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Problem Statement: Ionospheric scintillations, cause significant effects on satellite signals for communication and navigation in equatorial region and polar regions mainly during sever magnetic storms periods. This phenomenon is not fully understood due to few studies performed. The study investigates variability of Total Electron Content (TEC) and ionospheric scintillation during October 2003 magnetic storm over Antarctica using ground based GPS technique. Approach: The TEC/scintillation measuring system at Scott Base station, consists of Trimble TS5700 24-channel (a high-precision dual-frequency GPS receiver), a Trimble Zephyr Geodetic antenna and a notebook computer for data logging. The absolute GPS TEC was calculated from differential phase advance GPS observables (1-L2). The GPS signal-to-noise ratios (C/No) and 1/L2 carrier frequencies were employed to determine the scintillation index S 4 every 60 s, amplitude scintillation (in dB-Hz) and phase scintillation. Results: The GPS measurements during storm periods at Scott Base show pronounced phase and amplitude scintillation activities, sudden increase in TEC followed by trough-like figure depletions. The maximum value of phase scintillation during the main phase of third episode was 8.3 times the value during Sudden Storm Commencement (SSC) period. Measured amplitude scintillation and S4 index on both 1 and L2 signals are >15dB-Hz and >0.4dB-Hz respectively. Conclusion/Recommendation: The timing and intensity of TEC and scintillation measurements during the storm event were are in a good agreement with WDC measurements. For this particular event, the duration of enhanced periods were approximately 12 h while periods of TEC depletions were more than 30 h. This value implies better understanding of the polar ionospheric response to magnetic storm and eases efforts for better space weather prediction in this region.
Otto engine dynamics are similar in almost all common internal combustion engines. We can speak so about dynamics of engines: Lenoir, Otto, and Diesel. The dynamic presented model is simple and original. The first thing necessary in the calculation of Otto engine dynamics, is to determine the inertial mass reduced at the piston. One uses then the Lagrange equation. Kinetic energy conservation shows angular speed variation (from the shaft) with inertial masses. One uses and elastic constant of the crank shaft, k. Calculations should be made for an engine with a single cylinder. Finally it makes a dynamic analysis of the mechanism with discussion and conclusions. The ratio between the crank length r and the length of the connecting-rod l is noted with landa. When landa increases the mechanism dynamics is deteriorating. For a proper operation is necessary the reduction of the ratio landa, especially if we want to increase the engine speed. We can reduce the acceleration values by reducing the dimensions r and l.
This paper presents the dynamic, original, machine motion equations. The equation of motion of the machine that generates angular speed of the shaft (which varies with position and rotation speed) is deduced by conservation kinetic energy of the machine. An additional variation of angular speed is added by multiplying by the coefficient dynamic D (generated by the forces out of mechanism and or by the forces generated by the elasticity of the system). Kinetic energy conservation shows angular speed variation (from the shaft) with inertial masses, while the dynamic coefficient introduces the variation of w with forces acting in the mechanism. Deriving the first equation of motion of the machine one can obtain the second equation of motion dynamic. From the second equation of motion of the machine it determines the angular acceleration of the shaft. It shows the distribution of the forces on the mechanism to the internal combustion heat engines. Dynamic, the velocities can be distributed in the same way as forces. Practically, in the dynamic regimes, the velocities have the same timing as the forces. Calculations should be made for an engine with a single cylinder. Originally exemplification is done for a classic distribution mechanism, and then even the module B distribution mechanism of an Otto engine type.
The paper presents an original method to determine the efficiency of the gear, the forces of the gearing, the velocities and the powers. It is analyzing the influence of a few parameters concerning gear efficiency. These parameters are: z1 - the number of teeth for the primary wheel of gear; z2 - the number of teeth of the secondary wheel of gear; alpha0 - the normal pressure angle on the divided circle; beta - the inclination angle. With the relations presented in this paper, it can synthesize the gear’s mechanisms. Today, the gears are present everywhere, in the mechanical’s world (In vehicle’s industries, in electronics and electro-technique equipments, in energetically industries, etc). Optimizing this mechanism (the gears mechanism), we can improve the functionality of the transmissions with gears. At the gear mechanisms an important problem is the interference of the teeth. To avoid the interference between teeth, we must know the minimum number of teeth of the driving wheel, in function of the pressure angle (normal on the pitch circle, alpha0), in function of the tooth inclination angle (beta), and in function of the transmission ratio (i).
