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To enable wind energy to surpass fossil fuels, the power-to-cost ratio of wind turbines must be competitive. Increasing installation capacities and wind turbine sizes indicates a strong trend toward clean energy. However, larger rotor diameters, reaching up to 170 m, introduce stability and aeroelasticity concerns and aerodynamic phenomena that cause noise disturbances. These issues hinder performance enhancement and social acceptance of wind turbines. A critical aerodynamic challenge is flow separation on the blade's suction side, leading to a loss of lift and increased drag, ultimately stalling the blade and reducing turbine performance. Various active and passive flow control techniques have been studied to address these issues, with passive techniques offering the advantage of no external energy requirement. High-lift devices, such as leading-edge slats, are promising in improving aerodynamic performance by controlling flow separation. This study explores the geometric parameters of slats and their effects on wind turbine blades' aerodynamic and acoustic performance. Using an adequate turbulence model at Re = 106 for angles of attack from 14° to 24°, 77 slat configurations were evaluated. Symmetric slats showed superior performance at high angles of attack, while slat chord length was inversely proportional to aerodynamic improvement. A hybrid method was employed to predict noise, revealing slat-induced modifications in eddy topology and increased low- and high-frequency noise. This study's main contribution is correlating slat-induced aerodynamic improvements with their acoustic effects. The directivity reveals a 10–15 dB reduction induced by the slat at 1 kHz, while the slat induces higher noise at higher frequencies. [ABSTRACT FROM AUTHOR]

Indoor air quality determines the comfort, health, and wellbeing of people in buildings. Windows are the optimal elements for providing natural ventilation and fresh air, but the outside contains suspended particles that can be harmful in high concentrations. This work presents an openable and double-glazed façade component with a cavity that includes a series of slats that filter the air and depurate it by means of a photocatalytic reaction (TiO2). This component integrates the functions of ventilation, solar protection, and air purification, which were analysed in the slat and the façade component to approve a preliminary design. To this end, it was applied to a specific case, a non-residential building at a latitude 41° N in a Mediterranean climate. The results show the optimal dimensions according to solar radiation and ventilation in this specific case and the method used to obtain them, along with the increase in the temperature of the incoming air with respect to the outside (10 °C). Finally, the results obtained from a photocatalytic coating sample show that the NOx degradation can be up to 9%. All these results confirm the applicability of this component in buildings and pave the way for further research. [ABSTRACT FROM AUTHOR]

To enable wind energy to surpass fossil fuels, the power-to-cost ratio of wind turbines must be competitive. Increasing installation capacities and wind turbine sizes indicates a strong trend toward clean energy. However, larger rotor diameters, reaching up to 170 m, introduce stability and aeroelasticity concerns and aerodynamic phenomena that cause noise disturbances. These issues hinder performance enhancement and social acceptance of wind turbines. A critical aerodynamic challenge is flow separation on the blade’s suction side, leading to a loss of lift and increased drag, ultimately stalling the blade and reducing turbine performance. Various active and passive flow control techniques have been studied to address these issues, with passive techniques offering the advantage of no external energy requirement. High-lift devices, such as leading-edge slats, are promising in improving aerodynamic performance by controlling flow separation. This study explores the geometric parameters of slats and their effects on wind turbine blades’ aerodynamic and acoustic performance. Using an adequate turbulence model at Re = 106 for angles of attack from 14° to 24°, 77 slat configurations were evaluated. Symmetric slats showed superior performance at high angles of attack, while slat chord length was inversely proportional to aerodynamic improvement. A hybrid method was employed to predict noise, revealing slat-induced modifications in eddy topology and increased low- and high-frequency noise. This study’s main contribution is correlating slat-induced aerodynamic improvements with their acoustic effects. The directivity reveals a 10–15 dB reduction induced by the slat at 1 kHz, while the slat induces higher noise at higher frequencies.

Indoor air quality determines the comfort, health, and wellbeing of people in buildings. Windows are the optimal elements for providing natural ventilation and fresh air, but the outside contains suspended particles that can be harmful in high concentrations. This work presents an openable and double-glazed façade component with a cavity that includes a series of slats that filter the air and depurate it by means of a photocatalytic reaction (TiO2). This component integrates the functions of ventilation, solar protection, and air purification, which were analysed in the slat and the façade component to approve a preliminary design. To this end, it was applied to a specific case, a non-residential building at a latitude 41° N in a Mediterranean climate. The results show the optimal dimensions according to solar radiation and ventilation in this specific case and the method used to obtain them, along with the increase in the temperature of the incoming air with respect to the outside (10 °C). Finally, the results obtained from a photocatalytic coating sample show that the NOx degradation can be up to 9%. All these results confirm the applicability of this component in buildings and pave the way for further research.

