Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.59011
Z. G. Mascarenhas, Igor Amorim Beja, K. Vasconcelos, L. Bernucci
Heavy traffic and high temperatures are a common cause of rutting in paved areas, which reduces the time needed between pavement maintenance interventions. Large-stone asphalt mixtures (LSAMs) can reduce rutting when used as intermediate layers in pavement rehabilitation. LSAM is asphalt concrete with a nominal maximum aggregate size of at least 25 mm. In this study, we provide a brief literature review of the historical use of LSAMs, as well as the relevant characteristics of LSAM design. Three LSAMs were designed using different compaction methods: (i) Marshall compaction; (ii) rolling compaction; and (iii) Superpave gyratory compaction (SGC) by varying the compaction energy in 75, 100, and 125 gyrations. Depending on the mix design method used, the designed asphalt content ranged from 3.0 to 4.3%. The locking point from the SGC was evaluated at different gyratory compaction energies, which were related to the porosity of the dominant aggregate size range. These parameters are considered to be of great value when evaluating the LSAM design.
{"title":"Mix design of large-stone asphalt mixtures for heavy-traffic roads","authors":"Z. G. Mascarenhas, Igor Amorim Beja, K. Vasconcelos, L. Bernucci","doi":"10.4025/actascitechnol.v45i1.59011","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.59011","url":null,"abstract":"Heavy traffic and high temperatures are a common cause of rutting in paved areas, which reduces the time needed between pavement maintenance interventions. Large-stone asphalt mixtures (LSAMs) can reduce rutting when used as intermediate layers in pavement rehabilitation. LSAM is asphalt concrete with a nominal maximum aggregate size of at least 25 mm. In this study, we provide a brief literature review of the historical use of LSAMs, as well as the relevant characteristics of LSAM design. Three LSAMs were designed using different compaction methods: (i) Marshall compaction; (ii) rolling compaction; and (iii) Superpave gyratory compaction (SGC) by varying the compaction energy in 75, 100, and 125 gyrations. Depending on the mix design method used, the designed asphalt content ranged from 3.0 to 4.3%. The locking point from the SGC was evaluated at different gyratory compaction energies, which were related to the porosity of the dominant aggregate size range. These parameters are considered to be of great value when evaluating the LSAM design.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77603571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60212
T. Silva, H. Pitanga, M. H. R. Rodrigues, Juliana de Paula Rezende, Geraldo Marques, Felipe de Andrade Simões
This was a study on the mechanical behavior of hot asphalt mixtures with regard to permanent deformation, considering static creep tests and the parameters derived from the Superpave compaction curve. For the asphalt mixture production, mineral aggregates and two types of asphalt binder (CAP 50/70 and AMP 60/85) were used. These mixtures were designed using the Superpave methodology and compacted in the content and number of gyrations according to the design. For the design condition, asphalt mixtures using the conventional CAP 50/70 asphalt binder showed better workability and lower deformation than asphalt mixtures with the AMP 60/85 polymer binder. Furthermore, the influence of asphalt binder content on the behavior of asphalt mixtures in relation to permanent deformation and compaction indices was studied, considering the maximum number of gyrations in the design. Regarding this investigation, asphalt mixtures with higher asphalt binder content tend to show higher permanent deformation and better workability. Complementarily, the compaction curve indices (Construction Densification Index, CDI; modified Traffic Densification Index, TDIm and Locking Point, LP) were correlated with parameters obtained from static creep tests (total deformation after the recovery period, Dt; creep modulus, CM and curve inclination, Icurve) through curves obtained by the correlation between these indices. Based on this analysis, a good correlation was found between the results of static creep tests and compaction indices, showing the potential of these indices for predicting the mechanical behavior of the analyzed mixtures in relation to the development of permanent deformations.
