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Transonic buffet flow is a classical complex and unstable flow that has a negative effect on aircraft fly safety. Therefore, it is crucial to study the unsteady characteristics of buffet flow. The numerical analysis method is very useful in achieving the aforementioned goal. In this paper, focused on the typical supercritical airfoil OAT15A in fixed and pitching conditions, unsteady Reynolds averaged Navier–Stokes (URANS) closed with the sst-kω turbulence mode, coupled with the structure dynamical equation, is utilized to investigate the transonic buffet flow. Firstly, from the perspective of coherent flow structure, flow velocity divergence snapshots constructed from unsteady flow solutions are used to analyze the feature of transonic buffets in the two cases mentioned. Then, DMD modes are extracted by the dynamic mode decomposition technique from the velocity snapshots and adopted to analyze the flow modes of the two distinct flow fields. The numerical simulation results show that, in the fixed case, the regular motion feature of the buffet is present, the shock oscillation is closely related to the vortex structure, and the durations of rearward and forward movements of the shock are both equal to half of the buffet period. In the pitching case, the duration of the rearward motion of the primary shock is approximately five eighths of one buffet period, and the secondary shock appears with the primary one moving downstream, and they interact with each other. The region of the shock movement is larger than that of the fixed case, and there is chaotic flow rather than periodic flow in its wake. Structural elastic oscillation changes the characteristics of the aerodynamic response, which is solely affected by the frequency of the pitching oscillation. [ABSTRACT FROM AUTHOR]

Transonic buffet flow is a classical complex and unstable flow that has a negative effect on aircraft fly safety. Therefore, it is crucial to study the unsteady characteristics of buffet flow. The numerical analysis method is very useful in achieving the aforementioned goal. In this paper, focused on the typical supercritical airfoil OAT15A in fixed and pitching conditions, unsteady Reynolds averaged Navier–Stokes (URANS) closed with the sst-kω turbulence mode, coupled with the structure dynamical equation, is utilized to investigate the transonic buffet flow. Firstly, from the perspective of coherent flow structure, flow velocity divergence snapshots constructed from unsteady flow solutions are used to analyze the feature of transonic buffets in the two cases mentioned. Then, DMD modes are extracted by the dynamic mode decomposition technique from the velocity snapshots and adopted to analyze the flow modes of the two distinct flow fields. The numerical simulation results show that, in the fixed case, the regular motion feature of the buffet is present, the shock oscillation is closely related to the vortex structure, and the durations of rearward and forward movements of the shock are both equal to half of the buffet period. In the pitching case, the duration of the rearward motion of the primary shock is approximately five eighths of one buffet period, and the secondary shock appears with the primary one moving downstream, and they interact with each other. The region of the shock movement is larger than that of the fixed case, and there is chaotic flow rather than periodic flow in its wake. Structural elastic oscillation changes the characteristics of the aerodynamic response, which is solely affected by the frequency of the pitching oscillation.

The application of the variable camber technology has promising results in improving the lift-to-drag performance during the cruise phase, particularly under multi-lift conditions. This improvement is crucial for enhancing the economic benefits of the entire flight. A smooth and continuous flow separation function was developed to constrain the buffeting performance. An optimization model for cruise performances under multi-lift conditions of wing cross sections was constructed through combination of this function with the variable camber technology and an artificial neural network surrogate model. The deep deterministic policy gradient (DDPG) method was used to optimize this model, resulting in a cruise average lift-to-drag ratio improvement of 6.8% under buffeting constraints. This improvement surpasses the results obtained by other optimization algorithms, such as the particle swarm optimization (PSO) and the improved gray wolf optimization (GWO). The results of the generation and analysis of 2 conical swept wings with the unoptimized and optimized airfoils, show the contribution of the 2D variable camber airfoil optimization to 3D wings. [ABSTRACT FROM AUTHOR]

