Abstract:
Minimizing the formation of inorganic scale deposits in industrial water continues to be a challenge for water treatment systems. In order to meet this challenge a novel biodegradable poly(DL-malic acid-co-citric acid) copolymer, effective in providing calcium carbonate scale inhibition was developed. Synthesis and characterization of the biodegradable, water-soluble and polyester copolymer was performed. Synthesis was done by direct bulk melt condensation in the absence of a catalyst above 150°C. Characterization of the copolymer was carried out using infrared absorption spectra (FTIR), differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) equipment. In the present work the precipitation of calcium carbonate from relative supersaturated solutions at different weight ratios of comonomer inhibition rates have been studied. The results indicate that the copolymer is an effective calcium carbonate descaling inhibitor that suppresses the growth process against calcium mineral scale deposits.

Abstract:
Recently automated and / or robotic welding systems have received a great deal of attention
because they are highly suitable not only to enhance production rate and quality, but also to
decrease cost and time to manufacture for a given product. To get the desired quality welds it is
essential to have complete control over the relevant process parameters in order to obtain the
required bead geometry. Mathematical models need to be developed to have such control and to
make effective use of automated and / or robotic arc welding process.

Abstract:
The unique anywhere,
anytime wireless communication support offers, tremendous potential for the
next generation of applications in a Mobile Ad-hoc Network (MANET). The Quality
of Service (QoS) has been the ever demanding task of wireless communication to satisfy
the application requirements. Geographical routing employs a greedy forwarding
technique to deliver the packets to the destination and to owe the
communication void, it fails to render the expected level of QoS. Opportunistic
routing technique effectively utilizes the advantages of broadcasting nature of
the？wireless medium and selects a
set of forwarding candidates instead of relying on a greedy node.？To improve the efficiency of QoS
routing in sparse and highly dynamic network topology, this paper proposes the
Void-Aware Position based Opportunistic Routing (VAPOR). The VAPOR maintains
2-hop neighbor information to take a routing decision, but it is limited to
1-hop information？when the node
density is high. It efficiently balances the storage overhead and communication？delay due to void and it increases the
network throughput even under a sparse network. To provide a certain assurance
level for packet reachability, VAPOR decides the potential forwarders？based on the forwarding probability
that measures link stability, capacity, and connectivity factor. It adaptively
favors a path that avoids frequent link failure and unreliable link usage. By
limiting？the propagation area of
duplicate packets, VAPOR reduces wastage of network resources, and ittakes the
advantage of concurrent batch forwarding to avoid further duplication and
unnecessary delay.

Two very important
factors which determine the effectiveness of a pump are its volumetric and
power efficiencies. Yin and Ghoneim constructed a prototype of a Flexible-Matrix-Composite
(FMC) body pump with a very high volumetric efficiency or pumping potential
(the relative volume reduction due to a relative input stroke). The high
volumetric efficiency is attributed to the geometry of the pump’s structure
(hyperboloid) as well as the high negative effective Poisson’s ratio of the
3-layer [θ/β/θ]
flexible-matrix-composite (carbon/polyurethane) laminate adopted for the body
of the pump. However, the power efficiency of the pump was not evaluated. It is
the objective of the current paper to obtain an estimate of the power
efficiency of the pump. The viscoelastic properties of the 3-layer FMC
(carbon/polyurethane) laminate are evaluated experimentally using the Dynamic
Mechanical Analyzer (DMA) as well as analytically by applying the correspondence
principle together with the micro-mechanics approach. In order to obtain an
estimate of the power efficiency of the FMC body pump, the axial and shear loss
factors of a laminated infinitely long cylindrical tube as functions of β and θ fiber orientation angles are determined employing the Adam and
Bacon approach. The analysis engenders high loss factors (greater than 0.4),
which suggests that the power efficiency of the proposed pump using the 3-layer
carbon/polyurethane laminate may be low.

Abstract:
Present study is an attempt
to analyse the presence of herding in different economic conditions. A mix of
developed and developing countries is selected from different corners of the
word. Our sample comprises 35 world markets, out of which 18 are emerging
markets while 17 are developed markets. Daily data of all constituents stocks
of the representative indices of these markets are extracted over most recent
period ranging from Jan. 2000 to Apr. 2018. Applying different methodologies
static and time varying, we find that only 11 markets out of 35 exhibit
significant herding behaviour. These markets majorly belong to Asia, Africa and
Middle East. We also try to relate herding with region, culture and state of
economy and do not find any significant relation of these variables with
herding.

