Publications by authors named "Ahmad Hajjar"

An interosseous ganglion cyst is a very rare entity, found mostly in skeletally mature patients, particularly in long bones such as the tibia and femur. However, we are the first to report here an unusual case of interosseous ganglion cyst of the upper ribs in a young female patient, which she had an unpredicted presentation of cough and hemoptysis and a large painful lump over the anterior left upper chest. The radiological and pathological workup confirmed the presence of a benign interosseous ganglion cyst arising from the left first rib, invading the second rib and the apex of the left lung.

View Article and Find Full Text PDF

A wavy shape was used to enhance the thermal heat transfer in a shell-tube latent heat thermal energy storage (LHTES) unit. The thermal storage unit was filled with CuO-coconut oil nano-enhanced phase change material (NePCM). The enthalpy-porosity approach was employed to model the phase change heat transfer in the presence of natural convection effects in the molten NePCM.

View Article and Find Full Text PDF

Thermal energy storage units conventionally have the drawback of slow charging response. Thus, heat transfer enhancement techniques are required to reduce charging time. Using nanoadditives is a promising approach to enhance the heat transfer and energy storage response time of materials that store heat by undergoing a reversible phase change, so-called phase change materials.

View Article and Find Full Text PDF

In the present study, the thermal energy storage of a hot petal tube inside a shell-tube type Thermal Energy Storage (TES) unit was addressed. The shell is filled with the capric acid Phase Change Material (PCM) and absorbs the heat from a hot U-tube petal. The governing equations for the natural convection flow of molten PCM and phase change heat transfer were introduced by using the enthalpy-porosity approach.

View Article and Find Full Text PDF

Thermal energy storage is a technique that has the potential to contribute to future energy grids to reduce fluctuations in supply from renewable energy sources. The principle of energy storage is to drive an endothermic phase change when excess energy is available and to allow the phase change to reverse and release heat when energy demand exceeds supply. Unwanted charge leakage and low heat transfer rates can limit the effectiveness of the units, but both of these problems can be mitigated by incorporating a metal foam into the design of the storage unit.

View Article and Find Full Text PDF

Artificial intelligence (AI) is now a trendy subject in clinical medicine and especially in gastrointestinal (GI) endoscopy. AI has the potential to improve the quality of GI endoscopy at all levels. It will compensate for humans' errors and limited capabilities by bringing more accuracy, consistency, and higher speed, making endoscopic procedures more efficient and of higher quality.

View Article and Find Full Text PDF

Introduction: Following publication of improved patients' outcome using first line FOLFIRINOX for metastatic pancreatic adenocarcinoma, many physicians now prescribe it as neo-adjuvant or induction treatment for borderline and locally advanced pancreatic cancer. A pathologic complete response, rarely seen with previous preoperative regimens, is sometimes observed in these patients. The aim of this study was to assess long-term outcomes of patients presenting pathologic complete response after preoperative FOLFIRINOX usually followed by chemo-radiation therapy for non-metastatic pancreatic adenocarcinoma.

View Article and Find Full Text PDF