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Influence of Geological Factor on Indoor Radon Concentrations in Dwelling of Queretaro,Mexico

Open Journal of Geology 2014年第12期4卷 627-635页

作者： Rocio García Martínez Anatoliy Kotsarenko Roman Pérez Enriquez Jose Antonio López Cruz Abeyro svetlana Koshevaya jesús efrén ospina norena Centro de Ciencias de la Atmósfera Universidad Nacional Autónoma de MéxicoCiudad UniversitariaMéxico CityMéxico Universidad Autónoma del Carmen(UnACAR) Facultad de IngenieríaCiudad del CarmenMéxico Centro de Geociencias Universidad Nacional Autónoma de MéxicoCampus JuriquillaQuerétaroMéxico CIICAp Autonomous University of State Morelos(UAEM)CuernavacaMéxico Programa de Investigación de Cambio Climático Universidad Nacional Autónoma de MéxicoCiudad UniversitariaMéxico CityMéxico

In this study, radon-222 concentrations were measured within 34 houses distributed in the northern, southern, and central areas of the city of Querétaro in 2007. The objective of this study was to establish the spatial distribution of radon with respect to geological faults and its relation to certain environmental variables. For each sampling site, the radon-222 concentration was analyzed as a function of various climate variables, relative humidity, temperature, and atmospheric pressure, in addition to the ventilation of the house and distance of each site from any geological faults in the area. A multivariate statistical technique was used to analyze these variables based on two components. For component 1, the relative humidity and temperature had the greatest weight, 0.677 and 0.492, respectively, while for component 2, the greatest weights corresponded to radon and the temperature with 0.693 and 0.609, respectively. The average radon concentration across the entire sampling period was 38.92 Bq/m3, the minimum detected value was 6.01 Bq/m3?for site 91GAG0607, and the maximum detected value was 225.95 Bq/m3?for site 91CAM20907. This last value is outside the standards permitted by the Environmental Protection Agency of the United stated, which is 148 Bq/m3?for indoor environments. With respect to geological faults and their relationship to radon-222, the concentrations for the sampling sites had no relationship to the closeness or distance to these faults.

关键词： Indoor Radon Geology Building Characteristics and seasonal Variations

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Experimental model for the description of the behaviour of a 9-mm projectile at a target

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Forensic sciences Research 2021年第1期6卷 67-74页

作者： Patricia Morales-Vega Daniel Esteban Jaramillo-Arango Jaime Alberto Osorio-Velez David norena-Blandon Instituto de Fısica Universidad de AntioquiaMedellınColombia

Analysis of crime scenes involving single-fire-gun projectiles requires the determination of the direction of arrival of a projectile at the target and other factors to reconstruct *** movement of a projectile can be analyzed by applying Euler’s equations to a solid symmetrical rigid *** present work starts from a newtonian reformulation of these equations to show that,in the presence of a gravitational field,the system can be expressed with a complex variable nonlinear equation,where the inclusion of small nutation variables allows us to find possible *** a particular case,we analyzed the movement of a 9-mm projectile fired from distances greater than 1 m to demonstrate that the direction of arrival of the projectile at the target cannot be traced by a stick placed in the target hole,as is usually performed in crime investigations.A series of shots were fired from distances varying between 1 m and 7 *** data were recorded on Riemann planes of projection for the description of nutation and precession motions,allowing the observation of the motion dynamics of the *** show that the direction of arrival at the target can be determined approximately from the analysis of the nutation and precession curves through Riemann planes of *** results presented in this work will allow more accurate judgements to be made in judicial investigations.

