Model for autonomous agents in machine‐to‐machine navigation networks

Machine‐to‐machine (M2M) is an evolving architecture and tends to provide enormous services through the swarm presence of the networked devices. Localization is one of those services. Previous localization techniques require complex computation that is not suitable and affordable in such architecture. Moreover, integrating intelligent multiagents on these ubiquitous devices makes the network more independent and reactive requiring for a less complex localization model. This paper reviews the present localization techniques and discusses their infeasibility for M2M communication while proposing a mathematical model that is derived from Anderson model for the distributed structure of machine‐type‐communication network involving autonomous agents. This paper has made an attempt to use the property of Anderson model that structures the distributed objects. This paper also classifies autonomous agents according to their functionalities in a navigational network. Recently, Anderson model have been customized for implication of optical communication; in this paper, the proposed mathematical model involves intelligent agents for localization that aim to reduce complexity of positioning computations for nodes having restricted computational resources and battery life, which are the main characteristics of M2M communication.     

Recent developments and progress of aerogel assisted environmental remediation: a review

Journal of Porous Materials - Aerogel is a special type of porous material with many outstanding physical and chemical properties, such as low density, high porosity, high surface area, and...     

Application of BCP-2007 and UBC-97 in seismic vulnerability assessment of gravity designed RC buildings in Pakistan

Recent earthquakes in Pakistan (Kashmir 2005, Balochistan 2008, and Balochistan 2013) revealed the vulnerability of existing building stock and the deficiencies in the then prevalent Pakistan Seismic Code (PSC-86 (1986)). This study investigates, through an analytical framework, the seismic vulnerability of these and other such buildings, in accordance with the newly developed Building Code of Pakistan – Seismic Provisions 2007 (BCP-SP 07). Detailed failure mode is presented for buildings designed as per the new code. Collapse of structures is predicted for only 8% increase in PGA after moderate damage. A previously developed method, based on Eurocode-8 (2004), is used as baseline. A deficient reinforced concrete frame, typical to local building practices, is analyzed and assessed for vulnerability using the BCP-SP 07 (2007) framework. A comparison is drawn for the same building, based on Eurocode-8 (2004). Derived vulnerability curves show that the previous framework overestimated the damage and hence the vulnerability. Comparison of vulnerability parameters with previous studies show slight difference in performance of buildings.     

A Study on Physical Properties of Melt Blended Acrylonitrile Butadiene Styrene/Ethylene Vinyl Acetate Modified with Linear Low Density Polyethylene and Montmorillonite

In this study, acrylonitrile butadiene styrene/ethylene vinyl acetate-based melt blends were prepared using linear low-density polyethylene as modifier. Commercially available sodium montmorillonite clay was organically modified and incorporated in blends. Fourier transformed infrared was used to confirm the structure of the blend and composites. Morphology of acrylonitrile butadiene styrene / ethylene vinyl acetate blend showed two-phase structure that formed a well-aligned pattern with fine nanoclay distribution. Addition of organo-modified clay depicted increase in tensile strength (43%) and modulus (89%) in damage-free range. XRD results of sodium montmorillonite, organically modified Na-montmorillonite, and PNCs were compared to investigate the degree of dispersion in matrix.     

First principles density functional calculations of half-metallic ferromagnetism in Zn1-xCrxS and Cd1-xCrxS

We employ the full-potential linearized augmented plane wave plus local orbital (FP-L/APW + lo) method based on spin-polarized density functional theory (DFT) in order to investigate the structural, electronic and magnetic properties of ordered dilute ferromagnetic semiconductors Zn_1?xCr_xS and Cd_1?xCr_xS (x = 0.25) in the zinc blende (B3) phase. For the exchange-correlation functional, the generalized gradient approximation GGA (Wu-Cohen 06) has been used. Results of calculated electronic band structures and density of states of these dilute magnetic semiconductors (DMSs) are discussed in terms of the contribution of Cr 3d⁵ 4s¹, Zn 3d¹⁰ 4s², Cd 4d¹⁰ 5s² and S 3s² 3p⁴ partial density of states. For Cr-based systems without n or p-type doping, the stability of the ferromagnetic spin state versus the antiferromagnetic state is predicted. Band structure and density of states studies show half-metallic ferromagnetic nature for both alloys, Zn_1?xCr_xS and Cd_1?xCr_xS. Calculations of the s–d exchange constant N₀α and p–d exchange constant N₀β clearly indicate the magnetic nature of these compounds. From the calculated total magnetic moments we observe that p–d hybridization reduces the local magnetic moment of Cr from its free space charge value and produces small local magnetic moments on the nonmagnetic Zn, Cd and S sites. The robustness of half-metallicity of Zn_1?xCr_xS and Cd_1?xCr_xS as a function of lattice constant is also discussed.     

