Potential hydraulic barrier performance of cyclic organic carbonate modified bentonite complexes against hyper salinity

The effect of adding glycerol carbonate (GC) or propylene carbonate (PC) to sodium (Na)-bentonite on the hydraulic performance of geosynthetic clay liners (GCLs) under hypersaline conditions is examined. Fluid loss (FL), swell index (SI) and solution retention capacity (SRC) measurements were carried out to compare the potential hydraulic performance of these two cyclic organic carbonates (COCs) as bentonite modifiers. A modified FL test enabled quantitative measurement of both the water retention characteristics of untreated and COC modified bentonites as well as calculation of hydraulic conductivity values. Tests under aggressively saline conditions (ionic strength, I ≥ 1 M of NaCl and ≥3 M of CaCl2) showed that at a mass ratio of 1:1 (GC to bentonite), the FL of a GC-Na-bentonite was ≈40–104 mL in NaCl and ≈61–91 mL in CaCl2. This was about 10–20 mL and 70–200 mL, respectively, lower than that of a comparable PC-Na-bentonite (1:1 PC to bentonite) and untreated Na-bentonite. Greater swelling (SI) and greater solution retention capacity (SRC) was observed for the GC treated Na-bentonite compared to untreated Na-bentonite in all salt solutions, and for PC-Na-bentonite at high ionic strength of both NaCl and CaCl2 solutions, demonstrating the superior hydraulic barrier performance of COC-bentonites under severely saline conditions. Experiments conducted in flexible-wall permeameters with I = 3 M CaCl2 showed approximately one order of magnitude lower (∼10−11 m/s vs ∼1.9 × 10−10 m/s) hydraulic conductivity of GC treated bentonite cake compared to the k value of the untreated Na-bentonite cake. Calculated hydraulic conductivity from fluid loss tests estimated the measured values in a conservative way (overestimation).

Non-equal channel angular pressing of aluminum alloy

Strain history, microstructure and texture were studied in an aluminum alloy processed by the recently proposed process of non-equal channel angular pressing (NECAP). Comparison with alloy processed by equal channel angular pressing (ECAP) has been performed. A much finer microstructure was obtained in NECAP, showing that in this modified ECAP test the grain-refinement process was more efficient. The results indicate that the NECAP test has some interesting features that may be of interest for further research.

A modified LLC panel unit root test of the PPP hypothesis

In a recent study, Westerlund (Empir Econ 37:517–531, 2009) shows that the performance of the popular LLC (Levin et al., J Econ 108:1–24, 2002) panel unit root test depends critically on the choice of lag truncation used when correcting for serial correlation, and that it is only when this parameter is set as a function of time that the power raises above size. The purpose of the current paper is to propose a modified test that does not suffer from this drawback. The new test is not only simpler to compute but also superior in terms of small-sample performance, which is illustrated using an example purchasing power parity for less developed countries.

A non-destructive test to assess the axial heterogeneity of in situ modified monoliths for HPLC

This paper describes a non-destructive "peak parking" protocol in order to assess the axial heterogeneity of an in situ modified monolithic column for high performance liquid chromatography; a "gradient stationary phase" was designed whereby the ligand density decreases along the length of the rod in the "forward flow" configuration. The results of multi-location peak parking demonstrated a consistent increase in peak variance from the 1 cm position of the column to the 9 cm location. This increase in band broadening supported the theory of a decreasing ligand density along the length of this gradient column. This is consistent with efficiency measurements performed in both the forward and reverse flow directions, with an improved efficiency (15% increase in N m^-1) in the reverse direction. These results are consistent with theoretical investigations into stationary phase gradients.

Cement composites reinforced with surface modified coir fibers

An experimental investigation of coir mesh reinforced mortar (CMRM) is conducted using nonwoven coir mesh matting. The main parameters in this study are the fiber volume fraction (number of mesh layers) and fiber surface treatment with a wetting agent. The composites are subjected to the four-point bending test. The short-term mechanical properties of CMRM are discussed. Scanning electron micrograph analysis is used to observe the fiber—matrix interfacial characteristics. The results indicate that the addition of coir mesh to mortar significantly improves the composite post-cracking flexural stress, toughness, ductility, and toughness index, compared to plain mortar materials. The Albatex © FFC wetting agent (2-ethylhexanol) can effectively improve water absorption of coir fiber and enhance the fiber—matrix bonding strength. These coir mesh reinforced composites may be useful in civil engineering applications.

