Presence Of Admixtures Research Articles

Ultrasonic treatment for waste-water cleaning

Purification of liquids from undesirable admixtures and malignant bacteria is one of the most important problems of the mankind. It is especially sharply appeared at the cleaning of sewage. At present in the most part of the world (in densely populated territories) there is a lack of pure fresh water. Industrial and domestic waste waters negatively influence on the ecological situation in stretches of fresh water. It is evident, that it is caused by the large quantity of insufficiently cleaned sewage, which constantly comes to rivers and ponds in the connection with functioning of the industrial enterprises and households. The presence of admixtures and malignant bacteria in different liquid food (beverages, acetic seasonings) decreases their consumer properties and can be harmful for people health. So there is no doubt of the development new methods of liquid purification. The article is devoted to the analysis of the problem of purification of domestic and industrial waters from pathogenic microorganisms, undesirable admixtures and malignant bacterium. It is considered existing industrial solutions and their disadvantages. The theoretical research of optimum ultrasonic influence modes providing maximum diffusion coefficient was performed and example of US apparatus was presented.

The impact of granulation on the mineralogy of a modified-BOF slag and the effect on kinetics and compressive strength after alkali activation

This work explored the effect of mineralogical changes of a modified basic-oxygen furnace slag (BOFS) on the properties of alkali-activated binders. The study quantified the amorphous-crystalline proportions of particles from three different size ranges. These size fractions were finely milled and activated with NaOH solutions. The effects on the reaction kinetics and the mechanical strength of the produced binders were established. The early-stage reaction kinetics were tracked, and the significance of the precursor fraction, the addition of admixtures (gypsum and plasticizer), and the liquid-to-solid ratio (L/S) on the reaction kinetics were identified. The relative variation in the amorphous content between fine and coarse fractions was 45%. These mineralogical differences interacted with the presence of admixtures and the L/S, which impacted the kinetics of the cementitious reactions and the rate of strength development of the binder. Nevertheless, the 30-day strength was similar for all specimens (58 MPa).

Spectroscopic characterisation of Naples yellow variations in paintings from the turn of the 20th century

AbstractThe research presented in this study aimed to document the variability of synthetic lead antimonate pigments known as Naples yellow in selected artworks by Czech landscape painters from the turn of the 20th century. Spectra obtained through Raman spectroscopy show considerable difference in the position of main band maximum (from 110 to 145 cm−1) characteristic of cubic pyrochlore structure Pb2Sb2O7—the major phase of the Naples yellow pigment. In several samples, hexagonal PbSb2O6 with main band at 655 cm−1 was identified as a dominant phase, a finding that is somewhat surprising because PbSb2O6 has been generally considered a minor admixture to cubic Pb2Sb2O7. Reference pigment samples were synthesised under known conditions, and their spectra were collected in order to get more comparative material. Also, commercially available Naples yellow pigments were characterised in the same way. We observed considerable differences of the obtained spectra caused by the presence of admixtures and diverse production conditions. The diversity of Naples yellow and the corresponding Raman spectra makes their identification problematic. Presented data thus may serve as a reference material in the identification process.

Study on the effect of VMA admixture for concrete cured under different conditions on air permeability and sorptivity

• Application of VMA resulted in a decrease in compressive strength of concrete in most cases. • VMA resulted in an increase in sorptivity with increasing admixture dosage regardless of the specimen curing applied. • The effect of VMA application on concrete air permeability is negative in most cases. • The use of the plasticiser cause an elongation of initial setting time resulting from retardation of hydration processes. • In general, the same kinds of hydration products were identified in all the hardened samples after long time of hydration. The main goal of this research was to determine the effect of viscosity modifying agent admixture and specimen curing conditions on air permeability, sorptivity and mechanical properties of concrete and determining the effect of the admixture on the intensity of early cement hydration and the phase composition of the hardened cement paste. Used admixtures decreases 28 day compressive strength and the reduction depends on the kind of cement and curing conditions. VMA admixture did not significantly affect the sorptivity of the CEM I series, while in the case of the CEM III series, the sorptivity increased with increasing admixture dosage. The effect of VMA application on concrete permeability is negative in most cases and is most evident in the specimens tested after drying at 65 °C. The rate of heat release during hydration and the related parameters depend primarily on the type of cement, and in the case of admixtures, the use of plasticiser has a much greater effect than VMA. In general, the same kinds of hydration products were identified in all the hardened samples after long time of hydration. The quantitative composition of hardened cement paste depends mainly on the kind of cement used. It was found that the presence of admixtures had a greater impact on the quantitative composition of the cement paste in the case of samples made with CEM I.