这是一项关于热沥青混合料的力学行为的研究，考虑到静态蠕变试验和Superpave压实曲线的参数。在沥青混合料的生产中，使用了矿物集料和两种沥青粘结剂(CAP 50/70和AMP 60/85)。使用Superpave方法设计了这些混合物，并根据设计在内容和旋转次数上进行了压实。在设计条件下，使用常规CAP 50/70沥青粘结剂的沥青混合料比使用AMP 60/85聚合物粘结剂的沥青混合料具有更好的和易性和更低的变形。此外，考虑设计中的最大旋转次数，研究了沥青粘结剂含量对沥青混合料永久变形和压实指标的影响。在本研究中，沥青粘结剂含量越高，沥青混合料的永久变形越大，和易性越好。与之相辅相成的是压实曲线指数(Construction density Index, CDI;修正交通密度指数(TDIm)和锁定点(LP)与静力蠕变试验参数(恢复期后总变形Dt;蠕变模量，CM和曲线倾角，Icurve)通过这些指标之间的相关性得到的曲线。基于此分析，静态蠕变试验结果与压实指标之间存在良好的相关性，表明这些指标在预测所分析混合物的力学行为与永久变形的发展之间具有潜力。
{"title":"Study of the mechanical behavior of asphalt mixtures in terms of creep and Superpave compaction parameters","authors":"T. Silva, H. Pitanga, M. H. R. Rodrigues, Juliana de Paula Rezende, Geraldo Marques, Felipe de Andrade Simões","doi":"10.4025/actascitechnol.v45i1.60212","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60212","url":null,"abstract":"This was a study on the mechanical behavior of hot asphalt mixtures with regard to permanent deformation, considering static creep tests and the parameters derived from the Superpave compaction curve. For the asphalt mixture production, mineral aggregates and two types of asphalt binder (CAP 50/70 and AMP 60/85) were used. These mixtures were designed using the Superpave methodology and compacted in the content and number of gyrations according to the design. For the design condition, asphalt mixtures using the conventional CAP 50/70 asphalt binder showed better workability and lower deformation than asphalt mixtures with the AMP 60/85 polymer binder. Furthermore, the influence of asphalt binder content on the behavior of asphalt mixtures in relation to permanent deformation and compaction indices was studied, considering the maximum number of gyrations in the design. Regarding this investigation, asphalt mixtures with higher asphalt binder content tend to show higher permanent deformation and better workability. Complementarily, the compaction curve indices (Construction Densification Index, CDI; modified Traffic Densification Index, TDIm and Locking Point, LP) were correlated with parameters obtained from static creep tests (total deformation after the recovery period, Dt; creep modulus, CM and curve inclination, Icurve) through curves obtained by the correlation between these indices. Based on this analysis, a good correlation was found between the results of static creep tests and compaction indices, showing the potential of these indices for predicting the mechanical behavior of the analyzed mixtures in relation to the development of permanent deformations.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86262368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60876
R. Palhares, Renato Silva Nicoletti, Maicon de Freitas Arcine, Alex Sander Clemente de Souza
This article aims to perform the thermal analysis of different welded profiles of the VS and CS series with and without thermal protection subjected to fire action according to the nominal fire curve ISO 834. The fire protection studied was the contour type of constant thickness and the coating material considered was Blaze Shield II mortar. The temperature evolution in the profiles was evaluated using the analytical models prescribed by ABNT NBR 14323:2013 and three-dimensional numerical models using the ABAQUS® software. In general, it was observed that the results obtained by the analytical methods were in agreement with the numerical ones and that the use of mortar as fire protection evaluated in this study proved to be an efficient solution for fire protection. It was also possible to demonstrate that the increase in coating thickness, the reduction in thermal conductivity, and the increase in the specific heat of the constituent material provide a slower evolution of the temperature of the steel structural elements.
