La categoría ambiental en el paradigma del desarrollo sustentable, la visión de la ciencia económica

Tlatemoani, Revista Académica de Investigación. Año 7. Número 21. Abril 2016. Pp. 124-139. ISSN. 19899300. http://www.eumed.net/rev/tlatemoani/21/index.htmCon el proceso de expansión social, se asumió que el ambiente ofrecía todos los recursos necesarios, y que el ser humano debía controlarla y manipularla, provocando un rompimiento en el paradigma vigente, marcando así el paso del mundo mítico al universo racional y al mundo clásico, surgiendo y consolidando el racional empirista. A partir de ello, se desarrollaron diferentes concepciones y múltiples interpretaciones sobre la importancia y papel del ambiente en la sociedad y en la propia economía, imponiéndose una visión utilitarista, quedando atrás los miedos ante el entorno, convirtiéndolo en una canasta de recursos que pueden ser extraídos y utilizados. Desde esta perspectiva, los componentes del medio fueron considerados como recursos con valor nominal directo e indirecto que influyen en el bienestar social y económico de los territorios. La conceptualización del desarrollo en esta transición paradigmática ha sido correlato de la modernidad, pues los supuestos epistemológicos dominantes impedían aprehender la realidad social en su complejidad, por lo que el desarrollo devino en sinónimo de crecimiento económico al cual podía accederse de manera lineal desde la sociedad tradicional agrícola a la sociedad industrial, subestimando los factores sociales, políticos, culturales e históricos involucrados estructuralmente en dicho desarrollo. Todo ello asociado a un particular modo de interacción del hombre con la naturaleza y consigo mismo, emanado del comentado discurrir de la civilización occidental que abrió los horizontes del capitalismo, la ciencia, la técnica y la conducta humana individual y social. La incorporación del ambiente a la concepción del desarrollo es visto no sólo como un proceso histórico, de carácter continuo e integral, sino como un entorno de igualdad de oportunidades y justicia que permite una plena valorización de la dignidad humana, esto es, un proceso de cambio dirigido al logro de los objetivos específicos cuya dirección y velocidad constituyen puntos de controversia en los planos económico, político, social, ambiental, tecnológico y territorial, asociado a procesos y cuestiones de crecimiento de la producción, el progreso técnico, la distribución del poder, del ingreso, de oportunidades individuales y colectivas; la preservación de los recursos y del medio ambiente en general, así como de la organización territorial de la sociedad, donde está implícito la imagen del futuro deseado, en el que generalmente predomina la visión de bienestar y justicia social. El punto de partida de lo que ahora se concibe como desarrollo sustentable fue el medio humano, donde se integraron los aspectos económicos y sociales con la dimensión ambiental, ya que es una forma de explicar el funcionamiento de los mercados, el crecimiento económico y el desarrollo de la sociedad. Con esta relación tripartida, se empezó a teorizar al ambiente, explicando su importancia e influencia en los niveles de progreso económico. El desarrollo sustentable, busca minimizar los efectos y externalidades negativas hacia los recursos de los cuales se nutre, interesándose al contrario en proteger su entorno ecológico, económico y social, ya que la sustentabilidad no es simplemente un asunto del ambiente, de justicia y de desarrollo, sino más bien de la gente y de sobrevivencia como individuos y culturas, por ello debe verse no sólo como un paradigma contemporáneo sino un objetivo alcanzable en el tiempo en las diferentes escalas territoriales. En esta contribución se enfatiza la concepción e importancia que algunas doctrinas económicas le atribuyeron al ambiente, no sólo como factor determinante de los ritmos de crecimiento y desarrollo humano, sino como generador de recientes paradigmas teóricos como el desarrollo sustentable. La gran diversidad de las posturas teóricas, a pesar de mostrar algunas discrepancias interpretativas, hay coincidencias en la importancia del ambiente para determinar el desenvolvimiento del entorno