A combined IR and XRD study of natural well crystalline goethites (α-FeOOH)

Goethite (α-FeOOH) is one of the most abundant minerals on the Earth surface, occurring in temperate, tropical and equatorial climates. Fe in goethite can be substituted by many cations such as Al, Ni for instance. A large amount of research has been conducted on the effect of varying elemental compositions (mainly Al-content) on the spectral features of goethites with most of the studies based on materials synthesized with different elemental ratios. The different elemental ratios, however, may not only affect the composition of the products but also their crystallinity and/or particle size and shape. Both parameters are known to affect results of both X-ray diffraction (XRD) and infrared spectroscopy (IR). These methods are predominantely used to characterize goethites. In the present study, therefore, a significant set of natural goethites was considered in order to investigate the effect of elemental composition on XRD and IR results. The focus was on crystallised samples which had a limited chemical variability but artefacts caused by the presence of admixtures could be excluded in most cases. First of all Rietveld refinement was optimized based on varying different parameters. A fairly good correlation of Rietveld derived crystallite sizes and specific surface area determined by N2-adsorption (SSA) was found which proves the importance of considering the crystallite size parameters for Rietveld refinement and at the same times proves the quality of it. Using IR spectroscopy yet published relations of band position and Al-content could be confirmed despite the fact that the range of Al-contents was small. However, the band position of the Fe–O stretching, previously used as proxy for crystallinity assessment, was found to be least variable hence contradicting yet published results. Controversial results were also published for the effect of the Al-content on the position of the asymmetric FeOH stretching band at 450 cm−1. The goethites investigated in the present study indicate that the crystallite size determines the band position rather than the Al-content which is at least valid for the limited range of Al-contents. The results of the present study indicate that using synthetic sample sets bears the problem that more than one parameter might show systematic differences (e.g. crystallite size in a set of chemically varied goethites). The paper, therefore, provides IR reference data based on a set of natural well crystallised goethites.

Effects of natural and accelerated carbonation on the properties of lime-based materials

This work aims at evaluating the influence of curing conditions on the carbonation process of lime-based mortars and pastes and on the resulting mineralogical, macro- and microstructural properties. To this end, lime-based materials (mortars and pastes) were subjected to natural (0.05 % CO2) and accelerated (5 % CO2) carbonation. The influence of factors such as water/binder ratio, lime (agglomerated) particle size (surface area) and presence of admixtures on the carbonation process was also addressed. The materials cured under the CO2-rich atmosphere carbonated faster and reached a higher degree of carbonation after only 7 days than those cured naturally for 3 years, even though total carbonation was not achieved. Nevertheless, due to the high conversion rate, the evolution of the properties of the tested materials after being subjected to accelerated carbonation for 7 days is expected to be minimal (stable properties were reached). Portlandite was mostly converted into calcite that precipitated as rhombohedral and scalenohedral crystals regardless of the curing environment. The crystals appeared to be larger and better developed in the specimens subjected to accelerated carbonation, which contributed to the higher mechanical strength displayed by these mortars.

