Abstract
Since during this era, Yazd involve less social vicissitudes and because of the training performance in the middle ages of Islam, the tradition of school building that started from the Seljuk dynasty in a quiet environment. Being away from security concerns and creating relative peace during the middle ages and the high acceptability of building a school has provided the emergence of its construction in the city of Yazd. Therefore, considering the numerous references to the schools of this era in Yazd historical texts and the absence of research on the architecture of the historical schools of this city, the article describes the building features of these ones. Answering this question is the purpose of this article: what are the features of school mentioned in the historical texts and what were components of spatialization and arrays of these schools? The research method of this article is based on historical documents and library studies. This is a historical-analytical research and its main reference is historical sources such as books of Ta’rikh-e Yazd (History of Yazd), Ta’rihk-e Jadid Yazd (New History of Yazd) and Ja’me’ Mofidi. Historical schools are explored in this article from the aspects of architecture, decoration, function and constructers. The results of this research show that schools in Yazd have local and indigenous features that were prevalent in this area, before Ilkhanate dynasty, and the influence of local architectural and decoration methods on the school building is undeniable according to historical sources. Schools have a lot in common with the architecture of mosques, houses and Khaneqahs (monasteries) considering that schools are usually used as a graveyard, these buildings can be classified as burial schools, and finally, various classes of people have played a major role in building these historical schools as founders.
Keywords: School Architecture, Muzaffarids, Timurid Era, Yazd.

Introduction
In the 77-year rule of Muzaffarids dynasty (718-785 A.H.), in addition to the proceedings taken in the field of city development and increasing the area of battlement, basic measures were done in the field of the construction of religious schools and Khaneqahs (monasteries), so that it can be said that this region reached the glory of cultural prosperity within itself (Shamseh, 2006, P.31). Muzaffarids rule, whose beginning coincided with the end of the Ilkhanate era, should be considered one of the most powerful, best and most prosperous governments in the middle history of Iran, because at that time nowhere in Iran had cultural, social and economic development as much as their territory, and the importance of cultural affairs and attention to science and schools was so much that most possession of the desert region, means water aqueducts and gardens were dedicated to school, and this was apart from the devoted Bazaars and Caravanserais. (Mohammadzadeh & Razavi, 2011, P.21). It has been mentioned in various sources that nearly one hundred schools, two hundred Gonbadkhaneh (domes) and Khaneqahs (monasteries) as well as twelve mosques were built in the 8th century A.H. in Yazd city (Masahebi Naini, 1997, P.302), from the abundance of schools that were built in Yazd, Kerman, Shiraz and other cities during this period, it is possible to understand the level of people’s attention and dedication to the study of religious sciences. (Setoodeh, 1967,P.274). Muzaffarids kings, as well as the great personalities of this era, paid special attention to religious buildings such as mosques, schools and Dar-al Siadeh {a porch that is a gathering place for Seyeds and followers of Imam Ali (peace be upon him)}. In fact, the movement that started during the era of Khajeh Rashid- al Din with the construction of building such as “Gonbad Soltaniyeh” and “Rabَ –e Rashidi” ,other schools and religious places and the tradition of endowment became common in them; then in this era, it grew and expanded significantly, so that whenever there is talk of building a mosque, an order was given to build a school next to it, and endowments were also awarded to (Rais- al Sadat, et al., 2011,P.96). The cultural and artistic actions of Muzaffarids rulers caused the growth and development of Islamic culture and civilization, which provided the basis for its connection with later periods, so that the Timurid and Safavid eras, which are considered the glory the growth and development of Islam can be attributed to Muzaffarids proceedings. (Sarabadani, 2010,P.102). 
Questions of Research: 1- What architecture and arrays do the Yazd schools have, referring to historical texts? 2- What developments and functions do schools have?
Method of Research: The current research has explained the architecture of the historical schools of Yazd from the Ilkhanid to the Timiurid era with an analytical historical approach. In this research, the necessary historical information has been collected, especially from local historical texts such as Ta’rikh-e Yazd (History of Yazd), Ta’rikh Jadid Yazd (New History of Yazd) and Ja’me’ Mofidi, because these texts refer to different schools that were used in that era, but today there are no traces of some of those schools. Discussions such as examining architectural spaces, decorations, performance, development and school constructer are the subjects of this research.

