Graphic summary
  • Show / hide key
  • Information


Scientific and technological production
  •  

1 to 23 of 23 results
  • Towards online measurement of roughness using laser speckle contrast

     Pladellorens Mallofre, Josep; Cusola Aumedes, Oriol; Caum Aregay, Jesus Maria; Royo Royo, Santiago; Tosas Fuentes, Agustín; Pino, Abdiel
    Appita journal
    Date of publication: 2014-04-01
    Journal article

    Read the abstract Read the abstract  Share Reference managers Reference managers Open in new window

    Roughness of a paper surface is particularly important in paper and board destined to be printed. Surfaces are often: coated and the amount of coating and method of application used depends on the roughness Of the base paper: WO present a Method to measure the roughness of paper based on the analysis of speckle contrast pattern on the surface: Images are captured by means of a simple configuration using a laser and a camera CCD. Then, We apply digital image processing, so this method can be considered as a non-contact surface profiling method that Can be used online.

  • Química industrial. Campo: papel

     Colom Pastor, Josep Francesc; Cusola Aumedes, Oriol
    Date of publication: 2014-01-01
    Book chapter

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    El idioma español se ha convertido en un vehículo de comunicación y en los organismos internacionales en los que se usa este idioma los profesionales de la Lengua y de la Ingeniería necesitan un diccionario que traduzca los términos del español al inglés y viceversa. Además, la Ingeniería tiene como objetivo transformar diariamente el conocimiento en soluciones prácticas y de esta labor nacen nuevos términos que deben ser recogidos y estudiados minuciosamente. Por esta razón, desde la Real Academia de Ingeniería se pensó en confeccionar un repertorio que recogiese los vocablos de cada una de las disciplinas que forman la Ingeniería y que además fuese pionero en accesibilidad y usabilidad

  • Functionalization of cellulosic model substrates via laccase-mediated coupling of non-polar particles

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca; Rojas, Orlando J.
    European Workshop on Lignocellulosics and Pulp
    Presentation's date: 2014-06-27
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    In the present work we investigate the physicochemical interactions between silica and nanofibrillar cellulose (CNF) with a multi component system (MCS) obtained from an enzymatic reaction of a laccase enzyme and a short-chain organic molecule, dodecyl 3,4,5-trihydroxybenzoate (commonly known as lauryl gallate, LG) as well as sulphonated lignin (SL). Hydrophobic chains of enzyme-modified LG were coupled onto CNF and silica surfaces by direct adsorption of the MCS. Quartz crystal microgravimetry (QCM-D), Atomic Force Microscopy (AFM) and water contact angle (WCA) were used to monitor in situ and characterize the hydrophobization process. Efficient adsorption of the MCS onto CNF and silica surfaces increased their WCA by 88° and 78°, respectively. Dynamic Light Scattering (DLS) measurements revealed an effect of the enzyme on LG: reducing particle size from several microns down to 300 nm. The laccase (Lacc) treatment in the presence of SL reduced even more the LG particle size to 80 nm through a dispersive effect of SL

    In the present work we investigate the physicochemical interactions between silica and nanofibrillar cellulose (CNF) with a multi component system (MCS) obtained from an enzymatic reaction of a laccase enzyme and a short-chain organic molecule, dodecyl 3,4,5-trihydroxybenzoate (commonly known as lauryl gallate, LG) as well as sulphonated lignin (SL). Hydrophobic chains of enzyme-modified LG were coupled onto CNF and silica surfaces by direct adsorption of the MCS. Quartz crystal microgravimetry (QCM-D), Atomic Force Microscopy (AFM) and water contact angle (WCA) were used to monitor in situ and characterize the hydrophobization process. Efficient adsorption of the MCS onto CNF and silica surfaces increased their WCA by 88° and 78°, respectively. Dynamic Light Scattering (DLS) measurements revealed an effect of the enzyme on LG: reducing particle size from several microns down to 300 nm. The laccase (Lacc) treatment in the presence of SL reduced even more the LG particle size to 80 nm through a dispersive effect of SL

  • Coating of laccase-activated phenols for the industrially-feasible functionalization of cellulose-based substrates

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    Presentation's date: 2014-06-25
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    The present work describes an innovative method for the hydrophobization of cellulosic material by impregnation with an enzymatically obtained functionalization solution (FS). Application of FS to the surface of previously formed cellulose sheets was found to confer them hydrophobic properties. The absorbance of functionalized sheets was assessed with the water-drop test (WDT), and their hydrophobicity from their contact angle (WCA) and the surface free energy (SFE) as determined with a goniophotometer. The proposed method is an effective choice for the hydrophobization of paper sheets, with absorption times of up to 4000 s and WCA values around 130°. Treating eucalyptus paper sheets dramatically decreased SFE (from 55 to 10 mJ/m2), and evidences on the grafting of the FS onto the cellulosic sheets were assessed by using ATR-FTIR. The stability of FS and the control solutions was characterized in terms of Z potential and light scattering measurements

