Browse

You are looking at 171 - 180 of 91,436 items

Open access

Daiva Mikucioniene, Lina Cepukone, Khalifah A. Salmeia and Sabyasachi Gaan

Abstract

A very promising cellulose-based natural fibre that is suitable for use in the textile industry is peat fibre. This fibre is a by-product of peat excavation, purified by separating it from other components. In this study, the morphological, chemical and mechanical properties of peat fibres as well as flammability of peat-based knitted fabrics were analysed. The average diameter of the peat fibres is ~60 μm, but it varies in very wide ranges – 25–150 μm; however, the number of fibres with diameter more than 100 μm is very low. As the peat fibre contains a high amount of lignin, lignin amount in the mixed peat/cotton yarn is relatively high too. Lignin is responsible for enhanced flame retardancy; therefore, time to ignition of the peat knit is ~30% higher than that of the cotton knit. Consequently, peat fibre can be used in the knitted structure in order to significantly reduce its flammability. In order to increase the flame retardancy, the knits have been treated by flame retardant in various concentrations. It was found that around the burned hole on the peat knit, treated by very low concentration flame retardant, forms charred area and the knit stops to burn even if the flame source is not removed.

Open access

Olayinka O. Ajani, Martins T. Nlebemuo, Joseph A. Adekoya, Kehinde O. Ogunniran, Tolutope O. Siyanbola and Christiana O. Ajanaku

Abstract

Surpassing heart diseases, cancer is taking the lead as the deadliest disease because of its fast rate of spreading in all parts of the world. Tireless commitment to searching for novel therapeutic medicines is a worthwhile adventure in synthetic chemistry because of the drug resistance predicament and regular outbreak of new diseases due to abnormal cell growth and proliferation. Medicinal chemistry researchers and pharmacists have unveiled quinoxaline templates as precursors of importance and valuable intermediates in drug discovery because they have been established to possess diverse pharmacological potentials. Hence, this review highlights the current versatile routes to accessing functionalized quinoxaline motifs and harnessing their documented therapeutic potentials for anticancer drug development.

Open access

Lingjie Zhang, Xuhong Miao and Ailan Wan

Abstract

The lapping angle, which affects the style and quality of production, has been studied as a parameter of weft knitting. But the importance of the lapping angle has not been considered during the warp-knitting cycle. This paper shows that the lapping angle exists in the process of warp knitting and can be divided into horizontal and vertical lapping angles. Models for the lapping angles of closed and open loops were devised, and the lapping angles (horizontal and vertical lapping angles) of closed and open loops were calculated and analyzed. Furthermore, the paper seeks to investigate the factors that influence the lapping angle of tricot warp-knitted fabrics and summarize the rules. Moreover, the vertical lapping angle can affect the loop coverage. Results reveal that the decrease in number of underlaps and an increase in take-off density enables loops of the front guide bar to show on the face of the fabric. Moreover, it is also advantageous for an apparent front loop visibility when the front guide bar knits in open loop.

Open access

Zuzana Allmanová, Mária Vlčková, Martin Jankovský, Matúš Jakubis and Michal Allman

Abstract

This paper focused on predicting the bank erosion through the Bank Assessment for Non-point source Consequences of Sediment (BANCS) model on the Tŕstie water stream, located in the western Slovakia. In 2014, 18 experimental sections were established on the stream. These were assessed through the Bank Erosion Hazard Index (BEHI) and the Near Bank Stress (NBS) index. Based on the data we gathered, we constructed two erosion prediction curves. One was for BEHI categories low and moderate, and one for high, very high, and extreme BEHI. Erosion predicted through the model correlated strongly with the real annual bank erosion – for low and moderate BEHI, the R2 was 0.51, and for high, very high and extreme BEHI, the R2 was 0.66. Our results confirmed that the bank erosion can be predicted with sufficient precision on said stream through the BANCS model.

Open access

Zhongjian Li, Fei Yu, Ning Zhang, Yichen Lu, Ruru Pan and Weidong Gao

Abstract

In this article, a computerized method is proposed for simulating digital woven fabric (DWF) based on sequential yarn images captured from a moving yarn. A mathematical model of woven fabric structure is established by assuming that the crimped shape of yarns in weave structure is elastica, and the cross-sections of yarn in sequence image and fabric are circular and ellipse, respectively. The sequential yarn images, which are preprocessed and stitched first by image processing methods, are resized based on the mathematical model. Then a light intensity curve, which consists of radial curve model and axial curve model, is used to simulate the gray texture distribution of interlacing points in radial and axial directions. Finally, a Boole Matrix model is used to control the woven pattern. In the experiment, a slub yarn and a normal yarn samples with same count are applied to simulate gray texture fabrics. Then the gray fabrics are transformed to color fabrics based on three color maps. The fabric simulations are confined to single fabrics of plain, 2/2 matt, and 1/3 twill weaves.

