Combustion instability is a very important issue in the development of the propulsion systems used in aerospace. It is very important to associate the high frequency combustion instabilities with the acoustic characte...Combustion instability is a very important issue in the development of the propulsion systems used in aerospace. It is very important to associate the high frequency combustion instabilities with the acoustic characteristics of the combustion chamber. In this paper, the effects of various baffle injectors which were installed on the injector faceplate on the first-order tangential acoustic mode were investigated theoretically and experimentally. The effects of the gap between adjacent injectors on the first-order tangential acoustic mode in a cylindrical chamber were considered. The acoustic admittance of the injectors was derived. The results showed that the amplitude and frequency of the first-order tangential acoustic mode increase with the increase in the gap between adjacent injectors, but decrease with the increase in the number and height of the baffles.The baffle injectors have a greater influence on the amplitude and frequency of the first-order tangential acoustic mode than the baffle blades.展开更多
<strong>Background:</strong> The implantation of the intraocular lens (IOL) is still subject to error and complication, as it can result in traumatic opening of the IOL leading to rupture of the posterior ...<strong>Background:</strong> The implantation of the intraocular lens (IOL) is still subject to error and complication, as it can result in traumatic opening of the IOL leading to rupture of the posterior capsule and zonular dialysis, it takes time to train paramedic teams to assemble such IOLs with the manual injectors. Moreover, there is a potential risk of comtamination and endophthalmitis as there is manipulation of the IOL and cartridge. The preloaded IOLs tend to reduce those unwanted results and may optimize the surgical time. <strong>Purpose:</strong> The aim of this study is to compare the effectiveness and implantation time between three injectors and three intraocular lenses, two pre-loaded and one conventional. <strong>Methodology:</strong> Videos of thirty patients undergoing cataract surgery from December 2019 to December 2020 at the Hospital Oftalmológico de Brasília (HOB), Brasília, Brazil were included in this observational, analytical retrospective study, non randomized. All patients had their surgeries recorded, from which the time of injection and opening of the intraocular lens (IOL) was extracted, 20 eyes were implanted with preloaded intraocular lens, and 10 eyes with conventional IOL implant. The patients were divided into three groups with similar eye characteristics. The first received the AutonoMe<sup>TM</sup> (CE) injector with the Clareon<span style="white-space:nowrap;"><sup>®</sup></span><span style="font-size:10px;"> </span><span style="white-space:nowrap;"><span style="color:#FFFFFF;font-family:Roboto, "white-space:normal;background-color:#D46399;"><span style="white-space:nowrap;"></span></span></span>IOL, the second the Isert<sup>TM</sup> injector (I) with the Hoya<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">®</span></sup></span> IOL, and the third was injected with Johnson & Johnson Platinum 1 Series injector used to deliver Sensar<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">®</span></sup></span> One AAB展开更多
The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with an...The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with any model of Bosch injection pump test benches for PT Pumps and injector calibration. During PT Pump calibration, the type PT-821 test stand should be used in conjunction with a Bosch injection pump lest bench. The PT Pump to be tested is installed on the Bosch injection pump test bench through a mounting bracket and is driven by the bench shaft. When calibrating PT injectors, both the PT-881 injector test stand and the PT-821 PT Pump test stand should be used in conjunction with a Bosch injection pump test bench, with the PT-881 injector test stand installed on Bosch test bench. The injector to be tested is driven by the Bosch injection pump test bench through a coupling. This paper describes the structure and function of the PT-821 PT Pump test stand and PT-881 injector test stand. Some technical problems arc described in detail.展开更多
Fuel injectors are considered as an important component of combustion engines. Operational weakness can possibly lead to the complete machine malfunction, decreasing reliability and leading to loss of production. To o...Fuel injectors are considered as an important component of combustion engines. Operational weakness can possibly lead to the complete machine malfunction, decreasing reliability and leading to loss of production. To overcome these circumstances, various condition monitoring techniques can be applied. The application of acoustic signals is common in the field of fault diagnosis of rotating machinery. Advanced signal processing is utilized for the construction of features that are specialized in detecting fuel injector faults. A performance comparison between novelty detection algorithms in the form of one-class classifiers is presented. The one-class classifiers that were tested included One-Class Support Vector Machine (OCSVM) and One-Class Self Organizing Map (OCSOM). The acoustic signals of fuel injectors in different operational conditions were processed for feature extraction. Features from all the signals were used as input to the one-class classifiers. The one-class classifiers were trained only with healthy fuel injector conditions and compared with new experimental data which belonged to different operational conditions that were not included in the training set so as to contribute to generalization. The results present the effectiveness of one-class classifiers for detecting faults in fuel injectors.展开更多
基金the National Natural Science Foundation of China (Nos. 51806057, 52005152 and 12042211)the Natural Science Foundation of Hebei, China (Nos. E2019202460 and E2019202451)+2 种基金Tianjin Science and Technology Project, China (No. 19YFZCSF00850)the Key Research Program Projects of Hebei Province, China (No. 19274502D)the Industrial Technology Research of Hebei University of Technology, China (No. ZBYJY201902)
文摘Combustion instability is a very important issue in the development of the propulsion systems used in aerospace. It is very important to associate the high frequency combustion instabilities with the acoustic characteristics of the combustion chamber. In this paper, the effects of various baffle injectors which were installed on the injector faceplate on the first-order tangential acoustic mode were investigated theoretically and experimentally. The effects of the gap between adjacent injectors on the first-order tangential acoustic mode in a cylindrical chamber were considered. The acoustic admittance of the injectors was derived. The results showed that the amplitude and frequency of the first-order tangential acoustic mode increase with the increase in the gap between adjacent injectors, but decrease with the increase in the number and height of the baffles.The baffle injectors have a greater influence on the amplitude and frequency of the first-order tangential acoustic mode than the baffle blades.
