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In this paper, based on the Diophantine equation technique, we first prove the circulant graph C (Z n , { k 1 , k 2 }) is isomorphic to the disjoint union of gcd (n , k 1 , k 2) identical graphs, which belong to one of the three types of graphs: (i) C (Z n { 1 , k }) ; (i i) the Cartesian graph bundle C s □ φ C t over cycles; (i i i) the Cartesian product of the complete graph K 2 and a cycle. Naturally, to study the dispersability of C (Z n , { k 1 , k 2 }) can be reduced to study that of the above three types. Next, we solve the dispersability of the circulant graph C (Z n , { 1 , k }). Specifically, C (Z n , { 1 , k }) is dispersable if it is a bipartite; otherwise, it is nearly dispersable. In addition, we prove that bipartite circulant graphs are dispersable. [ABSTRACT FROM AUTHOR]

In order to solve the problems of time-consuming and low precision in characterizing the dispersion uniformity of fiber suspensions in traditional wet-laid non wovens, image analysis is proposed to characterize the dispersion uniformity of fiber suspensions.Through the digital image processing technology, the fiber suspension image collected by the digital camera is preprocessed by graying and Gaussian filtering et al, and then the sample analysis of the image is carried out to obtain the variation coefficient of the image gray value, so as to characterize the uniformity of the fiber dispersions;and to compare with the uniformity results obtained by the weighing method. The results show that there is a strong linear positive correlation between the results of digital image analysis method and the weighing method, which can better characterize the dispersion uniformity of fiber suspensions. The digital image analysis method has the characteristics of fast speed and high efficiency to characterize the dispersion uniformity of fiber suspensions. [ABSTRACT FROM AUTHOR]

Surface modification of carbon black (CB) is an important tool to refashion properties of its composites. CB surface modification is usually practiced through thermal procedures. However, environmental concerns have provided the base to rethink for alternate methods, particularly photochemical methods that are considered comparatively eco-friendly due to reduced chemical and thermal waste. Present investigation is based on a photochemical method for CB surface modification that has effectively modified particle surface with alkoxysilane. This method carries the active centers, generated by photoinitiator, to the shaded areas which otherwise are not possible to reach. Hence, this reaction scheme has prevailed over huge activation barrier without thermal support. A photo-thermal modification method has also been utilized for comparative analysis. Effectiveness of photochemical modification method to alter the surface of CB has been confirmed through different instrumental techniques, including XPS, TGA, FTIR, Raman and SEM. [ABSTRACT FROM AUTHOR]

• Ultra-fast mechanochemical strategy to obtain stable colloidal dispersions of MWCNT in hydrophilic media: never has been so easy. • An ultra-fast and easy mechanochemical strategy for MWCNT dispersion is showed. • Reproducible non-covalent functionalization of MWCNT with surfactants (cationic, anionic or neutral). • Preservation of the pristine sp2 hybrid state of the carbon atoms. • Long-term stable MWCNT colloids in hydrophilic media are achieved. In this paper, we present a new protocol that allows the dispersion of multi-wall carbon nanotubes (MWCNT) in the form of stable colloids in a hydrophilic medium up to concentrations of ca. 0.06 % (w/w). The strategy involves using a combination of mechanochemical treatment and surfactants. In this study, we processed MWCNTs with surfactants in a ball mill without using any solvents. The mechanochemical treatment consists of processing mixtures of MWCNTs (0.35 g) with different surfactants (4.5 g of CTAB, 3.6 g of SDS and 4.5 g of F127 as cationic anionic and neutral surfactants, respectively) in a ball mill for only 20 min at 300 rpm. The resulting black powder is then used directly to prepare dispersions in hydro-alcoholic media, which maintain colloidal stability for at least 25 days. Although various strategies for dispersal have been proposed in the literature, many involve time-consuming and multi-step processes with low yields. The MWCNTs modified non-covalently using our protocol are synthesised in a single step with a 100 % yield without any loss of reagents. MWCNT have shown potential in many emerging applications of great interest. Its use necessarily implies the achievement of a good dispersion in different solvents, and this aspect, in the case of hydrophilic media, still does not have a satisfactory answer. The absence of solvent during the mechanochemical treatment is the key aspect of our strategy. This small change represents a significant improvement. We demonstrate the outstanding stability of the obtained suspensions and the preservation of the nano-/microstructure of the MWCNTs, which remains unaltered during their preparation. Furthermore, using environmentally friendly solutions for dispersion makes this protocol a Green Chemistry approach. [ABSTRACT FROM AUTHOR]

