Original Design Research Articles

Reconstructing the invention of the wheel using computational structural analysis and design

The invention of the wheel is widely credited as a pivotal moment in human history, yet the details surrounding its discovery are shrouded in mystery. There remains no scholarly consensus on key questions such as where, how and by whom this technology was originally invented. In this study, we employ state-of-the-art techniques from computational structural mechanics to shed light on this long-standing puzzle. Based on this analysis, we propose a probable path along which the wheel evolved via a sequence of three major innovations. We also introduce an original computational design algorithm that autonomously generates a wheel-and-axle system using an evolutionary process that offers insight into the way in which the first wheels probably evolved nearly 6000 years ago. Our analysis provides new supporting evidence for the recently advanced theory that the wheel was probably invented by Neolithic miners harvesting copper ore from the Carpathian Mountains as early as 3900 BC. Moreover, we show how the discovery of the wheel was made possible by the unique physical features of the mine environment, whose impact was analogous to the selective environmental pressures that drive biological evolution.

Effect of packaging label color on consumer perception of Greek protected designation of origin table olives "Kalamata".

Kalamata table olives are a widely exported Greek protected designation of origin (PDO) product with distinct organoleptic profile. This study aimed to evaluate the effect of label color on the flavor perception of pasteurized and unpasteurized Kalamata PDO olives. Consumer perception was assessed in two studies. First, four packaged products with green, blue, red, and purple labeling were assessed by participants (n=106) for preference using rating scales, and emotional profiles were obtained using a check-all-that-apply list of 33 emotions developed in language native to the participants (Greek). The green label resulted to more positive emotion profiling of olive products (i.e., "healthy," "pleased," and "satisfied" with mean scores correspondingly equal to 2.99, 2.95, and 2.87), and red labeled olives resulted to willingness to pay more. In the second study, unpasteurized and pasteurized olives in red and green labeled glass jars were sensorially assessed by participants (n=124) using rating scales, showing that green labeled products are liked most (mean scores; 5.12 and 5.12), whereas red labeled was scored less (mean scores; 4.96 and 4.67), along emotion profiles with emojis. Principal component analysis of emotional reactions revealed grouping of samples based only on pasteurization/no pasteurization, without been affected by the color of the label, and did not relate to the liking scores. The results showed that sensory perception of olives is significantly affected by the color of packaging (p-value <0.05) due to emotional reactions and color of packaging can enhance the perception of olives' quality as improvement of the processing is limited by the PDO status.

Preliminary study on the influence of the geographical origin of ‘Nero dei Nebrodi’ pork and the farming system by means of chemical and isotopic fingerprinting

In this study, the geographical origin of longissimus dorsi meat from 'Nero dei Nebrodi' pigs reared in two distinct regions of north-eastern Sicily was indagated by correlating chemical-nutritional parameters, stable isotope composition, fatty acid and sterol profiles, and mineral element content. Significant differences (p ≤ 0.05) between the 'Nebrodi group' (NG) and the 'External Nebrodi group' (ENG) were found for 51 over 80 variables. The δ2H, δ18O, δ13C and δ15N of the defatted meat were statistically different (p<0.01) between NG and ENG animals, indicating a change in the composition of the diet and drinking water consumed. The results showed that the characteristic rich endemic vegetation of the Nebrodi influences not only the chemical-nutritional parameters of the meat but also its isotopic ratios, allowing for a geographical characterization required for the traceability of this peculiar product, aspiring to a protected designation of origin.

Creative and accurate method for optimal hardware implementation of neurons and biological cells: Application in FPGA-based implementation of cardiac pacemaker cell

The sinoatrial (SA) node cells play a vital role as the principal pacemaker in mammalian hearts, generating regular and spontaneous action potentials to regulate the heart’s rhythm. Comprehending the intricate activity of the SA node’s operation necessitates a collection of differential formulas that tackle non-linear functions. The study presents a new technique to improve the digital representation of the SA node cell model, offering benefits such as decreased hardware needs, enhanced processing speed and accuracy, and reduced implementation expenses by transforming the original model’s differential equations into a unified trigonometric function. This transformation significantly simplifies the computational complexity by eliminating the need for multipliers, resulting in a streamlined set of mathematical expressions. The digital implementation of this novel method can be efficiently realized using the Coordinate Rotation Digital Computer (CORDIC) algorithm, which circumvents the necessity for cumbersome mathematical operations. To demonstrate the viability of this approach, the proposed model is successfully synthesized and implemented on a Field-Programmable Gate Array (FPGA). The results of the implementation demonstrate a significant rise in the operating frequency, which is approximately 6.14 times greater than that of the original model. Furthermore, there is a notable 45 percent decrease in power usage. The lowered hardware needs make significant scalability possible, thus allowing for the inclusion of approximately 12 times as many SA node cells on a sole FPGA board in comparison to the original design.