    The present work describes an innovative method for the hydrophobization of cellulosic material by impregnation with an enzymatically obtained functionalization solution (FS). Application of FS to the surface of previously formed cellulose sheets was found to confer them hydrophobic properties. The absorbance of functionalized sheets was assessed with the water-drop test (WDT), and their hydrophobicity from their contact angle (WCA) and the surface free energy (SFE) as determined with a goniophotometer. The proposed method is an effective choice for the hydrophobization of paper sheets, with absorption times of up to 4000 s and WCA values around 130°. Treating eucalyptus paper sheets dramatically decreased SFE (from 55 to 10 mJ/m2), and evidences on the grafting of the FS onto the cellulosic sheets were assessed by using ATR-FTIR. The stability of FS and the control solutions was characterized in terms of Z potential and light scattering measurements

  • EWLP 2014 - 13th European Workshop on Lignocellulosics and Pulp

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Award or recognition

     Share

  • Valortec

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Award or recognition

     Share

  • Application of surface enzyme treatments using laccase and a hydrophobic compound to paper-based media

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Bioresource technology
    Date of publication: 2013-01-11
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination with lauryl gallate (LG) as hydrophobic compound. The efficiency of the method was increased by the use of a lignosulfonate as a natural dispersant to improve the surface distribution of LG on the paper, raise its hydrophobicity and help preserve the enzyme activity. No similar threefold effect from a single compound for the improvement of enzymatic treatments was previously reported. The influence of processing conditions including the LG dose, treatment time and temperature was also examined, resulting in further increased hydrophobicity. Efficient fiber bonding and chemical functionalization were confirmed by thorough washing and Soxhlet extraction of the paper. As shown here for the first time, enzyme treatments have the potential to improve the surface hydrophobicity of paper-based media.

    A new approach for the hydrophobization of finished cellulosic substrates based on a previously reported enzymatic technique is proposed. Commercial finished paper was hydrophobized by using laccase from Trametes villosa in combination with lauryl gallate (LG) as hydrophobic compound. The efficiency of the method was increased by the use of a lignosulfonate as a natural dispersant to improve the surface distribution of LG on the paper, raise its hydrophobicity and help preserve the enzyme activity. No similar threefold effect from a single compound for the improvement of enzymatic treatments was previously reported. The influence of processing conditions including the LG dose, treatment time and temperature was also examined, resulting in further increased hydrophobicity. Efficient fiber bonding and chemical functionalization were confirmed by thorough washing and Soxhlet extraction of the paper. As shown here for the first time, enzyme treatments have the potential to improve the surface hydrophobicity of paper-based media

  • Surface functionalization of cellulosic substrates by using chemical and biotechnological methods.

     Cusola Aumedes, Oriol
    Defense's date: 2013-12-20
    Universitat Politècnica de Catalunya
    Theses

    Read the abstract Read the abstract  Share Reference managers Reference managers Open in new window

