Growing environmental and social concerns demand development of environ mentally friendly and res... more Growing environmental and social concerns demand development of environ mentally friendly and resource efficient solutions in road construction sector. Consequently, the current research is devoted to valorization of two types of industrial wastecement bypass dust (BPD) and biomass fly ash (FA)to develop efficient binder for construction of more durable asphalt pavements. Within the research certain amounts of BPD and FA (6, 7 and 8 wt.%) have been introduced within styrene butadiene styrene (SBS) modified 70/100 grade bitumen to develop environmentally friendly hybrid binder systems (HBS) by high shear mixing. Structure, chemical composition and thermal stability of FA and BPD fillers have been characterized. Performance of the developed HBS have been assessed by means of rheological investigations (DSR and MSCR tests). It has been observed that HBS are characterized with improved rutting resistance in com parison to neat bitumen as well as improved elastic recovery and hence low-temperature charac teristics in comparison to SBS modified bituminous compositions.
IOP Conference Series: Materials Science and Engineering, 2019
Reactive dyes are one of the most popular dyes for cotton goods and other cellulosic fibres. The ... more Reactive dyes are one of the most popular dyes for cotton goods and other cellulosic fibres. The main investigations for application of reactive dyes for cellulosic fibres are devoted to cotton textiles. In this paper the research results of investigation of colour properties, colour and rubbing fastness, mechanical properties of pre-modified with alkali and enzyme linen fabric dyed with colour triad of Cibacron reactive dyes are presented. The investigation results show that the main factor influencing the colour properties of linen fabric dyed with examined reactive dyes is used dye. The modifiers use increases the rubbing fastness of dyed linen textile. The modifiers influence on colour and colour properties before and after light test is selective for used dye, but not significant.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study was planned to evaluate the effect of varying levels of enzyme supplementation with hi... more This study was planned to evaluate the effect of varying levels of enzyme supplementation with high levels of paddy replacing maize on the nutrient utilization and carcass traits of broilers. The study was conducted for a period of five weeks. In experiment 126, day old chicks were randomly distributed into 07 dietary treatments each with 3 replicates of 6 chicks each and T1 acted as a control. The control diets were formulated to contain 2800 Kcal ME/kg and 22% CP and enzymes @ 30gm/100kg feed. Remaining 06 treatments, were formulated by supplementing higher levels (60%,80% and 100%) of paddy replacing maize and varying levels (@ 30gm/100kg feed and @ 50gm/100kg feed) of enzymes. Use of higher level of enzymes had caused higher retention of nutrients. The percent carcass yield was maximum in broilers assigned T5 diet. No specific trend was found in organ weight and processing losses of broilers.
The research focuses on hemp yarns activity in the woven reinforcements, depending on the product... more The research focuses on hemp yarns activity in the woven reinforcements, depending on the production method as well as production of reinforcement of natural yarns and thermoplastic yarns as matrix in one woven product for production of composites of building materials. The reinforcements of hemp yarns (100 tex), polypropylene yarns (100 tex) and polyethylene yarn (220 tex) were produced using plain weaving technique on a craftsman’s loom. The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. Fabric thickness of hemp yarns reinforcement was 0.61-0.69 mm and density 91-100 g/m2. Tensile strength of hemp reinforcement on warp direction are 241.7N-279.8N and on weft direction 249.4N -302.9N; tensile modulus 218.48MPa-271.24MPa and 189.3 MPa-196.1MPa. Laboratory Press LP_S_50/SASTM) was used for production of composites. The mechanical properties of composite were established according to ISO 527-5:2009 standard and thickness swelling in water was conducted in accordance to EN 622-2: 2004 standard. Composite thickness depending of reinforcement layers in composites was 0.34mm to1.1mm; the density of composites varied from 311 g/m2 to 1040 g/m.2 Tensile strength of composites varied from 303.09N (one layer) to 2019.39N (five layers) and the elastic modulus of same composites are 908.24MPa and 1809.64 MPa
Tehniskās tekstilijas ir strauji augoša tekstilrūpniecības nozare. Tekstilmateriāli aizstāj tradi... more Tehniskās tekstilijas ir strauji augoša tekstilrūpniecības nozare. Tekstilmateriāli aizstāj tradicionālos materiālus dažādās tautsaimniecības nozarēs. Publikācijā apkopotas Krievijas bazalta šķiedras ražotnes ”Kamenny Vek” bazalta šķiedras mehāniskās īpašības balstoties uz publicētiem avotiem, testēšanas rezultāti ar INSTRON raušanas iekārtu, testējot šķiedru mehāniskās īpašības pirms iestrādes audumā un pēc aušanas amatnieku stellēs. Parādīti izstrādāto bazalta šķiedru armējošo audumu iekārtošanas parametri
IOP Conference Series: Materials Science and Engineering, 2019
The application of nonwoven composites expands each year. The heat-bonded nonwovens (NW) are used... more The application of nonwoven composites expands each year. The heat-bonded nonwovens (NW) are used for geotextile production due to the simple production cycle and low processing cost. To create the geotextile with desirable properties the mix of fibres are used. The aim of this study is to use recycled hemp, polyethylene terephthalate and polypropylene fibres for the development of new materials and technologies for nonwoven material composites (NWC) production. The series of NWC from mix of natural and synthetic fibres and series with one or two sides thermoplastic net reinforcing are manufactured. The NWC characterization parameters, water penetration, air permeability and results of physicomechanical properties are presented.
