EGYPTOLOGY IN THE SERVICE OF LEARNING CHEMISTRY IN INDUSTRIAL ENGINEERING

Ancient cultures or civilizatons carried out diferent technological improvements without the knowledge of the scientfc processes involved. At the Escola Tècnica Superior d’Enginyeria Industrial de Barcelona (ETSEIB), some courses deal with the technological achievements in the antquity and, in partcular, one course deals with the achievements of the Ancient Egyptans, not only to learn what the Ancient Egyptans knew and made but also to look for scientfc solutons to modern problems related with the antquity. In this sense, this work considers the teaching of the chemical basis involved in one technological development of the ancient Egyptans which is taught in one Electve Course enttled: “Questons of technology and civilizaton in the Ancient Egypt”. The students use their knowledge on Basic Chemistry as well as on Inorganic and Analytcal Chemistry in order to understand the chemistry involved in the technological development carried out at the Bronze Age (3000-1200 BC) and propose solutons to the variaton in the color of the hieroglyphs painted in papyri. The experience acquired in the lessons taught in the Electve Course together with the feed-back from the students is used to implement a new optonal course in the Bachelor’s Degrees in Industrial Engineering, Chemical Engineering and Materials Engineering named “Technological and Scientfc Developments in Antquity: Ancient Egypt and Middle East and North Africa”.


INTRODUCTION
The Degree in Industrial Engineering and the Degree in Chemical Engineering are carried out at the Barcelona School of Industrial Engineering (Escola Tècnica Superior d'Enginyeria Industrial de Barcelona, ETSEIB, htp://www.etseib.upc.edu/) in the Universitat Politècnica de Catalunya (UPC-Barcelona Tech) from 1994 and are now in the process of extncton, substtuted by the Bachelor's Degree in Industrial Technology and the Bachelor's Degree in Chemical Engineering, respectvely).In additon, the new Bachelor's Degree on Materials Engineering has started.The Degrees started at the ETSEIB in the course 2010-2011.
In the former Degrees, some of the credits that the student must make during their studies are related to Electve Courses, including technological and scientfc courses but also some humanistc courses, because one of the objectves of the Elected Courses is giving the student a humanistc profle always related to the technological or scientfc feld.From the course 2010-2011, one of the Electve Courses is called " Questons of technology and civilizaton in the Ancient Egypt" (htps://bibliotecnica.upc.es/gd240/ales/51811.pdf QOTCAE, 4.5 ECTS credits) which mainly wants the students: • To establish the main characteristcs of the pharaonic civilizaton • To apply scientfc and technological concepts learned during the Degree to the technological questons found in Ancient Egypt Especially related to the second objectve, some technological issues with a chemical basis are taught during the course, e.g. the chemistry behind the pigments used by the ancient Egyptans in their tombs decoraton, the chemical reactons involved in the frst pigment synthesized in history (the so-called 'Egyptan Blue') and the degradaton and chemical reactons sufered by these pigments with tme, and the chemistry of the compounds used by the ancient Egyptans in the mummifcaton process.
The course starts with the explanaton of the main characteristcs of the ancient Egyptan civilizaton.In this sense, it is noteworthy to say that usually the students do not have a good knowledge on themes such as Ancient History and Ancient Religion, which are critcal in order to understand why the ancient Egyptans (and the ancient peoples before the development of the logic discourse) were more interested on the transcendent nature of the things than on their immanent nature.The characteristcs explained in the course include history, geography, language and religion, as well as the so-called 'Egyptan Context', the interacton of the Egyptan civilizaton with other civilizatons developed at Greece, Anatolia, Syria-Palestne, Mesopotamia, Iran, and the Arabic Peninsula.
Considering the extncton programme of the Degrees at the ETSEIB, it is scheduled that Electve Courses will fnish in 2014-2015.However, in the new Bachelor's Degrees, startng on February 2014 there will be an optonal subject at the last semester of the Degrees named "Technological and Scientfc Developments in Antquity: Ancient Egypt and Middle East and North Africa" (TSDA), whose syllabus will include some of the themes and objectves of the QOTCAE course.
In this work, in one hand, the methodology to incorporate chemical concepts learned by the students during the Degrees to the study of the ancient Egyptan technology will be discussed and the degree of achievement of the objectves by the students will be tested.This will be done by studying one of the examples taught during the course 2012-2013.On the other hand, the experience gained by the QOTCAE course will be used to help implementng the new TSDA Optonal Course in the Bachelor's Degrees in Industrial Engineering, Chemical Engineering and Materials Engineering, the three Bachelor's Degrees taught at the ETSEIB from 2010-2011.
The main beneft of the approaches of the courses is that the students learn not only chemical concepts but also realise that the chemical concepts learned during the studies are useful and applicable to real cases, in partcular, in felds which could be thought to be very far from Chemistry or Industrial Engineering, as it is the study of the technological knowledge in the antquity.

