Zone Dispersion Research Articles

An Innovative Approach to Assessing the Distribution of Stored Freshwater while Injecting it through a Well Partially Screening the Brackish Aquifer

Over-exploitation of groundwater in the regions favorable for human settlements around the world has raised uncertainties on the sustainability of this precious resource in the future. However, the stress on the fresh groundwater zones can be reduced substantially by managing inland brackish/saline aquifers. Freshwater when available in excess can be stored judiciously in such aquifers for later on use; though a certain quantity of fresh water is lost during its storage and recovery depending upon the in situ groundwater gradient and buoyancy effect (caused due to density difference in the injected and ambient waters). Hence, increasing the efficiency of freshwater recovery was our prime concern, and for which there was a need to know the interface boundaries of freshwater stored in the ambient water. For the purpose, a new method has been developed and proposed in this paper that is based on the hydraulics of an injection well and the breakthrough curve of the injected tracer through the storage medium (i.e. aquifer). The close agreement between the outcome of the proposed model and method with the field observations has validated the acceptance of this innovative concept. The model results show that the shape acquired by the injected freshwater in the brackish/saline aquifer depends upon the screened location of the well about its centerline. Additionally, the storage of freshwater in the upper portion of the aquifer is the most efficient way to minimize its contact with the ambient water and subsequently its loss due to the development of the dispersion zone.

Does the Contrast Dispersion Pattern During Fluoroscopically Guided Cervical Transforaminal Epidural Steroid Injection Predict Short-Term Pain and Functional Outcomes? An Exploratory Analysis of Prospective Cohort Data

No study has evaluated the relationship between contrast dispersion patterns and outcomes after fluoroscopically guided cervical transforaminal epidural steroid injection (CTFESI). Determine whether contrast dispersion patterns predict pain and functional outcomes after CTFESI. Secondary analysis of data collected during two prospective studies of CTFESI for the treatment of refractory radicular pain. Contrast dispersion patterns visualized by true anteroposterior (AP) projections during CTFESIs were categorized by flow: 1)completely external to the lateral border of the neuroforamen (zone 1); 2)within the neuroforamen but without entry into the lateral epidural space (zone 2); and 3)with extension into the lateral epidural space (zone 3). At baseline and at 1 month post-CTFESI, neck pain, arm pain, and "dominant index pain" (the greater of arm or neck pain) were evaluated using a numeric rating scale (NRS); physical function was assessed using the Five-Item Version of the Neck Disability Index (NDI-5). One-month post-CTFESI, neck pain, arm pain, and "dominant index pain" reductions of ≥50% were observed in 39.4% (95% confidence interval [CI], 28.2-51.8), 55.6% (95% CI, 43.0-67.5), and 44.1% (95% CI, 32.7-56.2) of participants, respectively. Regarding "dominant index pain," 72.7% (95% CI, 40.8-91.2), 39.4% (95% CI, 24.2-57.0), and 37.5% (95% CI, 20.5-58.2) of participants reported ≥50% pain reduction when zone 1, zone 2, and zone 3 contrast flow patterns were observed. Contrast dispersion zone was not significantly associated with subgroup differences in neck pain, arm pain, or NDI-5 scores (P>0.05). Improvements in pain and function 1 month after treatment with CTFESI did not differ significantly based on the contrast dispersion pattern. Future study is needed to confirm or refute these findings in other procedural settings, in broader patient populations, and with longer-term outcome assessment.

