90 Matching Annotations
  1. Nov 2023
    1. Indios y negros en América Latina

      Pablo González Casanova

      1997

      Pablo González Casanova (1922) sociólogo mexicano. Se inicia en el campo de la interpretación filosófica de la historia, destacándose por dos trabajos: El misoneísmo y la modernidad cristiana en el siglo XVIII y Una Utopía de América. Su preocupación le llevará, en adelante, al conocimiento social de México y la América Latina, siendo ya uno de los clásicos en este campo. Su nombre está unido al de los creadores de la sociología latinoamericana contemporánea, campo en el que la América Latina ha hecho importantes aportes a la sociología en general. En este sentido ha escrito, entre otros, dos importantes libros, La Democracia en México y Sociología de la Explotación. Su último trabajo es el titulado Imperialismo y Liberación en América Latina. Es miembro destacado de diversas instituciones que trabajan en el campo social, nacionales e internacionales. Ha estimulado y coordinado trabajos colectivos como el titulado América Latina: historia de medio siglo y recientemente con la Universidad de Naciones Unidas coordinó un amplio estudio sobre La creación Cultural de América Latina. Ha sido Director de la Escuela de Ciencias Políticas y Sociales, del Instituto de Investigaciones Sociales y Rector de la Universidad Nacional Autónoma de México, Sus preocupaciones sociológicas y sociales le han llevado a analizar a dos grupos raciales que forman destacada parte de las sociedades latinoamericanas. Grupos una y otra vez discriminados y sobre los cuales se ha asentado la explotación interna y externa: indios y negros. Grupos raciales que en las sociedades latinoamericanas han jugado centralmente el papel de proletarios. Pablo González Casanova analiza cuidadosamente el papel que juegan estos grupos en la dinámica y dialéctica de las sociedades latinoamericanas.

      Palabras clave: Estudios Latinoamericanos; Historia intelectual de América Latina; Indigenismo; Negritud;

      González Casanova, Pablo. “Indios y negros en América Latina”. Cuadernos de Cultura Latinoamericana 97 (1979)

      Coordinación de Humanidades, Centro de Estudios Latinoamericanos, Facultad de Filosofía y Letras, Unión de Universidades de América Latina, Centro de Estudios sobre la Universidad, Universidad Nacional Autónoma de México.

      URI: http://hdl.handle.net/10391/3041 Colecciones

      ESTUDIOS LATINOAMERICANOS - Cuadernos de Cultura Latinoamericana [101]


      https://web.archive.org/web/20191108135255/http://ru.ffyl.unam.mx/handle/10391/3041

      accessed:: 2023-11-25 00:15

  2. Feb 2023
  3. Sep 2022
    1. T od alaen se ñ a n zaseday se re cib ee nsupro p i oidio m a n atura l , qu einterpretasusse nti m i entos ye sta dos de á n i mo m ejorquecualq ui erotro.De tod o sl os fil óso fo sc é lebre sen t od o elorbec o-nacid o porno s otros no t e nían n oti cia, ni de ni n·gu no d e e ll os l e s hab ía ll egado la fama h as ta ahora,al ll e g arno s otro s a la Isl a . A p e s ard e e sto, entaM ús ica , e n l aDi a l écti c a , e n l aAr i tm é ti ca y e n laGeometríaestánprácticos,yconunasuficienciaanálogaalad�nue strosmayores.Enelcurso d e las estrella s y movim ientosdel osastrossonmuyprácticos,y.ha nconstruido.instru-m ento s d e forma sdiversa sc onlos que midenconexactitud-losmovimientos delSol , delaLun a,ydelasEstre llas enelhoriz onte

      Estudios

  4. Jan 2021
  5. Sep 2020
  6. Jun 2019
    1. Dichasnociones construidas por las personas que asisten a la biblioteca complementan o difieren de lo establecido por la institucionalidad, reflejando la manera en que los significados no son únicos, ni son transferidos por la institución o la academia de manera transparente

      La institución propone, pero cada persona podría resignificar.

    2. un análisis dedichas prácticas y de las tensiones que surgen entre las formas de usoy lo planeado institucionalmente, mediante la observación, la conversación y la revisión documental.

