352 research outputs found

    Importance of Solar & Renewable Energy in United States

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    As climate change remains a problem in the United States, renewable energy provides an optimal solution to replace fossil fuels using the energy available from the sun, wind, and water. Unfortunately, developing renewable energy hinders many people due to the amount of time, cost, and maintenance to provide plenty of energy to multiple communities, industries, and businesses. We are using case studies, scholarly articles and textbooks that focuses on solar energy as our main focus of the topic. Specifically, we analyze ways for the United States to use solar energy using solar panel or photovoltaics in their homes and industries to educate people to take advantage of solar panels to be installed in their homes. We will demonstrate solutions using engineering to help save land, cost, and time to show the society in using solar first and later other renewable energy techniques. Our goal is to demonstrate the importance in developing photovoltaics as well as planning to develop existing solutions into new and improve for upcoming research and development.Ope

    Importance of Solar & Renewable Energy in United States

    Get PDF
    As climate change remains a problem in the United States, renewable energy provides an optimal solution to replace fossil fuels using the energy available from the sun, wind, and water. Unfortunately, developing renewable energy hinders many people due to the amount of time, cost, and maintenance to provide plenty of energy to multiple communities, industries, and businesses. We are using case studies, scholarly articles and textbooks that focuses on solar energy as our main focus of the topic. Specifically, we analyze ways for the United States to use solar energy using solar panel or photovoltaics in their homes and industries to educate people to take advantage of solar panels to be installed in their homes. We will demonstrate solutions using engineering to help save land, cost, and time to show the society in using solar first and later other renewable energy techniques. Our goal is to demonstrate the importance in developing photovoltaics as well as planning to develop existing solutions into new and improve for upcoming research and development.Ope

    O-band N-rich silicon nitride MZI based on GST

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordWe have experimentally demonstrated an O-band Mach-Zehnder interferometer (MZI) based on a N-rich silicon nitride platform combined with Ge2Sb2Te5 for future optical communication applications. The device operation relies on controlling the waveguide’s losses using a phase change material cell which can be changed from amorphous (lowloss) to crystalline (high-loss). An extinction ratio (ER) as high as 11 dB was obtained between the amorphous (ON) and the crystalline (OFF) states of the MZI optical building block. The insertion loss of the MZI structure per cell unit length was measured to be as high as 0.87 dB/”m in OFF state and as low as 0.064 dB/”m in ON state for TM polarisation.Engineering and Physical Sciences Research Council (EPSRC

    Reconfigurable photonic integrated circuits (RPICs) based on functional materials for integrated optical communication applications

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    This is the final version. Available from the publisher via the DOI in this record.In this work we combine the already mature silicon and silicon nitride platforms with novel reconfigurable materials such as 2D materials, liquid crystals and phase change materials. An actively reconfigurable 1D photonic crystal multi-channel filter based on Si-on-insulator and liquid crystal platforms is demonstrated with extraordinary large quality factor, Q ∌ 104 . A complete study and design of an optical routing and multilevel volatile photonic memory based on graphene capacitor concept for future high performance computing using Silicon rich nitride is shown with a bandwidth of 64 GHz and energy power consumption per bit as low as 0.22 pJ. Finally, an optical switch based on germanium-antimony-tellurium phase change material (GST) is experimentally demonstrated for O-band operation with the extinction ratio as high as 10 dB between the amorphous and the crystalline statesEngineering and Physical Sciences Research Council (EPSRC

    Effect of Co-Inoculation with Mycorrhiza and Rhizobia on the Nodule Trehalose Content of Different Bean Genotypes

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    Studies on Rhizobium-legume symbiosis show that trehalose content in nodules under drought stress correlates positively with an increase in plant tolerance to this stress. Fewer reports describe trehalose accumulation in mycorrhiza where, in contrast with rhizobia, there is no flux of carbohydrates from the microsymbiont to the plant. However, the trehalose dynamics in the Mycorrhiza-Rhizobium-Legume tripartite symbiosis is unknown. The present study explores the role of this tripartite symbiosis in the trehalose content of nodules grown under contrasting moisture conditions. Three wild genotypes (P. filiformis, P. acutifolis and P. vulgaris) and two commercial genotypes of Phaseolus vulgaris (Pinto villa and Flor de Mayo) were used. Co-inoculation treatments were conducted with Glomus intraradices and a mixture of seven native rhizobial strains, and trehalose content was determined by GC/MS. The results showed a negative effect of mycorrhizal inoculation on nodule development, as mycorrhized plants showed fewer nodules and lower nodule dry weight compared to plants inoculated only with Rhizobium. Mycorrhizal colonization was also higher in plants inoculated only with Glomus as compared to plants co-inoculated with both microsymbionts. In regard to trehalose, co-inoculation negatively affects its accumulation in the nodules of each genotype tested. However, the correlation analysis showed a significantly positive correlation between mycorrhizal colonization and nodule trehalose content

