Isocontour Maps Research Articles

Unveiling the effects of thermodynamic interaction of basalt fibers/epoxy interfaces on thermal stability, mechanical properties and corrosion resistance of basalt fibers reinforced waterborne epoxy coatings

AbstractIn this study, the interfacial interaction between the 3‐aminopropyltriethoxysilane (APTES) modified basalt fibers (BF@Ax) and waterborne epoxy was studied by using thermodynamic approaches and creating a “wetting‐reagglomeration‐adsorption” isocontour map of waterborne epoxy. Combined with the TG‐DSC, dynamic thermomechanical analysis (DMA), tensile, flexural, electrochemical impedance spectrum (EIS) and salt spray tests, the enhancement effects of interfacial interaction on thermal stability, mechanical properties and corrosion resistance were demonstrated. From the isocontour map, APTES modification reduces the surface energies of BF@Ax fillers from 53.05 to 50.27 mJ/m2, which results in the driving energy for reagglomeration decreasing from 17.04 to 10.41 mJ/m2 and the adsorption energy increasing from 20.24 to 20.77 mJ/m2, suggesting that the BF fillers' dispersion performance and interfacial strengths of BF composite coatings are enhanced. Compared to the varnish coating, the tensile and flexural strengths of the epoxy (EP)/BF@A9.5 coating are increased by 55.87% and 36.36%, respectively, and the thermal stability is enhanced, due to the BF@A9.5 fillers' optimal dispersion. Meanwhile, EP/BF@A5.0 coating has the best corrosion resistance with |Z|0.01Hz value above 109 Ω cm2 after 35 days and salt spray resistance exceeding 120 days. This work provides a new insight into how the interfacial interaction between the one‐dimensional rod fillers and matrices affects the composites' properties from the thermodynamics.Highlights Waterborne epoxy coatings were reinforced by the modified chopped BFs. Impact of APTES modification on the BF surface energy was uncovered. Interaction of BFs/epoxy interfaces was studied by thermodynamic approaches. Effect of interfacial interaction on properties of coatings was unveiled.

Thermodynamic prediction of filler surface modification by APTES on corrosion resistance of nano-TiO2/waterborne epoxy coatings

Common techniques for creating novel coatings include chemically modifying inorganic fillers and exploring how modifications affect coating service performance. However, it frequently takes a lot of time and tedious attempts to get the ideal alteration degree for fillers. Although the surface energy of the fillers is thought to be a significant thermodynamic parameter, it is still unknown how chemical modification affects surface energy and how the properties of fillers in a coating relate to the quantization difference of thermodynamic parameters. In this study, the impact of chemical modification on the quantization difference of nano-TiO2 surface energy has been uncovered. Creating a “wetting-reagglomeration-adsorption” isogram by utilizing three surface interfacial parameters has also been achieved: the contact angle between the liquid resin and the filler, the driving energy of the filler reagglomeration, and the polymer molecules' diffusion energy at the filler/coating interface. The relationship between the quantitative difference of thermodynamic parameters and the dispersion, compatibility and interfacial strength of the fillers in the waterborne epoxy was predicted by the isocontour map. From the isocontour map, the modified nano-TiO2 fillers with 4.04 APTES molecules/nm2 shows the minimum ∆Wa of 16.17 mJ/m2 and the maximum Ws of 23.15 mJ/m2 in the composite coating, which is predicted to exhibit the best dispersibility and the strongest interfacial strength. The prediction results were successfully verified by the techniques of microscopic morphology observation (TEM and SEM), mechanical properties tests (DMA and tensile tests), and corrosion resistance tests (EIS and salt spray tests). This work has a significant guiding role in the development of the filler modifications for the creation of novel coatings.