    La present tesi tracta sobre la modificació superficial de substrats cel·lulòsics utilitzant mètodes químics i enzimàtics. Lafuncionalització de la cel¿lulosa consisteix en ajustar-ne les seves propietats, per a poder-la utilitzar en gran varietatd'aplicacions. Habitualment aquesta modificació s'aconsegueix tractant les fibres en suspensió aquosa i abans de laformació del substrat. No obstant, en la present tesi els tractaments s'apliquen utilitzant substrats cel¿lulòsics ja formats(FCS), obtenint una sèrie d'avantatges en termes de formació, consum de químics, i velocitat de fabricació. S¿han estudiatdos enfocaments diferents per a la funcionalització: tècniques no-enzimàtiques i enzimàtiques. Els esforços s¿han centrat enl'enfoc enzimàtic.Aquest treball es va dur a terme en el grup de recerca CELBIOTECH (UPC-BarcelonTech), en el marc dels projectesFUNCICEL (CTQ2009-12904) , BIOSURFACEL (CTQ2012-34109) , BIOFIBRECELL (CTQ2010-20238-CO3-01), del MICINNEspanyol i el Projecte integrat BIORENEW (NMP2-CT-2006-026456) del sisè Programa Marc.Pel que fa a la funcionalització no-enzimàtica, s¿han utilitzat -ciclodextrines (-CD) per a la modificació superficial de tresFCS comercials. L'empelt s¿ha avaluat mitjançant microscòpia electrònica de rastreig i anàlisi FTIR. Els substrats empeltatsamb -CDs s¿han carregat amb digluconat de clorhexidina (digCHX), i s¿ha analitzat l¿alliberament d¿aquest principi actiuutilitzant espectroscòpia UV. Diversos substrats han estat capaços de retenir quantitats significatives de digCHX, i demantenir-ne l¿alliberament durant períodes de temps de fins a 20 dies.La funcionalització enzimàtica per al desenvolupament de derivats de la cel·lulosa ha guanyat interès en la comunitatcientífica i industrial darrerament. No obstant, l'ús de sistemes enzimàtics superficials encara es troba en una fase moltprematura; la present tesi fa èmfasi en aquest aspecte. En un primer estudi s¿analitza la hidrofobització superficial de FCScomercials, mitjançant una lacasa en combinació amb compostos hidròfobs. L'eficiència s¿ha vist augmentada amb l'ús delignosulfonats (SL), els quals milloren la distribució superficial, augmenten els nivells d¿hidrofobicitat, i ajuden a preservarl'activitat enzimàtica. La dosi de LG i el temps de tractament s¿han optimitzat resultant en una major hidrofobicitat.Seguidament, els tractaments han evolucionat cap a un nou mètode basat en l¿obtenció d'una solució funcionalitzadora (FS),consistent en un producte derivat d¿una reacció enzimàtica, el qual és aplicat posteriorment a la superfície dels FCS. Aquestmètode també s¿ha mostrat efectiu, i proporciona avantatges importants respecte a la possible aplicació industrial; de fet, elnou mètode ha permès realitzar una sol·licitud internacional de patent. L¿aplicació de la FS a la superfície de FCS elsconfereix propietats hidrofòbica i antioxidant gràcies a les interaccions fisicoquímiques que es produeixen. S¿han utilitzatsuperfícies model de cel·lulosa per tal d¿avaluar l'adsorció de la FS, i s¿han emprat les tècniques de WDT, WCA, SEM, AFM iSFE per caracteritzar-les. La força de l¿enllaç s¿avalua mitjançant rentats agressius i extraccions Soxhlet. Es demostra perprimer cop el potencial dels tractaments enzimàtics superficials per a conferir propietats avançades als substrats cel·lulòsics. La tècnica també s¿ha assajat emprant diverses lacases.S¿han utilitzat diverses tècniques d¿anàlisi per estudiar els mecanismes de reacció, i les interaccions FS-substrat. Lestècniques han estat: DLS, QCM, FTIR, espectroscopia UV-VIS, potencial-Z, Turbiscan® i Voltametria Cíclica. S¿ha proposatl¿estructura química de les molècules resultants de l¿oxidació del LG, els possibles mecanismes d'oxidació, i possiblesmecanismes d'empelt entre els compostos modificats i la cel·lulosa. També s¿ha analitzat l'efecte de la longitud de lacadena alquílica i dels tractaments tèrmics en les propietats antioxidant i hidrofòbica

  • Functionalization of cellulosic substrates using a product derived from an enzymatic reaction

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    International Symposium on Wood, Fiber and Pulping Chemistry
    Presentation's date: 2013
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    The present work describes a new method for the surface functionalization of cellulosic sheets, overcoming the limitations of the traditional treatments, which are usually performed using fibrous suspensions. The method consists in obtaining a product (post-enzymatic) derived from an enzymatic reaction using Laccase and a compound showing a specific property. The obtained product, which has aqueous consistency, is then applied to the surface of a finished paper sheet (or cellulosic substrate) by means of impregnation, spray, size-press, or other available surface deposition technique used in the industry. The functionalization is produced by means of physicochemical interaction between the product and the substrate. In the present research, the methodology is developed to achieve the hydrophobization of finished paper sheets using Lauryl Gallate (LG) as hydrophobic compound, and a laccase derived from Trametes Villosa, reaching absorption times of up to 4000 s and CA values around 130° as assessed by the water drop test (WDT) and contact angle measurements (CA) respectively.