Evaluation of compression behaviour of 316L SS Gyroid and Diamond structures using SLM process – Experimental programme under static and dynamic compression loadings

The relative comparison in terms of energy absorption efficiency for a set of 4 structures made of various Triply Periodic Minimal Surfaces (TPMS) topologies is experimentally investigated. These TPMS structures are printed by Selective Laser Melting AM process using 316L SS. The study is carried out in consideration of the effect of parameters such as relative density, compressive loading directions and loading rates, number of unit cells for Diamond and Gyroids TPMS both declined for Sheet and Skeletal topologies. The objective is to quantify their structural responses in terms of apparent stress and strain, dynamic enhancement and Specific Energy Absorbed (SEA) and to evaluate their structural integrity in terms of collapse stability. The results reveal that the Sheet pattern of TPMS structures with its constant wall thickness and uniform geometry exhibits better energy absorption capabilities than the Skeletal pattern. The Diamond family shows greater interest rather than the Gyroid family only in the case of the Sheet pattern. The increase in relative density from 20 to 30% is characterized by improved manufacturing quality, an increase in energy absorption capacity and more homogeneous progressive deformations during compression. On the whole, the set of TPMS geometries exhibits energy absorption capacities prior to those of other conventional cellular materials currently used for impact engineering applications. Finally, in a first approach, an original design methodology using charts can be developed to establish a link between the energy absorption capabilities and the design geometric parameters of TPMS structures.

Automatic Optimal Design Method for Minimum Total Resistance Hull Based on Enhanced FFD Method

Hull optimization plays a crucial role in enhancing ship performance and efficiency. This study aimed to improve ship performance, particularly by reducing total resistance, through automated optimization methods. To this end, an integrated, fully automated optimization program was developed based on Python, incorporating Enhanced Free-Form Deformation (FFD) technology, scripted CFD numerical evaluation, and the Particle Swarm Optimization (PSO) algorithm. This program allowed precise control of hull form, improving efficiency while reducing costs. The KCS hull, known for its excellent resistance performance, was chosen as the optimization target, with the goal of minimizing total resistance by adjusting the bulbous bow line plan. The research results indicated that the optimized scheme exhibited lower resistance characteristics compared to the original design while satisfying design constraints. This study not only provides a new optimization strategy for ship design but also lays a foundation for future hull optimization research.

Aircraft Structural Assessments in Data-Limited Environments: A Validated FE Method

Aircraft operators often modify aircraft configurations, install new equipment, and alter airframes to accommodate this equipment, leading to operations in flight envelopes different from original design profile. These modifications necessitate airframe structural assessments, which typically require comprehensive aircraft design data, often unavailable to operators. This study aims to develop and validate a practical method for finite element analysis (FEA) of aircraft structures in the absence of this detailed design data. Focusing on a case study involving structural analysis of an aircraft wing, this study presents assumptions and idealizations used to develop 2.5D finite element (FE) model of the wing. Fidelity of this model is established by comparing FE analysis results with experimental data. Key validation metrics include reaction forces, load distribution at wing-fuselage attachments, and deformation at reference points on the wing under design load. Comparison between FE analysis and experimental results is carried out to substantiates accuracy of these geometric simplifications and idealizations of load-carrying behaviour of structural members. Therefore, practicality of these idealizations in absence of design data is demonstrated. This study offers a novel approach for structural assessments of aircraft without relying on proprietary design data. The validated method enhances capability of aircraft operators to perform effective structural analyses, thereby extending service life of aircraft with continued airworthiness.

Resistance performance study and hull form optimization of aquaculture vessel by CFD method

Abstract Aquaculture vessel is a novel form of deep-sea aquaculture engineering with a wide range of applications. The resistance performance of the aquaculture vessel was studied by the computational fluid dynamics method and compared with the experiment. Two optimization schemes, namely, straight bow and bulbous bow, are designed to optimize the original design, focusing on improving the bow profile. The effectiveness of the two optimization schemes in terms of resistance reduction was evaluated by the CFD method. The resistance calculated by numerical calculations was found to be in good agreement with the experimental results. The bulbous bow scheme reduces resistance better than the upright scheme, with a resistance reduction of 2.92% at 11 kn. This study can guide the overall design of an aquaculture vessel.

