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Abstract

This study focuses to develop a new hybrid Engineered Cementitious Composite (ECC) and assesses the performance of a new hybrid ECC based on the steel short random fiber reinforcement. This hybrid ECC aims to improve the tensile strength of cementitious material and enhance better flexural performance in an RC beam. In this study, four different mixes have been investigated. ECC with Poly Vinyl Alcohol (PVA) fiber and PolyPropylene (PP) fiber of 2.0% volume fraction are the two Mono fiber mixes; ECC mix with PVA fiber of 0.65% volume fraction hybridized with steel fiber of 1.35% volume fraction, PP fiber of 0.65% volume fraction hybridized with steel of 1.35% volume fraction are the two additional different hybrid mixes. The material properties of mono fiber ECC with 2.0 % of PVA is kept as the reference mix in this study. The hybridization with fibers has a notable achievement on the uniaxial tensile strength, compressive strength, Young’s modulus, and flexural behavior in ECC layered RC beams. From the results, it has been observed that the mix with PVA fiber of 0.65% volume fraction hybrid with steel fiber of 1.35% volume fraction exhibit improvements in tensile strength, flexural strength, and energy absorption. The PP fiber of 0.65% volume fraction hybridized with steel of 1.35% volume fraction mix has reasonable flexural performance and notable achievement in displacement ductility over the reference mix.

Abstract

Fibers are raw materials used for manufacturing yarns and fabrics, and their properties are closely related to the performances of their derivatives. It is indispensable to implement fiber identification in analyzing textile raw materials. In this paper, seven common fibers, including cotton, tencel, wool, cashmere, polyethylene terephthalate (PET), polylactic acid (PLA), and polypropylene (PP), were prepared. After analyzing the merits and demerits of the current methods used to identify fibers, near-infrared (NIR) spectroscopy was used owing to its significant superiorities, the foremost of which is it can capture the tiny information differences in chemical compositions and morphological features to display the characteristic spectral curve of each fiber. First, the fibers’ spectra were collected, and then, the relationships between the vibrations of characteristic chemical groups and the corresponding wavelengths were researched to organize a spectral information library that would be beneficial to achieve quick identification and classification. Finally, to achieve intelligent detection, pattern recognition approaches, including principal component analysis (PCA) (used to extract information of interest), soft independent modeling of class analogy (SIMCA), and linear discrimination analysis (LDA) (defined using two classifiers), assisted in accomplishing fiber identification. The experimental results – obtained by combining PCA and SIMCA – displayed that five of seven target fibers, namely, cotton, tencel, PP, PLA, and PET, were distributed with 100% recognition rate and 100% rejection rate, but wool and cashmere fibers yielded confusing results and led to relatively low recognition rate because of the high proportion of similarities between these two fibers. Therefore, the six spectral bands of interest unique to wool and cashmere fibers were selected, and the absorbance intensities were imported into the classifier LDA, where wool and cashmere were group-distributed in two different regions with 100% recognition rate. Consequently, the seven target fibers were accurately and quickly distinguished by the NIR method to guide the fiber identification of textile materials.

Abstract

The main purpose of the present research was to investigate the changes in physical-chemical parameters of fresh Latvian cranberries during storage. Cranberry (′Steven′, ′Bergman′, ′Pilgrim′, ′Early Black′, and ′Ben Lear′) fruit were collected at a processing plant in Kurzeme region, Latvia, in the first part of October 2010. For the experiments, also wild cranberries were collected in the bogs of the same region and at the same time. The berries were rinsed with tap water for 3±1 min, then strained for 10±1 min (mainly for visual cleanness), and afterwards stored in closed non-perforated polypropylene (PP) boxes in air ambiance and in glass jars in a cold boiled-water ambiance at 3±1 °C. Quality parameters of the berries were tested each three months using standard methods: vitamin C content - by high-performance liquid chromatography (HPLC); organic acids - by HPLC; moisture - by oven-dry method; colour parameters - by device COLOR TEC PMC; pH - by potentiometric method; anthocyanin - by spectrophotometrical method; and phenolic compounds - by HPLC. The shelf life of cranberries packaged in closed PP boxes in air ambiance was six months, but of cranberries packaged in glass jars in water ambiance - 12 months. The research showed that differences in moisture content, pH value, colour intensity, and anthocyanin content among the cranberry cultivars under different ambient conditions during storage were not significant. During 12 months of cranberry storage in glass jars in water ambiance, the content of vitamin C decreased on average by 90%, organic acids - by 54%, and phenolic compounds - by 60%. During six-month storage in closed PP boxes in air ambiance, the content of vitamin C decreased on average by 99%, organic acids - by 30%, and phenolic compounds - by 34%.

