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1 – 10 of 15Nausheen Bibi Jaffur, Pratima Jeetah and Gopalakrishnan Kumar
The increasing accumulation of synthetic plastic waste in oceans and landfills, along with the depletion of non-renewable fossil-based resources, has sparked environmental…
Abstract
The increasing accumulation of synthetic plastic waste in oceans and landfills, along with the depletion of non-renewable fossil-based resources, has sparked environmental concerns and prompted the search for environmentally friendly alternatives. Biodegradable plastics derived from lignocellulosic materials are emerging as substitutes for synthetic plastics, offering significant potential to reduce landfill stress and minimise environmental impacts. This study highlights a sustainable and cost-effective solution by utilising agricultural residues and invasive plant materials as carbon substrates for the production of biopolymers, particularly polyhydroxybutyrate (PHB), through microbiological processes. Locally sourced residual materials were preferred to reduce transportation costs and ensure accessibility. The selection of suitable residue streams was based on various criteria, including strength properties, cellulose content, low ash and lignin content, affordability, non-toxicity, biocompatibility, shelf-life, mechanical and physical properties, short maturation period, antibacterial properties and compatibility with global food security. Life cycle assessments confirm that PHB dramatically lowers CO2 emissions compared to traditional plastics, while the growing use of lignocellulosic biomass in biopolymeric applications offers renewable and readily available resources. Governments worldwide are increasingly inclined to develop comprehensive bioeconomy policies and specialised bioplastics initiatives, driven by customer acceptability and the rising demand for environmentally friendly solutions. The implications of climate change, price volatility in fossil materials, and the imperative to reduce dependence on fossil resources further contribute to the desirability of biopolymers. The study involves fermentation, turbidity measurements, extraction and purification of PHB, and the manufacturing and testing of composite biopolymers using various physical, mechanical and chemical tests.
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Millets are ancient grains, following wheat, that have been a fundamental source of human sustenance. These are nutrient-rich small-seeded grains that have gained prominence and…
Abstract
Purpose
Millets are ancient grains, following wheat, that have been a fundamental source of human sustenance. These are nutrient-rich small-seeded grains that have gained prominence and admiration globally due to their super resilience in diverse climates and significant nutritional benefits. As millets are renowned for their nutritional richness, the demand for millet-based products increases. Hence, this paper aims in identifying the growing need for innovative processing techniques that not only preserve their nutritional content but also extend their shelf life.
Design/methodology/approach
In traditional times, heat was the only means of cooking and processing of the foods, but the amount of damage they used to cause to the sensorial and nutritional properties was huge. Millets’ sensitivity toward heat poses a challenge, as their composition is susceptible to disruption during various heat treatments and manufacturing processes. To cater to this drawback while ensuring the prolonged shelf life and nutrient preservation, various innovative approaches such as cold plasma, infrared technology and high hydrostatic pressure (HPP) processing are being widely used. These new methodologies aim on inactivating the microorganisms that have been developed within the food, providing the unprocessed, raw and natural form of nutrients in food products.
Findings
Among these approaches, nonthermal technology has emerged as a key player that prioritizes brief treatment periods and avoids the use of high temperatures. Nonthermal techniques (cold plasma, infrared radiation, HPP processing, ultra-sonication and pulsed electric field) facilitate the conservation of millet’s nutritional integrity by minimizing the degradation of heat-sensitive nutrients like vitamins and antioxidants. Acknowledging the potential applications and processing efficiency of nonthermal techniques, the food industry has embarked on substantial investments in this technology. The present study provides an in-depth exploration of the array of nonthermal technologies used in the food industry and their effects on the physical and chemical composition of diverse millet varieties.
Originality/value
Nonthermal techniques, compared to conventional thermal methods, are environmentally sound processes that contribute to energy conservation. However, these conveniences are accompanied by challenges, and this review not only elucidates these challenges but also focuses on the future implications of nonthermal techniques.
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Pian Pu, Li Cheng, WHMS Samarathunga and Geoffrey Wall
Tour guides play a significant role in sustainable tourism development as leaders, mediators, resource managers and promoters of economic prosperity. This paper aims to show how…
Abstract
Purpose
Tour guides play a significant role in sustainable tourism development as leaders, mediators, resource managers and promoters of economic prosperity. This paper aims to show how local Tibetan tour guides practice sustainable tourism in their encounters with Western tourists.
