The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
James N Palmer - One of the best experts on this subject based on the ideXlab platform.
-
computational fluid dynamic modeling of nose to ceiling head positioning for sphenoid sinus Irrigation
International Forum of Allergy & Rhinology, 2017Co-Authors: John R Craig, James N Palmer, Kai ZhaoAbstract:Background After sinus surgery, patients are commonly instructed to irrigate with saline Irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although Irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus Irrigations to assess the difference in sphenoid sinus delivery of Irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position. Methods Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL Irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of Irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning. Results In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the Irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position. Conclusion CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL Irrigation to the sphenoid sinuses.
-
cadaveric validation study of computational fluid dynamics model of sinus Irrigations before and after sinus surgery
International Forum of Allergy & Rhinology, 2016Co-Authors: John R Craig, Ngoc Doan, John Y K Lee, Sammy Khalili, Kai Zhao, Nithin D Adappa, James N PalmerAbstract:Background Investigations into the distribution of sinus Irrigations have been limited by labor-intensive methodologies that do not capture the full dynamics of Irrigation flow. The purpose of this study was to validate the accuracy of a computational fluid dynamics (CFD) model for sinonasal Irrigations through a cadaveric experiment. Methods Endoscopic sinus surgery was performed on 2 fresh cadavers to open all 8 sinuses, including a Draf III procedure for cadaver 1, and Draf IIb frontal sinusotomies for cadaver 2. Computed tomography maxillofacial scans were obtained preoperatively and postoperatively, from which CFD models were created. Blue-dyed saline in a 240-mL squeeze bottle was used to irrigate cadaver sinuses at 60 mL/second (120 mL per side, over 2 seconds). These parameters were replicated in CFD simulations. Endoscopes were placed through trephinations drilled through the anterior walls of the maxillary and frontal sinuses, and sphenoid roofs. Irrigation flow into the maxillary, frontal, and sphenoid sinuses was graded both ipsilateral and contralateral to the side of nasal Irrigation, and then compared with the CFD simulations. Results In both cadavers, preoperative and postoperative Irrigation flow into maxillary, frontal, and sphenoid sinuses matched extremely well when comparing the CFD models and cadaver endoscopic videos. For cadaver 1, there was 100% concordance between the CFD model and cadaver videos, and 83% concordance for cadaver 2. Conclusion This cadaveric experiment provided potential validation of the CFD model for simulating saline Irrigation flow into the maxillary, frontal, and sphenoid sinuses before and after sinus surgery.
John R Craig - One of the best experts on this subject based on the ideXlab platform.
-
computational fluid dynamic modeling of nose to ceiling head positioning for sphenoid sinus Irrigation
International Forum of Allergy & Rhinology, 2017Co-Authors: John R Craig, James N Palmer, Kai ZhaoAbstract:Background After sinus surgery, patients are commonly instructed to irrigate with saline Irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although Irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus Irrigations to assess the difference in sphenoid sinus delivery of Irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position. Methods Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL Irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of Irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning. Results In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the Irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position. Conclusion CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL Irrigation to the sphenoid sinuses.
-
cadaveric validation study of computational fluid dynamics model of sinus Irrigations before and after sinus surgery
International Forum of Allergy & Rhinology, 2016Co-Authors: John R Craig, Ngoc Doan, John Y K Lee, Sammy Khalili, Kai Zhao, Nithin D Adappa, James N PalmerAbstract:Background Investigations into the distribution of sinus Irrigations have been limited by labor-intensive methodologies that do not capture the full dynamics of Irrigation flow. The purpose of this study was to validate the accuracy of a computational fluid dynamics (CFD) model for sinonasal Irrigations through a cadaveric experiment. Methods Endoscopic sinus surgery was performed on 2 fresh cadavers to open all 8 sinuses, including a Draf III procedure for cadaver 1, and Draf IIb frontal sinusotomies for cadaver 2. Computed tomography maxillofacial scans were obtained preoperatively and postoperatively, from which CFD models were created. Blue-dyed saline in a 240-mL squeeze bottle was used to irrigate cadaver sinuses at 60 mL/second (120 mL per side, over 2 seconds). These parameters were replicated in CFD simulations. Endoscopes were placed through trephinations drilled through the anterior walls of the maxillary and frontal sinuses, and sphenoid roofs. Irrigation flow into the maxillary, frontal, and sphenoid sinuses was graded both ipsilateral and contralateral to the side of nasal Irrigation, and then compared with the CFD simulations. Results In both cadavers, preoperative and postoperative Irrigation flow into maxillary, frontal, and sphenoid sinuses matched extremely well when comparing the CFD models and cadaver endoscopic videos. For cadaver 1, there was 100% concordance between the CFD model and cadaver videos, and 83% concordance for cadaver 2. Conclusion This cadaveric experiment provided potential validation of the CFD model for simulating saline Irrigation flow into the maxillary, frontal, and sphenoid sinuses before and after sinus surgery.