Monitoring Urban Green Infrastructure Changes and Impact on Habitat Connectivity Using High-Resolution Satellite Data

In recent decades, the City of Stockholm, Sweden, has grown substantially and is now the largest city in Scandinavia. Recent urban growth is placing pressure on green areas within and around the city. In order to protect biodiversity and ecosystem services, green infrastructure is part of Stockholm municipal planning. This research quantifies land-cover change in the City of Stockholm between 2003 and 2018 and examines what impact urban growth has had on its green infrastructure. Two 2018 WorldView-2 images and three 2003 QuickBird-2 images were used to produce classifications of 11 land-cover types using object-based image analysis and a support vector machine algorithm with spectral, geometric and texture features. The classification accuracies reached over 90% and the results were used in calculations and comparisons to determine the impact of urban growth in Stockholm between 2003 and 2018, including the generation of land-cover change statistics in relation to administrative boundaries and green infrastructure. For components of the green infrastructure, i.e., habitat networks for selected sensitive species, habitat network analysis for the European crested tit (Lophophanes cristatus) and common toad (Bufo bufo) was performed. Between 2003 and 2018, urban areas increased by approximately 4% while green areas decreased by 2% in comparison with their 2003 areal amounts. The most significant urban growth occurred through expansion of the transport network, paved surfaces and construction areas which increased by 12%, mainly at the expense of grassland and coniferous forest. Examination of urban growth within the green infrastructure indicated that most land area was lost in dispersal zones (28 ha) while the highest percent change was within habitat for species of conservation concern (14%). The habitat network analysis revealed that overall connectivity decreased slightly through patch fragmentation and areal loss mainly caused by road expansion on the outskirts of the city. The habitat network analysis also revealed which habitat areas are well-connected and which are most vulnerable. These results can assist policymakers and planners in their efforts to ensure sustainable urban development including sustaining biodiversity in the City of Stockholm.

Analysis of material distribution in dissimilar friction stir welded joints of Al 1050 and copper

The objective of this work is to analyse the material distribution in dissimilar friction stir welded joints of Al 1050 and Copper. During dissimilar friction stir welding, mixing of materials leads to the emergence of interfaces between two dissimilar materials. These interfaces provide venues for the formation of intermetallic compounds, which significantly affect the joint properties. Therefore it is of interest to understand the material movement and track the interfaces which are generated during friction stir welding. A three-dimensional computational fluid dynamics model is developed for the dissimilar friction stir welding. The volume of fluid method is used to track the material movement during the process. Friction stir welds of Al 1050 and Copper are prepared, with different tool rotational speeds and tool offsets towards Al 1050 side. Optical microscopy of the weld cross-sections is performed to observe the final status of material movement and material dispersion in the stir zone. Despite the absence of direct contact between copper and FS tool initially, copper is pulled into the stir region. Numerical results suggest that the temperature, stress and strain rates in the vicinity of FS tool are sufficient to pull copper into the stir zone. Relatively lower viscosities in shoulder driven region promote material mixing and uniform distribution of both materials. While pockets rich in copper or Al 1050 are observed in pin driven region. For the same strain rate and temperature, copper exhibits higher viscosity than Al 1050. This impedes the movement of copper and prevents it from moving all around the tool. This allows Al 1050 to displace copper at advancing side, which leads to shifting of initial copper-Al 1050 interface towards advancing side. Small offset towards Al 1050 and high tool rotation speed promotes pulling in of the copper and vice versa. This leads to larger interface shifts at smaller offsets and higher tool rotations speeds and vice versa. These trends are well captured by the numerical model.

A four-zone drag model based on cluster for simulating gas-solids flow in turbulent fluidized beds

Gas-solids drag model is crucial for the accurate prediction of gas-solids flow in turbulent fluidized bed (TFB). A four-zone drag model based on cluster was proposed to describe the gas-solids interactions in TFB. The model considers the cluster effect in the bottom dense bubbling zone while regards the particles as discrete ones in the top dilute dispersed zone. The structural parameter model was used to calculate the equivalent cluster diameter in the drag model. Validations against experiments show that the drag model can accurately simulate the gas-solids flow characteristics in TFBs with Geldart A and B particles. Besides, the non-uniform flow structures resulting from gas voids and particle clusters were successfully captured with the model. Compared with the bubbling fluidized bed, more small bubbles with a more uniform size distribution exist in TFB and the variation of operating conditions has little effect on gas voids characteristics in TFB.