Design/methodology/approach
The data consists primarily of 15 in-depth interviews with native Tibetan guides,Content analysis of the data were undertaken.
Findings
It was found that the guides adopt sustainable tourism practices based on their local religious wisdom and experiences as they try to establish harmonious host–guest relationships. Western clients also encourage guides to adopt more proenvironmental behaviors. The “hosts” live by Buddhist concepts such as samsara that are in line with concepts such as altruism and benevolence. Most “guests” are well-behaved and try to build sincere mutual relationships with local people. Host and guest cocreate value for local sustainable tourism practice.
Practical implications
Tour guides can practice sustainable tourism in a leadership role or as mediators, resource managers or promoters of economic prosperity. They also maintain a sincere and kind relationship with their guests that goes beyond the instrumental host–guest relationship and might help to cocreate value for local sustainable tourism practices.
Originality/value
Tour guides’ sustainable practices have been examined in the past based on their roles as leader, mediator, resource manager and promoter of economic prosperity. But researchers have seldom examined circumstances in which the tourists and tour guides were from different cultures. This paper addresses this gap.
目的
导游作为领导者、中介者、资源管理者和经济繁荣的促进者, 在旅游可持续发展中发挥着重要的作用。本文展示了藏族导游在与西方游客的接触中如何实践可持续旅游。
设计/方法/方法
深度访谈15个对当地藏族导游, 对收集的数据进行内容分析。
研究发现
导游基于本土的宗教智慧和经验, 尝试与建立更加和谐的主客关系时, 从而实现可持续旅游实践。西方客户也鼓励导游采取更环保的行为。“主人” 的生活遵循佛教轮回等观念, 提倡“利他”、“仁爱”。大多数“客人” 都行为得体, 试图与当地人建立真诚的相互关系。主客共同为当地可持续旅游实践创造价值。
实践意义
导游可以作为领导角色或中介、资源管理者或经济繁荣的促进者实践可持续旅游。他们还与客人保持真诚和友好的关系, 这超越了工具性的主客关系, 可能有助于共同为当地可持续旅游实践创造价值。
原创性/价值
在过去的研究中, 导游的可持续实践基于他们作为领导者、中间人、资源管理者和经济繁荣的促进者。但研究人员对游客和导游来自不同文化的情境缺少关注, 我们的研究试图解答这一问题。
Propósito
Los guías turísticos desempeñan un papel importante en el desarrollo del turismo sostenible como líderes, mediadores, administradores de recursos y promotores de la prosperidad económica. Este documento muestra, cómo los guías turísticos tibetanos locales practican el turismo sostenible en sus encuentros con turistas occidentales.
Diseño/metodología/enfoque
Los datos consisten principalmente en 15 entrevistas en profundidad con guías tibetanos nativos. Los datos fueron analizados mediante el método de análisis de contenido.
Hallazgos
Se encontró que, los guías adoptan prácticas de turismo sostenible basadas en su sabiduría y experiencias religiosas locales, mientras intentan establecer relaciones armoniosas entre el anfitrión y el huésped. Los clientes occidentales, también alientan a los guías a adoptar comportamientos más proambientales. Los “anfitriones”, viven según conceptos budistas, como el samsara, que están en línea con conceptos como el altruismo y la benevolencia. La mayoría de los “visitantes” se comportan bien y tratan de construir relaciones mutuas sinceras con la gente local. El anfitrión y el huesped, co-crean valor para la práctica local de turismo sostenible.
Implicaciones prácticas
Los guías turísticos pueden practicar el turismo sostenible en un papel de liderazgo o como mediadores, administradores de recursos o promotores de la prosperidad económica. También mantienen una relación sincera y amable con sus huéspedes que va más allá de la relación instrumental anfitrión-huésped y podría ayudar a co-crear valor para las prácticas locales de turismo sostenible.
Originalidad/valor
Las prácticas sostenibles de nuestra guía han sido examinadas en el pasado en función de sus roles como líder, mediador, gestor de recursos y promotor de la prosperidad económica. Pero los investigadores, rara vez han examinado las circunstancias en las que los turistas y los guías turísticos eran de diferentes culturas. Abordamos esta brecha.
