Copper-cysteamine and methods of use

Structure and luminescence properties of a new Cu-Cyteamine (Cu-Cy) crystal material are provided. The crystal structure of the Cu-Cy is determined by single crystal X-ray diffraction. It is found that the compound crystallizes in the monoclinic space group C2/c and cell parameters are a=7.5510(4) Å, b=16.9848(7) Å, c=7.8364(4) Å, β=104.798(3)°. The new Cu-Cy crystal material of the invention is also useful for treatment of cancer.Board of Regents, University of Texas Syste

Preliminary estimate of the impact of support structures on the aerodynamic performance of very large wind farms

An extended theoretical model, which is based on a two-scale coupled momentum conservation argument, is proposed to estimate aerodynamic effects of support structures on the performance of ideal very large wind farms. A key implication of this extended model is that the parameter (As /A) bold dot ${C}_{D}^{* }$ where A and As are the rotor swept area and support-structure frontal projected area, respectively, and ${C}_{D}^{* }$ is an effective support-structure drag coefficient, plays an important role in the design of very large wind farms. In particular, the optimal farm density tends to decrease as the normalised support-structure drag increases. To validate this extended model, Wall-Modelled Large-Eddy Simulations (WMLES) of a periodic array of actuator discs with and without support structures are conducted; results agree qualitatively with the model

Categorizing FTE-like Boundary Layer Signatures Produced by the Kelvin-Helmholtz Instability Using Hall-MHD Simulations and Virtual Spacecraft

Magnetic reconnection and Kelvin-Helmholtz instability (KHI) are two fundamental processes at the planetary magnetospheres that can lead to plasma, momentum and energy transport over magnetospheric boundary. Flux Transfer Events (FTEs) are generally accepted to be produced by the magnetic reconnection at the dayside magnetopause. However, there are still other possible mechanisms which create FTE-like features in the boundary layer. Kelvin-Helmholtz instability can be one of the candidates. The deformed boundary driven by the KHI at the interface of two fluids usually leads to the bipolar signatures of the normal component of the magnetic field. By using two-dimensional Hall-MHD simulations, we study signatures observed by virtual satellites as they pass through KHI along different trajectories. For the same plasma parameters across the magnetosphere and magnetosheath, slightly adjusting the projection angle of the magnetic field will give us 12 combinations of in-plain components at both sides of the boundary. In addition, we assume 3 sets of spacecraft trajectories in each simulation, which totally bring 36 different KHI signatures. While the satellites encountered well-developed KH vortex and spine region, the signatures, when detected by a spacecraft in the magnetosphere, would be easily misidentified as FTEs. The presented analysis examines and categorizes these observed signatures that are clearly generated by the KHI. These results can be used as diagnostic when analyzing spacecraft data to help distinguish KHI created signatures from FTEs

Constructions of Semi-regular Relative Difference Sets

AbstractJ. A. Davis, J. Jedwab, and M. Mowbray (1998, Des. Codes Cryptogr.13, 131–146) gave two new constructions for semi-regular relative difference sets (RDSs). They asked if the two constructions could be unified. In this paper, we show that the two constructions are closely related. In fact, the second construction should be viewed as an extension of the first. Furthermore, we generalize the second construction to obtain new RDSs

Two-step hyperparameter optimization method: Accelerating hyperparameter search by using a fraction of a training dataset

Hyperparameter optimization (HPO) is an important step in machine learning (ML) model development, but common practices are archaic -- primarily relying on manual or grid searches. This is partly because adopting advanced HPO algorithms introduces added complexity to the workflow, leading to longer computation times. This poses a notable challenge to ML applications, as suboptimal hyperparameter selections curtail the potential of ML model performance, ultimately obstructing the full exploitation of ML techniques. In this article, we present a two-step HPO method as a strategic solution to curbing computational demands and wait times, gleaned from practical experiences in applied ML parameterization work. The initial phase involves a preliminary evaluation of hyperparameters on a small subset of the training dataset, followed by a re-evaluation of the top-performing candidate models post-retraining with the entire training dataset. This two-step HPO method is universally applicable across HPO search algorithms, and we argue it has attractive efficiency gains. As a case study, we present our recent application of the two-step HPO method to the development of neural network emulators for aerosol activation. Although our primary use case is a data-rich limit with many millions of samples, we also find that using up to 0.0025% of the data (a few thousand samples) in the initial step is sufficient to find optimal hyperparameter configurations from much more extensive sampling, achieving up to 135-times speedup. The benefits of this method materialize through an assessment of hyperparameters and model performance, revealing the minimal model complexity required to achieve the best performance. The assortment of top-performing models harvested from the HPO process allows us to choose a high-performing model with a low inference cost for efficient use in global climate models (GCMs)

Direct Radiative Effect of Mineral Dust on the Development of African Easterly Wave in Late Summer, 2003-2007

Episodic events of both Saharan dust outbreaks and African Easterly Waves (AEWs) are observed to move westward over the eastern tropical Atlantic Ocean. The relationship between the warm, dry, and dusty Saharan Air Layer (SAL) on the nearby storms has been the subject of considerable debate. In this study, the Weather Research and Forecasting (WRF) model is used to investigate the radiative effect of dust on the development of AEWs during August and September, the months of maximum tropical cyclone activity, in years 2003-2007. The simulations show that dust radiative forcing enhances the convective instability of the environment. As a result, most AEWs intensify in the presence of a dust layer. The Lorenz energy cycle analysis reveals that the dust radiative forcing enhances the condensational heating, which elevates the zonal and eddy available potential energy. In turn, available potential energy is effectively converted to eddy kinetic energy, in which local convective overturning plays the primary role. The magnitude of the intensification effect depends on the initial environmental conditions, including moisture, baroclinity, and the depth of the boundary layer. We conclude that dust radiative forcing, albeit small, serves as a catalyst to promote local convection that facilitates AEW development

Exponent Bounds for a Family of Abelian Difference Sets

Which groups G contain difference sets with the parameters (v, k, λ)= (q3 + 2q2 , q2 + q, q), where q is a power of a prime p? Constructions of K. Takeuchi, R.L. McFarland, and J.F. Dillon together yield difference sets with these parameters if G contains an elementary abelian group of order q2 in its center. A result of R.J. Turyn implies that if G is abelian and p is self-conjugate modulo the exponent of G, then a necessary condition for existence is that the exponent of the Sylow p-subgroup of G be at most 2q when p = 2 and at most q if p is an odd prime. In this paper we lower these exponent bounds when q ≠ p by showing that a difference set cannot exist for the bounding exponent values of 2q and q. Thus if there exists an abelian (96, 20, 4)-difference set, then the exponent of the Sylow 2-subgroup is at most 4. We also obtain some nonexistence results for a more general family of (v, k, λ)-parameter values