Influence of Alkali Treatment and Maleated Polypropylene (MAPP) Compatibilizer on the Dry-Sliding Wear and Frictional Behavior of Borassus Fruit Fine Fiber (BFF)/Polypropylene (PP) Polymer Composites for Various Engineering Applications

Tribological properties of the novel Borassus fruit fine fiber- (BFF-) reinforced polypropylene (PP) composites with respect to fiber matrix surface modifications have been described. Composites were fabricated by an injection molding process using Borassus fruit fine fiber (BFF) of 5 wt.% as reinforcement and polypropylene (PP) as a matrix component. Fibers were treated with alkali (T) to remove the residual lignin (if present) and to enhance the interfacial adhesion between the fiber/matrix interface. Alkali treatment reveals additional reactive functional groups here on the surface of the Borassus fiber, allowing effective interaction bonding with the polypropylene matrix. Borassus fibers are primarily treated with an alkali solution to extract weaker unstructured amorphous constituents so that the fibers retain crystallized components, thereby strengthening the fiber’s strength. A 5 wt.% of maleated polypropylene (MAPP) was used as a compatibilizer to improve the interfacial adhesion between fiber and the polymer matrix. The wear and frictional behavior of BFF/PP composites with respect to the modifications were evaluated by steel counterface utilizing pin-on-disc test contraption under dry-sliding conditions. The sliding velocity, applied load, and sliding distance were maintained as 2.198 m/s, 9.81–29.43 N, and 4000 m, respectively. The results demonstrate that the reinforcement of BFF to polypropylene matrix and the modifications improved the wear properties of the neat polymer matrix. Findings concluded that the abrasive wear resistance of T + PP + MAPP composite showed better interfacial adhesion and bonding, thus resulting in better tribological performance as compared to the other three compositions under different loading conditions. The effective substantial improvement of the coefficient of friction has been observed in alkali-treated fiber and polypropylene matrix with MAPP compatibilizer (T + PP + MAPP) composites due to the presence of MAPP compatibilizer and alkali-treated fibers. The frictional coefficient of T + PP + MAPP possesses better interfacial bonding strength upon NaOH treatment, and coupling agent, which results in enhancement of effective contact surface area and good surface friction characteristics, has been observed under different loading conditions. The fracture mechanism of worn-out portions of BFF/PP composites was studied using high-resolution scanning electron microscopy to analyze various imperfections like debonding, splits, fiber cracks, and wreckage or fragments formation.

Elastic melt-blown nonwoven fabrication of styrene‐ethylene/butylene‐styrene copolymer and polypropylene blends: a study of morphology and properties

Fabrics produced by the melt-blown nonwoven process have the advantage over competing materials of possessing an ultrafine fibrous and porous structure. However, their brittleness and poor toughness restrict their wider application. There is increasing demand for nonwovens that have high stretchability and elasticity while maintaining a melt-blown structure. In this study, polypropylene (PP) and styrene‐ethylene/butylene‐styrene copolymer (SEBS) were blended at different ratios and subsequently used in the melt-blowing process. The morphology of the blends displayed a co-continuous structure when the ratio of SEBS to PP in blends was similar. Furthermore, it was found that all the blends had good spinnability from the melt-blowing process during rheological and thermal properties tests. All the elastic melt-blown nonwovens fabricated in this research had elongations higher than 400% and elastic recoveries higher than 50%, which was indicative of good elasticity. Meanwhile, the nonwovens maintained fine fiber diameters and good filtration properties, in keeping with traditional melt-blown nonwovens.

Development Of Feeding Norms for Medium-Fiber and Fine-Fiber Cotton Varieties

In the Strategy of Agricultural Development of the Republic of Uzbekistan for 2020-2030, the President of the Republic of Uzbekistan identified the development of the production system of research, educational and consulting services in agriculture as a priority and developed a roadmap for its implementation.