The Use of Augmented Reality for the Management of Equipment Ageing with a Virtual Sensor

Much of the equipment that is used in the chemical and process industry and for handling or treating hazardous substances is subject to deterioration. To manage the risk of major accidents due to this deterioration, the current legislation requires periodic controls that must be carried out to verify the health conditions (ageing). To support the inspectors performing this task, a virtual sensor has been designed and developed. It is a system composed of hardware and software that uses mathematical models and augmented reality to assist in on-field inspections for monitoring and predicting equipment ageing. Currently, there are no AR devices to perform inspections aimed at verifying the integrity of equipment. The virtual sensor collects ageing-related information and returns the corrosion rate, the probability of the critical pit, the corrosion evolution through iso-contour corrosion maps, and the RUL; finally, it allows visualising the equipment condition through augmented reality, (e.g., by means of thickness maps and tables that overlay the equipment). The aim of this paper is to present the graphical interface of the software application, which has been improved to minimise errors due to human–machine interaction. A large diesel storage tank has been used to show how the virtual sensor works.

Simultaneously acquired PET and ASL imaging biomarkers may be helpful in differentiating progression from pseudo-progression in treated gliomas.

The aim of this work was investigating the methods based on coupling cerebral perfusion (ASL) and amino acid metabolism ([18F]DOPA-PET) measurements to evaluate the diagnostic performance of PET/MRI in glioma follow-up. Images were acquired using a 3-T PET/MR system, on a prospective cohort of patients addressed for possible glioma progression. Data were preprocessed with statistical parametric mapping (SPM), including registration on T1-weighted images, spatial and intensity normalization, and tumor segmentation. As index tests, tumor isocontour maps of [18F]DOPA-PET and ASL T-maps were created and metabolic/perfusion abnormalities were evaluated with the asymmetry index z-score. SPM map analysis of significant size clusters and semi-quantitative PET and ASL map evaluation were performed and compared to the gold standard diagnosis. Lastly, ASL and PET topography of significant clusters was compared to that of the initial tumor. Fifty-eight patients with unilateral treated glioma were included (34 progressions and 24 pseudo-progressions). The tumor isocontour maps and T-maps showed the highest specificity (100%) and sensitivity (94.1%) for ASL and [18F]DOPA analysis, respectively. The sensitivity of qualitative SPM maps and semi-quantitative rCBF and rSUV analyses were the highest for glioblastoma. Tumor isocontour T-maps and combined analysis of CBF and [18F]DOPA-PET uptake allow achieving high diagnostic performance in differentiating between progression and pseudo-progression in treated gliomas. The sensitivity is particularly high for glioblastomas. • Applied separately, MRI and PET imaging modalities may be insufficient to characterize the brain glioma post-therapeutic profile. • Combined ASL and [18F]DOPA-PET map analysis allows differentiating between tumor progression and pseudo-progression.

Accurate Detection of Distorted Pectoral Muscle in Mammograms Using Specific Patterned Isocontours

Automatic detection of the pectoral muscle in mammograms is widely used in computer-aided diagnostic (CAD) systems for breast cancer. The pectoral muscle region has some prominent features such as the upper corner position, high density, and triangular shape. But, these features may be distorted due to the masses, artifacts, skin folds, and overlapping tissues, and other reasons. Despite recent developments in CAD technology, accurate detection of distorted pectoral muscle images remains a challenging task. In this study, we proposed an automatic method that uses a divided topographic representation to detect distorted pectoral muscle boundaries. After the preprocessing stage, firstly an isocontour map is generated and then divided into horizontal blocks. The contours of the pectoral muscle boundary in the blocks often reveal specific patterns in terms of location, geometric and topological features. We developed a new segmentation algorithm, rule-based contour detection (RBCD), to detect these specific patterned isocontours. The method applied to two datasets consisting of 84 and 201 mammogram images from MIAS and Inbreast databases respectively. Besides, some distorted pectoral muscle samples selected from these datasets were used to further analyze the performance of the proposed method. The mean False-Positive and the mean False-Negative rates of the proposed method for MIAS and Inbreast datasets were 0.92%, 1.26%, and 2.34%, 1.15%, respectively. The quantitative and qualitative results for the distorted pectoral muscle samples show that the proposed method outperformed the compared methods.

2D- and 3D-QSAR Modeling of Imidazole-Based Glutaminyl Cyclase Inhibitors.

