Open Journal of Science and Technology <p>Open Journal of Science and Technology (OJST)” is an international, double-blind peer-reviewed journal which aims to bring its readers the very best analysis and discussion in varied multidisciplinary fields. The journal publishes outstanding academic research providing a platform for publishing innovative and research works in the field of science and technology, promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in science, technology and related disciplines. The journal covers issues addressed by researchers within academic and independent research organizations in different areas aiming principally at publishing articles resulting from original research whether pure or applied in the various aspects of academic endeavor broadly classified as Science (Physical, Biological and Chemical), Humanities, Technology, Computers, Information systems and Big Data. It is also an international medium for the publication of social research methodology and practices across a wide range of disciplines and avenue for researchers in different sectors to consider and evaluate methods as these relate to research practice.</p> en-US (Sobia Irum) (Dr. Muhammad Imran qureshi) Wed, 14 Nov 2018 15:15:27 +0000 OJS 60 CLAY ROOFING TILE: A COOL ROOF? <p>The aim of this study is to determine if the clay roofing tile in its natural albedo can be considered “cool” in the thermal performance through a comparison of its surface temperature to a cool coated clay tile using the exposure rack method. It begins with highlighting the expectation (from review) of the thermal performance of a cool colored tile and comparing the surface temperature (maximum, mean and minimum) of the tiles. Day and night time temperature behaviors were also compared using graphs on excel software. A python t- test of means was also carried out to determine if there was any significant difference in the performance of the materials. It was found that the performance of the clay tile in its natural albedo is a cool tile in its thermal performance. The implication of this is a cost saving strategy. However, further research is needed as a form of coating may be needed in order to enhance its life span. A non- color coat whose only function is to protect the surface of the tile. This does not in any way disregard the use of coated tiles as user preference may still tend towards non- natural clay colored tiles, its purpose is to encourage informed cheaper methods of achieving cool roof strategies</p> Anumah, Lesado ##submission.copyrightStatement## Wed, 14 Nov 2018 14:56:53 +0000 Performance evaluation on aggregate bases of real estate in a mixed asset portfolio in Lagos <p>This paper evaluates the performance of direct real estate in a mixed-asset portfolio, to ascertain whether the inclusion of real estate in the portfolio helps it perform better or not. Annual Transaction prices of government bonds, treasury bills, development stocks and commercial papers for a ten year period (2005-2014) were retrieved from the CBN bulletin. Annual rental values for commercial offices were collected through questionnaires administered on 220 out of 309 estate firms within the study location using simple random sampling technique. 165 questionnaires were returned and analyzed. The portfolio risk and returns were calculated with and without real estate to check performance at both levels. Correlation analysis was used to compare the strength of relationship and co-movement of assets. Findings show that real estate performed better than other assets giving higher returns though with higher risk. This can be attributed to the 2009 crash in the Nigerian stock market which made investors turn to real estate on the basis of security. However, correlation analyses of the assets revealed a moderately positive correlation indicating little or no diversification benefit. This paper recommends further study using direct and indirect real estate only to determine the level of performance on a risk and return basis.</p> S.A Anule, Z.T Jagun, M.M Omirin, A. H Bornoma, A.A Ahmed ##submission.copyrightStatement## Wed, 14 Nov 2018 14:51:30 +0000 A NEW VIEW OF FUZZY ORDERED SEMIGROUPS <p>fuzzy coding theory, fuzzy finite state machines, and fuzzy languages. In this paper, we introduce the concept of an interval-valued -fuzzy filter of an ordered semigroup, where with. Since the concept of an interval-valued -fuzzy filter is an important and useful generalization of the ordinary interval-valued fuzzy filter, we discuss some fundamental aspects of an interval-valued -fuzzy filters. An interval-valued -fuzzy filter is a generalization of the existing concept of an interval-valued fuzzy filter. We discuss the concept of an interval-valued -fuzzy left (right)-filters and provide some characterization theorems. Finally, we extend the concept of an interval-valued fuzzy subgroup with thresholds to the concept of an interval-valued fuzzy left (right)-filter with thresholds of s.</p> Hidayat Ullah Khan, Asghar Khan, Faiz Muhammad Khan, Amir Khan, Muhammad Taj ##submission.copyrightStatement## Wed, 14 Nov 2018 00:00:00 +0000