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The effect of trimesic acid (TA) on the surface of γ-Al2O3 for CoMoP catalysts has been investigated in the hydrodesulfurization (HDS) of straight-run gas oil. The γ-Al2O3 support was modified by surface impregnation of a solution of TA to afford TA/Co molar ratios (0.5, 1.0 and 2.0) in the final composition. The CoMoP material with atomic ratio of TA/Co = 1.0 displayed the highest HDS activity. FT-IR results suggest that the carboxylic acid moieties (AA) of the TA deposited on the γ-Al2O3 interact with the Mo and Co species. The DRS UV vis revealed the presence of Co species in distorted octahedral symmetry. The MoOh/MoTh ratio varied depending on the amount of the organic additive. TGA results indicated that the TA on the catalyst with TA/Co ratio = 1.0 often decomposes at lower temperature in comparison with the other samples. Thus, a lower temperature decomposition favors the surface concentration of metals species for the sulfurization degree. The interaction of the TA induces moderate metal-support interaction. Raman spectroscopy showed that the presence of TA influenced significantly on the ratio Mo O/(Mo O + Mo O Mo + Mo O) on the catalyst surface. Raman results also evidenced the highest ratio Mo O/(Mo O + Mo O Mo + Mo O) for the CoMoP (1.0) sample. Apparently, the augment of the Mo O species is related to a major availability of Mo species for the formation of MoS2 for HDS reaction. The XPS and HRTEM results showed higher formation and more dispersed MoS2 and CoMoS species for the catalysts modified by TA compared to that of the reference sample. The CoMoP (1.0) showed higher Moe/Mot ratio in comparison with CoMoP (0.0), which resulted in a higher gas oil HDS activity.

Peptide epitopes have been widely used to develop synthetic vaccines and immunotherapies. However, peptide epitopes may exhibit poor absorption or immunogenicity due to their low molecular weights. Conversely, fourth-generation polyamidoamine (G4-PAMAM) dendrimers are nonimmunogenic and relatively nontoxic synthetic nanoparticles that have been used as adjuvants and nanocarriers of small peptides and to improve nasal absorption. Based on this information, we hypothesized that the combination of intranasal immunization and G4-PAMAM dendrimers would be useful for enhancing the antibody responses of HIV-1 gp120 peptide epitopes. Therefore, we first used structural data, peptide epitope predictors and docking and MD simulations on MHC-II to identify two peptide epitopes on the CD4 binding site of HIV-1 gp120. The formation of G4-PAMAM-peptide complexes was evaluated in silico (molecular docking studies using different G4-PAMAM conformations retrieved from MD simulations as well as the MMGBSA approach) and validated experimentally (electrophoresis, 1H NMR and cryo-TEM). Next, the G4-PAMAM dendrimer-peptide complexes were administered intranasally to groups of female BALB/cJ mice. The results showed that both peptides were immunogenic at the systemic and mucosal levels (nasal and vaginal), and G4-PAMAM dendrimer-peptide complexes improved IgG and IgA responses in serum and nasal washes. Thus, G4-PAMAM dendrimers have potential for use as adjuvants and nanocarriers of peptides.

The absence of a treatment efficient in the control of type 2 diabetes mellitus requires more functional products to assist treatment. Luteolin (LU) and diosmin (DIO) have been known as bioactive molecules with potential for the treatment of diabetes. This work aimed to establish the role that a combination of LU and DIO in selenium nanoparticles (SeNPs) played in streptozotocin (STZ)- induced diabetes mice. Green synthesis of Se NPs was performed by mixing luteolin and diosmin with the solution of Na2SeO3 under continuous stirring conditions resulting in the flavonoids conjugated with SeNPs. The existence of flavonoids on the surface of SeNPs was confirmed by UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) images, and DLS graphs via Zetasizer. The average diameter of GA/LU/DIO-SeNPs was 47.84 nm with a PDI of −0.208, a zeta potential value of −17.6, a Se content of 21.5% with an encapsulation efficiency of flavonoids of 86.1%, and can be stabilized by gum Arabic for approximately 175 days without any aggregation and precipitation observed at this time. Furthermore, The C57BL/6 mice were treated with STZ induced-diabetes and were exposed to LU/DIO, SeNPs, and GA/LU/DIO-SeNPs for six weeks. The treatment by nanospheres (GA/LU/DIO-SeNPs) in the mice with diabetes for a period of 6 weeks restored their blood glucose, lipid profile, glycogen, glycosylated hemoglobin, and insulin levels. At the same time, there were significant changes in body weight, food intake, and water intake compared with the STZ- untreated induced diabetic mice. Moreover, the GA/LU/DIO-SeNPs showed good antioxidant activity examined by catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) in liver and kidney and can prevent the damage in the liver evaluated by aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) activities. The nanospheres exhibited a significant anti-diabetic activity with a synergistic effect between the selenium and flavonoids. This investigation provides novel SeNPs nanospheres prepared by a high-efficiency strategy for incorporating luteolin and diosmin to improve the efficiency in type 2 diabetes.

