WE PROPOSE A GENERALIZED BOX FRACTAL ALGORITHM TO SEGMENT ACTIVITY SPECKLE IMAGES. THE TIME HISTORY OF THE INTENSITY VALUE AT EVERY PIXEL OF THE FRAMES IS TAKEN AS A TIME SERIES. THE PLOT OF THIS TIME SERIES IS THEN CONSIDERED AN IMAGE IN A PLANE, AND ITS BOX FRACTAL DIMENSION IS THEN CALCULATED WITH THE USUAL METHOD. ITS VALUE IS ASSIGNED TO A PIXEL AND AN IMAGE IS CONSTRUCTED THAT SHOWS THE ACTIVITY FROM A FRACTAL VIEWPOINT. WE SHOW SOME CASES OF THE APPLICATION OF THIS APPROACH TO SEGMENT IMAGES IN DIFFERENT DYNAMIC SITUATIONS.

THE USE OF QUALITATIVE ALGORITHMS IN IMAGES WITH DYNAMIC SPECKLE ALLOWS GENERATING A THREE-DIMENSIONAL INTENSITY MAP, WHICH CORRELATES WITH THE SAMPLE ACTIVITY. SAMPLES IN AN EVAPORATION STATE WILL PRESENT TEMPORARY MOBILITY RELATED TO THEIR VOLUME, WHICH ALLOWS CHARACTERIZING THEIR TOPOGRAPHY. HOWEVER, THE QUALITY OF THE TOPOGRAPHIC CHARACTERIZATION DEPENDS ON THE ILLUMINATION PROFILE AND THE NUMBER OF IMAGES OR FRAMES USED. IN THIS PAPER, A REVIEW OF VARIOUS QUALITATIVE PROCESSING ALGORITHMS IS CARRIED OUT IN ORDER TO EVALUATE THEIR ROBUSTNESS TO THE NUMBER OF FRAMES AND THEIR DEPENDENCE ON THE BEAM PROFILE, EVALUATING THE CHARACTERIZATION OF TOPOGRAPHY HIDDEN BY A LAYER OF PAINT IN PROCESS OF DRYING. WE USE AN ALUMINUM STRUCTURE WITH PERFORATIONS OF DIFFERENT DIAMETERS AND DEPTHS AS A SAMPLE. AMONG THE ALGORITHMS USED, WE HIGHLIGHT THE RESULTS OBTAINED BY THE NORMALIZED DJC METHOD, WHICH CHARACTERIZES THE TOPOGRAPHY OF OUR SAMPLE WITH A CORRELATION OF 0.98 AND PRESENTS STABILITY TO THE NUMBER OF FRAMES USED. THUS, WITH THESE RESULTS WE VALIDATE THE USE OF DYNAMIC SPECKLE IN THE CHARACTERIZATION OF A SURFACE COVERED WITH PAINT.

EL PRESENTE TIENE POR FINALIDAD MEDIR EL CONTENIDO DE HUMEDAD EN FARDOS DE PAPEL Y CARTÓN APLICANDO TÉCNICA DE MICROONDA EN EL ESPACIO LIBRE DEFINIDO POR LA TRAYECTORIA DE LA ONDA ELECTROMAGNÉTICA, PARTICULARMENTE EN ESTE TRABAJO ES ANTENA TRANSMISORA, AIRE, MUESTRA, AIRE Y ANTENA RECEPTORA.SE REALIZARON A ESCALA DE LABORATORIO MEDICIONES EN DIFERENTES PROBETAS QUE SIMULAN LAS CARACTERÍSTICAS DE LOS FARDOS A DISTINTOS CONTENIDOS DE HUMEDAD. LA CUANTIFICACIÓN DE LA INTERACCIÓN ENTRE EL MATERIAL Y LAS MICROONDAS SE LOGRA A TRAVÉS DE MEDICIONES DE POTENCIA EN RECEPCIÓN EN UN RANGO DE FRECUENCIA DE LOS 3,84-12,5GHZ PARA LUEGO ESTABLECER LA FRECUENCIA ÓPTIMA DE MEDICIÓN.LA INFORMACIÓN OBTENIDA EXPERIMENTALMENTE SE SOMETE A UNA FASE DE ANÁLISIS DE LAS DISTRIBUCIONES MEDIAS DE LAS VARIABLES ESTUDIADAS, EN BUSCA DE UNA O VARIAS CURVAS DE CALIBRACIÓN QUE PERMITAN ESTIMAR EL CONTENIDO DE HUMEDAD EN CADA FARDO. LOS RESULTADOS OBTENIDOS EVIDENCIAN UNA RELACIÓN ENTRE LA POTENCIA DE RECEPCIÓN A DIFERENTES CONTENIDOS DE HUMEDAD, POR OTRA PARTE, LA VARIABILIDAD DE LAS MUESTRAS Y EL AMBIENTE DEL LABORATORIO INFLUYE EN LAS MEDICIONES.

