خيارات البحث
النتائج 981 - 990 من 1,022
Groundwater quality and associated health risks in flood affected public schools: A case study of district Sanghar, Pakistan / Calidad del agua subterránea y riesgos de salud asociados en las escuelas públicas afectadas por inundaciones: un estudio de caso del distrito Sanghar, Pakistán النص الكامل
2020
Muhammad Sarfraz | Nargis Sultana | Muhammad Ilyas Tariq
Drinking water quality is of vital importance for the healthy life of a community especially if consumer is a teenager. In order to compare groundwater profile of flooded area (FA) and non-flooded area (NFA) of district Sanghar, 120 water samples from public schools were collected and investigated for physico-chemical parameters, essential metals, trace elements and microbiological indicators. Analysis data revealed that 47% samples in FA were contaminated with faecal coliform bacteria as compared to only 8.3% in NFA. On the other hand, chemical indicators like TDS, Ca, Na, K, SO4, Mg and hardness were higher in FA. Comparison of trace elements content with WHO guidelines revealed that concentration of Fe, As and Zn was higher in 66.7%, 31.7% and 13.3% water samples, respectively in FA whereas content of these elements was also on higher side in 3.3%, 23.3% and 1.7% samples in NFA, respectively. Health risk assessment due to high concentration of Fe, As and Zn showed that As HRI>1, for children in 35 and 23% water samples in FA and NFA, respectively.
اظهر المزيد [+] اقل [-]Population biology and sexual dimorphism in the freshwater prawn Atya scabra (Decapoda: Atyidae) in the De Contas River, Bahia, Brazil | Biología poblacional y dimorfismo sexual en la gamba de agua dulce Atya scabra (Decapoda: Atyidae) en el río de Contas, Bahía, Brasil. النص الكامل
2020
de Barros, Matheus Souza Ferreira | Calado, Tereza Cristina dos Santos | dos Santos, Ewerton Vieira | Silva, Alberis Santos | Albuquerque, Letícia Gomes de Andrade
Abstract. Introduction: Crustaceans have economic and ecological importance and the role of caridean crustaceans in lentic environments is crucial to maintain the trophic structure. The species Atya scabra is occasionally associated with fisheries, especially in Northeast and Northern Brazil. Objective: To determine the population structure, reproductive period, patterns of growth and distribution of size classes among sexes in a population of the prawn A. scabra in the De Contas River, Bahia, Brazil. Methods: Individuals were sampled in a period of one year by passing sieves through marginal vegetation and using dragnets. In the laboratory, we recorded the sex of the individuals and measured them using a pachymeter with 0.001 mm precision. The dimensions measured were CL (carapace length), TL (total length) and CW (carapace width). In order to analyze data, linear models for the relationships CL × CW were constructed and the type of allometry for each sex was determined. Individuals were grouped into size classes of 5 mm intervals. A chi-square test (χ2) was used to test deviation from the 1:1 sex ratio. The proportion of ovigerous females was registered for each month to determine the breeding period. Results: A total of 517 individuals were collected, 328 were males and 186 females of which 169 were ovigerous. Males showed a polymodal distribution in size classes and were significantly larger than females, which presented a unimodal distribution in size classes. The observed growth patterns demonstrated that both sexes present negative allometry. However, sexual dimorphism was detected when comparing the growth parameters. Ovigerous females were sampled the entire year and size-frequency data demonstrated that recruitment also occurs throughout the year, which allowed us to classify their reproduction as continuous. Conclusions: Our data is essential to draw sustainable fishery management strategies. We suggest a minimum capture size of 70 mm and capture restrictions from May to August. Key words: ecology; freshwater; limnology; conservation; morphometry.