In English

The experimental results obtained in the study on the possibility of sensitizing titanium dioxide (polymorphic anatase phase) to the visible region of the spectrum by doping and co-doping with impurities of non-metals in order to create effective photocatalysts for the decomposition of organic compounds have been analyzed. The presence of impurity atoms appears to result in a change in the electronic structure of the titanium dioxide matrix, in the appearance of “impurity bands” and in the narrowing of the energy gap of titanium dioxide. Such a modification is accompanied by an extension of the spectral range of sensitivity of photoactive solids to the long-wavelength region of the spectrum and, therefore, can be used to improve the catalytic properties of these materials. Spectral manifestations of carbon impurities in titanium dioxide in the form of carbide and carbonate, as well as sulfur in the forms of sulfite, sulfide, and sulfate, have been studied by the density functional theory method. A Ti14H22O39 cluster model was chosen for the titanium dioxide matrix. The calculations were carried out in the framework of the cluster approximation, using functional B3LYP and basis set 6-31G (d, p). Comparison of the results of quantum chemical calculations with the available experimental data shows that the impurity sulfur and carbon atoms in titanium dioxide, which are in different coordination states and different oxidation states, appear in different spectral ranges. This circumstance makes it possible to elucidate the structure of the samples based on the experimental spectra. A change in the coordination and oxidation states of impurity atoms leads to spectral shifts and splitting of peaks, which can reach 1.5 eV (XPS). The presence of admixtures of non-metals leads to a change in color (deepening in the case of sulfide or carbide) of the samples, appearing in the corresponding UV spectra.

Catalytic and photocatalytic oxidation of diphenyl sulphide to diphenyl sulfoxide over titanium dioxide doped with vanadium, zinc, and tin.

Samples of TiO2 (P25) doped with zinc, tin, and vanadium, thermally treated at 550 °C for 6 h, were tested as catalysts and photocatalysts for the oxidation of diphenyl sulphide to diphenyl sulfoxide and sulfone, using hydrogen peroxide as an oxidation agent. Thermal treatment of pure TiO2 and its vanadium-doped forms resulted in a decrease of anatase and an increase of rutile content. The opposite effect was observed for TiO2 doped with zinc or tin, where thermal treatment resulted in the rutile to anatase phase transition. The role of V, Zn, and Sn admixtures as TiO2 phase-composition controllers was postulated. The catalytic and photocatalytic activity was found to be influenced more by the rutile and anatase contents of the samples than the presence of admixtures. The rutile-containing samples, TiO2 and V-TiO2, presented much better activity in the catalytic oxidation of diphenyl sulphide compared with the catalysts that only contained the anatase phase, Sn-TiO2 and Zn-TiO2. The reaction efficiency was significantly improved under UV radiation. In this case, the best photocatalytic activity was found for calcined TiO2, containing both anatase and rutile components. An increase in rutile content, observed in the vanadium-doped TiO2, decreased the efficiency of the photocatalytic diphenyl sulphide oxidation. Thus, the presence of both anatase and rutile phases, with their favourable contributions, typical for P25, is necessary for the effective oxidation of Ph2S to Ph2SO. Moreover, it was shown that for the second oxidation stage, Ph2SO to Ph2SO2, the presence of the rutile phase is very important.

Symptoms of colorectal cancer contributes to its localization and advancement

<b>Introduction:</b> Colorectal cancer is one of the most common cancers occurring in Poland. Unfortunately, this cancer is most often diagnosed at the time of great advancement. This is caused by the appearance of specific symptoms only in the late stages of cancer. Also, such low detection of early stages of adenocarcinoma may be caused by disregarding of slight symptoms. <br/>Purpose:</b> To analyse symptoms in patients with colorectal cancer and correlate with chosen clinical-pathological parameters. <br/>Materials and methods:</b> The study group consisted of 46 patients diagnosed with colorectal cancer. Information on symptoms associated with cancer (subjective and objective) have been selected from patients' medical history. The presence of these symptoms was correlated with the age and sex of patients, tumor location, histological type of cancer, grade of histological malignancy (G), stage of tumor (T stage), presence of lymph node metastases and distant metastases. <br/><b>Results:</b> It has been shown that the presence of pain complaints described by the patient are associated with the occurrence of cancer in the colon. The painfulness and pathological resistance diagnosed by the physician are more often associated with cancer located in the colon. In the case of tumors located in the rectum, faecal admixtures appear more frequently. It has also been shown that the presence of admixtures of blood and mucus in the stool is associated with more advanced local tumors, infiltrating pericolorectal tissues (T3 + T4). <br/><b>Conclusions:</b> Familiarity with clinical symptoms of colorectal cancer could make patients more sensitive to more often screening for cancer. Analysis of these symptoms could indicate to the physician the location or stage of the cancer.

