Starch Hydrolysate,an Optimal and Economical Source of Carbon for the Secretion of Citric Acid by Yarrowia lipolytica (DS-1)

Using Yarrowia lipolytica (DS-1), secretion of citric acid is studied as a function of carbon sources such as glucose, fructose, hydrol, sucrose, cane sugar molasses, kerosene (all available commercially) and tapioca starch hydrolysate, invert sucrose and invert cane sugar molasses (all prepared in laboratory). On the basis of their acceptability by DS-1 for citric and isocitric acid secretion, it is concluded that (a) sucrose and cane sugar molasses (with/without inversion) served as poor carbon sources, (b) fructose, hydrol, impure tapioca starch hydrolysate (96 DE w/w) and invert sucrose served as relatively better carbon sources and (c) purified tapioca starch hydrolysate (96 DE w/w) was the best carbon source to substitute glucose by giving comparable (75%) efficiency of conversion and economical advantage.     

Mass transfer of viscous gas flow over porous stretching/shrinking sheet in the presence of slip and mass transpiration

The effect of the mass transpiration parameter on the viscous gas flow past a porous stretching/shrinking sheet in the presence of Navier's slip is investigated, and also, the mass transfer characteristics are examined. The physical flow problem executes the Navier–Stokes and the mass equation, which forms the system of nonlinear partial differential equations. These are transformed via similarity variables into a system of ordinary differential equations. The slip flow model of the total mass transfer on the moving sheet is modeled by introducing gas slip velocity. The total mass transfer on the moving sheet is modeled by inducing slip models of first and second order. Further, the suction which induces the slip velocity as opposed to the surface movement is examined. The mass suction-induced slip forces the adjacent gases to flow in the reverse direction to sheet movement. Thus, the solution space expands with the slip-induced suction and sheet movement. In the mass injection case, the induced slip increases the effect of the fluid flow for sheet movement. Upon all previous flow models, the present investigation is significant due as it investigates the mass transfer of viscous gasses flow past a porous medium in the presence of slip and mass transpiration.     

Darcy–Brinkman bio-thermal convection in a suspension of gyrotactic microorganisms in a porous medium

Neural Computing and Applications - On the basis of Darcy–Brinkman model, linear stability analysis is used to study bio-thermal convection in a suspension of gyrotactic microorganisms in a...     

Impacts of slip and mass transpiration on Newtonian liquid flow over a porous stretching sheet

This article focuses on analytic solutions for Newtonian fluid flow with slip and mass transpiration on a porous stretching sheet using the differential transform method and Pade approximants of an exceptionally nonlinear differential equation. The impacts of different parameters including mass transpiration (suction/injection), Navier's slip, and Darcy number parameters on the velocity of the liquid and tangential stress are discussed. A comprehensive comparison of our results with the previous one in the literature is made, and the results showed good agreement. An investigation is conducted of a combination of magnetic liquids that are conceivably pertinent for wound medicines, skin repair, and astute coatings for natural gadgets. It is found that there is a decrease in the velocity profiles and the boundary layer thickness for the case of suction.     

Identification of Semiochemicals Released by Cotton, Gossypium hirsutum, Upon Infestation by the Cotton Aphid, Aphis gossypii

The cotton aphid, Aphis gossypii (Homoptera: Aphididae), is increasing in importance as a pest worldwide since the introduction of Bt-cotton, which controls lepidopteran but not homopteran pests. The chemical ecology of interactions between cotton, Gossypium hirsutum (Malvaceae), A. gossypii, and the predatory lacewing Chrysoperla lucasina (Neuroptera: Chrysopidae), was investigated with a view to providing new pest management strategies. Behavioral tests using a four-arm (Pettersson) olfactometer showed that alate A. gossypii spent significantly more time in the presence of odor from uninfested cotton seedlings compared to clean air, but significantly less time in the presence of odor from A. gossypii infested plants. A. gossypii also spent significantly more time in the presence of headspace samples of volatile organic compounds (VOCs) obtained from uninfested cotton seedlings, but significantly less time with those from A. gossypii infested plants. VOCs from uninfested and A. gossypii infested cotton seedlings were analyzed by gas chromatography (GC) and coupled GC-mass spectrometry (GC-MS), leading to the identification of (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), methyl salicylate, and (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMTT), which were produced in larger amounts from A. gossypii infested plants compared to uninfested plants. In behavioral tests, A. gossypii spent significantly more time in the control (solvent) arms when presented with a synthetic blend of these four compounds, with and without the presence of VOCs from uninfested cotton. Coupled GC-electroantennogram (EAG) recordings with the lacewing C. lucasina showed significant antennal responses to VOCs from A. gossypii infested cotton, suggesting they have a role in indirect defense and indicating a likely behavioral role for these compounds for the predator as well as the aphid.     

