Recent Developments on Colloidal Deposits Obtained by Evaporation of Sessile Droplets on a Solid Surface

Understanding flow patterns and coupled transport phenomena during evaporation of droplets loaded with colloidal particles is central to design technical applications such as organizing proteins/DNA on a solid surface. We review recent reports on evaporating sessile droplets of colloidal suspensions on a solid surface. Starting from the classical mechanism of formation of a ring-like deposit, we discuss the influence of several problem parameters. Notably, thermal or solutal Marangoni effect, particle size, particle concentration, particle shape, substrate wettability, pH of the suspension etc have been found important in controlling the deposition pattern. The deposit pattern complexity and shape have been attributed to the underlying coupled transport phenomena during the evaporation. We discuss important regimes maps reported for different types of deposit, which allow us to classify the deposits and coupled physics. We also present studies that have demonstrated particles sorting in an evaporating bi-dispersed colloidal suspensions on a solid surface. Finally, some remarks for the future research opportunities in this arena are presented

Electrochemical incineration of wastes

The novel technology of waste removal in space vehicles by electrochemical methods is presented to convert wastes into chemicals that can be eventually recycled. The important consideration for waste oxidation is to select a right kind of electrode (anode) material that should be stable under anodic conditions and also a poor electrocatalyst for oxygen and chlorine evolution. On the basis of long term electrolysis experiments on seven different electrodes and on the basis of total organic carbon reduced, two best electrodes were identified. The effect of redox ions on the electrolyte was studied. Though most of the experiments were done in mixtures of urine and waste, the experiments with redox couples involved 2.5 M sulfuric acid in order to avoid the precipitation of redox ions by urea. Two methods for long term electrolysis of waste were investigated: (1) the oxidation on Pt and lead dioxide electrodes using the galvanostatic methods; and (2) potentiostatic method on other electrodes. The advantage of the first method is the faster rate of oxidation. The chlorine evolution in the second method is ten times less then in the first. The accomplished research has shown that urine/feces mixtures can be oxidized to carbon dioxide and water, but current densities are low and must be improved. The perovskite and Ti4O7 coated with RuO2 are the best electrode materials found. Recent experiment with the redox agent improves the current density, however, sulphuric acid is required to keep the redox agent in solution to enhance oxidation effectively. It is desirable to reduce the use of acid and/or find substitutes

Irradiation of benzene molecules by ion-induced and light-induced intense fields

Benzene, with its sea of delocalized $\pi$-electrons in the valence orbitals, is identified as an example of a class of molecules that enable establishment of the correspondence between intense ion-induced and laser-light-induced fields in experiments that probe ionization dynamics in temporal regimes spanning the attosecond and picosecond ranges.Comment: 4 ps figure

Indications of caesarean section in a tertiary care teaching hospital

Background: The rising trend of caesarean deliveries is noticed across the globe. The caesarean deliveries are associated with costlier health care, increased risk of maternal and perinatal morbidity as compared to vaginal deliveries. This study was aimed to find out the rate and various indications of caesarean deliveries and to amend the current protocols based on these findings to reduce the incidence of caesarean in our institute in future.Methods: A cross sectional observational study was done to find the caesarean delivery rate and various indications contributing to it for a period of one year. All pregnant women with period of gestation more than 28 weeks who delivered in hospital were included in the study. All women with period of gestation less than 28 weeks and in labour irrespective to mode of delivery and foetal outcome were excluded from the study.Results: The overall Caesarean section (CS) rate was 34.23% out of 2676 deliveries. The commonest indication was repeat CS (45.09%) followed by foetal distress (12.66%), failed induction (12.34%) and arrest of labour (10.26%). The commonest cause for the repeat CS was patient refusal for trial of labour 195 (47.22%).Conclusions: The common indications of CS found are repeat CS, Foetal distress, NPOL and failed induction. Foetal distress, NPOL and failed induction are amenable to intervention and needs to be introspected at institutional levels. Trial of labour after CS (TOLAC) should be encouraged to control the rising trend of CS.

