Numerical Methods with Matlab : Implementations and Applications

Upper Saddle Riverxxviii,786 p: Illus,Tab ; 23c

Thermal Footprint Effect of Rooftop Urban Cooling Strategies

Simulation results indicate that urban morphology plays an important role in determining the efficacy of rooftop urban cooling strategies for improving pedestrian thermal comfort. Results suggest that a white roof has the greatest effect on near-surface air temperatures within the urban canyon when used on buildings of 1–2 stories height and almost no near-surface effect when applied to 4 story buildings. However, the near-surface effect is more substantial when complex urban morphology introduces enhanced vertical mixing. Of the cases studied the largest near-surface cooling benefit of implementing white roofs was found for the case when a taller building existed downwind from a building with a white roof. Using the Thermal Footprint Ratio it was found that by placing a tall building behind a building with a white roof in an otherwise uniform array of 2 story buildings, the cool roof would be twice as effective at reducing air temperatures at the pedestrian level. Calculations of the volumetric heat removal confirmed this result, indicating that the positioning of the tall building downwind of the modified roof would be 2.6 times as effective at cooling the pedestrian level air volume as compared to the case where all buildings were a uniform height

CyberPDX: A Camp for Broadening Participation in Cybersecurity

With society’s increasing dependence on technology infrastructure, the importance of securing the computers, networks, data, and algorithms that run our digital and physical lives is becoming critical. To equip the next generation of citizens for the challenges ahead, an effort is underway to introduce security content early in a student’s academic career. It is important that these efforts broaden participation and increase diversity in the field. While many camps and curricula focus on introducing technical content and skills related to cybersecurity, such approaches can prematurely limit how students view career opportunities in the field, potentially limiting those who ultimately pursue it. In addition, it is likely that many problems in cybersecurity can only be addressed in an interdisciplinary manner by those trained in the arts and humanities as well as in technical fields [1]. This paper describes CyberPDX, a residential summer camp that introduces cybersecurity to high school students. Key to CyberPDX is its focus on the range of societal issues that will be impacted by cybersecurity as well as its coverage of the breadth of roles that students can play to help address them. Through four learning threads taught by faculty in Computer Science, Sociology, and Film Studies, the CyberPDX curriculum spans topics from constitutional law, cyberpolicy, ethics, and filmmaking to programming, cryptography, security, and privacy in order to show students how broad cybersecurity issues are and the many ways they can participate in helping to solve them

Infinite Photovoltaic Solar Arrays: Considering Flux of Momentum and Heat Transfer

Large scale solar farms supply an increasing amount of the worlds electricity supply. However, high operation temperatures can strongly reduce efficiency and panel lifetime, negatively affecting the levelized cost of energy. In this work, the convective heat transfer coefficient for a utility-scale solar farm is studied with combined thermal and particle-image-velocimetry measurements in a scaled wind tunnel experiment. The measurements confirm the applicability of the scaled experimental setup to study large solar arrays. Further, the velocity measurements indicate the complex flow structure within the solar array, governed by wakes directed upwards due to the orientation of the solar panels

Configuration Effects on Flow Dynamics and Convective Behavior in Large-Scale Solar Arrays

Effects of height and orientation within a model solar farm are studied with respect to heat transfer characteristics and flow mechanisms. Four configurations varying height and inclination were considered in a 4 × 10 unit, heated array. Temperature data compared panel surface convection, and Particle Image Velocimetry (PIV) captured corresponding velocity data. Array height increases produced greatest overall convection, promoting higher velocities and inducing sub-panel flow. Array reversal with respect to inflow captures high-momentum flow, increasing convective cooling on lower panel surfaces

Liquid-Liquid Domains in Bilayers Detected by Wide Angle X-Ray Scattering

Wide angle x-ray scattering (WAXS) from oriented lipid multilayers is used to examine liquid-ordered (Lo)/liquid-disordered (Ld) phase coexistence in the system 1,2-dioleoyl-sn-glycero-3-phosphocholine/1,2-dipalmitoyl-sn-glycero-3-phosphocholine/cholesterol (DOPC/DPPC/Chol), which is a model for the outer leaflet of the animal cell plasma membrane. Using the method of analysis developed in the accompanying work, we find that two orientational distributions are necessary to fit the WAXS data at lower temperatures, whereas only one distribution is needed at temperatures higher than the miscibility transition temperature, Tmix = 25–35°C (for 1:1 DOPC/DPPC with 15%, 20%, 25%, and 30% Chol). We propose that the necessity for two distributions is a criterion for coexistence of Lo domains with a high Sx-ray order parameter and Ld domains with a lower order parameter. This criterion is capable of detecting coexistence of small domains or rafts that the conventional x-ray criterion of two lamellar D spacings may not. Our Tmix values tend to be slightly larger than published NMR results and microscopy results when the fluorescence probe artifact is considered. This is consistent with the sensitivity of WAXS to very short time and length scales, which makes it more capable of detecting small, short-lived domains that are likely close to Tmix

Guidelines for the use of flow cytometry and cell sorting in immunological studies

International audienceThe classical model of hematopoiesis established in the mouse postulates that lymphoid cells originate from a founder population of common lymphoid progenitors. Here, using a modeling approach in humanized mice, we showed that human lymphoid development stemmed from distinct populations of CD127(-) and CD127(+) early lymphoid progenitors (ELPs). Combining molecular analyses with in vitro and in vivo functional assays, we demonstrated that CD127(-) and CD127(+) ELPs emerged independently from lympho-mono-dendritic progenitors, responded differently to Notch1 signals, underwent divergent modes of lineage restriction, and displayed both common and specific differentiation potentials. Whereas CD127(-) ELPs comprised precursors of T cells, marginal zone B cells, and natural killer (NK) and innate lymphoid cells (ILCs), CD127(+) ELPs supported production of all NK cell, ILC, and B cell populations but lacked T potential. On the basis of these results, we propose a "two-family" model of human lymphoid development that differs from the prevailing model of hematopoiesis