Examining the effect of nano-additions of rare earth elements on the hardness of body armor ceramic

64-72Body armor is a very critical entity in protecting soldier's live. Soldiers carry heavy stuff on duties, and the ceramic insert in those body armors is one of them. The purpose of this paper is to investigate the effect of Nano-rare-earth elements as additives to the ceramic base material on the armor's performance. Aluminum oxide (Al2O3) has been selected as the base material of the ceramic in this study. This study has chosen two additives: Zirconium dioxide (ZrO2) and Nano-ceramic lab composite (NCLC). In this work, we have presented results of mechanical characterization for alumina-nanocomposites armor plates. Three different concentrations of NCLC and ZnO2 alumina-based compositions have been prepared and pressed at 40 and 50 MPa and sintered at 1350°C for 120 min. X-ray diffraction and scanning electron microscopy (SEM) techniques have been employed to characterize structural, morphological, and phase identification of the films. Mohs test hardness measurements of samples after sintering have been performed. Results have shown that the compositions with NCLC showed a higher hardness than a composition with ZrO2. This result has indicated that the addition of NCLC to Alumina enhances the microstructure and increases the ceramics' hardness

Criticality Analysis of Medical Equipment: A Case Study at King Hussein Cancer Center (KHCC) Amman-Jordan

Proper maintenance management of medical equipment is of prime importance to the health sector as otherwise this would result in poor treatment, longer waiting times and patients suffering as well as draining, the normally limited, financial resources of most public medical institutions. King Hussein Cancer Center (KHCC), Amman-Jordan is a unique medical institution where treatment of different types of cancer is provided and where equipment unavailability is considered a risky event which may result in life-threatening complications.  This is especially true for critical treatment equipment. Criticality analysis was performed on a representative sample of medical equipment at KHCC in order to assess and improve the effectiveness of current maintenance management policy. A sample of twenty-one medical devices was selected for this study. Past failure and maintenance data, in addition to relevant financial information, were collected for these devices and compiled into criticality ranks.  In order to take account of the special nature of these equipment medical criticality (in terms of risk score) values were also calculated based on relevant tables of the American Society for Healthcare Engineering (ASHE). Overall criticality ranking of medical equipment was then determined based on equipment cost, ASHE risk score, reliability and maintenance cost.  The present results have revealed major flaws within the purchase and maintenance policies at KHCC. For example, some extremely expensive devices with extremely high-cost maintenance contracts were revealed to exhibit low reliability values and suffer from repeated failures. These were within patient-sensitive equipment cancer treatment devices. The results also have shown that under "less than optimum" maintenance practice, the ASHE risk score may be a misleading measure of equipment criticality. This was shown by comparing the obtained overall equipment criticality to their ASHE risk score where high level of discrepancy was present between the two measures.</p

Downtime Reduction on Medical Equipment Maintenance at The Directorate of Biomedical Engineering in the Jordanian MOH

Medical equipment needs to be managed effectively and carefully from the first step of buying the equipment till being scraped. This includes purchasing procedure, operational procedures and he maintenance policies used in this regards. Managing the maintenance of medical equipment is vital for the patient and for the hospital itself. One of the main problems in healthcare sector today is the availability of medical equipment, which is largely affected by downtime variation needed to repair the medical equipment. This study presents a process improvement study applied on the Downtime of the medical equipments during the maintenance work in the Jordanian of Health Hospitals, based on customized Six Sigma methodology- DMAIC- (Define, Measure, Analyze, Improve and Control). Data was collected from different locations and different equipments to study the problem and make the necessary actions to resolve or reduce downtime. Obtained results indicate that the downtime reduced by 35% by introducing a new procedure to the clinical engineer to used when dealing with any medical equipment for maintenance work

Radiative transport of MHD stagnation point flow of chemically reacting Carreau nanofluid due to radially stretched sheet

The flow of Carreau nanofluid with generation/absorption and magnetic field can be valuable for modifying solar energy production. In this work, we extended the study of the MHD boundary layer flow of Carreau nanofluid with heat generation/absorption close to a stagnation point over the radially extending plate. Likewise, the features of radiation and magnetic field with convective boundary conditions are considered. Further, keeping in view the importance of chemical reactions, their effect is also incorporated during the modelling process. For motivation, the impact of thermophoresis and Brownian motion has been taken into account. Using appropriate similarity transformation, we converted nonlinear governing partial differential equations of Carreau nanofluid into a couple of nonlinear ODEs. Using a recognized shooting technique and the MATLAB bvp4c solver and Mathematica ND-solve built-in command, we were able to get numerical results for these modeled ODEs. Through graphs and tables, the effects of different physical parameters like magnetic, Weissenberg number, Brownian motion, thermal radiation, thermophoresis, Prandtl number, chemical reaction, and rate of heat generation/absorption on non-dimensional velocity, temperature, and concentration profile are discussed

Examining the effect of nano-additions of rare earth elements on the hardness of body armor ceramic

Body armor is a very critical entity in protecting soldier's live. Soldiers carry heavy stuff on duties, and the ceramic insert in those body armors is one of them. The purpose of this paper is to investigate the effect of Nano-rare-earth elements as additives to the ceramic base material on the armor's performance. Aluminum oxide (Al2O3) has been selected as the base material of the ceramic in this study. This study has chosen two additives: Zirconium dioxide (ZrO2) and Nano-ceramic lab composite (NCLC). In this work, we have presented results of mechanical characterization for alumina-nanocomposites armor plates. Three different concentrations of NCLC and ZnO2 alumina-based compositions have been prepared and pressed at 40 and 50 MPa and sintered at 1350°C for 120 min. X-ray diffraction and scanning electron microscopy (SEM) techniques have been employed to characterize structural, morphological, and phase identification of the films. Mohs test hardness measurements of samples after sintering have been performed. Results have shown that the compositions with NCLC showed a higher hardness than a composition with ZrO2. This result has indicated that the addition of NCLC to Alumina enhances the microstructure and increases the ceramics' hardness