Determination and dispersion of pollutants from different fuel types used in brick kilns by using Gaussian’s plume model

The present study was conducted to compare the concentration of pollutants and their level of dispersion in the atmosphere from the plume of brick kilns using different types of fuels. For this purpose, two brick kilns were selected based on their fuel type. One type of fuel was good quality coal (F1) and the other was low-quality coal mixed with wood (F2). The air emissions data illustrated that carbon monoxide concentration was more (108 ± 0.90 ppm) in the plume of F1 than in the plume of F2 (82 ± 0.98 ppm) and sulfur dioxide was more (1955 ± 3.76 ppm) in the plume of F2 than in the plume of F1 (6 ± 0.07 ppm). The Gaussian plume model showed that plume from good quality coal as fuel (F1) disperses 0.7 ± 0.01 km horizontally and 4 ± 0.03 km vertically whereas the plume from low-quality coal mixed with wood (F2) disperse 1 ± 0.01 km horizontally and 2 ± 0.02 km vertically. Pearson correlation also showed a significant (p < 0.05) difference between both fuel types. These high concentrations can have negative impacts on the atmospheric environment as well as community health.     

Mechanical and thermal properties of polyimide/silica hybrids with imide‐modified silica network structures

A series of hybrid materials incorporating imide‐modified silica (IM‐silica) network structures into a polyimide (PI) matrix were produced with a sol–gel technique from solution mixtures of poly(amic acid) and tetraethoxysilane (TEOS) containing alkoxysilane‐terminated amic acids with various degrees of polymerization. The hybrid films, obtained by solvent evaporation, were heated successively to a maximum temperature of 300°C to carry out the imidization process and silica network formation in the PI matrix. The morphology and mechanical properties of these hybrids with IM‐silica networks were studied and compared with the properties of one in which reinforcement of the matrix was achieved with a pure silica network generated from TEOS. The introduction of longer imide spacer groups into the silica network led to a drastic decrease in the silica particle size. Improved tensile modulus was observed in such compatibilized hybrid systems. Comparative thermogravimetric measurements of these hybrids showed improved thermooxidative resistance. A PI hybrid with 30% IM‐silica had a thermal decomposition temperature nearly 260°C higher than that of the pure PI matrix. The high surface area of the interconnected silica domains and increased interfacial interaction were believed to restrict the segmental motion of the polymer and thus slow the diffusion of oxygen in the matrix, thereby slowing the oxidative decomposition of the polymer. The reinforcement of existing and new PIs by this method offers an opportunity for improving their thermooxidative stability without degrading their mechanical strength. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Theoretical Investigation of Structural,Electronic, and Magnetic Properties of V-Doped MgSe and MgTe Semiconductors

In this study, we have explored the structural, electronic, and magnetic properties of V-doped zincblende MgSe and MgTe compounds using density functional calculations. The Wu-Cohen generalized gradient approximation is used for optimizing the structural properties, while the modified Becke and Johnson local (spin) density approximation functional has been employed to compute the electronic and magnetic properties. The spin dependent band structures, electronic density of state, and magnetic moments calculated for V-doped MgSe and MgTe semiconductors exhibit occurrence of 100 % spin polarization at the Fermi level which confirms stable half-metallic ferromagnetism in these materials. The spin-down gaps and the half-metallic gaps are analyzed in terms of V-3d and Se-4p (Te-5 p) hybridization, where it is observed that the V-3dstates play a key role in generating spin polarization and the magnetic moment in these compounds. The exchange constants N ₀ αand N ₀ β have been calculated to demonstrate the effects resulting from exchange splitting process. Furthermore, spin-polarized charge density calculation is presented for elucidating the bonding nature, while pressure dependence of total magnetic moment for three concentrations of V-doped MgSe and MgTe are also discussed.     

