Acoustic and optical phonon dynamics from femtosecond time-resolved optical spectroscopy of superconducting iron pnictide Ca(Fe_0.944Co_0.056)_2As_2

We report temperature evolution of coherently excited acoustic and optical phonon dynamics in superconducting iron pnictide single crystal Ca(Fe_0.944Co_0.056)_2As_2 across the spin density wave transition at T_SDW ~ 85 K and superconducting transition at T_SC ~20 K. Strain pulse propagation model applied to the generation of the acoustic phonons yields the temperature dependence of the optical constants, and longitudinal and transverse sound velocities in the temperature range of 3.1 K to 300 K. The frequency and dephasing times of the phonons show anomalous temperature dependence below T_SC indicating a coupling of these low energy excitations with the Cooper-pair quasiparticles. A maximum in the amplitude of the acoustic modes at T ~ 170 is seen, attributed to spin fluctuations and strong spin-lattice coupling before T_SDW.Comment: 6 pages, 4 figures (revised manuscript

Ultrafast quasiparticle dynamics in superconducting iron pnictide CaFe1.89Co0.11As2

Nonequilibrium quasiparticle relaxation dynamics is reported in superconducting CaFe1.89Co0.11As2 single crystal using femtosecond time-resolved pump-probe spectroscopy. The carrier dynamics reflects a three-channel decay of laser deposited energy with characteristic time scales varying from few hundreds of femtoseconds to order of few nanoseconds where the amplitudes and time-constants of the individual electronic relaxation components show significant changes in the vicinity of the spin density wave (T_SDW ~ 85 K) and superconducting (T_SC ~ 20 K) phase transition temperatures. The quasiparticles dynamics in the superconducting state reveals a charge gap with reduced gap value of 2$\Delta$_0/k_BT_SC ~ 1.8. We have determined the electron-phonon coupling constant \lemda to be ~ 0.14 from the temperature dependent relaxation time in the normal state, a value close to those reported for other types of pnictides. From the peculiar temperature-dependence of the carrier dynamics in the intermediate temperature region between the superconducting and spin density wave phase transitions, we infer a temperature scale where the charge gap associated with the spin ordered phase is maximum and closes on either side while approaching the two phase transition temperatures.Comment: 6 pages, 4 figures (revised manuscript); http://dx.doi.org/10.1016/j.ssc.2013.02.00

Magnetotransport in the CeIrIn5{_5} system: The influence of antiferromagnetic fluctuations

We present an overview of magnetotransport measurements on the heavy-fermion superconductor CeIrIn$_5$. Sensitive measurements of the Hall effect and magnetoresistance (MR) are used to elucidate the low temperature phase diagram of this system. The normal-state magnetotransport is highly anomalous, and experimental signatures of a pseudogap-like precursor state to superconductivity as well as evidence for two distinct scattering times governing the Hall effect and the MR are observed. Our observations point out the influence of antiferromagnetic fluctuations on the magnetotransport in this class of materials. The implications of these findings, both in the context of unconventional superconductivity in heavy-fermion systems as well as in relation to the high temperature superconducting cuprates are discussed

When Stakeholder Pressure drives the Circular Economy: Measuring the Mediating Role of Innovation Capabilities

Sustainability is hinged on innovation. The importance of sustainable innovation management in sustainable supply chain management (SSCM) cannot be underestimated. Studies on SSCM have emphasised the need for sustainable innovation in achieving sustainability but none provide deep insights into sustainable innovation management in SSCM implementation. This lack of research depth stimulates this study to identify and investigate criteria for sustainable supply chain management innovation advancement. This paper proposes a sustainable innovation criteria framework for investigating sustainable supply chains in manufacturing companies. To exemplify the applicability and efficiency of the proposed framework, a sample of five Indian manufacturing companies are used to evaluate and prioritise the sustainable innovation management criteria, using the ‘best–worst’ multi-criteria decision-making (BW-MCDM) model. The criteria weights for all companies from BWM are aggregated, averaged and used for ranking. The respondent managers viewed ‘financial availability for innovation’ as the most important sustainable innovation sub-criteria. The results of the study will inform industrial managers, practitioners and decision-makers on which criteria to focus on during the implementation stage, to increase sustainability in manufacturing supply chains, and further advance corporate and supply chain sustainable development. The framework may also serve as a theoretical construct for a future empirical study on sustainable supply chain innovation in the manufacturing sector. This paper sets the stage for further research in sustainable innovation practices in the manufacturing sector and its supply chains

Amoxicillin and amoxicillin/clavulanate reduce ethanol intake and increase GLT-1 expression as well as AKT phosphorylation in mesocorticolimbic regions.