{"title":"Influence of mortar coating on the thermal analysis of steel profiles in a fire situation","authors":"R. Palhares, Renato Silva Nicoletti, Maicon de Freitas Arcine, Alex Sander Clemente de Souza","doi":"10.4025/actascitechnol.v45i1.60876","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60876","url":null,"abstract":"This article aims to perform the thermal analysis of different welded profiles of the VS and CS series with and without thermal protection subjected to fire action according to the nominal fire curve ISO 834. The fire protection studied was the contour type of constant thickness and the coating material considered was Blaze Shield II mortar. The temperature evolution in the profiles was evaluated using the analytical models prescribed by ABNT NBR 14323:2013 and three-dimensional numerical models using the ABAQUS® software. In general, it was observed that the results obtained by the analytical methods were in agreement with the numerical ones and that the use of mortar as fire protection evaluated in this study proved to be an efficient solution for fire protection. It was also possible to demonstrate that the increase in coating thickness, the reduction in thermal conductivity, and the increase in the specific heat of the constituent material provide a slower evolution of the temperature of the steel structural elements.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77837359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.61153
R.T.S. Santos, Reinaldo Ricarte da Silva Junior, M. Ferreira, L. Soares, L. Stragevitch, Leandro Danielski
Annona muricata (soursop) is a native American plant and is well known for its leafy canopy and its fruits, widely consumed in South America and Southeast Asia. The objective of this work was to obtain Annona muricata leaf extracts and to evaluate their antioxidant activities, which were obtained by four different extraction methods: Soxhlet, maceration, ultrasound, and pressurized hot (subcritical) water. In order to assess and compare the extracts bioactivities, total polyphenol contents of the extracts were evaluated by the Folin-Ciocalteu method and the antioxidant activities were determined by DPPH and ABTS methods. High performance liquid chromatography was used to identify and quantify rutin, a special flavonoid, which was found to be the most representative component, for all extracts obtained. Rutin is known for its benefits has a potential natural antioxidant. Among all extraction methods investigated, extracts obtained by the Soxhlet method using ethanol as solvent showed a higher total polyphenol content, 2.83% of gallic acid equivalent/g plant material, as well as higher antioxidant activity. A correlation between rutin content and antioxidant activity was found. Soxhlet extractions revealed samples with the highest rutin content of 0.130 ± 0.003 g g-1, what may explain the high antioxidant activity of the obtained A. muricata leaf extracts.
番荔枝(番荔枝)是一种美洲本土植物，以其多叶的树冠和果实而闻名，在南美洲和东南亚广泛食用。采用索氏提取法、浸渍法、超声提取法和加压热水(亚临界)水提取法分别获得了番荔枝叶提取物，并对其抗氧化活性进行了评价。采用Folin-Ciocalteu法测定提取物的总多酚含量，DPPH法和ABTS法测定提取物的抗氧化活性，以评价和比较提取物的生物活性。采用高效液相色谱法对芦丁进行鉴定和定量，芦丁是一种特殊的类黄酮，是所有提取物中最具代表性的成分。芦丁以其潜在的天然抗氧化剂而闻名。在所有的提取方法中，以乙醇为溶剂的索氏法提取的总多酚含量较高，没食子酸当量/g含量为2.83%，并且具有较高的抗氧化活性。芦丁含量与抗氧化活性之间存在相关性。索氏提取显示，芦丁含量最高，为0.130±0.003 g g-1，这可能解释了所获得的木香叶提取物具有较高的抗氧化活性。
{"title":"Annona muricata leaf extracts obtained with subcritical water and conventional methods: evaluation of antioxidant activities, total polyphenol and rutin contents","authors":"R.T.S. Santos, Reinaldo Ricarte da Silva Junior, M. Ferreira, L. Soares, L. Stragevitch, Leandro Danielski","doi":"10.4025/actascitechnol.v45i1.61153","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.61153","url":null,"abstract":"Annona muricata (soursop) is a native American plant and is well known for its leafy canopy and its fruits, widely consumed in South America and Southeast Asia. The objective of this work was to obtain Annona muricata leaf extracts and to evaluate their antioxidant activities, which were obtained by four different extraction methods: Soxhlet, maceration, ultrasound, and pressurized hot (subcritical) water. In order to assess and compare the extracts bioactivities, total polyphenol contents of the extracts were evaluated by the Folin-Ciocalteu method and the antioxidant activities were determined by DPPH and ABTS methods. High performance liquid chromatography was used to identify and quantify rutin, a special flavonoid, which was found to be the most representative component, for all extracts obtained. Rutin is known for its benefits has a potential natural antioxidant. Among all extraction methods investigated, extracts obtained by the Soxhlet method using ethanol as solvent showed a higher total polyphenol content, 2.83% of gallic acid equivalent/g plant material, as well as higher antioxidant activity. A correlation between rutin content and antioxidant activity was found. Soxhlet extractions revealed samples with the highest rutin content of 0.130 ± 0.003 g g-1, what may explain the high antioxidant activity of the obtained A. muricata leaf extracts.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80834040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60764
