cssi/SciSciGPT-SciSciNet huggingface dataset:
Performance and Reliability Implications of Two-Dimensional Shading in Monolithic Thin-Film Photovoltaic Modules

We analyze the problem of partial shading in monolithically integrated thin-film photovoltaic (TFPV) modules, and explore how the shape and size of the shadows dictate their performance and reliability. We focus on the aspects of the shading problem unique to monolithic TFPV, arising from thin long rectangular series-connected cells, with partial shadows covering only a fraction of the cell area. Using calibrated 2-D circuit simulations, we show that due to the cell shape, the unshaded portion of partially shaded cell experiences higher heat dissipation due to redistribution of voltages and currents across the cells. We then use thermal imaging techniques to compare our results with module behavior under shade in realistic situations. We also analyze the effect of shadow size and orientation by considering several possible shading scenarios. We find that thin edge shadows can cause potentially catastrophic reverse bias damage, depending on their orientation. Finally, we show that external bypass diodes cannot protect the individual cells from shadow-induced reverse stress, but can limit the string output power loss for larger shadows.
Infinite product decomposition of orbifold mapping spaces

Physicists showed that the generating function of orbifold elliptic genera of symmetric orbifolds can be written as an infinite product. We show that there exists a geometric factorization on space level behind this infinite product formula, and we do this in the much more general framework of orbifold mapping spaces, where factors in the infinite product correspond to finite connected coverings of domain spaces whose fundamental groups are not necessarily abelian. From this formula, a concept of geometric Hecke operators for functors emerges. This is a nonabelian geometric generalization of the usual Hecke operators. We show that these generalized Hecke operators indeed satisfy the identity of the usual Hecke operators for the case of 2‐dimensional tori. 55N20, 55N91
Spitzer Observations of High-Redshift QSOs

We have observed 13 z ≥ 4.5 QSOs using the Multiband Imaging Photometer for Spitzer, nine of which were also observed with the Infrared Array Camera. The observations probe rest wavelengths ~0.6-4.3 μm, bracketing the local minimum in QSO spectral energy distributions (SEDs) between strong optical emission associated directly with accretion processes and thermal emission from hot dust heated by the central engine. The new Spitzer photometry combined with existing measurements at other wavelengths shows that the SEDs of high-redshift QSOs (z ≥ 4.5) do not differ significantly from typical QSOs of similar luminosity at lower redshifts (z ≾ 2). This behavior supports other indications that all the emission components and physical structures that characterize QSO activity can be established by z = 6.4. The similarity also suggests that some QSOs at high redshift will be very difficult to identify because they are viewed along dust-obscured sight lines.
Massless BPS-saturated states on the two-torus moduli sub-space of heterotic string

Abstract Within a four-dimensional, toroidally compactified heterotic string, we identify (quantized) charge vectors of electrically charged BPS-saturated states (along with the tower of SL (2, Z ) related dyonic states), which preserve 1 2 of N = 4 supersymmetry and become massless along the hyper-surfaces of enhanced gauge symmetry of the two-torus moduli sub-space. In addition, we identify charge vectors of the dyonic BPS-saturated states (along with the tower of SL (2, Z ) related states), which preserve 1 4 of N = 4 supersymmetry, and become massless at two points with the maximal gauge symmetry enhancement.
Coupling Translocation with Nucleic Acid Unwinding by NS3 Helicase

NS3 helicase from hepatitis C virus (HCV) uses the free energy from ATP hydrolysis to translocate along single stranded DNA (ssDNA) or RNA, unwind double-stranded (ds) duplex, or displace proteins along the track. In this work, we present a semi-quantitative model for translocation and unwinding activities of monomeric NS3 helicase. The model is based on structural, biochemical and single molecule measurements of the helicase. First, we have assumed that NS3 helicase walks unidirectionally by alternately moving its two translocase domains forward one nucleotide (nt) at a time, as that being suggested for a similar helicase PcrA. Second, in our model NS3 helicase displays diffusive character upon ATP binding (before helicase dissociation), due to weak affinity of the helicase to the ssDNA. The helicase diffusion leads to occasional backward steps and increases displacement fluctuations that are supposedly detectable from single molecule experiments. Further, our model suggests that NS3 helicase interacts with the duplex at the ss-ds junction such that (i) the helicase can actively unwind the duplex by reducing free energy of base pairing /stacking at the duplex end; (ii) the helicase can be stabilized at the junction by its favorable association with the duplex backbone. By fitting with NS3 unwinding data from single molecule optical-tweezer measurements, our model explains sequence dependences of the unwinding velocity, efficiency, and helicase dissociation rate. In particular, based on the experimental data, we have quantified how active the NS3 helicase is in its unwinding, and estimated how fast the helicase diffuses in its ATP bound state. The generic features of coupling ssDNA/RNA translocation with duplex unwinding presented in our NS3 helicase model may apply as well to other similar systems.
Safety considerations for IMRT: executive summary.

