes in the luminescence spectra. This paper reports on spectral changes induced in the TL of quartz as a result of a variety of thermal treatments. Emission spectra obtained from synthetic, hydrothermal and volcanic quartz samples were compared. Heat treatments to 1000°C enhanced the TL signals by factors of up to 1000 times. The rate of cooling changed the relative intensities of the component emission bands in all samples. In the volcanic quartz material, the ratio of red to blue emission is particularly sensitive to the cooling rate. The influence of the spectral features on conventional polychromatic TL data is discussed.

Quaternary Science Reviews, 1992

physica status solidi (b), 1997

Measurements of infrared stimulated luminescence (IRSL) emission spectra are presented for detrit... more Measurements of infrared stimulated luminescence (IRSL) emission spectra are presented for detrital potassium-rich feldspars separated from sands and for museum specimens of low albite and intermediate microcline. The samples show common emission bands at 335, 400 and 550 nm and a thermally unstable emission band at 290 nm which is associated with sodic phases in the crystal structure. Rapid preheating and room temperature storage causes a decrease in emission from the 290 nm centre with a corresponding increase in the other emission centres, with potential problems for pulse annealing routines. This may be due to charge transfer or structural transformations in the defect. A sustained preheat regime is essential if detrital potassium-rich feldspars are to be used for IRSL dating.

Journal of Physics D: Applied Physics, 1995

Inorganic dusts from different herbs and spices are investigated in this study using both standar... more Inorganic dusts from different herbs and spices are investigated in this study using both standard thermoluminescence measurements of integrated intensity versus temperature and measurements of the thermoluminescence emission spectra (intensity as a function of both temperature and wavelength). The importance of particular minerals in the composition of glow peaks detected is discussed. Thermoluminescence emission spectra of the samples studied reveal

Journal of Archaeological Science - J ARCHAEOL SCI, 1980

The Pleistocene sequence of the northern areas of Pakistan, which have abundant evidence of palae... more The Pleistocene sequence of the northern areas of Pakistan, which have abundant evidence of palaeolithic industries, is discussed in the light of our own field observations and of recent published studies. It is clear that the pioneering work of de Terra & Paterson (1939) needs to be fundamentally re-examined using modern, interdisciplinary, approaches. We describe a sequence of Pleistocene and Holocene deposits from the northern Peshawar Basin near the ruined Buddhist monastery of Takht-i-Bahi. Pleistocene lacustrine siltstones and red weathered deposits are discussed and compared with other deposits both within the Peshawar Basin and in the adjacent Potwar region. A Holocene colluvium of soil, slates and schists is interpreted as indicating landscape changes due to erosion following the abandonment and probable destruction of the monastery in the latter part of the 5th century AD.

Geological Society, London, Special Publications, 1995

Geographical Analysis, 2010

Recently developed techniques for time series analysis are applied to channel width and slope ser... more Recently developed techniques for time series analysis are applied to channel width and slope series collected in small ephemeral channels in Southern Italy. Tests for the difference between trend and difference stationarity, although developed in the field of econometrics, are found to be more suitable for data generation processes in geomorphology, where physical causes of deterministic trends are evident. These tests are important because the modeling of causal flows and development of dynamic predictive models depends on the type of data generation process that is identified. The ephemeral channel data exhibit trend stationarity and the results of spectral analysis and vector autoregression analysis of detrended channel width and slope data are described.

Geoarchaeology, 1987

ABSTRACT