Psychometric properties of the modified Emory functional ambulation profile in stroke patients

Objective: To examine the test – retest reliability, convergent and predictive validity and responsiveness of the modified Emory Functional Ambulation Profile (mEFAP) in assessing gait function in stroke patients undergoing rehabilitation. Subjects: Forty subacute stroke inpatients were enrolled in the validity and responsiveness study. Twenty chronic patients participated in the reliability study. Setting: Rehabilitation department of a medical centre. Design: In the validity and responsiveness study, patients were tested using the mEFAP, 10-m walking speed test, Barthel Index and Rivermead Mobility Index at admission and at discharge. For the reliability study, the patients completed the mEFAP twice one week apart. Results: The patients' performances on the mEFAP were moderately to highly correlated with results of the 10-m walking speed test and Rivermead Mobility Index (absolute correlation coefficients ≥ 0.67), indicating good convergent validity. Patients' performance on the mEFAP at admission was moderately correlated with the Barthel Index and Rivermead Mobility Index scores at discharge (Spearman's rank correlation coefficients = -0.52 and -0.78, respectively), indicating good predictive validity. The standardized response mean of the mEFAP was 1.1 (P < 0.0001), suggesting good responsiveness. The intraclass correlation coefficient ICC(3,1) for the mEFAP was 0.997, indicating excellent test – retest reliability. Conclusions: Our results provide strong evidence that the mEFAP has good reliability, validity and responsiveness for assessing stroke patients undergoing rehabilitation. The mEFAP is a useful scale for measuring walking function and recovery in stroke patients.

Clinical measurement of muscle tone using a velocity-corrected modified ashworth scale

Objective: To develop a new form of the modified Ashworth scale (MAS) for muscle-tone assessment that combines the MAS score with the passive muscle-stretching velocity during the assessment of muscle tone, resulting in a measure that has higher intertester reliability than the MAS.

Design: Twanty-two volunteer subjects with spinal cord injuries at a tertiary care outpatient and inpatient spinal cord injury rehabilitation center affiliated with a university were recruited for this study.

Results: A decision tree in which V-MAS scores were obtained was developed. The data obtained from three independent raters, when adjusted by means of the V-MAS, showed an excellent interrater reliability.

Conclusions: Results indicated that the V-MAS is a more reliable measure. In addition, the resulting units of the V-MAS, ranging from 0 to 1, are of the same form as pendulum test data. The V-MAS method is quite simple to use because the rater need only measure the angular range and duration of the passive movement to calculate average velocity during the MAS assessment in addition to the normal MAS rating of muscle tone.

Reliability of the modified child and adolescent physical activity and nutrition survey, physical activity (CAPANS-PA) questionnaire among chinese-australian youth

Background : Evidence suggests that differences exist in physical activity (PA) participation among Culturally and Linguistically Diverse (CALD) children and adolescents. It is possible that these differences could be influenced by variations in measurement technique and instrument reliability. However, culturally sensitive instruments for examining PA behaviour among CALD populations are lacking. This study tested the reliability of the Child and Adolescent Physical Activity and Nutrition Survey (CAPANS-PA) recall questionnaire among a sample of Chinese-Australian youth.
Methods : The psychometric property of the CAPANS-PA questionnaire was examined among a sample of 77 Chinese-Australian youth (aged 11 - 14 y) who completed the questionnaire twice within 7 days. Test-retest reliability of individual items and scales within the CAPANS-PA questionnaire was determined using Kappa statistics for categorical variables and intraclass correlation coefficients (ICC) for continuous variables.
Results : The CAPANS-PA questionnaire demonstrated acceptable test-retest reliability for frequency and duration of time spent in weekly Moderate to Vigorous Physical Activity (MVPA) (ICC ≥ 0.70) for all participants. Test-retest reliability for time spent in weekly sedentary activities was acceptable for females (ICC = 0.82) and males (ICC = 0.72).
Conclusions : The results suggest the CAPANS-PA questionnaire provides reliable estimates for type, frequency and duration of MVPA participation among Chinese-Australian youth. Further investigation into the reliability of the sedentary items within the CAPANS-PA is required before these items can be used with confidence. This study is novel in that the reliability of instruments among CALD groups nationally and internationally remains sparse and this study contributes to the wider body of available psychometrically tested instruments. In addition, this study is the first to our knowledge to successfully engage and investigate the basic health enhancing behaviours of Chinese-Australian adolescents.