IN GENERAL, DATA REGARDING THE MECHANICAL PROPERTIES OF WOOD IS STILL INCOMPLETE, MAINLY OWING TO THE DIFFICULTIES INVOLVED IN PREPARING WELL-MADE STANDARD TESTING SAMPLES, AS WELL AS THE TIME-CONSUMING EVALUATION TESTS. THEREFORE, THE ELASTIC CONSTANTS FOR PINUS RADIATA IN THIS PAPER WERE DETERMINED USING ULTRA SOUND TECHNOLOGY. IN PARALLEL, TYPICAL COMPRESSION MECHANICAL TESTING WAS CARRIED OUT TO COMPARE THE EFFECTIVENESS OF THE NONDESTRUCTIVE TEST USING THE ULTRASOUND. THE LONGITUDINAL ELASTIC CONSTANT VALUES WERE SIMILAR TO THE MECHANICAL TESTING (ULTRASOUND WAS 12,8 % HIGHER THAN MECHANICAL TESTING), SHOWING THAT ULTRASOUND TECHNIQUE IS A RELIABLE AND VALID TOOL. THE VALUES FOR RADIAL AND TANGENTIAL MODULI OBTAINED BY THE ULTRASOUND VERSUS MECHANICAL TESTING SHOWED STATISTICALLY SIGNIFICANT DIFFERENCES. THIS MAY BE DUE TO THE DIFFICULTY IN OBTAINING ADEQUATE SAMPLES FOR MECHANICAL TESTING. THE SYMMETRY OF THE SHEAR MODULUS WAS REVEALED BY THE ULTRASOUND TECHNIQUE (GIJ = GJI). POISSON?S RATIOS WERE NOT COMPARABLE USING EITHER METHOD; HOWEVER, VALUES OBTAINED WERE MORE CONSISTENT WITH THE EXISTING LITERATURE FOR PINUS SPECIES. ADDITIONALLY, THE ELASTIC ANISOTROPY OF THE ANALYZED WOOD SAMPLES WAS DEMONSTRATED THROUGH THE ULTRASOUND VELOCITY PROPAGATION IN THE MATERIAL. IT WAS THUS POSSIBLE TO OBTAIN THE TWELVE ENGINEERING CONSTANTS THAT CHARACTERIZE THE MECHANICAL BEHAVIOR OF WOOD EMPLOYING OF THE PROPOSED ULTRASOUND TECHNIQUE. THE RESULTS PROVED THAT THIS TECHNIQUE COULD BE A USEFUL TOOL FOR SUCH HARACTERIZATION

THE AIM OF THIS WORK IS TO DETERMINE THE YOUNGS MODULES AND SHEAR MODULES OF ELASTICITY OF FOUR NATIVE CHILEAN HARDWOODS (TEPA (LAURELIOPSIS PHILIPIANÀ), OLIVILLO (AEXTOXKON PUNCTATUM), LAUREL (LAURELIA SEMPERVIRENS) AND LENGA (NOTHOFAGUS PUMILIO) AND TWO CHILEAN SOFTWOODS (ALERCE (FITZROYA CUPRESSOIDES) AND MANIO (PODOCARPUS NUBIGEND)) USING ULTRASOUND TECHNIQUES. LONGITUDINAL AND TRANSVERSAL WAVES WERE USED TO DETERMINE THE THREE MOE IN THE LONGITUDINAL, RADIAL AND TRANSVERSAL DIRECTIONS AND ALSO THE SHEAR MODULES 0 LR, GLT AND G RT\ THE RESULTS SHOW HIGHER ANISOTROPY BEHAVIOR FOR THE TESTED HARDWOODS IN RELATION TO SOFTWOODS. THIS IS IN CONTRAST TO MOST EUROPEAN SPECIES, WHICH HAVE A HIGHER ANISOTROPY FOR SOFTWOOD THAN FOR HARDWOOD.