Bell Helicopter is always preparing beautiful surprises for us, so this year has not been outdone and has revealed its vision of its future aircraft model FCX-001, a true vertical elevator, ment to can climb to high altitudes in a record time, with an enviable dynamics and maneuverability. The first appearance of the new model FCX-001 took place at Heli Expo 2017 in Dallas, Texas, where the new concept of the aircraft was presented in this highly stylized form. The aircraft appeared in the Bell stand, both in the form of a large-scale layout and in the virtual reality by using immersive helmets, the two-engine ship incorporating some of the new technologies currently under development at Bell and it is very likely to mature in the near future. At first glance, you are astonished at a cockpit that is totally devoid of physical controls, as if the ship were to run alone, fully automated. Notable elements in the design of the FCX-001 include a fan-driven anti-torque system, hybrid propulsion system, main rotor blade tips, extensive use of fuselage glass, winged doors and the use of augmented reality in the cockpit to control the aircraft. On the very roomy cabin ceiling of the aircraft, configured for only eight passengers in the Heli-Expo model, but able to adapt up to 12 passengers, Bell introduced a "drop-down" control module to allow personalization maximum and increased passenger comfort. The concept is provided with various modules that provide passengers with the ability to adjust their own things, such as cabin light intensity, interior temperature, or infotainment system. When looking closely at the new FCX-001 concept, starting with the back of the aircraft, it does not have a tail rotor (which is essential and notable for Bell's new model). In order to achieve the anti-torque instead, a new multi-rotor system is needed in the hood. It gives the aircraft the ability to push in both directions and also has vector control of the traction, also allowing it to give up a horizontal stabilizer. The anti-torque system is acted by an electric motor as part of a hybridized propulsion system. At the top of the aircraft, the main rotor blades (morphing) have an attractive design. At the same time, technology aims to allow the tip of each blade to move between the different flight regimes, just like a "swing wing" on an airplane to maximize efficiency and performance and reduce noise. The actual airframe of the aircraft is also very different from what Bell used in the past. In terms of ladder, the FCX-001 is slightly larger than a Bell 412 both in terms of its length and width, its new lines and its use of massive glass exhibiting some production challenges that rely on the new composite structures, today so widely used in the aviation and aerospace industries.
High consumption of fuel and emissions from ships has brought a new perspective tospeed optimization of ship. The reducing in fuel consumption can provide higher savings on the total cost of the vessel. Some regulations on environmental issues have been designated by International Maritime Organization (IMO) and other bodies. This research is based on the development of speed optimization. With case studies of MV. Meratus Mamiri which serving routes of Tj. Priok port-Tj. Perak port, Indonesia. The result of this study expected reduce the fuel consumption and emission of the ship based on speed optimization.
The current work describe the enhancement and improvisation of polymer composite repose of sisal fiber reinforcement, Biaxially Oriented Polypropylene (BOPP) and thermoplastic LLDPE: LDPE particulate fillers. The composite were prepared with fiber content 5, 10, 15 and 20% (by weight). The composite are characterized with respect to their mechanical properties (Tensile, flexural and impact strength) were studied. Tensile strength showed an increasing trend with increase in fiber content up to 15% then decreases. Impact strength increases with the increase in fiber content. SEM, DSC analysis shows the morphology and material identification respectively.
Geometrically nonlinear FE-analysis of active piezoelectric thinwalled shell structures, based on a Co-Rotational (CR) formulation and the Cell-Smoothed Discrete-Shear-Gap 3-node shell element (CS-DSG3) is presented in this study. The electric potential across the thickness of piezolayers is approximated by a linear function. The basic assumption of the applied Co-Rotational (CR) FEM formulation is that translations and rotations are finite, whereas the strains are small. Large rotation theory is used to update the rotational degrees of freedom. The proposed formulation is tested by means of the originally developed program. A set of piezoelectric coupled static linear and nonlinear cases are studied and the obtained results are compared with those available in the literature. A very good agreement of the results is noted, whereby the numerical effort could be reduced and numerical stability improved compared to other geometrically nonlinear FEM formulations.
The man has always wanted to be able to fly. The dream or although it has achieved, has not been reached yet fully. The fuse of the flight today is much higher than in the past, but is not yet complete. Although they have carried out the steps in the increase of the safety of a ship in flight, there are still many steps to do. For our passengers, but also for our pilots, these brave people and beautiful, it's time to do something in addition, something more. All those who are to get into a ship must be confident that they will fly absolutely without any problems, regardless of the weather, time, climate, brightness, weather conditions, temperature, altitude... In order to achieve a flight higher quality, it is first necessary to know the history of the flight of the man from its inception up today. The present paper wants to present history human flight, as she was in a vision as realistic as possible. The paper is addressed to in the first place to all those who contributed or still contribute to the achievement of this beautiful dream of the man, the flight. According to Aulus Gellius, Archytas philosopher of the old Greek, a mathematician, astronomers, law and political strategist, was considered that has designed and built around 400 B.C., first artificial device of the flight is self-propelled, a model in the form of bird propelled by an steam boost (an engine with the steamer) used as the reactor with steam, about whom they say he flew effectively to about 200 m altitude. This machine, named by its inventor " The Dove " , could be suspended on a wire to fly securely on a path of feed. The inventor of the berbers from the ninth century, Abbas Ibn Firnas, is considered by John Harding to be the first attempt of the flight heavier than air in the history of aviation. In 1010 AD, a British (English) monk, Eilmer of Malmesbury, assumed the piloting of a primitive sliding boat from the Malmesbury Abbey tower. It is said that Eilmer flew over 200 m (180 m) before landing and breaking his legs. He later remarked that the only reason he did not fly further was that he forgot to design his flight instrument and a queue, for which he redesigned his aircraft more technically, but his ancestor took Forbidden any other experiments on the grounds that they are bad (Satanic inspiration) and lead to serious accidents.
