Diffuse Functions Research Articles

P solubility and release kinetics in the leachate of saline–sodic soil: Effect of reclamation strategies and water quality

Phosphorus release kinetics of soil undergoing intensive leaching is important for evaluating the mobility of the soil phosphorus in an agroecosystem. The interactive effect of organic and inorganic amendments and irrigation water quality regulate the P release kinetics in the leachate during reclamation. This study attempted to characterize the P release behavior of the saline–sodic soil amended with gypsum alone (G25 and G50: 25 and 50% gypsum requirement:) or with farmyard manure (G25FYM) and city waste compost from Karnal (G25CK) and Delhi (G25CD). Amended soils were leached with canal water (CW), and saline water [60.0 me L–1 with SAR 5 (SAR5), and SAR 15 mmol1/2 L–1/2(SAR15)]. The P release was best described by the Elovich equation followed by parabolic-diffusion and power function. The slope of the Elovich (1/β), power function (b), and parabolic diffusion function (R) were 1.36, 2.62, 3.63, and 1.48, 2.43, 3.98 times greater for SAR5 and SAR15, respectively, compared to CW. The 1/β and R were lowest for G50 irrespective of water quality and increased with a decrease in gypsum applied. The 1/β and R for G25FYM, G25CK, and G25CD were 11–31% higher than the G25. The leachate index of Ca2+, HCO3–, SO42–, pH, Na+: (Cl–+SO42–) ratio explained about 76% variability in the P release rate. The 1/β and R showed a significant correlation with CEC, CaCO3, and pHs of the soil. The saturation index of P minerals was significantly greater for CW compared to SAR5 and SAR15. The higher 1/β value was associated with lower post-leaching PNaHCO3 content in the soil. During leaching, soil solution P concentration was regulated by TCP2, TCPb, and HP. This study infers that desorption and diffusion–dissolution reactions based kinetic equations can successfully explain the P release behavior in saline-sodic soil. Further, high SAR water tended to increase the leaching rate of P during reclamation and it can be managed by manipulating the Ca2+ supply in soil solution.

Risk factors for impaired pulmonary diffusion function in convalescent COVID-19 patients: A systematic review and meta-analysis.

SummaryBackgroundThe long-term prognosis of COVID-19 survivors remains poorly understood. It is evidenced that the lung is the main damaged organ in COVID-19 survivors, most notably in impairment of pulmonary diffusion function. Hence, we conducted a meta-analysis of the potential risk factors for impaired diffusing capacity for carbon monoxide (DLCO) in convalescent COVID-19 patients.MethodsWe performed a systematic search of PubMed, Web of Science, Embase, and Ovid databases for relevant studies from inception until January 7, 2022, limited to papers involving human subjects. Studies were reviewed for methodological quality. Fix-effects and random-effects models were used to pool results. Heterogeneity was assessed using I2. The publication bias was assessed using the Egger's test. PROSPERO registration: CRD42021265377.FindingsA total of eighteen qualified articles were identified and included in the systematic review, and twelve studies were included in the meta-analysis. Our results showed that female (OR: 4.011; 95% CI: 2.928–5.495), altered chest computerized tomography (CT) (OR: 3.002; 95% CI: 1.319–6.835), age (OR: 1.018; 95% CI: 1.007–1.030), higher D-dimer levels (OR: 1.012; 95% CI: 1.001–1.023) and urea nitrogen (OR: 1.004;95% CI: 1.002–1.007) were identified as risk factors for impaired DLCO.InterpretationPulmonary diffusion capacity was the most common impaired lung function in recovered patients with COVID-19. Several risk factors, such as female, altered chest CT, older age, higher D-dimer levels and urea nitrogen are associated with impairment of DLCO. Raising awareness and implementing interventions for possible modifiable risk factors may be valuable for pulmonary rehabilitation.FundingThis work was financially supported by Emergency Key Program of Guangzhou Laboratory (EKPG21-29, EKPG21-31), Incubation Program of National Science Foundation for Distinguished Young Scholars by Guangzhou Medical University (GMU2020-207).

