Lift Capability Research Articles

An angle speed and thrust relationship of the rotor system in the quadcopter aircraft

Utilizing Quadcopter were still many obstacles such as; plane easy to fall; the battery is not durable; vulnerable to weather conditions and others. The research and development has grown to improve aircraft facilities and capabilities. Many parameters related to aircraft lift capability factors; fly long; flying high; type of motor; the type of propeller: including the sensors and control systems used. This study was to find the relationship between changes in the BLDC motor voltage source to the rotor angle velocity <em>(ω)</em>; rotor speed to rotor lift <em>(Ft)</em>; wind speed to rotor lift; push the following rotor <em>(Ct)</em>. Empirical testing was conducted in the laboratory to find the relationship of these parameters. The results data show that; the lift power generated with rotational speed was not proportional, non linearity occurs when the rotor was released from the self and starts pulling the strain gauge when the rotation speed reaches around 65 <em>rps</em>. Once the rotation speed of the rotor is able to reach up to 1.5 Newton lift then the thrust rising trend sharply<strong> </strong>increasing <strong>to</strong>increasing <strong>of </strong>the rotor speed. A motor hade 1200 <em>KV</em> and blade with a radius of 0.12 <em>m</em>, then obtained thrust <em>(Ct)</em> of 1.732.

An angle velocity of blade and lift force relationship of the single rotor system

Problems in utilizing Quadcopter, either as a hobby or as special needs are still many obstacles or weaknesses such as; plane easy to fall; plane easy hit; the battery is not durable; vulnerable to weather conditions and others. In this regard, Quadcopter's research and development has grown to include weaknesses of existing Quadcopter planes and to improve aircraft facilities and capabilities. In developing the knowledge and information about the Quadcopter aircraft, the data or parameters related to aircraft lift capability factors; fly long; flying high; type of motor used; the type of propeller used; including the sensors and control systems used. Thus, this study was to find the relationship between changes in the BLDC motor voltage source to the rotor angle velocity (ω); Change of rotor speed to wind velocity through rotor (v); change of rotor speed to rotor lift (Ft); change of wind speed to rotor lift; push the following rotor (Ct). In this study, empirical testing was conducted in the laboratory to determine the relationship among others: changes in the BLDC motor voltage source to the rotor angle velocity (ω); Change of rotor speed to wind velocity through rotor (v); change of rotor speed to rotor lift (Ft); change of wind speed to rotor lift; push the following rotor (Ct). Test and measurement results data show that; the relationship between lift power generated with rotational speed is not proportional Nonlinearity occurs when the rotor is released from the self and starts pulling the strain gauge when the rotation speed reaches around 65 rps. Once the rotation speed of the rotor is able to reach up to 1.5 Newton lift then the thrust rising trend increasing sharply to the increasing the speed of rotation of the rotor. A special rotor that has BLDC motor specifications such as; 1200 KV, 5 Volt and 30 Ampere; blade with a radius of r 0.12 m; at a temperature of about 27 o C; in the condition there are no other wind currents then obtained thrust (Ct) of 1.732. Keywords: Rotation Speed, Thrust Coefficient, Quadcopter.

Bioinspired Low-Noise Wing Design for a Two-Winged Flapping-Wing Micro Air Vehicle

This work investigates the acoustic and thrust performances of different wing designs for a two-winged flapping-wing micro air vehicle (FW-MAV). The reference wings, made of a Mylar film membrane supported by carbon-fiber rods, produce a perceived overall noise of about 68.8 dBA when operating at the flapping frequency of 10 Hz typically required for flying such a flapping wing vehicle. This noise is much higher than the value of the environmental background. Wings of various materials and structural configurations are designed and tested in order to reduce the flapping-wing noise. Sound and force measurements are used to assess their acoustic and lift capabilities. It is found that a wing made with a highly elastic dielectric elastomer membrane can reduce the overall perceived noise of the flapping wing by 12 dBA while slightly increasing the thrust. The mechanisms leading to this noise reduction and their potential applications in quiet FW-MAVs are discussed.

