Artificial fly ash based aggregates properties influence on lightweight concrete performances

The effect of the application of pelletized fly ash based aggregates obtained through different processing techniques on the behavior of lightweight concretes was analyzed. Experimental program implied production of four lightweight artificial aggregates - cold bonded and sintered pellets based on either mechanically activated or non-activated low-calcium fly ash and water glass. The lightweight concrete behavior was compared to that of normal-weight concrete through compressive strength, flexural strength, porosity, shrinkage, and modulus of elasticity investigation. Differences in concretes characteristics were discussed with SEM imagining support. The statistical analysis of lightweight aggregate and ash properties contribution on concrete performances was realized by analysis variance model (ANOVA). Optimal production combination that maximizes lightweight concrete performance was determined by employing response surface methodology. An increase in concrete strength induced by the increase in ash fineness was noticed. Mechanical activation also had effect on the pellets sintering period and sintering temperature reduction. The 28- and 56-day lightweight concrete specimens exhibited properties that met the requirements for normal-weight concretes. Finally, the ideal combinations of ash pellets production parameters and properties that gave the lightweight concrete with behavior matching to that of standard concrete were established. The production capability of lightweight concrete with advanced performances based on artificial aggregate approves the principle of waste material reusing and enables cleaner and economically sustainable concrete manufacturing procedure. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved

Theoretical design proposal for simulated hot asphalt mixture at a temperature below zero degrees Celsius

In the world there are adverse climates, climates that hinder the good construction and paving of roads, generating insecurity among the locals and visitors. This over time affects the economy of a country, as a road boosts tourism, transport and commerce. Therefore, a mixture was designed to mitigate a problem in the placement of hot asphalt mixture at temperatures below zero degrees Celsius. That is, a conventional mix design was proposed, but with different types of filler (lime, Portland cement type I and silica) tested with the Marshall and Lottman method which are governed according to the EG-2013 standards [1] and parameters established in the Asphalt Institute [2]. To find the optimum, it was tested with 5.0%, 5.5% 6.0% and 6.5% asphalt cement. Then with the results obtained a comparative analysis was performed. Finally, specimens without any additives were made, the specimens once prepared at 140°C were subjected to freezing, resulting in the three types of filler, that the hot asphalt mixture with incorporation of Portland cement type I to a 5, 90% of asphalt cement is the optimum since, subject to extreme temperatures below 0°C they comply with the parameters required in the standards

Surface and thermomechanical characterization of polyurethane networks based on poly(dimethylsiloxane) and hyperbranched polyester

Two series of polyurethane (PU) networks based on Boltorn® hyperbranched polyester (HBP) and hydroxyethoxy propyl terminated poly(dimethylsiloxane) (EO-PDMS) or hydroxy propyl terminated poly(dimethylsiloxane) (HPPDMS), were synthesized. The effect of the type of soft PDMS segment on the properties of PUs was investigated by Fourier transform infrared spectroscopy (FTIR), contact angle measurements, surface free energy determination, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC). The surface characterization of PUs showed existence of slightly amphiphilic character and it revealed that PUs based on HP-PDMS have lower surface free energy, more hydrophobic surface and better waterproof performances than PUs based on EO-PDMS. PUs based on HPPDMS had higher crosslinking density than PUs based on EO-PDMS. DSC and DMTA results revealed that these newlysynthesized PUs exhibit the glass transition temperatures of the soft and hard segments. DMTA, SEM and AFM results confirmed existence of microphase separated morphology. The results obtained in this work indicate that PU networks based on HBP and PDMS have improved surface and thermomechanical properties

Serbian aromatized wine “Bermet”: Electrochemical, chemiluminescent and spectrophotometric determination of antioxidant activity

