An assembly-oriented novel low-carbon masonry building method with unfired 3D printed earthen blocks

Conventional earthen building methods such as cob and adobe are relevant for developing countries but labour-intensive, expensive and slow for developed countries. Automation in construction has been increasingly favourable in developed countries, especially buildings constructed with 3D printed cementitious materials. 3D printed earthen materials demonstrate a better environmental performance compared to 3D printed cementitious materials due to the energy intensive manufacturing of cement. Moreover, conventional earthen methods, such as cob, create earthen buildings with solid sections while 3D printing allows a hollow section and various infill designs using less material. Despite the benefits, the research on the mechanical strength of 3D-printed earthen structures is still limited. The lack of data on the mechanical performance of 3D printed earthen structures, is one of the obstacles preventing the mainstream construction industry from approaching this novel building method. Our research investigates an assembly-oriented novel low-carbon masonry building method with unfired 3D-printed earthen blocks and explores its adaptability to the mainstream construction industry with a critical comparison based on mechanical properties

The Power of Poincar\'e: Elucidating the Hidden Symmetries in Focal Conic Domains

Focal conic domains are typically the "smoking gun" by which smectic liquid crystalline phases are identified. The geometry of the equally-spaced smectic layers is highly generic but, at the same time, difficult to work with. In this Letter we develop an approach to the study of focal sets in smectics which exploits a hidden Poincar\'e symmetry revealed only by viewing the smectic layers as projections from one-higher dimension. We use this perspective to shed light upon several classic focal conic textures, including the concentric cyclides of Dupin, polygonal textures and tilt-grain boundaries.Comment: 4 pages, 3 included figure

Socio-economic factors Influencing Infant and Child Mortality among the Zou of Manipur

The present study was conducted to find out the influence ofsocio-economic factors on infant and child mortality among the Zou,a tribal population of Manipur. A cross-sectional study was executedamong 533 mothers of age 17- 49 years following house to housevisits from December 2016 to February 2017. The finding showsthere is a significant correlation of the educational level of themother, household income, child immunization to that of infant andchild mortality in the study population

Minimal resonances in annular non-Euclidean strips

Differential growth processes play a prominent role in shaping leaves and biological tissues. Using both analytical and numerical calculations, we consider the shapes of closed, elastic strips which have been subjected to an inhomogeneous pattern of swelling. The stretching and bending energies of a closed strip are frustrated by compatibility constraints between the curvatures and metric of the strip. To analyze this frustration, we study the class of "conical" closed strips with a prescribed metric tensor on their center line. The resulting strip shapes can be classified according to their number of wrinkles and the prescribed pattern of swelling. We use this class of strips as a variational ansatz to obtain the minimal energy shapes of closed strips and find excellent agreement with the results of a numerical bead-spring model. Within this class of strips, we derive a condition under which a strip can have vanishing mean curvature along the center line.Comment: 14 pages, 13 figures. Published version. Updated references and added 2 figure

Robotic 3D printing with earth: A case study for optimisation of 3D printing building blocks

The interest in 3D printed earthen buildings in developed countries has increased due to the demand for healthy, comfortable and sustainable buildings constructed with low carbon materials and laboursaving methods. However, the amount of research about this field is still limited. Our research aims to contribute to this field by optimising the robotic 3D printing process by investigating issues such as buckling while printing, adequate soil mix recipe for printing, print and extrusion speed calibration. This paper illustrates the process and the results of the temporary research project and the Robotic Cob Printing Workshop with MSc Computational Methods in Architecture (CMA) students at the Welsh School of Architecture, Cardiff University, in March 2022. The project aims to achieve structural stability with less material by using the geometry and the infill of the building block while exploring the role of computational design, robotic extrusion and material understanding in robotic 3D printing with earth as a low-carbon novel building method

Topological mechanics of origami and kirigami

Origami and kirigami have emerged as potential tools for the design of mechanical metamaterials whose properties such as curvature, Poisson ratio, and existence of metastable states can be tuned using purely geometric criteria. A major obstacle to exploiting this property is the scarcity of tools to identify and program the flexibility of fold patterns. We exploit a recent connection between spring networks and quantum topological states to design origami with localized folding motions at boundaries and study them both experimentally and theoretically. These folding motions exist due to an underlying topological invariant rather than a local imbalance between constraints and degrees of freedom. We give a simple example of a quasi-1D folding pattern that realizes such topological states. We also demonstrate how to generalize these topological design principles to two dimensions. A striking consequence is that a domain wall between two topologically distinct, mechanically rigid structures is deformable even when constraints locally match the degrees of freedom.Comment: 5 pages, 3 figures + ~5 pages S