RESUMEN El trabajo tuvo el propósito de caracterizar, desde el punto de vista químico, físico, granulométrico y mineralógico, un residuo industrial de hidróxido de calcio generado en el proceso de fabricación de acetileno. Las muestras se analizaron, primeramente, sin neutralizar; luego se realizó el mismo procedimiento, usando ácido sulfúrico a un 98 % de pureza. Para ambos casos, las temperaturas de calentamiento fueron de 500 oC y 900 oC. Para identificar las fases, los patrones de difracción fueron obtenidos usando fuente de radiación de cobre (CuKα, λ=1,5418 Å). Se determinó que el residual presenta CaO y MgO, lo que garantiza su pureza. Al calentarlo sin neutralizar a 500 oC se transforma el hidróxido de calcio y a los 900 oC hay pérdida del carbonato y del agua. En el residual, tanto sin tratamiento como neutralizado, está presente el hidróxido de calcio.

ABSTRACT The purpose of the work was to characterize, from the chemical, physical, granulometric and mineralogical point of view, an industrial residue of calcium hydroxide generated in the acetylene manufacturing process. Samples were first analyzed without neutralization; then the same procedure was performed using 98 % purity sulphuric acid. For both cases, the heating temperatures used were 500 °C and 900 °C. To identify the phases, diffraction patterns were obtained using copper radiation source (CuKα, λ = 1.5418 Å). It was determined that residual contains CaO and MgO, which guarantees its purity; heated at 500 °C, and without neutralizing, calcium hydroxide is transformed and there is loss of water and carbonate at 900 °C. In both untreated and neutralized waste, calcium hydroxide is present.

This research investigates the effects of accelerated spheroidizing of cementite on the mechanical properties and microstructural characteristics of commercial steel grades (Fe-0.2C, Fe-0.5C, Fe-0.7C wt%), emphasizing the role of cold-rolling reduction followed by stress relief annealing. Utilizing SEM imaging, X-ray diffraction, and EBSD measurements, this study comprehensively examines how variations in carbon content influence hardness, dislocation density, and crystallographic texture orientation. Microhardness measurements reveal a direct relationship with carbon content, yielding values of 28.0±1.0 HRC for DT-1020, 36.0±1.0 HRC for DT-1050, and 39.0±1.0 HRC for DT-1070. Texture analysis through EBSD demonstrates distinct patterns among the grades: DT-1020 displays a dominant (111) texture, DT-1050 exhibits a (101) orientation, and DT-1070 features a more refined (101) texture. Dislocation density analysis further corroborates the impact of carbon content, with DT-1050 presenting the highest density at approximately 7.8×1016 m-2. This detailed exploration elucidates the intricate interplay between carbon content, cementite morphology, and their collective influence on mechanical performance of steel, providing valuable guidance for tailoring steel properties via microstructural control. Fe0.2C, Fe02C FeC Fe 0.2C, 0 2C C (Fe-0.2C Fe0.5C, Fe05C 0.5C, 5C Fe-0.5C Fe0.7C Fe07C 0.7C 7C wt%, wt wt% , wt%) coldrolling cold rolling annealing imaging Xray X ray diffraction hardness orientation 28010 28 1 28.0±1. DT1020, DT1020 DT 1020, 1020 36010 36 36.0±1. DT1050, DT1050 1050, 1050 39010 39 39.0±1. DT1070. DT1070 1070. 1070 DT-102 111 (111 DT-105 101 (101 DT-107 781016 7 8 1016 7.8×101 m2. m2 m 2. 2 m-2 morphology control Fe0 Fe0.2C 02C 0.2C Fe0.5C 05C 0.5C 07C 2801 28.0±1 DT102 102 3601 3 36.0±1 DT105 105 3901 39.0±1 DT107 107 DT-10 11 (11 10 (10 78101 7.8×10 m- 280 28.0± DT10 360 36.0± 390 39.0± DT-1 (1 7810 7.8×1 28.0 DT1 36.0 39.0 DT- ( 781 7.8× 28. 36. 39. 78 7.8 7.

