cssi/SciSciGPT-SciSciNet huggingface dataset:
Effective kinetic theory for high temperature gauge theories

Quasiparticle dynamics in relativistic plasmas associated with hot, weakly-coupled gauge theories (such as QCD at asymptotically high temperature T) can be described by an effective kinetic theory, valid on sufficiently large time and distance scales. The appropriate Boltzmann equations depend on effective scattering rates for various types of collisions that can occur in the plasma. The resulting effective kinetic theory may be used to evaluate observables which are dominantly sensitive to the dynamics of typical ultrarelativistic excitations. This includes transport coefficients (viscosities and diffusion constants) and energy loss rates. In this paper, we show how to formulate effective Boltzmann equations which will be adequate to compute such observables to leading order in the running coupling g(T) of high-temperature gauge theories [and all orders in 1/log g(T)?1]. As previously proposed in the literature, a leading-order treatment requires including both 22 particle scattering processes as well as effective ``12'' collinear splitting processes in the Boltzmann equations. The latter account for nearly collinear bremsstrahlung and pair production/annihilation processes which take place in the presence of fluctuations in the background gauge field. Our effective kinetic theory is applicable not only to near-equilibrium systems (relevant for the calculation of transport coefficients), but also to highly non-equilibrium situations, provided some simple conditions on distribution functions are satisfied.
Synthesis of ultrafine single crystals and nanostructured coatings of indium oxide from solution precursor

Abstract Indium oxide (In2O3) has been widely used in sensors, solar cells and microelectronics. There are several techniques available for making In2O3 such as vapor, electrochemical and atomic layer deposition, which are not only expensive but also time consuming processes. In this study, an inexpensive and straightforward synthesis approach is being presented to make micron/submicron size single crystals as well as nanostructured adherent coatings of In2O3 using Indium Chloride (InCl3) powders and InCl3 solution precursor. Both the powders and the solution precursor were calcined in a furnace to obtain the crystals; however, the liquid precursor was also treated by a DC plasma jet to obtain the nanostructured coatings. The phase transformations during thermal decomposition of InCl3 powders and solution precursor were investigated via differential scanning calorimetry studies. The phase structure and crystallinity of the crystals and coatings were confirmed by X-ray diffraction. Microstructural characterization of the crystals and coatings was done by scanning electron microscopy, transmission electron microscopy and atomic force microscopy techniques. Size of the crystals was observed to be dependent on the heating schemes adapted during calcination. Solution precursor plasma sprayed In2O3 coatings showed porosity and ultrafine particulates with grain size ranging between 10 and 75 nm. Resistivity was determined to be ∼0.553 ± 0.337 kΩ cm. Optical transmittance of In2O3 coatings was ∼60–78% in the visible region and it was observed to decrease with increasing the number passes or the thickness of the coatings. Based on the optical transmission data, direct band gap of 3.57 eV was determined.
Syntheses of 2-Bromopyrene and 2-Hydroxypyrene

Abstract Regiospecific monobromination of 4,5,9,10-tetrahydropyrene in the 2-posiuon is accomplished in aqueous dimethylformamide. Conversion of the previously unknown 2-bromo-4,5,9,10-tetrahydropyrene to the title compounds is described.
Gluon-fusion Higgs production at NNLO for a non-standard Higgs sector

We consider an extension of the Standard Model with an arbitrary number of heavy quarks having general couplings to the Higgs boson. We construct an effective Lagrangian integrating out quarks that are heavier than half the mass of the Higgs boson and compute the Wilson coefficient for the effective gluon-Higgs vertex through NNLO. We apply our result to a composite Higgs model with vector-like quarks coupling to the third generation quarks. In the heavy quark-mass approximation, we show that the suppression of the leading-order cross section with respect to the Standard Model does not depend on the number of vector-like multiplets introduced. We analyse the effects of QCD and electroweak corrections through three loops, as well as bottom-quark contributions through two loops.
A Foreign Field No Longer: India, the IPL, and the Global Business of Cricket

In the past decade India has become the financing hub for cricket, a broadcaster in its own right, and an agenda-setter in the management of all forms of the game. What some commentators have calle...
Validation of a computer performance model of the exponential queuing network family

Beginning in mid-1974, the Data Management Center of the Office of the Secretary of the Department of Health, Education, and Welfare undertook to validate an analytic model of computer performance in the context of a large multiprogrammed configuration operating under a variety of actual production workload conditions. A primary goal of this validation effort was to test the adequacy of the framework offered by the “exponential queuing network” model schema (as developed by Buzen, et al.) in representing “real world” situations with sufficient accuracy to be useful as a general tool in support of long range planning. The purpose of this paper is to report on the results of that validation effort.
High energy beam lifetime analysis

