Experimental study of the Ca2 1S+1S asymptote

The filtered laser excitation technique was applied for measuring transition frequencies of the Ca$_2$ B-X system from asymptotic levels of the X$^1\Sigma_{\mathrm g}^{+}$ ground state reaching $v''=38$. That level has an outer classical turning point of about 20~\AA which is only 0.2 \rcm below the molecular $^1$S$+^1$S asymptote. Extensive analysis of the spectroscopic data, involving Monte Carlo simulation, allowed for a purely experimental determination of the long range parameters of the potential energy curve. The possible values of the s-wave scattering length could be limited to be between 250$a_0$ and 1000$a_0$.Comment: 10 pages, 7 figure

Fourier-transform spectroscopy of Sr2 and revised ground state potential

Precise potentials for the ground state X1Sigma+g and the minimum region of the excited state 2_1Sigma+u of Sr2 are derived by high resolution Fourier-transform spectroscopy of fluorescence progressions from single frequency laser excitation of Sr2 produced in a heat pipe at 950 Celsius. A change of the rotational assignment by four units compared to an earlier work (G. Gerber, R. M\"oller, and H. Schneider, J. Chem. Phys. 81, 1538 (1984)) is needed for a consistent description leading to a significant shift of the potentials towards longer inter atomic distances. The huge amount of ground state data derived for the three different isotopomers 88Sr2, 86Sr88Sr and 87Sr88Sr (almost 60% of all excisting bound rovibrational ground state levels for the isotopomer 88Sr2) fixes this assignment undoubtedly. The presented ground state potential is derived from the observed transitions for the radial region from 4 to 11 A (9 cm-1 below the asymptote) and is extended to the longe range region by the use of theoretical dispersion coefficients together with already available photoassociation data. New estimations of the scattering lengths for the complete set of isotopic combinations are derived by mass scaling with the derived potential. The data set for the excited state 2_1Sigma+u was sufficient to derive a potential energy curve around the minimum.Comment: 10 pages, 7 figures, some small corrections done especially to the potential description of the excited state (already included in the published journal version

Strategies for the analysis of osteitic bone defects at the diaphysis of long bones

Septic diseases of the bone and the immediate surrounding soft tissue, i.e., osteitis, belong to the most alarming findings in recent traumatology and orthopedic surgery. The paramount goal of this therapy is to preserve the stable weight-bearing bones while maintaining a correct axis and proper working muscles and joints, in order to avoid permanent disability in the patient. “State-of-the-art” therapy of osteitis/osteomyelitis therapy has two priorities: eradication of the infection and reconstruction of bone and soft tissue. Surgical treatment of the affected bone segments and soft tissue, followed by reconstructive methods, continues to be the main basic therapy. It is often extremely difficult to decide whether the affected bone segment has to be resected, or whether bone continuity can be preserved. The following paper provides strategies and guidance to help guide decisions in this complex and challenging area

The potential of the ground state of NaRb

The X$^{1}\Sigma ^{+}$ state of NaRb was studied by Fourier transform spectroscopy. An accurate potential energy curve was derived from more than 8800 transitions in isotopomers $^{23}$Na$^{85}$Rb and $^{23}$Na$^{87}$Rb. This potential reproduces the experimental observations within their uncertainties of 0.003 \rcm to 0.007 \rcm. The outer classical turning point of the last observed energy level ($v''=76$, $J''=27$) lies at $\approx 12.4$ \AA, leading to a energy of 4.5 \rcm below the ground state asymptote.Comment: 8 pages, 6 figures and 2 table

The coupling of the X1Σ+^{1}\Sigma ^{+} and a3Σ+^{3}\Sigma ^{+} states of KRb

A comprehensive study of the electronic states at the 4s+5s asymptote in KRb is presented. Abundant spectroscopic data on the \astate state were collected by Fourier-transform spectroscopy which allow to determine an accurate experimental potential energy curve up to 14.8 \AA . The existing data set (C. Amiot et al. J. Chem. Phys. 112, 7068 (2000)) on the ground state \Xstate was extended by several additional levels lying close to the atomic asymptote. In a coupled channels fitting routine complete molecular potentials for both electronic states were fitted. Along with the line frequencies of the molecular transitions, recently published positions of Feshbach resonances in $^{40}$K and $^{87}$Rb mixtures (F. Ferlaino et al. Phys. Rev. A 74, 039903 (2006)) were included in the fit. This makes the derived potential curves capable for an accurate description of observed cold collision features so far. Predictions of scattering lengths and Feshbach resonances in other isotopic combinations are reported.Comment: 14 pages, 5 figure

Feshbach spectroscopy and analysis of the interaction potentials of ultracold sodium

