Characterization of the Physical - Mechanical Properties of Alpaca Fiber (Vicugna Pacos) at the Tunshi Experimental Station

The alpaca is one of the four South American camelids that mainly inhabit the inter-Andean zone of Ecuador. Alpaca fiber is characterized by being a natural, soft and resistant fiber, of which, the fleece is the most valued part. The objective of this research was to evaluate the quality parameters of alpaca fiber in terms of physical-mechanical properties. The research was carried out in the Tunishi Experimental Station, ESPOCH. A descriptive statistic of mean, minimum and maximum range, and separation of means per student was applied. The alpaca with characteristics of Huacaya breed was selected and the shearing was carried out manually to obtain the fleece. Later, the performance of the fleece was evaluated, which was 85.71%. Two categories of fiber were selected: fine and thick. Sixty samples were taken for analysis by stretched and unstretched fiber length. The measurements of unstretched fiber length in cm for the thin and thick fiber were 12.50 cm and 13.52 cm respectively, presenting significant differences (p≤0.05). The measurements of the stretched fiber length in cm were 17.29 cm for fine fiber and 17.27 cm for thick fiber, presenting no significant differences (p≥0.05). The resistance of thread and fabric for fine fiber was 590 N/cm2, and for thick fiber was 2835.5 N/cm2, presenting highly significant differences (p≤0.01). Regarding the percentage of yarn elongation, the values obtained were 19% for fine fiber and 12% for thick fiber, observing highly significant differences (p≤0.01). The thick fiber fabric had a better resistance (2.3 BAR) than the fine fiber fabric (1.7 BAR), with a time of 2.34 s and 1.88 s respectively. The classification of the fiber by its softness did not present significant differences. Finally, regarding the sensory classification, it was established as a soft fiber with 91%. Keywords: alpaca, fleece, fine fiber, thick fiber, fiber properties. Resumen La alpaca es uno de los cuatro camélidos sudamericanos que principalmente habitan en la zona interandina del Ecuador. La fibra de alpaca se caracteriza por ser una fibra natural, suave y resistente; de la cual, el vellón es la parte de la fibra del animal más valorada. El objetivo de esta investigación fue evaluar los parámetros de calidad de fibra de alpaca en cuanto a las propiedades físico - mecánicas. La investigación se la realizó en la Estación Experimental TUNSHI - ESPOCH. Se aplicó una estadística descriptiva de media, rango mínimo y máximo y separación de medias por t estudent. Se seleccionó a la alpaca con características de la raza Huacaya y se realizó la esquila por el método manual para la obtención del vellón. Posteriormente, se evaluó el rendimiento del vellón el cual fue de 85,71%, se seleccionaron dos categorías de fibra fina y gruesa. Sesenta muestras fueron tomadas para su análisis: longitud de mecha estirada y sin estirar. La media de longitud de fibra sin estirar en cm para la fina y gruesa fueron de 12,50 y 13,52 correspondientemente, presentando diferencias significativas (p≤0,05), La media de la longitud en cm de fibra estirada determinó que la fibra fina presentó una media de 17,29 y la fibra gruesa de 17,27 cm, sin presentar diferencias significativas (p≥0,05). La resistencia del hilo y tejido para la fibra fina fue de 590 N/cm2 y para la gruesa fue de 2835,5 N/cm2, presentando diferencias altamente significativas (p≤0,01). Finalmente, en cuanto al porcentaje de elongación de hilo, presentó un 19% para fibra fina y un 12% para gruesa, observándose también diferencias altamente significativas (p≤0,01). El tejido de la fibra gruesa tuvo mejor resistencia (2,3 BAR) que el de la fibra fina (1,7 BAR), con un tiempo de 2,34 s y 1,88 s respectivamente. La clasificación de la fibra por su suavidad, no presentó diferencias significativas. En cuanto a la clasificación sensorial se la ubico como una fibra suave con el 91%. Palabras clave: alpaca, vellón, fibra fina, fibra gruesa, propiedades de la fibra.

