Beta decay Research Papers - Academia.edu (original) (raw)

Imaging was done in 80 patients with gastrointestinal hemorrhage using red blood cells labeled with 99mTc by a modified in vivo technique. Bleeding was detected in 65% of 40 patients with bright red blood per rectum, 71% of 35 patients... more

Imaging was done in 80 patients with gastrointestinal hemorrhage using red blood cells labeled with 99mTc by a modified in vivo technique. Bleeding was detected in 65% of 40 patients with bright red blood per rectum, 71% of 35 patients with melena, and in none of the five patients with occult bleeding and chronic anemia. No clinical evidence of further

The constant photocurrent method was implemented to determine the density of states in tritiated hydrogenated amorphous silicon below the Fermi level. The tritiated hydrogenated amorphous silicon samples were grown using a mixture of... more

The constant photocurrent method was implemented to determine the density of states in tritiated hydrogenated amorphous silicon below the Fermi level. The tritiated hydrogenated amorphous silicon samples were grown using a mixture of silane and tritium gases in the dc saddle-field deposition system. Over time the tritium incorporated in the amorphous silicon undergoes beta decay and transmutation into helium. The transmutation leads to an increase in the density of states in the energy gap of the material. These states are linked to silicon dangling-bond defects. Given its well-characterized decay process, tritium can be used as an experimental tool to study the behavior of hydrogenated amorphous silicon thin films as a function of their defect state density. The density-of-states information in this work indicates a dominant peak of doubly occupied dangling bonds (D-) positioned 1.24 eV below the conduction band. The defect density was monitored in time showing an increase of more than two orders of magnitude over a period of 20 days and a decrease of similar magnitude upon thermal annealing.

Contemporary physics states that an electron neutrino takes part in all events of beta decay. Here we show that electron-positron pairs participate in all beta decay events. For this reason, the hypothesis of electron neutrino presence is... more

Contemporary physics states that an electron neutrino takes part in all events of beta decay. Here we show that electron-positron pairs participate in all beta decay events. For this reason, the hypothesis of electron neutrino presence is not necessary in β¯, β + and electron capture reactions.

This paper presents a convenient calculation formula of energy density for nuclear fuel or nuclear battery that outputs energy by whatever decay. Also a relative formula is deduced for easy comparison between different fuels. At last,... more

This paper presents a convenient calculation formula of energy density for nuclear fuel or nuclear battery that outputs energy by whatever decay. Also a relative formula is deduced for easy comparison between different fuels. At last, with the convenient formula, the energy density comparison and possibility of applying different isomer beta fuels are proactively calculated and aggressively discussed.

The last decade has witnessed both quantitative and qualitative progresses in Shell Model studies, which have resulted in remarkable gains in our understanding of the structure of the nucleus. Indeed, it is now possible to diagonalize... more

The last decade has witnessed both quantitative and qualitative progresses in Shell Model studies, which have resulted in remarkable gains in our understanding of the structure of the nucleus. Indeed, it is now possible to diagonalize matrices in determinantal spaces of dimensionality up to 10^9 using the Lanczos tridiagonal construction, whose formal and numerical aspects we will analyze. Besides, many new approximation methods have been developed in order to overcome the dimensionality limitations. Furthermore, new effective nucleon-nucleon interactions have been constructed that contain both two and three-body contributions. The former are derived from realistic potentials (i.e., consistent with two nucleon data). The latter incorporate the pure monopole terms necessary to correct the bad saturation and shell-formation properties of the realistic two-body forces. This combination appears to solve a number of hitherto puzzling problems. In the present review we will concentrate on those results which illustrate the global features of the approach: the universality of the effective interaction and the capacity of the Shell Model to describe simultaneously all the manifestations of the nuclear dynamics either of single particle or collective nature. We will also treat in some detail the problems associated with rotational motion, the origin of quenching of the Gamow Teller transitions, the double beta-decays, the effect of isospin non conserving nuclear forces, and the specificities of the very neutron rich nuclei. Many other calculations--that appear to have ``merely'' spectroscopic interest--are touched upon briefly, although we are fully aware that much of the credibility of the Shell Model rests on them.

Nuclear and neutron beta decays have historically played a central role in determining the V Ą A structure of weak interactions and in shaping what we now call the standard model (SM)[1, 2]. Nowadays, precision measurements of low-energy... more

Nuclear and neutron beta decays have historically played a central role in determining the V Ą A structure of weak interactions and in shaping what we now call the standard model (SM)[1, 2]. Nowadays, precision measurements of low-energy processes such as neutron decay can be used to probe the existence of non-SM interactions, such as novel scalar and tensor structures. Considerable experimental efforts using both cold and ultracold neutrons are underway worldwide, with the aim to improve the precision of various neutron decay ...

