scholarly journals Effects of non-solvents and electrolytes on the formation and properties of cellulose I filaments

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ling Wang ◽  
Meri J. Lundahl ◽  
Luiz G. Greca ◽  
Anastassios C. Papageorgiou ◽  
Maryam Borghei ◽  
...  

Abstract Coagulation is a critical process in the assembly of cellulose nanofibrils into filaments by wet spinning; however, so far, the role of the coagulation solvent has not been systematically elucidated in this context. This work considers organic non-solvents (ethanol, acetone) and aqueous electrolyte solutions (NaCl(aq), HCl(aq), CaCl2(aq)) for the coagulation of negatively charged cellulose nanofibrils via wet spinning. The associated mechanisms of coagulation with such non-solvents resulted in different spinnability, coagulation and drying time. The properties of the achieved filaments varied depending strongly on the coagulant used: filaments obtained from electrolytes (using Ca2+ and H+ as counterions) demonstrated better water/moisture stability and thermomechanical properties. In contrast, the filaments formed from organic non-solvents (with Na+ as counterions) showed high moisture sorption and low hornification when subjected to cycles of high and low humidity (dynamic vapor sorption experiments) and swelled extensively upon immersion in water. Our observations highlight the critical role of counter-ions and non-solvents in filament formation and performance. Some of the fundamental aspects are further revealed by using quartz crystal microgravimetry with model films of nanocelluloses subjected to the respective solvent exchange.

2020 ◽  
Vol 6 (4) ◽  
pp. 155
Author(s):  
Nagwan AlQershi ◽  
Sany Sanuri Mohd Mokhtar ◽  
Zakaria Bin Abas

Customer Relationship Management (CRM) is more than an information tool and plays a critical role in small and medium enterprises (SMEs). The present study explored the moderating effect of relational capital (RC) on the relationship between CRM dimensions and the performance of 284 Yemeni manufacturing SMEs. Partial Least Squares-Structural Equation Modelling (PLS-SEM) was used to test the study’s hypotheses. Results indicate that only three of the CRM dimensions have a significant effect on performance. The moderating effects of relational capital on this relationship were also examined and were found to be significant for only two CRM dimensions: technology-based CRM and CRM organization. Key customer focus and CRM knowledge management had no effect. The findings of this study offer important insights for owners and managers of SMEs, researchers, and policymakers to further understand the effects of relational capital and CRM on SMEs’ performance. SMEs should be encouraged to develop their CRM and relational capital to improve their performance.


2021 ◽  
Author(s):  
Antonio Cunha

In De Architectura, Vitruvius makes note of three criteria that define architecture; firmitas (durability), utilitas (function) and venustas (delight). These ideals form the philosophical foundations of virtually all modern architectural theory. With the advent of computational tools, many advocates, commonly armed with staggering statistics, frame these methods as a means of increasing efficiency in collaboration, construction and performance - muting the critical role of a sentient designer in architectural discourse of the digital age. The role of the parti has eroded in favour of computational strategies that constrain utilitas to a measure of quantifiable “fitness”. The research herein unveils and reflects upon the mutating role of the architect in computational design, advocating for the importance of qualitative reasoning in a parametric process. Where the current paradigm is negligent, the project aims to illuminate and reinforce the role of today’s sentient designer nested in a cultural milieu of computation.


2021 ◽  
Author(s):  
Antonio Cunha

In De Architectura, Vitruvius makes note of three criteria that define architecture; firmitas (durability), utilitas (function) and venustas (delight). These ideals form the philosophical foundations of virtually all modern architectural theory. With the advent of computational tools, many advocates, commonly armed with staggering statistics, frame these methods as a means of increasing efficiency in collaboration, construction and performance - muting the critical role of a sentient designer in architectural discourse of the digital age. The role of the parti has eroded in favour of computational strategies that constrain utilitas to a measure of quantifiable “fitness”. The research herein unveils and reflects upon the mutating role of the architect in computational design, advocating for the importance of qualitative reasoning in a parametric process. Where the current paradigm is negligent, the project aims to illuminate and reinforce the role of today’s sentient designer nested in a cultural milieu of computation.


