Valorización de Gas Natural de Lima y Callao S.A.

El presente trabajo de investigación tiene como objetivo cuantificar el valor de la compañía Gas Natural de Lima y Callao S.A., conocida también como Cálidda. Cálidda es la compañía que forma parte del Proyecto Camisea y es la concesionaria cuyo rol es el de distribución (downstream) de gas natural por red de ductos dentro del departamento de Lima y la Provincia Constitucional del Callao. Esta empresa se constituye en el año 2002 e inicia operaciones comerciales el 20 de agosto de 2004. Cálidda, en el 2002, recibe a través de TGP (Transportadora de Gas del Perú S.A.) y a título no oneroso, los derechos y obligaciones del Contrato BOOT, (siglas en inglés que significan build, operate, own and transfer, cuya traducción equivale a construir, operar, poseer y traspasar) que le otorga el derecho a la concesión. Dicho contrato establece un periodo de concesión de 33 años contados desde diciembre de 2000. La empresa es un activo estratégico para el desarrollo de la economía del país, así también para el cambio en la matriz energética del Perú. Para el presente trabajo, se valorizó Cálidda mediante la metodología de flujo de caja descontado, que tomando en consideración un detallado listado de supuestos, proporciona una valoración para Cálidda estimada de aproximadamente USD 2 000 millones, y un valor patrimonial aproximado de USD 1 340 MM, importes que se encuentran dentro de los rangos aceptables para una empresa de similares dimensiones y condiciones operativas

Factor de cielo visible y el efecto de isla de calor en Valparaíso

Urban form transforms territory and its climatic behavior. The morphology of a city varies from its centers to its periphery, as do population density, the temporal use of buildings, the presence or absence of vegetation and transport density. These variables condition the thermal behavior of public spaces. Sky View Factor (SVF) is defined by taking into account sky visibility from an urban canyon, which is related to the thermal storage and ventilation of street space. Both variables are key to pedestrian comfort and city warming. This paper presents climate performance data associated with the morphology of the city of Valparaíso, which has a coastal Mediterranean climate. Simultaneous climate measurements were taken in different parts of the city. These were then correlated with the geometric and material parameters of the locations studied. A close relationship was found between urban morphology, the thermal behavior of public spaces and an increased temperature favoring the urban heat island phenomenon (UHI). This data would make it possible to more accurately predict street level climate conditions and how they affect the UHI.La forma urbana transforma el territorio y su comportamiento climático. La morfología de la ciudad varía desde sus centros hasta su periferia, así como también varía en densidad poblacional, en el uso temporal de las edi caciones, en la presencia o ausencia de vegetación o en la densidad de transporte. Estas variables condicionan el comportamiento térmico del espacio público. A partir de la consideración de la visibilidad del cielo desde el cañón urbano se de ne el SVF (Sky View Factor), que está relacionado con el almacenamiento térmico y la ventilación del espacio de la calle. Ambas variables son fundamentales en el confort peatonal y en el calentamiento de la ciudad. En este trabajo se presentan desempeños climáticos asociados a la morfología de la ciudad de Valparaíso, ubicada en un clima mediterráneo costero. Se realizaron mediciones climáticas simultáneas en diversos lugares de la ciudad que se correlacionaron con parámetros geométricos y materiales de los lugares registrados. Se determina una estrecha relación entre morfología urbana, comportamiento térmico del espacio público y aumento de la temperatura favoreciendo el fenómeno de isla de calor (UHI). Estos valores permitirían predecir en forma más precisa las condiciones climáticas en el nivel de calle y la manera cómo afecta en el fenómeno urbano de isla de calor (UHI)

Exposición a la violencia y tolerancia a la frustración en estudiantes de secundaria de una institución educativa pública, Pisco, 2021