Kennia Mendes Prietsch, Bruna Santos Wachholz, Shanise Lisie Mello El Halal, E. A. Gandra, C. Mendonça, C. D. Borges
Although freezing is considered one of the easiest ways to preserve the quality of food, it is harmful to strawberries. Thus, the objective of this study is to evaluate the conservation of frozen strawberries using gelatin as a coating and of the probiotic yeast, Saccharomyces boulardii. Strawberries were selected, sanitized and subjected to the following treatments: Treatment 1 - control 1 (strawberries stored at -18ºC); Treatment 2 - control 2 (strawberries stored at -80ºC); Treatment 3 - strawberries added with citric acid, calcium chloride and S. boulardii stored at -18ºC; Treatment 4 - strawberries with gelatin, citric acid, calcium chloride, glycerol and S. boulardii stored at -18ºC. Drip loss, soluble solids, titratable acidity, color, firmness, ascorbic acid, total phenolic compounds, monomeric anthocyanins, antioxidant activity, polyphenoloxidase activity and viability of S. boulardii were analysed. The gelatin coating added with citric acid and calcium chloride, in combination with freezing at -18ºC, reduced the drip loss, the metabolic reactions and exerted a protective effect on bioactive compounds, making it possible to use them instead of deep-freezing, mainly for agribusinesses that do not have the equipment. The use of gelatin coating on strawberries minimized the effects of freezing and promoted the protection of S. boulardii, obtaining in up to 60 days of storage the minimum viable concentration of the microorganism to exercise its functional property. On the other hand, in the absence of gelatin, S. boulardii had a negative influence on the physical-chemical parameters, in addition to showing less viability. Thus, the study demonstrated that the coating composed of gelatin, citric acid and calcium chloride can represent an interesting alternative for application on frozen strawberries enriched with S. boulardii.
{"title":"Preservation of frozen strawberries enriched with Saccharomyces boulardii using gelatin-based coating","authors":"Kennia Mendes Prietsch, Bruna Santos Wachholz, Shanise Lisie Mello El Halal, E. A. Gandra, C. Mendonça, C. D. Borges","doi":"10.4025/actascitechnol.v45i1.60764","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60764","url":null,"abstract":"Although freezing is considered one of the easiest ways to preserve the quality of food, it is harmful to strawberries. Thus, the objective of this study is to evaluate the conservation of frozen strawberries using gelatin as a coating and of the probiotic yeast, Saccharomyces boulardii. Strawberries were selected, sanitized and subjected to the following treatments: Treatment 1 - control 1 (strawberries stored at -18ºC); Treatment 2 - control 2 (strawberries stored at -80ºC); Treatment 3 - strawberries added with citric acid, calcium chloride and S. boulardii stored at -18ºC; Treatment 4 - strawberries with gelatin, citric acid, calcium chloride, glycerol and S. boulardii stored at -18ºC. Drip loss, soluble solids, titratable acidity, color, firmness, ascorbic acid, total phenolic compounds, monomeric anthocyanins, antioxidant activity, polyphenoloxidase activity and viability of S. boulardii were analysed. The gelatin coating added with citric acid and calcium chloride, in combination with freezing at -18ºC, reduced the drip loss, the metabolic reactions and exerted a protective effect on bioactive compounds, making it possible to use them instead of deep-freezing, mainly for agribusinesses that do not have the equipment. The use of gelatin coating on strawberries minimized the effects of freezing and promoted the protection of S. boulardii, obtaining in up to 60 days of storage the minimum viable concentration of the microorganism to exercise its functional property. On the other hand, in the absence of gelatin, S. boulardii had a negative influence on the physical-chemical parameters, in addition to showing less viability. Thus, the study demonstrated that the coating composed of gelatin, citric acid and calcium chloride can represent an interesting alternative for application on frozen strawberries enriched with S. boulardii.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81172573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.58733