This report on intensity-modulated radiation therapy(IMRT) is part of a series of white papers addressing patient safety commissioned by the American Society for RadiationOncology’s (ASTRO) Target Safely Campaign. The document has been approved by the ASTRO Board of Directors, endorsed by the American Association of Physicists in Medicine (AAPM) and American Association of MedicalDosimetrists (AAMD), and reviewed and accepted by the American College of Radiology’s Commission on RadiationOncology. This report is related to other reports of the ASTRO white paper series on patient safety which are still in preparation, and when appropriate it defers to guidance that will be published by those groups in future white papers. This document takes advantage of the large body of work on quality assurance and quality control principles within radiationoncology whenever possible. IMRT provides increased capability to conform isodose distributions to the shape of the target(s), thereby reducing dose to some adjacent critical structures. This promise of IMRT is one of the reasons for its widespread use. However, the promise of IMRT is counterbalanced by the complexity of the IMRT planning and delivery processes, and the associated risks, some of which have been demonstrated by the New York Times reports on serious accidents involving both IMRT and other radiation treatment modalities. This report provides an opportunity to broadly address safe delivery of IMRT, with a primary focus on recommendations for human error prevention and methods to reduce the occurrence of errors or machine malfunctions that can lead to catastrophic failures or errors.
Rhodium-catalyzed asymmetric cyclization/hydroboration of 1,6-enynes.

Reaction of enyne 1 with catecholborane catalyzed by a 1:1 mixture of [Rh(COD)2]+SbF6- and (S)-BINAP (5 mol %) followed by Pd-catalyzed arylation with p-IC6H4CF3 gave benzylidenecyclopentane 5 in 65% yield with 88% ee. Rhodium-catalyzed asymmetric cyclization/hydroboration followed either by Pd-catalyzed arylation or by oxidation was applied to the synthesis of a number of chiral, nonracemic carbocycles and heterocycles.
Chemical Surface Modification of Poly(ethylene terephthalate)

Reactions of semicrystalline poly(ethylene terephthalate) (PET) film with ester-selective reagents at the film−solution interface can be controlled to produce modified film samples containing a thin (less than ∼ 40 A) surface layer of the reagent-induced functionality. Hydrolysis of PET yields a surface mixture of alcohol and carboxylic acid groups. Reduction with lithium aluminum hydride and transesterification with ethylene glycol (glycolysis) both produce surfaces with alcohol functionality (PET−OHR and PET−OHG, respectively). Each of these modification reactions involves chain cleavage and can lead to significant sample degradation (reactive dissolution); for each modification reaction, conditions were optimized to maximize conversion and minimize degradation. The reactivity of surface alcohols (PET−OH) was assessed for samples prepared by both reduction and glycolysis, and a comparative analysis was made: the presence of benzylic alcohols in reduced samples and their absence in glycolyzed samples as...
THE LIMITING EFFECTS OF DUST IN BROWN DWARF MODEL ATMOSPHERES

We present opacity sampling model atmospheres, synthetic spectra, and colors for brown dwarfs and very low mass stars in the following two limiting cases of dust grain formation: (1) Inefficient gravitational settling (i.e., the dust is distributed according to the chemical equilibrium predictions) and (2) efficient gravitational settling (i.e., the dust forms and depletes refractory elements from the gas, but their opacity does not affect the thermal structure). The models include the formation of over 600 gas-phase species and 1000 liquids and crystals and the opacities of 30 different types of grains including corundum (Al2O3), the magnesium aluminum spinel MgAl2O4, iron, enstatite (MgSiO3), forsterite (Mg2SiO4), amorphous carbon, SiC, and a number of calcium silicates. The models extend from the beginning of the grain formation regime well into the condensation regime of water ice (Teff = 3000-100 K) and encompass the range of log g = 2.5-6.0 at solar metallicity. We find that silicate dust grains can form abundantly in the outer atmospheric layers of red and brown dwarfs with a spectral type later than M8. The greenhouse effects of dust opacities provide a natural explanation for the peculiarly red spectroscopic distribution of the latest M dwarfs and young brown dwarfs. The grainless (cond) models, on the other hand, correspond closely to methane brown dwarfs such as Gliese 229B. We also discover that the λλ5891, 5897 Na I D and λλ7687, 7701 K I resonance doublets play a critical role in T dwarfs, in which their red wings define the pseudocontinuum from the I to the Z bandpass.
Why the Poor Vote in India: “If I Don’t Vote, I Am Dead to the State”

Our empirical research in India shows the poor and the non-poor report different motivations for voting. The poor say they turn out to vote because it is their right while the non-poor report they vote because they expect material benefits from the state, some kind of access to the state, or because voting is their civic duty. We attribute the different reasons for voting offered by the poor and non-poor to their different relationships with the state. Unlike the non-poor, the poor mostly report the state mistreats or ignores them yet makes every effort on Election Day to ensure they are treated equally. The recognition the state grants to the poor on Election Day leads them to view voting as a valued right, one that gives them a rare chance to associate with those who govern as equals. The evidence in this paper was drawn from 30 focus groups with a total of 445 participants and 150 open-ended interviews conducted across Maharashtra, Tamil Nadu, and Uttar Pradesh and three state and national-level surveys.
Measurement of the electronic compressibility of bilayer graphene

