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This paper describes a one dimensional moving grid model for the pyrolysis of charring materials. In the model, the solid is divided by a pyrolysis front into a char and a virgin layer. Only when the virgin material reaches a critical temperature it starts to pyrolyse. The progress of the front determines the release of combustible volatiles by the surface. The volatiles, which are produced at the pyrolysis front, flow immediately out of the solid. Heat exchange between those volatiles and the char layer is taken into account. Since the model is used here as a stand‐alone model, the external heat flux that heats up the solid, is assumed to be known. In the future, this model will be coupled with a CFD code in order to simulate fire spread. The char and virgin grid move along with the pyrolysis front. Calculations are done on uniform and on non‐uniform grids for the virgin layer. In the char layer only a uniform grid is used. Calculations done with a non‐uniform grid are about 3 times faster than with a uniform gird. The moving grid model is compared with a faster but approximate integral model for several cases. For sudden changes in the boundary conditions, the approximate integral model gives significant errors.

Thermochemical conversion processes are one of the possible solutions for the flexible production of electric and thermal power from biomass. The pyrolysis degradation process presents, among the others, the interesting features of biofuels and high energy density bio-oil production potential high conversion rate. In this paper, numerical results of a slow batch and continuous fast pyrolyzers, are presented, aiming at validating both a tridimensional computational fluid dynamics-discrete element method (CFD–DEM) and a monodimensional distributed activation energy model (DAEM) represents with data collected in dedicated experiments. The purpose of this paper is then to provide reliable models for industrial scale-up and direct design purposes.

The slow pyrolysis experimental system, a batch of small-scale constant-pressure bomb for allothermic conversion processes, is presented. A DEM numerical model has been implemented by means of a modified OpenFOAM solver. The fast pyrolysis experimental system and a lab scale screw reactor designed for biomass fast pyrolysis conversion are also presented along with a 1D numerical model to represent its operation. The model which is developed for continuous stationary feeding conditions and based on a four-parallel reaction chemical framework is presented in detail.

The slow pyrolysis numerical results are compared with experimental data in terms of both gaseous species production and reduction of the bed height showing good predictive capabilities. Fast pyrolysis numerical results have been compared to the experimental data obtained from the fast pyrolysis process of spruce wood pellet. The comparison shows that the chemical reaction modeling based on a Gaussian DAEM is capable of giving results in very good agreement with the bio-oil yield evaluated experimentally.

As general results of the proposed activities, a mixed experimental and numerical approach has demonstrated a very good potential in developing design tools for pyrolysis development.

The effective heat capacity is a key index to estimate the thermal protection performance of charring ablative materials in reentry vehicles subjected to aerodynamic heat loads. The purpose of this paper is to investigate the effects of gradient density on the effective heat capacity.

Based on the Fourier law and the pyrolysis interface model, the authors establish the governing equations for the transient heat conduction with variable density, and then simulate one-dimensional transient thermal behavior of a homogeneous and three types of non-homogeneous charring ablative material in reentry capsules by using the implicit numerical method.

The moving rate of pyrolysis interface and the surface temperature of charring ablative material depend on not only the surface heating history, but also the gradient density. And the gradient density can improve the insulation performance of charring materials, e.g. the effective heat capacity in the bilinear design is larger than that in the homogeneous design under a given heat flux condition.

This study will help the design of the thermal protection system in reentry vehicles.

In many Third World countries tourism is an economic activity the importance of which can hardly be ignored 1). Thus it is obvious that the governments of those countries, besides paying attention to the usual sectors such as agriculture, industry, mining, transport and communication, public health and hygiene and education, should also engage in sectoral programs with regard to tourism. Since “a sector comprises, for the most part, the producing or operating units in the economy that share a common function or output” 2), tourism lays claim to a sectoral approach. In tourism there clearly exists a common function of activities, comprising both Services and production of goods ‐Pertot speaks of a mixed commodity‐service exchange 3) — for the sake of the tourist. The separate activities together constitute the compound tourist product.