Evoluția și etica eugeniei

În acest articol încerc să argumentez opinia că, așa cum este definită eugenia, este foarte dificil de făcut o diferențiere clară între știință (medicină, ingineria genetică) și eugenie. Și de stabilit o linie peste care ingineria genetică nu ar trebui să treacă, conform unor norme morale, juridice și religioase. Atâta timp cât acceptăm ajutorul geneticii în găsirea unor modalități de combatere a cancerului, diabetului sau HIV, acceptăm în mod implicit și eugenia pozitivă, conform definiției actuale. Și atâta timp cât acceptăm screening-ul genetic, și intervenții asupra fătului nenăscut, sau avortul, acceptăm în mod implicit și eugenia negativă. În plus, la nivel de guverne, deși oficial eugenia este repudiată, ea a fost legalizată în foarte multe țări până de curând, și încă mai este acceptată și legalizată, chiar dacă în forme mai subtile, și în prezent. În Introducere definesc termenul și modurile de clasificare. Urmează Istoria eugeniei pornind din perioada antică, introducerea eugeniei de Francis Galton, practica eugeniei ca politică de stat în diverse țări, și eugenia actuală (eugenia liberală). Analizez apoi diverse probleme ridicate de Etica eugeniei liberale, și am dezvoltat o secțiune aparte pentru Viitorul eugeniei, cu accent pe proiectul genomului uman. În final, în secțiunea Concluzii expun opiniile personale cu privire la practica actuală a eugeniei. Am folosit ca surse principale de investigație articolele lui Kenneth M. Ludmerer, ”American Geneticists and the Eugenics Movement: 1905-1935”, Kathy J. Cooke, ”Duty or Dream? Edwin G. Conklin's Critique of Eugenics and Support for American Individualism”, Jonathan Anomaly, ”Defending Eugenics”, John R. Harding Jr. ”Beyond Abortion: Human Genetics and the New Eugenics”, Michael Boulter, ”Bloomsbury Scientists”, Chapter Title: The rise of eugenics, 1901–14, Michael Ruse and Edward O. Wilson, ”Moral Philosophy as Applied Science” și Goering, Sara, "Eugenics"

Nanostructured LaFeO3 Photocathodes with Onset Potentials for the Hydrogen Evolution Reaction Over 1.4 V vs RHE

The photoelectrochemical properties of phase-pure LaFeO3 (LFO) nanostructured films are investigated upon modification with a thin TiO2 film and Pt nanoparticles as a catalyst. LaFeO3 with crystallite domains in the range of 60 nm are prepared by thermolysis of an ionic-liquid precursor and subsequently deposited onto FTO electrode by spin-coating. Deposition of a TiO2 layer by solution-based methods leads to the formation of a heterojunction, attenuating dark current associated with hole-transfer (water oxidation) at potential above 1.4 V. The LFO/TiO2 heterojunction features photocurrent onset potential for the hydrogen evolution reaction of 1.47 V vs the reversible hydrogen electrode (RHE), which is one of the most positive values reported for a single absorber. Deposition of Pt nanoparticles at the LFO/TiO2 heterostructure generates a significant increase in the HER photocurrent, although bulk recombination remains an important challenge in these constructs

High Interfacial Hole-Transfer Efficiency at GaFeO3 Thin Film Photoanodes

The photoelectrochemical properties of polycrystalline GaFeO3 (GFO) thin films are investigated for the first time. Thin films prepared by sol–gel methods exhibit phase‐pure orthorhombic GFO with the Pc21n space group, as confirmed by X‐ray diffraction and Raman spectroscopy. Optical responses are characterized by a 2.72 eV interband transition and sub‐bandgap d–d transitions associated with octahedral and tetrahedral coordination of Fe3+ sites. DFT‐HSE06 electronic structure calculations show GFO is highly ionic with very low dispersion in the valence band maximum (VBM) and conduction band minimum (CBM). Electrochemical impedance spectroscopy reveals n‐type conductivity with a flat band potential (Ufb) of 0.52 V versus reversible hydrogen electrode, indicating that GFO has the most positive CBM reported of any ferrite. The photoelectrochemical oxidation of SO32− shows an ideal semiconductor–electrolyte interfacial behavior with no evidence of surface recombination down to the Ufb. Surprisingly, the onset potential for the oxygen evolution reaction also coincides with the Ufb, showing interfacial hole‐transfer efficiency above 50%. The photoelectrochemical properties are limited by bulk recombination due to the short‐diffusion length of minority carriers as well as slow transport of majority carriers. Strategies towards developing high‐efficiency GFO photoanodes are briefly discussed

Crystal and Electronic Structure of Bismuth Thiophosphate, BiPS4:An Earth Abundant Solar Absorber

