Nutritional Requirements Of The Fry Of Gold-Spot Mullet Liza Parsa (Hamilton)

Most tropical aquatic environments are naturally fertile and their natural fertility is renewed very rapidly. Natural food for many cultivable organisms can be grown to the maximum by proper management. However, enrichment of the environment can be done through rational fertilization. Still further increase in stocking rates, can yield increased crop if adequate feeding is done. Thus fish and shellfish nutrition is an important aspect of the multidisciplinary subject of aquaculture. The oldest and most classical studies in physiology have investigated the nutritional needs of the species of interest to aquaculture. The alimentary requirements for proteins, lipids, mineral salts and vitamins have been established for some temperate species. But, the nutritional requirements of only few tropical species have been studied. Before formulating a diet, a thorough knowledge of the nutrient requirement of the species is essential. It is against this background that the present area of investigation has been identified. "Nutritional requirements of the fry of gold-spot mullet Liza parsia" is a comprehensive attempt to quantify the nutritional factors that are essential for producing healthy fingerlings for stocking the farms. Aspects such as the protein and lipid requirements of the fry, the vitamin essentiality, nutritive evaluation of protein and lipid sources suitable for compounding diets were covered in this research project. The ultimate aim has been to evolve practical diets which could be applied in the nursery phase for juvenile production.

Adsoption-induced restructuring of gold nanochains

The chemical properties of single-atomic chains of gold atoms are investigated using density functional calculations. The nanochains are shown to be unusually chemically active with strong chemisorption of oxygen atoms and carbon monoxide. The chemisorption energies vary significantly with the strain/stress conditions for the chain. Oxygen atoms are found to energetically prefer to get incorporated into a chain forming a new type of gold-oxygen nanochain with a conductance of one quantum unit. We suggest that the long bond lengths observed in electron microscopy investigations of gold chains can be due to oxygen incorporation.

Photoschaltbare Azobenzol-modifizierte selbstorganisierte Monoschichten auf Gold(111)-Oberflächen

Für die Entwicklung photoschaltbarer selbstorganisierter Monoschichten (SAMs) auf Gold(111)-Oberflächen wurden neue Azobenzol-terminierte Asparagussäure - und Liponsäurederivate synthetisiert. Um den Einfluss lateraler Wasserstoffbrückenbindungen auf Qualität und Orientierungsordnung der Schichten zu untersuchen, wurden Monolagen, die durch amid- und esterverknüpfte Verbindungen gebildet wurden, miteinander verglichen. Die Filmbildung aus der Lösung wurde in situ durch optische Frequenzverdopplung (SHG) untersucht und die Photoreaktivität mittels Kontaktwinkelmessungen, Oberflächen-Plasmonenresonanz (SPR) und Ellipsometrie verfolgt. SAMs auf Gold wurden außerdem mit Hilfe von Röntgenphotoelektronenspektroskopie (XPS), Nahkanten-Reflexions-Röntgenabsorptionsspektroskopie (NEXAFS) und Infrarot-Reflexionsabsorptionsspektroskopie (IRRAS) charakterisiert, um die Filmqualität, die Bindung ans Substrat und Orientierungsordnung im Film zu ermitteln. Da die Chemisorption auf polykristallinem Gold formal der Koordinationschemie von 1,2-Dithiolan-Derivaten gegenüber nullwertigen Edelmetall-Zentralatomen entspricht, wurden etliche Pt-Komplexe durch oxidative Addition an [Pt(PPh3)4] dargestellt. Im Zusammenhang mit der Darstellung der Asparagussäure wurde die Kristallstruktur von [pipH]2[WS4] und der neuen Verbindungen [pipH]3[WS4](HS) und [pipH]4[WS4][WOS3] (pip = Piperidin) bestimmt. Wasserstoffbrückenbindungen zwischen den Piperidinium-Kationen und den Thiowolframat-Anionen spielen eine dominante strukturelle Rolle.

Predicted properties of the superheavy elements, II. Element 111, Eka-Gold

The chemical properties of element 111, eka-gold, are predicted through the use of the periodic table, relativistic Hartee-Fock-Slater calculations, and various qualitative theories which have established their usefulness in understanding and correlating properties of molecules. The results indicate that element 111 will be like Au(III) in its chemistry with little or no tendency to show stability in the I or II states. There is a possibility that the 111 - ion, analogous to the auride ion, will be stable.

