Extravehicular mobility unit subcritical liquid oxygen storage and supply system

The storage of life support oxygen in the Extravehicular Mobility Unit in the liquid state offers some advantages over the current method of storing the oxygen as a high pressure gas. Storage volume is reduced because of the increased density associated with liquid. The lower storage and operating pressures also reduce the potential for leakage or bursting of the storage tank. The potential for combustion resulting from adiabatic combustion of the gas within lines and components is substantially reduced. Design constraints on components are also relaxed due to the lower system pressures. A design study was performed to determine the requirements for a liquid storage system and prepare a conceptual design. The study involved four tasks. The first was to identify system operating requirements that influence or direct the design of the system. The second was to define candidate storage system concepts that could possibly satisfy the requirements. An evaluation and comparison of the candidate concepts was conducted in the third task. The fourth task was devoted to preparing a conceptual design of the recommended storage system and to evaluate concerns with integration of the concept into the EMU. The results are presented

Studies of the catalysis of cyanide addition and substitution

The chiral diphenylphosphinites of menthol and binaphthol have been prepared. The zerovalent palladium complexes of these phosphinites were found to be poor catalysts for the hydrocyanation of alkenes. The enantiomeric purity of the exo-norbornane carbonitrile produced from the hydrocyanation of norbornene catalysed by Pd(DI0P)(_2) was found to be considerably lower than originally surmised. In the same reaction, the zerovalent palladium complexes of BPPM and BINAP were found to give the highest reported enantiomeric purities for a transition metal catalysed hydrocyanation reaction. The mechanism of transition metal catalysed asymmetric hydrocyanation was examined. Preliminary mechanistic investigations were conducted using (DIOP) platinum(O) alkene complexes. The formation of a platinum hydrido cyanide complex was observed by (^i)H and (^31)P N.M.R. spectroscopy. The novel complex (DIOP) palladium(O) ethene has been prepared and isolated, yielding the first crystal structure of a palladium ethene complex. Oxidative addition of HCN to the complex generated (DIOP) palladium hydrido cyanide. The complex also underwent other oxidative addition reactions; some may involve one electron processes. The use of PNP salts to effect the introduction of CN" by addition or substitution reactions is described. The salts are particularly suited to reactions with hydrolysis sensitive substrates. The salts are used under both phase transfer and stoichiometric conditions

The role of the ventrolateral frontal cortex in inhibitory oculomotor control

It has been proposed that the inferior/ventrolateral frontal cortex plays a critical role in the inhibitory control of action during cognitive tasks.However, the contribution of this region to the control of eye movements has not been clearly established.Here, we describe the performance of a group of 23 frontal lobe damaged patients in an oculomotor rule switching task for which the association between a centrally presented visual cue and the direction of a saccade could change from trial to trial. A subset of 16 patients also completed the standard antisaccade task.Ventrolateral damage was found to be a significant predictor of errors in both tasks. Analysis of the rate at which patients corrected errors in the rule switching task also revealed an important dissociation between left and right hemisphere damaged patients.Whilst patients with left ventrolateral damage usually corrected response errors with secondary saccades, those with right hemisphere lesions often failed to do so. The results suggest that the inferior frontal cortex forms part of a wider frontal network mediating inhibitory control over stimulus elicited eye movements. The critical role played by the right ventrolateral region in cognitive tasks may arise due to an additional functional specialization for the monitoring and updating of task rules

Laser surface alloying of 316L stainless steel coated with a bioactive hydroxyapatite-titanium oxide composite.

