Coordination of Cu(II) and Ni(II) in polymers imprinted so as to optimize amine chelate formation

Molecular imprinting has become an established technique. However, little was done on direct investigation of the sorbents produced. In the present work, en ESR method was used for the investigation of the complex formation processes within the sorbents imprinted with copper(II) and nickel(II). The sorbents were synthesized from a mixture of linear low molecular weight polyethyleneimine oligomers. The composition, structure and distribution of complexes in the resin phase were investigated. The effects of the synthesis conditions, loading degree and water content were examined. The presence of certain copper complexes was found to be a convenient characteristic of the imprinting efficiency. The optimum synthesis conditions for obtaining sorbents imprinted with copper(II) or nickel(II) were identified. The imprinting results in the improvement of the stability of the complexes and the selectivity and working capacity of the sorbents. The imprinted samples are also characterized by a more even distribution of chelating sites. The synthesis conditions and loading by ions allow for the regulation of the ratio between individual complexes and magnetic associates in the resin phase. This is a critical point on the future use of the metal containing imprinted sorbents as catalysts. (C) 2003 Published by Elsevier Science Ltd

Online Web Page Classification

The World Wide Web (www) is growing at an uncontrollable rate, hundreds of thousands of web site appear every day, with the added challenge of keeping the web directories up-to-date  , further the uncontrolled   nature of web presents difficulties for  w eb page classification , the proposed system about  using neural network  technique for automatically online web pages classification according to their domain , the system provide ability to online web page classification ,which make the   system   sensible  to any change happen to the website . Keywords: Classifier, Neural Network classifier, web crawling, data cleaning

Aqueous to organic phase transfer of Au<SUB>25</SUB> clusters

Aqueous to organic phase transfer of water soluble sub-nanocluster, Au25SG18 (-SG, glutathione thiolate) is demonstrated using the phase transfer reagent, tetraoctylammonium bromide. The phase transfer occurred by the electrostatic attraction between the hydrophilic carboxylate anion of the glutathione ligand on the cluster surface in the aqueous phase and the hydrophobic tetraoctylammonium cation in the toluene phase. Detailed spectroscopic characterization of the phase transferred cluster using optical absorption, photoluminescence and X-ray photoelectron spectroscopy showed that the cluster retains its integrity during the phase transfer. The interaction of the cluster with the phase transfer reagent can be studied with infrared spectroscopy. The phase transferred cluster can be dried and redissolved in an organic medium, just as the original cluster. This is the first report of the phase transfer of a sub-nanocluster, keeping the cluster core intact. The effect of dilution and pH on phase transfer of this cluster is studied in detail. This method promises several possibilities to explore the properties, reactivity and applications of sub-nanoclusters both in the aqueous and organic phases

Max-Average: An Extended Max-Min Scheduling Algorithm for Grid Computing Environtment

Sharing numerous computational and communication power from connected heterogeneous systems over the world are the two key points of Grid computing. Grid computing can also be referred as a computing platform for users to utilise the remote heterogeneous resources for solving their large scale jobs that require a huge amount of processing power or a huge data storage. Sharing these resources that way effectively requires a very good scheduling strategy, which is the focus of this research. This paper presents a new proposed grid based scheduling algorithm called Max-Average, inspired from Max-Min algorithm. In order to produce good quality solutions, the proposed algorithm is designed in two phases; firstly it uses an initial task queue like the traditional Max -Min for estimating task completion time for each of resources, and in the second phase choose the fitting resource for scheduling according to requirements. The results from our simulation showed that our proposed algorithm is performing better in producing good quality solutions, particularly in executing tasks fast and in balancing the load (resource utilisation) among the resources more effectively when compared to standard Minimum Execution Time (MET), Minimum Completion Time (MCT), Min-Min, and Max-Min heuristic approache

Mapping and Identification of Suitable Dumping Sites for Solid Waste Management in Gwagwalada Area Council of the F.C.T. Nigeria

Urban solid waste is one of the major threats to global environment in the world today. As global civilization keeps improving, there is increase in commercial, residential and infrastructural development due to the population growth which has a negative impact on the environment if not properly planned, monitored and maintained. One of the negative impacts is the problem of waste disposal which if not properly managed could lead to environmental problems and to avoid the negative repercussion of improper waste disposal, an area has to be put in place for solid waste disposal and management also referred to as dump site. Geographical Information System and Remote sensing Techniques were used in the process of site selection which is accurate, less expensive and less time consuming compared to the conventional method. The aim of this study was to identify a suitable sites for solid waste disposal in Gwagwalada town of the Federal Capital Territory (F.C.T), Abuja. An image of the study area was digitized to identify the different features on the ground and also the Digital Terrain Model (DTM) to show differencse in surface elevation. The Digital terrain model shows that the lowest elevation point is 176m while the highest point is 226m above the sea level. Three Data analysis types were used and this includes Buffering, Overlay and Query. The analysis was carried to ascertain that the proposed dump sites pose no threat to agriculture, life and property. The result of all analysis carried out shows that the location of the proposed dump sites is 184m in elevation and 1km off the exit route of Gwagwalada along the Gwagwalada- katse road. It is highly recommended that urban settings should have an open space for dump site on remote areas of little or no economic importance far from the residents and should be monitored properly. Concerned Environmental Maintenance Authorities can now used the knowledge of GIS and Remote Sensing Application in monitoring the environment and improve management. Keywords: Solid Waste, Management, Dump Site, Mapping, Urba