We present measurements of the electronic compressibility, K, of bilayer graphene in both zero and finite magnetic fields up to 14 T, and as a function of both the carrier density and electric field perpendicular to the graphene sheet. The low-energy hyperbolic band structure of bilayer graphene is clearly revealed in the data, as well as a sizable asymmetry between the conduction and valence bands. A sharp increase in K^(−1) near zero density is observed for increasing electric field strength, signaling the controlled opening of a gap between these bands. At high magnetic fields, broad Landau level (LL) oscillations are observed, directly revealing the doubled degeneracy of the lowest LL and allowing for a determination of the disorder broadening of the levels.
Probabilistic Quantitative Precipitation Estimation in Complex Terrain

Abstract This paper describes a flexible method to generate ensemble gridded fields of precipitation in complex terrain. The method is based on locally weighted regression, in which spatial attributes from station locations are used as explanatory variables to predict spatial variability in precipitation. For each time step, regression models are used to estimate the conditional cumulative distribution function (cdf) of precipitation at each grid cell (conditional on daily precipitation totals from a sparse station network), and ensembles are generated by using realizations from correlated random fields to extract values from the gridded precipitation cdfs. Daily high-resolution precipitation ensembles are generated for a 300 km × 300 km section of western Colorado (dx = 2 km) for the period 1980–2003. The ensemble precipitation grids reproduce the climatological precipitation gradients and observed spatial correlation structure. Probabilistic verification shows that the precipitation estimates are reliab...
Synthesis and chloride binding properties of a Lewis acidic tetratin(IV) calixarene

The Lewis acidic calix[4]arene with four covalently attached diphenylmonochlorotin(IV) centers was synthesized and its stannate complex with chloride was studied by 119Sn NMR.
Can MEMS Take Advantage of Advances in Semiconductor Lithography

This PDF file contains the editorial “Editorial: Can MEMS Take Advantage of Advances in Semiconductor Lithography?” for JM3 Vol. 9 Issue 01
Atmospheric noble gas signatures in deep Michigan Basin brines as indicators of a past thermal event

Abstract Atmospheric noble gases (e.g., 22 Ne, 36 Ar, 84 Kr, 130 Xe) in crustal fluids are only sensitive to subsurface physical processes. In particular, depletion of atmospheric noble gases in groundwater due to boiling and steam separation is indicative of the occurrence of a thermal event and can thus be used to trace the thermal history of stable tectonic regions. We present noble gas concentrations of 38 deep brines (~ 0.5–3.6 km) from the Michigan Basin. The atmospheric noble gas component shows a strong depletion pattern with respect to air saturated water. Depletion of lighter gases ( 22 Ne and 36 Ar) is stronger compared to the heavier ones ( 84 Kr and 130 Xe). To understand the mechanisms responsible for this overall atmospheric noble gas depletion, phase interaction models were tested. We show that this atmospheric noble gas depletion pattern is best explained by a model involving subsurface boiling and steam separation, and thus, consistent with the occurrence of a past thermal event of mantle origin as previously indicated by both high 4 He/heat flux ratios and the presence of primordial mantle He and Ne signatures in the basin. Such a conceptual model is also consistent with the presence of past elevated temperatures in the Michigan Basin (e.g., ~ 80–260 °C) at shallow depths as suggested by previous thermal studies in the basin. We suggest that recent reactivation of the ancient mid-continent rift system underneath the Michigan Basin is likely responsible for the release of both heat and mantle noble gases into the basin via deep-seated faults and fracture zones. Relative enrichment of atmospheric Kr and Xe with respect to Ar is also observed, and is interpreted as reflecting the addition of sedimentary Kr and Xe from associated hydrocarbons, following the hydrothermal event. This study pioneers the use of atmospheric noble gases in subsurface fluids to trace the thermal history of stable tectonic regions.
Management and outcomes of primary coloduodenal fistulas.

Primary coloduodenal fistula (CDF) is a rare entity. We review our experience with the management and outcomes of CDF. This is a retrospective review from 1975 to 2005 of patients with primary CDF. Patients were followed through clinic visits and mail correspondence with a mean (±SE) follow-up of 56 ± 14 months. Twenty-two patients were diagnosed at a mean age of 54 ± 3 years with primary CDF: benign (n = 14) or malignant (n = 8). Benign CDF were due to Crohn's disease (n = 9) or peptic ulcer disease (n = 5); malignant CDF was primarily due to colon cancer (n = 7) plus 1 patient with lymphoma. Indications for operative intervention included intractable symptoms (n = 15), gastrointestinal bleeding (n = 14), and to rule out malignancy (n = 8). Complete resection of malignant CDF with negative margins was achieved in half of patients after en bloc resection. Palliative bypass was performed in those patients with unresectable disease. Thirteen patients with benign CDF had resection of the fistula—2 of these patients required a duodenal bypass. There were no perioperative deaths, and the morbidity rate was 38%. Median survival for patients with malignant CDF was 20 months (range 1–150 months). Two patients with malignant CDF had >5-year survival. All patients with benign CDF who underwent fistula resection had resolution of fistula-related symptoms with one recurrence. Benign CDF is amenable to operative therapy with resolution of symptoms and a low recurrence rate. Complete resection of malignant CDF can impart survival benefit.
Applying advanced surface analysis techniques to small defect characterization on EUV ML blanks