The potential of airfoil optimisation for the specific requirements of airborne wind energy (AWE) systems is investigated. Experimental and numerical investigations were conducted at high Reynolds numbers for the S1223 airfoil and an optimised airfoil with thin slat. The optimised geometry was generated using the NSGA-II optimisation algorithm in conjunction with 2D-RANS simulations. The results showed that simultaneous optimisation of the slat and airfoil is the most promising approach. Furthermore, the choice of turbulence model was found to be crucial, requiring appropriate transition modeling to reproduce experimental data. The k-ω-SST-γ-Reθ model proved to be most suitable for the geometries investigated. Wind tunnel experiments were conducted with high aspect ratio model airfoils, using a novel structural design, relying mostly on 3D-printed airfoil segments. The optimised airfoil and slat geometry showed significantly improved maximum lift and a shift of the maximum power factor to higher angles of attack, indicating good potential for use in AWE systems, especially at higher Reynolds numbers. The combined numerical and experimental approach proved to be very successful and the overall process a promising starting point for future optimisation and investigation of airfoils for AWE systems.

The potential of airfoil optimisation for the specific requirements of airborne wind energy (AWE) systems is investigated. Experimental and numerical investigations were conducted at high Reynolds numbers for the S1223 airfoil and an optimised airfoil with thin slat. The optimised geometry was generated using the NSGA-II optimisation algorithm in conjunction with 2D-RANS simulations. The results showed that simultaneous optimisation of the slat and airfoil is the most promising approach. Furthermore, the choice of turbulence model was found to be crucial, requiring appropriate transition modeling to reproduce experimental data. The k- ω - S S T - γ - R e θ model proved to be most suitable for the geometries investigated. Wind tunnel experiments were conducted with high aspect ratio model airfoils, using a novel structural design, relying mostly on 3D-printed airfoil segments. The optimised airfoil and slat geometry showed significantly improved maximum lift and a shift of the maximum power factor to higher angles of attack, indicating good potential for use in AWE systems, especially at higher Reynolds numbers. The combined numerical and experimental approach proved to be very successful and the overall process a promising starting point for future optimisation and investigation of airfoils for AWE systems. [ABSTRACT FROM AUTHOR]

The flow around the slat cove of a two-dimensional 30P30N multi-element airfoil is investigated with time-resolved particle image velocimetry (TR-PIV) at low Reynolds number (Rec = 2.41 × 104 and 4.61 × 104). The effects of angle of attack (α = 8°, 12°, and 16°) on the mean flow characteristics and vortex dynamics are discussed. The size of the recirculation within the slat cove and the intensity of the shed vortices originating from the slat cusp shear layer are found to generally decrease as the angle of attack increases. The joint time-frequency analyses show that disturbances of different frequencies exist in the slat cusp shear layer and they trigger the different vortex shedding patterns of the slat cusp shear layer. The self-sustained oscillation within the slat cove, normally observed at high Reynolds number (Rec ~ 106), is proved to be responsible for the disturbances of different frequencies and the related vortex dynamics in the current study. [ABSTRACT FROM AUTHOR]

Recently, there have been significant developments in the field of vibration energy harvesters to feed sensors for structural health monitoring in aeronautics and other high technology fields. Within the framework of the EU InComEss project, new eco-friendly piezoelectric materials are under development. A foreseen application is vibration energy harvesting from the wing slats of aircraft. Semi-analytical models of the vibrating slat make it possible to estimate the maximum voltage that can be generated by a piezoelectric patch bonded to a slat surface. A more detailed analysis must consider details of the three-dimensional geometry of both the harvester and the bonding layer. This can only be carried out with multiphysics finite element software. A finite element model of a whole slat would require a large computational effort as millions of elements are typically needed to model very thin piezoelectric layers. To simplify this analysis, an integrated analytical–numerical method is proposed in this paper. A large-scale analytical model of the whole slat was used to calculate loads on the portion of the slat where a piezoelectric patch was attached. Then, a small-scale finite element model of the portion of the slat with the piezoelectric patch was used to calculate the open circuit voltage generated by the patch. The response of the harvester to random excitation, typical of aeronautic applications, was calculated. The effects of the details of the harvester design on the generated voltage were analyzed and discussed. [ABSTRACT FROM AUTHOR]

Combining the existing slat cusp extension with the noise reduction technique proposed in this paper, based on the 30P30N multi-segment aerofoil, unsteady flow of three-dimensional airfoil structure is simulate by DDES algorithm.Firstly, the pressure and vorticity transient parameters of the model are obtained.And then, the sound pressure level and directivity are studied by FW-H integration method to study the effects of slat cusp geometric extensions on the surrounding flow field and noise characteristics.Finally, based on the instantaneous vortex structure analysis method of ▽2ρ, the generation and evolvement of flow structures in slat cove and corresponding noise distributions are investigated for various extensions.The investigation shows, cusp extension can effectively change the distribution of parameters of slat flow.Among which, extensions along the sheer layer can reduce the strength of turbulence kinetic energy in slat cove and decrease the characteristic dimension of vortices of separating flow, as a result, suppressing the radiation of slat noise(narrow band noise can be reduced by 3 dB in low frequencies).