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Yajun Chen, Zehuan Sui and Juan Du
This paper aims to focus on the research progress of intelligent self-healing anti-corrosion coatings in the aviation field in the past few years. The paper provides certain…
Abstract
Purpose
This paper aims to focus on the research progress of intelligent self-healing anti-corrosion coatings in the aviation field in the past few years. The paper provides certain literature review supports and development direction suggestions for future research on intelligent self-healing coatings in aviation.
Design/methodology/approach
This mini-review uses a systematic literature review process to provide a comprehensive and up-to-date review of intelligent self-healing anti-corrosion coatings that have been researched and applied in the field of aviation in recent years. In total, 64 articles published in journals in this field in the last few years were analysed in this paper.
Findings
The authors conclude that the incorporation of multiple external stimulus-response mechanisms makes the coatings smarter in addition to their original self-healing corrosion protection function. In the future, further research is still needed in the research and development of new coating materials, the synergistic release of multiple self-healing mechanisms, coating preparation technology and corrosion monitoring technology.
Originality/value
To the best of the authors’ knowledge, this is one of the few systematic literature reviews on intelligent self-healing anti-corrosion coatings in aviation. The authors provide a comprehensive overview of the topical issues of such coatings and present their views and opinions by discussing the opportunities and challenges that self-healing coatings will face in future development.
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Jiaxin Li, Zhiyuan Zhu, Zhiwei Li, Yonggang Zhao, Yun Lei, Xuping Su, Changjun Wu and Haoping Peng
Gallic acid is a substance that is widely found in nature. Initially, it was only used as a corrosion inhibitor to retard the rate of corrosion of metals. In recent years, with…
Abstract
Purpose
Gallic acid is a substance that is widely found in nature. Initially, it was only used as a corrosion inhibitor to retard the rate of corrosion of metals. In recent years, with intensive research by scholars, the modification of coatings containing gallic acid has become a hot topic in the field of metal protection. This study aims to summarize the various preparation methods of gallic acid and its research progress in corrosion inhibitors and coatings, as well as related studies using quantum chemical methods to assess the predicted corrosion inhibition effects and to systematically describe the prospects and current status of gallic acid applications in the field of metal corrosion inhibition and protection.
Design/methodology/approach
First, the various methods of preparation of gallic acid in industry are understood. Second, the corrosion inhibition principles and research progress of gallic acid as a metal corrosion inhibitor are presented. Then, the corrosion inhibition principles and research progress of gallic acid involved in the synthesis and modification of various rust conversion coatings, nano-coatings and organic resin coatings are described. After that, studies related to the evaluation and prediction of gallic acid corrosion inhibition on metals by quantum chemical methods are presented. Finally, new research ideas on gallic acid in the field of corrosion inhibition and protection of metals are summarized.
Findings
Gallic acid can be used as a corrosion inhibitor or coating in metal protection.
Research limitations/implications
There is a lack of research on the synergistic improvement of gallic acid and other substances.
Practical implications
The specific application of gallic acid in the field of metal protection was summarized, and the future research focus was put forward.
Originality/value
To the best of the authors’ knowledge, this paper systematically expounds on the research progress of gallic acid in the field of metal protection for the first time and provides new ideas and directions for future research.
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Marcelo Pereira Duarte and Fernando Manuel P.O. Carvalho
This study analyses configurations of national culture as boundary conditions of countries’ national systems of innovation (NSI). Drawing from the NSI approach, we argue that…
Abstract
Purpose
This study analyses configurations of national culture as boundary conditions of countries’ national systems of innovation (NSI). Drawing from the NSI approach, we argue that culture’s role is that of a contingency factor shaping the relationship between investments in innovation and national innovation outputs.
Design/methodology/approach
We assessed the moderation effect of national culture through a systematic, two-stage approach using fuzzy-set Qualitative Comparative Analysis (fsQCA), which allows the analysis of changes induced by the moderator variables. Analyses were conducted with a diverse sample of 61 countries over a period spanning 12 years, from 2011 to 2022.
Findings
Findings reveal that investments in innovation, but not individual cultural dimensions, is a necessary condition for high innovation outputs. Furthermore, several configurations of cultural dimensions were identified as moderators of the relationship between investments in innovation and innovation outputs.
Originality/value
This study provides insights into cross-national innovation research by exposing the role of cultural configurations, rather than just individual cultural dimensions, as boundary conditions involved in the achievement of high levels of innovation.