    The present work describes a new method for the surface functionalization of cellulosic sheets, overcoming the limitations of the traditional treatments, which are usually performed using fibrous suspensions. The method consists in obtaining a product (post-enzymatic) derived from an enzymatic reaction using Laccase and a compound showing a specific property. The obtained product, which has aqueous consistency, is then applied to the surface of a finished paper sheet (or cellulosic substrate) by means of impregnation, spray, size-press, or other available surface deposition technique used in the industry. The functionalization is produced by means of physicochemical interaction between the product and the substrate. In the present research, the methodology is developed to achieve the hydrophobization of finished paper sheets using Lauryl Gallate (LG) as hydrophobic compound, and a laccase derived from Trametes Villosa, reaching absorption times of up to 4000 s and CA values around 130° as assessed by the water drop test (WDT) and contact angle measurements (CA) respectively

  • Cyclodextrin functionalization of several cellulosic substrates for prolonged release of antibacterial agents

     Cusola Aumedes, Oriol; Tabary, Nicolas; Naceur Belgacem, Mohamed; Bras, Julien
    Journal of applied polymer science
    Date of publication: 2012-11-13
    Journal article

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    Several cellulosic substrates have been surface-functionalized with cyclomaltoheptaose (b-cyclodextrin, b-CD) using citric acid as a crosslinker agent to obtain new surface-modified materials able to release antiseptic molecules over a prolonged period, in view of their use in medical domain. Three different commercial cellulosic substrates were used, namely: (i) an uncoated paper, (ii) a crepe paper, and (iii) a medical bandage. They were successfully grafted by a crosslinked polymer consisting on b-CD molecules as assessed by scanning electron microscopy and Fourier transform infrared spectroscopy analysis. Several time–temperature kinetic cycles were performed to reach the optimum curing parameters. The grafted and nongrafted samples were loaded with chlorhexidine digluconate (digCHX), a widely used antiseptic agent. The drug-delivery kinetics of the encapsulated digCHX was carried out by immersing the sample under investigation into an aqueous medium, and the quantity of the released digCHX was measured, as a function of time, by UV spectroscopy. The optimal grafting conditions were established on the basis of the highest weight gain. These samples did not give the best release performance. Nevertheless, several grafted substrates were able to uptake an appreciable amount of active molecules and release them over a prolonged time of about 20 days

  • Funcionalización de sustratos celulósicos mediante un producto derivado de una reacción enzimática

     Cusola Aumedes, Oriol; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    Reunión de la Red Temática Española Lignocel
    Presentation's date: 2012-11-14
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Paper functionalization by means of enzymatic surface treatments using hydrophobic compounds and lignosulfonates

     Cusola Aumedes, Oriol; Garcia Ubasart, Jordi; Valls Vidal, Cristina; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca
    European Workshop on Lignocellulosics and Pulp
    Presentation's date: 2012-08-30
    Presentation of work at congresses

    Read the abstract Read the abstract View View Open in new window  Share Reference managers Reference managers Open in new window

    In the present work an innovative method for achieving enzymatic surface functionalization on finished paper sheets is presented. A commercial filter paper was surface sized with laccase derived from Trametes Villosa, Lauryl Gallate (LG) as hydrophobic compound, and soluble lignin. Moreover, this study shows the positive influence of sulfonated lignin (SL) acting as a dispersant improving the surface distribution of the LG along the paper sheet. The hydrophobic behavior of obtained sheets is comparable to the commercial ones. Hydrophobicity was measured by the water absorption test, and the variation in the contact angle through time was monitorized by a contact angle goniometer. Hydrophobized paper absorption was compared with Teflon® in order to determine the evaporated and absorbed water amounts from the paper surface. The treatment time, was also studied

    Postprint (author’s final draft)

  • Preparación enzimática acuosa aislada y su uso para la funcionalización de la superficie del papel o soportes celulósicos

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Valls Vidal, Cristina; Vidal Llucia, Teresa
    Date of request: 2012-06-04
    Invention patent

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Preparación enzimática acuosa aislada y uso para la funcionalización de la superficie del papel o soportes celulósicos.

    En un primer aspecto, la presente invención se refiere a una preparación enzimática acuosa aislada obtenida a partir de la reacción de por lo menos una enzima oxidorreductasa, preferiblemente una lacasa, y por lo menos un producto natural o sintético, preferiblemente un compuesto natural, cuyo producto natural o sintético comprende en su estructura por lo menos un grupo fenol o alcohol, que opcionalmente tiene una o más cadenas hidrofóbicas, o por lo menos un grupo esterol.

    En un segundo aspecto, la presente invención se refiere a la utilización de dicha preparación enzimática acuosa aislada en la funcionalización de la superficie del papel o soportes celulósicos.

