3,425 research outputs found
Self-consistency of relativistic observables with general relativity in the white dwarf-neutron star binary pulsar PSR J1141-6545
Here we report timing measurements of the relativistic binary pulsar PSR
J1141-6545 that constrain the component masses and demonstrate that the orbital
period derivative \dot Pb = (-4+/-1)x10^-13 is consistent with gravitational
wave emission as described by the general theory of relativity. The mass of the
neutron star and its companion are 1.30+/-0.02 Mo and 0.986+/-0.020 Mo
respectively, suggesting a white dwarf companion, and extending the range of
systems for which general relativity provides a correct description. On
evolutionary grounds, the progenitor mass of PSR J1141-6545 should be near the
minimum for neutron star production. Its mass is two standard deviations below
the mean of the other neutron stars, suggesting a relationship between
progenitor and remnant masses.Comment: 10 pages, 2 figures, revised version to Ap J Letter
Polygonal gold nanoplates in a polymer matrix
Polygonal gold nanoplates are generated in situ in poly(vinyl
alcohol) film through thermal treatment, the polymer serving as the reducing agent and stabilizer for the nanoparticle formation and enforcing preferential orientation of the plates. The rare pentagonal as well as the more commonly observed hexagonal, triangular and square/rectangle shapes are obtained by finetuning the Au/PVA ratio and the time and temperature of fabrication
Modelling and control of crystallization process
Batch crystallizers are predominantly used in chemical industries like pharmaceuticals, food industries and specialty chemicals. The nonlinear nature of the batch process leads to difficulties when the objective is to obtain a uniform Crystal Size Distribution (CSD). In this study, a linear PI controller is designed using classical controller tuning methods for controlling the crystallizer outlet temperature by manipulating the inlet jacket temperature; however, the response is not satisfactory. A simple PID controller cannot guarantee a satisfactory response that is why an optimal controller is designed to keep the concentration and temperature in a range that suits our needs. Any typical process operation has constraints on states, inputs and outputs. So, a nonlinear process needs to be operated satisfying the constraints. Hence, a nonlinear controller like Generic Model Controller (GMC) which is similar in structure to the PI controller is implemented. It minimizes the derivative of the squared error, thus improving the output response of the process. Minimization of crystal size variation is considered as an objective function in this study. Model predictive control is also designed that uses advanced optimization algorithm to minimize the error while linearizing the process. Constraints are fed into the MPC toolbox in MATLAB and Prediction, Control horizons and Performance weights are tuned using Sridhar and Cooper Method. Performances of all the three controllers (PID, GMC and MPC) are compared and it is found that MPC is the most superior one in terms of settling time and percentage overshoot
കക്കവര്ഗ്ഗ ജീവികളുടെ ഉല്പാദനരംഗത്ത് വനിതകള്ക്ക് തൊഴിലവസരങ്ങള്
Training Material for Post Harvest handling of Shrimp and Clam Products കക്കവര്ഗ്ഗ ജീവികളുടെ ഉല്പാദനരംഗത്ത് വനിതകള്ക്ക് തൊഴിലവസരങ്ങള്
Comparison of haematological parameters between alcoholics and non-alcoholics
Background: Alcohol being one of the most commonly used drug, whose consequences include changes of CBC. The main causes leading to changes of CBC (complete blood count) are: myelosuppression that is accompanying with slight reduction in all blood cells, blood loss from gastrointestinal tract, malnutrition etc. Alcoholics may suffer from moderate anemia, characterized by enlarged, structurally abnormal RBC’s; mildly reduced numbers of WBC’s, especially of neutrophils; and moderately to severely reduced numbers of platelets. The objective of the study was to study the haematological manifestation among alcoholics based on the quantity and duration of alcohol intake and compare them with non-alcoholics.Methods: A cross-sectional study was conducted for a period of one year in our medical college hospital in medicine OPD with the collaboration of department of pathology and bio-chemistry. The study was started after getting the approval from the institutional ethical committee. A total of 150 study subjects were included in the study in which 50 were non-alcoholics, 50 were moderate alcoholics (less than or equal to two drinks per day for men and less than or equal to one drink per day for women) and the remaining 50 were severe alcoholics (more than 7 drinks a week in women and more than 14 drinks in a week in men). Blood investigations such as CBC, prothrombin time, liver function test, renal function test, folic acid levels and vitamin B12 levels were measured and the levels were compared between alcoholics and non-alcoholics.Results: Mean RBC count, mean MCH, MCHC were normal among the non-alcoholic group and it started decreasing among moderate alcoholics and more so with severe alcoholics and a similar type of result was also seen with total count and platelet count and the difference was found to be statistically significant. LFT, RFT, prothrombin time and vitamin B12 levels were found to be high and folate levels were decreased among alcoholics group when compared to non-alcoholics and the difference was statistically significant.Conclusions: Detection of hematological changes in chronic alcoholics and giving psychiatric counseling and treatment for alcohol dependence will decrease the future complications like cirrhosis liver, cardiac and renal disease, cerebellar degeneration, neuropathy, pancreatitis, etc. and reduce the morbidity and mortality in alcoholics
Bis{l-2,20-[1,10-(ethane-1,2-diyldinitrilo)- diethylidyne]diphenolato}bis[(benzoatojO)manganese(III)] dihydrate
The title compound, [Mn2(C18H18N2O2)2Cl2], was synthesized by the reaction between manganese(II) o-chlorobenzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxyacetophenone. The centrosymmetric dimer contains two Jahn-Teller-distorted manganese(III) ions, each in an octahedral geometry, connected through two phenoxy bridges from two ligands
Bis{μ-2,2′-[1,1′-(ethane-1,2-diyldinitrilo)diethylidyne]diphenolato}bis[(benzoato-κO)manganese(III)] dihydrate
The title compound, [Mn2(C18H18N2O2)2(C7H5O2)2]·2H2O, was synthesized by the reaction between manganese(II) benzoate and the Schiff base generated in situ by the condensation of ethane-1,2-diamine and o-hydroxyacetophenone. The Jahn–Teller-distorted manganese(III) ions of the centrosymmetric dimer are connected through phenoxy bridges. Hydrogen-bonding interactions between the uncoordinated C=O of the benzoate and uncoordinated water molecules link the dimers into a chain running parallel to the c axis
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