Evaluation of Energy Consumption using Receiver–Centric MAC Protocol in Wireless Sensor Networks

At present day’s wireless sensor networks, obtain a lot consideration to researchers. Maximum number of sensor nodes are scattered that can communicate with all others. Reliable data communication and energy consumption are the mainly significant parameters that are required in wireless sensor networks. Many of MAC protocols have been planned to improve the efficiency more by enhancing the throughput and energy consumption. The majority of the presented medium access control protocols to only make available, reliable data delivery or energy efficiency does not offer together at the same time. In this research work the author proposes a novel approach based on Receiver Centric-MAC is implemented using NS2 simulator. Here, the author focuses on the following parametric measures like - energy consumption, reliability and bandwidth. RC-MAC provides high bandwidth without decreasing energy efficiency. The results show that 0.12% of less energy consumption, reliability improved by 20.86% and bandwidth increased by 27.32% of RC-MAC compared with MAC IEEE 802.11

Ternary Complexes of some Divalent Metal Ions with Potentially Tridentate Ligands in Dioxane-Water Mixtures

Chemical speciation of mixed ligand complexes of Ca(II), Mg(II) and Zn(II) with L-histidine and L-glutamic acid have been studied in varying concentrations (0.0–60.0 % v/v) of 1, 4-dioxane-water mixtures maintaining an ionic strength of 0.16 mol L–1 sodium chloride at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M:L:X = 1.0:2.5:2.5, 1.0:2.5:5.0, 1.0:5.0:2.5) of metal (M) to L-histidine (L) to L-glutamic acid (X) with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The predominant species detected were ML2XH2, MLXH2 and MLX2 for Ca(II), Mg(II) and Zn(II). The formation and distribution of different species with relative concentrations of metal and ligands with varying pH are represented in the form of distribution diagrams. The influence of the solvent on the speciation is discussed in terms of the dielectric constant of the medium.Keywords: Speciation, mixed ligand complexes, L-histidine, L-glutamic acid, essential metals, dioxan

Speciation of Co(II), Ni(II) and Cu(II) Complexes with L-Glutamic Acid in Dioxan–Water Mixtures

Chemical speciation of Co(II), Ni(II) and Cu(II) complexes of L-glutamic acid in the presence of Dioxan-Water mixtures at an ionic strength of 0.16 mol L–1 at 303 K was studied pH–metrically. Glu is taken as a model compound for amino acid residues and dioxan is used to mimic the low dielectric constant at the active site cavities in bioactive molecules like enzymes and proteins. The active forms of the ligand were LH3+, LH2, LH– and L2–. The models containing different numbers of species were refined using the computer program, MINIQUAD75. The predominant species detected were ML2H2, ML2H–, ML22–, MLH+ and ML. The best fit chemical models were arrived at based on statistical parameters. The trend in variation of complex stability constants with the medium composition was explained on the basis of changes in the dielectric constant of the solution. Effect of errors in the ingredients on the stability constants was also studied. Chemical speciation is discussed based on the distribution diagrams.Keywords: Complex equilibria, chemical speciation, L-glutamic acid, essential metals, dioxa

Vefrifikacija prognoza oborine WRF modelom nad Indijom tijekom monsuna 2010.: CRA metoda

