Africa and China: Is it about time Africa introduces rules?

In this post, LSE’s Maddalena Procopio puts forward the African view on the flow of Chinese cash into the continent.

No limits for Kenya as she looks East and West #Kenya@50

LSE’s Maddalena Procopio concludes our series celebrating Kenya’s 50th anniversary of independence by examining how the country’s popularity means she can pick and choose with whom she does business

Backreaction in Acoustic Black Holes

The backreaction equations for the linearized quantum fluctuations in an acoustic black hole are given. The solution near the horizon, obtained within a dimensional reduction, indicates that acoustic black holes, unlike Schwarzschild ones, get cooler as they radiate phonons. They show remarkable analogies with near-extremal Reissner-Nordstrom black holes.Comment: 4 pages, revtex, 1 figure. revised version, published in pr

The Holographic Interpretation of Hawking Radiation

Holography gives us a tool to view the Hawking effect from a new, classical perspective. In the context of Randall-Sundrum braneworld models, we show that the basic features of four-dimensional evaporating solutions are nicely translated into classical five-dimensional language. This includes the dual bulk description of particles tunneling through the horizon.Comment: 10 pages, 1 figure, Honorable Mention in the Gravity Research Foundation Essay Competition 200

Foreground Implications in the Scientific Exploitation of CMB Data

The study of the Cosmic Microwave Background (CMB) represents one of the main sources of information on which the modern cosmology is based. The observables characterizing the CMB are: its own photon distribution function, the temperature anisotropies and its polarization. Any of these is affected by astrophysical foregrounds: spurious signals that contaminate the CMB observations. The level of contamination depends on the frequency of observation and on the region of the sky observed. Full-sky observation must face with high level of contamination, because of the strong Galactic emission in microwave bands. The first part of my thesis work focus on the CMB photon distribution function. In particular, I show the implementations and the updating phases characterizing a numerical integration code (KYPRIX) for the solution of the Kompaneets equation in cosmological context. The updating is mainly related to the formalism that must be used in order to include FORTRAN libraries necessary for the integral quantities computation and to the platform transfer of the code itself. Physical implementations were also performed: the introduction of the cosmological constant in the equations dedicated to compute the evolution of the primordial Universe; the choice of the primordial chemical abundances of H and He is now possible; the ionization fractions for the species involved in the physical processes were introduced; it was created an optional interface that links KYPRIX with codes, like RECFAST, in order to calculate a recombination history of the ionization fraction of H and He. A general gain in the performances of the code was obtained and some test on the accuracy of the code are shown. All of the physical implementations contributed to perform more realistic simulation of the spectral distortion of the CMB. Some of the highlighted case are related to the contribution of the cosmological constant for the generation of spectral distortions in late epochs (like reionization induced distortions) and to the more precise estimate of the spectral distortions that could occur just before the recombination. In the last case, a recombination history, instead of an instantaneous recombination, plays a fundamental role for precise spectral simulations. After a brief review on the past, on-going and future CMB dedicated experiments, the thesis focus on the importance of foregrounds in CMB experiment, paying attention on their description and the way they affect all the CMB osservables. In order to subtract the foregrounds from sky maps, their morphological characteristics and their spectral behavior must be know as better as possible. The Planck Sky Model (PSM) is a complete and versatile set of programs and data, to be used for the simulation or the prediction of sky emission in the frequency range of typical CMB experiments, and in particular of the upcoming Planck sky mission (the 10-1000 GHz range). It is being developed as part of the activities of Planck Working Group 2 (WG2) on component separation, and of the AD AMIS team at APC. During my second stage at APC I performed several tests on the PSM. The tests involved the latest two release of Galactic emission model, the Galactic foreground template derived by WMAP data and a clean CMB anisotropy map. For what concerns the PSM polarization prediction of the Galactic emission processes, the tests showed a clear improvement, at all the frequencies tested (the five WMAP bands), both for Q and U Stokes parameters. The last release of the PSM total intensity prediction of the Galactic processes showed results consistent with the previous ones for almost all the frequencies tested, while it still needs some tuning at 23 GHz, where synchrotron emission and free-free emission are more prominent. In order to recover the CMB signal, it is necessary to disentangle the mixed signals that a receiver collect looking at the sky. Component separation technics provide the tools to do it. In the thesis are exposed the main features of the component separation methods most used in CMB context, focusing on a particular tool: SMICA. I started using SMICA during my first stage at APC, in 2007. I used SMICA, and another filter (FFT filter) I developed, for a reprocessing of the IRIS mapset. Being already a reprocessing of the IRAS maps at 12, 25, 60 and 100 microm, the IRIS mapset still suffered from a non-optimal subtraction of the Zodical Light Emission (ZLE) residuals. The oscillations induced by these residuals affect any large scale statistical analysis of the mapset. Some preliminary operations had to be performed on the maps, like the subtraction of point sources and the masking Galactic plane and other relevant compact regions. The first phase of the reprocessing I performed consists in recovering the ZLE residuals pattern and power through SMICA, at all the IRIS frequencies. After several code runs and a continuos tuning of the maps and the code, the ZLE residuals pattern was clearly detected at 12,25 and 60 microm, while at 100 microm its contribution resulted to be totally negligible. The recovered component was then subtracted from the maps, but in some confined regions the subtraction wasn't optimal. A FFT filter was developed for this purpose and I used the filter only on localized regions, not on the full-sky maps. The dramatic improvements obtained on the IRIS maps are clearly visible just by eye. Anyway, a statistical analysis is in progress and preliminary results are showed in the thesis

