Development of a Repairable Heat Exchange for Disposal Considerations for Household and Municipal Waste

Evolvent form can be applied in the new design of an air cooler and shell and tube heat exchanger used in the oil and gas industry. The air cooler is constructed as a vertically cylindrical multi-section with the evolvent-profile tube row in tube bundle. Tubes have a U-shape form for solving the problem of destruction from linear thermal expansion during maintenance. The dismountable shell-and-tube heat exchanger has an evolvent-profile tube bundle. The advantage of this heat exchanger is its dismountable construction, maintainability and energy efficiency. This is enhanced by the construction of the heat exchange element, which consists of stainless corrugated flexible tubes. Dismountable construction is achieved by a set of flanges and fittings. The energy efficiency of the heat exchanger is determined by thin wall of the corrugated tube, which is 0.3 mm, whereby a heat energy will be transferred faster from a hot stream to cold liquid. Also, energy efficiency is enhanced by tight packing of the tube bundle, which contributes to increase heat transfer area per unit volume. Such solutions contribute to the promotion of more efficient technological equipment and promising ideas for further development and improvement of technical and technological complexes. Keywords: tube, heat, corrugated, flexible, evolvent, constructio

Resonance states of superheavy hydrogen nuclei obtained in transfer reactions with exotic beams

A resonance state situated at 1.8 ± 0.1 and, most likely, another state positioned at 2.7 ± 0.1 MeV above the t+n+n decay threshold were observed in the missing mass energy spectrum of the 5H nucleus produced in the reaction 3H(t,p) 5H. The peak located close to E 5 ≈ H = 1.8 MeV also was seen in the 5H spectrum obtained from the energy distributions of 3H nuclei emitted in the reaction 2H( 6He, 5H) 3He. The width ( ≤ obs ≤ 0.5 MeV) obtained for the two 5H resonance states is surprisingly small. A state of 4H with E res = 3.3 MeV and γ 2 = 2.3 MeV was obtained in the reaction 2H(t,p) 4H from the proton spectrum.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Resonance States of Hydrogen Nuclei 4H and 5H Obtained in Transfer Reactions with Exotic Beams

To investigate 5H resonance states with a better instrumental resolution, we utilized the two-neutron transfer reaction 3H(t, p)5H accomplished with the use of a cryogenic liquid-tritium target and 57.5-MeV triton beam. As a result of this study, a valuable fraction of protons detected at θlab = 18°-32° in ptn coincidence events was attributed to the states of the 5H nucleus. Two resonance states situated at 1.8 plusmn; 0.1 and 2.7 ± 0.1 MeV above the t + n + n decay threshold were obtained in the missing mass energy spectrum of the 5H nucleus. The peak located close to E5H = 1.8 MeV was clearly seen in the H spectrum obtained from the energy distributions of 3H nuclei emitted in the reaction 2H(6He, 5H)3He at θ lab = 17°-32°. The width (Γobs ≤ 0.5 MeV) obtained for the two 5H resonance states is surprisingly small. A state of 4H with Eres = 3.3 MeV and γ2 = 2.3 MeV was obtained in the reaction 2H(t, p)4H from the spectra of protons leaving the target at θlab = 18°-32° and detected in coincidence with neutrons emitted in the decay of 4H nuclei. © 2003 MAIK "Nauka/Interperiodica".SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Prompt neutrons accompanying the spontaneous fission of 250^{250}No

International audienceThis paper describes the experiment conducted on the SHELS (Separator for Heavy Element Spectroscopy) separator [1] aimed at studying the properties of spontaneous fission of 250No. A separator detection system consists of a time-of-flight system and SFiNx (Spontaneous Fission, Neutrons and x-rays) detection system [2] is described. The SFiNx detection system consists of an assembly of double-sided Si detectors, around which 116 proportional neutron counters filled with 3He are placed. During experiment, 1366 events of spontaneous fission of 250No were registered. The average number of neutrons per one fission (⁠v¯ = 4.24 ± 0.13) and the distribution of neutron multiplicities were obtained, and the half-lives of the 250No were measured for the ground T1/2 = (3.89 ± 0.17) µs and isomeric states T1/2 = (39.14 ± 3.34) µs