We have studied magnetic Feshbach resonances in an ultracold sample of Na prepared in the absolute hyperfine ground state. We report on the observation of three s-, eight d-, and three g-wave Feshbach resonances, including a more precise determination of two known s-wave resonances, and one s-wave resonance at a magnetic field exceeding 200mT. Using a coupled-channels calculation we have improved the sodium ground-state potentials by taking into account these new experimental data, and derived values for the scattering lengths. In addition, a description of the molecular states leading to the Feshbach resonances in terms of the asymptotic-bound-state model is presented.Comment: 11 pages, 4 figure

Study of coupled states for the (4s^{2})^{1}S + (4s4p)^{3}P asymptote of Ca_{2}

The coupled states A^{1}\Sigma_{u}^{+} (^{1}D +}1}S), c^{3}\Pi_{u} (^{3}P + ^{1}S) and a^{3}\Sigma_{u}^{+} (^{3}P +}1}S) of the calcium dimer are investigated in a laser induced fluorescence experiment combined with high-resolution Fourier-transform spectroscopy. A global deperturbation analysis of the observed levels, considering a model, which is complete within the subspace of relevant neighboring states, is performed using the Fourier Grid Hamiltonian method. We determine the potential energy curve of the A^{1}\Sigma_{u}^{+} and c^{3}\Pi_{u} states and the strengths of the couplings between them. The c^{3}\Pi_{u} and \as states are of particular importance for the description of collisional processes between calcium atoms in the ground state ^{1}S_{0} and excited state ^{3}P_{1} applied in studies for establishing an optical frequency standard with Ca.Comment: 15 pages, 12 figure

Effect of the tropical tannin-rich shrub legumes Calliandra calothyrsus and Flemingia macrophylla on methane emission and nitrogen and energy balance in growing lambs

The objective of this study was to test whether the use of tannin-rich shrub legume forage is advantageous for methane mitigation and metabolic protein supply at unchanged energy supply when supplemented in combination with tannin-free legumes to sheep. In a 6 × 6 Latin-square design, foliage of two tannin-rich shrub legume species (Calliandra calothyrsus and Flemingia macrophylla) were used to replace either 1/3 or 2/3, respectively, of a herbaceous high-quality legume (Vigna unguiculata) in a diet composed of the tropical grass Brachiaria brizantha and Vigna in a ratio of 0.55 : 0.45. A Brachiaria-only diet served as the negative control. Each experimental period lasted for 28 days, with week 3 serving for balance measurement and data collection inclusive of a 2-day stay of the sheep in open-circuit respiration chambers for measurement of gaseous exchange. While Vigna supplementation improved protein and energy utilisation, the response to the partial replacement with tannin-rich legumes was less clear. The apparent total tract digestibilities of organic matter, NDF and ADF were reduced when the tannin-rich plants partially replaced Vigna, and the dose-response relationships were mainly linear. The tannin-rich plants caused the expected redistribution of more faecal N in relation to urinary N. While Flemingia addition still led to a net body N retention, even when fed at the higher proportion, adding higher amounts of Calliandra resulted in body protein mobilisation in the growing lambs. With respect to energy, supplementation of Vigna alone improved utilisation, while this effect was absent when a tannin-rich plant was added. The inclusion of the tannin-rich plants reduced methane emission per day and per unit of feed and energy intake by up to 24% relative to the Vigna-only-supplemented diet, but this seems to have been mostly the result of a reduced organic matter and fibre digestion. In conclusion, Calliandra seems less apt as protein supplement for ruminants while Flemingia could partially replace a high-quality legume in tropical livestock systems. However, methane mitigation would be small due to associated reductions in N and energy retentio

The X1Σ+^1\Sigma^+ and a3Σ+^3\Sigma^+ states of LiCs studied by Fourier-transform spectroscopy

We present the first high-resolution spectroscopic study of LiCs. LiCs is formed in a heat pipe oven and studied via laser-induced fluorescence Fourier-transform spectroscopy. By exciting molecules through the X$^1\Sigma^+$-B$^1\Pi$ and X$^1\Sigma^+$-D$^1\Pi$ transitions vibrational levels of the X$^1\Sigma^+$ ground state have been observed up to 3cm^{-1} below the dissociation limit enabling an accurate construction of the potential. Furthermore, rovibrational levels in the a$^3\Sigma^+$ triplet ground state have been observed because the excited states obtain sufficient triplet character at the corresponding excited atomic asymptote. With the help of coupled channels calculations accurate singlet and triplet ground state potentials were derived reaching the atomic ground state asymptote and allowing first predictions of cold collision properties of Li + Cs pairs.Comment: 10 pages, 5 figures. Submitted for publicatio