An overview of using small punch testing for mechanical characterization of MCrAlY bond coats

Considerable work has been carried out on overlay bond coats in the past several decades because of its excellent oxidation resistance and good adhesion between the top coat and superalloy substrate in the thermal barrier coating systems. Previous studies mainly focus on oxidation and diffusion behavior of these coatings. However, the mechanical behavior and the dominant fracture and deformation mechanisms of the overlay bond coats at different temperatures are still under investigation. Direct comparison between individual studies has not yet been achieved due to the fragmentary data on deposition processes, microstructure and, more apparently, the difficulty in accurately measuring the mechanical properties of thin coatings. One of the miniaturized specimen testing methods, small punch testing, appears to have the potential to provide such mechanical property measurements for thin coatings. The purpose of this paper is to give an overview of using small punch testing to evaluate material properties and to summarize the available mechanical properties that include the ductile-to-brittle transition and creep of MCrAlY bond coat alloys, in an attempt to understand the mechanical behavior of MCrAlY coatings over a broad temperature range

People, governance and forests -- the stumbling blocks in forest governance reform in Latin America

This article examines common barriers to achieving adequate levels of forest resource governance in countries of Latin America. It looks at the deficiencies of the policy and regulatory frameworks affecting forests, the common failure to impose the rule of law, the main factors that constrain the effectiveness of government actions in the forest sector and at the political barriers to introducing reforms for change in governance structures. The elimination of these barriers acquires new importance in the implementation of successful REDD+ programs in the countries of the region

The underlying causes of forest decline

Loggers, miners and rural communities all exploit forests in unsustainable ways in search of profits and means of subsistence. They are the primary actors in forest decline and their immediate motivations are the direct causes of deforestation and degradation. However, these motivations are determined, through complex causation chains, by deeper and much more fundamental forces: the underlying causes of deforestation. Effective action against forest decline requires an understanding of these underlying causes and their distant impacts on forests. Underlying causes originate in some of the most basic features of society, such as the distribution of economic and political power, attitudes towards corruption, population growth, flaws in the market system and in seemingly unrelated government policies. They may originate in other countries and transmit their effects through trade and the operation of transnational corporations. Underlying causes are many and operate in numerous and variable combinations. Forest decline is a complex socio-economic, cultural and political event. Thus, it is a mistake to attribute forest decline to a simple cause-effect relationship or assume that a relationship will remain unaltered over time. A single force, such as agricultural intensification, may operate in diametrically opposite ways, depending of the context of other variables and circumstances prevailing in a particular situation. Accordingly, remedial measures need to be tailored to the very specific milieu in which they will be introduced. There are no simple solutions to this complex phenomenon

Las dimensiones sociales, ambientales y economicas de las reformas a la politica forestal de Bolivia

This paper looks at the experience of designing and implementing policy reforms in the Bolivian forestry sector. It does not attemp to evaluate the process of reform itself but rather to examine the main obstacles faced in its planning and implementation and how the lessons of the Bolivian experience could be transferred to other countries attempting similar changes. Given the drastic nature of reform, it is not surprising that problems along the way were numerous. However, despite difficulties, progress has been significant. This, largerly, was due to a successful alliance between committed Bolivian reformers and a very effective effort by international assistance agencies. Much remains to be done. However, the Bolivian experience shows that a dedicated government can do much to modify the management of the national forest resources

Social, environmental and economic dimensions of forest policy reforms in Bolivia

This paper looks at the experience of designing and implementing policy reforms in the Bolivian forestry sector. It does not attemp to evaluate the process of reform itself but rather to examine the main obstacles faced in its planning and implementation and how the lessons of the Bolivian experience could be transferred to other countries attempting similar changes. Given the drastic nature of reform, it is not surprising that problems along the way were numerous. However, despite difficulties, progress has been significant. This, largerly, was due to a successful alliance between committed Bolivian reformers and a very effective effort by international assistance agencies. Much remains to be done. However, the Bolivian experience shows that a dedicated government can do much to modify the management of the national forest resources