Improvement of bagasse fiber–cement composites by addition of bacterial nanocellulose: an inverse gas chromatography study

The design of green fiber-reinforced nanocomposites with enhanced properties and dura bility has attracted attention from scientists. The present study aims to investigate the potential of bacterial nanocellulose (BNC) as a green additive for fiber–cement composites. Inverse gas chromatography (IGC) was used to evaluate the influence of incorpo ration of BNC as powder or gel, or coated onto the bagasse fibers, on the fiber–cement composite (FCC) surface. The results indicated that BNC incorporation made the FCC surface more reactive, increasing the dispersive component of the surface energy. The most relevant effects were found for BNC incorporation as gel or coated on the fibers. Incorporation of BNC as gel resulted in a predominantly organic FCC surface with substantial decreased surface basicity (Ka/Kb ratio from 2.88 to 5.75). IGC also showed that FCC with BNC incorporated as gel was more susceptible to hydration. However, BNC coated on fibers prevented fiber mineralization, increasing the inorganic materi als at the surface, which caused an increase in the surface basicity (Ka/Kb ratio decrease to 2.00). These promising results could contribute to development of a new generation of green hybrid composites. The IGC technique enabled understanding of the physicochem ical changes that occur on deliberate introduction of nanosized bacterial cellulose into fiber–cement composites.info:eu-repo/semantics/publishedVersio

In situ biosynthesis of bacterial nanocellulose-CaCO3 hybrid bionanocomposite: one-step process

In this work, a simple and green route to the synthesis of the bacterial nanocellulose-calcium carbonate (BNC/CaCO3) hybrid bionanocomposites using one-step in situ biosynthesis was studied. The CaCO3 was incorporated in the bacterial nanocellulose structure during the cellulose biosynthesis by Gluconacetobacter xylinus PTCC 1734 bacteria. Hestrin-Schramm (HS) and Zhou (Z) culture media were used to the hybrid bionanocomposites production and the effect of ethanol addition was investigated. Attenuated total reflection Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, inverse gas chromatography and thermogravimetric analysis were used to characterize the samples. The experimental results demonstrated that the ethanol and culture medium play an important role in the BNC/CaCO3 hybrid bionanocomposites production, structure and properties. The BNC/CaCO3 biosynthesized in Z culture medium revealed higher O/C ratio and amphoteric surface character, which justify the highest CaCO3 content incorporation. The CaCO3 was incorporated into the cellulosic matrix decreasing the bacterial nanocellulose crystallinity. This work reveals the high potential of in situ biosynthesis of BNC/CaCO3 hybrid bionanocomposites and opens a new way to the high value-added applications of bacterial nanocellulose.info:eu-repo/semantics/publishedVersio

Computer Games and Their Impact on Creativity of Primary Level Students in Tehran

Creativity is about being sensitive to dilemmas, losses, problems, and existing errors, making propositions about and examining such issues, which finally leads to innovative findings. On the other hand, it seems that games are important in this process; since they can improve creativity of the individuals. Thus, this research pays attention to the question that whether computer games affect creativity of students at primary level in schools or not? Moreover, in this study, students of 3 main districts of Tehran municipality were studied. Based on the available data of the ministry, there were 51740 students studying in these three districts. Thus, 381 students were randomly selected as the research sample. Findings revealed that all computer games, i.e. puzzle, intellectual, and enigma, affect creativity of students at primary level in schools to different extents.

Agro-industrial byproducts as modification enhancers of the bacterial cellulose biofilm surface properties: an inverse chromatography approach

Bacterial cellulose (BC) has remarkable and excellent properties. However, the high-cost production and the use of chemicals for BC modification make its application unattractive. A simple approach to modify the properties of BC during biosynthesis, by using alternative low-cost carbon sources from agro-industrial byproducts, was studied. The carbon source (date syrup, mannitol, sucrose, food-grade sucrose, and glucose) significantly changed the BC network morphology and structure. Date syrup source induces the highest modifications in the surface properties of BC: smaller area (SBET = 4.04 m2 /g), higher hydrophobic (γd s = 45.79 mJ/ m2 ) and basic character (Kb/Ka = 1.10), at 25 ºC. Food-grade sucrose source resulted in the lowest yield of BC production (37% less), however caused an increase in the BC network reticulation and a high crystalline structure (IC = 82.3%). This sustainable and simple methodology presents a low-cost and efficient approach allowing the modulation of the surface properties of BC.info:eu-repo/semantics/publishedVersio

Identification and ranking of the marketing mix of services in the banking industry, using DEMATEL

In the current competitive market, identifying the major factors affecting the behavior of customers considered very important. Every organization needs to know, investing on which factor results in higher efficiency. Banks face a complex world of competition thus; they need to identify these factors. These factors differ from the factors in manufacturing industry. Therefore, banks need to understand their own marketing mix factors and identify the most important ones. As a result, in this research after a literature review, the factors identified and then by using DEMATEL, a ranking has done and the most important factor introduced. According to the results, price and staff have the most impact

The Effect of Use of Text Messaging on Soccer Fans’ Behavior (The Case of Iranian Professional League-Persian Gulf League)

