Closed total talus dislocation without fracture: a case report

Total dislocation of the talus from all of its joints is a rare injury specially when the talus and malleoli are not fractured and frequently it is as a result of a high-energy trauma. It usually leads to degenerative changes in neighboring joints and frequently avascular necrosis is a predictable outcome. We present a case of total talus dislocation because of a high-energy trauma in association with other major fractures resulting from a fall from height, but no fracture could be detected in the talus and any of malleols. Closed reduction was unsuccessful and we performed open reduction. At 6 month post operation follow-up, the talus didn't show subluxation and avascular necrosis could not be detected

Pathologic dislocation of the shoulder secondary to septic arthritis: a case report

Septic arthritis of the shoulder is uncommon in adults, and complete dislocation of the glenohumeral joint following septic arthritis is extremely rare. We report a case of pathologic shoulder dislocation secondary to septic arthritis in an intravenous drug abuser

Effect of variation of specifications of quantum well and contact length on performance of InP-based Vertical Cavity Surface Emitting Laser (VCSEL)

Abstract: In this study, the effects of variation of thickness and the number of quantumwells as well as the contact length were investigated. In this paper, a vertical cavity surfaceemitting laser was simulated using of software based on finite element method. Thenumber of quantum wells was changed from 3 to 9 and the results which are related tooutput power, resonance wavelength and threshold current were extracted. Outputspecifications in terms of quantum wells thicknesses of 3.5nm to 9.5nm were evaluated.Contact thickness is also changed from 0.5μm to 3μm. Results showed that as the numberof quantum wells increased, the resonance wavelength also increased and photon energydecreased. By reducing the thickness of the quantum well, the threshold current andradiation wavelength were also decreased. By increasing the contact length, thresholdcurrent and output power increased. Temperature inside the network and density ofphoton were increased as the contact length increase

Time Response of a Resonant Tunneling Diode Based Photo- Detector (RTD-PD)

در این مقاله ، یک دیود تونل زنی تشدید با ساختار سد مضاعف AlAs / GaAs با استفاده از عملکرد سبز غیر تعادلی شبیه سازی شده است. یک لایه جذب InGaAs منطبق شده برای تشخیص نور در طول موج λ = 600 نانومتر به دستگاه اضافه می شود . میدان الکتریکی از طریق دستگاه و مشخصات نمودار باند انرژی ارائه شده است. جریان عکس دستگاه و منحنی های جریان جریان منبع در مقابل شدت نور مقایسه می شوند . در دمای اتاق ، بازده کوانتومی 95/0 برای دستگاه بدست آمد . پاسخ زمان گذرا دستگاه به دست آمد و وابستگی آن به پارامترهای ساختاری (ضخامت لایه جذب ، ضخامت کلکتور و انتشار دهنده ودوپینگ مخاطبین) ، شدت نور ، زاویه نور ساطع شده و سوگیری ولتاژ شبیه سازی شده و تأثیر آنها بر عملکرد دستگاه مورد تجزیه و تحلیل قرار گرفت. پهنای باند دستگاه به دست آمد. نتایج شبیه سازی نشان می دهد که وقتی بایاس ولتاژ افزایش یابد ، زمان افتادن کاهش می یابد و پاسخ دستگاه سریعتر است. با تغییر ضخامت لایه جذب و مخاطب ، پاسخ زمان RTD-PD تغییر می کند. تغییرات دوپینگ در لایه های تماس بر روی پهنای باند تأثیر می گذارد. نتیجه نشان می دهد که تغییرات شدت نور و زاویه نور ساطع شده ، پاسخ زمان گذرا را تغییر می دهند