Improved Neutron Capture Cross Section Measurements with the n_TOF Total Absorption Calorimeter

E. Mendoza,V. Becares,A. Casado,D. Cano-Ott,M. Fernandez-Ordonez,E. Gonzalez-Romero,C. Guerrero,T. Martinez,J. J. Vidriales,J. Andrzejewski,J. Marganiec,J. Perkowski,L. Audouin,B. Berthier,L. Tassan-G 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

The n_TOF collaboration operates a Total Absorption Calorimeter (TAC) [1] for measuring neutron capture cross-sections of low-mass and/or radioactive samples. The results obtained with the TAC have led to a substantial improvement of the capture cross sections of ^(237)Np and ^(240)Pu [2].The experience acquired during the first measurements has allowed us to optimize the performance of the TAC and to improve the capture signal to background ratio, thus opening the way to more complex and demanding measurements on rare radioactive materials. The new design has been reached by a series of detailed Monte Carlo simulations of complete experiments and dedicated test measurements. The new capture setup will be presented and the main achievements highlighted. KEYWORDS: ND2010, nuclear data, n\textunderscore TOF, background, Monte Carlo, neutron, time of flight, cross section, calorimeter, shielding, simulation, total absorption, gamma ray, neutron capture.

Characterization of the New n_TOF Neutron Beam: Fluence, Profile and Resolution

C. Guerrero,V. Becares,D. Cano-Ott,M. Fernandez-Ordonez,E. Gonzalez-Romero,F. Martin-Fuertes,T. Martinez,E. Mendoza,G. Pina,J. Quinones,V. Vlachoudis,M. Calviani,S. Andriamonje,M. Brugger,F. Cerutti,E 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

After a halt of four years, the n_TOF spallation neutron facility at CERN has resumed operation in November 2008 with a new spallation target characterized by an improved safety and engineering design, resulting in a more robust overall performance and efficient cooling. The first measurement during the 2009 run has aimed at the full characterization of the neutron beam. Several detectors, such as calibrated fission chambers, the n\textunderscore TOF Silicon Monitor, a MicroMegas detector with ^(10)B and ^(235)U samples, as well as liquid and solid scintillators have been used in order to characterize the properties of the neutron fluence. The spatial profile of the beam has been studied with a specially designed "X-Y" MicroMegas which provided a 2D image of the beam as a function of neutron energy. Both properties have been compared with simulations performed with the FLUKA code. The characterization of the resolution function is based on results from simulations which have been verified by the study of narrow capture resonances of ^(56)Fe, which were measured as part of a new campaign of (n, γ) measurements on Fe and Ni isotopes.

Biological treatment performance of hypersaline wastewaters with high phenols concentration from table olive packaging industry using sequencing batch reactors

E. Ferrer-Polonio,J.A. Mendoza-Roca,A. Iborra-Clar,J.L. Alonso-Molina,L. Pastor-Alcañiz 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.43 No.-

Biological treatment of hypersaline wastewaters such as fermentation brine from table olive processing(FTOP), was carried out using four sequential biological reactors (SBRs). These wastewaters werecharacterized by conductivities higher than 90 mS cm 1 together with COD and total phenolsconcentration values of more than 15 g L 1 and 1000 mg L 1, respectively. In order to increase theorganic removal efficiency and to reduce the hydraulic retention time (HRT), extra nutrients were addedand pre-treatment by adsorption was performed. Results showed that the COD/N/P relationship, in theFTOP, of 250/5/1 was appropriate for the biological process reaching COD removal efficiencies of around80%. The FTOP adsorption pre-treatment with powder activated carbon for the reduction of phenolsconcentration to 400 mg L 1 led to a HRT reduction from 40 to 15 days, maintaining the COD and totalphenols removal percentages around 78% and 97%, respectively. On the other hand, g-Proteobacteria wasthe main bacterial class, representing around 74% of the microbial community in the reactors.

Photo-catalysis of phenol derivatives with Fe2O3 nanoparticles dispersed on SBA-15

E. Montiel-Palacios,A. K. Medina-Mendoza,A. Sampieri,C. Angeles-Chávez,I. Hernández-Pérez,R. Suarez-Parra 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.4