Perancangan Pengukur Kekuatan Motor Brushless Berbasis ESP8266

Dunia aeromodelling saat ini dapat dibilang sedang berkembang pesat, berbagai jenis pengembangan teknologi merambah didunia ini. Penghobi dunia aeromodelling juga cukup banyak, hal ini ditandai dengan bermunculan orang-orang yang bermain aeromodelling. Ketika bicara membuat sebuah airframe yang berhubungan dengan aeromodelling, terkadang membutuhkan aktuator (motor listrik) dalam hal ini motor brushless. Motor jenis ini banyak sekali digunakan dan juga saat ini banyak sekali tersedia dipasaran. Tetapi terkadang ketika membeli motor jenis ini tidak terdapat spesifikasi motor yang jelas untuk kemampuan motor dan kombinasi propeller yang digunakan. Penelitian ini bertujuan mengetahui kemampuan maksimal gaya dorong sebuah motor brushless dengan kombinasi propeller yang berbeda. Pengujian ini dilengkasi dengan ESP8266 sebagai otak pemroses data, Load Cell ditambah modul HX711 dan sensor arus dan daya digunakan untuk memantau kemampuan motor. Penelitian ini menggunakan metodologi Prototyping. Hasil yang didapat dalam penelitian pengukur kekuatan motor brushless ini yaitu mendapatkan kemampuan maksimal dimana setiap kecepatan motor (Throttle) dinaikkan maka akan menghasilkan nilai kemampuan daya angkat meningkat. Hasil lain yaitu penggunaan jenis propeller dari ukuran dan jenis berbeda akan mendapatkan kemampuan daya angkat yang berbeda

The lifting force relationship of a BLDC motor rotor system to the blade rotation speed

In developing the knowledge and information about the Quadcopter aircraft, the parameters related to aircraft lift capability factors; fly long; flying high; type of motor; the type of propeller; including the sensors and control systems used. To find out of the BLDC motor voltage source to the rotor angle velocity (ω) relationship; rotor speed to wind velocity through rotor (v); rotor speed to rotor lift (Ft); wind speed to rotor lift; push the following rotor (Ct).Test and measurement results data show that; the lift force generated with rotational speed relationship is not proportional Nonlinearity occurs when the rotor is released from the self and starts pulling the strain gauge when the rotation speed reaches around 65 rps. Once the rotation speed of the rotor is able to reach up to 1.5 Newton lift then the thrust rising trend increasing sharply to the increasing the speed of rotation of the rotor. A special rotor that has BLDC motor specifications such as; 1200 KV, 12 Volt and 30 Ampere; blade with a radius of r 0.12 m; at a temperature of about 27 oC; in the condition there are no other wind currents then obtained thrust (Ct) of 1.732.

Multidisciplinary optimisation of single-stage sounding rockets using solid propulsion

Existing sounding rockets are based on earlier proven designs and often utilize surplus military solid rocket motors. Therefore commonly non-optimal, in terms of performance for a given payload, configurations are utilized. This paper presents a methodology for finding close-to-optimal, in terms of launch mass minimization, design configurations for small unguided sounding rockets. A numerical, multidisciplinary approach is used. During the optimization process vehicle sizing and corresponding aerodynamics modelling is done. The implemented flight simulation module is simplified due to unknown, during the conceptual design phase, rocket mass distributions along vehicle major axes. Special attention is given to propulsion system sizing and thrust level selection. This paper presents optimization of sounding rockets with lift capabilities equivalent to sending small payloads above the Von Karman line. The ultimate aim of this paper is to present methods to improve sounding rocket performance at an early stage of design, to enable conducting more efficient microgravity research. Various concepts, such as using different expansion ratio nozzles for different payload envelopes and masses, are discussed. Optimization results for maximizing the apogee of a small sounding rocket are presented. Due to the lack of published corresponding research, guidelines for future sounding rocket developments, based on numerical investigations, are given. The significance of the study is due to the emergence of new sounding rocket designs, without use of surplus motors, and the possibility to improve vehicle efficiency after a few decades of little alteration.

