Policies and joint activities

The development potential of Organic Sectors in a concrete context heavily depends on the policies and frameworks provided by local or national Governments. Legal production requirements, subsidies, land tenure rights, security issues, participation options, market infrastructure, available institutions, education and training, innovation/knowledge management etc. strongly influence the likelihood that organic production, processing and trade will emerge and/or expand

Analysis of Connecting Rod for Static Stress and Deformation for Different Materials

In the ever-evolving field of automotive engineering, the connecting rod assumes a pivotal role in the seamless transformation of reciprocating piston motion into the rotary motion that propels an engine's crankshaft. Traditionally crafted from carbon steel, recent strides in materials science have unveiled the potential of aluminium alloys as a compelling alternative. These alloys, lauded for their lightweight attributes and remarkable impact resistance, particularly excel in the demanding realm of high-speed motorcycle engines.Our investigation meticulously assesses crucial parameters including von Mises stress, Equivalent Elastic Strain and total Deformation

Statefinder -- a new geometrical diagnostic of dark energy

We introduce a new cosmological diagnostic pair $\lbrace r,s\rbrace$ called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters $H(z)$ and $q(z)$, is constructed from the scale factor of the Universe and its derivatives only. The parameter $r(z)$ forms the next step in the hierarchy of geometrical cosmological parameters used to study the Universe after $H$ and $q$, while the parameter $s(z)$ is a linear combination of $q$ and $r$ chosen in such a way that it does not depend upon the dark energy density $\Omega_X(z)$. The Statefinder pair $\lbrace r,s\rbrace$ is algebraically related to the the dark energy pressure-to-energy ratio $w=p/\epsilon$ and its time derivative, and sheds light on the nature of dark energy/quintessence. Its properties allow to usefully differentiate between different forms of dark energy with constant and variable $w$, including a cosmological constant ($w = -1$). The Statefinder pair can be determined to very good accuracy from a SNAP type experiment.Comment: 7 pages, 3 figures. Final version to be published in JETP Lett., presentation shortened, references added and updated, consideration of brane cosmological models included, conclusions unchange

Effect of Charge on the Deposition of Electrostatically Charged Inhalable Aerosol in Lung Model

Inhalable drugs are widely used for treating lung diseases such as asthma, emphysema, and cystic fibrosis. The aerosol particles in these inhalable drugs may be charged electrostatically. The deposition of these inhaled therapeutic aerosol particles in the different regions of the lung depends on the particle aerodynamic diameter, electrostatic charge distribution, particulate number density, breathing rate, aerodynamics of the lung, ambient temperature, and relative humidity (RH). The primary mechanisms for lung deposition of inhaled particles are impaction, gravitational settling, diffusion, interception, and electrostatic attraction. To simulate lung deposition, electrostatically charged aerosol particles are introduced through a throat section into a glass bead lung model. The E-SPART analyzer was used to measure aerosol deposition as a function of the particle charge and size. Experiments were carried out to determine the increase in deposition efficiency as a function of the net charge-to-mass ratio (Q/M) of aerosol particles. Using a fairly monodisperse aerosol of 5.0 um count median aerodynamic diameter, it was found that the total deposition efficiency increased from 54% to 91% when Q/M increased from 0.5 to 9.67 |muC/g. The data show that enhanced delivery of the therapeutic aerosol in the lung can be achieved by controlling the electrostatic charge on the inhaled aerosol particles

Using Gravitational Lensing to study HI clouds at high redshift

We investigate the possibility of detecting HI emission from gravitationally lensed HI clouds (akin to damped Lyman-$\alpha$ clouds) at high redshift by carrying out deep radio observations in the fields of known cluster lenses. Such observations will be possible with present radio telescopes only if the lens substantially magnifies the flux of the HI emission. While at present this holds the only possibility of detecting the HI emission from such clouds, it has the disadvantage of being restricted to clouds that lie very close to the caustics of the lens. We find that observations at a detection threshold of 50 micro Jy at 320 MHz (possible with the GMRT) have a greater than 20% probability of detecting an HI cloud in the field of a cluster, provided the clouds have HI masses in the range 5 X 10^8 M_{\odot} < M_{HI} < 2.5 X 10^{10} M_{\odot}. The probability of detecting a cloud increases if they have larger HI masses, except in the cases where the number of HI clouds in the cluster field becomes very small. The probability of a detection at 610 MHz and 233 MHz is comparable to that at 320 MHz, though a definitive statement is difficult owing to uncertainties in the HI content at the redshifts corresponding to these frequencies. Observations at a detection threshold of 2 micro Jy (possible in the future with the SKA) are expected to detect a few HI clouds in the field of every cluster provided the clouds have HI masses in the range 2 X 10^7 M_{\odot} < M_{HI} < 10^9 M_{\odot}. Even if such observations do not result in the detection of HI clouds, they will be able to put useful constraints on the HI content of the clouds.Comment: 21 pages, 7 figures, minor changes in figures, accepted for publication in Ap