اظهر المزيد [+] اقل [-]Evaluación experimental e informatizada de la reducción de arsénico total en el agua potable distribuida en el distrito de Quequeña, Arequipa, utilizando sistemas de tratamiento basados en carbón activado de coronta de maíz blanco ( Zea mays l) y cáscara de plátano ( Musa paradisiaca) النص الكامل
2020
Gonzales Fuentes, Cinthia Sofía | Segovia Alcázar, Claudia Alejandra
El arsénico y sus compuestos son considerados como cancerígenos para los humanos y en ciertas regiones existe evidencia epidemiológica de alteraciones a la salud ante el consumo prolongado de aguas arsenicales. En el distrito de Quequeña, el agua potable distribuida a la población excede la concentración máxima permisible dada por el Reglamento de la Calidad del Agua para Consumo Humano. Este trabajo tuvo como objetivo evaluar la reducción de arsénico total en el agua potable distribuida en el distrito de Quequeña – Arequipa, utilizando sistemas de tratamiento basados en carbón activado de coronta de maíz blanco (Zea mays l) y cáscaras de plátano (Musa paradisiaca) y finalmente realizar una propuesta de diseño de la planta de tratamiento de agua potable del distrito. En los ensayos realizados se utilizó 03 precursores: cáscara de plátano, coronta de maíz y una mezcla de ambos, se realizó la variación de cantidades de cada precursor en un tratamiento de 1 litro de agua, la concentración inicial de arsénico fue de 0.014 mg/L. De los resultados obtenidos el precursor que realizo una mejor remoción de la concentración de arsénico fue el carbón activado de coronta de maíz, el cual logró reducir un 48.8% la concentración de arsénico en el agua, permitiendo que la calidad de agua potable cumpla con la normativa vigente. A partir de los resultados obtenidos y su análisis mediante regresiones lineales con valor de R > 0.90, se realizó un diseño de la Planta de Tratamiento de Agua potable del Distrito, incluyendo este proceso en su tratamiento y mejorando algunas etapas de la misma, con la finalidad de que cumpla con el Reglamento de Calidad de Agua Potable. | Tesis
اظهر المزيد [+] اقل [-]Implementación de una unidad didáctica mediada por el juego como estrategia para un aprendizaje en ciencias naturales que concientice en el cuidado del agua con estudiantes de educación inicial de la Institución Madre María Berenice de Villa del Rosario Norte de Santander النص الكامل
2020
Torres Herrera, Nohora Constanza | Barragán Rivera, Miguel Ángel
Tesis de pregrado, diseñada desde la licenciatura de Biología con énfasis en educación ambiental, con el fin de desarrollar el proyecto de investigación, a través de la implementación de una unidad didáctica mediada por el juego que permita la sensibilización sobre el cuidado del agua en la Institución Madre María Berenice de Villa del Rosario Norte de Santander | Undergraduate thesis, designed from the Biology degree with an emphasis on environmental education, in order to develop the research project, through the implementation of a didactic unit mediated by the game that allows awareness about the care of water in the Mother María Berenice Institution of Villa del Rosario North of Santander | Licenciado en Biología con Énfasis en Educación Ambiental | http://www.ustadistancia.edu.co/?page_id=3956 | Pregrado
اظهر المزيد [+] اقل [-]ACEITABILIDADE DO USO DE ÁGUA DA CHUVA POR MORADORES DE CONJUNTOS HABITACIONAIS DA REGIÃO METROPOLITANA DE BELÉM | ACCEPTABILITY OF RAINWATER USE BY RESIDENTS OF BELÉM METROPOLITAN REGION | ACEPTABILIDAD DEL USO DE AGUAS LLUVIAS POR RESIDENTES DE CONJUNTOS DE VIVIENDA DE LA REGIÓN METROPOLITANA DE BELÉM النص الكامل
2020
da Silva, Ana de Nazare Martins | Lopes, Eliane Araujo de Souza | Mendes, Ronaldo Lopes Rodrigues | Silva Junior, Monaldo Begot
O objetivo deste estudo foi investigar a aceitabilidade do uso de água da chuva por moradores de conjuntos habitacionais de Belém e Ananindeua, Pará, Brasil, e ainda verificar a existência de Sistema de Aproveitamento de Água da Chuva – SAAC, nesses locais. A pesquisa foi realizada com 160 moradores dos conjuntos habitacionais Gleba 1, Jardim Tropical e Residencial Jardim Universitário e a maioria declarou que utilizaria água da chuva em suas residências, destinando-a, principalmente, para usos mais gerais. Apenas 23,1% deles relataram que poderiam utilizar para consumo humano. Em nenhum dos conjuntos estudados havia SAAC para uso coletivo, mas no Jardim Tropical identificou-se em uma