Conclusion
Construction of Muzaffarids and Timurid Schools in Yazd continues the school-building tradition that began in the Kakuyids dynasty. The speed of school-building in Yazd during the Muzaffarid era is very intense, but it moderates during the Timurid dynasty. The concern of school-building in this era includes different strata of society from the aristocratic and royal class to religious scholars and all of them involved in this noble tradition. These schools were mostly built for the burial place of their founder after their death, and in order to legitimize it, the tomb was dome-shaped. For this reason, the Gonbadkhaneh (dome) is an integral part of Yazd schools, and in some ones, they are satisfied with the construction of this morsel. Parts such as elongated Soffeh (terrace), the pair of minarets on the façade, Tanabi (a large room in the middle of the building, without a window or door, surrounded by other spaces), and dome usually with an array, the central courtyard, the Baghtche-e Moshajar (a garden planted with different trees) at the end of the building are considered parts of the school spaces of this era. Utilizing the native structure and decoration methods in “Gonbadkhaneh and Tanabi”, and local architectural mechanisms all give these schools a regional display. The schools of this era with local and indigenous basis have adopted some of their architectural and array features from the era of “Kakuyids and Atabakan”. According to the remaining schools and with the help of historical texts, a general model for schools can be presented (Scheme 1). Schools like mosques and houses of this era, have a similar pattern, although there are common spaces between these functions. The existence of the elongated and lofty porch, which is usually located on the south facade, a small and compact yard,”Gonbadkhaneh or Tanabi” next to or behind the south porch, three-part divisions similar to mosques in the view facing the yard, the presence of a rear garden behind the porch or Gonbadkhaneh like the houses or Khaneqahs, creating a linear structure in spatial organization and many other cases, all confirm this paradigmatic similarity. The tradition and pattern of building these schools were forgotten after the abundance of school building in the Timurid era. The studies and researches of this article can be extended to the Safavid to Qajar era as well, so that a detailed understanding of the architecture and school building method in Yazd throughout history can be obtained through it.

Abstract
Bulbous domes are among discontinuous double-shell domes and were built in Iran in the early nineth century A.H. Previous domes were shaped pointed and there was no bulge coming out beyond their base diameters. But in the Timurid period, dome profile was changed so that it began a return below the base of the arch, producing thereby a slight bulge. The main question is that what are the reasons for the changes in the appearance and structural elements between two shells after the initial formation of these domes in Central Asia and then their evolution in Iran. This research is written with the aim of finding the hidden aspects in the development of bulbous domes based on both historical documents, and architectural remains, and also examines the reasons of the changes created in these kinds of domes during four centuries in the context of cultural Iran. This study has a descriptive-analytical approach for exploring case studies, which are selected based on primary and secondary sources and also field research. The appearance changes of bulbous domes include removing flutes from the outer shell, adjusting the height of the drum and creating more bulge at the place where the outer shell joins the drum. In this article, the structural changes to improve the strength of the domes, the change in the number and proportions of the stiffeners to prevent the damage of the dome, as well as the shape and arrangement of the wooden struts to increase domes flexibility against seismic shocks, have been examined.
Keywords: Bulbous dome, narrow ribs, stiffeners, wooden struts, Timurid-Safavid architecture.