Developing capability in detection, review, and characterization of sub-100 nm defects on EUV multilayer blanks has become critical in enabling the defect root-cause analysis and the eventual elimination of all defects. We have developed a functional method to apply surface analytical techniques (AES, SEM, EDX, and AFM) to characterize individual defects on EUV multilayer blanks. Optical defect inspection is first done with the Lasertec M1350 which does defect scanning, mapping, image review, and fiducial marking. A defect map is then used to navigate defect search on other tools. Those surface analysis techniques and tools are complementary in uncovering defect elemental as well as morphological data. Our experimental results demonstrated that Auger spectroscopy provides the best lateral resolution and surface-specific elemental information. It is capable of detecting and analyzing compositions of sub-100nm defects, either embedded in or on the surface of the multilayer blanks. The composition defect data serve as the crucial “fingerprints” of the blank fabrication process. SEM provides the morphological shape and size data, which are also critical in the identification of defects. AFM gives the precise defect height data, important for defect smoothing and printability analysis. The EDX/FIB tool provides capability of cross sections of embedded defects.
STELLAR-MASS BLACK HOLES IN THE SOLAR NEIGHBORHOOD

We search for nearby, isolated, accreting, "stellar-mass" (3-100 M☉) black holes. Models suggest a synchrotron spectrum in visible wavelengths and some emission in X-ray wavelengths. Of 3.7 million objects in the Sloan Digital Sky Survey Early Data Release, about 150,000 objects have colors and properties consistent with such a spectrum, and 87 of these objects are X-ray sources from the ROSAT All-Sky Survey. Thirty-two of these have been confirmed not to be black holes using optical spectra. We give the positions and colors of these 55 black hole candidates and quantitatively rank them on their likelihood to be black holes. We discuss uncertainties in the expected number of sources and the contribution of black holes to local dark matter.
Elegant propositions of the boundary-value problem☆

Abstract The fundamental ellipse of the two-body, two-point orbital boundary-value problem of orbital mechanics is introduced and its key role in the basic geometry of this famous problem is developed. Analytic formulas for the orbital parameters of conjugate orbits are derived together with further interesting properties of the mean point-locus.
Fiber Fracture in Continuous Fiber Ceramic Composites: Concepts and Observations

The knowledge of fiber behavior in CMCs is rather modest, and models tend to be based on concepts that are less than complete. The present paper addresses several aspects of this problem. Fundamental assumptions for tensile strength models are discussed, and some basic modeling approaches are described. The effects of fiber fracture on the quasi-static stress-strain behavior are described (from physical measurements), and some models of that behavior discussed. Finally, a summary of the state of affairs for this subject will be attempted, and the needs for further investigation, especially to support improved modeling, will be presented.
Numerical Simulation of Wing-Fuselage Aerodynamic Interaction

Numerical solutions of the mass-averaged Navier-Stokes equations were accomplished for a wing-body configuration at a nominal Mach number of 6 and a Reynolds number of 15 x 10. The computations were performed on a CRAY-1 computer utilizing a grid consisting of 56,730 points. The wing-fuselage configuration is comprised of a tangent-ogive forebody and highly swept wedge delta wing. The present results, using a branchcut mesh system, were verified by comparing with experimental measurements. An improvement in numerical resolution over the previous solution, utilizing a wraparound grid distribution, is clearly demonstrated. The flowfield structure is delineated by identifying the shock wave system and the cross-flow velocity field.
SU(3) string tension and the presence of vortices

Abstract Lattice simulations are presented showing the expectation of the fluctuation of the Wilson loop solely by elements of the center to fully reproduce the SU(3) heavy quark potential. The results are stable under smoothing, and point to thick vortices as being responsible for the full SU(3) tension. An analytic result on the necessary presence of thick vortices for confinement at weak coupling is also presented.
Developments in high-precision gamma-ray burst source studies

The source location data analyzed by the first and second interplanetary gamma ray burst spacecraft networks are reviewed. The possibilities of additional networks and of related studies in other disciplines, and the prospects for real time optical transient observations and for the definition of gamma ray burst sources by optical transient astronomy are also reviewed.
WISE BROWN DWARF BINARIES: THE DISCOVERY OF A T5+T5 AND A T8.5+T9 SYSTEM ∗

The multiplicity properties of brown dwarfs are critical empirical constraints for formation theories, while multiples themselves provide unique opportunities to test evolutionary and atmospheric models and examine empirical trends. Studies using high-resolution imaging cannot only uncover faint companions, but they can also be used to determine dynamical masses through long-term monitoring of binary systems. We have begun a search for the coolest brown dwarfs using preliminary processing of data from the Wide-field Infrared Survey Explorer and have confirmed many of the candidates as late-type T dwarfs. In order to search for companions to these objects, we are conducting observations using the Laser Guide Star Adaptive Optics system on Keck II. Here we present the first results of that search, including a T5 binary with nearly equal mass components and a faint companion to a T8.5 dwarf with an estimated spectral type of T9.
Smooth actions of Lie groups and Lie algebras on manifolds