Speaking about a new engine ionic means to speak about a new aircraft. The paper presents in a short time the actual engines ion chambers (called the ion thrusters) and other new ionic motors proposed by the authors. The engine (ionic propulsion unit of ions, that accelerates the positive ions through a potential difference) is approximately ten times more efficient than classic system based on combustion. We can further improve the efficiency of the 10-50 times in the case in which is used the pulses of positive ions accelerated in a cyclotron mounted on the ship; efficiency may increase with ease of a thousand times in the case in which the positive ions will be accelerate in a synchrotron high energy, synchrocyclotron or isochronous cyclotron (1-100 GeV). For this, the great classic synchrotron is reduced to a surface-ring (magnetic core). The future (ionic) engine will have a circular particle binding (energy high or very high speed). Thus we can increase the speed and autonomy of the vessel, using a smaller quantity of fuel. It can be used a radiation synchrotron (synchrotron high intensity), with X-ray or gamma radiation. In this case, will result in a beam engine with the wiring (not an ionic engine), which will use only the power (energy, which may be solar energy, nuclear energy, or a combination) and so we will eliminate the fuel. It is suggested to use a powerful LINAC at the outlet of the synchrotron (especially when one accelerates the electron beam) in order not to lose power by photons of the emission premature. With a new ionic engine practically builds a brand new aircraft that can move through the water and air with the same ease. This new aircraft will be able to expedite directly, without an engine with the additional combustion and without the gravity assistance.
This paper presents and treats (in an original way) the specific elements of the structures of robotic solid mobile anthropomorphic type. Are " placed on the wallpaper " , the geometry and kinematics of the anthropomorphic robotic solid systems, in an original vision of the authors. One presents the inverse kinematics of anthropomorphic systems, with mechanical elements and points: Geometry, kinematic, positions, displacements, velocities and accelerations. They will be presented further two methods (as the most representatives): First one the method trigonometric and second one the geometric method.
The today main challenge to protect the environment through the development of new and more efficient transportation systems is presented. The absolutely necessary goods distribution and human transfers are polluting and damaging the environment and new solution should be envisaged; the conflicting strategies to adopt new types of environment friendly transportation while maintaining operative the more economically convenient, but largely polluting, already existing machines are discussed and compared. Shipment is an activity that is occurring since the existence of man who felt the need to find ways for him and his goods transportation. Physical human body limits have led to the discovery of a variety of systems for a continuous transportation evolution. This work analyzes the new environment friendly technologies that have been recently developed or that could be further implemented in the next near future. In view of the constantly improvement of the quality of transportation to be carried out, the transportation sector has various aspects that need to be investigated. Passenger comfort, flexible design, maximum interior space, safety and greater range are main features that improve transportation efficiency while making these technologies more familiar and accepted by consumers. Avoiding any excessive generalization, the three major transportation interacting branches, namely, infrastructures, vehicles and management have been reviewed. Such a complex system needed the application of an evolutionary design approach considering renewable energy sources for Hydrogen production as well as electric or internal combustion engines. The overall transportation network and related terminals have been involved as infrastructures, while all aspects of design, construction, operation diagnostics and traffic interactions have been considered for the vehicles. Finally, the management of the engineering responsibilities chain to ensure quality, safety and environmental impact of the transportation systems has been assessed.
