The long road to universal electrification:A critical look at present pathways and challenges

Nearly 840 million people still lack access to electricity, while over a billion more have an unreliable electricity connection. In this article, the three different electrification pathways-grid extension, centralized microgrids, and standalone solar-based solutions, such as pico-solar and solar home systems (SHS)-are critically examined while understanding their relative merits and demerits. Grid extension can provide broad scale access at low levelized costs but requires a certain electricity demand threshold and population density to justify investments. To a lesser extent, centralized (off-grid) microgrids also require a minimum demand threshold and knowledge of the electricity demand. Solar-based solutions are the main focus in terms of off-grid electrification in this article, given the equatorial/tropical latitudes of the un(der-)electrified regions. In recent times, decentralized solar-based off-grid solutions, such as pico-solar and SHS, have shown the highest adoption rates and promising impetus with respect to basic lighting and electricity for powering small appliances. However, the burning question is-from lighting a million to empowering a billion-can solar home systems get us there?The two main roadblocks for SHS are discussed, and the requirements from the ideal electrification pathway are introduced. A bottom-up, interconnected SHS-based electrification pathway is proposed as the missing link among the present electrification pathways.Management SupportDC systems, Energy conversion & StorageElectrical Sustainable Energ

Nicht Aufgeben bei seltenen Erkrankungen

Der Patient in unserem Fallbericht stellte sich erstmals 2004 aufgrund belastungsabhängiger Muskelschmerzen bei seinem Hausarzt vor. Es folgten über die Jahre viele Untersuchungen und diagnostische Irrwege bis die tatsächliche Ursache dank der Beharrlichkeit des Patienten und seines Hausarztes gefunden wurd

Análisis de las cirugías cardíacas y mortalidad operatoria en el Instituto Nacional Cardiovascular durante el 2022

Objective. To describe cardiac surgeries, their approaches, and determine operative mortality according to the type of surgery and the main complications recorded within 30 days postoperatively, performed at the National Cardiovascular Institute of Peru. Materials and methods. A descriptive study was conducted on all patients over 18 years of age who underwent cardiovascular surgery at the National Cardiovascular Institute “Carlos Alberto Peschiera Carrillo”. Results. During the year 2022, a total of 503 cardiac surgeries were performed. Of the patients undergoing surgery, 63.6% (320) were males. Isolated valvular surgery, primarily aortic or mitral valve replacement, was the most frequent surgical procedure, with 136 surgeries (27.0%). This was followed by myocardial revascularization surgery with 110 procedures (21.9%). Throughout the year, there were 23 deaths, resulting in an overall mortality rate of 4.5%. The mortality rate for elective surgeries was 2.8%, while for emergency surgeries, it was 14.3%. The most common complication was paroxysmal atrial fibrillation (14.0%), followed by surgical site infection with 52 cases (10.3%). Conclusions. Valvular surgery, whether isolated or combined with other procedures, was the most frequently performed. The obtained mortality rate is considered acceptable for a reference center.Objetivo. Describir las cirugías cardíacas, su abordaje y determinar la mortalidad operatoria según el tipo de cirugía y las principales complicaciones registradas hasta los 30 días del posoperatorio realizadas en el Instituto Nacional Cardiovascular de Perú. Materiales y métodos. Se llevó a cabo un estudio descriptivo en todos los pacientes mayores de 18 años que fueron sometidos a cirugía cardiovascular en el Instituto Nacional Cardiovascular «Carlos Alberto Peschiera Carrillo». Resultados. Durante el año 2022 se realizaron 503 cirugías cardíacas. De los pacientes intervenidos, el 63,6% (320) fueron varones. La cirugía valvular aislada, principalmente el reemplazo de la válvula aórtica o mitral, fue el procedimiento quirúrgico más frecuente, con 136 cirugías (27,0%). Le siguió la cirugía de revascularización de miocardio con 110 procedimientos (21,9%). A lo largo del año se registraron 23 fallecimientos, lo que resultó en una mortalidad general del 4,5%. La mortalidad en cirugías electivas fue del 2,8%, mientras que en cirugías de emergencia fue del 14,3%. La complicación más común fue la fibrilación auricular paroxística (14,0%), seguida de la infección del sitio quirúrgico con 52 casos (10,3%). Conclusiones. La cirugía valvular, ya sea aislada o en combinación con otros procedimientos, fue realizada con más frecuencia. La tasa de mortalidad obtenida se considera aceptable para un centro de referencia

Análisis comparativo de diferentes estructuras de compensación por carga balasto, aplicadas a generadores de inducción autoexcitados para pequeñas centrales hidroeléctricas