The WRF model forecast during monsoon season 2010 has been verified with daily observed gridded rainfall analysis with 0.5° spatial resolution. First- ly, the conventional neighborhood technique has been deployed to calculate common scores like mean error and root mean square error. Along with, widely used two categorical skill scores have been computed for seven different rainfall thresholds. The scores only found the general nature of the model performance and depicted the degradation of forecast accuracy exceeding moderate rainfall category of 7.5 mm. The object oriented Contiguous Rain Area method also has been considered for the verification of rainfall forecasts to gather more informa- tion about model performance. The method similarly has endorsed that the performance of the model degrades along with the increase in rainfall amount. But at the same time, the decomposition of mean square error has pointed out that the maximum error occurred due the shifting of rain object or event in the forecast compared to observation. The volume error contributes less as compared to pattern error in 24 hour forecasts irrespective of rainfall thresholds. But in 48 hour forecasts, their values are comparable and change along with rainfall threshold. During whole monsoon season, all contiguous rain areas in model forecasts have been searched over observed rainfall analyses applying best-fit criteria. For contiguous rain areas below 50 mm more than 70 percent match was found.Prognoza oborine dobivena modelom WRF za monsunsku sezonu 2010. verificirana je korištenjem analize dnevne opažene oborine u mreži prostorne rezolucije od 0,5°. Određeni su jednostavni, standardni pokazatelji poput srednje pogreške i srednje kvadratne pogreške, a također i dva uobičajena kategorička pokazatelja uspješnosti koji su izračunati za sedam različitih pragova oborine. Ti pokazatelji su omogućili općenitu procjenu uspješnosti modela te su ukazali na smanjenu pouzdanost za kategorije oborine veće od 7,5 mm. kako bi se detaljnije procijenila uspješnost modela, verifikacija prognoze oborine je također napravljena pomoću objektno orijentirane metode bliskih oborinskih područja CRA (Contiguous Rain Area). Ova metoda je također ukazala na smanjenje uspješnosti modela s povećanjem količine oborine. Međutim, dekompozicija srednje kvadratne pogreške je ukazala da najveću pogrešku uzrokuje pomak prognoziranog oborinskog područja ili događaja u odnosu na izmjerene vrijednosti. Za 24-satne prognoze volumna pogreška doprinosi manje u usporedbi s prostornom pogreškom, neovisno o pragovima oborine. Međutim, za 48-satne prognoze iznosi volumne i prostorne pogreške su usporedivi te rastu s pragom oborine. Susjedna oborinska područja za prognoziranu oborinu su određena obzirom na izmjerenu oborinu primjenom kriterija nabolje podudarnosti. Postupak je proveden za cijelu monsunsku sezonu. Za područja s količinom oborine manjom od 50 mm podudaranje je veće od 70%

Anti-tumor and anti-angiogenic activity of novel hydantoin derivatives: Inhibition of VEGF secretion in liver metastatic osteosarcoma cells

A series of new azaspiro bicyclic hydantoin derivatives has been designed and synthesized. Initially, the anti-proliferative effect of the hydantoin derivatives was evaluated against human ovarian cancer cells (SKOV-3 and OVSAHO) and murine osteosarcoma cells (LM8 and LM8G7). Among the tested compounds, 8-(3-fluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7h) and 8-(3,4-difluorobenzyl)-1′-(4-(methylsulfonyl)benzyl)-8-azaspiro[bicyclo[3.2.1]octane-3,4′-imidazolidine]-2′,5′-dione (7i) showed a significant anti-proliferative activity against the OVSAHO and LM8G7 cells. The real-time monitoring of the effect of the compounds 7h and 7i against the proliferation of LM8G7 was revealed that resulting IC50 values were 102 μM and 13 μM, respectively. We reasoned that the presence of fluorine atom at the 3rd position of the phenyl ring of the hydantoin side chain may determine the potency of the molecule. Furthermore, the compound 7i inhibited the tube formation of the mouse endothelial cells. Finally, the treatment of the compound 7i against the proliferation of LM8G7 cells demonstrated the down regulation of the secretion of VEGF, indicate the potential angioinhibitory effects. In conclusion, our findings demonstrate the suppression of the secretion of VEGF by LM8G7 cells by the compound 7i might contribute at least in part to the antitumor action

Corrosion resistant behaviour of PANI–metal bilayer coatings

The present work discusses on the corrosion resistant behaviour of polymer metal bilayer coatings, viz. polyaniline (PANI), polyaniline–nickel (PANI–Ni), nickel–polyaniline (Ni–PANI), polyaniline–zinc (PANI–Zn) and zinc–polyaniline (Zn–PANI). The coatings were synthesized by means of cyclic voltametric method. The coatings thus obtained were uniform in nature and highly adherent to the mild steel substrate. The effectiveness of the coatings in preventing corrosion was tested by electrochemical impedance studies (EIS) using Nyquist and Bode plots and potentiodynamic polarization studies as well. Among the various coatings synthesized, the PANI–Zn coating was found to offer the maximum protection, followed by PANI–Ni coatings. Metal–PANI coatings were found to offer the least resistance to corrosion. The coatings thus obtained were characterized by scanning electron microscopic (SEM) analysis and the results are discussed

