Abrasive water jet machining and mechanical behavior of banyan tree saw dust powder loaded polypropylene green composites

Banyan tree saw dust powder (BSD) filled Polypropylene (PP) green composites have been fabricated with varying amounts viz., 0%, 20%, and 40% of BSD particulate filler by using a co‐rotating twin screw extruder followed by injection molding. The mechanical properties such as surface hardness, tensile behavior, and impact strength of the fabricated PP/BSD green composites have been studied in order to standardize the composites. Abrasive water jet (AWJ) machining has been reported mainly for ceramics, concrete, and glass but not much literature is available on AWJ machining of polymer composites. This research is aimed at examining the AWJ machining of green polymer composites. The effect of BSD loading on the AWJ machining behavior of the PP/BSD green composites has been investigated. Furthermore, the effect of addition of 4% maleic anhydride grafted PP (coupling agent) and 4% talc (mineral filler) on the machining behavior of PP/BSD composites has also been evaluated. Surface roughness and optical micrographs of the AWJ cut composite specimens were examined to assess the effect of BSD content, AWJ traverse speed and pressure on the machining behavior of the composites. In order to probe the mechanism of AWJ machining behavior of PP/BSD composites, the kerf width and taper have been measured and results are correlated. POLYM. COMPOS., 37:1754–1764, 2016. © 2014 Society of Plastics Engineers     

Hybrid area exploration–based mobility‐assisted localization with sectored antenna in wireless sensor networks

In common practice, sensor nodes are randomly deployed in wireless sensor network (WSN); hence, location information of sensor node is crucial in WSN applications. Localization of sensor nodes performed using a fast area exploration mechanism facilitates precise location‐based sensing and communication. In the proposed localization scheme, the mobile anchor (MA) nodes integrated with localization and directional antenna modules are employed to assist in localizing the static nodes. The use of directional antennas evades trilateration or multilateration techniques for localizing static nodes thereby resulting in lower communication and computational overhead. To facilitate faster area coverage, in this paper, we propose a hybrid of max‐gain and cost‐utility–based frontier (HMF) area exploration method for MA node's mobility. The simulations for the proposed HMF area exploration–based localization scheme are carried out in the Cooja simulator. The paper also proposes additional enhancements to the Cooja simulator to provide directional and sectored antenna support. This additional support allows the user with the flexibility to feed radiation pattern of any antenna obtained either from simulated data of the antenna design simulator, ie, high frequency structure simulator (HFSS) or measured data of the vector network analyzer (VNA). The simulation results show that the proposed localization scheme exhibits minimal delay, energy consumption, and communication overhead compared with other area exploration–based localization schemes. The proof of concept for the proposed localization scheme is implemented using Berkeley motes and customized MA nodes mounted with indigenously designed radio frequency (RF) switch feed network and sectored antenna.     

Reconfiguration on nanocrossbar using material implication

Reconfigurable architectures (FPGA) with embedded memory elements face problems in retaining data for longer duration due to leakage current as it becomes dominant in nanometer devices in conventional technologies. Also, LUT-based designs consume more area, are slow in processing data and dissipate more power because of complex interconnection network. Memristor, a new nonvolatile memory element, can be used to overcome these limitations. In this paper, we propose an implication-NOR logic-gate-based FPGA architecture using memristors for implementation of logic functions and with embedded memory for storing data. The automation algorithm for the same is presented.     

In-situ formation of graphene–lead oxide composite and its use in trace arsenic detection

Reduced graphene oxide–lead dioxide composite is formed when EGO coated surface is electrochemically reduced along with lead ions in the solution. This composite has been shown to be an excellent material for low level detection of arsenic. Various functional groups present on EGO, in a wide pH range of 2–11, are responsible for the favorable interaction between metal ion and the modified electrode surface and subsequent trace level detection. X-ray photoelectron spectroscopy and Raman spectroscopic techniques confirm the formation of composite and its composition. Thin layer of lead dioxide along with reduced exfoliated graphene oxide has been shown to be responsible for the enhanced activity of the surface. The detection limit of arsenic is found to be 10 nM. This study opens up the possibility of using the composites for sensing applications and possibly simultaneous detection of arsenic and lead.     

p-TSA Modified Montmorillonite Catalyst for Free Fatty Acid Reduction in Rubber Seed Oil

Silicon - Rubber seed oil containing free fatty acid (FFA) to the extent of 2% is difficult to transesterify and does not undergo transformation at all for the free acid value beyond 3%. This oil...     