Glutaminyl Cyclase (QC) is a novel target in the battle against Alzheimer's disease, a highly prevalent neurodegenerative disorder. QC inhibitors have the potential to be developed as therapeutically useful anti-Alzheimer's disease agents. Linear and non-linear 2D-Quantitative Structure-Activity Relationship (QSAR) models were developed using Stepwise Multiple Linear Regression (S-MLR) and neural networks. Partial least squares (PLS) method was used to develop a 3D-QSAR model. Also, the developed models were used in virtual screening of the ZINC database to identify potential QC inhibitors. The 2D neural network model showed superior predictive ability, as demonstrated by the validation parameters R2 = 0.933, Q2 = 0.886 and R2 pred = 0.911. The 3D-QSAR model's steric and electrostatic fields' isocontour maps were visualized and revealed important structural requirements associated with good activity. The virtual screening identified six compounds as potentially active QC inhibitors with improved pharmacokinetic profiles. The developed QSAR models can be used to predict the activity of compounds not yet synthesized and prioritized for their synthesis and biological evaluation. Also, potentially active QC inhibitors have been identified with attractive lead-like properties that can be used to develop anti- Alzheimer's disease agents.

Step-drawdown test as a tool for the assessment of the Nubia sandstone aquifer in East El-Oweinat Area, Egypt

The Cretaceous Nubia sandstone aquifer is the main aquifer in East El-Oweinat area along the Egyptian–Sudanese borders and in NE Africa. East El-Oweinat project has been recently considered one of the main agricultural projects in the southwest of the Egyptian Western Desert. So, the hydrogeological assessment for the Nubia aquifer in East El-Oweinat area has been done through studying and characterising the hydraulic parameters and step-drawdown test. The well and aquifer losses coefficients (C and B, respectively), the specific capacity, and the well efficiency as well as the aquifer and aquitard thickness have been estimated and traced through a total of 46 wells that have been distributed through the study area in two sectors, southern and northern. For the purpose of further exploration, the effective porosity (∅), hydraulic conductivity (K), and transmissivity (T) have been estimated for the wells in the northern sector. In addition, an aquifer assessment quality index has been introduced to assess and to rank the studied aquifer. Therefore, it is concluded that the hydraulic and the step-draw down parameters as well as the aquifer and aquitard thicknesses are prospective for further exploration to the north and the east of the northern sector in the study area. The well efficiency is mostly affected by the studied parameters, particularly the well loss coefficient, the hydraulic parameters and the well design as well. GIS approach and ArcGIS software have been applied to delineate the spatial distribution of the well performance characteristics, in order to compare between the studied groundwater wells and to integrate the different-acquired data. A set of isocontour maps have been introduced to match the lateral variation of the studied parameters and the aquifer potential to refer to the best direction for further underground water exploration.

A kinetic modeling study on octane rating and fuel sensitivity in advanced compression ignition engines

With the development of advanced compression ignition (ACI) engines such as the homogeneous charge compression ignition (HCCI) and the reactivity controlled compression ignition (RCCI), the long existing research and motor octane rating for fuels, i.e., RON and MON, might be insufficient to describe fuel reactivity and performance with these new combustion strategies due to their distinctive engine operating conditions. It is also noted that with stringent regulation of CO2 emissions, a detailed knowledge of fuel reactivity is urgently needed for the selection of novel alternative bio-fuels for transportation, and optimization of their engine performance in the future. It is therefore very important to understand the general fuel properties such as reactivity and sensitivity under different ACI operating conditions. In this modeling study, using validated kinetic mechanisms for ignition, different classes of fuels including hydrogen, alkanes (straight and branched) and alcohols have been simulated under typical HCCI engine conditions using detailed chemical kinetics. The crank angle corresponding to 50% total heat release (CA50) was utilized as an indicator of the fuel reactivity, and iso-contours of CA50 were then plotted in engine operating parameter coordinates, such as the intake temperature, and pressure. It is shown that fuels with the same RON/MON could even exhibit both qualitatively and quantitatively different CA50 iso-contours in specific operating regimes, implying the insufficiency of RON/MON as comprehensive metrics of fuel reactivity in ACI strategies. In addition, operating regimes with high and low sensitivity, as well as potential non-monotonic change in fuel reactivity have been identified by the CA50 iso-contour map for all fuels studied. It is also shown that the combustion phasing can increase, decrease, or exhibit non-monotonic changes with equivalence ratio variation, subject to fuel and operating conditions. This study provides useful insights into the control of ACI combustion phasing and the understanding of SI end-gas auto-ignition, as well as implications on the selection of future alternative fuels and the derivation of fuel surrogate models.