Safety Analysis of Perioperative Period in Non-Small Cell Lung Cancer Patients with Comorbid Pneumoconiosis

To explore the surgical safety of patients with comorbid non-small cell lung cancer (NSCLC) and pneumoconiosis. In this study, the clinical data of 165 NSCLC patients treated at West China Fourth Hospital, Sichuan University from August 2019 to May 2021 were collected. Among them, 21 patients with comorbid pneumoconiosis were included in the pneumoconiosis group, and the remaining 144 patients were included in the general group. Radical resection for lung cancer was performed in both groups. The perioperative clinical data, including preoperative, intraoperative and postoperative indicators, of the two groups were compared and analyzed. There was no perioperative death in either group. The proportions of male patients and patients with smoking history in the pneumoconiosis group were significantly higher than those in the general group ( P<0.05). The body mass index (BMI), pulmonary ventilation function and diffusion function in the pneumoconiosis group were significantly lower than those in the general group ( P<0.05). There was no significant difference in the median operative time and the median volume of intraoperative blood loss between the pneumoconiosis group and the general group. In the pneumoconiosis group, the proportion of advanced tumors (stage Ⅱ/Ⅲ), incidence of postoperative complications, median duration of postoperative intubation, and postoperative length of hospital stay were higher/longer than those of the normal group ( P<0.05). Compared with the general group, the incidences of lymph node calcification, dense pleural adhesion and surgical method alteration (switching from thoracoscopic surgery to open surgery or video-assisted thoracoscopy) were also significantly higher in the pneumoconiosis group ( P<0.05). Univariate analysis showed that age, smoking history, pneumoconiosis, pulmonary ventilation dysfunction, lymph node calcification, dense pleural adhesion and the volume of intraoperative blood loss were the risk factors for postoperative complications. Further multivariate regression analysis demonstrated that smoking history ( OR=1.37, P<0.05), lymph node calcification ( OR=2.36, P<0.05) and pulmonary ventilation dysfunction ( OR=5.21, P<0.05) were independent risk factors for postoperative complications. NSCLC patients with comorbid pneumoconiosis face relatively greater risks during the perioperative period when they undergo radical resection for lung cancer. Therefore, the close attention of surgeons and the nursing staff should be raised accordingly.

Space Weathering Effects in Troilite by Simulated Solar-Wind Hydrogen and Helium Ion Irradiation.

Space weathering is a key process in the interpretation of airless planetary surfaces. As we engage new missions to planetary objects with potentially novel surfaces such as 16 Psyche, there is renewed interest in expanding our knowledge of space weathering effects to a wider variety of analog materials, including the physical/chemical effects of solar‐wind ions on planetary regoliths. We have experimentally simulated the effects of solar ions on two polished thick sections of meteoritic troilite (FeS) via irradiation with 1 keV hydrogen (H+) and 4 keV helium (He+), to investigate effects resulting from different ion species. We detected depletion of sulfur over the course of each irradiation using in situ X‐ray photoelectron spectroscopy. Sulfur depletion rates were surprisingly similar for H+ and He+, interpreted as a function of subsurface ion‐activated diffusion. By comparing XPS‐derived elemental abundances with SDTrimSP computer simulations, we further quantified sulfur diffusion, sputtering yield, and altered‐layer composition with respect to incident‐ion fluence, and accounted for the influence of surface oxidation due to atmospheric sample storage. Using scanning electron microscopy, we detected an increase in nanoscale surface roughness resulting from the irradiation, which we quantified using atomic force microscopy. Based on these results, we estimate that an exposure time of order 103 Earth‐years is required for troilite on Psyche to reach equilibrium sulfur depletion within the first atomic layer.