Kai Zhao - One of the best experts on this subject based on the ideXlab platform.
-
computational fluid dynamic modeling of nose to ceiling head positioning for sphenoid sinus Irrigation
International Forum of Allergy & Rhinology, 2017Co-Authors: John R Craig, James N Palmer, Kai ZhaoAbstract:Background After sinus surgery, patients are commonly instructed to irrigate with saline Irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although Irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus Irrigations to assess the difference in sphenoid sinus delivery of Irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position. Methods Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL Irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of Irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning. Results In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the Irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position. Conclusion CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL Irrigation to the sphenoid sinuses.
-
cadaveric validation study of computational fluid dynamics model of sinus Irrigations before and after sinus surgery
International Forum of Allergy & Rhinology, 2016Co-Authors: John R Craig, Ngoc Doan, John Y K Lee, Sammy Khalili, Kai Zhao, Nithin D Adappa, James N PalmerAbstract:Background Investigations into the distribution of sinus Irrigations have been limited by labor-intensive methodologies that do not capture the full dynamics of Irrigation flow. The purpose of this study was to validate the accuracy of a computational fluid dynamics (CFD) model for sinonasal Irrigations through a cadaveric experiment. Methods Endoscopic sinus surgery was performed on 2 fresh cadavers to open all 8 sinuses, including a Draf III procedure for cadaver 1, and Draf IIb frontal sinusotomies for cadaver 2. Computed tomography maxillofacial scans were obtained preoperatively and postoperatively, from which CFD models were created. Blue-dyed saline in a 240-mL squeeze bottle was used to irrigate cadaver sinuses at 60 mL/second (120 mL per side, over 2 seconds). These parameters were replicated in CFD simulations. Endoscopes were placed through trephinations drilled through the anterior walls of the maxillary and frontal sinuses, and sphenoid roofs. Irrigation flow into the maxillary, frontal, and sphenoid sinuses was graded both ipsilateral and contralateral to the side of nasal Irrigation, and then compared with the CFD simulations. Results In both cadavers, preoperative and postoperative Irrigation flow into maxillary, frontal, and sphenoid sinuses matched extremely well when comparing the CFD models and cadaver endoscopic videos. For cadaver 1, there was 100% concordance between the CFD model and cadaver videos, and 83% concordance for cadaver 2. Conclusion This cadaveric experiment provided potential validation of the CFD model for simulating saline Irrigation flow into the maxillary, frontal, and sphenoid sinuses before and after sinus surgery.
Paul L. G. Vlek - One of the best experts on this subject based on the ideXlab platform.