Highly ordered hexagonal (p6mm) mesoporous silica SBA-15 was synthesized through a hydrothermal treatment under acidic conditions. Fe2O3/SBA-15 catalysts were prepared by impregnation of SBA-15 media with iron(III) acetylacetonate, iron(III) chloride or iron(II) sulfate solutions. X-ray Diffraction (XRD), X-ray fluorescence (XRF), high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy dispersive X-ray (EDX) spectroscopy and nitrogen physisorption characterization were carried out for SBA-15 and Fe2O3/SBA-15 materials. After impregnation and calcination at 823 K, the iron oxide dispersion in SBA-15 was analyzed by STEM and EDX. FeCl3 provides the highest amount of Fe loading in mesoporous SBA-15. The photocatalytic properties of Fe2O3/SBA-15 samples at pH = 3 and pH = 6 were evaluated in catechol and hydroquinone photodecomposition by inducing visible radiation. The conversion of catechol and hydroquinone, at pH = 3 and pH = 6 with iron(III) acetylacetonate and FeCl3 as the precursor of iron oxide nanoparticles, were measured by UV-Vis spectroscopy, chemical oxygen demand (COD) and total organic carbon (TOC) analysis. Highly ordered hexagonal (p6mm) mesoporous silica SBA-15 was synthesized through a hydrothermal treatment under acidic conditions. Fe2O3/SBA-15 catalysts were prepared by impregnation of SBA-15 media with iron(III) acetylacetonate, iron(III) chloride or iron(II) sulfate solutions. X-ray Diffraction (XRD), X-ray fluorescence (XRF), high angle annular dark field scanning transmission electron microscopy (HAADF-STEM), energy dispersive X-ray (EDX) spectroscopy and nitrogen physisorption characterization were carried out for SBA-15 and Fe2O3/SBA-15 materials. After impregnation and calcination at 823 K, the iron oxide dispersion in SBA-15 was analyzed by STEM and EDX. FeCl3 provides the highest amount of Fe loading in mesoporous SBA-15. The photocatalytic properties of Fe2O3/SBA-15 samples at pH = 3 and pH = 6 were evaluated in catechol and hydroquinone photodecomposition by inducing visible radiation. The conversion of catechol and hydroquinone, at pH = 3 and pH = 6 with iron(III) acetylacetonate and FeCl3 as the precursor of iron oxide nanoparticles, were measured by UV-Vis spectroscopy, chemical oxygen demand (COD) and total organic carbon (TOC) analysis.

Biological treatment of hypersaline wastewater from table olive processing: Process performance and protist population under different operating conditions

E. Ferrer-Polonio,B. Pérez-Uz,J.A. Mendoza-Roca,A. Iborra-Clar,L. Pastor-Alcañiz 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.56 No.-

Biological treatment of fermentation brines from table olive processing (FTOP) entails many difficultiesdue to their very high salinity and high COD concentration, which include some phenolic compounds. These extreme conditions limit the biodiversity of the microbial population. Experiments treating FTOPwere performed in laboratory sequencing batch reactors (SBR) changing operating conditions duringtheir operation, in order to study the effects on the SBR performance and on the protist population. Thestatistical study showed that the SBRs with high influent COD, pH and volatile solids and low influentphenol concentration, hydraulic retention time and temperature achieved the highest COD removalefficiencies. These operational conditions also provided the highest ciliate population and the lowestflagellate presence.

Integrating History of Mathematics in Teaching Cartesian Coordinate Plane: A Lesson Study

( Mendoza Jay-r M ),( Alegario Joan Marie T ),( Blanco Miguel G ),( De Torres Reynold ),( Igay Roselyn B ),( Elipane Levi E ) 한국수학교육학회 2016 수학교육연구 Vol.20 No.1

The History of Mathematics (HOM) was integrated in teaching the Cartesian Coordinate Plane (CCP) to Grade Seven learners of Moonwalk National High School using Lesson Study. After the lesson was taught, there were three valuable issues emerged: (1) HOM is a Springboard and/or a Medium of Motivation in Teaching CCP; (2) The History of CCP Opened a Wider Perspective about Its Real-life Application in the Modern World (3) In-tegration of History Developed a Sense of Purpose and an Appreciation of Mathematics Among Learners. Feedbacks solicited from the learners showed that they have under-standing of the importance of studying Mathematics after they learned the life and con-tributions of Rene Descartes to Mathematics. Hence, integration of history plays a vital role in developing positive attitudes among learners towards Math.

First-principles study on structural, electronic and ferroelectric properties of Bi2VO5.5 compound

Hmok HLinh,Martínez-Aguilar E.,Alanis Javier,Mendoza M.E. 한국물리학회 2022 Current Applied Physics Vol.44 No.-

A first-principles investigation of the origin of ferroelectricity in the Aurivillius compound Bi2VO5.5 is presented. Calculations with the density functional theory, in conjunction with the modern theory of polarization, allowed us to study the structural, electronic, and polar properties of two configurations built with oxygen vacancies, causing a charge imbalance and a subsequent displacement of the ions, generating two maximum polarizations, one of 14.75 μC/cm2 and one of 4.31 μC/cm2 along [011] direction. Electron localization function schemes were used to identify the asymmetry of charges in (001), (010) and (100) planes. The results obtained in this study establish that the origin of ferroelectricity is due to the displacement of the ions caused by oxygen vacancies and the asymmetric distribution of the isolated pair of Bi ions. On the other hand, the bandgap calculations and the results of Ps establish that Bi2VO5.5 is a candidate ferro-photovoltaic material.

