Inter comparison of the magneto transport of La2/3Ca1/3MnO3: Ag/In polycrystalline composites

In this article, we report the synthesis, magneto transport features, and magnetization of polycrystalline La2/3Ca1/3MnO3:Agx/Inx composites with x = 0, 0.1, 0.2, 0.3 and 0.4. In case of Ag the temperature coefficient of resistance (TCR) near ferromagnetic (FM) transition enhances significantly with addition of Ag. The FM transition temperature (TFM) is also increased slightly with Ag doping. Magneto-transport measurements revealed that magneto-resistance (MR) is found to be maximum near TFM. Very sharp TCR is seen near TFM with highest value of up to 15 % for Ag (0.4) sample, which is an order of magnitude higher than as for pristine sample and is the best value yet reported for any polycrystalline LCMO compound. Increased TCR, TFM and significant above room temperature MR of La2/3Ca1/3MnO3:Agx composites is explained on the basis of improved grains size. Interestingly the La2/3Ca1/3MnO3:Inx composites behaved exactly in opposite way resulting in decreased TFM, and TCR compared to pristine LCMO compound. In fact the grains morphology of LCMO:Inx composites is seen inferior to pristine LCMO which is opposite to the LCMO:Agx case.Comment: 13 pages of TEXT+Fig

Enhanced Room Temperature Coefficient of Resistance and Magneto-resistance of Ag-added La0.7Ca0.3-xBaxMnO3 Composites

In this paper we report an enhanced temperature coefficient of resistance (TCR) close to room temperature in La0.7Ca0.3-xBaxMnO3 + Agy (x = 0.10, 0.15 and y = 0.0 to 0.40) (LCBMO+Ag) composite manganites. The observed enhancement of TCR is attributed to the grain growth and opening of new conducting channels in the composites. Ag addition has also been found to enhance intra-granular magneto-resistance. Inter-granular MR, however, is seen to decrease with Ag addition. The enhanced TCR and MR at / near room temperature open up the possibility of the use of such materials as infrared bolometric and magnetic field sensors respectively.Comment: 22 pages of Text + Figs:comments/suggestions([email protected]

A Case Study of Three Drum Parameter Control in Boiler Using Discrete PID Controller Based on Simulation

ABSTRACT: In the global world, the energy demand increases in a broad level to solve the demand of energy supply. In this field a research program working in a broad level by scientist or knowledgeable engineers. In This methodology of Unified controls for a Power plant is conceived by the consultants and discrete PID contractor to improve the plant efficiency. This is implemented in few projects and various options are also indicated in the methodology. In this paper an attempt has been made to design discrete PID controller for drum parameter control. In the initial stage used in a Boiler by use MATLAB. Comparison of discrete PID controller with conventional controller is also discussed in this paper

Insecticidal and ovicidal activity of the essential oil of Anethum sowa kurz against Callosobruchus maculatus F. (Coleoptera: bruchidae)

The fumigant toxicity, ovicidal and oviposition-deterrent potential of the essential oil of Indian dill, Anethum sowa and its three major fractions against the grain beetle Callosobruchus maculatus (Coleoptera: Bruchidae) on chickpea were investigated. Two fractions produced 100% mortality of adult beetles at 3.0 μl/ml dosage, whereas the essential oil was the least effective. Fraction III was 100% ovicidal at a 70 μl/ml concentration. The essential oil and fraction III both completely deterred oviposition at the lowest concentration tested, 10 μl/ml. Neither the essential oil nor its fractions had any significant effect on chickpea seed germination. RÉSUMÉ La toxicité fumigène, la potentialité ovicide et antiovipositionnelle de l'huile essentielle de l'aneth Indien, Anethum sowa et de ses trois principales fractions, contre la bruche Callosobruchus maculatus (Coleoptera: Bruchidae) ont été étudiées sur pois chiche. Deux fractions produisent 100% de mortalité des bruches adultes à la dose de 3.0 μl/ml, tandis que l'huile essentielle est la moins efficace. La fraction III provoque 100% de mortalité des oeufs à la concentration de 70 μl/ml. L'huile essentielle et la fraction III inhibent complètement l'oviposition à la plus faible concentration testée, 10 μl/ml. Ni l'huile essentielle, ni ses fractions n'ont d'effet significatif sur la germination des graines de pois chiches