Unit cell structure of water-filled monoolein in inverted hexagonal mesophase in the presence of incorporated tricaprylin and entrapped lysozyme.

Molecular dynamics (MD) was employed by means of a specific simulation protocol to investigate the equilibrium structure at 25 °C of the hexagonal inverted (HII) mesophase composed from water, 1-monoolein (GMO), and tricaprylin, with or without entrapped lysozyme. Based on robust and fast MD simulations, the study provides a comprehensive analysis and visualization of the local structure of HII mesophase containing admixtures. The most important physical insight is the possibility to observe the strong self-recovery capacity of the GMO layer, which allows the HII mesophase tubes to reorganize and host lysozyme molecules with a size bigger than the diameter of the water channel. This is a direct message to the experimenters that the HII mesophase has the potential to host molecules larger than the diameter of the water channel. Collective character of the interlipid interactions is outlined, which is not affected by the presence of the cargo and may be the reason for the efficient GMO reorganization. Another important result is the possible explanation of the role of triacylglycerols on the low-temperature stabilization of the HII mesophase. The analysis shows that despite the low amount of tricaprylin, its molecules prevent the extreme inclination of the lipid tails and thus optimize the alignment capacity of the lipid tails layer. The study also reveals that the packing frustration does not depend on the temperature and the presence of admixtures. Hence, it might be numerically defined as a universal invariant parameter of a stable HII mesophase composed of a certain lipid.

EST‐SSR analysis provides insights about genetic relatedness, population structure and gene flow in grass pea (Lathyrus sativus)

AbstractGrass pea (Lathyrus sativus) is an important food‐legume crop for resource‐poor farmers in the developing world. However, given its cultivation in the most underprivileged regions, the crop has not received appropriate scientific attention particularly from the genomic perspective, thereby giving it a status of genomic orphan. Nevertheless, some recent studies have attempted to develop modern molecular tools to strengthen the genetic and genomic research. In the present investigation, a comprehensive collection comprising 176 accessions was analysed using EST‐simple sequence repeats (SSRs). The SSR analysis revealed existence of a total of 51 alleles with an average polymorphic information content value of 0.35. A moderate level of gene diversity was noticed that ranged from 0.04 to 0.73 with an average of 0.43. Noticeably, two distinct subpopulations were recovered using cluster analysis. In addition, the presence of admixtures in population reflected the strong possibilities of gene flow between the accessions across the geographical boundary. In summary, we provide additional insights about the informativeness of available EST‐SSR markers along with an extended understanding of relatedness, genetic structure and gene flow in an under‐researched legume crop.

A statistical approach to the study of concrete carbonation

Carbonation is one of the factors that conditions reinforced concrete durability, while porosity is one of the parameters that determines the carbonation rate: as a rule, the greater the porosity, the higher the rate. While many papers have been published on the effect of CO2 penetration in the pore solutions of concretes prepared under different experimental conditions, the literature has yet to address the joint effect of the factors considered in concrete design, such as the water/cement (w/c) ratio, type of cement, type of aggregate and presence of admixtures. The present paper discusses the findings of a statistical study of the impact of the aforementioned factors on both system porosity and carbonation rate. The type of cement, individually and in its interaction with the rest of the factors, proved to be the major determinant in concrete carbonation.