The Northrop Grumman (formerly Ryan Aeronautical) RQ-4 Global Hawk (known as Tier II+ during development) is an Unmanned Aerial Vehicle (UAV) used by the United States Air Force and Navy and the German Air Force as a surveillance aircraft. The Northrop Grumman B-2 Spirit (also known as the Stealth Bomber) is an American strategic bomber, featuring low observable stealth technology designed for penetrating dense anti-aircraft defenses; it is able to deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty 500 lb (230 kg)-class JDAM GPS-guided bombs, or sixteen 2,400 lb (1,100 kg) B83 nuclear bombs. The B-2 is the only aircraft that can carry large airto-surface standoff weapons in a stealth configuration. The BQM-74 Chukar is a series of aerial target drones produced by Northrop. The Chukar has gone through three major revisions, including the initial MQM-74A Chukar I, the MQM-74C Chukar II and the BQM-74C Chukar III. They are recoverable, remote controlled, subsonic aerial target, capable of speeds up to Mach 0.86 and altitudes from 30 to 40,000 ft (10 to 12,000 m). Northrop Grumman Corporation (NYSE: NOC) is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010 and the largest builder of naval vessels. Northrop Grumman employs over 75,
In this study, the authors want to present a few more distinct aircraft from a constructive and functional point of view. Their role has often been determined by the need to achieve or fulfill certain more or less strategic objectives. Such ships will also be built in the future more and more often in order to be able to respond to all new flight requirements and to meet, under optimal conditions, the new and increasingly demanding requirements. Many of the new special aircraft have been built so far to achieve special tasks, or at the request of the defense ministry in some highly developed countries, even with the United States of America. The PA-23 was the first twin-engine design from Piper and was developed from a proposed "Twin Stinson" design inherited when Piper bought the Stinson Division of the Consolidated Vultee Aircraft Corporation. The prototype PA-23 was a four-seater low-wing all-metal monoplane with a twin tail, powered by a two 125 hp Lycoming O-290-D piston engines the prototype first flew 2 March 1952. The aircraft performed badly and it was redesigned with a single vertical stabilizer and an all-metal rear fuselage and more powerful 150 hp Lycoming O-320-A engines. Two new prototypes of redesigned aircraft now named Apache were built in 1953 and entered production in 1954; 1,231 were built. In 1958, the Apache 160 was produced by upgrading the engines to 160 hp (119 kW) and 816 were built before being superseded by the Apache 235, which went to 235 hp (175 kW) engines and swept tail surfaces (119 built). In 1958 an upgraded version with 250 hp (186 kW) Lycoming O-540 engines and adding a swept vertical tail was produced as the PA-23-250 and was named Aztec. These first models came in a five-seat configuration which became available in 1959. In 1961 a longer nosed variant the Aztec B entered production. The later models of the Aztec were equipped with IO-540 fuel injected engines and six-seat capacity and continued in production until 1982. There were also turbocharged versions of the later models, which were able to fly at higher altitudes. The US Navy acquired 20 Aztecs, designating them UO-1, which changed to U-11A when unified designations were adopted in 1962. In 1974, Piper produced a single experimental PA-41P Pressurized Aztec concept.
The shipments were absolutely necessary at all times, but still have polluted and damaged the environment. The technique of transport or the engineering of transport is the application of the principles of technology and scientific findings to the planning, design check, operation and plan management for any mode of transport, in order to ensure that the conditions of safety, efficiency, quick, comfortable and convenient, economic and environmentally compatible movement of persons and goods (transport). It is a sub-discipline for civil engineering. The importance of the transport engineering in the framework of the profession of civil engineering can be evaluated by the number of divisions of the ASCE (American Society of Civil Engineers), which are directly related to the transport. There are six such divisions (Aerospace; Air Transport, motorways, pipes, watercourses, port, of coastal and ocean and urban transport), which represents one third of the total 18 technical divisions of the ASCE (1987). Humanity is struggling between technological tests of deployment of new types of mild transport for the environment and the need to maintain still in the operation the machines already polluting products in large quantity, cheaper, more convenient economically, that customers have already been accustomed. Transport is at the heart of major cross-cutting issues that are inseparable from issues related to the development and sustainable management of the mobility of goods and people. The automotive sector must meet several challenges to reduce the emission of particulate and gaseous pollutants while limiting the increase in the cost of vehicles. The development of "clean" or "sustainable" vehicles requires the integration of innovative technologies to meet all these requirements. Those all problems need to be addressed by the discipline named Transportation (Transport) Engineering, in view of the constantly improving the quality of transport carried out.
The paper presents a few original elements about the dynamics and kinematics of piston mechanism, used like motor mechanism from OTTO engines. One presents an original method to determine the efficiency of the piston mechanism, used like motor mechanism. This method consists of eliminating the friction modulus. One determines the efficiency of the piston mechanism in two ways: 1. When the piston mechanism works like a motor; 2. When the piston mechanism works like a steam roller. Finally one determines the total motor efficiency, for the four cycle engine and for two cycle engine. With the relation of motor efficiency one optimizes the Otto mechanism, which is the principal mechanism from the internal-combustion engines. This is the way to diminish the acceleration of the piston and to maximize the efficiency of motor mechanism. One optimizes the constructive parameters: e, r, l, taking into account the rotation speed of drive shaft, n.