IOP Conference Series: Materials Science and Engineering, 2016
The aim of this research is the investigation of burning characteristics and abrasion resistance ... more The aim of this research is the investigation of burning characteristics and abrasion resistance of the Latvian local raw and bleached linen fabrics and the same fabrics with continuous anti flammable coating, containing commercial printing paste Printperfect EX-TS, pigment Bezaprint GELB (both of the producer CHT BEZEMA) and antimony trioxide (Sb2O3) as the flame-retardant additive. For the coating of the linen fabrics the flat screen method was used. After the coating 5 washing cycles were applied to the half of the fabrics. The burning test of the raw and the bleached linen fabrics and those coated with commercial printing paste and antimony trioxide, as well as the washed fabrics was accomplished. The results of the test shove, that the raw and the bleached linen fabrics burn completely. The flame extinction was observed for coated fabrics and coated washed fabrics. The abrasion resistance of coated fabrics depends on thickness of coating.
Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference, 2015
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. Reinforcing 2D and 3D woven structures for fibers reinforced polymer composites were developed from renewable natural fibers and tested in this research work. Results and discussion are presented in the paper.
The increase of production of woven structures from natural fibres for reinforced composites can ... more The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structures and the composites produced from them. The woven structures were manufactured using hand looms or industrial looms (CТБ-175) using one layer technique. The mechanical testing of the reinforcements showed that the parameters of the looms had significant impact on the properties of the reinforcements. However, the desired improvement of strength by adding glass fibre to the fabric was not achieved. The one, two, three and four layer composites were produced in a hydraulic press using reinforcements woven from hemp yarn and polypropylene yarn. The mechanical testing of composites showed that the tensile strength of the composites and the tensile stress at maximum load depends on number of the reinforcement layers, but the tensile extension of the composites and the modulus of elasticity are not closely related to the number of reinforcement layers, but rather on elasticity of yarn used in weaving. Swelling of composites in water was detected.
Proceedings of the Estonian Academy of Sciences, 2015
The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultiva... more The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. This paper presents the results of a first study about the usage of pectinase enzyme Beisol PRO (4% water solution) for Latvian hemp sort "Purini" retting at different time and temperatures conditions and treatment influence on obtained fibres quality. Gravimetrical examination of the quantity of fibres and sheaves after retting, physical-mechanical tests and TG analysis, colour properties, and selected samples microscopy evaluation show that enzyme treatment is not significant for fibre separation from stem as well as TG characteristics at investigated time and temperature conditions. Use of pectinase enzyme for hemp retting in some cases increases tensile strength of fibres and causes changes of colour characteristics.
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. The aim of this work is focused on production methods of 2D woven reinforcing structures and studies of mechanical properties of produced reinforcements from renewable natural fibers - hemp and flax yarns. Results and discussion are presented in the research paper.
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. Reinforcing 2D and 3D woven structures for fibers reinforced polymer composites were developed from renewable natural fibers and tested in this research work. Results and discussion are presented in the paper
The requirements regarding the properties of fibres are closely linked to their further applicati... more The requirements regarding the properties of fibres are closely linked to their further application. The demands for garment and home textile considerably differ from requirements for fibres that are used for technical purposes. This paper presents the results on investigation of raw flax and hemp fibres after their initial treatment with two step method (cold or hot alkaline, enzyme treatment and bleaching as after-treatment). The properties of hemp and flax fibres are evaluated by colorimetric analysis, mechanical testing, and microscopy of the surface of fibres.
