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Physicochemical properties of poly-l-lysine (PLL) hydrobromide were determined by molecular dynamics (MD) modeling and a variety of experimental techniques. Primarily, the density, the chain diameter, the monomer length, and the PLL molecule conformations were theoretically calculated. These results were applied for the interpretation of experimental data acquired for the PLL sample of average molar mass equal to 122 kg/mol. They comprised the diffusion coefficient, the hydrodynamic diameter, and the electrophoretic mobility of molecules determined for the ionic strength ranging from 2 × 10–5 to 0.15 M and pH 5.6. Using these data, the electrokinetic charge and the effective ionization degree of PLL molecules were determined as a function of ionic strength. Additionally, precise dynamic viscosity measurements for dilute PLL solutions were performed yielding the intrinsic viscosity, which decreased from 2420 to 120 for ionic strengths of 2 × 10–5 and 0.15 M, respectively. This confirmed that PLL molecules ...

In this study, we have determined the main important physical and chemical properties as well as the heavy metal concentrations of the primary and secondary wastewater treatment sludge from a pulp and board mill complex located in Finland in order to evaluate the utilization of these by-products as a soil amendment agent or a fertilizer product. Easily soluble Ca, Mg, K, Na, P and S concentrations in the sludges were extracted by ammonium acetate (CH 3 COONH 4 ) and easily soluble Cu, Mn and Zn concentrations by CH 3 COONH 4 + Na 2 EDTA. For the determination of total nutrient and total heavy metal concentrations in sludges, they were digested using aqua regia (3 mL HCl + 9 mL HNO 3 ). The total heavy concentrations in the primary sludge were lower than the Finnish heavy metal limit values for fertilizer products. In the secondary sludge, all other total heavy metals than the total Cd concentration (4.8 mg/kg; d.w.) were lower than the heavy metal limit values for fertilizer products. Due to the low total heavy metal concentrations, which were lower than the Finnish limit values for fertilizer products, the primary sludge is a potential fertilizer. Although the total Cd concentration (4.8 mg/kg; d.w.) in the secondary sludge exceed the limit value of 1.5 mg/kg (d.w.) for fertilizer products, this residue may be used as a soil improver, a growing media or as a fertilizer product in landfill sites or in other closed industrial areas, because the Finnish limit values for fertilizer products are not applied at these sites.

International audience; A promising method of enhancing the circular economy is distributed plastic recycling. In this study plastic waste is upcycled into 3-D printing filament with a recyclebot, which is an open source waste plastic extruder. The recyclebot is combined with an open source self-replicating rapid prototyper (RepRap) 3-D printer, to enable post-consumer ABS plastic filament from computer waste to be further upcycled into valuable consumer products pre-designed in the digital commons. The total electrical energy consumption for the combined process is monitored and an economic evaluation is completed. The coupled distributed recycling and manufacturing method for complex products reduces embodied energy by half, while reducing the cost of consumer products to pennies. This economic benefit provides an incentive for consumers to both home recycle and home manufacture, which tightens the loop on the circular economy by eliminating waste associated from transportation and retail. It is clear from the results that waste plastic can be significantly upcycled at the individual level using this commons-based approach. This tightening of the loop of the circular economy benefits the environment and sustainability as well as the economic stability of consumers/prosumers.

Knowledge of the mechanical properties and fatigue behavior of thin films is important for the design and reliability of microfabricated devices. This study uses the bulge test to measure the residual stress, Young's modulus, and fracture strength of aluminum nitride (AlN) thin films with different micro-structures prepared by sputtering, metalorganic vapor phase epitaxy (MOVPE), and atomic layer deposition (ALD). In addition, the fatigue behavior is studied under cyclic loading. The results indicate that the fracture strength and Young's modulus of AlN are mainly determined by the film microstructure, which is consecutively influenced by the deposition method and conditions. A microstructure with a higher order of crystallinity has increased fracture strength and Young's modulus. Additionally, the strength limiting defects are located at the film-substrate interface. The measured residual stresses were 249, 876, 1,526, and 272 MPa for two sputtered films of different thicknesses, MOVPE and ALD films, respectively. The fracture strengths were 1.42, 1.54, 2.76, and 0.61 GPa, and Young's moduli were 335, 343, 346, and 272 GPa. No clear signs of fatigue were observed after 10,000 cycles at a load corresponding to 83% of the fracture strength. (C) 2018 Elsevier B.V. All rights reserved.