Quantum illumination using polarization-path entangled single photons for low reflectivity object detection in noisy background

Detecting object with low reflectivity embedded within a noisy background is a challenging task. Quantum correlations between pairs of quantum states of light, though are highly sensitive to background noise and losses, offer advantages over traditional illumination methods. Instead of using correlated photon pairs which are sensitive, we experimentally demonstrate the advantage of using heralded single-photons entangled in polarization and path degree of freedom for quantum illumination. In the study, the object of different reflectivity is placed along the path of the signal in a variable thermal background before taking the joint measurements and calculating the quantum correlations. We show the significant advantage of using non-interferometric measurements along the multiple paths for single photon to isolate the signal from the background noise and outperform in detecting and ranging the low reflectivity objects even when the signal-to-noise ratio is as low as 0.03. Decrease in visibility of polarization along the signal path also results in similar observations. This will have direct relevance to the development of single-photon based quantum LiDAR and quantum imaging.Comment: 8 pages and 6 figure

The implications of agro-chemical compounds (fertilizers, pesticides and herbicides) on farming/aquaculture activities in the lake-Chad and its possible current/future social effects

Field survey and Laboratory analysis were carried out to determine the implications of agro-chemicals effluent on Lake Chad water. Historically societies used traditional farming methods involving rainfed agriculture and limited ground water withdrawal with irrigation though an ancient practice, it affected only small parts of the world. Water in Lake Chad is facing serious environmental problems from prolong drought to desertification, pollution and biodiversity reduction. The use of water for extensive agriculture by the lakes riparian states is reducing the water and stressing the ecological balance affecting the organisms depending on it and also its availability to its inhabitants. Water quality is also an important issue in the Lake Chad especially where the rainfall being the natural input into the system is small, greater risk of fertilizer, pesticides, and other agro-chemicals/inputs, runoff from the soil to the lake water and also salt accumulation threat are imminent. The assessment of the Lake Chad water resource quality was therefore carried out carefully while understanding the linkage and interaction with Agro-chemicals using stratified random sampling method for data acquisition and assessment on the site. The results of the experiment indicated that five parameters, namely, PH, Cadmium, Iron, Magnesium and chlorine have contaminant levels above the threshold limit as major sources of pollution in the lake with possible existing and future problem. As a result of the adverse effect of the agrochemicals runoff in the Chad water at Kirinowa. It can be concluded from the results of this study that the lake is under pollution of metals from sources of agricultural operations, due to indiscriminate application of pesticides, herbicides and fertilizers.Key words: Lake Chad, Agro-chemicals, Accumulation, Contamination, Pollution

Second-order correlations and purity of unheralded single photons from spontaneous parametric down-conversion

Various quantum technology applications require high-purity single photons with high generation rate. Although different methods are employed to generate such photons, heralded single photons from spontaneous parametric down-conversion (SPDC) is the most commonly used approach. Photon generation rate from the heralded single-photon sources are limited by the efficiency of the detectors to record coincidence detection of the photon pairs which are lower than the single-photon counts recorded separately on each detector. In this paper we present a revised expression to calculate second-order temporal correlation function, $g^{(2)}$ for any fixed time window (bin) and report the experimental characterization of purity of unheralded and heralded single photons from the SPDC process. With an appropriate choice of time bin for a given pump power, without heralding we show that higher rate of single photons with $g^{(2)}(0) = 0$ can be generated with very high probability.Comment: 7 pages, 6 figure

Online Education and its Effect on the workforce

The use of technology in education, commonly defined as electronic learning (e-learning), is commonplace in the curricula of the 21st century. The role of e-learning in professional development and workforce advancement, and more specifically, its impact on Louisiana`s workforce, was analyzed. Broader statewide efforts to address barriers and challenges that impact local adult learning opportunities are also examined. This paper also reviews the benefits of online education as it impacts on students, institutions, state and federal government, and the society in its entirety. Two models are proposed: the first addresses outreach programs to improve enrollment and retention of adult students; the second discusses methodologies to ensure the successful implementation of online programs to help those adult students to succeed