Slat aerodynamic noise is one of important components of the frame noise. Adjusting the parameters of the slat structure can suppress the slat noise radiation effectively. Based on the typical multi-element airfoil 30P30N, firstly, by means of adjusting the parameters of slat structure, such as changing relative positions between slat and main airfoil and closing slat gap etc., a new slat profile is obtained; Then, based on the DDES simulation method, the characteristics of vortex distribution is analyzed for the new airfoil structure model, and the directivity and SPL of the far field noise are also investigated; Finally, through comparison analysis of the parameters, the physics of the generation of slat aerodynamic noise is discovered, and effects of slat parameters on the features of slat aerodynamic noise are also obtained. The results of the study show that the vortex strength of the flow around the slat has close relation to the source of slat noise. By means of adjusting slat position parameters and morphing of the slat's trailing edge, the vortex strength of the flow close to the slat cusp is reduced effectively, and further largely reducing the slat noise radiation, which can be achieved with preserving high lift coefficient of the airfoil.

Slat aerodynamic noise is largely dependent on its structure parameters(geometric position and variable outline). The analysis of the effects of these two parameters on the features of flow and aerodynamic noise for an airfoil is an effective method of developing techniques for the slat noise suppression. On the basis of three-element airfoil model 30P-30N, the flow field analysis model is established. The RANS and LES(large-eddy simulation) methods are used to analyze the steady and transient state flow field characteristics of the airfoils with typical geometric positions(overlap length, gap width and rotation angle) and morphed profiles(curved close gap of slat tailing edge respectively, which can obtain the corresponding distributions of pressure and turbulent kinetic energy of airfoil, and transient state pressure distribution of flow field. The FW-H acoustic analogy integral method is employed to solve the far-field noise distribution characteristic. The inter-relationship of various slat structure parameters with the far-field acoustic pressure level and its directional distribution features are investigated. According to various slat structure parameters, the coupling relationship between slat noise suppression and corresponding airfoil lift change is analyzed. The results show that the adjustment of slat geometry position and structural deformation parameters can effectively reduce the far-field noise radiation, but the lift coefficient can be reduced to some extent when the angle of attack is increased.

Aerodynamic performance of aircraft wings vary with flight path conditions and depend on efficiency of high lift systems. In this work, a study on high lift devices and mechanisms that aim to increase maximum lift coefficient and reduce drag on commercial aircraft wings is discussed. Typically, such extensions are provided to main airfoil along span wise direction of wing and can increase lift coefficient by more than 100% during operation. Increasing the no of trailing edge flaps in chord wise direction could result in 100% increment in lift coefficient at a given angle of attack but leading edge slats improve lift by delaying the flow separation near stall angle of attack. Different combinations of trailing edge flaps used by Airbus, Boeing and McDonnel Douglas manufacturers are explained along with kinematic mechanisms to deploy them. The surface pressure distribution for 30P30N airfoil is evaluated using 2D vortex panel method and effects of chord wise boundary layer flow transitions on aerodynamic lift generation is discussed. The results showed better agreements with experiment data for high Reynolds number (9 million) flow conditions near stall angle of attack.

The tooth root bending fatigue durability is the main content of the structural strength specification in developing the slat gear-rack mechanism. The design is difficult and the development cycle is long considering the motion coordination and later test validation. Based on the analysis of aerodynamic loads, the virtual bending fatigue durability model of slat gear-rack mechanism is established by using ANSYS and nCode. The virtual bending fatigue life data of slat gear-rack mechanism under different surface roughness factors are obtained through the analysis. The results show that the virtual bending fatigue life of slat gear-rack mechanism can be predicted and the economic surface roughness parameters can be determined by using the virtual fatigue durability analysis method. Meanwhile, the design result can be revised when the structural strength specification is not satisfied before testing. The best design result is obtained, and the development cycle is shortened.

In order to verify the components strength of slat sector gear transmission mechanism,moreover improve its service life,transmission stability and transmission accuracy,the loading and control method of slat sector gear transmission mechanism testing is analyzed according to the development and production demand of a certain type aircraft slat sector gear transmission mechanism. The test equipment of slat sector gear transmission mechanism is developed by using the principle of motion similarity and dynamic similarity,and the equipment adopted closed loop control and hydraulic loading. The static strength test and delivery running-in of the slat sector gear transmission mechanism are carried out by this equipment,and the results of these works are good.The requirements of running-in and relevant test is satisfied.

