Environmental investigation using geophysical data at East Sadat City,Egypt

Three geophysical techniques such as resistivity, seismic refraction, and GPR have been applied to delineate the depth to the groundwater surface, subsurface stratigraphy and subsurface structures which control the configuration and distribution of the groundwater aquifer. Five vertical electrical sounding (VES) were measured by using Syscal-R2 instrument of electrode separation ranging from AB/2?=?1–500?m to reach depth of investigation about 150?m. The results of quantitative interpretation of the VES data indicate that the subsurface sequence composed of six geoelectric units; the first unit is characterized by resistivity values up to 2007?Ohm.m corresponding to sand & gravel and thickness up to 1.2?m. The second geoelectric unit is corresponding to sandy clay which exhibits resistivity up to 235?Ohm.m and depth up to 1.2?m. The third geoelectric unit is characterized by resistivity values up to 1483?Ohm.m corresponding to dry sand which of depth up to 2.6?m. The fourth geoelectrical unit consists of sand saturated with ground water and exhibits resistivity values ranging from 20.2 to 52.9?Ohm.m and depth ranging from 7 to 16.8?m. The fifth geoelectrical unit reveals resistivity values ranging from 7 to 32.6?Ohm.m and consists of sandy clay saturated with groundwater of depth up to 111?m overlaying the sixth unit which reached to depth up to 165?m and characterized by resistivity values ranging from 54 to 91?Ohm.m corresponding to sandstone saturated with ground water. Five shallow seismic refraction spreads of geophone spacing 4?m were measured to investigate the subsurface sequence, where the results of interpretation indicate that the subsurface section consists of three seismic layers; the first layer is unsaturated overburden with seismic velocity range from 280 to 770?m/s and thickness reach about 6?m. The second layer is sand saturated with ground water with velocity range from 760 to 1300?m/s and maximum thickness of about 7?m overlaying the third layer reached to depth up to 24?m and corresponding sandy clay saturated with groundwater with seismic velocity range from 1130 to 2260?m/s. Five GPR profiles are measured using MALA RAMAC GPR System with a Rough Terrain Antenna (RTA) system of central frequency of 100?MHz. The interpretation of GPR data indicate that the expected water table ranging from 8?m to 11?m in the study area. Interpretation of the obtained results and correlation with the available geological and different geophysical data revealed that, the depth to the groundwater table of the investigated area ranges between 7 and 16.8?m.     

Energy-efficient bootstrapping for wireless sensor networks

Wireless sensor networks are poised for increasingly wider uses in many military and civil applications. Such applications has stimulated research in a number of research areas related to energy conservation in such networks. Most such research focuses on energy saving in tasks after the network has been organized. Very little attention has been paid to network bootstrapping as a possible phase where energy can be saved. Bootstrapping is the phase in which the entities in a network are made aware of the presence of all or some of the other entities in the network. This paper describes a bootstrapping protocol for a class of sensor networks consisting of a mix of low-energy sensor nodes and a small number of high-energy entities called gateways. We propose a new approach, namely the slotted sensor bootstrapping (SSB) protocol, which focuses on avoiding collisions in the bootstrapping phase and emphasizes turning off node radio circuits whenever possible to save energy. Our mechanism synchronizes the sensor nodes to the gateway’s clock so that time-based communication can be used. The proposed SSB protocol tackles the issue of node coverage in scenarios, when physical device limitations and security precautions prevent some sensor nodes from communicating with the gateways. Additionally, we present an extension of the bootstrapping protocol, which leverages possible gateway mobility.     

Cryobiology of non-human primate oocytes

The responses to various stresses involved with cryopreservation protocols were investigated using non-human primate oocytes. Fluorescence microscopy was used to assess the status of the F-actin microfilament system of rhesus monkey oocytes after exposure to different concentrations of glycerol. The F-actin organization around the cortex and in the transzonal processes was modified by exposure to 1.0 ot 2.0 M glycerol at ambient temperature. These effects were reduced significantly when exposure to glycerol was combined with cooling to O degrees C. Cynomolgus monkey oocytes were also subjected to hyperosmotic stress and observed for morphological changes. An irregular shrinkage phenomenon was observed with germinal vesicle or metaphase I but not metaphase II (MII) oocytes. The irregular shrinkage became uniform and spherical when the oocytes were pretreated with ethyleneglycol-bis-(beta-aminoethyl ether)N,N,N'N' tetraacetic acid (EGTA) before exposure to hypertonic solution. Also, in-vitro-matured MII oocytes from cynomolgus monkeys were used to determine crucial biophysical parameters for freezing primate oocytes. The permeability of oocyte plasma membrane to water, Lpg, and its activation energy, ELp, were determined between 0 and -12 degrees C in the absence of cryoprotective additives. The Lpg was found to be 3.8x10(-14) m3N/s and the ELp was 141.5 kJ/mol. the pre-exponential kinetic and exponential thermodynamic parameters of intracellular ice formation were determined to be 8x108 m2/S and 2. 2x10(9) K5 respectively. By combining models of water transport and intracellular ice formation, the cumulative fraction of oocytes with intracellular ice as a function of the cooling rate was also predicted, and it was shown to correlate reasonably with experimental observations.     