Security and Privacy in IoT: A Survey

The Internet of Things (IoT) is a network of globally connected physical objects, which are associated with each other via Internet. The IoT foresees the interconnection of few trillions of intelligent objects around us, uniquely and addressable every day, these objects have the ability to accumulate process and communicate data about themselves and their surrounding environment. The best examples of IoT systems are health care, building smart city with advance construction management system, public and defense surveillance and data acquisition. Recent advancement in the technology has developed smart and intelligent sensor nodes and RFIDs lead to a large number of wireless networks with smart and intelligent devices (object, or things) connected to the Internet continuously transmit the data. So to provide security and privacy to this data in IoT is a very challenging task, which is to be concerned at highest priority for several current and future applications of IoT. Devices such as smart phone, WSNs and RFIDs etc., are the major components of IoT network which are basically resource constrained devices. Design and development of security and privacy management schemes for these devices is guided by factors like good performance, low power consumption, robustness to attacks, tampering of the data and end to end security. Security schemes in IoT provide unauthorized access to information or other objects by protecting against alterations or destruction. Privacy schemes maintain the right to control about the collected information for its usage and purpose. In this paper, we have surveyed major challenges such as Confidentiality, Integrity, Authentication, and Availability for IoT in a brief manner.

     

A novel numerical scheme for the analysis of effects of surface roughness on EHL line contact with couple stress fluid as lubricant

In this article, a Jacobian-free Newton Multigrid (JFNMG) method is used for obtaining the solution of isothermal, steady and compressible elastohydrodynamic lubrication (EHL) line contact problem with surface roughness. The lubricant is a couple stress fluid. A finite difference scheme is used for the solution of EHL equations. The proposed JFNMG method, for the solution of resulting nonlinear system of algebraic equations, comprises nonlinear Newton iterations on the outer loop and linear multigrid iterations on the inner loop. It overcomes the limitations of conventional schemes for the investigation of the problems covering wide range of physical parameters of interest. For increasing values of couple stress parameter, there is an increase in minimum film thickness and considerable decrease (in height as well as spread) of pressure spike. Also, the sensitivity of height and spread of pressure spike as a function of load, couple stress parameter and other parameters are investigated.     

An impact of heat and mass transpiration on magnetohydrodynamic viscoelastic fluid past a permeable stretching/shrinking sheet

The present paper investigates analytically a continuous stream of viscoelastic fluid and magnetohydrodynamic flow of second-grade fluids owing to protracted sheets in a permeable medium with the help of the Cattaneo–Christov pattern. This idea is a new generalization of the classical Fourier law. Also, in this analysis, heat as well as mass transfer in second-grade fluid past wall suction/injection is assumed. A few similarity transformations are used to simplify the addressing of boundary layer expressions. An analytical solution is obtained by applying the Appell hypergeometric properties. Furthermore, our work also describes an effect of the relaxation time variable, elasticity number, and Prandtl number together with temperature fields. Also, we studied the newly introduced parameter, that is, the thermal radiation parameter by Cattaneo, over a Fourier heat flux pattern. In addition, some physical presentation of the measurements is illustrated in the graphs.     

Flow due to a porous stretching/shrinking sheet with thermal radiation and mass transpiration

This study investigates the behavior of carbon nanotubes (CNT) approaching an unsteady flow of a Newtonian fluid over a stagnation point on a stretching surface employing porous media. It flows when the liquid begins to move with the progression of time. Heat exchange with the environment has an impact on the flow. The implicitly limited component technique is used to solve the nondimensional partial differential equation with an associated boundary layer, which is an unstable system. Analytically, the solutions, as well as the required boundary conditions, are obtained. The effects of mass transpiration, volume fraction, and heat radiation on Newtonian fluid flow through porous media are explored. Single- and multi-walled CNTs are used as well as water, as base fluids in the experiment. The impact of thermal radiation and heat source/sink is shown in the energy equation, which is solved under four different cases: uniform heat flux case, constant wall temperature case, general power-law wall heat flux case, and general power-law wall temperature case. By supplying distinct physical characteristics, a theoretical analysis of the existence and nonexistence of unique and dual solutions may be explored. These physical parameters determine the velocity distribution and temperature distribution. Prescribed surface temperature (PST) and prescribed wall heat flux (PHF) heat transfer solutions can be written using confluent hypergeometric equations, and generic power-law PST and PHF situations can also be expressed using confluent hypergeometric equations. The graphical representations assist in the discussion of the current study's findings.