Different gas-solids flow phenomenas have been observed during start-up of fluidized beds of different particulate materials. • Forces on a horizontal slat during start-up of fluidized beds of different particulate materials were measured. • The immersed internals will be subject to more severe during start-up of fluidized beds of small particle size. • Different gas–solids flow phenomenas have been observed during start-up of fluidized beds of different particulate materials To study the effect of particle properties on forces acting on immersed internals during start-up of fluidized bed reactors, forces on a horizontal slat were measured in fluidized beds of four types of particulate materials (i.e. FCC catalyst particles and three silica sands of different sizes). The forces were measured by strain gauges adhered on the slat surface. Transient pressure signals were also measured synchronously by pressure transducers. The experimental results show that a high upward stress impulse appears in the measured stress signals during start-up of the fluidized beds of FCC particles and the two smaller-size silica sands. The peak stress impulse was several times larger than the magnitude of stress signals measured during steady state operation. However, in the fluidized bed of the coarsest silica sand, the peak stress impulse during start-up was much smaller, which is close to the magnitudes measured during steady state fluidization. For the three sizes of silica sands, the effective peak load densities on the slat decreased significantly with increasing particle size and were approximately proportional to the calculated fixed bed pressure drops of these beds based on Ergun equation. On the other hand, during start-up of the fluidized bed of FCC particles, particles near the bottom of the bed were difficult to mobilize and collapse, resulting in the bed expanding considerably and requiring more time to transform into a fluidized state. Potentially, internals immersed in the fluidized beds of small particles are easier to damage during the start-up stage. Effective measures (e.g. starting up the bed gradually with small increments of superficial gas velocity) must be implemented to reduce the possible risks for internals immersed in these fluidized beds. [ABSTRACT FROM AUTHOR]

Aerodynamic performance of aircraft wings vary with flight path conditions and depend on efficiency of high lift systems. In this work, a study on high lift devices and mechanisms that aim to increase maximum lift coefficient and reduce drag on commercial aircraft wings is discussed. Typically, such extensions are provided to main airfoil along span wise direction of wing and can increase lift coefficient by more than 100% during operation. Increasing the no of trailing edge flaps in chord wise direction could result in 100% increment in lift coefficient at a given angle of attack but leading edge slats improve lift by delaying the flow separation near stall angle of attack. Different combinations of trailing edge flaps used by Airbus, Boeing and McDonnel Douglas manufacturers are explained along with kinematic mechanisms to deploy them. The surface pressure distribution for 30P30N airfoil is evaluated using 2D vortex panel method and effects of chord wise boundary layer flow transitions on aerodynamic lift generation is discussed. The results showed better agreements with experiment data for high Reynolds number (9 million) flow conditions near stall angle of attack. [ABSTRACT FROM AUTHOR]

Fase take off dan landing merupakan fase yang paling kritis diantara fase – fase dalam operasi penerbangan. Pada saat take off sayap pesawat diposisikan pada angle of attack yang cukup besar, sehingga aliran udara akan melawan adverse pressure yang lebih besar sampai saat dimana aliran tidak mampu melawan adverse pressure aliran akan terseparasi. Jika terjadi separasi permanen sesaat setelah aliran melintasi leading edge di sektor upper side maka bisa mengakibatkan terjadinya stall pada pesawat. Untuk mencegah hal tersebut terjadi, dibutuhkan slat pada bagian depan sayap sebagai penuntun aliran pada leading edge untuk memasuki daerah upper side secara halus dengan akselerasi yang kuat. Penelitian ini dilakukan dengan eksperimen dan numerik. Benda uji yang digunakan adalah airfoil NACA 2412 dengan slat dan tanpa slat. Variasi slat clearance dan slat angle yaitu S/c : 0,05; 0,07; 0,09; (β): 0°, 3°, 5°. Hasil penelitian ini adalah konfigurasi B merupakan konfigurasi optimum dalam mengeliminasi stall pada angle of attack (α) 8°, sedangkan konfigurasi H merupakan konfigurasi optimum dalam mengeliminasi stall pada angle of attack (α) 16°.

It considers the task of determination of parasite drag for subsonic commercial airplane on the base of theoretical calculation procedures. It contains the procedure for clarification of empirical approach to calculation of parasite drag at high speeds. It provides examples of calculation of parasite drag at transonic speeds as a result of step behind the slat on the wing of commercial airplane.

An immersed boundary method on unstructured meshes is used in serial eddy-resolving simulations of turbulent flows over individual bodies with a changeable configuration and position. The corresponding numerical technique is based on mesh deformation and dynamic adaptation of a moving mesh without changing its topology. The described approach makes it possible to substantially reduce the computational costs of serial computations with variations in geometric parameters aimed at optimizing the shapes of airfoil elements. The performance of the technique is demonstrated by simulating the aeroacoustic properties of a two-element airfoil segment involving a leading-edge slat with changeable geometry. [ABSTRACT FROM AUTHOR]

