Effect of two step cold rolling — continuous annealing on micro-structures,textures and mechanical properties in IF and IF-HS steel sheets

In the present work, the objectives were to investigate the type of microstructure and texture that developed after two step cold rolling — continuous annealing. Further, an attempt has been made to correlate the microstructure and texture with mechanical properties. Interstitial free (IF) and interstitial free — high strength (IF-HS) steel sheets which contain almost γ-fiber textures, were subjected to two step cold rolling for different percentage of reduction and further continuously annealed. It was observed that cold rolling strengthened the region of (223)[1$ \bar 1 $ \bar 1 0] and 335[1$ \bar 1 $ \bar 1 0] orientations of α-fiber as well as γ-fiber. After continuous annealing, cold rolled γ-fiber as well as (223)[1$ \bar 1 $ \bar 1 0] and 335[1$ \bar 1 $ \bar 1 0] orientations transformed to extremely strong new γ-fiber. It was found that at two steps 80% cold rolling -continuous annealing, drawability of IF steel sheet was exceptionally high i.e. around 3.15, whereas for IF-HS steel sheets, it was around 2.7. Although, two steps cold rolling -continuous annealing enhanced percentage elongation and stretchability exceptionally, but it reduced the yield strength substantially. However, ultimate tensile strength was hardly affected. In addition, it is also observed that two steps cold rolling — continuous annealing developed uniform grain size in both the grades of steel sheets.     

Comparative Performance of Different Sector Arrangement in a Desiccant Wheel Using a Mathematical Model

A one‐dimensional mathematical model has been used for a three‐sector desiccant wheel (two sectors with purge) with different flow arrangements. The model considers both gas and solid side resistance and shows a good agreement with experimental results. This model has been used to conduct a comparative performance analysis in both the effective adsorption and effective regeneration sector of a desiccant wheel. It was found that an effective regeneration sector gives better results for the performance parameters (rotation of wheel, regeneration temperature, velocity, and ambient moisture) as compared to an effective adsorption sector. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21103     

Multi-objective module placement for 3-D system-on-package

System-on-package (SOP) is a viable alternative to system-on-chip (SOC) for meeting the rigorous requirements of today's mixed-signal system integration. Thermal integrity is arguably the most crucial issue in three-dimensional (3-D) SOP due to the compact nature of the 3-D integration. In addition, the power supply noise issue becomes more serious as the supply voltage continues to decrease while the number of active devices consuming power increases. We propose a 3-D module and decap (decoupling capacitance) placement algorithm that evenly distributes the thermal profile and reduces the power supply noise. In addition, we allocate white spaces around the modules that require decaps to suppress the power supply noise while minimizing the area overhead. In our experimentation, we achieve improvements in both maximum temperature and decap amount with only small increase in area, wirelength, and runtime.     

Clinical and immunological profile of SLE: some unusual features

OBJECTIVE: To study the clinical and immunological profile of children with systemic lupus erythematosus (SLE). DESIGN: Retrospective hospital based study. SETTING: Tertiary level center of North India. SUBJECTS: Sixteen children in the age group 4-12 years. METHODS: Medical records of children with SLE were analyzed. Clinico pathological features were compared with 2 other series from India. RESULTS: Mean age of children at the time of diagnosis was 10 yr and 8 (50%) children were less than 10 yr of age. The female to male ratio was 7:1. Fever (56.2%), rash (87%) and arthritis (87%) were the common clinical manifestations, Renal involvement was noted in 56.2% of cases. Other clinical features included hemolytic anemia (31.2%), thrombocytopenia (18.6%) and Raynaud's phenomenon (12.5%). Cardiac involvement in the form of severe myocarditis and endocarditis occurred in one patient each. Pulmonary hypertension was the presenting feature in one child with right heart failure. One child had multiple sclerosis along with SLE--a rare combination. ANA positivity was seen in all children. Five children died; two had severe cardiac involvement. Three children had renal involvement and one died of pulmonary hypertension. Two-thirds of subjects with renal involvement improved after therapy according to NIH, Bethesda protocol. CONCLUSIONS: SLE must be considered in any child with multisystem disease, as the disease may have certain unusual presentations.     

