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ilustraciones, fotografías a color, mapas a color The Colombian Air Quality National Strategy have established that prevention actions, reduction, and control emissions should be focused mainly on particulate matter, PM10 and PM2.5, due to the consistent exceedances related to the air quality guidelines suggest by the World Health Organization and the Air Quality National Standard in urban areas. In addition, the harmful effects in public health of population exposed to airborne particles. Therefore, one of the aims of the Strategy is encouraging the scientific knowledge to improve the national air quality management. Therefore, the aim of this dissertation's is to further knowledge of particle size distribution (PSD) of aerosols in urban areas in Colombian, linking the local and regional sources of air pollutants and the local weather patterns. The study was conducted in two places of Colombia: Bogotá and Palmira (Cauca’s Valley). The airborne aerosols were investigated utilizing impactors cascades to measure the size of inhale particles. The particle number concentration and particle number size distribution were measured in the size range from 17 nm and 10 mm using an Electrical Low-Pressure Impactor (ELPI+). Also, was used an Andersen Non-viable Impactor Cascade to determinate the mass size distribution and collect samples size segregated in nine stages between 0.1 to 9 um, to determine the contained of organic carbon, elemental carbon, and water-soluble ions in airborne inhalable particles. The findings of this study revealed that Bogotá's urban background area had a higher average particle number concentration (3800 #/cm3) than the area that was most adversely affected by automobile emissions (2800 x103 #/cm3). The number particle size distribution was unimodal in the traffic station of “Las Ferias” with a diameter centered in 120 nm, which evidences the particles are formed and grow through atmospheric process. In other hand, the urban background area exhibited a bimodal distribution, with a larger mode centered in particles of 120 nm of diameter with a second mode centered in 30 nm of diameter, which is more relevant in morning rush traffic hours. The Lung Deposition Surface Area (LDSA) was estimated from the interaction between particle size distribution and the model of the particle deposition in the respiratory system published by the Commission on Radiological Protection (IRCP) (ICRP, 1994). In this study, the urban background area reveled higher concentrations than the area affected by traffic emissions in Bogota, and other similar environments reported in the scientific literature. The submicrometric particles PM1, which can enter the alveolar region of the human respiratory system, was 20.8 ug/m3 in Bogota and 13.8 ug/m3 in Palmira. The mass size distribution exhibits a bimodal distribution that is equally centered between 0.43 and 1.1 um and 4.7 and 9.0 um. According to the chemical composition size separated, elemental carbon was accumulated in the fine fraction of PM2.1 in Bogotá at a rate of 72%, relative to 57% in Palmira. On the other hand, organic carbon was more evenly distributed in fine and coarse fraction. The sulfate ion was one of the most abundant water-soluble ions in two sites, but the size distribution was different while in Palmira was mainly accumulated in fine mode, in Bogota was dispersed across the two-size fraction. (Texto tomado de la fuente) La Estrategia Nacional de Calidad del Aire de Colombia ha establecido que las acciones de prevención, reducción y control de emisiones deben estar enfocadas principalmente a las emisiones de material particulado, PM10 y PM2.5, debido a las excedencias con respecto a los lineamientos de calidad del aire sugeridos por la Organización Mundial de la Salud y la Norma Nacional de Calidad del Aire. Además de los efectos nocivos en la salud pública de la población expuesta a partículas dispersas en el aire. De allí que, uno de los objetivos de la Estrategia es fomentar el conocimiento científico para mejorar la gestión de la calidad del aire a nivel nacional. El objetivo de esta tesis es contribuir en el conocimiento de la distribución del tamaño de partículas (PSD) de los aerosoles en áreas