Temperature dependent damping studies of Ni-Mn-Ga polymer composites

Mechanical properties of ferromagnetic shape memory alloy (FSMA) polyurethane (PU) polymer composites are studied using dynamic mechanical analysis (DMA) at different temperatures. The sample used in the study is Ni-Mn-Ga/PU polymer composite. DMA studies reveal that the mechanical modulus decreases, when the temperature increases. The peak in internal friction (tanδ) appears twice due to martensite transformation of the reinforced particles and glass transition of the polymer matrix. The strain is due to the motion of twin boundaries rather than the phase transformations. Twin boundary motion is found to be the root cause for the martensite-austenite transformation and vice versa, and leads to enhanced damping mechanism. Speculations on twin boundaries of this sample to show concrete evidence on change in internal friction (tanδ) are still underway. This paper proposes that Ni-Mn-Ga/PU polymer composites can be used as efficient dampers.     

Contrasting bio-optical characteristics of coastal water prior to and in the aftermath of a tropical super cyclone

Apparent and inherent optical properties were measured in the coastal region off Visakhapatnam (Bay of Bengal) during pre-monsoon season (January–May) of successive years, in-between of which the (October 2014) Hudhud super cyclone had landfall across. For 5 months after the cyclone in the region up to 50 m isobath, or 15 km from the coast and 6 months after the cyclone in the region up to 30 m isobath, or 5 km away, the particle back-scattering coefficient (b_bp) and remote-sensing reflectance (R_rs) were anomalously higher throughout the spectral region (400–700 nm) than during other times. The b_bp spectral slope coefficient γ is abnormally higher than predicted from the b_bp(680)–γ model relationship, and R_rs(685) is also abnormally higher than the significant R_rs(685)–chlorophyll-a (chl-a) relationship would predict. These exceptional properties are attributed to the presence of little absorbing and highly reflecting sub-micrometre-sized particles in fine suspension that leached from the coastal deposits emplaced in the study region from the nearby harbour during the cyclone. The optical properties recovered subsequently. In the period when the reflectance and scattering spectra are not recovered, the R_rs(685) is no longer a proxy of chl-a. Remote-sensing algorithms for phytoplankton abundance of the coastal region during this period need correction.     

Big Data in Intelligent Information Systems

Mobile Networks and Applications -     

Anonymous and expeditious mobile user authentication scheme for GLOMONET environments

The Global Mobility Network (GLOMONET) is rapidly becoming important as well as a popular feature in today's high‐performance network. The legal mobile users enjoy life using the ubiquitous services via GLOMONET. However, because of the broadcast nature of the wireless channel, providing user authentication along with the privacy and anonymity of the users in GLOMONET is indeed a challenging task. In this article, we come up with a secure and expeditious mobile communication environment using symmetric key cryptosystem to ensure mobile users' anonymity and privacy against eavesdroppers and backward/forward secrecy of the session key. Our scheme can also protect numerous security threats, like man‐in‐the‐middle attack, known session key attack, lost smartcard attack, and forgery attack. Furthermore, we put forward a new technique named as “friendly foreign agent policy,” where many foreign agents can make different groups among themselves and perform important responsibilities to authenticate a legitimate mobile user without interfering his or her home agent even though the mobile user moves to a new location, covered by a new foreign agent (belongs to the same group). Security and performance analyses show that the proposed scheme is secure and more efficient as compared with other competitive schemes for GLOMONET environments.     

Multiobjective fuzzy dominance based bacterial foraging algorithm to solve economic emission dispatch problem

This paper proposes the bacterial foraging meta-heuristic algorithm for multiobjective optimization. In this multiobjective bacterial foraging optimization technique, the most recent bacterial locations are obtained by chemotaxis process. Next, Fuzzy dominance based sorting procedure is used here to select the Pareto optimal front (POF). To test the suitability of our proposed algorithm we have considered a highly constrained optimization problem namely economic/emission dispatch. Now-a-days environmental concern that arises due to the operation of fossil fuel fired electric generators and global warming, transforms the classical economic load dispatch problem into multiobjective environmental/economic dispatch (EED) problem. In the proposed work, we have considered the standard IEEE 30-bus six-generator test system and the results obtained by proposed algorithm are compared with the other recently reported results. Simulation results demonstrate that the proposed algorithm is a capable candidate in solving the multiobjective economic emission load dispatch problem.     

