In the context of designing solid polymer electrolytes for reliable, efficient, and durable lithium batteries, the present study was developed to have a better understanding of the role of the ...surface charge of ceramic nanoparticles, on the ionic transport used as additives in single lithium-ion conducting polymer electrolytes. A polymer based on sp
3
boron with polyethylene glycol (with an average Mn = 400 g mol
−1
) bridges was used as a model system; SiO
2
, ZrO
2,
and TiO
2
nanoparticles (NPs), having a negative, neutral, and positive effective surface charge, respectively, were incorporated during synthesis. Samples were characterized by XRD and EIS; a DRT analysis of impedance spectra was also performed. The results obtained showed that the electrostatic interactions of Li
+
with the surface charge of nanoceramics resulted in an enhancement of 2.5% of ionic conductivity for the TiO
2
-containing polymer with respect to the electrolyte without NPs (due to repulsion between Li
+
and nanoceramics surface. The sample with ZrO
2
, compared to the NP-free polymer showed a similar conductivity and a decreased conductivity of 1.2% with respect to the NP-free polymer for the SiO
2
case (due to attraction between Li
+
and nanoceramics surface, that anchors Li
+
, hindering its transport). The pseudo-activation energy values (from VTF plots) indicated no change in the transport mechanism for all samples.
In this paper, greenhouse gas (GHG) emissions derived from airport surface access of outbound German tourists travelling to the Canary Islands have been estimated. It is argued that carbon footprint ...estimations in tourism must be improved to incorporate the transport to the airports within the country of origin. To do so, statistical data from the Tourism Expenditure Survey of the Canary Islands have been used. In particular, the postcodes of a large sample of German tourists visiting the archipelago from 2012 to 2014 are used to identify their residence and the distances travelled to their chosen airport. The findings of the paper contribute to the literature on tourism carbon footprints, including an estimate of the share of airport surface access emissions in a typical outbound sun and beach holiday trip. Airport ground access accounted for 8.17% of transport-related emissions. These results have implications for urban planners, transport firms, and tourism management.
This paper is motivated by the lack of clarity in frequently used terms and definitions in tourism research complicating comparative studies of cases. This paper proposes an objective method that may ...help researchers gain awareness of different definitions of concepts in tourism research, avoiding misunderstandings. The paper focuses on four main concepts: destination, attraction, accommodation and point of interest. A bibliometric analysis is carried out to quantify how often researchers employ different definitions for each of these terms. This allowed for the most frequently used definition to be ascertained. The results show that bibliometrics can help identify the most frequent definitions given to a certain concept. This study may help future researchers to better define concepts in tourism studies, as it can be used to clarify meanings among researchers and practitioners when conducting research or making reports on tourism and hospitality
In this communication we elucidate a microstructural picture of proton conduction in nano-crystalline yttria-stabilized zirconia at low temperatures (Kim et al. Adv. Mater., 2008, 20, 556). Based on ...careful analysis of electrical impedance spectra obtained from samples with grain sizes of approximately 13 and approximately 100 nm under both wet and dry atmospheres over a wide range of temperatures (room temperature-500 degrees C), we were able to identify the pathway for proton conduction in this material. It was found that the grain boundaries in nano-crystalline yttria-stabilized zirconia are highly selective for ion transport, being conductive for proton transport but resistive for oxygen-ion transport.
Oxidative stress-induced retinal degeneration is among the main contributing factors of serious ocular pathologies that can lead to irreversible blindness. αB-crystallin (cry) is an abundant ...component of the visual pathway in the vitreous humor, which modulates protein and cellular homeostasis. Within this protein exists a 20 amino acid fragment (mini-cry) with both chaperone and antiapoptotic activity. This study fuses this mini-cry peptide to two temperature-sensitive elastin-like polypeptides (ELP) with the goal of prolonging its activity in the retina.