THE CAPACITY OF OPTICAL COMMUNICATION CHANNELS CAN BE INCREASED BY SPACE DIVISION MULTIPLEXING IN STRUCTURED OPTICAL FIBERS. RADIAL CORE OPTICAL FIBERS ALLOWS FOR THE PROPAGATION OF TWISTED LIGHT?EIGENMODES OF ORBITAL ANGULAR MOMENTUM, WHICH HAVE ATTRACTED CONSIDERABLE ATTENTION FOR HIGH-DIMENSIONAL QUANTUM INFORMATION. HERE WE STUDY THE GENERATION OF ENTANGLED PHOTONS THAT ARE TAILOR-MADE FOR COUPLING INTO RING CORE OPTICAL FIBERS. WE SHOW THAT THE COUPLING OF PHOTON PAIRS PRODUCED BY PARAMETRIC DOWN-CONVERSION CAN BE INCREASED BY CLOSE TO A FACTOR OF THREE BY PUMPING THE NON-LINEAR CRYSTAL WITH A PERFECT VORTEX MODE WITH ORBITAL ANGULAR MOMENTUM ?, RATHER THAN A GAUSSIAN MODE. MOREOVER, THE TWO-PHOTON ORBITAL ANGULAR MOMENTUM SPECTRUM HAS A NEARLY CONSTANT SHAPE. THIS PROVIDES AN INTERESTING SCENARIO FOR QUANTUM STATE ENGINEERING, AS PUMPING THE CRYSTAL WITH A SUPERPOSITION OF PERFECT VORTEX MODES CAN BE USED IN CONJUNCTION WITH THE MODE FILTERING PROPERTIES OF THE RING CORE FIBER TO PRODUCE SIMPLE AND INTERESTING QUANTUM STATES.

IN THIS WORK, A SYSTEM FOR MEASURING MOISTURE CONTENT IN BUNDLES OF RECYCLED CARDBOARD SHEETS USING MICROWAVES IS PROPOSED AND EVALUATED. FOR THE DEVELOPMENT OF THIS SYSTEM, A MICROWAVE GENERATOR AND AN ANTENNA TUNED IN THE X-BAND WERE USED. THE DETECTOR SYSTEM USED WAS FORMED BY A DIODE ARRAY POINT OF CONTACT. CALIBRATION CURVES OF MOISTURE CONTENT IN BALES VERSUS VOLTAGE IN THE ARRAY WERE OBTAINED FOR TWO ORIENTATIONS OR POSITIONS OF THE CARDBOARD SHEETS IN THE SAMPLE BALES. THE RESULTS SHOWED THAT THE HIGHER THE MOISTURE CONTENT, THE LOWER THE VOLTAGE IS INDUCED IN THE DIODES. IT WAS ALSO OBSERVED THAT THE ATTENUATION OF THE MICROWAVE SIGNAL DEPENDS ON THE POSITION OF THE CARDBOARD SHEETS AND THAT THE MEASUREMENT CAN BE MADE IN SAMPLES OF BALES WITH A MAXIMUM OF 35% HUMIDITY, BECAUSE ON THIS PERCENTAGE, THE VARIATION OF VOLTAGE IN THE DIODE ARRAY IS ALMOST ZERO.