Numerical Simulation and Validation of Mass Transfer Process of Ozone Gas in Rice Grain Bulks

Ozone is a potential alternative to commercial fumigants. The development of ozone fumigation technology for insects control requires a precise prediction of the distribution of introduced ozone gas in grain bulks. Hence, this study was conducted to investigate the mass transfer process of ozone gas in rice grain bulks. Experiments were conducted in a 0.6-m diameter flat-bottom bin filled with rice grains and ozonated using 5 g h^?1 capacity ozone generator. Simulation of transfer process of ozone through the rice grain bulks was conducted using the principle of the law of conservation employing the continuity equation. The experimental data for ozone transfer through connected the column of rice was used to validate the model. The relative error between the actual and predicted ozone concentration for the entire bin geometry was less than 33%. The predictions from the projected model were in accordance with the ozone concentrations obtained from the experimental results.     

Disinfestation techniques for major cereals: A status report

Management of stored product insects is a major concern and widely researched topic in the food and grain processing and storage industry. In the scenario of estimated utilization of produces exceeding the production, postharvest losses should be properly controlled to feed the growing population. The prevailing disinfestation techniques are forced to meet regulatory standards and market demands. The resistance developed by insects, environmental concerns, and occupational hazards lead to the vanishing of many chemicals used in insect and pest management programs. Some of the major disinfestation techniques such as the use of chemical fumigants, ozone, irradiation, dielectric heating, extreme temperature treatments, and bio rational approaches are discussed, particularly on the storage of cereal grains and its products, as they contribute to a significant proportion of food consumed worldwide. Newer techniques such as nonthermal plasma and metabolic stress disinfestation and decontamination for stored pest control are developed and evaluated in different parts of the world. The knowledge about the mode of action of these disinfestation techniques is important to avoid the cross‐resistance and multiple resistance developed by insects with frequently used techniques. Various alternatives to conventional fumigants are discussed in this review as there is a growing demand for toxic‐free, environment‐friendly, and, at the same time, efficient techniques.     

城市近山地带界壳特征解析与空间重构研究：多维价值导向下的城山边界思考

当下国土空间规划以“划线”的方式切分空间要素。然而在真实空间中,城市所接壤的边界地带并非一根清晰可见的线条,而是一条混合过渡带,在具备建设功能的同时也融合了周边自然环境的生态属性。城市与生态的一刀切是一种“算账式”的思维模式,界内是城市,界外是自然,容易导致过度城市化、城市边缘化等极端现象。且这一问题在近山地带尤为常见,面临着岩土植被开垦、建筑遮挡山体景观等诸多挑战。基于此,在揭示近山地带的空间本底逻辑与特征规律的基础上,尝试以界壳理论为切入点,从自然生态系统、宏观视觉景观、中观布局形态、微观公服职能4个价值维度对这条特殊的城山过渡带进行特征解析并建构评价模型。进而以威海为案例,基于多维评价结果找出导致景观遮挡、绿植带断裂、功能活力阻塞等问题症结,并提出优化设计策略和建设模式,为城山边界处的宏观设计和空间设计提供引导。     

Preparation and Impedance Analysis of Biodegradable Polymer Polyvinyl Alcohol with Amino Acid,Arginine

Biodegradable polymers have an innumerable use in the field of biomedicine, especially in drug delivery system. Polyvinyl alcohol is one of the biodegradable polymer used as a carrier for drug delivery. Amino acids are necessary for maintaining good health for human beings. The present study focuses on the interaction between polyvinyl alcohol and amino acids. An effort is being taken to prepare polymer membrane based on polyvinyl alcohol complexed with different concentration of arginine, a type of amino acids using water as solvent by solution-casting technique. The amphorousity and complex formation between polyvinyl alcohol and Arignine have been confirmed by X-ray diffraction and FTIR spectroscopy, respecticvely. The thermal behavior of PVA–arginine complexes has been analyzed by differential scanning calorimetry. From AC impedance spectroscopy, ion transport mechanism has been investigated in detail. By using Almond and West formulisms, the parameter such as ion hopping frequency ω_p, has been calculated. The polymer membrane 75 Mwt% PVA:25 Mwt% arginine has the highest ionic conductivity as 1.97 × 10^?6 S cm^?1 at ambient temperature.