Exploring the Lewis basicity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] on metal substrates by electrospray mass spectrometry. Synthesis, characterization and structural studies of new platinum selenido phosphine complexes containing the {Pt₂Se₂} core

Electrospray Mass Spectrometry (ESMS) has been used as a tool to probe the reactivity of the metalloligand [Pt₂(μ-Se)₂(PPh₃)₄] with metal substrates, which lead to the formation of charged coordination complexes via loss of halides or other labile ligands. Among the numerous metal substrates used in the displacement reactions are Au(anpy)Cl₂ (anpy = cyclometallated 2-anilinopyridyl), HgPhCl and Pb(NO₃)₂. Acid titration on the Lewis basic metalloligand leads to the identification and isolation of the doubly-protonated species, [Pt₂(μ-SeH)₂(PPh₃)₄]²⁺, whose sulfide analogue cannot be isolated. A three-step strategy is employed in the use of ESMS as a probe: (i) preliminary screening of the metalloligand with an array of acidic main group and transition group metal compounds, (ii) identification of potentially stable and isolable products formed in situ based on ion distribution and simulated isotope patterns and (iii) promising reactions are repeated on a laboratory scale, and target products are isolated and characterized. X-Ray diffraction studies have been performed on single crystals of [Pt₂(μ-SeH)₂(PPh₃)₄][ClO₄]₂, [Pt₂(μ₃-Se)₂(PPh₃)₄(CdCl₂)] and {Pt₂(μ₃-Se)₂(PPh₃)₄[Pb(NO₃)]}{NO₃}. These results suggested that in general a parallel chemistry can be developed on the intermetallic selenides as on the sulfides. However, there are chemical and structural differences which are highlighted in this paper

Mass spectrometry-directed synthesis of early–late sulfide-bridged heterobimetallic complexes from the metalloligand [Pt₂(PPh₃)₄(μ-S)₂] and oxo compounds of vanadium(V), molybdenum(VI) and uranium(VI)

The metalloligand [Pt₂(PPh₃)₄(μ-S)₂] has been found to react with the transition metal oxo compounds, ammonium metavanadate, sodium molybdate, and the actinide complex uranyl nitrate to give sulfide-bridged heterobimetallic complexes [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, [Pt₂(PPh₃)₄(μ₃-S)₂MoO₂(OMe)]⁺, and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], respectively. Electrospray mass spectrometry (ESMS) was used to probe the reactivity of [Pt₂(PPh₃)₄(μ-S)₂] and thus identify likely targets for isolation and characterization. ESMS has also been used to investigate fragmentation pathways of the new species. No bimetallic species were detected with hydrated La(NO₃)₃or Th(NO₃)₄, or with the lanthanide shift reagent Eu(fod)₃ (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate). X-Ray crystal structure determinations have been carried out on [Pt₂(PPh₃)₄(μ₃-S)₂VO(OMe)₂]⁺, 2, (as its hexafluorophosphate salt) and [Pt₂(PPh₃)₄(μ₃-S)₂UO₂( ₂-NO₃)₂], 4. The vanadium atom of 2 has a distorted square pyramidal geometry, while the uranium in 4 has the expected linear dioxo coordination geometry, with two bidentate nitrates and a bidentate {Pt₂S₂} moiety

Linear State Variable Dynamic Model And Estimator Design For Allison 1406 Gas Turbine Engine

This paper describes a procedure for developing a State Variable Model for the Allison T406 gas turbine engine. This linear model is useful for designing controllers using modern control techniques. The engine and V-22 rotor system is modeled around an operating point by using four state variables and one input variable. For a given power setting, it is observed that two linear models are sufficient to represent the engine dynamics over the entire flight envelope. A relationship between surge margin and the state variables is also developed. It is demonstrated that these linear models are useful in designing an estimator for accommodating hard sensor failures

A rapid screening, “combinatorial-type” survey of the metalloligand chemistry of Pt₂(PPh₃)₄(μ-S)₂ using electrospray mass spectrometry

Electrospray mass spectrometry is a rapid and powerful technique for a combinatorial-like survey of the chemistry of the metalloligand Pt₂(PPh₃)₄(μ-S)₂, leading to the successful isolation and crystallographic characterisation of the novel protonated species Pt₂(PPh₃)₄(μ-S)(μ-SH) together with a range of metallated derivatives

Effects of Housing First approaches on health and wellbeing of adults who are homeless or at risk of homelessness: systematic review and meta-analysis of randomised controlled trials

Background: Homelessness is associated with poor health. A policy approach aiming to end homelessness across Europe and North America, the ‘Housing First’ (HF) model, provides rapid housing, not conditional on abstinence from substance use. We aimed to systematically review the evidence from randomised controlled trials for the effects of HF on health and well-being. Methods: We searched seven databases for randomised controlled trials of interventions providing rapid access to non-abstinence-contingent, permanent housing. We extracted data on the following outcomes: mental health; self-reported health and quality of life; substance use; non-routine use of healthcare services; housing stability. We assessed risk of bias and calculated standardised effect sizes. Results: We included four studies, all with ‘high’ risk of bias. The impact of HF on most short-term health outcomes was imprecisely estimated, with varying effect directions. No clear difference in substance use was seen. Intervention groups experienced fewer emergency department visits (incidence rate ratio (IRR)=0.63; 95% CI 0.48 to 0.82), fewer hospitalisations (IRR=0.76; 95% CI 0.70 to 0.83) and less time spent hospitalised (standardised mean difference (SMD)=−0.14; 95% CI −0.41 to 0.14) than control groups. In all studies intervention participants spent more days housed (SMD=1.24; 95% CI 0.86 to 1.62) and were more likely to be housed at 18–24 months (risk ratio=2.46; 95% CI 1.58 to 3.84). Conclusion: HF approaches successfully improve housing stability and may improve some aspects of health. Implementation of HF would likely reduce homelessness and non-routine health service use without an increase in problematic substance use. Impacts on long-term health outcomes require further investigation. Trial registration number: CRD42017064457

Impact of PowerPoint and Chalkboard teaching in Physiotherapy Undergraduates.