Insecticidal and Ovicidal Activity of the Essential Oil of Anethum sowa Kurz against Callosobruchus maculatus F. (Coleoptera: Bruchidae)

The fumigant toxicity, ovicidal and oviposition-deterrent potential of the essential oil of Indian dill, Anethum sowa and its three major fractions against the grain beetle Callosobruchus maculatus (Coleoptera: Bruchidae) on chickpea were investigated. Two fractions produced 100% mortality of adult beetles at 3.0 μl/ml dosage, whereas the essential oil was the least effective. Fraction III was 100% ovicidal at a 70 μl/ml concentration. The essential oil and fraction III both completely deterred oviposition at the lowest concentration tested, 10 μl/ml. Neither the essential oil nor its fractions had any significant effect on chickpea seed germination. RÉSUMÉ La toxicité fumigène, la potentialité ovicide et antiovipositionnelle de l'huile essentielle de l'aneth Indien, Anethum sowa et de ses trois principales fractions, contre la bruche Callosobruchus maculatus (Coleoptera: Bruchidae) ont été étudiées sur pois chiche. Deux fractions produisent 100% de mortalité des bruches adultes à la dose de 3.0 μl/ml, tandis que l'huile essentielle est la moins efficace. La fraction III provoque 100% de mortalité des oeufs à la concentration de 70 μl/ml. L'huile essentielle et la fraction III inhibent complètement l'oviposition à la plus faible concentration testée, 10 μl/ml. Ni l'huile essentielle, ni ses fractions n'ont d'effet significatif sur la germination des graines de pois chiches

Influence of sintering temperature and oxygen annealing on transport properties of La0.67Ca0.33MnO3

We investigate the influence of sintering temperature and annealing conditions on the transport properties of La0.67Ca0.33MnO3 (LCMO) samples prepared by the solid-state reaction method. In the plot of resistance as a function of temperature, R(T), we observe two peaks for air-annealed samples, which is attributed to the inhomogeneous distribution of oxygen—whereas the sample annealed in oxygen shows only a single peak, which is explained on the basis of homogeneous distribution of oxygen and grain connectivity. The sharpness in the transition peak is described in terms of the temperature coefficient of resistance, which is calculated using R(T) data. We present and compare here the results of structural, transport and magnetic measurements of LCMO prepared at different sintering temperatures as well as under different annealing conditions. The results of the compound are mainly discussed in terms of grain growth and the grain boundaries

Novel Coronavirus: A Newly Arranged Mini-Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was originally known as a virus that infects animals and rarely can be transmitted to humans in large populations, is now transformed into one of the most feared pandemics causes worldwide. Infection by a virus that is officially known as COVID-19 has caused global concern mainly due to the number of deaths caused. Since it was first reported in Wuhan, China in December 2019, now COVID-19 has spread to almost all parts of the world with a very rapid spread rate. The main symptom of this infection is a respiratory disease accompanied by other symptoms that resemble flu-like illness. Everyone can suffer from COVID-19, but the elderly, toddlers, pregnant women, and people with certain diseases and disorders of the immune system show more severe symptoms. The disease is transmitted through inhalation or contact with droplets, where the incubation period ranges from 2 to 14 days. Until now, specific therapy to treat COVID-19 has not been found, with preventive measures taken to control its spread. In this mini-review, we will explain important information related to COVID-19

One-Step Atmospheric Pressure Synthesis of the Ground State of Fe based LaFeAsO(1-delta)

We report an easy and versatile one-step synthesis route for a newly discovered Fe based LaFeAsO(1-delta) compound with 0.0 <= delta <= 0.15. Instead of widely used high-pressure-high-temperature (HPHT) synthesis, we applied the normal atmosphere solid-state reaction route. The stoichiometric mixtures of Fe, La(2)O(3), La, and As in ratio LaFeAsO(1-delta) with 0.0 <= delta <= 0.15 are sealed in an evacuated quartz tube and further heated at 500, 850, and 1,100 C in Ar for 12, 12, and 33 hours, respectively, in a single step. The resulting compounds are single phase LaFeAsO crystallized in tetragonal P4/nmm structure. These samples showed the ground state spin density wave (SDW) like metallic behavior below around 150 K. In conclusion, the ground state (non-superconducting) of newly discovered Fe based superconductor is synthesized via an easy one-step solid-state reaction route