Abstract: A perforating gun string includes a release tool, a perforating gun, and a plug. The perforating gun string may include or be part of a downhole tool that is electrically communicable via a control system. A first switch (or “RT switch”) is associated with the release tool and is operably coupled to a first detonator. A second switch (or “gun switch”) is associated with the perforating gun and is operably coupled to a second detonator. A third switch (or “plug switch”) is associated with the plug and is operably coupled to an igniter. A counter system includes a plurality of counters adapted to track usage of one or more switches in the perforating gun string, including the first switch, the second switch, the third switch, or any combination thereof.

Abstract: A perforating gun string includes a release tool, a perforating gun, and a plug. The perforating gun string may include or be part of a downhole tool that is electrically communicable via a control system. A first switch (or “RT switch”) is associated with the release tool and is operably coupled to a first detonator. A second switch (or “gun switch”) is associated with the perforating gun and is operably coupled to a second detonator. A third switch (or “plug switch”) is associated with the plug and is operably coupled to an igniter. A counter system includes a plurality of counters adapted to track usage of one or more switches in the perforating gun string, including the first switch, the second switch, the third switch, or any combination thereof.

Abstract: A shard of a selected document is identified. A hierarchy of documents including the selected document are to be tagged with metadata in a data store of a search engine so that the related documents are queryable by the metadata using the search engine. The shard specifies a location of the related documents within the data store of the search engine. For each related document, a tagging operation is generated within a script, the tagging operation specifying the metadata, the shard, an identifier of the related document, and an identifier of the selected document. The script including the generated tagging operation for each related document is transmitted to the search engine to execute to tag the related documents in the data store with the metadata and with the selected document as a source of the metadata.

Abstract: A system for estimating tension in a post-tensioned rod is provided. The system includes an impact device for transversely-impacting a post-tensioned rod, an accelerometer configured to generate data indicative of a vibrational response in the post-tensioned rod, and a receiver communicatively coupled to the accelerometer. The receiver includes a display, at least one input device, a communication module, a processor, and one or more memory devices coupled to the processor. Instructions stored on the one or more memory devices, when executed by the processor, cause the processor to receiver the data indicative of a vibrational response in the post-tensioned rod, process the received data to determine a difference between a first and a second modal frequency corresponding to the vibrational response, and store the difference between a first and second modal frequency corresponding to the vibrational response.

Abstract: The present disclosure provides systems and methods for non-destructively estimating the thickness of buried concrete without excavation. An example method may include placing one or more first accelerometers at a plurality of vertical positions below the surface of the ground at an approximate first distance from a vertical edge of the buried concrete each time. The method may further include, for each position in the plurality of vertical positions, generating a dispersive wave in the buried concrete and determining a time of arrival of the dispersive wave at the one or more first accelerometers. The method may further include estimating the thickness of the buried concrete based on at least the times of arrival of the dispersive waves at the one or more first accelerometers.

Abstract: The present disclosure provides systems and methods for non-destructively estimating the thickness of buried concrete without excavation. An example method may include placing one or more first accelerometers at a plurality of vertical positions below the surface of the ground at an approximate first distance from a vertical edge of the buried concrete each time. The method may further include, for each position in the plurality of vertical positions, generating a dispersive wave in the buried concrete and determining a time of arrival of the dispersive wave at the one or more first accelerometers. The method may further include estimating the thickness of the buried concrete based on at least the times of arrival of the dispersive waves at the one or more first accelerometers.

Abstract: The present disclosure provides systems and methods for non-destructively estimating the thickness of buried concrete without excavation. An example method may include placing one or more first accelerometers at a plurality of vertical positions below the surface of the ground at an approximate first distance from a vertical edge of the buried concrete each time. The method may further include, for each position in the plurality of vertical positions, generating a dispersive wave in the buried concrete and determining a time of arrival of the dispersive wave at the one or more first accelerometers. The method may further include estimating the thickness of the buried concrete based on at least the times of arrival of the dispersive waves at the one or more first accelerometers.

Abstract: A system for estimating tension in a post-tensioned rod is provided. The system includes an impact device for transversely-impacting a post-tensioned rod, an accelerometer configured to generate data indicative of a vibrational response in the post-tensioned rod, and a receiver communicatively coupled to the accelerometer. The receiver includes a display, at least one input device, a communication module, a processor, and one or more memory devices coupled to the processor. Instructions stored on the one or more memory devices, when executed by the processor, cause the processor to receiver the data indicative of a vibrational response in the post-tensioned rod, process the received data to determine a difference between a first and a second modal frequency corresponding to the vibrational response, and store the difference between a first and second modal frequency corresponding to the vibrational response.

