A Visual Feedback Tool for Quantitative Pressure Monitoring in Lower-Limb Prosthetic Sockets

Obtaining a good socket fit is an iterative process dependent on the skill and experience of the prosthetist creating it and requires individualisation based on the size and shape. There is no standard measurement system used to aid prosthetic socket creation despite the severe impacts on physical health and quality of life if one is ill fitting. Pressure sensors embedded in a prosthetic socket were used to collect data at the socket–residuum interface. To choose an interpolation method, the sensor array was simplified to a 2D grid with a border for extrapolation and tested using previously collected walking test pressure data. Four multivariable interpolation methods were evaluated to create a colour map of the pressure data. Radial basis function interpolation was chosen, as it produced a clear image with a graduated interpolation between data points, and was used to create a colour map across the surface of a 3D prosthetic socket model. For the model to be accessible to clinical audiences, a desktop application was created using PyQt to view the model. The application allowed for connection to the sensors via Bluetooth, with the pressure data updating on the 3D model in real time. Clinician feedback on the application showed the potential for a clinical product; however, further development informed by feedback from rehabilitation clinicians and prosthesis users is required.

Visual Biofeedback Tool for Quantitative Pressure Monitoring in Lower-Limb Prosthetic Sockets

Obtaining a good socket fit is an iterative process dependent on the skill and experience of the prosthetist creating it, and requiring individualisation based on the size and shape. There is no standard measurement system used to aid prosthetic socket creation, despite the severe impacts on physical health and quality of life if one is ill-fitting. Pressure sensors embedded in a prosthetic socket were used to collect data at the socket-residuum interface. To choose an interpolation method, a 2D grid was used, with previously collected walking test pressure data, to simplify the sensor array with a border for extrapolation. Four multivariable interpolation methods were evaluated to create a colour map of the pressure data. Radial Basis Function interpolation was chosen as it produced a clear image with a graduated interpolation between data points and was used to create a colour map across the surface of a 3D prosthetic socket model. For the model to be accessible to clinical audiences, a desktop application was created using PyQt to view the model. The created application allowed for connection to the sensors via Bluetooth, with the pressure data updating the colour map on the 3D model in real-time. The created application shows the potential for a clinical product, however further development informed by feedback from rehabilitation clinicians and prosthesis users is required

CONCERNING THE DEVELOPMENT OF MODERN TEST EQUIPMENT FOR THE EVALUATION OF QUALITY INDICATORS OF FIRE-FIGHTING LAYFLAT DELIVERY HOSES FOR FIRE AND RESCUE VEHICLES

Pressure fire hoses are one of the main types of fire-fighting equipment, on the serviceable condition of which depends the operational activities of fire and rescue units and successful firefighting. At present, Ukraine has entered into force with (01.08.2021) the national standard, which contains modern European requirements for assessing the quality of flat-hose fire hoses for fire and rescue vehicles. This standard was developed by the Institute of Public Administration and Research in Civil Defense in the framework of research work "Fire hoses – test methods" and adopted by order of SE "UkrNDNC" from 23.03.2021 № 107. In order to assist in solving this problem, the Institute of Public Administration and Research in Civil Defense put into operation, tested and verified the installation for testing fire pressure hoses, which will check the quality of pressure flat hose for fire and rescue vehicles in accordance with modern European requirements. The installation is intended for tests of pressure fire hoses carried out on the following quality indicators: working, test and burst pressure; abrasion resistance; resistance to hot objects; resistance to open flame. The unit is operated at air temperature from 10 ° С to 25 ° С and relative humidity from 15% to 90%. The installation is a metal table, which consists of two levels (upper and lower). The main part of the tests is to be performed at the upper level with the help of three removable modules. The lower level provides one stationary module on which tests for working, test and burst pressure are carried out. The upper level of the installation is designed to test pressure fire hoses for the following quality indicators: resistance to surface abrasion, resistance to point abrasion, resistance to hot objects and resistance to open flames. For versatility and convenience of work on installation on the top level of a table the possibility of change of modules depending on their need is provided. The lower level of the installation is intended for carrying out tests of pressure fire hoses on quality indicators – working and test pressure, bursting pressure. At the lower level of the metal table is a rectangular metal box, which has a closing lid. During the tests, the sample of the test sleeve is automatically filled with water, which drains after the test. To fix the samples of fire hoses of different diameters (25, 32, 38, 51, 66, 77, 100, 125 and 150) mm, the installation includes special cones and plates.