Serbian aromatized wine “Bermet” from grapes grown on Fruška Gora Mountain has been in production since the 15th century. Ten commercial Bermets produced according to the traditional procedure by different manufacturers, and six prepared within the scope of this study were assessed for antioxidant (AO) activity using electrochemical, chemiluminescent and spectrophotometric AO assays. Direct current polarographic assay based on the decrease of anodic current of [hydrogen(peroxido)(1-)]hydroxidomercury(II) complex formation in alkaline H2O2 solution at potential of mercury oxidation, chemiluminescent H2O2 scavenging assay, as well as commonly used spectrophotometric assays (2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) based Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP)) were used. Total phenolic content (TPC) was determined by Folin–Ciocalteu assay. The results obtained were correlated using regression analysis, ANOVA and F-test. An integrated approach to AO capacity determination allowed a more comprehensive comparison between samples. The approach is based on the introduction of the relative antioxidant capacity index, calculated by assigning each AO assay equal weight, and by PCA analysis. In addition, the introduction of phenolic antioxidant coefficients, calculated as the ratio between individual AO capacity and TPC, enabled a better understanding of their relation

CaO&CaSO4 and CaO&Al2(SO4)3 as Pectin Precipitants–Model of Overlapping Diffuse Layers

This work is concerned with the theoretical basis of novel sugar beet juice purification method using binary systems CaO&CaSO4 and CaO&Al2(SO4)3. The Gouy–Chapman–Stern (GCS) model of overlapping of diffuse layers of EDLs on pectin surface and that on Ca2+ and Al3+ ions, theoretically explains this method. The change of the zeta potential was used to quantitatively indicate overlapping of diffuse layers. For the experiment two model solutions of pectin (0.1 % w/w) were prepared, while the concentrations of CaO&CaSO4 and CaO&Al2(SO4)3 in the range of 50–500 g dm-3 were used. The greater decrease in the absolute value of zeta potential indicated greater overlapping of diffuse layers between pectin particles and Ca2+ and Al3+ ions and faster coagulation of pectin. The overlapping degree increased with increased concentration of these binary systems. Pectin with a greater surface charge and multivalent Al3+ from CaO&Al2(SO4), exerted a greater impact on the zeta potential. Optimal quantities of the applied binary mixtures were as follows: 256–640 mg g-1 pectin. This is much lower than CaO commonly used in the conventional process of sugar beet juice purification (about 9 g g-1 pectin)

Konzervirana morska riba na srpskome tržištu: razine cinka, bakra i željeza i njihov doprinos dnevnom unosu ovih esencijalnih metala

The aim of this study was to determine the levels of Zn, Cu, and Fe in three canned fish species marketed Serbia to see if they meet recommended daily intake requirements or exceed safety limits. We collected a total of 207 samples of canned tuna, sardine, and mackerel, in oil or tomato sauce and analysed them with inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. The highest levels were obtained for Zn (15.1 mg kg-1) and Cu (1.37 mg kg-1) in sardine in oil and tomato sauce, respectively, and for Fe (18.98 mg kg-1) in mackerel in tomato sauce. Our results keep within the ranges reported by several national food databases and available literature data, with a few exceptions. Our findings also single out canned sardines as the richest source of the three essential elements combined. The estimated daily intake (EDI) of the three essential elements, however, was subpar, and ranged between 0.14 % and 0.72 % of the recommended dietary allowance (RDA) for Zn, Cu, and Fe.Cilj ovoga rada bio je utvrditi razinu cinka, bakra i željeza u trima vrstama ribljih konzervi sa srpskoga tržišta kako bi se ustanovilo zadovoljavaju li zahtjeve za preporučenim dnevnim unosom, ili pak prekoračuju sigurnosne granice. Sadržaj esencijalnih elemenata utvrđen je u ukupno 207 uzoraka konzerve tune, sardine i skuše primjenom masene spektrometrije s induktivno spregnutom plazmom (ICP-MS) nakon kisele digestije uzoraka. Najveći sadržaj cinka (15,1 mg kg-1) utvrđen je u sardini u ulju, bakra (1,37 mg kg-1) u sardini u umaku od rajčice, a željeza (18,98 mg kg-1) u skuši u umaku od rajčice. Dobiveni rezultati su u opsegu vrijednosti za analizirane elemente koje je objavilo nekoliko nacionalnih baza podataka o hrani, kao i u opsegu dostupnih literaturnih podataka, s nekoliko iznimaka. Rezultati istraživanja izdvajaju sardinu u konzervi kao najbogatiji izvor proučavanih esencijalnih elementa. Procijenjeni dnevni unos (EDI) bio je između 0,14 % i 0,72 % preporučenih dnevnih unosa cinka, bakra i željeza. Iako sardina u konzervi, u odnosu na tunu i skušu, doprinosi oko 1,5 puta više preporučenom dnevnom unosu (RDI) esencijalnih elemenata, konzervirana morska riba ne može se smatrati značajnim izvorom cinka, bakra i željeza u prehrani srpskoga stanovništva