La presente investigación tuvo como objetivo principal determinar la relación entre la exposición a la violencia y tolerancia a la frustración en estudiantes de secundaria de una Institución educativa pública de Pisco, 2021. El tipo de la investigación es básica de diseño no experimental, descriptivo correlacional de corte transversal. La población específica del estudio estuvo conformada por 219 estudiantes, donde se extrajo una muestra de 140 de ellos a través de un muestreo no probabilístico por conveniencia ya que se seleccionaron a los estudiantes que se tuvieron mayor acceso y disponibilidad para poder formar parte del estudio; del mismo modo, los instrumentos utilizados fueron Cuestionario de Exposición a la Violencia de Orue y Calvete (2010) y la Escala de Tolerancia a la Frustración que es una sub escala del instrumento Bar-On y Parker (2000). Se usó la prueba de estadística no paramétrica Rho de Spearman al presentar los datos una distribución no normal y con ello se obtuvo como una relación positiva directa y moderada con un Rho = .555 y un nivel de significancia o p valor < .05 por lo cual se indica que existe relación entre las variables de estudio

Implementación de un sistema informático para el monitoreo de concentración de gases contaminantes del aire para el distrito de Víctor Larco Herrera, Trujillo 2023

El presente trabajo de investigación se realizó con el objetivo de determinar la influencia de un sistema informático en la medición de concentración de gases contaminantes del aire en el distrito de Víctor Larco Herrera en el año 2023. El tipo de estudio fue cuasi-experimental; con una muestra constituida por 4 puntos en el distrito. Para la recolección de datos se aplicó listas de cotejo y listas de observación. Para el análisis de datos se utilizó la herramienta T-Student. Las dimensiones comprendidas en la medición de contaminantes del aire fueron las emisiones de gases contaminantes (Dióxido de Nitrógeno, Monóxido de Carbono y Ozono), mientras que las dimensiones comprendidas en el sistema informático fueron funcionalidad, usabilidad, disponibilidad. El sistema informático que se ha desarrollado nos sirve para la medición y el registro en tiempo real de la concentración de gases contaminantes del aire, está conformado por componentes de hardware y software que interactúan a través de un sistema de comunicaciones GSM/GPRS. Después de monitorear los gases contaminantes, los resultados obtenidos como es 91.75% para la dimensión de la funcionalidad, 88.25% para la dimensión de la usabilidad, 72.2% para la dimensión de la disponibilidad y sobre todo el 92.5 % de eficiencia, demostraron que si influye de manera positiva en la medición de concentración de contaminantes del aire en el distrito en el 2023. Con base en lo mencionado, podemos concluir que se logró el objetivo planteado

An estimate of overheating risk and cooling potential using natural ventilation in single-family dwellings in coastal chilean cities

Este trabajo presenta una propuesta de evaluación de la demanda de refrigeración y de la capacidad de refrigeración pasiva por ventilación natural en viviendas sociales. La propuesta se fundamenta en la EN ISO 13790:2008 que utiliza una metodología casi estacionaria de cálculo. Se evalúa una vivienda con ventanas de doble batiente en las dos fachadas, en las diferentes orientaciones N-S, E-O, NO-SE y NE-SO. Se suponen dos posibles caracterizaciones del interior: poco conectado y muy conectado. Los emplazamientos considerados presentan una variedad climática importante, desde los desiertos del norte hasta los climas con variabilidad estacional más marcada del centro- sur del País. Las ciudades consideradas en el estudio son: Arica, Iquique, Antofagasta, La Serena, Valparaíso, Concepción, Valdivia y Puerto Montt. Los resultados muestran la presencia de demanda de refrigeración en la mayoría de los emplazamientos analizados y una capacidad de evacuar el calor por ventilación natural media variable entre el 20% y el 80% de esta demanda, demostrando la importancia de la utilización de las brisas para la refrigeración de edificio y ciudades del País.&nbsp;This article presents a proposal to evaluate cooling demand and passive cooling capacity using natural ventilation in social housing. The proposal is founded on EN ISO 13790:2008, which uses a semi- dynamic calculation method. The dwellings evaluated have double casement windows in the two main facades, which are oriented N-S, E-W, NW-SE and NE-SW. Two possible internal distributions were tested: poorly-connected and well-connected. The locations evaluated have a variety of climates: from the northern deserts to the weather of central and southern Chile with more defined seasonal variability. The cities included in the study are: Arica, Iquique, Antofagasta, La Serena, Valparaíso, Concepción, Valdivia and Puerto Montt. The results show that cooling demand is present in the majority of the locations analyzed and the average capacity for heat evacuation by natural ventilation is between 20% and 80% of this demand, thereby demonstrating the usefulness of breezes for building and city cooling in Chile.&nbsp

