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Improving the thermal insulation and energy efficiency of building envelopes is a major objective worldwide and has significantly developed in the recent years. This study aims to evaluate the impact of ecological additive and passive strategies on building energy efficiency. An experimental study was carried out to examine the effect of the incorporation of treated Alfa and Posidonia-Oceanica fibers on the thermal properties of cement and gypsum composite samples. The experimental results were then introduced in a numerical study using TRNSYS software to perform a comparison of the energy efficiency and thermal performance of three individual buildings; two ones constructed with our ecological materials and the third one with typical materials is considered as a reference case under the Tunisian climate. The obtained results indicate that the buildings built with Alfa fibers (BAF) and Posidonia-Oceanica fibers (BPOF) are economically effective since they allow a decrease of about 48.20% and 43.48% in heating, 45.71% and 42.77% in cooling, leading to a reduction in CO2 emission of 47.90% and 43.40%, respectively, in comparison with the reference case. The investigation also focuses on the improvement of the ecological building envelope by a storage wall integrated on the south front and shaded by solar movable overhangs during the summer season. The indoor climate results reveal that incorporating passive strategies into the building improves indoor air temperature and preserves a comfortable indoor relative humidity. Heating requirements decrease by 82.82% for BAF and by 79.76% for BPOF. The cooling requirements of the reference building are also reduced by 63.46% for BAF and 60.45% for BPOF by the use of natural night ventilation (4 ACH) and the appropriate shading for Trombe walls and windows. Consequently, the implementation of passive strategies on the ecological buildings led to a net reduction in CO2 emissions by up to 80.55% for BAF, compared to the reference case. [ABSTRACT FROM AUTHOR]

Context: Cluster of differentiation 40 (CD40), and its ligand CD40L, are major co-stimulatory molecules whose interactions are important in both cellular and humoral immunity, and has been suggested to play a role in the pathogenesis of acute coronary syndrome. Objective: The aim of this study was to examine the association of CD40 polymorphisms (-1 C>T (rs1883832) and 945G>T (rs4810485)) and myocardial infarction (MI), and to test the association of CD40 gene haplotypes with MI in Tunisians. Materials and methods: Three hundred and fifty MI patients and 301 apparently healthy controls were included in the study. The polymorphisms of CD40 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: There were significant differences in the genotype and allele frequencies of CD40 gene -1 C>T (rs1883832) polymorphism between cases and controls. Stratifying according to gender, the association between the TT genotype and MI was statistically significant in males, only. Haplotype analysis revealed that the C-T and T-G haplotypes were associated with an increased risk of MI (p = 0.012 and p < 0.001, respectively). Conclusions: Our work showed a significant association between the -1 C>T (rs1883832) polymorphism of the CD40 gene and MI in the Tunisians. [ABSTRACT FROM AUTHOR]

Due to the economic development and occupancy requests, building thermal comfort reached higher levels during the last years. Energy consumption rates have become excessive and engendered an increasing reliance on fossil-fuel reserves. Hence, the conception of energy-efficient buildings as well as applying solar cooling techniques has become a promising solution. In this context, the current work dealt with the appraisal of a solar system that drives the cooling process in an office building located in the Center of Researches and Energy Technologies in Tunisia. The solar system consisting of linear parabolic trough solar collectors' field coupled to a 16 kW double effect Lithium Bromide absorption chiller, supplies chilled water to a set of fan coils installed in the 126 m 2 laboratory building. A dynamic model that couples the solar cooling system with the building was developed using the TRNSYS tool and several simulations were performed to assess the case study and improve its performance. The model results were compared to the data collected during the experimental campaign conducted in summer 2015 and showed that the collectors efficiency was at the range of 26–35%, the COP ranged between 0.65 and 1.29, the daily maximum solar COP was approximately at 35%. However, the solar system was unable to cover 32.3% of the cooling requirements, the absorption chiller was switched on only during 53.8% of its total operating time. An improved system configuration was then studied; the integration of an auxiliary heater prior to the chiller as well as the increase of the aperture area guaranteed high driving temperatures and more suitable conditions to the absorption chiller. As a result, the chiller operating time increased to 75.8%, the cooling power increased by 75.6%, the solar COP reaches 57% and the solar fraction averaged 87%. The summer season performances predict that the improved system configuration achieves primary energy savings that reach 82.3% compared to a classic air conditioning system producing the same cooling power, the yearly avoided CO 2 emissions are estimated to 2947 kg. [ABSTRACT FROM AUTHOR]

Highlights: [•] Appraisal of the impact of passive strategies on the energy requirements of a solar cooled building in Tunisia. [•] Comparative simulations of different envelope characteristics. [•] Effect of storage walls and solar overhangs on the thermal performance of the building. [•] Simulation of a predictive model featuring passive strategies and renovation measures. [ABSTRACT FROM AUTHOR]

This work is motivated by the difficulty of cultivating crops in horticulture greenhouses under hot and arid climate conditions. The main challenge is to provide a suitable greenhouse indoor environment, with sufficiently low costs and low environmental impacts. The climate control inside the greenhouse constitutes an efficient methodology for maintaining a satisfactory environment that fulfills the requirements of high-yield crops and reduced energy and water resource consumption. In hot climates, the cooling systems, which are assisted by an effective control technique, constitute a suitable path for maintaining an appropriate climate inside the greenhouse, where the required temperature and humidity distribution is maintained. Nevertheless, most of the commonly used systems are either highly energy or water consuming. Hence, the main objective of this work is to provide a detailed review of the research studies that have been carried out during the last few years, with a specific focus on the technologies that allow for the enhancement of the system effectiveness under hot and arid conditions, and that decrease the energy and water consumption. Climate control processes in the greenhouse by means of manual and smart control systems are investigated first. Subsequently, the different cooling technologies that provide the required ranges of temperature and humidity inside the greenhouse are detailed, namely, the systems using heat exchangers, ventilation, evaporation, and desiccants. Finally, the recommended energy-efficient approaches of the desiccant dehumidification systems for greenhouse farming are pointed out, and the future trends in cooling systems, which include water recovery using the method of combined evaporation–condensation, as well as the opportunities for further research and development, are identified as a contribution to future research work. [ABSTRACT FROM AUTHOR]