Reactive processing of formaldehyde and acetaldehyde in aqueous aerosol mimics: Surface tension depression and secondary organic products

The reactive uptake of carbonyl-containing volatile organic compounds (cVOCs) by aqueous atmospheric aerosols is a likely source of particulate organic material. The aqueous-phase secondary organic products of some cVOCs are surface-active. Therefore, cVOC uptake can lead to organic film formation at the gas-aerosol interface and changes in aerosol surface tension. We examined the chemical reactions of two abundant cVOCs, formaldehyde and acetaldehyde, in water and aqueous ammonium sulfate (AS) solutions mimicking tropospheric aerosols. Secondary organic products were identified using Aerosol Chemical Ionization Mass Spectrometry (Aerosol-CIMS), and changes in surface tension were monitored using pendant drop tensiometry. Hemiacetal oligomers and aldol condensation products were identified using Aerosol-CIMS. Acetaldehyde depresses surface tension to 65(\pm2) dyn/cm in pure water (a 10% surface tension reduction from that of pure water) and 62(\pm1) dyn/cm in AS solutions (a 20.6% reduction from that of a 3.1 M AS solution). Surface tension depression by formaldehyde in pure water is negligible; in AS solutions, a 9% reduction in surface tension is observed. Mixtures of these species were also studied in combination with methylglyoxal in order to evaluate the influence of cross-reactions on surface tension depression and product formation in these systems. We find that surface tension depression in the solutions containing mixed cVOCs exceeds that predicted by an additive model based on the single-species isotherms.Comment: Published in Atmospheric Chemistry and Physics 22 November 201

Circuit for clamping bridge over-voltages in a voltage-fed quasi Z-source converter

Unlike the voltage source converter, the Z-source converter can boost as well as buck the input voltage. However, the presence of physically large components in the impedance network introduces large parasitic inductances into power device commutation paths. This leads to consequent overvoltages at power device turn-off. A simple circuit for addressing this is presented. Practical results are given for a voltage-fed quasi- Z-source inverter with discontinuous input current

The Shape of Citizenship: Extraordinary Common Meaning and Constitutional Legitimacy

The United States, it is widely believed, is at a moment of constitutional crisis. At no time since the Civil War era has it seemed more likely that what James Madison called the “experiment entrusted to the hands of the American people”—the experiment in democratic constitutional self-governance—will fail. This article argues that one reason for this state of affairs is that the ‘people’ sense that they are no longer active participants in the experiment. While the historical etiology of this crisis is complex, and the forces involved not confined to the US, this article focuses on the crisis in the legitimacy of the Federal Judiciary—and the role that current orthodoxies in constitutional interpretation have played in fomenting that crisis. The immediate critical target of this article is contemporary jurisprudential uses of what is called “public meaning originalism,” specifically, and ‘textualist originalism’ more broadly, as a theory for the interpretation of those clauses in the US Constitution that refer to fundamental rights and freedoms. This concern with “textualism,” however, is primarily diagnostic. For, despite its relative unpopularity among most contemporary legal theorists, the application of “public meaning originalism” by the US Supreme Court is perfectly consistent with the dominant legal theoretical approach in the English-speaking world. The extremity of the Court’s recent ‘textualist’ jurisprudence provides an excellent illustration, or reminder, of the dangers of legal positivist jurisprudence. In arguing against textualist originalism, this article defends a version of the anti-positivist distinction between legal rules and legal principles, most famously associated with the work of Ronald Dworkin. It argues, however, that this distinction cannot be captured by understanding constitutional principles in terms of moral principles, as Dworkin suggests. Instead, constitutional principles must be understood as deliberative principles of political association and communal self-determination. The primary subject of this article, then, is the character of fundamental constitutional law; our hope is that the current crises in democratic constitutional legitimacy can help make salient certain aspects of the relation between popular sovereignty and constitutional legitimacy that are harder to discern in less fractured political climates. This article begins, in Part One, with a consideration of the Roberts Court’s recent jurisprudence, focusing on three landmark opinions issued in June of 2022: Dobbs v Jackson Women’s Health Organization, Kennedy v. Bremerton School Dist. and West Virginia v EPA. The point of revisiting this recent history will not be—or will not only be—to decry these rulings as anti-democratic and constitutionally ill-founded. The point, rather, will be 1) to see these rulings as consolidations of the Court’s newly asserted constitutional authority, and 2) show how contemporary positivist constitutional theory has helped prepare the way for the Court’s manipulation of the constitutional order. Part Two begins to elaborate an anti-positivist alternative both to legal positivism and to natural law legal theory. In agreement with traditional natural law theorists, it is argued that the distinction between illegitimate and legitimate expressions of political authority depends on the degree to which a system of authority is directed toward a common good. In disagreement with those theorists, however, this article contends that the common good of a political community is determined by the communal deliberative activity of a political community, and that the deliberative determination of a common good is the normative foundation of that community. Part Three focuses on the First Amendment of the US Constitution with two aims in mind. First, to illustrate the account of constitutional law here advocated, it offers a reading of the First Amendment as an attempt to put into words a shared understanding among the ratifiers of the Bill of Rights of what this article calls ‘the shape of citizenship’ in our constitutional democracy. Second, it shows how the Court’s recent opinions have radically subverted the last vestiges of this original connection between constitutional rights and the foundational principles of constitutional self-government. In Dobbs v Jackson, in particular, the Court asserts an understanding of constitutional rights as merely a particular structural variant of positive law, and in so doing effectively makes the legal order a sovereign power over the people, rather than an expression of and vehicle for their common self-determination

The Australian and New Zealand dialysis workforce

Aim: To capture a &quot;snapshot&quot; of the current Australian and New Zealand dialysis workforce in order to contribute to the future renal workforce challenges. Methods: A web-based survey of dialysis managers (n=221) were asked fifteen questions relating to demographics, age, full-time equivalent information, workforce designation, post-registration qualifications, subjective perceptions of staffing levels, staffing strategies and future dialysis research recommendations Results: In Australia in 2008 there were 2433 registered nurses, 188 enrolled nurses and 295 dialysis professionals (technicians) and 327 registered nurses (RNs), 8 enrolled nurses (ENs) and 64 dialysis professionals in New Zealand. There were significant variations in staff/patient ratios, workforce profiles and post-registration qualifications. There is a significant association between staff/ patient and home dialysis ratios. A high proportion of renal staff worked part-time, particularly in Australia. The dialysis workforce reflects the aging nature of the general nursing population in Australia and New Zealand. The majority of dialysis nurse managers perceived they had sufficient staff. Conclusion: Workforce variations found in this study may be useful to identify future workforce challenges and strategies. <br /

A nod in the wrong direction : Does nonverbal feedback affect eyewitness confidence in interviews?

Eyewitnesses can be influenced by an interviewer's behaviour and report information with inflated confidence as a result. Previous research has shown that positive feedback administered verbally can affect the confidence attributed to testimony, but the effect of non-verbal influence in interviews has been given little attention. This study investigated whether positive or negative non-verbal feedback could affect the confidence witnesses attribute to their responses. Participants witnessed staged CCTV footage of a crime scene and answered 20 questions in a structured interview, during which they were given either positive feedback (a head nod), negative feedback (a head shake) or no feedback. Those presented with positive non-verbal feedback reported inflated confidence compared with those presented with negative non-verbal feedback regardless of accuracy, and this effect was most apparent when participants reported awareness of the feedback. These results provide further insight into the effects of interviewer behaviour in investigative interviewsPeer reviewedFinal Accepted Versio