Biofilm Spreading by the Adhesin-Dependent Gliding Motility of Flavobacterium johnsoniae. 1. Internal Structure of the Biofilm

The Gram-negative bacterium Flavobacterium johnsoniae employs gliding motility to move rapidly over solid surfaces. Gliding involves the movement of the adhesin SprB along the cell surface. F. johnsoniae spreads on nutrient-poor 1% agar-PY2, forming a thin film-like colony. We used electron microscopy and time-lapse fluorescence microscopy to investigate the structure of colonies formed by wild-type (WT) F. johnsoniae and by the sprB mutant (ΔsprB). In both cases, the bacteria were buried in the extracellular polymeric matrix (EPM) covering the top of the colony. In the spreading WT colonies, the EPM included a thick fiber framework and vesicles, revealing the formation of a biofilm, which is probably required for the spreading movement. Specific paths that were followed by bacterial clusters were observed at the leading edge of colonies, and abundant vesicle secretion and subsequent matrix formation were suggested. EPM-free channels were formed in upward biofilm protrusions, probably for cell migration. In the nonspreading ΔsprB colonies, cells were tightly packed in layers and the intercellular space was occupied by less matrix, indicating immature biofilm. This result suggests that SprB is not necessary for biofilm formation. We conclude that F. johnsoniae cells use gliding motility to spread and maturate biofilms.

Effect of polypropylene thick/basalt composite fibers on the mechanical properties of large dose slag fly ash concrete

In this experiment, the effects of polypropylene thick fiber (PPTF) with different volume admixtures (0, 0.05%, 0.10%, 0.15%, 0.20%, 0.25%) on the compressive strength, splitting tensile strength and bending strength of large admixture of slag fly ash concrete were investigated with short-cut basalt fiber (BF) as a reference. The results show that the polypropylene thick fiber can work well with basalt fiber and improve its strengthening effect of single admixture. And 0.10% of polypropylene thick fiber and 0.10% of basalt fibers by volume have the best strengthening effect on the mechanical properties of the large amount of slag fly ash concret.

TUNNEL SUPPORT BY ROCK QUALITY INDEX (Q) SYSTEM FOR ULTRABASIC ROCK: A CASE STUDY IN TELUPID, SABAH, MALAYSIA

The study area is underlain by the ultrabasic rock of partly Sabah Ophiolite Complex of Cretaceous ages. The objectives of this study are to determine the Q-value and to estimate the permanent support measures for 20m span, 10m high and eastern direction of the proposed tunnel in the study area. Engineering geological mapping (lithological and surface mapping and discontinuity survey), laboratory study (petrographical study) and testing (Uniaxial Compressive Strength testing) and data analysis (stereographic plots, Q system parameters evaluation and support estimation) was used in this study. The results show that the rock mass is classified as lherzolite, strong, excellent quality, more than four joint sets, slightly altered discontinuity wall, dry excavation and favourable stress condition. The equivalence dimension (De) are 15.4 for the permanent roof. The Q-value for permanent roof and wall of the proposed tunnel are 1.4 (Class D or poor and type 5) and 3.5 (Class D or poor and type 3), respectively. The permanent and temporary supports for the roof and wall are systematic bolting, 700J energy absorption of fiber reinforce sprayed concrete, 9-12 and 5- 6 cm thick fiber reinforce shotcrete, respectively.

Aerosol light absorption from optical measurements of PTFE membrane filter samples: sensitivity analysis of optical depth measures