This study aims to understand if the appeals often used in social marketing, namely, fear and guilt, are effective in changing South African millennials’ intention to behave more pro-environmentally.

A primary quantitative research method was followed with a between-subject experimental design approach. The treatment took the form of fear- and guilt-based sustainability advertisements. Questions were asked in the form of a survey with the determinants of the theory of planned behaviour (TPB) model (i.e. attitude, subjective norm and perceived behavioural control) as its constructs.

Analysis of the collected data revealed that adding the appeal of fear or guilt to advertisements does not significantly change South African millennials’ intention to behave pro-environmentally. Furthermore, a deeper analysis of the TPB model’s determinants showed that attitude had the strongest effect on behavioural intention. Also, the use of fear or guilt in sustainability social marketing does not affect the subjective norms of South African millennials.

The study offers a greater understanding of customer engagement and motivational factors in the mobile instant messaging (MIM) environment. Future studies could consider more complex relationships with customer engagement in using MIM apps focussed on a younger generation.

It is therefore recommended that to significantly increase the South African millennials’ intention to behave pro-environmentally, social marketers should use other advertising tools or appeals, namely, positive attitude change.

The results of this study represent a contribution to the limited literature on TPB determinants and how they drive behavioural intention.

International tourism belongs to the so‐called tertiary or service sector. It distinguishes itself from a number of other components of the service sector, such as public administration, health‐care and education, by its export orientation, which it has in common with activities like international air and sea transport and international road transport. Contrary to the latter the so‐called invisible export of tourist services takes place within the exporting country. The international tourist services, apart from the international tourist transport services, do not leave the country of production, but the consumer travels to the country where these services are offered. In this way, the production of international tourist services distinguishes itself fundamentally from all other export oriented production processes.

Nowadays it is — to a certain extent — popular to criticize international tourism to third world countries. These criticisms may base on widely divergent aspects of the phenomenon, ranging from for instance the economic impact to the environmental impact or the psychological impact. Without implicitly suggesting that the non‐economic effects of international tourism in developing countries are unimportant we will concentrate in the following on the economic impact. The reason for this is twofold:

The purpose of this paper is to analyse social and environmental sustainability considerations developed in Lao People's Democratic Republic (Lao PDR) and to identify problems and challenges related to sustainable hydropower planning and development.

The paper is leaning on empirical analysis based on analysing primary and secondary data and information; official government documents and relevant literature, a series of workshops of the Future Resource and Economy Policies in Laos till 2020 Project (FREPLA2020), and interviews with government officials and experts.

To achieve its socio‐economic objectives, Lao PDR needs to manage its hydropower development to ensure environmental and social sustainability through developing of the legal, institutional and regulatory environment and strengthening of the institutional capacity of the sector, improving knowledge and data management, and developing institutional coordination across the government agencies.

The paper suggests that the Lao government assesses strategically the hydropower development options, prepares capacity building plans, develops risk assessment and management, and learns from past hydropower developments.

The paper recommends using hydropower development generated revenues to poverty reduction activities and to strengthen participatory approaches.

The paper can act as a discussion awakener, to help and give some guidance to decision makers and actors in the hydropower sector to integrate sustainable development considerations into hydropower development and planning.

Tourism research is usually based on quantitative rather than theoretical and conceptual studies. However, as a new discipline this phenomenon needs a more theoretical approach. It could help to find an interdisciplinary consensus on tourism. The authors consider service marketing as an interesting approach from an intradisciplinary perspective. They think that it could be an instrument for a better understanding of tourism.

For the islands of the Caribbean, tourism is more than an industry to be managed. Significantly, it is a socioeconomic phenomenon that if managed effectively can address some of the challenges facing the region. Tourism higher education plays a critical role in preparing graduates to shape an improved Caribbean tourism society and in performing research. Over the years, its tourism education has been framed by “Western models” that have not taken sufficient account of the Caribbean reality. The focus of this chapter is to define Caribbean education and to propose a tourism higher education strategy for the implementation in part of this education.