Drug rationalization: now for the hard part

In 1995 a national drug policy was finalized in Nepal. The authors outline the measures that were recommended for its implementation and the activities that have so far been undertaken. Much remains to be done, most notably in assisting, coordinating and supervising these activities.     

Removal of Metal Ions from Storm-Water Runoff by Low-Cost Sorbents: Batch and Column Studies

The possibility of using the sorption technology to reduce the levels of metal ions present in urban storm-water runoff was investigated in this study. Seven sorbent materials including Amberlite XAD7, chitosan, crab shell, peat, Sargassum, sawdust, and sugarcane bagasse were initially examined for removal of 11 metal ions (Na, K, Ca, Mg, Mn, Co, Ni, Cu, Zn, Cd, and Pb) from simulated storm-water runoff at different concentrations. Among these sorbents, crab shell performed well with removal efficiencies exceeding 93% for all heavy metal ions examined and thus selected for further studies. Based on scanning electron microscopy/energy-dispersive x-ray analysis, microprecipitation of metal carbonates followed by adsorption onto the surface of crab shell was identified as the major mechanism responsible for removal of heavy metal ions by crab shell. Crab shell exhibited rapid removal of meal ions with attainment of biosorption equilibrium within 20 min. A crab-shell-packed column was used to study the continuous metal retention process. The column performed very well in the removal of heavy metal ions and was able to operate up to 192 h at a flow rate of 10 mL/min before outlet concentrations of Mn and Co reached 0.3 times of their respective inlet concentrations. Other metal ions such as Pb, Zn, Ni, Cd, and Cu were only in trace levels in the final effluent until 192 h. These findings would form the basis for the future development of crab-shell-based biofilters for removal of dissolved heavy metal ions from storm-water runoff.     

Energy‐based predictive criterion for LCP fibrillation in LCP/thermoplastic polymer blends under shear

This article relates the fibrillation of liquid crystalline polymer (LCP) under shear in its blend with a thermoplastic polymer (TP) to the relative rate of energy utilization in the LCP and TP phases. The development of a criterion based on the energy relationship for predicting LCP fibrillation in the blend is discussed. The formation of LCP fibers in the blends of LCP with polycarbonate (PC), polyethylene naphthalate (PEN), high‐density polyethylene (HDPE), polypropylene (PP), and silica‐filled polypropylene (PP) was studied to validate the criterion and to demonstrate its applicability. For all the blends, viscosity data were obtained by using a capillary rheometer, which was subsequently used to estimate the rate of energy utilization in the LCP and the matrix phases. The predictions based on the proposed criterion were verified through the morphological investigations carried out on the extrudates obtained from the same capillary experiments. The energy‐based criterion was easy to implement, could account for the effect of variable LCP concentration and fillers in the blend, and could provide reliable predictions for a variety of LCP/TP blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3314–3324, 2003     

Numerical analysis to study the effect of through thickness reinforcement with different stitch orientations on open-hole laminates

The effect of through thickness reinforced open-hole laminates was analysed in terms of laminate behaviour under in-plane tensile loading based on continuum mechanics. Stitches around the notch were oriented in the longitudinal and transverse directions. To obtain the macroscopic damage and the local stress–strain constitutive behaviour, laminates were modelled on a lamina-wise basis. Interfaces between lamina and stitch yarns were assumed to be perfectly glued and modelled by the contact capability. Discretisation procedures using the principle of virtual work were applied in addition to discretisation of the contact traction. Progressive failure analysis with Puck’s failure criteria was conducted to characterise the failure behaviour of the laminate. In both cases, damage was initiated by a matrix crack in the perpendicular direction of the loading axis on the notch. The longitudinally stitched laminate showed a 14.29% higher strength compared to the transversely stitched laminate by suppressing damage propagation. The results obtained using this finite element technique was consistent with the experimental results.     