Neuropatia de fibras finas na doença de Wilson: revisão de literatura / Small fiber neuropathy in Wilson's disease: literature review

Introdução: A neuropatia periférica é um distúrbio neurológico bastante comum e vem aumentando sua prevalência devido ao processo de envelhecimento da população e aumento de comorbidades como diabetes e obesidade. A neuropatia periférica de fibras finas (NFF) é considerada uma síndrome que apresenta manifestações sensitivas isoladas, ou a combinação de manifestações sensitivas e autonômicas. A doença de Wilson (DW) é um transtorno autossômico recessivo causado por deficiência na metabolização do cobre decorrente de mutações no gene ATP7B. Entre as alterações neurológicas apresentadas pelos pacientes com DW está a neuropatia periférica. Objetivo: Revisar a literatura acerca da neuropatia de fibras finas na Doença de Wilson aumentando a compreensão dessa disfunção sobre suas causas e tipos de abordagens apresentadas na literatura. Métodos: Foi realizada uma revisão bibliográfica a partir do levantamento de dados presente nas bases de dados Scielo e PUBMED no período de janeiro a junho de 2021, utilizando os descritores: “Small Fiber Neuropathy”, “Wilson’s Disease”, “Peripheral Neuropathy". Resultados: Foram selecionados 29 artigos, cujos originais foram utilizados para composição deste estudo. Para melhor compreensão, os resultados encontrados no levantamento bibliográfico foram divididos em tópicos. Dos 29 artigos recrutados 15 foram excluídos, pois apresentavam outras doenças de base que pudessem justificar a presença de neuropatia além da doença de Wilson. Dos 14 artigos incluídos na pesquisa: 3 descreveram a presença de neuropatia de fibras finas na DW, 4 artigos destacaram a presença de leve polineuropatia sensitivo motora axonal na DW, 7 artigos mostraram evidência de neuropatia autonômica, sendo 2 com disfunção predominantemente simpática e 1 parassimpática. Conclusão: Neuropatia de fibras finas permanece como um diagnóstico desafiador na literatura, podendo estar presente em formas leves, mesmo em doenças com envolvimento predominante do SNC. Na DW também há relatos desse acometimento neurológico periférico, com predomínio de envolvimento de fibras finas autonômicas de repercussões ainda não completamente compreendidas. A compreensão dessa disfunção ainda não está totalmente esclarecida e ainda há muitas coisas a serem compreendidas sobre a doença de Wilson, portanto faz-se necessário mais estudo sobre essa temática uma vez que ainda é escasso na literatura estudos que abordem esse assunto mesmo havendo aumento do número de casos diagnosticados com doença de Wilson e que apresentam queixas sensitivas associadas. Palavras chave: Neuropatia de fibras finas, Doença de Wilson, Doenças do sistema nervoso periférico, Neuropatias periféricas Abstract Introduction: Peripheral neuropathy is a very common neurological disorder and its prevalence is increasing due to the aging process of the population and the increase in comorbidities such as diabetes and obesity. Fine fiber peripheral neuropathy (NFF) is considered a syndrome that presents isolated sensory manifestations, or a combination of sensory and autonomic manifestations. Wilson's disease (WD) is an autosomal recessive disorder caused by impaired copper metabolism due to mutations in the ATP7B gene. Among the neurological alterations presented by patients with WD is peripheral neuropathy. Objective: To review the literature about thin fiber neuropathy in Wilson's Disease, increasing the understanding of this dysfunction about its causes and types of approaches presented in the literature. Methods: A literature review was carried out based on the data survey present in the Scielo and PUBMED databases from January to June 2021, using the descriptors: "Small Fiber Neuropathy", "Wilson's Disease", "Peripheral Neuropathy". Results: 29 articles were selected, whose For a better understanding, the results found in the literature review were divided into topics.From 29 recruited articles, 15 were excluded, as they had other underlying diseases that could justify the presence of neuropathy in addition to Wilson's disease. Of the 14 articles included in the research: 3 described the presence of fine fiber neuropathy in WD, 4 articles highlighted the presence of mild axonal sensory motor polyneuropathy in WD, 7 articles showed evidence of autonomic neuropathy, 2 with predominantly sympathetic dysfunction and 1 parasympathetic. Conclusion: Fine fiber neuropathy remains a challenging diagnosis in the field. and may be present in mild forms, even in diseases with predominant involvement of the CNS. In WD there are also reports of this peripheral neurological involvement, with a predominance of involvement of thin autonomic fibers with repercussions that are not yet completely understood. The understanding of this dysfunction is still not fully clarified and there are still many things to be understood about Wilson's disease, so further study on this topic is necessary since studies addressing this issue are still scarce in the literature, even with an increase in number of cases diagnosed with Wilson's disease and presenting associated sensory complaints. Keywords: Small fiber neuropathy, Wilson disease, Peripheral nervous system diseases, Peripheral neuropathies