The optoelectronic properties of crystalline BiPS4 have been described for the first time for solar energy conversion. Detailed structural analysis is extracted from XRD refinement of powders synthesized by the solid-state method. BiPS4 exhibits a rather unusual 3-dimensional orthorhombic structure with two distinctive Bi sites with octahedral coordination distorted by 6s2 lone pairs. High-resolution TEM imaging clearly shows the two Bi–Bi interatomic distances in close agreement with the XRD analysis. BiPS4 displays a complex Raman spectrum under near-resonant conditions which is rationalized by density functional perturbation theory. Hybrid-functional-DFT calculations show significant spin–orbit coupling effects in Bi 6p bands, not only affecting the band dispersion but also lowering the conduction band minimum by approximately 0.5 eV. The optical properties of BiPS4 powders are dominated by a direct transition at 1.72 eV, closely matching the calculated band gap. Electrochemical experiments revealed n-type conductivity with a flat band potential located at 0.16 V vs RHE. We also show a remarkable agreement between the position of the band edges estimated from first-principles calculations and electrochemical measurements. The time-resolved photoluminescence transient revealed a carrier lifetime of approximately 1 ns, manifesting as strong potential- and wavelength-dependent photocurrent responses. Finally, the nature of the structural defects responsible for the relatively short lifetime is briefly discussed

The Effects of Contralateral Exercise On Patient Pain and Range of Motion

Clinicians are commonly tasked with treating patients suffering from range of motion (ROM) deficits, pain, or both. Treatment options intended to increase ROM, decrease pain and restore function are vast. Often interventions are used that focus on a singular symptom location (e.g., stretching and joint mobilizations) although a long-standing call exists to utilize global approaches to treating dysfunction. This review was conducted to determine whether evidence exists to support the use of contralateral exercise (CE)to treatROM deficits or pain

Impact of Sb and Na Doping on the Surface Electronic Landscape of Cu2ZnSnS4 Thin Films

Open-circuit voltage deficiency is the key limiting factor in Cu2ZnSnS4 (CZTS) thin-film solar cells, which is commonly associated with band tails and deep gap states arising from elemental disorder. The introduction of dopants such as Na and Sb has led to improvement in device performance, yet their effects on the optoelectronic properties of CZTS are yet to be fully elucidated. In this Letter, we unraveled the effect of Sb and Na:Sb co-doping on the surface energy landscape of solution-processed CZTS films employing energy-filtered photoelectron emission microscopy. In the absence of the additives, 150 nm resolution photoemission maps reveal oscillations in the local effective work function as well as areas of low photoemission energy threshold. The introduction of dopants substantially reshapes the photoemission maps, which we rationalize in terms of Cu:Zn and Sn disorder. Finally, we establish unprecedented correlations between the photoemission landscape of thin films and the performance of over 200 devices

Pulsed laser deposition of single phase n- and p-type Cu2O thin films with low resistivity

Low resistivity (~3-24 mOhm.cm) with tunable n- and p-type phase pure Cu2O thin films have been grown by pulsed laser deposition at 25-200 0C by varying the background oxygen partial pressure (O2pp). Capacitance data obtained by electrochemical impedance spectroscopy was used to determine the conductivity (n- or p-type), carrier density, and flat band potentials for samples grown on indium tin oxide (ITO) at 25 0C. The Hall mobility of the n- and p-type Cu2O was estimated to be ~ 0.85 cm2.V-1s-1 and ~ 4.78 cm2.V-1s-1 respectively for samples grown on quartz substrate at 25 0C. An elevated substrate temperature ~ 200 0C with O2pp = 2 - 3 mTorr yielded p-type Cu2O films with six orders of magnitude higher resistivities in the range ~ 9 - 49 kOhm.cm and mobilities in the range ~ 13.5 - 22.2 cm2.V-1s-1. UV-Vis-NIR diffuse reflectance spectroscopy showed optical bandgaps of Cu2O films in the range of 1.76 to 2.15 eV depending on O2pp. Thin films grown at oxygen-rich conditions O2pp > 7 mTorr yielded mixed-phase copper oxide irrespective of the substrate temperatures and upon air annealing at 550 0C for 1 hour completely converted to CuO phase with n-type semiconducting properties (~12 Ohm.cm, ~1.50 cm2.V-1s-1). The as-grown p- and n-type Cu2O showed rectification and a photovoltaic (PV) response in solid junctions with n-ZnO and p-Si electrodes respectively. Our findings may create new opportunities for devising Cu2O based junctions requiring low process temperatures.Comment: 41 pages(including suppl. material), 7 figures (14 suppl. figures