Reliability and validity of the modified Chinese version of the children's leisure activities study survey (CLASS) questionnaire in assessing physical activity among Hong Kong children

This study aimed to examine the reliability and validity of the modified Children’s Leisure Activities Study Survey (CLASS) Chinese-version questionnaire in assessing physical activity among Hong Kong Chinese Children. Test-retest reliability was examined in 84 boys and 136 girls aged 9–12 years by comparing data from two administrations of the survey conducted one week apart. Validity was determined by comparing data from the second administration with accelerometer estimates. The results suggested that the questionnaire provided reliable and valid estimates in overall physical activity patterns in Hong Kong Chinese children. However, substantial overestimation was observed in vigorous activity.

A test of core assumptions of the catastrophic misinterpretation model of panic disorder

The catastrophic misinterpretation model of panic disorder proposes that spontaneous panic attacks are the result of misinterpretation of harmless autonomic arousal as precursors to physical (e.g. heart attack) or psychological (e.g. insanity) emergency. Mixed research findings to date have provided equivocal support. A modified form of the Body Sensations Interpretation Questionnaire was used to investigate core assumptions of the model amongst 38 people with panic disorder (PD), 20 with non-clinical panic, 21 with social anxiety disorder, and 34 non-anxious controls. The PD group gave more harm-related interpretations of ambiguous internal stimuli than all other groups only when anxiety-related responses (e.g. “I'm going to panic”) were scored as harm, however there was no evidence that anxiety-related interpretations were masking perceived catastrophic physical or psychological outcomes. Despite this, people with PD rated harm and anxiety outcomes as more negative than non-anxious controls. Results failed to unequivocally support core assumptions of the model.

A modified micro genetic algorithm for undertaking multi-objective optimization problems

In this paper, a Modified micro Genetic Algorithm (MmGA) is proposed for undertaking Multi-objective Optimization Problems (MOPs). An NSGA-II inspired elitism strategy and a population initialization strategy are embedded into the traditional micro Genetic Algorithm (mGA) to form the proposed MmGA. The main aim of the MmGA is to improve its convergence rate towards the pareto optimal solutions. To evaluate the effectiveness of the MmGA, two experiments using the Kursawe test function in MOPs are conducted, and the results are compared with those from other approaches using a multi-objective evolutionary algorithm indicator, i.e. the Generational Distance (GD). The outcomes positively demonstrate that the MmGA is able to provide useful solutions with improved GD measures for tackling MOPs.

Riparian vegetation has disproportionate benefits for landscape-scale conservation of woodland birds in highly modified environments