A. F. F. Gomes, Fernando Menezes de Almeida Filho, J. C. Molina, F. Mascarenhas, F. Lahr, A. Christoforo
The Brazilian standard ABNT NBR 7190 (Associação Brasileira de Normas Técnicas [ABNT], 1997) recommends adopting the mean value of the modulus of elasticity to compression in the direction parallel to the grain (Ec0,m) in the calculation of displacements. The values of wood stiffness vary considerably, and they can generate displacements above the limit (L 200-1, where L is the span) established by the referred standard, which contributes to the appearance of pathologies in the structure. To evaluate the influence of the adoption of Ec0,m in the calculation of displacements, mechanical properties of wood species were obtained experimentally. With the aid of numerical models and experimental values, ten types of trusses were analyzed (Porch, Inclined Chord, Top Inclined Chord, Parallel Chord, Bowstring, Fink, Howe, K Truss, Pratt, Scissor), three spans (5, 10, and 20 m) and two species (Hymenolobium petraum Ducke e Hymenolobium sp). Initially, adopting Ec0,m for all members and performing a linear analysis, the maximum loads for the displacement L 200-1 were determined. Subsequently, experimental stiffness values were randomly assigned to each bar, and the maximum displacements were determined through nonlinear geometric analyses. Based on 1260 numerical simulations, deflections of approximately 17% (span of 5 m), 30% (span of 10 m), and 34% (span of 20 m) were observed to be higher than the result considering Ec0,m. This problem can be overcome by using non-destructive methods in the pre-classification of the structure bars, positioning the elements rationally in the regions of the highest demand.
巴西标准ABNT NBR 7190 (associa o Brasileira de Normas t cnicas [ABNT]， 1997)建议在计算位移时采用平行于颗粒方向的压缩弹性模量的平均值(Ec0,m)。木材刚度的值变化很大，它们可以产生超过参考标准规定的极限(l200 -1，其中L是跨度)的位移，这有助于结构出现病态。为了评价采用Ec0、m对位移计算的影响，对不同树种木材的力学性能进行了实验研究。利用数值模型和实验值，对10种桁架类型(Porch、Inclined Chord、Top Inclined Chord、Parallel Chord、Bowstring、Fink、Howe、K Truss、Pratt、Scissor)、3种跨度(5、10和20 m)和2种(Hymenolobium petraum Ducke和Hymenolobium sp .)进行了分析。首先，对所有构件采用Ec0,m并进行线性分析，确定了位移l200 -1的最大载荷。随后，随机分配每个杆的试验刚度值，并通过非线性几何分析确定最大位移。基于1260次数值模拟，观测到挠度约为17%(跨度为5 m)， 30%(跨度为10 m)和34%(跨度为20 m)高于考虑Ec0,m的结果。采用非破坏性的方法对结构杆进行预分类，将构件合理定位在需求最高的区域，可以克服这一问题。
{"title":"Influence of mean value of the modulus of elasticity in compression parallel to the grain on the design of timber trusses","authors":"A. F. F. Gomes, Fernando Menezes de Almeida Filho, J. C. Molina, F. Mascarenhas, F. Lahr, A. Christoforo","doi":"10.4025/actascitechnol.v45i1.58733","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.58733","url":null,"abstract":"The Brazilian standard ABNT NBR 7190 (Associação Brasileira de Normas Técnicas [ABNT], 1997) recommends adopting the mean value of the modulus of elasticity to compression in the direction parallel to the grain (Ec0,m) in the calculation of displacements. The values of wood stiffness vary considerably, and they can generate displacements above the limit (L 200-1, where L is the span) established by the referred standard, which contributes to the appearance of pathologies in the structure. To evaluate the influence of the adoption of Ec0,m in the calculation of displacements, mechanical properties of wood species were obtained experimentally. With the aid of numerical models and experimental values, ten types of trusses were analyzed (Porch, Inclined Chord, Top Inclined Chord, Parallel Chord, Bowstring, Fink, Howe, K Truss, Pratt, Scissor), three spans (5, 10, and 20 m) and two species (Hymenolobium petraum Ducke e Hymenolobium sp). Initially, adopting Ec0,m for all members and performing a linear analysis, the maximum loads for the displacement L 200-1 were determined. Subsequently, experimental stiffness values were randomly assigned to each bar, and the maximum displacements were determined through nonlinear geometric analyses. Based on 1260 numerical simulations, deflections of approximately 17% (span of 5 m), 30% (span of 10 m), and 34% (span of 20 m) were observed to be higher than the result considering Ec0,m. This problem can be overcome by using non-destructive methods in the pre-classification of the structure bars, positioning the elements rationally in the regions of the highest demand.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78578423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60443
L. Castro, Rosana Rabelo Mançano, Débora Alessandra Jones Battocchio, L. M. S. Colpini