• Straw was the most preferred material. • Rubber and solid wooden can be alternatives to straw. • Slated floors was hygienic, but was not preferred. Barn flooring and bedding management are two critical issues in intensive dairy goat facilities. This study aimed at identifying the most appropriate seasonal floorings through observation of the behavioral characteristics of dairy goats. Four different trials were carried out in two different seasons (summer and winter). Wooden and rubber floorings were compared in the 1st trial; solid wood and slatted wooden floorings in the 2nd trial; 5% and 10% sloped floors in the 3rd trial, and 5-cm and 10-cm wide wooden slats were compared in the 4th trial. A total of 20 polled Turkish Saanen goats at 3-years of age were used in the experiments. During the temperature and relative humidity measurements taken in the morning hours, the floors were also scored for dirtiness. The floor dirtiness scores did not vary significantly by season or by season x type of flooring (P > 0.05). While there were no significant differences in the dirtiness scores of the flooring in the 1st and 3rd trials, the slatted floors of the 2nd and 4th trials had relatively lower dirtiness scores than the other floorings (P ≤ 0.05). Goats spent the majority of their time lying (74.88%) and were observed to favor reclining onto pen fences while lying. The lying behavior did not vary significantly regarding season in any trials (P > 0.05). However, the lying behavior of the goats significantly varied according to floor type in all trials (P ≤ 0.0396). Goats lay mostly over straw bedding in all trials, followed by rubber material, solid surface and 5% slope, which had rates close to that of straw bedding (P ≥ 0.05). In trial 4, goats demonstrated significantly lower lying behavior over both types of slats (5 cm and 10 cm) than straw bedding (P ≤ 0.05). Goats lay significantly more over the rubber floor compared to the wooden floor, more over the solid floor than the slatted floor, and more over the 10 cm slats than 5 cm slats. Goats demonstrated standing behavior more over the slatted floors (trials 2 and 4) (P ≤ 0.05). In this study, straw bedding was primarily chosen by dairy goats. Following straw bedding, goats largely opted for rubber flooring and solid wooden flooring and they showed no liking for slatted floors. [ABSTRACT FROM AUTHOR]

Earthquake is an unpredictable natural phenomenon that create a vast amount of damage, affecting communities and their environment. To reduce the effects of such hazards, frameworks like building resilience have emerged. These frameworks target on increasing recovery after such disaster, by introducing new designs, technologies, and components to the building. To calculate the value of such improvements, use of loss estimation systems are essential. This paper compares and contrasts two most widely adopted loss assessment tools available, namely PACT and SLAT. Comparison of these tools mainly focuses on the consequence functions of the two methods. Recommendations are suggested to improve and complement these tools in future use. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) control key events of immune tolerance, primarily by suppression of effector T cells. We previously revealed that Tregs rapidly suppress T cell receptor (TCR)-induced calcium store depletion in conventional CD4+CD25− T cells (Tcons) independently of IP3 levels, consequently inhibiting NFAT signaling and effector cytokine expression. Here, we study Treg suppression mechanisms through unbiased phosphoproteomics of primary human Tcons upon TCR stimulation and Treg-mediated suppression, respectively. Tregs induced a state of overall decreased phosphorylation as opposed to TCR stimulation. We discovered novel phosphosites (T595_S597) in the DEF6 (SLAT) protein that were phosphorylated upon TCR stimulation and conversely dephosphorylated upon coculture with Tregs. Mutation of these DEF6 phosphosites abrogated interaction of DEF6 with the IP3 receptor and affected NFAT activation and cytokine transcription in primary Tcons. This novel mechanism and phosphoproteomics data resource may aid in modifying sensitivity of Tcons to Treg-mediated suppression in autoimmune disease or cancer.

Sheep farming makes an important socio-economic contribution to Spain’s rural areas by sustaining farming and employment in less favored regions, but it is a low-profit sector because of high operating and regulatory costs. One possible solution would be to raise for slaughter lambs from dairy sheep that are not required as replacements. However, the early weaning of these lambs and their artificial rearing generally lead to reduced growth rates and high mortalities. In the work presented herein, three housing systems (slat + heating plate, slat + infrared lamp, and deep-litter + infrared lamp) were tested on 763 lambs over an eight-month period in a farm located in Ejea de los Caballeros (Zaragoza, Spain), with a view to reducing mortality during the period of artificial lactation. The effect of the environmental parameters of the lamb housing on the development of the lambs was evaluated by monitoring environmental (temperature, relative humidity, CO2 and NH3) and productive parameters (weight, average daily gain, and deaths). The results suggested that the combination of deep litter with straw bedding and infrared lamp heating would be the most favorable option, as it led to the highest average daily gain and the lowest percentage of deaths. From the study of the relationship of the initial weight with deaths, a prediction curve was obtained, defining the maximum prices to be paid per lamb as a function of their initial weight to guarantee the profitability of the raising process. This may be regarded as a valuable guidance for Spanish sheep farmers, as it can reduce their economic uncertainty.

