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WOOD though in many ways an attractive structural material has the disadvantage of being water absorbent. In itself this characteristic would be of minor significance were it not for the fact that it is accompanied by considerable swelling at right angles to the axes of the wood fibres. Great interest is being shown at the present time in the possibility of reducing this swelling by the use of synthetic resins. In this article the possibility of preventing swelling by such means is discussed and it is concluded that complete immunity from swelling could only be attained at the expense of the strength of the wood. The article gives an original analysis which enables the magnitude of swelling to be predicted and the expression derived is shown to be in agreement with experiment.

The estimation of bearing capacity for shallow foundations in swelling soil is an important and complex context. The complexity is due to the unsaturated swelling soil related to the drying and humidification environment. Hence, a serious study is needed to evaluate the effect of swelling potential soil on the foundation bearing capacity. The purpose of this paper is to analyze the bearing capacity of a rough square foundation founded on a homogeneous swelling soil mass, subjected to vertical loads.

A proposed numerical model based on the simulation of the swelling pressure in the initial state, followed by an elastoplastic behavior model may be used to calculate the foundation bearing capacity. The analyses were carried out using the finite-difference software (FLAC 3 D) with an elastic perfectly plastic Mohr–Coulomb constitutive model. Moreover, the numerical results obtained are compared with the analytical solutions proposed in the literature.

The numerical results were in good agreement with the analytical solutions proposed in the literature. Also, reasonable capacity and performance of the proposed numerical model.

The proposed numerical model is capable to predict the bearing capacity of the homogeneous swelling soil mass loaded by a shallow foundation. Also, it will be of great use for geotechnical engineers and researchers in the field.

This paper aims to investigate the sealing characteristic of the rubber X-ring combined seal used in high-pressure hydrogen service and clarify the effect of swelling due to dissolved hydrogen on the sealing behavior.

A finite element analysis method with a user subroutine is proposed to investigate the sealing characteristic of rubber X-ring seals in conjunction with the swelling effect.

The swelling has a noticeable impact on the sealing behavior. The higher peak contact stress suggests that the X-ring seal may be superior to the O-ring seal, while the calculated increase in Mises stress suggests the X-ring exhibits a higher propensity to mechanical damage under low pressure conditions.

This paper describes a method with a user subroutine developed within ABAQUS to simulate the sealing performance coupled hydrogen swelling. The suitability of X-ring seals is evaluated. This work provides insight into the swelling effect on sealing behavior of an X-ring, which is of great value for the design and application of rubber seals used in hydrogen service.

The purpose of this paper is to evaluate the possible use of oil shale as a soil stabilizing agent for expansive soils.

An experimental work has been fulfilled to investigate the influence of oil shale ash (OSA) on the geotechnical behavior of the expansive soil of Irbid, Jordan. Three swelling-shrinkage soils were considered in this study along with various percentages of OSA varying at 2, 4, 6, 8, 10 and 12 per cent by dry weight of the soil. A series of laboratory tests were conducted on the soil samples before and after mixing it with OSA. These tests were soil classification, Atterberg limits, compaction test, falling head permeability test, unconfined compression test, free swelling, swelling pressure and California bearing ratio (CBR) test.

Laboratory tests results indicated that OSA is effective in improving the texture and strength of the treated soil by reducing plasticity index, swelling potential and swelling pressure and moderately enhancing soil strength properties including the unconfined compressive strength (q_u), maximum dry unit weight (γ_d-max.) and CBR test.

OSA showed potential as a low-cost soil stabilizing agent for swell-shrink soils.

This article focuses on the comparative study of annular wire‐coating flows with polymer melt materials. Different process designs are considered of pressure‐ and tube‐tooling, complementing earlier studies on individual designs. A novel mass‐balance free‐surface location technique is proposed. The polymeric materials are represented via shear‐thinning, differential viscoelastic constitutive models, taken of exponential Phan‐Thien/Tanner form. Simulations are conducted for these industrial problems through distributed parallel computation, using a semi‐implicit time‐stepping Taylor‐Galerkin/pressure‐correction algorithm. On typical field results and by comparing short‐against full‐die pressure‐tooling solutions, shear‐rates are observed to increase ten fold, while strain rates increase one hundred times. Tube‐tooling shear and extension‐rates are one quarter of those for pressure‐tooling. These findings across design options, have considerable bearing on the appropriateness of choice for the respective process involved. Parallel finite element results are generated on a homogeneous network of Intel‐chip workstations, running PVM (Parallel Vitual Machine) protocol over a Solaris operating system. Parallel timings yield practically ideal linear speed‐up over the set number of processors.

The casts sector is an important sector for orthopaedic textile products. Plaster and plastics casts are widely used in hospitals, pharmacies and health care centers, but they are heavy, not washable and do not offer a suitable fixation for bone fractures (e.g. hand wrist), especially when operated under different swelling conditions. After decreasing of the swelling, the cast is in a hard form and the stabilization effect of the cast is insufficient due to the occurring of distance between the skin and the cast. The purpose of this paper is to develop a new pneumatic cast that depends on Polyvinylchlorid coated fabric as an outer layer, skin friendly internal layers, an air chamber, and metal braces.

For more comfort, the cast is anatomically formed and the internal layers are made of cotton‐viscose fabrics and Polyester spacer fabrics. The pressure on the injured part can be controlled by using a pneumatic structure.