Necessary or sufficient conditions are presented for the existence of various types of actions of Lie groups and Lie algebras on manifolds.
Modeling strategies for unsteady turbulent flows in the lower plenum of the VHTR

Abstract Validation simulations are presented for turbulent flow in a staggered tube bank, geometry similar to the lower plenum of a gas-cooled high temperature reactor. Steady 2D RANS results are compared to unsteady 2D RANS results and experiment. The unsteady calculations account for the fact that nonturbulent fluctuations (due to vortex-shedding) are present in the flow. The unsteady computations are shown to predict the mean variables and the total shear stress quite well. Previous workers’ results indicate that 3D simulations are needed to obtain reasonable agreement; present results indicate 2D is sufficient. Best practices are based on requirements for the ASME Journal of Fluids Engineering.
Reusable Launch Vehicle Control in Multiple Time Scale Sliding Modes

A reusable launch vehicle control problem during ascent is addressed via multiple-time scaled continuous sliding mode control. The proposed sliding mode controller utilizes a two-loop structure and provides robust, de-coupled tracking of both orientation angle command profiles and angular rate command profiles in the presence of bounded external disturbances and plant uncertainties. Sliding mode control causes the angular rate and orientation angle tracking error dynamics to be constrained to linear, de-coupled, homogeneous, and vector valued differential equations with desired eigenvalues placement. Overall stability of a two-loop control system is addressed. An optimal control allocation algorithm is designed that allocates torque commands into end-effector deflection commands, which are executed by the actuators. The dual-time scale sliding mode controller was designed for the X-33 technology demonstration sub-orbital launch vehicle in the launch mode. Simulation results show that the designed controller provides robust, accurate, de-coupled tracking of the orientation angle command profiles in presence of external disturbances and vehicle inertia uncertainties. This is a significant advancement in performance over that achieved with linear, gain scheduled control systems currently being used for launch vehicles.
Low-spin identical bands in neighboring odd-A and even-even nuclei

A comprehensive study of odd-A rotational bands in normally deformed rare-earth nuclei indicates that a large number of seniority-one configurations (21% for odd-Z nuclei) at low spin have moments of inertia nearly identical to that of the seniority-zero configuration of the neighboring even-even nucleus with one less nucleon. It is difficult to reconcile these results with conventional models of nuclear pair correlation, which predict variations of about 15% in the moments of inertia of configurations differing by one unit in seniority.
The Thermal Evolution of Ultramagnetized Neutron Stars

Using recently calculated analytic and numerical models for the thermal structure of ultramagnetized neutron stars, we estimate the effects that ultrastrong magnetic fields B≥1014 G have on the thermal evolution of a neutron star. Understanding this evolution is necessary to interpret models that invoke "magnetars" to account for soft gamma-ray emission from some repeating sources.
Generative Growth Model for Power Grids

The inherent structure of the power grid deeply influences its secure functioning and stability. As power grids move towards becoming 'smarter' with increased demand response and decentralized control, the topological aspects of the grid have become even more important. Understanding the topology can thus lead to better strategies to control the smart grid as well as enable rapid identification and prevention of risks such as blackouts. This paper focuses on modeling and analyzing basic similarities in network structure of large power grids across America and Europe. A simple but accurate model of the power grid can help generate real-sized test cases to evaluate new grid technologies as well as aid in tractable theoretical analysis of the grid structure.
Developing a Repeated Multi-agent Constant-Sum Game Algorithm Using Human Computation

In repeated multi-agent constant-sum games, each player's objective is to maximize control over a finite set of resources. We introduce Tens potter, an easy-to-use publicly-available game designed to allow human players to compete as agents against a machine algorithm. The algorithm learns play strategies from humans, reduces them to nine basic strategies, and uses this knowledge to build and adapt its collusion strategy. We use a tournament format to test our algorithm against human players as well as against other established multi-agent algorithms taken from the literature. Through these tournament experiments, we demonstrate how learning techniques adapted using human computation -- information obtained from both human and machine inputs -- can contribute to the development of an algorithm able to defeat two well-established multi-agent machine algorithms in tournament play.
The equivariant Orlik–Solomon algebra

Abstract Given a real hyperplane arrangement A , the complement M ( A ) of the complexification of A admits an action of the group Z 2 by complex conjugation. We define the equivariant Orlik–Solomon algebra of A to be the Z 2 -equivariant cohomology ring of M ( A ) with coefficients in the field F 2 . We give a combinatorial presentation of this ring, and interpret it as a deformation of the ordinary Orlik–Solomon algebra into the Varchenko–Gelfand ring of locally constant F 2 -valued functions on the complement M R ( A ) of A in R n . We also show that the Z 2 -equivariant homotopy type of M ( A ) is determined by the oriented matroid of A . As an application, we give two examples of pairs of arrangements A and A ′ such that M ( A ) and M ( A ′ ) have the same nonequivariant homotopy type, but are distinguished by the equivariant Orlik–Solomon algebra.
Aryl methyl sulfides via SNAr using DMSO as the source of the thiomethyl moiety