Abstract

Field experiments using ‘melt-blown’ biodegradable nonwovens were carried out on the ‘Melodion’ butterhead lettuce (Lactuca sativa var. capitata L.) cultivar for early harvest. All biodegradable nonwovens were manufactured in the Institute of Biopolymers and Chemical Fibres and POLMATEX CENARO in Łódź, Poland. Lettuce seeds were sown into boxes in a greenhouse at the beginning of March, and transplants were planted into the field at the beginning of April. Biodegradable nonwovens - aromatic polyester IBWCH 75 g m-2, polybutylene succinate Bionolle 100 g m-2 and standard polypropylene PP Agro 20 g m-2 - were stretched over the lettuce in the field. The covers were kept on until 4-5 days before harvest. Plots without covers were defined as the control. Ascorbic acid, soluble sugar, dry matter, nitrates, chlorophyll a, chlorophyll b and carotenoid contents were recorded in the leaves. All biodegradable nonwovens showed a positive effect on yielding in comparison to the control in 2009. In the second year of the experiment, there were no significant differences between covers with regard to the yield. Dry matter and soluble sugar content in both years of the experiment was diversified. Nonwovens used as covers in 2009 significantly increased the content of nitrates in comparison to the control. In the second year, the highest level of nitrates was demonstrated in the control object. It is worth underlining that the maximum allowed limit of nitrate content in lettuce (4000 mg kg f.w.) was not exceed. The kind of cover had no significant effect on the level of chlorophyll a in 2009 or chlorophyll b and carotenoids in 2009 and 2010 in the lettuce

-356. [4] Bolt, A., Duszyńska, A. (2010). Static puncture resistance of non-woven geotextiles. In: Modern Building Materials, Structures and Techniques, Vilnius, Lithuania, pp.1083-1088. [5] Koerner, G. R., Koerner, R. M. (2010). Puncture resistance of polyester (PET) and polypropylene (PP) needle-punched nonwoven geotextiles. Geotextiles and Geomembranes, 29, 360-362. [6] Carvalho, R., Fangueiro, R., Soutinho F. (2011). Mechanical properties of needle-punched nonwovens for geotechnical applications. In: International Conference on Engineering UBI2011, Covilhã, Portugal

,” The Journal of Strain Analysis for Engineering Design, p. 0309324717727235, 2017. [26] S. Nohut and T. Arici, “Estimation of Areal Weight, Grab Tensile Strength, and Elongation at Break of PP Spunbond Nonwovens using Digital Image Analysis and Artificial Neural Networks,” Journal of Engineered Fabrics & Fibers (JEFF), vol. 10, 2015. [27] M. Taşcan and S. Nohut, “Nondestructive prediction of areal weight, grab tensile strength and elongation at break of polypropylene (PP) spunbond nonwoven fabrics using digital image analysis,” Journal of Textile & Apparel/Tekstil ve

Value Added Concrete: Construction and Building Materials , Vol. 2, No. 2, pp. 103–106, DOI: 10.15373/22778179/feb2013/37. Litvin, A. (1985). Properties of concrete containing polypropylene fibers. Report to Wire Reinforce Institute.: López-Buendía, A.M., Romero-Sánchez, M.D., Climent, V., and Guillem, C. (2013). Surface treated polypropylene (PP) fibres for reinforced concrete: Cement and Concrete Research , DOI: 10.1016/j.cemconres.2013.08.004. Malhotra, V.M., Carette, G.G., and Bilodeau, A. (1994). Mechanical Properties and Durability of Polypropylene Fibre

quantitatively. Just the other day (autumn 2018), a total of nine different petrochemical plastics, predominantly polypropylene (PP) and polyterephtalate (PET) with particle sizes between 50 and 500 μm were for the first time identified by an Austrian research team in the human intestinal system; it is suspected that these microparticles can potentially be forwarded from the intestine to the blood and the lymphatic system and to various organs ( 11 ). Apart from plastics themselves, other products associated to polymer production and processing cause harmful effects to the