Bending Stability of Corrugated Tubes with Anisotropic Frustum Shells

Thin-walled corrugated tubes that have a bending multi-stability, such as the bendy straw, allow for variable orientations over the tube length. Compared to the long history of corrugated tubes in practical applications, the mechanics of the bending stability and how it is affected by the cross-sections and other geometric parameters remain unknown. To explore the geometry-driven bending stabilities, we used several tools, including a reduced-order simulation package, a simplified linkage model, and physical prototypes. We found the bending stability of a circular two-unit corrugated tube is dependent on the longitudinal geometry and the stiffness of the crease lines that connect separate frusta. Thinner shells, steeper cones, and weaker creases are required to achieve bending bi-stability. We then explored how the bending stability changes as the cross-section becomes elongated or distorted with concavity. We found the bending bi-stability is favored by deep and convex cross-sections, while wider cross-sections with a large concavity remain mono-stable. The different geometries influence the amounts of stretching and bending energy associated with bending the tube. The stretching energy has a bi-stable profile and can allow for a stable bent configuration, but it is counteracted by the bending energy which increases monotonically. The findings from this work can enable informed design of corrugated tube systems with desired bending stability behavior.

Growth Analysis of Joint Liability Groups (JLGs) in India - With Special Reference to Tamil Nadu

Joint Liability Groups (JLGs) has been a noteworthy developmental mechanism in microfinance group-lending model advancing towards uplifting materialistic collateral-less and unbanked poor society in the direction of self-sustainability through easing access to formal financial services with a proposal for self-employment which remained to be pursued as their dream for so long. The present study seeks to document expansionary trend in JLGs and to identify major benefits, constraints and suggestions of JLG member-beneficiaries with purview of supporting further development towards promoting and financing more JLGs in India. Aim: The present study attempts to document the trend in growth of JLGs supported by National Bank for Agriculture and Rural Development (NABARD) in India and to identify major benefits, constraints and suggestions in functioning of JLGs through Bank-Business Corporate (BC) linkage model among its member-beneficiaries which would serve researchers and policy makers to arrive at appropriate measures to expedite advancement in expansion and magnification of trend of JLGs in India. Design of Study: The study employed secondary data from annual publication of NABARD “Status of Micro Finance in India” for 2011-12 to 2019-20 for JLG trend analysis. Following purposive sampling, 3 blocks of Namakkal district were studied during August 2021, purposively selecting Bank-Business Corporate (BC) linkage model and randomly selecting well-experienced 30 member-beneficiary groups. Methodology: The study adopted Compound Annual Growth Rate (CAGR) for JLG trend analysis and Garrett’s ranking procedure to prioritize major benefits, constraints and suggestions of JLG members. Findings: Overall growth rate of India stands at 44.86% in terms of number of JLGs promoted and 60.73% in terms of quantum of JLG loan disbursed. Northern region excels growing at the rate of 62.53% in the former category while Western region exhibits expeditious rate of growth (75.19%) in the latter. Tamil Nadu leads the lane in terms of cumulative quantum of credit disbursed ranking second to Bihar in terms of cumulative number of JLGs promoted in India. Orissa manifests rapid growth among leading five states in both categories cumulatively. With women empowerment socially and economically, easy access to formal credit and better repayment as major benefits of JLG participation, hiking initial loan amount, aiding in identification of microenterprise, training and capacity building in related fields, introducing technological innovation on demand-side and linkage to product marketing and brand promotion on supply side were suggested areas of concern towards encouraging massive promotion of JLGs..

Stiffness compensation through matching buckling loads in a compliant four-bar mechanism

In this paper a novel alternative method of stiffness compensation in buckled mechanisms is investigated. This method involves the use of critical load matching, i.e. matching the first two buckling loads of a mechanism. An analytical simply supported four-bar linkage model consisting of three rigid links and four torsion springs in the joints is proposed for the analysis of this method. It is found that the first two buckling loads are exactly equal when the two outer springs are three times stiffer than the two inner springs. The force-deflection characteristic of this linkage architecture showed statically balanced behavior in both symmetric and asymmetric actuation. Using modal analysis, it was shown that the sum of the decomposed strain energy per buckling mode is constant throughout the motion range for this architecture. An equivalent lumped-compliant four-bar mechanism is designed; finite element and experimental analysis showed near zero actuation forces, verifying that critical load matching may be used to achieve significant stiffness compensation in buckled mechanisms.

