Mobile Paving System (MPS): A New Large Scale Freeform Fabrication Method

In the last decade, significant opportunities for automation have been identified in the area of construction. Soaring labor and material costs have driven multiple research efforts in construction automation. In this paper, we present a novel means for construction automation that involves the fusion of the rapid prototyping, controls and mechatronics technologies. The resultant autonomous construction mechanism has been designed for commercial applications. Mobile Paving System (MPS) is a new freeform fabrication process which is capable of rapidly producing variable profiles such as curbs and sidewalks out of materials like cement and asphalt. Path generation and guidance of the construction operation is controlled by a mobile robot. This article presents an overview of research and development efforts that are aimed at establishing the feasibility and the potential of the process.Mechanical Engineerin

Staple Line Polyposis and Cytomegalovirus Infection after Stapled Haemorrhoidectomy

Early bleeding after stapled haemorrhoidectomy (SH) is not uncommon. Late and persistent bleeding occurring weeks or months after SH, however, is rare; it has only been described in more than 10% of cases. It is attributed to the development of inflammatory polyps at the staple line. Occurrence of rectal bleeding in the presence of palpable polypoid lesions at the stapled anastomotic line can cause diagnostic confusions, and it is not uncommon that such lesions are initially confused with rectal carcinoma. We report a case of a 38-year-old male who presented with persistent rectal bleeding some 6 months after SH performed in another hospital. Rectal and colonoscopic examinations revealed polypoid lesions at the anastomotic line. The biopsy failed to confirm malignancy, but identified cytomegalovirus (CMV) infection. The development of multiple inflammatory polypoid lesions in conjunction with CMV infection at the stapled anastomotic line has caused a diagnostic confusion, but – after exclusion of cancer – this complication was efficiently treated by CMV infection eradication combined with surgical excision of the remaining polyps due to persistence of bleeding. This case is reported to highlight late bleeding due to inflammatory polyps after SH and to increase the awareness of surgeons and gastroenterologists of this benign but somewhat common complication

Blood Transfusion in Patients with Sickle Cell Disease Requiring Laparoscopic Cholecystectomy

Laparoscopic cholecystectomy in patients with sickle cell disease was found to be safe without preoperative blood transfusion

Cone beam CT evaluation of the presence of anatomic accessory canals in the jaws

Objectives: To assess the prevalence, location and anatomical course of accessory canals of the jaws using cone beam CT. Methods: A retrospective analysis of 4200 successive cone beam CT scans, for patients of both genders and ages ranging from 7 to 88 years, was performed. They were exposed at the School of Dentistry, University of Michigan, Ann Arbor, MI. After applying the exclusion criteria (the presence of severe ridge resorption, pre-existing implants, a previously reported history of craniofacial malformations or syndromes, a previous history of trauma or surgery, inadequate image quality and subsequent scans from the same individuals), 4051 scans were ultimately included in this study. Results: Of the 4051 scans (2306 females and 1745 males) that qualified for inclusion in this study, accessory canals were identified in 1737 cases (42.9%; 1004 females and 733 males). 532 scans were in the maxilla (13.1%; 296 females and 236 males) and 1205 in the mandible (29.8%; 708 females and 497 males). Conclusions: A network of accessory canals bringing into communication the inner and outer cortical plates of the jaws was identified. In light of these findings, clinicians should carefully assess for the presence of accessory canals prior to any surgical intervention to decrease the risk for complications

Investigating the Potential of High-Density Polyethylene and Nano Clay Asphalt-Modified Binders to Enhance the Rutting Resistance of Asphalt Mixture

This study investigates the potential of two bitumen modifiers, high-density polyethylene (HDPE) and nano clay (NC), to enhance the rutting resistance of asphalt mixture. Four HDPE asphalt binders were prepared by mixing the HDPE at percentages of 2%, 4%, 6%, and 8% with the virgin binder, while four NC asphalt binders were produced by mixing the NC at percentages of 1%, 2%, 3%, and 4%. The consistency and flow of virgin binder, HDPE binders, and NC binders were evaluated by penetration, softening point, and viscosity tests. The results show a gradual increment in the binder stiffness by increasing the percentage of both modifiers. The static creep test was conducted at a temperature of 40 °C to evaluate the rutting resistance. The results confirm that both modifiers can greatly improve the rutting resistance of the asphalt mixture, where 8% HDPE and 3% NC modifications reduce the strains provoked in the asphalt mixture under loading by about 50%. According to the correlation analysis, the mixture rutting performance is highly attributed to the binder stiffness, where the lower the penetration value of the asphalt binder, the lower the strains in the asphalt mixture and the higher the stiffness modulus of the asphalt mixture

Investigation of enhanced double weight code in point to point access networks

© 2020 Published under licence by IOP Publishing Ltd. In this paper, an investigation and evaluation to enhanced double weight (EDW) code is performed, a new technique for code structuring and building using modified arithmetical model has been given for the code in place of employing previous technique based on Trial Inspections. Innovative design has been employed for the code into P2P networks using diverse weighted EDW code to be fitting into optical CDMA relevance applications. A new developed relation for EDW code is presented, the relation is based on studying and experimenting the effect of input transmission power with code weight, and the relation developed using numerical analysis method. This relation makes the estimation for the system input power needed more efficient. The results of the code has been explained by eye diagram and parametric illustrations from the simulated results. The result shows a magnificent performance of the code during high number of users and weight. On the other hand, the relation developed for power measurement helps to prevent power loss and consumption