High efficiency n-type silicon solar cells featuring passivated contact to laser doped regions

Minimizing carrier recombination at cell contacts becomes increasingly important for reaching high efficiency. In this work, the passivated contact concept is implemented into n-type silicon solar cells with laser-processed local back surface fields. The passivation and contact characteristics of the SiO2/amorphous silicon (a-Si:H) stack on localized laser doped n+ regions are investigated. We find that the SiO2/a-Si:H stack provides not only good passivation to laser doped n+ regions but also allows a low contact resistivity after thermal annealing. With the implementation of the SiO2/a-Si:H passivated contact, an absolute efficiency gain of up to 1.5% is achieved for n-type solar cells

Indexation as a response to inflation : an examination

Inflation (Finance)

Teaching Professionalism Skills to Secondary Students: An Improvement Science Dissertation on the Efficacy of a Professionalism Skills System: An Improvement Science Study

This research provided Salem Keizer Public Schools (SKPS) with much-needed information on how to teach and grade secondary students on professional skills. The research was conducted at The Career Technical Education Center (CTEC) in Salem, Oregon. CTEC employs 35 staff members who serve 780 high school students. This research followed an improvement science dissertation in practice model (ISDiP) by implementing a 64-day Plan-Do- Study-Act (PDSA) cycle. A networked improvement community (NIC) met throughout the PDSA cycle to analyze and implement the research. The NIC and CTEC staff developed a new system to teach, grade, and provide feedback on students\u27 professional skills (communication, collaboration, productivity, and safety). This research analyzed the effectiveness of the new system, which was measured by teacher perception and student grade data. The results from teacher perception data and student grade data indicated that the new professionalism system at CTEC effectively taught students professional skills

Afforestation’s potential to help Cambridgeshire reach net-zero by 2050

I present a preliminary assessment of afforestation’s ability to help Cambridgeshire reach net zero emissions by 2050. Considering 7 different planting scenarios with different tree species over 3,000 hectares (about 1% of the county), I calculate a maximum cumulative net sequestration of 1.44 Mt CO2 over the period 2020-2050, about 2.3% of the county’s projected total emissions over that period under an ambitious decarbonisation strategy (or about double the county’s projected emissions in the single year 2050). In addition, a methodology for calculating carbon sequestration and the associated abatement cost is presented, with sensitivity to land price and timber revenue explored. I calculate abatement costs of £20-50 per tonne CO2, considerably less than those from bio-energy carbon capture and storage (BECCS) and direct air carbon capture and storage (DACCS), although it depends strongly on timber price. This suggests afforestation has the potential to be a cost-efficient method for contributing to Cambridgeshire’s ambitious climate change strategy, but significantly larger areas would need to be planted if it were chosen to be a major driver in reducing net emissions

The Use and Value of Data Warehousing in Higher Education

Industry is experiencing a dramatic increase in the use of data warehousing techniques, but higher education has been slow to follow suit. This paper illustrates some common uses of data warehousing in industry, provides higher education analogues and suggests the potential value of data warehousing techniques to colleges and universities

Impact of E22 on two-stroke and four-stroke snowmobiles

A push to reduce dependency on foreign energy and increase the use of renewable energy has many gas stations pumping ethanol blended fuels. Recreational engines typically have less complex fuel management systems than that of the automotive sector. This prevents the engine from being able to adapt to different ethanol concentrations. Using ethanol blended fuels in recreational engines raises several consumer concerns. Engine performance and emissions are both affected by ethanol blended fuels. This research focused on assessing the impact of E22 on two-stroke and four-stroke snowmobiles. Three snowmobiles were used for this study. A 2009 Arctic Cat Z1 Turbo with a closed-loop fuel injection system, a 2009 Yamaha Apex with an open-loop fuel injection system and a 2010 Polaris Rush with an open-loop fuel injection system were used to determine the impact of E22 on snowmobile engines. A five mode emissions test was conducted on each of the snowmobiles with E0 and E22 to determine the impact of the E22 fuel. All of the snowmobiles were left in stock form to assess the effect of E22 on snowmobiles currently on the trail. Brake specific emissions of the snowmobiles running on E22 were compared to that of the E0 fuel. Engine parameters such as exhaust gas temperature, fuel flow, and relative air to fuel ratio (λ) were also compared on all three snowmobiles. Combustion data using an AVL combustion analysis system was taken on the Polaris Rush. This was done to compare in-cylinder pressures, combustion duration, and location of 50% mass fraction burn. E22 decreased total hydrocarbons and carbon monoxide for all of the snowmobiles and increased carbon dioxide. Peak power increased for the closed-loop fuel injected Arctic Cat. A smaller increase of peak power was observed for the Polaris due to a partial ability of the fuel management system to adapt to ethanol. A decrease in peak power was observed for the open-loop fuel injected Yamaha

Intermediate Wheatgrass Seed Production Responses to Fertilizers and Cultural Practices

Intermediate wheatgrass Agropyron intermedium (Host) Beauv. is a cool season, sod farming rhizomatous and/or stoloiferous grass, best adapted to upland silt or silty clay loam soils. Intermediate wheatgrass has a fast rat9 of root spread by rhizomes and sometimes stolon’s with late summer (July 15 August 30) seed maturity. The major area of distribution of intermediate wheatgrass in the United States is central North Dakota, South Dakota, Nebraska, Idaho and Washington, with a minor distribution area east to Minnesota and west to Colorado, Montana, and Wyoming. A growing interest in reseeding the Great Plains, both to improve the rangeland and to convert some cropland to grassland, has increased the demand for grass seed. Intermediate wheatgrass has increased the livestock carrying capacity of the western rangeland in the areas where it is grown with a highly digestible, palatable feed. Skills required to produce high yields of grass seed are much the same as those needed to produce high yields of other farm crops. Seed production fields need to be carefully selected. Cultivation, fertilization, and harvesting must be timely and intelligently carried out. Special skills are necessary in selecting a proper seedbed, planting date and rate, planting machinery, and land free of quack grass. The objectives of this research were to determine the effect· of certain cultural practices and nitrogen fertilizer treatments on the seed yield of intermediate wheatgrass in South Dakota. The experimental hypothesis set up for this experiment was that added nitrogen and selected cultural practices have no significant effect on the seed yield of intermediate wheatgrass

Clinical applications of Genome Polymorphism Scans

Applications of Genome Polymorphism Scans range from the relatively simple such as gender determination and confirmation of biological relationships, to the relatively complex such as determination of autozygosity and propagation of genetic information throughout pedigrees. Unlike nearly all other clinical DNA tests, the Scan is a universal test – it covers all people and all genes. In balance, I argue that the Genome Polymorphism Scan is the most powerful, affordable clinical DNA test available today. Reviewers: This article was reviewed by Scott Weiss (nominated by Neil Smalheiser), Roberta Pagon (nominated by Jerzy Jurka) and Val Sheffield (nominated by Neil Smalheiser)