Abstract We have developed a positron lifetime defect analysis capability based on a 3 MeV electrostatic accelerator. The high energy beam lifetime spectrometer is operational with a 100 mCi 22 Na source providing a current of 5.5×105 positrons per second. Lifetime data are derived from a thin plastic transmission detector providing an implantation time and a BaF2 detector to determine the annihilation time. Positron lifetime analysis is performed with a 3 MeV positron beam on thick sample specimens at counting rates in excess of 2000 per second. The instrument is being used for bulk sample analysis and analysis of samples encapsulated in controlled environments for in situ measurements.
ANALYSIS OF HEAT PIPE VAPOR DYNAMICS

The transient behavior of vapor flow in heat pipes is analyzed numerically using a two dimensional compressible Row model. The vapor core response to changes in the evaporation and condensation rates following a sudden increase, or decrease, in the input heat flux, or the condensation temperature is studied. The numerical scheme is fully implicit using a staggered grid to overcome the numerical stability problem. When the input heat flux is low, the vapor flows smoothly towards the condensation region. However, with high input heat flux, reverse flow was detected in the adiabatic as well as the condensation region.
On representing some lattices as lattices of intermediate subfactors of finite index

Abstract We prove that the very simple lattices which consist of a largest, a smallest and 2 n pairwise incomparable elements where n is a positive integer can be realized as the lattices of intermediate subfactors of finite index and finite depth. Using the same techniques, we give a necessary and sufficient condition for subfactors coming from Loop groups of type A at generic levels to be maximal.
Endogenous Neighborhood Selection and the Attainment of Cooperation in a Spatial Prisoner's Dilemma Game

There is a large literature in economics and elsewhere on the emergence and evolution of cooperation in the repeated Prisoner’s Dilemma. Recently this literature has expanded to include games in a setting where agents play only with local neighbors in a specified geography. In this paper we explore how the ability of agents to move and choose new locations and new neighbors influences the emergence of cooperation. First, we explore the dynamics of cooperation by investigating agent strategies that yield Markov transition probabilities. We show how different agent strategies yield different Markov chains which generate different asymptotic behaviors in regard to the attainment of cooperation. Second, we investigate how agent movement affects the attainment of cooperation in various networks using agent-based simulations. We show how network structure and density can affect cooperation with and without agent movement.
Vertical cavity surface emitting lasers with 21% efficiency by metalorganic vapor phase epitaxy

Proton implanted, vertical cavity top-surface emitting lasers exhibit the highest single-mode and multi-mode output powers, highest power conversion efficiency, and lowest threshold voltage for such devices reported to date. These lasers use new mirror grading designs that are enabled by metalorganic vapor phase epitaxy's capabilities of alloy grading and carbon doping. The results validate this growth technology by exceeding the previous best results which were based on molecular beam epitaxy. >
On the use of the haloetherification method to synthesize fully functionalized disaccharides

Abstract Synthetic routes to the fully functionalized α-linked disaccharides 19 21 and 25 are described starting from a common intermediate the iodo acetate 15. This substance was in turn prepared via a haloetherification reaction between the allal derivative 13 the galactose alcohol 14 and an “iodonium” equivalent.
Investigation into the Operating Characteristics of a “Microarc” Atmospheric-Pressure Glow Discharge:

Details of the processes occurring during sample atomization from a ''microarc'' discharge have been studied photometrically, by use of high-speed color cinematography and through current-voltage waveforms. The microarc studied here is an atmospheric-pressure inert-gas glow discharge supported between 0.25 mm diameter tungsten wires; quiescent argon-1% H/sub 2/ provides reactive-sputtering conditions and improved behavior in the presence of oxygen impurities. Excitation temperatures of ca. 5000 /sup 0/K are measured for the argon glow. Samples of Na, Al, and Sr illustrate the influence of votatile, refractory, insulating, and electron-emitting sample properties on the temporal-spatial-electrical behavior of the discharge. The step-by-step events occurring in the discharge are described qualitatively and a variety of proceses are invoked to explain sample volatization, including sputtering, chemical reactions, and purely thermal effects. In the first stages of the discharge, instabilities are related to the placement and insulating character of deposits. With heating, electron emission becomes important in directing the discharge to or away from the sample; abnormal glow wandering and glow-to-arc transitions can ensue. Improved stability is achieved by uniformly depositing multi-element samples along the electrode, which localizes the initial discharge and promotes ablative cooling of the sample and electrode.
Tax incidence in a two good model

Abstract In a two consumer, two commodity economy with an excise tax on one good, analysis is done of the effects of lump sum transfers between consumers and of an increase in the excise tax, proceeds being returned as a lump sum. Changes in price, incomes, and utilities are calculated in terms of demand and supply derivatives and changes in profit shares going to the two consumers. Analysis complements that of Harberger by concentrating on the demand side and considering only a reduced form of supply responses. Some of the analysis parallels consideration of the classical transfer problem in international trade.
Structure and energetics of ammonia clusters (NH3)n (n = 3-20) investigated using a rigid-polarizable model derived from ab initio calculations.