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Upendra S. Gupta, Sudhir Tiwari and Uttam Sharma
The incompatibility of natural fibers with polymer matrices is one of the key obstacles restricting their use in polymer composites. The interfacial connection between the fibers…
Abstract
Purpose
The incompatibility of natural fibers with polymer matrices is one of the key obstacles restricting their use in polymer composites. The interfacial connection between the fibers and the matrix was weak resulting in a lack of mechanical properties in the composites. Chemical treatments are often used to change the surface features of plant fibers, yet these treatments have significant drawbacks such as using substantial amounts of liquid and chemicals. Plasma modification has recently become very popular as a viable option as it is easy, dry, ecologically friendly, time-saving and reduces energy consumption. This paper aims to explore plasma treatment for improving the surface adhesion characteristics of sisal fibers (SFs) without compromising the mechanical attributes of the fiber.
Design/methodology/approach
A cold glow discharge plasma (CGDP) modification using N2 gas at varied power densities of 80 W and 120 W for 0.5 h was conducted to improve the surface morphology and interfacial compatibility of SF. The mechanical characteristics of unmodified and CGDP-modified SF-reinforced epoxy composite (SFREC) were examined as per the American Society for Testing and Materials standards.
Findings
The cold glow discharge nitrogen plasma treatment of SF at 120 W (30 min) enhanced the SFREC by nearly 122.75% superior interlaminar shear strength, 71.09% greater flexural strength, 84.22% higher tensile strength and 109.74% higher elongation. The combination of improved surface roughness and more effective lignocellulosic exposure has been responsible for the increase in the mechanical characteristics of treated composites. The development of hydrophobicity in the SF had been induced by CGDP N2 modification and enhanced the size of crystals and crystalline structure by removing some unwanted constituents of the SF and etching the smooth lignin-rich surface layer of the SF particularly revealed via FTIR and XRD.
Research limitations/implications
Chemical and physical treatments have been identified as the most efficient ways of treating the fiber surface. However, the huge amounts of liquids and chemicals needed in chemical methods and their exorbitant performance in terms of energy expenditure have limited their applicability in the past decades. The use of appropriate cohesion in addition to stimulating the biopolymer texture without changing its bulk polymer properties leads to the formation and establishment of plasma surface treatments that offer a unified, repeatable, cost-effective and environmentally benign replacement.
Originality/value
The authors are sure that this technology will be adopted by the polymer industry, aerospace, automotive and related sectors in the future.
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Fernando Augusto Gouvea-Reis, Danniely Carolinne Soares da Silva, Lairton Souza Borja, Patrícia de Oliveira Dias, Jadher Percio, Cassio Peterka, Janaína de Oliveira, Giselle Sodré, Claudia Mendes Feres, Wallace Dos Santos, Fábio Souza, Ana Izabel Passarella Teixeira, Daiani Cristina Cilião-Alves, Gustavo Adolfo Sierra Romero, Elza Ferreira Noronha, Julio Croda, Rodrigo Haddad, Walter Massa Ramalho, Camile de Moraes and Wildo Navegantes de Araújo
This study aims to estimate the overall SARS-CoV-2 seroprevalence and evaluate the accuracy of an antibody rapid test compared to a reference serological assay during a COVID-19…
Abstract
Purpose
This study aims to estimate the overall SARS-CoV-2 seroprevalence and evaluate the accuracy of an antibody rapid test compared to a reference serological assay during a COVID-19 outbreak in a prison complex housing over 13,000 prisoners in Brasília.
Design/methodology/approach
The authors obtained a randomized, stratified representative sample of each prison unit and conducted a repeated serosurvey among prisoners between June and July 2020, using a lateral-flow immunochromatographic assay (LFIA). Samples were also retested using a chemiluminescence enzyme immunoassay (CLIA) to compare SARS-CoV-2 seroprevalence and 21-days incidence, as well as to estimate the overall infection fatality rate (IFR) and determine the diagnostic accuracy of the LFIA test.
Findings
This study identified 485 eligible individuals and enrolled 460 participants. Baseline and 21-days follow-up seroprevalence were estimated at 52.0% (95% CI 44.9–59.0) and 56.7% (95% CI 48.2–65.3) with LFIA; and 80.7% (95% CI 74.1–87.3) and 81.1% (95% CI 74.4–87.8) with CLIA, with an overall IFR of 0.02%. There were 78.2% (95% CI 66.7–89.7) symptomatic individuals among the positive cases. Sensitivity and specificity of LFIA were estimated at 43.4% and 83.3% for IgM; 46.5% and 91.5% for IgG; and 59.1% and 77.3% for combined tests.