Introduction. The work objection is the investigation of the industrial safety of the foundry. The task to estimate a disperse composition of dust which determines the microclimate of the foundry working area is being solved. The dependence between the particle size and their motion speed under the gravitational or centrifugal forces is revealed. Materials and Methods. The granulometric composition analysis of a powder dust sample is carried out by the laser diffraction method implemented on the laser particle analyzer Fritsch NanoTec “ANALISETTE 22”. Research Results . The data analysis shows that all phases of the process determine the microclimate of the internal environment and, under the emission dispersion, the medium in the intercase zone. The impact degree depends on the dispersion and chemical composition of dust particles. The other harmful airborne substances deposited on dust particles make it more dangerous. For example, an increase in SiO2 content toughens the requirements for clean air in the working area. Therefore, it is necessary to take into account more rigorous values of maximum permissible concentrations (MPC). Discussion and Conclusions. The most dangerous areas of the foundry production in the eco-risk terms are identified; and proposals on the development of the dust-collecting system with water wash are made. The research results can be used in foundries of the machinery production.

• The problem about the matching book embedding of toroidal grids is completely solved. • Introduce the definition of colored well for edge subset of a graph. • Adopting the recursive method to color the edges from local to whole. • Find vertex order by alternating trick to matching-book embed toroidal grids in 5 pages. In this work, we study the dispersability of the odd toroidal grid T s , t and get that T s , t is nearly dispersable, which completely solves the problem about the matching book embedding of toroidal grids. [ABSTRACT FROM AUTHOR]

Novel functionalized carbon nanotubes (CNTs) were prepared by grafting disulfide-containing polyethyleneimine (SSPEI) to CNTs. The SSPEI were synthesized by Michael addition between cystamine bisacrylamide and low molecular weight branched 1.8 kDa PEI. Three SSPEI grafted carbon nanotubes (CNTs-SSPEI) were successfully prepared through grafting SSPEI to CNTs. The grafted ratios were 32.26%, 43.11%, and 51.50%, respectively. Moreover, the grafted ratio could be tuned by adjusting the CNTs/SSPEI ratio during the process of preparation. The CNTs-SSPEI was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The CNTs-SSPEI showed better dispersability and stability in water than CNTs. In addition, the SSPEI on the surface of CNTs-SSPEI could be degraded in the presence of dithiothreitol. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs), owing to their inherently unique properties in the domain of biomedical sciences including drug delivery, offer an exciting platform to the researchers. Of late, their applications have also been successfully established. Recently, single-walled CNTs (SWCNTs) have been explored for antibacterial efficacy, but naïve multi-walled CNTs (MWCNTs) still remained unearthed. The present studies endeavor the investigation of the potential of various non-ionic surfactants in solubility enhancement of MWCNTs and their subsequent antibacterial efficacy against Escherichia coli and Staphylococcus aureus. Polysorbates offer more solubility to MWCNTs vis-à-vis the phospholipids. However, the antibacterial effect was found to be less influenced by solubility but significantly determined by the type of surfactant. Transmission electron photomicrographs confirmed significant adhesion of MWCNTs to the bacterial walls only in the presence of unsaturated phospholipids and this was expressed in the form of lowest minimum inhibitory concentration (MIC) values of MWCNTs dispersed with the same. The findings are unique as MWCNTs were found to be active against both Gram-negative and Gram-positive bacteria to a similar extent, though somewhat milder than SWCNTs. However, when dispersed with unsaturated phospholipids, the former offer almost comparable antibacterial effects to that of the latter. The study opens a new research domain to further explore the antibacterial effects of non-functionalized and relatively safer MWCNTs, accentuating the importance of biocomponents like unsaturated phospholipids in this purview. [ABSTRACT FROM AUTHOR]