Preparation and applications of periodical gold nanoparticle arrays

Diese Arbeit beschäftigt sich mit der Herstellung und Anwendungen von periodischen Goldnanopartikel-Arrays (PPAs), die mit Hilfe von Nanosphären-Lithografie hergestellt wurden. In Abhängigkeit der verwendeten Nanosphären-Größe wurden dabei entweder kleine dreieckige Nanopartikel (NP) (bei Verwendung von Nanosphären mit einem Durchmesser von 330 nm) oder große dreieckige NPD sowie leicht gestreckte NP (bei Verwendung von Nanosphären mit einem Durchmesser von 1390 nm) hergestellt. Die Charakterisierung der PPAs erfolgte mit Hilfe von Rasterkraftmikroskopie, Rasterelektronenmikroskopie und optischer Spektroskopie. Die kleinen NP besitzen ein Achsverhältnis (AV) von 2,47 (Kantenlänge des NPs: (74+/-6) nm, Höhe: (30+/-4) nm. Die großen dreieckigen NP haben ein AV von 3 (Kantenlänge des NPs:(465+/-27) nm, Höhe: (1530+/-10) nm) und die leicht gestreckten NP (die aufgrund der Ausbildung von Doppelschichten ebenfalls auf der gleichen Probe erzeugt wurden) haben eine Länge von (364+/-16)nm, eine Breite von (150+/-20) nm und eine Höhe von (150+/-10)nm. Die optischen Eigenschaften dieser NP werden durch lokalisierte Oberflächenplasmon-Polariton Resonanzen (LPPRs) dominiert, d.h. von einem eingestrahlten elektromagnetischen Feld angeregte kollektive Schwingungen der Leitungsbandelektronen. In dieser Arbeit wurden drei signifikante Herausforderungen für Plasmonik-Anwendungen bearbeitet, welche die einzigartigen optischen Eigenschaften dieser NP ausnutzen. Erstens wurden Ergebnisse der selektiven und präzisen Größenmanipulation und damit einer Kontrolle der interpartikulären Abstände von den dreieckigen Goldnanopartikel mit Hilfe von ns-gepulstem Laserlicht präsentiert. Die verwendete Methode basiert hierbei auf der Größen- und Formabhängigkeit der LPPRs der NP. Zweitens wurde die sensorischen Fähigkeiten von Gold-NP ausgenutzt, um die Bildung von molekularen Drähten auf den PPAs durch schrittweise Zugabe von unterschiedlichen molekularen Spezies zu untersuchen. Hierbei wurde die Verschiebung der LSPPR in den optischen Spektren dazu ausgenutzt, die Bildung der Nanodrähte zu überwachen. Drittens wurden Experimente vorgestellt, die sich die lokale Feldverstärkung von NP zu nutze machen, um eine hochgeordnete Nanostrukturierung von Oberflächen mittels fs-gepulstem Laserlicht zu bewerkstelligen. Dabei zeigt sich, dass neben der verwendeten Fluenz die Polarisationsrichtung des eingestrahlten Laserlichts in Bezug zu der NP-Orientierung sowie die Größe der NP äußerst wichtige Parameter für die Nanostrukturierung darstellen. So konnten z.B. Nanolöcher erzeugt werden, die bei höheren Fluenzen zu Nanogräben und Nanokanälen zusammen wuchsen. Zusammengefasst lässt sich sagen, dass die in dieser Arbeit gewonnen Ergebnisse von enormer Wichtigkeit für weitere Anwendungen sind.

Adsorption kinetic investigations of phthalocyanine derivatives self assembled monolayers (SAMs) on gold: Temperature influence on the SAM formation process and quality