ABSTRACT Hybrid materials formed between polyaniline and layered double hydroxides of Zn and Al (Pani/ZnAlHDL) were obtained by adding previously prepared polyaniline (Pani) to the reaction medium during the synthesis of the HDLs, including HDLs modified with the anionic surfactants sodium dodecyl sulfate and sodium dodecylbenzenesulfonate. The composites exhibited a blue color characteristic of the emeraldine base phase of Pani. X-ray diffraction (XRD) patterns of these compounds showed a shift of the peaks (003) and (006) of ZnAlHDL to lower 2θ values, indicating the presence of both phases in the composites. Additionally, it was observed that the anionic surfactants also influence the structural characteristics of the composites. Fourier-transform infrared (FTIR) spectra support the XRD results. Composites obtained with surfactants were subjected to colorimetric sensor tests for HCl. After only 5 minutes of exposure to HCl vapors, the materials changed their color from blue to green, indicating the formation of the Pani emeraldine salt phase. This indication was confirmed by UV-Vis spectroscopy, as spectra after acid interaction showed new bands in the 400 nm and 820 nm regions, characteristic of the emeraldine salt, the green-colored structural form of Pani. These results demonstrate the feasibility of using these materials in acid sensing, providing a rapid and effective response. Pani/ZnAlHDL PaniZnAlHDL (Pani/ZnAlHDL (Pani dodecylbenzenesulfonate Xray X ray (XRD 003 (003 006 (006 θ values Additionally Fouriertransform Fourier transform FTIR (FTIR vapors green UVVis UV Vis spectroscopy 40 82 regions greencolored colored sensing response 00 (00 4 8 0 (0 (

RESUMO Materiais híbridos formados entre polianilina e hidróxidos duplos lamelares de Zn e Al (Pani/ZnAlHDL) foram obtidos adicionando a Polianilina (Pani) previamente preparada ao meio reacional da síntese dos HDLs e também HDLs modificado com os surfactantes aniônicos dodecilsulfato de sódio e dodecilbenzenosulfato de sódio. Os compósitos apresentaram cor azul que é característica da fase base esmeraldina da Pani. Os difratogramas de raios X destes compostos apresentaram deslocamento dos picos (003) e (006) do ZnAlHDL para menores valores de 2θ, indicando a presença das duas fases nos compósitos. Além disso, foi constatado também que os surfactantes aniônicos também exercem influência nas características estruturais dos compósitos. Os espectros de FTIR corroboram os resultados do DRX. Os compósitos obtidos com os surfactantes foram submetidos à testes de sensor colorimétrico para HCl. Após 5 minutos apenas de exposição aos vapores do HCl, os materiais apresentaram mudança na sua coloração de azul para verde, indicando a formação da fase da Pani, sal esmeraldina. Esse indício foi confirmado por espectroscopia na região do UV-Vis, uma vez que os espectros após interação com ácido, apresentaram novas bandas, nas regiões de 400 nm e 820 nm, que são características do sal esmeraldina, forma estrutural da Pani de coloração verde. Esses resultados mostram a viabilidade da utilização destes materiais no sensoriamento de ambientes ácidos, apresentando resposta rápida e eficaz. Pani/ZnAlHDL PaniZnAlHDL (Pani/ZnAlHDL (Pani 003 (003 006 (006 2θ θ disso DRX HCl verde UVVis, UVVis UV Vis, Vis UV-Vis ácido bandas 40 82 ácidos eficaz 00 (00 4 8 0 (0 (

The main objective of this paper is to produce an anodic layer of TiO2 rich in calcium, phosphorus, and magnesium using the anodizing technique known as micro-arc oxidation (MAO) on the Ti-25Ta alloy together with the incorporation of silver (Ag), copper (Cu) and zinc (Zn) metallic ions using different electrolytes. The structural changes and microstructures on the MAO surfaces were analyzed using the X-ray diffraction (XRD) technique and scanning electron microscopy (SEM). The chemical composition to verify whether silver, copper, and zinc were incorporated via energy dispersive spectroscopy (EDS) and surface characteristics such as wettability and hardness of the coatings were also investigated. From the EDS mapping results, it is observed that the MAO process was effective in incorporating the ions present in the electrolyte. Regarding X-ray diffraction patterns, the TiO2 phases formed in the Ti-25Ta alloy has a mixture of anatase and rutile, making the MAO surface hydrophilic. The Ag element surface is thicker than the films containing Cu and Zn, as the Ag ions have high electrical conductivity, accelerating the oxidation process during surface treatment. Regarding hardness, coating containing Cu have a higher hardness value. TiO calcium phosphorus microarc micro arc (MAO Ti25Ta TiTa Ti 25Ta Ta Ag, , (Ag) (Cu Zn (Zn electrolytes Xray X ray XRD (XRD SEM. SEM . (SEM) (EDS investigated results electrolyte patterns rutile hydrophilic conductivity treatment value (Ag (SEM

