KAJI AWAL TURBIN AIR DARRIEUS 3 BLADE HYDROFOIL NACA 0018 PADA VARIASI BILANGAN REYNOLD

Kebutuhan akan energi dari tahun ke tahun semakin meningkat sementara cadangan energi yang berasal dari fossil seperti minyak bumi dan batu bara semakin menipis. Hal ini akan menyebabkan terjadinya krisis energi karena sumber energi tersebut adalah sumber energi yang tak terbarukan. Untuk mengatasi permasalahan energi ini perlu dicari sumber-sumber energi baru yang terbarukan, sehingga tidak akan terjadi krisis energi di masa yang akan datang. Indonesia memiliki lautan yang sangat luas, sehingga potensi arus lautnya dapat dimanfaatkan sebagai energi alternatif. Penelitian ini adalah melakukan pengujian terhadap turbin Darrieus. Turbin ini memiliki diameter 20 cm dan tinggi 20 cm, blade yang digunakan adalah hydrofoil NACA 0018 dengan panjang chord 6,5 cm. Pengujian dilakukan pada sebuah saluran uji yang memiliki penampang persegi panjang 30 x 32 cm dengan variasi bilangan Reynold 6370, 11980 dan 17615 untuk mencari daya dan efisiensi yang dihasilkan turbin tersebut. Dari hasil pengujian, daya yang dihasilkan turbin Darrieus tersebut pada bilangan Reynold 6370, 11980 dan 17615 berturut-turut adalah 0,00339 Watt, 0,009 Watt dan 0,018 Watt sedangkan efisiensinya 21,95 %, 7,37 % dan 4,52 %. Kata kunci: Turbin Darrieus, NACA 0018, bilangan Reynold dan efisiens

Regulatory Fitness: Fintech, Funny Money, and Smart Contracts

© 2019, The Author(s). This article argues that there are many questions that lawyers might ask, and conversations that they might have, about smart contracts; that some questions that are asked are more important than others; and that there are some questions that are not asked but which should be asked. First, it is argued that the question that preoccupies ‘coherentists’ (concerning the application of the law of contract to smart contracts, and the fit between smart contracts and the paradigmatic ‘fiat contracts’ that are recognised by the law of contract) is neither as puzzling nor as important as might be supposed. Secondly, it is argued that, if there are concerns about the acceptability of smart contracts, then the conversation that needs to be had is of a ‘regulatory-instrumentalist’ nature; in particular, if the question is one of public policy restrictions on the use of smart contracts, then the appropriate balance of interests needs to be made by an institution that has both the necessary mandate and the appropriate mind-set. Thirdly, it is argued that there are conversations that we currently do not have but which urgently need to be had. Blockchain is a potentially transformative technology and it is important to have more fundamental conversations about the kind of community that we want to be

Taking Blockchain Seriously

In the present techno-political moment it is clear that ignoring or dismissing the hype surrounding blockchain is unwise, and certainly for regulatory authorities and governments who must keep a grip on the technology and those promoting it, in order to ensure democratic accountability and regulatory legitimacy within the blockchain ecosystem and beyond. Blockchain is telling (and showing) us something very important about the evolution of capital and neoliberal economic reason, and the likely impact in the near future on forms and patterns of work, social organization, and, crucially, on communities and individuals who lack influence over the technologies and data that increasingly shape and control their lives. In this short essay I introduce some of the problems in the regulation of blockchain and offer counter-narratives aimed at cutting through the hype fuelling the ascendency of this most contemporary of technologies

Molecular absorption lines toward star-forming regions : a comparative study of HCO+, HNC, HCN, and CN