Open access

Narjes Azizi, Masoud Sheidai, Valiollah Mozaffarian, Mitra Arman and Zahra Noormohammadi

Abstract

This study conducted to determine relationship among and within Iranian Helichrysum species (Asteraceae). In this study based on ISSR markers, the highest percentage of ISSR loci polymorphism (54.7%) occurred in H. armenium. The highest gene diversity over loci (1.224), Shannon’s Information Index (0.224%) and Expected Heterozygosity (0.142%) occurred in H. armenium (0.18) and the lowest of these parameters (0%) were observed in H. araxinum, H. graveolens, H. persicum and H. psychrophilum. The highest genetic similarity occurred between H. armenium and H. rubicundum (0.989), while the lowest was between H. polyphyllum and H. graveolens (0.213). The analysis of molecular variance (AMOVA), showed significant genetic variation among (24%) and within (76%) species. In morphological analysis traits such as indumentum, resting bud, achene length, achenial papillae, dimension of receptacle and form and apex of phyllaries were main diagnostic features. Results obtained from the morphological cluster were greatly consistent with the molecular data, to elucidating taxonomic relationships, as well as both attributed the higher diversity in H. armenium and H. rubicundum in comparison with other species and also indicated that H. persicum is a member of H. oocephalum species. Totally we confirmed the presence of 18 species in Iran.

Open access

Elena Nakvasina, Nadezhda Demina, Nadezhda Prozherina and Natalia Demidova

Abstract

Phenotypic plasticity of 22 spruce provenances in three test plots located in the European North of Russia was studied. Parent spruce stands are located within the Russian Plain and are represented by Picea abies (L.) Karst., P. obovata (Ledeb.) and two introgressive hybrids. In the test plots located in the middle and southern taiga subzones P. abies provenances are tested northward of its distribution area and P. obovata provenances are tested within the distribution area and nearby its boundaries. phenotypic plasticity of the spruce provenances was assessed. Straight-line regression coefficient based on survival, diameter, and height was calculated. All provenances are divided into two groups: plastic and non-plastic provenances. High plasticity is observed more often for P. abies and hybrids forms with properties of P. abies. Plastic provenances based on three parameters grow in the Leningrad, Pskov, Vologda, Kostroma and Karelia. Area of parent stands growing is quite small-size and lies between 56º30´ – 61º40´ N and 30º30´ – 42º30´ E. Adaptive provenances of P. obovata and its related hybrids forms grow in the North-Eastern part of the Russian Plain that could be consequence of its distribution in Holocene. Picea abies being the more adaptive species would be more responsive to climate changes in terms of survival and growth rate than P. obovata. Therefore, in case of sustainable climate warming in the Northern areas of the Russian Plain, the further propagation and major distribution of P. abies with further competitive replacement of P. obovata can be expected.

Open access

Jaime G. Cuevas, José L. Arumí and José Dörner

Abstract

Lagtimes and times of concentration are frequently determined parameters in hydrological design and greatly aid in understanding natural watershed dynamics. In unmonitored catchments, they are usually calculated using empirical or semiempirical equations developed in other studies, without critically considering where those equations were obtained and what basic assumptions they entailed. In this study, we determined the lagtimes (LT) between the middle point of rainfall events and the discharge peaks in a watershed characterized by volcanic soils and swamp forests in southern Chile. Our results were compared with calculations from 24 equations found in the literature. The mean LT for 100 episodes was 20 hours (ranging between 0.6–58.5 hours). Most formulae that only included physiographic predictors severely underestimated the mean LT, while those including the rainfall intensity or stream velocity showed better agreement with the average value. The duration of the rainfall events related significantly and positively with LTs. Thus, we accounted for varying LTs within the same watershed by including the rainfall duration in the equations that showed the best results, consequently improving our predictions. Izzard and velocity methods are recommended, and we suggest that lagtimes and times of concentration must be locally determined with hyetograph-hydrograph analyses, in addition to explicitly considering precipitation patterns.

Open access

Livio Poldini and Stefano Tasinazzo

Abstract

Recent original data concerning vineyard spring vegetation from Veneto hilly belt (North-eastern Italy) highlighted once again the phytogeographic originality of south-eastern territories with respect to Central European ones, also in anthropogenic coenosis. New relevés suggested to restate the association Cerastio tenoreani-Geranietum dissecti as vicarious vegetation of Geranio rotundifolii-Allietum vinealis occurring on the north side of the Alps. The comparison of autumn material from terracing vineyards of the sandy-marly Eocene flysch around Trieste coast with similar European relevés enabled to reject the not validly described Anagallido-Mercurialetum and to replace it with Mercurialetum annuae. In modern winegrowing Cerastio-Geranietum and Mercurialetum annuae are vanishing due to changing of agronomic schemes, as some relevés reported in the text document.

Open access

Abul Basar

Abstract

In this paper, we study the concept of ordered (m, n)-Г-hyperideals in an ordered LA-Г-semihypergroup. We show that if (S, Г, ◦,⩽) is a unitary ordered LA-Г-semihypergroup with zero 0 and satisfies the hypothesis that it contains no non-zero nilpotent (m, n)-Г-hyperideals and if R(L) is a 0-minimal right (left) Г-hyperideal of S, then either (R◦ Г ◦L] = {0} or (R◦ Г ◦ L] is a 0-minimal (m, n)-Г-hyperideal of S. Also, we prove that if (S, Г, ◦,⩽) is a unitary ordered LA-Г-semihypergroup; A is an (m, n)-Г-hyperideal of S and B is an (m, n)-Г-hyperideal of A such that B is idempotent, then B is an (m, n)-Г-hyperideal of S.