14,506 research outputs found
Using a laser aureole to invert lidar return
An aureole generated by a laser beam was studied. The strength of the signal redirected towards a sensor high above the surface by a combination of one scattering event in the marine boundary layer (mbl) and one single reflection event from the ocean surface was estimated. A model of mbl aerosol size distributions was used to estimate Mie scattering for a wide range of meteorolocial conditions. The sea surface reflection was determined from a Gaussian model of the wave slopes. These laser aureoles which were estimated over the wide range of conditions and were normalized by the reflected laser light were found to be highly correlated with the optical depth of the boundary layer. By estimating optical depth from the aureole, the Bernoulli-Riccati inversion of lidar return could be constrained and the inversion accuracy improved. A Monte Carlo program was developed to study the laser aureole generated by up to 8 orders of reflection and scattering. The aureole was generated by a narrow, 10 nsec laser pulse at 1.06 microns and measured by a receiver 10 km above the ocean surface. The original theoretical computation compared well with the Monte Carlo method. When multiple scattereffects were included, the normalized aureole was still highly correlated with the mbl optical depth over the range of conditions
Investigation of dual polarization laser modulation
Dual polarization lasers for wideband optical communication
Determinants of participation in child’s education and alternative activities in Pakistan
Using data from Pakistan, this study analyzed the effect of various individual, household, and community level characteristics on the probability that children engage in different activities. According to the existing trend of their prevalence, we considered five child’s activities, namely: secular schooling; religious education; child labor; a combination of child labor and secular schooling; and inactivity (including leisure). Data was collected through field surveys conducted in over 40 villages in four Pakistani provinces: Balochistan, Khyber Paktunkhwa, Punjab, and Sind. A total of 963 households were interviewed on the activities of 2,496 children. Multinomial Probit model was used for the analyses. Results indicated that parental perception had significant relationship to the probability of engagement in secular school attendance, religious education, and child labor. In addition, we investigated the relationships between participation in the different child activities with location (rural/urban) and children’s gender. We detected a lower probability of attending secular school and a higher probability of engaging in child labor among female children in rural areas. We also found that even parents who openly expressed appreciation of the importance of secular schooling were more likely to send male children to school than female children.Child productivity, Child’s activities, Parental perception, Gender, Community/Rural/Urban Development, Labor and Human Capital, Teaching/Communication/Extension/Profession,
Recommended from our members
Experimental and Theoretical Studies of the Environmental Sensitivity of the Absorption Spectra and Photochemistry of Nitenpyram and Analogs
Neonicotinoid (NN) pesticides have widespread use, largely replacing other pesticides such as the carbamates. Hence, there is a need to understand their environmental fates at a molecular level in various media, especially water. We report here the studies of a nitroenamine NN, nitenpyram (NPM), in aqueous solution where the absorption cross sections in the actinic region above 290 nm are observed to dramatically decrease compared to those in nonaqueous solvents. Quantum chemical calculations show that addition of a proton to the tertiary amine nitrogen in NPM breaks the conjugation in the chromophore, shifting the absorption to shorter wavelengths, consistent with experiment. However, surprisingly, adding a proton to the secondary amine nitrogen leads to its immediate transfer to the NO2 group, preserving the conjugation. This explains why the UV absorption of ranitidine (RAN), which has a similar chromophore but only secondary amine nitrogens, does not show a similar large blue shift in water. Photolysis quantum yields in aqueous NPM solutions were measured to be φ = 0.18 ± 0.07 at 254 nm, (9.4 ± 1.6) × 10-2 with broadband radiation centered at 313 nm and (5.2 ± 1.1) × 10-2 for broadband radiation centered at 350 nm (errors are 2σ). The major products in aqueous solutions are an imine that was also formed in the photolysis of the solid and a carboxylic acid derivative that is unique to the photolysis in water. Combining the larger quantum yields in water with the reduced absorption cross sections results in a calculated lifetime of NPM of only 5 min at a solar zenith angle of 35°, typical of 40°N latitude on April 1. The products do not absorb in the actinic region and hence will be long-lived with respect to photolysis
Pregnancy-associated breast cancer - Special features in diagnosis and treatment
For obvious psychological reasons it is difficult to associate pregnancy - a life-giving period of our existence with life-threatening malignancies. Symptoms pointing to malignancy are often ignored by both patients and physicians, and this, together with the greater difficulty of diagnostic imaging, probably results in the proven delay in the detection of breast cancers during pregnancy. The diagnosis and treatment of breast cancer are becoming more and more important, as the fulfillment of the desire to have children is increasingly postponed until a later age associated with a higher risk of carcinoma, and improved cure rates of solid tumors no longer exclude subsequent pregnancies. The following article summarizes the special features of the diagnosis and primary therapy of pregnancy-associated breast cancer with particular consideration of cytostatic therapy