Unsteady high-lift mechanisms from heaving flat plate simulations

Flapping animal flight is often modeled as a combined pitching and heaving motion in order to investigate the unsteady flow structures and resulting forces that could augment the animal’s lift and propulsive capabilities. This work isolates the heaving motion of flapping flight in order to numerically investigate the flow physics at a Reynolds number of 40,000, a regime typical for large birds and bats and challenging to simulate due to the added complexity of laminar to turbulent transition in which boundary layer separation and reattachment are traditionally more difficult to predict. Periodic heaving of a thin flat plate at fixed angles of attacks of 1°, 5°, 9°, 13°, and 18° are simulated using a large-eddy simulation (LES). The heaving motion significantly increases the average lift compared with the steady flow, and also surpasses the quasi-steady predictions due to the formation of a leading edge vortex (LEV) that persists well into the static stall region. The progression of the high-lift mechanisms throughout the heaving cycle is presented over the range of angles of attack. Lift enhancement compared with the equivalent steady state flow was found to be up to 17% greater, and up to 24% greater than that predicted by a quasi-steady analysis. For the range of kinematics explored it is found that maximum lift enhancement occurs at an angle of attack of 13°, with a maximum lift coefficient of 2.1, a mean lift coefficient of 1.04.

Simulation research on a variable-lift absorption cycle and its application in waste heat recovery of combined heat and power system

To solve the dilemma between temperature lift capability and coefficient of performance (COP) when absorption heat pump is applied in low grade heat utilization, a variable-lift absorption cycle and an improved one based on it are introduced here. The variable-lift absorption cycles have relatively simple systems and contains enough number of absorbers and condensers to develop plenty of gradually increasing temperature levels to match heating process. For a given heating demand and waste heat temperature level, the results of application of variable-lift absorption cycles in waste heat recovery of combined heat and power(CHP) system show that, the variable-lift cycles can always work efficiently when return water temperature of primary heating network (PHN) varies from 30 °C to 50 °C. The needed heat source temperatures of variable-lift cycles are always over 12 °C lower than single effect cycle. The higher return water temperature of PHN yields more obvious advantage of the improved cycle. When the return water temperature of PHN is 50 °C, variable lift-2C cycle and variable lift-3C cycle can reduce the equivalent power consumption for space heating by 8.5% and 15% respectively when comparing to single effect cycle. The essence of the variable-lift cycles is further clarified from the heat transfer analysis in T-Q diagram.

Passive Aerial Grasping of Ferrous Objects

Aerial transportation is probably the most efficient way to supply quick and effective aid especially in cases of emergency like search and rescue operations. Thus the ability to grasp and deliver objects is of vital importance in all sorts of unmanned and autonomous aerial operations. We detail a simple yet novel approach for aerial grasping of ferrous objects using a passive magnetic pickup and an impulse based drop mechanism. The design enables our gripper to grasp ferrous objects using single as well as multiple gripping pads, with visual as well as pickup and drop feedback. We describe the various components of the gripper with emphasis on its low mass and high lift capability since weight is a matter of high consideration in all aerial applications. In addition, we investigate and address the issues that may cause our design to fail. We demonstrate by experiments that the proposed design is robust and effective, based on its high payload capability, its sturdiness against possible slide during aggressive aerial maneuvers, and optimum performance of the drop mechanism for the designed range of payloads. We also show that the gripper is able to pick up and drop a single as well as multiple ferrous objects of different shapes, curvature, and inclination, which also involves picking up an object and then grasping the next, while keeping hold of the previous one.