Appropriate sample for determination of protein in sorghum (Sorghum bicolor (L.) Moench) raised in agricultural trials

Sampling of cereal foods from bulk samples for analyses of nutrients is a well-known procedure, but a satisfactory sampling scheme for such analyses from breeding and agronomic trials has not been defined. However, selection of five plants from each experimental plot is a common procedure among agricultural scientists. The validity of using grains from such a sample for analysis of protein was tested in the present investigation. Values obtained by analysis of pooled samples of five randomly selected ear-heads or the average values of five such ear-heads were not significantly different from those obtained by analyses of sampled aliquots from net plot.     

Nitrates-melt synthesized LiNi0·8Co0·2O2 and its performance as cathode in Li-ion cells

Layered LiNi_0·8Co_0·2O₂ crystallizing in R $\bar 3$ m space group is synthesized by decomposing the constituent metal-nitrate precursors. Oxidizing nature of metal nitrates stabilizes nickel in +3 oxidation state, enabling a high degree of cation ordering in the layered LiNi_0·8Co_0·2O₂. The powder sample characterized by XRD Rietveld refinement reveals < 2% Li-Ni site exchange in the layers. Scanning electron microscopic studies on the as-synthesized LiNi_0·8Co_0·2O₂ sample reflect well defined particles of cubic morphology with particle size ranging between 200 and 250 nm. Cyclic voltammograms suggest that LiNi_0·8Co_0·2O₂ undergoes phase transformation on first charge with resultant phase being completely reversible in subsequent cycles. The first-charge-cycle phase transition is further supported by impedance spectroscopy that shows substantial reduction in resistance during initial de-intercalation. Galvanostatic charge-discharge cycles reflect a first-discharge capacity of 184 mAh g^?1 which is stabilized at 170 mAh g^?1 over 50 cycles.     

Web data retrieval: solving spatial range queries using k-nearest neighbor searches

As Geographic Information Systems (GIS) technologies have evolved, more and more GIS applications and geospatial data are available on the web. Spatial objects in a given query range can be retrieved using spatial range query − one of the most widely used query types in GIS and spatial databases. However, it can be challenging to retrieve these data from various web applications where access to the data is only possible through restrictive web interfaces that support certain types of queries. A typical scenario is the existence of numerous business web sites that provide their branch locations through a limited “nearest location” web interface. For example, a chain restaurant’s web site such as McDonalds can be queried to find some of the closest locations of its branches to the user’s home address. However, even though the site has the location data of all restaurants in, for example, the state of California, it is difficult to retrieve the entire data set efficiently due to its restrictive web interface. Considering that k-Nearest Neighbor (k-NN) search is one of the most popular web interfaces in accessing spatial data on the web, this paper investigates the problem of retrieving geospatial data from the web for a given spatial range query using only k-NN searches. Based on the classification of k-NN interfaces on the web, we propose a set of range query algorithms to completely cover the rectangular shape of the query range (completeness) while minimizing the number of k-NN searches as possible (efficiency). We evaluated the efficiency of the proposed algorithms through statistical analysis and empirical experiments using both synthetic and real data sets.

An interactive framework for spatial joins: a statistical approach to data analysis in GIS

Many Geographic Information Systems (GIS) handle a large volume of geospatial data. Spatial joins over two or more geospatial datasets are very common operations in GIS for data analysis and decision support. However, evaluating spatial joins can be very time intensive due to the size of datasets. In this paper, we propose an interactive framework that provides faster approximate answers of spatial joins. The proposed framework utilizes two statistical methods: probabilistic join and sampling based join. The probabilistic join method provides speedup of two orders of magnitude with no correctness guarantee, while the sampling based method provides an order of magnitude improvement over the full indexing tree joins of datasets and also provides running confidence intervals. The framework allows users to trade-off speed versus bounded accuracy, hence it provides truly interactive data exploration. The two methods are evaluated empirically with real and synthetic datasets.     

Rapid synthetic routes to prepare LiNi1/3Mn1/3Co1/3O2 as a high voltage, high-capacity Li-ion battery cathode material

LiNi_1/3Mn_1/3Co_1/3O₂, a high voltage and high-capacity cathode material for Li-ion batteries, has been synthesized by three different rapid synthetic methods, viz. nitrate-melt decomposition, combustion and sol–gel methods. The first two methods are ultra rapid and a time period as small as 15 min is sufficient to prepare nano-crystalline LiNi_1/3Mn_1/3Co_1/3O₂. The processing parameters in obtaining the best performing materials are optimized for each process and their electrochemical performance is evaluated in Li-ion cells. The combustion-derived LiNi_1/3Mn_1/3Co_1/3O₂ sample exhibits large extent of cation mixing (10%) while the other two methods yield LiNi_1/3Mn_1/3Co_1/3O₂ with cation mixing <5%. LiNi_1/3Mn_1/3Co_1/3O₂ prepared by nitrate-melt decomposition method exhibits superior performance as Li-ion battery cathode material.