Problems relating to operation of geothermal power stations stemming from the presence of admixtures in the geothermal heat carrier

The effects the specific features of chemical composition and the thermophysical properties of geothermal heat carrier have on the metal erosion-corrosion processes and on the formation of deposits during operation of a geothermal power station are analyzed. Methods for preventing the formation of deposits and making the geothermal power station equipment more resistant to erosion and corrosion are considered. Results from calculation and experimental investigations aimed at studying how the concentration of silicic acid and other admixtures vary in the working loop and turbine flow path at the Verkhne-Mutnovsk geothermal power station are presented. The possibility of using surface-active inhibitors to prevent the formation of deposits and erosion-corrosion processes in the geothermal power station equipment is demonstrated.

Calorimetric monitoring of early hardening of cement in the presence of admixtures

This paper considers the key ideas and results of temperature-time monitoring of cement hardening in the presence of admixtures. We demonstrate that the proposed method is highly informative for quantitatively assessing the effectiveness of admixtures in the technologies of cement and concrete.

Influence of some admixtures on the formation of primary and secondary ettringite

Different types of admixtures (2% each of superplasticiser, barium nitrate and stearic acid) were added to examine their effect on the hydration reactions of pure tricalcium aluminate (C3A) in presence of gypsum (G). The effect of 5% magnesium sulfate solution on the formation of secondary ettringite was examined for different time intervals, 3, 7, 28, 60 and 90 days. The hydration products were investigated using X-ray diffraction, Fourier transform infrared and scanning electron microscopy. The time taken for ettringite formation was determined without admixture and in the presence of admixtures. The results showed that superplasticiser, barium nitrate and stearic acid retard ettringite formation whereas they accelerate the formation of calcium mono-sulfoaluminate hydrate phase and tetracalcium aluminate.

Abstract LB-266: Clonal analysis of aneuploid pancreatic ductal adenocarcinoma genomes in patient biopsies using Agilent oligonucleotide technologies and Pacific Biosciences SMRT™ sequencing system

Abstract One of the challenges for the application of emerging genome technologies to the study of human cancer in patients in vivo is the presence of admixtures of normal cells and stroma in patient samples. Furthermore, tumor samples frequently contain multiple neoplastic populations even in small clinical biopsies. Consequently, it is difficult to accurately detect the multiple genomic aberrations typically present in a biopsy of interest and to distinguish whether they arise concurrently or are present in distinct cell populations in the same sample. Recent advances in flow cytometry technology provide high throughput flow rates and the detection of relatively rare events in dilute samples. Coupling this technology with robust methods to label cells and advanced data acquisition and analyses methods enables the application of flow cytometry to high definition cancer genomics in patients. In our current studies of pancreatic ductal adenocarcinoma (PDA) we developed methods that enable whole genome analyses of clonal populations of sorted aneuploid and diploid nuclei from patient biopsies with as little as 1–5% tumor cell content. Our aCGH studies using Agilent 400k oligonucleotide arrays and flow sorted samples identified 19q13.2 as a region that is recurrently targeted by gene amplification in PDA genomes. Significantly, we identified this amplicon in two distinct aneuploid populations representing 19.8% and 17.4% of the total cellular fraction of a PDA biopsy. We mapped the amplicon to an interval spanning from 43,526,781-cen to 46,171,091-tel, a region targeting 2,644,310 bases in each of the aneuploid populations. This region of interest is relatively gene rich and contains a series of cancer associated genes of interest (e.g. PAK4, AKT2, HIPK4, MAP3K10, RAB4B) to PDA. In addition, our data suggests this region contains variable internal regions of copy number changes suggesting structural rearrangements within the amplicon and its immediate boundaries. To further study this clonally selected region we used the Agilent Sure Select Target Enrichment System to design capture oligonucleotides to sample the 19q13.2 amplicon and its boundaries in the aneuploid PDA genome. These sequences were then interrogated with the PacBio RS system. The integration of these data provides a high resolution clonal analysis of genomic aberrations including point mutations, inversions and insertions that are present in the 19q13.2 amplicon, its immediate boundaries, and the genomes in which it arose. These data provide a highly unique and valuable proof of concept for the application of our integrated clonal genomics methods to the advancement of personalized medicine for patients with PDA and other malignancies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-266. doi:10.1158/1538-7445.AM2011-LB-266