The paper describes a general analytical sensitivity analysis method for the composite laminated plates and shells, which is applied to both classical and first-order shear deformation theories and based on the finite element methods. The first derivatives of engineering constants of lamina with respect to fibre volume fractions are computed based on the micromechanics theory. The first derivatives of extensional, bending and bending-extensional coupling stiffnesses of laminate with respect to fibre volume fractions and fibre orientations are derived using classical and first order theories of laminate. Computational methods for the first derivatives of total stiffness and mass matrices are proposed based on finite element method. The analytical sensitivity analysis methods for static responses, eigenvalues and eigenvectors are described using the total stiffness and mass matrices, and their first derivatives. Sensitivity analyses of composite laminated plate and shell are demonstrated. The merits and disadvantages are also discussed.

An analytical method to estimate the heat fluxes received by horizontal targets from two buoyant turbulent diffusion flames was proposed. Two identical square gas burners with side length of 15 cm were used as the fire sources with propane burning in still air. The heat release rate (HRR) and burner edge spacing were changed in experiments. Heat fluxes received by four external horizontal targets were measured. In cases with one burner or two burners with zero spacing, there is one single flame and the vertical centerline temperature distribution were divided into four zones including core zone, constant zone, intermittent flame zone and plume zone. Based on the established piecewise function for predicting the flame temperature, the cuboid flame model with hierarchical temperatures was proposed to determine the flame emissivity, the mean flame temperature of the model and the corresponding blackbody emissive power. The results showed that when the HRR of single flame ranges from 10.8 kW to 64.8 kW, the flame emissivity of 15 cm square burner ranges from 0.125 to 0.387, and the absorption coefficient ranges from 0.99 m−1 to 3.62 m−1. At a given HRR, the flame emissivities of two burners with zero spacing and infinite spacing are nearly identical, suggesting that the influence of spacing on flame emissivity is marginal. For two burners with spacing higher than zero, by assuming that the flame radiative fraction of propane is 0.3 and the flame emissivity is equal to that of the single flame, the flame radiative heat fluxes received by external targets are calculated by modeling the flame shapes as two right or tilted cuboids. The comparison validates that the calculations using the proposed cuboid models for both one and two flames agree well with the experimental results.

The crystal and molecular structures and magnetic properties of two new complexes (HMepy)2[CuCl4]·2H2O, 2, and (H2Me2ppz)[CuCl4], 3, formed by tetrachlorocuprate(II) anions and organic heterocyclic cations, bis(3-amino-2-chloro-5-methylpyridinium) (HMepy) and trans-2,5-dimethylpiperazinium (H2Me2ppz), respectively, have been determined by the analysis of their X-ray diffraction data, magnetic susceptibility behaviour and EPR spectral parameters. These characteristics differentiate the [CuCl4]2− anions in 2 and 3 as well as that previously reported in (H2bipip)[CuCl4]·H2O, 1, (bipip = 4,4′-bipiperidine) (Tuikka et al., CrystEngComm, 2013, 15, 6177; Wikaira et al., J. Coord. Chem., 2016, 69(1), 57). The present study reveals a significant effect of the organic cations on the geometry and magnetic properties of the [CuCl4]2− anions caused evidently by the changes in the crystal packing structure. A characteristic relationship was observed between the average cis-angles around the Cu(II) ions in [CuCl4]2− for 1–3, affected by the Cu(II) coordination geometry, and g-tensor components derived from the EPR spectra, a measure of interaction of copper(II) unpaired electrons in the [CuCl4]2− anions with an external magnetic field. The magneto-structural correlations revealed weak antiferromagnetic exchange interactions between the [CuCl4]2− anions transmitted by different pathways.