  • BIO2011-15394-E. Biotecnología de Materiales Lignocelulósicos. Retos enzimáticos, químicos y moleculares para su aplicación industrial, energética y medioambiental

     Camarero, Susana; Vidal Llucia, Teresa; Roncero Vivero, Maria Blanca; Valls Vidal, Cristina; Cusola Aumedes, Oriol; Quintana Vilajuana, Elisabet; Beltramino Heffes, Facundo
    Participation in a competitive project

     Share

  • Using laser speckle to measure the roughness of paper

     Pino, Abdiel; Pladellorens Mallofre, Josep; Colom Pastor, Josep Francesc; Cusola Aumedes, Oriol; Tosas Fuentes, Agustín
    TAPPI journal
    Date of publication: 2011-03
    Journal article

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Roughness measurement of paper using speckle

     Pino, Abdiel; Pladellorens Mallofre, Josep; Cusola Aumedes, Oriol; Caum Aregay, Jesus Maria
    Optical engineering
    Date of publication: 2011-09
    Journal article

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Effect of the laccase mediator system on the fibre properties of TCF bleached kraft pulp

     Cadena Chamorro, Edith Marleny; Cusola Aumedes, Oriol; Vidal Llucia, Teresa; Torres Lopez, Antonio Luis
    International Colloquium on Eucalyptus Pulp
    Presentation's date: 2011-05-11
    Presentation of work at congresses

     Share Reference managers Reference managers Open in new window

  • Enzymatic treatments of paper surface using laccase, hydrophobic compounds and lignin

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Garcia Ubasart, Jordi; Valls Vidal, Cristina
    International Colloquium on Eucalyptus Pulp
    Presentation's date: 2011-05-12
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Tratamientos enzimáticos superficiales utilizando lacasa, compuestos hidrófobos y surfactantes

     Cusola Aumedes, Oriol; Roncero Vivero, Maria Blanca; Garcia Ubasart, Jordi; Valls Vidal, Cristina
    Reunión de la Red Temática
    Presentation's date: 2011-09-06
    Presentation of work at congresses

    View View Open in new window  Share Reference managers Reference managers Open in new window

  • Sistema y procedimiento para la medida de la rugosidad de una muestra de papel mediante el análisis del patrón de textura del speckle

     Pladellorens Mallofre, Josep; Caum Aregay, Jesus Maria; Cusola Aumedes, Oriol; Osvan Pino, Abdiel; Tosas Fuentes, Agustín
    Date of request: 2011-05-04
    Invention patent

    Read the abstract Read the abstract Access to the full text Access to the full text Open in new window  Share Reference managers Reference managers Open in new window

    Sistema y procedimiento para la medida de la rugosidad de una muestra de papel mediante el análisis del patrón de textura del speckle.

    Sistema para la medida de la rugosidad de una muestra (2) de papel, que con un láser (1) y un expansor del haz (11) en ángulo y distancia determinada respecto a la muestra (3), una cámara (3) digital en dirección normal a la muestra (2), un dispositivo de procesado (4) con un adaptador, y con al menos una fuente de alimentación.

    Procedimiento para la medida de la rugosidad de una muestra (2) de papel, que comprende las siguientes etapas

    (a) se proyecta y expande un haz láser sobre una muestra (3)

    (b) una cámara (3) capta la imagen, obteniendo un patrón de speckle

    (c) la cámara (3) envía dicho patrón de speckle al dispositivo de procesado (4)

    (d) el dispositivo de procesado (4) obtiene el parámetro de rugosidad de la muestra (2) a través de un descriptor de la matriz de co-ocurrencia de niveles gris.

  • NUEVOS PROCESOS OBTENCION PRODUCTOS CELULOSICOS ALTO VALOR AÑADIDO

     Torres Lopez, Antonio Luis; Fillat Latorre, Amanda; Garcia Ubasart, Jordi; Cusola Aumedes, Oriol; Vidal Llucia, Teresa
    Participation in a competitive project

     Share

  • La química i la societat

     Grau Vilalta, Maria Dolors; Font Soldevila, Jose; Sanz Balague, Joaquim; Guaus Guerrero, Ester; Calvet Tarragona, Aurelio; Salán Ballesteros, Mª Núria; Martínez Martínez, María R.; Farran Marsa, Adriana; Gorchs Altarriba, Roser; Alvarez Del Castillo, M. Dolores; Garrido Soriano, Nuria; Morillo Cazorla, Margarita; Almajano Pablos, Maria Pilar; Cardona Planes, Anna Maria; Macanás de Benito, Jorge; Bonsfills Pedros, Ana; Gamisans Noguera, Javier; Dorado Castaño, Antonio David; Lao Luque, Concepcion; Torrent Burgues, Juan; Molins Duran, Gemma; Colom Fajula, Xavier; Carrillo Navarrete, Fernando; Ramon Portés, Eva; Garriga Sole, Pere; Sole Sardans, M. Montserrat; Ardanuy Raso, Monica; Pares Sabates, Ferran; Roncero Vivero, Maria Blanca; Cusola Aumedes, Oriol
    Collaboration in exhibitions

     Share