Conveyor chain is one kind of chain which has been used worldwide to transport or carry an object from one place to anywhere on the production line. In fact, a key factor of conveyor chain design is tension on chain link plate which the traditional static design method has not precise and accurate enough for production line has complex and large size. MBD (multi-body dynamic) is a new way to analyze system which static analysis method cannot investigate any problem. This paper aims to apply commercial code software to find tension on chain link plate of conveyor chain by using multi-body dynamics (MBD) simulation method which simple model of chain alignment such as vertical, horizontal and incline alignment is fundamental of complex alignment that apply in rubber gloves industry. Finally, the results obtained from numerical formula and multi-body dynamics (MBD) simulation have an average error less than 7, 5 and 7 percent in horizontal, vertical and incline layout, respectively. Percent error disregards the oscillation effect from increasing the velocity of the conveyor chain while the mathematical formula is not.
Managing traffic in developing countries has become topical in recent years because of the externalities of transport-traffic congestion, air and noise pollution as well as RTCs (Road Traffic Crashes). This paper considers how these externalities are managed in the Cape Coast Metropolis. The study adopts a desktop review of transport related externalities in the metropolis. In an attempt to address these externalities, traffic management measures have been adapted in Cape Coast Metropolis such as one-way system, pedestrian safety measures, provision of on-street parking, improved junction control measures, and pedestrainisation, with minimal impacts. Therefore, it is recommended in this paper that Cape Coast Metropolitan Assembly in conjunction with the Department of Urban Roads of the Ministry of Roads and Highways adopt an integrated approach to managing traffic placing emphasis on the behavior of road users.
Railway vehicle stability is an important factor affecting operational safety and ride quality. This study applies D3DCG (Detection of Three-Dimensional Center of Gravity) to evaluate the running stability of passenger railway vehicles without requiring prior knowledge of vehicle mass or spring stiffness. Field measurements were conducted on two commuter railway lines in the Greater Tokyo area, Japan using a motion sensor installed inside operating vehicles. After vertical acceleration and roll angular velocity measurements were taken during service operation, data were analyzed using FFT (Fast Fourier Transform) to extract dominant vibration frequencies. The obtained natural frequencies were substituted into the D3DCG equations to estimate the vehicle center of gravity height and the corresponding critical center of gravity position (𝐿𝑚𝑎𝑥), which were used as rollover stability indicators. The estimated center-of-gravity positions were generally distributed within a physically reasonable range relative to the vehicle structure. Furthermore, an interesting tendency was observed in the calculated 𝐿𝑚𝑎𝑥 values: the values initially decreased and subsequently increased along the measured sections. This tendency suggests that the stability margin of railway vehicles might vary depending on running conditions and vibration characteristics. The findings indicate that D3DCG-based analysis can provide a practical approach for evaluating railway vehicle stability using operational vibration data without requiring direct structural measurements.
The purpose of this study is to deepen the understanding of the economic impact of transitioning from outsourced to insourced public bus transportation operations within a Swedish context. The research scrutinized an uncommon occurrence in Sweden where a regional PTA (public transport authority) transitioned their public bus services to an in-house operation after previously contracting them out to a private provider, a move that goes against the growing trend of competitive tendering in bus transportation services. Data were collected through document analysis and interviews with industry experts and managers from public and private bus operators. The study concludes that public transportation costs would have been lower if the services had been procured through a competitive tendering process, with estimated potential savings in the range of 3.5% to 6.4%. Additionally, the study finds that the purchaser’s specifications and demands contributed to increased costs for public transportation by enforcing strict age requirements for buses and specifying bus sizes for each departure.
Fatigue failure of asphalt pavement roads is getting increasingly rampant with the increasing climate impacts resulting in cracks and potholes. This is supported by many researchers on the subject matter. The specified asphalt mixtures intended for road construction are tested using various methods to quantify fatigue resistance. However, the advent of several reinforcing agents in asphalt mixtures calls for new testing approaches to quantify the fatigue resistance coming from these reinforcing agents. This study explores use of recycled waste plastics that are fabricated into stranded plastic beads as a reinforcing medium to enhance the asphalt layer’s fatigue strength. In this study SMA (Stone Mastic Asphalt) with a nominal aggregate size of 20 was selected as it provides a higher Voids in Mineral Aggregate for the plastic bead incorporation and interlocking as compared with the traditional dense graded asphalt mixtures. It is envisioned that the dual end beads with a link enhance the lateral resistance as the end beads get interlocked between compacted aggregates, allowing for better load distribution under heavy axle loads. A four-point dynamic bending testing jig was developed and integrated with a Universal Testing Machine to evaluate the ability of the bead system to resist flexural deformation through the interlocking SPB (Stranded Plastic Bead) system under variousloading conditions. The results showed that the SMA (Stone Mastic Asphalt) mixturesreinforced with SPB were able to resist flexural deformation under higher axle loads with longer rest durations with increased resistance from 11 to 22%. SMA20 with SPB effectively mitigated deflection and delayed crack propagation until it’s maximum load-bearing capacity. These findings make it a promising solution for sustainable road construction while simultaneously addressing the plastic waste crisis.
