Effect of a surface tension imbalance on a partly submerged cylinder

We perform a static analysis of a circular cylinder that forms a barrier between surfactant-laden and surfactant-free portions of a liquid$-$gas interface. In addition to determining the general implications of the balances for forces and torques, we quantify how the imbalance $\Delta\gamma=\gamma_a-\gamma_b$ between the uniform surface tension $\gamma_a$ of the surfactant-free portion of the interface and the uniform surface tension $\gamma_b$ of the surfactant-laden portion of the interface influences the load-bearing capacity of a hydrophobic cylinder. Moreover, we demonstrate that the difference between surface tensions on either side of a cylinder with a cross-section of arbitrary shape induces a horizontal force component $f^h$ equal to $\Delta \gamma$ in magnitude, when measured per unit length of the cylinder. With an energetic argument, we show that this relation also applies to rod-like barriers with cross-sections of variable shape. In addition, we apply our analysis to amphiphilic Janus cylinders and we discuss practical implications of our findings for Marangoni propulsion and surface pressure measurements

Laser Induced Damage Studies in Borosilicate Glass Using nanosecond and sub nanosecond pulses

The damage mechanism induced by laser pulse of different duration in borosilicate glass widely used for making confinement geometry targets which are important for laser driven shock multiplication and elongation of pressure pulse, is studied. We measured the front and rear surface damage threshold of borosilicate glass and their dependency on laser parameters. In this paper, we also study the thermal effects on the damage diameters, generated at the time of plasma formation. These induced damage width, geometries and microstructure changes are measured and analyzed with optical microscope, scanning electron microscope and Raman spectroscopy. The results show that at low energies symmetrical damages are found and these damage width increases nonlinearly with laser intensity. The emitted optical spectrum during the process of breakdown is also investigated and is used for the characterization of emitted plasma such as plasma temperature and free electron density. Optical emission lines from Si I at 500 nm, Si II at 385nm and Si III at 455 nm are taken for the temperature calculations.Comment: 9 figures, 3 table

From Single to Core-Shell Drops in Non-Confined Microfluidics

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.For many encapsulation applications such as nutrients, cells and drugs, large core-shell drops are required. Conventional confined microfluidic devices are limited to a rather small sized (< 1mm) droplets because of difficulties associated with phase separation at low flow rates. We report a microfluidic device which can produce such large range of drop sizes (~200 Am- 6 mm) with varying shell thickness (~1 Am- 1 mm) under the maximum influence of buoyancy, which has so far remained unexplored. The existing physical model for single drop formation is extended for the core-shell drop. The facile nature of working with such systems means scale up would be easy

Double and single recycled pulsars: an evolutionary puzzle?

We investigate the statistics of isolated recycled pulsars and double neutron star binaries in the Galactic disk. Since recycled pulsars are believed to form through accretion and spinup in close binaries, the isolated objects presumably originate from disrupted progenitors of double neutron stars. There are a comparable number of double neutron star systems compared to isolated recycled pulsars. We find that standard evolutionary models cannot explain this fact, predicting several times the number of isolated recycled pulsars than those in double neutron star systems. We demonstrate, through population synthesis calculations, that the velocity distribution of isolated recycled pulsars is broader than for binary systems. When this is accounted for in a model for radio pulsar survey selection effects, which include the effects of Doppler smearing for the double neutron star binaries, we find that there is a small (25%) bias towards the detection of double neutron star systems. This bias, however, is not significant enough to explain the observational discrepancy if standard (sigma = 265 km/s) neutron star natal kick velocities are invoked in binary population syntheses. Population syntheses in which the 1D Maxwellian velocity dispersion of the natal kick is sigma=170 km/s are consistent with the observations. These conclusions further support earlier findings the neutron stars formed in close interacting binaries receive significantly smaller natal kicks than the velocities of Galactic single pulsars would seem to indicate.Comment: 12 pages, MNRAS (accepted

Severe Penetrating Craniofacial Stab Injury with Retained Sharp Knife with Rounded Handle: A Very Rare Case

Background: Craniofacial penetrating injuries are unusual but may cause massive injury to facial tissues and severe brain damage if cranium is entered. Because of the very critical anatomical area involved, these injuries can be challenging to the physicians who first receive them as well as the treating team. Prompt evaluation by utilizing the best diagnostic modality available and timely interference to remove foreign objects is the key aspects to avoid damage to vital organs surrounding the injury and to minimize the late complications. Case Report: We report a case of 24 year old male presented in surgical emergency that sustained a severely penetrating craniofacial assault with a 15 centimeter long sharp knife with intact iron handle and retained blade. Patient was adequately resuscitated and x- ray skull and CT of head along with 3 dimensional reconstruction of face was done to assess any injury. CT scan showed no brain parenchymal injury and only undisplaced fracture of the anterior cranial fossa. Methods and Result: Patient was explored surgically on an emergency basis. The debridement of the wound was done, bone fragments and necrotic tissue was excised. The penetrating knife was gradually removed after surgical procedure. The patient recovered well, and there was no neurological deficit on discharge. Conclusion: The management of penetrating craniofacial trauma is a challenging task and should be handled by multidisciplinary team, so that the management and outcome can be favorable

