ABSTRACT
Reinforced aluminum composites are the basic class of materials for aviation and transport industries. The machinability of these composites is still an issue due to the presence of hard fillers. The current research is aimed to investigate the drilling topographies of AA7075/TiB2 composites. The samples were prepared with 0, 3, 6, 9 and 12 wt.% of fillers and experiments were conducted by varying the cutting speed, feed, depth of cut and tool nose radius. The machining forces and surface topographies, the structure of the cutting tool and chip patterns were examined. The maximum cutting force was recorded upon increase in cutting speed because of thermal softening, loss of strength discontinuity and reduction of the built-up-edge. The increased plastic deformation with higher cutting speed resulted in the excess metal chip. In addition, the increase in cutting speed improved the surface roughness due to decrease in material movement. The cutting force was decreased upon high loading of TiB2 due to the deterioration of chips caused by fillers. Further introduction of TiB2 particles above 12 wt.% weakened the composite; however, due to the impact of the microcutting action of the fillers, the surface roughness was improved.
ABSTRACT
One of the vital hitches in today's world of research is ensuring the security of the Cloud. This security can be ensured by inventing new techniques that may possibly help in safeguarding and assuring the optimal status of information in the cloud. Contents that are stored in the Cloud are majorly affected by the attempts made by illegitimate sources that are trying to access it. The security level of the contents that are stored in the cloud can be guaranteed by focusing on a task that helps in both securing and verifying the data. In order to manage the security level, (SE-KAC) which is also known as Scalable and Enhanced Key-Aggregate Cryptosystem was initiated in current research method. But this method of securing and sharing secret keys cannot be used in the stage of decryption. However this problem can be resolved in proposed method since it introduces sharing of the data securely using a method called Improved Diffie Hellman Key Exchange Algorithm (IDHKE). By introducing the Improved Diffie Hellman Key Exchange Algorithm, securely sharing the secret keys to the receivers of the data has been achieved. The secret key details can be exchanged securely using this method. By this means it makes sure its affirmations. Here the key is safely generated using one random prime number, a master secret key and parameter value. Intended for the secured and consistent access control limitation, an encryption which is attribute-based is used. The proposed method thus ensures the protected data transmission with exact and trustworthy validation.
Subject(s)
Access to Information , Cloud Computing , Computer Security , Algorithms , Information Dissemination , Information Storage and RetrievalABSTRACT
The reaction of CdCl(2), 18-crown-6 and KI in water yields the title coordination polymer, [{K(C(12)H(24)O(6))}(2)Cd(2)I(6)](n). The potassium ion lies approximately in the plane of the crown ether, coordinated by all six crown ether O atoms and also by an iodide anion bound to a cadmium atom. A C atom of the crown ether is disordered over two positions with site occupancies of 0.77â (2) and 0.23â (2). Two K(18-crown-6)(+) units are linked by inversion symmetry, forming a [bis-(µ(2)-18-crown-6)dipottasium] system with approximately square-planar K(2)O(2) units. Inversion symmetry also generates the Cd(2)I(6) fragment and the polymeric system is extended along the c axis by the formation of K-I-Cd bridges.