关键词： Forensic sciences forensic ballistics firearm gyroscopic motion Euler equations nutation precession projectile motion

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Ethyl Levulinate Obtained from Lignocellulosic Waste Material with Previous Delignification by Ultrasonic-Assisted Technique

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Journal of Agricultural Chemistry and Environment 2017年第1期6卷 93-103页

作者： Jorge Ernesto solá-Pérez Hugo saldarriaga-norena Mario Murillo-Tovar Centro de Investigaciones Químicas ICCBAUniversidad Autónoma del Estado de MorelosCuernavacaMéxico

Ultrasound-assisted pretreatment under mild operating conditions has been investigated for intensification of delignification to facilitate the obtaining of ethyl levulinate from biomass. The effect of pH (2 - 12), temperature (30°C - 70°C) and pretreatment time (0 - 120 minutes) has been studied for different biomass samples. The most favorable conditions were basic pH, temperature of 70°C and pretreatment time of 2 h, obtaining values of delignification near 80 percent. The ethyl levulinate is obtained in microwave directly via from samples before and after delignification and analyzed for GC-Ms. The results evidenced better yields for the delignified samples.

关键词： Ethyl Levulinate Delignification Wheat straw sugarcane Bagasse Maguey Bagasse

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Optimization of Analytical Conditions to Determine steroids and Pharmaceuticals Drugs in Water samples Using solid Phase-Extraction and HPLC

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American Journal of Analytical Chemistry 2011年第8期2卷 863-870页

作者： Ramiro Vallejo-Rodriguez Alberto Lopez-Lopez Hugo saldarriaga-norena Mario Murillo-Tovar Leonel Hernandez-Mena Centro de Investigacion y Asistencia en Tecnologia y Diseno del Estado de Jalisco(CIATEJ) Normalistas 800Colinas de la NormalGuadalajaraMexico Facultad de Ciencias Quimicas Universidad Autonoma de CoahuilaRepublica Ote.SaltilloMexico

Two reliable methods were optimized to determine two steroids (17?-Estradiol and 17?-Ethinylestradiol) and two pharmaceutical drugs (ibuprofen and naproxen) using solid-Phase Extraction (sPE) for sample preparation and High Performance Liquid Chromatography (HPLC) for analysis. sPE (C18) conditions were evaluated varying elution solvent volume, pH conditions and sample mass in the cartridge and reduction techniques of the extract. The efficiency of the analytical methods was evaluated by spiking ultrapure water samples with compounds at three and four levels of concentration for steroids and pharmaceutical drugs, re- spectively. The recoveries were independent (P > 0.05) of added mass of target analytes with a repeatability lower than 6.5% for steroids and 12.1% for pharmaceutical compounds. The recovery factor (coefficient of variation, CV) was higher than 83% for steroids (CV 93% for pharmaceuticals (CV nalytical method was applied for the evaluation of a steroid degradation test using ozone, finding that the estimated limit of detection is sufficient to determine the residual mass (μg?L–1) of 17β-Estradiol after the experiment.

关键词： steroids Pharmaceuticals Drugs solid-Phase Extraction HPLC-DAD

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Chemical Evaluation of Groundwater from supply Wells in the state of Coahuila,Mexico

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Journal of Water Resource and Protection 2014年第1期6卷 49-54页

作者： Hugo saldarriaga-norena Iliana de la Garza-Rodriguez stefan Waliszewski Edith Colunga-Urbina Omar Amador-Munoz Mayela Moreno-Davila Rodrigo Morales-Cueto Centro de Investigaciones Quimicas Universidad Autonoma del Estado de MorelosCuernavacaMéxico Facultad de Ciencias Quimicas Universidad Autónoma de CoahuilaSaltilloMexico Instituto de Medicina Forense Universidad VeracruzanaVeracruzMexico Centro de Ciencias de la Atmosfera Universidad Nacional Autonoma de MexicoCiudad de MexicoMexico