Growing environmental and social concerns demand development of environ mentally friendly and res... more Growing environmental and social concerns demand development of environ mentally friendly and resource efficient solutions in road construction sector. Consequently, the current research is devoted to valorization of two types of industrial wastecement bypass dust (BPD) and biomass fly ash (FA)to develop efficient binder for construction of more durable asphalt pavements. Within the research certain amounts of BPD and FA (6, 7 and 8 wt.%) have been introduced within styrene butadiene styrene (SBS) modified 70/100 grade bitumen to develop environmentally friendly hybrid binder systems (HBS) by high shear mixing. Structure, chemical composition and thermal stability of FA and BPD fillers have been characterized. Performance of the developed HBS have been assessed by means of rheological investigations (DSR and MSCR tests). It has been observed that HBS are characterized with improved rutting resistance in com parison to neat bitumen as well as improved elastic recovery and hence low-temperature charac teristics in comparison to SBS modified bituminous compositions.
IOP Conference Series: Materials Science and Engineering, 2019
Reactive dyes are one of the most popular dyes for cotton goods and other cellulosic fibres. The ... more Reactive dyes are one of the most popular dyes for cotton goods and other cellulosic fibres. The main investigations for application of reactive dyes for cellulosic fibres are devoted to cotton textiles. In this paper the research results of investigation of colour properties, colour and rubbing fastness, mechanical properties of pre-modified with alkali and enzyme linen fabric dyed with colour triad of Cibacron reactive dyes are presented. The investigation results show that the main factor influencing the colour properties of linen fabric dyed with examined reactive dyes is used dye. The modifiers use increases the rubbing fastness of dyed linen textile. The modifiers influence on colour and colour properties before and after light test is selective for used dye, but not significant.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
This study was planned to evaluate the effect of varying levels of enzyme supplementation with hi... more This study was planned to evaluate the effect of varying levels of enzyme supplementation with high levels of paddy replacing maize on the nutrient utilization and carcass traits of broilers. The study was conducted for a period of five weeks. In experiment 126, day old chicks were randomly distributed into 07 dietary treatments each with 3 replicates of 6 chicks each and T1 acted as a control. The control diets were formulated to contain 2800 Kcal ME/kg and 22% CP and enzymes @ 30gm/100kg feed. Remaining 06 treatments, were formulated by supplementing higher levels (60%,80% and 100%) of paddy replacing maize and varying levels (@ 30gm/100kg feed and @ 50gm/100kg feed) of enzymes. Use of higher level of enzymes had caused higher retention of nutrients. The percent carcass yield was maximum in broilers assigned T5 diet. No specific trend was found in organ weight and processing losses of broilers.
The research focuses on hemp yarns activity in the woven reinforcements, depending on the product... more The research focuses on hemp yarns activity in the woven reinforcements, depending on the production method as well as production of reinforcement of natural yarns and thermoplastic yarns as matrix in one woven product for production of composites of building materials. The reinforcements of hemp yarns (100 tex), polypropylene yarns (100 tex) and polyethylene yarn (220 tex) were produced using plain weaving technique on a craftsman’s loom. The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. Fabric thickness of hemp yarns reinforcement was 0.61-0.69 mm and density 91-100 g/m2. Tensile strength of hemp reinforcement on warp direction are 241.7N-279.8N and on weft direction 249.4N -302.9N; tensile modulus 218.48MPa-271.24MPa and 189.3 MPa-196.1MPa. Laboratory Press LP_S_50/SASTM) was used for production of composites. The mechanical properties of composite were established according to ISO 527-5:2009 standard and thickness swelling in water was conducted in accordance to EN 622-2: 2004 standard. Composite thickness depending of reinforcement layers in composites was 0.34mm to1.1mm; the density of composites varied from 311 g/m2 to 1040 g/m.2 Tensile strength of composites varied from 303.09N (one layer) to 2019.39N (five layers) and the elastic modulus of same composites are 908.24MPa and 1809.64 MPa
Tehniskās tekstilijas ir strauji augoša tekstilrūpniecības nozare. Tekstilmateriāli aizstāj tradi... more Tehniskās tekstilijas ir strauji augoša tekstilrūpniecības nozare. Tekstilmateriāli aizstāj tradicionālos materiālus dažādās tautsaimniecības nozarēs. Publikācijā apkopotas Krievijas bazalta šķiedras ražotnes ”Kamenny Vek” bazalta šķiedras mehāniskās īpašības balstoties uz publicētiem avotiem, testēšanas rezultāti ar INSTRON raušanas iekārtu, testējot šķiedru mehāniskās īpašības pirms iestrādes audumā un pēc aušanas amatnieku stellēs. Parādīti izstrādāto bazalta šķiedru armējošo audumu iekārtošanas parametri
IOP Conference Series: Materials Science and Engineering, 2019
The application of nonwoven composites expands each year. The heat-bonded nonwovens (NW) are used... more The application of nonwoven composites expands each year. The heat-bonded nonwovens (NW) are used for geotextile production due to the simple production cycle and low processing cost. To create the geotextile with desirable properties the mix of fibres are used. The aim of this study is to use recycled hemp, polyethylene terephthalate and polypropylene fibres for the development of new materials and technologies for nonwoven material composites (NWC) production. The series of NWC from mix of natural and synthetic fibres and series with one or two sides thermoplastic net reinforcing are manufactured. The NWC characterization parameters, water penetration, air permeability and results of physicomechanical properties are presented.