urbanas de Colombia, vinculando las fuentes locales y regionales de contaminantes del aire y las condiciones meteorológicas locales. Este estudio se realizó en dos lugares de Colombia: Bogotá y Palmira (Valle del Cauca). Los aerosoles en el aire se investigaron utilizando impactadores en cascada para medir el tamaño de las partículas inhaladas. La concentración del número de partículas y la distribución del tamaño del número de partículas se midieron en el rango de tamaño de 17 nm y 10 um usando un Impactador Eléctrico de Baja Presión (ELPI+). Adicionalmente, se utilizó un impactador en cascada Non-Viable Andersen para determinar la distribución de tamaño en masa y recolectar muestras segregadas en nueve etapas entre 0.1 y 9 um, para determinar el contenido de carbono orgánico, carbono elemental e iones solubles en agua de las partículas inhalables. Los hallazgos de este estudio revelaron que el área de fondo urbano de Bogotá tenía una concentración promedio de partículas más alta (3800 #/cm3) que el área más afectada por las emisiones de los automóviles (2800 #/cm3). La distribución del tamaño de partículas en número fue unimodal en la estación de calidad del aire “Las Ferias”, principalmente afectada por emisiones de tráfico vehicular, con un diámetro centrado en 120 nm, lo que evidenció que las partículas se forman y crecen a través de procesos atmosféricos del entorno. Por otro lado, el área de fondo urbano exhibió una distribución bimodal, con un diámetro modal de 120 nm y un segundo modo centrada en 30 nm de diámetro, la cual es más relevante en las horas pico de la mañana. El Área de superficie de deposición pulmonar (LDSA) se estimó a partir de la interacción entre la distribución del tamaño de las partículas y el modelo de deposición de partículas en el sistema respiratorio publicado por la Comisión de Protección Radiológica (IRCP) (ICRP, 1994). En este estudio, el área de fondo urbano mostro concentraciones más altas que el área afectada por las emisiones de tráfico en Bogotá, y otros ambientes similares reportados en la literatura científica. Las partículas submicrométricas PM1, que pueden ingresar a la región alveolar del sistema respiratorio humano, fue de 20,8 ug/m3 en Bogotá y 13,8 ug/m3 en Palmira. La distribución de tamaño de masa exhibe una distribución bimodal que está igualmente centrada entre 0.43 y 1.1 um, y 4.7 y 9.0 um. De acuerdo con la composición química separada por tamaño, el carbono elemental se acumuló en la fracción fina de PM2.1 en Bogotá a una tasa del 72%, frente al 57% en Palmira. Por otro lado, el carbono orgánico se distribuyó más uniformemente en la fracción fina y gruesa. El ion sulfato fue uno de los iones solubles en agua más abundantes en dos sitios, pero la distribución de tamaños fue diferente, mientras que en Palmira se acumuló principalmente en modo fino, en Bogotá se dispersó en la fracción de dos tamaños. Doctorado Doctor en Ingeniería Ciencias Atmosféricas

Number preference, i.e., the human tendency to gravitate toward or away from specific numbers, is a potential source of measurement error in forest inventory. Identifying its presence is an important step to ensure unbiased results. This study evaluated U.S. national forest inventory data for number preference and identified factors that influence the proportion of tree cull volume, tree diameter, tree height, and seedling count observations ending with the digit zero or five (ED0,5) and seedling count observations that were multiples of four (M4). Two-sided hypothesis tests determined that ED0,5 occurred significantly more frequently than expected by chance for all metrics tested, though not in every inventory region of the country nor to the same degree. Consistently, tree-level ED0,5 was more likely when metrics were estimated visually rather than measured instrumentally. Logistic regression indicated that the effect of species class, species type, tree status, treetop status, and stem size on tree-level ED0,5 and the effect of plot-level water depth on seedling count ED0,5 also varied by region. Though the effect was small, findings suggest that some inventory regions may be employing an approved multiplicative shortcut that results in a greater-than-expected proportion of M4 observations among seedling counts.