Abstract: The present study investigated the influence of a covalently grown polythiophene (polyTh)-based adlayer on the N-methyl-2-pyrrolidone (NMP) dispersion of chemically modified multi-walled carbon nanotubes (MWCNTs). Poly(thiophen-3-yl-acetic acid) (PTAA), poly(ethylenedioxythiophene) (PEDOT), and PTAA/PEDOT co-polymer have been oxidatively grown from the surface of functional MWCNTs afforded corresponding polyThA-, polyThB-, and polyThA/B-MWCNTs, respectively. To study and quantify the MWCNT particle sedimentation behavior of corresponding dispersion systems, an analytical centrifuge system was used. Comparison of dispersion quality of such polyTh-MWCNT composites with both commercial MWCNTs (COM-MWCNTs) and oxidized MWCNTs (polyCOOH-MWCNTs) was established. Analysis of sedimentation results combined with TGA, Elemental Analysis (EA), and Kaiser Test data showed that the COOH groups present on the surface of MWCNTs strongly promote the dispersability much beyond current sedimentation rate observed for COM-MWCNTs, – sedimentation rates were higher than 80% and below 2% for oxidized polyCOOH-MWCNTs. However, regarding MWCNTs coated with polyTh polymers in a core (MWCNT)–shell (polyTh) structure, outer functional groups are not the only influential factor for promoting high dispersion qualities. For these dual phase composite systems, the weight and thickness of polyTh-shell on the composite must be considered. [Copyright &y& Elsevier]

Abstract: Spherical, rod and fibroid hydroxyapatite [HAp, Ca10(PO4)6(OH)2] nanoparticles were prepared and dispersed in aqueous media. Temperature and solution pH were the key factors to synthesis of different morphology and crystallinity. Processing conditions were selected from ternary diagram of pH, temperature and Ca:P ratio. High hydroxyl ion concentration (12.25≥pH≥10.5) and low temperature (298K) favored isotropic non-confined spherical particles, intermediate concentration (9.5≥pH≥7.75) and low temperature (303K) initiated the anisotropic growth of rod shaped particles but low concentration (7≥pH≥5.25) and high temperature (353K) accelerated one-dimensional fibroid morphology. The dispersed HAp–citrate complex exhibited a constant zeta potential and size distribution for six months. [Copyright &y& Elsevier]

Abstract: Two multiwalled carbon nanotube hybrids have been prepared: (a) multiwalled carbon nanotubes (MWCNTs) functionalized with amphiphilic poly(propyleneimine) dendrimer (APPI), viz. MWCNTs-APPI, and (b) silver nanoparticles (AgNPs)-deposited multiwalled carbon nanotubes functionalized with an amphiphilic poly(propyleneimine) dendrimer (MWCNTs-APPI-AgNPs). The degree of covalent functionalization of APPI in MWCNTs and deposition of AgNPs in MWCNTs-APPI were examined by Fourier transform infrared spectroscopy, zeta potential, scanning and high-resolution transmission electron microscopy, energy-dispersive spectroscopy, thermogravimetric analysis, and Raman spectroscopy. The amount of APPI functionalized on MWCNTs determined by thermal gravimetric analysis was about 67% which enables an effective dispersability in aqueous and organic solvents without sonication and these solutions were stable for 6months without undergoing aggregation of MWCNTs. The electronic properties of the hybrid materials were not altered drastically as verified by the Raman studies. The antimicrobial activities of MWCNTs-APPI and MWCNTs-APPI-AgNPs against three different bacteria, viz. Bacillus subtilis, Staphylococcus aureus, and Escheriachia coli illustrated excellent activity. [Copyright &y& Elsevier]