Soil C Storage Potential of Exogenous Organic Matter at Regional Level (Italy) Under Climate Change Simulated by RothC Model Modified for Amended Soils

Soil amendment with exogenous organic matter (EOM) represents an effective option for sustainable management of organic residues and enhancement of soil organic C (SOC) content. Optimization of soil amendment is hampered by the high variability in EOM quality and pedoclimatic conditions. A possible solution to this problem could be represented by spatially explicit soil C modeling. The aim of this study was the evaluation at regional level of the long term C storage potential of EOM added to the soil under climate change by using a modified version of the RothC specifically developed for C simulation in amended soil. To achieve this goal a spatially explicit version of the modified RothC model was deployed to assess at a national scale the potential for C storage of agricultural soils amended with different EOMs. Long term model simulations of continuous amendment (100 years) indicated that EOMs greatly differ for their soil C sequestration potential (range 0.110–0.385 t C ha−1 y−1), mainly depending to their degree of stabilization. Spatial explicit modeling of amended soil, taking into account the different combinations of EOMs and application sites, indicated a high variability in the potential of SOC accumulation at the national level (range: 0.06–0.62 t C ha−1 y−1). EOM quality showed a larger impact on long term SOC accumulation than variability in pedoclimatic conditions. Model simulations predicted that the contribution of soil amendment in tackling greenhouse gas (GHG) emissions is limited: soil C sequestration potential of compost applied to all Italian agricultural land corresponded to 5.3% of the total annual GHG emissions in Italy. Large scale modeling enables areas with the largest potential for EOM accumulation to be identified, therefore suggesting ways for optimizing resources. The spatially explicit version of the modified RothC model improves the predictive power of SOC modeling at regional scale in amended soils, because it takes into account, besides variability in pedoclimatic conditions, the large differences in EOMs quality

Intensity of singular stress field (ISSF) variation as a function of the Young\u27s modulus in single lap adhesive joints

Employing mixed adhesive joints has been proven to be very useful. This type of joint leads to improved performance by increasing strength and decreasing stresses in critical areas of the joint. In the same way, the use of the Intensity of Singular Stress Field (ISSF) has been shown to be suitable for adhesive joint calculation, since the adhesive strength can be controlled by the ISSF at the interface end. Four finite element models have been created by combining two epoxy adhesives with different mechanical properties, and therefore with different Young\u27s moduli. New mixed adhesive joints have been compared with respect to only-one adhesive joints in terms of the ISSF. The results show a clear improvement with one of the configurations of mixed adhesive joints. A significant decrease of 35.64% in the ISSF is obtained compared to the only-one adhesive configuration

Detecting Magnetic Permeability and Electrical Conductivity Fluctuations in Metallic Ferromagnetic Sheets through the Shielding Effect

In this report, a method is proposed for determining the fluctuations of physical and structural properties in metallic ferromagnetic samples by magnetic scanning. The method is based on the shielding of a circular loop electromagnetic field source using a ferromagnetic and metallic sheet. The shielding of the electromagnetic field depends on the field frequency and amplitude as well as the electrical conductivity and magnetic permeability of the sheet. The proposed method does not require winding around the sheet. The experimental AC shielding results are reported

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication