Permeability Measurement of Hot Mix Cold Laid Containing Asbuton as Porous Asphalt

Porous asphalt is a pavement layer structure with aggregate gradations with a coarse fraction greater than 70-85% of the total weight of the mixture so that the resulting structure is more open and porous, which prevents water from stagnating on the road surface reduces water splash and makes the road less slippery. This study aims to analyze the permeability properties of a mixture of hot mix cold laid containing Asbuton in the form of porous asphalt. The research used was an experimental laboratory method. This study used Buton granular asphalt (Buton granular asphalt) with variations in BGA content of 4.5%, 5%, 5.5%, 6%, and 6.5%. The use of BGA is aimed at improving the performance of porous asphalt mixtures without using oiled asphalt. Manufacture of test objects through permeability tests. The results showed that the permeability value for the BGA content of 4.5% was 0.05 cm/s, the BGA content of 5% was 0.06 cm/s, the BGA content of 5.5% was 0.06 cm/s, the BGA content was 6%. is 0.03 cm/s and the BGA content of 6.5% is 0.02 cm/s.

Bilge System Design on 500 GT Ferry for Bulukumba–Selayar Route

A piping system is the main part of a system that connects the point where the fluid is stored to the point of accessing the pipe. Both pipe strength and pump capacity must be carefully considered because the safety of a ship will depend on the piping arrangement as well as on other ship equipment. The main function of the bilge pipe system is the drainage system in case of flooding in the compartment due to grounding or collision. Another function is the drainage system in the event of leaks on the welding root, condensation on the side shell leaks on the piping system (particularly in the engine room), and discharge water due to water-splash over the hatch. This study aimed to design a bilge piping system design using Autopipe Software with ASME B31.3 standard for the piping process. The design phase of the system is collecting data, then determining the load case. After that, selecting components needed for the construction of the system. The following step, making 3-dimensional modeling on Autopipe by entering input based on the determining components. Finally, validating the model, and proceed with the running model according to the specified load case. The result of the running model is the pipe stress level which is described in the stress code in the Autopipe. The final results are 3-dimensional drawings of the system and the number of components needed for constructing the system under Indonesian Classification Bureau (BKI) rules and ASME B31.3 standards for the piping process.

Influence of Texture on Drainability, Splash and Spray in Flexible Pavements

Although the splash and spray phenomenon produced by heavy trucks on road pavements is not a significant issue in relation to traffic safety, it may cause considerable inconveniences for those driving cars or motorbikes. This paper addresses the issue of pavement engineering with regard to surface characteristics; particularly pavement texture and its influence on water mobilization and projection in conditions of wet weather and heavy traffic. Considering the theoretical concept of pavement macrotexture, the analysis starts with the hypothesis concerning a relationship between Mean Profile Depth (MPD) and water splashed during rain. In order to focus on the impact of texture on splash and spray, a field experiment was carried out to test the hypothesis using 5 test tracks on a range of different pavement textures. The experiment was performed using a Traffic Speed Drain Meter (TSDM), which is a new drainability survey device presented to PIARC for approval. This equipment employs the laser and image technology and allows one to simultaneously obtain MPD and water splash data. The results of drainability and MPD were compared for each test track. Having analysed the pavements with different MPD ranges in the experiment, it has been concluded that MPD and water splashed apparently have an inversely proportional relationship. In addition, the TSDM proved to be a suitable equipment (repeatability) at an affordable cost (high performance of data collection). Finally, it has been concluded that there is a way to reduce splash and spray adjusting the infrastructure rather trying to solve the issue modifying vehicle moving modes. Therefore, if the issue is properly addressed by civil engineers and road managers, road safety in the areas of heavy rain may be improved at an affordable cost. The experiment presented here is considered a starting point opening the path for further research.

Factors affecting boxwood blight spread under landscape conditions

We investigated the spread of boxwood blight in a simulated landscape under conducive natural conditions from 2017 to 2019. We used strict sanitation to greatly reduce or eliminate spread by contact. Movement of the pathogen from an infected source plant was limited to one plant, likely spread by means of water splash. Plants were mulched with composted hardwood chips and mulching likely was primarily responsible for limiting spread to only the adjacent plant. Boxwood (Buxus spp.) cultivar susceptibility and fungicide spray programs influenced the incidence of spread and severity of disease; in 2018 and 2019 the more susceptible cultivar had higher disease incidence and severity, respectively, than less susceptible cultivars. Fungicide application only caused a small reduction in disease incidence in 2018. We also demonstrated that spores in clumps could survive extended dry conditions, indicating the importance of sanitation procedures on reducing spread. This experiment demonstrates that boxwood blight can be controlled in a landscape by following best management practices including cultural, sanitation, host susceptibility and fungicide application tactics. Index words: epidemiology, fungicide management, Buxus, chemical disease management, mulch, resistance. Chemicals used in this study: chlorothalonil (Daconil WeatherStik 54.0% F), fludioxonil plus cyprodinil (Palladium 25% and 37.5% WDG), mancozeb (Manzate 80% WP), metconazole (Tourney 50% WDG), propiconazole (ProCon-Z 14.3 L), pyraclostrobin (Insignia 20 WG), pyraclostrobin plus fluxapyroxad (Orkestra Intrinsic 21.26 SC), tebuconazole (Torque 38.7 SC), thiophanate-methyl (Spectro90 50% WP). Species used in this study: boxwood (Buxus L.), boxwood blight (Calonectria pseudonaviculata (Crous, J.Z. Groenew. & C.F. Hill) L. Lombard, M. J. Wingf. & Crous.

Limiting potential COVID-19 contagion in squatting public toilets

Background: Since the outbreak of the SARS-CoV-2 virus in December 2019, the COVID-19 pandemic continues to threaten global stability. Transmission of SARS-CoV-2 is mostly by respiratory droplets and direct contact but viral RNA fragments have also been detected in the faecal waste of patients with COVID-19. Cleanliness and effective sanitation of public toilets is a concern, as flushing the toilet is potentially an aerosol generating procedure. When the toilets are of the squatting type and without a cover, there exists a risk of viral contamination through the splashing of toilet water and aerosol generation. Objective: This study aims to determine whether the cleanliness of public toilets was a concern to the general population during the COVID-19 pandemic, and whether a squatting toilet was preferred to a seated design. Methods: A questionnaire was designed and posted on “WeChat” contact groups of the investigators. Results: The survey showed that 91% of participants preferred squatting toilets, but that 72% were apprehensive of personal contamination when using public toilets. Over 63% of the respondents had encountered an incidence of water splash and would prefer public toilets to be covered during flushing and 83% of these respondents preferred a foot-controlled device. Conclusion: This survey suggests that consideration should be given to the installation of a simple foot-controlled device to cover public squatting toilets to help restrict potential COVID-19 contamination and to meet hygienic expectations of the public.

Design and analysis of a waterproof capacitive touch key sensor interface circuit

Traditional mechanical keys are gradually replaced with touch keys. Capacitive touch keys have advantages in achieving higher sensitivity with a longer service life and lower cost. Hence, the capacitive touch key technology is widely used in consumer electronic products. In use of household electric appliances, such as electric kettle, induction cooker and exhaust hood, sometimes the water vapor would condense into visible moisture or even the water would splash out of the pot when overheated, which may lead to a falsely trigger of touch key. So, waterproof becomes a big challenge in household electric appliances. This paper analyzes how water affects capacitive touch key and proposes a waterproof capacitive touch key sensor interface circuit to overcome the challenge. Sensing of touch key capacitor would be influenced only when water covers more than two touch keys. Compensating channels working in certain strategy are used to decrease the influence of water. For the same water capacitor, the bigger threshold voltage, the bigger change of the counting number. A much smaller threshold voltage is better to further weak the effect of water. The circuit is implemented in a standard 110 nm CMOS process. The measured results show that the touch Signal to Noise and Water Disturb Ration (SNWDR) is 20.7 dB which proves that the proposed waterproof capacitive touch key sensor interface circuit is effective against water splash.