Application of the SWAT-EFDC Linkage Model for Assessing Water Quality Management in an Estuarine Reservoir Separated by Levees

Estuarine reservoirs are available for use in various water resource systems. In agriculture, supplying irrigation water that meets water quality standards is essential for food safety. This study focused on the Ganwol estuarine reservoir in the midwestern region of South Korea, which suffers from water quality deterioration problems. To explore the water quality improvement in an estuarine reservoir, it is essential to understand the characteristics of water quality changes in the reservoir following water pollution control management. Therefore, the purpose of this study is to evaluate the effects of water quality management on the estuarine reservoir, which is separated by levees, using the soil and water assessment tool (SWAT)-environmental fluid dynamics code (EFDC) linkage model. In this study, soil remediation by dredging the reservoir’s bottom soil and effluent control from public sewage treatment works were considered as the water management plans. The results of this study indicate that reducing the internal load of the reservoir increases internal resilience and reducing the external inflow load decreases the impact on the system. Hence, comprehensive measures are effective in improving water quality.

A particle-linkage model for elongated asteroids with three-dimensional mass distribution

ABSTRACT The goal of this paper is to develop a simplified model to describe the gravitational fields of elongated asteroids. The proposed model consists of representing an elongated asteroid using a triple-particle-linkage system distributed in the three-dimensional space and it is an extension of previous planar models. A nonlinear optimization method is used to determine the parameters of our model, minimizing the errors of all the external equilibrium points with respect to the solutions calculated with a more realistic approach, the Mascon model, which are assumed to give the real values of the system. The model considered in this paper is then applied to three real irregular asteroids: 1620 Geographos, 433 Eros, and 243 Ida. The results show that the current triple-particle-linkage three-dimensional model gives better accuracy when compared to the axisymmetric triple-particle-linkage model available in the literature, and provides an advantage in terms of accuracy over the mass point model, while keeping computational time low. This model is also used to carry out simulations to characterize regions with solutions that remain bounded or that escape from around each asteroid under analysis. We investigated initial inclinations of 0° (direct orbits) and 180° (retrograde orbits). We considered the gravitational field of the asteroid, the gravitational attraction of the Sun, and the SRP. Our results are then compared to the results obtained using the Mascon gravitational model, based on the polyhedral shape source. We found good agreement between the two models.

Cooperation and Innovation in Data Linkage Creates A Linked, Multi-Sectoral Data Repository for Western Australia – The SIDR Project

IntroductionDuring 2019, the Western Australian (WA) government and Curtin University’s Centre for Data Linkage (CDL) created a large, de-identified researchable database – the Social Investment Data Resource (SIDR) – to support government in delivering targeted early interventions to young offenders and their families to reduce the likelihood of re-offending (the Target 120 program). Objectives and ApproachSIDR brings together administrative data from health, education, justice, child protection, disability and housing sectors. The linked, de-identified data provides an invaluable resource for actuarial assessment and social investment analytics to assess long-term costs and benefits of the Target 120 program. SIDR also provides an invaluable tool for academic research. SIDR adopted a distributed linkage model where linkage workload was shared between the Department of Health Data Linkage Branch who create and maintain the WA Data Linkage System (WADLS) and the CDL. Design elements of the model included a common spine (embedded into the infrastructure of both groups), methods for leveraging quality from WADLS, and inclusion of family relationships data from the WA Family Connections database. The linkage model within SIDR uses a combination of traditional and privacy-preserving record linkage (PPRL) methods. PPRL does not require release of personal identifiers; instead, data is irreversibly hashed prior to release for probabilistic linkage. ResultsThrough cooperation (distributed linkage) and innovation (a mix of traditional and PPRL linkage), the project has delivered a large, linked, cross-sectoral data resource for policymakers and researchers. Sharing of the linkage workload maximised the capacity and unique capabilities of each linkage unit. PPRL enabled ‘hard to get’ datasets from justice to be included. SIDR is being updated in 2020. Conclusion / ImplicationsSIDR provides a resource for whole-of-government policy development, service evaluation, academic research and social investment analytics for T120 and beyond. The SIDR linkage model has potential for adaptation and use elsewhere.