Cooperative control system of the floating cranes for the dual lifting

This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

Risk-Based Abandonment-Prioritization Strategy for Inactive Subsea Wells

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 181020, “Risk-Based Abandonment-Prioritization Strategy for Inactive Subsea Wells,” by Abimbola Oladipo, Maersk Oil North Sea UK, and Adrian Houlbrook, DNV GL, prepared for the 2016 SPE Intelligent Energy International Conference and Exhibition, Aberdeen, 6–8 September. The paper has not been peer reviewed. This paper describes how an exploration-and-production company successfully developed and applied a qualitative risk-based abandonment-prioritization strategy for an inventory of inactive subsea wells. The exercise entailed a qualitative-assessment methodology using 25 well-integrity-related criteria. An aggregate of weighted scores was subsequently applied to the company’s corporate risk-assessment matrix on the basis of the escalation potential in the event of a loss of containment. The results clearly highlighted the wells with the highest risks. Well History The inactive subsea wells relevant to the exercise are distributed across the central North Sea in water depths ranging from 244 to 474 ft. These normal-pressure/normal-temperature subsea wells are all located in the mature UK Central North Sea offshore basin and were completed in relatively benign reservoirs with comparatively low corrosion susceptibility. Each inactive subsea well evaluated had functioned earlier in its life as an oil producer (with gas lift capability), water injector, or aquifer well. The majority of these subsea wells were shut in and disconnected from their flowlines and hydraulic-control and data-acquisition systems. However, the wells’ physical isolation from the flowlines and great distance from the host installation meant that they presented negligible safety risks to personnel onboard the installations. Methodology Because degradation is not driven solely by age, and having recognized that each well behaves differently, the methodology (Fig. 1) required each well to be assessed on the basis of evidential information presented and in accordance with how closely the well followed the corporate standard ideal integrity model of its well type. A specific set of scoring guidelines was developed and reflected corporate risk-management protocols to achieve a consistent, fair, and accurate risk ranking. These guidelines were based on a number of factors, including but not limited to the technical integrity of key elements, evidential documentation, field service history, incident records, and well-integrity maintenance records. An initial classification was applied on the basis of the available design life of key surface equipment (in this case, subsea horizontal spool trees and wellheads) and well functionality, thus enabling each well to be classified broadly into one of three preliminary-risk-assessment categories: high, medium, or low.

Numerical and experimental analysis of the flow around a two-element wingsail at Reynolds number 0.53 × 106

The rigid wingsail is a propulsion system, utilized in sailing competitions in order to enhance the yacht performance in both upwind and downwind conditions. Nevertheless, this new rig is sensitive to upstream flow variations, making its steering difficult. This issue suggests the need to perform a study on wingsail aerodynamics. Thus this paper reports some investigations done to better understand the flow physics around a scaled model of an America’s Cup wingsail, based on a two-element AC72 profile. First a wind tunnel test campaign was carried out to generate a database for aerodynamic phenomena analyses and CFD validation. Unsteady RANS simulations were performed to predict and validate the flow characteristics on the wingsail, in the wind tunnel test conditions. The wind tunnel domain was fully modeled, in order to take into account the facility confinement effects. Numerical simulations in freestream and wind tunnel conditions were then compared with experimental data. This analysis shows the necessity to consider the wind tunnel walls when experimental and numerical data are compared. Numerical simulations correctly reproduce the flow field for low-to-moderate flow angles. However, discrepancies on the pressure distribution increase when the boundary layer starts to separate from the wingsail. In this regard, the flow generated by the slot between both elements of the wingsail is of paramount importance. This slot flow is analyzed in details through PIV measurements and numerical simulations. While the numerical simulation correctly predicts the jet flow itself, it only partially reproduces the interaction between the jet flow and the main flow, especially at high angle of attacks. More precisely, the numerical simulation fails to predict the correct jet flow trajectory, which affects the lift capabilities of the entire wing. The influence of the wingsail deformation during experimental campaigns has been investigated to explain this behavior.

A Rehabilitation First-Tournament Between Teams of Nursing Home Residents with Chronic Stroke.