    Hedonic perception and preference analysis of double cream cheeses formulated with raw and pasteurized milk

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    Objective: To compare the characteristics of double cream cheeses made with raw and pasteurized milk per liking and preference level. Design/Methodology/Approach: Cheeses from three brands were evaluated: Santa Teresa, Montero, and Colegio de Postgraduados (CP). The first two cheeses were formulated with raw milk, while the CP cheese was formulated with pasteurized milk inoculated with lactic cultures. The hedonic perception study was carried out in monadic series with 19 volunteers who blind tasted the three types of cheese. The evaluation attributes were: appearance, taste, aroma, and general acceptability on a 9-point scale; and saltiness, acidity, and creaminess on a 3-point scale (JAR). Preferences were evaluated by rank and multiple comparison tests. Results: No differences were found in the aroma, taste, and texture liking level of the cheeses (p>0.05); nevertheless, there were differences in the appearance and general acceptance (p˂0.05). The general acceptance of the CP cheese was significantly lower than that of the two raw milk cheeses (p˂0.05). The penalty analysis showed that low acidity and low creaminess attributes are related to a low general acceptance (p˂0.05). Limitations/Implications: The study has enough evaluations for statistical tests. Findings/Conclusions: Raw milk cheeses obtained the highest marks in all attributes. Determining if there are other sensory attributes —in addition to those that were the subject of this study— will help to explain the greater preference and global acceptance of raw milk cheeses

    HAp Nanofibers Grown with Crystalline Preferential Orientation and Its Influence in Mechanical Properties of Organic-Inorganic Composite Materials

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    There are several synthesis techniques to obtain hydroxyapatite (HAp). Some use surfactant agents, amino acids or halogen salts to control structural nucleation and crystal growth. In others, the use of hydrothermal process to carry out the reaction is effective for HAp synthesis. Microwave-assisted hydrothermal method (MAHM) has been successfully applied in the synthesis of HAp nanostructures, which present well-defined morphologies, high crystallinity and high purity. This is important because nano-HAp is attracting interest as a biomaterial for use in prosthetic applications due to its similarity in size, crystallinity and chemical composition with human hard tissue. In this chapter, developments in obtaining HAp nanofibers, with a crystal growth with preferential orientation, as well as morphology control achieved by using the MAHM is discussed. Also, the synthesized fibers were used to cast ceramics with controlled and interconnected porosity through the modified gelcasting process. Then, these HAp ceramics were impregnated with a water solution of gelatin in order to obtain an organic-inorganic composite material, similar to natural bone tissue. The maximum compressive strengths were determined and the composite materials showed mechanical properties that make them suitable to be used as bone tissue implants

    Nitrogen forms affect root structure and water uptake in the hybrid poplar

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    The study analyses the effects of two different forms of nitrogen fertilisation (nitrate and ammonium) on root structure and water uptake of two hybrid poplar (Populus maximowiczii x P. balsamifera) clones in a field experiment. Water uptake was studied using sap flow gauges on individual proximal roots and coarse root structure was examined by excavating 18 whole-root systems. Finer roots were scanned and analyzed for architecture. Nitrogen forms did not affect coarse-root system development, but had a significant effect on fine-root development. Nitrate-treated trees presented higher fine:coarse root ratios and higher specific root lengths than control or ammonium treated trees. These allocation differences affected the water uptake capacity of the plants as reflected by the higher sapflow rate in the nitrate treatment. The diameter of proximal roots at the tree base predicted well the total root biomass and length. The diameter of smaller lateral roots also predicted the lateral root mass, length, surface area and the number of tips. The effect of nitrogen fertilisation on the fine root structure translated into an effect on the functioning of the fine roots forming a link between form (architecture) and function (water uptake)

    A mechanistic framework for auxin dependent Arabidopsis root hair elongation to low external phosphate

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    Phosphate (P) is an essential macronutrient for plant growth. Roots employ adaptive mechanisms to forage for P in soil. Root hair elongation is particularly important since P is immobile. Here we report that auxin plays a critical role promoting root hair growth in Arabidopsis in response to low external P. Mutants disrupting auxin synthesis (taa1) and transport (aux1) attenuate the low P root hair response. Conversely, targeting AUX1 expression in lateral root cap and epidermal cells rescues this low P response in aux1. Hence auxin transport from the root apex to differentiation zone promotes auxin-dependent hair response to low P. Low external P results in induction of root hair expressed auxin-inducible transcription factors ARF19, RSL2, and RSL4. Mutants lacking these genes disrupt the low P root hair response. We conclude auxin synthesis, transport and response pathway components play critical roles regulating this low P root adaptive response
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