The characteristics of the developed pneumatic cast are found to be: easy to use, comfortable, washable, and light weight.

The paper describes the development of a new pneumatic cast that can overcome the difficulties of cast fixation with the injured part of the body: an economic product, that should be easy to use, light weight, comfortable, skin friendly, water resistant, easy to clean, and affordable.

This paper aims to develop a novel micro-ablation system to realise micrometric and well-defined hydrogel structures. To engineer a tissue it is necessary to evaluate several aspects, such as cell-cell and cell-substrate interactions, its micro-architecture and mechanical stimuli that act on it. For this reason, it is important to fabricate a substrate which presents a microtopology similar to natural tissue and has chemical and mechanical properties able to promote cell functions. In this paper, well-defined hydrogel structures embedding cells were microfabricated using a purposely developed technique, micro-laser ablation, based on a thulium laser. Its working parameters (laser power emission, stepper motor velocity) were optimised to produce shaded “serpentine” pattern on a hydrogel film.

In this study, initially, swelling/contraction tests on agarose and alginate hydrogel in different solutions of main components of cell culture medium were performed and were compared with the MECpH model. This comparison matched with good approximation experimental measurements. Once known how hydrogel changed its topology, microstructures with a well-defined topology were realised using a purposely developed micro-laser ablation system design. S5Y5 neuroblastoma cell lines were embedded in hydrogel matrix and the whole structure was ablated with a laser microfabrication system. The cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam.

The hydrogel structure is able to reproduce extracellular matrix. Initially, the hydrogel swelling/contraction in different solutions, containing the main components of the most common cell culture media, was analysed. This analysis is important to evaluate if cell culture environment could alter microtopology of realised structures. Then, the same topology was realised on hydrogel film embedding neuronal cells and the cells did not show damages due to mechanical stress present in the hydrogel matrix and to thermal increase induced by the laser beam. The interesting obtained results could be useful to realise well-defined microfabricated hydrogel structures embedding cells to guide tissue formation

The originality of this paper is the design and realisation of a 3D microfabrication system able to microfabricate hydrogel matrix embedding cells without inducing cell damage. The ease of use of this system and its potential modularity render this system a novel potential device for application in tissue engineering and regenerative medicine area.

Introduction As long ago as 18411 it was known that trees can cause movements of adjacent ground if the soil contains appreciable quantities of clay. However, it is in comparatively recent times that researchers in the UK have attempted to understand how the process of tree‐induced ground volume change comes about. In the first instance, studies were inspired at the Building Research Station, immediately following the Second World War, by investigations of claims for compensation for bomb damage that revealed the close proximity of trees to buildings that were remote from locations where bombs had fallen. These studies concentrated on establishing the ability of vegetation to dry the ground, and on determining the depth at which building foundations should be placed to prevent damaging movements occurring through the action of light vegetation. This early work also pointed out the risks of subsidence from tree root activity and the need for deeper, piled foundations when building close to trees. Though several BRS publications were issued, the problem was not widely appreciated.

A fully coupled numerical model to simulate the complex behaviour of soil deformation, water flow, airflow, and heat flow in porous media is developed. The following thermal effects are taken into account: heat transfer through conduction and convection, flow, as well as viscosity and density variation of the fluids due to temperature gradients. The governing equations in terms of soil displacements, water and air pressures, and temperature are coupled non‐linear partial differential equations and are solved by the finite element method. Two examples are presented to demonstrate the model performances.

The purpose of this paper is to introduce the numerical methods in tunnel engineering and their capabilities to indicate the fracture and failure in all kinds of tunneling methods such as New Austrian Tunneling Method, tunnel boring machine and cut‐cover. An essential definition of numerical modeling of tunnels to determine the interaction between geo‐material (soil and rock) surrounding the tunnel structure is discussed.

Tunnel geo‐material (soil and rock) interaction requires advanced constitutive models for the numerical simulation of linear, nonlinear, time‐dependent, anisotropic, isotropic, homogenous and nonhomogeneous behaviors. The numerical models discussed in this paper are developed in finite element method (FEM), finite deference method (FDM), boundary element method and discrete element method and these tools are used to illustrate the behavior of tunnel structure deformation under different loads and in complicated conditions. The disadvantage of this method is the tunnel lining assumed an independent structure under fixed load which is unable to model soil‐lining interaction. Predicting the effect of all natural factors on tunnels is the most difficult method. The above‐mentioned numerical methods are very simple and quick to use and the results are conservative and practical for users. One of the most significant advantages of the numerical method is in predicting the critical area surrounding the tunnel and the tunnel structure before making the tunnel construction due to different loads.

Numerical modeling is used as control method in reducing the risk of tunnel construction failures. Since some factors such as settlement and deformation are not completely predictable in rock and soil surrounding the tunnel, using numerical modeling is a very economical and capable method in predicting the behavior of tunnel structures in various complicated conditions of loading. Another benefit of using numerical simulation is in the colorful illustrations predicting the tunnel behavior before, during and after construction and operation.

There are not many conducted studies using numerical models to tunnel structures that estimate the critical zones. As some of the methods available have limitation in simulating and modeling the whole tunnel design factors, numerical modeling seems to be the best option, because it is fast, economical, accurate and more interesting in predicating critical zones in tunnel. However, what softwares predict are not always the same as real ground nature conditions in which there is tunnel.