Mass absorption cross section (MAC) measurements of atmospherically relevant aerosols are required to quantify their effect on Earth's radiative budget. Estimating aerosol light absorption from transmittance and/or reflectance measurements through filter deposits is an attractive option because of their ease of deployment in field settings, low cost, and the ability to revisit previously analyzed samples. These measurements suffer from artifacts that depend on a given filter measurement system and aerosol optics. Empirical correction algorithms are available for commercial instruments equipped with optically thick fiber filters, but optically thin filter media have not been characterized in detail. Here, we present empirical relationships between particle light absorption optical depth – measured using multiwavelength integrated photoacoustic spectrometers – and filter optical depth measurements for polytetrafluoroethylene (PTFE) membrane filter samples of carbonaceous aerosols generated from combustion of diverse biomass fuels and kerosene (surrogate for fossil fuel combustion). Through radiative transfer modeling, we assessed the suitability of three measures of filter-based optical depth for robustly describing particulate-phase light absorption over a range of single scattering albedo (SSA) values: (1) ODs – a measure of transmission of the fraction of incident radiation that is not backscattered by the filter system – which utilizes transmittance and reflectance of the sample side of the filter; (2) the commonly used ODc, which uses transmittance and reflectance of the clean side of the filter; and (3) ATN or the Beer–Lambert attenuation. Modeling results were also validated experimentally, with ODs showing the least variability around the mean in this multidimensional parameter space. We establish a simple, wavelength-independent formulation for calculating aerosol MAC and absorption coefficients from measurements of ODs. We find the ratio between in situ particulate absorption optical depth and ODs to be inversely proportional to aerosol SSA. Our findings underscore that ODs is a better optical depth measure than ODc for applying appropriate correction factors when estimating particle-phase light absorption from filter-based techniques.

Aerosol light absorption from attenuation measurements of PTFE-membrane filter samples: implications for particulate matter monitoring networks

Mass absorption cross-section (MAC) measurements of atmospherically-relevant aerosols are required to quantify their effect on Earth’s radiative budget. Estimating aerosol light absorption from transmittance and/or reflectance measurements through filter deposits is an attractive option because of ease of deployment in field settings and low cost. These measurements suffer from artifacts that depend on a given filter measurement system and type of aerosol. Empirical correction algorithms are available for commercial instruments equipped with optically-thick fiber filters, but optically-thin filter media have not been characterized in detail. Here, we present empirical relationships between particle light absorption–measured using multi-wavelength integrated photoacoustic spectrometers and nephelometers–and attenuation measurements for polytetrafluoroethylene (PTFE) membrane filter samples of carbonaceous aerosols generated from combustion of diverse biomass fuels and kerosene (surrogate for fossil-fuel combustion). We establish a simple, wavelength-independent formulation for calculating aerosol MAC and absorption coefficients from filter attenuation measurements. We find the ratio between in-situ absorption and bulk attenuation to be inversely proportional to aerosol single scattering albedo. As a case study, we apply our formulations on 2010 attenuation datasets of the Interagency Monitoring of PROtected Visual Environments (IMPROVE) network to quantify the overestimation in their filter-based absorption coefficients.

Long Period Grating-Based Fiber Coupling to WGM Microresonators

A comprehensive model for designing robust all-in-fiber microresonator-based optical sensing setups is illustrated. The investigated all-in-fiber setups allow light to selectively excite high-Q whispering gallery modes (WGMs) into optical microresonators, thanks to a pair of identical long period gratings (LPGs) written in the same optical fiber. Microspheres and microbubbles are used as microresonators and evanescently side-coupled to a thick fiber taper, with a waist diameter of about 18 µm, in between the two LPGs. The model is validated by comparing the simulated results with the experimental data. A good agreement between the simulated and experimental results is obtained. The model is general and by exploiting the refractive index and/or absorption characteristics at suitable wavelengths, the sensing of several substances or pollutants can be predicted.

Long Period Grating-Based Fiber Coupling to WGM Microresonators for Sensing Applications

A comprehensive model for designing robust all-in-fiber microresonator-based optical sensing setups is illustrated. The investigated all-in-fiber setups allow light to selectively excite high-Q whispering gallery modes (WGMs) into optical microresonators, thanks to a pair of identical long period gratings (LPGs) written in the same optical fiber. Microspheres and microbubbles are used as microresonators and evanescently side-coupled to a thick fiber taper, with a waist diameter of about 18 µm, in-between the two LPGs. The model is validated by comparing the simulated results with the experimental data. A good agreement between the simulated and experimental results is obtained. As an application example, the sensing of the concentration of an aqueous glycerol solution is demonstrated. The model is general and by exploiting the refractive index and/or absorption characteristics at suitable wavelengths, the sensing of other substances or pollutants can be also predicted.