The paper presents an original method to determine the efficiency of a mechanism with cam and follower. The originality of this method consists of eliminating the friction modulus. In this paper one analyzes four types of cam mechanisms: 1.The mechanism with rotary cam and plate translated follower; 2.The mechanism with rotary cam and translated follower with roll; 3.The mechanism with rotary cam and rocking-follower with roll; 4.The mechanism with rotary cam and plate rocking-follower. For every kind of cams and followers mechanism one uses a different method in determining the best efficiency design. One takes into account the cam's mechanism (distribution mechanism), which is the second mechanism from the internal-combustion engines. The optimizing of this mechanism (the distribution mechanism), can improve the functionality of the engine and may increase the comfort of the vehicle too.
The paper presents a new and original internal-combustion engine. It is presenting a method in determining the kinematics and the efficiency of a new mechanism, MF1, proposed (designed) to work and be tested like an internal-combustion engine. One determines the mechanical momentary efficiency, when the mechanism works like a steam roller and when the mechanism works like a motor. The determined efficiency is different in the two described situations. One presents an original way to determine the dynamic efficiency too. The dynamic momentary efficiency is the same in the two situations: when the mechanism works like a steam roller and when it works like a motor. One determines the efficiency without friction, but one can anytime add the effect of friction modulus. One presents the dynamic kinematics of this mechanism too: the dynamic velocity and the dynamic acceleration. When the constructive parameters are normal, the dynamic velocities take the same values like the classical speeds and the dynamic accelerations take the same values like the classical accelerations.
The paper presents an original method in determining a general, dynamic and differential equation for the motion of machines and mechanisms, particularized for the mechanisms with rotation cams and followers. This equation can be directly integrated by an original method presented in this paper. After integration the resulted mother equation may be solved immediately. One presents an original dynamic model with one degree of freedom, with variable internal amortization. One determines the resistant force reduced at the valve (4), the motor force reduced at the valve (5), and the coefficient of variable internal amortization (6). The reduced mass can be calculated with the form (8). The differential motion equation takes the exact form (31), and the approximate form (32). The equation (31) is preparing for its integration with the form (35, 36, 37). The (37) form can be directly integrated and one obtains the parental equation (38). The equation (38) can be arranged in forms (39, 40, 41). The mother equation (41) can be solved directly (42-45), or more elegant with finished differences (48 and 49-50).
Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines a few main elements of Stewart platforms. Begin with the geometry platform, kinematic elements of it, and presented then and a few items of dynamics. Dynamic primary element on it means the determination mechanism kinetic energy of the entire Stewart platforms. It is then in a record tail cinematic mobile by a method dot matrix of rotation. If a structural mottoelement consists of two moving elements which translates relative, drive train and especially dynamic it is more convenient to represent the mottoelement as a single moving components. We have thus seven moving parts (the six motoelements or feet to which is added mobile platform 7) and one fixed.
The paper presents an original method to determine the general dynamics of mechanisms with rotation cams and followers, particularized to the plate translated follower. First, one presents the dynamics kinematics. Then one solves the Lagrange equation and with an original dynamic model with one degree of freedom, with variable internal amortization, it makes the dynamic analysis of two models.
Abstract
Boeing is an aeronautical and aerospace manufacturer. Its head office is located in Chicago, Illinois. Its two largest plants are located in Wichita, Kansas and Everett, near Seattle. This aircraft manufacturer specializes in the design of civil aircraft, but also in military aircraft, helicopters and in satellites and rockets with its Boeing Defense, Space and Security division. In 2012, it ranks second in world military equipment sales. The company was born on July 15, 1916, thanks to its two fathers William E. Boeing and George Conrad Westervelt and is named "B and W". Shortly afterwards, his name became "Pacific Aero Products" and finally "Boeing Airplane Company". In 1938, Boeing commissioned the 307 Stratoliner; It was the first airplane with pressurized cabin; He was able to fly at a cruising altitude of 20,000 feet, so above most weather disturbances, making him the strongest aircraft in the Boeing fleet. In response to the concentration move in the US defense industry initiated by its competitor Lockheed in 1995, Boeing acquired Rockwell International's space and defense operations in August 1996 for $3.2 billion. Rockwell was the manufacturer of the seven US space shuttles (Enterprise, Pathfinder, Columbia, Atlantis, Endeavor, Discovery and Challenger). Then, Boeing bought the number two defense equipment behind Lockheed Martin that is McDonnell Douglas, for $13 billion in August 1997. McDonnell Douglas was the manufacturer of the Delta launchers. In 1999, the Boeing aircraft manufacturer sold 620 aircraft; in 2004, deliveries fell to 285 aircraft. It is now overtaken by its European competitor Airbus in orders since 2002 and in deliveries since 2004 (Source: Le Monde, 13 June 2005). In 2005, in a record market, the company announces 1,005 orders (of which 569 B737, 235 B787 and 154 B777) surpassed again by Airbus of about fifty aircraft. Boeing became the world's first aircraft manufacturer in 2006 with 1,044 orders versus 824 for Airbus. In 2008, Boeing is the world leader in the defense sector. In November 2016, Boeing announced a restructuring of its defense arm with the suppression of 500 positions, the closure of two plants in El Paso and Newington and the displacement of 2,000 employees.
