3,12-Diaza-6,9-diazo­nia-2,13-dioxotetra­decane bis­(perchlorate)

The crystal structure of the title diprotonated diacetyl­triethyl­ene­tetra­mine (DAT) perchorate salt, C10H24N4O2 2+·2ClO4 −, can be described as a three-dimensional assembly of alternating layers consisting of diprotonated diacetyl­triethyl­ene­tetra­mine (H2DAT)2+ strands along [100] and the anionic species ClO4 −. The (H2DAT)2+ cations in the strands are connected via N—H⋯O hydrogen bonding between the acetyl groups and the amine groups of neighbouring (H2DAT)2+ cations. Layers of (H2DAT)2+ strands and perchlorate anions are connected by a network of hydrogen bonds between the NH and NH2 groups and the O atoms of the perchlorate anion. The asymmetric unit consits of one perchlorate anion in a general position, as well as of one cation that is located on a center of inversion

The SFT property and the ring R((X))

An ideal I is called,in SFT-ideal if there exist a natural number n and a finitely generated ideal J subset of I such that x(n) is an element of J for each x is an element of I. An SFT-ring is a ring such that every ideal is an ideal SFT-ideal. For a commutative ring D, let D((X)) he the power series ring D parallel to X parallel to localized at the power series with unit content ideal. We. show that fora Prufer domain D, all the prime ideals of D((X),) are formally extended from D if and only if D((X)) is SFT if and only if D is SFT. (c) 2005 Elsevier B.V. All rights reserved.X112sciescopu

Hygrothermal Behavior of a Washing Fines-Hemp Wall under French and Tunisian Summer Climates: Experimental and Numerical Approach

International audienceThis study experimentally and numerically investigates the hygrothermal behavior of a wall made of washing fines hemp composite under typical French and Tunisian summer climates. Actually, insulating bio-based building materials are designed in order to reduce energy and non-renewable resources consumptions. Once their multiphysical properties are characterized at material scale, it is necessary to investigate their behavior at wall scale. Washing fines hemp composite shows low thermal conductivity and high moisture buffer ability. The test wall is implemented as separating wall of a bi-climatic device, which allows simulating indoor and outdoor climates. The numerical simulations are performed with WUFI Pro 6.5 Software. The results are analyzed from the temperature, relative humidity and vapor pressure kinetics and profiles and from heat and moisture transfer and storage. The thermal conductive resistance calculated at the end of the stabilization phase is consistent with the theoretical one. The hygric resistance is consistent for simulation up to steady state. The dynamic phase under daily cyclic variation shows that for such cycles two thirds of the thickness of the wall on the exterior side are active. It also highlights sorption-desorption phenomena in the wall

Experimental Investigation of Air Conditioning in a Bi-climatic Room

International audienceThis paper is a preliminary study to the investigation of hygrothermal behavior of wall implemented as separating wall of bi-climatic rooms. One room simulates indoor environment while the second simulates exterior climatic solicitations (temperature and relative humidity). Four typical Tunisian winter climate are selected for this study. The aims are to check the homogeneity of ambient conditions in the rooms, the reaching of the set point, the delay to reach it after setting then if the ambient conditions remain constant once they are reached, and finally the response time of the whole system. The results underline that some climate are easy to reach while other may be difficult to obtain due to competitions between climatic systems. This may be solved by acting on the device management. The typical response times are short enough to plan daily cyclic variations in the following steps of the study and ambient conditions are homogeneous in the room. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

Degradation of chloramphenicol in water by oxidation on a boron-doped diamond electrode under UV irradiation

A combined advanced oxidation process based on the electrochemical oxidation of chloramphenicol (CHL) on a boron-doped diamond (BDD) electrode under UV irradiation was investigated. The influence of the main process parameters (current density, pH, temperature, and chloride concentration) on CHL degradation and mineralization was assessed. An estimation of the energy consumption required to mineralize CHL was also made. The results showed that CHL can be completely degraded and extensively mineralized by 3-h UV-assisted anodic oxidation on BDD. The process can be further accelerated by chlorides, as these species act as precursors for the photo-induced formation of radical species contributing to CHL oxidation. Under optimal conditions (300 mA m–2, 0.01 M NaCl, ambient temperature, and pH 10), complete CHL removal occurred after 150 min of treatment, and approximately 95 % mineralization was achieved in 180 min. Overall, the results obtained suggest that the investigated process may represent a promising approach to treat wastewaters containing CHL or other recalcitrant antibiotics

Electrochemical degradation of sinapinic acid on a BDD anode

The electrochemical oxidation of sinapinic acid (4-hydroxy-3,5-dimethoxy-cinnamic acid), one of the most representative polyphenolic type compounds present in olive oil mill wastewater, was studied by galvanostatic electrolysis using boron-doped diamond (BDD) as anode. The influence of several operating parameters, such as applied current density, initial sinapinic acid concentration, temperature, flow rate and initial pH value was investigated. UV spectroscopy and Chemical Oxygen Demand measurements were conducted to study the reaction kinetics of sinapinic acid mineralization. The experimental results showed that the electrochemical process was suitable for almost completely removing COD, due to the production of hydroxyl radicals on the diamond surface. In particular, the COD removal follows a pseudo first-order kinetics and the apparent rate constant increased with flow rate and temperature, while it is almost unaffected by applied current and pH. Under optimal experimental conditions of flow-rates (i.e. 300 L h-1), temperature (T=50 \ub0C) and current density (i.e. 10 mA cm-2), 97% of COD was removed in 3 h electrolysis, with 17 kWh m-3 energy consumption