De Values Research Articles

Effect of die exit stress state, Deborah number, uniaxial and planar extensional rheology on the neck-in phenomenon in polymeric flat film production

In this work, effect of the second to first normal stress difference ratio at the die exit, −N2/N1, uniaxial extensional strain hardening, ηE,U,max3η0, planar-to-uniaxial extensional viscosity ratio, ηE,PηE,U, and Deborah number, De, has been investigated via viscoelastic isothermal modeling utilizing 1D membrane model and a single-mode modified Leonov model as the constitutive equation. Based on the performed parametric study, it was found that there exists a threshold value for De and ηE,U,max3η0, above which, the neck-in starts to be strongly dependent on −N2/N1. It was found that such critical De decreases if −N2/N1, ηE,U,max3η0 increases and/or ηE,PηE,U decreases. Numerical solutions of the utilized model were successfully approximated by a dimensionless analytical equation relating the normalized maximum attainable neck-in with ηE,U,max3η0, ηE,PηE,U, −N2/N1 and De. Suggested equation was tested by using literature experimental data considering that −N2/N1 depends on die exit shear rate, temperature and utilized constitutive model parameters for given polymer melt. It was found that approximate model predictions are in a very good agreement with the corresponding experimental data for low as well as very high Deborah numbers, at which neck-in strongly depends on −N2/N1. It is believed that the obtained knowledge together with the suggested simple model can be used for optimization of the extrusion die design (influencing flow history and thus die exit stress state), molecular architecture of polymer melts and processing conditions to suppress neck-in phenomenon in production of very thin polymeric flat films.

Drying of grape pomace with a double pass solar collector

ABSTRACTThis study aims to analyze the performance of a novel design of the double pass solar air collector (DPSAC)-assisted drying system and investigate the drying kinetics of grape pomace which is an agricultural by-product. The samples were dried to a moisture content of 0.01 g water/g dry matter between 100 and 250 min depending on the weather conditions. The average thermal efficiencies of DPSAC were calculated as 79.77, 79.85, and 69.46%. Average values of the coefficient of performance of DPSAC were determined as 5.32, 5.13, and 4.32. The highest specific moisture extraction rate value was achieved as 617.18 g water/kWh. Whereas the mass transfer coefficient (hm) values ranged from 9.15E−11 to 1.04E−7 m/s, the effective moisture diffusivity (De) values were obtained between 3.04E−13 and 1.02E−10 m2/s. The qualitative analysis showed that the drying using DPSAC may be an alternative for drying applications in terms of short drying time and energy usage. Nevertheless, these results clearly suggest a complex and effective interplay between thermal performance and drying kinetics.

Single-grain OSL dating of the Middle Palaeolithic site of Galería de las Estatuas, Atapuerca (Burgos, Spain)

This study presents single-grain optically stimulated luminescence (OSL) chronologies for the archaeological site of Galeria de las Estatuas – the first systematically excavated Middle Palaeolithic site within the karst system of the Sierra de Atapuerca archaeological complex, northern Spain. The single-grain OSL ages are compared with paired single-grain thermally transferred OSL (TT-OSL) dating results for a selection of samples in order to better assess quartz signal bleaching characteristics of endokarstic deposits preserved at Atapuerca. In total, seven luminescence dating samples were collected from four lithostratigraphic units exposed in two excavation pits (GE-I and GE-II). The single-grain OSL equivalent dose (De) distributions are characterised by generally low overdispersion (20–30%), suggesting appropriate bleaching at deposition. The resultant single-grain OSL ages reveal that the sediment sequence and archaeological remains excavated in pit GE-I accumulated 80–112 ka, while the upper layers of excavation area GE-II were deposited 70–79 ka. The replicate single-grain TT-OSL ages are in agreement with the OSL chronologies at 2σ for three of the four samples investigated; although in all cases the TT-OSL ages were systematically older than their single-grain counterparts. Apparent TT-OSL residual doses (i.e., TT-OSL De values in excess of their corresponding OSL De values) of 9–65 Gy were observed for all samples. These excess TT-OSL De values are generally low in comparison to the natural dose ranges of TT-OSL dating applications undertaken elsewhere in the Atapuerca karst system. The single-grain TT-OSL and OSL dating comparisons build on daylight bleaching experiments and modern analogue studies performed on other Atapuerca exogeneous infill deposits and suggest reasonable potential for TT-OSL signal resetting down to relatively low levels for at least some sediments preserved in the Atapuerca karstic cavities. The quartz single-grain OSL chronologies obtained in this study place the Middle Palaeolithic sequence of Galeria de las Estatuas within marine isotope stage (MIS) 5 and the beginning of MIS 4, and provide firm evidence for human occupation of the Sierra de Atapuerca during a previously unreported time period.

