Study of gold-based alloy phase diagrams

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The partial constitutions of the Au-Ge-X and Au-Pb-X ternary alloys have been investigated, where X is a metallic element, selected from the sub-groups period 1m and rrm of the periodic table (In, Ga, Zn, or Cd), which forms one or more stable compounds with gold, but which forms no stable compound with Ge and Pb. The Smith Thermal Analysis Method, supplemented by metallographic and X-ray techniques, was used to determine the constitutions of the ternary systems. Eutectiferous, pseudobinary systems were found between Ge and the stable congruent intermediate compounds, AuIn, Auln2' AuGa, AuGa2' AuZn and AuCd. The solubility of Ge in the AuX compounds was not determined directly. However, it was 1.3 at.% Ge for Zn and Cd containing alloys and less than 1.0 at. % Ge for In and Ga containing alloys at the eutectic temperatures, which is in accordance with the Hume-Rothery rule. Ternary eutectic points were also determined in the Auln-AuIn2-Ge, Auln2-In-Ge and AuGa-AuGa2-Ge partial ternary systems. No evidence of liquid immiscibility was found in any of these ternary systems. The experimental results obtained were in good agreement with computed features of the diagrams. However, pseudobinary systems were not found between Pb and the stable congruent melting intermediate compounds, AuGa, AuGa2, AuZn and AuCd (the AuIn-Pb and AuIn2-Pb sections had already been investigated). The evidence of an extensive liquid immiscibility was found in each of these systems. The miscibility in the liquid state was found to decrease progressively down group IV when the elements of this group react with AuX compounds, which can be attributed to the progressive increase of the atomic size and decrease in electronegativities and solubility parameters of the elements, down this group. Two rules were derived to relate the liquid immiscibility/miscibility of ternary systems. One of the rules based upon the atomic sizes and melting points of the constituent elements showed a fair agreement with many systems. However, the other rule based upon the solubility parameter and electronegativities of the constituent elements showed good agreement with immiscible systems, but gave a poor predictability for miscible systems. The lower temperature equilibria of the Au-rich portion of the Au-Sn binary phase diagram are not well defined. So, long term heat treatment of samples at appropriate temperatures and compositions was carried out. Optical microscopy and SEMIEDAX techniques were employed and hence the low temperature equilibria of the Au-Sn binary system have been amended.This study is partly funded by the Ministry of Science and Technology, Government of Pakistan for the S & T scholarship award and Punjab University, Lahore

Postretrieval new learning does not reliably induce human memory updating via reconsolidation

Reconsolidation theory proposes that retrieval can destabilize an existing memory trace, opening a time-dependent window during which that trace is amenable to modification. Support for the theory is largely drawn from nonhuman animal studies that use invasive pharmacological or electroconvulsive interventions to disrupt a putative postretrieval restabilization ("reconsolidation") process. In human reconsolidation studies, however, it is often claimed that postretrieval new learning can be used as a means of "updating" or "rewriting" existing memory traces. This proposal warrants close scrutiny because the ability to modify information stored in the memory system has profound theoretical, clinical, and ethical implications. The present study aimed to replicate and extend a prominent 3-day motor-sequence learning study [Walker MP, Brakefield T, Hobson JA, Stickgold R (2003) Nature 425(6958):616-620] that is widely cited as a convincing demonstration of human reconsolidation. However, in four direct replication attempts (n = 64), we did not observe the critical impairment effect that has previously been taken to indicate disruption of an existing motor memory trace. In three additional conceptual replications (n = 48), we explored the broader validity of reconsolidation-updating theory by using a declarative recall task and sequences similar to phone numbers or computer passwords. Rather than inducing vulnerability to interference, memory retrieval appeared to aid the preservation of existing sequence knowledge relative to a no-retrieval control group. These findings suggest that memory retrieval followed by new learning does not reliably induce human memory updating via reconsolidation

The role of different antioxidant agents in human infertility and assisted reproductive techniques