Sa1687 - Feasibility and Testing of Group HRM Isocontour Maps as a Means to Facilitate Comparison Across Individuals and Conditions: Development of a Learning Comparative "Manobank"

Sa1687 - Feasibility and Testing of Group HRM Isocontour Maps as a Means to Facilitate Comparison Across Individuals and Conditions: Development of a Learning Comparative "Manobank"

Active optical-based detuning circuit for receiver endoluminal coil

In this paper we demonstrate the effectiveness of an active optical detuning circuit for magnetic resonance imaging endoluminal receiver coil. Three endoluminal coils prototypes were built: a coil without any detuning circuit, a coil with a galvanic (classic) detuning circuit using a PIN diode, and a coil with an optical detuning circuit using two photodiodes in parallel with a PIN diode. These coils were built and characterized on a laboratory experimental bench. Then, an in vitro experiment was performed with a 3.0 T MR system to evaluate the impact of the endoluminal receiver coils in detuned phase on the image uniformity distribution measured using the body coil. Next, the endoluminal coil was used as a receiver coil to compare the signal-to-noise ratio (SNR) distribution based on iso-contour maps. On experimental bench, the results show an increase delay of the switching times (tuned-detuned or detuned-tuned) for optical-detuned coils of about 10 μs due to the electro-optical circuits, delay still compatible with requirements. When the body coil is used as a transceiver, the SNR uniformity is similar whether the galvanic or the optical detuning circuit is used. Finally, the SNR iso-contours of the different endoluminal coils prototypes are comparable.

Caracterização dos rejeitos das minas do Camaquã para reaproveitamento sustentável

O reaproveitamento de rejeitos provindos de atividades mineiras é de extrema importância, pois são possíveis poluidores do meio ambiente. Este trabalho visou à reutilização sustentável, social e econômica dos rejeitos remanescentes do beneficiamento do minério de cobre das Minas do Camaquã. Na 1ª fase do estudo, foram empregadas metodologias de amostragem, separação granulométrica, análises físico-químicas, análise mineralógica, ensaios físico-químicos de concentração de minerais, elaboração de mapa de isocontorno de teores do elemento químico principal Cu. Nesta 2ª fase, aprofundou-se a análise granulométrica para detalhamento do percentual de distribuição de finos, classificação do resíduo para verificação segundo a norma da ABNT 10004 e avaliar a pré-viabilidade econômica para verificação da alternativa de recuperação do Cu pelo método de lixiviação e ensaios para uma possível utilização do material na construção civil. Concluiu-se pela inviabilidade econômica através da recuperação do Cu contido, por lixiviação, de acordo com o modelo de análise econômica. A pré-viabilidade técnica da utilização na fabricação de tijolos foi constatada conforme resultados das simulações em ensaios realizados de acordo com a fabricação industrial e normas de índice de qualidade (NBR 8492). O resíduo apresentou “inerte” de acordo com a ABNT 10004 e granulometria entre areia fina até areia muito fina.

International Research Journal of Geology and Mining

An Evaluation of Self-Potential anomaly over sulphide ore deposits has been undertaken at Ishiagu, Ebonyi State, Southeastern Nigeria. The Project site is about 5sqkm, underlain by two main geologic units. The Abakaliki Shale and the Ezeaku Formation. The potential gradient array technique of Self- Potential method was employed. Data was interpreted using surfer 8 computer software and Ms Excel tool Kits. Iso-contour maps of Self Potential and profile plots for anomaly variations were constructed. Results show positive Self-Potential closures, with corresponding peaks in the profile plots which are indicative of sulphide ore deposits. Trend orientations of anomaly peaks occur roughly NW – SE and NE – SW in a cross – cutting stress pattern.