      Es decir que compara la dirección institucional vs los usos de las personas ¿verdad?

    3. los significados culturales que las bibliotecas públicas tienenactualmente, mediante el análisis de las prácticas de uso que se llevan a caboen ellas,entendiendo por significados culturales los sentidos construidos de manera colectiva en la interacción de los seres humanos.
    4. Línea de Investigación:Comunicación, Cultura y Poder

      Muy interesante esta línea de investigación. ¿Qué otros trabajos tendrán?

    5. Prácticas socialesy configuración de significados de/enla Biblioteca Pública Francisco José de CaldasMyriam Teresa Marín Pedraza

      Trabajo de maestría en estudios culturales de Myriam Marín Pedraza

  7. Mar 2018
    1. What is claimed is:

      Seguir leyendo...

    2. Design or demand specifications deter mine material parameters for a recycled battery by identi fying a molar ratio and elements of cathode materials corresponding to a charge material chemistry of a recycled battery.
    3. For the recovery and synthesis of LiNiCoAlO. there are at least two approaches.
    4. it is desirable that the batteries be of a single stream chemistry (LiNiCoAlO) however if there are other chemistries present in the LiMO (where M is manganese, as well as Ni, Al and Co), the manganese can be removed from Solution. Ni, Co and Al can be used to precipitate precursor and synthesize cathode materials.
    5. Battery chemistries including aluminum (Al) are becoming popular for applications such as electric vehicles, using chemistry Such as LiNiCoAlO. Conventional approaches for recovering active materials from lithium ion batteries with chemistry LiNiCoAlO in a manner that can be used to make new active materials for new lithium ion batteries have been met with several shortcomings.
    6. It can be complex to sort out lithium ion batteries based on the battery chemistry and conventional methods cannot effectively recycle lithium ion batteries with mixed chemistries because different procedures are required to separate the respective compounds for reuse as active cath ode material.
    7. with the development of lithium ion battery technologies, different cathode materials are now being used to produce lithium ion batteries Such as LiCoO, LiFePO, LiMnO, LiNiCo, Al-O, and LiNi,Mn, Co-O.
    8. Primary functional parts of the lithium-ion battery 140 are the anode 160, cathode, 162 electrolyte 168, and separator 172. LIBs use an intercalated lithium compound as the electrode materials.
    9. Physical separation is applied to remove the battery cases (plastic) and electrode materials, often via magnetic separation that draws out the magnetic steel.
    10. The proposed approach is an example and is applicable to other lithium and non-lithium batteries for recycling spent batteries and recovering active cathode material suitable for use in new batteries.
    11. is a process flow diagram of recycling lithium-aluminum ion batteries

