Two men die in well cleaning operation - Maryland, May 1, 1993.

1993 ◽  
Keyword(s):  
Author(s):  
J.P. Benedict ◽  
Ron Anderson ◽  
S. J. Klepeis

Traditional specimen preparation procedures for non-biological samples, especially cross section preparation procedures, involves subjecting the specimen to ion milling for times ranging from minutes to tens of hours. Long ion milling time produces surface alteration, atomic number and rough-surface topography artifacts, and high temperatures. The introduction of new tools and methods in this laboratory improved our ability to mechanically thin specimens to a point where ion milling time was reduced to one to ten minutes. Very short ion milling times meant that ion milling was more of a cleaning operation than a thinning operation. The preferential thinning and the surface topography that still existed in briefly ion milled samples made the study of interfaces between materials such as platinum silicide and silicon difficult. These two problems can be eliminated by completely eliminating the ion milling step and mechanically polishing the sample to TEM transparency with the procedure outlined in this communication. Previous successful efforts leading to mechanically thinned specimens have shown that problems center on tool tilt control, removal of polishing damage, and specimen cleanliness.


2019 ◽  
Vol 33 ◽  
pp. 248-254
Author(s):  
Laura Troșan ◽  

The workpiece approached in this paper is part of the category of port textiles (head adornment), with the purpose of emphasizing the social and economic status, but it also has a decorative role. The bonnet comes from the Odorheiul Secuiesc area and can be dated between 1880-1910. When the bonnet first entered the restoration laboratory it was investigated and the following degradations were found: functional wear, dust and dirt deposits, aging and brittleness of the fabric thread, dehydration and stiffening of the embroidery thread, stains of unknown origin, not very visible, improper interventions. The restoration work started with the dry mechanical cleaning of the workpiece, which was performed using the Minivacuum cleaner. Before the wet cleaning operation, the ribbons, bottoms and all the decorative elements of the piece, paper flowers, were disassembled, each component being cleaned and consolidated independently. The drying was controlled, the silk ribbons were dried on a glass support, and for the rest of the workpiece was made a drying support, which imitates the shape of the head. Together with the museologist, it was decided to coat the entire piece with transparent material (creplină) for the exterior, and a cotton cloth was used for the interior.


2012 ◽  
Vol 184-185 ◽  
pp. 793-797
Author(s):  
Zi Dong Yang ◽  
Xu Dong Wang ◽  
Xia Kan Su

According to the purpose and requirements of a virtual test, the complex mechanism of the combine harvester was abstracted and simplified to some extent during modeling, but in order to guarantee the closeness between simulation result and the reality, attention was paid to keeping the total mass of all components close to the actual mass of the combine harvester and reducing workload during modeling. The vibration test of the cleaning operation includes horizontal vibration and vertical vibration. The test conditions are that: the combine harvester is still and has no load and only the engine runs, or the engine and the cleaning component run simultaneously. To guarantee the extractions are thrown out of the machine in the rear end of the screen, the backward slip of the extractions is greater than forward slip. The simulation result satisfactorily reflects the real situation and is same as theoretical analysis. The result indicates the virtual test and the real test are consistent.


2021 ◽  
pp. 485-494
Author(s):  
Hongguang Yang ◽  
Huanxiong Xie ◽  
Hai Wei ◽  
Jianchun Yan ◽  
Huichang Wu ◽  
...  

Aiming at the problem that contain more soil impurities of potato post-harvest, which affects subsequent deep processing, an apparatus for removing soil impurities from potato was developed. The whole structure is mainly composed of frame, feeding port, flexible rubber finger conveying mechanism, slender filament rotary brushing mechanism, discharging port and the like. The research and analysis determined that the main parameters influencing the soil impurities removal performance were the movement speed of conveying mechanism, the movement speed of brushing mechanism and the clearance between conveying mechanism and brushing mechanism (hereinafter referred to as the mechanism clearance). Taking the main influencing parameters as test factors, and the soil impurities removal rate and potato damage rate as indexes, the orthogonal test with three factors and three levels was carried out. The optimal parameter combination was obtained as follows: the movement speed of conveying mechanism was 0.35m/s, the movement speed of brushing mechanism was 0.40m/s, and the mechanism clearance was 55mm. At this time, the average soil impurities removal rate was 87.18%, and the potato average damage rate was 1.95%, which met the requirements of potato cleaning operation.