Propagation of a lithospheric tear fault (STEP) through the western boundary of the Calabrian accretionary wedge offshore eastern Sicily (Southern Italy)

The rollback of a segmented slab of oceanic lithosphere is typically accompanied by vertical lithospheric tear fault(s) along the lateral slab edge(s) and by strike slip movement in the upper plate, defined as a STEP fault (Subduction Tear Edge Propagator). The Neogene evolution of the Central Mediterranean is dominated by the interaction between the slow Africa–Eurasia convergence and the SE-ward rollback of the Ionian slab, that leads to the back-arc opening of the Tyrrhenian Sea. Here, we present post-stack time migrated and pre-stack depth migrated Archimede (1997) multichannel seismic lines, that were acquired offshore eastern Sicily, at the foot of the Malta escarpment . First, we identify the recent deformation along the lateral ramp of the Calabrian accretionary wedge. Towards the east, the Calabrian wedge is formed by the accretion of the post-evaporitic sediments, above a decollement at the base of the Messinian evaporites . At the latitude of Syracuse, 50 km east of the Malta escarpment, a major N150°E trending crustal scale and vertical fault slices through the entire accretionary wedge. This fault cuts by several kilometers, through the pre-evaporitic Messinian sediments and into the basement. The vertical offset along this vertical fault decreases from north to south, and the fault is no longer observed on the seismic lines, 50 km SE of the Alfeo seamount . A previously published Moho depth isocontour map, offshore Sicily and the recent GPS data, combined with the presence of strike slip movements NE onshore Sicily, allow us to identify this 200 km long crustal-scale fault as the surface expression of a STEP fault. The presence of syntectonic Pleistocene sediments on top this crustal-scale fault suggests a recent lithospheric vertical movement of the STEP fault, in response to the rollback of the Ionian slab and to the SE-ward advance of the Calabria-Peloritan block. ► Depth migrated seismic reflection profiles from the Calabria/Sicily active margin. ► A N150°E striking, lithospheric scale fault, 50 km east of the Malta escarpment ► Interpreted to be a “Subduction Tear Edge Propagator” (STEP) fault ► Fault offset decreases to the S until termination (at the propagating tip) ► Deformed sediments suggest recent fault activity (related to Calabrian subduction).

Karst springs as “natural” pluviometers: Constraints on the isotopic composition of rainfall in the Apennines of central Italy

This paper describes an indirect method to calculate the isotopic composition of rainfall by using the isotopic composition of karst springs fed by waters circulating in the most important regional aquifer of central Italy, i.e. the Mesozoic limestone sequence that forms the backbone of the Apennines. By using δ18O and δD data and the δ18O (and/or δD) average gradient for elevation, evaluated through the use of literature rainfall data and new measurements from a typical Alpine valley in northern Italy, the altitude of precipitation of their parent water has been re-calculated. Vertical descents of more than 2000 m, from recharge to discharge, have been assessed in some high flow-rate cold springs in the morphologically steep Adriatic sector of central Italy. A clear correlation between the vertical descents and more negative isotopic compositions at their relative emergence elevations is highlighted. In contrast, in the Tyrrhenian sector lower karstic drops (generally lower than 500 m) correlate with less negative isotopic composition of recharge areas. The δ18O iso-contour map of the “recalculated” parent rainfall in central Italy is more detailed than any possible isotopic map of rainfall made using pluviometers, unless large number of rainfall collectors were deployed on mountaintops. The data also show that the isotopic composition of rainfall depends on the source of the storm water. In particular, precipitation is isotopically heavier when originating in the Mediterranean Sea, and lighter when formed in the Atlantic Ocean. Consequently, the collision between air masses with such a different isotopic signature results in a relatively small latitudinal fractionation effect. The peninsular part of central Italy is very narrow, with several mountains and massifs more that 2000 m high, and any latitudinal variation in the isotopic composition between rainfall sourced in the Atlantic Ocean and in the Mediterranean Sea is much lower than that due to the isotopic fractionation due to elevation.

