International Journal of Engineering Science Technologies

EXPLORING DIURNAL PATTERNS: DROP SIZE AND RAINFALL RATE DYNAMICS AT SHILLONG STATION

Nita H. Shah, Jyoti Chahal, Bipasha Paul Shukla — Wed, 03 Apr 2024 00:00:00 +0000

Rainfall prediction is crucial for various aspects of human life, environmental sustainability, and agriculture. Understanding rainfall intensity and its dependence on factors such as drop size distribution (DSD) is essential. This study investigates the relationship between drop size distribution and rainfall rate at Shillong station, Meghalaya, India, utilizing RD-80 disdrometer data for the year 2005. DSD plays a pivotal role in quantitative precipitation estimation, impacting rainfall properties like water content, intensity, and kinetic energy. Moreover, it is integral to satellite communication, aiding in the prediction of wave attenuation. We analyze the data to ascertain the correlation between rainfall rate and DSD, with an assumption of an exponential form for DSD. The analysis categorizes the daytime into four segments: Morning (6:00 AM-12:00 PM), Afternoon (12:00 PM-6:00 PM), Evening (6:00 PM-12:00 AM), and Night (12:00 AM-6:00 AM) to observe rain's diurnal variations. Notably, variations in correlation coefficients suggest differing rainfall patterns and intensity levels throughout the day and across months. These insights contribute to a deeper understanding of rainfall dynamics in the region, which is critical for effective water resource management and disaster preparedness.

ENHANCING DECISION-MAKING IN WATER RESOURCES MANAGEMENT: AN INNOVATIVE ASSESSMENT OF EXPERT CONSISTENCY AND COMPETENCE

Bojan Srdjevic, Zorica Srdjevic, Milica Ilić, Senka Ždero — Fri, 19 Apr 2024 00:00:00 +0000

In the assessment of principles and guidelines to achieve specific goals before strategies in water resources and related sectors are formulated, the quality of experts participating in making group decisions should be evaluated. This paper introduces an innovative approach designed to evaluate the quality of group members based on their consistency and deviations from the group's decision. The group members are considered as alternatives within a multi-criteria framework, employing several typical performance indicators as criteria to assess their competence and compliance with the group. Considering the policy-making, the paper provides a rationale for possibly excluding certain members from the decision-making process to prevent making unsustainable decisions. A case study is presented about the evaluation of the importance of six Ramsar sites in Serbia, facing imminent threats from water regime disturbances and climate change-induced droughts. Seven experts participated in the process and the results revealed that several experts displayed the poorest performance across all three prioritization schemes. This suggests the necessity for re-evaluating their judgments or considering their exclusion from the final decision-making process. The proposed assessment procedure holds promise for enhancing the potential to derive sustainable solutions in any complex and critical domain of water resources policy-making and strategic planning.

PRECISE PEENING OF NI-CR-MO STEEL BY ENERGY-INTENSIVE MULTIFUNCTION CAVITATION IN CONJUNCTION WITH POSITRON IRRADIATION

Toshihiko Yoshimura, Shintaro Yamamoto, Hayato Watanabe — Fri, 19 Apr 2024 00:00:00 +0000

The peening characteristics of Ni-Cr-Mo steel were investigated using energy-intensive multifunction cavitation using positron irradiation (PMEI-MFC). It was found that PMEI-MFC in a high magnetic field, multifunction cavitation in a high magnetic field (MEI-MFC), laser irradiation ultrasonic cavitation (LMEI-UC), and a combination of positron and laser irradiation ultrasonic cavitation in a high magnetic field (PLMEI-UC) could reduce the surface roughness of unprocessed metal specimens by approximately one-fourth. Furthermore, the PMEI-MFC method greatly improved the residual stress at the metal surface by up to 1155 MPa. Each of these technologies was found to increase the surface hardness although the PLM-WJC and PMEI-MFC processes, which generated high temperatures, produced smaller increases than were obtained using the LMEI-MFC technique. This difference is attributed to recrystallization, which eliminated work hardening at the outermost metal surface during processing using positrons. The data also indicate that the PMEI-MFC method was able to both smooth and flatten the metal surface. This research demonstrates an approach to precision peening that can reduce surface roughness while imparting high compressive residual stress.