Copyright
© 2017 Relly Victoria Virgil Petrescu, Raffaella Aversa, Bilal Akash, Juan Corchado, Filippo Berto, Antonio Apicella and Florian Ion T. Petrescu. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Moving mechanical systems parallel structures are solid, fast, and accurate. Between parallel systems it is to be noticed Stewart platforms, as the oldest systems, fast, solid and precise. The work outlines some few main elements of Stewart platforms. It begins with the geometry platform and structure, and then one presents the kinematic elements of it, positions, velocities and accelerations. If a structural motto element consists of two moving elements which translate relative, drive train and especially dynamic it is more convenient to represent the motto element as a single moving component. One has thus seven moving parts (the six motto elements or feet to which is added mobile platform 7) and one fixed. The whole work is based on knowledge of analytic geometry, so we can consider this work as a study of the applied mathematics.
The paper presents an original geometrical and kinematic method for the study of geometry and determining positions of a MP-3R structure. It presents shortly the MP-3R direct and inverse kinematics, the inverse kinematics being solved by an original exactly method. One presents shortly an original method to solve the robot inverse kinematics exemplified at the 3R-Robots (MP-3R). The system which must be solved has three equations and three independent parameters to determine. Constructive basis is represented by a robot with three degrees of freedom (a robot with three axes of rotation). If one study (analyzes) an anthropomorphic robot with three axes of rotation (which represents the main movements, absolutely necessary), it already has a base system, on which one can then add other movements (secondary, additional). Calculations were arranged and in the matrix form.
WELCOME
CELE TREI LEGI FUNDAMENTALE ALE ROBOŢILOR
1. Robotul n-are voie să pricinuiască vreun rău omului sau să îngăduie, prin neintervenţie, să i se întâmple ceva unei fiinţe umane.
2. Robotul trebuie să asculte poruncile omului, dar numai atunci când ele nu contrazic legea 1.
3. Robotul trebuie să-şi apere existenţa, dar numai atunci când grija de sine nu contrazice legea 1 sau legea 2.
Structurile seriale cele mai utilizate, conţin în marea lor majoritate o componentă de bază, 3R, din care două rotaţii se situează într-un plan, astfel încât se poate trece de la studiul spaţial la cel plan, uşurându-se astfel mult modalităţile de calcul. Pentru lanţul cinematic reprezentând cele două rotaţii plane, se urmăreşte, structura, geometria, cinematica directă şi inversă, trecerea de la mişcarea plană la cea spaţială, echilibrarea statică totală, cinetostatica lanţului echilibrat, dinamica lanţului echilibrat, cinematica dinamică directă şi inversă.
Cu stimă şi respect, autorii.
CUPRINS
Welcome.......................................................................... 003
Cuprins............................................................................. 010
Introducere........................................................................011
Cap 01 Structura mecanismelor………………………….. 039
Cap 02 Mecanismul bielă-manivelă-piston .......................083
Cap 03 Mecanismul patrulater articulat.......……………... 190
Cap 04 Mecanismul care are o culisă oscilantă.........….. 231
Cap 05 Mecanismul în cruce .....................................….. 241
Cap 06 Mecanismul unei prese............………………….. 247
Cap 07 Un mecanism cu o triadă 6R...........…………….. 257
Cap 08 Un mecanism de tip cruce de Malta
(Geneva driver) ..............................................…….…….. 275
Cap 09 Mecanisme cu camă şi tachet .…………………… 278
Cap 10 Angrenaje cu axe fixe, sau
mecanisme cu roţi dinţate cu axe fixe..…………….…….. 330
Cap 11 Transmisii mecanice cu axe fixe..……………….. 369
Cap 12 Angrenaje cu axe mobile (Sinteza sistemelor planetare)................................................................…….. 378
Cap 13 Transmisii mecanice cu axe mobile
(Trenuri planetare) ….......................................………….. 400
Cap 14 Echilibrări statice şi dinamice ............................... 407
Cap 15 Determinarea momentelor de inerţie masice (mecanice)........................……………………….. 419
It is an entry technique in use recently, albeit in selected centers and represents a further step in the field of minimally invasive surgery. Basically it has the same indications but, at present, is reserved for selected patients. Compared to traditional video-assisted surgery presents some important differences. The surgeon is physically distant from the operative field and sits at a console, equipped with a monitor, from which, through a complex system, controls the movement of the robotic arms. These are fixed the various surgical instruments, tweezers, scissors, dissectors, that team shall present to the operating table to introduce into the cavity operative site. The use of mechanical arms has the advantage of allowing a three dimensional view an image with more stops and to make the most delicate maneuvers purposes and also because the tools are articulated to the distal end. The disadvantage is related to the times longer operative and the difficulty of determining the strength (as can happen in giving the right tension to a surgeon's knot). In the future it can be assumed that robotic surgery will allow, with the development of the experience, the spread of the equipment and improvement of telecommunication systems and data, to operate at ever greater distances. If you think that today, the space centers, you can operate the robots sent to the moon or farther away, it is not hard to believe that it will become usual to operate from side to side of the area, providing you with all the best and specific skills. The first surgical robot called da Vinci, in honor of Leonardo da Vinci, was developed in Silicon Valley by Intuitive Surgical and in 2000 he obtained the authorization of the American Food and Drug Administration (FDA) for use in laparoscopic surgery. The present paper wishes to show briefly several models of the main robots placed in the service of human medicine.