There is an alarming surge in food wastage stemming from culinary practices and intricate cuisines despite technological advancements. The reduction in food wastage is a pivotal sustainable development goal, yet statistics indicate high levels of wastage. Scholars have investigated food waste extensively with a focus on the hospitality sector, which accounts for nearly 12% of total waste. Factors contributing to food waste have been examined, yet findings tend to be isolated and lack a holistic approach. Existing research leans heavily toward developed countries despite the issue being more pronounced in developing economies. Investigations into hotel-related food wastage in Taiwan remain scarce. Effective waste management can curtail expenditures and enhance brand reputation and underscore a commitment to environmental sustainability for hoteliers and culinary managers. This study offers actionable insights to guide sustainable development. The current research employs qualitative interviews and structured questionnaires with culinary experts and hotel management to decode intricacies of food wastage across procurement, inventory, and preparation in Taiwanese hotels. Utilizing the Analytic Network Process methodology, the research provides insights to guide hoteliers in achieving sustainable development goals. [ABSTRACT FROM AUTHOR]

The article presents new data from the history of the municipality of Buzău. The research focuses, in particular, on the history of the material heritage of the municipality of Buzău. The history of the parks in the city of Buzău before the First World War and of the Municipal Palace after 1944 is being reconstructed. During the years of the Old Kingdom, the city of Buzau experienced an interesting modernization process. In the years before the First World War, The mayors of Buzău tried in the years before the First World War to bring the city up to European standards. After 1877, Buzăul began a series of modernization and beautification actions. As a result, the appearance of the city has changed quite a bit. The town hall paid attention to the maintenance of public parks, by planting saplings, installing statues and recreational buildings. The Grove also entered the views of the city councils to be transformed into a real public garden. During the Second World War, until August 1944, Buzăul was relatively little affected. After August 23, the situation changed dramatically, and heavy battles were fought with the German army on the territory of the city. On August 27, 1944, the Municipal Palace burned completely. The local authorities began, in the fall of 1944, the works to restore it. In 1949, the restoration of the Municipal Palace was completed, but for financial reasons, the interior was never authentically restored. However, the Municipal Palace was reborn, to the joy of the residents.

Covid-19 conditions force hotels to change the mechanism of breakfast serving system, which was previously done in a buffet. This is because buffet breakfast is the time for hotel guests to gather with each other, but this is not in accordance with the Covid-19 health protocol. Besides, the buffet method also caused food surplus because the hotel had to prepare more food than the number of guests. The food surplus has the potential to become food waste if not utilised. The purpose of this research was to provide an overview of the amount of food loss from the producer side, both in terms of resources and the economy from buffet breakfast activities at hotel, and provide options for breakfast serving at hotels during the Covid-19 pandemic. This research was conducted at a two-star hotel in Bandung using survey, observation, and interview methods. The results of this research indicated that the breakfast serving method during a pandemic could be done by room service mechanism. The potential for food waste from food surplus comes mostly from the main course menu, especially carbohydrate (rice) group with 48%. If food surplus is not managed, it could become a large loss potential in both resources and economic. What is significant from this research is that this research was carried out from the producer's side, by managing the food surplus from the serving container and not from the hotel guest plate. Thus, the research results can be used as a reference for environmentally friendly hotel management.

During the SARS-CoV-2 pandemic, the self-service restaurant sector, as well as other types of food services, are facing an unprecedented crisis needing to adapt their service to avoid closing their doors. With varied and quick meals, the self-service buffet is one of the most important types of outside services. However, the type of service where the clients follow a line on the buffet and serve their meals has impaired traditional restaurant operation during the SARS-CoV-2 pandemic and, perhaps, after it. In this sense, this study presents an overview of the self-service buffet restaurant operational system in the context of the SARS-CoV-2 pandemic.

