14 research outputs found
Prehistorical and prothistorical societies of Ouled Nail region. Algeria
The present paper investigates, using a multidisciplinary approach, the dynamic of the settlements in the mountains of Ouled Nail (Algeria) during the Holocene as an attempt to reveal an important historic phenomenon in connection with the expansion of the human establishment. Indeed, the archaeological researches led from 1939 to 1955 in North Africa support the Capsanisation movement where the excavated sites were dated back to the Upper Pleistocene and constitutes the most complete archaeological sequence known until today in the Atlas region.
The presented results will display the first systematic analysis of rock art, lithic industries and funeral monuments during the Capsien period which is supported by chronological, and palaeoenvironmental data. Today, using geomatics and analytical techniques such as GIS as well as and archaeological investigations, allow us to understand the settlement processes during prehistorical and protohistorical periods
Evaluation of phase change material and thermochromic layers in a âsmart wallâ in different climates for improving thermal comfort in a building
Analyse et synthese structurale de poignets de robots
SIGLEINIST T 72998 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
New Method for Solving the Inverse Thermal Conduction Problem (Ξ-Scheme Combined with CG Method under Strong Wolfe Line Search)
Most thermal researchers have solved thermal conduction problems (inverse or direct) using several different methods. These include the usual discretization methods, conventional and special estimation methods, in addition to simple synchronous gradient methods such as finite elements, including finite and special quantitative methods. Quantities found through the finite difference methods, i.e., explicit, implicit or CrankâNicolson scheme method, have also been adopted. These methods offer many disadvantages, depending on the different cases; when the solutions converge, limited range stability conditions. Accordingly, in this paper, a new general outline of the thermal conduction phenomenon, called (Ξ-scheme), as well as a gradient conjugate method that includes strong Wolfe conditions has been used. This approach is the most useful, both because of its accuracy (16 decimal points of importance) and the speed of its solutions and convergence; by addressing unfavorable adverse problems and stability conditions, it can also have wide applications. In this paper, we applied two approaches for the control of the boundary conditions: constant and variable. The Ξ-scheme method has rarely been used in the thermal field, though it is unconditionally more stable for Ξâ [0.5, 1]. The simulation was carried out using Matlab software
Concept development and experimentation of a Phase Change Material (PCM) enhanced domestic hot water
International audienc
Morbidity and Mortality in Patients over 90 Years of Age Following Posterior Stabilization for Acute Traumatic Odontoid Type II Fractures: A Retrospective Study with a Mean Follow-Up of Three Years.
Odontoid type II fractures represent the most common cervical spine injuries in the elderly. The decision for surgical treatment in very elderly patients is still controversial. The aim of this study was to assess morbidity and mortality in patients over 90 years of age undergoing CT-guided posterior stabilization for unstable odontoid type II fractures. A total of 15 patients with an acute traumatic odontoid type II fracture who received surgical treatment for unstable odontoid type II fractures were retrospectively analyzed. Complications, morbidity, and mortality as well as length of ICU and hospital stay were determined. Clinical follow-up evaluation was based on outpatient presentation and information from family members and general practitioners. Finally, we conducted a comparison of complications rates between patients over 90 years of age and patients between 65 and 89 years old with a type II odontoid fracture after CT-guided posterior stabilization in our institution. The mean age was 91.4 years. Patients were predominately female (87%). In-hospital deaths did not occur. The average length of the hospital stay was 13.4 days and 1.9 days for the ICU. Blood transfusion was necessary in two patients (13%). Two patients (13%) developed urinary tract infection, one patient (7%) a delirium, and another epistaxis (7%). One patient (7%) developed pneumonic sepsis and fully recovered within several weeks. The mean follow-up was 36 months (range 9-72 months). Implant-related complications developed in one patient (7%). Five patients died during the follow-up period, with an average time to death of 26.6 months. Postoperative bracing was not needed in any of the patients. Posterior stabilization of unstable odontoid fractures type II using CT-guided navigation in patients over 90 years of age is a safe and effective procedure with low complications and mortality rates
Experimental study on effects of CO2 concentrations on concrete carbonation and diffusion mechanisms
Methods to improve microstructural properties of recycled concrete aggregate : a critical review
Recycled concrete aggregate is a demolition concrete waste, which could be an environmental-friendly building material and can be a serious contender for saving natural aggregate and reducing environmental pollution. Nevertheless, the use of the same is limited, as it has inferior qualities compared to virgin aggregate, such as low density, high porosity, high water absorption rate, micro cracks in residual mortar and at the interfacial transition zones. Thereby, the need of improving the properties of recycled aggregate is vital to enable a wider adoption of the same. This paper provides an insight into identifying knowledge gaps and as a critical review for the methods, technologies, its advantages and disadvantages for
improving the microstructural and mechanical properties of recycled aggregate, such as self-healing methods of re-hydration, bacterial and micro-encapsulation, sequential mixing approaches, removal of adhered mortar, permeation of solutions, coating with solutions and CO2 carbonation approaches. The existing studies to improve the properties of the recycled aggregate, are limited and the density improvement techniques by permeation of chemicals and/or reactions have only been superficially studied