Abstract EUROFER is a reduced-activity ferritic-martensitic steel used in the construction of nuclear fusion reactors. Despite its good properties of mechanical strength, corrosion, creep, and radioactive damage, its maximum working temperature is 500 °C due to microstructural changes that occur above this condition. This study aims to investigate the use of niobium pentoxide (Nb2O5) in EUROFER-based alloys through a high-energy milling technique. EUROFER chips were processed in a planetary ball mill with different concentrations of Nb2O5 for 10 h. The results showed a reduction of approximately 32% in the particle size distribution of the milled powders compared to pure EUROFER. The X-ray diffraction patterns revealed a decrease solely in the lattice parameters of pure EUROFER and samples containing 3% Nb2O5. The addition of Nb2O5 also resulted in a reduction in saturation magnetization, and an increase in coercivity and magnetic remanence. reducedactivity reduced activity ferriticmartensitic ferritic martensitic reactors strength corrosion creep damage 50 C condition NbO Nb O (Nb2O5 EUROFERbased based highenergy high energy technique Nb2O 1 h 32 Xray X ray 3 magnetization remanence 5 (Nb2O

Phenylphosphonates of zinc (Zn-PPh), calcium (Ca-PPh) and magnesium (Mg-PPh) were synthesized by the hydrothermal method. Samples showed characteristic X-ray diffraction (XRD) patterns of layered compounds with basal spacing in the range of 14-15 Å. According to Fourier transform infrared spectroscopy (FTIR), all compositions showed the presence of characteristic bands attributed to phenyl aromatic rings, phosphonate and lattice metal-oxygen (M-O) vibrations. Different concentrations of phenylphosphonate particles were applied to stabilize water-in-oil Pickering emulsions using vaseline oil in different w/o fractions. The three particle types showed greater affinity for the oil phase (wettability) and the ability to stabilize the emulsions via the Pickering effect. Ca-PPh particles contained a greater emulsified fraction after 20 days of evaluation. This result can be attributed to the particle morphology observed by scanning electron microscopy (SEM). The fibrous morphology of Ca-PPh particles is believed to increase the steric hindrance effect at the surface around the droplets, while the Zn-PPh and Mg-PPh layered particles tended to form clusters. ZnPPh, ZnPPh Zn PPh , (Zn-PPh) CaPPh Ca (Ca-PPh MgPPh Mg (Mg-PPh method Xray X ray XRD (XRD 1415 14 15 14-1 Å FTIR, FTIR (FTIR) rings metaloxygen metal oxygen MO M O (M-O vibrations waterinoil water wo w o fractions wettability (wettability 2 evaluation SEM. SEM . (SEM) droplets clusters (Zn-PPh 141 1 14- (FTIR (SEM

Layered double hydroxides (LDH) with the composition Zn2Cr, intercalated with acetate and chloride ions were synthesized by co-precipitation with increasing pH and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). The samples synthesized at optimized pH showed XRD patterns with basal diffraction peaks typical of layered structures, with basal distances of 7.88 and 12.69 Å for intercalated chloride (Zn2Cr/Cl) and acetate (Zn2Cr/Ac), respectively. After optimization experiments, exchange reactions were performed with different anions, using an excess of five times the anions to be intercalated. Zn2Cr/Cl was exchanged with CH3COO-, F-, Br-, I-, SO42- and NO3-, and Zn2Cr/Ac was exchanged with F-, Cl-, Br-, I-, SO42- and NO3-. Not all reactions were effective, indicating that among the evaluated anions, CH3COO- was preferred for exchange, mainly attributed to the pre-expansion with bigger anions, facilitating the exchange with smaller anions. LDH (LDH Zn2Cr ZnCr Zn Cr coprecipitation co precipitation Xray X ray XRD, , (XRD) Fouriertransform Fourier transform FTIR, FTIR (FTIR) SEM, SEM (SEM) EDS (EDS plasmaoptical plasma optical ICPOES. ICPOES ICP OES . (ICP-OES) structures 788 7 88 7.8 1269 12 69 12.6 Zn2CrCl ZnCrCl Cl (Zn2Cr/Cl Zn2Cr/Ac, Zn2CrAc ZnCrAc Ac (Zn2Cr/Ac) respectively experiments CH3COO, CH3COO CHCOO CH COO F, F F- Br, Br Br- I, I I- SO42 SO NO3, NO3 NO NO3- Cl, Cl- NO3. effective preexpansion pre expansion (XRD (FTIR (SEM (ICP-OES 78 8 7. 126 1 6 12. CrCl CrAc (Zn2Cr/Ac SO4