ilustraciones, fotografías a color, gráficas Se diseñó y construyó una balanza de Kibble, utilizando piezas de Lego® para formar la estructura, y elementos no ferromagnéticos para las partes móviles. Haciendo uso de un multímetro calibrado de 51/2 dígitos, un giroscopio y un sensor de ultrasonido, se determinó la masa de cargas de prueba de 1 𝑔, 2 𝑔, 5 𝑔, 10 𝑔 y 20 𝑔, pertenecientes a un juego de masas clase OIML E2, lo que permitió hallar una diferencia en masa menor al 1,5 % del valor nominal. La incertidumbre expandida obtenida fue hasta cuatro (4) órdenes de magnitud superior a la de la clase OIML E2, con lo cual se pudo identificar la velocidad como la magnitud de influencia dominante en el presupuesto de incertidumbre. (Texto tomado de la fuente) A Kibble Balance was designed and built, using Lego pieces to form the structure with non-ferromagnetic elements for the moving parts. A 51/2-digit calibrated multimeter, a gyroscope and an ultrasound sensor were used. The mass of test loads of 1 𝑔, 2 𝑔, 5 𝑔, 10 𝑔 and 20 𝑔 belonging to a set of OIML E2 class masses was determined. Thus, finding a difference in mass less than 1,5% of the nominal value. The expanded uncertainty obtained was up to four (4) orders of magnitude higher than that of the OIML E2 class, identifying speed as the magnitude of dominant influence on the uncertainty budget Maestría Master en ciencias - física

ilustraciones, diagramas, fotografías a color Se diseñó, construyó y evaluó de manera satisfactoria una celda de punto fijo de indio cerrada. Se desarrolló un modelo computacional para estudiar el proceso de solidificación de un metal puro, el cual permite variar los parámetros geométricos de la celda. Este modelo se validó con los resultados experimentales obtenidos de la celda. Finalmente, se realizó un ejercicio de calibración con un termómetro de resistencia de platino en el sub-intervalo H2O-In. Se realizaron once curvas de solidificación y se obtuvo una temperatura de solidificación promedio de 429.746493 K con una incertidumbre expandida de 2.7 mK, para un factor de cobertura 𝜅= 2, con una duración máxima del plateau de 8 h. Estos resultados son satisfactorios ya que son comparables con los de celdas de punto fijo de indio de otras instituciones metrológicas. Los resultados obtenidos se validaron a partir de dos métodos: 1. La prueba de error normalizado, donde se concluyó que la temperatura de solidificación de la celda construida es comparable con la celda de punto fijo de un proveedor externo que posee actualmente el Instituto Nacional de Metrología (INM) 2. Al evaluar la incertidumbre de medición debido a la repetibilidad de la transición de fase de la celda, cuya contribución a la incertidumbre expandida fue menor al 5 %. La validación del modelo computacional fue exitosa al obtener un error absoluto de 0.86 mK respecto al valor experimental y una incertidumbre expandida máxima en sub-intervalo H2O-In de 3.0 mK. Se concluye que los objetivos de este trabajo fueron alcanzados exitosamente y la celda construida es apropiada para las actividades de laboratorio intencionadas por la Subdirección de Metrología Física del INM. (Texto tomado de la fuente) A closed indium fixed point cell was satisfactorily designed, built and evaluated. A computational model was developed to study the solidification process of a pure metal, allowing the variation of design geometric parameters of the cell. This model was validated from the experimental results obtained from the cell, finally, a calibration exercise was carried out with a thermometer of platinum resistance in the H2O-In sub-range. Eleven solidification curves were carried out and an average solidification temperature of 429.746493 K was obtained with an expanded uncertainty of 2.7 mK for a coverage factor 𝜅= 2, with a maximum duration of the plateau of 8 h. These results are satisfactory as they are comparable with those of indium fixed point cells from other metrological institutions. The results obtained were validated using two methods: 1. The normalized error test, where it was concluded that the solidification temperature of the built cell is comparable with the fixed-point cell of an external provider currently owned by the National Institute of Metrology (INM) 2. By evaluating the measurement uncertainty due to the repeatability of the phase transition of the cell, whose contribution to the expanded uncertainty was less than 5 %. The validation of the computational model was successful, obtaining an absolute error of 0.86 mK with respect to the experimental value and a maximum expanded uncertainty in the H2O-In sub-interval of 3.0 mK. We concluded that the objectives of this work were satisfactorily achieved and the cell built is appropriate for the laboratory activities intended by the INM Physical Metrology Sub directorate. Esta tesis se realizó en el marco del proyecto Plan de Fortalecimiento del INM como Centro de Investigación (código 9932100271370); financiado por el Ministerio de Ciencia, Tecnología e Innovación (Minciencias) y realizado conjuntamente entre el INM y la Universidad Nacional de Colombia a través del convenio especial de cooperación 001 de 2020. Maestría Magíster en Ciencias - Física Termometría

This study applied phenomenological design to explore the ethnomathematical aspects of the Toor Kyo la Nam and Ishiva-dar indigenous games of the Tiv people of Mbayom Village of Gwer-East Local Government Area of Benue State, Nigeria. The sample comprises 15 Mbayom indigenes selected via purposive sampling. The instrument for the study is a semi-structured interview rubric. Narrative analysis was used to analyze and interpret the shared experience of Mbayom people with the local children plays. The results of the study revealed the richness of the Toor Kyo la Nam and Ishiva-dar indigenous games as basis for mathematics instruction in the core areas of Arithmetic, Geometry, Logic, Everyday Statistics, Mensuration and Trigonometry. The outcomes also revealed that Mbayom people through the help of Toor Kyo la Nam and Ishiva-dar can identify smart and intelligent children who can keep correct records and are responsible for their actions or inactions and can also take right decision under pressure or in a very critical situation. Based on the findings, the study recommended that Curriculum developers should carefully consider these local indigenous games in the design of the mathematic curriculum and Mathematics teachers who are the curriculum implementers should as a matter of fact appreciate the mathematical aspects of indigenous games and should relate them with topics in mathematics for easier understanding.