The vibration characteristics of thick rectangular multilayered plates

We develop the analysis and numerical calculations for the exact free vibration characteristics of simply-supported, rectangular, thick, multilayered composite plates. We assume that each layer of the composite plate is of arbitrary thickness, is perfectly bonded to adjacent layers, possesses up to orthotropic material symmetry and that its material crystallographic axes are oriented either parallel or perpendicular to the plate's boundaries. Exact formal solutions are obtained for the individual layers which are, in turn, used to relate the field variables at the upper and lower layer surfaces. The solution is carried through by the successive application of appropriate interfacial continuity conditions between adjacent lamina. We facilitate our analysis and its numerical implementation by making use of the matrix transfer technique, thereby rendering the order of the resulting eigenproblem independent of the number of lamina. Numerical results are given in the form of scaled natural frequency versus nondimensionalized mode numbers. The effect of the plate's microstructure on its vibrational characteristics is investigated by examining changes in natural frequency and modal response for selected laminate lay-ups and material combinations.     

A robust quadrilateral membrane finite element with drilling degrees of freedom

A quadrilateral membrane finite element with drilling degrees of freedom is derived from variational principles employing an independent rotation field. Both displacement based and mixed approaches are investigated. The element exhibits excellent accuracy characteristics. When combined with a plate bending element, the element provides an efficient tool for linear analysis of shells.     

Staphylococcus aureus leucocidin, a virulence factor in bovine mastitis

The involvement of Staphylococcus aureus exosecretions in bovine udder infection (Younis et al. 2003) suggests that four different monomer protein bands appearing between 36 and 31 kDa, are associated with the severity of the cow's infection response. Three out of these four bands have been identified by means of protein sequencing. Band B, with a MW of 35 kDa was identified as Panton-Valentaine leucocidin LukF'-PV chain- Staph. aureus; band C, with a MW of 32 kDa was identified as leucocidin chain LukM precursor- Staph. aureus; and band D was found to be similar, but not identical, to phosphatidylinositol-specific phospholipase-C-X. Bands B and C were purified by gel filtration using FPLC. The ability of these proteins to induce udder inflammation in vivo, and proliferation response in vitro and cytokine secretion were tested for both the crude exosecretions and purified bands. Three cows were inoculated intracisternally, with three quarters receiving either 0.007-0.008 mg (as total proteins) of Staph. aureus FR2449/1 bacterial exosecretion, pooled fraction 39-41 (bands B and C), or culture broth medium. The fourth quarter was left free as a control. Quarters that received fraction 39-41 of Staph. aureus FR2449/1, exhibited induced inflammation, which was indicated by increased somatic cell count and enhanced NAGase activity that was significantly higher than that of the original Staph. aureus FR2449/1 bacterial exosecretion. Proliferation tests of bovine blood lymphocytes in vitro showed that the pooled fraction 39-41 stimulated bovine proliferation of mononuclear cells much more than the original Staph. aureus FR2449/1 bacterial exosecretion. Secretion of TNF-alpha, IL-1beta, IL-6 and IL-8 was in accordance with the contents of LukF'-PV and LukM precursor in the exosecretions. The results suggest that LukM/ LukF' induce inflammation into the udder by a mechanism similar to that of LPS or by a unique mechanism(s) which requires further investigation.     

Fingerprint classification: a review

Biometrics is the automatic identification of an individual that is based on physiological or behavioural characteristics. Due to its security-related applications and the current world political climate, biometrics is currently the subject of intense research by both private and academic institutions. Fingerprints are emerging as the most common and trusted biometric for personal identification. The main objective of this paper is to review the extensive research that has been done on fingerprint classification over the last four decades. In particular, it discusses the fingerprint features that are useful for distinguishing fingerprint classes and reviews the methods of classification that have been applied to the problem. Finally, it presents empirical results from the state of the art fingerprint classification systems that have been tested using the NIST Special Database 4.     

Dynamic analysis of a multibody open-chain system

The free plane motion of a compound pendulum is studied using the Lagrange equations of motion. The specific compound pendulum consists of a main plane disk from which are suspended two chains, each of which is composed of m and n rigid plane disks, respectively. A nonlinear system of m + n + 1 ordinary differential equations (ODEs) with respect to the properly selected generalized coordinates, is obtained. For small-amplitude swing the above system becomes a linear differential system. The eigenvalues and eigenvectors constitute the eigenfrequencies and the modeshapes, respectively, of the free swing of the considered compound pendulum. Also, relations are extracted which ensure a unique swing with no relative rotation between any two disks. Finally, several numerical results are given.