Spectroscopic and Theoretical Study of the Intramolecular π-Type Hydrogen Bonding and Conformations of 2-Cyclopenten-1-ol

The conformations of 2-cyclopenten-1-ol (2CPOL) have been investigated by high-level theoretical computations and infrared spectroscopy. The six conformational minima correspond to specific values of the ring-puckering and OH internal rotation coordinates. The conformation with the lowest energy possesses intramolecular π-type hydrogen bonding. A second conformer with weaker hydrogen bonding has somewhat higher energy. Ab initio coupled-cluster theory with single and double excitations (CCSD) was used with the cc-pVTZ (triple-ζ) basis set to calculate the two-dimensional potential energy surface (PES) governing the conformational dynamics along the ring-puckering and internal rotation coordinates. The two conformers with the hydrogen bonding lie about 300 cm−1 (0.8 kcal/mole) lower in energy than the other four conformers. The lowest energy conformation has a calculated distance of 2.68 Å from the hydrogen atom on the OH group to the middle of the C=C double bond. For the other conformers, this distance is at least 0.3 Å longer. The infrared spectrum in the O-H stretching region agrees well with the predicted frequency differences between the conformers and shows the conformers with the hydrogen bonding to have the lowest values. The infrared spectra in other regions arise mostly from the two hydrogen-bonded species.

Effects of Obstructions on the Accuracy of Bluetooth Contact Tracing

During the COVID-19 pandemic, the idea of facilitating contact tracing using Bluetooth is becoming widespread due to the prevalence of smartphones. The automatic classification of encounters between smartphones is challenging due to variations in signal strength – resulting in high false positive and false negative rates. For example, obstructions between two smartphones can reduce the strength of received signals and thus increase the calculated distance. This can benefit contact tracing by preventing a contact from being added to the database when people are on opposite side of a wall, but can also harm tracing efforts if two people are close together but their bodies reduce the signal between devices. A Raspberry Pi Bluetooth emitter and a phone receiver were placed 1 meter apart, and various obstacles were placed between them to simulate normal obstacles. Drywall and stud walls were shown to be ineffective at reducing Bluetooth signal strength. Cinder block, and especially the human body, were found to effectively lower Bluetooth strength so that the distance estimate was higher. The results of these experiments imply Bluetooth contact tracing will involve many false positives and negatives.

Evaluation of Content Based Image Retrieval Technique Using an Efficient Hybrid Model

Due to vast enhancement in the field of visual technology, there are various sets of images. In order to reduce the complexity in retrieval of relevant images CBIR (Content Based Image Retrieval) technique can be used. CBIR using only color feature does not result in required output. So in this paper we introduced the concept of hybrid model which deals with color, texture along with shape features which gives an efficient output. A set of images are used to test the accuracy and the precision of each methods. Using Euclidean distance and Manhattan distance, similarity between query image and all the other images in database are calculated. Then the calculated distance values are arranged in ascending order. Based on this required images are retrieved. Experiment results shows that Hybrid model method had high accuracy and precise output compared to Color Histogram. Future work will be made to add one more feature (shape features) in order to get better results.

Wearable Indoor Tracking Device using Wi-Fi Positioning System with PPG Sensor and Android Application

Many inventions that manifest the required qualities for the improvement of the search and rescue operations are made. However, the present inventions do not cover accurate tracking of the victims which contributes to a delay during operation. Thus, a Wearable Indoor Tracking Device using Wi-Fi Positioning System with PPG Sensor and Android Application is developed to uplift the limitations of the devices present today which can resolve the delay of search and rescue operation. This project focuses on detecting the specific location of the victims which includes distance and direction from rescuer’s perspective as well as the victim's status. Moreover, the location and status of the victim can be viewed simultaneously through an Android Application. To achieve the tracking technology, trilateration technique is used. It manipulates the calculated distance of the beacons by finding their intersection. To get the measured distance the researchers use an algorithm named Free Space Path Loss wherein it converts the Wi-Fi strength into distance. For the direction, slope formula is used to determine the measured angle between the rescuer and the victim. Therefore, by making this wearable device, the search and rescue operation will increase its accuracy to 80% in finding the distance of the rescuer and the victim and by 100% in finding the direction of the rescuer from the victim.

Determination of the Fault Zone by the Level of Short-Circuit Currents

The methods of determination the fault zone according to the parameters of the emergency mode, which can be used to improve the performance of technical perfection of current protection lines of distributive 6–10 kV one-way power networks, are considered. The advantage of the algorithm of determination the zones of short circuit (SC) according to the level of emergency currents as compared to the remote unilateral method addressing the parameters of the damaged loop corrupted loops (loops) is noted. Calculation of the estimated distance to the point of SC on the basis of difference of damaged phase currents has been proposed, that enables the independence of the obtained result on the type of the fault. A technique for increasing the reliability of the method for determination the short-circuit zone by the level of emergency currents based on information about the type of damage has also been proposed. The effect of load currents and contact resistances of different levels on the magnitude and nature of the changes in the errors of the calculated distance to the short circuit was investigated by the method of computational experiment. The levels of contact resistances relative to the total resistance of the line depending on the place of SC occurrence are determined that provides reliable determination of the fault zone; it is demonstrated that the nature of their alteration is approximately the same for lines of medium and long length. The expediency of correction of the calculated distance to the fault location in many cases of short circuits through the contact resistance so to improve the protection capacity of the high-speed current protection stage is demonstrated. Based on the results of the computational experiment, correction factors for the correction of the value of the emergency current have been obtained; on the basis of the latter the fault zone is determined. The estimation of efficiency of the proposed method of correction has been carried out; it is shown that its application makes it possible to improve the accuracy of determination the fault zone and to expand the zone of instantaneous shutdown of short circuit. The dynamic properties of the proposed algorithm for different modes of the line operation have been investigated; it is ascertained that, in the worst case, the determination of the short circuit zone for a time not exceeding 27 ms is provided.