Production of green surfactants: Market prospects     

《Electronic Journal of Biotechnology》2021

Science has greatly contributed to the advancement of technology and to the innovation of production processes and their applications. Cleaning products have become indispensable in today’s world, as personal and environmental hygiene is important to all societies worldwide. Such products are used in the home, in most work environments and in the industrial sectors. Most of the detergents on the market are synthesised from petrochemical products. However, the interest in reducing the use of products harmful to human health and the environment has led to the search for detergents formulated with natural, biodegradable surfactant components of biological (plant or microbiological) origin or chemically synthesised from natural raw materials usually referred to as green surfactants. This review addresses the different types, properties, and uses of surfactants, with a focus on green surfactants, and describes the current scenario as well as the projections for the future market economy related to the production of the different types of green surfactants marketed in the world.How to cite: Farias CBB, Almeida FCG, Silva IA, et al. Production of green surfactants: Market prospects. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.002  相似文献   

The role of task and ego-oriented climate in explaining students’ bright and dark motivational experiences in Physical Education     

Luis García-González  Javier Sevil-Serrano  Angel Abós  Nathalie Aelterman  Leen Haerens 《Physical Education & Sport Pedagogy》2019,24(4):344-358

Background: A distinction is made in Achievement Goal Theory (AGT) between task-oriented (i.e. effort, intra-individual progress, and self-comparison) and ego-oriented (i.e. inter-individual progress and normative comparison) climates. Combining insights from AGT and Self-Determination Theory (SDT), studies in the PE context have shown that a task-oriented climate positively relates to need satisfaction, although the findings regarding the motivating role of an ego-oriented climate are inconsistent. Moreover, little is known about the role of task- or ego-oriented climates in explaining experiences of basic psychological need frustration.

Purpose: Grounded in AGT and SDT, the aim of the present study was to examine if experiences of basic psychological need satisfaction and need frustration can explain why task- and ego-oriented climates elicit positive and negative motivational outcomes in PE, respectively.

Research design: Cross-sectional study.

Method: A sample of 524 secondary school students (51.1% boys, M_age?=?14.51; SD?=?1.81) from five different secondary schools participated in this study. Students reported on their perceptions of task- and ego-oriented climates, motivational regulations, basic psychological need satisfaction, and need frustration, as well as positive and negative outcomes in PE. Structural equation modeling was used to investigate our objective.

Results: We found that a task-oriented climate had a strong and positive relationship with basic psychological need satisfaction, eliciting a bright pathway to autonomous motivation and affective attitude. An ego-oriented climate was positively related to basic psychological need frustration, eliciting a dark pathway to amotivation and boredom. A negative cross-path from task-oriented climate to basic psychological need frustration was also found, while no significant cross-paths were found from ego-oriented climate to basic psychological need satisfaction.

Conclusions: This study provides a better understanding of the mechanisms that explain why task- and ego-oriented climates shape students’ motivational experiences in PE lessons. It is suggested that a task-oriented climate elicits a bright pathway towards more optimal functioning, because it fosters experiences of need satisfaction and buffers against experiences of need frustration. In contrast, an ego-oriented climate is primarily positively related to feelings of need frustration and negative motivational outcomes. Practical implications for PE teacher training are discussed.  相似文献   

粤港澳大湾区跨境体育消费实证研究* ——以广东居民赴香港参加体育赛事为例     

王淋燕  周良君  李洋洋  丘庆达 《广州体育学院学报》2020,(5):1-8

粤港澳大湾区以其独特的地理优势，在国家发展大局中具有重要的战略地位。采用问卷调查、深度访谈和中介效应分析等方法，选取广东居民赴香港参加体育赛事者为调查对象，了解两岸居民参与体育赛事受到哪些因素的影响及其影响程度，帮助相关部门企业制定合理策略促进两岸体育爱好者交流及地方经济增长，同时进一步拓展了跨境消费行为研究,特别是跨境体育消费研究。结果显示，赛事产品因素及相关吸引因素对个人态度及行为意愿具有重要影响，而经济因素和交通因素对于跨境体育消费者的决策影响十分有限。通关因素、货币汇率因素对跨境参加体育赛事影响不明显。  相似文献   