Aims. The comparative study of several molecular species at the origin of the gas phase chemistry in the diffuse interstellar medium (ISM) is a key input in unraveling the coupled chemical and dynamical evolution of the ISM. Methods. The lowest rotational lines of HCO+, HCN, HNC, and CN were observed at the IRAM-30m telescope in absorption against the \lambda 3 mm and \lambda 1.3 mm continuum emission of massive star-forming regions in the Galactic plane. The absorption lines probe the gas over kiloparsecs along these lines of sight. The excitation temperatures of HCO+ are inferred from the comparison of the absorptions in the two lowest transitions. The spectra of all molecular species on the same line of sight are decomposed into Gaussian velocity components. Most appear in all the spectra of a given line of sight. For each component, we derived the central opacity, the velocity dispersion, and computed the molecular column density. We compared our results to the predictions of UV-dominated chemical models of photodissociation regions (PDR models) and to those of non-equilibrium models in which the chemistry is driven by the dissipation of turbulent energy (TDR models). Results. The molecular column densities of all the velocity components span up to two orders of magnitude. Those of CN, HCN, and HNC are linearly correlated with each other with mean ratios N(HCN)/N(HNC) = 4.8 $\pm$ 1.3 and N(CN)/N(HNC) = 34 $\pm$ 12, and more loosely correlated with those of HCO+, N(HNC)/N(HCO+) = 0.5 $\pm$ 0.3, N(HCN)/N(HCO+) = 1.9 $\pm$ 0.9, and N(CN)/N(HCO+) = 18 $\pm$ 9. These ratios are similar to those inferred from observations of high Galactic latitude lines of sight, suggesting that the gas sampled by absorption lines in the Galactic plane has the same chemical properties as that in the Solar neighbourhood. The FWHM of the Gaussian velocity components span the range 0.3 to 3 km s-1 and those of the HCO+ lines are found to be 30% broader than those of CN-bearing molecules. The PDR models fail to reproduce simultaneously the observed abundances of the CN-bearing species and HCO+, even for high-density material (100 cm-3 < nH < 104 cm-3). The TDR models, in turn, are able to reproduce the observed abundances and abundance ratios of all the analysed molecules for the moderate gas densities (30 cm-3 < nH < 200 cm-3) and the turbulent energy observed in the diffuse interstellar medium. Conclusions. Intermittent turbulent dissipation appears to be a promising driver of the gas phase chemistry of the diffuse and translucent gas throughout the Galaxy. The details of the dissipation mechanisms still need to be investigated

Migrants, State Responsibilities, and Human Dignity

This article addresses two questions: First, how does the value of human dignity distinctively bear on a state’s responsibilities in relation to migrants; and, secondly, how serious a wrong is it when a state fails to respect the dignity of migrants? In response to these questions, a view is presented about the distinction between wrongs that violate cosmopolitan standards and wrongs that violate the standards that are distinctive to a particular community; about when and how the contested concept of human dignity might be engaged; and, elaborating a three-tiered and lexically ordered scheme of state responsibilities, about how we should assess the seriousness of a state’s failure to respect the dignity of migrants

Impact of detecting potentially serious incidental findings during multi-modal imaging [version 3; peer review: 2 approved, 1 approved with reservations]

Background: There are limited data on the impact of feedback of incidental findings (IFs) from research imaging.  We evaluated the impact of UK Biobank's protocol for handling potentially serious IFs in a multi-modal imaging study of 100,000 participants (radiographer 'flagging' with radiologist confirmation of potentially serious IFs) compared with systematic radiologist review of all images. Methods: Brain, cardiac and body magnetic resonance, and dual-energy x-ray absorptiometry scans from the first 1000 imaged UK Biobank participants were independently assessed for potentially serious IFs using both protocols. We surveyed participants with potentially serious IFs and their GPs up to six months after imaging to determine subsequent clinical assessments, final diagnoses, emotional, financial and work or activity impacts. Results: Compared to systematic radiologist review, radiographer flagging resulted in substantially fewer participants with potentially serious IFs (179/1000 [17.9%] versus 18/1000 [1.8%]) and a higher proportion with serious final diagnoses (21/179 [11.7%] versus 5/18 [27.8%]). Radiographer flagging missed 16/21 serious final diagnoses (i.e., false negatives), while systematic radiologist review generated large numbers of non-serious final diagnoses (158/179) (i.e., false positives). Almost all (90%) participants had further clinical assessment (including invasive procedures in similar numbers with serious and non-serious final diagnoses [11 and 12 respectively]), with additional impact on emotional wellbeing (16.9%), finances (8.9%), and work or activities (5.6%). Conclusions: Compared with systematic radiologist review, radiographer flagging missed some serious diagnoses, but avoided adverse impacts for many participants with non-serious diagnoses. While systematic radiologist review may benefit some participants, UK Biobank's responsibility to avoid both unnecessary harm to larger numbers of participants and burdening of publicly-funded health services suggests that radiographer flagging is a justifiable approach in the UK Biobank imaging study. The potential scale of non-serious final diagnoses raises questions relating to handling IFs in other settings, such as commercial and public health screening