Copyright
© 2016 Relly Victoria V. Petrescu, Raffaella Aversa, Antonio Apicella and Florian Ion T. Petrescu. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Globally, there is a great need for portable, inexpensive diagnostic tools that can provide quick, accurate results using relatively small sample volumes. Point-Of-Care (POC) measurements of human saliva, sweat and/or blood capable of detecting glucose levels, foreign pathogens such as bacteria, fungi and many different viruses (HIV, Ebola, Influenza, etc.) that use microfluidics and optofluidics are close to commercial availability. These diagnostic tools use both optical and electrical methods for the detection and analysis of single biomolecules. The applications extend beyond healthcare and can be used for pathogen detection in aquatic environments such as drinking water. Additional research in handheld Optical Coherence Tomography (OCT) offers the possibility for inexpensive diagnosis and treatment of tissue like middle ear infection and breast cancer. Finally, microscopes are also getting smaller and cheaper, with an inexpensive plastic florescence microscope that can quantify white blood cell levels and a suitcase sized microscope that can look at a single drop of blood for a million biomarkers, searching for signs of sepsis and infectious disease. POC devices such as these will provide medical care to poor, remote areas that can be administered by junior physicians or even used for self-diagnosis. In this study, a review of advances in POC devices reported in recent literature is conducted, in order to provide the reader with a thorough description of new diagnostic techniques that have taken place in the last couple of years.
The present work describes the analysis, modeling and control of a cascade DC-DC and DC-AC power conditioning stage to control a output voltage to supply a DC and AC load systems. To maximize energy extracted from PV generator and control output voltage a RCC MPPT and backstepping controller are designed. The stability of the control algorithm is demonstrated by means of Lyapunov analysis. The achievement of the DC-DC and DC-AC conversions and the efficient PV’s energy extraction are validated with simulation results.
This paper presents a numerical analysis of a trigeneration system in a hospital, aiming at determining the cost-optimal operating strategy as a function of the energy demands to be matched. The system includes: A natural gas fired reciprocating engine, heat exchangers for waste-heat recovery, a single-stage LiBr-H2O Absorption Chiller (ACH), a cooling tower, pumps, a backup boiler, a backup vapour-compression electric chiller, storage tanks, valves, mixers. For such system, a dynamic simulation model was developed in TRNSYS environment; the model includes detailed algorithms for all the components of the system. A case study was developed, referred to a hospital application, in which a Combined Heat, Cooling and Power (CHCP) system provides electricity, thermal and cooling energy. The electric energy demand was obtained by using real measured data and calibrating hospital literature data, whereas the demand for heating and cooling was estimated by means of a detailed simulation model. A detailed economic analysis was also included in the model, aiming at investigating the optimal control strategy needed to maximize the overall thermo economic performance of the system. To this scope, different control strategies were analysed. The most conventional operating strategy, Thermal Load Tracking mode (TLT), was compared with two alternative strategies: The Maximum Power Thermal Load Tracking mode (MPTLT) and the Electricity Load Tracking mode (ELT). MPTLT is a strategy featured by a thermal load tracking mode, but the engine, differently from TLT one, operates always at maximum power. ELT is a strategy in which the power provided by the engine is always less or equal to the electrical demand. In the paper, the results of the case study are presented on different time bases (days, weeks, years). Such results show that the ELT control strategy can achieve a better profitability, with a simple pay-back period, SPB, equal to 4 years. The conventional strategy (TLT) is shown to be the worst from the economic point of view, but among the best as for energy saving potential. © 2016 Francesco Calise, Massimo Dentice d’Accadia, Luigi Libertini, Edoardo Quiriti and Maria Vicidomini.
