Density Of Units Research Articles

Stimulus-Responsive Nanoporous System Based on a Redox-Active Molecular Self-Assembled Monolayer.

Ordered arrays of electrically conducting cylindrical nanotubes are created by atomic layer deposition of a thin titanium dioxide layer onto the pore walls of an anodic alumina matrix. All geometric parameters (pore length and diameter and TiO2 layer thickness) are defined and tunable experimentally. The titanium dioxide surface is subsequently functionalized with ferrocenylacetic acid. The chemisorbed ferrocene moieties are oxidized chemically and electrochemically. Monitoring the redox chemistry by UV-visible absorption spectroscopy allows for the quantification of the total density of redox-active units grafted to the surface, as well as the fraction of them oxidized at a given applied potential. The capillary properties of the surface can be adjusted by the applied potential, as quantified by contact angle measurements.

Study of Heavy Metal Distribution and Hydrodynamic Simulation in Green Mussel Culture Net, Cilincing Water - Jakarta Bay

This study aimed to investigate the heavy metals distribution in the surrounding area of green mussel culture net, Cilincing water, Jakarta Bay, and its distribution behavior. The water sampling was carried out during the ebb tide. The heavy metal concentration was then measured by using atomic absorption spectroscopy (AAS). In order to understand the water circulation behavior related to heavy metal distribution in the study area, the Princeton Ocean Model was applied, and the model design was developed based on a scenario of an open canal in the eastern and western sides, while the center canal was placed with net cages in the water column resembling the green mussel culture net. The observed heavy metal distribution showed an intensified concentration in the green mussel culture location. The observed water current also showed a reduced velocity in the location. The modeling approach could explain the water circulation behavior in response to the presence of net units in the water column. In this case, the density of net units for green mussel culture potentially produced shear stress in the water column, which affected the flow pattern and the distribution of heavy metals. Therefore, the existence of green mussel culture nets has a potential to become a trap for pollutant distribution in the water.

Quality Assurance of Solid Oxide Fuel Cell (SOFC) and Electrolyser (SOEC) Stacks

Many research facilities and industrial companies worldwide are engaged in the development and the improvement of solid oxide fuel cells/stacks (SOFC) and also of solid oxide electrolysis cells/stacks (SOEC). However, the different stacks cannot be easily compared due to non-standardized test programs. Therefore the EU-funded project “SOCTESQA” which started in May 2014 has the aim to develop uniform and industry wide test modules and programs for SOC cells/stacks. New application fields which are based on the operation of the SOC cell/stack assembly in the fuel cell (SOFC), in the electrolysis (SOEC) and in the combined SOFC/SOEC mode are addressed. This covers the wide range of power generation systems, e.g. stationary SOFC µ-CHP, mobile SOFC auxiliary power unit (APU) and SOFC/SOEC power-to-gas systems. In order to optimize the test programs, which consist of different test modules, several testing campaigns have been performed. The project partners apply the developed test procedures on identical SOC stacks. In this project 5-cell short-stacks with anode supported cells (ASC) were used, which were provided by an established stack supplier. Altogether 10 pre-normative test modules were developed: Start-up, current-voltage curve, electrochemical impedance spectroscopy, reactant utilization, reactant gas composition, temperature sensitivity, operation at constant current, operation at varying current, thermal cycling and shut-down. The presentation compares the results of the test modules of the different project partners. Important aspects are the evaluation of the results in terms of repeatability of the different testing campaigns and the reproducibility of the results among the partners. Electrochemical properties, e.g. open circuit voltage (OCV), area specific resistance (ASR), power density, fuel utilization (FU) and impedance values of both stack and repeat units (RU) are presented. Moreover, the results are discussed in context to the test input parameters. Another important issue is the reproducibility of the different test methods, e.g. jV-characteristics and EIS-spectra. Finally, important aspects for the determination of reproducible degradation rates of SOC stacks will be presented and discussed.

