ПРОЕКТУВАННЯ СТУЛКОВОГО ВІДСІКУ ХВОСТОВИХ ВАНТАЖНИХ ЛЮКІВ ЛІТАКІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

The method for determining the main parameters of the tail cargo doors of transport category aircraft is developed. There have been prepared initial data and described the methodology for finding them. An example based on an existing transport aircraft is considered. The basic nomenclature of transported cargoes of the designed aircraft, its dimensions and weight, methods of loading and mooring, additional loading equipment were taken as initial data. As well as such necessary design, operational and regulatory parameters and data as landing gear type, its “kneeling” system, rails of the upper loading equipment for loading and unloading, cargo trajectories during loading and landing, requirements of international regulatory organizations FAR, CS, AP. The principle of determining the dimensions of the cargo compartment, cargo floor and the hitting platforms in the form of ramp with pressure door, ladders is presented, based on the initial data. Taking into account the loading and unloading, landing operations described the dependence of the ramp length on the length of the cargo floor. The correct formation of these parameters is one of the most important tasks, from the solution of which directly depend the operational characteristics of the future transport aircraft. A method for designing cargo door fairings in the transport category aircraft fuselage tail part is also presented. There have been determined the main features of the fairings compartment, its main components and their varieties, depending on the scheme of the cargo door. At the stage of preliminary design, the principles for determining the main parameters of the fairings compartments based on their design purpose are outlined.Also provided information on the fairings compartment structural elements parameters selection: the axes of the fairings hinge, the selection of control cylinders and their installation, the parameters of the open and closed position locks, pressurization and sealing of the fairings compartment. Considered the design features of the fuselage tail section various theories fairings compartment - made in cross-section with one radius (in the shape of a cylinder) and given in cross-section with two radii (double-deck).

Mechanical Innovations Developed for the Lille Langebro Swing Bridge, Copenhagen

<p>The Lille Langebro (Little Langebro) pedestrian and cycle swing bridge opened to the public in August 2019. The bridge provides a quay-level crossing of the harbour for pedestrians and cyclists and was the outcome of an international design competition. In order to enable the passage of marine craft along the harbour the central sections of the bridge rotate. This paper gives a brief overview of the operating equipment associated with the movement of the two rotating spans before a more detailed discussion on the innovative moment connection developed to secure the joint between the two moving spans when in the bridge closed position.</p>

Design of an Anti-Slip Mechanism for Wheels of Step Climbing Robots

This manuscript presents a shape memory alloy (SMA) actuated anti-slip mechanism for the wheels of step climbing robots. The proposed mechanism comprises three kinematic chains considering the Lazy Tong and the bi-stable four-bar mechanism. Chain 1 of the mechanism is used to clamp on the edges of the stairs to avoid slipping. The second chain of the mechanism is used to switch the mechanism between two stable positions, i.e., open position and closed position, of chain 1. For activating the mechanism, the third chain is employed which is based on SMA wire. Furthermore, the mechanism is designed to achieve passive switching from the open position to the closed position. Equations are developed to determine the dimensions of various members. Using those parameters, a 3D model of the proposed mechanism is developed. Stress analysis is performed and the model is found to be safe under a load of 250 N with a factor of safety of 3.025. The mechanism is attached to either side of a wheel of the outer radius of 290 mm. To analyze the kinematics of the mechanism, a three-dimensional model in MSC Adams is developed and studied. The force required by SMA actuator is found to be less than 5 N. The proposed mechanism may be used for various unmanned robotic systems while mitigating step-like obstacles in the path.

Successful Intervention of Coiled Tubing Rugged Tool with Real-Time Telemetry System in Saudi Arabia First Multistage Fracturing Completion with Sand Control System

