The Anatomic Relationship of the Tibial Nerve to the Common Peroneal Nerve in the Popliteal Fossa: Implications for Selective Tibial Nerve Block in Total Knee Arthroplasty

Background. A recently described selective tibial nerve block at the popliteal crease presents a viable alternative to sciatic nerve block for patients undergoing total knee arthroplasty. In this two-part investigation, we describe the effects of a tibial nerve block at the popliteal crease. Methods. In embalmed cadavers, after the ultrasound-guided dye injection the dissection revealed proximal spread of dye within the paraneural sheath. Consequentially, in the clinical study twenty patients scheduled for total knee arthroplasty received the ultrasound-guided selective tibial nerve block at the popliteal crease, which also resulted in proximal spread of local anesthetic. A sensorimotor exam was performed to monitor the effect on the peroneal nerve. Results. In the cadaver study, dye was observed to spread proximal in the paraneural sheath to reach the sciatic nerve. In the clinical observational study, local anesthetic was observed to spread a mean of 4.7+1.9 (SD) cm proximal to popliteal crease. A negative correlation was found between the excess spread of local anesthetic and bifurcation distance. Conclusions. There is significant proximal spread of local anesthetic following tibial nerve block at the popliteal crease with possibility of the undesirable motor blocks of the peroneal nerve

Coherent summation of emission from relativistic Cherenkov sources as a way of production of extremely high-intensity microwave pulses

For relativistic Cherenkov devices, we investigate the process of high-power microwave pulse generation with its phase correlating to the sharp edge of an e-beam current pulse. Our theoretical consideration is referred to quasi-stationary and superradiative (SR) generation regimes when spontaneous emission of the e-beam edge serves as the seed for the development of further coherent oscillations. Phase correlation of the excited microwave pulses with the characteristics of the current pulse front and/or an initial external electromagnetic pulse has been additionally confirmed by particle-in-cell simulations. Pulse-to-pulse stability of the radiation phase within several percents of the oscillation period makes it possible to arrange multichannel schemes producing mutually coherent microwave pulses. In the experiments that have been carried out, the cathodes of independent generators were powered by identical accelerating pulses from strictly synchronized voltage modulators, or by splitting the pulse from a single powerful modulator. For the 2-ns regime with the power of each Ka-band backward-wave oscillator about 100 MW, we demonstrate quadratic growth of the power density in the interference maximum of the directional diagram. In a short pulse SR regime, with the peak power of 600 MW in a single channel, for a four-channel 2-D array, we attained a 16-fold radiation intensity gain

Competitive Equilibrium in the Random Assignment Problem

This paper studies the problem of random assignment with fractional endowments. In the random assignment problem, a number of objects has to be assigned to a number of agents. Though the objects are indivisible, an assignment can be probabilistic: it can give an agent some probability of getting an object. Fractional endowments complicate the matter because the assignment has to make an agent weakly better off than his endowment. I first formulate an exchange economy that resembles the random assignment problem and prove the existence of competitive equilibrium in this economy. I then propose a pseudo-market mechanism for the random assignment problem that is based on the competitive equilibrium. This mechanism is individually rational, Pareto Optimal and justified envy-free but not incentive compatible

Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar

Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism

Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar

Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism

Sedimentation of bentonite suspensions under the influence of low molecular weight polymers based on amino ester salts

Among the available technologies for treating natural and wastewater from clay materials, coagulation/flocculation is the most common method due to its high efficiency, simplicity, and cost-effectiveness. Inorganic coagulants such as aluminum sulfate and ferric chloride, widely used as destabilizing agents for colloidal particles, have several significant drawbacks: low efficiency and toxicity. Organic reagents of both natural and synthetic origin are a good alternative. This work is devoted to the evaluation of the flocculation action of new reagents, which are low molecular weight polymers based on amino ester salts on clay suspensions, as well as the selection of their optimal concentration, providing the maximum sedimentation rate. Studies have shown that amino ester salts can be effectively used for the treatment of water-clay suspensions. An important factor is the nature of the anion used, which has a significant influence on the oagulation ability of esters. Thus, 40–50 % (wt.) aqueous solutions of amino ester chlorides added to clay suspensions in an amount not exceeding 0.1% (vol.) can be used to thicken clay suspensions. At the same time, aqueous solutions of amino ester bromides regardless of the concentration, introduced into bentonite suspensions of 0.1–0.4 % (vol.), contribute to improved sedimentation, reducing viscosity, and increasing filtration capacity. These results allow us to recommend the use of amino ester chlorides as a thickener in the preparation of drilling muds for strengthening the walls of wells during drilling, and bromides – for flocculation of bentonite suspensions in oil productio

Caracterização de módulos fotovoltáicos orgânicos (P3HT:PCBM) com radiação solar

Los principales parámetros que influyen en la eficiencia de módulo solar orgánico de capa activa P3HT:PCBM, se analizan en este trabajo en condiciones reales de la radiación solar. Los experimentos se llevaron a cabo en la Universidad Federal de Pernambuco en Recife, Pernambuco, Brasil. Por medio del análisis de los resultados se puede observar el comportamiento de los parámetros eléctricos de un módulo orgánico en función de la irradiación y, por tanto, entender cómo funcionaría un sistema que utiliza la electricidad generada a partir de paneles orgánicos.The main parameters that influence the efficiency of organic solar module active layer P3HT:PCBM, are analyzed in this work in real conditions of solar radiation. The experiments were conducted at the Federal University of Pernambuco in Recife, Pernambuco, Brazil. Through analysis of the results, it is possible to observe the behavior of the electrical parameters of an organic module depending on the irradiance and thus, better understand how it would work in a system using electricity generated from organic panels.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Antiracist Feminism and the Politics of Solidarity in Neoliberal Times

The chapter analyses the establishment and expansion of antiracist feminism in the last decade throughout the Nordic region, with new groups, media sites, and public events organised, especially in the large cities. Keskinen examines antiracist feminist and queer of colour activism in which the main or sole actors belong to groups racialised as non-white or ‘others’ in Nordic societies. A fundamental argument developed in the chapter is the central role and potential of these emerging social movements in the reconfiguring of political agendas and tackling pressing societal issues, due to its capacity to overlap and connect the borders of antiracist, feminist, and (to some extent) class-based politics. The chapter further argues for the usefulness of theorising the neoliberal turn of racial capitalism as the societal condition in which feminist activism takes place.Peer reviewe