An analytical model has been developed to describe the interaction between rigid ammonia molecules including the explicit description of induction. The parameters of the model potential were chosen by fitting high quality ab initio data obtained using second-order Moller−Plesset (MP2) perturbation theory and extended basis sets. The description of polarization effects is introduced by using a noniterative form of the “charge on spring model”, the latter accounting for more than 95% of the dipole induction energy and of the increased molecular dipole. Putative global minima for (NH3)n (n = 3−20) have been optimized using this new model, the structure and energetics of the clusters with n = 3−5 being found in good agreement with previous ab initio results including electronic correlation. Results for larger species have been compared with previous structural studies where only nonpolarizable models were employed. Our model predicts larger binding energies for any cluster size than previous analytical surfac...
Rational Conformal Field Theories and Complex Multiplication

We study the geometric interpretation of two dimensional rational conformal field theories, corresponding to sigma models on Calabi-Yau manifolds. We perform a detailed study of RCFT’s corresponding to the T2 target and identify the Cardy branes with geometric branes. The T2’s leading to RCFT’s admit ‘‘complex multiplication’’ which characterizes Cardy branes as specific D0-branes. We propose a condition for the conformal sigma model to be RCFT for arbitrary Calabi-Yau n-folds, which agrees with the known cases. Together with recent conjectures by mathematicians it appears that rational conformal theories are not dense in the space of all conformal theories, and sometimes appear to be finite in number for Calabi-Yau n-folds for n>2. RCFT’s on K3 may be dense. We speculate about the meaning of these special points in the moduli spaces of Calabi-Yau n-folds in connection with freezing geometric moduli.
Luteinizing hormone secretion and female lordosis behavior in male pigs.

Serum concentrations of luteinizing hormone (LH) and testosterone were monitored during the first 9 weeks of life in male pigs. In boars, testosterone was constant during this period, and LH was elevated from birth through day 21 and declined between days 21 and 28 to levels observed in adult boars. Castration on day 3 reduced testosterone concentrations without having an immediate effect on LH, but after day 21, LH was consistently greater in castrated males than in boars. Responsiveness of the early postnatal testes to LH was shown by reduced testosterone concentrations after treatment with LH-antiserum on day 2. Norethindrone had no effect on LH or testosterone when given on day 2 but decreased the concentrations of these hormones in 5-month-old boars. Similarly, estrogen had no effect on LH secretion in 4-day-old boars. In 9-month-old castrated males, estrogen decreased LH concentrations during the first 48 h of daily treatment, but after this, LH increased and returned to pretreatment levels by 88 h....
The chromoelectric and purely gluonic operator contributions to the neutron electric dipole moment in N=1 supergravity

Abstract A complete one loop analysis of the chromoelectric dipole contribution to the electric dipole moment (edm) of the quarks and of the neutron in N=1 supergravity including the gluino, chargino and neutralino exchange contributions and exhibiting the dependence on the two CP violating phases allowed in the soft SUSY breaking sector of minimal supergravity models is given. It is found that in significant parts of the supergravity parameter space the chromoelectric dipole contribution to the neutron edm is comparable to the contribution from the electric dipole term and can exceed the contribution of the electric dipole term in certain regions of the parameter space. An analysis of the contribution of Weinberg's purely gluonic CP violating dimension six operator within supergravity unification is also given. It is found that this contribution can also be comparable to the contribution from the electric dipole term in certain regions of the supergravity parameter space.
Synthesis of 1‐azapyrene

The environmental contaminants 1-azapyrene 15, 2-azapyrene 13 and several other azapyrene derivatives were synthesized from a common intermediate, 2,2a,3,4-tetrahydrocyclopenta[cd]phenalen-1-one oxime 6. The synthesis of 1-azapyrene 15 completes the series of azapyrenes.
A sequential problem in decentralized detection with communication

We consider a sequential problem in decentralized detection. Two observers can make repeated noisy observations of a binary hypothesis on the state of the environment. At any time, observer 1 can stop and send a final message to observer 2 or it may continue to take more measurements. Every time observer 1 postpones its final message to observer 2, it incurs a penalty. We consider observer 2's operation under two different scenarios. In the first scenario, observer 2 waits to receive the final message from observer 1 and then starts taking measurements of its own. It is then faced with a stopping problem on whether to stop and declare a decision on the hypothesis or to continue taking measurements. In the second scenario, observer 2 starts taking measurements from the beginning. It is then faced with a different stopping problem. At any time, observer 2 can decide whether to stop and declare a decision on the hypothesis or to continue to take more measurements and wait for observer 1 to send its final message. We obtain parametric characterization of optimal policies for the two observers under both scenarios. We then extend these characterizations to a problem with multiple peripheral sensors that each send a single final message to a coordinating sensor who makes the final decision on the hypothesis.
Active x-ray optics for Generation-X, the next high resolution x-ray observatory

X-rays provide one of the few bands through which we can study the epoch of reionization, when the first galaxies, black holes and stars were born. To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics. Generation-X (Gen-X) is currently the only X-ray astronomy mission concept that addresses this goal. Gen-X aims to improve substantially on the Chandra angular resolution and to do so with substantially larger effective area. These two goals can only be met if a mirror technology can be developed that yields high angular resolution at much lower mass/unit area than the Chandra optics, matching that of Constellation-X (Con-X). We describe an approach to this goal based on active X-ray optics that correct the mid-frequency departures from an ideal Wolter optic on-orbit. We concentrate on the problems of sensing figure errors, calculating the corrections required, and applying those corrections. The time needed to make this in-flight calibration is reasonable. A laboratory version of these optics has already been developed by others and is successfully operating at synchrotron light sources. With only a moderate investment in these optics the goals of Gen-X resolution can be realized.
EVIDENCE OF UNDERTOW FROM ENGINEERING PRACTICE.