Brewers' spent grains are the main residue generated from the brewery industry; they are produced on a large scale and at a low cost. During the brewing process, approximately 85% of all barley used is transformed into solid residue, which is currently destined for animal feed or just discarded. A possibility to increase the value of this byproduct is the production of carbonaceous materials, such as activated carbon, for the treatment of tartrazine yellow dye solutions. The structures and morphologies of the samples were characterized. Furthermore, the adsorptive capacity and kinetic behavior were studied. Regarding the characterization of the material, the activated carbon presented a porous morphology and high surface area (768.4 m² g-1). Additionally, the kinetic study showed that the equilibrium time of the adsorption process from the tartrazine yellow dye discoloration was 60 min., and the data presented dispersion according to Elovich’s kinetics. It was possible, from the experimental design, to evaluate the adsorptive capacity of the material in which it performed best at pH < 5. Finally, in the equilibrium study carried out by the adsorption isotherms, it was found that the increase in temperature influenced the process, raising the maximum adsorptive capacity in which the data fit into the Langmuir isothermal model
{"title":"Adsorption of food dye using activated carbon from brewers’ spent grains","authors":"L. Castro, Rosana Rabelo Mançano, Débora Alessandra Jones Battocchio, L. M. S. Colpini","doi":"10.4025/actascitechnol.v45i1.60443","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60443","url":null,"abstract":"Brewers' spent grains are the main residue generated from the brewery industry; they are produced on a large scale and at a low cost. During the brewing process, approximately 85% of all barley used is transformed into solid residue, which is currently destined for animal feed or just discarded. A possibility to increase the value of this byproduct is the production of carbonaceous materials, such as activated carbon, for the treatment of tartrazine yellow dye solutions. The structures and morphologies of the samples were characterized. Furthermore, the adsorptive capacity and kinetic behavior were studied. Regarding the characterization of the material, the activated carbon presented a porous morphology and high surface area (768.4 m² g-1). Additionally, the kinetic study showed that the equilibrium time of the adsorption process from the tartrazine yellow dye discoloration was 60 min., and the data presented dispersion according to Elovich’s kinetics. It was possible, from the experimental design, to evaluate the adsorptive capacity of the material in which it performed best at pH < 5. Finally, in the equilibrium study carried out by the adsorption isotherms, it was found that the increase in temperature influenced the process, raising the maximum adsorptive capacity in which the data fit into the Langmuir isothermal model","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80360491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.61270
Amanda Rodrigues Vinhandelli, Annelisa Arruda de Brito, R. Faria, L. F. C. Campos, Gilberto Alessandre Soares Goulart, G. Teixeira, A. R. Nascimento, L. C. Cunha Junior
Tomatoes are one of the most prominent vegetables globally, with significant cultural and economic relevance in various nations, including Brazil. The term ‘safe food’ is becoming more popular as consumer preferences and supply chain dynamics become evolved in these processes. In light of these issues, the use of safety and quality management methods for fruits and vegetables have increased dramatically, with traceability being one of these solutions worth highlighting. When it comes to traceability, evaluation of tomato seedlings, plants, and fruits to identify groups or hybrids becomes particularly crucial throughout the marketing process, since the consumer of seedlings or fruit has difficulties recognizing whether that product truly belongs to the group indicated by the merchant. Thus, the potential of near infrared spectroscopy (NIRS) combined with the PC-LDA and PLS-DA algorithms was tested for the discrimination of two significant commercial groups, Salada and Saladete, as well as eleven cultivars belonging to these groups, which were tested for this purpose. The results show that, by using the PLS-DA model, the portable NIR equipment is capable of differentiating tomato seedlings in nurseries of the Salada and Saladete groups, with an accuracy of 99.7% and sensitivity of 100%. The technique showed to be efficient for individual models of tomato seedlings in the Salada group, with accuracy over 90% and sensitivity above 93% for all models. For the Saladete group's individual models, the technique proved effectiveness for the hybrids Parma, BS-110012, Giácomo, Guara, and Tyna.