The investigation of properties of short-lived SF isotopes (Z > 100) at the focal plane of VASSILISSA separator

For experiments aimed at the study of spontaneous fission of transfermium nuclei improvements in the focal plane detector system of recoil separator VASSILISSA have been made. A neutron detector consisting of 54 3He-filled counters has been mounted around the focal-plane detector chamber. The reaction 48Ca + 206Pb = 2n + 252No is used for tuning the separator settings and calibrating the detector system with the spontaneous fission of the 252No. The average neutron number per 252No spontaneous fission event is as large as ν̅ = 4.06 ± 0.12. The short-lived heavy isotopes 244,246Fm, produced in the complete fusion reactions 40Ar + 206,208Pb, are investigated. The average number of neutrons per spontaneous fission of 244,246Fm from the experimental data were (ν̅ = 3.3 ± 0.3) and (ν̅ = 3.55 ± 0.50), respectively. Both values are determined for the first time

High-K,t1/2=1.4(1) ms, isomeric state in Lr255

An isomeric state in Lr255 with a half-life of t1/2=1.4(1) ms and Ex>720-keV has been observed for the first time using the GABRIELA setup at the focal plane of the VASSILISSA separator. Based on its K-forbiddeness, the configuration of the state is most probably formed by coupling the valence proton to a two quasiparticle neutron excitation. Possible three quasiparticle configurations are discussed. © 2008 The American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Gamma and electron spectroscopy of heavy nuclei at FLNR JINR

Detailed spectroscopic information of excited nuclear states in deformed transfermium nuclei is scarce. Most of the information available today has been obtained from investigations of fine structure α decay. Although α decay gives access to hindrance factors and lifetimes which are strongly correlated to shell/subshell closures and the presence of isomers, only the combined use of γ and conversion electron spectroscopy allows the precise determination of excitation energy, spin and parity of nuclear levels. In particular, the study of odd isotopes gives crucial information on the single particle states available at and around the Fermi surface. In the following, the preliminary results of decay studies using α - γ and α - beta coincidences at the focal plane of the VASSILISSA recoil separator are presented. © 2007 American Institute of Physics.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Detailed spectroscopy in 249^{249}Fm

Excited states in 249Fm were populated via the alpha decay of 253No and the subsequent decay was observed with the GABRIELA detection system installed at the focal plane of the VASSILISSA recoil separator. The energies, spins, and parities of these states could be established through combined alpha, gamma, and conversion-electron spectroscopy. The first members of the ground-state rotational band were identified. Their excitation energies as well as the observation of a cross-over E2 transition confirm the assignment of 7/2+[624] for the ground state of 249Fm. Two excited states were also observed and their decay properties suggest that they correspond to the particle excitation 9/2-[734] and hole excitation 5/2+[622]. The analysis suggests that the 279-keV transition de-exciting the 9/2- state has anomalous E1 conversion coefficients

Isomeric states in 253No

Isomeric states in 253No have been investigated by conversion electron and γ -ray spectroscopy with the GABRIELA detection system. The 31μs isomer reported more than 30 years ago is found to decay to the ground state of 253No by the emission of a 167keV M2 transition. The spin and parity of this low-lying isomeric state are established to be 5/2 + .The presence of another longer-lived isomeric state is also discussed. © Società Italiana di Fisica and Springer-Verlag 2007.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Spectroscopy of heavy elements at Dubna

In 2004, the GABRIELA (Gamma Alpha Beta Recoil Investigation with the Electromagnetic Analyzer VASSILISSA) collaboration started a twofold scientific program at the FLNR (Dubna) laboratory: (a) the systematic study of the behaviour of single particle states within isotopic and isotonic chains with Z = 100-104 as N varies from 152 to 162 and (b) the study of isotopes for which very little spectroscopic information is known. After discussing the Physics motivations and the experimental setup, some new results concerning the structure of 249Fm and 253No nuclei, and some preliminary results on the decay of 217Pa decay are presented.SCOPUS: cp.pinfo:eu-repo/semantics/publishe