FREQUENCY DISPERSION DEPENDENCE OF DIELECTRIC PERMITTIVITY OF CRYOGENIC ROCKS AT THE MACRO LEVEL

Purpose. The purpose of this article is to establish the analytical expression of the frequency dispersion dependence of the real part of the dielectric permittivity of cryogenic rocks according to experimental studies. Methodology. Analytical and experimental investigations of the dependence of dielectric permittivity of cryogenic rocks on the field frequency of applied loads at the macro level have been carried out. An empirical analysis of the obtained results was carried out and a comparison of these data with experimental data was performed to prove the adequacy of the proposed mathematical models. Findings. The dielectric permittivity decreases exponentially with increasing frequency at all temperature values. The dependence parameter that corresponds to the frequency at the moment of electrical relaxation (anomalous dispersion zone) shifts toward low frequencies as the temperature decreases. The maximum and minimum values of the dielectric permittivity of cryogenic rocks are constant and independent of temperature change for a particular cryogenic rock and are dependent on humidity, mineralization and morphological structure. Originality. In this article, mathematical expressions are developed to describe the frequency dependence of dielectric permittivity under low frequency and high frequency loading, which is described by a single analytical dependence. Practical implications. The practical significance of the results obtained is the ability to establish seismic-acoustic, elastic-deformation and strength properties of rocks through the study of the characteristics of the electromagnetic properties of cryogenic rocks. Conclusions. The obtained analytical dependence of the dielectric permittivity of mountain cryogenic rocks in the form of a double exponent allows to adequately describe the influence of an external electric field, taking into account the humidity and temperature of the rocks.

On High-Speed Rotary Dispersion of Liquid Media

The article presents the description of the structural design schematic of the developed high-speed rotary disperser of liquid media and the conditions of motion of emulsions and suspensions in the dispersion zone.

Justification of the method of dust emissions localization on mobile crushing and sorting complexes of quarries with the use of air-and-water ejectors

Rock mass transloading from bunkers to conveyors or from conveyors to conveyors in quarries is accompanied by intense releases of dust into the atmosphere, which is a significant danger to the environment. The regularities of the interaction process between dust particles and droplets of a liquid (water) in polluted air flow are determined. It is established that when the pressure of compressed air is changed from 0.1 to 0.4 MPa (approximately in the range of 1 to 4 atm.), the average size of droplets decreases from 26 to 9 microns. Justification of the localization method of dust emissions into the atmosphere, arriving from the units of dust formation in crushing and sorting complexes of quarries, is done with the use of air-and-water ejectors − irrigators with highly efficient water use, sprayed with separate nozzles. Variants of air-and-water ejectors placement on dust formation sources are grounded. The choice of the optimal mode of air-and-water ejectors operation depends on the characteristic sizes of the formed dust particles, which are determined by the parameters of the crushing and sorting equipment in the quarry. Reducing dust emissions within the sanitary protection zone of the quarries prevents its dispersion in the adjacent zone.

Effects of Aquifer Bed Slope and Sea Level on Saltwater Intrusion in Coastal Aquifers

The quality of groundwater resources in coastal aquifers is affected by saltwater intrusion. Over-abstraction of groundwater and seawater level rise due to climate change accelerate the intrusion process. This paper investigates the effects of aquifer bed slope and seaside slope on saltwater intrusion. The possible impacts of increasing seawater head due to sea level rise and decreasing groundwater level due to over-pumping and reduction in recharge are also investigated. A numerical model (SEAWAT) is applied to well-known Henry problem to assess the movement of the dispersion zone under different settings of bed and seaside slopes. The results showed that increasing seaside slope increased the intrusion of saltwater by 53.2% and 117% for slopes of 1:1 and 2:1, respectively. Increasing the bed slope toward the land decreased the intrusion length by 2% and 4.8%, respectively. On the other hand, increasing the bed slope toward the seaside increased the intrusion length by 3.6% and 6.4% for bed slopes of 20:1 and 10:1, respectively. The impacts of reducing the groundwater level at the land side and increasing the seawater level at the shoreline by 5% and 10% considering different slopes are studied. The intrusion length increased under both conditions. Unlike Henry problem, the current investigation considers inclined beds and sea boundaries and, hence, provides a better representation of the field conditions.