Forces acting on a horizontal slat immersed in a fluidized bed during its start-up stage were investigated systematically. Both stress and pressure signals were measured by using strain gauges and pressure transducers to describe the forces and their relationship with gas-solids hydrodynamics. The main influencing parameters are the increment of superficial gas velocity, installation height, inclination angle, static bed height, and installation method of the slat. The experimental results indicated that there is a dangerous upward impulse with a high peak and a long duration in the measured stress signal during starting up a fluidized bed. The effects of various operating and structural parameters on the forces acting on the test slat were elucidated in detail. Effective measures to alleviate the forces and critical conditions where the strength of internals needs to be re-enforced are proposed. The obtained knowledge is helpful to engineering design to ensure the safety of immersed internals in fluidized bed reactors. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) control key events of immune tolerance, primarily by suppression of effector T cells. We previously revealed that Tregs rapidly suppress T cell receptor (TCR)-induced calcium store depletion in conventional CD4+CD25- T cells (Tcons) independently of IP3 levels, consequently inhibiting NFAT signaling and effector cytokine expression. Here, we study Treg suppression mechanisms through unbiased phosphoproteomics of primary human Tcons upon TCR stimulation and Treg-mediated suppression, respectively. Tregs induced a state of overall decreased phosphorylation as opposed to TCR stimulation. We discovered novel phosphosites (T595_S597) in the DEF6 (SLAT) protein that were phosphorylated upon TCR stimulation and conversely dephosphorylated upon coculture with Tregs. Mutation of these DEF6 phosphosites abrogated interaction of DEF6 with the IP3 receptor and affected NFAT activation and cytokine transcription in primary Tcons. This novel mechanism and phosphoproteomics data resource may aid in modifying sensitivity of Tcons to Treg-mediated suppression in autoimmune disease or cancer. [ABSTRACT FROM AUTHOR]

Effect of jet applied to the leading edge slat on the flowfield for multi-element airfoils were investigated to improve the high-lift aerodynamic performance of multi-element airfoils. The influences of key parameters, such as the jet flow rate and the speed of jet on the leading edge slat were studied. CFD method was adopted to analyze the effect of jet on the aerodynamic performance and the shear layer development behind the gap between slat and main element. Two dimensional unsteady Reynolds-averaged Navier-Stokes equations was solved by finite volume method to obtain two dimensional unsteady flowfield of multi-element airfoils. The results indicated that the slat trailing edge jet flow has significant effect on the pressure coefficient of each section of the multi-element airfoils and the maximum lift coefficient simultaneously. The maximum lift coefficient, the total maximum lift coefficient of main element, and the lift coefficients of slat and flap would increase with the jet momentum coefficient increases. [ABSTRACT FROM AUTHOR]

Focusing the influence of high-lift configuration of an airplane on wing aerodynamic characteristics， an experiment is conducted in NH-2 low-speed wind tunnel over a swept constant chord half-model (SCCH) high-lift configuration of a civil aircraft. In this experiment， the Mach number is 0.2 and the Reynolds number is 1.85×106. The effect of salt deployment angle， gap and over-lap on efficiency of high-lift configuration is investigated. Based on the test results， best slat parameters of this model are obtained for both take-off and landing configurations. The results show that both the stall angle of attack and the maximum lift coefficient increase with the slat deployment angle increasing from 18° to 24°， and only the stall angle of attack increases while the maximum lift coefficient does not change obviously when the angle increasing from 25° to 31°. The best slat gap width is from 1.5% to 2.0% for take-off configuration， while 2.0% to 2.5% for landing configuration. The best over-lap is around 1.0% for take-off configuration， while －1.0% to 0% for landing configuration. The best slat gap width presents increasing trend with the increase of the slat deployment angle. [ABSTRACT FROM AUTHOR]

Forces on a single horizontal slat immersed in a fluidized bed of Geldart A particles were investigated for the purpose of providing useful design guidelines for long-period reliability of horizontal baffles in industrial reactors. The characteristics of slat forces in the fluidized and de-fluidized states of a reactor were measured using adhered strain gauges. The main parameters influencing these characteristics were superficial gas velocity, installation height, inclination angle, and method of slat installation. The experimental results show that the measured force on the slat in the fluidized state is highly fluctuating, but its root-mean-square is usually significantly lower than for the de-fluidized state, especially at the bottom of the bed. The effects of various operating and structural parameters were determined. Critical locations and operating conditions under high load are indicated and warrant more attention in structural design of horizontal baffles. [ABSTRACT FROM AUTHOR]

