Electrical Stress Induced Structural Dynamics in Silicon Oxide Resistive Memories

In this thesis, the effects of electrical stress on silicon oxide resistive random access memory (RRAM) devices are studied with a view of understanding the individual mechanisms involved in RRAM operation. This is achieved through a combination of density functional theory (DFT) modelling and characterisation using transmission electron microscopy (TEM). In Part I of the thesis, DFT is used to model the incorporation, diffusion, reduction, and cluster nucleation of Ag in Ag/SiO2/Pt RRAM devices. It is found that Ag incorporates into SiO2 as a Ag+1 ion, which is mobile through large rings, grain boundaries and column boundaries. An O vacancy (VO) mediated Ag cluster model is then proposed, where Ag+1 reduction is shown to occur at 33% and 11% of VO sites at the Ag and Pt electrodes, respectively. In this case, Ag+1 ions bind to VO forming the [Agi/VO] j complex, which is favoured to trap electrons from the electrodes. In this way, as a Ag cluster grows, the metallic Ag-Ag bonding compensates strain in the lattice leading to the breaking of Si-O bonds. The broken Si-O bonds open access to new voids into which small Ag clusters may break from the original Ag cluster and form, providing new sites for cluster nucleation. In Part II of the thesis, Au-Ti-SiOx-Mo, Au-SiOx-Mo and Ti-SiOx-Mo (x approx 1.95) RRAM devices are characterised through TEM. It is shown the roughness of the Mo layer leads to patterning in the device, where voids and column boundaries form in SiOx at the troughs of the SiOx/Mo interface. The column boundaries are shown to facilitate the transport of Ti and Mo during positive electroforming leading to conductive metal-oxide filaments in the SiOx layer. Conversely, oxygen is dispelled from SiOx under negative electroforming, allowing electron tunneling via trap assisted tunnelling through VO sites

Management of Open Apex in Permanent Anterior Teeth-Case Reports

The new developments have greatly enhanced the clinician’s ability to achieve the biologically-based objectives of root canal treatment, which include removal of all tissue, bacteria and bacterial products and substrates from the root canal system, shaping and filling the canal system

Comment on Quantum teleportation via GHZ-like state

Recently Yang et al. [Int. J. Theo. Phys. 48 (2009) 516] have shown that an unknown qubit can be teleported by using a particular GHZ-like state as quantum channel. However, there are several errors in the calculation which lead to incorrect conclusions. The errors have been indicated and corrected. It is also noted that their scheme and the independently proposed teleportation scheme of Zhang et al. [Int. J. Theo. Phys. 48 (2009) 3331] uses quantum channel from the same family and any state of that family may be used for teleportation.Comment: 2 page

Arthroscopic anterior cruciate ligament reconstruction using single bundle hamstring tendon autograft

Background: The present study was designed to analyze the postoperative outcome of arthroscopic anterior cruciate ligament (ACL) reconstruction with anatomical single bundle hamstring tendons autograft fixed in femoral tunnel using endobutton and in the tibial tunnel using interference screws and reinforced by anterior half of peroneus longus tendon (AHPLT), wherever required.Methods: 39 patients of complete ACL tear underwent arthroscopic anatomical single bundle ACL reconstruction using quadrupled hamstring tendon autograft. It was ensured that the quadrupled graft had a length of at least 7 cm and thickness of at least 8 mm. If either of these requirements were not met, then the graft was supplemented by AHPLT. For functional assessment, international knee documentation committee (IKDC) knee score was taken and clinical tests for antero-posterior stability were done. In addition, the foot and ankle disability index (FADI) scores were used to evaluate the ankle donor site of the AHPLT.Results: The average graft diameter was 8.74 mm and average graft length was 9.12 cm. There was significant improvement in post op IKDC score when compared with pre op score. There was no antero-posterior instability seen in any of the patients during follow up. 10 patients required an additional graft augmentation with AHPLT. There was no complaint about weakness of the ankle joint after surgery.Conclusions: Arthroscopic ACL reconstruction with anatomical single bundle hamstring tendon autograft is an excellent treatment option for ACL deficient knees. It gives excellent functional outcome with minimal complications. Graft if small in diameter can be reinforced by AHPLT without any detrimental effect on ankle function

Functional outcome of comminuted upper metaphyseal tibial fracture treated with circular external fixators

Background: High speed motor vehicle accidents are on the rise over the past few years. These are responsible for most of the complex fractures of the tibial metaphysic. Proper treatment of these fractures is of paramount importance. The use of circular fixators for the definitive treatment of such fractures entails a minimally invasive technique of insertion that gives good fracture reduction and stability combined with minimal postoperative complications.Methods: This study was prospective and conducted over 22 patients diagnosed with upper comminuted metaphyseal tibial fracture treated with circular external fixator.Results: In this series, all 22 patients (100%) were male. Fourteen cases (64%) involved the left tibia and eight (36%) fractures were on right. The mean patient age was 49.5 years (range 26-75). Road traffic collisions accounted for most of the injuries (n=14), while fall from bike (n=8). In this study, using knee society score evaluation, excellent results (KSS>80) were seen in 8 patients (36.36%), good results (KSS 70-79) were seen in 10 patients (45.45%), fair (KSS 60-69) in 4 patient (18.18%) and poor (KSS< 60) in 0 patient (0%). Complication seen was pin tract infection in 2 patients (9.9%), which was managed by regular pin site dressings. Another complication was non-union in 1 patient (4.54%). No other complication was encountered.Conclusions: Circular external fixation is a promising modality for surgical treatment of comminuted upper metaphyseal tibial fractures. It allows satisfactory realignment of the fractured fragments and their stabilization, besides early mobilization of the joints and care of associated soft tissue injuries, without significant complications