Abstract A unique synthesis of aryl methyl sulfides is reported proceeding via reduction of dimethylsulfoxide to dimethylsulfide at elevated temperature in the presence of Hunig’s base followed by nucleophilic aromatic substitution and demethylation. Activated aryl fluorides, chlorides, and nitrobenzenes are suitable substrates with 13 examples provided. Dimethylsulfoxide serves as a simple and inexpensive formal source of the thiomethyl moiety.
Banking with nominal deposits and inside money

Abstract Bank runs in the literature take the form of withdrawals of demand deposits payable in real goods, which deplete a fixed reserve of goods in the banking system. That framework describes traditional bank runs based on currency withdrawals as occurred historically in the US and more recently in developing countries. However, in a modern banking system, large withdrawals typically take the form of electronic payments of inside money, with no analog of a depletion of a scarce reserve from the banking system. In a new framework of nominal demand deposits repayable in inside money, pure liquidity-driven bank runs do not occur. If there were excessive early withdrawals, nominal deposits would hedge the bank and flexible monetary prices in the goods market would limit real consumption. The maturity mismatch of short term liabilities and long term assets is not sufficient for multiple equilibria bank runs without other frictions. A key role of the bank is to ensure optimal real liquidity, which allows markets to optimally distribute consumption goods through the price mechanism.
Optimal life insurance, consumption and portfolio: A dynamic programming approach

A continuous-time model of optimal life insurance, consumption and portfolio is examined by dynamic programming technique. The Hamilton-Jacobi- Bellman (HJB in short) equation with the absorbing boundary condition is derived. Then explicit solutions for constant relative risk aversion (CRRA in short) utilities with subsistence levels are obtained. Asymptotic analysis is used to analyze the model.
Stability of the double gyroid phase to nanoparticle polydispersity in polymer-tethered nanosphere systems

Recent simulations predict that aggregating nanospheres functionalized with polymer “tethers” can self-assemble to form the double gyroid (DG) phase seen in block copolymer and surfactant systems. Within the struts of the gyroid, the nanoparticles pack in icosahedral motifs, stabilizing the gyroid phase in a small region of the phase diagram. Here, we study the impact of nanoparticle size polydispersity on the stability of the double gyroid phase. We show for low amounts of polydispersity the energy of the double gyroid phase is lowered. A large amount of polydispersity raises the energy of the system, disrupts the icosahedral packing, and eventually destabilizes the gyroid. Our results show that the DG forms readily up to 10% polydispersity. Considering polydispersity as high as 30%, our results suggest no terminal polydispersity for the DG, but that higher polydispersities may kinetically inhibit the formation of phase. The inclusion of a small population of either smaller or larger nanospheres encourages low-energy icosahedral clusters and increases the gyroid stability while facilitating its formation. We also introduce a new measure for determining the volume of a component in a microphase-separated system based on the Voronoi tessellation.
Liquidity and Liquidation

The manager of a firm that is selling an illiquid asset has discretion as to the sale price: if he chooses a high (low) selling price, early sale is unlikely (likely). If the manager has the option to default on the debt that is collateralized by the illiquid asset, the optimal selling price depends on whether the manager acts in the interests of owners or creditors. We model the former case. In equilibrium the owner will always offer the illiquid asset for sale at a strictly higher price than he paid, and will default if he fails to sell. As a result, upon successful sales the illiquid asset changes hands at successively higher prices. We also consider a generalization of the model which permits sellers to finance sales using either debt or preferred stock, or both. This allows derivation of an optimal capital structure.
Intramolecular [1 + 2] and [3 + 2] Cycloaddition Reactions of Cyclopropenone Ketals

The first intramolecular thermal reactions of cyclopropenone ketals are reported and the work examined substrates tethered to an electron-deficient olefin bearing a single electron-withdrawing substituent. Whereas the intermolecular variants of the reactions provide only the products of an endo-selective [1 + 2] cycloaddition or a carbonyl addition reaction of a thermally generated π-delocalized singlet vinylcarbene, the intramolecular variants provide either [1 + 2] or [3 + 2] cycloadducts in reactions that depend on the reaction conditions, the alkene-activating substituent, and the nature of the tethering. In addition to providing key mechanistic insights into the thermal [3 + 2] cycloaddition reaction for such substrates, they were also found to proceed under conditions that reflect the ease and regioselectivity of the cyclopropenone ketal cleavage for π-delocalized singlet vinylcarbene generation. The most effective combination of structural features that impact the reactivity was observed with subst...
A finitely presented group with unbounded dead-end depth

The dead-end depth of an element g of a group G, with respect to a generating set A, is the distance from g to the complement of the radius d A (1, g) closed ball, in the word metric d A defined with respect to A. We exhibit a finitely presented group G with a finite generating set with respect to which there is no upper bound on the dead-end depth of elements.
Prolonged hemodynamic stability during arteriovenous carbon dioxide removal for severe respiratory failure