A study on the engineering properties of sandcrete blocks produced with rice husk ash blended cement

Sandcrete blocks have been in used in many nations of the world including Nigeria, playing a major role in the building industry. The material constituents, their mix, presence of admixtures and the manufacturing process are important factors that determine the properties of sandcrete blocks. This paper investigates the effects of a partial replacement of cement with rice husk ash (RHA) on some engineering properties of hollow sandcrete blocks with 1:6 cement-sand mix ratios. Single block size 225 x 225 x 450 mm, is produced with a vibrating machine. Results show that the addition of RHA produces blocks of lower density. Particularly, the density of the blocks decreases as the RHA content increases. The compressive strength of the block is also not enhanced. Results also reveal that the thermal and hygrothermal properties of the blocks are significantly affected. Key words: Sandcrete blocks, rice husk ash, compressive strength, hygrothermal properties, thermal properties.

Abstract A206: Clinically relevant perspectives of the clonal nature of cancer

Abstract It has been hypothesized and subsequently shown that tumors arise as a result of an acquired genomic instability and the subsequent evolution of clonal populations of neoplastic cells. Thus the pattern and behavior of distinct genomically aberrant clones may underlie multiple clinical phenotypes in a variety of cancers. A fundamental hypothesis of cancer genome studies is that genes and cellular networks targeted by selected aberrations represent vulnerabilities that can be exploited for effective personalized therapies. However, the heterogeneity of neoplastic cells and the presence of admixtures of genomically normal cells make it difficult to comprehensively define cancer genomes in patients in vivo. By applying single parameter and multi parameter DNA content based flow cytometry of nuclei to isolate clonal populations from solid tumor biopsies, and coupling this strategy with array CGH, we obtained high definition genomic profiles of clonal populations from pancreatic adenocarcinomas (PA), adrenal cortical carcinomas (ACC), and prostate carcinomas (PC). The genomes of clonal populations in these disparate cancers have distinct patient-specific sets of aberrations with clinical relevance. For example, our clonal analyses detected unique gene-specific homozygous deletions converging on NOTCH signaling and multiple focal amplicons that target cell migration in PA, distinguished divergent clones within single biopsies, and identified genomic aberrations specific to therapeutically sensitive and resistant clones arising during the evolution of androgen independent metastatic PC. Application of these technologies in combination with next generation sequencing allows for elucidation of the unique clonal identities of cancer genomes in patients in vivo, which in turn can help guide diagnoses and tailor approaches to treatment. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A206.

EFFECT OF SOME ADMIXTURES ON HEAT OF HYDRATION REACTION OF CEMENT PASTES PRODUCED IN YEMEN, SAUDI ARABIA, AND EGYPT.

Blended cement pastes were prepared with and without silica fume and fly ash using an initial water/cement ratio of 0.40. Effect of these two mineral admixtures (silica fume, and fly ash) on the heat evolution of hydration reactions of Portland cement produced in Yemen, Egypt and Saudi Arabia has been studied at various hydration times. The heat of hydration of OPC in the presence of admixtures was studied, by using calorimetric method. The results show that the heat of hydration of Portland cement is retarded in the presence of both the admixtures

Portland cement hydration in the presence of admixtures: black gram pulse and superplasticizer

Effect of admixtures such as black gram pulse (BGP) and sulfonated naphthalene based superplasticizer (SP) on the hydration of Portland cement has been studied. The hydration characteristics of OPC in the presence of BGP and SP were studied with the help of non evaporable water content determinations, calorimetric method, Mossbauer spectroscopic and atomic force microscopic techniques. Results have shown that both BGP and SP get adsorbed at the surface of cement and its hydration products. The hydration of Portland cement is retarded in the presence of both the admixtures and nanosize hydration products are formed.