In Vitro and In Vivo Nematicide Effect of Extract Fractions of Pleurotus djamor Against Haemonchus contortus

Manases González-Cortázar,José E Sánchez,Magaly Huicochea-Medina,Victor M Hernández-Velázquez,Pedro Mendoza-de-Gives,Alejandro Zamilpa,Ma Eugenia López-Arellano,Jesús Antonio Pineda-Alegría,Liliana Ag 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.3

Sheep haemonchosis is a disease that causes anemia, diarrhea, weight loss, low production, and even death of young animals. This represents a negative economic impact on the livestock sector. For decades, chemicals have been used to control this parasitic disease; however, cases of anthelmintic resistance have increased around the world. For this reason, the search for control alternatives is necessary. Several studies have shown that edible mushrooms of Pleurotus genus have different medicinal properties, including nematicidal activity. In this study, the chromatographic fractionation of the hydroalcoholic extract of fruiting bodies Pleurotus djamor was carried out to identify and isolate the metabolites responsible for nematicidal activity. From the fractionation of the extract, the fraction PdR2 and the subfraction PdB were obtained, which were evaluated against Haemonchus contortus under in vitro conditions. The nematicidal effect of the fraction PdB in gerbils infected artificially with H. contortus was evaluated. Finally, the analysis of the PdB fraction by gas chromatography-mass spectrometry and nuclear magnetic resonance was carried out. The results showed that the PdB had 100% of egg hatching inhibition from 5 mg/mL. Regarding larvicidal activity, it presented >97.2% from 24 h to 20 mg/mL. The in vivo evaluation of the PdB fraction showed a reduction of H. contortus larvae of 92.56%. The compounds present in this fraction were the mixture of allitol and an unidentified terpene in a ratio of 9:1. The PdB fraction is a potential alternative for the control of H. contortus, where allitol and a terpene could be responsible for nematicidal activity.

Total Transit Time and Probiotic Persistence in Healthy Adults: A Pilot Study

Annie Tremblay,Jeremie Auger,Zainab Alyousif,Sara E Caballero Calero,Olivier Mathieu,Daniela Rivero-Mendoza,Amal Elmaoui,Wendy J Dahl,Thomas A Tompkins 대한소화기 기능성질환∙운동학회 2023 Journal of Neurogastroenterology and Motility (JNM Vol.29 No.2

Background/AimsMotility, stool characteristics, and microbiota composition are expected to modulate probiotics’ passage through the gut but their effects on persistence after intake cessation remain uncharacterized. This pilot, open-label study aims at characterizing probiotic fecal detection parameters (onset, persistence, and duration) and their relationship with whole gut transit time (WGTT). Correlations with fecal microbiota composition are also explored. MethodsThirty healthy adults (30.4 ± 13.3 years) received a probiotic (30 × 109 CFU/capsule/day, 2 weeks; containing Lactobacillus helveticus R0052, Lacticaseibacillus paracasei HA-108, Bifidobacterium breve HA-129, Bifidobacterium longum R0175, and Streptococcus thermophilus HA-110). Probiotic intake was flanked by 4-week washout periods, with 18 stool collections throughout the study. WGTT was measured using 80% recovery of radio-opaque markers. ResultsTested strains were detected in feces ~1-2 days after first intake and persistence after intake cessation was not significantly different for R0052, HA-108, and HA-129 (~3-6 days). We identified 3 WGTT subgroups within this population (named Fast, Intermediate, and Slow), which could be classified by machine learning with high accuracy based on differentially abundant taxa. On average, R0175 persisted significantly longer in the intermediate WGTT subgroup (~8.5 days), which was mainly due to 6 of the 13 Intermediate participants for whom R0175 persisted ≥ 15 days. Machine learning classified these 13 participants according to their WGTT cluster (≥ 15 days or < 5 days) with high accuracy, highlighting differentially abundant taxa potentially associated with R0175 persistence. ConclusionThese results support the notion that host-specific parameters such as WGTT and microbiota composition should be considered when designing studies involving probiotics, especially for the optimization of washout duration in crossover studies but also for the definition of enrollment criteria or supplementation regimen in specific populations.

Adsorption capacity of bone char for removing fluoride from water solution. Role of hydroxyapatite content, adsorption mechanism and competing anions

N.A. Medellin-Castillo,R. Leyva-Ramos,E. Padilla-Ortega,R. Ocampo Perez,J.V. Flores-Cano,M.S. Berber-Mendoza 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

The adsorption of fluoride from water on bone char (BC) was investigated in this work, and the fluorideadsorption capacity of BC was compared to that of hydroxyapatite (HAP). The adsorption capacity of BCand HAP drastically increased while decreasing the pH from 7.0 to 5.0. Furthermore, the fluorideadsorption on BC was due to its HAP content and was not considerably affected by the presence of theanions Cl-, HCO3-, CO32-, SO42-, NO3- and NO2-. The mechanism of fluoride adsorption on BC wasattributed to electrostatic interactions between surface charge of BC and fluoride ions in solution.