ABSTRACT Cobalt oxides (Co3O4) are highly explored as electrodes due to some of their properties such as high theoretical capacitance, low cost and their eco-friendly characteristics. In this study, Co3O4 was synthesized by calcining ZIF-67 and physicochemical characterizations such as infrared (IR) spectroscopy, Raman spectroscopy, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) with X-ray dispersive spectroscopy (EDS) were performed. For ZIF-67, IR spectroscopy revealed the presence of Co-N bonds associated with the coordination of cobalt with the 2-methylimidazole ligand, and XRD patterns confirm the typical crystalline structure of the material. In the case of the oxides resulting from the calcination of ZIF-67, the presence of Co-O bonds associated with the spinel structure of Co3O4 is evident, along with a typical crystalline structure. On the other hand, the electrochemical evaluation of Co3O4 showed a specific capacitance of 179.5 F g-1 at 2 A g-1 (186.3 F g-1 at mV s-1), with a retention of 92% after 100 charge/discharge cycles in alkaline media. Finally, this electrochemical behavior combined with the versatility of the synthesis makes these oxides potential materials for use in charge storage systems.

RESUMEN Los óxidos de cobalto (Co3O4) son de gran interés para su uso en supercapacitores (SCs) por su alta capacitancia teórica, baja toxicidad y costo. En este estudio, se sintetizó Co3O4 mediante la calcinación del ZIF-67 y se caracterizó fisicoquímica y estructuralmente con espectroscopia infrarroja (IR) y Raman, difracción de rayos X (DRX) además de microscopía electrónica de barrido (SEM-EDS). Para el ZIF-67, los espectros IR muestran enlaces Co-N asociados a la coordinación del cobalto con el 2-metilimidazol, además, los patrones de difracción confirman la estructura cristalina típica del material. Para los óxidos resultantes de la calcinación del ZIF-67 se evidencia la presencia de enlaces Co-O asociados a la estructura de espinela del Co3O4, además de presentar una estructura cristalina típica. Por otro lado, la evaluación electroquímica reveló que los Co3O4 tienen capacitancias específicas de 179,5 F g-1 a 2 A g-1 (186,3 F g-1 a 10 mV s-1), con una retención del 92 % después de 100 ciclos de carga/descarga en medio alcalino. Finalmente, este comportamiento electroquímico sumado a la versatilidad de la síntesis hace de los Co3O4 derivados de ZIF-67 potenciales candidatos para su incorporación en SCs.

Abstract The near subsurface imaging strength of Ground Penetrating Radar (GPR) which can delineate regions of contrasting dielectric properties has been explored in this study to identify the contentious burial tomb of the biblical Queen Sheba (Bilikisu Sungbo) located in the Oke-eri area of Ijebu province in southwestern, Nigeria. The site is highly revered as sacred by Christians, Muslims and Traditional worshippers and claimed by the Ijebus as heroin who came back from King Solomon’s voyage to build a fortified city. The filtered and processed GPR data acquired using a 400 MHz antenna GSSI SIR-3000 for GPR system via twenty-three (23) established profiles, surveyed at 2 m inter-profile separation, presented varying amplitude GPR reflection which characterize the entire study area at different depths as observed from the various iso-depth slices extracted from the combined GPR radargrams. Unique and consistent high amplitude GPR reflection patterns and classic hyperbolic diffraction curves dominate part of the burial site cordoned off and claimed by the local as the grave of the queen. The reflection pattern beneath the grave is observed to be consistent in amplitude, size, shape and exist right from 0.91 m to 1.83 m depth beneath the surface. The unique reflection signatures beneath the burial site suggest occurrence of materials which differ considerably in dielectric properties from that of the surrounding geologic rocks which could be tomb walls, void or simply non-geologic / anthropogenic materials consistent with burial activities.