Studies have shown that administration of the β-lactam antibiotic, ceftriaxone (CEF) attenuates ethanol consumption and cocaine seeking behavior as well as preventing ethanol-induced downregulation of glutamate transporter 1 (GLT-1) expression in central reward brain regions. However, it is not known if these effects are compound-specific. Therefore, the present study examined the effects of two other β-lactam antibiotics, amoxicillin (AMOX) and amoxicillin/clavulanate (Augmentin, AUG), on ethanol drinking, as well as GLT-1 and phosphorylated-AKT (pAKT) levels in the nucleus accumbens (Acb) and medial prefrontal cortex (mPFC) of alcohol-preferring (P) rats. P rats were exposed to free-choice of ethanol (15% and 30%) for five weeks and were given five consecutive daily i.p. injections of saline vehicle, 100 mg/kg AMOX or 100 mg/kg AUG. Both compounds significantly decreased ethanol intake and significantly increased GLT-1 expression in the Acb. AUG also increased GLT-1 expression in the mPFC. Results for changes in pAKT levels matched those for GLT-1, indicating that β-lactam antibiotic-induced reductions in ethanol intake are negatively associated with increases in GLT-1 and pAKT levels within two critical brains regions mediating drug reward and reinforcement. These findings add to a growing literature that pharmacological increases in GLT-1 expression are associated with decreases in ethanol intake and suggest that one mechanism mediating this effect may be increased phosphorylation of AKT. Thus, GLT-1 and pAKT may serve as molecular targets for the treatment of alcohol and drug abuse/dependence

A Quantitative Approach to Prioritize Sustainable Concrete

Cement industry consumes high energy and produces major emissions to the environment. In order to reduce the effects (environmental impact, energy, and resources) caused by conventional materials, various by-products and pozzolonic material are used to achieve sustainable concrete. Assessing the concrete performance based on multiple conflicting attributes is decisive and compelling. It is difficult to choose an alternative among the Supplementary Cementitious Materials (SCM) considering a set of quantitative performance attributes. Hence, the present study utilizes the theories of decision making to prioritize an alternative environmentally and technologically. The purpose of the present study is to observe the sustainable performance of five different concretes made of OPC, Fly ash, GGBS, Metakaolin and Composite Cement for a particular grade of concrete. The study has considered workability, strength attribute (compressive strength, split tensile and flexural strength) and durability attribute (Sorptivity and RCPT) at their respective optimum replacements. To prioritize an alternative material considering quantitative attributes, Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) is utilized. From the results, it is observed that considering all attributes, flyash based concrete has higher performance and is prioritized among others. The developed approach facilitates the decision-makers in the selection of a sustainable alternative

A precursor state to unconventional superconductivity in CeIrIn5{_5}

We present sensitive measurements of the Hall effect and magnetoresistance in CeIrIn${_5}$ down to temperatures of 50 mK and magnetic fields up to 15 T. The presence of a low temperature coherent Kondo state is established. Deviations from Kohler's rule and a quadratic temperature dependence of the cotangent of the Hall angle are reminiscent of properties observed in the high temperature superconducting cuprates. The most striking observation pertains to the presence of a \textit{precursor} state--characterized by a change in the Hall mobility--that appears to precede the superconductivity in this material, in similarity to the pseudogap in the cuprate high $T_c$ superconductors.Comment: 4 figure

Self-organized Pattern Formation in Motor-Microtubule Mixtures

We propose and study a hydrodynamic model for pattern formation in mixtures of molecular motors and microtubules. The steady state patterns we obtain in different regimes of parameter space include arrangements of vortices and asters separately as well as aster-vortex mixtures and fully disordered states. Such stable steady states are observed in experiments in vitro. The sequence of patterns obtained in the experiments can be associated with smooth trajectories in a non-equilibrium phase diagram for our model.Comment: 11 pages Latex file, 2 figures include

The impact of freight transport capacity limitations on supply chain dynamics

We investigate how capacity limitations in the transportation system affect the dynamic behaviour of supply chains. We are interested in the more recently defined, 'backlash' effect. Using a system dynamics simulation approach, we replicate the well-known Beer Game supply chain for different transport capacity management scenarios. The results indicate that transport capacity limitations negatively impact on inventory and backlog costs, although there is a positive impact on the 'backlash' effect. We show that it is possible for both backlog and inventory to simultaneous occur, a situation which does not arise with the uncapacitated scenario. A vertical collaborative approach to transport provision is able to overcome such a trade-off. © 2013 Taylor & Francis

Iliac wing osteochondroma in a 16-year-old boy: a case report

Osteochondroma is the most common benign bone tumour. Commonly seen in the long bones of the lower extremity. Ilium is a rare site. We present a 16-year-old boy with swelling in the right groin for 8 months. After clinical and radiological evaluation, it was diagnosed as osteochondroma of right iliac wing. Patient underwent en-bloc excision of the lesion and histopathology confirmed the diagnosis. Pelvic osteochondroma is a rare entity but not unusual. Extra periosteal en-bloc excision is the management of choice in patients with cosmetic deformity, neurovascular compression and malignant transformation with very low recurrence rate