Study on System Design and Integration of Variable Buoyancy Systems for Underwater Operation

This paper presents the design and analysis of the ‘Variable Buoyancy System (VBS)’ for depth control which is an essential operation for all underwater vehicles. We use the ‘Water Hydraulic Variable Buoyancy System (WHVBS)’ method to control the buoyancy and discuss details of the system design architecture of various components of VBS. The buoyancy capacity of the developed VBS is five kilograms and the performance of the VBS in standalone mode is analysed using numerical simulation. Presented VBS is operable to control the buoyancy up to sixty meters of depth and it can be directly installed to medium size UVs. Simulation results show that the developed VBS can reduce the energy consumption significantly and higher in each cycle (i.e. descending and ascending) of the same VBS in standalone mode being operated with either propeller or thruster for sixty meters depth of operation. Our results conclude and demonstrate that the designed VBS is effective in changing the buoyancy and controlling the heave velocity efficiently and this serves the purpose of higher endurance and better performances desired in rescue/attack operations related to the UVs both in civilian and defense domains

Load Balancing of Tasks on Cloud Computing Using Time Complexity of Proposed Algorithm

Cloud Computing is a developing field and lean toward by numerous one at current yet it's rage is part more rely upon its execution which thusly is excessively rely upon the powerful booking algorithm and load adjusting . In this paper we address this issue and propose an algorithm for private cloud which has high throughput and for open cloud which address the issue of condition awareness likewise with execution. To enhance the throughput in private cloud SJF is utilized for planning and to conquer shape the issue of starvation we utilize limited pausing. For stack adjusting we screen the heap and dispatch the activity to the minimum stacked VM. To acquire advantage and to have open door for future upgrade out in the open cloud condition cognizance is the key factor and for better execution and load adjusting likewise wanted. While stack adjusting enhances the execution, the earth awareness increment the benefit of cloud suppliers

Choice of Interceptor Aerodynamic Lifting Surface Location based on Autopilot Design Considerations

Interceptors operate at wide range of operating conditions in terms of Mach number, altitude and angle of attack. The aerodynamic design caters for such wide operating envelope by appropriate sizing of lifting and control surfaces for meeting the normal acceleration capability requirements. The wide range of operating conditions leads to an inevitable spread in center of pressure location and hence spread in static stability. The performance of control design is a strong function of the aerodynamic static stability. The total operating envelope can be bifurcated into statically stable and unstable zones and the aerodynamic lifting surface location can be used as a control parameter to identify the neutral stability point. During the homing phase lesser static stability is desirable for good speed of response, hence the lifting surface location needs to be chosen based on the capability of control to handle instability. This paper analyses the limitations of autopilot design for the control of an unstable interceptor and brings out a method to identify the optimum aerodynamic lifting surface location for efficiently managing static margin while satisfying the control limitations and homing phase performance. This provides an input on the most appropriate lifting surface location to the aerodynamic designer during the initial CFD based aerodynamic characterisation stage itself, before commencing the rigorous wind tunnel based characterisation

Coupling between feedback loops in autoregulatory networks affects bistability range, open-loop gain and switching times

Biochemical regulatory networks governing diverse cellular processes such as stress-response, differentiation and cell cycle often contain coupled feedback loops. We aim at understanding how features of feedback architecture, such as the number of loops, the sign of the loops and the type of their coupling, affect network dynamical performance. Specifically, we investigate how bistability range, maximum open-loop gain and switching times of a network with transcriptional positive feedback are affected by additive or multiplicative coupling with another positive- or negative-feedback loop. We show that a network's bistability range is positively correlated with its maximum open-loop gain and that both quantities depend on the sign of the feedback loops and the type of feedback coupling. Moreover, we find that the addition of positive feedback could decrease the bistability range if we control the basal level in the signal-response curves of the two systems. Furthermore, the addition of negative feedback has the capacity to increase the bistability range if its dissociation constant is much lower than that of the positive feedback. We also find that the addition of a positive feedback to a bistable network increases the robustness of its bistability range, whereas the addition of a negative feedback decreases it. Finally, we show that the switching time for a transition from a high to a low steady state increases with the effective fold change in gene regulation. In summary, we show that the effect of coupled feedback loops on the bistability range and switching times depends on the underlying mechanistic details

Electrochemical and mechanical behavior of laser processed Ti–6Al–4V surface in Ringer’s physiological solution

Laser surface modification of Ti–6Al–4V with an existing calcium phosphate coating has been conducted to enhance the surface properties. The electrochemical and mechanical behaviors of calcium phosphate deposited on a Ti–6Al–4V surface and remelted using a Nd:YAG laser at varying laser power densities (25–50 W/mm 2 ) have been studied and the results are presented. The electrochemical properties of the modified surfaces in Ringer’s physiolog- ical solution were evaluated by employing both potentio- dynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The potentiodynamic polar- izations showed an increase in the passive current density of Ti–6Al–4V after laser modification at power densities up to 35 W/mm 2 , after which it exhibited a decrease. A reduction in the passive current density (by more than an order) was observed with an increase in the laser power density from 25 to 50 W/mm 2 . EIS studies at the open circuit potential (OCP) and in the passive region at 1.19 V showed that the polarization resistance increased from 8.274 9 10 3 to 4.38 9 10 5 X cm 2 with increasing laser power densities. However, the magnitudes remain lower than that of the untreated Ti–6Al–4V at OCP. The average hardness and modulus of the laser treated Ti–6Al–4V, evaluated by the nanoindentation method, were deter- mined to be 5.4–6.5 GPa (with scatter \±0.976 GPa) and 124–155 GPa (with scatter \±13 GPa) respectively. The corresponding hardness and modulus of untreated Ti–6Al–4V were *4.1 (±0.62) and *148 (±7) GPa respec- tively. Laser processing at power densities [35 W/mm 2 enhanced the surface properties (as passive current density is reduced) so that the materials may be suitable for the bio-medical applications