An Investigation of Fractional One-Dimensional Groundwater Recharge by Spreading Using an Efficient Analytical Technique

In the present work, the q-homotopy analysis transform method (q-HATM) was used to generate an analytical solution for the moisture content distribution in a one-dimensional vertical groundwater recharge problem. Three scenarios for the Brooks–Corey model are studied based on linear and nonlinear diffusivity and conductivity functions. The governing nonlinear fractional partial differential equations are solved effectively by the combination of a hybrid analytical technique, which is the combination of the q-homotopy analysis method and the Laplace transform method. Figures and tables are used to discuss the outcomes for fractional values of the time derivative. Mathematica software is used to plot the figures. The examples used in this paper demonstrate the accuracy and competence of the considered algorithm. The acquired results demonstrate the efficiency and reliability of the projected scheme and are also suitable to carry out the highly nonlinear complex problems in a real-world scenario.

A sorption-kinetics coupled dual-porosity poromechanical model for organic-rich shales

The flow of gas in shale formations is influenced by several coupled processes including matrix and fractures deformations, and gas sorption. An increase in effective stress by pore-pressure decline, for example, reduces the formation’s porosity and permeability whereas gas desorption results in shrinkage of the rock matrix, causing an increase in permeability. The sorption-driven characteristics of such coupled systems, however, are dependent on gas sorption kinetics. In this study, we thus utilized the concepts of non-equilibrium thermodynamics and continuum mechanics to develop a fully coupled sorptive-poroelastic constitutive equations to describe the impact of sorption kinetics induced deformation on the dual porosity behaviour of gas-shales. These developed constitutive equations were then solved using the finite element method. After verifying the model performance against existing analytical solutions and experimental data from the literature, numerical sensitivity analyses were performed to specifically investigate the gas sorption kinetics on multi-physical processes. Additional numerical sensitivity analyses were performed to assess the importance of the newly derived coupling thermodynamics coefficients. The results showed that the effect of the coupling coefficient between the chemical potential of the adsorbed gas and the porosity of the bedding planes is important in gas production, especially in the long term. Numerical results also showed that the effect of sorption kinetics on gas production is a strong function of gas diffusivity in the matrix and desorption rate. It is also realized that the effect of sorption kinetics on gas production cannot be ignored when the matrix has high gas diffusivity.

Theoretical Protocol Based on Long-Range Corrected Density Functional Theory and Tuning of Range-Split Parameter for Two-Electron Two-Proton Reduction of Phenylazocarboxylates.

A theoretical protocol based on long-range corrected density functional theory is suggested for a highly accurate estimation of the two-electron two-proton (2e2p) reduction potential of ethyl 2-phenylazocarboxylate derivatives. Geometry optimization and single-point energy refinement with ωB97X-D are recommended. The impact of polarization and diffusion functions in the basis sets on the 2e2p reduction potential is discussed. Further improvements can be achieved by tuning the range-split parameter based on the linear relationship between the Hammett constant of phenyl substituents and the optimal ω value that most accurately reproduces the experiments. The suggested protocol can accurately predict the 2e2p reduction potential of five ethyl 2-phenylazocarboxylate derivatives. Based on these findings, 22 additional candidates are suggested to enlarge the electrochemical window and to increase the selectivity of 2e2p reactions. This study contributes to the development of a theoretical approach to accurately estimate the 2e2p reduction potential of azo groups.

Clinical analysis for 15 patients with pulmonary Langerhans cell histiocytosis and literature review.