Effect of green synthesised silver nanoparticles on morphogenic and biochemical variations in callus cultures of kinnow mandarin (Citrus reticulata L.)

Citrus reticulata is economically important tree fruit crop in Pakistan, fortified with various nutrients and minerals including Vitamin C and secondary metabolites. Nanotechnology is a twenty‐first century science and deals with production of minute particles termed as nanoparticles. In present study, silver nanoparticles (AgNPs) were synthesised through green method by utilising leaves of Olea europea as main reducing and capping agent. The synthesised AgNPs were characterised through UV visible spectroscopy, SEM, and energy dispersive X‐ray. Furthermore, different concentrations of AgNPs (10, 20, 30 ppm) in combination with Thidiazuron (0.5, 1.0 mg/l) were added onto MS medium to study development and secondary metabolites production in callus culture of C. reticulata. Callus induction percentage (96%) was more in 20 ppm AgNPs and 1 mg/l TDZ concentration. Moreover, high total phenolic, flavonoid contents, and antioxidant activity was observed in 20 ppm AgNPs combined with 0.5 and 1 mg/l TDZ. Enzymatic components (SOD, POD and CAT) were increased in MS medium augmented with 30 ppm AgNPs and TDZ. The total protein content (TPC) was significant in callus cultures treated with TDZ only. This study provides the first evidence of green synthesised AgNPs on callus culture developments and further quantification of biochemical profiling in C. reticula. Inspec keywords: nanoparticles, silver, ultraviolet spectra, scanning electron microscopy, antibacterial activity, agricultural products, nanotechnology, biotechnology, agricultural engineering, nanofabrication, genetic engineering, cropsOther keywords: green synthesised silver nanoparticles, morphogenic variations, biochemical variations, kinnow mandarin, citrus reticulata L, nutrients, minerals, green method, UV visible spectroscopy, energy dispersive X‐ray, MS medium, secondary metabolites production, callus induction percentage, TDZ, flavonoid contents, callus culture developments, capping agent, phenolic contents, tree fruit crop     

Potential nutritive value and tannin bioassay of selected Acacia species from Kenya

Six Acacia forage species–A. brevispica, A. elatior, A. mellifera, A. nilotica, A. senegal and A. seyal—were analysed for their chemical composition, including phenolics and rumen fermentation characteristics. In vitro gas production technique was used to study the rumen fermentation characteristics and the effect of tannins present in the browse forages on in vitro fermentation by including polyethylene glycol (PEG‐6000) in the incubation. The forages had high crude protein content (145.7–270.1 g kg^?1 DM) and low to moderate content of neutral detergent fibre (220.2–442.8 g kg^?1 DM). The forages had variable content of total extractable phenolics ranging from 18.4 to 384.2 g kg^?1 DM and total extractable tannins ranging from 7.1 to 364.8 g kg^?1 DM (tannic acid equivalent). Fractionation of the condensed tannin flavonoids showed that the delphinidin/cyanidin ratio ranged from not detected:100 to 71:29. The gas production potential ranged from 28.4 to 40.8 mL gas 0.2 g^?1 DM. The rate of gas production was highest in A. elatior and lowest in A. nilotica. Addition of PEG‐6000 increased gas production significantly (P < 0.05) in all species except A. mellifera. PEG‐6000 addition did not have any significant effect on in vitro true dry matter and organic matter degradability but decreased the partitioning factor in all the species. Gas production and degradability parameters correlated positively with the CP content and negatively with the fibre and phenolics contents. Based on chemical composition, gas production and degradability, the forages have high potential nutritive value, especially as supplements to low‐quality feeds in the tropics and particularly during the dry season. However, the presence of tannins in terms of high levels and biological antinutritive activity may limit the nutritive potential of some of the forages, such as A. seyal and A. nilotica. Copyright © 2007 Society of Chemical Industry