1. Identifying landscape patterns that allow native fauna to coexist with human land use is a global challenge. Riparian vegetation often persists in anthropogenic environments as strips of natural or semi-natural vegetation that provide habitat for many terrestrial species. Its relative contribution to landscape-scale conservation is likely to change as environments become increasingly modified. We used a ‘whole of landscape’ approach to test the hypothesis that riparian vegetation offers disproportionate benefits, relative to non-riparian vegetation, for the conservation of woodland birds in highly modified agricultural landscapes. 2. We selected 24 landscapes, each 100 km2, along a gradient of landscape change represented by decreasing cover of native vegetation (from 60% to <2%), in an agricultural region in SE Australia. Bird species were systematically surveyed at three riparian and seven non-riparian sites in wooded vegetation in each landscape. 3. Riparian sites supported a greater richness of woodland-dependent species, a group of conservation concern, than did non-riparian sites. The composition of assemblages also differed between site types. 4. At the landscape scale, the pooled richness of bird assemblages at riparian and non-riparian sites, respectively, decreased with overall loss of tree cover despite constant sampling effort. Within landscapes, the β-diversity of woodland species among non-riparian sites increased (composition became less similar) as landscape tree cover declined. In contrast, riparian assemblages were relatively stable with no change in β-diversity. Importantly, as landscape tree cover declined, the proportion of woodland species uniquely present at riparian sites increased and made a greater contribution to overall landscape diversity. 5. Synthesis and applications. Landscape-scale richness of woodland species declines as landscape tree cover is lost. In highly depleted landscapes, riparian vegetation retains a relatively rich, stable assemblage compared with that in heterogeneous remnants of non-riparian vegetation and consequently contributes disproportionately to landscape-scale diversity. These observations, together with the diverse benefits of riparian vegetation for aquatic ecosystems, mean that protection and restoration of riparian vegetation is a high priority in anthropogenic environments. Importantly, such actions are directly amenable to individual land managers, and the benefits will accumulate to enhance the persistence and conservation of species at landscape and regional scales.

Real-time measurement of phloem turgor pressure in Hevea brasiliensis with a modified cell pressure probe

Background: Although the pressure flow theory is widely accepted for the transport of photoassimilates in phloem sieve elements, it still requires strong experimental validation. One reason for that is the lack of a precise method for measuring the real-time phloem turgor pressure from the sink tissues, especially in tree trunks. Results: Taking the merits of Hevea brasiliensis, a novel phloem turgor pressure probe based on the state of the art cell pressure probe was developed. Our field measurements showed that the phloem turgor pressure probe can sensitively measure the real-time variation of phloem turgor pressure in H. brasiliensis but the calculation of phloem turgor pressure with xylem tension, xylem sap osmotic potential and phloem sap osmotic potential will under-estimate it. The measured phloem turgor pressure gradient in H. brasiliensis is contrary to the Münch theory. The phloem turgor pressure of H. brasiliensis varied from 8-12 bar as a consequence of water withdrawal from transpiration. Tapping could result in a sharp decrease of phloem turgor pressure followed by a recovery from 8-45 min after the tapping. The recovery of phloem turgor pressure after tapping and its change with xylem sap flow suggest the importance of phloem water relationship in the phloem turgor pressure regulation. Conclusion: The phloem turgor pressure probe is a reliable technique for measuring the real-time variation of phloem turgor pressures in H. brasiliensis. The technique could probably be extended to the accurate measurement of phloem turgor pressure in other woody plants which is essential to test the Münch theory and to investigate the phloem water relationship and turgor pressure regulation. © 2014 An et al.

Water-soluble complexes of hydrophobically modified polymer and surface active imidazolium-based ionic liquids for enhancing oil recovery

The current study introduces the water-soluble complexes containing hydrophobically associating copolymer and a series of surface activity imidazolium-based ionic liquids (CnmimBr, n=6, 8, 10, 12, 14 and 16). The polymer, denoted as PAAD, was prepared with acrylamide (AM), acrylic acid (AA) and N,N-diallyl-2-dodecylbenzenesulfonamide (DBDAP). And the hydrophobic associative behavior of PAAD was studied by a combination of the pyrene fluorescence probe and viscosimetry. Incorporation of CnmimBr (n=10, 12, 14 and 16) in PAAD leaded to the white thick gel, while the pellucid solutions were obtained in complexes of PAAD and CnmimBr (n=6 and 8); addition of C6mimBr around critical micelle concentration resulted in a large decrease in viscosity of solution. Therefore, we particularly investigated the performance of PAAD/C8mimBr complex. The interfacial tension of PAAD/C8mimBr complex solution and crude oil under different conditions was examined. Moreover, PAAD/C8mimBr complex exhibited superior temperature resistance and shear reversible performance for enhancing oil recovery (EOR) by rheological test. The promising EOR of 21.65% can be obtained by PAAD/C8mimBr complex showing high potential to utilize this kind of new complex in EOR processes.