Originality/value
The authors found high seroprevalence of anti-SARS-CoV-2 antibodies within the prison complex. The occurrence of asymptomatic infection highlights the importance of periodic mass testing in addition to case-finding of symptomatic individuals; however, the field performance of LFIA tests should be validated. This study recommends that vaccination strategies consider the inclusion of prisoners and prison staff in priority groups.
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N. Dhanunjayarao Borra and Venkata Swamy Naidu Neigapula
The tear strength (Ts) is a significant property for any kind of soft polymeric material such as rubber, elastomer, viscoelastic material and its composites, to quantify the…
Abstract
Purpose
The tear strength (Ts) is a significant property for any kind of soft polymeric material such as rubber, elastomer, viscoelastic material and its composites, to quantify the suitability of a material for any shape memory applications. Many times, the soft elastomeric polymer material has to be capable enough to deform to a maximum extent of displacement but at the same time, it has to withstand the maximum load without fail. Along with shape recovery properties (i.e. the ability to recover its shape from programmed to the original), the success of the shape memory cycle is mainly depending on its stiffness and strength. It has to resist tear during stretching (i.e. programming stage) as repeatedly subjected to deformation, and, hence, it is important to study the tear behaviour for shape memory polymers (SMPs) and their composites. The purpose of the work is to investigate the effect of parameters on Ts of 4D printed specimen using Taguchi method.
Design/methodology/approach
The objective of the work is to tailor the Ts of SMPs by reinforcing the graphene nano particles (GNPs) in a blended photopolymer (PP) resin with flexible PP and hard PP resin. In this study, a total of nine experiments were designed based on the L9 orthogonal array (OA) using the design of experiments (DOEs). All the shape memory photopolymer composite’s (SMPPCs) specimens are fabricated using masked stereolithography (MSLA), also known as resin three-dimensional printing (R3DP) technique.
Findings
Specimens are tested using universal testing machine (UTM) for maximum tear force (Fmax) and displacement (δ) caused by tearing the specimen to evaluate the strength against the tear. The results showed that the Wt.% of resin blend highly influenced both Fmax and δ, while GNPs also had an impact on δ. The specimens are offering more tear resistance for those specimens blended with less Wt.% of flexible PP at the same time the specimens enable more δ for those specimens reinforced with 0.3 Wt.% GNPs at 10-s exposure time. The optimum combinations are A1, B1 and C3 for the Fmax and Ts and at the same time A1, B3 and C3 for δ.
Research limitations/implications
To customise the tear resistance of SMPPCs using MSLA 3 D printing, this study suggested a blend of PP resins reinforced with GNPs. This opens up a new path for creating novel, inexpensive multi-functional 4-dimensional (4D) printed parts.
Originality/value
The use of flexible PP and hard PP resin blends, fabricating the SMPPCs specimens using 3 D printed MSLA technology, investigating the effect of GNPs, resin blend and exposure time, optimizing the process parameters using Taguchi and the work were all validated using confirmation tests and regression analysis using test train method, which increases the originality and novelty.
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Genta Kulari and Giulia Francisca Sarantakos Cordeiro
This study aims to examine the impact that diagnostic factors such as duration of diagnostic period, number of professionals consulted and perceived social support have on…
Abstract
Purpose
This study aims to examine the impact that diagnostic factors such as duration of diagnostic period, number of professionals consulted and perceived social support have on parental stress during the diagnostic process of autism spectrum disorder (ASD).
Design/methodology/approach
Forty parents of 2–18 year-old children/adolescents with a formal ASD diagnosis recruited from five specialized private clinics in Lisbon completed a survey which included diagnostic questionnaire, parental stress scale and social support scale from April to December 2022.
Findings
Data analysis indicated that the mean age of the diagnosis was 5.6 years with a delay of 3.95 years from first concern until final diagnosis. On average, parents consulted a mean of 3.62 professionals. Other findings indicated that as age of parents increased, levels of parental stress decreased. Parents with higher levels of social support had lower levels of parental stress. Furthermore, higher age of child at first concern predicted higher affective social support.
Originality/value
This study reflects on the experience of obtaining the ASD diagnosis in Portugal, raising awareness on the importance of providing early detection and social support for distressed parents.
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