The local structures of ternary alkaline-earth hexaborides (MB6, M = Ca0.5Sr0.5, Ca0.5Ba0.5 and Sr0.5Ba0.5) have been analysed using X-ray pair distribution function (PDF) analysis, Raman spectroscopy and transmission electron microscopy (TEM). The results show significant local deviations from the average cubic structure within the boron sub-lattice and support the conclusion that rapid synthesis processes lead to the formation of coherent nanodomains over length scales of about 10 nm. Reverse Monte Carlo fitting of the PDFs allows for quantification of the displacement disorder within the boron sub-lattice as a function of sample composition. Detailed Raman spectroscopy studies and high-resolution TEM support the models derived from X-ray scattering. The average magnitude of the static displacement disorder varies by sample composition and positively correlates with the cation radius ratios across the three compositions. The new models form a foundation for future computational and experimental studies aimed at understanding and predicting properties of hexaborides.

We present the behavior of multiple solid solutions within ternary (BaxCa1–x)B6 and (BaxSr1–x)B6 compounds and demonstrate that nanodomain formation is preferred over uniform solid solutions under certain processing conditions. Instead of the expected single solid solution of M1 and/or M2 atoms within the MB6 phase, we note separation into nanodomain regions rich in either M1 or M2. This phase separation has been observed from detailed analyses of the shapes of the peaks in X-ray diffraction data, where peak splitting and asymmetry are the result of multiple solid solutions with lattice parameters differing by up to 1.4%. High-resolution transmission electron microscopy confirms the presence of these nanodomains, which are about 2–3 nm in size, and reveals varying degrees of lattice misalignment. We also present X-ray diffraction analysis of (BaxCa1–x)B6 powders calcined from 1273 to 1973 K and document the enhancement in sample homogeneity as the separated phases merge into a uniform solid solution. As s...

In this study, tomato plants were grown in vitro with and without incorporation of TiO2 nanoparticles in Murashige and Skoog (MS) growth medium. The aim of this study was to describe the morphological (area and roundness cell) and mechanical (Young’s Modulus) change in the different tissue of tomato root, epidermis (Ep), parenchyma (Pa), and vascular bundles (Vb), when the whole plant was exposed to TiO2 nanoparticles (TiO2 NPs). light microscopy (LM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM), wavelength dispersive X-ray fluorescence (WDXRF) techniques were used to identify changes into the root cells when TiO2 NPs were incorporated. TiO2 NPs incorporation produces changes in the area, roundness, and Young’s Modulus of the tomato root. When tomato root is exposed to TiO2 NPs, the Ep and Vb area size decreases from 260.92 µm2 to 160.71 µm2 and, 103.08 µm2 to 52.13 µm2, respectively, compared with the control area, while in Pa tissue the area size was increased considerably from 337.72 mm2 to 892.96 mm2. Cellular roundness was evident in tomato root that was exposed to TiO2 NPs in the Ep (0.49 to 0.67), Pa (0.63 to 0.79), and Vb (0.76 to 0.71) area zones. Young’s Modulus in Pa zone showed a rigid mechanical behavior when tomato root is exposed to TiO2 NPs (0.48 to 4.98 MPa control and TiO2 NPs, respectively). Meanwhile, Ep and Vb were softer than the control sample (13.9 to 1.06 MPa and 6.37 to 4.41 MPa respectively). This means that the Pa zone was stiffer than Ep and Vb when the root is exposed to TiO2 NPs. Furthermore, TiO2 NPs were internalized in the root tissue of tomato, accumulating mainly in the cell wall and intercellular spaces, with a wide distribution throughout the tissue, as seen in TEM.

