Natural substrates like sand, soil, leaf litter and snow vary widely in penetration resistance. To search for principles of appendage design in robots and animals that permit high performance on such flowable ground, we developed a ground control technique by which the penetration resistance of a dry granular substrate could be widely and rapidly varied. The approach was embodied in a device co...

Studies on the effects of off-road driving on soils were conducted in the Makuleke Contractual Park of the Kruger National Park. The studies were conducted on three different soils with different textures and soil compactibilities. Traffic pressure was applied with a game drive vehicle loaded with 11 sand bags, each weighing 70 kg. This gave a total vehicle mass of 3,795 kg, simulating a vehicl...

The potential health risk from exposure to chemically contaminated soil can be assessed from bioavailability studies. The aims of this research were: (a) to determine the dermal bioavailability of contaminants in soil for representatives of the polycyclic aromatic hydrocarbon class of chemicals, namely, benzo(a)pyrene and naphthalene, and (b) to examine the relative contribution of soil matrix ...

One of the most valid and efficient models of long rod projectile penetration in homogeneous targets is Tate and Alekseevskii’s (A&t) model. Based on Tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. The proposed collision speed-penetration depth diagrams are developed using Tate’s model. In this way, va...

The work is a primary approach to grab attention on probability of liquefaction hazard in Rangpur City Corporation area. The investigated area of Rangpur was suspected to have high liquefaction potential since the foundation soil consists of loose sandy silt with a very shallow aquifer. Standard Penetration Test (SPT), which follows the general format of the Seed-Idriss simplified procedure for...

The efficiency of ground-based antennas is highly determined by the power dissipated in the ground plane, which can be separated into H-field and E-field losses. In this paper, a new approach is presented for the separation of ground losses that is based on Joule's law. It is theoretically valid at any frequency. Nevertheless, some simplifications can be applied in the lowand medium-frequency b...

Multiple antibiotic resistant bacterial pathogens pose a major threat for the successful therapeutic use of antibiotics in human and veterinary medicine. Veterinary antibiotics used in animal husbandry are assumed to contribute to an increased antibiotic resistance among bacteria in manure. Bacteria carrying transferable antibiotic resistances, antibiotics, metabolites and nutrients are inevita...

In this review, we examine how roots penetrate a structured soil. We first examine the relationship between soil water status and its mechanical strength, as well as the ability of the soil to supply water to the root. We identify these as critical soil factors, because it is primarily in drying soil that mechanical constraints limit root elongation. Water supply to the root is important becaus...

Subsoil compaction can result in unfavourable soil physical conditions and hinder the root growth of maize. The effects of deep tillage and conventional tillage on soil physical properties and root growth of maize were studied during 2010–2011 at two sites (loam at Hebi and clay at Luohe) in central China. The results showed that soil penetration resistance, bulk density, water content and root...