Introduction
Since the most obvious feature of Timurid architecture is its splendor, the architects of this period paid special attention to the dome than other architectural elements. In this era, domes were raised on high drums, and in order to achieve desired height on the exterior, architects usually built another shell on the top of the internal one. In such a way the dome profile is changed, so that it began a return below the base of the arch, producing thereby a slight bulge. Therefore, the bulbous dome is one of the innovations of the Central Asian architects during the Timurid period. The first cases of the bulbous domes in Central Asia have flutes on the outer shell; in addition, they have an oval-shaped structure. Construction of this domes continued with a few changes during the reign of Timur’s successors in Great Khorasan and within the current borders of Iran. To put it more clearly, after the Timurid period and during the rule of Safavids in Iran, construction of these domes continued with few changes. This study is dedicated to the analysis of the process of changes and also reasons for these changes in the appearance and structural elements of the bulbous domes according to the case studied in Central Asia and Iran during the Timurid and Safavid eras. The main question is, what changes have occurred in the appearance as well as structural elements, and as a result, the stability of these domes in the Timurid and Safavid periods in Central Asia and Iran, and what were the reasons for them.
Theoretical method of this research is based on the cultural history approach. Therefore, each case is viewed as a culture. Concerning this, three domes were selected from different regions of Central Asia (Turkestan, Samarkand, and Herat) and seven cases from Iran (Khorasan and Isfahan). Three main criteria for selecting the case studies can be listed: 1. Geographical and historical context; 2. Similarities of the cases during the Timurid period in Central Asia and the Safavid period in Iran, and; 3. Authenticity of the domes.  

Discussion
All the studied domes in Central Asia have a lofty cylindrical drum. The height of the drums was adjusted in Iran during the Timurid era, in Khorasan and also in the central regions of Iran. It is worth to mention that, construction of high drums in Central Asia, during the reign of Timur, and in Iran, during the reign of Shah Abbas I, can be seen as an expression of the visual effects of architecture as a manifestation of the power and reflection of the perfectionist personality of those Kings. 
The most important exterior characteristic of the studied domes is in the external shell (Avgon), where the drum and the external shell connected to each other. Therefore, in the bulbous domes, part of the weight load of the outer shell at the junction of the dome and drum is directed inward and less pressure is applied to the base of the monument.
Flutes move from their common place at the top of the external shell to the bottom, and transfer forces and lateral loads to the inside, and enhance the resistance of the dome against the thrust forces.
In Central Asia’s domes, we couldn’t find narrow ribs on the surface of internal shell. This is despite the fact that in most of the studied cases from the Safavid period, narrow ribs were used to transfer the weight of the stiffeners to the lower parts and base of the monument. It seems that, utilize of the narrow ribs in the Safavid domes was the invention of the Iranian elite architects to give cohesion to the double-shell domes, especially bulbous ones.
From the earliest bulbous domes, we can see stiffeners between two shells. These elements have different shapes. Establishing stiffeners, especially in the Avgon part, greatly reduce the destruction of the dome during earthquakes and shows the architects’ awareness of stiffener’s structural role and function.
The wooden struts are arranged somewhat circularly to help connect the stiffeners to increase flexibility against earthquake shocks.

Conclusion 
Changing process of bulbous domes in Iran includes removing the flutes from the external shell, adjusting the height of the drum and creating an avgon with more bulge at the junction of the external shell and drum. Domes with flutes in the Central Asia were a main characteristic of monuments. It seems that use of flutes, in addition to structural reasons, also had an aesthetic aspect; because, vertical and parallel concave and convex lines on the external shell make the domes look higher and add to the glory of the whole monument. Moreover, flutes help in transferring the thrust forces entered into the building and have a function like an avgon at the place of joining the dome’s drum. It seems that removing the flutes from domes in Iranian architecture of Timurid period should be considered as a result of the lack of a single political power in different regions of the country. Among other fundamental changes, we can notice domes with more bulge. During the Safavid period, architects learned and experienced the basic stages of bulbous domes and gained sufficient skill with regard to the morphological elements of dome and its strength. In this way, for aesthetic purposes, structural solutions such as creating narrow ribs on the internal shell of the dome and deepening the stiffeners in the avgon part have been used to maintain the integrity of the external shell. One of the reasons for the construction of narrow ribs is to transfer the compressive force of the stiffeners to the lower parts and bases of the dome and to strengthen their stability. In some cases, ribs were not used to connect stiffeners to the internal shell due to small diameter of the dome span. The changes made in the stiffeners from the Timurid period to the end of the Safavid period should be considered more related to their number, shape and proportions, which can be attributed not only to the creativity of local architects, but also to the architects’ complete awareness of the role and function of the stiffeners. These structural elements prevent the destruction of domes due to thrust forces (wind and earthquake). Wooden struts also make it possible to create a better connection between the stiffeners and external shell, as well as the connection between the components of the dome.