文摘<strong>Background:</strong> The implantation of the intraocular lens (IOL) is still subject to error and complication, as it can result in traumatic opening of the IOL leading to rupture of the posterior capsule and zonular dialysis, it takes time to train paramedic teams to assemble such IOLs with the manual injectors. Moreover, there is a potential risk of comtamination and endophthalmitis as there is manipulation of the IOL and cartridge. The preloaded IOLs tend to reduce those unwanted results and may optimize the surgical time. <strong>Purpose:</strong> The aim of this study is to compare the effectiveness and implantation time between three injectors and three intraocular lenses, two pre-loaded and one conventional. <strong>Methodology:</strong> Videos of thirty patients undergoing cataract surgery from December 2019 to December 2020 at the Hospital Oftalmológico de Brasília (HOB), Brasília, Brazil were included in this observational, analytical retrospective study, non randomized. All patients had their surgeries recorded, from which the time of injection and opening of the intraocular lens (IOL) was extracted, 20 eyes were implanted with preloaded intraocular lens, and 10 eyes with conventional IOL implant. The patients were divided into three groups with similar eye characteristics. The first received the AutonoMe<sup>TM</sup> (CE) injector with the Clareon<span style="white-space:nowrap;"><sup>®</sup></span><span style="font-size:10px;"> </span><span style="white-space:nowrap;"><span style="color:#FFFFFF;font-family:Roboto, "white-space:normal;background-color:#D46399;"><span style="white-space:nowrap;"></span></span></span>IOL, the second the Isert<sup>TM</sup> injector (I) with the Hoya<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">®</span></sup></span> IOL, and the third was injected with Johnson & Johnson Platinum 1 Series injector used to deliver Sensar<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;">®</span></sup></span> One AAB
文摘The type PT-821 PT Pump test stand and type PT-881 injector test stand are a set of special test stands for calibration of PT Pumps and injectors of Cummins engines. Both test stands may be used in conjunction with any model of Bosch injection pump test benches for PT Pumps and injector calibration. During PT Pump calibration, the type PT-821 test stand should be used in conjunction with a Bosch injection pump lest bench. The PT Pump to be tested is installed on the Bosch injection pump test bench through a mounting bracket and is driven by the bench shaft. When calibrating PT injectors, both the PT-881 injector test stand and the PT-821 PT Pump test stand should be used in conjunction with a Bosch injection pump test bench, with the PT-881 injector test stand installed on Bosch test bench. The injector to be tested is driven by the Bosch injection pump test bench through a coupling. This paper describes the structure and function of the PT-821 PT Pump test stand and PT-881 injector test stand. Some technical problems arc described in detail.
文摘Fuel injectors are considered as an important component of combustion engines. Operational weakness can possibly lead to the complete machine malfunction, decreasing reliability and leading to loss of production. To overcome these circumstances, various condition monitoring techniques can be applied. The application of acoustic signals is common in the field of fault diagnosis of rotating machinery. Advanced signal processing is utilized for the construction of features that are specialized in detecting fuel injector faults. A performance comparison between novelty detection algorithms in the form of one-class classifiers is presented. The one-class classifiers that were tested included One-Class Support Vector Machine (OCSVM) and One-Class Self Organizing Map (OCSOM). The acoustic signals of fuel injectors in different operational conditions were processed for feature extraction. Features from all the signals were used as input to the one-class classifiers. The one-class classifiers were trained only with healthy fuel injector conditions and compared with new experimental data which belonged to different operational conditions that were not included in the training set so as to contribute to generalization. The results present the effectiveness of one-class classifiers for detecting faults in fuel injectors.