The biophysical properties and chaperone activity of cry-ELPs were confirmed by mass spectrometry, cloud-point determination, and dynamic light scattering 'DLS'. For the first time, this work compares a simpler ELP architecture, cry-V96, with a previously reported ELP diblock copolymer, cry-SI. Their relative mechanisms of cellular uptake and antiapoptotic potential were tested using retinal pigment epithelial cells (ARPE-19). Oxidative stress was induced with H
O
and comparative internalization of both cry-ELPs was made using 2D and 3D culture models. We also explored the role of lysosomal membrane permeabilization by confocal microscopy.
The results indicated successful ELP fusion, cellular association with both 2D and 3D cultures, which were enhanced by oxidative stress. Both constructs suppressed apoptotic signaling (cleaved caspase-3); however, cry-V96 exhibited greater lysosomal escape.
ELP architecture is a critical factor to optimize delivery of therapeutic peptides, such as the anti-apoptotic mini-cry peptide; furthermore, the protection of mini-cry via ELPs is enhanced by lysosomal membrane permeabilization.
The effect of crystallite size on cation coordination environments and oxygen vacancy ordering has been investigated in micro- and nanocrystalline Y- and Sc-doped ZrO2 and CeO2 by using ...high-resolution 89Y and 45Sc magic-angle-spinning nuclear magnetic resonance (MAS NMR) spectroscopy. Our results indicate that irrespective of crystallite size the vacancies are preferentially associated with the host cation (i.e., Zr) in Y-doped ZrO2 while they display a preference for the dopant cation (i.e., Sc) in Sc-doped ZrO2. On the other hand, vacancies prefer to be associated with the dopant cation in both Y- and Sc-doped CeO2. However, the reduction of crystallite size to a few nanometers shows an unexpected and remarkable effect of increasing randomness in the vacancy distribution in all materials. Such an effect is hypothesized to result from a higher degree of short-range structural disorder in the cation coordination environments in nanocrystals compared to that in their microcrystalline counterparts that controls the energetics of vacancy ordering via a complex balance between electrostatic and strain energy terms. Finally, a clear connection is established between vacancy ordering, oxygen ion transport, and electrical conductivity in microcrystalline Y-doped CeO2 and its possible implications on ionic transport in nanocrystalline materials are discussed.
Here we elucidate the origin of the characteristic development of grain-boundary conductivity and of its activation energy measured in Gd-doped ceria (GDC) ceramics upon change in the dopant ...concentration in the context of the space-charge effect. The grain-boundary conductivity in GDC was measured as a function of the dopant concentration (1-20 cat.%). The total conductivity of the sample with 1 cat.% dopant is lower than the bulk conductivity by several orders of magnitude largely due to exceedingly high grain-boundary resistance in the sample, consistent with the results previously reported in literature. The specific grain-boundary conductivity of GDC however rapidly increases with increasing dopant content to approach a plateau at concentrations above 15 cat.%, leading to the total conductivity being close to its bulk conductivity at the relatively high dopant level. On the other hand, the grain-boundary width estimated experimentally in GDC is found to decrease substantially as the dopant concentration increases, implying that the observed increase in the grain-boundary conductivity is correlated with such reduction in the grain-boundary width. In addition, the values of the grain-boundary width determined at each dopant concentration are in quantitative agreement with those calculated based on a space-charge model, in which the grain-boundary resistance is attributed to the Schottky-type potential barrier present at the grain boundaries. Furthermore, the values of activation energy of the grain-boundary conductivity measured at different dopant concentrations can also be reproduced quantitatively using the space-charge model. It is therefore verifed unambiguously that the characteristic increase in the grain-boundary conductivity measured in GDC upon increasing dopant concentration results from concurrent reduction in the height of the potential barrier formed inherently at the grain boundaries.
The effect of applied uniaxial pressure on the densification and grain size of nanocrystalline cubic zirconia (c-YSZ) was investigated during sintering by the pulsed electric current sintering (PECS) ...method. The role of the pressure depended on temperature, being highly significant at lower temperatures and of little significance at higher temperatures. The kinetics of grain growth were determined under PECS conditions. Analysis of the results indicated a grain growth process that is retarded, probably due to the effect of the current on grain boundary energy or dopant segregation. The activation energy for grain growth of c-YSZ was determined as 252
±
34
kJ
mol
−1, a value that is slightly smaller than reported values for microcrystalline samples.
