Simulation of Thematic Mapper performance as a function of sensor scanning parameters

The investigation and results of the Thematic Mapper Instrument Performance Study are described. The Thematic Mapper is the advanced multispectral scanner initially planned for the Earth Observation Satellite and now planned for LANDSAT D. The use of existing digital airborne scanner data obtained with the Modular Multispectral Scanner (M2S) at Bendix provided an opportunity to simulate the effects of variation of design parameters of the Thematic Mapper. Analysis and processing of this data on the Bendix Multispectral Data Analysis System were used to empirically determine categorization performance on data generated with variations of the sampling period and scan overlap parameters of the Thematic Mapper. The Bendix M2S data, with a 2.5 milliradian instantaneous field of view and a spatial resolution (pixel size) of 10-m from 13,000 ft altitude, allowed a direct simulation of Thematic Mapper data with a 30-m resolution. The flight data chosen were obtained on 30 June 1973 over agricultural test sites in Indiana

A technique for correcting ERTS data for solar and atmospheric effects

The author has identified the following significant results. Based on processing ERTS CCTs and ground truth measurements collected on Michigan test site for January through June 1973 the following results are reported: (1) atmospheric transmittance varies from: 70 to 85% in band 4, 77 to 90% in band 5, 80 to 94% in band 6, and 84 to 97% in band 7 for one air mass; (2) a simple technique was established to determine atmospheric scattering seen by ERTS-1 from ground-based measurements of sky radiance. For March this scattering was found to be equivalent to that produced by a target having a reflectance of 11% in band 4, 5% in band 5, 3% in band 6, and 1% in band 7; (3) computer ability to classify targets under various atmospheric conditions was determined. Classification accuracy on some targets (i.e. bare soil, tended grass, etc.) hold up even under the most severe atmospheres encountered, while performance on other targets (trees, urban, rangeland, etc.) degrades rapidly when atmospheric conditions change by the smallest amount

QQˉQ\bar Q (Q∈{b,c}Q\in \{b, c\}) spectroscopy using Cornell potential

The mass spectra and decay properties of heavy quarkonia are computed in nonrelativistic quark-antiquark Cornell potential model. We have employed the numerical solution of Schr\"odinger equation to obtain their mass spectra using only four parameters namely quark mass ($m_c$, $m_b$) and confinement strength ($A_{c\bar c}$, $A_{b\bar b}$). The spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction are computed perturbatively to determine the mass spectra of excited $S$, $P$, $D$ and $F$ states. Digamma, digluon and dilepton decays of these mesons are computed using the model parameters and numerical wave functions. The predicted spectroscopy and decay properties for quarkonia are found to be consistent with available experimental observations and results from other theoretical models. We also compute mass spectra and life time of the $B_c$ meson without additional parameters. The computed electromagnetic transition widths of heavy quarkonia and $B_c$ mesons are in tune with available experimental data and other theoretical approaches

Large-amplitude chirped coherent phonons in tellurium mediated by ultrafast photoexcited carrier diffusion

We report femtosecond time-resolved reflectivity measurements of coherent phonons in tellurium performed over a wide range of temperatures (3K to 296K) and pump laser intensities. A totally symmetric A$_{1}$ coherent phonon at 3.6 THz responsible for the oscillations in the reflectivity data is observed to be strongly positively chirped (i.e, phonon time period decreases at longer pump-probe delay times) with increasing photoexcited carrier density, more so at lower temperatures. We show for the first time that the temperature dependence of the coherent phonon frequency is anomalous (i.e, increasing with increasing temperature) at high photoexcited carrier density due to electron-phonon interaction. At the highest photoexcited carrier density of $\sim$ 1.4 $\times$ 10$^{21}$cm$^{-3}$ and the sample temperature of 3K, the lattice displacement of the coherent phonon mode is estimated to be as high as $\sim$ 0.24 \AA. Numerical simulations based on coupled effects of optical absorption and carrier diffusion reveal that the diffusion of carriers dominates the non-oscillatory electronic part of the time-resolved reflectivity. Finally, using the pump-probe experiments at low carrier density of 6 $\times$ 10$^{18}$ cm$^{-3}$, we separate the phonon anharmonicity to obtain the electron-phonon coupling contribution to the phonon frequency and linewidth.Comment: 22 pages, 6 figures, submitted to PR

Osseous metaplasia of endometrium: a rare cause of secondary infertility

Osseous metaplasia of the endometrium is a rare condition with formation of bony tissue inside the uterus, particularly the endometrium. The etiology of this disorder is not completely understood, with various hypotheses being put forward to explain its occurrence. It is an important cause of secondary infertility, although it may present with various other gynecological symptoms. It can be suspected on ultrasonography due to its peculiar appearance and can be completely cured following hysteroscopic resection. Here we present a case of a 30 years old female presenting with hypomenorrhoea and secondary infertility following a first trimester abortion. Ultrasonography showed presence of dense linear echogenic band in the uterus suggestive of calcification. Hysteroscopy revealed multiple bony fragments of varying shapes and sizes (0.2-2cm) in the uterine cavity which were removed using a hysteroscopic grasper and the cavity was restored to normal. There were no procedure related complications. Presence of bony tissue was confirmed on histopathology. Patient had a spontaneous conception 3 months after the procedure and delivered a healthy male child at term. Thus, in our case, hysteroscopy was a safe and effective modality for diagnosis as well as treatment of this rare condition. Successful hysteroscopic treatment was followed by a spontaneous conception and a good pregnancy outcome

