NEEM BIODIESEL: AN ALTERNATIVE FUEL

Objective: Fossil fuels are a major source of energy in today’s world but due to the limited availability of fossil fuels and its harmful emissions, it is now very important to shift our focus toward other sources of energy. Biofuels can help us meet this energy requirement. This study is aimed at producing neem biodiesel from neem oil by “transesterification process” using sodium hydroxide (NaOH) and studying its various fuel properties. Methods: First, extraction was done to produce neem oil from its seeds. Free fatty acid content was reduced and transesterification reaction was carried out at temperature of around 55–65°C in the presence of alkali catalyst, NaOH to produce neem biodiesel. Properties of biodiesel produced such as viscosity and flash point were then determined using redwood viscometer, Abel-Pensky apparatus, and their respective methods for other properties. Results: Produced neem biodiesel showed higher pour point than that of conventional diesel. Viscosity of neem oil was much higher than standards and was greatly reduced when converted to biodiesel using transesterification and biodiesel showed kinematic viscosity of 5.2 cSt at 35°C. Conclusion: Neem biodiesel produced has many fuel properties close to that of conventional diesel. Furthermore, the biodegradable, non-toxic nature of biodiesel is another reason for considering it as an alternative fuel. As we cannot directly use neem oil in diesel engine due to its high viscosity, so it is needed to convert it into biodiesel so that its properties become comparable to the conventional diesel.

ACTIVE-HASH-TABLE BASED PUBLIC AUDITING FOR SECURE CLOUD STORAGE

Public auditing scheme for secure cloud storage based on dynamic hash table, which is a new two-dimensional data structure located at a third-party auditor (TPA) to record the data property information for dynamic auditing. Differing form the existing works, the proposed scheme migrates the authorized information from the cloud services provider to the TPA and thereby significantly reduces the computational cost and communication overhead. Our scheme can also achieve higher updating efficiency than the state of the art schemes. In addition, we extend our scheme to support privacy preservation by combining the homomorphic authenticator based on the public key with the random masking generated by the TPA and achieve batch auditing by employing the aggregate BLS signature technique. We formally prove the security of the proposed scheme and evaluate the auditing performance by detailed experiments and comparisons with the existing ones. The results demonstrate that the proposed scheme can effectively achieve secure auditing for cloud storage and outperform the previous schemes’ in computation complexity, storage costs, and communication overhead.