Consumer Response to PDO Table Olives: An Analysis of Consumer Behavior for Using Ordered Logistic Regression

The table olive sector in Italy is a vital component of the national economy and cultural heritage. Italy ranks third in the European Union and eighth globally in table olive production. Through an analysis conducted from June to September 2023, this study explores consumer preferences, purchasing habits, and the willingness to pay for Protected Designation of Origin certified olives. The study actively contributes to the literature by shedding light on consumer preferences and behaviors regarding table olives, a topic that has been largely neglected in both national and international research. The results reveal insights into how age, gender, educational level, residence city, purchasing location, willingness to pay, and preferred olive types influence consumer behavior. These findings provide valuable information for stakeholders and policymakers to enhance market competitiveness, promote sustainable growth, and preserve Italy’s rich olive heritage.

Impact of the use of an indigenous starter on microbial community structuring and aromatic profile of rocamadour protected designation of origin cheese

The use of indigenous strains as starters offers new opportunities that challenge the use of industrial starters, especially to strengthen the link between Protected Designation of Origin (PDO) cheeses and their terroir. This study investigated the effect of two starters, industrial and indigenous, on the microbial ecosystem and volatile organic compounds (VOCs) in Rocamadour PDO cheese. Metabarcoding analysis showed that regardless of the type of starter used, Lactococcus lactis and Geotrichum candidum largely dominated the microbial communities of Rocamadour (>96 %). The analysis of β-diversity based on the Bray-Curtis indices differentiated the starters according to their bacterial communities. VOC analysis showed that the starters were distinguished by three fatty acids characteristic of the goat cheese aroma (p-value <0.05): decanoic, hexanoic, and octanoic acids. Hexanoic acid was not present in cheeses produced with the indigenous starter. This fatty acid was positively correlated with the presence of Paucilactobacillus nenjiangensis, Lactiplantibacillus sp. and Enterobacteriaceae, these microorganisms that were also characteristic of cheeses made with the industrial starter. Octanoic and decanoic acid, on the other hand, were suggested to be correlated with the presence of Leuconostoc mesenteroides.Cheeses produced with the indigenous starter differed in bacterial communities and aromatic signatures.

Multi-Objective Optimisation and Deformation Analysis of Double-System Composite Guideway Based on NSGA-II

To study the optimal design of the section of the double-system composite guideway under the economic, steel consumption, and carbon emission characteristics, this paper introduced the multi-objective constrained optimisation model, which was established by the non-dominated sorting genetic algorithm II. In addition, the finite element model was established to further analyse the optimised section’s deformation and summarise the rail girder’s deformation law under different loads. The results showed that compared with the original design scheme, the optimised scheme can effectively reduce carbon emission during the construction of the double-system composite guideway, by 23.67% for Scheme I and 42.03% for Scheme II. On the other hand, steel had the largest share in the economic targets of the three design options, accounting for about 75% to 88.5% of the total cost. Concrete had the highest share of carbon emissions, ranging from 90% to 95% of the total carbon emissions. The distribution patterns of horizontal and vertical deformations in the three design options were independent of the load type as well as the load magnitude, but the vertical deformations were related to the load type, especially the self-weight load. The conclusions of this paper aim to fill the gap in the theoretical study of section optimisation of the double-system composite guideway and lay the theoretical foundation for developing the multi-system monorail transportation system.

Beyond Harmful: Exploring Biofilm Formation by Enterococci Isolated from Portuguese Traditional Cheeses.

This study investigated the biofilm-forming capabilities of Enterococcus isolates from Portuguese traditional cheeses with protected designation of origin (PDO) status, specifically Azeitão and Nisa. Given the absence of added starter cultures in the cheesemaking process, the characteristics of these cheeses are intrinsically linked to the autochthonous microbiota present in the raw materials and the production environment. Our findings demonstrate that all isolates possess biofilm production abilities, which are crucial for their colonization and persistence within cheese factories, thereby maintaining factory-specific microbial heritage. Through an integrated analysis utilizing principal component analysis (PCA), a direct correlation between biofilm formation and cell viability was established. Notably, these results underscore the adaptive capacity of enterococci to survive environmental fluctuations and their role in the unique characteristics of Portuguese traditional cheeses. Overall, this research enhances our understanding of the microbial dynamics in cheese production and highlights the importance of enterococci in preserving cheese quality and heritage.