IN THIS ARTICLE, IT IS INVESTIGATED THE EFFECT OF AL DOPING IN THE JUNCTION PARAMETERS OF AG/CDS:AL THIN-FILM SCHOTTKY DIODES AND THEIR ELECTRICAL RESPONSE TO MICROWAVE IRRADIATION. NANOCRYSTALLINE CDS:AL THIN-FILMS WITH THICKNESSES BETWEEN 109 AND 173 NM WERE PREPARED BY CHEMICAL BATH DEPOSITION AND, SUBSEQUENTLY, AG THIN-FILMS WITH AN AVERAGE THICKNESS OF 102 NM WERE GROWN ON THE CDS:AL USING DC SPUTTERING. THE STRUCTURAL, CHEMICAL, MORPHOLOGICAL AND OPTICAL PROPERTIES OF CDS:AL AND AG FILMS WERE CHARACTERIZED BY X-RAY DIFFRACTION (XRD), SCANNING ELECTRON MICROSCOPE, ATOMIC FORCE MICROSCOPE, ENERGY-DISPERSIVE X-RAY SPECTROSCOPY AND UV-VIS SPECTROPHOTOMETER, RESPECTIVELY. CURRENT-VOLTAGE (I - V) CHARACTERISTICS OF AG/CDS:AL DIODES, WITH DIFFERENT AL CONTENT, WERE OBTAINED AT ROOM TEMPERATURE IN DARK CONDITIONS. XRD STUDIES SHOWS THAT CDS:AL AND AG THIN-FILMS HAVE AN HEXAGONAL AND CUBIC STRUCTURE, RESPECTIVELY. CRYSTALLITE SIZES DECREASES WITH AL CONTENT FOR CDS:AL FILMS AND WERE FOUND TO BE IN THE 15-40 NM RANGE. A DECREASE IN THE INTENSITY OF THE XRD MAIN PEAK OF CDS:AL FILMS IS OBSERVED, CAUSED BY THE INCLUSION OF AMORPHOUS AL2O3 ON THE CDS FILM. IT WAS FOUND THAT BAND GAP OF CDS:AL FILMS INCREASES WITH INCREASING AL CONTENT, FROM 2.28 EV TO 2.40 EV. BASED ON THE I - V CHARACTERISTICS OF THE DIODES, THEIR BARRIER HEIGHT (0), IDEALITY FACTOR N, AND SERIES RESISTANCE R-S WERE CALCULATED, AND IT WAS FOUND THAT THESE VALUES ARE MODIFIED BY INCREASING AL CONTENT IN CDS FILMS, IN THE RANGES: (0): 0.7037-0.8426 EV; N: 3.485-4.213; R-S: 0.54-9.86 M OMEGA. BESIDES, IT WAS STATED THAT AL DOPING CHANGES THE AVERAGE SURFACE ROUGHNESS AND THE ENERGIES OF THE CHARGE NEUTRALITY LEVELS OF CDS:AL FILMS. THE EFFECTS OF PHYSICAL PROPERTIES OF THE FILMS ON THE JUNCTION PARAMETERS OF THE DIODES WERE ALSO DISCUSSED. FINALLY, I - V CHARACTERISTICS OF THE AG/CDS:AL DIODES WERE STUDIED UNDER X-BAND MICROWAVE IRRADIATION AT ROOM TEMPERATURE IN DARK CONDITIONS. FOR A SPECIFIC AL DOPING VA