Resumen En este estudio se exploró la intensidad de las imágenes cercanas al subsuelo con el radar de penetración terrestre (GPR, por sus siglas en inglés), el cual puede delinear regiones de propiedades dieléctricas contrastantes con el propósito de identificar la polémica tumba funeraria de la bíblica reina Sheba (Bilikisu Sungbo), la cual se encuentra ubicada en el área de Oke-eri de Ijebu, provincia en el suroeste de Nigeria. El sitio es muy venerado por cristianos, musulmanes y adoradores tradicionales, y los Ijebus lo reclaman como una heroína que regresó del viaje del rey Salomón para construir una ciudad fortificada. Los datos GPR filtrados se procesaron adquiridos utilizando una antena GSSI SIR-3000 de 400MHz a través de 23 perfiles establecidos,medidos con una separación entre unos de 2 m. Los resultados nos muestran una reflexión GPR de amplitud variable, la cual caracteriza toda el área de estudio en diferentes profundidades. Éstas, se observan a partir de los diversos cortes de isoprofundidad extraídos de los radargramas GPR combinados. Dominan parte del sitio de entierro patrones de reflexión GPR únicos y consistentes de alta amplitud y curvas de difracción hiperbólica clásicas. Se observa que el patrón de reflexión debajo de la tumba es consistente en amplitud, tamaño, forma y existe desde 0,91 a 1,83 m de profundidad. Las firmas de reflexión únicas debajo del sitio del entierro sugieren la presencia demateriales que difieren considerablemente en propiedades dieléctricas de las rocas geológicas circundantes que podrían ser paredes de tumbas, vacíos o simplemente materiales no geológicos / antropogénicos consistentes con las actividades del entierro.

Abstract Three different Heat Affected Zones (HAZ) in hot rolled Nickel Free High Nitrogen Stainless Steels (NFHNSS) based on three different peak temperatures were physically simulated using Gleeble Simulator to investigate microstructural evolution and structure-property correlation. Optical microscopy revealed that the austenite grains are recrystallized in the simulated heat affected zone in the peak temperature range of 750 oC to 1050 oC. Extent of recrystallization of grains and nucleation of precipitates varied with peak temperatures. TEM characterization showed the presence of Cr2N precipitate having an average particle size in the range of 300 nm to 395 nm in the simulated HAZ were confirmed by Selected Area Electron Diffraction (SAED) analysis. Precipitation kinetics of Cr2N were simulated using Thermo-Calc were found to correlate well with experimental values. Mechanical properties of specimens taken from three different HAZ were evaluated for tensile strength and hardness. Variation in strength of the different specimens has been discussed using various strengthening models. Fractography analysis was also carried out to understand the effect of peak temperature on fracture behaviour. Transition in fracture patterns in NFHNSS from ductile to mixed mode was observed for different specimens. (HAZ (NFHNSS structureproperty structure property correlation 75 105 CrN Cr N 30 39 SAED (SAED ThermoCalc Thermo Calc values hardness models behaviour 7 10 3 1

Thin films of titanium aluminum nitride (Ti(1-x)AlxN) were deposited on silicon, copper, and plasma nitrided AISI D2 tool steel substrates through reactive direct current grid-assisted magnetron sputtering. The depositions were performed in the metal and compound modes using nitrogen flow rates of (7.2 ± 0.1) sccm and (6.8 ± 0.2) sccm, respectively. The relations between the process parameters and the crystallographic orientation were investigated. Chemical and mechanical properties were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and instrumented indentation technique (IIT). X-ray diffraction spectra and electron diffraction patterns revealed the presence of a Ti(1-x)AlxN phase with a face-centered cubic structure in both films. In metal mode, the coatings exhibited a preferential (111) plane orientation, changing to (200) in the compound mode. The change in preferential orientation was influenced by the reactive gas partial pressure. Ti1xAlxN TixAlxN Ti 1 x AlxN (Ti(1-x)AlxN silicon copper D gridassisted grid assisted sputtering 7.2 72 7 2 (7. 0.1 01 0 6.8 68 6 8 (6. 0.2 02 respectively investigated Xray X ray XPS, XPS , (XPS) XRD, XRD (XRD) SEM, SEM (SEM) TEM, TEM (TEM) IIT. IIT . (IIT) facecentered face centered mode 111 (111 200 (200 pressure xAlxN 7. (7 0. 6. (6 (XPS (XRD (SEM (TEM (IIT 11 (11 20 (20 ( (1 (2