Triggering of the antigen-specific T cell receptor (TCR) can lead to various functional outcomes, such as activation and proliferation, anergy or cell death. This differential signaling is mainly determined by the quality and quantity of TCR signals, the nature of accessory signals and the differentiation/maturation status of the T cell. In this regard, T cell development and differentiation of the two major T helper (Th) subsets, namely Th1 and Th2 cells, can also be viewed as examples of differential signaling. In the present report, we review two T cell-selective signaling molecules (protein kinase C (PKC) θ and SLAT), which we have studied extensively and that appear to play important roles in the process of differential signaling. The novel PKC isoform PKCθ is selectively expressed in T lymphocytes and is essential for TCR-triggered activation of mature T cells via activation of the nuclear factor-κB and activator protein-1 pathways. Productive engagement of T cells by antigen-presenting cells (APC) results in recruitment of PKCθ to the T cell-APC contact area, the immunological synapse (IS), where it interacts with several signaling molecules to induce activation signals essential for productive T cell activation and interleukin-2 production. These events are associated with PKCθ translocation to membrane lipid rafts, which also localize to the IS. The Vav/Rac pathway promotes the recruitment of PKCθ to the IS or lipid rafts as well as its activation. SLAT is a novel adapter protein, which we isolated recently. It is selectively expressed in Th2 lineage cells, where it is found associated with the TCR-coupled protein tyrosine kinase ZAP-70. Our initial characterization of SLAT indicates that, by regulating the overall strength of TCR signaling, it may play an important role in differential signaling processes, which promote the differentiation and activation of allergy promoting and anti-inflammatory Th2 cells.

One of the most commonly implemented devices for stall control on wings and airfoils is a leading-edge slat. While functioning of slats at high Reynolds number is well documented, this is not the case at the low Reynolds numbers common for small unmanned aerial vehicles. Consequently, a low-speed wind tunnel investigation was undertaken to elucidate the performance of a slat at Re = 250,000. Force balance measurements accompanied by surface flow visualization images are presented. The slat extension and rotation was varied and documented. The results indicate that for small slat extensions, slat rotation is deleterious to performance, but is required for larger slat extensions for effective lift augmentation. Deployment of the slat was accompanied by a significant drag penalty due to premature localized flow separation.

RANKL induces the formation of osteoclasts, which are responsible for bone resorption. Herein, we investigated the role of SWAP-70-like adapter of T cells (SLAT) in RANKL-induced osteoclastogenesis. Expression levels of SLAT were reduced during RANKL-induced osteoclastogenesis. Overexpression of SLAT in BMMs inhibited TRAP-positive multinuclear osteoclast formation and attenuated the expression of NFATc1, which is an important modulator in osteoclastogenesis. Furthermore, silencing of SLAT by RNA interference enhanced osteoclast formation as well as NFATc1 expression. In addition, SLAT was involved in RANKL-induced JNK activation in osteoclasts. Taken together, our data suggest that SLAT acts as a negative modulator of RANKL-induced osteoclastogenesis. [ABSTRACT FROM AUTHOR]

Commercial poultry production management practices have been under increased public scrutiny driven by concerns for food safety and animal welfare. Within the United States, wood shavings and raised plastic floors are common flooring systems used in duck production. It is intuitive that each flooring type would present different management challenges influencing physical characteristics of growing ducks. This study evaluated the relationship between flooring type and duck condition during the winter. Random samples of 20 ducks from 5 predetermined areas (n = 100) were examined in commercial duck houses (n = 9, litter; n = 11, raised plastic slats). Ducks were assessed at 7, 21, and 32 d of age for eye, nostril, and feather cleanliness, feather and foot pad quality, and gait. The data were analyzed to determine the proportion of ducks with a given score. In both housing types, the proportion of 0 scores for foot pad quality improved during the production cycle (P<0.0001). Feather hygiene declined with age in ducks reared on litter flooring, whereas ducks reared on slatted flooring had cleaner feathers at d 32 (P<0.011). With the exception of foot pad scores, the majority of ducks had no detectable problems for any single trait. The only main effect due to flooring pertained to feather quality with the proportion of ducks having a 0 or 1 score greater in litter flooring systems than slats (P<0.05). Overall, the condition of ducks reared, regardless of flooring system, was considered to be good. [ABSTRACT FROM AUTHOR]

The far-field noise of two dimensional multi-element high lift device L1T2 slat model was calculated using commercial CFD software FLUENT. LES model was used in flow field analysis to provide noise source data, while the FW-H method was used to calculate the far-field noise levels. To study the effects of gap and overlap on both maximum lift coefficient and noise levels, a total of 24 different combinations of gap and overlap were analyzed, and two response surface models were built from the results. The response surface models indicate that it is possible to find reasonable combinations of gap and overlap to achieve a balance between aerodynamic performance and noise characteristics. [ABSTRACT FROM AUTHOR]