Pulmonary Langerhans cell histiocytosis (PLCH) is a clonal disease, characterized by proliferation of Langerhans cells that derived from bone marrow infiltrating the lungs and other organs. Due to the rarity of the disease, the current understanding of the disease is insufficient, often misdiagnosed or missed diagnosis. This study aims to raise clinicians' awareness for this disease via summarizing the clinical characteristics, imaging features, and treatment of PLCH. We retrospectively analyzed clinical and follow-up data of 15 hospitalized cases of PLCH from September 2012 to June 2021 in the Second Xiangya Hospital of Central South University. The age of 15 patients (9 men and 6 women, with a sex ratio of 3 to 2) was 21-52 (median 33) years. Among them, 8 had a history of smoking and 5 suffered spontaneous pneumothorax during disease course. There were 3 patients with single system PLCH and 12 patients with multi-system PLCH, including 7 patients with pituitary involvement, 7 patients with lymph node involvement, 6 patients with bone involvement, 5 patients with liver involvement, 2 patients with skin involvement, 2 patients with thyroid involvement, and 1 patients with thymus involvement. The clinical manifestations were varied but non-specific. Respiratory symptoms mainly included dry cough, sputum expectoration, chest pain, etc. Constitutional symptoms included fever and weight loss. Patients with multi-system involvement experienced symptoms such as polyuria-polydipsia, bone pain, and skin rash. All patients were confirmed by pathology, including 6 by lung biopsy, 3 by bone biopsy, 2 by lymph node biopsy, and 4 by liver, skin, suprasternal fossa tumor, or pituitary stalk biopsy. The most common CT findings from this cohort of patients were nodules and/or cysts and nodular and cystic shadows were found in 7 patients. Three patients presented simple multiple cystic shadows, 3 patients presented multiple nodules, and 2 patients presented with single nodules and mass shadows. Pulmonary function tests were performed in 4 patients, ventilation dysfunction was showed in 2 patients at the first visit. Pulmonary diffusion function tests were performed in 4 patients and showed a decrease in 3 patients. Smoking cessation was recommended to PLCH patients with smoking history. Ten patients received chemotherapy while 2 patients received oral glucocorticoid therapy. Among the 11 patients with the long-term follow-up, 9 were in stable condition. PLCH is a neoplastic disease closely related to smoking. The clinical manifestations and laboratory examination are not specific. Pneumothorax could be the first symptom which is very suggestive of the disease. Definitive diagnosis relies on histology. There is no unified treatment plan for PLCH, and individualized treatment should be carried out according to organ involvement. Early smoking cessation is essential. Chemotherapy is the main treatment for rapidly progressing PLCH involved multiple organs. All diagnosed patients can be considered for the detection of BRAFV600E gene and relevant targeted therapies have been implemented recently.

Electromagnetic Diffusion and Encryption Holography Integration Based on Reflection–Transmission Reconfigurable Digital Coding Metasurface

AbstractThe integration of different functionalities into a real‐time reconfigurable metasurface can give it more powerful ability in manipulation of electromagnetic (EM) waves. Here, a reflection–transmission (R‐T) reconfigurable digital coding metasurface, which can be flexibly switched between the reflection and transmission working states with the completely different functions, is proposed and demonstrated. As a proof of concept, an R‐T reconfigurable metasurface with integrated functions of EM diffusion in reflection state and encryption holography in transmission state is designed and demonstrated. The results have been validated by both numerical simulations and experimental measurements, showing that the proposed R‐T reconfigurable metasurface can be real‐timely controlled to work in reflection state or transmission state by adjusting bias voltage, in which the incident EM waves are totally reflected and randomly diffused to achieve low radar cross section (RCS) in reflection state and efficiently transmitted to realize encrypted holographic images in transmission state.

Comprehensive Basis-Set Testing of Extended Symmetry-Adapted Perturbation Theory and Assessment of Mixed-Basis Combinations to Reduce Cost.

Hybrid or "extended" symmetry-adapted perturbation theory (XSAPT) replaces traditional SAPT's treatment of dispersion with better performing alternatives while at the same time extending two-body (dimer) SAPT to a many-body treatment of polarization using a self-consistent charge embedding procedure. The present work presents a systematic study of how XSAPT interaction energies and energy components converge with respect to the choice of Gaussian basis set. Errors can be reduced in a systematic way using correlation-consistent basis sets, with aug-cc-pVTZ results converged within <0.1 kcal/mol. Similar (if slightly less systematic) behavior is obtained using Karlsruhe basis sets at much lower cost, and we introduce new versions with limited augmentation that are even more efficient. Pople-style basis sets, which are more efficient still, often afford good results if a large number of polarization functions are included. The dispersion models used in XSAPT afford much faster basis-set convergence as compared to the perturbative description of dispersion in conventional SAPT, meaning that "compromise" basis sets (such as jun-cc-pVDZ) are no longer required and benchmark-quality results can be obtained using triple-ζ basis sets. The use of diffuse functions proves to be essential, especially for the description of hydrogen bonds. The "δ(Hartree-Fock)" correction for high-order induction can be performed in double-ζ basis sets without significant loss of accuracy, leading to a mixed-basis approach that offers 4× speedup over the existing (cubic scaling) XSAPT approach.

