Hybrid bypass technique to mitigate leakage current in the grid-tied inverter

The extensive use of fossil fuel is destroying the balance of nature that could lead to many problems in the forthcoming era. Renewable energy resources are a ray of hope to avoid possible destruction. Smart grid and distributed power generation systems are now mainly built with the help of renewable energy resources. The integration of renewable energy production system with the smart grid and distributed power generation is facing many challenges that include addressing the issue of isolation and power quality. This paper presents a new approach to address the aforementioned issues by proposing a hybrid bypass technique concept to improve the overall performance of the grid-tied inverter in solar power generation. The topology with the proposed technique is presented using traditional H5, oH5 and H6 inverter. Comparison of topologies with literature is carried out to check the feasibility of the method proposed. It is found that the leakage current of all the proposed inverters is 9 mA and total harmonic distortion is almost about 2%. The proposed topology has good efficiency, common mode and differential mode characteristics.

The “Needle bypass” technique: Percutaneous anatomical bypass with needle rendezvous for patients with peripheral arterial disease that have no other surgical options

Background The ideal method for recanalization of complex peripheral lesions has not been determined, despite the use of the latest endovascular devices. We describe a novel method for a fully percutaneous anatomical bypass, named the “needle bypass” technique, for treatment of complex vascular lesions with failed previous surgical therapy. Main text A 68-year-old male patient with chronic limb-threatening ischemia presented to our department. He previously had received surgical treatment 10 years prior that included the removal of the right distal common femoral artery and two surgical bypasses, an axillary-femoral bypass and an iliofemoral bypass, because he had repeated infections. He was referred to our center in order to have peripheral interventions. Since the previous conventional bridging/revascularization of the removed common femoral bifurcation had failed, the “needle bypass” technique was then used. With this novel technique, the tips of two percutaneous and bidirectional inserted needles were aligned (“needle rendezvous”) for the externalization of a guidewire in a through-and-through manner. Once this was achieved, an endovascular stent graft and an interwoven stent were deployed to cover and connect the lesion. This new technique is a minimally invasive anatomical bypass that directly connects artery to artery without any disturbance of the venous flow, and this technique, as the only option available, was performed successfully in our no-option patient. Conclusions The “needle bypass” technique is an effective percutaneous treatment method in patients with no other surgical options.

Minimizing deviations of car sequencing in a JIT production painting line

Purpose The first in first out (FIFO) rule is an indispensable rule in the automotive industry. However, during production, the order of coming to welding operation and exiting through the painting operation is broken. Consequently, the rule of FIFO also gets broken. The purpose of this paper is to eliminate the deviations of the automotive painting process in a just in time (JIT) environment. Design/methodology/approach The paper has been solved using observations and expert’s opinions and recorded data in the real problem area. Bypass technique and express line have been used as a real problem for the minimization of these deviations. The current process and the bypass process have been compared with simulation optimization. Findings This paper provides analytical insights about how to prevent delays during the JIT production painting process. Delays have been prevented by using the bypass technique and express line together. The number of delays reduced with an improvement of 129. The ratio of effect (for four months) has been founded to be 0.12. The output rate has been increased from 80% to 89%. Research limitations/implications This paper focused on the number of vehicles in the cooling area of the painting process in the study; there may occur bottleneck processes or products. It does not contain station-based bottleneck processes. Practical implications From the real-case problem, one will see that the bypass technique and the express line can be applied and generalized to many similar problems and help companies conduct their assembly lines more efficiently. Originality/value This paper is the only example that has been used to bypass technique and express line together on the paint/cooling process in a JIT production system.