Investigations on TaC Localized Dispersed X38CrMoV5-3 Surfaces with Regard to the Manufacturing of Wear Resistant Protruded Surface Textures

The potential of lowered surface features as well as the application of wear resistant coatings have been known for many years to improve the tribological behavior of forming tools. More recent studies also discuss the capability of protruded microfeatures for adjusting the tribological behavior between contacting surfaces. The demand for a high wear resistance of such structures as well as their economical and reliable production, however, often limits the industrial application. The laser implantation process can overcome these limitations. In contrast to conventional cw-laser dispersing processes, where the formation of uniform metal matrix composite layers is intended, this surface engineering technique aims to improve the tribological behavior of contacting surfaces by a localized dispersing of pre-placed hard ceramic particles. This enables the formation of deterministic textures composed of separated wear resistant dome- or ring-shaped microstructures (implants). Since TaC shows very promising material properties for improving the wear resistance of tools exposed to severe operating conditions, this paper analyzes its suitability for pulsed laser implantation on X38CrMoV5-3 tool steel for the first time. In the experiments, the influence of the particles and the laser parameters (pulse power, pulse duration and focal diameter) on the material properties of the localized dispersed zones was studied by optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The composite’s (micro-) hardness was measured and calculated by using a rule of mixture. Additionally, the influence of the laser parameters and the TaC particles on the geometrical properties of the implants was studied by optical microscopy and white light interferometry. The results showed that defect-free implants with hardness values of ~900 HV1 can be obtained at the focal spot, since a localized dispersing of the TaC particles is possible using a pulsed millisecond laser. However, in dependence of the laser intensity, also a partial dissolution of the initial particles occurs. This leads to the precipitation of new dendritic TaC nanoparticles and to varying contents of retained austenite in the matrix. Both effects have a strong influence on the implant hardness and must be considert by the rule of mixture. Regarding the geometrical response it was pointed out that protruded microfeatures with heights up to 10 μm can be created. In comparison to laser remelted zones, the implanted zones showed significantly altered weld pool profiles due to the influence of the particles on the melt convection. A transition of the implant shape from predominantly dome-shaped to predominantly ring-shaped was observed for intensities >1.7∙106 W/cm2 due to the onset of the keyhole effect. In conclusion, TaC particles seem to be very suitable for laser implantation on hot-work tool steels. The implants can be used for textures, where flat structures are needed. Since the TaC particles can be dispersed in the LIZ, it may be possible to reduce abrasive and adhesive wear due to the promising material properties of this hard phase and the improved hardness of the implants.

On the Impact of Trees on Ventilation in a Real Street in Pamplona, Spain

This paper is devoted to the quantification of changes in ventilation of a real neighborhood located in Pamplona, Spain, due to the presence of street trees Pollutant dispersion in this urban zone was previously studied by means of computational fluid dynamic (CFD) simulations. In the present work, that research is extended to analyze the ventilation in the whole neighborhood and in a tree-free street. Several scenarios are investigated including new trees in the tree-free street, and different leaf area density (LAD) in the whole neighborhood. Changes between the scenarios are evaluated through changes in average concentration, wind speed, flow rates and total pollutant fluxes. Additionally, wind flow patterns and the vertical profiles of flow properties (e.g., wind velocity, turbulent kinetic energy) and concentration, horizontally-averaged over one particular street, are analyzed. The approach-flow direction is almost perpendicular to the street under study (prevailing wind direction is only deviated 4º from the perpendicular direction). For these conditions, as LAD increases, average concentration in the whole neighborhood increases due to the decrease of wind speed. On the other hand, the inclusion of trees in the street produces an increase of averaged pollutant concentration only within this street, in particular for the scenario with the highest LAD value. In fact, the new trees in the street analyzed with the highest LAD value notably change the ventilation producing an increase of total pollutant fluxes inward the street. Additionally, pollutant dispersion within the street is also influenced by the reduction of the wind velocity along the street axis and the decrease of turbulent kinetic energy within the vegetation canopy caused by the new trees. Therefore, the inclusion of new trees in a tree-free street should be done by considering ventilation changes and traffic emissions should be consequently controlled in order to keep pollutant concentration within healthy levels.