      Ver figura

    12. is a diagram of recycling the cathode material in the battery

      Ver figura

    13. FIG. 1 is a context diagram of a battery recycling environment Suitable for use with configurations herein;

      Ver figura

    14. It should be noted that although the methods and apparatus disclosed herein employ Li-ion bat teries as an example, the principles are intended as illustra tive and could be applied to other types of cathode materials suited to other battery chemistries.
    15. The recovered precursor material NiCoAl(OH) or NiCo(OH) can be used for making new LiNiCoAlO, or LiNiCoO cathode materials.
    16. he solution includes recovering active materials from lithium ion batteries with LiNiCoAlO. chemistry in a manner that can be used to make new active materials for new lithium ion batteries.
    17. Unfortunately, conventional approaches to the above approaches Suffer from the shortcoming that recycling approaches include high temperature processes to separate the compounds of the desirable materials of cobalt, manga nese, nickel and lithium.
    18. The disclosed approach results in synthesis of cathode materials (particularly valuable in Li-ion batteries) from recycled components. In contrast to conventional approaches, the disclosed approach does not separate Ni, Mn, and Co out. Instead, uniform-phase pre cipitation is employed as starting materials to synthesize the cathode materials as active charge material Suitable for new batteries.
    19. Current recycling procedures for Li-ion cells are generally focused on LiCoO cathode materials. Although some posted their methods to recycle more kinds of cathode materials, all are complex and not necessarily economical or practical.
    20. In short, recycling of lithium ion batteries not only protects the environment and saves energy, but also presents a lucrative outlet for battery manufacturers by providing an inexpensive Supply of active cathode material for new batteries.
    21. Exhausted LIBs undergo a physical separation pro cess for removing Solid battery components, such as casing and plastics, and electrodes are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Mn (manganese), and Li (lithium), from mixed cathode materi als and utilizing the recycled elements to produce active materials for new batteries
    22. For decades, portable electrical power supplies have taken the form of batteries that release electrical energy from an electrochemical reaction.
    23. Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (21) Appl. No.: 15/358,862 (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to (22) Filed: Nov. 22, 2016 produce active cathode materials for new batteries.
  8. www.nature.com.wdg.biblio.udg.mx:2048 www.nature.com.wdg.biblio.udg.mx:2048
    1. Al battery pouch cellsduringbattery operation and observed no safety hazard, owing to the lack offlammability of the ionic liquid electrolyte in air
    2. We have developed a new Al-ion battery using novel graphitic cath-odematerialswithastablecyclinglifeupto7,500charge/dischargecycleswithout decay at ultrahigh current densities.
    3. We propose that simplified Al/graphite cell redox reactions duringcharging and discharging can be written as
    4. Because high-rate and high-power batteries are highly desirable forapplications such as electrical grid storage, the next step in the investi-gation was to developa cathode material that wouldhave reduced ener-getic barriers to intercalation during charging
    5. Rechargeable Al/graphite cel

      Ver figura

    6. Owing to the low-cost, low-flammability and three-electron redoxproperties of aluminium (Al), rechargeable Al-based batteries could inprincipleoffer cost-effectiveness,highcapacity and safety, which wouldlead to a substantial advance in energy storage technology
    7. Rechargeable aluminium-based batteries offer the possibilities oflow cost and low flammability, together with three-electron-redoxproperties leading to high capacity
  9. www.nature.com.wdg.biblio.udg.mx:2048 www.nature.com.wdg.biblio.udg.mx:2048
    1. Moreover, the chemistry of recycling will become more important than ever and let’s hope that chemists can successively give a second life to wastes. Undoubtedly, sustainable batteries can be made and bring major advances in the protection of our environment, provided we realize such an effort is only worthwhile if we use CO2-free electricity.
    2. This has resulted in the enabling of new plans and programmes that tackle shortcom-ings and take into consideration energy and development. Most of these programmes stress the importance of education, research and public funding to achieve sustainable production and consumption patterns.
    3. d, the main ones being pyro-metallurgy and hydrometallurgy processes, which proceed at high (pyrolysis) and low (solution chemistry) temperatures, respec-tively.
    4. d, the main ones being pyro-metallurgy and hydrometallurgy processes, which proceed at high (pyrolysis) and low (solution chemistry) temperatures, respec-tively.
    5. A systematic extrapolation of our Li-ion knowledge will therefore not be sufficient, as it has already been shown that the best electrolyte additive for Li-ion cells (vinylidene carbonate) drastically increases the lifetime of Li-ion cells, but has no effect on Na-ion ones.
    6. Such findings, although not viable for practical applications, have at least the merit to demonstrate that such a system can work and be made practical provided further breakthroughs are made in terms of elec-trolytes and catalysts.
    7. Li–O2 and Li–S. Another option towards more sustainable bat-tery systems is moving to metal–air systems (Li–, Na– and Mg–air batteries) using O2 as the positive electrode, which is similar to the concept of fuel cells
    8. These challenges call for a collaborative effort between inorganic, organic and biochemists to develop innovative and diversified syn-thetic approaches to optimize existing materials and design new materials for batteries.
    9. Organic batteries with minimal CO2 footprints, assuming all other challenges (materials solubility, finding a highly oxidizing Li-based positive electrode, and so on) are overcome, should ena-ble the use of Li-ion batteries for large-scale applications
    10. A great advantage of the Li-ion battery, as opposed to Pb–acid, Ni–Cd and Ni–metal hydride batteries, is its versatility with respect to the wide range of positive and nega-tive electrodes that can be used, which offers possibilities in terms of designing new high-performance electrodes based on low-cost
    11. Mismatch between the elements constituting biomass and the main constituents of our present Li-ion batteries.