Although In our geological textbooks the undertow has been described as a well known phenomenon, some doubts have been expressed In recent years as to Its reality. This question was first raised by Professor W. M. Davis In 1925 as the result of some observations made by him along the Florida coast. A few years later independent investigations regarding the existence of the undertow were made by Dr. F. P. Shepard and by the writer. Dr. Shepard believes that the undertow, as a current of sufficient velocity to be dangerous to swimmers, Is non-exiatent and that the water carried shoreward by the Incoming waves moves out again in localized currents at the surface.
A parallel method for computing the generalized singular value decomposition

We describe a new parallel algorithm for computing the generalized singular value decomposition of two n × n matrices, one of which is nonsingular. Our procedure requires O (n) time and one triangular array of O(n2) processors.
Strategies for Asymmetric Synthesis of Amino Acids with γ,δ-Unsaturation

The amino acid is a fundamental molecule of life. They serve as building blocks for polypeptides and proteins, which are essential parts of all living systems and are involved in almost every proce...
1,3-Dipolar cycloaddition reactions of pyrazolidinium ylides with vinyl sulfones. A regioselective synthesis of bicyclic pyrazolidinone antibacterial agents

Abstract The 1, 3-dipolar cycloaddition reaction of pyrazolidinium ylide 1 with substituted vinyl sulfones 5 was studied. Elimination of benzenesulfinic acid from the resulting cycloadducts gave rise to bicyclic pyrazolidinones 3 . The (E)-olefin isomers were found to undergo cycloaddition in a highly regioselective fashion. These pyrazolidinones 3 represent the nuclei of an exciting new class of potent antibacterial agents that mimic β-lactams.
Bounded geometry for Kleinian groups

We show that a Kleinian surface group, or hyperbolic 3-manifold with a cusp-preserving homotopy-equivalence to a surface, has bounded geometry if and only if there is an upper bound on an associated collection of coefficients that depend only on its end invariants. Bounded geometry is a positive lower bound on the lengths of closed geodesics. When the surface is a once-punctured torus, the coefficients coincide with the continued fraction coefficients associated to the ending laminations.
Automating the DNA computer: solving n-Variable 3-SAT problems

In the decade since the first molecular computation was performed, it has been shown that DNA molecules can perform sophisticated, massively parallel computations avoiding the Von Neumann bottleneck. However, progress in the field has been slow. The largest problem solved to date is an instance of the 20-variable 3-CNF SAT problem. Performing the computation took more than two man-weeks to complete because every aspect of the computation was performed by hand. Molecular computations are extremely labor intensive and error prone---automation is necessary for further progress. The next step, (the second generation DNA computer--that of taking the laborious, laboratory bench protocols performed by hand, and automating them), has been achieved with the construction of an automated DNA computer dubbed EDNAC. It employs the same paradigm that was used to solve the labor-intensive instance of the 20-variable 3-CNF SAT problem. Using a combinatorial DNA library and complementary probes, EDNAC solves instances of the n-variable 3-CNF SAT problem. A 10 variable instance of the 3-CNF SAT problem was essayed. The computation took 28 h to perform. EDNAC correctly computed nine of the 10 variables, with a tenth variable remaining ambiguous. This result is comparable to current results in the molecular computation community. This research tested the critical properties, such as complexity, robustness, reliability, and repeatability necessary for the successful automation of a molecular computer.
Optimized multi-floor throughflow micro heat exchangers

Abstract Multi-floor networks of straight-through counterflow liquid cooled microchannels have been investigated by performing conjugate heat transfer in a silicon substrate of size 15 × 15 × 1 mm. Two-floor and three-floor cooling configurations were analyzed with different numbers of microchannels on each floor, different diameters of the channels, and different clustering among the floors. Direction of microchannels on each floor changes by 90° from the previous floor. Direction of flow in each microchannel is opposite of the flow direction in its neighbor channels. Conjugate heat transfer analysis was performed by developing a software package which uses quasi-1D thermo-fluid analysis and a fully 3D steady heat conduction analysis. These two solvers are coupled through their common boundaries representing surfaces of the cooling microchannels. Using quasi-1D solver significantly decreases overall computing time and its results are in good agreement with 3D Navier–Stokes equations solver for these types of application. Multi-objective optimization with modeFRONTIER software was performed using response surface approximations and genetic algorithm. Maximizing total amount of heat removed, minimizing coolant pressure drop, minimizing maximum temperature on the hot surface, and minimizing non-uniformity of temperature on the hot surface were four simultaneous objectives of the optimization. Maximum number of cooling microchannels on each floor, diameter ranges of the microchannels on each floor, and vertical clustering range of the floors were the specified constraints. Pareto-optimal solutions demonstrate that thermal loads of 800 W cm −2 can be effectively managed with such multi-floor microchannel cooling networks. Two-floor microchannel configuration was also simulated with 1000 W cm −2 uniform thermal load and shown to be feasible.
Consumer Segmentation and Changing Food Purchase Patterns in Nanjing, PRC