The pair of lunar rovers discussed in this report will return video and state data to various ventures, including theme park and marketing concerns, science agencies, and educational institutions. The greatest challenge accepted by the... more

The pair of lunar rovers discussed in this report will return video and state data to various ventures, including theme park and marketing concerns, science agencies, and educational institutions. The greatest challenge accepted by the design team was to enable operations throughout the extremely cold and dark lunar night, an unprecedented goal in planetary exploration. This is achieved through the use of the emerging technology of Alkali Metal Thermal to Electric Converters (AMTEC), provided with heat from a innovative beta-decay heat source, Krypton-85 gas. Although previous space missions have returned still images, our design will convey panoramic video from a ring of cameras around the rover. A six-wheel rocker bogie mechanism is implemented to propel the rover. The rovers will also provide the ability to safeguard their operation to allow untrained members of the general public to drive the vehicle. Additionally, scientific exploration and educational outreach will be supporte...

We have measured the angular distribution of recoiling daughter nuclei emitted from the Gamow-Teller beta\betabeta decay of spin-polarized 80^{80}80Rb. The asymmetry of this distribution vanishes to lowest order in the Standard Model (SM) in pure... more

We have measured the angular distribution of recoiling daughter nuclei emitted from the Gamow-Teller beta\betabeta decay of spin-polarized 80^{80}80Rb. The asymmetry of this distribution vanishes to lowest order in the Standard Model (SM) in pure Gamow-Teller decays, producing an observable very sensitive to new interactions. We measure the non-SM contribution to the asymmetry to be ATA_{T}AT= 0.015 pm\pmpm 0.029 (stat) pm\pmpm 0.019 (syst), consistent with the SM prediction. We constrain higher-order SM corrections using the measured momentum dependence of the asymmetry, and their remaining uncertainty dominates the systematic error. Future progress in determining the weak magnetism term theoretically or experimentally would reduce the final errors. We describe the resulting constraints on fundamental 4-Fermi tensor interactions.

We have cloned and sequenced a human islet amyloid polypeptide (IAPP) cDNA. A secretory 89 amino acid IAPP protein precursor is predicted from which the 37 amino acid IAPP molecule is formed by amino-and carboxyterminal proteolytic... more

We have cloned and sequenced a human islet amyloid polypeptide (IAPP) cDNA. A secretory 89 amino acid IAPP protein precursor is predicted from which the 37 amino acid IAPP molecule is formed by amino-and carboxyterminal proteolytic processing. The IAPP peptide is ...

In the first part all the available measurements for the first-forbidden beta-transition 2-(1.41 MeV beta-)2+ in 122Sb are analyzed and the extraction of the corresponding beta-moment is made. In the second part, the... more

In the first part all the available measurements for the first-forbidden beta-transition 2-(1.41 MeV beta-)2+ in 122Sb are analyzed and the extraction of the corresponding beta-moment is made. In the second part, the pairing-plus-quadrupole model is used to calculate the same beta-moments. The result shows that this is not a satisfactory description of the nuclear states involved in the beta-decay

Hepatic Kupffer cells are a major component of the reticuloendothelial or macrophage system. They were the first phagocytic cell type whose phagocytosis was shown to be influenced by plasma fibronectin, a dimeric opsonic glycoprotein. In... more

Hepatic Kupffer cells are a major component of the reticuloendothelial or macrophage system. They were the first phagocytic cell type whose phagocytosis was shown to be influenced by plasma fibronectin, a dimeric opsonic glycoprotein. In the current study, the binding of soluble radioiodinated fibronectin purified from rat serum to isolated rat hepatic Kupffer cells was investigated using a cultured Kupffer cell monolayer technique. Binding was specific, since unlabeled purified fibronectin competed in a dose-dependent manner with the 125I-fibronectin for binding to the Kupffer cells. Addition of gelatin enhanced the binding of 125I-fibronectin to Kupffer cells. The phagocytosis of gelatinized-coated red cells by Kupffer cells was increased either by preopsonizing the target particles with purified fibronectin or by the addition of purified fibronectin to the culture medium. In contrast, exposure of the Kupffer cells to medium containing purified fibronectin followed by wash-removal...