Numerical Study of Tide-Induced Airflow and Salt-Fresh Water Dynamics in Unconfined Aquifers.

This study employed a coupled water-air two-phase flow and salt water transport model to analyze the behaviors of generated airflow in unsaturated zones and the fluctuations of salinity at the salt-fresh water interface in a two-layered unconfined aquifer with a sloping beach surface subjected to tidal oscillations. The simulation results show that as the new dynamic steady state including effects of tidal fluctuations is reached through multiple tidal cycles, the dispersion zone in the lower salt water wedge is broadened because fresh water/salt water therein flows continuously landward or seaward during tidal cycles. The upper salt-fresh water interface exhibits more vulnerable to the tidal fluctuations, and the variation of salinity therein is periodic, which is irrelevant to the hydraulic head but is influenced by the direction and velocity of surrounding water-flow. With the tidal level fluctuating, airflow is mainly concentrated in the lower permeable layer due to the restraint of the upper semi-permeable layer, and the time-lag between the pore-air pressure and the tidal level increases with distance from the coastline. The effect of airflow in unsaturated zones can be transmitted downward, causing both the magnitude of salinity and its amplitude in the upper salt-fresh water interface to be smaller for the case with airflow than without airflow due to the resistance of airflow to water-flow. Sensitivity analysis reveal that distributions of airflow in unsaturated zones are affected by the permeability of the upper/lower layer and the van Genuchten parameter of the lower layer, not by the van Genuchten parameter of the upper layer, whereas the salinity fluctuations in the salt-fresh water interface are affected only by soil parameters of the lower layer.

Geochemistry of metamorphic rocks and mineralization in the Golgohar iron ore deposit (No. 1), Sirjan, SE Iran: Implications for paleotectonic setting and ore genesis

The Golgohar iron mine is located southwest of Sirjan in the Sanandaj-Sirjan structural zone. The Golgohar ore deposit occurs mainly in the forms of massive, dispersed in altered rocks and rarely stratabound mineralizations, which is related to a fault zone. The mineralization is hosted by metapelites and metabasites. To clarify the paleotectonic, P-T condition of metamorphism and the genesis of the Golgohar ore deposit we report ICP-MS data of metamorphic rocks and EPMA data of feldspar, biotite, amphibole, and magnetite of host rocks and the mineralization. The protolith of metapelites are classified as shale and Fe-bearing shale. The chondrite-normalized REE patterns show enrichment in LREE, fairly flat HREE and negative Eu anomaly. The REE and other geochemical features of the shales support an undifferentiated arc precipitation environment. Based on the relative age of the protoliths, the shales formed during the Late Precambrian-Early Cambrian Pan-African orogeny. The protoliths of amphibolites were calc-alkaline basalt to andesite, which formed in a continental island arc setting. Geochemical data of the amphibolites suggest that the magma was derived from a depleted mantle that was contaminated by melts of subducted sediments. The igneous rocks were also formed during the Pan African orogeny. At the orogenic episode, the deep faulting generated a hydrothermal conduit to form the mineralization in this area. The compositional variations of the magnetite in the mineralization zones and the altered rocks were controlled by the compositions of fluid and the host rocks, the fugacity of oxygen and sulfur, the temperature, and the solubility of elements in the fluid. Large volume of the mineralization crosscutting the host rock is clearly controlled by structure. The presence of dispersed alteration zones, geochemical features such as high values of transitional elements (Co, V) in the magnetite mineral, the presence of xenoliths with high V and Ti contents in the mineralization zones and the stable isotope data indicate that the Golgohar ore deposit formed from high-density magmatic fluids in a subduction zone. The amphibolite host rock contains repidolite, magnesio-hornblende, pargasite, tschermakite, actinolite, phlogopite, andesine-oligoclase-albite, K-feldspar, and quartz. The sedimentary, igneous, and mineralized rocks had undergone metamorphism in the upper greenschist and amphibolite facies (450–700 °C and 6–10 kbar) at the Middle Jurassic, during the Middle Cimmerian tectonic phase. After these events, the deposit has been exposed, oxidized, weathered, and then buried by the Quaternary sediments. Thus, sedimentation and magmatism events occurred during Proto-Tethys subduction in the Cadomian arc, which is related to the Pan-African orogeny. Subsequently, in the late stage of subduction, magmatic fluids were responsible for the multiphase mineralization in the Golgohar area, while at the lateral stage of mineralization, they were accompanied by the mixing of sulfur-rich fluids (evaporative sulfate).