Writer identification approach based on bag of words with OBI features     

Amal Durou  Ibrahim Aref  Somaya Al-Maadeed  Ahmed Bouridane  Elhadj Benkhelifa 《Information processing & management》2019,56(2):354-366

Handwriter identification aims to simplify the task of forensic experts by providing them with semi-automated tools in order to enable them to narrow down the search to determine the final identification of an unknown handwritten sample. An identification algorithm aims to produce a list of predicted writers of the unknown handwritten sample ranked in terms of confidence measure metrics for use by the forensic expert will make the final decision.Most existing handwriter identification systems use either statistical or model-based approaches. To further improve the performances this paper proposes to deploy a combination of both approaches using Oriented Basic Image features and the concept of graphemes codebook. To reduce the resulting high dimensionality of the feature vector a Kernel Principal Component Analysis has been used. To gauge the effectiveness of the proposed method a performance analysis, using IAM dataset for English handwriting and ICFHR 2012 dataset for Arabic handwriting, has been carried out. The results obtained achieved an accuracy of 96% thus demonstrating its superiority when compared against similar techniques.  相似文献   

新冠肺炎后演艺行业的走势     

姚石 《演艺科技》2020,(3):1-3

2020年,演艺行业虽受新冠肺炎疫情影响,但需求始终存在,并能够随着经济的增长而增长。5G、大数据中心、人工智能和工业互联的发展,将推动演艺行业在在线化、专业音视频与消费类产品融合发展。  相似文献   

SPOC在线课程在大学计算机基础课程教学中的应用实践     

于丽 《教育教学论坛》2020,(16):366-367

随着网络和信息技术的发展,现如今越来越多的课程通过网络和各种网络工具进行混合式教学。大学计算机基础课程是大学生的第一门计算机公共基础课程,同时也是大学生学习后续其他课程的重要基础课。为了提高该课程的教学效果,实现人才培养目标,教学团队针对该课程教学中存在的主要问题,通过结合SPOC在线课程的混合教学模式及运用多种教学方法,将线下和线上教学相结合。实践教学表明,混合式的教学模式不仅提高了学生的学习积极性和兴趣,而且达到了较好的教学效果。  相似文献   

高校基建工程非招标采购管理廉政风险刍议     

李丽霞 《中国现代教育装备》2011,(17):39-40

通过对高校基建工程零星项目非招标采购现实状态的分析,指出了其潜在风险。并进行了相应的风险防范措施探讨,为高校基建工程采购非招标管理决策提供了参考依据。  相似文献   

基于“质量工程”的机械基础课程群精品化建设研究与实践     

王瑾  张国海  王保民  宋春明  贾吉林 《中国现代教育装备》2011,(1):103-105

机械基础课程群精品化建设是实施“质量工程”项目的重要内容之一。文章从教学团队建设,教学体系及教学内容改革,教学方法与教学手段改革等方面进行了研究与实践。  相似文献   

产业集聚对出口贸易的影响研究——基于湖南省冶金及金属制品产业的实证分析     

仇怡  吕焕芬  文红艳 《湖南城市学院学报》2011,32(4):54-57

产业集聚作为一种空间地理特征,对于一国或地区的对外贸易与经济增长具有重要影响。以湖南省冶金及金属制品产业出口贸易与产业集聚的状况为例,实证分析产业集聚对出口贸易的影响,研究结果表明,从长期来看,湖南省冶金及金属制品产业出口贸易与产业集聚之间存在着长期稳定的关系,产业集聚有效促进了出口贸易的增长,且集聚规模每增长1%,出口规模增长0.41%。  相似文献   

我国基层统计市场主导模式建设初探     

罗放华 《湖南城市学院学报》2011,32(6):55-59

基层统计市场主导模式是由政府规范、市场主导、中介执业的基层统计生产管理模式。它是基层统计生产方式和管理方式的重大变革,对于完善我国统计管理理论,推动基层统计制度、体制机制创新具有深远的理论意义,同时对于稳固统计基础,提高宏观统计数据质量和政府统计公信力都有十分重要的现实意义。  相似文献