In this study, a laccaic acid-modified TiO2 photocatalyst (Lac-TiO2) was prepared via an impregnation method with 0.50, 1.00, 2.50, and 5.00 wt.% laccaic acid. The products’ physical properties were examined through X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), X-ray photoemission spectroscopy (XPS), UV-Vis diffused reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption, and photoluminescence (PL) spectroscopy. A possible photocatalytic mechanism was also proposed. XRD patterns revealed the anatase phase of TiO2 and Lac-TiO2 samples. High-magnification FE-SEM images showed that the TiO2 and Lac-TiO2 samples exhibited spherical-like structures. XPS results complementarily confirmed the presence of Ti, O, and C as the main elements of the Lac-TiO2 samples. Interestingly, the DRS spectra of the Lac-TiO2 samples extended into the visible region. FTIR spectra presented the characteristic bands of TiO2 and hydroxyl groups on the TiO2 surface. Instead of hydroxyl groups, the characteristic bands of laccaic acid were observed on the surface of the Lac-TiO2 samples. The photocatalytic properties of the Lac-TiO2 samples were evaluated in terms of methyl orange degradation under visible light irradiation. The Lac-TiO2 samples showed higher photocatalytic performance than the TiO2 sample.

Resumen Caracterización y distribución de adularia y otros minerales de alteración mediante análisis de difracción de rayos X en el depósito epitermal El Peñón, norte de Chile. El depósito epitermal de baja sulfuración El Peñón, ubicado en el cinturón metalogénico del Paleoceno, en la región de Antofagasta, norte de Chile, está constituido por vetas y brechas portadoras de Au-Ag hospedadas en rocas volcánicas hidrotermalmente alteradas. Las vetas y halos de roca alterada contienen minerales como adularia, carbonatos y arcillas generados por el metasomatismo producto de la interacción de la roca huésped con fluidos hidrotermales, de características reducidas, pH cercano a neutro y enriquecidos en oro que circularon por estructuras. En este trabajo se estudia la distribución espacial de estos minerales (en particular de adularia) en la veta Aleste y en su roca hospedante, localizada en la parte norte del distrito, con la finalidad de establecer su relación con la mena de Au-Ag y, así, apoyar la identificación de nuevos objetivos de exploración. Para esto se desarrolló una metodología de difracción de rayos X, en muestras de roca total, para diferenciar adularia de otros feldespatos potásicos mediante 4 picos secundarios presentes en el patrón de difracción de este mineral. Además, se realizaron perfiles de distribución de adularia y otros minerales de alteración hidrotermal en una sección transversal a la veta Aleste. Los resultados indican que la adularia se produce en asociación con rocas félsicas y está restringida en unidades de composición intermedia. Este mineral se correlaciona con las zonas mineralizadas y su abundancia semicuantitativa entre 25 a 40% de adularia es un buen indicador de mineralización. La sericita e illita se presentan principalmente donde la adularia es escasa o ausente. Estos minerales mostraron el control estructural en la evolución y trayectoria de los fluidos hidrotermales hacia la superficie. La caolinita está relacionada con la alteración argílica causada por el vapor de fluidos hidrotermales y la alteración argílica avanzada asociada a una alteración supérgena posterior. La clorita suele estar lejos de las áreas mineralizadas; por lo tanto, podría ser un indicador confiable de los márgenes del sistema. La caracterización y distribución de los minerales de alteración por el método de difracción de rayos X en las vetas del depósito El Peñón muestran la capacidad de este tipo de análisis para determinar posibles objetivos de prospección.