Density of CaO–Al2O3–SiO2 glasses with (CaO/Al2O3) ≥ 1; the hidden factors

Density of CaO–Al2O3–SiO2 glasses with SiO2≥50mol% and CaO/Al2O3≥1 has been analyzed. The basis of analysis is that the entire Al2O3 content forms AlO4 tetrahedra by association with an equivalent amount of CaO. The rest of CaO forms Q3 and Q2 units in the silicate network. The results indicate that the density of structural units decreases in the sequence DAlO4>DQ3>DQ4. Nevertheless, at a constant content of SiO2, the density decreases with replacing CaO by Al2O3. This unexpected trend has been explained by taking in account the contribution of various structural units to the glass density.

THE VOLUMETRIC DENSITY OF ORE – RESOURCE PARAMETER OF SECONDARY IMPORTANCE? THE POLKOWICE–SIEROSZOWICE CU-AG DEPOSIT, LEGNICA-GŁOGÓW COPPER DISTRICT

Volumetric density of the detailed lithological units in Polkowice-Sieroszowice Cu-Ag deposit has been compared to the density of the three basic ore types. Eight diferrent lithologies of the Cu-Ag deposit have been taken into account. It appeared that the resources in them estimated on the basis of volumetric densities are approximately 3% higher than analogous estimates for volumetric densities attributed to the basic ore types. The correlation and regression analysis have shown that the porosity of rocks is the dominant factor affecting the volumetric density, whereas the Cu content plays a secondary role. Some of the lithologies have revealed some heterogeneity of spatial density that can be explained by the variability of mineral cement and porosity as well as the presence of non-copper heavy minerals (e.g. galena, pyrite). The knowledge of the density of individual lithologies enables more accurate estimation of their resources leading to more effective production.

Association of aortic perivascular adipose tissue density with aortic calcification in women with systemic lupus erythematosus

Background and aimsWomen with systemic lupus erythematosus (SLE) have an increased risk of cardiovascular disease (CVD). Perivascular adipose tissue (PVAT) surrounds the vascular wall, is associated with CVD risk factors, and may contribute to premature CVD in SLE. We previously found greater volumes of aortic PVAT associated with aortic calcification (AC) in female SLE patients. There is recent evidence that not only volume but adipose density may also be indicative of inflammation. We hypothesized that female SLE patients would have a difference in aPVAT quality associated with AC that is independent of volume. MethodsAorta PVAT quality was evaluated using the average radiodensity (density) of adipose tissue-specific Hounsfield Units (−190 to −30 HU) within each clinical CT scan of CVD-free, age-/race-matched SLE women (n = 143) and healthy controls (HC, n = 143). ResultsAorta PVAT density was significantly higher in SLE (mean (SD): (−83.6 (1.9) HU) versus HC (−84.1 (1.8) HU), p=0.03). Increasing aPVAT volume was correlated with denser aPVAT in SLE (ρ, p-value: 0.75,<0.0001) and HC (0.74,<0.0001). Increasing AC score (log) was correlated with denser aPVAT for SLE (0.31, 0.0005) and HC (0.23, 0.008). In linear regression, denser aPVAT was more strongly associated with AC score in SLE (β (SE): 0.445 (0.11), p<0.0001) versus HC (0.335 (0.12), p=0.006) independent of age, circulating inflammatory markers, CVD risk factors and BMI (p<0.05), but was attenuated with aPVAT volume (p=0.3). ConclusionsDenser aPVAT is associated with aPVAT volume and AC in SLE women. Adjusting for aPVAT volume attenuated the detected association between aPVAT density and AC, which may be indicative of adipose dysfunction.

The effect of adding NaCl on thermal aggregation and gelation of soy protein isolate

Thermal aggregation and gelation of soy protein isolate (SPI) was studied at fixed charge density over a wide range of protein concentrations (1–95 g/L), NaCl concentrations (0–0.5 M) and temperatures (30–85 °C). Gelation was studied with oscillatory shear measurements and aggregation with light scattering. At all conditions, self-similar aggregates were formed by random association of elementary units consisting of dense SPI particles with radii between 30 nm and 50 nm that were formed in a first step of the thermal aggregation process. Two distinct irreversible aggregation processes were identified: one dominating between 30 and 45 °C and one dominating above 65 °C. Addition of salt led to faster aggregation and gelation, but did not influence the gel stiffness at steady state. The size and density of the elementary units of the aggregates increased with increasing NaCl concentration and confocal laser scanning microscopy images showed increasingly heterogeneous gels structures. The effect of varying the ionic strength on thermal aggregation is compared with that of varying the net charge density of the proteins.