THE NON-DESTRUCTIVE TECHNIQUES ARE A VERY IMPORTANT TOOL IN THE PROCESS OF WOOD CHARACTERIZATION AND EVALUATION. IN THIS WORK, THE OBJECTIVE IS THE EVALUATION OF PHYSICAL AND MECHANICAL PROPERTIES OF SOME NATIVE CHILEAN WOOD SPECIES BY USING THE ULTRASOUND TECHNIQUES AND THEIR COMPARISION WITH THE RESULTS OF TYPICAL MECHANICAL TESTS. THE SELECTED WOODS WERE FOUR HARDWOODS: TEPA (LAURELIOPSIS PHILIPIANA), OLIVILLO (AEXTOXICON PUNCTATUM), LAUREL (LAURELIA SEMPERVIRENS) AND LENGA (NOTHOFAGUS PUMILIO) AND TWO SOFTWOODS: ALERCE (FITZROYA CUPRESSOIDES) AND MAÑÍO (PODOCARPUS NUBIGENA). THE EQUIPMENT USED WERE TWO TYPES OF ULTRASOUND GENERATORS: STEINKAMP BP5 AND PANAMETRIC EPOCH XT. THE RESULTS SHOWN A HIGHER ANISOTROPY FOR HARDWOODS THAN FOR SOFTWOODS, AND A RELATIVELY SYMMETRY FOR TRANSVERSAL WAVE PROPAGATION VELOCITIES AND FOR SHEAR MODULUS OF ELASTICITY, ALONG THE PRINCIPAL DIRECTIONS OF THE TREE. AT THE SAME TIME THE MEAN VALUES OF YOUNG MODULUS OF ELASTICITY (MOE) OBTAINED BY USING THE ULTRASOUND EQUIPMENTS WERE A 25-47 % HIGHER THAN THE SAME MODULUS MEASURED BY MECHANICAL TESTS.

DATA SETS WITH MECHANICAL AND PHYSICAL PROPERTIES OF WOOD SPECIES CAN AID THE RECOGNITION OF BIOMECHANICAL CORRELATIONS, AND THEY CAN ALSO BE VALUABLE TOOLS TO ASSIST DECISION MAKING REGARDING THE PRACTICAL INDUSTRIAL EMPLOYMENT OF THE SPECIES. HOWEVER, SUCH DATA SETS ARE STILL LACKING FOR MANY SPECIES, PARTICULARLY NON-EUROPEAN AND NON-NORTH-AMERICAN SPECIES. THEREFORE, THE GOAL OF THIS STUDY WAS TO DETERMINE THE MECHANICAL PROPERTIES OF FOUR CHILEAN SPECIES (THE SOFTWOODS ALERCE AND MANIO, AND THE HARDWOODS LINGUE AND ROBLE), INCLUDING THE THREE YOUNGS MODULI AND THE THREE SHEAR MODULI. DYNAMIC METHODS WERE APPLIED AS WELL AS STATIC ONES. THE RESULTS SUGGEST THAT BRINELL HARDNESS, COMPRESSION STRENGTH AND YOUNGS MODULI ARE CLEARLY CORRELATED WITH THE DENSITY AND CAN PARTLY BE RELATED TO ANATOMICAL DETAILS. SINCE THE INVESTIGATED SPECIES COVER ONLY A FRACTION OF THE CHILEAN SPECIES THAT ARE SUITABLE FOR CONSTRUCTION PURPOSES, FOR EXAMPLE, FURTHER FUTURE EXAMINATION OF RELEVANT SPECIES WOULD BE BENEFICIAL FOR BASIC RESEARCH AND INDUSTRY.

COMPREHENSIVE DATASETS OF THE ELASTIC CONSTANTS ARE AVAILABLE FOR ONLY A FEW EUROPEAN WOOD SPECIES, ESPECIALLY SPRUCE. THE GOAL OF THIS STUDY, THEREFORE, WAS TO PROVIDE YOUNG?S AND SHEAR MODULI FOR THE PRINCIPAL DIRECTIONS AND PLANES FOR FURTHER SELECTED EXTRANEOUS SPECIES TO EXTEND THE CURRENTLY EXISTING DATASETS. FOR THIS PURPOSE, A DYNAMIC TECHNIQUE WAS CHOSEN: THE MODULI WERE ESTIMATED ON THE BASIS OF SOUND VELOCITY AND DENSITY MEASUREMENTS. THE COLLECTED DATA MAY BE HELPFUL FOR SPECIALISTS IN THE RELEVANT RESEARCH AND PRACTICAL FIELDS, PARTICULARLY WHEN STRESSES AND STRAINS OF STRUCTURAL ELEMENTS HAVE TO BE CALCULATED USING MODELING APPROACHES.