The ordered nano-structured surfaces, like self-assembled monolayers (SAMs) are of a great scientific interest, due to the low cost, simplicity, and versatility of this method. SAMs found numerous of applications in molecular electronics, biochemistry and optical devices. Phthalocyanine (Pc) complexes are of particular interest for the SAM preparation. These molecules exhibit fascinating physical properties and are chemically and thermally stable. Moreover their complex structure is advantageous for the fabrication of switchable surfaces. In this work the adsorption process of Pcs derivatives, namely, subphthalocyanines (SubPcB) and terbium (2TbPc) sandwich complexes on gold has been investigated. The influence of the molecular concentration, chain length of peripheral groups, and temperature on the film formation process has been examined using a number of techniques. The SAMs formation process has been followed in situ and in real time by means of second harmonic generation (SHG) and surface plasmon resonance (SPR) spectroscopy. To investigate the quality of the SAMs prepared at different temperatures atomic force microscopy (AFM) and X-Ray photoelectron spectroscopy (XPS)measurements were performed. Valuable information about SubPcB and 2TbPc adsorbtion process has been obtained in the frame of this work. The kinetic data, obtained with SHG and SPR, shows the best conformance with the first order Langmuir kinetic model. Comparing SHG and SPR results, it has been found, that the film formation occurs faster than the formation of chemical bonds. Such, the maximum amount of molecules on the surface is reached after 6 min for SubPcB and 30 min for 2TbPc. However, at this time the amount of formed chemicals bonds is only 10% and 40% for SubPcB and 2TbPc, respectively. The most intriguing result, among others, was obtained at T = 2 °C, where the formation of the less dense SAMs have been detected with SHG.However, analyzing XPS and AFM data, it has been revealed, that there is the same amount of molecules on the surface at both temperature T = 2 °C, and T = 21 °C, but the amount of formed chemicals bond is different. At T = 2 °C molecules form aggregates, therefore many of available anchor groups stay unattached.

Microbial response to restoration of tantalite mine soils in western Rwanda

Artisanal columbite-tantalite (coltan) mining has had negative effects on the rural economy in the great Lakes region of Africa through labor deficits, degradation and loss of farmland, food insecurity, high cost of living, and reduced traditional export crop production alongside secondary impacts that remotely affect the quality of air, water, soil, plants, animals, and human wellbeing. The situation is multifaceted and calls for a holistic approach for short and long-term mitigation of such negative effects. This study focuses on the effects of mine land restoration on soil microbiological quality in the Gatumba Mining District of western Rwanda. Some coltan mine wastelands were afforested with pine and eucalyptus trees while farmers directly cultivated others due to land scarcity. Farmyard manure (FYM) is the sole fertilizer applied on the wastelands although it is insufficient to achieve the desired crop yields. Despite this, several multi-purpose plants such as Tithonia diversifolia, Markhamia lutea, and Canavalia brasiliensis thrive in the area and could supplement FYM. The potential for these “new” amendments to improve soil microbial properties, particularly in the tantalite mine soils was investigated. The specific objectives of the study were to: (a) evaluate the effects of land use on soil microbial indices of the tantalite mine soils; (b) investigate the restorative effects of organic amendments on a Technosol; and (c) estimate the short-term N and P supply potential of the soil amendments in the soils. Fresh soils (0-20 cm) from an unmined native forest, two mine sites afforested with pine and eucalyptus forests (pine and eucalyptus Technosols), an arable land, and two cultivated Technosols (Kavumu and Kirengo Technosols) were analyzed for the physicochemical properties. Afterwards, a 28-day incubation (22oC) experiment was conducted followed by measurements of mineral N, soil microbial biomass C, N, P, and fungal ergosterol contents using standard methods. This was followed by a 12-week incubation study of the arable soil and the Kavumu Technosol amended with FYM, Canavalia and Tithonia biomass, and Markhamia leaf litter after which soil microbial properties were measured at 2, 8, and 12 weeks of incubation. Finally, two 4-week incubation experiments each were conducted in soils of the six sites to estimate (i) potential mineralizable N using a soil-sand mixture (1:1) amended with Canavalia and goat manure and (ii) P mineralization mixtures (1:1) of soil and anion exchange resins in bicarbonate form amended with Tithonia biomass and goat manure. In study one, afforestation increased soil organic carbon and total N contents in the pine and eucalyptus Technosols by 34-40% and 28-30%, respectively of that in the native forest soil. Consequently, the microbial biomass and activity followed a similar trend where the cultivated Technosols were inferior to the afforested ones. The microbial indices of the mine soils were constrained by soil acidity, dithionite-extractable Al, and low P availability. In study two, the amendments substantially increased C and N mineralization, microbial properties compared with non-amended soils. Canavalia biomass increased CO2 efflux by 340%, net N mineralization by 30-140%, and microbial biomass C and N by 240-600% and 240-380% (P < 0.01), respectively after four weeks of incubation compared with the non-amended soils. Tithonia biomass increased ergosterol content by roughly 240%. The Kavumu Technosol showed a high potential for quick restoration of its soil quality due to its major responses to the measured biological parameters. In study three, Canavalia biomass gave the highest mineralizable N (130 µg g-1 soil, P < 0.01) in the Kavumu Technosol and the lowest in the native forest soil (-20 µg g-1 soil). Conversely, the mineralizable N of goat manure was negative in all soils ranging from -2.5 µg N g-1 to -7.7 µg N g-1 soil except the native forest soil. However, the immobilization of goat manure N in the “cultivated soils” was 30-70% lower than in the “forest soils” signifying an imminent recovery of the amended soils from N immobilization. The mineralization of goat manure P was three-fold that of Tithonia, constituting 61-71% of total P applied. Phosphorus mineralization slightly decreased after four weeks of incubation due to sulfate competition as reflected in a negative correlation, which was steeper in the Tithonia treatment. In conclusion, each amendment used in this research played a unique role in C, N, and P mineralization and contributed substantially to microbial properties in the tantalite mine soils. Interestingly, the “N immobilizers” exhibited potentials for P release and soil organic carbon storage. Consequently, the combined use of the amendments in specific ratios, or co-composting prior to application is recommended to optimize nutrient release, microbial biomass dynamics and soil organic matter accrual. Transport of organic inputs seems more feasible for smallholder farmers who typically manage small field sizes. To reduce acidity in the soils, liming with wood ash was recommended to also improve P availability and enhance soil biological quality, even if it may only be possible on small areas. Further, afforestation with mixed-species of fast-growing eucalyptus and legume or indigenous tree species are suggested to restore tantalite mine wastelands. It is emphasized most of this research was conducted under controlled laboratory conditions, which exclude interaction with environmental variables. Also fine fractions of the amendments were used compared with the usual practice of applying a mixture of predominantly coarser fractions. Therefore, the biological dynamics reported in the studies here may not entirely reflect those of farmers’ field conditions.