Additive manufacturing (AM) is now regularly used for customised fabrication of parts with complex shapes and geometries. However, the large range of relevant scales, high slopes, step-like transitions, undercuts, alternation between dark and overly bright regions and other complex features present on the surfaces, in particular of metal additive parts, represent a significant challenge for current optical measurement technologies. Measuring surfaces with such complex features requires high numerical aperture (NA) optics, and state-of-the-art systems commonly include optics that can only reliably acquire surface topographies over a small field of view (FOV), typically tens or hundreds of micrometers. Such measurements are often insufficient for practical applications. Here, we present an optical system that features a large NA ( > 0.3) and a wide FOV 2.9 × 2.9 mm, capable of measuring AM parts in a single measurement, without the need for lateral stitching to increase the FOV. The proposed system exhibits optical properties that provide facility for large-field, high-resolution measurement of industrially-produced additively manufactured parts.

Aquest TFG tracta de fer el disseny complet d'un sistema de mesura del transport sòlid de fons a rius amb un Helley-Smith HS152. Helley-Smith és com de forma comuna es coneix l'aparell de recerca per prendre mostres puntuals del sediment (sorra i grava) que circula pel fons de la llera quan un riu va crescut. Aquest aparell de mostreig, d’uns 75 kg de massa aproximadament, es deixa caure des d'un pont sobre el fons del riu quan es vol fer una mesura del sediment transportat per un riu en avinguda. A causa del pes de l’aparell i a l'empenta de l’aigua, cal dotar-lo d'un sistema que permeti pujar i baixar l’aparell des del pont on es prenen les mesures fins al fons del riu. Aquest sistema inclou un sistema motoritzat amb una politja. També caldrà dissenyar una estructura capaç de subjectar tot l’exposat amb anterioritat. Finalment, a més a més del disseny complet del sistema de mesura, el TFG farà la selecció d'un sistema motoritzat que permeti desplaçar amb facilitat tot el sistema de mesura d'un punt a un altre del pont. El TFG inclourà la definició geomètrica de cadascun dels elements del sistema i un pressupost. Aquest TFG s'emmarca dins del projecte de recerca Hydrological extremes, Historic-Environmental Changes and River Resilience: the Ebro River (EXCHAREbro), presentat en la convocatòria de Projectes I+D+i 2020 del Ministeri de Ciència i Innovació. Este TFG trata de hacer el diseño completo de un sistema de medida del transporte sólido de fondo a ríos con un Helley-Smith HS152. Helley-Smith es como se conoce de forma común el aparato de investigación para tomar muestras puntuales del sedimento (arena y grava) que circula por el fondo del cauce de un río cuando este va crecido. Este aparato de muestreo, de unos 75 kg de masa aproximadamente, se deja caer desde un puente sobre el fondo del río cuando se quiere hacer una medida del sedimento transportado por un río en avenida. Debido al peso del propio aparato y al empuje del agua, hay que dotarlo de un sistema que permita subir y bajar el aparato desde el puente donde se toman las medidas hasta el fondo del río. Este sistema incluye un sistema motorizado con una polea. También será necesario diseñar una estructura capaz de sujetar todo lo expuesto con anterioridad. Finalmente, además del diseño completo del sistema de medida, el TFG hará la selección de un sistema motorizado que permita desplazarse con facilidad todo el sistema de medida de un punto a otro del puente. El TFG incluirá la definición geométrica de cada uno de los elementos del sistema y un presupuesto. Este TFG se enmarca dentro del proyecto de investigación Hydrological extremas, Histórico-Environmental Changes and River Resilience: the Ebro River (EXCHAREbro), presentado en la convocatoria de Proyectos I + D + i 2020 del Ministerio de Ciencia e Innovación. This TFG tries to do the complete design of a solid bedload transport measurement system with a Helley-Smith HS152. Helley-Smith is how the research apparatus is commonly known to take specific samples of the sediment (sand and gravel) that circulates along the bottom of a river bed when it is high. This sampling device, with a mass of approximately 75 kg, is dropped from a bridge over the river bottom when it is desired to measure the sediment transported by an avenue river. Due