The Turban helmet is a type of war helmet during the 14th to 16th centuries AD in Middle East countries. This type of helmet has become known by Western scholars by this name because of the special decorations that made it look like a turban as well as the visibility of the helmet from under the warriors’ turban. Based on the numerous documents remaining, one can say that the use of Turban helmets was popular in Middle East territories’ armies during the Middle Ages. Despite being widely used and in style for more than two centuries and among many west Asian countries, among all the remaining samples of this type of middle eastern helmet, only two distinct styles, the Turkoman and the Ottoman styles, have been examined and introduced. This can be due to a large number of remaining samples of these two being kept for years in the armouries of the Ottoman Empire. Apart from these two known styles, few studies have been done so far on investigating other possible types of turban helmets. The purpose of this research is to study the turban helmets that were popular among the armies of the Il-khanid, Jalayirid, Muzaffarid, Timurid, Turkoman, and Safavid that ruled respectively in the cultural Iran region, by relying on the remaining documents from the 14th to the 16th centuries, such as the collection of helmets and illustrated manuscripts. The results of this research reveal that the changes that occurred in the making of turban helmets during the 14th to the 16th centuries have led to the representation of four different types of helmets: Mongolian style, Timurid style, Turkoman style, and Qizilbash style.

The depiction of camel fighting in rock art to express certain rituals of human can be traced back to the late Paleolithic period and is believed to have originated in present-day northwestern Kazakhstan. After the domestication of Bactrian camels, depictions of camel fighting developed a relatively standardized format, primarily presenting paired camels engaged in aggressive biting matches. This motif of camel fighting may have originated in the Karate and Baikonur regions of Kazakhstan during the Bronze Age. Due to geographical proximity, the custom of camel fighting was introduced to the Sarmatians in the Ural steppes early on, and through the Sarmatians, it spread to the Huns (Xiongnu) in the north and the Qiemo people in Xinjiang, China, and later to Kangju. The camel fighting depicted in the Sulaek petroglyphs in the Minusinsk Basin should be attributed to the Kyrgyz, and its origin is likely the Huns. The fighting camels in the Loulan mural tombs may have been inherited from Qiemo or originated from the Huns. The camel fighting motif in Persian miniature paintings first emerged during the Timurid period in the latter half of the 15th century CE. The Timurid Empire was founded by Timur, a noble from the Barlas tribe historically affiliated with Mongol aristocratic lineages. This Central Asian polity maintained profound Mongol cultural influences. Notably, camel fighting had already been practiced as courtly entertainment in the Yuan Dynasty (established by the Mongols) as early as the first half of the 14th century CE. This chronology demonstrates that the Mongols long upheld camel fighting rituals, and the motif in Persian miniatures was transmitted westward through Mongol cultural and political influence.