In the present work, the synthesis of micro- and nano-sized spheres of metallic bismuth by microwave-assisted solvothermal method is reported. The synthesis method was carried out at different power levels and at a unique frequency of microwave irradiation. The sphere sizes were controlled by the microwave power level and the concentration of dissolved precursor. Structural and morphological characterization was performed by SEM, HRTEM, EELS and XRD. The results demonstrated that rhombohedral zero valent Bi spheres were synthesized after microwave radiation at 600 and 1200 W. However, if the power level is decreased to 120W, a monoclinic phase of Bi2O3 is obtained with a flake-like morphology. In comparison with a conventional hydrothermal process, the microwave-assisted solvothermal approach provides many advantages such as shorter reaction time, optimum manipulation of morphologies and provides a specific chemical phase and avoids the mixture of structural phases and morphologies which is essential for further applications such as drug delivery or functionalization with organic materials, thanks to its biocompatibility.

Self-assembling systems of amphiphilic molecules display structures similar to those of biomineralization natural systems. This allows to somehow mimic nature to synthesize nanomaterials with low polidispersity and with diverse morphologies. In this work we describe the synthesis and characterization of gold-copper, silver-copper, and gold-silver bimetallic nanoparticles by chemical reduction in self-assembling systems of two surfactants. The nanoparticles were characterized by Transmission Electron Microscopy and UV-Vis spectroscopy. We have prepared a composite material using mesoporous silica as support of the AuAg bimetallic nanoparticles. The system was used in photocatalysis experiments for water remediation applications. Our results show that the AuAg/SBA15 composite material degrades methyl orange in water from 17 ppm to 4 ppm in 30 minutes.

Core–hole spectroscopies such as x-ray photoelectron spectroscopy (XPS) and high-resolution electron energy loss spectroscopy (HR-EELS) in combination with multiplet calculation are important tools to elucidate the electronic structure of transition metal compounds. This work presents a comparison between the electronic structure obtained by XPS and HR-EELS for polycrystalline perovskite-type Ba0.9Ca0.1Ti0.9Zr0.1O3. Raman analysis suggests that Ca2+ cations could partly occupy the Ti4+ cations in the B-site of a perovskite structure with the tetragonal phase. A multiplet structure was determined by XPS for Ti 2p and by HR-EELS for Ca L2,3 and Ti L2,3 edges. Octahedral (Oh) symmetry in the crystal field (CF) effects reproduces the local distortion of TiO6 octahedra. The charge transfer (CT) effects were also considered to reproduce L3-edge EELS shoulders and the satellite in the Ti 2p XPS region. CF and CT parameters, 10 Dq, (charge transfer energy) Δ, and (Coulomb repulsion energy) Udd, are reported for future reference. The broadening of the Ti L2-edge suggests the presence of the Coster–Kronig electron decay process. Multiplet calculation in Oh symmetry for the Ca L2,3-edge could support the Raman interpretation.

With the aim of exploring and comparing the photocatalytic degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D) under visible light, BiVO4 was synthesized by using coprecipitation and hydrothermal methods and modified with silver nanoparticles (AgNP) employing a photo-deposition method. X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy were some of the characterization techniques used. A particular synergy was observed when decorating the hydrothermally prepared BiVO4 with AgNP, showing the higher degradation/mineralization of 2,4-D. According to the results, AgNP served as efficient co-catalysts of BiVO4, allowing the electron separation/transfer to generate the OH radicals required for the reaction. A parallel pathway of 2,4-D photodegradation was proposed, including 2,4-Dichlorophenol and oxalic acid as the main intermediary compounds. Active species trapping experiments demonstrated that the photogenerated holes play a fundamental role in promoting both the direct oxidation of 2,4-D and generation of OH radicals.