Testing single aliquot regenerative dose (SAR) protocols for violet stimulated luminescence

Basic assumptions of the single aliquot regenerative dose (SAR) protocol are tested using the violet stimulated luminescence (VSL) signal from quartz. The VSL signal is shown to be reduced to a sufficiently low background level between SAR steps, and the SAR protocol appears to adequately correct for sensitivity changes during measurement. The VSL SAR protocol can recover a large (405 Gy) laboratory beta dose within uncertainties, however the mean value for the dose recovery ratio is commonly 0.8 or less. This poor behaviour is echoed in the measurements of equivalent dose (De) for a sample with an expected De of ∼354 Gy, which underestimates De by 50–70%. Further investigations are required to understand the mechanisms underlying these underestimations in VSL SAR De values.

Chemical composition, energy, and amino acid digestibility in 7 cottonseed co-products fed to growing pigs.

The objective of this study was to determine the chemical composition, DE and ME contents, and apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of AA in 7 cottonseed co-products fed to growing pigs. The 7 cottonseed co-products were: cottonseed meals (solvent extracted) with CP level of 46%, 50%, and 55% (46CSM, 50CSM, and 55CSM), cottonseed protein with CP level of 50% and 55% (50CSP and 55CSP), fermented cottonseed meal (CSMF), and expelled cottonseed meal (CSME). The DE and ME contents of the 7 test ingredients were measured using 48 crossbreed barrows (BW: 44.1 ± 4.2 kg) and 8 diets (including a corn-soybean meal basal diet) in a completely randomized design. The AID and SID of AA of the 7 test ingredients were determined using 7 crossbreed barrows (initial BW: 67.4 ± 8.5 kg) in a 6 × 8 Youden square design with 6 periods and 8 diets (including one N-free diet). The DE and ME values of the 7 cottonseed co-products varied from 12.72 to 15.63 MJ/kg and 12.24 to 14.83 MJ/kg, respectively. Among the 7 cottonseed co-products, 55CSP and CSME had the greatest (P < 0.05) ME and DE values compared to the other cottonseed co-products. In addition, 55CSP had the greatest (P < 0.05) AID and SID of all the AA tested except for Gly and Pro. In contrast, 46CSM or 55CSM had the lowest (P < 0.05) AID and SID of all the AA tested except for Gly and Pro. The 55CSP also had the greatest (P < 0.05) concentrations of standardized ileal digestible CP and all the AA tested except for Gly and Pro. In conclusion, the chemical composition, energy, and AA digestibility of cottonseed co-products with different processing techniques varied widely. Based on the energy and AA digestibility, cottonseed protein with CP level of 55% is a better dietary ingredient for growing pigs compared with the other cottonseed co-products.

Single-grain dating of potassium-rich feldspar grains: Towards a global standardised growth curve for the post-IR IRSL signal

Abstract Potassium-rich feldspar (K-feldspar) grains were extracted from 28 sediment samples from sites in Asia, Europe and Africa and the dose response curves — or growth curves — were constructed from the post-infrared infrared stimulated luminescence (pIRIR) signals emitted by individual grains. The samples exhibit large between-grain variation in both pIRIR signal intensity and the shape of the corresponding growth curves; the latter can be largely explained as a result of measurement uncertainties, including counting statistics and instrumental irreproducibility. This between-grain variation can be reduced by applying a least-squares normalisation (LS-normalisation) procedure, which allows a common growth curve — or global standardised growth curve (gSGC) — to be established for individual K-feldspar grains from the range of samples investigated. Equivalent dose (De) values for single grains can be estimated using the fitting parameters of the gSGC, together with measurements of the natural signal (Ln), one regenerative-dose signal (Lx) and their corresponding test-dose signals (Tn, Tx). The De values obtained using the gSGC approach are consistent at 2σ with those obtained from the individual growth curves constructed for each of the grains. The establishment of a gSGC greatly reduces the time required to measure a large number of grains for old samples, and it also overcomes the problem of De underestimation that can occur using a full single-aliquot (or single-grain) regenerative-dose (SAR) procedure when a large number of grains are rejected due to issues of ‘saturation’. The construction of a gSGC may, therefore, potentially extend the dating range of pIRIR signals beyond the reliable limit of De estimation using the standard SAR method.