Abstract The remarkable economic changes occurring within the People’s Republic of China since 1978 have resulted in striking alteration in food consumption patterns for urban Chinese residents. Higher incomes, busier life styles, greater choices in food retailers, the increasing availability of refrigeration, and the greater variety in food choice have all resulted in shifts of household consumption. This study, based on a convenience survey of urban households in Nanjing, Jiangsu Province, PRC finds that three distinct patterns of food shopping exist. The significance of these findings to the global agro-food system and the agricultural sector of China are examined.
Pathway Shifts and Thermal Softening in Temperature-Coupled Forced Unfolding of Spectrin Domains

Pathways of unfolding a protein depend in principle on the perturbation—whether it is temperature, denaturant, or even forced extension. Widely-shared, helical-bundle spectrin repeats are known to melt at temperatures as low as 40–45°C and are also known to unfold via multiple pathways as single molecules in atomic force microscopy. Given the varied roles of spectrin family proteins in cell deformability, we sought to determine the coupled effects of temperature on forced unfolding. Bimodal distributions of unfolding intervals are seen at all temperatures for the four-repeat β1–4 spectrin—an α-actinin homolog. The major unfolding length corresponds to unfolding of a single repeat, and a minor peak at twice the length corresponds to tandem repeats. Increasing temperature shows fewer tandem events but has no effect on unfolding intervals. As T approaches Tm, however, mean unfolding forces in atomic force microscopy also decrease; and circular dichroism studies demonstrate a nearly proportional decrease of helical content in solution. The results imply a thermal softening of a helical linker between repeats which otherwise propagates a helix-to-coil transition to adjacent repeats. In sum, structural changes with temperature correlate with both single-molecule unfolding forces and shifts in unfolding pathways.
Incompressibility criteria for spun-normal surfaces

We give a simple sufficient condition for a spun-normal surface in an ideal triangulation to be incompressible, namely that it is a vertex surface with non-empty boundary which has a quadrilateral in each tetrahedron. While this condition is far from being necessary, it is powerful enough to give two new results: the existence of alternating knots with non-integer boundary slopes, and a proof of the Slope Conjecture for a large class of 2-fusion knots.
Analytical development of an equivalent system mismatch function

A mismatch function is used to check the validity of a low-order equivalent system model that has been derived from a high-order system representation. If the difference between the low- and high-order models is greater than allowed by the mismatch function, the flying qualities predictions obtained from parameters of the low-order equivalent system may not be representative of the ratings a pilot would give the actual aircraft. A methodology is developed in this paper to derive equivalent system mismatch functions analytically. The methodology is used to analytically determine a mismatch function for the longitudinal axis of a class IV fighter aircraft in the category A, nonterminal flight phase.
Cohomogeneity one manifolds with a small family of invariant metrics

In this paper, we classify compact simply connected cohomogeneity one manifolds up to equivariant diffeomorphism whose isotropy representation by the connected component of the principal isotropy subgroup has three or less irreducible summands. The manifold is either a bundle over a homogeneous space or an irreducible symmetric space. As a corollary such manifolds admit an invariant metric with non-negative sectional curvature.
A numerical fluid dynamics calculation method for all flow speeds

Abstract The ICE technique for numerical fluid dynamics has been revised considerably, and generalized in such a way as to extend the applicability to fluid flows with arbitrary equation of state and the full viscous stress tensor. The method is useful for the numerical solution of time-dependent fluid flow problems in several space dimensions, for all Mach numbers from zero (incompressible limit) to infinity (hypersonic limit). This new version is considerably less complicated than the original form. The present description does not assume a familiarity with the previous one.
5-Day Methotrexate for Women with Metastatic Gestational Trophoblastic Disease

The objective of this study was to analyze the toxicity and the efficacy of single-agent 5-day methotrexate for women with metastatic gestational trophoblastic disease. The study is a retrospective analysis of 52 patients who received repetitive 5-day cycles of intramuscular methotrexate as primary therapy for metastatic trophoblastic disease between 1975 and 1990. The majority of patients were low-risk by both clinical and World Health Organization prognostic index score criteria. Sixty percent achieved primary remission with a median of 3 cycles of single-agent methotrexate. Therapy was changed because of toxicity and drug-resistance by hCG criteria in 11 (21%) and 10 (19%) patients, respectively. Pretherapy hCG > 10,000 mIU/ml was associated with the development of drug-resistance. Remission was achieved in all patients, with only 2 (4%) requiring multiagent therapy. The use of repetitive 5-day cycles of methotrexate is efficacious therapy of low-risk metastatic trophoblastic disease. Future studies are needed to define a cost-effective and minimally toxic therapy that retains a high primary remission rate in these patients.
On the satisfiability threshold and clustering of solutions of random 3-SAT formulas