-
Soil salinity management on raised beds with different furrow Irrigation modes in salt-affected lands
Agricultural Water Management, 2015Co-Authors: M. Devkota, Raj K. Gupta, John P. A. Lamers, K.p. Devkota, Kenneth D. Sayre, Christopher Martius, Paul L. G. VlekAbstract:a b s t r a c t Mismanagement of Irrigation water and the ensuing secondary salinization are threatening the sus- tainability of irrigated agriculture especially in many dryland regions. The permanent raised-bed/furrow system, a water-wise conservation agriculture-based practice, is gaining importance for row- and high value-crops in irrigated agriculture. However, because of additional surface exposure and elevation, raised beds may be more prone to salt accumulation especially under shallow water table conditions. A field study was carried out in 2008 and 2009 in the Khorezm region, Central Asia, to investigate the effect of three furrow Irrigation methods on salt dynamics of the soil and the performance of the cot- ton crop on the raised bed-furrow system. The Irrigation methods compared included (i) Conventional furrow Irrigation wherein every furrow was irrigated (EFI) at each Irrigation event; (ii) Alternate skip furrow Irrigation (ASFI where one of two neighbouring furrows were alternately irrigated during con- secutive Irrigations events; and (iii) Permanent skip furrow Irrigation (PSFI) during which Irrigation was permanently skipped in one of the two neighbouring furrows during all Irrigation events. For salinity management with PSFI a 'managed salt accumulation and effective leaching' approach was pursued. The EFI method increased salt accumulation on the top of the raised beds. In contrast, the PSFI method allowed an effective salt leaching from the top of the raised beds. After leaching, salinity on top of the beds under PSFI was reduced to
-
soil salinity management on raised beds with different furrow Irrigation modes in salt affected lands
Agricultural Water Management, 2015Co-Authors: M. Devkota, Raj K. Gupta, John P. A. Lamers, K.p. Devkota, Kenneth D. Sayre, Christopher Martius, Paul L. G. VlekAbstract:a b s t r a c t Mismanagement of Irrigation water and the ensuing secondary salinization are threatening the sus- tainability of irrigated agriculture especially in many dryland regions. The permanent raised-bed/furrow system, a water-wise conservation agriculture-based practice, is gaining importance for row- and high value-crops in irrigated agriculture. However, because of additional surface exposure and elevation, raised beds may be more prone to salt accumulation especially under shallow water table conditions. A field study was carried out in 2008 and 2009 in the Khorezm region, Central Asia, to investigate the effect of three furrow Irrigation methods on salt dynamics of the soil and the performance of the cot- ton crop on the raised bed-furrow system. The Irrigation methods compared included (i) Conventional furrow Irrigation wherein every furrow was irrigated (EFI) at each Irrigation event; (ii) Alternate skip furrow Irrigation (ASFI where one of two neighbouring furrows were alternately irrigated during con- secutive Irrigations events; and (iii) Permanent skip furrow Irrigation (PSFI) during which Irrigation was permanently skipped in one of the two neighbouring furrows during all Irrigation events. For salinity management with PSFI a 'managed salt accumulation and effective leaching' approach was pursued. The EFI method increased salt accumulation on the top of the raised beds. In contrast, the PSFI method allowed an effective salt leaching from the top of the raised beds. After leaching, salinity on top of the beds under PSFI was reduced to <3 dS m−1 compared to 5-6 dS m−1 under ASFI and EFI indicating an effective leaching with the PSFI method. Raw cotton (Gossypium hirsutum L., cv. Khorezm 127) yield was higher under the PSFI (2003 kg ha−1) method having yield increases of 984 kg ha−1 (96% higher) and 787 kg ha−1
Yuefen Zhao - One of the best experts on this subject based on the ideXlab platform.
-
impact of drip and level basin Irrigation on growth and yield of winter wheat in the north china plain
Irrigation Science, 2013Co-Authors: Jiandong Wang, Shihong Gong, Yingduo Yu, Di Xu, Yuefen ZhaoAbstract:A field experiment was conducted for 3 consecutive years (2007–2009) to study the effects of two different Irrigation methods, that is, level-basin Irrigation (BI) and drip Irrigation (DI), and different treatment levels on crop growth, yield, and WUE of winter wheat (Triticum aestivum L.) in the North China Plain (NCP). The results indicate that Irrigation methods and treatment levels had significant effects on crop growth and yield of winter wheat. Irrigation amounts significantly influenced plant heights, LAI, and winter wheat grain yields (P < 0.05 level) for both Irrigation methods. Further, the DI method significantly improved yield and WUE compared with the BI method (P < 0.05 level) under conditions of deficit Irrigation. Without Irrigation system investment consideration, crop water productivity was highest when DI was used and Irrigations were scheduled when soil water was depleted to 60 and 50 % of field capacity.