Reactive oxygen species (ROS) are a group of oxidants formed during oxygen metabolism. ROS appears to be involved in the pathogenesis of many human diseases. In reproductive medicine, ROS have both physiological and pathological role in male and female reproduction. Oxidative stress causes damage to spermatozoa, oocyte and embryos. It appears to play a role in both natural and in vitro fertilization and pregnancy.  In In recent years there has been a tremendous increase in couples seeking assisted reproductive technology (ART) procedures in order to have children. However, the success rates of these procedures still remain very low. The negative impact of oxidative stress on fertility has become widely recognized. Several studies have demonstrated its negative effect on the number and quality of retrieved oocytes and embryos following in-vitro fertilization (IVF).   One of the major contributing factors to the low success rate in ART has been the damage caused by free radicals to the gametes and the developing embryo. Oxidative stress can originate from the early steps of ART involving the oocyte, sperm and embryo, as well as in the endometrial environment later on following embryo transfer. The patients with oxidative stress may benefit from the strategies to reduce oxidative stress and treatment with antioxidants. This review assessed the evidence for the effectiveness of different antioxidants in female and male subfertility. Keywords: infertility, assisted reproductive techniques, antioxidants, vitamin E, coenzyme Q10,  L-Carnitine ,  pentoxifylline, N-Acetyl cysteine, Zinc, melatonin, vitamin

Challenges to urban cultural heritage conservation and management in the historic centre of Sulaimaniyah, Kurdistan-Iraq

Purpose: The purpose of this paper is to examine the challenges to urban cultural heritage management conservation in the historical city of Sulaimaniyah, Kurdistan-Iraq. The paper focusses on the roles and interactions of stakeholders and the issues that confront the decision-making processes that underpin the management of historic city towns. Design/methodology/approach: A case study methodology is utilised for this research. It involves documentary analysis and interviews with stakeholders who are part of the management of the historic city centre of Sulaimaniyah, Kurdistan-Iraq. The findings from this case study are analysed in a systematic way before being discussed in the context of the literature on urban cultural heritage management. Findings: The research shows that although there is a shared vision of the need to preserve and conserve urban cultural heritage, the management process is a contentious one. Stakeholders have different ideas as to how to achieve conservation goals which leads to increasing conflicts among stakeholders. This situation is compounded by the limited financial resources available to local government agencies, political interference in the work of implementation agencies and the lack of capacity in local government to enforce rules and carry out conservation projects. There are also significant power differentials among stakeholders in the decision-making process which often means that local residents are excluded from the process of conserving their built urban heritage. Practical implications: This research can help practitioners who are in charge of urban cultural heritage management in dealing with stakeholder conflicts. The paper offers insight into a number of sources of stakeholder conflicts and on ways to overcome these in the planning process. Originality/value: The originality of research lies in the novelty of the case study area. This research highlights the issues of built heritage conservation management and planning practices in an area – Sulaimaniyah, Kurdistan-Iraq – that is geographically less represented in the extant literature. The research also identifies some of the key sources of conflict in urban heritage conservation projects and provides an insight into the roles of stakeholders in the management of smaller locally-dependent historic city centres

Screening of high risk infants for metabolic disease in a metropolitan hospital

Screening of symptomatic infants for metabolic diseases is described which led to an improved detection rate because of better awareness and case selection, as well as the use of a test for urinary organic acids.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147121/1/jimd0081.pd

Estimating the natural and artificial radioactivity in soil samples from some oil sites in Kirkuk-Iraq using high resolution gamma rays spectrometry

The natural and artificial radioactivity in soil samples from some oil sites of Kirkuk-Iraq have been estimated using a gamma spectrometry based on a high purity germanium (HPGe) detector. For this reason, soil samples have been collected from four sites; Henjera, Jabel Boor, Jambor and Qutan. It was found that the specific activity ranged from 7.31 to 63.33 Bq kg−1 for 226Ra, from 3.54 to 42.95 Bq kg−1 for 232Th, from 103.21 to 798.52 Bq kg−1 for 40K and from 0.7 to 9.53 Bq kg−1 for 137Cs. The results have been compared with the worldwide average values. The radium equivalent activity (Raeq), the absorbed gamma dose rate (D), the annual effective dose rate (AEDE), the external hazard (Hex), the internal hazard (Hin) and Gamma radiation representative level Index (Iγ) have also been calculated. The Raeq was 92.173 Bq kg−1, the D was 45.53 nGyh-1, the AEDE outdoor and indoor were 0.0959 and 0.224, respectively, the Hex was 0.242, the Hin was 0.329, and Iγ was 0.680. It has been concluded that no harmful radiation effects have posed to the population who live in the study area. Although, there are some areas where radiation effects have resulted higher than that of the international allowable radiation values

OBKA-FS: an oppositional-based binary kidney-inspired search algorithm for feature selection

