10 resultados para Improves
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
Tillage systems play a significant role in agricultural production throughout Iowa and the Midwest. It has been well documented that increased tillage intensities can reduce soil organic matter in the topsoil due to increased microbial activity and carbon (C ) oxidation. The potential loss of soil organic matter due to tillage operations is much higher for high organic matter soils than low organic matter soils. Tillage effects on soil organic matter can be magnified through soil erosion and loss of soil productivity. Soil organic matter is a natural reservoir for nutrients, buffers against soil erosion, and improves the soil environment to sustain soil productivity. Maintaining soil productivity requires an agriculture management system that maintains or improves soil organic matter content. Combining cropping systems and conservation tillage practices, such as no-tillage, strip-tillage, or ridge-tillage, are proven to be very effective in improving soil organic matter and soil quality.
Resumo:
The addition of supplementary cementitious materials (SCMs), such as fly ash (FA) and slag, generally improves concrete workability, durability, and long-term strength. New trends in sustainable development of concrete infrastructure and in environmental regulations on waste disposal are spurring use of SCMs in concrete. However, use of SCM concrete is sometimes limited due to a lack of understanding about material behaviors and lack of proper specifications for its construction practice. It is believed that SCM concrete performance varies significantly with the source and proportion of the cementitious materials. SCM concrete often displays slower hydration, accompanied by slower setting and lower early-age strength, especially under cold weather conditions. The present research was conducted to have a better understanding of SCM concrete behaviors under different weather conditions. In addition to the study of the effect of SCM content on concrete set time using cementitious materials from different sources/manufacturers, further research may be needed to investigate the effects of SCM combinations on concrete flowability, air stability, cracking resistance, and durability.
Resumo:
For a variety of reasons, the concrete construction industry is not sustainable. First, it consumes huge quantities of virgin materials. Second, the principal binder in concrete is portland cement, the production of which is a major contributor to greenhouse gas emissions that are implicated in global warming and climate change. Third, many concrete structures suffer from lack of durability which has an adverse effect on the resource productivity of the industry. Because the high-volume fly ash concrete system addresses all three sustainability issues, its adoption will enable the concrete construction industry to become more sustainable. In this paper, a brief review is presented of the theory and construction practice with concrete mixtures containing more than 50% fly ash by mass of the cementitious material. Mechanisms are discussed by which the incorporation of high volume of fly ash in concrete reduces the water demand, improves the workability, minimizes cracking due to thermal and drying shrinkage, and enhances durability to reinforcement corrosion, sulfate attack, and alkali-silica expansion. For countries like China and India, this technology can play an important role in meeting the huge demand for infrastructure in a sustainable manner.
Resumo:
Nitrogen (N) is typically one of the largest corn fertilization expenses. Nitrogen application is critical because it signifi cantly improves corn yield in many crop rotations. When choosing N rates, producers need to carefully consider both achieving most profi table economic return and advancing environmental stewardship. In 2004, university agronomists from the Corn Belt states began discussions regarding N rate use for corn production. The reasons for the discussions centered on apparent differences in methods for determining N rates across states, misperceptions regarding N rate guidelines, and concerns about application rates as corn yields have climbed to historic levels. An outcome of those discussions was an effort with the objectives to: ▪ develop N rate guidelines that could be applicable on a regional basis and ▪ identify the most profi table fertilizer N rates for corn production across the Corn Belt. This publication provides an overview of corn N fertilization in regard to rate of application, investigates concepts for determining economic application rates, and describes a suggested regional approach for developing corn N rate guidelines directly from recent research data.