Necessity-oriented materials design has become a priority for every nation conscious of the well-being of the environment. A suitable environmentally friendly microwave-hydrothermal reaction was used to synthesize BaZrO3. A study of the properties of pure Si doped, and Bi–Si co-doped BaZrO3 semiconductors is presented. Crystalline structure, morphology and optical properties were dependent on the concentration of bismuth. Well faceted and spherical particles with increasing sizes from 90 up to 500 nm were obtained as the bismuth concentration increased. The highly crystalline compounds produced, maintain the BaZrO3 cubic perovskite phase even at bismuth–silicon concentrations as high as 50 and 1.5 mol%, respectively. The optical absorption edge shifts into the visible-light region and the band gap narrows as the bismuth concentration increases. Suitable compounds were obtained at reaction times of 1 and 4 h at 170 °C in water–ethanol solvent for non-doped BaZrO3 and doped BaZrO3, respectively. Since similar properties of other semiconductor materials have practical application as visible light-active photocatalysts, we propose the potential use of nanocomposite BaZrO3 as a green photocatalyst. The effects of bismuth–silicon inclusions on the properties of BaZrO3 and its relation with photocatalytic properties are exposed. HREM, HAADF and dopant distributions inside the perovskite structure are presented.

This work shows the comparison of high-resolution electron energy loss spectra (HR-EELS) in the low loss region (0−15 eV) to investigate the electronic structure from koechilinite Bi 2 MoO 6 to rusellite Bi 2 WO 6 varying the stoichiometric relation Bi 2 Mo x W 1−x O 6 . The effect of the Mo to W ratio on the bandgap energy was evaluated on individual particles. Two approximations were considered in order to determine the band gap energy value, the first one was a linear fit and the second one was a mathematical fit. Both analyses are in agreement with those ones collected and analyzed by UV–Vis characterization. Our results suggest a direct electronic transition that increases from about 2.53 eV to about 3 eV as the W content increase from 0% to 100% wt. X-ray diffraction was used to corroborate the crystal structure and crystal size; transmission electron microscopy was used to monitor the morphology evolution and UV–Vis spectroscopy in diffuse reflectance mode to determine the Eg. These techniques complement the characterization of these materials.

This study presents multiwall and bamboo-like carbon nanotubes found in samples from the Allende carbonaceous chondrite using high-resolution transmission electron microscopy (HRTEM). A highly disordered lattice observed in this material suggests the presence of chiral domains in it. Our results also show amorphous and poorly-graphitized carbon, nanodiamonds, and onion-like fullerenes. The presence of multiwall and bamboo-like carbon nanotubes have important implications for hypotheses that explain how a probable source of asymmetry in carbonaceous chondrites might have contributed to the enantiomeric excess in soluble organics under extraterrestrial scenarios. This is the first study proving the existence of carbon nanotubes in carbonaceous chondrites.

Codoped Er 3+ and Yb 3+ nanocrystalline ZrO 2 –B 2 O 3 phosphor obtained by a modified sol–gel method is demonstrated. The addition of up to 2.5 mol% B 2 O 3 to nanocrystalline ZrO 2 :Yb(2%), Er(1%) keep the tetragonal rare-earth stabilized ZrO 2 phase; whereas higher B 2 O 3 content destabilize the tetragonal phase, leading to the tetragonal to monoclinic transition with no tetragonal ZrO 2 phase segregation. Visible upconversion of the luminescent active ions, Er 3+ and Yb 3+ , depend strongly on B 2 O 3 content. The PL intensity is strongly quenched for high B 2 O 3 content due to increasing multiphonon relaxation processes related to B O and B O B vibronic modes.

a b s t r a c t Wide band gap nanocrystalline bismuth doped barium zirconate is synthesized by a facile hydrother- mal method at 100 ◦C. The obtained cubic perovskites are characterized by powder X-ray diffraction (XRD), UV-VIS diffuse reflectance spectroscopy, photoluminescence (PL) spectroscopy, and photocat- alytic activity. The estimated band gap in the 2.4-4.9 eV range, depending on Bi concentration, suggests nanocrystalline BaZrO3:Bi as a useful visible-light activated photocatalyst under excitation wavelengths

The wet synthesis hydrothermal method at 100 °C was used to elaborate barium zirconate (BaZrO3) unpurified with 0.5 mol% of different rare earth ions (RE = Yb, Er, Dy, Eu, Ce). Morphological, structural and UV-photoluminescence properties depend on the substituted rare earth ionic radii. While the crystalline structure of RE doped BaZrO3 remains as a cubic perovskite for all substituted RE ions, its band gap changes between 4.65 and 4.93 eV. Under 267 nm excitation the intrinsic green photoluminescence of the as synthesized BaZrO3: RE samples is considerably improved by the substitution on RE ions. For 1000 °C annealed samples, under 267 nm, the photoluminescence is dominated by the intrinsic BZO emission. It is interesting to notice that Dy3+, Er3+ and Yb3+ doped samples present whitish emissions that might be useful for white light generation under 267 nm excitation. CIE color coordinates are reported for all samples.