residência um SAAC de uso familiar. Considera-se que a boa aceitabilidade dos moradores de condomínios residenciais de Belém e Ananindeua para uso da água da chuva um fator preponderante à implantação de SAAC nestes tipos de empreendimento, tanto para uso familiar quanto coletivo.PALAVRAS-CHAVE: Água da chuva, Fonte alternativa de água, Região Metropolitana de Belém. | The aim of this study was to investigate the acceptability of rainwater use by residents of housing estates in Belém and Ananindeua, Pará, Brazil, and to verify the existence of Rainwater Utilization System - SAAC, in these locations. The survey was conducted with 160 residents of the Gleba 1, Jardim Tropical and Residential Jardim Universitário housing estates, most of whom stated that they would accept rainwater in their homes, mainly for general use. Only 23.1% them reported that they could use for human consumption. None of the studied sets there are SAAC for collective use, but in the Jardim Tropical, a family-owned SAAC was identified in a residence. Good acceptability for rainwater among residents of residential condominiums in Belém and Ananindeua is considered to be a major factor in the implementation of SAACs in these types of enterprise, both for family and collective use. KEYWORDS: Rainwater, Alternative water source, Belém Metropolitan Region. | El objetivo de este estudio fue investigar la aceptabilidad del uso del agua de lluvia por parte de los residentes de las urbanizaciones en Belém y Ananindeua, Pará, Brasil, y verificar la existencia del Sistema de Utilización del Agua de Lluvia - SAAC, en estos lugares. La encuesta se realizó con 160 residentes de las urbanizaciones Gleba 1, Jardim Tropical y Residential Jardim Universitário, quienes declararon que usarían agua de lluvia en sus hogares, principalmente para usos más generales. Solo 23.1% de ellos informaron para consumo humano. Ninguno de los grupos estudiados tenía SAAC para uso colectivo, pero en el Jardín Tropical se identificó un SAAC de propiedad familiar en una residencia. La buena aceptación del uso del agua de lluvia entre los residentes de condominios residenciales en Belém y Ananindeua se considera un factor importante en la implementación de SAAC en este tipo de empresas, tanto para uso familiar como colectivo. PALABRAS CLAVES: Agua de lluvia, Fuente alternativa de agua, Región Metropolitana de Belém.
اظهر المزيد [+] اقل [-]Assessment of groundwater ingress to a partially pressurized water-conveyance tunnel using a conduit-flow process model: a case study in Iran | Evaluation de la pénétration des eaux souterraines dans un tunnel transportant de l’eau en partie sous pression, d’après un modèle du processus d’écoulement en conduite: une étude de cas en Iran Evaluación de la afluencia de aguas subterráneas a un túnel de conducción de agua parcialmente presurizado mediante un modelo de flujo por conducto: un estudio de caso en Irán 使用管流模型评估地下水进入部分加压输水隧道的入口:以伊朗某案例为例 Avaliação do ingresso de águas subterrâneas em um túnel de transporte de água parcialmente pressurizado utilizando um método de processo de fluxo-conduíte: um estudo de caso no Irã النص الكامل
2020
Gholizadeh, Hossein | Behrouj Peely, Ahmad | Karney, Bryan W. | Malekpour, Ahmad
Construction of a conveyance tunnel through rock often induces the ingress of groundwater into the tunnel, a flow that changes both the hydrogeological regime of the tunnel and its environment. To explore this key interaction, a novel modeling approach using the conduit flow process (CFP) is developed that considers both the hydraulic head and the ingress of water from the rock matrix during excavation. The resulting flow values are predicted through an adapted MODFLOW numerical model into which the tunnel is introduced with the aid of the new CFP approach. The CFP approach can simulate both laminar and turbulent flow in the tunnel whether the flow is free surface or pressurized. Several simulations, including one for which the permeability of the tunnel perimeter is assumed to be identical to the hydraulic conductivity of the surrounding rock matrix, are then used to explore the sensitivity of the predicted head and flow conditions to the permeability of the tunnel perimeter. Comparisons of the numerical results with field data from the Kerman Water Conveyance Tunnel in Iran show that the proposed approach accurately predicts the spatial variation of both groundwater ingress and hydraulic head.