Beam scanning annular slot‐ring antenna array with via‐fence for wireless power transfer

Wireless power transfer has been the field of research for many decades, and with technological advancement and increase in wireless mobile devices, the future of wireless power transfer technology is very promising. The major requirement of wireless power transfer is an efficient and compact antenna array with high gain and flawless scanning performance. In this article, a 4 × 8 element array is proposed with a gain of 18 dB and scanning capability of ±45^° in azimuth and elevation plane at 5.8 GHz. The overall size of the array is 100 mm × 200 mm. The element separation in the array is only 0.48 λ. There was strong mutual coupling due to smaller separation, which has been minimized with the application of via‐fence around the antenna element. A dual feed circularly polarized annular slot‐ring antenna is proposed and analyzed with via‐fence to develop an array of 4 × 8 elements. The antenna array reflection coefficient obtained is less than 20 dB for different scan angles and the gain of the array obtained is also within 2 dB for ±45^° scan angles.     

Correlation of Microstructure and Texture in a Two-Phase High-Mn Twinning-Induced Plasticity Steel During Cold Rolling

Metallurgical and Materials Transactions A - The evolution of microstructure and texture of a two-phase austenite-ferrite twinning-induced plasticity steel during cold rolling was investigated and...     

Comparative analysis of different design of rotary dehumidifier

A one‐dimensional mathematical model has been developed to do the comparative analysis of four design of the desiccant wheel. The mathematical model has been validated with experimental results and shows good agreements with experimental results. In this study, a two‐sector desiccant wheel is modified into a three‐sector wheel by introducing a purge section in the desiccant wheel. Similarly, a four‐sector desiccant wheel is reformed into a six‐sector wheel by installing two purge section in the desiccant wheel and comparative study of these designs have been carried for given ranges of operating conditions. The effect of purge conditions has been also investigated and found that in all operating conditions six‐sector design is a better choice for optimum MRC and ?T.     

Catalytic wet peroxide oxidation of 4-Nitrophenol over Al–Fe PILC: Kinetic study using Fermi’s equation and mechanistic pathways based on TOC reduction

The Al–Fe pillared interlayered clay catalyst (PILC) was synthesized by pillaring bentonite clay with Al and Fe metal cations. 4-Nitrophenol (4-NP) was oxidized over Al–Fe PILC using catalytic wet peroxide oxidation process. The catalyst was characterized using X-ray diffraction, BET, wavelength-dispersive X-ray fluorescence, FTIR, and thermogravimetric analysis/derivative thermogravimetric techniques. The Al–Fe PILC was thermally stable as compared to bentonite clay. Reaction kinetics for the catalytic oxidation of 4-NP onto Al–Fe PILC was described using Fermi’s equation. Fermi’s model was fitted well to the experimental data for the degradation of 4-NP and total organic carbon (TOC) removal histories and followed pseudo-first-order rate equation. The apparent activation energies for 4-NP degradation and TOC removal histories were 21.17 and 14.12?kJ/mol, respectively. In the present study, the mechanistic pathways for the catalytic oxidation of 4-NP based upon TOC reduction have been proposed. The toxicity of 4-NP after oxidation decreased as the zone of inhibition decreased to 5?mm from 12?mm.     

Strength characteristics and stability analysis of GGBS stabilised fly ash-overburden dump

ABSTRACT

Stability of OB dump slope has been a major concern and require a proper design for safe mining operation. Utilisation of fly ash with OB material for construction of mine haul road and external dumping, may provide an alternative mode of fly ash disposal. In this study, fly ash was mixed with OB material at different percentages to evaluate the compaction characteristics, California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS) and shear strength parameter. Tests were also performed with the addition of a different percentage of Ground Granulated Blast Furnace Slag (GGBS) with fly ash-OB mix. Further, the effects of GGBS at various curing period on CBR and UCS characteristics were highlighted. Numerical modelling was carried out for dump containing OB material, fly ash and GGBS at different proportions to evaluate the Factor of Safety (FoS) and to suggest the optimum dump geometry. Experimental result infers that maximum CBR and UCS values were obtained for 78% OB material, 10% fly ash and 12% GGBS at 28 days curing period. Based on the observed FoS from numerical modelling, an optimal multiple regression model and artificial neural network model have been suggested for the direct prediction of FoS by various input parameters.