Resumo:
The passage of the Workforce Investment Act (WIA) of 1998 [Public Law 105-220] by the 105th Congress has ushered in a new era of collaboration, coordination, cooperation and accountability. The overall goal of the Act is “to increase the employability, retention, and earnings of participants, and increase occupational skill attainment by participants, and, as a result improve the quality of the workforce, reduce welfare dependency, and enhance the productivity and competitiveness of the Nation.” The key principles inculcated in the Act are: • Streamlining services; • Empowering individuals; • Universal access; • Increased accountability; • New roles for local boards; • State and local flexibility; • Improved youth programs. The purpose of Title II, The Adult Education and Family Literacy Act (AEFLA), of the Workforce Investment Act of 1998 is to create a partnership among the federal government, states, and localities to provide, on a voluntary basis, adult education and literacy services in order to: • Assist adults become literate and obtain the knowledge and skills necessary for employment and self-sufficiency; • Assist adults who are parents obtain the educational skills necessary to become full partners in the educational development of their children; • Assist adults in the completion of a secondary school education. Adult education is an important part of the workforce investment system. Title II restructures and improves programs previously authorized by the Adult Education Act. AEFLA focuses on strengthening program quality by requiring States to give priority in awarding funds to local programs that are based on a solid foundation of research, address the diverse needs of adult learners, and utilize other effective practices and strategies. To promote continuous program involvement and to ensure optimal return on the Federal investment, AEFLA also establishes a State performance accountability system. Under this system, the Secretary and each State must reach agreement on annual levels of performance for a number of “core indicators” specified in the law: • Demonstrated improvements in literacy skill levels in reading, writing, and speaking the English language, numeracy, problem solving, English language acquisition, and other literacy skills. • Placement in, retention in, or completion of postsecondary education, training, unsubsidized employment or career advancement. • Receipt of a secondary school diploma or its recognized equivalent. Iowa’s community college based adult basic education program has implemented a series of proactive strategies in order to effectively and systematically meet the challenges posed by WIA. The Iowa TOPSpro Data Dictionary is a direct result of Iowa’s pro-active efforts in this educational arena.
Resumo:
Iowa is a state rich in libraries, with 543 public libraries; more than 80 college and university libraries; and about 1,000 school libraries. Libraries enrich Iowa and support lifelong learning. The State Library of Iowa actively champions libraries and improves library services for Iowans through its management of the Enrich Iowa program. In accordance with 2006 IOWA ACTS, Chapter 1180 (16)(6), the State Library of Iowa is pleased to submit this report on the impact of state funding on Iowans and Iowa libraries through the Enrich Iowa Program.
Resumo:
The Weatherization Assistance Program is a low-income energy efficiency program administered by the Department of Energy (DOE). Its purpose is to make the homes of low-income clients more energy efficient, thereby reducing the households’ energy bills. The program also improves the health and safety of low-income homes. The energy efficiency and health and safety work is done using the most advanced technologies and testing protocols available in the housing industry. States administer the program in accordance with DOE rules and regulations.
Resumo:
Iowa is a state rich in libraries, with 543 public libraries; more than 80 college and university libraries; and about 1,000 school libraries. Libraries enrich Iowa and support lifelong learning. The State Library of Iowa actively champions libraries and improves library services for Iowans through its management of the Enrich Iowa program. In accordance with 2006 IOWA ACTS, Chapter 1180 (16)(6), the State Library of Iowa is pleased to submit this report on the impact of state funding on Iowans and Iowa libraries through the Enrich Iowa Program.
Resumo:
Iowa is a state rich in libraries, with 543 public libraries; more than 80 college and university libraries; and about 1,000 school libraries. Libraries enrich Iowa and support lifelong learning. The State Library of Iowa actively champions libraries and improves library services for Iowans through its management of the Enrich Iowa program. In accordance with 2006 IOWA ACTS, Chapter 1180 (16)(6), the State Library of Iowa is pleased to submit this report on the impact of state funding on Iowans and Iowa libraries through the Enrich Iowa Program.
Resumo:
Iowa is a state rich in libraries, with 543 public libraries; more than 80 college and university libraries; and about 1,000 school libraries. Libraries enrich Iowa and support lifelong learning. The State Library of Iowa actively champions libraries and improves library services for Iowans through its management of the Enrich Iowa program. In accordance with 2006 IOWA ACTS, Chapter 1180 (16)(6), the State Library of Iowa is pleased to submit this report on the impact of state funding on Iowans and Iowa libraries through the Enrich Iowa Program.