Estimating age at death from an archaeological bone sample – a preliminary study based on comparison of histomorphometric methods

The estimation of age at death is one of the most fundamental biological parameters, determined on skeletal remains in anthropological context. That is why, there is a constant need to improve applied methods. Histomorphometry, which uses microscopic analysis of bone tissue is suggested to be one alternative method. In general, this technique is based on measurements and the determination of the number and density of basic bone structural units, osteons. Osteon density is found to be related with age of the individual. The main goal of this research was to compare results of determined age at death, on the basis of ribs histology, comes from methods proposed by different authors. We analyzed ground cross sections of ribs from archeological origin. The presented methodology is simple in use and effective. Four different methods were tested (Stout and Paine 1992; Cho et al. 2002; Kim et al. 2007; Bednarek et al. 2009). The obtained age results were compared with each other as well as related to the age estimated by standard macroscopic method used in anthropology. Bednarek’s method is recognized to be the most supportive for anthropological analyzes. Methodological issues connected with grinding methodology and results interpretation are also presented. Hypothesis about interpopulation as well as histological and dimorphic differences were confirmed.

Flow unit model in metallic glasses

Metallic glass is a promising metallic material with many unique properties, and also considered as a model system to study the mysteries of amorphous materials. Recently, many experimental and simulation results supported the existence of “flow unit” in metallic glass. In this paper, we review the background, the theoretical and experimental evidences of flow unit model. Flow units are considered as those loosely packed regions embedded inside the elastic matrix and behave like viscous liquid. Compared with the matrix, flow unit regions have low modulus and strength, low viscosity, high atomic mobility and stand in the saddle points on energy landscape. Therefore, flow units can be treated as dynamical defects in metallic glass. The feature, activation and evolution process of flow unit region in metallic glass as well as their correlation with property in metallic glass are also reviewed. Through dynamical mechaincal methods like dynamical mechanical spectra and stress relaxation, flow unit region and its properties can be distinguished and studied. A three-parameter physical model is proposed to describe the mechnical behaivors of flow units. The activations and evolutions of flow unit under different temperature and strain conditions are studied. A three-stage evolution process is found and the relation with mechanical performance and relaxation behavior is established. The characteristics of flow units are also related to various properties of metallic glass, like plasticity, strength, fracture and boson peaks. By using the thermal, mechanical and high pressure aging procedues, the properties of metallic glass can be manipulated as desired through adjusting the density of flow units. We show that the flow unit model not only helps to understand the mechanism behind many long-standing issues like deformation, glass transition dynamic relaxations, and the connection between strucutre and properties and performance of metallic glasses, but also is crucial for tuning and designing the properties of metallic glasses.

Changes of meibomian glands in patients with type 2 diabetes mellitus.

To investigate the morphological changes of meibomian glands in patients with type 2 diabetes mellitus (DM). Of 118 eyes (118 patients) with type 2 DM (DM group) and 100 eyes of 100 control subjects (control group) were enrolled. After completing an ocular surface disease index (OSDI) questionnaire, the non-invasive tear film break-up time (NI-BUT) and the structure of the meibomian glands (MGs, meibography) were assessed by the Keratograph 5M system. Partial or complete loss of MG was scored for each eyelid from grade 0 (no loss) to grade 3 (lost area was >2/3 of the total MG area), which were also examined by laser scanning confocal microscopy (LSCM). The primary outcomes were meibomian gland acinar unit density (MGAUD), meibomian gland acinar longest diameter (MGALD) and meibomian gland acinar shortest diameter (MGASD). Compared with control group, the OSDI was significantly higher in DM group (Z=-5.916; P<0.001), while the NI-BUT was significantly lower (Z=-7.765; P<0.001). Keratograph showed that there were more MGs dropout in DM group than that in control group. The meiboscore was significantly higher in DM group compared with control group (Z=-3.937; P<0.001). LSCM revealed that there were cytological alterations of MGs in DM group compared with control group, which included enlargement of MG acinar units and decreased in density of MG acinar units. Specifically, there were lower MGAUD, larger MGALD and MGASD in DM group than control group (Z=-10.120, -9.4442, -7.771; P<0.001). Compared with the normal control participants, the patients with type 2 DM had more unstable tear films and severe symptoms of dry eye. Using Keratograph 5M system and LSCM, we found that the patients with type 2 DM had more significant morphological and cytological changes and dysfunction in MGs.