Structural characterisation of starch based edible films with essential oil addition

Present study investigated structure of starch based edible films with essential oil addition. Films were obtained from water solutions containing gelatinized modified starch, polyol, guar-xantan gum modified mixture and essential oil by casting it on a Petri dish and evaporating at room temperature for 72h. Both, glycerol and guar-xantan modified mixture, had role to improve film flexibility and enable better film folding and handling. Two sample groups were obtained: starch based edible films with black cumin oil addition and starch based edible films with black pepper oil addition. Both essential oils were added in three different concentrations. Starch based edible film without essential oil addition was used as blank shot. Structural properties were determined by analyzing spectra obtained by FT-IR Spectrometer in the spectral range of 4000–400 cm−1 with a 4.0 cm−1 resolution. Software Omnic 8.1. and TQ Analyst were used to operate the FTIR spectrometer, collect and present all the data. Results pointed to quantitative law dependency between added amount of essential oils and spectra absorption values for both sample groups and FTIR spectra were used to calculate coefficient of correlation

HISTOLOGICAL DESCRIPTION OF THE HAIR FOLLICLE IN THE YOUNG ALPACA

El presente estudio tuvo el propósito de caracterizar la distribución y asociación de los folículos que conforman la piel de la alpaca. Se tomaron muestras de piel de 42 crías de alpacas Suri y Huacaya, de ambos sexos, y diversos colores de manto. Las muestras se colectaron con sacabocado de la zona del costillar medio y fueron procesadas mediante técnicas histológicas estándares, utilizando la coloración H y E. Los folículos pilosos se encuentran formando nidos foliculares, distribuidos como grupos foliculares compuestos (GFC) y grupos foliculares simples (GFS). Los primeros se encuentran conformados por folículos primarios rodeados de folículos secundarios, mientras que los GFS solo están conformados por folículos secundarios. Además, los folículos primarios pueden ser solitarios, denominados folículo primario extra grupo folicular (FPEGF) o formando parte de un grupo folicular compuesto denominado folículo primario intra grupo folicular (FPIGF). Los grupos foliculares están conformados uno o más folículos primarios y un número variable de folículos secundarios; sin embargo, en las alpacas Suri se observa un trío folicular primario, caracterizado por presentar un folículo primario central y dos laterales. Las características de asociación y distribución de los folículos, así como de su citoarquitectura permiten establecer la presencia del denominado “Complejo Folicular Piloso” en la piel de las alpacas.The present study was carried out to characterize the distribution and an association of hair follicles of alpaca skin. Samples were collected from 42 young Suri and Huacaya alpacas, of both sexes and with various hair colours. Samples were collected by punch skin biopsy in the middle costal zone and processed for histological study using H-E staining. Hair follicles formed follicular nests distributed as a compound follicle group (CFG) and simple follicle group (SFG). The first was composed of primary follicles surrounded by secondary follicles, while that latter was only composed of secondary follicles. Furthermore, primary follicles can be solitary and named Extra Primary Follicle Follicular Group (EPFFG) or forming compound follicle groups named Internal Primary Follicle Follicular Group (IPFFG). Follicular groups are formed by one or more primary follicles and a variable number of secondary follicles; however, in the Suri alpaca, was observed groups of three primary follicles, one larger and central and two smaller at each side. The characteristics of association and distribution of follicles and the cytoarchitecture allowed pointing out the presence of a Hair Follicular Complex in the alpaca skin