This study describes the BrightArm™ Duo virtual reality system (Bright Cloud International Corp., Highland Park, NJ) and determines its clinical benefit for maintenance of upper extremity function in nursing home residents who are chronic poststroke. Participants sat at a low-friction robotic table with tilt and lift capability and interacted with serious games through computerized supports that measured forearm movement and grasp. The rehabilitation simulations were designed to improve arm and hand function, increase range of motion, and improve emotional well-being and cognition (attention, memory, and executive functioning). After 8 weeks of initial intensive therapy, there were three booster periods at 8-week intervals, each consisting of four sessions over 2 weeks. The last booster was a tournament competition, where pairs of residents played games collaboratively from remote nursing homes. Participants were evaluated before and after each booster period using standardized clinical measures. Range of motion improved for 18 out of 23 upper extremity movement variables (P = 0.01) between pre- and post-tournament assessment, and the residents self-reported that they enjoyed playing with a partner (score of 4.7 out of 5.0). Participants were able to reduce game completion time through cooperative play (teamwork), and the times improved with successive sessions of the tournament. Affected hand and arm function and depression levels were maintained (no decline) after the tournament. A rehabilitation tournament using virtual reality between teams of nursing home residents chronic poststroke is the first of its kind in clinical practice. This study demonstrates its effectiveness in improving range of motion of the upper extremity while engaging residents in the maintenance program at their nursing home.

Lightning field behavior around grounded airborne systems

A variety of innovative airborne concepts are being developed to capture the wind energy available at higher altitudes, facilitate wireless communication and provide heavy lift capability. These airborne systems will be in close proximity to cloud cover and exposed to increased risk of lightning strikes. A two-dimensional physics based formulation that was recently developed to investigate the potential field behavior about circular sections was used to develop uniform and tapered cylindrical elements. These elements were then combined to approximate the total charge and lightning behavior about an airborne wind turbine and a heavy lift airship. Surface electrical charge and lightning collection area are developed as a function of elevation, body shape, cloud cover and leader properties. The surface charge density is utilized to compute the degree of field intensification on the body periphery in order to determine the level of susceptibility of the airborne system to lightning strikes. It was observed that as airborne bodies move closer to the thundercloud the ambient potential field becomes more highly perturbed and leads to greater risk of lightning strikes. The lightning collection area was shown to increase with elevation of the airborne body and decrease with increase in the leader propagation angle.

Operation “Artemis” : The First Autonomous EU-led Operation

In June 2003, the EU launched Operation “Artemis”, its first military mission outside Europe and independent of NATO, to the Democratic Republic of Congo. While it ultimately received an EU badge, its origin, command and control were French. The objective of Operation “Artemis” was to contribute to the stabilisation of the security conditions in Bunia, capital of Ituri, to improve the humanitarian situation, and to ensure the protection of displaced persons in the refugee camps in Bunia. Its mandate was to provide a short-term interim force for three months until the transition to the reinforced United Nations Mission in the Democratic Republic of Congo (MONUC – Mission de l’Organisation des Nations Unies en République Démocratique du Congo; English: United Nations Organization Stabilization Mission in the Democratic Republic of the Congo). Although the EU can be said to have passed the first “test” of the European Security and Defence Policy (ESDP) mechanisms for the conduct of an autonomous operation, this test was a limited one. Operational constraints were caused by inadequate strategic lift capabilities and the lack of a strategic reserve.

Interfacial Strain Energy Dissipation in Hybrid Nanocomposite Beams Under Axial Strain Fields

A micromechanics and structural dynamics analysis of inherent damping exhibited by representative hybrid nanocomposite beams under axial strains is presented. The approximate model is used to assess the potential aeroelastic/aeromechanical stability enhancement of helicopter rotor blades from carbon nanotube matrix inclusions. The matrix/nanoinclusion micromechanics before the occurrence of interfacial slip are based on the Cox model for discontinuous fiber reinforcement, and the frictional energy dissipation is assumed to be proportional to the interfacial shear force where slip has occurred. The validity of the model is established by comparing with experimental measurements of storage and loss moduli for a polymer nanocomposite. The relatively simple model captures the salient features of nanocomposite interfacial slip energy dissipation once uncertainties in fiber orientation and dispersion are accounted for in an approximate manner by using an effective volume fraction. The validated model is then used to calculate damping of the first in-plane bending mode when a beam is subjected to axial strain fields representative of hingeless rotor blades. Results indicate that hybrid nanocomposites with nanoinclusions show significant potential for contributing to future vertical lift capabilities by augmenting rotorcraft aeromechanical stability margins of hingeless/bearingless rotors.