Este artículo presenta el análisis comparativo de diferentes estructuras de compensación, destinadas al control de tensión y frecuencia en generadores de inducción autoexcitados, aplicados a pequeñas centrales hidroeléctricas (PCHs). El análisis es efectuado mediante los resultados obtenidos con la implementación de dos prototipos de control por carga balasto. Ambos prototipos permiten controlar la tensión y frecuencia, midiendo únicamente la tensión generada. Uno de los prototipos utiliza una estructura de compensación fija y el otro posee distintas estructuras, configurables para estudiar las características de control sobre el sistema de generación. El desempeño en régimen transitorio y permanente de estos prototipos fue verificado en un banco de ensayos, constituido por un grupo motor-generador de 1HP. El análisis comparativo de los resultados se efectúa observando la respuesta de la tensión generada para distintos niveles y tipos de carga, lineales como no lineales; utilizando las diferentes estructuras de compensación proporcionadas por los prototipos mencionados.This paper presents a comparative analysis of different compensation structures, for the control of voltage and frequency of self-excited induction generators, applied to small hydropower (SHP). The analysis is carried out by the results obtained with the implementation of two prototype of dummy load control. Both prototypes use only the measure of the generated voltage to control the voltage and frequency. The first prototype uses a fixed compensation structure and the second one has different structures, configurable to study the characteristics of control over the generation system. The transient and steady-state response of these prototypes has been verified in a motor-generator module of 1HP. Comparative analysis of the experimental results was done by observing the response of the voltage generated for different levels and types of loads, linear and nonlinear, using different compensation structures provided by the prototypes mentioned.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Embracing the Market: Entry into Self-Employment in Transitional China, 1978-1996

This paper introduces labor market transition as an intervening process by which the macro institutional transition to a market economy alters social stratification outcome. Rather than directly addressing income distribution, it examines the pattern of workers’ entry into self-employment in reform-era China (1978-1996), focusing on rural-urban differences and the temporal trend. Analyses of data from a national representative survey in China show that education, party membership and cadre status all deter urban workers’ entry into self-employment, while education promotes rural workers’ entry into self-employment. As marketization proceeds, the rate of entry into self-employment increases in both rural and urban China, but urban workers are increasingly more likely to take advantages of the new market opportunities. In urban China, college graduates and cadres are still less likely to be involved in self-employment, but they are becoming more likely to do so in the later phase of reform. The diversity of transition scenarios is attributed to rural-urban differences in labor market structures.http://deepblue.lib.umich.edu/bitstream/2027.42/39897/3/wp512.pd

Demineralization and sectioning of human kidney stones: A molecular investigation revealing the spatial heterogeneity of the stone matrix

The molecular mechanisms by which kidney stones grow are largely unknown. Organic molecules from the urine combine with mineral crystals to form stones, but analysis of the stone matrix has revealed over a thousand different proteins, with no clues as to which are important for stone growth. Molecules that are present in every layer of a stone would be candidates for having an essential function, and thus the analysis of the stone matrix at a microscopic level is necessary. For this purpose, kidney stones were demineralized, sectioned, stained, and imaged by microscopy, using micro CT for precise orientation. Histological staining demonstrated heterogeneity in the density of adjacent layers within stones. Additional results also showed brilliant and unique autofluorescence patterns in decalcified nephroliths, indicating heterogeneous organic composition in adjacent layers. Regions of calcium oxalate (CaOx) stones were dissected using laser microdissection (LMD) for protein analysis. LMD of broad regions of demineralized CaOx stone sections yielded the same proteins as those found in different specimens of pulverized CaOx stones. These innovative methodologies will allow spatial mapping of protein composition within the heterogeneous stone matrix. Proteins that consistently coincide spatially with mineral deposition would be candidates for molecules essential for stone growth. This kind of analysis will be required to assess which of the thousand proteins in the stone matrix may be fundamental for stone growth

Political Homophily and Collaboration in Regional Planning Networks

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98763/1/ajps12011.pd

Conserving Freshwater Biodiversity in an African Subtropical Wetland: South Africa’s Lower Phongolo River and Floodplain

Freshwater biodiversity is under constant threat from a range of anthropogenic stressors. Using South Africa’s Phongolo River and floodplain (PRF) as a study case, the aim of this chapter is to provide an overview of the conservation and management of freshwater biodiversity in a highly diverse subtropical ecosystem. The PRF is the largest floodplain system in South Africa which is severely threatened by irregularly controlled flood releases from a large upstream dam, prolonged drought, deteriorating water quality, organic pollutants and the increasing dependence of the local communities. Based on a decade of survey of the PRF conducted from 2010 to 2020, this chapter highlights the current diversity of aquatic organisms (invertebrates, fishes, frogs and their parasitic fauna), followed by an overview of their biological and physical stressors. The current challenges in the management of the aquatic biodiversity of this region and a way forward to conservation strategies are also addressed in this chapter

Measurements of differential cross sections of Z/gamma*+jets+X events in proton anti-proton collisions at sqrt{s}=1.96 TeV

We present cross section measurements for Z/gamma*+jets+X production, differential in the transverse momenta of the three leading jets. The data sample was collected with the D0 detector at the Fermilab Tevatron proton anti-proton collider at a center-of-mass energy of 1.96 TeV and corresponds to an integrated luminosity of 1 fb-1. Leading and next-to-leading order perturbative QCD predictions are compared with the measurements, and agreement is found within the theoretical and experimental uncertainties. We also make comparisons with the predictions of four event generators. Two parton-shower-based generators show significant shape and normalization differences with respect to the data. In contrast, two generators combining tree-level matrix elements with a parton shower give a reasonable description of the the shapes observed in data, but the predicted normalizations show significant differences with respect to the data, reflecting large scale uncertainties. For specific choices of scales, the normalizations for either generator can be made to agree with the measurements.Comment: Published in PLB. 11 pages, 3 figure