Molecular Aspects of Tonic B-Cell Receptor Signaling in Diffuse Large B-Cell Lymphoma Provide Biomarkers and Targets for Specific Inhibition

Introduction. Targeting antigen-driven B-cell receptor (BCR) signaling with the BTK inhibitor ibrutinib is clinically effective against most B-cell lymphomas, including activated B-cell diffuse large B-cell lymphoma (ABC-DLBCL), but not germinal center B-cell (GCB) DLBCL. We have formally confirmed that GCB-DLBCL cell lines utilize tonic BCR signaling, by showing: 1) sensitivity (variable) to knockout (KO) of the BCR, SYK, and CD19; 2) dependence on CD79A ITAM phosphorylation; and 3) independence from BCR antigen specificity. However, uncertainty remains about molecular events in upstream parts of tonic BCR signaling, why dependence of GCB-DLBCL cells on tonic BCR signaling is variable, and their clinical relevance.Methods. We used CRISPR/Cas9 methods to modify selected genes by KO and/or knock-in (KI) of the cDNA of a fluorescent protein (FP; e.g., GFP), with the FP serving as a marker of cells with gene KO or modification, or as a gene-fused tag for localization or quantitation. Cells expressing a membrane-targeted Forster resonance energy transfer (FRET) based AKT activity reporter (Lyn-AktAR2) were used to measure AKT activity directly by flow cytometry (FCM).Results. The effect of KI of CD79A Y188F mutation alone was similar to complete BCR KO, implying that CD79A Y188 phosphorylation is essential for tonic BCR signal transduction. Western blot analysis of GCB-DLBCL cell lines after BCR KO showed variable decreases of AKT S473 phosphorylation (frequently used as surrogate measure of AKT activity), but these did not correlate well with the variable decreases in proliferation of GCB-DLBCL cell lines caused by BCR KO. Measuring AKT activity directly (Fig. 1), or by another indirect approach (surface expression of CXCR4, a target gene of FOXO1 inhibited by AKT activity), showed high correlation between decreases in AKT activity and proliferation after BCR KO. In contrast to the variable effect of BCR KO on growth, pan-AKT KO was uniformly growth-slowing in GCB-DLBCL lines (Fig. 2). Interestingly, baseline surface density of BCR units in GCB lines, quantified by FCM using CD79A-GFP KI cells or anti-CD79B staining, correlated highly with reduction in growth or AKT activity caused by BCR KO (Fig. 3). These findings lead us to conclude that the BCR contributes to AKT activation in GCB-DLBCL cell lines, to a variable degree determined by BCR surface density. We also conclude that BCR surface density is determined by cell line-specific factors, as well as immunoglobulin heavy (IgH) and light (IgL) hypervariable region (HVR) sequences, based on measurements of BCR surface levels after exchanging endogenous HVR sequences in OCI-Ly19 and OCI-Ly7 cell lines for HVRs derived from other GCB and ABC-DLBCL cell lines.Reduction of AKT activity after BCR KO (measured by FRET reporter) and baseline BCR surface density in GCB-DLBCL cell lines also correlated well with the sensitivity of GCB-DLBCL lines to the clinically-tested SYK inhibitor (P505-15, PRT062607) or FDA-approved PI3K p110d isoform specific inhibitor (idelalisib). Interestingly, isogenic GCB-DLBCL cell lines with KO of PTEN, a negative regulator of AKT activation, were substantially more resistant to both inhibitors. A crucial role of PTEN deletion in overcoming dependence on tonic BCR signaling in GCB-DLBCL is supported by evidence from two naturally PTEN-deficient cell lines: SUDHL10, which adjusts to BCR KO and resumes normal growth, and HT, which lacks BCR expression, due to a frameshifting deletion in its IgH HVR. Re-expression of the BCR in HT, by KI to correct the IgH sequence, does not affect HT cell line growth.Conclusion. Our findings suggest a biomarker-guided therapeutic strategy in GCB-DLBCL: targeting tonic BCR signaling in BCR-high patients, by inhibiting CD79A phosphorylation, SYK, or PI3K, and downstream targeting of AKT in BCR-low and/or PTEN-deficient patients. [Display omitted] [Display omitted] [Display omitted] DisclosuresBurger:Pharmacyclics: Research Funding. Westin:Chugai: Membership on an entity's Board of Directors or advisory committees; Spectrum: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; ProNAi: Membership on an entity's Board of Directors or advisory committees.