Abstract: Maternal effects are one of the most important influences on the offspring phenotype and their adaptive significance has been increasingly recognized. In this study we document the role of two sources of maternal effects, position and heterocarpy, on juvenile and adult traits of Rumex bucephalophorus, an annual plant that occurs in heterogeneous and unstable environments. Up to three different diaspore types can be found in populations of this species: buried diaspores (BD) at the plant base, and fixed diaspores (FD) and long dispersible diaspores (LD) both borne along aerial stems. The two sources of maternal effects affected most stages of the life cycle of R. bucephalophorus: seed size, dispersability, seedling size and survival, and adult plant fecundity. Maternal effects due to position affected mainly juvenile traits, while those due to heterocarpy were stronger and more persistent. In general, seedlings from FD showed higher survival and originated plants with higher fecundity but with lower dispersability than those derived from BD and LD. Dispersability was markedly affected by the two maternal effects at two different stages: first, there was a trend to place the slighter and more easily detachable diaspores (LD) at the optimal positions for dispersal, and second maternal effect due to heterocarpy surprisingly affected dispersability of the second generation progeny. Our study shows that maternal effects can play an important role in ecology, dynamic and evolution of populations and it adds to growing evidence about the important role of maternal effects. [Copyright &y& Elsevier]

Abstract: Surface-modified ceria oxide (CeO2) nanoparticles were synthesized continuously in supercritical methanol at 400°C, 30MPa and a residence time of ∼40s using a flow type reactor system. Oleic acid and decanoic acid were used as the surface modifiers. Transmission electron microscopy (TEM) showed that the surface modifiers changed drastically the shape and size of the nanoparticles. When 0.3M of the surface modifiers were used, primary particles with diameter of 2–3nm loosely aggregated and formed secondary particles with size of 30–50nm. Wide angle X-ray diffraction (WAXD) analysis revealed that the surface-modified nanoparticles retained CeO2 crystalline structure. The surface-modified CeO2 nanoparticles had a very high surface area (140–193m2/g) compared to the unmodified CeO2 particles synthesized in supercritical water (8.5m2/g). Fourier transform infrared (FT-IR) and thermogravimetric analysis (TGA) indicated that aliphatic, carboxylate and hydroxyl groups were chemically bounded on the surface of CeO2 nanoparticles. Dispersability test using ultraviolet transmittance showed that most of the surface-modified CeO2 nanoparticles were dispersed in ethylene glycol for 30 days while the unmodified CeO2 particles synthesized in supercritical water or in supercritical methanol were precipitated after 7–15 days. [Copyright &y& Elsevier]

OCBIL theory aims to develop an integrated series of hypotheses explaining the evolution and ecology of, and best conservation practices for, biota on very old, climatically buffered, infertile landscapes (OCBILs). Conventional theory for ecology and evolutionary and conservation biology has developed primarily from data on species and communities from young, often disturbed, fertile landscapes (YODFELs), mainly in the Northern Hemisphere. OCBILs are rare, but are prominent in the Southwest Australian Floristic Region, South Africa’s Greater Cape, and Venezuela’s Pantepui Highlands. They may have been more common globally before Pleistocene glaciations. Based on the premise that natural selection has favoured limited dispersability of sedentary organisms, OCBILs should have elevated persistence of lineages (Gondwanan Heritage Hypothesis) and long-lived individuals (Ultimate Self Hypothesis), high numbers of localised rare endemics and strongly differentiated population systems. To counter such natural fragmentation and inbreeding due to small population size, ecological, cytogenetic and genetic mechanisms selecting for the retention of heterozygosity should feature (the James Effect). The climatic stability of OCBILs should be paralleled by persistence of adjacent semi-arid areas, conducive to speciation (Semiarid Cradle Hypothesis). Special nutritional and other biological traits associated with coping with infertile lands should be evident, accentuated in plants, for example, through water-foraging strategies, symbioses, carnivory, pollination and parasitism. The uniquely flat landscapes of southwestern Australia have had prolonged presence of saline lakes along palaeoriver systems favouring evolution of accentuated tolerance to salinity. Lastly, unusual resiliences and vulnerabilities might be evident among OCBIL organisms, such as enhanced abilities to persist in small fragmented populations but great susceptibility to major soil disturbances. In those places where it is most pertinent, OCBIL theory hopefully lays a foundation for future research and for better informed conservation management. [ABSTRACT FROM AUTHOR]