Forbidden oxygen lines at various nucleocentric distances in comets

To study the formation of the [OI] lines - i.e., 5577 A (the green line), 6300 A and 6364 A (the two red lines) - in the coma of comets and to determine the parent species of the oxygen atoms using the green to red-doublet emission intensity ratio (G/R ratio) and the lines velocity widths. We acquired at the ESO VLT high-resolution spectroscopic observations of comets C/2002 T7 (LINEAR), 73P-C/Schwassmann-Wachmann 3, 8P/Tuttle, and, 103P/Hartley 2 when they were close to the Earth (< 0.6 au). Using the observed spectra, we determined the intensities and the widths of the three [OI] lines. We have spatially extracted the spectra in order to achieve the best possible resolution of about 1-2", i.e., nucleocentric projected distances of 100 to 400 km depending on the geocentric distance of the comet. We have decontaminated the [OI] green line from C2 lines blends. It is found that the observed G/R ratio on all four comets varies as a function of nucleocentric projected distance. This is mainly due to the collisional quenching of O(1S) and O(1D) by water molecules in the inner coma. The observed green emission line width is about 2.5 km/s and decreases as the distance from the nucleus increases which can be explained by the varying contribution of CO2 to the O(1S) production in the innermost coma. The photodissociation of CO2 molecules seems to produce O(1S) closer to the nucleus while the water molecule forms all the O(1S) and O(1D) atoms beyond 1000 km. Thus we conclude that the main parent species producing O(1S) and O(1D) in the inner coma is not always the same. The observations have been interpreted in the framework of the coupled-chemistry-emission model of Bhardwaj & Raghuram (2012) and the upper limits of CO2 relative abundances are derived from the observed G/R ratios. Measuring the [OI] lines could indeed provide a new way to determine the CO2 relative abundance in comets.Comment: accepted for publication in A&A, the abstract is shortene

Inclusive and exclusive measurements of B decays to χ_{c1} and χ_{c2} at Belle

We report inclusive and exclusive measurements for χc1 and χc2 production in B decays. We measure B(B → χc1X)= (3.03 ± 0.05(stat) ± 0.24(syst)) × 10−3 and B(B → χc2X)= (0.70 ± 0.06(stat) ± 0.10(syst)) × 10−3 . For the first time, χc2 production in exclusive B decays in the modes B 0 → χc2π −K+ and B + → χc2π +π −K+ has been observed, along with first evidence for the B + → χc2π +K0 S decay mode. For χc1 production, we report the first observation in the B + → χc1π +π −K+, B 0 → χc1π +π −K0 S and B 0 → χc1π 0π −K+ decay modes. Using these decay modes, we observe a difference in the production mechanism of χc2 in comparison to χc1 in B decays. In addition, we report searches for X(3872) and χc1(2P) in the B + → (χc1π +π −)K+ decay mode. The reported results use 772 × 106 BB events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e +e − collider

Bounding Uncertainty:The Uses of Analogical Abduction in Entrepreneurship

Conceptualizing entrepreneurship as problem-solving has shed light on how problems are solved through entrepreneurial ventures. This approach presupposes that problems objectively exist, an assumption that is valid for the world of Knightian risk, in which categorization is possible. In the current study, we adopt the ontological stance of Knightian uncertainty, in which a priori categories cannot be assumed, and therefore problems do not objectively exist. We posit that in the world of Knightian uncertainty entrepreneurs who perceive certain situations as unsatisfactory but remediable engage in problematization which yields problem statements. These problem statements are operationalized to form the basis of entrepreneurial action aimed at remedying dissatisfaction. We submit that to problematize, entrepreneurs engage in analogical abduction, which allows them to develop problem statements by treating target domains replete with Knightian uncertainty as if they were similar to familiar source domains. Such conjectures are selected based on the likeness of relevant attributes between the source and target domains, aid entrepreneurs in bounding uncertainty, and guide entrepreneurial action. Entrepreneurs adopt positive feedback of entrepreneurial action as a rule to guide future action under similar circumstances, while negative feedback leads them to recalibrate problem statements and modify further action. We illustrate this process using the empirical vignette of Starbucks

Knowledge regarding Malnutrition and Its Prevention – A Study on Slum Dwelling Mothers

Introduction: A large proportion of under-five-year kids are suffering from malnutrition. A study was conducted to assess the knowledge of mothers regarding malnutrition and its prevention and evaluate effectiveness of structured teaching program regarding malnutrition and its prevention in terms of knowledge gain in mothers of under-five children attending a crèche run by an NGO in a slum area of New Delhi.Methodology: Quantitative research approach with one group pre-test, post-test design was used. Tool used for generating necessary data was a structured knowledge questionnaire, after establishing its validity and reliability. Purposive sampling technique was used to select 45 mothers having children under five years of age. The study was conducted at a crèche run by an NGO in a slum area of Delhi.Results: Before administration of the structured teaching program, 18 (40%) mothers had poor knowledge, 15 (33.3%) had average knowledge and 12 (26.7%) had good knowledge about malnutrition and its prevention, while after administration of structured teaching program, 12 (26.7%) had poor knowledge, 21 (46.7%) had average knowledge and 12 (26.7%) had good knowledge about malnutrition and its prevention indicating that the intervention was effective. There was significant relationship between knowledge gain and age, education and monthly family income of mothers. Conclusion: Finding of the study revealed that mothers having children under five years of age had poor knowledge about malnutrition and its prevention. The structured teaching program was an effective tool to enhance the knowledge of mothers