Abstract Objective: The effects of prolonged arteriovenous carbon dioxide removal on hemodynamics during severe respiratory failure were evaluated in adult sheep with severe smoke inhalation injury. Methods: Adult female sheep ( n = 6, 33.8 ± 5.2 kg) were subjected to intratracheal cotton severe smoke insufflation to a mean carboxyhemoglobin level of 83% ± 3%. Twenty-four hours after injury, a low-resistance 2.5 m 2 membrane oxygenator was placed in a carotid-to-jugular pumpless arteriovenous shunt at unrestricted flow to allow complete carbon dioxide removal and reductions in ventilator support. Animals remained conscious, and heart rate, cardiac output, mean arterial pressure, and pulmonary arterial pressure were measured at baseline, after injury, and daily during support with the arteriovenous carbon dioxide removal circuit for 7 days. Results: All animals survived the study period. Carbon dioxide removal ranged from 99.7 ± 13.7 to 152.2 ± 16.2 ml/min, and five (83%) of the six animals were successfully weaned from the ventilator before day 7. During full support with the arteriovenous carbon dioxide removal circuit, shunt flow ranged from 1.24 ± 0.06 to 1.43 ± 0.08 L/min and accounted for 20.1% ± 1.4% to 25.9% ± 2.4% of cardiac output. No statistically significant changes in heart rate, cardiac output, mean arterial pressure, or pulmonary artery pressure were demonstrated over the study course despite the extracorporeal shunt flow. Conclusions: Arteriovenous carbon dioxide removal as a simplified means of extracorporeal gas exchange support is relatively safe without adverse hemodynamic effects or complications. (J Thorac Cardiovasc Surg 1997;114:1107-14)
Discrete approximations to optimal trajectories using direct transcription and nonlinear programming

A recently developed method for solving optimal trajectory problems uses a piecewise-polynomial representation of the state and control variables, enforces the equations of motion via a collocation procedure, and thus approximates the original calculus-of-variations problem with a nonlinear-programming problem, which is solved numerically. This paper identifies this method as a direct transcription method and proceeds to investigate the relationship between the original optimal-control problem and the nonlinear-programming problem. The discretized adjoint equation of the collocation method is found to have deficient accuracy, and an alternate scheme which discretizes the equations of motion using an explicit Runge-Kutta parallel-shooting approach is developed. Both methods are applied to finite-thrust spacecraft trajectory problems, including a low-thrust escape spiral, a three-burn rendezvous, and a low-thrust transfer to the moon.
Experimental preparation and measurement of quantum states of motion of a trapped atom

Abstract We report the creation and full determination of several quantum states of motion of a 9Be+ ion bound in a RF (Paul) trap. The states are coherently prepared from an ion which has been initially laser cooled to the zero-point of motion. We create states having both classical and non-classical character including thermal, number, coherent, squeezed, and ‚Schrodinger cat‘ states. The motional quantum state is fully reconstructed using two novel schemes that determine the density matrix in the number state basis or the Wigner function. Our techniques allow well controlled experiments decoherence and related phenomena on the quantum-classical borderline.
What can we learn about battery materials from their magnetic properties

Electrode materials for Li-ion batteries should combine electronic and ionic conductivity, structural integrity, and safe operation over thousands of lithium insertion and removal cycles. The quest for higher energy density calls for better understanding of the redox processes, charge and mass transfer occurring upon battery operation. A number of techniques have been used to characterize long-range and local structure, electronic and ionic transport in bulk of active materials and at interfaces, with an ongoing move toward in situ techniques determining the changes as they happen. This paper reviews several representative examples of using magnetic properties toward understanding of Li-ion battery materials with a notion to highlight the intimate connection between the magnetism, electronic and atomic structure of solids, and to demonstrate how this connection has been used to reveal the fine electronic and atomic details related to the electrochemical performance of the battery materials.
Cash versus direct food relief

Abstract The usual method of providing relief to a famine region is to import food and distribute it to the needy (direct food relief). If there are markets for food in the region, however, a relief agency could just as easily distribute money to the needy and let them purchase food in the market (cash relief). This alternative has been much discussed in the famine literature recently. The purpose of this paper is to clarify the conditions under which cash relief will be more or less effective than direct food relief by analyzing the relative effectiveness of the two policies in a formal model.
Efficient parallel algorithms can be made robust

The efficient parallel algorithms proposed for many fundamental problems, such as list ranking, integer sorting and computing preorder numberings on trees, are very sensitive to processor failures. The requirement of efficiency (commonly formalized using Parallel-time × Processors as a cost measure) has led to the design of highly tuned PRAM algorithms which, given the additional constraint of simple processor failures, unfortunately become inefficient or even incorrect. We propose a new notion of robustness, that combines efficiency with fault tolerance. For the common case of fail-stop errors, we develop a general and easy to implement technique to make robust many efficient parallel algorithms, e.g., algorithms for all the problems listed above. More specifically, for any dynamic pattern of fail-stop errors on a CRCW PRAM with at least one surviving, processor, our method increases the original algorithm cost by at most a log2 multiplicative factor. Our technique is based on a robust solution of the problem of Write-All, i.e., using P processors, write 1's in all locations of an N-sized array. In addition we show that at least a log/log log multiplicative overhead will be incurred for certain patterns of failures by any algorithm that implements robust solutions to Write-All with P = N. However, by exploiting parallel slackness, we obtain an optimal cost algorithm when P ≤ N/log2N-logNloglogN.
Seismic evidence for a rapidly varying compositional anomaly at the base of the Earth’s mantle beneath the Indian Ocean