Abstract
Mausoleum buildings with ridged Dome, is one of the characteristics of religious architecture in the southern regions of Iran which was founded during the Ilkhanid to Safavid period. The main form of a ridged Dome is conical which the arrangement of its cubic components with different and varied shapes has a stepped mode. Studies that so far have been done on the structure of mausoleums with ridged Dome are more holistic. Therefore, the most important purpose of the present research is to explain and establish the architectural differences and similarities of four tombs which are located in different geographical areas in Southern Iran and belong to The Ilkhanid-Timurid era; and to study their susceptibility to various methods. The architecture of the mentioned historical periods under the title of Governmental (including the central sphere of governance of the Ilkhanid) and Local style (including special architectural and artistic features of the southern regions of Iran). The goal of the present research is to answer this question that what a meaningful form and decorative relationship is there between mausoleum buildings with non-governmental/indigenous ridged Dome and governmental structures? The result of the research clarifies that the architectural ornaments, which are used in the mausoleum of Mir Muhammad especially the high and deep vaults in the dome chamber and using the brick in the crown of its fluted Nar dome, represents the governmental style. The simplicity of the tomb form and usage of local material, building of conical Nar crown in the tombs of Baba Monir and Do-gonbadan and establishing symmetric ridged Dome in studied mausoleums is affected by local architecture of the mentioned regions. Also, it has been observed a kind of coexistence between local architecture and governmental style in some of the studied mausoleums. This research has been done with the approach of cultural history and descriptive-analytical method. The information has been gathered with the method of field investigation and library studies.
Keywords: Mausoleum Buildings, Ridged Dome, Ikhanid-Timurid Era, Architectural Style.

Introduction
The general shape of the ridged Dome is rock or conical; with the difference that its components, instead of a complete cone, has a scalariform (Zemorshidi, 2010: 349). This cover has been used in the late Seljuk era tomb buildings of Iran, especially in the south and southwest areas and its construction is significant throughout the Ilkhanid to Safavid eras (Sajjadi, 2017: 306). Most of the researchers believe that building of the ridged Dome follows specific geometric patterns. Its inner and outer cover represents that this structure comprises of several floors with similar geometric shapes and the geometric floors of the dome ascend rotationally from the Bashn of the dome chamber to its top. Moreover, meanwhile the floors of the dome go up, the dimensions of its ridged cubes become smaller and their height is reduced. Finally, they join together at the top of the dome (Zemorshidi,2017:350; Mashayekhi & Mahdavinejzad, 2012:297). Most of the conducted researches have a holistic framework and less attention has been paid to the structure of buildings with the ridged Dome and its changes in a certain period of time or a certain geographical area. The goal of the present research is to answer this question that what a meaningful form and decorative relationship is there between the non-governmental and governmental structures-at the intended political field-in the mausoleums with the ridged Dome. The importance of the present research and the necessity of doing it is also in identifying the tomb buildings with the ridged Dome that less researches have been done on it, and criticizing opinions which are provided by other researchers.

Materials and methods 
This research has been done with the approach of cultural history and descriptive-analytical method. The information has been gathered with the method of field investigation and library studies.

Data
Mausoleums of Do-gonbadan in Kookherd: The two mausoleums of Do-gonbadan are located in Hormozgan province, Bastak county and Kookherd village. Both mausoleums are burial places of two members of the Bani Abbasid family of Bastak (Bani Abbasian Bastaki,1960:57 & 58). The plan of both mausoleums is similar and consists of a simple square dome chamber. Also, both tombs have a ridged Dome with a star base. The decorations of Do-gonbadan tombs are associated with stucco, one of which is stalactite work in the interior view of the dome.

The mausoleum of Mir Muhammad 
The mausoleum of Mir Muhammad Hanafi is built on Kharg island of Bushehr county. Based on the tomb inscriptions, the building is attributed to Mir Muhammad Hanafi and was built during the Ilkhanid period. This tomb consists of a cruciform shrine and a square mausoleum which is adjoined to the south side of the dome chamber. A ridged Dome is constructed on top of the shrine that has a star base. The decorations of the tomb include mosaic-faience tilework and lustre tiles of dado which have animal, geometric and vegetal motifs on their surface, Also, the interior surface of the dome is decorated with chalky muqarnas.

The mausoleum of Baba Monir
The mausoleum of Baba Monir is located in Fars province, Noorabad Mamasani county and in a village called Baba Monir. The plan of the tomb is square. Its interior view includes a central dome chamber and a vaulted corridor that surrounds the dome chamber. Deep piers have given a cruciform design to the dome chamber. The dome of the tomb is ridged and has a star base. Chalky muqarnas is used in the interior surface of the dome.