Analyses of a novel SCN5A mutation (C1850S): conduction vs. repolarization disorder hypotheses in the Brugada syndrome.

AIMS: Brugada syndrome (BrS) is characterized by arrhythmias leading to sudden cardiac death. BrS is caused, in part, by mutations in the SCN5A gene, which encodes the sodium channel alpha-subunit Na(v)1.5. Here, we aimed to characterize the biophysical properties and consequences of a novel BrS SCN5A mutation. METHODS AND RESULTS: SCN5A was screened for mutations in a male patient with type-1 BrS pattern ECG. Wild-type (WT) and mutant Na(v)1.5 channels were expressed in HEK293 cells. Sodium currents (I(Na)) were analysed using the whole-cell patch-clamp technique at 37 degrees C. The electrophysiological effects of the mutation were simulated using the Luo-Rudy model, into which the transient outward current (I(to)) was incorporated. A new mutation (C1850S) was identified in the Na(v)1.5 C-terminal domain. In HEK293 cells, mutant I(Na) density was decreased by 62% at -20 mV. Inactivation of mutant I(Na) was accelerated in a voltage-dependent manner and the steady-state inactivation curve was shifted by 11.6 mV towards negative potentials. No change was observed regarding activation characteristics. Altogether, these biophysical alterations decreased the availability of I(Na). In the simulations, the I(to) density necessary to precipitate repolarization differed minimally between the two genotypes. In contrast, the mutation greatly affected conduction across a structural heterogeneity and precipitated conduction block. CONCLUSION: Our data confirm that mutations of the C-terminal domain of Na(v)1.5 alter the inactivation of the channel and support the notion that conduction alterations may play a significant role in the pathogenesis of BrS

Stretching and challenging the boundaries of law: varieties of knowledge in biotechnologies regulation

The paper addresses the question of adaptation of existing regulatory frameworks in the face of innovation in biotechnologies, and specifically the roles played in this by various expert knowledge practices. We identify two overlapping ideal types of adaptation: first, the stretching and maintenance of a pre-existing legal framework, and second, a breaking of existing classifications and establishment of a novel regime. We approach this issue by focusing on varieties of regulatory knowledge which, contributing to and parting of political legitimacy, in principle enable the making of legally binding decisions about risks and benefits of technologies. We base the discussion around two case studies, one of animal biotechnology ethical regulation, the other of ‘advanced therapy’ medicinal product regulation, both in the context of European Union frameworks. Specifically, we explore the knowledge configurations constituting expert committees and other institutional formations of expert regulatory knowledge in their political context. We show that where sectoral and moral boundaries are challenged, different modes of regulatory knowledge beyond scientific forms – legal, procedural, moral, economic and industrial – can shape regulatory innovations either by maintenance of regimes through commensuration and stretching, or through differentiation and separation creating new frameworks. We conclude that establishing an essential techno-scientific difference between pre-existing and novel technologies does not in itself require new regulatory structures, and that the regulatory strategy that is followed will be determined by a combination of different forms of knowledge