Segmentation of Regions of Interest in Mammograms in a Topographic Approach

This paper presents a novel method for the segmentation of regions of interest in mammograms. The algorithm concurrently delineates the boundaries of the breast boundary, the pectoral muscle, as well as dense regions that include candidate masses. The resulting representation constitutes an analysis of the global structure of the object in the mammogram. We propose a topographic representation called the isocontour map, in which a salient region forms a dense quasi-concentric pattern of contours. The topological and geometrical structure of the image is analyzed using an inclusion tree that is a hierarchical representation of the enclosure relationships between contours. The "saliency" of a region is measured topologically as the minimum nesting depth. Features at various scales are analyzed in multiscale isocontour maps, and we demonstrate that the multiscale scheme provides an efficient way of achieving better delineations. Experimental results demonstrate that the proposed method has potential as the basis for a prompting system in mammogram mass detection.

Helical structure of longitudinal vortices embedded in turbulent wall-bounded flow

Embedded vortices in turbulent wall-bounded flow over a flat plate, generated by a passive rectangular vane-type vortex generator with variable angle β to the incoming flow in a low-Reynolds-number flow (Re = 2600 based on the inlet grid mesh size L = 0.039 m and free stream velocity U∞ = 1.0 ms−1), have been studied with respect to helical symmetry. The studies were carried out in a low-speed closed-circuit wind tunnel utilizing stereoscopic particle image velocimetry (SPIV). The vortices have been shown to possess helical symmetry, allowing the flow to be described in a simple fashion. Iso-contour maps of axial vorticity revealed a dominant primary vortex and a weaker secondary one for 20° ≤ β ≤ 40°. For angles outside this range, the helical symmetry was impaired due to the emergence of additional flow effects. A model describing the flow has been utilized, showing strong concurrence with the measurements, even though the model is decoupled from external flow processes that could perturb the helical symmetry. The pitch, the vortex core size, the circulation and the advection velocity of the vortex all vary linearly with the device angle β. This is important for flow control, since one thereby can determine the axial velocity induced by the helical vortex as well as the swirl redistributing the axial velocity component for a given device angle β. This also simplifies theoretical studies, e.g. to understand and predict the stability of the vortex and to model the flow numerically.

Dose verification in clinical imrt prostate incidents

Purpose In view of the need for dose-validation procedures on each individual intensity-modulated radiation therapy (IMRT) plan, dose-verification measurements by film, by ionization chamber, and by polymer gel–MRI dosimetry were performed for a prostate-treatment plan configuration. Treatment planning system (TPS) calculations were evaluated against dose measurements. Methods and materials Intensity-modulated radiation therapy (IMRT) treatments were planned on a commercial TPS. Kodak EDR-2 films were used for the verification of two-dimensional (2D) dose distributions at 1 coronal and 5 axial planes in a water-equivalent phantom. Full three-dimensional (3D) dose distributions were measured by use of a novel polymer gel formulation and a 3D magnetic resonance imaging (MRI) readout technique. Calculations were compared against measurements by means of isocontour maps, γ-index maps (3% dose difference, 3-mm distance to agreement) and dose–volume histograms. Results A good agreement was found between film measurements and TPS predictions for points within the 60% isocontour, for all the examined plans (γ-index <1 for 96% of pixels). Three-dimensional dose distributions obtained with the polymer gel–MRI method were adequately matched with corresponding TPS calculations, for measurements in a gel phantom covering the planning-target volume (PTV). Conclusions Measured 2D and 3D dose distributions suggest that, for the investigated prostate IMRT plan configuration, TPS calculations provide clinically acceptable accuracy.