Design and characterization of non-toxic nano-hybrid coatings for corrosion and fouling resistance

AbstractEpoxy resin modified with nano scale fillers offers excellent combination of properties such as enhanced dimensional stability, mechanical and electrical properties, which make them ideally suitable for a wide range of applications. However, the studies about functionalized nano-hybrid for coating applications still require better insight. In the present work we have developed silane treated nanoparticles and to reinforce it with diglycidyl epoxy resin to fabricate surface functionalized nano-hybrid epoxy coatings. The effect of inorganic nano particles on the corrosion and fouling resistance properties was studied by various (1, 3, 5 and 7 wt%) filler loading concentrations. Diglycidyl epoxy resin (DGEBA) commonly was used for coating. 3-Aminopropyltriethoxysilane (APTES) was used as a coupling agent to surface treats the TiO2 nanoparticles. The corrosion and fouling resistant properties of these coatings were evaluated by electrochemical impedance and static immersion tests, respectively. Nano-hybrid coating (3 wt% of APTES–TiO2) showed corrosion resistance up to 108 Ω cm2 after 30 days immersion in 3.5% NaCl solution indicating an excellent corrosion resistance. Static immersion test was carried out in Bay of Bengal (Muttukadu) which has reflected good antifouling efficiency of the 3 wt% APTES–TiO2 loaded nano-hybrid coating up to 6 months

Bio-Based PLA Membranes for Ion Transport and Ion Filtration

Lithium-ion batteries require battery separators for both safety and electrochemical performance. Due to that, they have received a lot of attention. In order to prevent any electronic current from moving within the negative and positive electrodes and allow ions to flow through while avoidance of electric contact between them, a porous membrane used as a separator is positioned between the electrodes with opposing polarities. Accordingly, the objective of the present work is to build a biodegradable PLA based battery separator, which has exceptional thermal capabilities and can endure temperatures of up to 300°C. They also seem to serve as the least degree of barrier for the flow of an ionic current. In this study bio-polymer battery separator membranes were developed using PLA as matrix material and fillers such as Copper slag (CS) and Cardanol resin (CNSL). CS and CNSL were preferred for the reason to realize the concept of a wealth reclaimed from wastes that act as toughening and pore forming agent for PLA matrix. It is found that at PLA-CS film has more brittleness when compared to neat PLA and PLA-CNSL resin. On the other hand, PLA-CNSL films are the toughest ones. Overall, it has been demonstrated that obtaining more sustainable and high-performance is possible by the usage of such sustainable materials for futuristic developments

Pre-seismic, co-seismic and post-seismic displacements associated with the Bhuj 2001 earthquake derived from recent and historic geodetic data

The 26th January 2001 Bhuj earthquake occurred in the Kachchh Rift Basin which has a long history of major earthquakes. Great Triangulation Survey points (GTS) were first installed in the area in 1856-60 and some of these were measured using Global Positioning System (GPS) in the months of February and July 2001. Despite uncertainties associated with repairs and possible reconstruction of points in the past century, the re-measurements reveal pre-seismic, co-seismic and post-seismic deformation related to Bhuj earthquake. More than 25 M-strain contraction north of the epicenter appears to have occurred in the past 140 years corresponding to a linear convergence rate of approximately 10 mm/yr across the Rann of Kachchh. Motion of a single point at Jamnagar 150 km south of the epicenter in the 4 years prior to the earthquake, and GTS-GPS displacements in Kathiawar suggests that pre-seismic strain south of the epicenter was small and differs insignificantly from that measured elsewhere in India. Of the 20 points measured within 150 km of the epicenter, 12 were made at existing GTS points which revealed epicentral displacements of up to 1 m, and strain changes exceeding 30 M-strain. Observed displacements are consistent with reverse co-seismic slip. Re-measurements in July 2001 of one GTS point (Hathria) and eight new points established in February reveal post-seismic deformation consistent with continued slip on the Bhuj rupture zone