Journal of Research on Archaeometry
Year:2016 | Volume:2 | Issue:1 |Papers Count:6

Ground penetrating radar (GPR) method is a non-destructive geophysical method that is used to detect subsurface heterogeneities and also recognition of various shallow targets. In present research, forward and inverse modeling of GPR data applied for archaeological study has been made. The study area is Tappeh Hissar, Damghan, in which GPR data along several survey lines have been acquired using 250 MHz shielded antenna for archaeological investigations. To achieve the goal, the real radar-gram of a survey line in the area has been obtained after applying different processing operations containing signal saturation correction and applying band-pass, auto-gain control and background re-moval filters on the GPR data using Reflexw software. Then, the synthetic radargram corresponding to the real radargram has been simulated using finite-different time domain (FDTD) method. After-ward inversion method with solution of an optimization problem was employed for validation of in-terpretation of GPR radargram in order to detect buried targets. The results of this research, that are based on the agreement between the radargram obtained from the real GPR data and the synthetic radargram corresponding to the real radargram, confirm the correctness of the interpretation of sub-surface archaeological investigations in the area, and thus, indicate the capability of application of GPR method for archaeological exploration.

Archaeological sites in desert areas are at risk for destroying and reburied with sand dunes by sand storms. One of the most important issues for archaeologist and conservators in these regions is maintenance of archaeological remains, during the excavation process and after it. There are several sand dune stabilization methods such as mechanical dune stabilization, mulch or protective screen, aerodynamic method and biological fixation (woody and grassy species, planting). However they are mostly expensive and time consuming and may have some harmful effects on environment. In this regard, the bio-grouting technique which produce calcite cements are new approaches to consolidate land in geotechnical engineering. This method has created a potential for archaeological conservation, stabilization procedure for sand dunes or soil. This method works according to the chemical reactions of natural non-pathogenic microorganisms that exist in the soil. The main objective of this research work is to evaluate the possibility of using biological stabilization with calcite-forming bacteria, for consolidating of sand dunes in desert areas with an approach in the conservation of archaeological remains, and archaeological conservation during and after the excavations.In this case sand grains/soil particles are coagulated and make a more dense soil with higher mechanical properties than natural condition. Biological stabilization of sand dunes and soil has been conducted with Sporosarcina Pasteurii Bacteria. When this bacteria supplies with suitable substrates, micro-organisms can catalyze chemical reactions in the subsurface resulting in precipitation of inorganic minerals. These bacteria could microbially catalyze hydrolysis of urea and calcium carbonate reaction when it is cultivated with enough nutritions under proper environmental conditions at laboratory and then it is located on the soil surface with other reactive substances. It results a scaffolding calcite between soil/sand particles. The best reactive environment is achieved at pH 7-9, temperature of 25oC to examine the depth of penetration of biogrout, a cylindrical mold (PVC) tube (by 1 meter high) is filled with dry sand and consolidates with bio-grouts. The results show that the measured depth of bio-consolidation is 50cm in dry sand. Soil density is 1.6gr/cm3; the permeability of soil is smaller than the normal condition. To control the functional rate and also surface resistance of biogrouted sand, the standard penetration test with 250 g plummet in the dry and wet conditions have been examined. The results of this test show that bio-consolidation was successfully conducted and depth of plummet penetration becomes negligible.

Historical papers with all museum and aesthetic value have considerable cultural and scientific importance which represents how societies were during history improved. Studying historical papers is a way to discover the changes of human’s life in different cases such as economics, culture and politics.Between existing manuscripts prescriptions there are some, which are left unseen unfortunately due to lack of recognition of their writing date. So to understand their originality, we require technical and structural analyses. Quantitative and qualitative methods of analysis and identification of organic paper are able to recognize their structure and thus the probable time of the paper making process or use it as a cultural work. Today, using scientifically exact methods like radiocarbon dating of organic material such as dating paper results well. Unfortunately, it is impossible to use this method in our country because of high cost and lack of access for most of experts. In this research we seek to know the most used materials in a specific era and to make possible the indirect dating by studying and recognizing fibers and sizing in historical papers. We have used microscopic observations, color reagents and Fourier Transform Infrared Spectroscopy (FT-IR) methods. Results showed that linen, and hemp fibers have a high level of application in studied dated manuscripts and there is conformity in these results with results of studied undated ones.