DESIGN OF THE COURSE 2.1 General trends
The course consists of 45 hours of teaching at the classroom (in this kind of courses there is not predicted tme for homework) distributed in 15 weeks, with two weekly sessions of 1.5 h.The number of students is relatvely high, varying from 40 to 60 students per course depending on the year.The diferent themes together with their approximate duraton are shown in Table 1.To the total number of hours in Table 1, the tme of the diferent assessment tasks has to be added in order to reach the total of 45 h.

. List of subjects in the course and approximate duraton
The evaluaton of the students is carried out by means of four diferent exams during the course.The frst exam afer subject 1, the second afer subject 2, the third afer subjects 3 and 4, and the last one afer subjects 5 and 6.The student gets her/his qualifcaton afer the arithmetc media of the four exams.The exams usually consist of fve questons and the students might use books and notes.

Teaching the chemistry of the pigments used by the ancient Egyptans
This work will be focused in the subject four; Building and decoraton of the New Kingdom Tombs, in partcular in the chemical compositon of the minerals or solids used as pigments by the ancient Egyptans and their possible degradaton.
Most Egyptan pigments are the so-called 'earth colors', minerals ubiquitously found in the Egyptan landscape which gave black, white, red, yellow and orange colors (see  Other colors were not so easily found, especially the blue, because the few blue minerals that could be mined in the Bronze Age did not have optmal propertes to be used as a pigment.Azurite (Cu 3 (CO 3 ) 2 (OH) 2 , blue) was sometmes used, but the artsans probably realized very soon that it reacts with atmospheric humidity to produce malachite (Cu 2 (CO 3 )(OH) 2 , green) according to: The other blue mineral known in the Bronze Age was lapis lazuli, and, in fact, mining of lapis lazuli has been demonstrated to exist at least from 4000 BC in the Sar-e-Sang mines in the Badakhshan district in northeast Afghanistan (Casanova, 2001).Lapis lazuli was used by the Egyptans as a precious stone and arrived to Egypt via a long trade route through Afghanistan, Iran, Mesopotamia, Syria-Palestne and the Mediterranean (Majidzadeh, 1982).However, it was never used as a blue pigment by the Egyptans, probably because the technology to obtain a partcle size low enough to give a blue color was not known in Ancient Egypt, and lapis lazuli was not extensively used as a pigment untl the middle Ages, when it was named 'ultramarine'.
Instead of using minerals, Egyptans synthesized a blue pigment, the so-called 'Egyptan Blue', CaCuSi 4 O 10 , which was found last century as a mineral in the Vesuvius lavas and was called cuprorivaite (Delamare, 2007).The synthesis was carried out, according to Vitruvius, by mixing sand, a copper mineral or bronze and a fux, and heatng under oxidizing conditons to 950-1050°C.Under these conditons, the result is the formaton of a frit, cuprorivaite and quartz crystals immersed in an amorphous bulk (Pagès-Camagna, Colinart & Coupry, 1999).
In the course, the synthesis is taught in chemical terms.The teacher makes some questons that the students have to respond on the possible reactants, why is sand used?Why a copper mineral?What is a fux and why is it used in the reacton?And, fnally, why oxidizing conditons are needed?
Considering the chemical knowledge and, especially, the fact that most students have only made two chemistry courses during the Degree (and in many cases some years ago), these questons are usually difcult to answer.The teacher help is necessary for the students to learn that sand is used because of its content in silica, SiO 2 , the copper mineral (malachite or even bronze) is used because of its Cu 2+ content, the fux is an alkaline mixture of sodium carbonate, sodium bicarbonate and sodium hydroxide which is the medium where the reacton takes place.Oxidizing conditons are necessary in order to oxidize Cu(s) to Cu 2+ avoiding the formaton of Cu + , which easily forms the black copper(I) oxide, darkening the fnal product.
With the help of the teacher (by means of any critcal queston), students have to realize at this point that one element is missing: calcium.If an extra additon of calcium as lime, limestone or even shells, is not considered (actually, the Vitruvius recipe does not include any additon of calcium), the only probable source of calcium is the sand.The chemical compositon of some Egyptan sands (Table 3) shows that some of them have a relatvely high Ca-content and, comparatvely, the sands of many places around the Mediterranean have much lower calcium concentratons (Brems et al., 2012).The predominance of low-Ca content in the Mediterranean implied that 'Egyptan Blue' could only be synthesized in few places, such as Egypt and the coast near the Vesuvius.Table 3. Compositon of Egyptan sands.Data taken from Tite and Shortland (2003) 2.3 Teaching the chemistry of the degradaton of the pigments used by the ancient Egyptans.Case study: The whitening of the black hieroglyphs at the Papyrus Bakai

Origin
As it is said above, most pigments used by the ancient Egyptans come from minerals easily found in the landscape, and it is expected that they do not alter their color during the millennia.However, in some cases, the colors used by the Egyptans have changed or have sufered degradaton with tme, e.g.Egyptan Blue or the red obtained with realgar.