Adsorption kinetics of rhodium (III) acetylacetonate onto mesoporous silica adsorbents in the presence of supercritical carbon dioxide

The adsorption kinetics of rhodium (III) acetylacetonate (Rh(acac)3) onto three types of mesoporous silica adsorbents, MCM-41, HMS, and MSU-H, in the presence of supercritical carbon dioxide (scCO2) at temperatures from 313 to 353 K and at a pressure of 15.0 MPa were studied using fixed-bed adsorption measurements. The breakthrough curves obtained with the measurements were correlated by a mathematical kinetic model using only one fitting parameter, the effective diffusion coefficient of Rh(acac)3 in pores (De). The determined De values depended strongly on the temperature and the types of mesoporous silica used, which could be described using a generalized model that includes the parameters in consideration of the pore structure of the adsorbents (porosity and tortuosity) and the diffusion coefficient of Rh(acac)3 in the bulk scCO2 phase.

Nutrient composition and digestibility of energy and nutrients in wheat middlings and red dog fed to growing pigs.

This experiment was designed to determine nutrient composition and apparent total tract digestibility (ATTD) of GE, DM, OM, and NDF and the concentration of DE and ME in 10 sources of wheat middlings and in 1 source of red dog that were obtained from different flour mills in the United States. Twelve growing pigs (initial BW: 31.0 ± 1.0 kg) were randomly allotted to a 12 × 8 Youden square design with 12 dietary treatments and eight 14 d periods. Pigs were individually housed in metabolism crates for total collection of feces and urine. A basal diet based on corn and soybean meal, and 11 diets containing corn, soybean meal, and 39.4% of one of the 10 sources of wheat middlings or of red dog were formulated. The ATTD of GE, DM, OM, and NDF in all diets was calculated using the direct procedure, and the ATTD of GE, DM, OM, and NDF in each source of wheat middlings or red dog was calculated by difference. Values for DE and ME were calculated as well. The average concentration of CP was 17.67% in wheat midlings and 17.0% in red dog, and the concentration of acid hydrolyzed ether extract (AEE) and total dietary fiber (TDF) was 2.44 and 13.90% in red dog, but 4.07 and 36.45% in wheat middlings. Red dog also contained more starch (42.98%) than wheat middlings (20.28%). Red dog had greater bulk density (498.5 g/L) and smaller particle size (146 µm) compared with wheat middlings (315.1 g/L and 783 µm). The average ATTD of GE, DM, OM, and NDF in wheat middlings (67.2%, 71.2%, 72.9%, and 53.0%, respectively) was less (P < 0.05) than in red dog (79.35%, 82.9%, 86.6%, and 58.7%, respectively). The average concentrations of DE and ME in wheat middlings were 2,990 and 2,893 kcal/kg DM, and these values were less (P < 0.05) than the DE and ME in red dog (3,408 and 3,292 kcal/kg DM). In conclusion, wheat middlings contains more fiber and less starch than red dog and the ATTD of GE and nutrients is greater in red dog than in wheat middlings. As a consequence, concentrations of DE and ME are greater in red dog than in wheat middlings.