An openhole multistage completion required selective fracture stimulation, flow control, and sand control in each zone. An openhole multistage completion was designed by combining a production sleeve integrated with sand screens and inflow control devices and a fracture sleeve with high open flow port. The system was designed to use a ball drop to isolate the bottom intervals while fracturing upper intervals. After fracture stimulation, the fracture seat/ball needed to be milled. The production sleeve were designed to be shifted to the open position and the fracturing sleeve to the closed position through mechanical shifting tool to put the well on production. The fracturing sleeve and the production sleeve were located close to each other and a successful shifting operation needed an appropriate shifting tool, with a real-time downhole telemetry system that met the temperature limitations while providing accurate depth control, differential pressure readings, and axial force (tension and compression) measurements. Hydraulic-pressure-activated shifting tools were used to manipulate the sleeves. A coiled tubing (CT) rugged downhole tool with real-time telemetry was used to run the shifting tools. Yard tests were conducted to identify the optimum rates and pressures to actuate the hydraulically activated shifting tools and study their behavior. The expansion of the fracturing sleeve shifting tool keys initiated at 1.6 bbl/min (400 psi) and the keys were fully expanded at 1.8 bbl/min (600 psi), whereas the expansion of production sleeve shifting tool keys initiated at 0.3 bbl/min (700 psi), and the keys were fully expanded at 0.4 bbl/min (900 psi). During the design and planning of the shifting operation, simulations were conducted, and surface and downhole tools were selected carefully to ensure the CT could provide enough downhole upward force (5,000 to 6,000 lbf) to close the fracture ports and 2,000 to 4,000 lbf to open production sleeves. Following the fracturing operation, the first CT run aimed to mill fracture seats/balls to clear the path for the subsequent shifting operation. In the second CT run, all the fracturing sleeves were shifted to the closed position while production sleeves were shifted to the open position. The CT rugged downhole tool proved critical for depth correlation and accurate placement of the shifting tools. The real-time downhole acquisition of differential pressure across the toolstring also allowed operating the shifting tools under optimum conditions, while downhole force readings of tension and compression confirmed the shifting of completion accessories. Two fracturing sleeves were shifted to the closed position at 2.4 bbl/min and 700-psi downhole differential pressure, with the downhole weights of 700 lb and 1,000 lbf. Three production sleeves were shifted to open position at 0.6 bbl/min and 1,200-psi downhole differential pressure, and the maximum surface and downhole weights recorded were 73,000 lb and 19,200 lb, respectively. That operation led to sand-free production and confirmed the success of the first multistage completion enabling fracturing operation and controlling sand production in Saudi Arabia. This study describes the use of real-time downhole measurements and their significance when surface parameters do not give clear indication of shifting. It also features the first-time use of two hydraulically activated shifting tools operated during the shifting operation in Saudi Arabia's first multistage completion enabling fracturing operation and controlling flow/sand production.

Contribution of soil in the annual effective dose due to radon in the air of some dwellings in the city of Karbala, Iraq

Introduction: The radon isotopes are not as significant as (222Rn) due to the decay of the natural radionuclides (235U), (232Th) and (238U) due to their short half-life, at most. (222Rn) can be classified as among the most harmful radioactive elements in the world. Material and method: In this analysis, the closed-can technique was used with solid-state nuclear track detectors (CR-39). After forty days of closed dosimeter buried in the soil of the garden, and ninety days from the closed position in the air of some dwellings were collected dosimeter and stripped of nuclear detectors impact of closed groups. For 8 hours, CR-39 detectors were chemically etched by (6.25 N) NaOH solution at 70°C and then registered within an optical microscope. Result: The levels of soil radon concentrations ranged from 28.44±0.58 to 479.76±2.43 Bq/m3 with a mean value of 220.33±1.64 Bq/m3, while the concentration of radon in the air of certain dwellings varied from (1.95±0.27 to 46.82±0.75) Bq/m3 with an average value of 21.51±0.54 Bq/m3. In comparison, the annual effective dose attributed to radon in soil ranged from 0.71±0.09 mSv/y to 12.10±0.38 mSv/y with an average value of 5.55±0.261 mSv/y, while the annual effective dose in air differed from (0.04±0.02 mSv/y) to (1.18±0.12 mSv/y) with an average value of (0.60±0.09 mSv/y). Conclusion: Neglecting the effects of other radon sources, the percentage share of the annual effective dose due to radon in soil measured in the air home, ranged from 0.005±0.001 to 0.453±0.074 with an average value of 0.130±0.040. Weak correlation between concentrations of radon in households and soil air. But roughly speaking, one can say that in soil air every 1000 Bq/m3 and 1000 mSv/y contributes around 130 Bq/m3 and 130 mSv/y in indoor air.