Population growth coupled with significant pressure for clean agricultural practices puts a heavy burden on conventional crop treatments that target high yields with minimal cropland expansion. Optimization of fertilization systems is required as part of the solutions to current megatrends. Herein, we present a sustainable strategy to achieve controlled release formulations for nitrogen fertilization. Specifically, we used interfacial engineering to design alginate-based matrices that incorporated biogenic silica particles to achieve increased interfacial area for dynamic entrapment and release of ammonium nitrate. The incorporation of biogenic silica in the alginate matrix provided a porous architecture spanning length scales from the micro- (within particles) to the macrosize (within the polymeric matrix) levels, leading to tunable patterns of nitrogen release. Alginate–biogenic silica granules approached the European requirements of “slow-release” compositions. At optimized silica content, 15% of the n...

Methods based on X-ray tomography are developed to study the relevant statistical quantities describing the microstructural inhomogeneity of particulate reinforced composites. The developed methods are applied in estimating microstructural inhomogeneity parameters of composites containing metallic glass particles in metal matrix, extruded in varying pressure loads. This study indicates that the critical characteristics with regard to the effect of particle clustering are cluster size and shape, local volume fraction of particles in the cluster and the distance between clusters. The results demonstrate that the spatial distribution of reinforcement is very uneven and the amount of particle clustering varies with amount of reinforcement. Moreover, X-ray nanotomography was used to investigate the structure of individual clusters and the results suggest that high extrusion load may cause break-up of individual particle clusters so that their shape changes from solid and spherical to broken and ellipsoidal.

Ultrasonic testing is an important tool for assessing the structural integrity of pressurised components in nuclear power plants during in-service inspection. Consequently, the reliability of inspection is of high significance. In particular, it is important to determine the largest crack that could conceivably be missed during in-service inspection. This information is utilised in order to choose the most effective method for different situations. Probability of detection (POD) curves are used to quantify the effectiveness of the inspection. However, these POD curves require a lot of data points in order to provide reliable estimates of the lower limit performance. Traditionally, obtaining these curves has been relatively expensive and this is why different simulation tools have been used to reduce costs and the number of physical test-pieces needed. In the current study, a novel method based on limited test-pieces is explored to produce a POD curve from the measured data. The present data contains just three artificial cracks made with thermal fatigue. This is insufficient to produce a POD curve. However, the data was sufficient to evaluate the novel approach and to gain preliminary estimates of the expected POD and the most important influential parameters. In this study, the idea is to emulate the amplitude response from the measured crack in a way that represents an amplitude response from a certain crack size. This amplitude data is converted to a B-scan image from which the inspector will evaluate whether there is acrack or not. Then, a POD curve is generated from the achieved hit/miss data.

The H2020 BIOMOre project (www.biomore.info, Grant Agreement #642456) tests the feasibility of in situ bioleaching of copper in deep subsurface deposits in the Rudna mine, Poland. Copper is leached using biologically produced ferric iron solution, which is recycled back to the in situ reactor after re-oxidation by iron-oxidizing microorganisms. From a post operational point of view, it is important that the biological processes applied during the operation can be controlled and terminated. Our goal was to determine the possibility to use natural saline mine water for the inactivation of the introduced iron-oxidizing microorganisms remaining in the in situ reactor after completion of the leaching process of the ore block. Aerobic and anaerobic microcosms containing acid-leached (pH 2) sandstone or black shale from the Kupferschiefer in the Rudna mine were further leached with the effluent from a ferric iron generating bioreactor at 30 °C for 10 days to simulate the in situ leaching process. After the removal of the iron solution, residing iron-oxidizing microorganisms were inactivated by filling the microcosms with chloride-rich water (65 g L−1 Cl‐) originating from the mine. The chloride-rich water irreversibly inactivated the iron-oxidizing microorganisms and showed that the naturally occurring saline water of the mine can be used for long-term post process inactivation of bioleaching microorganisms