Backward Reachability of Array-based Systems by SMT solving: Termination and Invariant Synthesis
The safety of infinite state systems can be checked by a backward
reachability procedure. For certain classes of systems, it is possible to prove
the termination of the procedure and hence conclude the decidability of the
safety problem. Although backward reachability is property-directed, it can
unnecessarily explore (large) portions of the state space of a system which are
not required to verify the safety property under consideration. To avoid this,
invariants can be used to dramatically prune the search space. Indeed, the
problem is to guess such appropriate invariants. In this paper, we present a
fully declarative and symbolic approach to the mechanization of backward
reachability of infinite state systems manipulating arrays by Satisfiability
Modulo Theories solving. Theories are used to specify the topology and the data
manipulated by the system. We identify sufficient conditions on the theories to
ensure the termination of backward reachability and we show the completeness of
a method for invariant synthesis (obtained as the dual of backward
reachability), again, under suitable hypotheses on the theories. We also
present a pragmatic approach to interleave invariant synthesis and backward
reachability so that a fix-point for the set of backward reachable states is
more easily obtained. Finally, we discuss heuristics that allow us to derive an
implementation of the techniques in the model checker MCMT, showing remarkable
speed-ups on a significant set of safety problems extracted from a variety of
sources.Comment: Accepted for publication in Logical Methods in Computer Scienc
A Simplified Approach to Optimally Controlled Quantum Dynamics
A new formalism for the optimal control of quantum mechanical physical
observables is presented. This approach is based on an analogous classical
control technique reported previously[J. Botina, H. Rabitz and N. Rahman, J.
chem. Phys. Vol. 102, pag. 226 (1995)]. Quantum Lagrange multiplier functions
are used to preserve a chosen subset of the observable dynamics of interest. As
a result, a corresponding small set of Lagrange multipliers needs to be
calculated and they are only a function of time. This is a considerable
simplification over traditional quantum optimal control theory[S. shi and H.
Rabitz, comp. Phys. Comm. Vol. 63, pag. 71 (1991)]. The success of the new
approach is based on taking advantage of the multiplicity of solutions to
virtually any problem of quantum control to meet a physical objective. A family
of such simplified formulations is introduced and numerically tested. Results
are presented for these algorithms and compared with previous reported work on
a model problem for selective unimolecular reaction induced by an external
optical electric field.Comment: Revtex, 29 pages (incl. figures
54/07/12 (1) Marilyn Sheppard Blood Specimen Lab Report
Original lab report results from the Cuyahoga County Coroner\u27s Office regarding Marilyn Sheppard\u27s autopsy blood tests and her blood profiles conducted by University Hospitals of Cleveland.
The county\u27s lab report concerning blood alcohol and barbiturates were both negative. The blood data profile of her blood specimen confirmed that her blood was O, Rh negative, type MS. The memo from the laboratory director also explains the various test reactions for Marilyn Sheppard\u27s blood specimen along with the lab\u27s protocol using known positive control bloods
54/07/12 (1) Marilyn Sheppard Blood Specimen Lab Report
Original lab report results from the Cuyahoga County Coroner\u27s Office regarding Marilyn Sheppard\u27s autopsy blood tests and her blood profiles conducted by University Hospitals of Cleveland.
The county\u27s lab report concerning blood alcohol and barbiturates were both negative. The blood data profile of her blood specimen confirmed that her blood was O, Rh negative, type MS. The memo from the laboratory director also explains the various test reactions for Marilyn Sheppard\u27s blood specimen along with the lab\u27s protocol using known positive control bloods
The generalized Clapeyron equation and its application to confined ice growth
Most theoretical descriptions of stresses induced by freezing are rooted in
the (generalized) Clapeyron equation, which predicts the pressure that a solid
can exert as it cools below its melting temperature. This equation is central
for topics ranging beyond glaciology to geomorphology, civil engineering, food
storage, and cryopreservation. However, it has inherent limitations, requiring
isotropic solid stresses and conditions near bulk equilibrium. Here, we examine
when the Clapeyron equation is applicable by providing a rigorous derivation
that details all assumptions. We demonstrate the natural extension for
anisotropic stress states, and we show how the temperature and pressure ranges
for validity depend on well-defined material properties. Finally, we
demonstrate how the range of applicability of the (linear) Clapeyron equation
can be extended by adding higher-order terms, yielding results that are in good
agreement with experimental data for the pressure melting of ice.Comment: 2 Figure
- …