The antibacterial activity of thirty-one chalones is described. Some of the tested compounds showed fair to significant activity against Gram-positive bacteria.
The antibacterial activity of 31 ...chalcones was tested against bacterial strains,
Bacillus cereus ATCC 11778,
Escherichia coli ATCC 25922,
Pseudomonas aeruginosa ATCC 27853, and
Staphylococcus aureus ATCC 25923. Some of the tested chalcones showed fair to significant activity against Gram-positive bacteria. By comparison of the results obtained, the antibacterial activity can be related to features such as the presence of a C-4 hydroxyl group, a C-4′ oxygenated substituent or a C-3′ isoprenoid side chain, while the C-2′ hydroxyl group might have importance for the stability of the molecule. The inhibitory effect of chalcones on human pathogenic microorganisms can be correlated with the substitution patterns of the aromatics rings.
Purpose
This study aims to examining how tourists’ activities condition the relationship between destination image, satisfaction and loyalty.
Design/methodology/approach
This study used a ...constructive replication design (CRD) to investigate the alleged critical role of tourism activities in impacting the tourism experience dimensions of image, satisfaction and loyalty. The CRD approach does not include new concepts or original relationships. However, what is new in the established relationship between image, satisfaction and loyalty is discerning the role of tourism activities as a moderator conditioning the relationship between the three dimensions. The purpose is to establish the external validity of previous studies’ findings through a more stringent test of the findings’ replicability. The analysis used partial least square modeling to examine the relationship between activities, dimensions and multigroup analysis to estimate potential significant differences in group-specific parameters, which are not often used in destination analysis, ensuring rigor in the data analysis and model. The number and type of activities practiced moderate the relationships between these constructs.
Findings
The results indicate that tourists’ type and several destination activities moderate the relationship between tourists’ satisfaction, perceived image and loyalty. The results also suggest that the more destination activities tourists practice, the greater is their satisfaction. These two theoretical propositions put activities at the center of destination management and marketing and identify potential experiential consumption spheres. The analysis of activities’ central role is a productive research field.
Practical implications
This study made several recommendations to destination managers to increase activities participation such as strategic marketing opportunities, expansion of the activities portfolio with sports, wellness, nature based and life observation wildlife, voluntary and educational activities, revamping of the UNESCO heritage site and festivals. This study also recommended a strategic use of technology for information dissemination, the design of a daily activity agenda based on the identified segments’ activity patterns and a destination one-stop online travel shopping.
Originality/value
To the best of the authors’ knowledge, this study is the first to apply the tourism activity-based approach to examine actual tourist behavior regarding their engaged activities instead of their experience or perceptions with those activities in a small island destination. Another contribution lies in examining if tourists’ type and activity engagement moderate the relationship between tourists’ satisfaction, perceived image and loyalty. This paper requires researchers to consider tourism activities’ impact on tourists’ image, satisfaction and loyalty.