We study the structure of satisfying assignments of a random 3-Sat formula. In particular, we show that a random formula of density @a>=4.453 almost surely has no non-trivial ''core'' assignments. Core assignments are certain partial assignments that can be extended to satisfying assignments, and have been studied recently in connection with the Survey Propagation heuristic for random Sat. Their existence implies the presence of clusters of solutions, and they have been shown to exist with high probability below the satisfiability threshold for k-Sat with k>=9 [D. Achlioptas, F. Ricci-Tersenghi, On the solution-space geometry of random constraint satisfaction problems, in: Proc. 38th ACM Symp. Theory of Computing, STOC, 2006, pp. 130-139]. Our result implies that either this does not hold for 3-Sat, or the threshold density for satisfiability in 3-Sat lies below 4.453. The main technical tool that we use is a novel simple application of the first moment method.
Differences in quality of life estimates using rents and home values

Quality of life differences across areas can be measured by differences in “real wages,” where real wages are computed as nominal wages adjusted for the cost of living. Computing cost of living differences involves several important issues, including how housing prices should be measured. Previous researchers typically have used some combination of rental payments and homeowner housing values, but housing values are forward-looking and may not reflect current user costs. This paper examines differences in quality of life estimates for US metropolitan areas using, alternatively, rents and housing values. We find that the two measures of quality of life are highly correlated. Value-based estimates, however, are considerably more dispersed than rent-based estimates, likely because of the recent housing bubble and because housing values often provide an imperfect measure of the present user cost of housing.
The use of leached gradient index anti-reflection surfaces on borosilicate glass solar collector cover tubes

Abstract When alkali-borosilicate glasses are heat treated, they can be caused to phase separate. The silica and non-silica constituents are separated on a sub-microscopic scale. This enables small amounts of the non-silica phase to be chemically leached from the surface, which results in a graded reduction in the index of refraction near the surface. The index gradient can be controlled so that it leads to the most effective broad band, antireflection (A.R.) films known. At normal incidence, average reflection per surface can be kept well below 1% in the spectral region from 0.35 to 2.5 μm. Further, films produced by this method maintain their effectiveness even at incident angles up to 70°. All these aspects; i.e. manufacturing method, spectral response and angular response, combine to make the leached gradient index A.R. treatment ideally suited to enhance the efficiency of linear trough solar collector systems. Such systems typically use borosilicate glass cover tubes of the absorber tubes to cut heat losses, but in absence of A.R. treatment, reflective losses from the cover tubes can cut system output by about 7–8%. The leached A.R. surface eliminates reflective losses almost entirely. Exposure to the elements in an industrial environment for five (5) years has resulted in no degradation of the effectiveness of the leache A.R. surfaces. While the surface is somewhat sensitive to contamination by body oils because of its porous nature, once installed, the inherent chemical durability of the nearly pure silica leads to excellent long-term performance.
Techniques for cost estimating in early program phases

Abstract In the early concept phases of programs, some approximate cost figures are often required to scope system program costs for development, production or life cycle, and to provide preliminary identification of cost drivers. The cost estimation process in these early, formative program stages is, however, hampered by insufficient knowledge of mission, configuration and environmental parameters. It is therefore necessary to use a heuristic approach, i.e., to fall back on cost estimates using modifiers of analogous systems where historical data exist. This paper describes the process of eliciting cost estimates and modifying cost assumptions which enable cost prediction of not well defined systems. It describes what kinds of cost models are acceptable and usable and how the data may be efficiently obtained. The choice of the ‘right’ experts (generalists, people with perception), the proper interviewing techniques (written versus oral, delphi, argumentative, etc.), the important role of the interviewer or moderator (reinforcing behaviour versus objective criticism), and the transformation of question responses into cost model inputs are discussed. The paper reveals the thought process and includes several examples of actually performed, early concept phase cost estimates and contains a list of several do's and dont's the author experienced in arriving at these early cost predictions.
Wave-wave interactions in two-fluid cosmic-ray hydrodynamics