Cluster-like network structures of single-walled carbon nanotubes (SWNTs) were synthesized by chemical grafting poly 2-hydroxyethyl methacrylate (polyHEMA) to the sidewalls of SWNTs. Acid chloride-functionalized tubes were coupled with commercially available HEMA monomer, which was in turn polymerized using a radical initiator. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to identify the surface changes on the nanocomposites. Microscopic observations of the nanotube complexes by field emission scanning electron microscopy (FE-SEM) show that the tubes were dispersed and formed cluster-like network, branched structures with less bundling, thus, strongly suggesting a firm coating of the polymer on nanotube walls. The coating was further confirmed by transmission electron microscopy. The thermal properties of the nanotube complex as studied by thermal gravimetric analysis (TGA) revealed that coating enhanced stability of the complex, when compared to that of bulk polyHEMA and pristine SWNTs. The nanotube complexes showed excellent suspension stability when dispersed in organic solvent. [ABSTRACT FROM AUTHOR]

New microparticles containing amphotericin B (AMB) have been developed and manufactured by spray drying. To this end albumin, polylactic-co-glycolic acids (PLGA) and poly(sebacic anhydride) have been employed as drug carriers. The selection of the solvent used to disperse the drug and the vehicle before spray drying was critical on production yields and physical properties of the microparticles. Once particle size, morphology and dispersability in some aqueous media were shown to be acceptable for an intravenous administration, in vivo efficacy was evaluated and compared with the reference medicine Fungizone ® . Microparticles prepared with albumin, albumin heated at a high temperature, some kinds of PLGA or polyanhydride, as well as Fungizone ® , were tested in an experimental hamster model of infection with Leishmania infantum , by evaluating the evolution of parasitic burdens in spleen, liver and antibody responses. After the injection of three doses corresponding to 2  mg of AMB per kilogram each, diverse reactions were reported depending on the vehicle. The best dispersability, reduction of parasites and antibody response were achieved when the treatment was performed with AMB in albumin microspheres. [ABSTRACT FROM AUTHOR]

The effects of different solvent mixtures and dispersants on non-aqueous suspensions of silicon carbide SiC were investigated by measuring settling rate, sediment height and viscosity. Based on these results, solvents, dispersants and dispersant concentrations were optimised to give the slurry with the lowest settling rate, maximum packing density and minimum viscosity. Tape casting slurry of SiC with shear thinning behaviour was prepared after the addition of other constituents such as plasticisers, binder and homogeniser. Rheological measurements confirmed the shear thinning nature of the tape casting slurry. Green tapes free from visible defects were obtained with 62% solids loading. [ABSTRACT FROM AUTHOR]

An international group of scientists is building a 'trait base', an open internet database of life-history traits of the Northwest European flora (LEDA) that can be used as a tool in planning, in nature conservation and restoration, and in other applied research. The species-trait matrix will comprise referenced information under control of an editorial board, for species of the Northwest European flora, combining existing information and additional measurements. The focus will be on 26 plant traits that describe three key features of plant dynamics: persistence, regeneration, and dispersability. Currently 35% of the species-trait matrix has been filled; however, as the LEDA trait base consortium aims to deliver a database as complete as possible, all input from the scientific community is welcome. [ABSTRACT FROM AUTHOR]

The article presents the author's comments on the OCBIL theory in plant evolution. Information is provided on the researches by the Ecological Society of Australia (ESA) on plants in the Australian continent. Australia was reportedly chosen, as according to a 19th century naturalist, the plants and animals there seem to have peculiar laws not found anywhere else. The OCBIL theory was a product of these researches.

Dispersible, highly graphitic, and nitrogen-doped carbon hollow nanospheres (25-90 nm), termed 'nanobubbles', are prepared via confined carbonization through a silica nanocasting technique. Poly(ionic liquid) nanoparticles are employed as easy-to-make and multifunctional templates, which simultaneously act as both the carbon and nitrogen source. The promising potential of the nanobubbles in oxygen reduction reactions for fuel cells is demonstrated., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)