Believe it or not, over the last 70 years, the yellow change and red clearance intervals (CCI) at signalized intersections have been continually studied, researched, modified, improved, and vigorously debated. Still, we can see quite a variety of different CCI guidance applied from federal, state and local perspectives. The latest ITE journal article suggests that CCI “Research [is] Still Needed!” Within 11 areas of identified and related interests, “safety benefits of yellow change and red clearance intervals” is identified as the most important. In 2020, “ITE Releases Recommended Practice for Traffic Signal Change”; however, “this report is specifically focused on the timing of traffic signal change intervals and does not address pedestrian signal change intervals or enforcement of red light running”. If we seek to design surface transportation systems that promote the safety of all road users, we ask the question: do pedestrians and rollers/cyclists deserve all-red clearances that serve their needs in the way that the concurrent moving vehicles at signalized intersections receive. And, if so, what should the duration of the all-red indication be? To answer this question, the authors illustrate a thought experiment of five hypothetical signalization scenarios including dynamic traffic “simulation” by manually diagraming the three critical seconds of signal timing transition: yellow, red, green in one cycle with considerations of all approaches of passenger cars, pedestrians, cyclists and rollers. Through the scenarios, we can visually see the progressive safety improvements of reducing the frequency of “forced conflicts” as a surrogate for potential crashes. The authors randomly surveyed around 100 northwest urban signalized intersections among each of the states of Oregon and Washington, and Canadian British Columbia District (BC). The random survey findings are mostly supportive of the all-red-clearance signalization for all travelers, particularly the superior leading pedestrian intervals (LPI), which has also been incrementally implemented at major cities, such as Portland, Seattle and Vancouver.
An Introduction is provided, including the importance of light-duty vehicles (LDVs: cars and light duty trucks) and a definition of the top-level LDV requirements to limit their carbon dioxide (“CO2”) emissions. Anthropogenic climate change fundamentals are presented, including its cause, its potential for harm, California mandates, and a greenhouse gas (GHG) reduction road map to avoid disaster. A 2030 climate-stabilizing GHG reduction target value is calculated, using statements by climate experts. The formula for GHG emissions, as a function of per-capita driving, population, fleet CO2 emissions per mile, and the applicable lowcarbon fuel standard (LCFS) is given. The ratio of the 2015 value of car-emission-per-mileto the 2005valueof car-emission-per-mileis obtained. Internal Combustion Engine (ICE) mileage values from 2000 to 2030 are identified, as either mandates or new requirements. A table is presented that estimates 2015 LDV fleet mileage. Zero Emission Vehicle (ZEV) parameters are given. A table is shown that uses 2030 ZEV and ICE (ICE LDVs) requirements, named the “Heroic Measures” case,to compute the LDV fleet-equivalent mileage. That equivalent fleet mileage is used, with population and the requiredemission reduction, to compute a required per-capita driving reduction, with respect to 2005. Measures to achieve this per-capita driving reduction are described, with reductions allocated to each measure. The energy used per year for the Heroic Measures case is estimated The “Heroic Measures” set of fractions of ZEV’s purchased, as a function of year, is compared to the California Air Resources Board (CARB) goals.
This study examines Beijing subway network, bus network and the composite network of the two in 2022. Using stations as nodes and the lines between them as edges, the node degree probability distribution of the resulting complex networks is calculated. Through regression analysis, it is found that the node degree probability distributions for all three transportation modes follow a negative exponential function, and all three distribution curves decrease as the node degree increases. Among the three probability distribution curves, the node degree probability distribution curve of subway network is at the bottom, the probability distribution curve of bus network is in the middle, and the probability distribution curve of composite network is at the top.
The paper discusses the elements of logistic protection of works carried out on offshore and production (units) platforms. The article presents a system of supplying cargoes to off-shore units, which is provided to ensure safe operation of the system during daily operation and in an emergency situations. The logistics system for this type of units is a complex process involving, the 24/7 service personnel including specialists, delivers of cargo and standby offshore vessels which can deliver cargoes in variable weather conditions on time. The main aim of it is to obtain constant production and operation of the units and ensuring the safety of the crew, the environment and the protection of property.
In this paper, the vertical and transverse frequency response characteristics of steel rails under two track structure III fastener and upper locking double-layer nonlinear fasteners (GJ-32 fasteners) are compared by online detection and hamming method on the line of normal operation of subway tunnel from Shuanglong avenue to Nanjing South Station of Nanjing Metro Line 1. The results show that: (1) The GJ-32 fasteners has a better inhibitory effect on rail vibration between 200-400 Hz compared with the III fastener; (2) The GJ-32 fasteners has better damping performance and damping characteristics; (3) The development of corrugated rail of III fastener is serious, and the growth of corrugated rail is effectively inhibited by the upper locking double-layer nonlinear fasteners.
There are not so many off-the-shelf ITS services and solutions which makes purchasing/implementing such services and solutions challenging for public procurers. Challenges public procurers face when purchasing ITS solutions range from uncertainty in costs and time, risks in failed commercialisation of innovation, to difficulties of reviewing or extending contracts. However, many of the challenges can be addressed by innovation procurement procedures such as Competitive Dialogues. City of Copenhagen has used various procurement procedures to implement innovative and sustainable transport solutions which has set an outstanding example to other cities and authorities of using public procurement as an instrument for implementation of ITS. Analyses of the cases of using various procurement procedures have been carried out in order to identify how the city overcome the barriers, and benefits and lessons learnt from the procedures. The analyses aim to provide comprehensive references to other public authorities.