      Ver figura

    12. This strongly validates the move towards post-Li chemistries based on sodium and potassium, and encourages increased efforts on mag-nesium and calcium chemistries.
    13. Mismatch between the elements constituting biomass and the main constituents of our present Li-ion batteries.

      Ver figura

    14. attery technologies versus element abundanceThe abundance of an element is just one of the many criteria con-trolling its cost and availability.

      Problemática

    15. There are various approaches that have been explored towards this goal: (1) the development of novel eco-efficient processes18such as hydro-, solvo- and ionothermal19,20 and bio-inspired21–23approaches for the synthesis of inorganic compounds; (2) the pro-motion of a new concept of renewable electrodes based on the use of organic compounds synthesized using ‘green chemistry’24,25 from natural resources; and (3) the development of new technologies beyond Li-ion batteries such as Li–S and Li–air (Li–O2; ref.  26), Al–air27, Na-ion28, Mg, Ca29 and redox-flow systems30, in combina-tion with an increasing interest in recycling processes. Li–O2 cells are often synonymously called Li–air cells even though they cur-rently use pure O2 rather than ‘air’.

      Avances

    16. Past, present and forecast of the world’s energy needs up to 2050.

      Ver figura

    17. the most important consideration in our market econ-omy is the cost associated with producing conversion and stor-age devices

      Cuestión a resolver

    1. New sustainable technologies beyond Li-ion technology have been explored. Among those that use the more abundant monova-lent (Na+) and divalent (Mg2+, Ca2+) ions, Na-ion technology holds great promise for future commercialization. In contrast, the future of Mg-ion technology is more uncertain, owing to materials and electrolytes issues, while Ca-ion batteries currently remain a curi-osity. Metal–air technologies, based on unlimited O2, have greatly benefited from progress in materials science and in analytical tech-niques. However, owing to their electrochemical chemical complex-ity, many challenges remain to be solved if these technologies are to make a significant impact on the future energy-storage landscape. The horizon is brighter for Li–S, but a common issue inherent to both Li–O2 and Li–S technologies is the need to protect or ideally replace the negative Li metal electrode

      Resumen

    2. n terms of sustainability, rechargeable aqueous Na-ion tech-nology is attractive. But cost expectations have yet to be realized, raising the question of whether aqueous systems can ever be made cheaper than non-aqueous systems
    3. Operando neutron diffraction and tomography studies on ‘real-world’ (18650) batteries under realistic cycling conditions have recently allowed the visualization of Li concentration gradients across the battery, providing insight on electrode failures, degrada-tion mechanisms and diffusion kinetics
    4. . Grid and transport demonstration projects and bat-tery tests are already in progress to link traditional electrochemi-cal responses (such as current, voltage and impedance) with test routines appropriate to the technology and produce the ‘big data’ needed to extract new correlations and, ultimately, predict future performance.
    5. Trends towards sustainability for today’s batteries

      Ver la figura.

