An integrated approach to solve tool-part grouping, job allocation and scheduling problems in a flexible manufacturing system

An integrated approach is discussed in this article to solve the sub-problems like tool-part grouping, job allocation on machines and minimization of make-span in a FMS. Tool and part grouping is performed using “principal component analysis”, and tool allocation has been carried out using priority-based approach by developing a potency index. Thereafter, the concept has evolved based on threshold machining time, minimum operation time, and maximum possible operation time to minimize the make-span of the system. In order to validate the result “analysis of variance” has been employed, and on a simulated example the F ratio is enumerated.     

para‐Substituted 2‐Phenyl‐3,4‐dihydroquinazolin‐4‐ones As Potent and Selective Tankyrase Inhibitors

Human tankyrases are attractive drug targets, especially for the treatment of cancer. We identified a set of highly potent tankyrase inhibitors based on a 2‐phenyl‐3,4‐dihydroquinazolin‐4‐one scaffold. Substitutions at the para position of the scaffold′s phenyl group were evaluated as a strategy to increase potency and improve selectivity. The best compounds displayed single‐digit nanomolar potencies, and profiling against several human diphtheria‐toxin‐like ADP‐ribosyltransferases revealed that a subset of these compounds are highly selective tankyrase inhibitors. The compounds also effectively inhibit Wnt signaling in HEK293 cells. The binding mode of all inhibitors was studied by protein X‐ray crystallography. This allowed us to establish a structural basis for the development of highly potent and selective tankyrase inhibitors based on the 2‐phenyl‐3,4‐dihydroquinazolin‐4‐one scaffold and outline a rational approach to the modification of other inhibitor scaffolds that bind to the nicotinamide site of the catalytic domain.     

Repowering—Next big thing in India

Indian wind energy sector has seen a CAGR of more than 27% during the period 2002–2007. However, the annual capacity additions has been declining for the past 2 years and recently, India lost one place in the Global ranking on total installed wind capacity to China. While issues like unfavourable tariff, non-uniform state policies, unavailability of evacuation infrastructure, etc. can be attributed to the slower pace of capacity addition, the issue of unavailability of on-shore wind sites with sufficiently high wind velocity is expected to take centre stage in the next 2–3 years. Wind sites with low wind velocity make the investment unattractive to developers. Given the current situation, repowering as an investment option, which has already seen favourable response in countries like Germany and Denmark, would start maturing in India. This paper analyzes the present situation of the wind energy in India, evaluates the different wind energy market segments including repowering market, provides financial highlights of the repowering concept and ends with concluding remarks on major triggers which can set this concept in motion.     

Three octave spanning supercontinuum by red-shifted dispersive wave in photonic crystal fibers

This article presents a three-layer index guided lead silicate (SF57) photonic crystal fiber which simultaneously promises to yield large effective optical nonlinear coefficient and low anomalous dispersion that makes it suitable for supercontinuum (SC) generation. At an operating wavelength 1550 nm, the typical optimized value of anomalous dispersion and effective nonlinear coefficient turns out to be ~4 ps/km/nm and ~1078 W^?1km^?1, respectively. Through numerical simulation, it is realized that the designed fiber promises to exhibit three octave spanning SC from 900 to 7200 nm using 50 fs ‘sech’ optical pulses of 5 kW peak power. Due to the cross-phase modulation and four-wave mixing processes, a long range of red-shifted dispersive wave generated, which assists to achieve such large broadening. In addition, we have investigated the compatibility of SC generation with input pulse peak power increment and briefly discussed the impact of nonlinear processes on SC generation.     

Moisture Diffusivity During Drying of Pineapple and Mango Leather as Affected by Sucrose,Pectin, and Maltodextrin

The effect of the addition of sucrose (0, 5, 10%), pectin (0, 1, 2%), and maltodextrin (0, 2.5, 5%) on the moisture diffusion from pineapple and mango pulp during the making of fruit leather was studied in a cabinet drier. The drying rate of both pineapple and mango leather was reduced by the addition of sucrose, pectin, and maltodextrin. Drying rate constant of both pineapple and mango leather was most significantly affected by sucrose followed by maltodextrin and pectin. The drying rate constant (k) of 0.214 and 0.116 1/h was lowest in the pineapple and mango pulp containing 10, 2, and 5% of sucrose, pectin, and maltodextrin, respectively. The experimental moisture effective diffusivity varied from 6.64–12.93?×?10^?7 m²/sec and 1.65–4.03?×?10^?7 m²/sec for pineapple and mango leather, respectively, and the coefficient of determination (R²) of regression coefficients for effective moisture diffusivity was 0.82 and 0.96, respectively. The effect of addition of pectin was most significant on moisture diffusivity both in pineapple and mango leather.     

Traceability in the Indian dairy industry: Concept and practice

The rise in milk adulteration and contamination, fraud incidents and improper handling necessitates effective traceability systems in the Indian dairy industry. Thus, this review investigates current trends, associated challenges, traceability and its fundamental applications to address food safety and quality issues. The paper covers the evolution of milk adulteration and contamination detection techniques from conventional to emerging. Such information and analytical technologies can improve transparency and safety in the dairy industry by implementing effective traceability systems. This review will explore the challenges and future opportunities associated with the current situation in the Indian dairy industry.     