Raman Gain in Tellurite Glass: How Combination of IR, Raman, Hyper-Raman and Hyper-Rayleigh Brings New Understandings

A new multimodal approach that combines linear and nonlinear vibrational spectroscopies and hyper-Rayleigh scattering has been applied in the TeO2–TaO5/2–ZnO glass system to assess and quantify the relation between Raman gain and optical responses within the glass’ network arrangement. The level of polymerization of the TeO4 chain-like structure in a TeO2 glass system has been identified to be the main parameter for reaching high linear and nonlinear optical constant. We have observed that replacement of TaO5/2 by ZnO strongly modifies the optical properties and, primarily, the Raman and hyper-Raman spectra of the glasses. In particular, we clearly demonstrate a linear relationship between Raman gain and the linear and second-order optical response of the glass, which is directly related to the number density of TeO4 chain-like units. Assuming that only TeO4 chain-like units contribute significantly to the glass’ polarizability, we have found that about 30% of the Te atoms contribute to the hyperpolarizab...

Morphology and ultrastructure of Middle Devonian dispersed megaspores from Qujing, Yunnan, Southwest China

Lycopsid megaspores isolated from the Middle Devonian, Givetian, Shangshuanghe Formation at Qujing in Yunnan, Southwest China, were identified and illustrated using fluorescence microscopy (FLM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Three species (Longhuashanispora reticuloides Lu et Ouyang, 1978, Ocksisporites maclarenii Chaloner 1959, and Cereusisporites mirabilis Lu et Ouyang, 1978) are described. L. reticuloides is azonate. Both proximal and distal exines of L. reticuloides consist of a thin basal lamina with a high density of sporopollenin units, a loose spongy region with different types of voids, and a solid region with some processes. It is intriguing that the processes of L. reticuloides usually have a large cavity at their base. Coronispora sinica Lu et Ouyang ex Jansonius et Hills, 1992 is a junior synonym of Ocksisporites maclarenii Chaloner 1959. The other species currently accommodated in Coronispora is transferred to Ocksisporites resulting in the new combination O. variabilis (Fuglewicz et Prejbisz) comb. nov. O. maclarenii is zonate. The proximal exine of O. maclarenii primarily consists of a solid region while the distal exine is mainly composed of a loose spongy region. C. mirabilis is also zonate. Both proximal and distal exines of C. mirabilis could be divisible into a thin basal lamina, the first solid region with or without small voids, a loose spongy region with different types of voids, and the second solid region with some processes. Both proximal and distal processes of C. mirabilis have large internal cavities, although the distal processes are higher and more robust. Comparisons with in situ spores produced by plant fossils recovered from coeval horizons in adjoining region suggest that Longhuashanispora reticuloides shares ultrastructural and morphological characteristics of the in situ spores yielded by both heterosporous and homosporous ligulate lycopsids. Its parent plant probably represents a transitional form from the homosporous ligulate to the heterosporous ligulate lycopsids. It supports the previous conclusion that the homosporous ligulate lycopsid lineage and the heterosporous ligulate lycopsid lineage have diverged in the late Middle Devonian. The parent plants of O. maclarenii and C. mirabilis may have been a type of herbaceous lycopsid, which is rarely preserved as a fossil. The presence of the genus Ocksisporites in South China, Arctic Canada, and northern Poland indicates that in the Middle Devonian a migration pathway for plants existed between South China and Laurasia.

