Vortex characteristics due to nozzle clogging in water caster mould: modelling and validation

In continuous slab casting, clogging in the submerged entry nozzle (SEN) ports leads to flow asymmetry and vortex formation in the mould. Knowledge of vortexing and its influence on product quality is fundamental for defect-free production. In this study, the interconnected effects of nozzle clogging and SEN submergence depth, variation on flow asymmetry and vortex characteristics in a 0.4 scale water caster have been characterised by CFD investigation and validated with experimental results from the authors’ previous work. Mean flow velocities at the sub-meniscus and near the port exit predicted by the computational model are compared with the time-averaged values of the impeller probe velocity measurements and found to be in reasonable agreement. Three different clogging conditions (0, 33 and 66% in the left port of the SEN) for SEN submergence depth of 60?mm are studied and the 66% clogging produced vortices having largest diameter, which is consistent with the experimental observations. The effects of SEN submergence depth on flow asymmetry and vortexing are investigated with three different conditions – 40, 60 and 80?mm. It is found that the shallow SEN submergence depth (40?mm) produces vortices of largest diameter and the flow is most stable for a SEN submergence depth of 60?mm among the three cases. Vortex bending towards the SEN as noticed in the experimental observations is also observed in the computational study. This work illustrates the possibility of capturing features of vortexing using validated CFD model.     

Identification of Species Origin of Meat and Meat Products on the DNA Basis: A Review

The adulteration/substitution of meat has always been a concern for various reasons such as public health, religious factors, wholesomeness, and unhealthy competition in meat market. Consumer should be protected from these malicious practices of meat adulterations by quick, precise, and specific identification of meat animal species. Several analytical methodologies have been employed for meat speciation based on anatomical, histological, microscopic, organoleptic, chemical, electrophoretic, chromatographic, or immunological principles. However, by virtue of their inherent limitations, most of these techniques have been replaced by the recent DNA-based molecular techniques. In the last decades, several methods based on polymerase chain reaction have been proposed as useful means for identifying the species origin in meat and meat products, due to their high specificity and sensitivity, as well as rapid processing time and low cost. This review intends to provide an updated and extensive overview on the DNA-based methods for species identification in meat and meat products.     

Response of alkali activated fly ash mortars to microwave curing

Volumetric heating provided by microwave curing results in faster property development as compared to conventional heat curing that relies on heat conduction from the skin to the core. This paper discusses the compressive strength and microstructure development of microwave cured NaOH activated fly ash mortars, and relates them to the microwave energy absorption by the material which is a function of its dielectric properties. Microwave curing parameters are chosen so as to eliminate the effects of thermal runaway. Strengths that are comparable to or greater than those of mortars heat cured for 48 h at 75 °C are obtained in less than 120 min of microwave curing. The rate of energy absorption by the mortars is found to be relatively constant for a considerable fraction of the microwave curing duration, attributable to the compensation for the drop in dielectric loss factor as a result of moisture loss by the increase in internal electric field. Compressive strength is shown to be related to the microwave energy absorbed by the specimens, especially during the time when free water is present in the system.     

Current efficiency in electro-winning of lanthanum and cerium metals from molten chloride electrolytes

The objective of this study is to prepare lanthanum and cerium metals by fused salt electrolysis of their anhydrous chloride in molten media such as LiCl-KCl, NaCl-KCl, KCl, NaCl, and LiCl and to characterize the metal deposit by X-ray diffraction, energy dispersive X-ray fluorescence, and inductive coupled plasma-atomic emission spectroscopy. Deposit metal of purity more than 99 % was obtained in each of the experiments. The entire process starting from preparation of anhydrous lanthanum/cerium chloride to electrolysis yielding of metal deposits has been described. The effect of process parameters such as temperature, electrolyte composition, and current density on the current efficiency was studied. All these parameters were varied to get the highest current efficiency and metal yield. The major non-rare earth impurities with the deposit are found to be Fe, Cr, and Ni along with ～1×10-3 of total gaseous impurities.     