A comparative study of the effects of the anterior disc displacement with reduction and without reduction on the components of the temporomandibular joint by using magnetic resonance imaging – A Retrospective study

Background: Internal derangement of the temporomandibular joint (TMJ) results in anterior disc displacement with reduction (ADDR), the disc is ante- riorly displaced in the closed position whereas in the opened position the disc returns to its normal location. In anterior disc displacement without reduction (AD- DWR), the disc is anteriorly displaced in the closed po- sition but does not return to its original location in the opened position. Here we studied and compared the effects of the ADDR and the ADDWR on the components of the TMJ by using the magnetic resonance imaging technique (MRI). Methods and materials: From the archival MRI records, 214 joints from 107 patients were included. The selec- tion criteria for the patients complaints as TMJ pain, clicking, limited mouth opening, headache, jaw tenderness and difficulty in eating. MRI records with sequences Proton Density (PD), PD FAT SAT and T2* gradient in the closed position and T2* gradient echo in the opened position. Data analysis and frequency distribution of explanatory variables by disc position in the open state was performed using chi-square test Results: Statistically significant differences were observed between the variables such as the joint space (closed position), disc morphology (closed position) and range of movement (opened position) among the ADDR and the ADDWR. In ADDWR, 20.3% demonstrated narrowed joint space and 1.6% with widened joint space, while in ADDR, 2.5% of joints had narrowed joint space and 0% widened joint space. Same was observed with abnormal disc morphology and rang of movement. Conclusion: The disc deformity is more in ADDWR compared to ADDR which can be seen as an alteration in the signal intensity. The malaligned disc could lead to the narrowing of the joint space and decreased range of movement in the ADDWR affected individuals.

Numerical Analysis of Aluminium Oxide Nano Particles with Biodiesel in a Diesel Engine Fitted with Hemispherical Groove in the Piston

For proper combustion, bowl in the piston geometry plays a crutial role when the engine valves are in closed position. In the present work, the combustion geometry is of hemi-spherical groove in the upper region of the piston.simulations weres conducted for different blends( b20+al40, b20+al80) to analyze the combustion features in a four stroke diesel engine using ansys r18.1 software considering above geometry of the piston. . Pertaining to greater amount of density, viscosity of biodiesel blends, variations for b20+al80 render more performance than the biodiesel. Turbulent kinetic energy of both the fuels follow similar trend due to proper mixing of air with the fuel from fuel injector.

Lessons Learnt from the Structural Design and Construction of the Lille Langebro, Copenhagen

<p>The Lille Langebro is a major new pedestrian and cycle bridge over the harbour in Copenhagen. The bridge forms a sleek, low level crossing that curves in plan as well as elevation. The superstructure consists of fabricated steel box sections of complex geometry and includes two balanced double cantilever spans on slew bearings which rotate to allow the passage of large ships. The rotating spans are fixed together in the closed position by an arrangement of proprietary mechanical components which form an innovative structural moment connection at mid-span. The complex nature of the structure presented many challenges to the design and construction that were successfully overcome through close cooperation between the client, designers and contractors. This paper will explain some of these challenges and the lessons that can be learnt for use in future projects.</p>

Does Regular Dancing Improve Static Balance?

The aim of the study was to compare the static balance of dancers and non-dancers in a bipedal and unipedal stance. Twenty-three female dancers (mean age: 21.3 ± 1.7) and 24 age and sex-matched subjects (mean age 22.3 ± 1.0) participated in this study. A force platform was used to assess balance. The tests on the balance platform were performed in several positions with different foot placement, such as normal standing (NS) eyes open and eyes closed positions, semi-tandem position (ST), tandem position (TP), and one-leg standing (1L) eyes open and eyes closed position. Significant differences in balance between the dancers and the control group, especially in the tandem position and one-leg standing position with eyes closed were found. We observed higher results for the velocity of the COP in the frontal plane in the TP with a dominant limb in front (p = 0.04) and higher results for the velocity of the COP in the frontal plane (p = 0.01) and in the sagittal plane (p < 0.01) in the TP with a dominant limb in front in the control group. We also observed significant differences between groups in the mean velocity of COP sway in the sagittal plane in the 1 L position with eyes closed (p = 0.04). We concluded that dancing regularly for several years improves static balance.

A Four-Step Safety Integrity Level Analysis of Numerous Subsea Control System Components

In this paper, a four-step Safety Integrity Level (SIL) analysis is developed to analyze numerous components of the subsea control system based on the OREDA database. For this purpose, initially, a failure mode classification table is provided aiming to identify the number of dangerous as well as the prevalent failure modes. Then, several parameters such as the total time in service of the components are calculated. Also, failure rates are evaluated and the software checking is provided as the final step of the proposed framework. The results show that the number of dangerous failure modes is a noticeable value and the leakage in closed position is the failure mode occurring more than the other ones. Moreover, the quantification of parameters indicates that the process isolation valve of the subsea X-mass tree has the largest values in all the considered parameters. Besides, hydraulic coupling of the choke module and HC leak sensor are the two components with the highest value of failure rates.