Nonlinear multidimensional cosmological models with form fields: stabilization of extra dimensions and the cosmological constant problem

We consider multidimensional gravitational models with a nonlinear scalar curvature term and form fields in the action functional. In our scenario it is assumed that the higher dimensional spacetime undergoes a spontaneous compactification to a warped product manifold. Particular attention is paid to models with quadratic scalar curvature terms and a Freund-Rubin-like ansatz for solitonic form fields. It is shown that for certain parameter ranges the extra dimensions are stabilized. In particular, stabilization is possible for any sign of the internal space curvature, the bulk cosmological constant and of the effective four-dimensional cosmological constant. Moreover, the effective cosmological constant can satisfy the observable limit on the dark energy density. Finally, we discuss the restrictions on the parameters of the considered nonlinear models and how they follow from the connection between the D-dimensional and the four-dimensional fundamental mass scales.Comment: 21 pages, LaTeX2e, minor changes, improved references, fonts include

Jerk, snap, and the cosmological equation of state

Taylor expanding the cosmological equation of state around the current epoch is the simplest model one can consider that does not make any a priori restrictions on the nature of the cosmological fluid. Most popular cosmological models attempt to be ``predictive'', in the sense that once somea priori equation of state is chosen the Friedmann equations are used to determine the evolution of the FRW scale factor a(t). In contrast, a retrodictive approach might usefully take observational dataconcerning the scale factor, and use the Friedmann equations to infer an observed cosmological equation of state. In particular, the value and derivatives of the scale factor determined at the current epoch place constraints on the value and derivatives of the cosmological equation of state at the current epoch. Determining the first three Taylor coefficients of the equation of state at the current epoch requires a measurement of the deceleration, jerk, and snap -- the second, third, and fourth derivatives of the scale factor with respect to time. Higher-order Taylor coefficients in the equation of state are related to higher-order time derivatives of the scale factor. Since the jerk and snap are rather difficult to measure, being related to the third and fourth terms in the Taylor series expansion of the Hubble law, it becomes clear why direct observational constraints on the cosmological equation of state are so relatively weak; and are likely to remain weak for the foreseeable future.Comment: V1: 10 pages; uses iopart.cls setstack.sty V2: six additional references, some clarifying comments and discussion, no physics changes. V3: significant additions based on community feedback; explicit calculations now carried out to fourth order in redshift. V4: Discussion of current observational situation added. This version accepted for publication in Classical and Quantum Gravity. Now 15 page

No evidence for Dark Energy Metamorphosis ?

Recent attempts to fit Type Ia supernova data by modeling the dark energy density as a truncated Taylor series have suggested the possibility of metamorphosis, i.e., a rapidly evolving equation of state parameter, w_DE(z). However, we show that fits using that parametrization have significant problems: evolution of w_DE(z) is both favoured and in some sense forced, and the equation of state parameter blows up or diverges in large regions of the parameter space. To further elucidate these problems we have simulated sets of supernova data in a Lambda-universe to show that the suggested ``evidence'' for metamorphosis is also common for w_DE=-1.Comment: 12 pages, 5 figures, Minor revisions to match version accepted in Journal of Cosmology and Astroparticle Physic

Quintessential Inflation with Dissipative fluid

We have investigated cosmological models with a self-interacting scalar field and a dissipative matter fluid as the sources of matter. Different variables are expressed in terms of a {\it generating function}. Exact solutions are obtained for one particular choice of the {\it generating function} The potential corresponding to this generating function is a standard tree-level potential arising in the perturbative regime in quantum field theory. With suitable choice of parameters, the scale factor in our model exhibits both inflationary behaviour in the early universe as well as an accelerating phase at late times with a decelerating period in between. It also satisfies the constraints for primeval nucleosynthesis and structure formation and seems to solve the cosmic coincidence problem. The solution exhibits a attractor nature towards a asymptotic de-sitter universe.Comment: 8 pages, Revtex. The title has been changed. Some new features have been include

Quintessence Restrictions on Negative Power and Condensate Potentials

We study the cosmological evolution of scalar fields that arise from a phase transition at some energy scale \Lm_c. We focus on negative power potentials given by V=c\Lm_c^{4+n}\phi^{-n} and restrict the cosmological viable values of \Lm_c and $n$. We make a complete analysis of $V$ and impose $SN1a$ conditions on the different cosmological parameters. The cosmological observations ruled out models where the scalar field has reached its attractor solution. For models where this is not the case, the analytic approximated solutions are not good enough to determine whether a specific model is phenomenologically viable or not and the full differential equations must be numerically solved. The results are not fine tuned since a change of 45% on the initial conditions does not spoil the final results. We also determine the values of $N_c, N_f$ that give a condensation scale \Lm_c consistent with gauge coupling unification, leaving only four models that satisfy unification and SN1a constraints.Comment: 15 pages, LaTeX, 8 Figures. Minor changes in text, a discussion on initial conditions added (accepted in Phys.Rev.D