Search Results (8)

Multi-material additive manufacturing (MMAM) enables integration of multiple materials within single products, but existing design methodologies lack systematic frameworks linking detailed consolidation decisions to product-level functional requirements while preserving functional independence. This paper presents a methodology that extends the conventional design process model with a reverse-traced workflow connecting part-level decisions to higher-level product architecture. By tracing how Design for MMAM (DfMMAM) affects design decisions in reverse, designers can identify the best opportunities to use MMAM based on their project scope. The methodology introduces a Level of Process Integration (LPI) framework based on design novelty that structures redesign scope according to whether changes affect part geometry, component assembly, or function allocation, enabling designers to balance consolidation benefits against validation complexity at each level. Sequential decision-making workflows systematically determine which functions can be co-located within unified components while maintaining functional independence through zone-specific design parameters. The methodology is illustrated through a qualitative case study on trail running shoe design across three integration levels, identifying substantial consolidation potential while establishing the foundation for future quantitative validation. Unlike existing approaches limited to part-level redesign, this framework traces detailed consolidation decisions back to product architecture trade-offs, clarifying redesign scope and validation rigor required at each integration level. By operationalizing the relationship between functional decomposition, physical architecture, and MMAM capabilities, this framework provides designers with structured decision pathways to balance consolidation benefits against redesign complexity at each design phase. Full article

The inability to regain balance following a trip-induced event is one of the leading causes of falls and fall-related injuries in older adults. Virtual reality (VR) has the potential to expose individuals to realistic environments with minimal injury risk compared to real-world exposures. The purpose of this study was to compare lower extremity joint kinematics during overground walking when exposed to real and virtually generated trip obstacles. A total of 14 healthy participants [7 male, 7 female; age: 23.46 ± 3.31 years; height: 173.85 ± 8.46 cm; mass: 82.19 ± 11.41 kg; shoe size (men’s): 9.03 ± 2.71 s] were recruited for this study. Knee and ankle joint kinematics were recorded during obstacle negotiation when exposed to REAL and VR environments. Environmental exposure was assigned in a counterbalanced order to prevent an order effect. Knee and ankle joint kinematics were independently analyzed using a 2 × 3 repeated measures ANOVA to compare environmental conditions and gait type of the lead leg and trail leg at an alpha level of 0.05. No significant differences were observed between environmental conditions. However, significant differences were observed between gait types of the lead leg and trail leg. Current findings reveal similar gait kinematics during obstacle negotiation when exposed to real and virtually generated trip obstacles, suggesting the potential transfer of skill in fall prevention strategies to real-world conditions. Full article

In recent years, advanced footwear technology (AFT) has been shown to improve performance in long-distance road running by altering biomechanics and perceived comfort. This type of footwear is now being marketed for mountain running, although its effects in such races remain unevaluated. This study aimed to examine the impact of AFT on performance, biomechanics, and perceived comfort during a simulated mountain running event. Twelve trained mountain runners participated in a 3-day experiment, with a 7-day recovery between sessions. On the first day, a maximal aerobic speed test assessed the runners’ performance levels. On the second day, participants familiarized themselves with a 5.19 km mountain circuit and comfort scale. On the third day, they completed two time trials on the same circuit, separated by 30 min of passive recovery, using conventional and AFT shoes in a randomized order. Physiological and biomechanical variables were recorded, including body mass, blood lactate, running biomechanics, vertical stiffness, shoe comfort, and rating of perceived exertion (RPE). The findings indicate that AFT does not improve performance or physiological responses during a simulated mountain race, regardless of segment (uphill, downhill, or mixed). However, AFT significantly alters running biomechanics, reducing step frequency and increasing the vertical oscillation of the center of gravity, especially in uphill and downhill sections. While overall comfort remained unchanged, specific differences were observed with AFT. Coaches and practitioners should consider these findings when using AFT in mountain running training or competition. Full article

The current paper presents the results of a questionnaire survey which examines the trail path usage conditions on Peranthi Hill in Arta, a medium-sized city in northwestern Greece. The key element of the survey is the detailed mapping of the suburban trail path network of the city, and it focuses on questions about the types of activities of people who walk or bike on the trail paths and the day, time, duration and distance of their trips, as well as their equipment (bicycles, clothes, shoes, etc.). Further questions focus on maintenance and safety issues (e.g., security, guarding, cleanliness) and infrastructures which are considered necessary in order to improve the trail paths’ environment and their use. Taking into consideration that several routes are being developed on Peranthi Hill, with distinct differences in their layouts, the preferred layout is explored in relation to each activity selected by the users. The results of the questionnaire survey, and the cluster analysis specifically, aim to address these issues and assist stakeholders and policymakers in improving the trail paths in terms of their utility and usability level. Full article