Research on hydrodynamic characteristics of cylinder planing

This paper selects SST k-w turbulence model and VOF wave to construct a numerical calculation model of moving body planning on a flat free surface based on STAR-CCM+ numerical simulation software. The construction model is checked through foreign classic literature, and the numerical simulation results are in good agreement with the experimental results. The hydrodynamic numerical errors are less than 5%, which is within the engineering error range. The model can be used for the numerical simulation of the planning cylinder. In this paper, it is used to simulate the planing process of cylinder with different speeds and different submerged depths, and the flow field characteristics and hydrodynamic characteristics in the planing process are obtained. The results show that waves appear at the tail and the tail liquid splashes to form a water splash during the planing process of the cylinder on a flat surface. The higher the speed of the planning cylinder is, and the deeper the submersion depth, the more pronounced waves at the tail. When the cylinder has a Fr number Cv≥8, the hydrodynamic force of the cylinder is almost unchanged, and it is not affected by the speed. But when Cv=3, the hydrodynamic characteristic coefficient is higher. The drag coefficient is 20% higher than that in the high-speed (Cv≥8) planing process. The lift coefficient is 3 times of high-speed planing lift coefficient. It is related to the surface pressure and frictional force distribution of cylinder during the low-speed planing. There is a linear relationship between the drag coefficient and the submerged depth during the cylinder planing at different submerged depths.

Influences of polymer modifiers on Porous Hot Asphalt Mixture Property and Durability

Fundamentally, sustainability and cost-effectiveness in infrastructure development have received widespread attention. Permeable pavement is such a concept that it is sustainable in the field of transportation and is being tested. Fully permeable pavement is a modern design method in which each layer is porous and can store water, avoiding the impact of stormwater on the pavement to avoid stormwater, skidding, floods, and water splash on the road and parking area which decrease safety rate. Porous asphalt (PA) is an asphalt mixture with a little or no fine aggregate. Due to open structures and advantages are used as a drainage layer in highway pavements in reducing noise and decreasing safety hazards during rainfall. Besides, it reduces splash and spray effects and thus increases the visibility. The main aim of this study is to analyze the influence of two asphalt modifier types: Styrene butadiene styrene (SBS) and propylene modifier polypropylene (PP), on porous hot asphalt mixture performance. The PA evaluation influence findings are based on permeability, durability, and Marshall stability-flow for hot asphalt mixture. The test results emphasize the modifier usage in reducing the abrasion loss and increasing the stability with enhancing the durability of PA. PA mixture binder prepared with 4% SBS and 4% PP modifier was the most polymer binder in modifying the abrasion resistance and stability of mixture in pavements.

Friction and Snow–Pavement Bond after Salting and Plowing Permeable Friction Surfaces

Open graded, ultrathin, and permeable friction course surfaces (collectively referred to as PFSs) have been successfully used by many transportation agencies in several countries as a wearing surface to help reduce water splash and spray, reduce potential for hydroplaning, increase friction, and reduce noise. Despite these advantages, when used in colder climates PFSs tend to freeze more rapidly, transport deicing/anti-icing chemicals from the road surface, clog from sands and other debris, and retain snow and ice for a longer period of time. Most of the reported difficulties with PFSs are at near-freezing temperatures (28°F–35°F). Laboratory tests were conducted using samples of traditional dense graded pavement (DGP), cores from new and old in-service open graded friction course pavements, and ultrathin friction course samples made from hot mix asphalt collected from paving operations. The tests were conducted in a walk-in environmental chamber at 28°F. Snow–pavement bond strength and static friction were measured to determine the effectiveness of anti-icing with salt brine and deicing with dry and pre-wet solid salt. The test results revealed that compacted snow bonds more strongly to PFSs, yet friction of PFSs was significantly greater than DGPs after snow removal, even without the use of salt. The PFSs appeared more white and snowy, and this appearance may be contributing to unnecessarily high application rates of salt by practitioners. Field testing is recommended to better understand the frictional behavior of PFSs during a variety of winter storm conditions and deicer application strategies.