Multiple–scales perturbation methods are used to derive equations describing wave–wave interactions in two-fluid cosmic-ray hydrodynamics in one Cartesian space dimension. Two problems are considered: (a) the interaction between short-wavelength waves in a non-uniform large-scale background flow, and (b) wave interactions between long-wavelength waves propagating through a uniform background medium. The short-wavelength wave equations describe the interaction between the backward and forward thermal gas sound waves and the contact discontinuity eigenmode via ‘wave mixing’, in which the waves are reflected by gradients in the large scale background flow. The equations also contain quadratic wave interaction terms describing (i) the Burgers self-wave interaction term, (ii) mean–wave-field interaction terms in which a specific wave interacts with the mean field of the other waves, and (iii) three-wave resonant interactions that describe how a sound wave resonantly interacts with the contact discontinuity to generate a reverse sound wave. In the limit of no interaction between the cosmic rays and thermal gas, and for a uniform background state, the equations reduce to two coupled, integro-differential Burgers equations derived by Majda and Rosales for resonantly interacting waves in adiabatic gasdynamics. The short-wavelength equations also contain squeezing instability terms associated with the large-scale cosmic-ray pressure gradient, which were first investigated by Drury and Dorfi. A generalized wave-action equation, or canonical wave-energy equation, variational principles, and WKB analyses of the linearized equations are used to investigate the modification of the cosmic-ray squeezing instability by wave mixing. Coupled Burgers equations are also derived in the long-wavelength regime that describe resonant wave interactions for weak, diffusively smoothed cosmic-ray-modified shocks. In the latter equations, the cosmic-ray-modified sound waves can resonantly interact with either the contact discontinuity or the cosmic-ray pressure-balance mode to generate a reverse sound wave.
The use of soluble polymers to effect homogeneous catalyst separation and reuse

Abstract The use of soluble polymeric ligands for homogeneous catalysts separation is reviewed with emphasis on work from the author's laboratory. Examples discussed include polyethylene-bound catalysts, poly(alkene oxide)-bound catalysts, poly( N -isopropylacrylamide)-bound catalysts, fluorous polymer-bound catalysts and amphoteric polymer-bound catalysts. The utility of these systems is also discussed in the broader context of polymer-supported catalysis and the advantages and limitations of soluble polymeric ligands are discussed in this context.
Pd catalyzed chemoselective cyclization to cyclic ethers

Abstract Ring size control in cyclic ether formation derives from conformationally dictated chemoselectivity in Pd(O) catalyzed cyclization of vicinal diol allyl acetates.
A synthesis of quinoline-5,8-quinones via the benzannulation of 1,4-dihydro-2-pyridyl carbene complexes

Abstract A method for the preparation of quinoline-5,8-quinones is described with the key step the benzannulation of a dihydropyridyl Fischer carbene complex. The carbene complexes are generated by the standard Fischer method upon metallation of N-Boc protected 1,4-dihydropyridines and their reactions with alkynes to provide 1,4-dihydroquinolines. The latter are converted to quinoline,5,8-quinones by a two-step oxidation procedure involving ceric ammonium nitrate and trityl tetrafluoroborate.
The maintenance of common data in a distributed system

A basic task in distributed computation is the maintenance at each processor of the network, of a current and accurate copy of a common database. A primary example is the maintenance, for routing and other purposes, of a record of the current topology of the system.Such a database must be updated in the wake of locally generated changes to its contents. Due to previous disconnections of parts of the network, a maintenance protocol may need to update processors holding widely varying versions of the database.We provide a deterministic protocol for this problem, with only polylogarithmic overhead in both time and communication complexities. Previous deterministic solutions required polynomial overhead in at least one of these measures.
The performance of trellis coded multilevel DPSK on a fading mobile satellite channel

The performance of a trellis-coded multilevel differential phase-shift keying (DPSK) modulation over a mobile satellite channel characterized by additive white Gaussian noise (AWGN) and slow Rician fading is presented. Both the optimum and Gaussian (suboptimum) decoding metrics are considered, with performance results given only for the latter. Analytical results (upper bounds on bit error rate) are obtained wherever possible and illustrated by several numerical examples. Also given are simulation results which are more indicative of the exact system performance. Comparisons with results previously obtained for coherent detection of the same coded modulations are presented. >
Energy absorber R&D

Abstract We describe the program of research and development being undertaken by a consortium of Illinois university groups to develop liquid-hydrogen energy absorbers for muon-beam cooling.
The Invention of Chemical Reactions: the Last Five Years.

Abstract Recent progress at Texas A&M University and in France in the field of radical chemistry, based on the thiocarbonyl function, has been summarized.
ELEMENT NO. 102

