Biodeterioration of the Wooden Roof of the Phnom Penh National Museum

Within the framework of a training program in Cambodia, during a visit to the National Museum in Phnom Penh, the most important in the Kingdom of Cambodia, the authors noted the presence of some signs of a termite attack in the secondary elements of the roof of an inner garden. Following this observation, a further investigation was performed in order to evaluate the phytosanitary condition of the wooden bearing element of the roof. The inspection highlighted the presence of severe decay, constituting a real danger for the integrity of the roof; consequently, an intervention of restoration, conservation and safeguard was considered to be necessary and urgent. This paper presents the results of the investigation of the conservation state of the load bearing wooden structures of the National Museum in Phnom Penh, Kingdom of Cambodia; moreover, a proposal is put forward for a properly designed intervention to safeguard against the termites in the long term

Biodeterioration of the Wooden Roof of the Phnom Penh National Museum

Within the framework of a training program in Cambodia, during a visit to the National Museum in Phnom Penh, the most important in the Kingdom of Cambodia, the authors noted the presence of some signs of a termite attack in the secondary elements of the roof of an inner garden. Following this observation, a further investigation was performed in order to evaluate the phytosanitary condition of the wooden bearing element of the roof. The inspection highlighted the presence of severe decay, constituting a real danger for the integrity of the roof; consequently, an intervention of restoration, conservation and safeguard was considered to be necessary and urgent. This paper presents the results of the investigation of the conservation state of the load bearing wooden structures of the National Museum in Phnom Penh, Kingdom of Cambodia; moreover, a proposal is put forward for a properly designed intervention to safeguard against the termites in the long term.Nella cornice di un programma di formazione in Cambogia, durante una visita al Museo Nazionale di Phnom Penh, il più importante nel Regno di Cambogia, gli autori hanno notato la presenza di alcuni segni di attacco di termiti negli elementi secondari del tetto di un giardino interno. In base a questa osservazione, un’ulteriore indagine fu effettuata per valutare la condizione fitosanitaria dell’elemento portante in legno del tetto. L’ispezione ha evidenziato la presenza di un grave decadimento che costituiva un chiaro pericolo per l’integrità del tetto, dunque un intervento di restauro, conservazione e salvaguardia è stato considerato come necessario ed urgente. In questo lavoro sono presentati i risultati del lavoro di indagine sullo stato di conservazione delle strutture portanti in legno del Museo Nazionale di Phnom Penh, Regno di Cambogia; inoltre è riportata una proposta di intervento correttamente progettato per la salvaguardia contro le termiti per un lungo periodo di tempo

CHARACTERIZATION OF SERPOTTAS’ STUCCOS BY MEANS OF SIMULTANEOUS THERMAL ANALYSIS: PRELIMINARY RESULTS

In this paper the Simultaneous Thermal Analysis (STA), i.e. thermogravimetric and differential thermal analysis, was used as a diagnostic tool to better understand the matter composition of some very valuable artworks the Serpottas’ stuccoes in Palermo. Particularly the STA was used in order to exclude the presence of an unusual calcium-bearing magnesium carbonate, and the thermal data were also used to quantify the magnesite to calcite ratio. The latter was investigated in order to evaluate the amount of magnesium in the lime used as binder as during 17th and 18th century in Sicily magnesium rich lime was indicated as the most valuable binder probably because this kind of lime has a higher plasticity. The data obtained in this work are not conclusive but indicate a way to contribute to the comprehension of this unique work of art composition

New Applications in the Use of Cellulose Pulp for the Integration of Wooden Supports

Cellulose pulp, mainly utilized as a support for cleaning stone material, in this study, is proposed as a filler for wooden supports. In the last 10 years, pulp has been used in many restoration works carried out in the laboratory of the Diocesan Museum (MDP) in Palermo, including both wooden sculptures and panel paintings. These artworks, exhibited in the MDP, are constantly monitored in order to evaluate the effectiveness of cellulose pulp as a filler, assessing its durability and bio-receptivity. In particular, structural characteristics, drying time, shrinkage, loss in weight, affinity to the pigments, etc., were simultaneously evaluated. Tests were also carried out on artificially aged cellulose pulp samples, in order to appraise if cellulose could be a source of nourishment for microbial growth.Il presente studio propone l’analisi e l’approfondimento di un materiale già noto nel campo del restauro: la polpa di cellulosa, utilizzata da sempre come supportante per impacchi di pulitura su materiale lapideo, qui analizzata in veste di stucco per supporti lignei. Il materiale è stato utilizzato in alcuni interventi di restauro eseguiti nel laboratorio del Museo Diocesano di Palermo nel corso degli ultimi 10 anni su sculture lignee e dipinti su tavola. Le opere conservate in sale espositive costantemente monitorate hanno permesso, fino ad oggi, di valutare l’efficacia dell’intervento. Lo studio propone alcuni test eseguiti su campioni di stucco di cellulosa realizzati con leganti di origine diversa, valutando le caratteristiche di ciascuna tipologia, i tempi di essiccamento, ritiro, perdita in peso, affinità al colore, etc. Inoltre sono stati effettuati test d’invecchiamento, reversibilità e test microbiologici per determinare la resa della cellulosa all’invecchiamento e valutare se il substrato in cellulosa possa costituire un supporto alla colonizzazione microbica