Pneumatic Testing of Piping Assemblies: Criteria for Stored Energy and Pinhole Leak Detectability

Pneumatic testing is beneficial as an alternative to hydrotesting particularly in remote areas where access to hydrotest fluids becomes logistically difficult or impossible. The present work is aimed at addressing two salient questions often face pneumatic testing. First is related to the appropriate piping volume to consider for calculating the stored energy in use with ASME PCC-2 calculation for determining the safe exclusion distance for a given piping geometry and test conditions. It was found that the 8D criteria specified in ASME PCC-2 cannot be generalized for all pipe sizes, different material toughness, grades, wall thicknesses and test conditions. A criterion is developed based on the ductile fracture arrest length that considers all these factors combined. The second criterion is related to the ability to detect pinhole leak from the pneumatic test data, again for a given geometry and test conditions, and what constitutes the minimum pinhole effective area in relation to the system total volume, measured uncertainties in the test pressure and temperature over the duration of the test. A semi-normalized physics-based parameter is suggested that can be applied to determine the effective pinhole leak size in relation to the volume of the piping assembly and conditions for detectability limit. A methodology is developed and applied to a pneumatic filed test on DN200, 12.2 km pipeline lateral.

Toe Initiation Sleeve With Time-Delay Functionality Improves Operational Efficiency of Offshore NCS Wells

A toe initiation sleeve is a tool installed in the toe of a completion liner and is used to establish a flowpath to the reservoir without the use of intervention. Conventional toe initiation sleeves require either intervention or increasing pressure to higher than the liner test pressure to activate. These methods have inherent cost and operational risks. This paper will present the development, qualification, and deployment of a multicycle, time-delay cementable toe initiation sleeve that allows for interventionless activation without exceeding the liner test pressure. This development greatly improves operational efficiency and eliminates risk associated with conventional toe initiation sleeves. A major operator in the North Sea required an ISO V0 rated toe initiation sleeve to be developed and qualified. Design criteria for the tool was identified, and the design was developed based on field-qualified seal technology. Individual component and full-scale validation testing was performed to complete the product qualification, followed by field trials in 2019. With its unique time-delay feature, the newly developed ATS (Advanced Toe Sleeve) allows for an unlimited number of pressure cycles to be performed while also keeping the well V0 barrier in place, and activates at below liner test pressure. This paper will discuss the technology development and implementation project, resulting in ISO 14998 V0-qualified cemented ATS being installed in nearly 40 wells in the same field. This paper will also provide insight into how the ATS provides unique benefits to the operator during various phases of the well's life. Cementing: One moving part and opening sleeve isolated from the inside diameter (ID) allow for pumping darts through the ATS without the risk of opening Setting liner/testing liner: Time-delay features allow for setting liner and testing the liner at higher pressures than ATS opening pressure. Well cleanup/displacing to lower density fluid: Time-delay function allows for opening the ATS at lower pressure than the well has seen during previous operations. Completion: ATS design and qualification grade reduce completion steps and costs for the operator. Stimulation: ATS eliminates the need for intervention, reducing the operational steps and costs for the operator. The advanced toe sleeve with built-in time-delay features maintains the liner integrity throughout the various well operations. The number of available pressure cycles can be predetermined, and the activation of the various cycles can be precisely controlled thereby also controlling when the tool is activated to achieve injectivity. This paper will present the development and field-wide implementation of the ATS technology, which has rapidly gained operator acceptance and resulted in significant time and cost savings.

Considering Hydrotest Pressure Loading in the Calculation of MAWP of a Pressure Vessel

As defined in UG-98 of the Code, the Maximum Allowable Working Pressure (MAWP), is the maximum pressure permissible at the top of the vessel in its normal operating position. It is the least of the values calculated for each of the vessel part adjusted for the static head and by including the effect of any combination of loadings listed in UG-22 of the Code. Conventional method of calculating the MAWP is to consider only the main pressure parts viz., the shells and the heads and the significant UG-22 loading viz., the wind and the seismic. Once the MAWP is determined, the rest of the vessel design is completed considering this value of MAWP as design pressure combined with any other applicable UG-22 loading. At the end, the vessel is verified for its adequacy to the test condition. It is noted that, the MAWP obtained through this method is often higher than the design pressure thus leading to the overdesign of the vessel. Moreover, higher MAWP results in higher test pressure, which might have a considerable impact of its own on the design of the vessel. The objective of this paper is to propose a design approach in which the test pressure itself is included as one of the governing loads in the determination of the MAWP so that the impact on vessel design, as explained above, is minimized.

Evaluation of testing procedures for real-scale sewage pipes

Tests to determine the tightness of wastewater pipes can in some cases produce results that are worthy of discussion. Therefore, testing procedures for real-scale sewage pipes used for house connections were evaluated and data was statistically analyzed. The results of the investigation showed that leaky pipes are detected with a very high degree of reliability by all leak test methods. The test methods are also robust against errors by expert testers and deviations from the test specifications. In contrast, tight pipelines can also be incorrectly classified as ‘leaking’ (test failed) to a significant extent during leak tests. Even for the more reliable test methods, i.e. air overpressure, air underpressure and water with low test pressure, a tight pipe is incorrectly classified as leaking (false positive) in one out of ten cases (10%). The highest false positive rate was 20% for water with high test pressure. In addition to the leak test methods, the quality of the visual inspection was also analysed. Here it was found that visual inspection is not sufficiently reliable for determining the tightness of pipelines above the groundwater level. Error rates of approximately. 50% were found for the detection of tight and leaky pipelines.