By the use of a radically new method they have succeeded in identifying unambiguously an isotope of element 102. In other careful experiments conducted over a period of many months they find that they are unable to confirm the element 102 discovery work of Fields et al. reported in 1957. The experiments at Berkeley were performed with the new heavy ion linear accelerator (HILAC) over a period of several weeks and culinated the chemical identification of an isotope of fermium (Fm{sup 250}) as the daughter of an alpha-particle-emitting isotope of element 102 (102{sup 254}). The method used to detect the isotope of element 102 was essentially a continuous milking experiment wherein the atoms of the daughter element 100 were separated from the parent element 102 by taking advantage of the recoil due to the element 102 alpha particle decay. The target consisted of a mixture of isotopes of curium (95% Cm{sup 244} and 4.5% Cm{sup 246}) mounted on a very thin nickel foil. The target was approximately 0.5 mg/cm{sup 2} thick and was covered with 75 {micro}gm/cm{sup 2} aluminum to prevent curium 'knockover'. The curium was bombarded with mono-energetic C{sup 12} ions at energies from 60 to 100 Mev. The transmuted atoms were knocked into helium gas to absorb the considerable recoil energy. It was found that with a sufficient electric field strength practically all of these positively charged atoms could be attracted to a moving negatively charged metallic belt placed directly beneath the target. These atoms would then be carried on this conveyer belt under a foil which was charged negatively relative to the belt. Approximately half of the atoms undergoing alpha decay would cause their daughter atoms to recoil from the surface of the belt to the catcher foil. The catcher foil was cut transversely to the direction of the belt motion into five equal length sections after a time of bombardement suited to the half-life of the daughter atom to be examined. The five foils were then alpha-pulse-analyzed simultaneously in a multiplex assembly consisting of five Frisch grid chambers, amplifiers, a single Wilkinson type 'kick-sorter', and a printer. With this equipment it was easily possible to make all the desired measurements for identifying the atoms caught on the catcher foils and thus to measure the half-life of the parent of the recoiling atoms. The method was first successfully used in bombardments of Pu{sup 240} with C{sup 12} ions to identify a new isotope of element 100, Fm{sup 248}. It was shown to have a half-life of 0.6 minutes by analysis of the amounts of the 20-minute Cf{sup 244} caught on the catcher foils.
Counterion effects in the catalytic stereoselective synthesis of 2,3′-pyrrolidinyl spirooxindoles

A Lewis acid-catalyzed stereoselective [3+2] annulation of crotylsilanes with iminooxindoles is reported to access 2,3′-pyrrolidinyl spirooxindoles with four stereocenters. The addition of NaBArF significantly enhances reactivity, allowing either metal salts or acidic clay to be effective catalysts for the stereoselective reaction.
The Public–Private Distinction: Insights for Public Administration from the State Action Doctrine

Public administration scholars continue to grapple with how and why public organizations differ from private organizations. The judiciary deals with similar questions in ruling on constitutional claims that apply exclusively to state actors. The authors consider similarities and differences between scholarly and judicial approaches, adding to the body of research attempting to capture the complexities of the public–private distinction. The application in this article includes the coding of seminal court decisions and qualitative comparative analysis (QCA) to find combinations of causal conditions that lead to state action rulings. The specifics revealed through QCA provide valuable lessons for extending public norms and preserving constitutional protections when outsourcing public services.
Sound and light in turbid media

Two imaging techniques combining ultrasound and light are reviewed. The motivation is to combine the advantages of optical information and acoustic imaging resolution. The first technique is sonoluminescence tomography, where a sonoluminescence signal generated internally in the media by continuous-wave ultrasound is used. Two-dimensional images can be produced for objects embedded in turbid media by raster scanning the media. The second technique is ultrasound- modulated optical tomography, where a frequency-swept ultrasonic wave was used to modulate the laser light passing through a scattering medium. Multiple 1D images obtained at various positions perpendicular to the ultrasonic axis were composed to obtain a 2D tomographic image of the medium.
Fipronil-based photoaffinity probe for Drosophila and human β3 GABA receptors

Abstract Modification of the major insecticide fipronil (1) by replacing three pyrazole substituents (hydrogen for both cyano and amino and trifluoromethyldiazirinyl for trifluoromethylsulfinyl) gives a candidate photoaffinity probe (3) of high potency (IC50 2–28 nM) in blocking the chloride channel of Drosophila and human β3 GABA receptors.
Halide-templated assembly of polynuclear lanthanide-hydroxo complexes.

A series of pentadecanuclear lanthanide-hydroxo complexes possessing a common core of the formula [Ln15(μ3-OH)20(μ5-X)]24+(1, Ln = Eu, X = Cl-; 2, Ln = Nd, X = Cl-; 3, Ln = Gd, X = Cl-; 4, Ln = Pr, X = Br-; 5, Ln = Eu, X = Br-) were prepared by L-tyrosine-controlled hydrolysis of corresponding lanthanide perchlorates in the presence of added Cl- or Br-. The cationic cluster core comprises five vertex-sharing cubane-like [Ln4(μ3-OH)4]8+ units centered on the halide template. In the case of templating I-, dodecanuclear complexes were isolated instead. The core component, [Ln12(μ3-OH)16(I)2]18+ (6, Ln = Dy; 7, Ln = Er), consists of four vertex-sharing cubane-like [Ln4(μ3-OH)4]8+ units and exists as a square-shaped cyclic structure with one I- located on each side of the square plane. An analogous hydrolytic reaction involving Er(NO3)3, L-tyrosine, and NaOH affords the known hexanuclear complex [Er6(μ6-O)(μ3-OH)8(NO3)6(H2O)12](NO3)2 whose core component is a face-capped octahedral [Er6(μ6-O)(μ3-OH)8]8+ cluste...