Case study: degradaton of the black ink in a papyrus
In partcular, in the course, the whitening of the black used in one papyrus is studied in detail.The Papyrus Bakai in the Warsaw Natonal Museum (Poland) showed a mixture of black and white hieroglyphs (Figure 1) although it was supposed to be writen in black (white was never used as 'ink' for papyrus).Wagner, Donten, Donten, Bulska, Jackowska and Sobucki (2007) studied the papyrus in order to • know the processes behind the color change; • propose a methodology to restore the original color of the hieroglyphs.The main objectve of introducing this case in the course is to show the students not only the chemical compositon of the pigments but also the chemical reactons derived from the contact of the pigments with the environment.Students at this point already know that PbS(s) was used by the Egyptans as a pigment for the black ink in papyri and now they have to propose the chemical reactons that would explain the whitening of the PbS(s).The teacher gives some clues to the students because most of them do not have a strong knowledge on Analytcal Chemistry.One of the clues is an image obtained by Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (SEM-EDS) of the hieroglyphs, showing in both the black and the white pigments the presence of lead.As another clue given to the students the teacher reminds the chemical compositon of the air and, in partcular, the presence of a relatvely high oxygen partal pressure.Students should identfy the chemical compositon of the white 'ink' as well as propose a chemical reacton explaining the black-to-white transformaton.Wagner et al. (2007) proposed that the white ink was composed of lead sulphate and the chemical reacton explaining the color change was a redox reacton where sulfur (from the galena) was the reducing reagent and oxygen was the oxidizing species: This reacton is very favored, with log K = 128.The species detected by the EDS were, thus, PbS(s) and PbSO 4 (s) in the black and white inks, respectvely.
Afer the knowledge of the chemical mechanism of color alteraton, Wagner et al. (2007) tried to restore the original aspect of the papyrus.Because the black-white process degradaton was an oxidaton they proposed a reducton for the white-black process restoraton.In this sense, they used one of the most used reducing agents in conservaton: sodium tetrahydridoborate, NaBH 4 .
NaBH 4  Na + + BH 3 + ½ H 2 (g) + e - Considering the reducton semi-reacton: However, the results were as expected from a 'macroscopic' point of view but could not be the expected considering the chemistry of the process involved.The white hieroglyphs did change their color to black but the reducing species used in the restoraton of the papyrus, NaBH 4 , instead of reducing sulphate to sulphur could reduce Pb 2+ to Pb(s) which could be the species responsible of the black color of the hieroglyphs: The global redox reacton being: Considering if a chemist could have predicted the restoraton mechanism by using redox reactons, it is important at this point to make the students thinking over the applicability of Chemistry to Egyptology (or the applicability of Egyptology to Chemistry).In additon, students should also ponder the place of the chemist and the egyptologist in the process of studying an ancient Egyptan artefact, being aware of the diferent expertse of both specialists (see, for example, Figure 2 on the felds of expertse of chemists and egyptologists in the study of the black color degradaton in papyri).
In additon, although the test was anonymous, the students had to include more 'technical' informaton related with their studies: • These data are especially important in order to explore the responses given to queston number 2.
The results obtained in the questonnaire are shown in Table 4.This table only shows the results of the responses given by the students of the ETSEIB in the Industrial Engineering Degree and the Chemical Engineering Degree, whose syllabi are very similar to the ones of the Bachelor's Degree in Industrial Engineering and Bachelor's Degree in Chemical Engineering, in which the future Optonal Course will be included.
Questons 1 and 3 are related to the egyptological concepts taught and learned, and, according to the students, the explanatons given were enough in order to understand the importance of the study explained and the example was useful in order to learn historical/egyptological concepts, because all the responses are situated between the "agree" and the "absolutely agree".The results are very similar for both degrees, as expected because before the explanaton the students have similar egyptological knowledge independently on the Degree.However, there is a clear diference when considering the responses of the students of both degrees to the queston 2, what deals with the chemical concepts of the students before the explanaton.This diference was also expected due to the own syllabi of the degrees.Obviously, students of the Chemical Engineering Degree have learned more chemistry than students from the Industrial Engineering Degree, which study chemistry only during the frst year.In additon, according to the questonnaire, the last tme the students of the Industrial Engineering Degree learned chemistry was more than 4 years before the present course.On the other hand, the response to queston 3 (related to the new chemistry learned during the example) was similar in both degrees and the results were once more between the 'agree' and the 'absolutely agree', what means that in spite of a diferent previous level of chemistry all the students have learned new chemical concepts.