Microwave and hot air drying of garlic puree: drying kinetics and quality characteristics

In this study, the effect of hot air and microwave drying on drying kinetics and some quality characteristics such as water activity, color, optic index and volatile oil of garlic puree was investigated. Optic index representing browning of the garlic puree increased excessively with an increase in microwave power and hot air drying temperature. However, volatile oil content of the dried samples was decreased by increasing of temperature and microwave power. By increasing drying temperature (50, 60 and 70 °C) and microwave power (180, 360 and 540 W), the drying time decreased from 8.5 h to 4 min. In order to determine the kinetic parameters, the experimental drying data were fitted to various semi-empirical models beside 2nd Fick’s diffusion equation. Among them, the Page model gave a better fit for microwave-drying, while Logarithmic model gave a better fit for hot air drying. By increasing the microwave power and hot air drying temperature, the effective moisture diffusivity, De values ranged from 0.76×10−8 to 2.85×10−8 m2/s and from 2.21×10−10 to 3.07×10−10 m2/s, respectively. The activation energy was calculated as 20.90 kJ/mol for hot air drying and 21.96 W/g for microwave drying using an Arrhenius type equation.

Diffusion of Water through the Dual-Porosity Swelling Clay Mineral Vermiculite.

Prediction of water and solute migration in natural clay-based materials requires a detailed understanding of the roles played by different porosity types (around or inside clay particles) on the overall transfer process. For smectite, a reference material for the design of migration models, this discrimination is complex because of osmotic swelling of the structure under water-saturated conditions. Diffusion experiments with a water tracer (HDO) were conducted on 0.1-0.2, 1-2, and 10-20 μm size fractions of Na-vermiculite, a swelling clay mineral with no osmotic swelling. Results obtained for the two finest fractions suggest that osmotic swelling and the associated impact on pore structure are responsible for the low De values reported in the literature for smectite compared to those of vermiculite. When considering only interparticle porosity, De values for vermiculite are similar to those reported for nonporous grains (Na-kaolinite and Na-illite). This indicates that interparticle porosity has a primary effect on the overall water diffusion process, whereas interlayer porosity is shown to imply a small proportion of HDO adsorption. This study provides evidence that vermiculite is a promising reference mineral for the understanding of the roles played by pore structure and mineral-water interaction in the transport properties of water in claystones and for associated refinement of dual-porosity diffusion models.

Single-grain TT-OSL bleaching characteristics: Insights from modern analogues and OSL dating comparisons

Previous assessments of thermally transferred optically stimulated luminescence (TT-OSL) signal resetting in natural sedimentary settings have been based on relatively limited numbers of observations, and have been conducted primarily at the multi-grain scale of equivalent dose (De) analysis. In this study, we undertake a series of single-grain TT-OSL bleaching assessments on nineteen modern and geological dating samples from different sedimentary environments. Daylight bleaching experiments performed over several weeks confirm that single-grain TT-OSL signals are optically reset at relatively slow, and potentially variable, rates. Single-grain TT-OSL residual doses range between 0 and 24 Gy for thirteen modern samples, with > 50% of these samples yielding weighted mean De values of 0 Gy at 2σ. Single-grain OSL and TT-OSL dating comparisons performed on well-bleached and heterogeneously bleached late Pleistocene samples from Kangaroo Island, South Australia, yield consistent replicate age estimates. Our results reveal that (i) single-grain TT-OSL residuals can potentially be reduced down to insignificant levels when compared with the natural dose range of interest for most TT-OSL dating applications; (ii) the slow bleaching properties of TT-OSL signals may not necessarily limit their dating applicability to certain depositional environments; and (iii) non-trivial differences may be observed between single-grain and multi-grain TT-OSL bleaching residuals in some modern samples. Collectively, these findings suggest that single-grain TT-OSL dating may offer advantages over multi-grain TT-OSL dating in certain complex depositional environments.

Multitechnique characterization of conventional and experimental Ag-based brazing alloys for orthodontic applications