IOP Conference Series: Materials Science and Engineering, 2016
The aim of this research is the investigation of burning characteristics and abrasion resistance ... more The aim of this research is the investigation of burning characteristics and abrasion resistance of the Latvian local raw and bleached linen fabrics and the same fabrics with continuous anti flammable coating, containing commercial printing paste Printperfect EX-TS, pigment Bezaprint GELB (both of the producer CHT BEZEMA) and antimony trioxide (Sb2O3) as the flame-retardant additive. For the coating of the linen fabrics the flat screen method was used. After the coating 5 washing cycles were applied to the half of the fabrics. The burning test of the raw and the bleached linen fabrics and those coated with commercial printing paste and antimony trioxide, as well as the washed fabrics was accomplished. The results of the test shove, that the raw and the bleached linen fabrics burn completely. The flame extinction was observed for coated fabrics and coated washed fabrics. The abrasion resistance of coated fabrics depends on thickness of coating.
Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference, 2015
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. Reinforcing 2D and 3D woven structures for fibers reinforced polymer composites were developed from renewable natural fibers and tested in this research work. Results and discussion are presented in the paper.
The increase of production of woven structures from natural fibres for reinforced composites can ... more The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structures and the composites produced from them. The woven structures were manufactured using hand looms or industrial looms (CТБ-175) using one layer technique. The mechanical testing of the reinforcements showed that the parameters of the looms had significant impact on the properties of the reinforcements. However, the desired improvement of strength by adding glass fibre to the fabric was not achieved. The one, two, three and four layer composites were produced in a hydraulic press using reinforcements woven from hemp yarn and polypropylene yarn. The mechanical testing of composites showed that the tensile strength of the composites and the tensile stress at maximum load depends on number of the reinforcement layers, but the tensile extension of the composites and the modulus of elasticity are not closely related to the number of reinforcement layers, but rather on elasticity of yarn used in weaving. Swelling of composites in water was detected.
Proceedings of the Estonian Academy of Sciences, 2015
The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultiva... more The analysis of hemp cultivation and usage trends in the world and Europe shows that hemp cultivation and processing in Latvia has good perspectives. This paper presents the results of a first study about the usage of pectinase enzyme Beisol PRO (4% water solution) for Latvian hemp sort "Purini" retting at different time and temperatures conditions and treatment influence on obtained fibres quality. Gravimetrical examination of the quantity of fibres and sheaves after retting, physical-mechanical tests and TG analysis, colour properties, and selected samples microscopy evaluation show that enzyme treatment is not significant for fibre separation from stem as well as TG characteristics at investigated time and temperature conditions. Use of pectinase enzyme for hemp retting in some cases increases tensile strength of fibres and causes changes of colour characteristics.
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. The aim of this work is focused on production methods of 2D woven reinforcing structures and studies of mechanical properties of produced reinforcements from renewable natural fibers - hemp and flax yarns. Results and discussion are presented in the research paper.
For a variety of applications it is desirable to produce textile materials with specially designe... more For a variety of applications it is desirable to produce textile materials with specially designed properties. Reinforcing 2D and 3D woven structures for fibers reinforced polymer composites were developed from renewable natural fibers and tested in this research work. Results and discussion are presented in the paper
The requirements regarding the properties of fibres are closely linked to their further applicati... more The requirements regarding the properties of fibres are closely linked to their further application. The demands for garment and home textile considerably differ from requirements for fibres that are used for technical purposes. This paper presents the results on investigation of raw flax and hemp fibres after their initial treatment with two step method (cold or hot alkaline, enzyme treatment and bleaching as after-treatment). The properties of hemp and flax fibres are evaluated by colorimetric analysis, mechanical testing, and microscopy of the surface of fibres.
Uploads
Papers by Aina Bernava