2012 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Rina Herani ◽  
Otto Andersen

Small and medium enterprises (SMEs) have a critical role in economic growth in Indonesia and become the backbone for job creation, poverty alleviation, and safeguard during the crisis. However, they are highly exposed to uncertain environments. The present study aimed to investigate the influence of SMEs’ entrepreneurial orientation on business performance when uncertain environments exist. A total of 152 Indonesian SMEs were studied in order to assess this relationship. Moderated regression analysis is performed as the main statistical procedures to analyse the moderating role of environmental uncertainty on the influence of entrepreneurial orientation on business performance. Surprisingly, the result of the present study did not confirm the previous predominant studies which found that entrepreneurialorientation dimensions are positively associated with business performance in growing in an uncertain environment. Indonesian entrepreneurs were reluctant to innovate, be proactive, and take risks when an uncertain environment exists. The present study was an endeavour to provide better insight in explaining the inconsistent and ambiguous findings from existing literature.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2177
Author(s):  
Belinda Ruettimann ◽  
Claudio Perret ◽  
Jill A. Parnell ◽  
Joelle Leonie Flueck

The Paralympic movement is growing in popularity, resulting in increased numbers of athletes with a spinal cord injury (SCI) competing in various sport disciplines. Athletes with an SCI require specialized recommendations to promote health and to maximize performance, as evidenced by their metabolic and physiological adaptations. Nutrition is a key factor for optimal performance; however, scientifically supported nutritional recommendations are limited. This review summarizes the current knowledge regarding the importance of carbohydrates (CHO) for health and performance in athletes with an SCI. Factors possibly affecting CHO needs, such as muscle atrophy, reduced energy expenditure, and secondary complications are analyzed comprehensively. Furthermore, a model calculation for CHO requirements during an endurance event is provided. Along with assessing the effectiveness of CHO supplementation in the athletic population with SCI, the evaluation of their CHO intake from the available research supplies background to current practices. Finally, future directions are identified. In conclusion, the direct transfer of CHO guidelines from able-bodied (AB) athletes to athletes with an SCI does not seem to be reasonable. Based on the critical role of CHOs in exercise performance, establishing recommendations for athletes with an SCI should be the overall objective for prospective research.


2007 ◽  
Vol 3 (2) ◽  
Author(s):  
Kerry McDonald

If New Zealand is to be able to arrest its steadily deteriorating economic performance and position compared with many other countries, particularly Australia, one thing it must do urgently is to radically improve the quality of leadership and performance within its central government agencies. Substantial economic and social benefits will flow from such remedial action, but high costs will be paid if it is not taken.


1999 ◽  
Vol 6 (4) ◽  
pp. 347-362 ◽  
Author(s):  
Frank W. Ohl ◽  
Wolfram Wetzel ◽  
Thomas Wagner ◽  
Alexander Rech ◽  
Henning Scheich

This study examines the role of auditory cortex in the Mongolian gerbil in differential conditioning to pure tones and to linearly frequency-modulated (FM) tones by analyzing the effects of bilateral auditory cortex ablation. Learning behavior and performance were studied in a GO/NO-GO task aiming at avoidance of a mild foot shock by crossing a hurdle in a two-way shuttle box. Hurdle crossing as the conditioned response to the reinforced stimulus (CR+), as false alarm in response to the unreinforced stimulus (CR−), intertrial activity, and reaction times were monitored. The analysis revealed no effects of lesion on pure tone discrimination but impairment of FM tone discrimination. In the latter case lesion effects were dependent on timing of lesion relative to FM tone discrimination training. Lesions before training in naive animals led to a reduced CR+ rate and had no effect on CR− rate. Lesions in pretrained animals led to an increased CR− rate without effects on the CR+ rate. The results suggest that auditory cortex plays a more critical role in discrimination of FM tones than in discrimination of pure tones. The different lesion effects on FM tone discrimination before and after training are compatible with both the hypothesis of a purely sensory deficit in FM tone processing and the hypothesis of a differential involvement of auditory cortex in acquisition and retention, respectively.


2020 ◽  
Vol 32 (3) ◽  
pp. 605-612
Author(s):  
Jieun Lee ◽  
Genya Abe ◽  
Kenji Sato ◽  
Makoto Itoh ◽  
◽  
...  

With the successful introduction of advanced driver assistance systems, vehicles with driving automation technologies have begun to be released onto the market. Because the role of human drivers during automated driving may be different from the role of drivers with assistance systems, it is important to determine how general users consider such new technologies. The current study has attempted to consider driver trust, which plays a critical role in forming users’ technology acceptance. In a driving simulator experiment, the demographic information of 56 drivers (50% female, 64% student, and 53% daily driver) was analyzed with respect to Lee and Moray’s three dimensions of trust: purpose, process, and performance. The statistical results revealed that female drivers were more likely to rate higher levels of trust than males, and non-student drivers exhibited higher levels of trust than student drivers. However, no driving frequency-related difference was observed. The driver ratings of each trust dimension were neutral to moderate, but purpose-related trust was lower than process- and performance-related trust. Additionally, student drivers exhibited a tendency to distrust automation compared to non-student drivers. The findings present a potential perspective of driver acceptability of current automated vehicles.


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