{"title":"Near infrared spectroscopy as a tool for agricultural expertise: identification of tomato seedlings","authors":"Amanda Rodrigues Vinhandelli, Annelisa Arruda de Brito, R. Faria, L. F. C. Campos, Gilberto Alessandre Soares Goulart, G. Teixeira, A. R. Nascimento, L. C. Cunha Junior","doi":"10.4025/actascitechnol.v45i1.61270","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.61270","url":null,"abstract":"Tomatoes are one of the most prominent vegetables globally, with significant cultural and economic relevance in various nations, including Brazil. The term ‘safe food’ is becoming more popular as consumer preferences and supply chain dynamics become evolved in these processes. In light of these issues, the use of safety and quality management methods for fruits and vegetables have increased dramatically, with traceability being one of these solutions worth highlighting. When it comes to traceability, evaluation of tomato seedlings, plants, and fruits to identify groups or hybrids becomes particularly crucial throughout the marketing process, since the consumer of seedlings or fruit has difficulties recognizing whether that product truly belongs to the group indicated by the merchant. Thus, the potential of near infrared spectroscopy (NIRS) combined with the PC-LDA and PLS-DA algorithms was tested for the discrimination of two significant commercial groups, Salada and Saladete, as well as eleven cultivars belonging to these groups, which were tested for this purpose. The results show that, by using the PLS-DA model, the portable NIR equipment is capable of differentiating tomato seedlings in nurseries of the Salada and Saladete groups, with an accuracy of 99.7% and sensitivity of 100%. The technique showed to be efficient for individual models of tomato seedlings in the Salada group, with accuracy over 90% and sensitivity above 93% for all models. For the Saladete group's individual models, the technique proved effectiveness for the hybrids Parma, BS-110012, Giácomo, Guara, and Tyna.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89047978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60188
P. Vieira, W. T. M. Silva
The scope of the work involves reinforced concrete frame structures with variations in structural design conception for columns with biaxial bending or uniaxial bending. The beams are designed with simple bending criteria for singly or doubly reinforced beams, or uniaxial bending. The analysis and design criteria are according to NBR 6118:2014. Structure analysis in elastoplastic regimen with the incremental analysis method is performed to detect plastic hinge formation order, collapse load factor, displacements, and rotation capacity of cross sections with the criteria established in the current building codes. The study evaluates the influence of the defined concepts on the structure’s elastoplastic behavior. The biaxial and uniaxial bending method is presented as an important formulation for obtaining the collapse load factor using the elastic stiffness matrix with modifications. The algorithms presented enable the development of research without the need for expensive commercial software licenses.