2018 ◽  
Vol 9 (08) ◽  
pp. 20203-20217
Author(s):  
Chandra Sekhar Mishra ◽  
Zenawi Fitwi ◽  
Habtom Imuru

,


Author(s):  
Stefano Papa ◽  
Giuseppe di Gironimo ◽  
Federica Casoria ◽  
Gioacchino Micciché

The paper describes the activities of conceptual design of tools and procedures and the virtual simulation of the Remote Handling (RH) tasks provided in the maintenance of the systems present in the Access Cell (AC) of DONES (DEMO Oriented Neutron Source) facility. In particular, the RH maintenance of the Target Assembly (TA) is critical because of its position in the most severe region of neutron irradiation, the Test Cell (TC), where the material specimen are tested to understand the degradation of the materials properties throughout the reactor operational life. The main RH maintenance activity includes the replacement of the entire TA and the cleaning of the surfaces of connection in the TC. The cleaning operation is fundamental because it allows the removal of any lithium solid deposition from the surfaces: any further deposition on the surfaces could compromise the sealing of the TA. The RH is based on the idea of a reconfigurable modular chain of devices connected to the Access Cell Mast Crane (ACMC) located in the AC. To increase the modularity and to reduce the costs of the Remote Handling System (RHS), a telescopic boom is used equipped with a Gripper Change System (GCS) that allows the use of different end effectors. To perform the tasks, a Parallel Kinematic Manipulator (PKM) and a Robotic Arm (RA) are proposed, allowing the tools to move with more degree of freedom in the AC space. The modeling of the devices and the 3D kinematic simulations maintenance operations tasks were simulated and tested in virtual reality environment, aimed at developing and validating the implemented maintenance procedures, in collaboration with the IDEAinVR Laboratory of CREATE/University of Naples Federico II, and the research center at ENEA Brasimone, Italy.


2013 ◽  
Vol 393 ◽  
pp. 863-871
Author(s):  
Lawrence H.P. Yong ◽  
William K.S. Pao ◽  
Fakhruldin M. Hashim

Coiled Tubing (CT) services are widely applied in oil field to remove fill from wellbore. Its function is to restore the productivity of oil and gas well since fill such as sand will regularly block the production line especially at the well bottom. Predicting the behaviors of cleaning fluid and particle transports during the CT cleanout is a major challenge because there are many variables which affect the cleaning operation resulting in loss of cleaning efficiency, waste of cleaning fluid and increase in cost of well services. The objective of this study is to perform detailed analyses of both flow pattern of cleaning fluids and particle transports in wellbore during cleaning process at different cleaning operating conditions and well geometries. In order to achieve the objective, the problem is broken down into two parts; namely the well string and the well bottom/annulus. The well string, which is the coiled tubing itself, is first solved semi-analytically to obtain the exit velocity of the flow nozzle and the accompanying surface pump operating conditions. Once the exit velocity in the coil tubing is known, the value is used as an inlet velocity boundary condition for the bottomhole and the well annulus for the subsequent CFD analysis. Simulating the cleaning process along the entire well span is impractical due to limitation in computational resources. Hence, only a limited section in the bottomhole and annulus were considered, where the calculated transport properties there is sufficient to inform the likelihood of fill being circulated to the surface. The present study identified that diameter ratio of CT and annulus, properties of the cleaning fluid, design of downhole nozzle are the three most important factors influencing the cleanout. The result of this study is a linearized CT parameters design chart that allows user to plan for cleaning operation.


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