Pediatric obesity is associated with an altered gut microbiota and discordant shifts in Firmicutes populations.

SummaryAn altered gut microbiota has been linked to obesity in adulthood, although little is known about childhood obesity. The aim of this study was to characterize the composition of the gut microbiota in obese (n = 42) and normal‐weight (n = 36) children aged 6 to 16. Using 16S rRNA gene‐targeted sequencing, we evaluated taxa with differential abundance according to age‐ and sex‐normalized body mass index (BMI z‐score). Obesity was associated with an altered gut microbiota characterized by elevated levels of Firmicutes and depleted levels of Bacteroidetes. Correlation network analysis revealed that the gut microbiota of obese children also had increased correlation density and clustering of operational taxonomic units (OTUs). Members of the Bacteroidetes were generally better predictors of BMI z‐score and obesity than Firmicutes, which was likely due to discordant responses of Firmicutes OTUs. In accordance with these observations, the main metabolites produced by gut bacteria, short chain fatty acids (SCFAs), were higher in obese children, suggesting elevated substrate utilisation. Multiple taxa were correlated with SCFA levels, reinforcing the tight link between the microbiota, SCFAs and obesity. Our results suggest that gut microbiota dysbiosis and elevated fermentation activity may be involved in the etiology of childhood obesity.

A study to design the emergency reaction plan for LPG tanks in 5&lt;sup&gt;th&lt;/sup&gt; refinery, south pars gas-condensate by using phast software

Outcome Assessment is a tool applied by safety engineers in order to evaluate the risk resulting from industrial activities and determine the level of risk and damage arising from work-related accidents. After identifying and evaluating the risks, it is essential to estimate the intensity and consequences of the risks because the intensity of adverse effects and the likelihood of occurrence determine the risk. On the other hand, today, with increased density and proximity of industrial units, the adverse consequences of an accident cannot be limited to one unit. The damaging effects can spread to adjacent units or the surrounding residential area. This study aims to identify the risks in LPG storage unit, 5 th South Pars Gas Refinery and possible events in the process by using PHAST software. In order to enhance the modeling accuracy, Pseudo-Component Method was replaced with Multi-Component Method and it was employed to model combined hydrocarbons such as LPG. The results show that sudden explosion of tank is more dangerous than others, leaving irreparable financial and human damages. LPG export pipeline requires more protection due to the radiation radius as a result of fire induced by fracture. Keywords: Outcome analysis; phast software; accident modeling; risk assessment; safety

Effect of Cu Salt Molarity on the Nanostructure of CuO Prolate Spheroid

Copper sulfate pentahydrate was used as a source of Cu ion with five different molarities (0.02, 0.05, 0.1, 0.15, 2 and 0.25[Formula: see text]M). XRD, FE-SEM and TEM techniques all showed that CuO samples have polycrystalline monoclinic structure. CuO prolate spheroid is assembled from nanoparticles as building units. It was demonstrated that the purity, morphology, size range of prolate spheroid and density of nano building units are significantly influenced by Cu precursor’s molarity. The pure phase of CuO prolate spheroid was produced via molarity of 0.2[Formula: see text]M with crystallite size of 15.1565[Formula: see text]nm while the particle size of building units ranges from 16[Formula: see text]nm to 21[Formula: see text]nm. The stability of CuO nanosuspension or nanofluid was evaluated by zeta potential analysis. The obtained properties of specific structure with large surface area of CuO prolate spheroid make it a promising candidate for wide range of potential applications as in nanofluids for cooling purposes.