    6. Examples of operando techniques.

      Ver la figura

    7. Many of these techniques have provided considerable insight into electrolyte and electrode degrada-tion.
    8. The move away from the traditional and well-understood battery chemistries to more complex redox processes such as alloying and conversion, and the need to optimize more established chemis-tries, has motivated the development of new analytical operandotechniques that allow study of the fundamental mechanisms by which these materials operate, together with the kinetics of these processes
    9. The Zn–air battery represents another potentially sustainable technology, but it has been challenging to develop a rechargeable cell, owing to side reactions such as carbonization and the for-mation of Zn dendrites.
    10. Sustainability and cost have driven work on aqueous Li–O2 and Li–S systems, being aided by Visco’s pioneering work on the devel-opment of protected Li-anodes together with a ceramic membrane separator to obtain a two-compartment cell.
    11. The Li–S system has been recently revisited as part of the quest for new sustainable storage technologies
    12. But Li–S batteries were never commercialized, owing to severe hur-dles
    13. challenges such as cathode/electrolyte stability and air handling remain to be tackled. It is still unknown whether a commercial cell can be developed. Recent results have demon-strated that reversible cycling by means of discharge products other than Li2O2, such as LiOH (ref. 66), LiO2 (ref. 67) and Li2CO3 (ref. 68) is also possible, with suitable redox mediators or catalysts.
    14. Although the addition of LiNO3 helps to protect the Li anode64,65, either the generally ignored problem of the Li metal anode must be solved or it must be replaced by another (Li-containing) anode if practical batteries are to be developed.
    15. They demonstrate that Li–air does not necessarily mean a low-rate, low-capacity battery, contrary to earlier views.
    16. LiFePO4 is, in practice, no cheaper than the less environmentally friendly Co- and Ni-containing phase of formula LiNi1/3Mn1/3Co1/3O2, termed NMC
    17. The use of more complex anions such as pyrophosphates (P2O7)4–,borosilicates, borophosphates and carbonophosphates17 is not competitive performance-wise, owing to the weight penalty associated with the heavier polyanions.
    18. Gravimetric and volumetric capacities for the more abundant elements Mg and Ca (Fig.  1) are significantly higher than that of graphite. But making batteries from these elements is far from being a practical reality
    19. However, the unrealistic expecta-tions of quick commercialization have diminished, as the early cells exhibited rapid capacity fade, large overpotentials, particularly on charging, and poor rate performance
    20. Metal–air batteries have a theoretical energy density exceeding that of Li-ion batteries and the posibility of using unlimited fuel O2 as the posi-tive electrode.
    21. Research into Na-ion technology is now accelerating, progress being rapid because of the many similar-ities of Li-ion and Na-ion chemistry
    22. Replacing Li by more abundant metals Na, Mg and Ca.
    23. Si, has received considerable attention, because its capacity is 10 times that of carbon. But the Li-alloying reactions (LixSi, where x ≤ 3.75) are accompanied by extremely large volume changes, owing to the large amount of inserted Li
    24. Although some of these (with schematics shown in Fig. 2) are in the very early stages of commercialization, there is no clear-cut winner; several advances have, however, been made, and so optimism must prevail, motivating continued research and development of all of these technologies
    25. The continued push for cheaper, higher-energy-density and more sustainable battery technology has led to a blossoming of research activities centred on new chemistries such as Na-ion, metal–air (Li, Na, Zn), Li–S, multivalent ions and redox flow, to name but a few.
    26. Lithium-rich NMC phases with high Mn contents and extremely high capacities (>280  mAh  g–1) have been discovered
    27. Renewable organic electrodes based on redox-active molecules containing electrochemically active C=O functions, such as the oxo-carbons Li2+xC6O6,which can be synthesized via ‘green chemistry’ from natural organic sources, represent one approach to developing greener Li-ion batteries
    28. The LiFePO4 ‘success’ story has triggered extensive research on Fe-based polyanionic compounds including the silicates (Li2FeSiO4) (ref. 14) and borates (LiFeBO3)
    29. Past efforts devoted to developing positive electrode materials with minimum ecological footprint have been rewarded by the develop-ment and commercialization of Fe-based polyanionic compounds, most notably olivine LiFePO4
    30. This concern has driven researchers to explore new, potentially more sustainable chemis-tries, including Na-ion, metal–air chemistries Li(Na)–O2, Li–S, multivalent (Mg, Ca), redox flow batteries (RFBs) and aqueous-based technologies,
    31. consider the elemental abundance of any new materials or electrolytes, motivating work on, for exam-ple, Fe-, Mn- and S-containing cathodes and electroactive organic molecules.
  10. Jan 2018
    1. la arquitectura ha dejado de ser una pariente pobre de la teoría social para convertirse en un importante espacio de debate sobre la globalización, la urbanización, el medio ambiente, la modernidad, los medios y la cultura digital; a menudo los arquitectos están sintonizados con acuciantes problemas sociales actuales, como la globalización y el Antropoceno (e.g., Turpin, ed. 2013), y con los problemas teóricos y filosóficos con los que tratan las ciencias sociales y las humanidades (e.g., Mitrovic 2011; Sykes, ed. 2010). Los críticos también reconocen, sin embargo, que cierto estilo de arquitectura ha contribuido a la inflación del diseño
    2. El capítulo termina discutiendo si existe o no un campo de estudios críticos de diseño —que pudiera estar surgiendo en la intersección de la teoría social crítica y los estudios de diseño