Solubilities of metals in sodium silicate slags have been studied at 1000–1300°C in oxygen pressures of P(O2) = 10−4 to 0.5 atm, in Dore alloy smelting of copper anode slimes. The boundary conditions for the slags were silica saturation, magnesia saturation with about 10 wt% and without BaO. The trace elements studied were copper, gold, palladium, rhodium, and tellurium. The analytical methods used in the phase composition analyses of equilibrated samples, quenched in brine, were electron probe X-ray microanalysis and laser ablation-inductively coupled plasma-mass spectrometry. Thermodynamic features of the slags, trace element solubilities with the given constraints, and their oxidation mechanisms were determined. The data allow optimizing the anode slime-smelting for the metals’ maximum recovery in sodium silicate fluxing.

openaire: EC/H2020/788489/EU//BioELCell The shear and extensional rheology of aqueous suspensions of cellulose nanofibrils (CNF) were investigated under dynamic and steady flow fields. The results were compared to those for two biopolymer solutions, cellulose acetate, CA, and guar gum, GG. Wet-spinning experiments were conducted for each system and the outcome related to the respective rheological profile. The spinnability of the system correlated with strong Newtonian and viscous responses under shear as well as long breakup time in capillary breakup experiments. CA solution was the most spinnable, also displaying the strongest Newtonian liquid behavior and the longest capillary breakup time. In contrast, the most shear-thinning and elastic CNF suspension showed instant capillary breakup and was considerably less spinnable. This is due to the limited entanglement between the rigid cellulose fibrils. In order to enable continuous wet-spinning of CNF without filament breakup, GG and CA were used as carrier components in coaxial spinning. The shear and extensional rheology of the system is discussed considering both as supporting polymers.

Light- and elevated temperature-induced degradation (LeTID) is a detrimental effect observed under operating conditions in p-type multicrystalline silicon (mc-Si) solar cells. In this contribution, we employ synchrotron-based techniques to study the dissolution of precipitates due to different firing processes at grain boundaries in LeTID-affected mc-Si. The synchrotron measurements show clear dissolution of collocated metal precipitates during firing. We compare our observations with degradation behavior in the same wafers. The experimental results are complemented with process simulations to provide insight into the change in bulk point defect concentration due to firing. Several studies have proposed that LeTID is caused by metal-rich precipitate dissolution during contact firing, and we find that the solubility and diffusivity are promising screening metrics to identify metals that are compatible with this hypothesis. While slower and less soluble elements (e.g., Fe and Cr) are not compatible according to our simulations, the point defect concentrations of faster and more soluble elements (e.g., Cu and Ni) increase after a high-temperature firing process, primarily due to emitter segregation rather than precipitate dissolution. These results are a useful complement to lifetime spectroscopy techniques, and can be used to evaluate additional candidates in the search for the root cause of LeTID.

Man-made lignocellulosic fibres were successfully prepared from unbleached birch kraft pulps by using the Ioncell-F technology. Pulps with different lignin content were produced by tailored kraft pulping with varying intensity. The degree of polymerization of the pulps was adjusted by acid-catalyzed hydrolysis and electron beam treatment. All substrates were completely soluble in 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH] OAc) and the respective solutions were spinnable to yield fibres with good to excellent mechanical properties despite the use of only mildly refined wood pulp. The tensile properties decreased gradually as the lignin concentration in the fibres increased. Changes in the chemical composition also affected the structure and morphology of the fibres. Both the molecular orientation and the crystallinity decreased while the presence of lignin enhanced the water accessibility. The effects of the crystallite size and lignin content on monolayer water adsorption are discussed.