The present article assesses the capability of the partially averaged Navier-Stokes (PANS) method to reproduce accurately the self-sustained shock oscillations, also known as transonic buffet, occurring on airfoils and wings at transonic regime under certain conditions of Mach number and angle of attack. The test case under analysis is an OAT15A unswept wing at Mach number M ∞ = 0.73 and Reynolds number Re c = 3 × 10 6. The three-dimensional flow is studied by accounting for the wind tunnel walls adopted in the experiments of Jacquin et al. [1] in the simulations. The computations on a large-span, confined configuration reveal a strong three-dimensionality of the flow both before and after the buffet onset. Attention is paid to the comparison with unsteady Reynolds-averaged Navier Stokes (URANS) results, to show the benefits of PANS in resolving flow unsteadiness at different flow resolutions, especially on affordable CFD grids, at limited additional cost. In this context, the role of the mesh metrics and the local turbulence level in the formulation of the model is described, as well as the relation of this latter with the spatiotemporal discretization used for the numerical simulations. The aim is to extend the use of PANS and obtain accurate predictions of flow cases involving shock-wave boundary layer interactions without expensive approaches. [ABSTRACT FROM AUTHOR]

Early feminist or pro-woman works often combine the claim that the rational souls of men and women are the same with an argument for the superiority of women. This article considers two such works, Lucrezia Marinella's The Nobility and Excellence of Women and the Defects and Vices of Men (Venice, 1601 [1999]) and Marguerite Buffet's In Praise of Illustrious Learned Women, both Ancient and Modern (Paris, 1668), in order to show the continuities and distinctive features of feminist arguments for superiority, to emphasize the differences in the conceptions of reason and physiology that distinguish them, and to demonstrate that claims of superiority persisted even as those defending women's worth began to adopt egalitarian positions. [ABSTRACT FROM AUTHOR]

In this paper, the methods to address the transonic aeroelastic problems like flutter and buffet are discussed. Aerospace vehicles have to obtain the structural design clearance from transonic flutter and buffet, to fly in supersonic and hypersonic speeds. Transonic aerodynamics are actually complex in nature and simulating its flow physics through unsteady CFD is now forthcoming. Nevertheless, for a developmental space vehicle and weaponization of in-service aircraft, there is a need to have reliable and trustworthy methods to solve these important design-related aeroelastic problems in flight critical transonic regime (M = 0.9–1.1). Accordingly, the author has presented the novel transonic aeroelastic techniques that can be applied for the store integration on a fixed wing aircraft and for the mission clearance of space vehicle from the structural flexibility point of view. Case studies with results are presented to substantially validate the outlined techniques. [ABSTRACT FROM AUTHOR]

Freshman-15 is a phenomenon of first-year university students resulting in weight gain partly due to new cafeteria eating patterns and stress. This study determined if a premeal walnut snack alters planned eating behavior and mealtime nutrient intake during a subsequent buffet-model meal. Healthy university students (n = 36; 18.1 ± 0.5 years; body mass index: 23.6 ± 3.9) received three treatments (90 min premeal) in randomized order on 3 consecutive days: (1) snack of 190 Cal (1 oz) of walnuts (WS), (2) snack of 190 Cal of gummy candy (GS), or (3) no snack (NS; control) before a standard cafeteria dinner (1760 Cal). Visual analog scale (VAS) surveys were administered before and after dinner, and caloric intake was determined. Premeal VAS desire to eat was lower after WS and GS than NS, whereas the sense of hunger and sense of fullness were higher after WS and GS compared with NS. Postmeal VAS was not different between treatments. Mealtime calories, total fat, saturated fat, cholesterol, protein, sodium, fiber, and sugar consumed after WS were significantly less than NS. Total fat and sodium consumed after GS did not significantly differ from NS. Mealtime total fat, sodium, and fiber for WS were significantly less than GC, and a trend was observed for total calories. Differences in calorie intake were not observed between treatments when snack calories were included as part of the mealtime caloric intake. These findings could be helpful for promoting WS and to a lesser degree GS for increased satiety before meals possibly leading to reduced food intake during dinner by university students. [ABSTRACT FROM AUTHOR]