Thymus vulgaris Essential Oil and Hydro-Alcoholic Solutions to Counteract Wooden Artwork Microbial Colonization

Aromatic plants represent a source of natural products with medicinal properties, and are also utilized in the food and pharmaceutical industries. Recently, the need for eco-compatible and non-toxic products, safe for both the environment and human health, have been proposed for the sustainable conservation of historic–artistic artifacts. In this study, in order to counteract microbial colonization (Aspergillus sp., Streptomyces sp., Micrococcus sp.) on wooden artwork surfaces, Thymus vulgaris L. (Lamiaceae) essential oil (EO) and hydro-alcoholic (HA) solutions were applied in a polyphasic approach. The antimicrobial activities of EO and HA solutions were preliminarily assessed by agar disc diffusion (ADD) and well plate diffusion (WPD) in vitro methods, defining the specific concentration useful for bacterial and fungal genera, identified by optical microscopies, in vitro cultures (nutrient or Sabouraud agar), and DNA base molecular biology investigations. Specifically, the microbial patina was directly removed by a hydro-alcoholic solution (while evaluating the potential colorimetric change of the artwork’s surface) combined with exposure to EO volatile compounds, performed in a dedicated “clean chamber”. This study proposes, for the first time, the combined use of two plant extracts to counteract microbial development on wooden artworks, providing supplementary information on these products as bio-agents

Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo [1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, in vitro antimicrobial activity and X-ray crystallography

Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me3SnL(H2O), (1), [n-Bu3SnL]2(H2O), (2), Ph3SnL(MeOH), (3), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, 1H, 13C and 119Sn NMR, IR, Raman and 119Sn Mössbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds (2) and (3). Ph3SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated to tin through the carboxylate, and a solvent molecule, MeOH. A similar structure is proposed for Me3SnL(H2O) on the basis of analytical and spectroscopic data. The tributyltin(IV) derivative, [n-Bu3SnL]2(H2O), is characterized by two different tin sites with similar tbp geometry featured by butyl groups on the equatorial plane. Sn(1) and Sn(2) atoms are axially bridged by a ligand molecule binding through the N(4) and the carboxylate group; the two coordination spheres are saturated by another ligand molecule, binding the metal through the carboxylate group, and a water molecule, respectively. Antimicrobial tests on compounds 1 and 2 showed in vitro activity against Gram-positive bacteria

Catalytic Dehydration of Fructose to 5-Hydroxymethylfurfural in Aqueous Medium over Nb2O5-Based Catalysts

The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) in water was performed in the presence of pristine Nb2O5 and composites containing Nb and Ti, Ce or Zr oxides. In all experiments, fructose was converted to HMF using water as the solvent. The catalysts were characterized by powder X-ray diffraction, scanning electron microscopy, N2 physical adsorption, infrared and Raman spectroscopy and temperature-programmed desorption of NH3. Experimental parameters such as fructose initial concentration, volume of the reacting suspension, operation temperature, reaction time and amount of catalyst were tuned in order to optimize the catalytic reaction process. The highest selectivity to HMF was ca. 80% in the presence of 0.5 g\ub7L 121 of bare Nb2O5, Nb2O5-TiO2 or Nb2O5-CeO2 with a maximum fructose conversion of ca. 70%. However, the best compromise between high conversion and high selectivity was reached by using 1 g\ub7L 121 of pristine Nb2O5. Indeed, the best result was obtained in the presence of Nb2O5, with a fructose conversion of 76% and a selectivity to HMF of 75%, corresponding to the highest HMF yield (57%). This result was obtained at a temperature of 165\ub0 in an autoclave after three hours of reaction by using 6 mL of 1 M fructose suspension with a catalyst amount equal to 1 g\ub7L 121