Understanding the influence of family context on entrepreneurial characteristics

It has been widely established that small businesses fuel the growth and expansion of an economy. Entrepreneurial activities in South Africa are not sufficient to sustain growth that the country requires and a lack of an entrepreneurial mindset and skills have been found to be a significant challenge. The capacity for this country to develop and grow entrepreneurs to feed the growing economy will significantly determine its future. The purpose of this research paper is to explore the environmental factors that influence the development of entrepreneurs, in order to contribute to understanding how to effectively develop entrepreneurs. The family context within which an individual grows up is investigated as a possible source of developing strength of entrepreneurial characteristics. A survey of individuals from both entrepreneurial families and nonentrepreneurial families was conducted. Their entrepreneurial characteristics were tested against their family context and any significant relationships were identified. The results revealed that only Self-confidence, out of the six characteristics, was influenced by the family context. The other five characteristics do not show a relationship and are possibly influenced by other environmental factors. The study also revealed significant relationships between some of the characteristics. This may prove to derive some interesting research questions for future research.Dissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte

Study of discrepancies in ABO blood grouping: experience of a tertiary health-care center

Background: An accurate ABO grouping is the most important test which is done in the blood bank. Mistyping can lead to transfusion with ABO incompatible blood which results in severe intravascular haemolysis and may even result in the death of the recipient. An ABO discrepancy implies that the forward or red cell ABO grouping does not agree with the reverse or serum ABO grouping. The study was conducted to evaluate the frequency of ABO blood group discrepancies, to identified main causes of discrepancies, to avoid chances of wrong interpretation of blood group and to mitigate clinical impact associated with mismatch ABO transfusion.Methods: A prospective study of ABO discrepancies and their causes was performed on 25,129 samples of the patients and 13,251 samples of blood donors at the red cell serology laboratory in tertiary care teaching hospital and blood bank over the period from February 2017 to July 2018.Results: ABO group discrepancies were mainly divided in 4 different groups. Out of 51 discrepancies 32 (62.74%) were found in group-IV category, being highest amongst all; 10 (19.60%) in group-II which was second highest; other were 8 (15.69%) in group-I and 1 (1.96%) in group-III category.Conclusions: All discrepancies reported on ABO cell and serum grouping must be investigated further, so that correct blood group is reported, minimizing the chances of transfusion reaction. A note of caution should be mentioned on the blood group card to prevent ABO incompatibility in case of transfusion

A five years retrospective analytic study of maternal deaths at tertiary care centre, Gujarat, India

Background: Maternal mortality is one of the major challenges which face the developing countries throughout the world. The aim of the study is to assess the causes of maternal mortality at P.D.U. Medical College, and to identify the avoidable ones.Methods: Data were collected from records of patients who presented to and/or delivered at P.D.U. Medical College between 2011 and 2015. Only cases of maternal mortality were included in this study. In our study, we found 120 maternal deaths at our hospital between 2011 and 2015.Results: We found that the indirect causes of maternal mortality accounted for 29.3% of all mortalities. The leading cause of death in the 5 years was uncontrollable postpartum haemorrhage (23.3%), preeclampsia with its complications (15.8%), Anemia (14.1%), Abruption placentae 12.5% and Septicaemia 5% .Direct maternal deaths accounted for 70.7%.Conclusions: Preeclampsia and PPH, as well as their complications are the leading causes of death in one of the biggest tertiary care university hospitals in Egypt. However, there are other important avoidable predisposing factors that should be dealt with including lack of patient education, delayed transfer from other hospitals, and substandard practice

Efficacy and superiority of an innovative method (IM) of intravenous (IV) fluid drip drop rate calculation using IV set and its comparison with conventional methods (CM)

Background: Almost every indoor patient requires some form of intravenous (IV) fluids and its infusion rate should be proper as recommended for best treatment outcomes. To overcome the same, a simple, quick and easily applicable new method for drip drop rate calculation is proposed, which is user-friendly at bedside and doesn’t require mathematical skills or help.Methods: Author compared this novel innovative method (IM) of IV fluid drip drop rate method for both regular macro and micro drop infusion set against conventional mathematical calculation method (MC) of infusion in various IV fluid indoor orders and assessed for time-to-initiation of treatment (TI) required and its accuracy. Ten resident doctors and ten nursing staff participated to grade both conventional and novel methods by using pre-printed forms of various parameters like time consumption, comfort level, accuracy and applicability in ward and these both methods were scored on a scale of 1 to 10.Results: Conventional method (CM) required 14.23±1.10seconds, while novel method (IM) required average 3.63±0.73seconds for calculation of drop rate. Average grading for conventional method was 3.63±0.49 and for novel method was 7.84±0.6 out of 10.Conclusions: Novel method of IV fluid drip drop rate formula is easy, quick and superior in comparison to conventional method and it doesn’t require any additional instrumental help. It is good alternative to conventional formula for IV drip drop rate calculation in absence of infusion pump