Second record of Tadarida brasiliensis (I. Geoffroy St.-Hilaire, 1824) (Chiroptera, Molossidae) in Santa Cruz Province, Argentina

Although Tadarida brasiliensis is one of the most widely distributed species of bats in Argentina, it is nevertheless extremely scarce in Patagonia. We report a second record of T. brasiliensis for Santa Cruz province, which fills a gap in the geographical distribution of this species in that province and is also the third southernmost record for the species and for any molossid bat in the world.Fil: Zapata, Sonia Cristina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; ArgentinaFil: Procopio, Diego Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; ArgentinaFil: Morgenthaler, Annick. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; ArgentinaFil: Travaini, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentin

Product Lifecycle Management - Application of Patterning Methods to Gas Turbine Blades and Creation of Learning Materials

To compete in the global marketplace, companies need to embrace virtual design and manufacturing methods. Product Lifecycle Management (PLM) embodies both the workflow processes and tools to bring forth products from conception to design to fabrication to service to decommissioning, and to eventual recycling. In response to the growing demand for engineers and technicians with these critical skills, colleges and universities should introduce these virtual tools through seminars, software workshops, and computer laboratory sessions. Some of the opportunities in the PLM Center at Clemson University include short courses on PLM practices, focused software training sessions, hands-on exploration activities, and research projects. The participants across campus include creative inquiry students, capstone design classes, graduate researchers, and community outreach for K-12 students. Through these interactions, participants will gain insight into the challenges and opportunities with virtual engineering processes and software. The recent worldwide pandemic has demonstrated the need for engineers skilled in virtual design methods to enable the digital design, manufacturing, and support processes to occur in, and remote of, the workplace. Computer-aided design (CAD) and computer-aided engineering (CAE) methods embody the software tools that bring forth products from conception to design. A variety of packages are available, which allow for the progress of a product to be tracked and detailed changes to be made along the way. One complex product currently designed using CAE software is a natural gas fired turbine for electrical power generation. In these thermo-dynamic rotational systems, blade cooling using internal forced airflow is vital to withstand the operating temperatures in the combustion chamber. Accordingly, ribbed surface disruptors, known as turbulators, are placed inside the turbine blades to promote air mixing to help remove heat from the hot surfaces. Three CAE patterning features will be examined to create these turbulators with evaluation metrics based on the execution speed, accessibility, accuracy, adaptability, and relevance. The numerical case study results revealed that the face pattern method was the most suitable option with productivity time improvements of 5% in comparison to the feature and geometry pattern approaches. The feature pattern method proved to be viable for smaller modeling changes which require significant detail. However, the geometry patterning method did not show any indications of being a usable option over the others in any scenario tested. To prepare the next generation of engineers for these PLM processes and software tools, a PEER & WISE workshop module has been created for students to engage with these virtual concepts. In these four-day, 90-minute sessions, middle school students will learn about engineering design processes, fundamental engineering and science concepts, and CAD software. They will create virtual mechanical components using CAD software, while hands-on tasks will enable the creation of mechanical assemblies using discrete components to demonstrate the functionality of gears and drivelines. To assess the student experience, a survey was created and submitted for IRB approval. The pandemic created a unique situation for these prepared sessions as students could not participate right away, however, they will be offered in the future

“Oh! Dr. Kinsey!”: The Life and Work of America’s Pioneer of Sexology

Alfred Kinsey’s two most famous books Sexual Behavior in the Human Male and Sexual Behavior in the Human Female characterized the sexual behaviors of thousands of Americans. The content of these texts shocked the nation and initiated public discourse on one of the last great taboos in our society. Sex was a controversial topic of discussion in the mid-twentieth century and many researchers had flirted with sex research as it related to hygiene, or as we would refer to it today, the prevention of sexually transmitted infections. But for all the research that was available, no one really knew what people did sexually. Kinsey took sexual behavior to task. He interviewed thousands of Americans to discover and report not what people were supposed to do, but what they were actually doing. The publication of his findings and his testimony to the outdated nature of 1950s sex laws started a discourse on sex that is still alive and well today. Looking back, Kinsey’s work has not only influenced our culture, laws, and public opinion, but it set the stage for generations of sex researchers to come