The Atomic and Magnetic Structure of NdMn(6−x)FexGe6 Solid Solutions

The magnetic and crystallographic properties of induction-melted NdMn(6−x)FexGe6 intermetallics (x=0, 1.0, and 1.5) in the temperature range of 30–475 K have been studied by x-ray and neutron diffraction techniques and SQUID measurements. All of the samples crystallized in the YCo6Ge6-type structure (P6/mmm). A small amount (\u3c5 mol%) of Nd(MnFe)2Ge2 is present as an impurity. As expected, iron replaces manganese at the 3g site. The unit cell volume decreases slightly with increasing iron content at an average rate of 1.3% per substituted atom. Lattice parameters a and c contract at a rate of 0.6% and 0.2% per substitution atom, respectively. The net magnetization of these samples decreases rapidly with increasing iron content. According to neutron diffraction data, the magnetic moment of the iron sublattice couples negatively with ferromagnetically coupled manganese and neodymium moments. Addition of iron suppresses the spin reorientation processes observed in NdMn6Ge6. Whereas the net moment in NdMn5Fe1Ge6 slowly cants away from the c-axis with increasing temperature, the easy direction of NdMn4.5Fe1.5Ge6 is approximately parallel to the c-axis in the temperature range mentioned above

A Magnetic and Crystallographic Study of (Sm/Gd)₂(Fe/Si)₁₇C\u3csub\u3ez\u3c/sub\u3e Solid Solutions

The crystallographic and magnetic properties of SmyGd2-yFe17-xSix (0 ≤ x ≤ 3 and y = 1 and 1.5) solid solutions and their interstitial carbides have been investigated using x-ray diffraction and magnetic measurements. The SmyGd2-yFe17-xSix samples crystallized in the rhombohedral Th2Zn17 structure with less than 5 mol % of impurities. The unit cells of the mixed rare-earth (R) samples are smaller than those of Sm2Fe17 and Gd2Fe17. The carbided samples contain up to a total of 15 mol % of free iron, an iron suicide, and/or cubic Si5C3. The unit cells of the carbided samples are 1%-4% larger than those of the parent samples. For a given silicon concentration, the Curie temperatures (Tc) of SmyGd2-yFe17-xSix intermetallics are higher than those of the two end members. For example, the Tc of SmGdFe17 (280°C) is approximately 160° and 80° higher than that of Sm2Fe17 and Gd2Fe17, respectively. The Tc measured for the SmyGd2-yFe17-xSx samples, 280-290°C, are among the highest values observed for a R2Fe17-xMx intermetallic where M is a substituent other than cobalt. Except in the case of SmGdFe16SiCz (z unknown), the Tc of the carbided samples are 20%-25% higher than those of the parent samples. A Tc of 426°C and a magnetization of 120.6 emu/g observed for SmGdFe16SiCz are the highest values measured for the intermetallics investigated herein. As determined by x-ray diffraction studies of magnetically aligned samples, the easy axis of magnetization is parallel to the c axis

Crystal and Magnetic Structures of LaNi5−xMnx

The crystallographic and magnetic properties of LaNi5−xMnx with x=1, 1.5, and 2, have been investigated using x-ray and neutron diffraction, vibrating sample magnetometer and superconducting quantum interference device measurements. All the samples crystallize in the hexagonal CaCu5-type (P6/mmm) structure. Manganese atoms preferentially occupy the 3g site in the LaNi5 structure. The bulk magnetization of the LaNi5−xMnx powder samples decreases rapidly as nickel is replaced by manganese. A ferrimagnetic model is applied to describe the magnetic structure of the LaNi5−xMnx samples for x=1.5 and 2. A ferromagnetic model gives the best fit of the neutron diffraction data for the LaNi4Mn sample

Oxygen and Phosphorus Coordination Around Iron in Crystalline Ferric Ferrous Pyrophosphate and Iron-phosphate Glasses with UO₂ or Na₂O

Fe K-edge x-ray absorption fine-structure (XAFS) measurements were performed on glass samples of (Fe3O4)0.3(P2O5)0.7 with various amounts of Na2O or UO2. Near-edge and extended-XAFS regions are studied and comparisons are made to several reference compounds. We find that iron in the base glass is ~25% divalent and that the Fe2+ coordination is predominantly octahedral, while Fe3+ sites are roughly split between tetrahedral and octahedral coordinations. Also, we measure roughly one FeñOñP link per iron. Substitution of Na2O or UO2 up to 15 mo1% primarily affects the first FeñO shell. The results are compared to data from the related material Fe3(P2O7)2

A High Energy X-Ray and Neutron Scattering Study of Iron Phosphate Glasses Containing Uranium

The atomic structure of iron phosphate glasses containing uranium has been studied by complementary neutron and x-ray scattering techniques. by combining x-ray and neutron structure factors, detailed information about different pair interactions has been obtained. Most of the basic structural features such as coordination numbers and O-O and P-O distances in uranium containing glasses are the same as those in the base glass of batch composition 40Fe2O3-60P2O5 (mol %). However, the Fe-O distances change slightly with the addition of uranium. The observed structural parameters support a structural model in which the waste elements occupy voids in the Fe-O-P network, hence, not altering the basic structure of the parent iron phosphate glass