The synthesis and characterization of yttria-based organic–inorganic hybrid nanophosphors (HNP) are reported. These materials were synthesized by microwave-assisted solvothermal method in a short time of around 2 h and 30 min without any further thermal annealing. According to x-ray diffraction and transmission electron microscopy measurements, HNP have a lamellar structure formed by interleaved layers of organic species and inorganic yttria species. The luminescent properties of HNP are generated by the presence of Sm3 + ions, which produced light emission at 570, 610, 650, and 716 nm due to the G5 / 24 to H5 / 26, H7 / 26, H9 / 26, and H11 / 26 transitions, respectively; and a wide broadband centered at 446 nm as a result of the presence of organic species, particularly benzene rings. Hybrid phosphors have tunable luminescent properties as a function of the used excitation wavelength producing blue, white, and red light emission. Those properties are due to the hybrid’s absorption properties and the subsequent simultaneous organic and inorganic light emissions.

Under NIR excitation at 967 intense blue and red photoluminescence (PL) emissions are observed at room temperature in codoped Tm 3+ –Yb 3+ barium zirconate (BaZrO 3 :Yb,Tm) powders. Powders were prepared by a simple hydrothermal method, and present a wide band gap that depends on the total rare earth content due to the degree of disorder induced in the BaZrO 3 lattice by the substitution of the rare earth ions. Rietveld refinements of the XRD patterns indicated the presence of primary nanocrystallites with sizes between 50 and 70 nm depending on the Tm 3+ content. Scanning transmission electron microscopy (STEM) shows that these primary particles self-aggregated in larger secondary particles which present a regular morphology with sizes around 1 μm. The intense blue and red PL emissions in BaZrO 3 powders under 967 nm excitation are governed by energy transfer processes from Yb 3+ ions to Tm 3+ ions and crossrelaxation among Tm 3+ ions.

The optical and structural characteristics of Y2O3 : Eu (III)-benzoate hybrid nanophosphors, synthesized by the microwave-assisted solvothermal technique, are reported in this work. Benzyl alcohol was used during the synthesis, carried out at low temperatures in the microwave reactor, to obtain the Y2O3 : Eu(III)-benzoate-layered hybrid nanophosphors. The benzyl alcohol led to the incorporation of benzene rings (belonging to benzoate group) around the Y2O3 : Eu(III) molecules, promoting a lamellar structure and showing the previously reported luminescent “antenna effect” in the nanophosphors. Y2O3 : Eu(III)-benzoate nanophosphors showed a high photoluminescence emission intensity at 590, 612, 650, and 697 nm due to the interelectronic D05 to F17, F27, F37, and F74 transitions of the europium ions. A stark split might be present due to the variation of the annealing temperature given to the Y2O3 : Eu(III)-benzoate nanophosphors. The nanostructured hybrids showed the appearance of complex morphologies similar to flower petals. The as-obtained nanophosphors were in the range of ∼20 nm and showed the reported x-ray diffraction reflections for these kinds of materials.

This work presents the identification of inter-band transitions in the imaginary part of the dielectric function (e2) derived from the Kramers–Kronig analysis for [Ba0.9Ca0.1](Ti0.9Zr0.1)O3 (BCZT) nanocrystals synthesized by the modified Pechini method. The analysis started with the chemical identification of the atoms that conform BCZT in the valence loss energy region of a high energy-resolution of electron energy loss spectroscopy. The indirect band energy (Eg) was determined in the dielectric response function. This result is in agreement with the UV-Vis technique, and it obtained an optical band gap of 3.16 eV. The surface and volume plasmon peaks were observed at 13.1 eV and 26.2 eV, respectively. The X-ray diffraction pattern and the Rietveld refinement data of powders heat treated at 700 °C for 1 h suggest a tetragonal structure with a space group (P4 mm) with the average crystal size of 35 nm. The average particle size was determined by transmission electron microscopy.