A PROBLEM PRESENT IN THE WOOD BOARDS INDUSTRY IS THE LACK OF KNOWLEDGE OF ITS ROUGHNESS. THE ROUGHNESS CAUSES THE FORMATION OF VOIDS BETWEEN THE BOARD AND THE PROTECTIVE COVER COMMONLY USED TO GIVE A SPECIAL FINISH TO THE BOARD. THIS LEADS TO POOR ADHESION BETWEEN THE ADHESIVE AND THE COVER WHICH AFFECTS THE QUALITY OF THE FINAL PRODUCT. THUS, A PRECISE AND FAST WAY TO MEASURE THE ROUGHNESS THAT ALLOWS CHARACTERIZATION IN LINE AND ACROSS THE BOARD IS REQUIRED. SPECKLE INTERFEROMETRY IS A WIDELY USED TECHNIQUE TO PERFORM NON-INVASIVE MEASUREMENTS, MAINLY BY ILLUMINATING OBJECTS UNDER STUDY WITH COHERENT LIGHT. IN THIS STUDY, LASER SPECKLE INTERFEROMETRY IS USED TO DETERMINATE SURFACE ROUGHNESS IN DIFFERENT WOOD BOARDS. THE PROPOSED METHOD USES AN OPTICAL SYSTEM AND AN IMAGE PROCESSOR THAT CORRELATES A SERIES OF SUCCESSIVE IMAGES OF INTENSITY SPECKLE PATTERN. THESE IMAGES ARE OBTAINED VARYING THE ILLUMINATION ANGLE. IN ORDER TO OBTAIN THE ROUGHNESS PARAMETERS OF THE BOARDS, THE MEASURED CORRELATIONS WERE ADJUSTED TO A THEORETICAL FUNCTION BY USING A NUMERICAL REGRESSION ALGORITHM. THE OBTAINED VALUES OF ROUGHNESS FOR DIFFERENT BOARDS VARIED BETWEEN 1.55 ?M AND 12.69 ?M. OUR RESULTS SHOW A GOOD AGREEMENT WITH THE MEASUREMENTS OBTAINED USING CONVENTIONAL METHODS. FINALLY, WE PRESENT A DISCUSSION OF HOW LASER SPECKLE INTERFEROMETRY CAN BE ADAPTED TO CHARACTERIZE ROUGHNESS DURING PRODUCTION IN REAL TIME AND IN WIDE AREA BOARDS.

ORBITAL ANGULAR MOMENTUM CAN BE USED TO IMPLEMENT HIGH CAPACITY DATA TRANSMISSION SYSTEMS THAT CAN BE APPLIED FOR CLASSICAL AND QUANTUM COMMUNICATIONS. HERE WE EXPERIMENTALLY STUDY THE GENERATION AND TRANSMISSION PROPERTIES OF THE SO-CALLED PERFECT VORTEX BEAMS AND THE LAGUERRE-GAUSSIAN BEAMS IN RING-CORE OPTICAL FIBERS. OUR RESULTS SHOW THAT WHEN USING A SINGLE PREPARATION STAGE, THE PERFECT VORTEX BEAMS PRESENT LESS RING-RADIUS VARIATION THAT ALLOWS COUPLING OF HIGHER OPTICAL POWER INTO A RING CORE FIBER. THESE RESULTS LEAD TO LOWER POWER REQUIREMENTS TO ESTABLISH FIBER-BASED COMMUNICATIONS LINKS USING ORBITAL ANGULAR MOMENTUM AND SET THE STAGE FOR FUTURE IMPLEMENTATIONS OF HIGH-DIMENSIONAL QUANTUM COMMUNICATION OVER SPACE DIVISION MULTIPLEXING FIBERS.