Abstract: The present disclosure provides systems, methods, and apparatuses for estimating tension in post-tensioned rods, such as anchor rods that support structural steel to concrete. A method of estimating tension in a target post-tension rod may include selecting a plurality of post-tensioned rods and modeling tension for the plurality of post-tensioned rods as a function of frequency differences between a first and a second modal frequency and cantilever length of each rod. The method may further include measuring the length of a cantilever of the target post-tensioned rod, determining first and second modal frequencies of the target post-tensioned rod, and determining a frequency difference between the first and second modal frequencies. The method may further include estimating tension in the target post-tensioned rod based on at least the model.

Abstract: A shard of a selected document is identified. A hierarchy of documents including the selected document are to be tagged with metadata in a data store of a search engine so that the related documents are queryable by the metadata using the search engine. The shard specifies a location of the related documents within the data store of the search engine. For each related document, a tagging operation is generated within a script, the tagging operation specifying the metadata, the shard, an identifier of the related document, and an identifier of the selected document. The script including the generated tagging operation for each related document is transmitted to the search engine to execute to tag the related documents in the data store with the metadata and with the selected document as a source of the metadata.

Abstract: The present disclosure provides systems and methods for non-destructively estimating the thickness of buried concrete without excavation. An example method may include placing one or more first accelerometers at a plurality of vertical positions below the surface of the ground at an approximate first distance from a vertical edge of the buried concrete each time. The method may further include, for each position in the plurality of vertical positions, generating a dispersive wave in the buried concrete and determining a time of arrival of the dispersive wave at the one or more first accelerometers. The method may further include estimating the thickness of the buried concrete based on at least the times of arrival of the dispersive waves at the one or more first accelerometers.

Abstract: The present disclosure provides systems and methods for non-destructively estimating the thickness of buried concrete without excavation. An example method may include placing one or more first accelerometers at a plurality of vertical positions below the surface of the ground at an approximate first distance from a vertical edge of the buried concrete each time. The method may further include, for each position in the plurality of vertical positions, generating a dispersive wave in the buried concrete and determining a time of arrival of the dispersive wave at the one or more first accelerometers. The method may further include estimating the thickness of the buried concrete based on at least the times of arrival of the dispersive waves at the one or more first accelerometers.

Abstract: The present disclosure provides systems, methods, and apparatuses for estimating tension in post-tensioned rods, such as anchor rods that support structural steel to concrete. A method of estimating tension in a target post-tension rod may include selecting a plurality of post-tensioned rods and modeling tension for the plurality of post-tensioned rods as a function of frequency differences between a first and a second modal frequency and cantilever length of each rod. The method may further include measuring the length of a cantilever of the target post-tensioned rod, determining first and second modal frequencies of the target post-tensioned rod, and determining a frequency difference between the first and second modal frequencies. The method may further include estimating tension in the target post-tensioned rod based on at least the model.

Abstract: A pre-alloyed iron-based powder is provided including small amounts of alloying elements which make possible a cost efficient manufacture of sintered parts. The pre-alloyed iron-based powder comprises 0.2-1% by weight of Cr, 0.05-0.3% by weight of Mo, 0.1-1% by weight of Ni, 0.09-0.3% by weight of Mn, 0.01% by weight or less of C, less than 0.25% by weight of O, and less than 1% by weight of inevitable impurities, the balance being iron.

Abstract: A pre-alloyed iron-based powder is provided including small amounts of alloying elements which make possible a cost efficient manufacture of sintered parts. The pre-alloyed iron-based powder comprises 0.2-1% by weight of Cr, 0.05-0.3% by weight of Mo, 0.1-1% by weight of Ni, 0.09-0.3% by weight of Mn, 0.01% by weight or less of C, less than 0.25% by weight of O, and less than 1% by weight of inevitable impurities, the balance being iron.

Abstract: A point to multipoint system includes utilizing the FM 57 kHz Radio Broadcast Data System (RBDS) standard and a novel receiver. A single broadcast source sends messages from multiple senders, in a variety of manners including automatically and semi-automatically, to a plurality or receivers who may select to receive or not to receive particular senders' messages. The receiver may be remotely programmable, and may institute actions upon receipt of predetermined stimuli such as a smoke alarm tone. Various automatic and semiautomatic message initiators could include water level detectors, burglar ar alarms, school bus locators.