The purpose of study is to identify the effect of mobile marketing on the Top Iranian Football Clubs fans’ behavior in 2019-2020 season. The statistical population are the spectators who had signed up in the fan online system and had watched one of games in the stadium. As an accurate number of the statistical population could not be determined, a statistical population of 396 was considered based on the Morgan’s table. In this study, the author collects data on the behavioral loyalty, attitudinal loyalty, and mobile marketing using survey. The cross-sectional regression estimation used to analyze the data. The findings of this study indicate that there is a positive and meaningful relationship between mobile marketing and fans’ behavioral loyalty in Iranian soccer Pro league. Also, there is a positive and meaningful correlation between mobile marketing and the attitudinal loyalty of the soccer Club fans. This study has implications for managers and sponsors of soccer clubs

Conductive bacterial cellulose-polyaniline blends: Influence of the matrix and synthesis conditions

Bacterial cellulose/polyaniline (BC/PANi) blends present a great potential for several applications. The current study evaluates the impact of using different BC matrixes (drained, freeze-dried and regenerated) and different synthesis conditions (in situ and ex situ) to improve the inherent properties of BC, which were monitored through FTIR-ATR, EDX, XRD, SEM, AFM, swelling, contact angle measurement and IGC. The employment of in situ polymerization onto drained BC presented the most conductive membrane (1.4 × 10-1 S/cm). The crystallinity, swelling capacity, surface energy and acid/base behavior of the BC membranes is substantially modified upon PANi incorporation, being dependent on the BC matrix used, being the freeze-dried BC blends the ones with highest crystallinity (up to 54%), swelling capacity (up to 414%) and surface energy (up to 75.0 mJ/m2). Hence, this work evidenced that the final properties of the BC/PANi blends are greatly influenced by both the BC matrixes and synthesis methods employed.info:eu-repo/semantics/publishedVersio

Poly(glycidyl methacrylate)/bacterial cellulose nanocomposites: preparation, characterization and post-modification

Nanocomposites composed of poly(glycidyl methacrylate) (PGMA) and bacterial cellulose (BC) were prepared by the in-situ free radical polymerization of glycidyl methacrylate (GMA) inside the BC network. The resulting nanocomposites were characterized in terms of structure, morphology, water-uptake capacity, thermal stability and viscoelastic properties. The three-dimensional structure of BC endowed the nanocomposites with good thermal stability (up to 270 °C) and viscoelastic properties (minimum storage modulus = 80 MPa at 200 °C). In addition, the water-uptake and crystallinity decreased with the increasing content of the hydrophobic and amorphous PGMA matrix. These nanocomposites were then submitted to post-modification via acid-catalysed hydrolysis to convert the hydrophobic PGMA into the hydrophilic poly(glyceryl methacrylate) (PGOHMA) counterpart, which increased the hydrophilicity of the nanocomposites and consequently improved their water-uptake capacity. Besides, the post-modified nanocomposites maintained a good thermal stability (up to 250 °C), viscoelastic properties (minimum storage modulus = 171 MPa at 200 °C) and porous structure. In view of these results, the PGMA/BC nanocomposites can be used as functional hydrophobic nanocomposites for post-modification reactions, whereas the PGOHMA/BC nanocomposites might have potential for biomedical applications requiring hydrophilic, swellable and biocompatible materials.info:eu-repo/semantics/publishedVersio

Optimization and characterization of bacterial nanocellulose produced by Komagataeibacter rhaeticus K3

Supplementary material associated with this article can be found, in the online version, at doi:10.1016/j.carpta.2020.100022.In this work, a novel Bacterial NanoCellulose (BNC) producing strain, from Kombucha tea, was isolated and characterized. Based on 16S rRNA analysis the strain was identified as Komagataeibacter rhaeticus. Under static culture, K. rhaeticus K3 produces membranes with a relaxed structure, as observed by Scanning Electron Microscopy (SEM). The addition of 2% (v/v) ethanol to the culture media enhanced by more than 3-fold of the BNC yield. Response surface methodology (RSM) was performed with K. rhaeticus K3, using a new low cost Eucalyptus Biomass Hydrolysate (EBH). The maximum experimental BNC yield was of 5.46 g/L, obtained with the following composition: 31.4 g/L of EBH; 2.89% (v/v) of ethanol and 10.8 g/L of Yeast extract/peptone. Texture Profile Analysis (TPA) of BNC membranes obtained using Hestrin-Schramm culture (HS) medium and optimized medium from EBH showed that membranes from EBH had higher resistance to compression, higher cohesiveness and resilience.This study was supported with the funds of Institute of Technical Biochemistry, Lodz University of Technology, Lodz, Poland and from The Navigator Company through the I&D no. 21874, “Inpactus-– Produtos e Tecnologias Inovadores a partir do Eucalipto”, funded through the Fundo Europeu de Desenvolvimento Regional (FEDER) and the Programa Operacional Competitividade e Internacionalização (POCI) is greatly acknowledged. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.” The authors also acknowledge the financial support of the FCT (ESF) through the grant given to Francisco A.G. Soares da Silva (SFRH/BD/146375/2019).info:eu-repo/semantics/publishedVersio