Abstract Seismic observations recorded by an African seismic array reveal a low velocity anomaly at the base of the mantle beneath the Indian Ocean, with steeply dipping edges, rapidly varying thicknesses and geometries, and anomalously low shear wave velocities decreasing from −2% at 200 km above the core–mantle boundary to −9% to −12% at the core–mantle boundary (relative to the preliminary reference Earth model). These characteristics unambiguously suggest that it is a compositional anomaly and its velocity structures can be well explained by partial melt driven by a compositional change produced early in the Earth’s history. This chemical anomaly geographically coincides with the DUPAL geochemical anomaly observed in island volcanoes around the Indian Ocean and may provide an explanation for its distinctive isotope characteristics observed at the Earth’s surface.
Combining Gold(I)/Gold(III) Catalysis and C ? H Functionalization: A Formal Intramolecular [3+2] Annulation towards Tricyclic Indolines and Mechanistic Studies

Tricyclic indolines are obtained by the present new intramolecular [3+2] annulation between a vinyl group and an aniline moiety using Selectfluor as oxidant.
Laser inhibited diffusion in rhodamine-ethanol solutions

The diffusion of rhodamine-6G dye in ethanol is observed to be inhibited by optical pumping by a cadmium laser. The diffusion process is observed as a function of the solution temperature. The relative difference in diffusion coefficients with and without optical pumping is calculated. The effect is interpreted as being due to a stronger solvent-dye interaction in the first excited singlet state of rhodamine-6G.
SAPS: A new categorization for sub‐auroral electric fields

Sub-auroral electric fields play critical roles in energizing and transporting ring current ions, as well as convecting thermal plasma in the inner magnetosphere and in the mid- to low-latitude ionosphere. A number of terms have been employed to describe the sub-auroral electric fields and many of these are specifically associated with processes established through their prior use in the literature. The continued use of descriptive terms such as penetration electric fields, polarization jets, and sub-auroral ion drifts could lead to misunderstanding, especially when comparing the broad/narrow, persistent/transient regions of sub-auroral electric field and plasma flow. An inclusive name for these phenomena is sub-auroral polarization streams (SAPS).
Cooperation without coordination: signaling, types and tacit collusion in laboratory oligopolies

We study the effects of price signaling activity and underlying propensities to cooperate on tacit collusion in posted offer markets. The primary experiment consists of an extensively repeated baseline sequence and a ‘forecast’ sequence that adds to the baseline a forecasting game that allows identification of signaling intentions. Forecast sequence results indicate that signaling intentions differ considerably from those that are counted under a standard signal measure based on previous period prices. Nevertheless, we find essentially no correlation between either measure of signal volumes and collusive efficiency. A second experiment demonstrates that underlying seller propensities to cooperate more clearly affect collusiveness.
Is mediastinal irradiation necessary for stage I testicular seminoma

This study is a review of 39 patients with testicular seminoma, Stage I, treated at the Department of Radiation Oncology, James Graham Brown Cancer Center from 1959 to 1978. The age of the patients ranged from 16 to 70 years with a median of 37. Thirty-two (82%) patients presented with swelling or mass in the testis, four patients with pain, and three patients had seminoma diagnosed incidentally. Twenty (51%) patients had the tumor on the right side and 19 (49%) patients had the tumor on the left side. All patients received irradiation to the ipsilateral inguinal, iliac, and bilateral para-aortic nodes with "hockey stick" type fields. The majority of the patients received a midplane dose of 3,200 to 3,600 rad in 3-4 weeks time. None of the patients received prophylactic irradiation to the mediastinum and supraclavicular region. The 5-year actuarial survival rate is 96%. There is no additional benefit in giving prophylactic irradiation to the mediastinum and supraclavicular regions in Stage I testicular seminoma. A brief review of the literature regarding the role of prophylactic irradiation in this group of patients is done.
Pd(OAc)2-catalyzed cross-coupling of polyfluoroarenes with simple aromatics in imidazolium ionic liquids (ILs) without oxidant and additive and with recycling/reuse of the IL

Abstract Polyfluoroarenes can be cross-coupled with simple aromatics (benzene, toluene, and anisole), in good isolated yields, by using Pd(OAc) 2 dissolved in imidazolium ILs [(bmim)PF 6 and (bmim)BF 4 ] as solvent, without the need for an oxidant and an additive. The reaction is catalyzed by HOAc and it is subject to a primary isotope effect ( K H / K D = 4.87). Competitive cross-coupling reactions of 1,2,4,5-tetrafluorobenzene with benzene/toluene, benzene/anisole, and anisole/toluene gave K B / K T = 5.1, K B / K A = 5.7, and K A / K T = 5.0, respectively, indicative of a remote substituent effect on Pd insertion into the phenyl C–H bond. Mild reaction conditions, simple product isolation and recycling/reuse of the IL are additional advantages of this method.