Background: A teacher's basic tool for displaying lectures are through blackboards, pegboards, bulletin boards, transparencies with an overhead projector (TOHP), PowerPoint presentation and walk and talk. Nowadays PowerPoint presentation is commonly used as it has ability to present the information in a clear, organized and simpler manner. The present study was carried out to find out the best method of teaching amongst the undergraduate Physiotherapy students. Objective: To compare the impact of the PowerPoint multimedia presentation and chalkboard in teaching by assessing the knowledge based on the marks obtained in the pretest and posttest. Methodology: 40 students were divided into two groups and a selected content-based lecture in pharmacology was delivered. For one group lecture was delivered using PowerPoint presentation, for second group using Chalkboard. Single - best Multiple Choice Questions [MCQs] paper was used for assessing the knowledge gained. The differences in the marks obtained in the two groups were analyzed Results: Students who attended the class on chalkboard obtained significantly higher score in single best MCQ examination compared to those students who attended the same content based lecture on the PowerPoint. Conclusion: The chalkboard method of teaching was found more suitable tool of teaching and learning than PowerPoint for small group

Impact of PowerPoint and Chalkboard teaching in Physiotherapy Undergraduates.

Background: A teacher\u27s basic tool for displaying lectures are through blackboards, pegboards, bulletin boards, transparencies with an overhead projector (TOHP), PowerPoint presentation and walk and talk. Nowadays PowerPoint presentation is commonly used as it has ability to present the information in a clear, organized and simpler manner. The present study was carried out to find out the best method of teaching amongst the undergraduate Physiotherapy students. Objective: To compare the impact of the PowerPoint multimedia presentation and chalkboard in teaching by assessing the knowledge based on the marks obtained in the pretest and posttest. Methodology: 40 students were divided into two groups and a selected content-based lecture in pharmacology was delivered. For one group lecture was delivered using PowerPoint presentation, for second group using Chalkboard. Single - best Multiple Choice Questions [MCQs] paper was used for assessing the knowledge gained. The differences in the marks obtained in the two groups were analyzed Results: Students who attended the class on chalkboard obtained significantly higher score in single best MCQ examination compared to those students who attended the same content based lecture on the PowerPoint. Conclusion: The chalkboard method of teaching was found more suitable tool of teaching and learning than PowerPoint for small group

System Modeling and Control of Smart Structures

This paper presents multidisciplinary research and curriculum efforts at the University of Missouri-Rolla in the smart structures area. The primary objective of our project is to integrate research results with curriculum development for the benefit of students in electrical, and mechanical and aerospace engineering and engineering mechanics. The approach to the accomplishment of curriculum objectives is the development of a two-course sequence in the smart structures area with an integrated laboratory. The research portion of the project addresses structural identification and robust control methods for smart structures. A brief summary of the research results and a description of curriculum development in the smart structures area are described in this pape

Sex differences in the association between salivary telomere length and multimorbidity within the US Health & Retirement Study

Background: Telomere length is associated with several physical and mental health conditions, but whether it is a marker of multimorbidity is unclear. We investigated associations between telomere length and multimorbidity by sex. Methods: Data from adults (N = 5,495) aged ≥50 years were taken from the US Health and Retirement Study (2008–14). Telomere length was measured in 2008 from salivary samples. The cross-sectional associations between telomere length and eight chronic health conditions were explored using logistic regression, adjusting for confounders and stratified by sex. Logistic, ordinal and multinomial regression models were calculated to explore relationships between telomere length and multimorbidity (using a binary variable and a sum of the number of health conditions) and the type of multimorbidity (no multimorbidity, physical multimorbidity, or multimorbidity including psychiatric problems). Using multilevel logistic regression, prospective relationships between telomere length and incident multimorbidity were also explored. Results: In cross-sectional analyses, longer telomeres were associated with reduced likelihood of lung disease and psychiatric problems among men, but not women. Longer telomeres were associated with lower risk of multimorbidity that included psychiatric problems among men (OR=0.521, 95% CI: 0.284 to 0.957), but not women (OR=1.188, 95% CI: 0.771 to 1.831). Prospective analyses suggested little association between telomere length and the onset of multimorbidity in men (OR=1.378, 95% CI: 0.931 to 2.038) nor women (OR=1.224, 95% CI: 0.825 to 1.815). Conclusions: Although telomere length does not appear to be a biomarker of overall multimorbidity, further exploration of the relationships is merited particularly for multimorbidity including psychiatric conditions among men

Paving the way : a future without inertia is closer than you think

Unless you have been hibernating in a remote cave for the past decade, you will have noticed the explosion of variable renewable generation. Wind power and solar photovoltaics (PVs) have been the subject of dozens of articles, just within the pages of IEEE Power & Energy Magazine. Charts illustrating relentless growth, such as the example from the United States shown in Figure 1 with futures tending toward 100% renewable energy, are common. This figure, provided by the National Renewable Energy Laboratory (NREL), reflects a low-cost, high-renewable projection scenario