ObjectivesTo characterize the microstructure, mechanical properties, ionic release and tarnish resistance of conventional and experimental Ag-based soldering alloys for orthodontic applications. MethodsDisk shaped specimens were prepared from four commercial Ag based soldering alloys [Dentaurum Universal Silver Solder (DEN), Orthodontic Solders (LEO), Ortho Dental Universal Solder (NOB), and Silver Solder (ORT)] and four experimental alloys Ag12Ga, Ag10Ga5Sn, Ag20In and Ag7Sn. The elemental composition and microstructure was determined by SEM/EDX and XRD analysis, while the mechanical properties were determined by Instrumented Indentation Testing. Ionic release of Ag, Cu, Zn, Ga, In and Sn was determined by ICP-EAS in 0.9% NaCl and Ringer’s solutions after 28, 49 and 70 days. Tarnish resistance was also tested and colorimetry was applied to quantify the differences in color (DE) before and after immersion in testing media. DSC was used to determine the melting range of the experimental alloys. Mechanical properties, ionic release and DE were statistically compared by ANOVA and Holm-Sidak multiple comparison test (a=0.05). ResultsAll commercially alloys belong to the Ag–Zn–Cu ternary system and consist a Ag rich face centered cubic (FCC) and Cu (FCC) phase. The former is the predominant phase also in experimental alloys. Conventional alloys demonstrated higherhardness, less ductility and lower melting rangers compared to experimental alloys. Immersion testing revealed the release of Cu and Zn ions from the commercially alloys and Ga ions from AgGa and AgGaSn while no ionic release was identified for AgIn and AgSn. All alloys failed tarnish testing according to ISO 10271 showing DE values much higher than the clinical acceptable limit (3.7). SignificanceThe conventional Ag based soldering alloys showed substantial differences in their microstructure, mechanical properties and ionic release, and thus different clinical performance is anticipated. Ga, Sn and In might be employed as alloying addition to modify the properties of Ag brazing alloys.

Effect of Siwak Extract on the Microhardness and Microscopic Feature of Initial Caries-Like Lesion of Permanent Teeth, Compared to Fluoridated Agents

Siwak is a chewing stick used to clean the teeth and message the gum. Theirroutine use was shown to be associated with the reduction in severity of dental caries.This study aimed to test the effect of water Siwak extract on the microhardness andmicroscopic features of artificially initiated carious lesion of the outer enamel surface,in comparison to stannous fluoride and sodium fluoride. Upper first premolars wereextracted and subjected to pH cycling procedure. Teeth immerged individually in 20ml of selected agents for four minutes then rinsed by de ionized water. Agentsinvolved were 5% and 10% water Siwak extract, 8% stannous fluoride and 0.05%sodium fluoride. Samples were subjected to Vickers microhardness test andmicroscopic examination before and after the pH cycling and following insertion inthe agents. Water Siwak extract, stannous fluoride and sodium fluoride were found toincrease the microhardness values of de mineralized enamel surfaces, this werestatistically highly significant for Siwak extract and stannous fluoride (P&lt; 0.01) andsignificant for sodium fluoride. However none of the mentioned agents was able toincrease the micro hardness to approximate the original values of the sound enamel.Under polarized light results revealed that water Siwak extracts and stannous fluorideproduce the best remineralization surface zone. Water Siwak extracts is very effectivein remineralization of initial carious lesion.

Effect of ultrasound pretreatment on enzymolysis and physicochemical properties of corn starch

In the paper, the effects of ultrasound on the enzymolysis properties of corn starch were investigated. The results showed that the rate of enzymolysis changed with the change of ultrasonic conditions. Ultrasound pretreatment starches reduced the time in liquefaction process, and resulted in significantly higher DE value in saccharification process. DE value was negatively correlated to PV, BV, SV, To, Tp, ΔHg, DO, DD, N-O'KI, RC, Mw and DP, respectively, and positively correlated to Mw/Mn. X-ray diffraction analysis showed that the relative crystallinity was reduced, and the starch exhibited an A-pattern. Scanning electron microscope indicated that the notch and groove appeared on the surfaces of starch granules. The polarized cross of starch becomes smaller or even disappear. It was concluded that enzymolysis efficiency of different ultrasound pretreatment to changes due to its effect not only on the physicochemical properties, but also on the structural characteristics of corn starch.

