Search Results (8)

Wooden or bamboo fences, commonly used for coastal protection, have limited effectiveness in reducing wave height due to their porous structure, which provides only moderate wave damping. To address this issue, our study proposes a modification that retains these fences while strategically incorporating submerged rocks, similar to gabions, to exploit friction and achieve significant wave height reduction. We employed a mathematical model based on modified Shallow Water Equations to investigate the wave attenuation. A key measure, the wave transmission coefficient ($K_t$), for quantifying wave height reduction was determined using both analytical and numerical methods. The numerical $K_t$ obtained from simulations was $0.2831$, whereas the analytically computed $K_t$ value was $0.2622$, which indicates a reduction of over 70% in the initial wave amplitude due to the combined effect of submerged rocks and wooden fences. These results, which align closely with experimental data, validate the credibility of our approach. A detailed sensitivity analysis illustrates the effectiveness of both wooden fences and submerged rocks in attenuating wave height, which depends on structure dimensions and friction coefficients. Optimization studies present various optimal structures, underscoring the critical role of the structure’s friction coefficient in minimizing the wave transmission coefficient, and recommend the use of rough materials for optimal wave height reduction. In summary, our paper offers a robust exploration of an innovative coastal protection strategy that integrates wooden fences and rocks. The validated model, supported by analytical, numerical, and experimental evidence, has the potential to provide practical insights for coastal engineers seeking efficient wave attenuation solutions. Full article

Microorganisms are one of the most critical factors involved in the degradation of buildings. Fungi that develop in historic spaces not only cause the degradation of monuments (immovable and movable) but can also negatively affect those who visit or use such spaces. This article is a case study of the 16th-century St. Catherine Church in Cięcina (Poland), whose walls became severely damp as a result of changes made to the church’s surroundings (relocation of the riverbed of the Cięcinka River, raising the level of St. Catherine Street and building a wooden fence on a concrete foundation around the church). The effect of the severe dampness of the building was the intensive development of Serpula lacrymans fungus and mold. This article highlights the importance of a multidisciplinary approach to hazard diagnosis in historic buildings. Full article

The aim of this article is to assess which elements of street design impact subjective well-being in the central area of a city in southern Chile, based on residents’ perceptions. Fifty-six semi-structured walking interviews were conducted to obtain records of pedestrians’ self-reported perceptions of their environment. To categorize the emotions reported in the interviews, the Circumplex Model of Affect was used to organize and classify the declared emotions. The results revealed that street design elements such as heritage buildings with well-maintained facades with intense colors in their coatings, spacious front gardens, wooden facades, low fences, wide sidewalks, soft or rubberized floors, and trees with colorful fruits and leaves promote a greater dominance of high-intensity positive emotions such as enjoyment, joy, happiness, liking, and pleasure. In contrast, neglected or abandoned building facades, blind fronts with graffiti or murals, high fences, tall buildings, treeless or vegetation-free sidewalks, untrimmed bushes, and narrow and poorly maintained sidewalks promote negative emotions of both high and low activation such as fear, anger, dislike, rage, unsafety, discomfort, and stress. The article concludes with the development of an emotional map of momentary experiences, identifying places of well-being and discomfort in public spaces. The value of this map is discussed as a tool to inform urban design in the promotion of healthier pedestrian environments in Latin American cities. Full article

Sediment barriers are used on construction sites to protect downstream waterbodies from the impacts of sediment-laden stormwater runoff. Although ubiquitous on construction sites, many sediment barrier practices lack performance-based testing to determine effectiveness and treatment mechanisms, with previous evaluations being limited to conditions local to the Southeastern U.S., with conditions in other regions remaining untested. Testing was conducted to determine the effectiveness of woven silt fence barriers and provide structural improvements to common installation methods. Testing was conducted using a large-scale sediment barrier testing apparatus at the Auburn University—Stormwater Research Facility. The results from testing indicate that Nebraska DOT standard silt fence installations can be improved to reduce the risk of structural failures such as undermining, complete installation failure, slow dewatering, and overtopping. To improve structural performance, four modifications (a 15.2 cm [6 in.] offset trench, wooden posts, a dewatering board with an overflow weir, and a dewatering board with an overflow weir with adjusted post spacing) were tested. On average, 83% of introduced sediment was retained behind the tested barriers. The water quality results across the testing of standard and modified installations indicated that stormwater treatment was due to sedimentation within the impoundment formed by silt fence installations and not filtration through geotextile fabric. Full article