State‐owned industrial enterprises' non‐R&amp;D innovation and regional total factor productivity: An analysis based on the panel co‐integration method

State‐owned industrial enterprises' (SOIEs') non‐R&amp;D innovation activities have been ignored by scholars. Using panel data on the regions of China, this paper examines the impact of non‐R&amp;D innovation by SOIEs on regional total factor productivity (TFP) with panel Co‐integration and a panel vector error correction (VEC) model. The results show that SOIEs' non‐R&amp;D innovation is important for economic growth, and different types of non‐R&amp;D innovations have heterogeneous effects on regional TFP. Foreign technology acquisition (FTA) has more positive long‐term and short‐term impacts on regional TFP than do R&amp;D expenditures. Technology assimilation (TA) improves regional TFP, but the effect of R&amp;D expenditures on innovation is higher than that of TA in the eastern region. Domestic technology purchases (DTPs) have no significant impact on regional TFP in the central and western regions and even have a negative effect in the eastern region. Technology transformation (TT) has a stronger long‐term positive effect on regional TFP than R&amp;D expenditures, but R&amp;D innovation has a stronger short‐term positive effect than TT. We examine the impact of SOIEs' non‐R&amp;D innovation on regional economic efficiency and, to a degree, identify the source of its effect on innovation. This study emphasizes the critical function of technology diffusion in fostering economic efficiency.

Analysis of rotation and shift based diffusion functions

‘Rotation and shift’ based diffusion functions are used in modern ciphers especially in ARX (Addition, Rotation, and XOR) based designs. They are preferred over other alternatives as they are efficient and lightweight. Usually, such diffusion functions map an n-bit block to another n-bit block. One of the requirements for an n-bit to n-bit diffusion function is that, it should be invertible. In this paper, we present mathematical models for different classes of ‘rotation and shift’ based diffusion functions and explore their invertibility. We derive sufficient conditions under which diffusion functions of these classes are invertible.

Arterial partial pressure of oxygen and diffusion function as prognostic biomarkers for acute pulmonary embolism

BackgroundRisk stratification for acute pulmonary embolism (PE) ignores the roles of respiratory function and gas exchange. We aimed to identify the role of arterial partial pressure of oxygen (PO2) and diffusion function as prognostic biomarkers. MethodsWe collected the data from hospitalised patients with acute PE. We used Spearman's correlation coefficient and Cox regression analysis to explore the clinical and prognostic values of PO2 and predicted percentage diffusing lung capacity for carbon monoxide (DLCO%pred) to predict the 30-day mortality. ResultsWe included 309 patients (mean age: 67.93 ± 13.31 years); 46.6% were men, and 12.62% were haemodynamically unstable. The 30-day all-cause mortality rates in the high-, intermediate high-, intermediate low-, and low-risk groups were 7.7%, 4.7%, 2.9%, and 0.0%, respectively (P < 0.05). PO2 (P = 0.012) and DLCO%pred (P = 0.036) were significantly different between the four risk groups. There were strong correlations between PO2, DLCO%pred, PO2*DLCO%pred, and other markers (P < 0.05), especially troponin I, N-terminal pro-brain natriuretic peptide, and systolic pulmonary artery pressure. PO2 and PO2*DLCO%pred were prognostic factors for death in haemodynamically stable patients (hazard ratio [HR] 0.618, 95% confidence interval [CI] 0.389–0.980, P = 0.041, and HR 0.501, 95% CI 0.26–0.96, P = 0.036, respectively). A lower PO2 (<8 kPa) was associated with a higher risk of mortality in all patients and in haemodynamically stable ones (HR 9.462, 95% CI 2.365–37.860, P = 0.001, and HR 6.597, 95% CI 1.102–39.495, P = 0.039, respectively). ConclusionsPO2, PO2*DLCO%pred, and PO2 < 8 kPa were predictors of 30-day all-cause mortality in all patients and haemodynamically stable ones. Trial registrationChiCTR2000030448.