Feasibility of Using Secondary Attributes in Sensory Analysis to Characterize Protected Designation of Origin of Olive Oil

Feasibility of Using Secondary Attributes in Sensory Analysis to Characterize Protected Designation of Origin of Olive Oil

Lateralization and inclination angle in reverse arthroplasty-what do we know?

Since the original Grammont design of a reverse shoulder arthroplasty there has been a trend to decrease inclination angle from 155° to 145 or 135°. Furthermore, lateralization on the glenoid side has been advocated. These changes decrease the risk for impingement between humerus and the inferior part of the glenoid (notching). These changes were also made to improve restoration of rotation. However, there is very little evidence that rotation has improved due to these changes. A negative effect of lateralization is that it increases the risk for glenoid loosening. Furthermore, the stress on acromion increases which may lead to more acromion or scapula spine fractures. More randomized studies are needed to define optimal design of a reverse shoulder arthroplasty.

Motion-free high-resolution on-chip microscopy using LED matrix

Lensless microscopy is an imaging technique that allows high-resolution imaging over a large field of view with a cost-effective design. Conventional lensless microscopy often utilizes multi-height phase retrieval and pixel-super-resolution algorithms to reconstruct high-resolution images, requiring mechanical stages for three-dimensional relative movements between a light source, camera, and sample. However, the excessive use of stages inevitably increases the bulkiness of the system and extends the image acquisition time. Here, we propose a motion-free lensless microscope that incorporates an RGB LED matrix array. A high-resolution holographic image is reconstructed from subpixel-shifted color images obtained with LED illuminations without any mechanical movement. Using a prototype system, we have demonstrated a spatial-bandwidth product of 30 megapixels with a resolution of 0.87 µm and a field of view of 24 mm2. The usability of the proposed method has been further tested for histopathologic examination. Our system features a compact and high-performance design with inexpensive optoelectronic elements, a conventional CMOS sensor and an LED matrix, which are well-aligned with the original design motivation of lensless imaging methods.

Fatigue Life and Stress Analysis of a Single Cylinder Four Stroke Crankshaft

This paper focuses on the optimization of a crankshaft using ANSYS software in terms of weight and strength. The initial designs of the crankshaft, piston, and connecting rod were created using SolidWorks. The force generated by the gas during the combustion process was calculated to be 12017 N. Next, the SolidWorks assembled system was imported into ADAMS View software for simulation, which revealed a time-variant force of the crankpin of 14049 N. The calculated value was verified with results obtained from analytical calculations, showing a deviation of 0.23%. Finite element analysis was done for the crankshaft using ANSYS transient structural after applying loadings and boundary conditions. The optimization process aimed to minimize the crankshaft's weight while maintaining its strength and durability. The results of the ANSYS simulations showed a weight reduction of 2.5% from the original 2.983 kg to 2.907 kg, while maintaining the required strength and durability. The optimized crankshaft was compared to its original design in terms of fatigue life, weights, and stresses. The maximum von Mises stress was reduced by 16%, shear stress by 3.5%, and deformation by 3.5%, which were validated through analytical calculations. The crankshaft analysis resulted in a significant increase in fatigue life, calculated to be infinite under the given conditions. To conclude, the objective to optimize the crankshaft for performance and efficiency was achieved, demonstrating a 2.5% weight reduction and substantial improvements in fatigue life and stress distribution, proving the effectiveness of ANSYS software for the design optimization process.

Optimization of MOSFET Copper Clip to Enhance Thermal Management Using Kriging Surrogate Model and Genetic Algorithm

Metal–oxide–semiconductor field-effect transistors (MOSFETs) are critical in power electronic modules due to their high-power density and rapid switching capabilities. Therefore, effective thermal management is crucial for ensuring reliability and superior performance. This study used finite element analysis (FEA) to evaluate the electro-thermal behavior of MOSFETs with copper clip bonding, showing a significant improvement over aluminum wire bonding. The aluminum wire model reached a maximum temperature of 102.8 °C, while the copper clip reduced this to 74.6 °C. To further optimize the thermal performance, Latin Hypercube Sampling (LHS) generated diverse design points. The FEA results were used to select the Kriging regression model, chosen for its superior accuracy (MSE = 0.036, R2 = 0.997, adjusted R2 = 0.997). The Kriging model was integrated with a Genetic Algorithm (GA), further reducing the maximum temperature to 71.5 °C, a 4.20% improvement over the original copper clip design and a 43.8% reduction compared to aluminum wire bonding. This integration of Kriging and the GA to the MOSFET copper clip package led to a significant improvement in the heat dissipation and overall thermal performance of the MOSFET package, while also reducing the computational power requirements, providing a reliable and efficient solution for the optimization of MOSFET copper clip packages.

