Effect of niobium on the directional solidification and properties of alnico alloys

The effect of niobium on the extent of columnar growth of grains and on the magnetic properties in Alnico alloys has been studied. Alloys containing 1 % Nb show maximum growth of columnar crystals. In columnar alloys, coercivity increases slowly with increasing niobium content up to approximately 1 %. With further increase in niobium, coercivity and remanence decrease. The maximum energy product (55 kJ m-3) has been obtained at 1 % Nb. Niobium addition has also been found to suppress the precipitation of the undesirable gamma phase

Single spin universal Boolean logic

Recent advances in manipulating single electron spins in quantum dots have brought us close to the realization of classical logic gates based on representing binary bits in spin polarizations of single electrons. Here, we show that a linear array of three quantum dots, each containing a single spin polarized electron, and with nearest neighbor exchange coupling, acts as the universal NAND gate. The energy dissipated during switching this gate is the Landauer-Shannon limit of kTln(1/p) [T = ambient temperature and p = intrinsic gate error probability]. With present day technology, p = 1E-9 is achievable above 1 K temperature. Even with this small intrinsic error probability, the energy dissipated during switching the NAND gate is only ~ 21 kT, while today's nanoscale transistors dissipate about 40,000 - 50,000 kT when they switch

Size-dependent electronic-transport mechanism and sign reversal of magnetoresistance in Nd0.5Sr0.5CoO3

A detailed investigation of electronic-transport properties of Nd0.5Sr0.5CoO3 has been carried out as a function of grain size ranging from micrometer order down to an average size of 28 nm. Interestingly, we observe a size induced metal-insulator transition in the lowest grain size sample while the bulk-like sample is metallic in the whole measured temperature regime. An analysis of the temperature dependent resistivity in the metallic regime reveals that the electron-electron interaction is the dominating mechanism while other processes like electron-magnon and electron-phonon scatterings are also likely to be present. The fascinating observation of enhanced low temperature upturn and minimum in resistivity on reduction of grain size is found due to electron-electron interaction (quantum interference effect). This effect is attributed to enhanced disorder on reduction of grain size. Interestingly, we observed a cross over from positive to negative magnetoresistance in the low temperature regime as the grain size is reduced. This observed sign reversal is attributed to enhanced phase separation on decreasing the grain size of the cobaltite

An intensive audit on 250 patients of advanced ovarian cancer to improve quality of care in a tertiary referral oncology centre in India

Background: A clinical audit provides the framework to improve the quality of patient care in a systematic way. In this study, we intensively audited our 250 advanced epithelial ovarian cancer (EOC) patients aiming to improve our patient care.Methods: Ambispective study of 250 patients of advanced EOC was done from our prospectively maintained computerized database in the department of surgical oncology, AIIMS, New Delhi from 2013 to 2020.We audited the demographic profile, treatment patterns, perioperative and survival outcomes in different subgroups.Results: In this study, 83.6% stage III and 16.4% stage IV A. There was 62 (24.8%) upfront, 112 (44.8%) interval and 76 (30.4%) secondary group. 126 underwent cytoreductive surgery (CRS) and 124 CRS and hyperthermic intraperitoneal chemotherapy (HIPEC). There was 24.8% early and 8.4% late postop complications. Median follow up 50 months. Overall, the median disease-free survival (DFS) 39 months. PFS was 12 months among 68 patients with recurrence. Attrition rate 4%. In the upfront setting, the median DFS 44 months in CRS only group and DFS not reached (p=0.032) in CRS and HIPEC group still. In the interval setting, the median DFS 39 months in CRS only group and 44 months in CRS and HIPEC group (p=0.06). In recurrent setting, the median DFS 14 months in CRS group and 23 months in CRS and HIPEC group (p=0.02)Conclusions: Audit is an integral part of any clinical practice. It teaches us to improve the quality of care and thereby better outcomes. We recommend 6 monthly clinical audits in any cancer treatment for better outcomes in future

Development of an Advanced Engineering Polymer from the Modification of Nylon 66 by e-Beam Irradiation

When Nylon 66 was irradiated by an optimum dose of e-beam in presence of polyurethane as impact modifierin combination with triallyl isocyanurate as cross-linker, a superior performance was observed for the irradiatednylon 66. Significant improvement of properties, such as hardness, tensile strength, flexural modulus and impactstrength was obtained on radiation processing of nylon 66 by e-beam. More interestingly, percent water absorptionof such irradiated nylon 66 was reduced substantially. Improvement of mechanical properties and reduction of waterabsorption of irradiated nylon 66 were due to the cross-linking of the polymer system. Increase of cross-linkingwith dose of e-beam was verified by the increased gel content at higher doses. Irradiated nylon 66 showed betterdimensional stability than those achieved with pristine nylon 66. The increase in dimensional stability may beattributed to reduction in crystallinity with increasing dose of e-beam as revealed by DSC studies.Defence Science Journal, Vol. 64, No. 3, May 2014, pp. 281-289, DOI:http://dx.doi.org/10.14429/dsj.64.732

Comparison of Design of Experiments via Traditional and Taguchi Method

This paper presents a case study on comparison of Design of Experiments (DOE) via traditional and Taguchi methods in terms of efficiency. First, a three-level, four-parameter, full factorial DOE was conducted for finding the effects of machining parameters on the surface roughness (arithmetic average) of parts produced by turning operation. The results were analyzed applying average response, Taguchi's S/N ratio, and Pareto ANOVA. Subsequently, the same data was analyzed applying Taguchi's L9 orthogonal array. The comparison of two results revealed that despite an 88.9% savings of experimental runs with the Taguchi method, both methods produced similar results

Sizing Of Trousers and Shirts for Indian Army Personnel : An Anthropometric Application

The paper describes how anthropometric data obtained on 4400 Indian Army personnel was utilized in evolving size rolls for the trousers and shirts. A bivariate frequency distribution of abdominal circumference and abdominal height indicated that the data could be grouped into 14 sizes and such grouping could provide good fitting trousers to 92.52 percent of the troops. For shirts, the bivariate frequency distribution of chest circumference and arm length grouped army personnel again into 14 sizes. Such grouping encompassed 84.22 percent of the personnel studied. An extra large size has been provided for those not covered by these 14 size. In this study, 95 army officers’ clothing measurements essential for their good fitting trousers and shirts were taken along with the relevant body measurements. A stepwise linear regression analysis was also carried out to predict clothing measurements from body measurements. These regression equations were used to work out the dimensions of the trousers and shirts for different sizes from the classified anthropometric data

Thiol stabilized copper nanoparticles exert antimicrobial properties by preventing cell division in Escherichia coli

The uses of metallic nanoparticles have gained importance as one of the therapeutic options to treat infections. Here, we synthesized stable copper nanoparticles (CuNPs) using Thiosalicylic acid and assessed their antimicrobial activities against various Gram-negative bacteria. The synthesized CuNPs had absorption maxima of 570 nM with a size range of 5-11 nM and face-centred cubic (Fcc) crystal structure. The bacterial cells in their planktonic and sessile forms were susceptible to CuNPs. The nanoparticles did not show any cytotoxicity to murine macrophages (RAW264.7) below 60 µg/mL. However, the expression of oxidative stress defence gene ahpC revealed the possibility of ROS generation upon treatment with CuNPs. Interestingly, the cell division proteins like, FtsZ and FtsI were destabilized in the presence of CuNPs which in turn inhibited bacterial cell division. In conclusion, it may be stated that the synthesized CuNPs can kill bacteria by arresting cell division and/or by ROS generation