Rheology of diluted and semi-diluted partially hydrolyzed polyacrylamide solutions under shear: Experimental studies

Abstract Rheological properties of hydrolyzed polyacrylamide (HPAM) solutions were measured in oscillatory and flow shear. In oscillatory shear the storage and loss moduli increased as the concentrations of the solutions increased, but they decreased as salinity increased. The relaxation spectra were plotted using the Kontogiorgos method. As shown in the relaxation spectra, the number of density of segmental units increased at first and then the peaks shifted and split into several as the concentration increased. With salinity increasing, the number of motion units increase and the peaks of segmental units became broader. In flow shear tests, the curves of viscosity versus shear rate were fitted by a power law equation. The result showed that the flow behavior index decreased with increasing concentration, while it generally increased with increasing of salinity. Furthermore, the first normal stress difference increased as the concentration was increased, while it decreased as the salinity was increased. The first normal stress differences measured by the rheometer were compared with the first normal stress differences calculated by the Laun equation and the results showed that Laun equation deviates the experimental results.

Hydrogel Adhesion with Wrinkle Formation by Spatial Control of Polymer Networks.

We prepared a novel wrinkled adhesive interface of hydrogels for strong adhesion via spatial control of polymer networks, including the density, distribution, and mobility of interactive units. A wrinkle structure was formed by the elasticity mismatch of hydrogels and adhesive polyion complex layers when electrophoresis was carried out between cationic and anionic semi-IPNs. The wrinkling wavelength of interfaces was controlled by Young's modulus of hydrogels. The role of wrinkle structure in adhesion was investigated by the measurement of the adhesive strength of hydrogels which were adhered under the compression, resulting in the disappearance of the wrinkle structure by compression that induced a decrease in adhesive strength. These results indicate that strong hydrogel adhesion was achieved by both the spatial design of interactive units and wrinkle formation.

Fire Walls Made from Concrete and Masonry - Barriers against a Fire Spreading

Fire exposure of a construction represents an accidental load (temporary with a high intensity) and it´s appearance during service life of the construction is improbable. All structural eurocodes, which deal with the normal temperature (20°C) design of structures made from loadbearing materials (steel, steel and concrete composite, concrete, masonry and timber), include always Part 1-2: Structural fire design. Concrete, similar to the masonry, has (in comparison with other construction materials such as steel and timber), an excellent resistance against fire exposure. This is why both of these materials are used for construction of fire walls, which create barriers against the fire spreading. Fire walls separate two spaces and they are designed for fire resistance and structural stability, including resistance to mechanical impact. In the case of fire and failure of the structure on one side of the fire wall, fire spread beyond the wall is avoided. Properties of concrete and masonry walls, subject to fire exposure, are however negatively influenced. Concrete compressive strength is reduced depending on the aggregate choice. The strength of reinforcing bars is also reduced at elevated temperature, by an amount which strongly depends on the axis distance of the reinforcing bars from an edge of a cross section, too. The behaviour of a masonry wall depends on a masonry unit type and material, type of the mortar, the density of units, type of the wall construction, and applied surface finishes. In the present article we discuss basic principles of the design and assessment of various concrete and masonry fire walls and compare their effect - fire resistance period – depending on their thickness.

Revealing β-relaxation mechanism based on energy distribution of flow units in metallic glass.

The β-relaxation, which is the source of the dynamics in glass state and has practical significance to relaxation and mechanical properties of glasses, has been an open question for decades. Here, we propose a flow unit perspective to explain the structural origin and evolution of β-relaxation based on experimentally obtained energy distribution of flow units using stress relaxation method under isothermal and linear heating modes. Through the molecular dynamics simulations, we creatively design various artificial metallic glass systems and build a direct relation between β-relaxation behavior and features of flow units. Our results demonstrate that the β-relaxation in metallic glasses originates from flow units and is modulated by the energy distribution of flow units, and the density and distribution of flow units can effectively regulate the β-relaxation behavior. The results provide a better understanding of the structural origin of β-relaxation and also afford a method for designing metallic glasses with obvious β-relaxation and better mechanical properties.