Mitigate Wormhole Attack and Blackhole Attack Using Elliptic Curve Cryptography in MANET.

Numerous network can be connected by using the mobile ad hoc network. It can have security attacks like the worm hole, denial of service attack, jellyfish and also the blackhole. During this they take a path which is the shortest for the place where it has to reach. During sending of message two types of attacks are generally seen such as the blackhole attack and the wormhole attack. In this research we have tried to focus on two major attacks such as the black hole and the worm hole attack. In this we have used two types of protocol such as the AODV whose other name is SWBAODV and the scalable-dynamic elliptic curve cryptography. During the use the prime numbers are selected at random. We can also choose certain specific prime number. Moreover the security level does not depend on the size of the key. Keeping A as worm hole and B as the black hole we have made a two dimensional vector function named as F [A, B]. Two types of study is done by us in our research such as the with attack and without attack. In case of no attack study we have shown graphically using the AODV and the in case of attack we have given it as the BAODV and also the WAODV. Here we have applied a specific method SWBAODV to our selected attack case. The results were found to be interesting for the case of, packet delivery ratio and end to end delay was near 188.40 on comparing it with the BAODV and the WAODV. It has shown 51.38% more value compared to the BAODV and WAODV. There has been a drastic fall in the value of delay and it reached to a 63.2 for BAODV to WAODV. The other two things which we have discussed here is the consumption of energy and the overhead routing. The results in case of SWBAODV were good compared with the consumption of energy and save about 73.52% with the attacked case and around 69.35% with the routing done on the BAODV and WAODV. From our study we were able to say that it will give protection to the (MANET).

Idealization through interactive modeling and experimental assessment of 3D-printed gyroid for trabecular bone scaffold.

Porous scaffolds assisted bone tissue engineering is a viable alternative for reconstruction of large segmental bone defects caused by bone pathologies or trauma. In the current study, we intend to develop trabecular bone scaffolds using gyroid architecture. An interactive modeling framework is developed for the design of three-dimensional gyroid scaffolds using advanced generative tools including K3DSurf, MeshLab, and Netfabb. The suggested modeling approach resulted in uniform and interconnected pores. Subsequently, fused deposition modeling 3D-printing is employed to fabricate the scaffolds using poly lactic acid material. The pores interconnectivity, porosity, and surface finish of the fabricated scaffolds are characterized using micro-computer tomography and scanning electron microscopy. Additionally, to assess the performance of scaffolds as a bone substitute, compression, and in-vitro biocompatibility tests on sterilized scaffolds are conducted. Compression tests reveal mechanical strength in the range of native bone while human adipose-derived mesenchymal stem cells show high proliferation after 72 h of incubation. Based on these results, the fabricated gyroid scaffolds can be said to possess favorable properties for trabecular bone scaffold.

Multifunctional hydroxyapatite and hopeite coatings on SS254 by laser rapid manufacturing for improved osseointegration and antibacterial character: A comparative study.

Orthopaedic metallic implant's long-term success strongly depends upon the two main factors: osseointegration and antibacterial character. Bioceramic (hydroxyapatite and hopeite) coatings have been proven effective for getting strong osseointegration and antibacterial character. However, deterioration of bioceramic coatings during the implantation period can adversely affect its overall biological performance. To conquer this issue, this research work recommends an innovative process route of laser rapid manufacturing for depositing bioceramic (hydroxyapatite and hopeite) coatings with metallurgical bonding. Microstructure, phase composition, antibacterial efficacy and bioactivity were evaluated using scanning electron microscopy, X-ray diffraction, fluorescence-activated cell sorting technique and simulated body fluid immersion test. The promising results obtained from these characterizations and testing establish the new process route laser rapid manufacturing as an effective alternative to deposit multifunctional bioceramic (hydroxyapatite and hopeite) coatings on metallic prosthetic-orthopaedic implants.

Nano-magnesium oxide reinforced polylactic acid biofilms for food packaging applications.