Numerical Simulation of Dust Dispersion and Pollution in Breathing Zone of Fully Mechanized Mining Face

In order to more accurately analyze the law of dust escape in the position of breathing zone of fully mechanized coal face, a geometric model of fully mechanized coal face is established in 1205 fully mechanized coal face of Xinan Coal Mine. The movement law of dust with the wind field in the fully mechanized coal face is simulated by FLUENT software, and the dust in the area of breathing zone at different positions is also simulated. The situation is analyzed in detail. The simulation results show that the overall movement law of air flow in the whole working face is from small to large and then to small. When the air flow passes through the area near the shearer, the local space becomes smaller, the wind speed increases and transverse movement occurs. The dust produced by the shearer cutter diffuses into the space of the shearer and its downwind side roadway accompanied by the air flow. A high concentration dust belt is formed in the area near the shearer. The dust contaminated area in front of the Hydraulic support and the space breathing belt of the sidewalk increases gradually with the prolongation of dust production time and covers the height of the whole breathing belt after 80 s of dust production.

Enhance magnetoelectric coupling in xLi0.1Ni0.2Mn0.6Fe2.1O4–(1 − x)BiFeO3 multiferroic composites

Lead-free multiferroic composites of xLi0.1Ni0.2Mn0.6Fe2.1O4 (LNMFO)–(1 − x)BiFeO3 (BFO) were prepared. Multiferroic properties of LNMFO–BFO were analyzed. The compositions are a combination of ferrite and perovskite phases verified by the measurement of X-ray diffraction. FESEM image analyzed the surface morphology of the compositions. The EDX Spectroscopy performed quantitative elemental of the compositions. The $$\mu_{i}^{\prime }$$ increases in the samples with ferrite concentration. Dielectric properties were analyzed with frequency. The change in $$\varepsilon^{\prime }$$ with frequency displays dielectric dispersion in the low frequency zone because of interfacial polarization of Maxwell–Wagner type resulting from the two phase interface. Frequency autonomous behavior of the $$\varepsilon^{\prime }$$ is seen in the higher frequency region as electric dipoles can not follow the rapid change in the alternating electrical field. The $$\varepsilon^{\prime }$$ is reduced with ferrite concentration. Dielectric loss peaks occur when the electrons hopping frequency is almost equal to the applied field frequency. The $$\sigma_{AC}$$ of the samples follows the power law of Jonscher and increases with frequency, indicating that there is conduction of small polaron hopping. Impedance spectroscopy studies recommend that the grain and grain boundary perform to the conduction phenomena. Magnetization was measured to study the recompose of the ferrite phase with the magnetic field. Both $$M_{s}$$ and $$M_{r}$$ have been increased with ferrite content. The magnetoelectric voltage coefficient is reduced with ferrite concentration. The maximum value of the magnetoelectric voltage coefficient is quite high, up to ~ 98 × 103 Vm−1 T−1 for the composite 0.1LNMFO–0.9BFO.

