, revitalize, and add value to buildings/structures through adaptive reuse and renovation.
The underlying idea is to restore the identity of the city of Prishtina, which has been alienated and imposed upon for various reasons, by preserving the
Authors:Mohammad Abdollahi-Alibeik and Marjan Pouriayevali
of Lewis acids due to coordination of Lewis acids to the imine nitrogen, tedious workup and lack of reusability for the catalyst.
The use of solid acid catalysts in organic transformations has attracted considerable attention because of their
The effect of various temperature treatments on TL response characteristics of CaSO4: Dy has been investigated for its reusability when the phosphor has been previously irradiated to increasingly higher gamma doses. In practice, annealing at a standard temperature, namely 400 °C, usually precedes the use or reuse of the phosphor. However, the study demonstrates that the phosphor with a previous history of high accumulated doses does not completely retain its original TL response characteristics with 400 °C treatment unless the phosphor is treated at an elevated temperature, namely 650 °C.
In the present study, non-conventional solid acid catalysts such as NaY, metal ion exchanged zeolite NaY (Zn2+, Fe3+, Ce3+, La3+ and Nd3+), H-mordenite, H-β and HZSM-5 were used in order to overcome the disadvantages of conventional Friedel-Crafts catalysts for
the acylation of anisole with acetic anhydride. Among the various zeolites studied, the HY zeolite shows an intermediate activity.
Zeolite containing transition metal ions (Zn2+ and Fe3+) are less active and zeolite NaY is nearly inactive. The catalysts exhibit the activity in the order H-β>transition metal
ions (Zn2+ and Fe3+)>HY>NaY zeolite. The highest catalytic activity of H-β could be due to its larger pore size. The type of acidity and the
acid strength in zeolite Y were determined by FTIR and differential scanning calorimetric (DSC) studies on the pyridine adsorbed
catalysts. The correlation of catalytic activity with acidity reveals that Brönsted acid sites in zeolite promote the acylation
Authors:Songsheng Lu, Junzheng Xu, Caicai Zhang, and Zhiwei Niu
The adsorption of Eu(III) on multiwalled carbon nanotubes (MWCNTs) as a function of pH, ionic strength and solid contents
are studied by batch technique. The results indicate that the adsorption of Eu(III) on MWCNTs is strongly dependent on pH
values, dependent on ionic strength at low pH values and independent of ionic strength at high pH values. Strong surface complexation
and ion exchange contribute to the adsorption of Eu(III) on MWCNTs at low pH values, whereas surface complexation and surface
precipitation are the main adsorption mechanism of Eu(III) on MWCNTs. The desorption of adsorbed Eu(III) from MWCNTs by adding
HCl is also studied and the recycling use of MWCNTs in the removal of Eu(III) is investigated after the desorption of Eu(III)
at low pH values. The results indicate that adsorbed Eu(III) can be easily desorbed from MWCNTs at low pH values, and MWCNTs
can be repeatedly used to remove Eu(III) from aqueous solutions. MWCNTs are suitable material in the preconcentration and
solidification of radionuclides from large volumes of aqueous solutions in nuclear waste management.
Authors:Manuel Mora, M. Ángeles Carmona, César Jiménez-Sanchidrián, M. Isabel López, and J. Rafael Ruiz
The Henry reaction between nitromethane and benzaldehydes, which yields (E)-nitrostyrenes, was for the first time conducted by using a commercially available sepiolite calcined at 400 °C as catalyst.
The process is environmentally benign as it is performed in an aqueous medium and using a nitromethane/benzaldehydes ratio
of only 3. A reaction mechanism accounting for the results is proposed.
Authors:Patrizia Lamanna, H. Nilsson, and P. Reuse
When chemical reactions are performed in semi-batch mode and the reaction rate is relatively low, the reactant added may be
accumulated. The resulting thermal accumulation is of major concern regarding process safety, as a fault in the cooling system
may lead to a run-away reaction. The feed rate in semi-batch processes is usually constant, but this paper discusses methods
of optimizing the feed rate interactively, based on the measured heat flow and the calculated amount of compound that has
actually reacted. The prerequisite of such procedures is to run the experiments in a reaction calorimeter in which the heat
flows can be measured accurately and continuously. For this purpose a ChemiSens reaction calorimeter CPA202, which is calibration
free and gives stable, flat ‘zero-line-type’ baselines, was employed.
alcohols with hydrogen peroxide, such as Na 12 [WZnZn 2 (H 2 O) 2 (ZnW 9 O 34 ) 2 ] [ 13 , 14 ], Na 6 [SiW 11 ZnH 2 O 40 ]·12H 2 O [ 15 ], K 8 [BW 11 O 39 H]·13H 2 O [ 16 ] and K 8 [γ-SiW 10 O 36 ]·13H 2 O [ 17 ]. The catalysts could be reused without