Study of the propolis extract as a corrosion inhibitor of copper alloy in ethylene glycol/water 0.1 M NaCl

The effect of propolis extract as a corrosion inhibitor of copper alloy in ethylene glycol / water 0.1 M NaCl solution was studied by electrochemical measurements. The Tafel polarization curves showed that the propolis extract at different concentration acts as mixed inhibitor, and the maximum value of the inhibitory efficacy is 73.28% at optimum concentration of 1.25 g/L of propolis extract. The activation parameters reveal that the inhibitor molecules on copper surface are absorbed by physisorption and obey Langmuir isotherm adsorption. These results were supplemented by IR Spectroscopy, Scanning electron microscopy (SEM) and EDX spectrum of chemical composition. The metal solution interface is simulated as a physical model by using Electrochemical Impedance Spectroscopy (EIS).Keywords: Copper Alloy, Propolis extract, ethylene glycol; Corrosion inhibition; Adsorption, Electrochemical impedance Spectroscopy (EIS

A giant occipital encephalocele: A case report

Occipital encephalocele is a rare congenital anomaly that is characterized by herniation of brain tissue through a defect in the skull. Because of their enormous size, they pose a surgical challenge. Occipital encephalocele is the commonest of all encephalocele; the management of encephalocele defects requires immediate surgical closure. The author reports a case of a five months old female baby who presented a progressively increasing swelling over the occipital region. This swelling was present since birth. Surgery was planned to reduce the size of the swelling as well as its contents. The sac was excised and reduced sufficiently enough to accommodate the healthy-looking brain tissue. This infant did well postoperatively

Application of kinetic pyrolysis models to the analysis of flax chipboards under fire

This study presents a three-dimensional finite element model to describe the thermomechanical behaviour of flax chipboards under fire conditions. The model is based on kinetic models considering the thermal degradation during the pyrolysis phase and the evolution of the physico-mechanical properties as functions of temperature. The numerical model is integrated into Abaqus via user subroutines (Umat and Umatht) and applied to the analysis of the fire behaviour of panels made of flax chipboards. Thermogravimetric tests are performed on flax particles to serve for the identification of the kinetic parameters of the pyrolysis models. Once these kinetic parameters are determined, they are integrated into a complete numerical model to simulate the behaviour under fire of flax chipboards on small and large scales. The obtained trends in the predicted values indicate good agreements when compared to the measured values. The simulations show that the numerical model is capable of accurately modelling the thermomechanical transfers taking place within the material during exposure to fire

Treatment of chronic pain by spinal cord stimulation

Failed back surgery syndrome (FBSS) is often used to describe the condition of patients who have experienced continued pain after surgery. It is of multifactorial genesis and may be the consequence of various lumbar spinal diseases; lumbar disc herniation surgery or spinal canal stenosis laminectomy. The presented series included 13 patients affected with chronic pain related to FBSS who underwent implantation of spinal cord stimulation. The mean percentage of pain relief was 90 % for all patients. 60% of the patients were in a better psychological status and the intake of analgesic medications has been reduced of more than 70%. More than 50% of the patients could resume professional activities. Analysis of the risks and benefits comes in favour of spinal cord stimulation

Resection of giant invasive thoracic schwannoma: Case report

Even though spinal nerve sheath tumours, presented especially by schwannomas, are considered to be mostly benign; they can gain a huge size and have an invasive behaviour, causing spinal cord compression, bone destruction, and make the total removal of the tumour a real challenge for the surgeon. This type of tumours is recently described as giant invasive spinal schwannoma (GISS), this type rarely reported in the thoracic region; deserve a special studying vis-a-vis the diagnosis and the management of both the tumour and the bone destruction.       &nbsp

Early diagnosis and management of traumatic dura tear with brachial plexus injury without spinal lesions in childhood

Although the dura is a thick membrane, it could be severed in spine surgery and less frequently by a traumatism (7,8,10); in this case, it is usually accompanied with bone or ligamentous injury (2). Rare cases are reported of a traumatic dura tear without spinal lesion and would suspect in the first place a brachial plexus injury (2,8). Dura tears are rarely seen in childhood (3). We report a case of early diagnosis of dura tear in brachial plexus injury without bone or ligamentous lesions on a child of 4 years old and we discuss the diagnostic and treatment modalities

Communicating spinal epidural thoracic arachnoid cyst en-bloc resection: A case report

Background: Spinal extradural arachnoid cyst is an uncommon, expanding lesion which may communicate with the subarachnoid space, The etiology still remains unclear, but the most accepted explanation is the existence of areas of weakness in the spinal dura , Spinal arachnoid cysts are usually in the thoracic spine, and they may cause symptoms due to spinal cord compression. Case Presentation: Patient is a 54-years-old female who presented with progressive back pain and motor deficit, Magnetic resonance imaging (MRI) study revealed an extradural cyst extending from T2 to T4 isointense with the cerebrospinal fluid (CSF) on all sequences and did not enhance on T1-weighted post-contrast MRI. Patient underwent T2-T4 laminectomy, en-bloc resection of the lesion was achieved and the histopathological examination objectified an arachnoid cyst. Conclusion: Spinal extradural arachnoid cyst can cause neurologic deficit and the mainstay of treatment in patients with neurological symptoms is surgical removal of the cyst together with ligation of the communicating pedicle and closure of the dural defect

Thermal Performance of Hybrid PVT Collector with Natural Circulation

Hybrid photovoltaic thermal (PVT) collectors allow simultaneous production of electrical energy thus heat energy. There are several configurations of hybrid collectors (to produce water or air). For hybrids water collectors, there are several configurations that differ by the nature of the absorber (serpentine, tubes...). In this paper, an absorber tank is studied. The circulation of the coolant is natural (we do not use the pump). We present the obtained results in our experimental study and we analyzed the data, and then we compare the results with the theory practices. The electrical performances of the hybrid collector are compared with those of conventional photovoltaic module mounted on the same structure and measured under the same conditions. We conducted experiments with natural circulation of the coolant (Thermosyphon), for a flow rate of 0.025kg/m²