Application-specific carbon nanofibers grown from Pt-catalyst layers have been shown to be a promising material for biosensor development. Here we demonstrate immobilization of glutamate oxidase on them and their use for amperometric detection of glutamate at two different potentials. At −0.15 V vs. Ag/AgCl at concentrations higher than 100 μM the oxygen reduction reaction severely interferes with the enzymatic production of H2O2 and consequently affects the detection of glutamate. On the other hand, at 0.6 V vs. Ag/AgCl enzyme saturation starts to affect the measurement above a glutamate concentration of 100 μM. Moreover, we suggest here that glutamate itself might foul Pt surfaces to some degree, which should be taken into account when designing Pt-based sensors operating at high anodic potentials. Finally, the Pt-grown and Ni-grown carbon nanofibers were shown to be biocompatible. However, the cells on Pt-grown carbon nanofibers had different morphology and formation of filopodia compared to those on Ni-grown carbon nanofibers. The effect was expected to be caused rather by the different fiber dimensions between the samples than the catalyst metal itself. Further experiments are required to find the optimal dimensions of CNFs for biological purposes.

The fracture mechanics based methodology used to develop the Charpy-V transition temperature criteria in the Eurocode 3 standards EN1993-1-10 and EN1993-1-12, combined with an extension of the original method to higher yield strengths, is used to estimate impact toughness influence factors qi in line with the crane standard EN 13001-3-1. The inherent conservatism in the present Eurocode 3 methodology is quantified and new transition temperature requirements accounting for the built in conservatism in EN 1993-1-10 and EN 1993-1-12 are obtained in the form of a simple table based on the sum of the influence factors ∑qi. The new requirements are universal, i.e. they do not correspond to a specific material standard or sub-grade. The requirements are only a function of the sum of the influence factors ∑qi. The results can be extended to lower transition temperature requirements, if for the applied steels such transition temperatures can be fulfilled.

In this work, we present a new all-cellulose approach for modifying and functionalizing textiles. The use of 3D-printing and two acetylated cellulose derivatives, rigid cellulose acetate (CA) and flexible acetoxypropyl cellulose (APC), on cellulosic fabrics were studied. In addition, prototypes were generated using a design-driven approach. The interactions of cellulose derivatives with cellulose were assessed by quartz crystal microbalance with dissipation monitoring (QCM-D). 3D-printing of cellulosic materials on cellulosic fabrics was performed using a direct-write method by printing cellulose derivatives on woven and knitted cotton and woven viscose fabrics. The adhesion of the printed structures was evaluated via peeling and washability tests. The results indicated that although both cellulose derivatives had a positive attraction towards the cellulose substrate, CA had higher affinity and good adhesion properties, whereas the more branched molecular structure of APC was less firmly attached to cellulosic material. The applicability of 3D-printing cellulosic materials for textile modification and functionalization was assessed through iterative prototyping. Visual effects and functional surface structures were demonstrated. Utilization of 3D-printing of cellulosic materials for surface tailoring of cellulosic textiles, eliminates labour intensive processing or external glues and may enable new and simple customization processes with minimized material usage. Keywords: 3D-printing, Cellulose derivatives, Cellulose acetate, Acetoxypropyl cellulose, Design-driven, Prototyping

Microfluidic-based integrated molecular diagnostic systems, which are automated, sensitive, specific, user-friendly, robust, rapid, easy-to-use, and portable, can revolutionize future medicine. Current research and development largely relies on polydimethylsiloxane (PDMS) to fabricate microfluidic devices. Since the transition from the proof-of-principle phase to clinical studies requires a vast number of integrated microfluidic devices, there is a need for a high-volume manufacturing method of silicone-based microfluidics. Here we present the first roll-to-roll (R2R) thermal imprinting method to fabricate integrated PDMS-paper microfluidics for molecular diagnostics, which allows production of tens of thousands of replicates in an hour. In order to validate the replicated molecular diagnostic platforms, on-chip amplification of viral ribonucleic acid (RNA) with loop-mediated isothermal amplification (LAMP) was demonstrated. These low-cost, rapid and accurate molecular diagnostic platforms will generate a wide range of applications in preventive personalized medicine, global healthcare, agriculture, food, environment, water monitoring, and global biosecurity.