THERAPEUTIC TACTICS FOR ACUTE PERIITONITY IN PATIENTS WITH COMORBID PATHOLOGY

The objective of the study: justification of the treatment of patients with acute peritonitis (AP) with comorbid pathology (CP). Materials and methods: 420 white rats with simulated AP, diabetes mellitus, pathology of the liver, kidneys; 726 patients with acute surgical pathology. The clinical parameters, immune, proteolytic, cytokine, oxidative-reduction systems, hemostasis, biochemical, microbiological, morphological changes were investigated. Results. Mutual burdening syndrome was found to be a pathogenic basis of changes in the course of AP in patients with comorbid diseases. The stages of its development are determined. The new classification of CP for emergency abdominal surgery is developed, which involves the selection of four classes. A management tactics is developed within CP, which provides a differentiated choice of the activities amount at all stages of treatment, considering the classes of CP. The indications are extended before preoperation, which should be performed in patients who belong to the II and III class of CP. To assess AP spread a method has been developed, which is based on the changes of the laser beam dispersion zone width by the parietal peritoneum. For a reasonable choice of the amount of surgery and place of applying intestinal stitches a method of determining viability is developed, which involves the detection of the photoluminescence index. To increase the connection zone reliability of the hollow digestive organs continuous no-penetrating and single-row stitches are developed. To protect and fix the suture lines on the hollow digestive organs methods of local influence are developed, enabling to regulate the course of the regeneration processes. The indications for the use of programmed repeated sanitization of the peritoneal cavity are extended. For patients belonging to class II of CP such surgery is recommended to be performed starting with the II degree of severity of AP, and those belonging to the III class – starting with the I degree of severity. The method of the prolonged peritoneal cavity sanitization is developed by means of drainage devices, which enables to accelerate the regression of inflammation, reduce the number of repeated surgery and duration of treatment. Conclusions. 1. The pathogenetic and clinical features of AP in patients with CP are caused by mutual burdening syndrome. 2. The developed prognostic scale assuming four classes of CP, enables to reasonably choose the necessary volume of treatment for a particular patient. 3. The use of the developed therapeutic tactics, based on the suggested evaluation scale, can significantly improve the results of treatment of patients with AP.

Highly exfoliated epoxy/clay nanocomposites filled with novel cationic fluorinated polyacrylate modified montmorillonite: Morphology and mechanical properties

AbstractIn this investigation, a novel cationic fluorinated polyacrylate modified montmorillonite (CFPA‐MMT) were prepared. WAXRD results showed that the d‐spacing of CFPA‐MMTs expanded with an increase in the feeding amount of CFPA. FTIR spectra and TGA analysis were used to confirm the modification and organic content of CFPA‐MMTs. E51‐CFPA‐MMTs nanocomposites containing different amount of CFPA‐MMTs were fabricated using acetone slurry compounding method. WAXRD patterns in combination with TEM observations presented the intercalated structure of the E51‐0.5CFPA‐MMT‐3 nanocomposite and the intercalated/exfoliated morphologies of E51‐1CFPA‐MMT‐3 and E51‐2CFPA‐MMT‐3 nanocomposites, which revealed that an increase in the CFPA content of CFPA‐MMTs is conducive to form the exfoliated morphology. The SEM images showed that the dispersion zones of MMT platelets separately dispersed in the epoxy matrix at lower filler content (≤1 wt%) whereas connected with each other at higher filler content (≥3 wt%). The separate dispersion zones induced superior improvement in the tensile strength, especially with higher CFPA content. The E51‐2CFPA‐MMT‐1 nanocomposites obtained the largest tensile strength at 69.2 MPa which is an increase of 14.4% compared to that of the neat cured E51. The intercalated and exfoliated MMT platelets increased the storage modulus both in the glassy region and in the rubbery region while decreased the Tg of epoxy/clay nanocomposites compared to the neat cured epoxy.

Phylogeography of the Neotropical epiphytic orchid, Brassavola nodosa: evidence for a secondary contact zone in northwestern Costa Rica.