Chemical
One of the objectves of this work was using the informaton obtained by the students in order to plan and prepare the course in the Bachelor's Degrees.In this sense, some diferences between the Electve Course QOTCAE and the Optonal Course TSDA should be considered: • Optonal Courses are planned to be carried out at the fnal semester of the Bachelor Degrees and do not accept students from earlier semesters (see Figure 3), while in the Electve Courses, students from any semester are accepted.
• The Optonal Courses are planned only for three Bachelor's Degrees (the ones taught at the ETSEIB): Industrial Engineering, Chemical Engineering and Materials Engineering.In both Degrees, students make at least two basic chemistry courses (during the frst two semesters of the Degree).Students from the Bachelor's Degree in Chemical Engineering study in additon Analytcal Chemistry, Organic Chemistry and Experimental Chemistry during the third semester htp://www.etseib.upc.edu/ca/portaldassignatures.
The Optonal course shows a higher homogeneity of students than the Electve Course and also a minimum chemical knowledge of all the students.In this sense, an adequate soluton would be giving the students tasks outside classroom related with the concepts that will be taught (e.g.redox chemistry in the Papyrus Bakai example).The adequacy of the concepts learned with the homework could be tested in the classroom by means of a short questonnaire or even some questons put to some students.This adequacy should also be tested afer the teaching by using a similar questonnaire to the one shown in this work but also considering the results of the exams where such examples will be included.
However, one of the main diferences of the students coming from the diferent Bachelor's Degrees will stay the diferent previous chemical knowledge.In this sense, a possible soluton could be to establish diferent homework for the diferent Bachelor's students.Industrial Engineering and Materials Engineering students should learn before the teaching concepts related with the basics of the redox reactons (e.g.oxidaton, reducton and stoichiometry of the redox reactons).

CONCLUSIONS
The objectve of the QOTCAE Electve Course coincides with the main objectve of the Electve Courses ofered at the Polytechnic University of Catalunya: to introduce the students to the humanistc knowledge with the help of science and to learn science with the help of a humanistc mater.The teaching of the course permited to gain experience on teaching chemistry with the help of Egyptology, experience that, as it will be described below, will allow preparing a new course.However, the study of the technology of the ancient civilizatons usually needs knowledge on at least two diferent subjects: the scientfc/technological knowledge and the historical/anthropological knowledge.
The necessity of a basic knowledge on both subjects (in this work Chemistry and Egyptology) opens the applicaton of a wide range of educatonal aspects but the feed-back with the students is critcal.In this sense, it is strictly necessary to know the opinion of the students.The responses to the questonnaire presented in this work were between the "agree" and the "absolutely agree" but in one case, related with the adequacy of the level of chemistry of the students before the example taught.The results have shown that, as expected, students make the Electve course with a chemical knowledge that depends on the Degree and, in additon, responses of the students from the Industrial Engineering Degree were between the "disagree" and the "agree".This is evidence that must be considered during the planning and the preparaton of the Optonal Course that will start in February 2014.In order to accomplish its objectves, the previous knowledge of chemistry of the students should be carefully controlled and equilibrated.This could be done by diferent tasks that students have to make before the classroom, such as responding to questonnaires of chemical concepts with the help of both a short theoretcal summary and bibliographic recommendatons.

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1 Introducton: Mythical Discourse.Geography, Language and Religion of the Ancient Egypt 9 History of the Ancient Egypt (5000 BC to 30 BC) and interactons with the Near and Middle East 10 3 Technological aspects of the Egyptan Pyramids of the Old Kingdom (ca.2400 aC) 5 Building and decoraton of the New Kingdom tombs (ca.1500 aC) 5 5 The mummifcaton process in Ancient Egypt and Paleopathology 5 6 Building, decoraton and signifcance of the ancient Egyptan temples 5Table1

Figure 1 .
Figure 1.Examples of black hieroglyphs and white hieroglyphs in theBakai papyrus.Adapted fromWagner et al. (2007) Indicate your Degree• Indicate the courses of chemistry you have passed during your Degree and when you passed them:

Figure 3 .
Figure 3. Situaton of the Electve (Degrees) and Optonal (Bachelor's Degrees) Courses in the Syllabi.SN represents the semester number N Table 2).
*Ochre is a mixture of diferent components that contain iron oxides or iron oxihydroxides.Iron is the responsible of the color, red ochre contains hematte while yellow ochre contains goethite and limonite.**During all the pharaonic period, orange was obtained by mixtures of red (red ochre) and white(limestone)

Table 2 .
Minerals used by the Egyptans as pigments

Table 4 .
Results obtained in the questonnaire