A Cross Sectional Survey Study to find out the role of Avarana as a diagnostic tool in General Practice with special reference to Madhumeha

Srotas and Avarana are essential factors of Samprapti of almost all the Nija roga. Avarana is an underestimated and neglected aspect of Roga Samprapti. Therefore a survey study was conducted to gather data about understanding of Avarana w.s.r. to Madhumeha (Diabetes Mellitus). A dully prepared questionnaire pro forma on Avarana have been proposed and send it to 83 Ayurvedic doctors from NIA & across India to collect data. Questionnaire included choices of different samprapti ghataka like Agni, Dosha, Dushya, Srotasa, Ama, Avarana, Nidana and response against question “Is Avarana an important samprapti ghataka in day to day practice?On a small study of NIA it was found that 39.76% consultants included Avarana, 66.27% included dosha vighatana, 56.63% included dushya, 54.22% included Agni 53.01% included Ama, 48.19% included srotasa and 36.15% included nidana as a samprapti ghataka for diagnosing the disease in day to day practice. Response against question Is Avarana an important samprapti ghataka in day to day practice 62 (74.70%) consultants answered Yes, but Avarana the records show that only 28 (33.74%) were using Avarana as an important samprapti ghataka, 11 (13.25%) were seeing daily >10 patients in their OPD/IPD and 18 (21.69%) were unable to explain why Avarana should be an important samprapti ghataka. Out of rest 21 (25.30%) answered No, 14 (16.87%) were unable to explain their response & 7 (8.43%) cited difficulty in understanding Avarana in diagnosis in day to day practice.On an average it was found that 33.41% patients were consulted in OPD and 2.43% in IPD. Most of the consultants use only 7 samprapti ghataka for diagnosis of diseases. 62 (74.70%) consultants answered ‘Yes’ in response to question (Is Avarana an important samprapti ghataka in day to day practice?), but no satisfactory explanation was given

Estrogen treatment decreases matrix metalloproteinase (MMP)-9 in autoimmune demyelinating disease through estrogen receptor alpha (ERalpha).

Matrix metalloproteinases (MMPs) have a crucial function in migration of inflammatory cells into the central nervous system (CNS). Levels of MMP-9 are elevated in multiple sclerosis (MS) and predict the occurrence of new active lesions on magnetic resonance imaging (MRI). This translational study aims to determine whether in vivo treatment with the pregnancy hormone estriol affects MMP-9 levels from immune cells in patients with MS and mice with experimental autoimmune encephalomyelitis (EAE). Peripheral blood mononuclear cells (PBMCs) collected from three female MS patients treated with estriol and splenocytes from EAE mice treated with estriol, estrogen receptor (ER) alpha ligand, ERbeta ligand or vehicle were stimulated ex vivo and analyzed for levels of MMP-9. Markers of CNS infiltration were assessed using MRI in patients and immunohistochemistry in mice. Supernatants from PBMCs obtained during estriol treatment in female MS patients showed significantly decreased MMP-9 compared with pretreatment. Decreases in MMP-9 coincided with a decrease in enhancing lesion volume on MRI. Estriol treatment of mice with EAE reduced MMP-9 in supernatants from autoantigen-stimulated splenocytes, coinciding with decreased CNS infiltration by T cells and monocytes. Experiments with selective ER ligands showed that this effect was mediated through ERalpha. In conclusion, estriol acting through ERalpha to reduce MMP-9 from immune cells is one mechanism potentially underlying the estriol-mediated reduction in enhancing lesions in MS and inflammatory lesions in EAE

Antifungal activity of Leptadenia reticulata Wight and Arn. aerial parts

The petroleum ether, chloroform, acetone, methanol and aqueous extracts of the aerial parts of Leptadenia reticulata Wight and Arn. (Asclepiadaceae) were studied for in vitro antifungal activity against Aspergillus flavus, Aspergillus ruantti, Candida tropicalis, Candida albicans, Trichodermata viride and Trichodermata koningii respectively. The methanolic extract exhibited prominent antifungal activity against all the selected strains. Minimum inhibitory concentration of the extracts was performed by broth dilution method and the zone of inhibition was studied by agar disc diffusion method at concentrations of 2, 5 and 10mg/ml in DMSO. Cotrimazole (25μg/ml) was used as reference control for antifungal studies. Results of MIC study revealed the antifungal activities of the extracts against the tested strains in between concentration ranges 50-400μg/ml. The present study indicates the potential usefulness of L. reticulata aerial parts as antifungal agent.Keywords: Leptadenia reticulata Wight and Arn., Antifungal activity, Minimum inhibitory concentration, Zone of inhibition, Clotrimazol