Spatial patterns of genetic variation can reveal otherwise cryptic evolutionary and landscape processes. In northwestern Costa Rica, an approximately concordant genetic discontinuity occurs among populations of several plant species. We conducted phylogeographic analyses of an epiphytic orchid, Brassavola nodosa, to test for genetic discontinuity and to explore its underlying causes. We genotyped 18 populations with 19 nuclear loci and two non-coding chloroplast sequence regions. We estimated genetic diversity and structure, relative importance of pollen and seed dispersal, and divergence time to understand how genetic diversity was spatially partitioned. Nuclear genetic diversity was high with little differentiation among populations (GSTn = 0.065). In contrast, chloroplast haplotypes were highly structured (GSTc = 0.570) and reveal a discontinuity between northwestern and southeastern populations within Costa Rica. Haplotype differences suggest two formerly isolated lineages that diverged ~10,000-100,000 YBP. Haplotype mixing and greater genetic diversity occur in an intermediate transition zone. Patterns of nuclear and chloroplast data were consistent. Different levels of genetic differentiation for the two genomes reflect the relative effectiveness of biotic versus abiotic dispersers of pollen and seeds, respectively. Isolation of the two lineages likely resulted from the complex environmental and geophysical history of the region. Our results suggest a recent cryptic seed dispersal barrier and/or zone of secondary contact. We hypothesize that powerful northeasterly trade winds hinder movement of wind-borne seeds between the two regions, while the multi-directional dispersal of pollen by strong-flying sphinx moths resulted in lower differentiation of nuclear loci.

Estimating cumulative wastewater treatment plant discharge influences on acesulfame and Escherichia coli in a highly impacted watershed with a fully-integrated modelling approach

Wastewater treatment plant (WWTP) discharge is often considered a principal source of surface water contamination. In this study, a three-dimensional fully-integrated groundwater–surface water model was used to simulate the transport characteristics and cumulative loading of an artificial sweetener (acesulfame) and fecal indicator bacteria (Escherichia coli) from WWTPs within a 6800 km2 mixed-use, highly impacted watershed in Ontario, Canada. The model, which employed 3.5 × 106 computational nodes and 15 layers, facilitated a comprehensive assessment of groundwater–surface water interactions under high and low flow conditions; processes typically not accounted for in WWTP cumulative effects models. Simulations demonstrate that the model had significant capacity in reproducing the average and transient multi-year groundwater and surface water flow conditions in the watershed. As a proxy human-specific conservative tracer, acesulfame was useful for model validation and to help inform the representation of watershed-scale transport processes. Using a uniform WWTP acesulfame loading rate of 7.14 mg person−1 day−1, the general spatial trends and magnitudes of the acesulfame concentration profile along the main river reach within the watershed were reproduced; however, model performance was improved by tuning individual WWTP loading rates. Although instream dilution and groundwater–surface water interactions were strongly dependent on flow conditions, the main reach primarily consisted of groundwater discharge zones. For this reason, hydrodynamic dispersion in the hyporheic zone is shown as the predominant mechanism driving acesulfame into near-stream shallow groundwater, while under high flow conditions, the simulations demonstrate the potential for advective flushing of the shallow groundwater. Regarding the cumulative impact of the WWTPs on E. coli concentrations in the surface flow system, simulated transient E. coli levels downstream of WWTPs in the watershed were significantly lower than observed values, thus highlighting the potential importance of other sources of E. coli in the watershed.

Identification of salty zone in Grabagan salt mine, Kradenan sub-district, Grobogan district, Central Java, Indonesia

Grabagan Village is located to the southwest of Bledug Kuwu, the famous mud volcano in Central Java Province. In this area, there are surface manifestations such as mudflow and saltwater explosion. Mud volcano is a product of mountains that emit mud or clay onto the earth’s surface.The aim of this research is to know the dispersion of salty zones in Grabagan mud volcano using 3D model. This research was done by geoelectric method using Sclumberger configuration with stretch of approximately 300 meters at 8 measurement points. Based on the resistivity value distribution, the research area is dominated by salty zone with resistivity values of 0.0851- 8.22 Ωm and at depth of 0.75-129 meters. The salty zone leads to the northeast direction. Two vertical columns were identified in southeast and southwest of the measured area.