A Simple Method to Develop a Formula for Estimating Concentration Time of Drainage Design

Concentration time of rainfall is an important aspect to determine drainage design. A general rational formula is used to determine design flood or peak flow in urban drainage planning, especially for storm sewer design. The use of this balanced formula requires rainfall intensity, whose duration of rain is equal or more than the time of concentration. This time of concentration is determined using an estimation formula whose formation requires measurement data of the time of concentration. This study introduces how to measure the time of concentration using the concept of-rational-hydrograph, in which peak flow occurs at the time of concentration. To fulfill the aim of this research, an experimental of catchment area planted with Zoysia Japonica grass and showered with a rainfall simulator was conducted. The length of the flow path on the land, L, given in 5 variations, namely 50 cm, 100 cm, 150 cm, 200 cm, and 250 cm, was used. The slope of the land, S, is given in 3 variations, namely 2.8 %, 5,6%, and 8.8%. For each variation of L and S, the experimental catchment area was poured with a fixed rainfall intensity, which is 60 mm/hour. The flow was measured every 5 minutes intervals. Then, from the relationship of flow and time, a rational hydrograph was formed, from which the time of concentration, Tc, was deduced. This Tc value was treated as the measured Tc to form the Tc estimation formula using the regression formula. The formula is Tc = 3.543 + 1.211 L – 17.119 S, with the coefficient of determination R2 = 0.98. These results show that the determination of Tc using the concept of the rational- hydrograph is acceptable. This formula applies to L and S values greater than zero and applies to land covered by Zoysia Japonica grass. Further research is needed for other types of land cover to validate the formula obtained in this research

Integration + Innovation: Proceedings of the 2019 Building Technology Educators\u27 Society Conference

This volume contains papers, abstracts, and posters from the 2019 Building Technology Educators\u27 Society (BTES) Conference, which focused on Integration and Innovation as the theme. Innovation can begin with conjecture, with a searching for more effective solutions, or with an application to currently unknown or unarticulated needs. Innovation scholarship examines the personal intellectual habits that support new ideas, such as openness and exploratory behavior, as well as the circumstances behind the places in which creativity flourishes, such as support for cross-disciplinary fertilization and access to resources. The 2019 BTES conference explored the role of technology education and curriculum in cultivating these intellectual habits in our students (and ourselves) and in creating the organizational spaces in which the future of practice will be shaped. Sessions shared exemplary proposals of research and pedagogical applications that explore innovative practices and integrative thinking in the academy and profession

Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS 1994), volume 1

The AIAA/NASA Conference on Intelligent Robotics in Field, Factory, Service, and Space (CIRFFSS '94) was originally proposed because of the strong belief that America's problems of global economic competitiveness and job creation and preservation can partly be solved by the use of intelligent robotics, which are also required for human space exploration missions. Individual sessions addressed nuclear industry, agile manufacturing, security/building monitoring, on-orbit applications, vision and sensing technologies, situated control and low-level control, robotic systems architecture, environmental restoration and waste management, robotic remanufacturing, and healthcare applications

Importance of Characterizing the Variability for Batch Production using Laser Powder Bed Fusion

Additive Manufacturing (AM) of metals is passingthe research stage and finding application in the industrialenvironment as a manufacturing technology of choice. However,the quality of products fabricated using metal AM technologycould be considered inferior when used in batch manufacturing.Quality is generally defined as conformance to specification andis inversely proportional to process variation. Variation in aprocess signifies the number of possible defects per millionopportunities in a given production. This gives rise to the needto characterize process variation to improve quality. This paperexplores the characterization of variability in laser powder bedfusion (LPBF) AM of metals to improve the quality of partproduction with specific focus on batches. It summarizes thefactors that influence the variation and discusses the tools usedto improve part quality