Structure of ethyl 2-​(2-​amino-​3-​ethoxycarbonyl-​4H-​chromen-​4-​yl)​-​2-​cyanoacetate

The title compd. is monoclinic, space group P21/n, with a 21.335(2)​, b 8.516(1)​, c 9.273(1) Å, and β 93.645(1)​°, Z = 4, dm = 1.330, dc = 1.305, T = 300 K, final R = 0.059 for 3184 reflections. At. coordinates are given. The dihydropyran ring makes a dihedral angle of 14.6(3)​° with the benzene ring and is puckered. The ethoxycarbonyl group attached to C(3) makes a dihedral angle of 13.9(3)​° with the chromene ring but the 4-​(1-​ethoxycarbonyl) group is rotated about C(4) by 81.1(4)​°. The C-​C≡N chain is almost linear and makes a dihedral angle of 48.4(3)​° with the C(4) ethoxycarbonyl group. The mol. exhibits intramol. H bonding between the amino group at C(2) and the carbonyl O atom of the C(3) ethoxycarbonyl group. Intermol. N-​H...O bonds link the mols. across the center of symmetry

A Reconfigurable IoT Architecture with Energy Efficient Event-Based Data Traffic Reduction Scheme

Designing an Internet of Things (IoT) enabled environment requires integration of various things/devices. Integrating these devices require a generalized approach as these devices can have different communication protocols. In this paper, we have proposed generalized nodes for connecting various devices. These nodes are capable of creating a scalable local wireless network that connects to the cloud through a network gateway. The nodes also support over the air programming to re-configure the network from the cloud. As number of devices connected to the cloud increases, the network traffic also increases. In order to reduce the network traffic we have used different data transfer schemes for the network. We have also proposed an event-based data transfer scheme for situations where there is low probability of change in sensor value. The experimental results shows that the event-based scheme reduces the data traffic by up to 48% under practical conditions without any loss of information compared to priority based data transfer. We have also shown that the proposed scheme is more reliable for data transfer in a large network with a success rate of 99.5% measured over 200 minutes for 1201 data packets

Effect of pressure on the phase transition behavior of ammonium nitrate

Ammonium nitrate (AN) is used as oxidizer in solid propellants, explosives, gas generator systems and also as a fertilizer. The AN crystallizes in five polymorphic phases that appear at different temps. Phase transition of AN from one polymorphic phase to another is very important as an oxidizer and also as fertilizer. During its use as an oxidizer, whether pressure plays any role in phase transition is described in this paper. High pressure-DTA (HP-DTA) system is used for this study