Numerical simulation of thermo-elastic fracture problems using element free Galerkin method

In the present work, element free Galerkin method (EFGM) has been extended to solve thermo-elastic fracture problems in homogeneous and inhomogeneous materials (bi-materials). A thermo-elastic fracture problem is decoupled into two separate problems. At first, the temperature distribution is obtained by solving the heat transfer problem. The temperature field is then employed as input for the mechanical problem to determine the displacement and stress fields. The disturbances due to the presence of crack results in a non-smooth temperature distribution, and induces a singularity in the heat flux at the crack tip. Thermal as well as mechanical problems are enriched intrinsically in order to represent the discontinuous temperature, heat flux, displacement and traction across the crack surfaces. Both isothermal and adiabatic conditions are considered at the crack surfaces. Jump function technique has been employed to model a bi-material interface, and intrinsic enrichment has been used to model a crack at the bi-material interface. The conservative M-integral technique has been modified in order to extract the mixed mode stress intensity factor for thermo-elastic fracture problems. The present analysis shows that the results obtained by EFGM are in good agreement with those available in the literature.     

Prolonged zero‐order BSA release from pH‐sensitive hydrogels of poly(AAc‐co‐DMAPMA) having rich nano through micro scale morphology

New variety of pH‐sensitive hydrogels, having macroporous interior with honey‐comb type architecture and continuous skin at the surface, have been developed by single step aqueous copolymerization of acrylic acid (AAc) and N‐[3‐(dimethylamino)propyl]‐methacrylamide (DMAPMA) in different feed ratios at 41 ± 1°C. Interlocked nanogels of ～ 300 nm were identified as the building blocks in all of these cylindrical poly(AAc‐co‐DMAPMA) matrices (PDMAAc). The gels showed good compressive strength even at a swelling as high as 4330% (mass) at pH 7.0. Morphology of McCoy fibroblast cell line remained unchanged in direct contact with different PDMAAc gels, and cell viability (±SD) was recorded to be in the range of 105 (±3)% to 87 (±8)% after 72 h. Bovine serum albumin (BSA) loaded gels were prepared by means of equilibrium partitioning. Loading efficiency of PDMAAc gels has been found to be in the range of 210–277 mg/g dry gel. BSA release from PDMAAc gels at 37°C has been found to follow non‐Fickian diffusion mechanism in simulated gastric juice (pH 1.2), and Case II transport in simulated intestinal juice (pH 7.4). In vitro study showed that the gels are capable of retaining >95% of the loaded BSA in gastric medium through average gastric emptying period. Again, ～ 56% BSA release was recorded in 24 h at pH 7.4, indicating prolonged BSA diffusion in intestinal condition. Constant rate of BSA diffusion was reflected from the release profiles at both the pH. Diffusion exponents also supported the same and indicated for absolute zero‐order kinetics at pH 7.4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Influence of fiber orientation on abrasive wear of unidirectionally reinforced carbon fiber–polyetherimide composites

A composite with continuous carbon fibers (CF) (80% by vol.) and high performance thermoplastic polyetherimide (PEI) matrix was developed and evaluated for various mechanical properties as a function of fiber orientation angle (0°, 30°, 45°, 60° and 90°). It was observed that Young's modulus, Poisson's ratio, toughness and % strain decreased with the increase of fiber orientation angle with respect to loading direction. In-plane shear modulus was highest for fibers with 45°. Overall, unidirectional (UD) CF reinforcement enhanced all strength properties of PEI significantly. Composites with fibers in 0° (parallel to loading direction) proved best in almost all the properties. Tribological evaluation in abrasive wear mode under different loads and fiber orientations indicated that coefficient of friction (μ) and specific wear rate (K₀) decreased with load, in general. Comparatively low specific wear rate (K₀), (in the order of 0.7 1×10^?9 m³/Nm) was observed for 0° fiber orientation, while fibers in 90° showed almost three times higher wear rate. Overall fiber reinforcement in 0° orientations proved beneficial from both strength and tribological performance point of view. SEM proved useful to correlate wear rate with surface topography.     

Effect of Thermomechanical Treatment on the Microstructure and Mechanical Properties of an IF Steel

This study focused on thermomechanical treatment of an interstitial-free (IF) steel. As-received IF steel underwent cold reduction of 80% followed by subcritical annealing at 680 °C for 10, 20, 30, and 40 min. These cold-worked and annealed samples were characterized using optical microscopy and scanning electron microscopy (SEM). Mechanical properties such as hardness and tensile strength were determined. Fracture surface was studied using SEM. On the basis of resulting mechanical properties and fractographic study, it was concluded that employing annealing time between 20 and 30 min at 680 °C imparts the desired combination of strength and ductility required for deep-drawing applications in automotive industry.