Palm Kernel Shell (PKN), an eco-friendly biomass, was carbonized and activated for the removal of phosphorus from wastewater through batch adsorption process. The studies evaluate the effects of pH, particle size, dosage and contact time on the adsorption capacity of the prepared adsorbent. The equilibrium concentration data and the amount of adsorption were described using non-linear regression analysis of the curve fitting toolbox of MATLAB 7.0. The mechanism of adsorption was determined through thermodynamic properties such as change in free energy ΔG (KJ mol⁻¹) and change in entropy ΔS (Jmol⁻¹K⁻¹). Statistical modeling via Central Composite Design (CCD) for process optimization was carried out. The obtained results showed that, adsorption data conformed to Freundlick Isotherm. The positive values of ΔH (KJ mol⁻¹) and ΔS (J mol⁻¹ K⁻¹) indicate the endothermic character of the reaction and the increased randomness at the solid-solution interface respectively during the adsorption process. The most significant main effect for performance of the adsorbent is contact time (Pvalue = 0.0000). Based on the result of the optimization of response surface model fit to experimental data, PKN reduced the effluent concentration from 373 to 24.095 mg L⁻¹, a performance of 93.54%. The minimum pH2, dosage (1000 mg) and particle size (0.2 mm) are local while the contact time (4.1 h) is a global optimum.
Cryptography has been widely used as a mean to secure message communication. A cryptosystem is made up of a publicly available algorithm and a secretly kept key. The algorithm is responsible for transforming the original message into something unintelligible. The result of losing the key or cracked algorithm can be catastrophic, where all secret communications will be known to adversaries. One way to find the key is by brute-force attacks which try every possible combination of keys. The only way to prevent this is by having the key of sufficiently large enough such that finding the right key cannot be made in a reasonable time frame. However, large key size imposes extra computational works which result in larger energy consumption and thus more heat dissipation to the environment. Therefore, the selection of key size does not only depends on the required security level, but also factors such as the ability of the processor and the available memory resources. The advent of multi-core technology promises some improvements in the utilization of computational resources. Many reports support the idea that multi-core technology brought a significant improvement over the single core technology. In this study, we investigate this hypothesis on the RSA cryptosystem in relation to the key size. Earlier studies reported multi-core efficiency in normal applications, but the question arises if multi-core architecture remains superior to a single core architecture when dealing with applications involving large integers. From our experimentation, we observe that the higher the number of cores, the better the performance of the encryption and decryption processes. The quad-core technology can smoothly handle operations involving 8192 bits key. © 2016 Mohamad A. Mohamed, Ammar Y. Tuama, Mokhairi Makhtar, Mohd K. Awang and Mustafa Mamat.
Bird impacts can be extremely critical events for the air transport safety. Since aircraft structures have become more and more complex components, the numerical prediction of the damage onset and evolution induced by a bird impact has become a very challenging task. The aim of this work is to provide a brief overview of the numerical techniques adopted for the prediction of the bird impact phenomenon on a leading edge of a regional aircraft wing. Smooth Particle Hydrodynamics (SPH), Rigid and Lagrangian models have been investigated and the results have been compared and critically assessed. © 2016 Aversa Raffaella, Relly Victoria V. Petrescu, Apicella Antonio and Florian Ion T. Petrescu.
Solar Photovoltaic (PV) energy is becoming an increasingly important part of the world's renewable energy. In order to develop technology for efficient energy conversion from a solar PV system, this paper studies typical Maximum Power Point Tracking (MPPT) control techniques used in solar PV industry and then proposes a close-loop and adaptive MPPT method for reliable and rapid extraction of solar PV power. The paper emphasizes especially on how the proposed and conventional adaptive MPPT methods perform under highly variable weather and solar irradiation conditions in a digital control environment. A computer simulation system is developed by using Sim Power Systems and Opal-RT real-time simulation technology which allows for fast and efficient investigations of the MPPT algorithms under high switching frequency conditions for power converters. A hardware experiment system is built to validate and compare the proposed and conventional MPPT techniques in a more practical condition. Advantages, disadvantages and properties of different MPPT methods are compared and studied, evaluated.
In general, small part of fuel chemical energy transforms to effective power in diesel engines and other parts are going as energy losses, there for many researchers, as well as engine designers, are searching to increase this part by using various methods. In this study, the effect of pure biodiesel and biodiesel-diesel fuel blends on engine energy balance, compared with diesel fuel, has been performed. For this purpose, diesel engine coupled with a dynamometer, as well as, the thermocouples (to measure the temperatures in different locations) and the flow meter (to measure the water flow rate) have been used. In addition, biodiesel mixed with diesel fuel to obtain various proportions of the fuel blends. The engine heat losses through: Cooling water system, exhaust gases and by radiation have been calculated, on the base of experimental results. The results show that an increase of the biodiesel in the fuel blends lead to increase of heat losses. Moreover, the energy distribution from the fuel used for the experiments show a decrease in useful work, increase of heat lost with cooling water, heat lost with exhaust gases and by radiation by about of (average values) 7, 3.8, 4.8 and 4.5% respectively when compared with diesel fuel. The energy distributions were as 26, 27, 22 and 0.46% for useful work, heat losses with cooling water, with exhaust gases and by radiation, respectively.