Behavioural change research for environmental sustainability is currently guided almost exclusively by a cognitive paradigm, which assumes that cognitive constructs drive behaviour and must be influenced to change it. This study challenges this dominant paradigm and tests two non-cognitive theoretical constructs – respect for authority and empathy – in the context of reducing buffet plate waste. Respect for authority (in contrast to empathy) passes the manipulation check and significantly reduces plate waste in a quasi-experimental field study in a Chinese hotel, providing proof of concept for a new, urgently needed, re-orientation in behavioural change intervention design. The intervention tested in this study can immediately be deployed by tourism and hospitality businesses who want to make their buffets more cost-effective and environmentally sustainable. • Plate waste harms the environment and must urgently be reduced. • We developed non-cognitive behavioural change interventions. • We tested them in a survey and field experiment. • Plate waste per person per day was measured at a hotel buffet. • A respect for authority-based intervention reduced buffet plate waste by 6.8 %. [ABSTRACT FROM AUTHOR]

An experimental investigation of the transonic flow past the laminar OALT25 airfoil has been conducted to analyze the impact of laminar flow upon the shock wave dynamics and the existence of a laminar buffet like phenomenon. Tests have been carried out at freestream Mach numbers varying in the range of 0.7–0.8, angle of attack from 0.5° to 4°, and with two tripping configurations at the upper surface of the wing. The (airfoil) chord based Reynolds number is about three million. Results obtained from pressure taps and sensors measurements, as well as Schlieren visualizations of the flow reveal the presence of a laminar buffet phenomenon in sharp contrast with the turbulent phenomenon, as it features a freestream- and chord-based normalized frequency of about unity while turbulent buffet occurs for a frequency close to 0.07 (Jacquin et al., AIAA J 2009; 47). A low-frequency mode, at a frequency of about 0.05 is also present in the laminar situation, notably lower than the high-frequency component. The latter exhibits strong oscillations of the shock foot and vertical wavelike deformations of the shock wave and the former moves the shock back and forth over a small portion of chord, quite similar to the turbulent phenomenon. The mean flow past the laminar wing is characterized by a laminar separation bubble under the shock foot, which likely contributes much to the novel dynamics revealed by the present experiments. Two control strategies of the unsteady shock wave are implemented, one consisting of three-dimensional bumps and one consisting of steady jets blowing transversely to the freestream. It is found that bumps provide a significant reduction of the buffet intensity in the laminar situation. The jets are able to completely remove the flow unsteadiness in both laminar and turbulent conditions. [ABSTRACT FROM AUTHOR]

The effect of plasma actuators on shock wave–laminar boundary layer interaction was studied experimentally on transonic laminar aerofoil. The unsteady characteristics of the separation zone including the transonic buffet were measured. Two kinds of electrical discharge actuators were used for the flow control. Successful suppression of separated flow and laminar transonic buffet by plasma actuators was demonstrated. An analysis of the effect of power and frequency of the discharge on shock wave–laminar boundary layer interaction was carried out. High efficiency ratio of the separation control by plasma actuators was achieved in the experiments. [ABSTRACT FROM AUTHOR]

Hyatt Regency Yogyakarta has strategies to increase the number of visitors to the hotel. One of the strategies made by Hyatt Regency Yogyakarta regular event “Ramayana Night Market" which is held every Saturday night. The purposes of this research are to know the buffet menu and the layout of buffet in regular event “Ramayana Night Market” at Kemangi Bistro Hyatt Regency Yogyakarta. This research used observation, interview, and documentation techniques to collect the data. The results showed that the menu in regular event “Ramayana Night Market” are presented on the long table buffet and ranged from appetizer, main course, and dessert. Regular event “Ramayana Night Market” serve traditional food as concept. The layout of the buffet at regular event “Ramayana Night Market” is made to grouping the menu based on the type (appetizer, main course, and dessert) to make it easy for the customers to take the food from the buffet.