Microencapsulation properties of wall systems consisting of WHPI and carbohydrates

Microencapsulation allows entrapment, protection and delivery of sensitive desired nutrients and other food ingredients and compounds. The research has investigated the encapsulation, by spray drying (SD), of a model oil in wall systems consisting of blends of wheat proteins isolate (WHPI) and maltodextrins (MD, DE 5 or 15) or corn syrup solids (CSS, DE 24). Wall solutions contained 2.5–10% (w/w) WHPI and 17.5–10% (w/w) MD or CSS. Oil load in core-in-wall emulsions (CIWE) ranged from 25 to 75% (w/w). Mean particle diameter in CIWE was smaller than 0.5 µm. Surface excess in the CIWE ranged from 1.544 to 6.497 mg/mL and was influenced (p < 0.05) by the composition of the CIWE. Microcapsules exhibited structural characteristics that are typical to spray dried microcapsules and a limited extent of surface indentation. In all cases, the protein-coated lipid droplets were embedded throughout the wall matrices and no visible cracks connecting the core domains with the environment could be detected. Core retention during microencapsulation ranged from 77.7 to 97.2% and was governed by a combined influence of the wall composition and wall-to core ratio (p < 0.05). Microencapsulation efficiency, MEE, ranged from 11.71 to 97.79% and was significantly (p < 0.05) affected by the combined influence of the composition of the wall matrices, the DE value of the COH and by the wall-to-core ratio in the CIWE. Results indicated that wall solutions containing 2.5–10% WHPI and 17.5–10% maltodextrins can offer opportunities for microencapsulation, by spray drying, of high oil load. Results thus open a new horizon for utilization of WHPI as microencapsulating agent in food applications.

Coarse versus fine-grain quartz optical dating of the sediments related to the 1985 Ms7.1 Wuqia earthquake, northeastern margin of the Pamir salient, China

Optical dating of earthquake related sediments were investigated including one modern sample and three samples from a trench excavated across the 1985 Ms7.4 Wuqia Earthquake surface rupture. The results indicated that equivalent dose (D&lt;sub&gt;e&lt;/sub&gt;) values vary with grain size and the method used for D&lt;sub&gt;e&lt;/sub&gt; determination. The residual dose of the modern sample is 0.1 ka ( 0.2−0.1+0.2$\begin{array}{} 0.2_{-0.1}^{+0.2} \end{array} $ Gy) for the quartz single grain measurements. Only 1.5–3.6% of the grains have a detectable OSL signal. Single grain quartz ages are similar to the expected ages. Fine grain quartz results overestimate the D&lt;sub&gt;e&lt;/sub&gt; values and are much older than single grain quartz and coarse grain quartz small aliquot standardized growth curve (SA-SGC) ages. Single grain quartz OSL dating may be optimal for dating earthquake related deposits, but SA-SGC can save measurement time and has potential for dating some poorly bleaching samples.

Real world data on young patients with high-risk diffuse large B-cell lymphoma treated with R-CHOP or R-CHOEP - MYC, BCL2 and BCL6 as prognostic biomarkers.

BackgroundDouble expression of MYC and BCL2 proteins (DE) and double-hit MYC+BCL2/BCL6 translocations (DH) were established as important biomarkers in patients with diffuse large B-cell lymphoma (DLBCL) by the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Whether this applies to the subgroup of young patients with high risk DLBCL is not known. We previously found that in a uniform retrospective population-based cohort of patients aged 18–60 years with high-risk DLBCL, the addition of etoposide to R-CHOP chemotherapy (R-CHOEP) resulted in improved survival mainly in patients with germinal center B-cell like (GCB) immunophenotype. The aim of this study was to investigate the prognostic and predictive value of DE and DH in this patient cohort.MethodsData on all young Danish patients diagnosed with de novo high-risk DLBCL 2004–2008 and treated with R-CHOP or R-CHOEP were obtained from the Danish Lymphoma database (n = 159). Tumor samples were available from 103 patients. MYC and BCL2 proteins were analyzed with quantitative immunohistochemistry (IHC) using different cut off values. MYC-, BCL2- and BCL6-translocations were examined with fluorescent in situ hybridization (FISH).ResultsDE with MYC>75% and BCL2>85% was an independent negative prognostic marker of progression free survival (PFS) in patients treated with R-CHOP but not R-CHOEP (p<0.001), also after exclusion of patients with DH. A predictive effect of DE for response (PFS) to R-CHOEP vs. R-CHOP was almost significant (p = 0.07). DH was not prognostic in this patient cohort.ConclusionIn young patients with high-risk DLBCL, treatment with R-CHOEP may overcome the negative prognostic impact of DE observed in patients treated with R-CHOP.