اظهر المزيد [+] اقل [-]Evolution and sustainability of groundwater use from the Ica aquifers for the most profitable agriculture in Peru | Evolution et durabilité de l’utilisation de l’eau des aquifères d’Ica en vue de l’agriculture la plus rentable au Pérou Sostenibilidad y evolución del uso del agua subterránea de los acuíferos de Ica para la agricultura más beneficiosa del Perú 维系秘鲁最赚钱农业的Ica含水层中地下水利用的演变和可持续性 Evolução e sustentabilidade do uso da água subterrânea dos aquíferos Ica para a agricultura mais rentável do Peru النص الكامل
2020
Fernández-Escalante, Enrique | Foster, Stephen | Navarro-Benegas, Roberto
The Ica area of south-eastern Peru has evolved rapidly since the late 1990s into the most advanced agricultural development in the country. The intensive use of waterwells for year-round irrigation, primarily of asparagus, is the basis for an export industry worth about US$ 6,000 M/a, but one which is threatened by serious groundwater sustainability concerns. The public water-resource administration and private agricultural developers are beginning to confront the problem, which has already had a significant social cost, through developing measures to improve the groundwater balance whilst assuring agricultural production. This report presents the long-term evolution of land management and groundwater use in the area, and considers the feasibility of applying an adaptive and integrated water resources management (IWRM) approach to the system, with particular attention to managed aquifer recharge techniques.
اظهر المزيد [+] اقل [-]Identification of Potential Groundwater Recharge and Discharge Areas in the Ayuquila-Armeria River Basin Using GIS and Multi-Criteria Analysis | Identificación de zonas potenciales de recarga y descarga de agua subterránea en la cuenca del río Ayuquila-Armería mediante el uso de SIG y el análisis multicriterio النص الكامل
2020
Hernández-Juárez, Rodrigo Alejandro | Martinez Rivera, Luis Manuel | Peñuela-Arévalo, Liliana Andrea | Rivera-Reyes, Samuel
This research seeks to identify groundwater recharge and discharge areas in the administrative aquifers of the Ayuquila-Armeria river basin in the states of Jalisco and Colima, Mexico. The Ayuquila-Armeria river basin is one of the 15 most important of the 100 rivers running across the Pacific slope, and is among the 43 most important rivers at the country level. The regional climate is warm-humid in lowlands and subhumid temperate in highlands, with a summer rainy season (June to October) and a dry season the rest of the year. The basin shows a striking relief: from sea level to 4260 m a.s.l. at Nevado de Colima. The identification of these areas was based on a multi-criteria analysis of surface indicators of recharge and discharge areas supported by the flow systems theory (FST). This allows a systemic view of the environment, integrating various elements of nature, in addition to acknowledging groundwater and geological agent that causes a wide variety of processes and manifestations on the surface. The integration of Geographic Information Systems (GIS) and the Multi-Criteria Analysis (MCA) made possible to evaluate the potential recharge/ discharge at the regional level by analyzing physical variables such as lithology, soil, relief, slope, vegetation, precipitation, and a topographic humidity index. In the study area, the territory with high recharge potential ranges from 21% to 80%; the area with low and very low recharge potential, from 4% to 30%. The main potential recharge areas are located in the upper portion of mid-elevation and low mountains covered by pine-oak, oak, and tropical deciduous forests, and grasslands, and to a lesser extent, fir and mountain cloud forests. Soil types include mainly Regosol, Leptosol, Cambisol, Luvisol, Andosol, Umbrisol, and Phaeozem in slopes of 15%-30% covering units of rhyolitic tuff, andesite-basalt, andesite, lahar-pyroclastic rock, granite-granite diorite, and limestone. These areas are located mainly in Sierra de Cacoma-Manantl, Sierra Verde, Sierra de Quila, Sierra de Tapalpa, and the Nevado de Colima volcanic complex. For its part, discharge areas are found mainly in the coastal plains of Jalisco and Colima, associated with Calcisol, Arenosol, Fluvisol, Planosol, Gleysol, Solonchak, and Vertisol soils, and with with halophytic-hydrophytic grassland, bulrush, and mangrove vegetation. These are located in inland-lake areas in San