Discussion
The conducted researches indicate that all the studied mausoleums belong to religious personages. Also, all of them have been built on the commercial path or near the commercial path. Moreover, there are similarities and differences in the features of studied tombs; The most important similarities between studied tombs are the usage of cruciform plan in the dome chamber of Baba Monir and Mir Muhammad mausoleums, the usage of the ridged Dome with the star base on top of dome chambers of all mausoleums, and the application of chalky muqarnas in the interior view of the dome of these tombs. The differences include using the simple square plan in the mausoleums of Do-gonbadan in Kookherd, and existence of the fluted Nar crown on top of the Mir Muhammad dome while there is a simple conical crown on top of the Baba Monir and Do-gonbadan dome. Besides, the only tilework decoration is in the Mir Muhammad tomb. In sum, the architectural features represent that Mir Muhammad tomb is more affected by the architecture of the governmental style. Because, it was built on the main trade route. But, the architectural features of Baba Monir and particularly Do-gonbadan are more non-governmental/local. Because these tombs were built on the side trade roads. Therefore, architects of these two tombs have not had much chance to become familiar with other architectural methods.

Conclusion
Studied mausoleums are the burial place of important religious personages and are built single, in an open space. These tombs were located on the trade routes. The location of Mir Muhammad tomb in Kharg island and on the transregional trade route of Islamic lands with East Asia has increased its importance. The architectural decorations of Mir Muhammad mausoleum have more variety in comparison with other mausoleums and it reveals the influence of various architectural styles, especially the Ilkhanid-Timurid architectural style. This effectiveness has been observed to a small extent in Baba Monir tomb compared with Mir Muhammad tomb. Whereas, mausoleums of Do-gonbadan in Kookherd have the least influence from the governmental buildings of the Ilkhanid-Timurid era. However, the method of constructing the ridged dome in all mausoleums has been executed skillfully in terms of structural and geometric form. In general, the constructing of the ridged symmetric domes in each four tombs signifies the powerful influence of the local architectural style in their structure. However, the influence of other architectural styles in these mausoleums is not the same. There is a kind of coexistence between the local and governmental architectural styles in the tomb of Mir Muhammad in Kharg. The influence of the local architecture is more obvious in the mausoleums of Baba Monir and particularly Do-gonbadan.

Timurid coinage functions as a material repository, mirroring the significant economic and political shifts characterizing the era, thereby offering crucial insights into the socio-economic structure of the Timurid Empire. This investigation critically examines a collection of Timurid numismatic artifacts housed in the Avicenna tomb Museum utilizing X-ray Fluorescence (XRF) spectroscopy. The meticulous re-evaluation of preliminary XRF spectroscopic data is paramount, particularly within the discipline of numismatics, as it constitutes a foundational requisite for mitigating analytical errors and augmenting the precision of interdisciplinary assessments. While XRF technology provides a non-destructive means for the precise determination of elemental composition within the coinage, a failure to implement rigorous monitoring and comprehensive data scrutiny risks introducing substantial historical misinterpretation and analytical uncertainty. This study addresses core research questions concerning the substantive value of re-analyzing and interpreting XRF spectral outputs, specifically concerning their utility in authenticity verification (counterfeit identification) and the delineation of underlying economic and cultural characteristics. The central hypothesis asserts that unprocessed XRF spectral data lacks inherent accuracy and necessitates expert-driven, in-depth analysis for conclusive artifact examination. Furthermore, the research underscores the necessity of detailed spectral profiling, acknowledges inherent technical complexities in data interpretation, and advocates for interdisciplinary methodologies to substantially enhance result validity. The findings conclusively demonstrate that a profound reinterpretation of XRF analytical data significantly advances the comprehension of material provenance, safeguards cultural heritage assets, and yields more nuanced understandings of Timurid economic governance.