Unified covariant treatment of hyperfine splitting for heavy and light mesons

This paper aims at proving the fundamental role of a relativistic formulation for quarkonia models. We present a completely covariant description of a two-quark system interacting by the Cornell potential with a Breit term describing the hyperfine splitting. Using an appropriate procedure to calculate the Breit correction, we find heavy meson masses in excellent agreement with experimental data. Moreover, also when applied to light quarks and even taking average values of the running coupling constant, we prove that covariance properties and hyperfine splitting are sufficient to explain the light mesons spectrum and to give a very good agreement with the data.Comment: 4 page

Modeling Infiltration Kinetics Of Liquids Into Porous Alumina Preforms

MODELING INFILTRATION KINETICS OF LIQUIDS INTO POROUS ALUMINA PREFORMS. Alpha-alumina preform was infiltrated with different infiltrant and pressure for studying the infiltration kinetic. Effects of pre-sintering temperature, type of infiltrant, pressure and multiple infiltrations on the rate of infiltration into porous alumina preforms were described. The pore radius of alumina preform is calculated based on the preform water system by using Washburn model. The pore radius from this model, r of 0.0147 μm is good agreement to the average pore radius found by using mercury porosity measurement, r of 0.0170 μm. The pore radius of 0.0147 μm is used to calculate the rate of infiltration, k. The k factors are 64.83 x 10-5 ms½ and 27.11 x 10-5 ms½ for water and TiCl3 respectively without involving pressure in the calculation. On the other hand, by using pressure, the k factors are 75.14 x 10-5 ms½ and 31.40 x 10-5 ms½ for water and TiCl3 respectively. Other formulas were also included as comparisons. The kinetic of water and titanium trichloride alumina preform system is parabolic in time or linier in square root of time

Seleksi Bakteri Penambat Nitrogen Dan Penghasil Hormon Iaa (Indole Acetic Acid) Dari Rizosfer Tanah Perkebunan Kedelai (Glycine Max L.)

Rizosphere bacteria can be used to fix nitrogen and produce IAA (Indol Acetic Acid) as biofertilizer to support plant growth. The ability of rhizosphere bacteria can be improved using biotechnology. The aim of this study is to select the most potential nitrogen fixing and IAA producing bacteria. Nitrogen fixing and IAA producing bacteria were isolated using JNFB and Luria Bertani + L-tryptofan medium respectively. The ability of nitrogen fixing bacteria were tested by ARA method, while the ability of IAA producing bacteria were investigated by spectrophotometer technique of 535 nm. The highest IAA concentration was produced by isolate I3 which was 33.3 ppm and the highest concentration of nitrogen was yielded by isolate N3 which was 29.93 ppm. Both N3 isolate and I3 isolate potentially as biofertilizer known as PGPR (Plant Growth Promoting Rhizobacteria)

Pengendalian Sel Biofilm Bakteri Patogen Oportunistik dengan Panas dan Klorin

Opportunistic pathogenic bacteria are bacteria that are naturally not present in an environment that, but it dues to contamination of the environment by human waste. From previous research it was found E. coli, Staphylococcus sp. and Salmonella were opportunistic pathogens of the shrimp aquaculture (Percut, Pantai Labu, Pantai Cermin). The aims of this study is to know the ability of these bacteria to form biofilms as well as its control using chlorine and heat. In order to test the ability of the bacteria to form biofilms, the stainless steel have been soaked in SWC media for 1, 3, 6 days. E. coli, Salmonella, and Staphylococcus sp. may form biofilms on incubation of the 1st day but the highest growth was on the 6th day of incubation by E. coli with a 6,35 x 104 CFU/SS, whereas of the lowest biofilm number was found in Salmonella with a 0,28 x 104 CFU/SS. The number of biofilm cells grow in line with a length of incubation. In this research, the most effective concentration of chlorine to kill biofilm cell was 225 ppm for 2 minutes and heat was 100 0C for 5 minutes. The higher the concentration of chlorine and the temperature given more effective to kill the bacteria

Full coherent control of nuclear spins in an optically pumped single quantum dot

Highly polarized nuclear spins within a semiconductor quantum dot (QD) induce effective magnetic (Overhauser) fields of up to several Tesla acting on the electron spin or up to a few hundred mT for the hole spin. Recently this has been recognized as a resource for intrinsic control of QD-based spin quantum bits. However, only static long-lived Overhauser fields could be used. Here we demonstrate fast redirection on the microsecond time-scale of Overhauser fields of the order of 0.5 T experienced by a single electron spin in an optically pumped GaAs quantum dot. This has been achieved using full coherent control of an ensemble of 10^3-10^4 optically polarized nuclear spins by sequences of short radio-frequency (rf) pulses. These results open the way to a new class of experiments using rf techniques to achieve highly-correlated nuclear spins in quantum dots, such as adiabatic demagnetization in the rotating frame leading to sub-micro K nuclear spin temperatures, rapid adiabatic passage, and spin squeezing

Liver transplantation for type I and type IV glycogen storage disease

Progressive liver failure or hepatic complications of the primary disease led to orthotopic liver transplantation in eight children with glycogen storage disease over a 9-year period. One patient had glycogen storage disease (GSD) type I (von Gierke disease) and seven patients had type IV GSD (Andersen disease). As previously reported [19], a 16.5-year-old-girl with GSD type I was successfully treated in 1982 by orthotopic liver transplantation under cyclosporine and steroid immunosuppression. The metabolic consequences of the disease have been eliminated, the renal function and size have remained normal, and the patient has lived a normal young adult life. A late portal venous thrombosis was treated successfully with a distal splenorenal shunt. Orthotopic liver transplantation was performed in seven children with type N GSD who had progressive hepatic failure. Two patients died early from technical complications. The other five have no evidence of recurrent hepatic amylopectinosis after 1.1–5.8 postoperative years. They have had good physical and intellectual maturation. Amylopectin was found in many extrahepatic tissues prior to surgery, but cardiopathy and skeletal myopathy have not developed after transplantation. Postoperative heart biopsies from patients showed either minimal amylopectin deposits as long as 4.5 years following transplantation or a dramatic reduction in sequential biopsies from one patient who initially had dense myocardial deposits. Serious hepatic derangement is seen most commonly in types T and IV GSD. Liver transplantation cures the hepatic manifestations of both types. The extrahepatic deposition of abnormal glycogen appears not to be problematic in type I disease, and while potentially more threatening in type IV disease, may actually exhibit signs of regression after hepatic allografting

Belowground DNA-based techniques: untangling the network of plant root interactions

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