Low-mass X-ray binaries from black-hole retaining globular clusters

Recent studies suggest that globular clusters (GCs) may retain a substantial population of stellar-mass black holes (BHs), in contrast to the long-held belief of a few to zero BHs. We model the population of BH low-mass X-ray binaries (BH-LMXBs), an ideal observable proxy for elusive single BHs, produced from a representative group of Milky Way GCs with variable BH populations. We simulate the formation of BH-binaries in GCs through exchange interactions between binary and single stars in the company of tens to hundreds of BHs. Additionally, we consider the impact of the BH population on the rate of compact binaries undergoing gravitational wave driven mergers. The characteristics of the BH-LMXB population and binary properties are sensitive to the GCs structural parameters as well as its unobservable BH population. We find that GCs retaining $\sim 1000$ BHs produce a galactic population of $\sim 150$ ejected BH-LMXBs whereas GCs retaining only $\sim20$ BHs produce zero ejected BH-LMXBs. Moreover, we explore the possibility that some of the presently known BH-LMXBs might have originated in GCs and identify five candidate systems.Comment: 27 pages, 18 figures, 7 tables, submitted to MNRA

Extraction of silymarin compounds from milk thistle (Silybum marianum) seed using hot, liquid water as the solvent

High-value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs occur. When compared to traditional solvents, water is an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A, and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50°C, 70°C, 85°C and 100°C water as a function of time. For taxifolin, silychristin, silybinin A, and silybinin B, extraction with 100°C water resulted in the highest yields. After 210 min of extraction at 100°C, the yield of taxifolin was 1.2 mg/g of seed while the yields of silychristin, silybinin A, and silybinin B were 5.0, 1.8 and 3.3 mg/g of seed, respectively. The ratios of the extracted compounds, and particularly the ratios at long extraction times, showed that the more polar compounds (taxifolin and silychristin) were preferentially extracted at 85°C, while the less polar silybinin was preferentially extracted at 100°C

Modeling the natural freezeback of piles using COMSOL Multiphysics®

Thesis (M.S.) University of Alaska Fairbanks, 2017Slurried pile foundations installed in predrilled holes are one of the most common foundations for building major structures on permafrost. This installation method relies on the cold permafrost to freeze the backfilled slurry around the piles to provide the strength required to support loads of a structure. Nearly all evaluations of freezeback time to date stems from the work of Frederick Crory presented to the First International Conference on Permafrost in 1963 and published in 1966. Crory never published field data but he provided an equation to determine freezeback time. This work was later expanded upon by G.H. Johnston in 1981 however Johnston gives no explanation for how or why he varied from what Crory had done. The purpose of this research is to check the results predicted by both Crory and Johnston with a contemporary computer modeling using COMSOL ® Multiphysics. Due to the advancement in technology and the power of COMSOL as a program more variables and situations will be able to be examined than what was available to Crory or Johnston at the times of their publications. This will be the first research in over 50 years to revise the work first published by Crory and show that his equation produces results that are significantly shorter than what the model calculates

Conditional quantum state engineering in repeated 2-photon down conversion

The U(1,1) and U(2) transformations realized by three-mode interaction in the respective parametric approximations are studied in conditional measurement, and the corresponding non-unitary transformation operators are derived. As an application, the preparation of single-mode quantum states using an optical feedback loop is discussed, with special emphasis of Fock state preparation. For that example, the influence of non-perfect detection and feedback is also considered.Comment: 17 pages, 4 figures, using a4.st

An Unusual Type of Sterility in a Bull

A purebred 22-month-old Shorthorn bull was admitted to Stange Memorial Clinic on Oct. 4, 1950. The history indicated that the animal had normal sexual desire but was unable to protrude his penis

Study of a heat rejection system using capillary pumping

Results of an analytical study investigating the application of capillary pumping to the heat rejection loop of an advanced Rankine cycle power conversion system are presented. The feasibility of the concept of capillary pumping as an alternate to electromagnetic pumping is analytically demonstrated. Capillary pumping is shown to provide a potential for weight and electrical power saving and reliability through the use of redundant systems. A screen wick pump design with arterial feed lines was analytically developed. Advantages of this design are high thermodynamic and hydrodynamic efficiency, which provide a lightweight easily packaged system. Operational problems were identified which must be solved for successful application of capillary pumping. The most important are the development of start up and shutdown procedures, and development of a means of keeping noncondensibles from the system and of earth-bound testing procedures

Quantum state conversion by cross-Kerr interaction

A generalized Mach-Zehnder-type interferometer equipped with cross-Kerr elements is proposed to convert N-photon truncated single-mode quantum states into (N+1)-mode single-photon states, which are suitable for further state manipulation by means of beam splitter arrays and ON/OFF-detections, and vice versa. Applications to the realization of unitary and non-unitary transformations, quantum state reconstruction, and quantum telemanipulation are studied.Comment: 22 pages, 4 figures, using a4.st