• First food waste study at a university campus in Qatar. • Mixture of large-scale catering services and specialized franchise food outlets. • The per person food waste generation exceeds the highest globally reported rates. • Overproduction is the main driver for food wastage resulting from food display. • Highlights the possible scale of issue at cafeterias and need for caterer education. Food waste is a pressing issue that imposes economic, social and environmental impacts on both developing and developed countries. This study analyzes quantitatively and qualitatively the generated food waste at various food outlets of a university campus in Qatar. It is a fundamental step to manage the issue of food waste from educational institutes. The investigation comprised four stages: screening, sampling, surveying, and synthesis. Food waste generation at the sampled locations was estimated at 329.5 kg/day or 80 t/year. Based on per sales estimates, total food waste was 980 g/sale and 757 g/sale at the student male and female housing complexes, respectively, equating to roughly one wasted meal for each sold meal. The majority of this waste was avoidable waste and the root cause for the excessive food waste generation was overproduction rather than consumer wastage. The study found that the main food provider, who primarily serves buffet style meals, lacks the proper tools to measure food waste generated at their cafeterias. Past experience was the primary tool to support the company's demand management estimation which has proven unsuccessful and highlights the need to not only educate the consumer but also food providers. Possible treatments routes are discussed based on food waste characterization findings. [ABSTRACT FROM AUTHOR]

In this work, computational fluid dynamics simulations are carried out to assess the ability of control surfaces to alleviate or suppress transonic buffet. Among the available control surfaces, upper trailing edge flaps were considered since they modify the aerofoil pressure distribution and fix the shock at an upstream position. Spoilers were also studied as they produce a similar effect by interfering with the pressure disturbance propagation in the boundary layer and prevent buffet. For both devices, the sensitivities to geometric parameters are studied. The effectiveness of these buffet control methods is first assessed for 2D computations around different wing sections. As spoilers were considered more effective, results on a 3D configuration are provided to discuss the influence of finite-span devices on aerodynamic performance. In addition, a simple model accounting for changes in the flight Mach number together with the spoiler is presented to simulate a simple flight scenario and provide an effective strategy for buffet suppression. In the framework of numerical investigations, the adoption of virtual control surfaces allows for avoiding difficulties associated with the modelling of slotted and deployable devices. [ABSTRACT FROM AUTHOR]

A problem in the hotels that provide the "buffet" service, the price of which is included in that for overnight stay in the room, is the accounting and the effective control of the full use of the allowances groceries in finished kitchen products. Keeping track of changes in the prices of supplying goods at the height of the tourist season („Food and Beverage Cost Control“), the calculation of so-called "Food Costs for Day" and "Beverage Costs for Day", and frequent inventory inventories to excample date, relation to accurate and true cost accounting for a certain period, are objectively necessary. [ABSTRACT FROM AUTHOR]

A detailed survey of pressure fluctuations was conducted on a replica of the generic, “hammerhead” shaped space vehicle tested more than half century ago by Coe and Nute (1962). A large number of current and past space vehicles follow this general hammerhead configuration. The present test was conducted in the 11-by-11 ft Transonic Wind Tunnel of NASA Ames Research Center over the critical transonic Mach number range of 0.6 ≤ M ≤ 1.2 where typical vehicles encounter very high levels of surface pressure fluctuations during ascent through the atmosphere. Out of the many different types of instrumentations used for this test, data from the dynamic pressure sensors are presented in this paper. In addition, shadowgraph flow visualizations, and a qualitative measure of turbulent fluctuations, estimated from high-speed photography, are also presented. The data set provided a clear insight into the local high level of fluctuations from the formation of the transonic shocks on the payload fairing and also from the impingement of the separated shear layer on the second stage. Space–time correlation showed interesting physics of upstream propagation of pressure fluctuations on the payload fairing when local shock waves were present. A comparison of the magnitude of pressure fluctuations between the present test and that done earlier by Coe and Nute showed good agreement when the limited frequency bandwidth of equipment used in the latter was accounted for. Similarly, when accounting for the differences in the free-stream dynamic pressure, the spectra of surface pressure fluctuations were in reasonable agreement between the present and Coe–Nute tests. The present test provides a far more complete picture of pressure fluctuations due to the usage of a large number of pressure transducers (216 versus 30), wider frequency bandwidth (50 kHz versus 1 kHz), and unsteady pressure-sensitive paint. [ABSTRACT FROM AUTHOR]