GENETIC STRUCTURE OF UKRAINIAN MOUNTAIN CARPATHIAN SHEEP BY USE OFMICROSATELLITE LOCI

Significant reduction of sheep population and the lack of clear selection-breeding work in Ukraine, have led to partial and in some cases complete loss of specific gene pools of local breeds. Intensification of the selection process accelerates absorption of uncompetitive breeding material, which primarily is mostly local (native) breeds, reducing their number, in consequence of which is rapidly decreasing natural diversity of animals. Using crossed with imported breeds doesn't solve the general problem of reconstruction and development of the sheep industry, while resulting in the loss of local breeds features, increasing the number of diseases, including genetically caused ones. The natural basis of Carpathian Mountain sheep is native (local) thick-fiber wool sheep, a typical representative of such sheep breed is Tsakel. Since the middle of last century, by a long reproductive crossbreeding of local thick-fiber wool ewes of Carpathian Mountain sheep with the rams of Tsigay breed, a Ukrainian Carpathian Mountain sheep breed combined with wool-milk-meat-sheep skin direction of productivity was created, and, in 1993, was approved. To study the polymorphism of microsatellite loci and molecular genetic estimation of Ukrainian Mountain Carpathian sheep we investigated the use of molecular genetic markers – microsatellite DNA sequences recommended by FAO for assessing biodiversity sheep. Material was taken from both sexes sheep of different age groups in "Bansko" farm, Rakhiv district – mountainous area and "Saldobosh" farm, Khust district, Transcarpathian region – low-lying area in the amount of 49 head. Genetic analysis of groups of sheep by the use of DNA markers was conducted based on the recommended list of the International Society for Animal Genetics (ISAG), for assessing sheep biodiversity by using different fluorescent coloring for labelling fragments. Given the criteria and recommendations of ISAG, we selected 11 microsatellite loci: Oar304, HSC, Oar129, MAF214, Oar11, INRA063, CSRD247, SPS113, D5S2, MAF65, McM527. The analysis revealed significant genetic differences in the use of microsatellite markers in sheep of this breed. We found a total of 106 alleles, which number ranges from 6 (D5S2 locus) to 13 (INRA63 locus). The identified alleles were used to determine polymorphism of markers. Based on the calculation of allele frequencies heterozygosity values (H), polymorphic information content (PIC) and inbreeding coefficient (FIS) were determined. The results showed that the markers had a high degree of polymorphism. The polymorphic information content (PIC) averaged 0,740 and ranged from 0,53 (Oar304 locus) to 0,84 (HSC locus). In our studies, the highest polymorphism was typical for INRA 063 locus, which consisted of 13 alleles with polymorphic information content (PIC) – 0,838 and observed heterozygosity (HO) – 0,857. High variability was also detected for loci HSC, Oar11 and SPS113, where it was identified more than 9 alleles, and the value of PIC and HO varied from 0,74 and 0,84 (SPS113) to 0,89 and 0,81 (Oar11). The lowest polymorphism was noted for Oar304 locus where it was found 9 allelic variants, but two of them (164 and170 bp) had much higher frequency of 0,28 and 0,57. PIC and HO values for this locus were 0,53 and 0,47, respectively. The other markers exhibited a similar polymorphism, with the number of alleles in the range of 8-11 and PIC and HO values ranging from 0,65 and 0,61 (Oar129) to 0,72 and 0,70 (MAF65). Thus, information on the genetic structure of Ukrainian Mountain Carpathian sheep breed and its diversity at the genomic level was obtained by use of 11 microsatellite loci. The specific features of the structure of the gene pool were revealed. The analysis showed a significant genetic variability of the studied microsatellite loci. Totally 106 alleles were identified that were used to determine the discussed polymorphism markers. The highest polymorphism was characterized for Oar 11, INRA063 and SPS113 loci which had more than 9 alleles, whereas the index of polymorphism (PIC) and actual heterozygosity (HO) exceeded 0,80. The lowest polymorphism was revealed for Oar304 locus and at the presence of 9 alleles, PIC and HO values were 0,53 and 0,47 respectively. Average inbreeding coefficient had low negative value (0,070), indicating almost absent inbreeding within the studied breed. The obtained information at the appropriate assessment using classical methods of selection and breeding makes it possible to control the genetic structure directly with DNA markers, and the creation of targeted groups of animals through genetic selection based on appropriate economic characteristics.