Impacts of Technology Training Provided by Agricultural Cooperatives on Farmers’ Adoption of Biopesticides in China

As pesticide abuse becomes increasingly serious worldwide, it is necessary to pay attention to the biopesticide adoption behavior of agricultural producers. It is worth verifying whether agricultural cooperatives, as training organizations sharing the same social network with farmers, can promote the adoption of biopesticides through their technology diffusion function. Therefore, based on survey data of 837 citrus producers in Sichuan Province, China, the IV-probit regression model and a mediation effects model were used to empirically test the impact of technical training on farmers’ adoption of biopesticides in addition to its mechanism, considering the farmers’ perception of technology as the mediation variable. The results show that (a) participation in technical training can significantly enhance the probability of the adoption of biopesticides; (b) farmers’ perceptions of biopesticides’ economic and health benefits play a partial mediating role in the relationship; and (c) technical training has more significant effects on biopesticides adoption behavior for a household with higher-educated household heads, lower household total income, and smaller household size, relative to their counterparts. This study provides evidence for establishing relevant policy to encourage the full adoption of the technical training function of agricultural cooperatives and popularize the use of biopesticides.

Altered white matter diffusivity and subtle motor function in a pilot cohort of adolescents with sports-related concussion

ABSTRACT Background and objective Adolescents with sports-related concussion (SRC) demonstrate acute and persistent deficits in subtle motor function. However, there is limited research examining related neurological underpinnings. This pilot study examined changes in motor-associated white matter pathways using diffusion tensor imaging (DTI) and their relationship with subtle motor function. Methods Twelve adolescents with SRC (12–17 years) within two-weeks post-injury and 13 never-injured neurotypical peers completed DTI scanning. A subset of 6 adolescents with SRC returned for a follow-up visit post-medical clearance from concussion. Subtle motor function was evaluated using the Physical and Neurological Examination of Subtle Signs (PANESS). Results Adolescents with SRC showed higher mean diffusivity (MD) of the superior corona radiata and greater subtle motor deficits compared to controls. Across all participants, greater subtle motor deficits were associated with higher (more atypical) MD of the superior corona radiata. Preliminary longitudinal analysis indicated reduction in fractional anisotropy of the corpus callosum but no change in the MD of the superior corona radiata from the initial visit to the follow-up visit post-medical clearance. Conclusions These findings support preliminary evidence for a brain–behavior relationship between superior corona radiata microstructure and subtle motor deficits in adolescents with SRC that merits further investigation.

Employing Pseudopotentials to Tackle Excited-State Electron Spill-Out in Frozen Density Embedding Calculations.

In frozen density embedding (FDE), the properties of a target molecule are computed in the presence of an effective embedding potential, which accounts for the attractive and repulsive contributions of the environment. The formally exact embedding potential, however, is in practice calculated using explicit kinetic-energy functionals for which the resulting potentials are in many cases not repulsive enough to account fully for Pauli repulsion by the electrons of the environment and to compensate thereby the strong electron-nuclear attraction. For the excited states on the target molecule, this leads to charge spill-out when diffuse basis functions are included, which allow that valence electrons are excited to those regions of the environment where the strong nuclear attraction is not sufficiently compensated by repulsive contributions. To reduce this insufficiency, we propose in the present work the inclusion of atomic all-electron pseudopotentials for all environment atoms on top of the conventional embedding potential. In the current work, the pseudopotentials are applied for computing vertical excitation energies of local excited states in complex systems employing the second-order algebraic diagrammatic construction (ADC(2)) scheme. The proposed approach leads to significantly reduced charge spill-out and an improved agreement of FDE and supermolecular calculations in the frozen solvent approximation. In particular, when diffuse functions are employed, the mean absolute deviation (MAD) is reduced from 0.27 to 0.05 eV for the investigated cases.

