The challenges of safeguarding and securing cultural heritage materials during violent conflict in Nigeria.

Almost every community, country and continent is experiencing a form of conflict, war or disaster. These wars have claimed lives, antiquities, heritage materials, contemporary Arts, Galleries, Museums, Archives, Monuments andHeritage sites. The aim of this study is to explore the challenges of safeguarding cultural heritage material during violent conflict in Nigeria bearing in mind the two UNESCO world heritage sites in Nigeria: Sukur kingdom and Osun Oshogbo sacred Grove. The outcome of this study will help the policy makers to address the challenges of safeguarding cultural heritage materials in times of conflicts, bridge the gap on the existing literature concerning the safeguarding of cultural heritage materials in times of conflict and to make a modest contribution to the existing body of knowledge on cultural heritage protection in Nigeria in particular and other parts of the world in general. This study relies on both primary and secondary sources using questionnaire and oral interview to elicit information from selected relevant cultural agencies, journalists and scholars in the field of art and culture. Relevant literature and documents on the challenges of safeguarding and securing of cultural heritage materials during conflicts were reviewed. The data gathered from the questionnaires and the oral interview is presented in frequency tabular form to give precise and comprehensive insight into the study findings. Notable among the challenges were insecurity and lack of professionalism in the field of cultural heritage profession. The study also revealed that governments are not enforcing the global laws and conventions for the protection of cultural heritage materials in times of violent conflict. The communities where these materials are located have little or no knowledge about the import of these materials and do not take part in securing them in the event of conflict. It is crucial that we place high value on heritage materials since they are inextricably linked with our identity and where we come from. It is strongly recommended that Cultural Heritage Institutions should involve as much as possible the local communities living around the sites by creating awareness educating and encouraging them to take ownership of the Sites located within their communities. They must ensure that the site is safeguarded against all forms of threat. Items of heritage value are not often considered in most disaster management plans therefore there is the need to consider heritage as priority just as the protection of lives and property.

Properties of polycrystalline gas sensors based on d.c. and a.c. electrical measurements

Electrical properties of polycrystalline gas sensors are analyzed by d.c. and a.c. measurements. d.c. electrical conductivity values compared with those obtained by admittance spectroscopy methods help to obtain a detailed 'on line' analysis of conductivity-modulated gas sensors. The electrical behaviour of grain boundaries is obtained and a new design of sensors can be achieved by enhancing the activity of surface states in the detecting operation. A Schottky barrier model is used to explain the grain boundary action under the presence of surrounding gases. The height of this barrier is a function of gas concentration due to the trapping of excess charge generated by gas adsorption at the interface. A comparison between this dependence, and a plot of the real and imaginary components of the admittance versus frequency at different gas concentrations, provides information on the different parameters that play a role in the conduction mechanisms. These methods have been applied to the design of a CO sensor based on tin oxide films for domestic purposes, the characteristics of which are presented.