Marcos, Sayula, and Zapotlán. Other discharge areas are the plains and intermontane valleys of Union de Tula and Autlán-El Grullo, as well as the bottom of V-valleys in certain areas of the basin. These can act as natural hydraulic boundaries of flow systems, limiting the amount of groundwater in each zone. The lateral alternation of recharge and discharge areas implies that the water recharged in a particular region may flow to a number of discharge areas, i.e., the water discharged in a given region may come from different regions. The above has important implications in the estimation of the availability estimated from the water balance, since groundwater may flow to more than one discharge area within the same “administrative” aquifer. This type of studies are a first approach providing innovative evidence to the systemic study of groundwater, i.e., the recharge-discharge areas. Their application positively supplements the results of the water balance used in the official evaluation of groundwater availability in Mexico. | Esta investigación busca identificar las zonas de recarga y descarga del agua subterránea en la cuenca del río Ayuquila-Armería en los estados de Jalisco y Colima. La identificación de estas zonas se logró mediante un análisis multicriterio con la teoría de los sistemas de flujo (TSF). Esta teoría permite obtener una visión sistémica del ambiente, integrando diversos elementos de la naturaleza, además de reconocer el agua subterránea como agente geológico causante de una gran variedad de procesos y manifestaciones en la superficie a través de condiciones naturales contrastantes entre la zona de recarga y descarga de agua subterránea. La integración de los Sistemas de Información Geográfica (SIG) y el Análisis Multicriterio (AMC) permitió identificar los sitios con mayor potencial de recarga y descarga analizando geología, suelo, topoformas, pendiente, vegetación e índice topográfico de humedad (ITH). La superficie con alto potencial de recarga varía de 21% a 80%, mientras que la superficie de descarga, de 4% a 30%. Las principales zonas potenciales de recarga son la sierra de Cacoma-Manantlán, la sierra Verde, la sierra de Quila, la sierra de Tapalpa y el complejo volcánico del Nevado de Colima. Por su parte, las zonas de descarga se encuentran principalmente en las planicies costeras de Jalisco y Colima, así como en una zona de lagos interiores en San Marcos, Sayula y Zapotlán. Otras zonas de descarga las constituyen las planicies y los valles intermontanos de Unión de Tula y Autlán-El Grullo, así como los fondos de valles en V en determinadas zonas de la cuenca.
اظهر المزيد [+] اقل [-]Groundwater flow below construction pits and erosion of temporary horizontal layers of silicate grouting | Ecoulement des eaux souterraines sous des fouilles de chantier et érosion de couches horizontales provisoires d’injection de ciment silicaté Flujo de agua subterránea debajo de excavaciones para la construcción y erosión de capas horizontales temporarias de inyección de silicato 基坑地下水的流动和硅酸盐灌浆材料形成的临时水平层的侵蚀作用 Fluxo de água subterrânea sob cavas de construção e erosão de camadas horizontais temporárias de rejunte de silicato النص الكامل
2020
Dekker, Joris M. | Sweijen, Thomas | Zech, Alraune
Injection of silicate grouting materials is widely used to create temporary horizontal layers for reducing inflow of groundwater at construction sites, in regions with shallow water tables. The erosion of a grouting layer was investigated by means of analytical solutions for groundwater flow and transport within a pit after construction finished. Erosion is assumed to occur by dissolution of the temporary injection layer and subsequent advective transport. Thereby, the hydraulic conductivity changes with time. This paper presents novel analytical solutions and approximate solutions for the major fluxes in the construction pit as a function of the domain settings, aquifer gradient and hydraulic conductivity. In addition, the mass flux and the dilution ratio of erosion-related components leaving the construction pit and entering the aquifer are quantified. Derived solutions are verified against numerical simulations. A sensitivity study shows the impact of domain settings on fluxes and dilution ratio. The results confirm that mass flux of grout components increases with ongoing erosion. Thus, its effect on groundwater quality increases with time after construction ceased.