to the weight of the device itself and the pressure of the water, it must be equipped with a system that allows the device to be raised and lowered from the bridge where the measurements are taken to the bottom of the river. This system includes a motorized system with a pulley. It will also be necessary to design a structure capable of holding everything previously exposed. Finally, in addition to the complete design of the measurement system, the TFG will select a motorized system that allows the entire measurement system to be easily moved from one point of the bridge to another. The TFG will include the geometric definition of each of the elements of the system and a budget. This TFG is part of the research project Hydrological extremas, Histórico-Environmental Changes and River Resilience: the Ebro River (EXCHAREbro), presented in the call for I + D + iProjects 2020 of the Ministry of Science and Innovation.

[eng] The term light pollution refers to different harmful effects produced by artificial light sources. This phenomena affects observational astronomy, the flora and fauna of the species adapted to the natural cycles of light and it also contributes to climate change. With this thesis, we aim to contribute to the understanding of the physics behind light pollution and to provide strategies to improve and ease its assessments. We established two different lines of action: measuring and modelling. The objectives of the measuring branch are to characterise the quality of the night sky in large areas within Catalonia and to study in detail the sky over key locations from the territory. The first objective was addressed using dynamic Sky Quality Meter (SQM) measurements of the zenith sky brightness. With this methodology we covered more than 3500 km in a total of 26 nights distributed in four campaigns. We created a processing software to deal with the resulting data and to ease and homogenize the process for obtaining reliable zenith sky brightness maps. The resulting maps provided reliable information about the quality of the sky in vast areas of Catalonia. For the second objective, we used Digital Single Lens Reflex images processed with Sky Quality Camera software. The resulting all-sky maps are useful to point out the most polluted directions and as a consequence the most probable sources of light pollution. Eight different locations have been assessed using this methodology. Light pollution models estimate the sky brightness by reproducing the interactions between the electromagnetic radiation and the constituents of the atmosphere. They have been validated as a helpful tool for assessing the night sky brightness and to understand light pollution at a physics level. In particular we worked with the Illumina light pollution numerical model. The objectives of the modelling branch are to derive a tool to point out the principal sources of light pollution affecting a particular location, to find a methodology to reproduce measurements that can be used as a prediction tool and to define a process to assess very large areas. For each objective we created a different simulation product: contribution maps, all-sky brightness maps and zenith sky brightness maps of large areas. The spectral range studied goes from 350 nm to 830 nm covering the Johnson-Cousins B, V and R bands. Contribution maps show the percentage to the artificial radiance received that was emitted by each source. They are a useful tool to sort the light pollution sources that are affecting the sky over a particular location. They are also useful for deciding which sources to include in all-sky brightness simulations. All-sky brightness maps derived with Illumina are a reliable tool to reproduce all-sky brightness measurements. This kind of maps can be used for predicting the changes in the sky that would be produced by changes in the lighting systems. We have used Illumina to create a zenith sky brightness map of Catalonia in B and V bands with a sampling grid of 5 km. It provides an accurate picture of the light pollution current situation of the country. The maps reveal a complex pattern, in agreement with the obtained in the measurements campaign, linked to the heterogeneity of the territory regarding population distribution and orography. The principal sources of light pollution are Barcelona and Tarragona metropolitan areas. The coastal line, in general, is very polluted. The darkest regions of the country are the