Background: Bone mineral density (BMD) assessment by using dual-Energy X-ray absorptiometry (DXA) plays an important role in diagnosis and treatment of osteoporosis. Variation in soft tissue thickness may cause probability errors in DXA bone values. The aim of this study was to assess the effect of soft tissue thickness on bone mineral.Methods: A spine phantom consisting of bone and soft tissue equivalents (Aluminum and Perspex respectively) was made to simulate different status of bone (normal, osteopenia and osteoporosis) and abdominal thicknesses. BMD measurements were performed by DXA using a Norland XR-46 on 45 patients. The statistical analysis for determining the BMD, bone mineral content (BMC), bone area (BA) measurements was done using SPSS software.Findings: According to Pearson correlation test, variation of soft tissue thickness had no statistically significant relation on BMD, BMC and BA (P>0.05). But non-parametric regression determined soft tissue thickness had some effect on BMD and BMC (P<0.05), but no statistically effect on BA (P>0.05).Conclusion: Variation of soft tissue thickness had no considerable effect (less than1%) on bone mineral results, so errors arising from soft tissue thickness in DXA are negligible.

Background: Osteoporosis in the lumbar spine and hip are diagnosed using dual-Energy X-ray absorptiometry (DXA) scan. This method reveals remarkable accuracy and precision in the results. We aimed to determine the errors affecting measurements using DXA scan and investigate the changes in mineral density of hip and lumbar spine over one year.Methods: The study was performed on 65 patients referred to the Isfahan Osteoporosis Diagnosis Center, Iran, and changes in mineral density of the hip and lumbar spine were examined. Moreover, phantom study was conducted to determine the errors affecting the results of DXA scan including metal artifact, patient incorrect position, not calibration, and incorrect analysis of data gathered using DXA scan. Data were analyzed using SSPS software.Findings: This study showed that any error led to a slight change in measurements by DXA scan. Additionally, the mean value of changes in mineral density of hip and lumbar spine decreased 1.53 and 1.42 g/cm2, respectively, which was not significant (P>0.05).Conclusion: According to the present study, any minor error can impact on the results of DXA scan.Furthermore, the reduction in bone mineral density of the hip and lumbar spine occurs after one year; however, it was not statistically significant.

Energy security is one of the most prominent issues in the International Relations. Energy security returns to ensure and stable of supply Energy (oil and gas). The politician aim use to achieve Energy is three issues. First, the acquisition of threat and risk-free Energy sources is possible. Second, these resources have logically diversity geographical resources and transmission routes and third, the flows of oil and gas supply points are generally stable and not likely to change their governments, long-term and long. So, codification of Energy diplomacy with emphasize on role of Energy is located on the policy of various politicians. In this context, two factors make important issue in subject of Energy security.Firstly, doubled requires industrialized countries to Energy resources and in contrast, increased per capita Energy consumption in India & China.Secondly, from the perspective of western countries, Energy resources are located in region with unstable political regimes. Therefore, according to link economic growth and Energy demand and supply, Energy security becomes the most important issues in states foreign policy. Accordingly, different countries have chosen various policies for safe and uninterrupted access to Energy resources. Russia which is one of most important countries of global Energy producer has taken the following policies: 1. Diversity of supply resources 2. Diversity of region supply 3. Enhancement of Energy transition instructure 4. An active participation in international Energy markets, international financial markets and regional organization to gain international Energy investment.

In this paper, we obtain some upper and lower bounds for the general extended Energy of a graph. As an application, we obtain few bounds for the (edge) Zagreb Energy of a graph. Also, we deduce a relation between Zagreb Energy and edge-Zagreb Energy of a graph G with minimum degree   2. A lower and upper bound for the spectral radius of the edge-Zagreb matrix is obtained. Finally, we give some methods to construct (edge) Zagreb equienergetic graphs and show that there are (edge) Zagreb equienergetic graphs of order n  9.

Introduction: From beginning of 20th century in which crude oil gained gradually its position as the most significant source for maintaining Energy in the world, the rate of resources and status of demand and supply for possessors of such resources which are mainly producers and exporting countries and for importing and consuming of such type of Energy became increasingly importance.

Geothermal Energy is one of the most environmental-friendly and cost effective Energy sources with potential to replace fossil fuels and help mitigate global warming. Recent technological progress, Energy price variability, difficulty of oil and gas supply from foreign countries and the need to reduce fossil fuel deployment have made the exploitation of geothermal Energy, especially for heating and cooling purposes, an attractive and viable Energy alternative. The choice of the proper geothermal system (for heating or cooling) is essentially based on the need of cost containment and environmental constraints. Energy pile provides a mean to reduce Energy consumption for space heating and cooling, while functioning as a support for superstructure. Despite of the environmental benefits of Energy pile, some countries are still reluctant in implementing Energy pile. This is because of knowledge gap on the influence of temperature cycles on Energy pile ultimate and serviceability limit states. This paper reviews the geo exchanger and Energy pile systems and highlights their applicability and efficiency as well as advantages and limits.

Energy Service Contract is an important method for Energy saving. While taking some degree of risk, Energy Service Companies implement the Energy-saving projects in the form of Energy performance contracts for Energy consumers (clients). This kind of contracts enjoy some new, subtle and different features. The question is whether this type of contract can be classified as a new contractual form? If not under which type of existing contract forms are they classified? In this paper, the framework of shared savings and guaranteed savings contracts as the main types of Energy performance contracts is reviewed. Documents issued by the Ministry of Petroleum are compared to some certain contracts, including sales, promise of reward, hire-purchase and partnership; it is concluded that this specific kind of contract, is not compatible with any of the definite contract types mentioned above. Hence these contracts should be recognized under the principle of sovereignty and freeness of wills, Article 10 of the Civil Code. it is argued that these contracts are not marred by the risk of loss, so they are not defying the specific terms of law. it is argued that the structure of shared saving contracts is the same as of the reward contract under the definite contracts.

With the transfer of the discourse of geo-strategy to geo-economics in recent decades and the superior role of economy in the international relations, the geopolitics of Energy and its security has enjoyed a special place in international relations. In our era, Energy, particularly oil, has played a significant role in security and regional and international skirmishes. Hence, such concepts as security of Energy, strategic reserves, oil resources, consumers and producers of oil, oil and gas pipelines and their security has become very crucial. Today Iran is internationally important with regard to the production and transfer of Energy. On the one hand Iran is in the center of the strategic Energy circle and on the other it is located at the center of transfer of Energy to the world’s great Energy markets, that is, Europe and South and Southeast Asia. These features have potentially endowed Iran with special geoeconomic and geopolitical characteristics. Attempts should be made to actualize those potential charactersitics to promote Iran’s status in regional and international arena.

The existence of a successful internal and global experience in establishing an Energy management system, based on ISO 50001: 2018, is an acceptable method for organizations to reduce their Energy as well as environmental costs. In this standard, the methodology to promote Energy management in organizations is presented. In a sense, improving Energy performance leads to a reduction in consumption and, consequently, the Energy costs are organized as such. On the other hand, as well as raising competitiveness of the organization, and improving its profitability, it also covers part of their environmental commitments. This standard creates a framework for a systematic Energy management in industrial, commercial and governmental organizations/institutions. The Energy baselines, performance indicators, targets and Energy performance monitoring are important parts of this standard. In this study, using actual Energy consumption data and by identifying effective factors influencing on this parameter, a model has been developed for targeting, performance monitoring and compilation Energy bases in an administrative building in Tehran. Results show that the proposed model/methodology and its information can be used in any similar building in any geographic region.