Abstract: To quantify the combined effect of housing conditions and environmental enrichment on the behaviour and performance of pigs, a meta-analysis was performed using information from 45 experiments in 42 published manuscripts. Multiple regression models were applied to evaluate the effects of space allowance per pig (k-value; m2/BW0.667), group size (n), floor characteristics (solid, partly, or totally slatted floor), bedding (presence or absence), and the number and presentation sequence of point-source objects (no object, one object, two simultaneous objects, two alternated objects, three or more simultaneous objects or three or more alternated objects) on the general activity, enrichment and object-directed exploratory behaviour, social behaviour, and productive performance. A non-linear relationship between space allowance per pig and time spent sitting and lying was found (P <0.10 and P <0.01 for the k-value and its quadratic term respectively). Total time spent in exploration increased with space allowance per pig when bedding was present (P <0.01), and time spent exploring other pen items decreased with increasing space allowance per pig if no bedding was provided (P <0.001). Total time spent in exploration increased with group size (P <0.001). The lowest predicted total exploration time (least squares mean±standard error) was found in the absence of bedding and point-source objects (13±3%; P <0.05), and the highest when bedding (18±3%) or point-source objects (19±3%) were present. Time exploring point-source objects was higher when different objects were provided (P <0.001). Suspended (P <0.05) and deformable (P <0.05) enrichment items increased the time spent manipulating them. Time spent exploring point-source objects was predicted to be higher in the absence of slats and bedding (32±6%; P <0.05), and lower when bedding (8±9%) or slats (12±4%) were present. Time engaged in negative social behaviours decreased in the presence of point-source objects (P <0.01), and increased with group size in the absence of bedding (P <0.001). Time engaged in positive social behaviours tended to decrease in the presence of point-source objects (P <0.10), and when space allowance per pig increased in the absence of bedding (P <0.10). Slight trends towards lower FCR were predicted when point-source objects (P <0.10) and bedding (P =0.10) were present. This information can be utilised in the determination of the general effects of production systems on the welfare of pigs as well as in the development of new production systems. [Copyright &y& Elsevier]

Regarding aircrafts, the application of composites within impact endangered areas is unusual. Therefore, an advanced thermoplastic composite slat had been developed with the aim of minimizing weight and manufacturing costs in scheduled series production. The investigation of many manufacturing techniques had been performed as well as integration of new materials. Several generic and full-scale thermoplastic demonstrators were manufactured, using endless fibre-reinforced carbon-fibre-reinforced polyetheretherketone tapes. The critical point, concerning the casting of thick and highly tapered, single curved thermoplastic shells, was identified and new manufacturing methods had been developed. Additionally, the thermoplastic welding process was improved, resulting in a low-cost assembly technique as an alternative to state-of-the-art joining methods. In addition to conventional linear static analysis, dynamic high-velocity impact simulations were carried out. A numerical approach for high-velocity bird strike impact had been developed. The results were used to dimension the residual strength of a damaged slat. Furthermore, a good compliance between the dynamic analysis and the performed tests has been reached. It has been shown that a significant weight reduction is possible by numerical optimization, even if composites are used for impact-sensitive areas. [ABSTRACT FROM AUTHOR]

The present study considers the use of a slat near the leading edge of an airfoil to delay or completely cancel separation and thus improves the performance of small wind turbines, in addition to lowering the cost of the blade by reducing the used material. Flow around the S809 airfoil with a slat is numerically simulated using ANSYS 2019 R1 (CFD) program. The present work concentrates on two geometrical parameters namely the location of the slat relative to the base airfoil and the chord size of the slat. Relative to the total chord length of the main airfoil, a slat with a chord length 10% is located at range of distances +3.6% to +10.8% in y direction, slat located at 9% shows the best lift coefficient. To study the effect of slat size, slat sizes range from 5% to 12.5% are numerically investigated, slat size 7.5% shows the best lift coefficient and attached flow over the airfoil for a wide range of angles of attack. The improvement is achieved with the same total chord length with 12% saving of material which corresponds to 6% of the total cost of the turbine. • Improving the aerodynamic performance of the airfoil using leading edge slat. • ANSYS FLUENT is used to simulate the flow around the S809 airfoil with a slat. • The size and location of the leading-edge slat are investigated. • The proposed slat design reduced the material used in wind turbine blades by 12%. • The lift coefficient increased by 24.89% for the best slat design. [ABSTRACT FROM AUTHOR]

A new undergraduate laboratory exercise is described which explores the generation of lift over an aerofoil with and without a leading-edge slat. The experiment emphasises a fundamental understanding of the fluid-dynamic boundary layer and supports a second-year lecture course in fluid mechanics. A NACA 2415 aerofoil is used by the undergraduates in a simple open-return circuit wind tunnel at a Reynolds number of 2 × 105. Measurements of inviscid and viscous aerodynamic characteristics of the aerofoil are validated against cambered aerofoil theory and published NACA data. Oil surface-shear flow visualisation and the differences in the pressure distribution around the NACA 2415 with and without the leading-edge slat demonstrate the governing influence of the boundary layer on aerodynamic stall and the lift generated by the aerofoil. The new laboratory format was introduced to the undergraduates in 2007 and the response from student evaluation questionnaires confirmed that their understanding of basic fluid dynamics was greatly enhanced by the wind tunnel experiment. [ABSTRACT FROM AUTHOR]