Abstract The El Peñón low-sulfidation epithermal deposit, located in the Paleocene metallogenic belt in the Antofagasta region, northern Chile, consists of Au-Ag bearing veins and hydrothermal breccias hosted in volcanic rocks and surrounded by alteration haloes consisting of a series of minerals, such as adularia, carbonates and clay minerals. They are the result of metasomatism generated by the passage of reduced, and near neutral pH, hydrothermal fluids, that transported gold through structures and its interaction with the host rock. We investigated the spatial distribution of these minerals (mainly adularia) in the Aleste vein and its host rock, located in the northern part of the district, to establish their relationship with the Au-Ag ore and, thus, support the identification of new exploration targets. An X-ray diffraction technique to discriminate adularia from other K-feldspars in whole rock samples was developed by the detail study of the diffractogram patterns of an adularia standard. The study of an X-ray diffraction standard pattern allowed the recognition of this mineral by 4 secondary peaks. Our results indicated that adularia occurs in association with felsic volcanic rocks, and it is restricted in intermediate composition units. The spatial distribution of this mineral is correlated with the mineralized zones, being adularia semi-quantitative abundance in the range of 25 to 40% a good indicator of gold mineralization. Sericite and illite occur mainly where adularia is scarce or absent. The spatial distribution of these minerals showed the structural control in the evolution and flow path of the hydrothermal fluids toward the surface. Kaolinite is related to argillic alteration caused by steam-heated fluids, and the advanced argillic alteration associated with later supergene alteration. Chlorite usually is far from the mineralized areas; therefore, it could be a reliable indicator of the margins of the system. The characterization and spatial distribution pattern of the alteration minerals identified by the X-ray diffraction method in the veins of El Peñón deposit show the capability of this type of analyses in determining possible prospection targets.

Abstract: Plant biomass is a potential lignocellulose material for the synthesis of carbon nanostructures. Its characteristics as adsorbent and its particle size make it a good additive for liquid fertilizers. In this research, we study the influence of different sequential pyrolysis methods (the hydrothermal-microwave method and the reflux-microwave method) on the characteristics of carbon nanostructures from sugarcane leaf biomass. Both the reflux and hydrothermal methods were adjusted at 200 oC, then followed by microwave treatment at 800 W. Characterization using X-ray diffraction showed that the hydrothermal - microwave method indicated the diffractogram patterns of both carbon nanostructures and cellulose. SEM micrographs show sphere and block shapes. The FTIR spectra indicates different concentrations of oxy surface functional groups. The UV spectra of the dispersed product in water indicates the presence of aromatics C=C groups. The hydrothermal-microwave method resulted the product in which lower crystalinity index of cellulose, smaller particles, lower concentration of the oxy surface groups than the reflux - microwave one. The correlation of the chemical properties (aromaticity and fraction of polar groups) was more linier than of physical - chemical properties (index of cellulose crystalinity and fraction of polar groups). The test of dispersion stability showed that qualitatively sonication gave the most transparent brown colloid and after keeping for 11 h, the sonication gave the highest TDS.

Abstract Recently, there has been increasing importance on scaffold materials that could be used in biomaterials. In the present study, equimolar TiNbZr medium entropy alloys (MEAs) and porous TiNbZr alloy scaffolds were produced by mechanical alloying (MA) that is a powder metallurgy processing technique. The MA process was carried out using high energy planetary ball mill. Ammonium bicarbonate (NH4HCO3) at different percentage ratio was used as space holder to fabricate the porous TiNbZr scaffolds with using space-holder sintering method. Cold Isostatic Pressing (CIP) was performed for consolidation of mechanically alloyed powders. Finally, the green compact samples were sintered in tube furnace under vacuum atmosphere. The microstructural analyses, phase composition, porosity and density measurement, compression and microhardness tests and wear resistance of bulk alloys were examined. The X-Ray Diffraction (XRD) patterns of all samples indicated the dominant β-Ti phases and small amount of α-Ti phase. SEM (scanning electron microscope) images for porous TiNbZr alloy scaffolds demonstrated that porosity increased with increase of space holders amount. With the increasing porosity content, density, hardness, compressive strength and the elastic modulus of samples decreased while wear rate increased.