Freestanding fiber mats of zeolitic imidazolate framework 7 via one‐step,scalable electrospinning

We demonstrated the fabrication of freestanding zeolitic imidazolate framework 7 (ZIF‐7) nanofiber (NF) mats by means of one‐step, scalable electrospinning. The formation of ZIF‐7 nanoparticles embedded in polymer fibers was unambiguously pinpointed via X‐ray diffraction, transmission electron microscopy, and adsorption studies. The NF mats exhibited excellent characteristics, with an average diameter of 245 nm, in the adsorption and desorption of carbon dioxide (CO₂); this makes them attractive candidates for gas separation and other selective filtration applications. This excellent property of the ZIF‐7 mats was explained by the gate‐opening phenomenon of ZIF‐7, which yielded a stepwise increase in the overall CO₂ uptake capacity. The mechanical strength of the NF mats was also obtained via large‐strain uniaxial tensile deformation, which enabled preliminary assessment of the mat's suitability for textiles and membranes in targeting separation and filtration applications with large‐area permeability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43788.     

Hydrodynamics and liquid phase axial mixing in orifice pipe reactor

Two phase flow in a horizontal pipe, with orifice plates placed at regular intervals as obstructions, was studied for the effect of phase velocities on flow patterns, fractional phase hold-ups, pressure drop and liquid phase axial dispersion. Radioactive technetium-99m (as an aqueous solution of sodium pertechnatate) was used as tracer. A pulse injection technique with two point measurements was employed. Three different orifice diameters were used (8 mm, 16 mm, and 20 mm) in a pipe diameter of 32 mm. The orifice spacing was 500 mm in all cases. Superficial gas (air) velocity was varied over a range from 0.02 m/s to 1.0 m/s and superficial liquid (water) velocity from 0.03 m/s to 0.85 m/s. Different flow patterns under different flow conditions were identified and a generalised flow map is presented. Variations in hold-ups and pressure drop with flow patterns have been explained. Rational correlations have been developed for fractional phase hold-ups and pressure drop. A preliminary comparison of two phase gas-liquid flow in a horizontal pipe with orifice obstructions (to be called orifice pipe reactor), as a gas-liquid contacting device, is made with a conventional bubble column reactor. Recommendations have been made for future work.     

The yields of extracted leaf protein from lucerne (Medicago sativa L.)

The effects of fertilisers, frequency of cutting, row spacing and simazine on the yields of dry matter and extractable protein from lucerne (Medicago sativa L.) were studied using the laboratory-scale pulper and press. Between 40 and 65% protein nitrogen was extractable; extractability was not affected by the various treatments but altered with season. Lucerne responded with increased yields of dry matter and extractable protein to fertilisers, simazine (35 g/ha) and rows spaced at 30.5 cm. Six or 8 harvests were found to give greater yields than 5 harvests in 180 days. The annual yields of extractable protein reached 3100 kg/ha and it is felt that better control of pests could lead to even greater yields.     

CFD simulation of flow pattern and plume dimensions in submerged condensation and reactive gas jets into a liquid bath

Submerged gas jets into a liquid bath are widely used in metal processing and thermal processes. These systems are classified as (a) condensation jet and (b) reaction jet systems. This paper presents the CFD simulation of both the types of jets. The CFD model considers phase change, gas-liquid and gas-gas reactions and the accompanied rates of mass transfer. Mass transfer coefficient was estimated using small eddy model where the value of mass transfer coefficient is calculated based on the local values of turbulent kinetic energy (k) and the dissipation rate (ε). A good agreement with the available experimental data of plume length validates the CFD model. The CFD simulations have also been compared with the available experimental data on velocity and temperature profiles which shows excellent agreement. A comparison between the condensation and the reaction jets has been presented in terms of plume dimensions, flow and temperature patterns. The relative predictions of the present model and the rational correlations have been presented for the estimation of plume length for both the types of jet systems.     

Waste Eggshell-Derived Calcium Oxide and Nanohydroxyapatite Biomaterials for the Preparation of LLDPE Polymer Nanocomposite and Their Thermomechanical Study

Waste eggshells were utilized to make calcium oxide (E-CaO) and hydroxyapatite (E-HAP). E-CaO obtained by heat treatment to eggshells was utilized for the synthesis of E-HAP. Melt compounding of E-CaO/E-HAP was performed with linear low-density polyethylene (LLDPE) on a Brabender Plastograph and ground the obtained formulation for injection molding. Addition of E-CaO/E-HAP in the LLDPE significantly enhanced the flame retardant ability and thermal stability of resultant composites. In the comparative study, E-HAP nanopowder-containing polymer composite showed increment in thermal and mechanical properties than the composite prepared using E-CaO.