Laser surface alloying is a powerful technique for improving the mechanical and chemical properties of engineering components. In this study, laser surface irradiation process employed in the surface modification off 316L stainless steel substrate using hydroxyapatite-titanium oxide to provide a composite ceramic layer for the suitability of applying this technology to improve the biocompatibility of medical alloys and implants. Fusion of the metal surface incorporating hydroxyapatite-titania ceramic particles using a 30 W Nd:YAG laser at different laser powers, 40, 50 and 70% power and a scan speed of 40 mm s(-1) was observed to adopt the optimum condition of ceramic deposition. Coatings were evaluated in terms of microstructure, surface morphology, composition biocompatibility using XRD, ATR-FTIR, SEM and EDS. Evaluation of the in vitro bioactivity by soaking the treated metal in SBF for 10 days showed the deposition of biomimetic apatite

Sperm morphology in five species of cicadettine cicadas (Hemiptera: Cicadomorpha: Cicadidae)

Mature spermatozoa from five species of cicadas of the subfamily Cicadettinae (Quintilia wealei, Melampsalta leucoptera, Stagira simplex, Xosopsaltria thunbergi and Monomatapa matoposa) were examined by light and electron microscopy. In each species sperm are elongate, aggregated into organized bundles with their heads embedded in a homogenous matrix to form spermatodesmata, and exhibit polymegaly. The head of the sperm consist of an anteriorly positioned conical acrosome that has a tubular substructure and a deep, posterior invagination that forms the subacrosomal space (eccentrically positioned anteriorly). The acrosome is flattened anteriorly; posteriorly it extends along either side of the nucleus as two tubular processes that gradually decrease in diameter. The filiform nucleus tapers anteriorly and intrudes into the subscrosomal space. Posteriorly the nucleus has a lateral invagination that houses material of the so-called centriolar adjunct. Posterior to the centriolar adjuct and the nucleus are two crystalline mitochondrial derivatives and a centriole, respectively, the latter giving rise to the axoneme, which has a 9 + 9 + 2 arrangement of microtubules. In these respects the sperm are similar to those of platypleurine cicadas. However, some features seem unique to cicadettines, including the structural organization of an enlarged centriolar adjunct and the dimensions of the tails. The enlarged centriolar adjunct has a lamella-like substructure and can be considered a synapomorphic character in the Cicadettinae. It is, therefore, potentially useful in the separation of this subfamily from the Cicadinae. In addition, the great length of the sperm nucleus of long-headed sperm in M. matoposa could be a synapomorphy of this genus and related taphurine and cicadettine species

Sperm morphology in four species of African platypleurine cicadas (Hemiptera: Cicadomorpha: Cicadidae)

Mature spermatozoa from four species of platypleurine cicadas (Albanycada albigera, Azanicada zuluensis, Platypleura capensis and P. hirtipennis) were examined by light and electron microscopy. The filiform sperm have a similar ultrastructure in all species but notable variations were found in sperm dimensions. All species produce more than one discrete length of nucleated, motile sperm, a form of polymorphism termed polymegaly. Polymegaly is expressed in two ways: sperm have bi- or trimodal head and tail lengths. The anterior parts of sperm heads are embedded in an elongate homogenous matrix forming a spermatodesm. The conical acrosome is deeply invaginated posteriorly, and sits on top of the nucleus. The acrosomal contents are differentiated internally with an electron-lucent central medulla and a denser cortex. The homogenously electron-dense nucleus is pointed anteriorly and is generally cylindrical, although posteriorly there is a lateral invagination that extends part-way along the nucleus. This invagination houses fine granular material of the centriolar adjunct. Vesicle-like elements that are associated with both the posterior nucleus and the centriolar adjunct are also found within the invagination. Immediately posterior of and adjoining the centriolar adjunct is a pair of mitochondrial derivatives that are elongated and extend for almost the entire length of the tail. The absence of accessory bodies in cicada sperm suggests that within the Cicadomorpha, the families Cicadidae and Cercopidae are closely affiliated

Congruence and scope for incorporating ACTIVE principles into project management competency frameworks