{"title":"Elastoplastic analysis of reinforced concrete space frames using the uniaxial and biaxial bending method","authors":"P. Vieira, W. T. M. Silva","doi":"10.4025/actascitechnol.v45i1.60188","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60188","url":null,"abstract":"The scope of the work involves reinforced concrete frame structures with variations in structural design conception for columns with biaxial bending or uniaxial bending. The beams are designed with simple bending criteria for singly or doubly reinforced beams, or uniaxial bending. The analysis and design criteria are according to NBR 6118:2014. Structure analysis in elastoplastic regimen with the incremental analysis method is performed to detect plastic hinge formation order, collapse load factor, displacements, and rotation capacity of cross sections with the criteria established in the current building codes. The study evaluates the influence of the defined concepts on the structure’s elastoplastic behavior. The biaxial and uniaxial bending method is presented as an important formulation for obtaining the collapse load factor using the elastic stiffness matrix with modifications. The algorithms presented enable the development of research without the need for expensive commercial software licenses.","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81943902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-26DOI: 10.4025/actascitechnol.v45i1.60595
Tiago Hendrigo de Almeida, F. Icimoto, Diego Henrique Almeida, V. Aquino, A. Christoforo, F. Lahr
Dimensional stability of wood can be determined by measuring the total swelling percentage between 0% and FSP moisture content according to the ABNT NBR 7190 (Associação Brasileira de Normas Técnicas [ABNT], 1997). Wood dimensional variation by the moisture content modifications must influence both structural elements and connections into timber structures. The wood swelling procedure according to the Brazilian code for saturation of wood samples can take more than a month, but the use of autoclave devices may accelerate this activity, making easier the dimensional stability determination. This paper aims to investigate the possibility of accelerating the wood swelling activity using an autoclave device, considering the Brazilian code for thirteen Brazilian commercial wood species. Contrast test for comparison between accelerated process (Stage 4 – 225 min. at 0.49 MPa pressure) and the conventional procedure for wood swelling resulted in p-value equal to 0.0730 and the average difference between groups about 1.1307% (varying between -0.0541 and 2.3156 with 95% confidence level). According to results, 225 min. at 0.49 MPa pressure provides an equivalent wood swelling compared to the conventional procedure, which can make faster the wood dimensional stability evaluation according to the ABNT NBR 7190 (ABNT, 1997).
木材的尺寸稳定性可以根据ABNT NBR 7190 (associa o Brasileira de Normas t cnicas [ABNT]， 1997)，通过测量0%和FSP含水率之间的总膨胀率来确定。由含水率变化引起的木材尺寸变化必须影响结构元件和与木结构的连接。根据巴西木材样品饱和规范，木材膨胀过程可能需要一个多月的时间，但使用高压灭菌器设备可能会加速这一活动，使尺寸稳定性的测定更容易。本文旨在研究使用高压灭菌器装置加速木材膨胀活性的可能性，考虑到巴西十三种商业木材的巴西代码。对比加速过程(第4阶段- 225分钟，压力为0.49 MPa)和木材膨胀的常规过程，p值为0.0730，组间平均差异约为1.1307%(95%置信水平为-0.0541至2.3156)。结果表明，与常规方法相比，在0.49 MPa压力下225分钟可获得等效的木材膨胀，可根据ABNT NBR 7190 (ABNT, 1997)更快地进行木材尺寸稳定性评估。
{"title":"Accelerated swelling of wood for rapid dimensional stability","authors":"Tiago Hendrigo de Almeida, F. Icimoto, Diego Henrique Almeida, V. Aquino, A. Christoforo, F. Lahr","doi":"10.4025/actascitechnol.v45i1.60595","DOIUrl":"https://doi.org/10.4025/actascitechnol.v45i1.60595","url":null,"abstract":"Dimensional stability of wood can be determined by measuring the total swelling percentage between 0% and FSP moisture content according to the ABNT NBR 7190 (Associação Brasileira de Normas Técnicas [ABNT], 1997). Wood dimensional variation by the moisture content modifications must influence both structural elements and connections into timber structures. The wood swelling procedure according to the Brazilian code for saturation of wood samples can take more than a month, but the use of autoclave devices may accelerate this activity, making easier the dimensional stability determination. This paper aims to investigate the possibility of accelerating the wood swelling activity using an autoclave device, considering the Brazilian code for thirteen Brazilian commercial wood species. Contrast test for comparison between accelerated process (Stage 4 – 225 min. at 0.49 MPa pressure) and the conventional procedure for wood swelling resulted in p-value equal to 0.0730 and the average difference between groups about 1.1307% (varying between -0.0541 and 2.3156 with 95% confidence level). According to results, 225 min. at 0.49 MPa pressure provides an equivalent wood swelling compared to the conventional procedure, which can make faster the wood dimensional stability evaluation according to the ABNT NBR 7190 (ABNT, 1997).","PeriodicalId":7140,"journal":{"name":"Acta Scientiarum-technology","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77027849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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