Gossypiboma: a surgical menace

Gossypiboma is a rare yet devastating complication. It may be a sequela to any kind of surgical procedure, however intra-abdominal surgeries are commonly implicated as the cause for this entity. In chronic cases, it may even lead to severe morbidity. We report a case of gossypiboma post vaginal hysterectomy, diagnosed and treated successfully by laparoscopy

Curvature dependence of the effect of ionic functionalization on the attraction among nanoparticles in dispersion

Solubilization of nanoparticles facilitates nanomaterial processing and enables new applications. An effective method to improve dispersibility in water is provided by ionic functionalization.We explore how the necessary extent of functionalization depends on the particle geometry. Using molecular dynamics/umbrella sampling simulations, we determine the effect of the solute curvature on solventaveraged interactions among ionizing graphitic nanoparticles in aqueous dispersion. We tune the hydrophilicity of molecular-brush coated fullerenes, carbon nanotubes, and graphane platelets by gradually replacing a fraction of the methyl end groups of the alkyl coating by the ionizing –COOK or –NH3Cl groups. To assess the change in nanoparticles’ dispersibility in water, we determine the potential-of-mean-force profiles at varied degrees of ionization. When the coating comprises only propyl groups, the attraction between the hydrophobic particles intensifies from spherical to cylindrical to planar geometry. This is explained by the increasing fraction of surface groups that can be brought into contact and the reduced access to water molecules, both following the above sequence. When ionic groups are added, however, the dispersibility increases in the opposite order, with the biggest effect in the planar geometry and the smallest in the spherical geometry. These results highlight the important role of geometry in nanoparticle solubilization by ionic functionalities, with about twice higher threshold surface charge necessary to stabilize a dispersion of spherical than planar particles. At 25%–50% ionization, the potential of mean force reaches a plateau because of the counterion condensation and saturated brush hydration. Moreover, the increase in the fraction of ionic groups can weaken the repulsion through counterion correlations between adjacent nanoparticles. High degrees of ionization and concomitant ionic screening gradually reduce the differences among surface interactions in distinct geometries until an essentially curvature-independent dispersion environment is created. Insights into tuning nanoparticle interactions can guide the synthesis of a broad class of nonpolar nanoparticles, where solubility is achieved by ionic functionalization

An alternative explanation for the density depletions observed by Freja and Viking satellites

In this paper, we have studied the linear and nonlinear propagation of ion acoustic waves in the presence of electrons that follow the generalized (r,q) distribution. It has been shown that for positive values of r, which correspond to a flat-topped electron velocity distribution, the nonlinear ion acoustic waves admit rarefactive solitary structures or density depletions. It has been shown that the generalized (r,q) distribution function provides another way to explicate the density depletions observed by Freja and Viking satellites previously explained by proposing Cairns distribution function.In this paper, we have studied the linear and nonlinear propagation of ion acoustic waves in the presence of electrons that follow the generalized (r,q) distribution. It has been shown that for positive values of r, which correspond to a flat-topped electron velocity distribution, the nonlinear ion acoustic waves admit rarefactive solitary structures or density depletions. It has been shown that the generalized (r,q) distribution function provides another way to explicate the density depletions observed by Freja and Viking satellites previously explained by proposing Cairns distribution function

Dietary elimination of children with food protein induced gastrointestinal allergy – micronutrient adequacy with and without a hypoallergenic formula?

Background: The cornerstone for management of Food protein-induced gastrointestinal allergy (FPGIA) is dietary exclusion; however the micronutrient intake of this population has been poorly studied. We set out to determine the dietary intake of children on an elimination diet for this food allergy and hypothesised that the type of elimination diet and the presence of a hypoallergenic formula (HF) significantly impacts on micronutrient intake. Method: A prospective observational study was conducted on children diagnosed with FPIGA on an exclusion diet who completed a 3 day semi-quantitative food diary 4 weeks after commencing the diet. Nutritional intake where HF was used was compared to those without HF, with or without a vitamin and mineral supplement (VMS). Results: One-hundred-and-five food diaries were included in the data analysis: 70 boys (66.7%) with median age of 21.8 months [IQR: 10 - 67.7]. Fifty-three children (50.5%) consumed a HF and the volume of consumption was correlated to micronutrient intake. Significantly (p <0.05) more children reached their micronutrient requirements if a HF was consumed. In those without a HF, some continued not to achieve requirements in particular for vitamin D and zinc, in spite of VMS. Conclusion: This study points towards the important micronutrient contribution of a HF in children with FPIGA. Children, who are not on a HF and without a VMS, are at increased risk of low intakes in particular vitamin D and zinc. Further studies need to be performed, to assess whether dietary intake translates into actual biological deficiencies