Bayesian approach to OSL dating of poorly bleached sediment samples: Mixture Distribution Models for Dose (MD2)

Optically Stimulated Luminescence (OSL) is commonly used to date the last exposure of grains extracted from sediments to sunlight. However, it is frequent that some of the measured grains were not sufficiently exposed to light before burial. Such samples are said to be poorly bleached. We propose a new statistical model based on a Bayesian approach to analyse OSL measurements performed on poorly bleached sediment samples. For such data, we propose a mixture model of Gaussian distributions to analyse equivalent doses (De) distributions. This model can either be applied directly to the observed De values, or after a log-transformation. Bayesian analysis requires numerical approximation, to do this we use the JAGS (Just Another Gibbs Sampler) programme to run models using Markov Chain Monte Carlo simulations. We apply the model to synthetic datasets and real samples.

Diffusion of radiosulphate and radiocaesium in kaolinite clay (KGa-2): Testing the applicability of the pore water diffusion model

The effective diffusion coefficients (De) and rock capacity factors (α) for radiosulphate and radiocaesium in compacted kaolinite (KGa-2) were measured as a function of the concentration of NaClO4 in the contacting solution to test the effect of salinity on diffusion of these species. Solid-liquid distribution coefficients (Kd) were derived from α and compared with Kd values from batch sorption experiments using dispersed clay suspensions. De values for radiosulphate (3.3–8.0 × 10−11 m2 s−1) showed no substantial dependence on the concentration of NaClO4. The diffusion Kd values (9–40 L kg−1) indicated a weak sorption process, confirmed by the low Kd values measured in the batch sorption experiments. No unambiguous conclusion could be drawn regarding a potential salinity effect on radiocaesium De values (1.4–3.0 × 10−10 m2 s−1). The diffusion-derived Kd of 134Cs (53–498 L kg−1) varied inversely with the NaClO4 concentration, consistent with a cation exchange process, and substantially decreased in the presence of stable Cs, suggesting the presence of specific sites for 134Cs that become saturated at high Cs concentrations. Structural analyses indicated an illite content of around 1.7%, which explained the generally large Kd values for radiocaesium. Finally, the correlation between measured De values and the respective diffusion coefficients in bulk water (Dw) was examined for a number of species, including radiosulphate and radiocaesium in the presence of stable Cs, along with additional data gathered from other species. Both variables were highly correlated, confirming the validity of the pore water diffusion model, but only in the absence of specific interaction with the clay.

A Hybrid Pansharpening Algorithm of VHR Satellite Images that Employs Injection Gains Based on NDVI to Reduce Computational Costs

The objective of this work is to develop an algorithm for pansharpening of very high resolution (VHR) satellite imagery that reduces the spectral distortion of the pansharpened images and enhances their spatial clarity with minimal computational costs. In order to minimize the spectral distortion and computational costs, the global injection gain is transformed to the local injection gains using the normalized difference vegetation index (NDVI), on the assumption that the NDVI are positively or negatively correlated with local injection gains obtained from each band of the satellite data. In addition, the local injection gains are then applied in the hybrid pansharpening algorithm to optimize the spatial clarity. In particular, in the proposed algorithm, a synthetic intensity image is determined using block-based linear regression. In experiments using imagery collected by various satellites, such as KOrea Multi-Purpose SATellite-3 (KOMPSAT-3), KOMPSAT-3A and WorldView-3, the pansharpened results obtained using the proposed Hybrid Pansharpening algorithm using NDVI and based on the spectral mode (HP-NDVIspectral) provide a better representation of the values of the Erreur Relative Globale Adimensionnelle de Synthèse (ERGAS), the spectral angle mapper (SAM) and the Q4/Q8 than those produced by existing pansharpening algorithms. In terms of spatial quality, the pansharpened images obtained using the proposed pansharpening algorithm based on the spatial mode (HP-NDVIspatial) have higher average gradient (AG) values than those obtained using existing pansharpening methods. In addition, the computational complexity of our method is similar to that of a pansharpening algorithm that is based on a global injection model, although our methodology has characteristics that are similar to those of a local injection gain-based model that has a very high computational cost. Thus, the quantitative and qualitative assessments presented here indicate that the proposed algorithm can be utilized in various applications that employ spectral information or require high spatial clarity.