小型海岛旅游目的地的旅游活动, 形象, 和旅客的满意度和忠诚度
研究目的 (Purpose)
本案例研究考察了旅游活动如何影响目的地形象、游客满意度和忠诚度之间的关系。
研究设计 (Design)
本研究采用建设性复制设计 (CRD) 来分析旅游活动在影响目的地形象、游客满意度和忠诚度等三个旅游体验维度起到的关键作用。 CRD 方法并没有引进新概念或关系。然而, 本研究新颖的地方在于认证旅游活动在目的地形象、游客满意度和忠诚度三个维度之间建立的调节关系。该研究通过严格测试研究结果的可复制来建立先前研究的外部有效性。该分析使用 PLS建模 和多组分析（MGA）来检验旅游活动和旅游体验的多维度之间的关系和估计特定组参数的潜在显著差异。 这些参数在目的地研究中不常使用, 从而确保我们数据分析和模型的严谨性。该研究结果表明旅游活动的数量和类型调节了这些旅游体验维度的关系。
研究结果 (Findings)
研究结果表明游客的类型和某些旅游活动调节了游客满意度、目的地形象和忠诚度之间的关系。结果还表明, 游客参与的活动越多, 他们的满意度就越高。这两个研究结果确定了旅游活动在目的地管理和营销的中心地位, 同时也指出了潜在体验消费的范围。研究目的地活动的核心作用将会是一个富有成效的领域。
研究的创新性 (Originality)
本研究首次应用基于旅游活动的理论方法 (TAB) 来检查旅客在小型海岛旅游目的地的实际行为, 而不是他们的体验或看法。本研究的另一个贡献在于检验游客的类型和活动参与是否会调节他们满意度、感知目的地形象和忠诚度之间的关系。该论文结果表明未来的研究需要考虑旅游活动对目的地形象、游客满意度和忠诚度的影响。
实际意义 (Practical implications)
本研究向目的地管理人员提出了几项建议以提高旅游活动的参与度, 例如战略营销机会、扩大运动、康养、大自然和野生动物观摩的活动组合、志愿和教育活动、和改善联合国教科文组织遗产地和节日。该研究还建议战略性地使用技术进行信息传播, 根据确定的细分市场活动模式设计游客日常活动议程, 以及目的地一站式在线旅游购物。
Actividades, imagen, satisfacción Y fidelidad EN UN destino insular pequeño
Propósito
Este caso de estudio examina cómo las actividades de los turistas condicionan la relación existente entre la imagen del destino, la satisfacción y la fidelidad.
Diseño
El estudio empleó una replicación constructiva para investigar el supuesto papel crítico de las actividades turísticas en el efecto de la imagen, satisfacción y lealtad de los turistas en su experiencia turística. El enfoque usado no incluye nuevos conceptos ni relaciones originales. Sin embargo, lo novedoso de la relación establecida entre imagen, satisfacción y fidelidad es discernir el papel de las actividades turísticas como moderadoras condicionando la relación entre las tres dimensiones. El propósito es establecer la validez externa de los resultados de estudios previos a través de una prueba más estricta sobre la replicabilidad de dichos resultados. El análisis utilizó un modelo PLS para examinar la relación entre las actividades, las dimensiones mencionadas y el análisis multigrupo con el objetivo de estimar las posibles diferencias significativas entre los parámetros de cada grupo, método no se utiliza con frecuencia en el análisis de destinos turísticos, lo que garantiza el rigor de nuestro análisis y del modelo. El número y tipo de actividades practicadas moderan las relaciones entre los constructos.
Resultados
Los resultados indican que el tipo de turistas y las diversas actividades del destino moderan la relación entre la satisfacción, la imagen percibida y la lealtad de los turistas. Los resultados también sugieren que cuantas más actividades del destino sean practicadas por los turistas, mayor es su satisfacción. Estas dos propuestas teóricas sitúan las actividades en el centro de la gestión y el marketing de destinos e identifican esferas potenciales de consumo experiencial. El análisis del papel central de las actividades es un campo de investigación en auge.
Originalidad
Este estudio es el primero en aplicar el enfoque basado en actividades turísticas para analizar el comportamiento del turista con respecto a las actividades realizadas en relación con su experiencia o percepciones con esas actividades en un destino insular pequeño. Otra contribución radica en estudiar si el tipo de turista y su compromiso con la actividad moderan la relación entre la satisfacción de los turistas, la imagen percibida y la fidelidad. El estudio sugiere que los investigadores deben considerar el impacto de las actividades turísticas en la imagen, satisfacción y fidelidad de los turistas.
Implicaciones prácticas
El estudio realiza varias recomendaciones a los administradores de destinos para aumentar la participación en actividades, como oportunidades de marketing estratégico, expansión de la cartera de actividades con deportes, bienestar, observación de la vida y la naturaleza basada en la naturaleza, actividades voluntarias y educativas, renovación del sitio del patrimonio de la UNESCO y festivales. El estudio también recomendó un uso estratégico de la tecnología para la difusión de información, el diseño de una agenda de actividades diarias basada en los patrones de actividad de los segmentos identificados y una ventanilla única de viajes en línea.
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