Influence of the circumferential speed of the spiked cylinders on the efficiency of cleaning raw cotton

The article examines the dependence of the speed of rotation of the spiked cylinder of the machine for cleaning the raw cotton from fine impurities on the cleaning efficiency of the machine by different varieties. In addition, the article plotted the speed of rotation of the spiked cylinder as a function of mechanical damage to the seed. Based on experimental studies, the operation of the machine for cleaning cotton raw materials from fine contaminants is based. Experimental studies on raw cotton of medium and fine fiber varieties of hand and machine cotton picking on the value of constant and differentiated peripheral speeds of cylinders fully confirmed the theoretical conclusions. It is recommended to use a differentiated high-speed mode of rotation of the spiked cylinders: When cleaning medium-staple cotton - 10:11:12 m/sec, when cleaning fine-stapled cotton - 9:10:11 m/sec.

Enzymatic Synthesis of Cellulose in Space: Gravity Is a Crucial Factor for Building Cellulose II Gel Structure

We previously reported in vitro synthesis of highly ordered crystalline cellulose II by reverse reaction of cellodextrin phosphorylase from the cellulolytic bacterium Clostridium ( Hungateiclostridium ) thermocellum ( Ct CDP), but the formation mechanism of the cellulose crystals and highly ordered structure has long been unclear. Considering the specific density of cellulose versus water, the formation of crystalline and highly ordered structure in an aqueous solution should be affected by gravity. Thus, we synthesized cellulose with Ct CDP at the International Space Station, where sedimentation and convection due to gravity are negligible. Optical microscopic observation suggested that cellulose in space has a gel-like appearance without apparent aggregation, in contrast to cellulose synthesized on the ground. Small-angle Xray scattering (SAXS) and wide-angle X-ray scattering (WAXS) indicated that cellulose synthesized in space has a more uniform particle distribution in the ~100 nm scale region than cellulose synthesized on the ground. Scanning electron microscopy (SEM) showed that both celluloses have a micrometer scale network structure, whereas a fine fiber network was constructed only under microgravity. These results indicate that gravity plays a role in cellulose II crystal sedimentation and the building of network structure, and synthesis in space could play a role in the design of unique materials.

Piezoelectric Properties of PVDF-Zn2GeO4 Fine Fiber Mats

The current paper presents the development and characterization of polyvinylidene fluoride (PVDF)-Zn2GeO4 (ZGO) fine fiber mats. ZGO nanorods (NRs) were synthesized using a hydrothermal method and incorporated in a PVDF solution to produce fine fiber mats. The fiber mats were prepared by varying the concentration of ZGO NRs (1.25–10 wt %) using the Forcespinning® method. The developed mats showed long, continuous, and homogeneous fibers, with average fiber diameters varying from 0.7 to 1 µm, depending on the ZGO concentration. X-ray diffraction spectra depicted a positive correlation among concentration of ZGO NRs and strengthening of the beta phase within the PVDF fibers. The composite system containing 1.25 wt % of ZGO displayed the highest piezoelectric response of 172 V. This fine fiber composite system has promising potential applications for energy harvesting and the powering of wearable and portable electronics.

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.