Biological Routes to Gold Nanoplates

Much effort has been devoted to the synthesis of gold nanoparticles with different shapes, including the zero-dimensional nanospheres, one dimensional nanorods, and two-dimensional nanoplates. Compared to zero or one dimensional nanostructures, the synthesis of two-dimensional nanostructures in high yield has always been more involved, often requiring complex and time-consuming steps such as morphology transformation from the nanospheres, or the seeded growth process. Herein we report a high yield method for gold nanoplate synthesis using the extract of unicellular green alga Chlorella vulgaris, which can be carried out under ambient conditions. More than 90% of the total nanoparticle population is of the platelet morphology, surpassing the previously reported value of 45%. The control of the anisotropic growth of different planes; as well as the lateral size, has also been partially optimized.

Perfil logístico de Colombia sector minero

El proyecto “Perfil logístico de Colombia” tiene como objetivo poder suplir las falencias de información que existen actualmente en Colombia a la hora de proyectar el proceso logístico de un bien o servicio. Las empresas colombianas cuentan con pocos recursos para llevar la materia prima de forma eficaz a su fin o punto de consumo. Dentro de este proyecto se analizará el sector Minero en Colombia, donde este presenta un alto reconocimiento a nivel mundial. Posee metales preciosos y metales básicos, su principal producción es el carbón térmico, ferroníquel, oro y esmeraldas. De esta manera, la minería en mediana y pequeña escala presenta un alto potencial, el cual si es aprovechado de una manera adecuada puede llegar a convertirse en una fuente muy importante y representativa para el país en cuanto a ingresos y empleos. De acuerdo a los últimos años Colombia se ha convertido en un país atractivo en cuanto a la inversión de explotación minera, gracias al incremento de precios internacionales de los minerales y el desarrollo de la seguridad en Colombia. Se realizará un análisis global en el cual se mostrará la posición de Colombia frente a la situación internacional, esto se investigará de acuerdo a los diferentes indicadores como el PIB, índice global de competitividad, productividad, y balanza comercial. Así mismo, se examinará el nivel de infraestructura logística que promueve la planeación de los flujos logísticos teniendo variables de costo, tiempo, y transporte. Además se tendrán en cuenta factores como cadena de suministro, problemática del sector minero con el gobierno, caracterización mundial, panorama nacional, VSM (proveedores, productores, almacenamiento, distribución y logística inversa) y gremios.