The Moose Horn Pass Caribou Fence site (KjRx-1) consists of three wooden fences located in a remote area of the Mackenzie Mountains in Canada’s Northwest Territories. Situated in the traditional homeland of the Shúhtagot’ine (Mountain Dene), they were used to assist past hunters to harvest northern mountain caribou by channeling multiple animals toward kill zones. The main fence is nearly 800 m in length and terminates in a corral structure after descending from high ground into a valley. The two smaller fences are located north and south of the main fence, and they do not descend into the valley. Standard dendrochronological methods were employed to determine the ages of wood taken from the fence structures. Seventy-five living white spruce (Picea glauca) trees in the area were cored to determine the overall tree-ring growth patterns in the local environment. The chronology of living trees was supplemented by the inclusion of 29 standing-dead trees to establish a longer chronology of dated ring widths. Sixty-two of 89 cross-sections cut from the fence timbers were crossdated and added to the overall chronology, which created a well-replicated chronology of ring-widths from 972 to 2016 C.E. The terminal dates of material from the three fence systems suggest that the complex was built from trees that died over a wide temporal period, spanning the years 1314 to 1876 C.E, with clusters of dates between ca. 1420–1480 and 1580–1750 C.E. The millennial-long chronology developed in this study can now be used as a base to assist in dendroarchaeological dating of many more artifacts from the region. Full article

In the construction industry, a variety wooden products have been used for thousands of years, according to demand, accessibility/availability, and customers’ requirements. Wood is a preferred material due to its large range of properties, depending on the type of wood. It is an easily available and economically competitive material, and it is also extremely strong in relation to its weight. Therefore, it is used in the production of construction materials, building parts, and finishing components, as well as for furniture and decorative elements. Each of these products is commonly additionally chemically treated in order to improve its performance parameters. However, impregnated wooden products such as furniture and fence boards are often misused, including for house heating, waste incineration, bonfires, etc. For this reason, among the products of combustion, there is a whole range of different chemical compounds, frequently carcinogenic, and dangerous for health and the environment, for example, heavy metals. Knowledge in this field is important for professions, such as: firefighter, lifeguard, people dealing with environmental management, and units responsible for waste landfills. On the other hand, important recipients of this information are ordinary residents who, due to a lack of knowledge, use such materials as e.g., heating material. Full article

Wooden fences are applied as a nature-based solution to support mangrove restoration along mangrove coasts in general and the Mekong Delta coast in particular. The simple structure uses vertical bamboo poles as a frame to store horizontal bamboo and tree branches (brushwood). Fence resistance is quantitatively determined by the drag coefficient exerted by the fence material on the flow; however, the behaviour of drag is predictable only when the arrangement of the cylinders is homogeneous. Therefore, for more arbitrary arrangements, the Darcy–Forchheimer equations need to be considered. In this study, the law of fluid flow was applied by forcing a constant flow of water through the fence material and measuring the loss of hydraulic pressure over a fence thickness. Fences, mainly using bamboo sticks, were installed with model-scale and full-scale diameters applying two main arrangements, inhomogeneous and staggered. Our empirical findings led to several conclusions. The bulk drag coefficient ( $\overline{C_D}$ ) is influenced by the flow regime represented by Reynolds number. The drag coefficient decreases with the increase of the porosity, which strongly depends on fence arrangements. Finally, the Forchheimer coefficients can be linked to the drag coefficient through a related porosity parameter at high turbulent conditions. The staggered arrangement is well-predicted by the Ergun-relations for the Darcy–Forchheimer coefficients when an inhomogeneous arrangement with equal porosity and diameter leads to a large drag and flow resistance. Full article

A novel re-formative polymer composite manufacturing route has been developed by UK and Qatar-based Universities. This novel process recycles domestic-waste thermoplastic material, without the requirement for intensive filtering or washing operations. The produced polymer can be reinforced with recycled glass fibres, forming a structurally load-bearing composite, which may potentially be suitable for use in applications, including utility poles, railway sleepers, and fencing. Thus, infra-red (IR) analysis showed the presence of polypropylene (PP), polyethylene (PE), and polyethylene terephthalate (PET) in the commingled material. Differential scanning calorimetry (DSC) was used to determine glass transition temperatures and melting temperatures of each of the associated polymer types. Dynamic mechanical thermal analysis (DMTA) was used to determine the storage and loss modulus of the bulk commingled component. Lastly, flexural and tensile strengths of the re-formative polymer with differing proportions of glass fibre were assessed, giving a range of strengths at each glass fibre proportion for possible compositional variation in the polymer type. The recycled polymer is considered a viable structural material for replacing both wooden and concrete components, generating a polymer recycling route with concomitant environmental benefits. This plastic recycling route therefore offers a solution towards achieving climate change targets with a purposeful end-product component. Full article