DETECCIÓN DE ANTICUERPOS CONTRA PESTIVIRUS EN RUMIANTES DE UNA COMUNIDAD CAMPESINA DE LA PROVINCIA DE CANCHIS, CUSCO

El presente estudio tuvo como objetivo determinar la seroprevalencia de los pestivirus de la enfermedad de la diarrea viral bovina (DVB) y enfermedad de la frontera (EF) en rumiantes de la comunidad de Silly, provincia de Canchis, Cusco, a través de la detección de anticuerpos en el suero sanguíneo de alpacas (n=200), bovinos (n=38) y ovinos (n=45) hembras adultas, mediante la prueba de virus-neutralización. El 11.5 ± 4.4% (23/200) y el 9.5 ± 4.1% (19/200) de las alpacas presentaron anticuerpos neutralizantes contra los virus DVB y EF. El 73.7 ± 13.9% (28/38) y 76.3 ± 13.5% (29/38) de los bovinos y el 13.3 ± 9.9% (6/45) y 15.5 ± 10.6% (7/45) de los ovinos presentaron anticuerpos contra la DVB y EF, respectivamente. Estos resultados confirman la presencia de la infección pestiviral en rumiantes bajo un sistema de crianza mixto en una comunidad campesina del Cusco.The seroprevalence of bovine viral diarrhoea virus (BVDV) and border disease virus (BDV) in serum samples of alpacas (n=200), bovine (n=38) and ovine (n=45) of a rural community of Cusco, Perú was carried out by virus-neutralization test. The 11.5 ± 4.4% (23/200) and 9.5 ± 4.1% (19/200) of alpacas had neutralizing antibodies against BVD and BD virus. The 73.7 ± 13.9% (28/38) and 76.3 ± 13.5% (29/38) of bovine and the 13.3 ± 9.9% (6/45) and 15.5 ± 10.6% (7/45) of ovine had antibodies to BVDV and BDV respectively. These results confirm the presence of pestiviral infection in ruminants of a mixed breeding system in a rural community

PRESENCIA DE CARACOLES LYMNAEIDAE CON FORMAS LARVARIAS DE Fasciola hepatica EN ALTITUDES SOBRE LOS 4000 MSNM EN LA SIERRA SUR DEL PERÚ

The objective of the study was to determine the presence of F. hepatica larvae and the species of snails that are intermediary hosts of F. hepatica in altitudes over 4000 m above the sea level (masl). The study covered three altitudes (4000-4200, 4200-4300, 4300-4500 masl) and was collected 150 snails per each altitude during the rainy season (January-March, 2004). The area is part of La Raya Experimental Research Station of San Antonio de Abad University, Cusco. Fifty snails were used for measuring the shell, 50 for observing the reproductive organs and the radula to identify the species, and 50 to observe the larva forms of Fasciola hepatica. Snails found at 4000-4200 masl were of the Lymnaea viatrix species and at 4200-4500 of the Pseudosuccinea columella species. The level of infestation with larva forms of Fasciola hepatica was 48, 46 and 36% at 4000-4200, 4200-4300, and 4300-4500 masl respectively, and this shows that the parasite can survive over 4000 masl. The relationship between level of infestation and altitude was inversely proportional.El objetivo del estudio fue determinar la presencia de formas larvarias de F. hepatica y las especies de caracoles hospederos intermediarios de F. hepatica en altitudes superiores a 4000 msnm. Se trabajó en tres altitudes (4000 a 4200, 4200 a 4300, y 4300 a 4500 msnm) colectándose 150 caracoles por cada altitud en la época de lluvias (enero-marzo) del 2004. El área pertenece a la Estación Experimental de la Raya, Universidad Nacional de San Antonio Abad del Cusco. Se utilizaron 50 caracoles para la medición de la concha, 50 para observar el aparato reproductor y la rádula a fin de identificar las especies, y 50 para verificar la presencia de formas larvarias de Fasciola hepatica. Se encontró caracoles de la especie Lymnaea viatrix entre 4000 a 4200 msnm y de la especie Pseudosuccinea columella entre 4200 a 4500 msnm. El porcentaje de infestación de los caracoles con las formas larvarias de Fasciola hepatica fue de 48, 46 y 36% a 4000-4200, 4200-4300, y 4300-4500 msnm, respectivamente, demostrando que el parásito puede sobrevivir sobre los 4000 msnm. La relación entre el nivel de infestación y altitud fue inversamente proporcional