Wine Tourism as a Catalyst for Sustainable Performance: The Mediating Role of Corporate Legitimacy and Green Innovation

ABSTRACTThis study aims to explore the influence of Wine Tourism (WT) on the Sustainable Performance (SP) of wineries in Spain. It particularly investigates how Corporate Social Legitimacy (CSL) and Green Innovation (GI) may act as intermediary factors in this relationship. Additionally, the research considers the age of the winery, its size, and whether it is part of a protected designation of origin as control variables to enhance the accuracy of the identified cause‐and‐effect relationships. This research introduces a theoretical framework, grounded in prior literature, and examines it through structural equation modeling. The analysis is based on data gathered from 196 wineries in Spain, collected over the period from September 2022 to January 2023. The results of this study highlight a notable and positive correlation between the advancement of WT and the SP of wineries in Spain. Additionally, the study uncovers that CSL and GI play a partially mediating role in this connection. The uniqueness and significance of this study can be attributed to several crucial factors. First, it enhances the understanding and knowledge regarding the advantages associated with WT development. Second, no prior research has conducted a comprehensive study on the WT development as a catalyst for economic, social, and environmental outcomes within the context of Spanish wineries. Third, to the best of the authors' knowledge, no previous study has simultaneously analyzed the mediating role of CSL and GI as mediators in the relationship between WT development and the SP of wineries.

20th-Century World Built Heritage Facing Water: Conservation of Fallingwater and Boa Nova Tea House

The conservation of 20th-century architectural heritage presents unique challenges due to the modern materials and construction techniques used by pioneering architects. This paper investigates the preservation challenges of iconic architectural works exposed to water environments, focusing on Fallingwater by Frank Lloyd Wright and the Boa Nova Tea House by Álvaro Siza Vieira. These structures, situated in natural settings with significant exposure to water, serve as case studies for examining conservation methods and their broader implications. This study explores archival documents, interviews with conservation experts, and literature reviews to highlight the main degradation phenomena related to the impact of environmental conditions on the material’s integrity. Despite limited specific data on monitoring and maintenance, this research underscores the importance of ongoing conservation efforts. Fallingwater’s case highlights the necessity of restoration techniques, while the Boa Nova Tea House illustrates minimal intervention strategies to maintain authenticity. This study concludes that the effective conservation of 20th-century built heritage necessitates a balance between preserving original design intents and adapting to environmental challenges. It emphasizes the need for innovative conservation strategies, adherence to international guidelines, and the establishment of comprehensive management and monitoring plans to safeguard the integrity and authenticity of culturally significant architecture.

Biochemical and physicochemical characteristics and volatile profiles of Erzincan Tulum cheese coagulated by herb-fortified artisanal lamb rennet

The characteristics of Erzincan Tulum cheese (ETC), an artisanal ewe-milk cheese and the first cheese with the designation of origin in Türkiye, are closely related to the geographical location of production and the human factors influencing every stage of the production process. This study aims to determine the influence of different coagulants (namely, herb-fortified artisanal lamb rennet (ALR), artisanal calf rennet (ACR), and commercial calf rennet (CCR)) on the biochemical, physicochemical characteristics, and volatile compounds of ETC, produced on the Heybeli plateau of the Erzincan province. Using artisanal rennet increased total solids, fat content, and acidity while decreasing pH and aw values. The highest PTA-SN (soluble nitrogen in 5 % phosphotungstic acid, w/v) and TCA-SN (soluble nitrogen in 12 % trichloroacetic acid w/w) values at the end of the ripening period (day 150 of storage) were observed in the ALR-Cheese (ALR-C). Furthermore, this cheese exhibited the highest rate of lipolysis (P < 0.01). Electrophoretograms revealed that αs-1 and β-casein degradation rates were the most significant in ALR-C. Following the 30th day of storage, the highest counts of lactic acid bacteria (LAB) were found in ALR-C. The most rapid reduction of coliforms, E. coli, and yeast-mold was observed in this sample throughout the storage. Eighty-nine volatile compounds were identified in the samples. Particularly noteworthy, ALR-C exhibited the highest ratios of hexanoic, octanoic, and decanoic acids after 90 days of storage. Additionally, steroid compounds were exclusively detected in this sample. The findings of this research make a substantial contribution to the existing literature concerning rennet types and the aromatic profile of ETC. These aspects are crucial for further investigations to enhance the cheese's quality and safety.