The idea behind the principle of sustainability - which has shaped the entire body of contemporary conservation ethics- is to consider future users when making decisions and interventions. This principle tries to prevent extreme decisions based on taste and prejudice or interventions based on current knowledge. Ethical principles such as "reversibility" and "least intervention" have been shaped by different theoretical approaches and are widely used in conservation literature today. However, these fundamental principles, as influential variables in ethical and technical decision-making, have become a subject of debate and criticism in contemporary conservation thought. The aim of the present study is to address these criticisms from the perspective of sustainability in contemporary conservation by using the method of "deconstruction". Deconstruction is a critical thinking that examines variables in detail with the aim of showing gaps and contradictions. Having a critical approach means examining the causal relationships of issues and revealing what has remained hidden. Therefore, deconstruction does not want to destroy the truth, but rather restores it. Therefore, this research aims to reveal challenges such as the "subject of conservation", "reasons", "objectives" and "method" that have made the ethical principles of conservation contradictory, opaque and sometimes impossible, and also to criticize and deconstruct the principles that were accepted as axiomatic and unquestionable in classical conservation, trying to denaturalize what has always been natural. The present study has gone to the deconstructionist approach in order to examine the criticisms because it believes that with the deconstructionist approach, firstly, the real thing or, in other words, the "thing in itself" in the sense of pure truth, independent of human perception and senses, does not exist; secondly, theorists such as Marcuse (1988) and Nietzsche (1992) believe that what is known as truth within a culture is a form of communication and social peace contract between people. All moral standards are created by specific conditions (such as culture) and are solely related to these conditions. In this thinking, awareness of indeterminacy and uncertainty is the most real characteristic and truest characteristic of cultural and artistic phenomena. An issue in which moral standards and valuation do not remain in the monopoly of fixed principles and predetermined functions and roles and do not accept a fixed definition, but rather act as a fluid and changing factor in their cultural and situational context. The result is that contemporary ethics, with greater flexibility. Ethics are not applied as static and mechanical principles at the time of intervention, but are prepared to face unpredictable behavior by "adaptation" and "compatibility" and are considered as added values, that is, they are not mandatory in any case and can be ignored depending on the circumstances. Ethical principles and criteria such as minimal intervention, reversibility in interventions, similarity of materials and conservation techniques to the original part.

Calligraphy art in Islamic architecture has been existed in Kufic form especially in the 13thAD., this was the time of the Mongol Ilkhanids in Iran. The evidence for Square Kufic under Ilkhanid religious freedom bear variation of meanings which indicates the religious orientation of the constructors. Sometime between two square Kufic inscriptions on different buildings are seen similarity on the rules of design and religious orientation which suggest unique works of one calligrapher. One of the most innovative one is in the mausoleum PirBakran. A large square panel containing salutation on the Prophet Muhammad and Twelve Imams is in the main exterior of the mausoleum. A similar Square Kufic containing same salutation exist in the Haftshuiyeh Mosque in a Mihrab Panel. Both monuments are in two districts of the Isfahan province not far from each other.
The contribution of this work is to extract the pattern of a damaged Kufic calligraphy in Haftshuiyeh Mosque considering the similar inscription in the mausoleum of PirBakran. There are some other decorative motives on the Haftshuiyeh mihrab find similars in the ornament of the PriBakran. With attention to the Kufic calligraphy works of PirBakran and Haftshuiyeh, their similar unique content and similar designs of both inscriptions, support the suggestion that the inscription of Haftshuiyeh, may originate from the calligrapher of PirBakran mausoleum. The aim of this study is to describe, analyze and compare the inscription of Pirbakran with Haftshuiyeh in order to find the word formations and compositional schemes and the rules of calligrapher’s design. To identify different structure and variation of the alphabet of Kufic letters, each word has been studied as far as possible in the PirBakran and Haftshuiyeh. Following the calligrapher’s rules, forms of the words, authors redesign and give explanation on the missing part of the Haftshuiyeh inscriptions.

When dealing with historical bronze artifacts, we usually encounter a layer called patina on the surface of these artifacts. Understanding the nature, structure, and function of this layer is one of the fundamental issues in the field of conservation and restoration of historical metals In general, patina in metals is defined as a coating consisting of various chemical compounds such as oxides, carbonates, sulfides, and chlorides, which forms as a result of the long-term interaction of the metal with environmental and corrosive factors. The question of what role patina plays in the conservation, historical interpretation, and restoration decisions of bronze objects has provided the main motivation for the present study to investigate and scientifically understand this phenomenon. In this article, while introducing the concept of patina and its types in historical bronzes, we examine the factors affecting the formation and evolution of this layer, including environmental conditions and alloy composition.