Design optimization of first wall and breeder unit module size for the Indian HCCB blanket module

The Indian test blanket module(TBM) program in ITER is one of the major steps in the Indian fusion reactor program for carrying out the RD activities in the critical areas like design of tritium breeding blankets relevant to future Indian fusion devices(ITER relevant and DEMO).The Indian Lead–Lithium Cooled Ceramic Breeder(LLCB) blanket concept is one of the Indian DEMO relevant TBM,to be tested in ITER as a part of the TBM program.Helium-Cooled Ceramic Breeder(HCCB) is an alternative blanket concept that consists of lithium titanate(Li_2TiO_3) as ceramic breeder(CB) material in the form of packed pebble beds and beryllium as the neutron multiplier.Specifically,attentions are given to the optimization of first wall coolant channel design and size of breeder unit module considering coolant pressure and thermal loads for the proposed Indian HCCB blanket based on ITER relevant TBM and loading conditions.These analyses will help proceeding further in designing blankets for loads relevant to the future fusion device.     

NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY STUDIES OF SEDIMENTS DERIVED FROM VISBROKEN RESIDUES: STABILITY STUDIES.

The ¹H and ¹³C n.m.r analysis of the sediments derived from visbroken short residues (150°C+) obtained at different severity levels is reported. The nature of sediments and structural changes during visbreaking and on storage at ambient conditions are related to the processing characteristics of the residual fuel oils. The possible relationship between storage stability and processing conditions is also discussed.     

Nutritive value of mango seed kernel

Seed kernels of two cultivars (Chausa and Dusheri) of mango (Mangifera indica) were analysed for chemical composition, lipid classes, fatty acid composition, amino acid profile and chemical evaluation of protein quality. The seed kernels constituted about 18% of the total fruit and had 5% protein, 6–7% crude fat, 0.19–0.44% tannins, iodine value of 34–44 and saponification number 202–213. Oleic acid (42%) and stearic acid (39%) were the principal fatty acids in the oil. The in vitro digestibility was low in these cultivars, possibly due to the presence of tannins. Sulphur-containing amino acids (methionine+cystine) and isoleucine were the limiting amino acids in Chausa and Dusheri, respectively. The essential amino acid index and protein quality index were high, thus indicating the good quality of the protein in mango seed kernel.     

RFID-enabled item-level product information revelation

We consider a homogeneous product market and the incentive for oligopolists to share item-level product information with their customers. Enabled by Radio Frequency Identification technology, each firm has the option to record and reveal item-level information of a proportion of its products. We consider a two-stage game where each firm first decides its production plan and then determines its level of information revelation. With a constant clearance discount rate, we derive pure strategy equilibria that are subgame perfect and demonstrate that complete information sharing is the unique Nash equilibrium for the game when the common demand is volatile and that no information revelation is the unique Nash equilibrium when demand is not volatile. Furthermore, we show that the Nash equilibrium is the same with a decreasing clearance discount rate and that neither complete information revelation nor zero information revelation is consistent with an equilibrium with an increasing discount rate. Results are similar in a duopoly non-homogeneous product market scenario.     

DEVELOPMENT OF MECHANISTIC MODELS FOR THE PREDICTION OF MACHINING PERFORMANCE: MODEL BUILDING METHODOLOGY

ABSTRACT

In this paper, recent research efforts at the University of Illinois at Urbana-Champaign (UIUC) on the development of machining process models are summarized under a unified mechanistic modeling framework. The fundamental elements of the basic cutting force model are described first, which include the computation of chip load and chip flow, force transformation relations, workpiece-cutter intersection algorithm, and the model calibration procedure. Some advanced model enhancements are then presented, such as the modeling of process faults, modeling of chip-control tools, and the incorporation of ploughing and tool wear effects. The integration of the process model with the machining system dynamics is discussed next. Finally, representative results are shown to validate the mechanistic modeling approach.