"The current human lifestyle relays on the constant development of technology and scientific knowledge on a faster rate than it was on past decades, to support and solve future necessities of human societies. It exist therefore, a necessity to generate specialized human resources to work on and to develop the technological industries which will aid on the solution of current and future problems. It is through the thorough study of the properties of the materials used on industry, that more efficient used or new applications could be found for them. Such is the case of illumination and catalysis industries. Generation of efficient white-light sources and new photocatalyst materials active in the visible-light range, are now two hot trends on the materials science field. In particular, barium zirconate (BaZrO3) is a ceramic material of the perovskite family which had been intensively studied in the past, now it is found in a wide variety of useful applications. The present work focused on the study and characterization of BaZrO3 crystalline structure, composition, morphology, optical, luminescent and catalytic properties as a function of: 1) the ionic radii of the substituted rare earth elements (RE), 2) overall RE concentration and 3) total bismuth concentration. The first two were concerned on the generation of white-light and blue-light nanophosphors, respectively. In the case of white-light nanophosphor, RE single doping BaZrO3 approach was used. Photoluminescence (PL) of each material sample was obtained after UV excitation at 267 nm site. During the hydrothermal synthesis silicon atoms were inadvertently added to the compounds from the glass autoclave. Incorporation of slight concentrations of silicon atoms into the RE single doped BaZrO3 samples seems favorable to the PL properties. Dysprosium and europium doped samples had better energy distribution on the emission spectra. White and red color emissions were respectively obtained from each of these samples due to nonradiative energy transfer process from the host to the dopant. Emission spectra of dysprosium doped sample approach to a white emission according to the CIE 1931 color model. In the case of blue-light emission phosphors, it was obtained by upconversion (UC) process under NIR excitation. The color emission of ytterbiumthulium codoped BaZrO3 samples strongly depended on cross relaxation processes between thulium ions."

El presente trabajo de tesis comprende el estudio de la distribucién espacial de la uniformidad del color en pantallas de television digital de retroproyeccién. Se presenta informacion sobre los fundamentos de disefio de una televisién, los cuales son: a) bases psicofisicas de la vision humana, que consideran los pardmetros fisiolégicos sobre lade color, contraste y respuesta al brillo del sistema visual humano, b) colorimetria para television, donde los pardmetros de crominancia, brillo y la diferencia de color apenas perceptible (JND) son relacionados con la calidad de la imagen, y c) el principio de operacién del motor dptico de una television digital de retroproyeccién. Los parametros utilizados en la evaluacién de gamma y de uniformidad de color para las diferentes pantallas analizadas fueron: brillo (Lv), color (x, y) y diferencia de color apenas perceptible (IND). Con los resultados de los experimentos que se propusieron, se ha logrado estimar el factor de cambio inducido al color de la luz proyectada desde el bloque dptico, debido a la interaccién de la luz con la pantalla. Asi como también se logré descubrir la relacion que existe entre la pantalla original de la televisidn, y los ajustes de gammay uniformidad de color que se realizan de la manera tradicional al bloque dptico. Gracias al conocimiento de la tecnologia de los sistemas de una televisién de retroproyeccién, se puede generalizar que para las televisiones basadas en la tecnologia aqui estudiada, se genera una dependencia entre la pantalla y el bloque dptico de una televisional realizar los ajustes de gamma y uniformidad de color. This thesis work comprises a study of the spatial color uniformity distribution of the screen of a digital rear projection television. Fundamentals concerning the design of digital television are presented, which are: a) psychophysics of human vision, it considers ‘the physiologic parameters of color perception, contrast and brightnesssensitivity of the human visual system, b) colorimetry for television, were the parameters of chrominance and just noticeable difference are related to image quality, and c) the operational principles of the optical engine of a digital rear projection television. The parameters used to evaluate gamma and color uniformity of the screens, were: color (x, y), brightness (Lv) and just noticeable difference (JND). By the results obtained from the planned experiments, it was possible to estimate the change factor induced to the color of the light projected from the optical block, due to the interaction of the light and the screen. As well as finding the relation between the original screen of the television, and the gamma and color uniformity adjustments made to the optical block by means of the traditional manner. Owed to the achieved knowledgeofthe rear projectiontelevision systems and technology,it is possible to say, that in general forall the televisions systems based on the technology here studied, there is dependence between the screen and the optical block of a television whenthe adjustments of gammaandcolor uniformity are made.