Ammonia emissions following liquid manure application impair human health and threaten natural ecosystems. In growing arable crops, where immediate soil incorporation of the applied liquid manure is not possible, best-available application techniques are required in order to decrease ammonia losses. We determined ammonia emission, crop yield and nitrogen uptake of winter wheat in eight experimental sites across Germany. Each individual experiment consisted of an unfertilized control (N0), broadcast calcium ammonium nitrate (CAN) application as well as four different techniques to apply cattle slurry (CS) and biogas digestate (BD). Fertilizer was applied to growing winter wheat at a total rate of 170 kg N ha⁻¹ split into two equal dressings. The following application techniques were tested for both liquid manure types: (i) trailing hose (TH) application using untreated and (ii) acidified (~pH 6) liquid manure (+A), as well as (iii) a combination of open slot injection (SI) for the first dressing and trailing shoe (TS) application for the second dressing without and (iv) with the addition of a nitrification inhibitor (NI) for the first dressing. The highest ammonia emissions (on average 30 kg N ha⁻¹) occurred following TH application of BD. TH application of CS led to significantly lower emissions (on average 19 kg N ha⁻¹). Overall, acidification reduced ammonia emissions by 64% compared to TH application without acidification for both types of liquid manures. On average, the combination of SI and TS application resulted in 23% lower NH₃ emissions in comparison to TH application (25% for the first application by SI and 20% for the second application by TS). Supplementing an NI did not affect ammonia emissions. However, decreasing ammonia emissions by acidification or SI did not increase winter wheat yield and nitrogen uptake. All organically fertilized treatments led to similar crop yield (approx. 7 t ha⁻¹ grain dry matter yield) and above-ground biomass nitrogen uptake (approx. 150 kg ha⁻¹). Yield (8 t ha⁻¹) and nitrogen uptake (approx. 190 kg ha⁻¹) were significantly higher for the CAN treatment; while for the control, yield (approx. 4.5 t ha⁻¹) and above-ground biomass nitrogen uptake (approx. 90 kg ha⁻¹) were significantly lower. Overall, our results show that reducing NH₃ emissions following liquid manure application to growing crops is possible by using different mitigation techniques. For our field trial series, acidification was the technique with the greatest NH₃ mitigation potential. Full article

Ammonia (NH₃) emissions resulting from the field application of livestock slurry has both negative human health and environmental impacts. However, decreasing the exposed surface area (ESA) of slurry upon application can reduce NH₃ volatilization by limiting its atmospheric exposure. In the present study, three strategies for depositing slurry within a growing crop were studied, including: 1. standard trailing hoses (SA_hose), 2. trailing shoes (SA_shoes), and 3. the combination of rigid tines and trailing shoes (SA_tines+shoes). Application methods interact with the soil to varying degrees and were evaluated within the context of contemporary weed management practices, namely in cereals receiving inter-row hoeing. SA_hose, SA_shoes, and SA_tines+shoes were compared in three coinciding experiments that assessed slurry ESA, NH₃ emissions, and crop and weed effects. SA_tines+shoes resulted in smallest ESA, 70–72% and 61–66% less than SA_hose and SA_shoes, respectively. However, in only one of three site–years did SA_shoes and SA_tines+shoes reduce NH₃ emissions compared to SA_hose, by 46% and 29%, respectively. Crop yields, nitrogen (N) accumulation in crop biomass, and intra-row weed biomass were unaffected by the placement method. In heavily crusted soils, the SA_tines+shoes prototype worked well; however, the functional differences among placement strategies were not great enough to detect crop and NH₃ effects. Full article

The recent popularity of trail running and the use of portable sensors capable of measuring many performance results have led to the growth of new fields in sports science experimentation. Trail running is a challenging sport; it usually involves running uphill, which is physically demanding and therefore requires adaptation to the running style. The main objectives of this study were initially to use three “low-cost” sensors. These low-cost sensors can be acquired by most sports practitioners or trainers. In the second step, measurements were taken in ecological conditions orderly to expose the runners to a real trail course. Furthermore, to combine the collected data to analyze the most efficient running techniques according to the typology of the terrain were taken, as well on the whole trail circuit of less than 10 km. The three sensors used were (i) a Stryd sensor (Stryd Inc., Boulder, CO, USA) based on an inertial measurement unit (IMU), 6 axes (3-axis gyroscope, 3-axis accelerometer) fixed on the top of the runner’s shoe, (ii) a Global Positioning System (GPS) watch and (iii) a heart belt. Twenty-eight trail runners (25 men, 3 women: average age 36 ± 8 years; height: 175.4 ± 7.2 cm; weight: 68.7 ± 8.7 kg) of different levels completed in a single race over a 8.5 km course with 490 m of positive elevation gain. This was performed with different types of terrain uphill (UH), downhill (DH), and road sections (R) at their competitive race pace. On these sections of the course, cadence (SF), step length (SL), ground contact time (GCT), flight time (FT), vertical oscillation (VO), leg stiffness (Kleg), and power (P) were measured with the Stryd. Heart rate, speed, ascent, and descent speed were measured by the heart rate belt and the GPS watch. This study showed that on a ≤10 km trail course the criteria for obtaining a better time on the loop, determined in the test, was consistency in the effort. In a high percentage of climbs (>30%), two running techniques stand out: (i) maintaining a high SF and a short SL and (ii) decreasing the SF but increasing the SL. In addition, it has been shown that in steep (>28%) and technical descents, the average SF of the runners was higher. This happened when their SL was shorter in lower steep and technically challenging descents. Full article

Soil surface measurements play an important role in the performance assessment of tillage operations and are relevant in both academic and industrial settings. Manual soil surface measurements are time-consuming and laborious, which often limits the amount of data collected. An experiment was conducted to compare two approaches for measuring and analysing the cross-sectional area and geometry of a furrow after a trailing shoe sweep. The compared approaches in this study were a manual pinboard and a Light Detection and Ranging (LiDAR) sensor. The experiments were conducted in coarse sand and loamy sand soil bins exposed to three levels of irrigation. Using the LiDAR, a system for generating 3D scans of the soil surface was obtained and a mean furrow geometry was introduced to study the geometrical variations along the furrows. A comparison of the cross-sectional area measurements by the pinboard and the LiDAR showed up to 41% difference between the two methods. The relation between irrigation and the resulting furrow area of a trailing shoe sweep was investigated using the LiDAR measurements. The furrow cross-sectional area increased by 11% and 34% under 20 mm and 40 mm irrigation compared to non-irrigated in the coarse sand experiment. In the loamy sand, the cross-sectional area increased by 17% and 15% by irrigation of 20 mm and 40 mm compared to non-irrigated measured using the LiDAR. Full article