Human spaceflight and an asteroid redirect mission: Why?

The planning of human spaceflight programmes is an exercise in careful rationing of a scarce and expensive resource. Current NASA plans are to develop the new capability for human-rated launch into space to replace the Space Transportation System (STS), more commonly known as the Space Shuttle, combined with a heavy lift capability, and followed by an eventual Mars mission. As an intermediate step towards Mars, NASA proposes to venture beyond Low Earth Orbit to cis-lunar space to visit a small asteroid which will be captured and moved to lunar orbit by a separate robotic mission. The rationale for this and how to garner support from the scientific community for such an asteroid mission are discussed. Key points that emerge are that a programme usually has greater legitimacy when it emerges from public debate, mostly via a Presidential Commission, a report by the National Research Council or a Decadal Review of science goals etc. Also, human spaceflight missions need to have support from a wide range of interested communities. Accordingly, an outline scientific case for a human visit to an asteroid is made. Further, it is argued here that the scientific interest in an asteroid mission needs to be included early in the planning stages, so that the appropriate capabilities (here the need for drilling cores and carrying equipment to, and returning samples from, the asteroid) can be included.

On the development of the Anuloid, a disk-shaped VTOL aircraft for urban areas

This paper deals with the early development of the Anuloid, an innovative disk-shaped VTOL aircraft. The Anuloid concept is based on the following three main features: the use of a ducted fan powered by a turboshaft for the lift production to take-off and fly; the Coanda effect that is developed through the circular internal duct and the bottom portion of the aircraft to provide further lift and control capabilities; the adoption of a system of ducted fixed and swiveling radial and circumferential vanes for the anti-torque mechanism and the flight control. The early studies have been focused on the CFD analysis of the Coanda effect and of the control vanes; the flyability analysis of the aircraft in terms of static performances and static and dynamic stability; the preliminary structural design of the aircraft. The results show that the Coanda effect is stable in most of the flight phases, vertical flight has satisfactory flyability qualities, whereas horizontal flight shows dynamic instability, requiring the development of an automatic control system.

Prediction of Maximum Lift Capability of Helicopter Rotors

Maximum rotor lift capability is investigated using wind-tunnel test data of McHugh (modified 1/10-scale CH-47B rotor) and a full-scale UH-60A rotor. Rotor performance calculations with the comprehensive rotorcraft analysis CAMRAD II are compared with the wind-tunnel test data. The analysis of the McHugh rotor with the Reynolds-number-corrected airfoil table shows good correlation with the measurements for to 0.5 and is able to predict the maximum rotor lift reasonably well, especially at . The analysis is also able to predict the maximum lift of the full-scale UH-60A rotor within about 3.5% at and 0.3. Calculations with dynamic stall models, in general, show only a small influence on the rotor performance and are not necessary to predict maximum lift. Airfoils have an important role in defining the maximum lift capability of the rotor. The VR-12 airfoil, which has stall characteristics superior to the baseline V23010 airfoil, substantially improves the maximum lift capability of the McHugh rotor, showing the potential to improve the behavior of a rotor by improving the airfoil’s static stall characteristics.

SFB 880: fundamentals of high lift for future commercial aircraft

The recently founded Collaborative Research Centre SFB 880 of the Technische Universitat Braunschweig, “Fundamentals of High-Lift for Future Commercial Aircraft”, develops new knowledge in aircraft noise, advanced approaches towards active high lift, and in the dynamics of flight with active high lift during short takeoff and landing operations. The research centre has therefore devised a range of research projects that aim at integrated aeroacoustic and aerodynamic design capabilities for drastic noise reductions and the generation of active high lift with an extremely high efficiency of the used onboard power. Flight dynamics of commercial aircraft with increased lift capabilities for takeoff and landing by means of active control and including the effects of aeroelasticity and engine failure modes are also investigated. The research centre has developed a joint strategy for technology assessment using high-quality conceptual design data of a reference aircraft that represents the state of the art in CO2 reductions, low noise, and short takeoff and landing for point-to-point air connections within Europe. The paper describes the overall strategy of the coordinated research work and gives examples of recent results.