Evaluation of changes in fuel delivery rate by electromagnetic injectors in a common rail system during simulated operation

The objective of this study was to determine changes in fuel delivery rate by common rail system injectors during their simulated operation on a test stand. Four Bosch injectors used, among others, in Fiat 1.3 Multijet engines were tested. The injectors were operated on a test rig at room temperature for 500 hours (more than 72 million work cycles). During the test, pressure and injection frequency were changed. Changes in the operating parameters were estimated based on obtained injection characteristics and effective flow area determined thereby. The observed changes in fuel delivery rate were compared with results of the surface analysis of control valves and nozzle needles. Despite the stated lack of wear, significant changes in the dynamics of injector operation were observed, particularly at short injection times. Small pilot injections do not have to be corrected by the fuel injection control system because they do not affect the changes in torque; however, they do affect the combustion process. This creates conditions for increased emission of toxic exhaust components.

Analysis of blood clotting with the total thrombus analysis system in healthy dogs

To date, coagulation tests are unable to reflect in vivo coagulation status in the same system, including platelet function, fibrin clot formation, and whole blood flow. The Total Thrombus Analysis System (T-TAS), which is a microfluidic assay that simulates conditions in vivo, measures whole blood flow at defined shear rates under conditions designed to assess platelet function (PL-chip) or coagulation and fibrin clot formation (AR-chip). The T-TAS records occlusion start time, occlusion time, and area under the curve. We evaluated this test in healthy control dogs. We also investigated the effect in vivo of acetylsalicylic acid (ASA), and the effect in vitro of an anticoagulation drug (dalteparin; low-molecular-weight heparin; LMWH). The CV of the AUC of both chips was good (CVs of 6.45% [PL] and 1.57% [AR]). The inhibition of platelet function by ASA was evident in the right-shift in the PL test pressure curve. The right-shift in the AR test pressure curves showed that the administration of LMWH inhibited both platelets and the coagulation cascade. The T-TAS may be useful in the evaluation of canine blood coagulation.

ANALISA TEGANGAN PADA PLUG VALVE MENGGUNAKAN METODE ELEMEN HINGGA BERBASIS SIMULASI

Plug Valve adalah katup gerakan rotasi seperempat putaran yang menggunakan plug meruncing atau silinder untuk menghentikan atau mengarahkan laju aliran fluida. Plug Valve bisa dipakai mulai dari tekanan atmosfir hingga 10.000 psi (69.000 KPa) dan suhu dari 50 hingga 1.500 0F. Dalam penelitian ini, dilakukan analisa tegangan yang terjadi pada body plug valve akibat tekanan laju aliran fluida menggunakan Metode Elemen Hingga Ansys Workbench. Pada penelitian ini, body plug valve diberikan variasi tekanan Working Pressure berdasarkan standard ASME B16.34 pada suhu material 300ºC yang kemudian dengan Test Pressure hingga tegangan yang terjadi mencapai batas Yield Tensile Strength material ASTM A216 Grade WCB yaitu sebesar 280 MPa. Hasil tegangan yang didapat berdasarkan hasil simulasi pada body plug valve yang dimodelkan didalam software Ansys Workbench didapatkan bahwa pada Working Pressure 1.02 MPa tegangan maksimum yang terjadi sebesar 3.7625 MPa, selanjutnya pada Test Pressure 16 MPa didapatkan tegangan maksimum sebesar 59.02 MPa, lalu pada Test Pressure 36 MPa didapatkan tegangan maksimum sebesar 132.8 MPa, kemudian pada Test Pressure 56 MPa didapatkan tegangan maksimum sebesar 206.57 MPa, dan pada Test Pressure 76 MPa didapatkan nilai tegangan maksimum sebesar 280.35 MPa. Berdasarkan variasi tekanan yang diberikan pada body valve didapatkan, pada test pressure 76 MPa tegangan maksimum yang terjadi sudah melewati nilai batas Yield Tensile Strength dari material yang dipakai, dalam kondisi ini body plug valve akan mengalami kegagalan distrosi deformasi plastis (plastic deformation), dimana semua perubahan yang terjadi akan terjadi secara permanen dan akan terus berlanjut hingga mencapai batas tegangan maksimum material. Kata kunci: Body, Plug Valve, Tegangan Maksimum, Pressure