Flavor from the double tetrahedral group without supersymmetry

We consider a class of flavor models proposed by Aranda, Carone and Lebed, relaxing the assumption of supersymmetry and allowing the flavor scale to float anywhere between the weak and Planck scales. We perform global fits to the charged fermion masses and Cabibbo-Kobayashi-Maskawa angles, and consider the dependence of the results on the unknown mass scale of the flavor sector. We find that the typical Yukawa textures in these models provide a good description of the data over a wide range of flavor scales, with a preference for those that approach the lower bounds allowed by flavor-changing-neutral-current constraints. Nevertheless, the possibility that the flavor scale and Planck scale are identified remains viable. We present models that demonstrate how the assumed textures can arise most simply in a nonsupersymmetric framework

Exploration of two methods for quantitative Mitomycin C measurement in tumor tissue in vitro and in vivo

Two methods of quantifying Mitomycin C in tumor tissue are explored. A method of ultraviolet-visible absorption microscopy is developed and applied to measure the concentration of Mitomycin C in preserved mouse tumor tissue, as well as in gelatin samples. Concentrations as low as 60 μM can be resolved using this technique in samples that do not strongly scatter light. A novel method for monitoring the Mitomycin C concentrations inside a tumor is developed, based on microdialysis and ultraviolet-visible spectroscopy. A pump is used to perfuse a microdialysis probe with Ringer’s solution, which is fed to a flow cell to determine intratumor concentrations in real time to within a few μM. The success and limitations of these techniques are identified, and suggestions are made as to further development. To the authors’ knowledge these are the first attempts made to quantify Mitomycin C concentrations in tumor tissue

Pathogenesis of progressive scarring trachoma in Ethiopia and Tanzania and its implications for disease control: two cohort studies.

BACKGROUND: Trachoma causes blindness through a conjunctival scarring process initiated by ocular Chlamydia trachomatis infection; however, the rates, drivers and pathophysiological determinants are poorly understood. We investigated progressive scarring and its relationship to conjunctival infection, inflammation and transcript levels of cytokines and fibrogenic factors. METHODOLOGY/PRINCIPAL FINDINGS: We recruited two cohorts, one each in Ethiopia and Tanzania, of individuals with established trachomatous conjunctival scarring. They were followed six-monthly for two years, with clinical examinations and conjunctival swab sample collection. Progressive scarring cases were identified by comparing baseline and two-year photographs, and compared to individuals without progression. Samples were tested for C. trachomatis by PCR and transcript levels of S100A7, IL1B, IL13, IL17A, CXCL5, CTGF, SPARCL1, CEACAM5, MMP7, MMP9 and CD83 were estimated by quantitative RT-PCR. Progressive scarring was found in 135/585 (23.1%) of Ethiopian participants and 173/577 (30.0%) of Tanzanian participants. There was a strong relationship between progressive scarring and increasing inflammatory episodes (Ethiopia: OR 5.93, 95%CI 3.31-10.6, p<0.0001. Tanzania: OR 5.76, 95%CI 2.60-12.7, p<0.0001). No episodes of C. trachomatis infection were detected in the Ethiopian cohort and only 5 episodes in the Tanzanian cohort. Clinical inflammation, but not scarring progression, was associated with increased expression of S100A7, IL1B, IL17A, CXCL5, CTGF, CEACAM5, MMP7, CD83 and reduced SPARCL1. CONCLUSIONS/SIGNIFICANCE: Scarring progressed in the absence of detectable C. trachomatis, which raises uncertainty about the primary drivers of late-stage trachoma. Chronic conjunctival inflammation appears to be central and is associated with enriched expression of pro-inflammatory factors and altered expression of extracellular matrix regulators. Host determinants of scarring progression appear more complex and subtle than the features of inflammation. Overall this indicates a potential role for anti-inflammatory interventions to interrupt progression and the need for trichiasis disease surveillance and surgery long after chlamydial infection has been controlled at community level

Identification and Characterization of Pastureland and Other Grazing Resources of Jammu & Kashmir Using GIS and Satellite Remote Sensing Technique

Livestock acquires special importance in mountain farming system from both ecological and socioeconomic point of view. They are an integral part of the farming system and a “bridge’’ connecting two types of land viz., forest and cultivated. In hilly regions, the arable agriculture is not very remunerative; therefore farmers of all categories rear sheep, goats, cattle etc. under sedentary, semi-migratory and migratory systems to supplement family income (Dev et al., 2014). The common property resources (CPR) and degraded pasturelands are the major feed sources. Remotely sensed satellite imagery and Geographic Information System (GIS) are being widely used for the assessment of pasturelands and estimation of forage availability as well as monitoring of the range resources (Singh et al., 2011). Since, the grazing resources are limited and natural grasslands are becoming scarcer, there is a greater need to effectively manage grasslands for optimum forage production and eco-development (Roy and Singh, 2013). Precise information on extent, condition and forage availability is essential for developmental planning. In the present study information on current status of pasturelands in Jammu and Kashmir based on remotely sensed satellite data and GIS/GPS is carried out