Dim and Small Target Detection Based on Improved Spatio-Temporal Filtering

Small target detection in high strength clutter background is in great in remote imaging system, a new improved spatio-temporal filtering was proposed in this paper. Firstly, traditional anisotropy filtering has poor suppression effect in strength edge contour region, so a new diffusion filtering function proposed in paper. According to the analysis with difference of each component of the image, a new anisotropy diffusion function is constructed in this paper. When the difference of background and target is small, this algorithm will give in large diffusion coefficient to filter most background clutter and retain target signal well which achieves background prediction better. Secondly, because the traditional spatiotemporal filter algorithm cant follow the motion object in the fixed search pipe diameter what will make lose the target detection, a new weight constraint function of adaptive change of the search diameter in this paper is built which can change the search diameter with the moving of target, and improve the detection accuracy. Finally, experiments show that compared with traditional algorithms and detected in different scenes, this method can enhance small target detection effectively.

Elucidating the mass transfer mechanism of CrVI adsorption by encapsulated chitosan-carbon nanotubes-iron beads in packed-bed columns

This study evaluates the CrVI breakthrough behaviors of a continuous-flow column packed with composite chitosan-MWCNTs‑iron beads under various operating conditions. Under the tested range of experimental parameters, a maximum of 54% of CrVI removal was achieved at: water flow rate, 1 mL/min, feed CrVI concentration, 30 mg/L; and packed bed height 8 cm. A homogeneous surface diffusion model (HSDM) involving convection-dispersion and diffusion equations was formulated, numerically solved, and experimentally validated. The high degree of conformity between the calculated and experimental breakthrough curves facilitated the determination of mass transfer parameters including axial dispersion DL, (1.30 × 10−8 to 1.56 × 10−7 m2/s) and surface diffusion Ds, (7.28 × 10−11 to 1.80 × 10−10 m2/s) via an error minimizing approach. The DL value was a function of molecular diffusion, which varied with the flow velocity, mass loading, and bed height. The Ds values were slightly higher than those previously reported, owing to the heterogeneous nature of the adsorbent. The external film diffusion coefficient (kf) was also determined by using Wilson-Geankoplis empirical correlation, which was recognized as a rate-controlling factor during CrVI mass transfer to the adsorbent beads. Furthermore, sensitivity analysis showed that a transition from diffuse- to shock-front occurred with a decreasing DL, while a decrease in the slope of breakthrough curves was observed by decreasing Ds and bed porosity, and increasing kf and Langmuir parameters. Lastly, the study demonstrated a high correlation between utilization of fractional bed capacity and axial Peclet number. This method is suitable for optimizing operating conditions to maximize the utilization of a fixed-bed columns.

Kidney function, brain morphology and cognition in the elderly: sex differences in the Austrian Stroke Prevention Study.

Impaired kidney function is associated with structural brain changes and cognitive dysfunction. In the aging kidney, hemodynamic and structural alterations reduce the glomerular filtration rate (eGFR). Little is known about differences between men and women regarding decline of kidney function and brain damage.In this community-based study, we assessed associations between the eGFR, focal and diffuse brain abnormalities and cognitive functions. Sex-specific effects were analyzed by interaction terms eGFR x sex on brain structure and cognition. Interactive effects were assessed using mixed-models –stratified by sex.Overall, 196 women and 129 men (median age 68 years and mean eGFR 73.8±14.9 ml/min/1.73m2) were included. Significant associations existed between eGFR and cortical volume (β: 1.53E-04; SE: 6.72E-05; p=0.023 for neocortex). Sex exerted a significant interactive effect. Only in men, eGFR related to cortical volumes of all lobes and of deep gray matter structures (p= 0.001 for total gray matter, p=0.0004 for neocortex). In the whole group eGFR was not associated with cognition, but men with lower eGFR performed worse on tests for executive function, which, after FDR correction, was not significant.We conclude, that in community-dwelling middle-aged and elderly individuals, reduced eGFR relates to brain volume loss in men but not in women.

Application of diffuse source basis functions for improved near well upscaling

Application of diffuse source basis functions for improved near well upscaling