El problema de la represión en Herbert Marcuse y sus implicaciones en el campo de la educación.

Elaborar a partir de las teorías de Herbert Marcuse una visión del hombre en su dimensión psicológica y social, que sirva como posible punto de partida de una nueva orientación pedagógica que elimine la represión excedente. Obra de Herbert Marcuse. Inicia el trabajo con la vida de Marcuse y su relación con la filosofía negativa. Seguidamente realiza un análisis teórico de los conceptos: represión, sobrepresión y principio de actuación, para después observar su aplicación en el ámbito educativo. Ante este enfoque propone un tipo de educación antagonista a esta, que es la educación estética del hombre como principio de la creatividad, para acabar formando una idea educativa basada en Summerhill o la escuela en libertad, relacionando así a Marcuse con A.S.Neill. La educación, en muchos casos, ha negado la capacidad de actuación de los sujetos y nuestra mentalidad ha sido manipulada haciendo creer que la productividad es la base indispensable de nuestra vida y de la misma manera han conseguido ocupar nuestro tiempo con la obligatoriedad del trabajo, que el poco que nos queda es el que se necesita para recuperarse y descansar. Ante esto, Neill como Marcuse afirmaban que éstas eran las causas de que el sujeto no sea feliz, así, la finalidad de las teorías de ambos pensadores radica en la necesidad de hacer consciente al sujeto de su falta de libertad y de que bajo una organización más libre el sujeto podría ser feliz, su objetivo coincide en la búsqueda de la felicidad.

De la Educación Física' : Herbert Spencer, 1861.

Resumen tomado de la publicación

The hunt for gold.

Pertenece a un amplio programa infantil de lectura que abarca distintos niveles de edad y, por tanto, de conocimientos. Se abordan las necesidades de lectura en los niños y la amplia variedad de habilidades que necesitan adquirir para su aprendizaje y, se destaca, también, la importancia de la narración en las historias. Los niños protagonistas se transladan en el tiempo, con la ayuda de su llave mágica, a la época de los buscadores de oro.

Hidden gold.

Diseñado para proporcionar un fácil apoyo para los alumnos que necesitan para ganar la confianza y la motivación en su lectura. La historia trata de un grupo de amigos que viven y asisten a la escuela en una zona llamada Wolf Hill. Además de las divertidas aventuras, la historia también se ocupa de cuestiones sobre la amistad, la escuela y la vida en un moderno entorno urbano. Diseñada en capítulos, para que parezca novela popular para niños mayores, y así aumentar la confianza y el interés de aquellos que pueden gustarles la lectura de historias destinadas a los niños más pequeños. Loz y sus amigos encuentran algunas monedas antiguas en un escondite secreto y quieren saber si tienen valor.

Hodder science gold. Pupil's book C.

Destinado a los alumnos, tiene como objetivo estimularlos y motivarlos mediante la vinculación de la ciencia a la vida real. Cada capítulo abarca una serie de características:una actividad de iniciación al comienzo de cada capítulo, que permite a los profesores evaluar el nivel de comprensión del tema por el alumno antes de seguir avanzando; preguntas para garantizar que los alumnos han comprendido el trabajo; palabras clave para ampliar el vocabulario y fomentar el uso exacto de los términos científicos; recuerdo para resumir las conceptos; lista de los sitios web pertinentes para ayudar a ilustrar los temas tratados y estimular la investigación individual.

New Hodder English gold 1.

Es el primero de una serie de tres volúmenes, uno por cada año de estudio, de la etapa clave tres (Key Stage 3). Escrito en colaboración con la Agencia de Destrezas Básicas (The Basic Skills Agency) asegura a los estudiantes de los niveles 2-4 una cobertura total del currículo nacional inglés. Las unidades están diseñadas para complementar los esquemas de trabajo del año escolar y promueven un acercamiento interactivo a la enseñanza. Los textos literarios y no literarios proporcionan la base para las tareas que se centran en el desarrollo de habilidades específicas incluida la expresión oral.