AN MOOREICHENPROBEN (QUERCUS ROBUR L.), PRAPARIERT AUS EINEM IM FLUSS BUG (POLEN) GELAGERTEM STAMM, WURDEN UNTERSUCHUNGEN ZU PHYSIKALISCH-MECHANISCHEN EIGENSCHAFTEN DURCHGEFUHRT. DER AUF EIN ALTER VON 150 JAHREN DATIERTE BAUMSTAMM LAGERTE FUR 7100 ± 50 JAHRE IM BODEN UNTER EINER 3 M DICKEN SCHICHT AUS SAND UND SCHLICK. DIE AUSERE ZONE DES HOLZES WAR SEHR DUNKEL (TIEFSCHWARZ) GEFARBT, WOHINGEGEN DIE FARBE ZUR STAMMMITTE HELLER WURDE. ES KONNTEN KEINE WESENTLICHEN VERANDERUNGEN DER MECHANISCHEN EIGENSCHAFTEN UND DES SORPTIONSVERHALTENS AM GEPRUFTEN HOLZ FESTGESTELLT WERDEN. DIE QUELLUNG IN RADIALER RICHTUNG SANK ZUR AUSEREN ZONE DES STAMMES LEICHT AB UND KORRELIERT MIT DER FARBE. JE DUNKLER DAS HOLZ UND DAMIT INTENSIVER DIE FARBANDERUNG, UMSO GERINGER WAR DIE RADIALE QUELLUNG. TANGENTIAL WAR DER EINFLUSS DER POSITION IM STAMM AUF DIE QUELLUNG GERING. DIE POROSITAT BLIEB ANNAHERND UNVERANDERT. HINSICHTLICH DER MECHANISCHEN EIGENSCHAFTEN WURDE DIE BEKANNTE DIFFERENZIERUNG VON E- UND G-MODUL IN DEN HAUPTACHSEN ERMITTELT. EINE LEICHTE REDUZIERUNG DES DYNAMISCHEN E-MODUL WURDE BEI MESSUNGEN MITTELS ULTRASCHALL UND DEM GERAT BP5 (FREQUENZ 50 KHZ) IN FASERRICHTUNG BEOBACHTET. VOR ALLEM MIT ZUNAHME DER DUNKELFARBUNG SANK DER E-MODUL DES SUBFOSSILEN HOLZES.

THE CLOCK TOWER, A TYPICAL EXPRESSION OF THE SALTPETER PERIOD, IS LOCATED IN ARTURO PRAT SQUARE IN IQUIQUE, CHILE. THE BUILDING, COMPLETELY MADE OF WOOD, HAS ENDURED THE PASSING OF TIME WITHOUT MAJOR MODIFICATIONS. THERE IS CONCERN ABOUT ITS CONSERVATION STATE. HOWEVER, THERE ARE NO RECORDS OF IN-DEPTH EVALUATIONS THAT DETERMINE ITS CONSERVATION STATE. THE PRESENT STUDY, CARRIED OUT THROUGH THE USE OF NON-DESTRUCTIVE TESTING (NDT), IS AN EVALUATION OF ITS CURRENT STATE. BASIC INSPECTION AND STRUCTURAL ANALYSIS WERE ALSO INCLUDED. THE RESULTS INDICATE THAT THE WOOD OF THE BUILDING CORRESPONDS TO THE SPECIES PSEUDOTSUGA MENZIESII (OREGON PINE). THE BASIC INSPECTION DOES NOT REVEAL ANY SIGNIFICANT DAMAGE. HOWEVER, THERE IS EVIDENCE OF ATTACKS BY INSECTS IN THE LARVAL STAGE, SOCIAL INSECTS AND BROWN ROT FUNGI. ABIOTIC DETERIORATION BY DEFIBERING IS ALSO OBSERVED. NDT STUDIES?ULTRASOUND, RESISTOGRAPHY AND XYLO HYGROMETRY?ALLOWED THE ESTIMATION OF DENSITY AND STATIC MODULUS OF ELASTICITY (MOE) IN BENDING. THE LOW DENSITY OF WOOD IS SHOWN IN A STATIC MOE VALUE OF ONLY 4.4 GPA. ACCORDING TO CHILEAN REGULATIONS, WOOD ELEMENTS WERE CLASSIFIED AS STRUCTURAL CLASS F3. HOWEVER, THE STRUCTURAL ANALYSIS DETERMINED THAT THE WORKING STRESSES DID NOT EXCEED THE ADMISSIBLE STRESSES. AT THE FOUNDATIONS LEVEL, IT IS NECESSARY TO PERFORM INTERVENTION ACTIONS.