Project Management competency has been recognised as a critical source of competitive advantage and key to successful project delivery. For this reason it is important that the competency frameworks used to achieve competence in project organizations are effective and fit for purpose. The European Construction Institute (ECI) developed eight principles through the ACTIVE (Achieving Competitiveness Through Innovation and Value Enhancement) initiative in an attempt to add value to the delivery of projects. This research explored the congruence and scope for incorporating the ACTIVE principles into current competency frameworks in use by project organizations. An interpretive and qualitative research approach was adopted, using semi-structured interviews with eight Project Managers and Learning and Development Managers in project organizations. The use of competency frameworks is not as widespread as first thought. Current competency frameworks in use in project organizations are based on a fairly comprehensive body of knowledge and largely congruent with the ACTIVE principles centered around concept definition, team management, supply chain relationship management, communication, risk management, innovation, project execution and performance measurement. However, ACTIVE principles’ underpinning ethos of creating a collaborative working environment in projects is a missing piece worthy of incorporation into competency frameworks currently in use in project organizations

Exploration of implementation variables impacting trauma informed practices in schools: A narrative review

Current literature suggests that by using trauma- informed practices (TIP) in our schools and classrooms, positive short and long-term outcomes can be achieved for both children and their communities. However, there is little research identifying what helps or hinders the implementation of trauma-informed practice in schools or the development of a practitioner’s trauma-informed pedagogy. As part of this narrative review, 25 trauma- informed practice implementation variables were identified from 34 peer-reviewed works of current (2015-2020) literature using a process of thematic analysis. This review utilised an ecological model as an overlay to present these variables in a useable format. The results of this research may be utilised to identify unaddressed implementation variables that support practice change and TIP in schools. The literature and this review support the idea that, if given the right input, conditions and setting events, an effective trauma-informed practice or pedagogy can be developed. Furthermore, by helping practitioners fill the gaps in their knowledge and assisting them to develop their trauma-informed pedagogy, they are able to create an environment where students who have experienced complex trauma may be healthy, safe, engaged, and supported

Exploration of implementation variables impacting trauma informed practices in schools: A narrative review

Current literature suggests that by using trauma- informed practices (TIP) in our schools and classrooms, positive short and long-term outcomes can be achieved for both children and their communities. However, there is little research identifying what helps or hinders the implementation of trauma-informed practice in schools or the development of a practitioner’s trauma-informed pedagogy. As part of this narrative review, 25 trauma- informed practice implementation variables were identified from 34 peer-reviewed works of current (2015-2020) literature using a process of thematic analysis. This review utilised an ecological model as an overlay to present these variables in a useable format. The results of this research may be utilised to identify unaddressed implementation variables that support practice change and TIP in schools. The literature and this review support the idea that, if given the right input, conditions and setting events, an effective trauma-informed practice or pedagogy can be developed. Furthermore, by helping practitioners fill the gaps in their knowledge and assisting them to develop their trauma-informed pedagogy, they are able to create an environment where students who have experienced complex trauma may be healthy, safe, engaged, and supported

Involving patients and carers in developing the radiotherapy curriculum: enhancing compassion

Background:: This article describes a collaborative project that aimed to develop a patient-centred curriculum in radiotherapy. In the wake of the Francis report in 2013 and a call for compassion to be a central tenet of health programmes, the project was a timely opportunity to enhance the radiotherapy curriculum. Methods:: Collaboration between university staff and patients and carers using the service improvement model Plan-Do-Study-Act was the method employed for the curriculum project. Two key discussion forums helped shape the curriculum plan, with module and course evaluation continuing to inform developments. Results:: The key outcome of the project is that it has shaped the 'care' theme evident in the current undergraduate programme. Co-production methods resulted in the development of a range of shared classroom activities that focus on experiences, care values and communication strategies. The new curriculum has evaluated positively and the impact of learning is demonstrated both in the classroom and clinical setting. The project team have also influenced recruitment processes and patient and carer involvement in programme approval is embedded. Conclusion:: Working together, with patients and carers is an ideal method to enhance the curriculum and reflect the requirements in practice of current health and social care professions. Further developments in student assessment are planned