Illuminating the genetic relationships within soldier-producing aphid colonies is an essential element of any attempt to explain the evolution of the altruistic soldier caste. Pemphigus spyrothecae is a soldier-producing aphid that induces galls on the leaf petioles of its host (trees of the genus Populus). At least a quarter of the aphids within the clonally produced gall population are morpho...

1. Polyembryonic parasitoid wasps in the family Encyrtidae (Hymenoptera) have evolved a caste system consisting of morphologically and functionally distinct larvae called soldiers and reproductives. 2. Two selective pressures are thought to underlie the evolution of the soldier caste: defence against competitors and resolution of the sex ratio conflict. Previous studies also indicate that soldi...

Future capabilities of battle command systems and networked systems will increase Soldier situational awareness by providing access to information from various networked assets. We conducted a series of experiments at the United States Army Research Laboratory in Adelphi, MD and at C4ISR On-the-move (OTM) at Ft. Dix, NJ. Based on the quality of service of battle command systems, the Soldier wil...

The indispensable vital structure in any harbor is a breakwater in order to make available calm water region inshore. Pile breakwater can be employed as a small coastal protection structure where tranquility required is low. This study is concerned with CFD study on the performance of perforated hollow pile to dissipate wave energy and the novelty of this investigation is the role of perforatio...

Determination of the pile capacity is always a major concern for the safe geotechnical engineering design. Different direct and indirect methods have been proposed for determining pile bearing capacity such as static and dynamic approaches. Each method depends on the condition of the soil and type of pile as well as accessibility to necessary information. In this study bearing capacity of drive...

Abstract—Excavation and retaining walls are of challenging issues in civil engineering. In this study, the behavior of one important type of supporting systems called Contiguous Bored Pile (CBP) retaining wall is investigated using a physical model. Besides, a comparison is made between two modes of free end piles (soft bed) and fixed end piles (stiff bed). Also a back calculation of effective ...

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Simple methods of analysis are developed for computing the dynamic steady-state axial response of floating pile groups embedded in homogeneous and non-homogeneous soil deposits. Physically-motivated approximations are introduced to account for the interaction between two individual piles. It is found that such an interaction arises chiefly from the ‘interference’ of wave fields originating alon...

Impact assessments of offshore wind farm installations and operations on the marine fauna are performed in many countries. Yet, only limited quantitative data on the physiological impact of impulsive sounds on (juvenile) fishes during pile driving of offshore wind farm foundations are available. Our current knowledge on fish injury and mortality due to pile driving is mainly based on laboratory...

An overview of offshore wind turbine (OWT) foundations is presented, focusing primarily on the monopile foundation. The uncertainty in offshore soil conditions as well as random wind and wave loading is currently treated with a deterministic design procedure, though some standards allow engineers to use a probability-based approach. Laterally loaded monopile foundations are typically designed u...