Ictal MEG in two children with partial seizures

We report on the successful identification of epileptic foci in two children with partial epilepsy using ictal magnetoencephalography (MEG). Case 1 is a 12-year-old male suffering with simple partial seizures with leftwards nystagmus. Ictal SPECT revealed a hyperperfusion area in the right lateral occipital area, and MRI revealed cortical dysplasia in the same area. Interictal EEG dipoles were concentrated in the right mesial occipital lobe. Both interictal and ictal MEG dipoles were concentrated in the right mesial occipital lobe, which corresponded well with neuroimaging data and his clinical features. Case 2 is a 5-year-old female suffering with simple partial seizures with left-side facial twitching. Interictal EEG dipoles were located in her left motor area, the pre-sylvian fissure, close to the location of the interictal MEG-estimated dipoles. Ictal EEGs showed no remarkable changes associated with her clinical manifestations. However, ictal MEG showed high-voltage slow waves over her left hemisphere, and ictal MEG iso-contour maps revealed a clear dipolar pattern, which suggested that the MEG dipole was located in the area of the sylvian fissure. Ictal SPECT revealed hyperperfusion areas around the left sylvian fissure. Conclusion: Ictal MEG is useful for determining the precise location of epileptic focus in patients with motionless seizures, including children.

A chemical Hamiltonian approach study of the basis set superposition error changes on electron densities and one- and two-center energy components

The basis set superposition error-corrected first-order electron densities of several hydrogen bonded complexes of increasing molecular size have been obtained with the Hartree–Fock and density-functional theory versions of the chemical Hamiltonian approach (CHA) methodology. A detailed analysis of the local basis set superposition error (BSSE) effects has been carried out by comparing the uncorrected electron densities and energy components with the CHA ones. Topological analysis of the electron density through the atoms in molecules theory is used in order to obtain a quantitative measure of the BSSE effects in terms of the characterization of the critical points of the electron density. Density difference isocontour maps are also depicted in order to show the local electron density redistributions induced by the BSSE-correction. We show that the effects of the BSSE are common for all the complexes studied, namely water dimer, formic acid dimer and uracil–water complex. The formic acid dimer and uracil–water density difference maps at frozen geometry reveal that the effects of the BSSE do not extend significantly beyond the atoms involved in the interaction and their first neighbors. The main redistribution effects are not strictly localized on the intermolecular region and mostly take place in the valence shells of the heavy atoms directly involved in the intermolecular interaction. These trends are also confirmed by means of an energy decomposition analysis performed at the Hartree–Fock level of theory with the recently proposed chemical energy component analysis (CECA) method. In agreement to previous results, we found that inclusion of diffuse functions is of utmost importance in order to minimize the magnitude of the BSSE. However, both the electron density difference maps and the CECA analysis confirm that the local effects of the BSSE are very different when diffuse functions are present in the calculation.

Mapping of several soil properties using DAIS-7915 hyperspectral scanner data - a case study over clayey soils in Israel

The data acquired from the hyperspectral airborne sensor DAIS-7915 over Izrael Valley in northern Israel was processed to yield quantitative soil properties maps of organic matter, soil field moisture, soil saturated moisture, and soil salinity. The method adopted for this purpose was the Visible and Near Infrared Analysis (VNIRA) approach, which yields an empirical model for predicting the soil property in question from both wet chemistry and spectral information of a representative set of samples (calibration set). Based on spectral laboratory data that show a significant capability to predict the above soil properties and populations using the VNIRA strategy, the next step was to examine this feasibility under a hyperspectral remote sensing (HSR) domain. After atmospherically rectifying the DAIS-7915 data and omitting noisy bands, the VNIRA routine was performed to yield a prediction equation model for each property, using the reflectance image data. Applying this equation on a pixel-bypixel basis revealed images that described spatially and quantitatively the surface distribution of each property. The VNIRA results were validated successfully from a priori knowledge of the area characteristics and from data collected from several sampling points. Following these examinations, a procedure was developed in order to create a soil property map of the entire area, including soils under vegetated areas. This procedure employed a random selection of more than 80 points along non-vegetated areas from the quantitative soil property images and interpolation of the points to yield an isocontour map for each property. It is concluded that the VNIRA method is a promising strategy for quantitative soil surface mapping, furthermore, the method could even be improved if a better quality of HSR data were used.