Abstract:
Analytical and numerical solutions are obtained for dispersion of pollutants along unsteady groundwater flow in a longitudinal direction through semi-infinite aquifers the permeability of which is either uniform or varies with position. Sources of pollution are both a concentrated point input at the origin and a spatially distributed background source. One expression chosen to represent the seasonal pattern of the time dependent velocity is sinusoidal behaviour over a year. The solutions obtained predict the time and distance from the location at which an input concentration is introduced at which the pollution concentration becomes harmless. Also, the time period for rehabilitating a polluted aquifer for human use can also be assessed.

Abstract:
As the mass-energy is universally self-gravitating, the gravitational binding energy must be subtracted self-consistently from its bare mass value so as to give the physical gravitational mass. Such a self-consistent gravitational self-energy correction can be made non-perturbatively by the use of a gravitational `charging' technique, where we calculate the incremental change $dm$ of the physical mass of the cosmological object, of size $r_o$ due to the accretion of a bare mass $dM$, corresponding to the gravitational coupling-in of the successive zero-point vacuum modes, i.e., of the Casimir energy, whose bare value $\Sigma_{\bf k} \hbar ck$ is infinite. Integrating the `charging' equation, $dm = dM - (3\alpha/5)Gm\Delta M/r_o c^2$, we get a gravitational mass for the cosmological object that remains finite even in the limit of the infinite zero-point vacuum energy, i.e., without any ultraviolet cut-off imposed. Here $\alpha$ is a geometrical factor of order unity. Also, setting $r_o = c/H$, the Hubble length, we get the corresponding cosmological density parameter $\Omega \simeq 1$, without any adjustable parameter. The cosmological significance of this finite and unique contribution of the otherwise infinite zero-point vacuum energy to the density parameter can hardly be overstated.

Abstract:
The high speed of light in vacuo together with the weakness of Earth gravity rules out any experimental detection of gravitational deflection of light on the laboratory length scale. Recent advances in coherent optics that produce ultra slow light in highly dispersive media with the group velocities down to ~102 ms-1, or even less, however, open up this possibility. In this work, we present a theoretical study for a possible laboratory observation of the deflection of such an ultra slow light in the highly dispersive medium under Earth gravity. Our general relativistic calculation is based on the Gordon optical metric modified so as to include dispersion. The calculated linear vertical deflection turns out to be ~0.1 mm for a horizontal traversal of 0.1 m, and a group speed vg ~ 102 ms-1. Experimental realizability and some conceptual points involved will be briefly discussed.

Abstract:
Recent experiments on ultra slow light in strongly dispersive media by several research groups reporting slowing down of the optical pulses down to speeds of a few metres per second encourage us to examine the intriguing possibility of detecting a deflection or fall of the ultra slow light under Earth's gravity, i.e., on the laboratory length scale. In the absence of a usable general relativistic theory of light waves propagating in such a strongly dispersive optical medium in the presence of a gravitational field, we present a geometrical optics based derivation that combines {\it the effective gravitational refractive index} additively with the usual optical dispersion. It gives a deflection, or the vertical fall $\Delta$ for a horizontal traversal $L$ as \[ \Delta = \frac{L^2}{2}\big(\frac{R_{\oplus G}}{R_\oplus^2}\big) n_g \big(\frac{1}{1+n_g\frac{R_{\oplus G}}{R_\oplus}}\big), \] where $R_{\oplus G}/R_\oplus$ is the ratio of the gravitational Earth radius($R_{\oplus G}$) to its geometrical radius $R_\oplus$, and $n_g$ is the group refractive index of the strongly dispersive optical medium. The expression is essentailly that for the Newtonian fall of an object projected horizontally with the group speed $v_g=c/n_g$, and is tunable refractively through the index $n_g$. For $L \sim 1 m$ and $n_g = c/v_g \sim 10^8$ (corresponding to the ultra-slow pulse speed $\sim few \times 1 ms^{-1}$), we obtain a fall $\Delta \sim 1 \mu m$, that should be measurable $-$ in particular through its sensitive dependence on the frequency that tunes $n_g$.

Abstract:
We construct a model of non-uniform condensate having a spatially modulated complex order parameter that makes it kinematically an x-ray solid, i.e., a real mass density wave, but one admitting an associated superfluid flow. Intrinsic to this state is a non-classical translational inertia which we derive for the case of a potential flow. Connection to the non-classical rotational inertia observed in recent experiments on solid helium-4 is discussed. Our semi-phenomenological treatment suggests a flow-induced supersolid-to-superdfluid transition.