The settlement of Dava Goz situated about 15km SW of Khoy and 1.5km north of the Dizaj Diz town in NW Iran. Dava Goz is a small site at north of the Lake Urmia, measuring about 100×100m (ca.1ha). The first season of archaeological excavation primarily aimed to clarifying the chronology, settlement organization, and respond to some of the fundamental questions such as the transition process from Late Neolithic to Early Chalcolithic (Hajji Firuz to Dalma) and identifying different cultural horizon including Middle and Late Chalcolithic (LC1 and LC2) periods and also outlining cultural condition of the region during prehistoric periods. The present paper is intended to expose six absolute radiocarbon data from the site and preparing new data for revising prehistoric chronol-ogy of NW Iran. According to fresh absolute C14 radiocarbon date the stratigraphy and chronology of the settlement is now well understood and covers Transitional Chalcolithic (Dava Goz I: 5400-5000 BC), Early Chalcolithic or (Dalma Dava Goz II: 5000-4500 BC) and Middle and Late Chal- colithic 1 (Pisdeli, LC1: Dava Goz III: 4500-4200 BC) and Late Chalcolithic 2 (Chaff-Faced Ware horizon, LC2: Dava Goz IV: 4200-3900/3800 BC) phases of the regional culture of north of the Lake Urmia Basin. Actually, Dava Goz is one of the scant well excavated settlements that give new and fresh information on the developments of the Lake Urmia Basin communities between the sixth to fourth millennium BC (5400-3700/3600 BC), and on their relationships with the contem- porary Caucasian cultures as well as with those located further west and south, in Eastern Anatolia and in the Syro-Mesopotamian region. The first preliminary result of excavation, suggest special function for Dava Goz. It seems clear that this site could be consider as winter land for some agro-pastoral groups of Lake Urmia Basin who trying to find some pasturelands and preparing same raw materials like obsidian for the settlements of Urmia region The implications of the findings will dis- cuss along with limitations and future research directions.

Most of fungicides for prevention of biological degradation in historic papers, firstly have been used in the other scientific and industrial fields such as material preservation, agriculture and medical science. Other scientific fields have a great importance in the conservation of historic relics especially paper relics. Therefore, Tiophanate methyl and Carbendazim fungicides were studied for application in the conservation and restoration of paper relics. Each of these materials is one of most important and applied materials in agriculture which are effective against wide range of biological factors. Conservation material should not have intensive structural effects on paper relics.Accordingly, it is required to evaluate effects of Tiophanate methyl and Carbendazim treatments on paper. Fourier Transform Infrared Spectroscopy (FTIR) is one of most important methods for structural changes of paper. For the study, laboratory samples were prepared from filter paper.Samples were treated with Tiophanate methyl (dissolved in methanol) and Carbendazim (dissolved in distilled water) in 100ppm and 200ppm concentrations by spray method. Blank and treated samples were aged according to ISIRI4706 standard method for 288 hours. After aging, structural changes have been studied by application of Fourier Transform Infrared Spectroscopy. Results showed that spectra of treated paper samples with Tiophanate methyl and Carbendazim have no structural deformation in both 100ppm and 200ppm concentrations. According to resulted spectra, it was clear that treatment materials have been added to paper but there was not any sign of paper degradation. Accelerated aging caused to production of carbonyl adsorption of the spectra in 1742 cm-1. It was indicated decay of cellulose and presence of new degradation products which results to aesthetical change of paper. Aged samples compared with unaged ones did not show structural deformation in paper due to treatment materials and there was not any sign of breakdown in cellulose linkages. The both of 100ppm and 200ppm treated samples were without damage after accelerated aging. In general, the both treatments do not affect paper structure according to results of infrared spectra.

Making varnishes from diterpenoid resins with the several orders had been common in Iran from 12th Century and it has also been reported in Europe from medieval ages. Identification of these resins in old samples and investigation of their degradations through ageing process have performed by various methods. FTIR spectrometry has always been of interest to researchers because it is cheap, available and it requires little sample material. Ditepenoid resins are classified into two classes: mixture of abietane and pimarane structures resins that include colophony and venetian turpentine, and resins that are formed from labdane and pimarane structures which involve sandarac and copal types. Abietane structures do not polymerized in the time but labdanes and pimaranes polymeriz at a very short time. For this reason, they mostly are used in oil-resin varnishes. These characteristics have led the two classes of resins to operate differently during ageing process and production of degradation products. This differentiation helps to identify to characterize the original structure of resin in the varnish compound in FTIR spectrometry. This article reviews the identification characteristics of diterpenoid resins in FTIR spectrometry and it tries to investigate and introduce every resin characteristics according to their structure from several references. Moreover, identification characteristics of linseed oil is introduced because of its application in oil-resin varnishes.Also, degradation process and its production are also reviewed. Differentiation in chemical structures of diterpenoid resins causes the differentiation of ageing process such the polymerisation of labdanes and pimaranes and cross linking in ageing process produce some new functional groups. Also some functional groups are destroyed during ageing. The changes observed in FTIR spectrometry are inclined oxidation and polymerization of varnishes that in turn changes bands intensity related to OH region, especially in 3000 and 3450 cm-1 and carbonyl region bands. Degradation process of resins in solvent and oil-resin varnishes is same but identification of resin characteristics in oil-resin varnishes is difficult because of effects of oil oxidation on varnish spectra after aging process. Also cross links in varnish structure during aging process cause the formation of some new bands in aged varnishes spectra. Degradation products in resinits and ambers are to some extent like that of old resins and varnishes because their aging process is same.