اظهر المزيد [+] اقل [-]Estudio de conocimiento del riesgo para las plantas de tratamiento de agua de origen subterráneo que opera la empresa de acueducto y alcantarillado de Villavicencio ubicadas en los barrios, la reliquia, 13 de mayo y pinares del oriente como aporte al cumplimiento de la resolución 0549 de 2017. النص الكامل
2020
Maria Fernanda, Carrillo Cascavita | Arboleda Montes, Leydy Johanna | https://orcid.org/0000-0003-4234-5384 | http://scholar.google.com/citations?user=8Odmoc4AAAAJ&hl=es | https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000115799
En este trabajo se realizó la valoración de las amenazas naturales, antrópicas y socio-naturales, así como también la vulnerabilidad a las que se encuentran expuestas las Plantas de Tratamiento de Agua Potable Subterránea (PTAP) de los barrios La Reliquia, Pinares de Oriente y 13 de Mayo, ubicadas en la ciudad de Villavicencio, Meta, mediante la metodología Delphi y el método planteado en la Herramienta Metodológica para la Formulación de Programas de Gestión del Riesgo de Desastres en los Servicios de Acueducto, Alcantarillado y Aseo (Ministerio de vivienda, ciudad y territorio, 2014), con el fin de conocer el riesgo presente y la gravedad del mismo, para así poder contribuir al cumplimiento por parte de la Empresa de Acueducto y Alcantarillado de Villavicencio (EAAV) de la resolución 0549 de 2017 expedida por el ministerio de Salud y Protección Social y del Ministerio de Vivienda, Ciudad y Territorio donde se da una guía técnica para la elaboración del estudio del conocimiento del riesgo que deben cumplir los servicios públicos, como el servicio de acueducto. El método Delphi se desarrolló mediante un cuestionario realizado a cinco (5) trabajadores del área de planeación de la EAAV, en la cual se realizaron preguntas acerca de las amenazas y la vulnerabilidad a los que se encuentra expuesto el sistema de potabilización de agua, para conocer los riesgos más relevantes de cada una de las PTAP y así poder diseñar en el futuro el plan de riesgo por parte de la empresa y hacer planes para la disminución del riesgo en cada planta, para la identificación de los riesgos se tuvo en cuenta las matrices y el formato del conocimiento de riesgo descrito en la herramienta metodológica de la Unidad Nacional de Gestión del Riesgo (UNGR). Lo anterior, se realizó con el ánimo de que los resultados brinden un panorama de la situación actual o que se pueda presentar a futuro en las PTAP estudiadas con respecto a los riesgos evaluados, en los resultados se evidencia que los resultados son similares en varios tipos de riesgo como los naturales y socio-naturales, en cuanto a los riesgos antrópicos, estos difieren de una manera notable entre cada una de las plantas. Según el estudio realizado, la amenaza más alta que afecta a las tres plantas de tratamiento del estudio es el riesgo sísmico, seguido de las acciones violentas, debido el tipo de población que se maneja y a la ubicación geográfica del municipio de Villavicencio en el cual se encuentran ubicadas las PTAP de origen subterráneo. | In this work, the assessment of the natural, anthropic and socio-natural risks to which the Underground Drinking Water Treatment Plants (PTAP) of La Reliquia, Pinares de Oriente and 13 de Mayo neighborhoods, located in the city of Villavicencio, Meta, using the Delphi methodology and the method proposed in the Methodological Tool for the Formulation of Disaster Risk Management Programs in the Aqueduct, Sewerage and Sanitation Services (Ministry of Housing, City and Territory, 2014) , in order to know the present risk and its severity, in order to be able to contribute to compliance by the Villavicencio Aqueduct and Sewer Company (EAAV) of resolution 0549 of 2017 issued by the Ministry of Health and Social Protection and of the Ministry of Housing, City and Territory where a technical guide is given for the elaboration of the study of the risk knowledge that must be fulfilled. r public services, such as the aqueduct service. The Delphi method was developed through a questionnaire made to five (5) workers in the planning area of the EAAV, in which questions were asked about the threats and vulnerability to which the water purification system is exposed, for know the most relevant risks of each one of the PTAPs and thus be able to design in the future the risk plan by the company and make plans for the reduction of the risk in each plant, for the identification of the risks took into account the matrices and the risk knowledge format described in the methodological tool of the National Unit of Risk Management (UNGR). This was done with the aim that the results provide an overview of the current situation or that may be presented in the PTAP studied in the future with respect to the risks evaluated. The results show that the results are similar in several types risk as natural and socio-natural, in terms of anthropogenic risks, these differ in a remarkable way between each of the plants. According to the study carried out, the highest risk affecting the three treatment plants of the study is the seismic risk, followed by the violent actions, due to the type of population that is managed and the geographic location of the municipality of Villavicencio, in which located PTAPs of underground origin. | Ingeniero Ambiental | http://www.ustavillavicencio.edu.co/home/index.php/unidades/extension-y-proyeccion/investigacion | Pregrado
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