This study is aimed at producing biofilms by reinforcement of Magnesium Oxide (MgO) nanoparticles in polylactic acid (PLA) biopolymer using the solvent casting method. In this study MgO nanoparticles (up to 4wt%) were reinforced in PLA biopolymer and their key mechanical, barrier, thermal and antibacterial properties were investigated for food packaging applications. Among the prepared biocomposite films, the 2wt% reinforced PLA films showed the maximum improvement in tensile strength and oxygen barrier properties (up to 29% and 25% respectively) in comparison to pristine PLA films. However, the water vapor barrier properties decreased by nearly 25% due to interfacial behavior and presence of free volumes near MgO nanoparticles. PLA/MgO films also exhibited superior antibacterial efficacy. The 2wt% biofilms caused progressive damage and death of nearly 46% of E. coli bacterial culture after 12h treatment. The produced films are transparent, capable of screening UV radiations and exhibit superior antibacterial efficacy making them an excellent food packaging material.

Microstructures, hardness and bioactivity of hydroxyapatite coatings deposited by direct laser melting process.

Hydroxyapatite (HAP) coatings on bioinert metals such as Ti-6Al-4V are necessary for biomedical applications. Together, HAP and Ti-6Al-4V are biocompatible and bioactive. The challenges of depositing HAP on Ti-6Al-4V with traditional thermal spraying techniques are well founded. In this paper, HAP was coated on Ti-6Al-4V using direct laser melting (DLM) process. This process, unlike the traditional coating processes, is able to achieve coatings with good metallurgical bonding and little dilution. The microstructural and mechanical properties, chemical composition and bio-activities of the produced coatings were studied with optical microscopy, scanning electron microscope equipped with energy dispersive X-ray spectroscopy, and Vickers hardness machine, and by immersion test in Hanks' solution. The results showed that the choice of the laser power has much influence on the evolving microstructure, the mechanical properties and the retainment of HAP on the surface of the coating. Also, the choice of laser power of 750 W led to no dilution. The microhardness results inferred a strong intermetallic-ceramic interfacial bonding; which meant that the 750 W coating could survive long in service. Also, the coating was softer at the surface and stronger in the heat affected zones. Hence, this process parameter setting can be considered as an optimal setting. The soak tests revealed that the surface of the coating had unmelted crystals of HAP. The CaP ratio conducted on the soaked coating was 2.00 which corresponded to tetra calcium phosphate. This coating seems attractive for metallic implant applications.

Thermo-chemical extraction of fuel oil from waste lubricating grease.

This study investigated the recovery of oil from waste grease through the process of thermal degradation in an aqueous solution of potassium hydroxide (KOH) followed by solvent extraction. Waste high temperature metal bearing grease was dissolved in a 15 w/w% KOH solution at 80°C while being agitated at 2000 rpm using a shear action agitator for a period of 15 min. Two distinct layers were observed after 8 min of settling time. The top layer being of dark brown oil and the bottom layer was a heterogeneous mixture. The two layers were separated by decantation. The bottom layer was cooled down to 45°C followed by slow addition of toluene (C7H8) while agitating at 1200 rpm for 15 min to prevent solids settling and minimise rapid volatilisation of the organic compounds in the mixture. Two distinct layers were also formed, the top homogeneous mixture of light brown oil-toluene mixture and the bottom sludge layer. The solvent was recovered from the oil for re-use by fractional distillation of the homogenous mixture. It was observed that 15 w/w% potassium hydroxide solution can chemically degrade the soap matrix in the grease and extract up to 49 w/w% of the fuel oil when subjected to high shear stress at a temperature of 80°C. The 26 w/w% extraction of oil in the remaining sludge was obtained by solvent extraction process with mass ratios of sludge to solvent of 2:1. Solvent recovery of 88% by mass was obtained via fractional distillation method. The combined extraction processes brought an overall oil yield of 75 w/w% from the waste grease. The fuel oil obtained from this process has similar properties to paraffin oil and can be blended with other oils as an alternative energy source.