Elastic mechanisms are fundamental to fast and efficient movements. Mantis shrimp power their fast raptorial appendages using a conserved network of exoskeletal springs, linkages and latches. Their appendages are fantastically diverse, ranging from spears to hammers. We measured the spring mechanics of 12 mantis shrimp species from five different families exhibiting hammer-shaped, spear-shaped ...

Like most other fundamental mechanical components which form the basis of many mechanical systems, springs have existed since the Bronze Age for storage or release of energy, absorption or utilization of vibration, relaxation or absorption of impact force and when unloaded, return to the original position or to the original shape. Quality, service requirement, performance as well as durability ...

The leaf spring is widely used in automobiles and one of the components of suspension system. It needs to have excellent fatigue life. As a general rule, the leaf spring must be regarded as a safety component as failure could lead to severe accidents. The purpose of this paper is to predict the fatigue life of semi-elliptical steel leaf spring along with analytical stress and deflection calcula...

Abstract: It is difficult to weigh the light objects by weighing balance accurately when measured individually. If several light objects are weighed in groups rather than individually then the precision of the estimates increases quite considerably. There are two types of balances one is chemical balance and other is spring balance. Spring balance is similar when only one pan of chemical balanc...

We would like to welcome our readers to the twenty-eighth issue of 49 th Parallel and our second of 2012. In the last few months there have been some exciting developments at the journal and we hope that 49 th Parallel will continue to flourish in the future. We would like to welcome our new Articles Editor, Galateia Demetriou, to the 49 th Parallel team. Galateia is a second year doctoral rese...

THE RESPONSE of hitherto known practical forms of seismographs depends upon the relative motion of a pendulum and the moving ground to which ~ts supporting structure is fastened. The various kinds of seismographs differ in the type of pendulum used, such as gravity, spring, torsion, and/or they differ in the type of magnifying and recording elements which they employ. They all measure or indica...

There are approximately 470,000 km(2) of karst aquifers that feed many large springs in North China. Turbulent flow often exists in these karst aquifers, which means that the classical ground water model based on Darcy's law cannot be applied here. Ground water data are rare for these aquifers. As a consequence, it is difficult to quantitatively investigate ground water flow in these karst syst...

Beijing’s mountainous areas have an important ecological significance because they are ecological conservation and water source protection areas of Beijing. The impact of precipitation on the vegetation coverage of Beijing’s mountainous areas is qualitatively analyzed using multi-temporal Landsat images obtained during the last 20 years. Firstly, the influence of external factors, such as pheno...

We investigated the flexibility of body composition in relation to seasonally variable demands for endurance flight capacity and hyperphagia in a migratory shorebird. Migrating western sandpipers were sampled in spring and fall while refueling at a north temperate stopover and were compared with nonmigrating birds captured at a tropical wintering area in Panama. Sandpipers weighed 25% more at s...