Patients' perspectives on self-testing of oral anticoagulation therapy: Content analysis of patients' internet blogs

<p>Abstract</p> <p>Background</p> <p>Patients on oral anticoagulant therapy (OAT) require regular testing of the prothrombin time (PT) and the international normalised ratio (INR) to monitor their blood coagulation level to avoid complications of either over or under coagulation. PT/INR can be tested by a healthcare professional or by the patient. The latter mode of the testing is known as patient self-testing or home testing. The objective of this study was to elicit patients' perspectives and experiences regarding PT/INR self-testing using portable coagulometer devices.</p> <p>Methods</p> <p>Internet blog text mining was used to collect 246 blog postings by 108 patients, mainly from the USA and the UK. The content of these qualitative data were analysed using XSight and NVivo software packages.</p> <p>Results</p> <p>The key themes in relation to self-testing of OAT identified were as follows: Patient benefits reported were time saved, personal control, choice, travel reduction, cheaper testing, and peace of mind. Equipment issues included high costs, reliability, quality, and learning how to use the device. PT/INR issues focused on the frequency of testing, INR fluctuations and individual target (therapeutic) INR level. Other themes noted were INR testing at laboratories, the interactions with healthcare professionals in managing and testing OAT and insurance companies' involvement in acquiring the self-testing equipment. Social issues included the pain and stress of taking and testing for OAT.</p> <p>Conclusions</p> <p>Patients' blogs on PT/INR testing provide insightful information that can help in understanding the nature of the experiences and perspectives of patients on self-testing of OAT. The themes identified in this paper highlight the substantial complexities involved in self-testing programmes in the healthcare system. Thus, the issues elicited in this study are very valuable for all stakeholders involved in developing effective self-testing strategies in healthcare that are gaining considerable current momentum particularly for patients with chronic illness.</p

Older People’s Needs and Opportunities for Assistive Technologies

Older adults experience a disconnect between their needs and adoption of technologies that have potential to assist and to support more independent living. This paper reviewed research that links people’s needs with opportunities for assistive technologies. It searched 13 databases identifying 923 papers with 34 papers finally included for detailed analysis. The research papers identified needs in the fields of health, leisure, living, safety, communication, family relationship and social involvement. Amongst these, support for activities of daily living category was of most interest. In specific sub-categories, the next most reported need was assistive technology to support walking and mobility followed by smart cooking/kitchen technology and assistive technology for social contacts with family member/other people. The research aimed to inform a program of research into improving the adoption of technologies where they can ameliorate identified needs of older people

Feasibility of a randomised controlled trial of remotely delivered problem-solving cognitive behaviour therapy versus usual care for young people with depression and repeat self-harm: lessons learnt (e-DASH)

BackgroundSelf-harm and depression are strong risk factors for repeat self-harm and suicide. We aimed to investigate the feasibility of a randomised controlled trial (RCT) of remotely delivered problem-solving cognitive behaviour therapy (PSCBT) plus treatment as usual (TAU) versus TAU in young people with repeat self-harm and depression.MethodsSingle-blind multi-centre RCT with an internal pilot, pre-set stop-go criteria and qualitative semi-structured interviews. Eligible participants (aged 16–30 years) were recruited from 9 adult or child and adolescent self-harm and crisis services; had ≥ 2 lifetime self-harm episodes, one in the preceding 96 h; and Beck Depression Inventory-II (BDI-II) score ≥ 17. Participants were randomised (1:1) to either TAU or TAU and 10–12 sessions of PSCBT delivered by mobile phone or video-calling.ResultsTwenty-two participants were recruited (11 in each arm), 10 (46%) completed follow-up at 6 months, 9 (82%) started the PSCBT and 4 (36%) completed it. The study did not meet three of its four stop-go criteria, reflecting considerable barriers to recruitment and retention. Participants had severe depression symptoms: with mean BDI-II 38.9 in the PSCBT and 37.2 in TAU groups, respectively. Three (14%) unblindings occurred for immediate safety concerns. Barriers to recruitment and retention included lack of agency for participants, severity of depression, recency of crisis with burden for participants and clinicians who diagnosed depression according to pervasiveness.ConclusionsRCTs of PSCBT for young people with depression and self-harm are not feasible using recruitment through mental health services that conduct assessments following self-harm presentations. Clinician assessment following self-harm presentation mainly identifies those with severe rather than mild-moderate depression

The Usability of E-learning Platforms in Higher Education: A Systematic Mapping Study

The use of e-learning in higher education has increased significantly in recent years, which has led to several studies being conducted to investigate the usability of the platforms that support it. A variety of different usability evaluation methods and attributes have been used, and it has therefore become important to start reviewing this work in a systematic way to determine how the field has developed in the last 15 years. This paper describes a systematic mapping study that performed searches on five electronic libraries to identify usability issues and methods that have been used to evaluate e-learning platforms. Sixty-one papers were selected and analysed, with the majority of studies using a simple research design reliant on questionnaires. The usability attributes measured were mostly related to effectiveness, satisfaction, efficiency, and perceived ease of use. Furthermore, several research gaps have been identified and recommendations have been made for further work in the area of the usability of online learning