Feature selection is a key step when building an automatic classification system. Numerous evolutionary algorithms applied to remove irrelevant features in order to make the classifier perform more accurate. Kidney-inspired search algorithm (KA) is a very modern evolutionary algorithm. The original version of KA performed more effectively compared with other evolutionary algorithms. However, KA was proposed for continuous search spaces. For feature subset selection and many optimization problems such as classification, binary discrete space is required. Moreover, the movement operator of solutions is notably affected by its own best-known solution found up to now, denoted as Sbest. This may be inadequate if Sbest is located near a local optimum as it will direct the search process to a suboptimal solution. In this study, a three-fold improvement in the existing KA is proposed. First, a binary version of the kidney-inspired algorithm (BKA-FS) for feature subset selection is introduced to improve classification accuracy in multi-class classification problems. Second, the proposed BKA-FS is integrated into an oppositional-based initialization method in order to start with good initial solutions. Thus, this improved algorithm denoted as OBKA-FS. Third, a novel movement strategy based on the calculation of mutual information (MI), which gives OBKA-FS the ability to work in a discrete binary environment has been proposed. For evaluation, an experiment was conducted using ten UCI machine learning benchmark instances. Results show that OBKA-FS outperforms the existing state-of-the-art evolutionary algorithms for feature selection. In particular, OBKA-FS obtained better accuracy with same or fewer features and higher dependency with less redundancy. Thus, the results confirm the high performance of the improved kidney-inspired algorithm in solving optimization problems such as feature selection

Estimation of geostrophic current in the Red Sea based on sea level anomalies derived from extended satellite altimetry data

Geostrophic current data near the coast of the Red Sea have large gaps. Hence, the sea level anomaly (SLA) data from Jason-2 have been reprocessed and extended towards the coast of the Red Sea and merged with AVISO data at the offshore region. This processing has been applied to build a gridded dataset to achieve the best results for the SLA and geostrophic current. The results obtained from the new extended data at the coast are more consistent with the observed data (conductivity–temperature–depth, CTD) and hence geostrophic current calculation. The patterns of SLA distribution and geostrophic currents are divided into two seasons: winter (October–May) and summer (June–September). The geostrophic currents in summer are flowing southward over the Red Sea except for narrow northward flow along the east coast. In winter, currents flow to the north for the entire Red Sea except for a small southward flow near the central eastern and western coast. This flow is modified by the presence of cyclonic and anticyclonic eddies, which are more concentrated in the central and northern Red Sea. The results show anticyclonic eddies (AEs) on the eastern side of the Red Sea and cyclonic eddies (CEs) on the western side during winter. In summer, cyclonic eddies are more dominant for the entire Red Sea. The result shows a change in some eddies from anticyclonic during winter to cyclonic during summer in the north between 26.3 and 27.5∘&thinsp;N. Furthermore, the life span of cyclonic eddies is longer than that of anticyclonic eddies.</p

Missed Gastric Injuries in Blunt Abdominal Trauma : Case report with review of literature

Hollow viscus injuries of the digestive tract are an uncommon occurrence in blunt abdominal trauma. We report a 39-year-old male who was hit by a vehicle as a pedestrian and admitted to the Sultan Qaboos University Hospital, Muscat, Oman, in 2015. He underwent an exploratory laparotomy which revealed injuries to the distal stomach, liver and descending colon. Postoperatively, the patient was febrile, tachycardic and hypotensive. Abdominal examination revealed distention and tenderness. The next day, a repeat laparotomy identified a gastric injury which had not been diagnosed during the initial laparotomy. Although the defect was repaired, the patient subsequently died as a result of multiorgan failure. Missed gastric injuries are rare and are associated with a grave prognosis, particularly for trauma patients. Delays in diagnosis, in addition to associated injuries, contribute to a high mortality rate

INFANT AND YOUNG CHILD FEEDING PRACTICES IN THE EAST END OF FREETOWN, SIERRA LEONE

Adequate dietary intake may be a major determinant of the health outcome of children. This study aims at describing the infant and young child feeding practices amongst a group of mothers, factors affecting such practices and the effect of the practice on the nutritional status of the children.Semi-closed ended questionnaire was used to address some of the Infant and Young Child Feeding (IYCF) indicators among the three hundred and forty-seven mothers.Almost all of the index children in this study were breastfed with a majority within 30 minutes of delivery. Breast milk was the first drink in 79.8% of cases, and Exclusive breastfeeding rate was 26.3%. Breastfeeding for less than six months tends to be more prevalent among the low socioeconomic group and those who had Antenatal Care in the private clinics. Complimentary feeds for the majority of the children consisted mainly of cereal based gruels. There was a positive correlation between the nutritional status and the first drink, educational level of mother and length of breastfeeding.Poor infant and young child feeding practices impinged negatively on the nutritional status of the children. Improved training of health care workers, female education, and empowerment are recommended.