The present study is conducted with the purpose of determining the chemical characteristics of groundwater that supplies 16 wells in the state of Coahuila, which are used for different human activities. sampling was conducted in January 2011. For 56% of the fifteen wells tested, analysis did not detect the presence of aluminum;however, wells 2, 3, 6, 8 and 13 had concentrations above the permissible limit established by the Mexican standard nOM-127-ssA1-1994. For cadmium, only the well 3 was above the norm. Meanwhile, iron was above the permissible limit in eight wells (2, 4, 5, 6, 9, 12, 13 and 15). Lead exceeded the limit in wells 6, 7, 9, 10, 11 and 12. In general, for the rest of the parameters listed in the norm, values were below allowable limits. By using Piper diagrams, it was observed that in general, the waters tested showed characteristic calcium bicarbonate. By establishing a matrix of correlations between chemical parameters, it was observed that the highest significant correlations occurred among carbonate hardness, calcium, lead and total alkalinity, with r2 values greater than 0.82. Also, high correlations were found between some metal species, suggesting a common origin. The allowed Principal Component Analysis and Cluster Analysis establish the associations between all analyzed physicochemical parameters, and they also determine the wells with similar characteristics.

关键词： Groundwater Coahuila Physicochemical Parameters Piper’s Diagram PCA

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Chemical Characterization of n-Hexane Extract Obtained from Lignocellulose Residual Contained in Agroindustrial Wastes

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Journal of Agricultural Chemistry and Environment 2018年第2期7卷 94-104页

作者： Jorge Ernesto solá-Pérez Hugo saldarriaga-norena Mario Murillo-Tovar Gustavo Ronderos-Lara Verónica Gisela López-Martínez Centro de Investigaciones Químicas ICCBAUniversidad Autónoma del Estado de MorelosCuernavacaMéxico

The chemical composition of n-hexane extractives from lignocellulose residual contained in different agroindustrial wastes was studied. The n-hexane extract, which accounted for 1.6% of total lignocellulose residual weight, was analysed by 1H-nMR and gas chromatography/mass spectrometry. The most predominant compounds identified were aliphatic hydrocarbons (lineal alkanes, branched alkanes, alkenes). Additionally, terpenes, ketones, fatty alcohols, fatty acids and steroids were also found together in minor amounts. The lipophilic compounds in n-hexane extracts in three lignocellulosic wastes, which is highly valuable information for a more complete industrial utilization of these lignocellulosic materials.

关键词： Wheat straw Maguey Bagasse sugarcane Bagasse n-Hexane Extract

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Ionic Composition in Aqueous Extracts from PM2.5 in Ambient Air at the City of Cuernavaca,Mexico

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Journal of Environmental Protection 2014年第13期5卷 1305-1315页

作者： Hugo saldarriaga-norena Leonel Hernandez-Mena Enrique sanchez-salinas Fernando Ramos-Quintana Laura Ortiz-Hernandez Rodrigo Morales-Cueto Vanesa Alarcon-Gonzalez sandra Ramirez-Jimenez Chemical Research Center Autonomous University of the Morelos StateCuernavacaMexico Center for Research and Assistance in Technology and Design of the state of Jalisco GuadalajaraMexico Biotechnology Research Center Autonomous University of the Morelos StateCuernavacaMexico

The present study was carried out between May and June 2012 in the city of Cuernavaca, Mexico. During this time the average ambient temperatures were about 25°C, suggesting the formation of secondary aerosols, consisting mainly of ammonium and sulfate. The average PM2.5 concentration was 37 μg·m-3 for the entire urban area and there were only two days which exceeded the limit established by the official standards for periods of 24 h. The most abundant ionic species associated with PM2.5 were sulfates (3634.82 ng·m-3, average) and ammonium (1709.53 ng·m-3, average). The ratio estimated between total anions and total cations indicated that the concentration of total anions was 1.94 times total cations. The contribution percentage of the ionic species associated with PM2.5 revealed that 76% of the PM2.5 is sulfates and ammonium. The ion balance made for the urban area of Cuernavaca indicated that during the study period, the aerosols showed alkaline characteristics;that is to say the concentration of anions was not sufficient to neutralize the cations, specifically ammonia (m = 0.060). Finally, wind fields showed that during the study the winds came in 50% from the south west, followed by 25% from east and 12.5% of the south east, which in part allowed transport of contaminants into the portion of the city, where the AUsM campus site was located.

关键词： Ionic species Cuernavaca Ion Balance

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