Early Neurological Complications after Cardiac/Aortic Surgery with Cardiopulmonary Bypass: Incidence and Risk Factors

Objective: To examine the incidence and risk factors of early neurological complications after cardiac or aortic surgery using cardiopulmonary bypass technique in King Chulalongkorn Memorial Hospital, Thailand. Materials and Methods: The present study was a retrospective cohort study. Clinical data of adult patients that underwent cardiac or aortic surgery using cardiopulmonary bypass technique in 2018 were reviewed from the electronic medical record in the authors’ center. Results: Early postoperative neurological complications occurred in 33 (8.3%) of the 400 patients. Twenty of them (60.6%) had non-specific encephalopathy, three (9.1%) had hypoxic-ischemic encephalopathy, five (15.2%) had provoked seizure, four (12.1%) had cerebral infarction, and one (3.0%) had intracranial hemorrhage. Associated clinical factors included history of essential hypertension [adjusted odds ratio 3.448 (95% CI 1.266 to 9.391)], combined coronary artery bypass grafting and valve surgery [adjusted odds ratio 4.759 (95% CI 1.182 to 19.170)], multi-valve surgery [adjusted odds ratio 5.201 (95% CI 1.227 to 22.049)], aortic surgery [adjusted odds ratio 17.260 (95% CI 4.168 to 71.468)], higher midazolam dosage [adjusted odds ratio 1.009 (95% CI 1.002 to 1.015)], higher serum lactate prior to discontinuing cardiopulmonary bypass [adjusted odds ratio 1.263 (95% CI 1.093 to 1.460)], and presence of intraoperative intra-aortic balloon pump use [adjusted odds ratio 6.160 (95% CI 1.883 to 20.150)]. Conclusion: Early postoperative neurological complications rate of cardiac or aortic surgery using cardiopulmonary bypass technique in the present study settings was 8.3%. Preoperative and intraoperative clinical factors associated with such complications were the history of essential hypertension, the type of surgery such as combined coronary artery bypass grafting and valve surgery, multi-valve surgery, and aortic surgery, the higher midazolam dosage, the higher serum lactate prior to discontinuing cardiopulmonary bypass, and the presence of intraoperative intra-aortic balloon pump use. Keywords: Cardiac surgery; Aortic surgery; Cardiopulmonary bypass; Postoperative neurological complications; Encephalopath

"Needle Bypass" Technique: Percutaneous Anatomical Bypass with Needle Rendezvous for No-Option Peripheral Arterial Disease.

Background: The complex lesions failed by surgical bypass treatments have yet to be solved even with the latest endovascular devices. We describe a new method of fully percutaneous anatomical bypass, named the “Needle bypass” technique.Case presentation: A 68-year-old male patient was suffered from chronic limb-threatening ischemia due to the surgical removal of right distal common femoral artery to proximal superficial femoral artery and two surgical bypasses, axillary-femoral bypass and iliac-femoral bypass, repeated infection 10 years before. He was referred for peripheral intervention by vascular surgeons due to the surgical higher risk background. Conventional peripheral intervention for the removal of common femoral bifurcation failed. “Needle bypass” technique was successfully performed that the tips of the needles which are inserted bi-directionaly from outside the body are aligned in the body to perform the guidewire externalization through the needles, “Needle rendezvous”, and to deploy scaffolds the complex anatomical lesion including extravascular site. This technique provided the great success with this no-option patient.Conclusions:“Needle bypass” technique is a new effective percutaneous treatment option for no-option patient.

Separated Instrument Management as a Procedural Accident in Endodontics Using the EDTA (C10H16N2O8) Aided Bypassing Technique and the Ultrasonic Removal Method. An in vitro Study

Fracture of endodontic files can be considered a real concern during root canal treatment. This procedural accident is caused both by overusing instruments due to economic reasons and using an incorrect technique in root canals with difficult anatomy. A broken endodontic file does not always regard the treatment as a failure. Frequently the broken fragment can be bypassed, and the root canal treatment completed. In other cases, when the file is separated in a tooth with associated apical disease, its retrieval using ultrasonic tips is advised. Separation of a file usually occurs in molars, mainly in the mesiobuccal canal due to major curvature, poor access or small diameter. Our research was conducted to determine the in vitro efficiency of the ultrasonic removal method and the bypass technique by using 40 extracted molars with moderately curved roots. #25 K-files were deliberately broken in the middle third of mesiobuccal root canals after making a small excavation in the apical third of their active part. The results showed a significantly higher success rate of the ethylenediaminetetraacetic acid (EDTA) aided bypassing technique compared to the ultrasonic removal method.