The maximum efficiency of nano heat engines depends on more than temperature

Sadi Carnot's theorem regarding the maximum efficiency of heat engines is considered to be of fundamental importance in thermodynamics. This theorem famously states that the maximum efficiency depends only on the temperature of the heat baths used by the engine, but not on the specific structure of baths. Here, we show that when the heat baths are finite in size, and when the engine operates in the quantum nanoregime, a revision to this statement is required. We show that one may still achieve the Carnot efficiency, when certain conditions on the bath structure are satisfied; however if that is not the case, then the maximum achievable efficiency can reduce to a value which is strictly less than Carnot. We derive the maximum efficiency for the case when one of the baths is composed of qubits. Furthermore, we show that the maximum efficiency is determined by either the standard second law of thermodynamics, analogously to the macroscopic case, or by the non increase of the max relative entropy, which is a quantity previously associated with the single shot regime in many quantum protocols. This relative entropic quantity emerges as a consequence of additional constraints, called generalized free energies, that govern thermodynamical transitions in the nanoregime. Our findings imply that in order to maximize efficiency, further considerations in choosing bath Hamiltonians should be made, when explicitly constructing quantum heat engines in the future. This understanding of thermodynamics has implications for nanoscale engineering aiming to construct small thermal machines.Comment: Main text 14 pages. Appendix 60 pages. Accepted in Journal Quantu

Improving Palliative Care with Deep Learning

Improving the quality of end-of-life care for hospitalized patients is a priority for healthcare organizations. Studies have shown that physicians tend to over-estimate prognoses, which in combination with treatment inertia results in a mismatch between patients wishes and actual care at the end of life. We describe a method to address this problem using Deep Learning and Electronic Health Record (EHR) data, which is currently being piloted, with Institutional Review Board approval, at an academic medical center. The EHR data of admitted patients are automatically evaluated by an algorithm, which brings patients who are likely to benefit from palliative care services to the attention of the Palliative Care team. The algorithm is a Deep Neural Network trained on the EHR data from previous years, to predict all-cause 3-12 month mortality of patients as a proxy for patients that could benefit from palliative care. Our predictions enable the Palliative Care team to take a proactive approach in reaching out to such patients, rather than relying on referrals from treating physicians, or conduct time consuming chart reviews of all patients. We also present a novel interpretation technique which we use to provide explanations of the model's predictions.Comment: IEEE International Conference on Bioinformatics and Biomedicine 201

Experimental implementation of bit commitment in the noisy-storage model

Fundamental primitives such as bit commitment and oblivious transfer serve as building blocks for many other two-party protocols. Hence, the secure implementation of such primitives are important in modern cryptography. In this work, we present a bit commitment protocol which is secure as long as the attacker's quantum memory device is imperfect. The latter assumption is known as the noisy-storage model. We experimentally executed this protocol by performing measurements on polarization-entangled photon pairs. Our work includes a full security analysis, accounting for all experimental error rates and finite size effects. This demonstrates the feasibility of two-party protocols in this model using real-world quantum devices. Finally, we provide a general analysis of our bit commitment protocol for a range of experimental parameters.Comment: 21 pages (7 main text +14 appendix), 6+3 figures. New version changed author's name from Huei Ying Nelly Ng to Nelly Huei Ying Ng, for consistency with other publication

Filipino Bands Performing Hotels, Clubs, and Restaurants in Asia: Purveyors of Transnational Culture In a Global Arena

Filipino musicians can be found performing in many cities throughout Asia. They form the largest and most widely dispersed population of traveling entertainers in Asia. Their performance venues include five-star hotels, cruise liners, international chain pubs and restaurants like the Hard Rock Café and Planet Hollywood, and tiny karaoke lounges in Japan where entertaining entails singing karaoke with guests. Many Filipino musicians aspire to perform abroad because of the higher salaries and status it confers upon them. International hotels, and upscale clubs and restaurants are the mainstay for a large proportion of Filipino entertainers. Their audience ranges from tourists and business travelers to expatriates working for multinational corporations, and the local middle and upper classes. They are in demand in these venues for their ability to perform mainstream western pop and rock in the most ‘authentic’ style, including the ‘oldies’ and the latest 2 hits on the British and the American music charts. By ‘authentic,’ I mean they are able to imitate the voice quality, singing style, and dance movements of well-known singers from Britain and the United States. Filipino musicians are also in demand in Asia because they can sing and speak in many different languages and can appeal to the local audiences in the different countries where they perform. This dissertation examines the reasons behind the demand of Filipino bands performing Anglo-American mainstream popular music in Asia. It looks at the ways globalization has facilitated working transnationally, and explores the culture Filipino musicians employ in order to adapt to changing work environments. This dissertation also reveals the ways in which transnationals influence the culture of those in their own homeland and in the countries in which they are employed. This study will show that Filipino bands provide a ‘global performance,’ involving the singing of Anglo-American mainstream popular music, Asian hit songs, and international hits in other languages such as Spanish and Italian, so that they can cater to the entertainments need of their diverse audiences throughout Asia. Their performances reflect the global imaginings of their audiences in Asia, while their experiences abroad shape the global imagination of Filipinos in their homeland.Ph.D.Music: MusicologyUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/58624/1/ng_stephanie_dissertation.pd

Investigation of intramolecular [2+2] photocycloadditions : using new cycloaddition/fragmentation strategies toward medium ring-containing natural products

Thesis advisor: Marc L. SnapperIntramolecular [2+2] photocycloadditions have been studied: (i) Previous studies in our group have demonstrated that there is a regiochemical dependence of intramolecular [2+2] photocycloadditions on the solvent employed. In order to understand the generality of hydrogen bonding effects of photochemical reactions of β-hydroxyl enones, we examined the photochemical outcome of enones with both acyclic and cyclic olefin tethers. (ii) An application of an intramolecular [2+2] photocycloaddition/ fragmentation strategy to form 5-8-5 ring systems has been demonstrated toward the synthesis of the natural product cycloaraneosene.Thesis (PhD) — Boston College, 2008.Submitted to: Boston College. Graduate School of Arts and Sciences.Discipline: Chemistry

The second laws of quantum thermodynamics

10.1073/pnas.1411728112Proceedings of the National Academy of Sciences of the United States of America112113275-327