Friction surfacing is a solid state processing technology in the context of localized surface engineering. It is mainly used for coating applications to repair damaged or worn parts, to improve wear and corrosion resistance, to enhance surface properties at a specified area of the parts and tools and also to make metal matrix composites. This process is an environment-friendly technique in which friction between the substrate and consumable rod and the deformation of the consumable rod is the only source to generate heat. The different parameters for this process are rotational speed, pressure or force applied, tilt angle and friction time. The present study is a review of microstructructural evaluation of different materials after the friction surfacing process.

We investigate the dependence of magnetic properties on the B-site cation ordering for a series of (Sr0.5Ba0.5)2FeSbO6 double-perovskite samples for which the Fe/Sb long-range ordering ranges from nearly nonexisting to essentially complete. Also the size of crystallographically ordered domains varies among the samples. All the samples are antiferromagnetic at low temperatures independent of the level of ordering, indicating multiple co-existing exchange and/or superexchange interactions. Nevertheless, a clear trend is seen for the Néel temperature and the effective magnetic moment both increasing with increasing degree of order and the size of the ordered domains.

A multiscale numerical method to study the high cycle fatigue (HCF) and very high cycle fatigue (VHCF) properties of bearing steels is proposed in this study. The method is based on the microstructur sensitive modeling approach resulting from the integrated computational materials ensfginerrring concept, and further consider the effect of residual stress generated from the prior heat treatment processes. The microstructure features, including the grain size and shape distribution and inclusion size and shape description, are represented by the representative volume element (RVE) models. The matrix mechanical response to the cyclic loading is described by the crystal plasticity (CP) model. The CP material parameter set is calibrated inversely based on the strain-controlled low cycle fatigue tests. The results show that the residual stresses, especially those around the inclusion, have a great effect on the fatigue properties, which provides the key factor to give the correct prediction of the fatigue crack initiation site.

Layer-by-layer (LbL) fabricated oxidative multilayers consisting of successive layers of inorganic polyphosphate (PP) and Ce(IV) can electrolessly form thin conducting polymer films on their surface. We describe the effect of substituting every second PP layer in the (PP/Ce) multilayers for graphene oxide (GO) as a means of modifying the structure and mechanical properties of these (GO/Ce/PP/Ce) films and enhancing their growth. Both types of LbL films are based on reversible coordinative bonding between the metal ions and the oxygen-bearing groups in PP and GO, instead of purely electrostatic interactions. The GO incorporation leads to the doubling of the areal mass density and to a dry film thickness close to 300 nm after 4 (GO/Ce/PP/Ce) tetralayers. The film roughness increases significantly with thickness. The (PP/Ce) films are soft materials with approximately equal shear storage and loss moduli, but the incorporation of GO doubles the storage modulus. PP displays a marked terminating layer effect and practically eliminates mechanical losses, making the (GO/Ce/PP/Ce) films almost pure soft elastomers. The smoothness of the (PP/Ce) films and the PP-termination effects are attributed to the reversible coordinative bonding. The (GO/Ce/PP/Ce) films oxidize pyrrole and 3,4-ethylenedioxythiophene (EDOT) and form polypyrrole and PEDOT films on their surfaces. These polymer films are considerably thicker than those formed using the (PP/Ce) multilayers with the same nominal amount of cerium layers. The GO sheets interfere with the polymerization reaction and make its kinetics biphasic. The (GO/Ce) multilayers without PP are brittle and thin.