Pyrenees, especially in the west, the Ports de Beseit natural park in the south west of the country, and the area around Montsec mountain range in the west., [cat] El terme contaminació lumínica fa referencia als diferents efectes perjudicials derivats de les fonts de llum artificial. Aquest fenomen afecta l’astronomia observacional, la salut de les espècies que estan adaptades als cicles naturals de llum i a més a més contribueix al canvi climàtic. En aquesta tesi, l’objectiu és contribuir en l’estudi de la contaminació lumínica a nivell físic i proporcionar estratègies per millorar i facilitar la seva avaluació. Per assolir aquest objectiu hem establert dues línies de treball diferents: mesures i modelització. A la branca de mesures hem estudiat el zenit en grans territoris utilitzant mesures dinàmiques amb un fotòmetre SQM. Aquesta metodologia ens ha permès recórrer més de 3500 km en un total de 26 nits distribuïdes en quatre campanyes anuals. També hem estudiat tot el cel en vuit localitzacions prenent imatges amb càmeres comercials (DLSR) i processant-les amb el software Sky Quality Camera . Els models de contaminació lumínica reprodueixen les interaccions entre la radiació electromagnètica i els components de l’atmosfera per estimar la brillantor de cel. En particular hem treballat amb el model numèric de contaminació lumínica Illumina. L’hem utilitzat per crear tres tipus de productes diferents: mapes de contribució que mostren el percentatge de la llum artificial total que prové de cada font; mapes de brillantor de tot el cel i mapes de brillantor zenital de grans àrees. Catalunya té un patró de brillantor del cel complex, degut a la heterogeneïtat en la distribució de la població i en l’orografia del territori. Les principals fonts de llum són les àrees metropolitanes de Barcelona i Tarragona. La línia de costa està molt contaminada en general. Les regions més fosques del territori són el Pirineu, especialment a l’oest, el parc natural dels Ports de Beseit al sud-oest i l’àrea al voltant de la serra del Montsec.

An accurate transmission of the orientation between surface and underground workings, by means of vertical shafts, is a major challenge in the mining industry, especially for deep mines. We assessed the accuracy of this operation in a case study using the two-shaft plumbing and gyroscopic methods in order to compare and analyse the planimetric displacement of the baseline due to different sources of error in each method. The advantages and disadvantages of both methods are discussed. Some disadvantages in each method have been reduced thanks to technological progress, especially in the two-shaft plumbing method. The different sources of error that affect the measurements are analysed in detail with the aim of compensating them and achieving the required precision for an underground infrastructure. Mine ventilation has been identified as one of the most important sources of error in the plumbing method due to intake and return air flow producing a significant displacement of the verticality of the plumbs in the shafts. In this regard, we describe some measures to reduce the influence of ventilation and give details of a compensation method.

The Barbe horse occupies a prominent place in the history, culture and traditions of Algeria; it is at the base of the evolution of the main equine breeds in Maghreb. Nineteen (19) measurements were made on 58 pure and presumed Barbe horses (uncertain origins), all aged three years and over. From these, six body indices were calculated and live weight estimated. The cephalic profile survey was also performed. Statistical analyzes were carried out on these different measurements by software R 2.15.2 and XLSTAT2016. The statistical tests used were of the descriptive and analytical type including among others, the calculation of means, standard deviation, and principal componentanalysis (PCA) and ascending hierarchical classification (CAH). We also estimated genetic diversity by Shannon and Weaver index. They find that the Algerian Barbe horse is a eumetric, mediolinear horse with a body index of 0.955, (squared horse), with a median size of (152.5) cm, a chest of (175.5) cm and a posterior(19.8) cm and anterior (20.6) cm canon. It has a slightly hooked convex cephalic profile and a predominantly chestnut robe. Its characteristics make the horse Barbe of Algeria conform to the standard as defined by the world organization of the horse Barbe.