High Voltage Power Supply Design for Photo Multiplier Tube

CubeSats are playing a vital role in the development of new compact technologies for small satellites and because of their promising potential, the CubeSats have been widely embraced by universities for conducting space research projects. IITMSAT is a student driven Nano-satellite embraced by IIT Madras leading to the development of Space-based Proton-Electron Energy Detector (SPEED). It is a payload that is being developed to be launched on-board IITMSAT. The scientific objective of the payload is to gather data on the variations in the charge particle flux below the inner Van Allen radiation belts. SPEED is designed to obtain energy spectra of high-energy protons and electrons, specifically designed to investigate correlations between variations in these spectra and seismic activity, solar flares and lightning storms. The SPEED electronics consists of Peak hold Detector, Charge-Sensitive Pre-Amplifier, TIVVA microcontroller and Photo Multiplier Tubes. This paper describes the development of the high voltage power supply for the photo multiplier tubes (PMT) of SPEED. In SPEED, photo multiplier tubes operates at around 1000 V to 1300 V with very strict ripple requirements and requires very precise and controlled high voltage. Due to their high gain and extremely light sensitivity photomultipliers (PMTs) can easily be damaged by applying excessive light to the photocathode and thus exceeding the maximum output current. A novel compact and controllable high voltage power supply based on integrated DC-DC converters is developed which provides ultralow ripple of about 0.3% to 0.5% at an output of 1000 volts which is further reduced by the 5th order low-pass filter circuitry. Innovative automatic current protection circuitry is developed for protecting PMT from being damaged by saturation current. We are able to develop voltage monitoring and regulation system for high voltage with a voltage regulation of 0.1%. Voltage regulation is achieved by control software based on TIVA microcontroller based solution. A number of tests have been performed to provide very reliable and efficient high voltage power supply for PMT. This poster reflects upon the development of ultra-low noise and ripple power supply for the photo multiplier tube. The goal is to creat a very reliable high voltage power supply for the photo multiplier tubes of SPEED and this poster reflects upon the development of same

Emotion Recognition Of Animals Using Natural Language Processing

Sentiment analysis, also known as opinion mining, is a Natural Language Processing (NLP) technique that holds a pivotal role in discerning textual data's sentiments, categorizing them as positive, negative, or neutral. Its significance is underscored by its widespread use in aiding businesses to gauge brand and product sentiment from customer feedback, enhancing customer service, and identifying areas for product and service improvement. Moreover, sentiment analysis offers the ability to track sentiments in real-time, helping companies retain existing customers and attract new ones cost-effectively. Emotion recognition in animals using Natural Language Processing (NLP) is a challenging and less explored area compared to human emotion recognition. While animals do communicate their emotions through various non-verbal cues, such as body language, vocalizations, and facial expressions, applying NLP techniques directly may not be straightforward since animals don't use language in the same way humans do. However, if there are textual data associated with animal behavior, such as ethological observations or written descriptions of their activities, NLP techniques can be adapted to gain insights into their emotional states. &nbsp

Turmeric (Curcuma longa L.) products: What quality differences exist?

Curcuma longa L. (root and rhizome), commonly known as turmeric, is a plant of high medicinal and economic value globally, including within the EU where it is mainly used as a food and food supplement. Its key active ingredients have been studied extensively, but concerns remain about the composition and thus the quality of extracts and products on the market. Recently, problems of adulteration with other Curcuma species and general poor quality have been detected within crude turmeric powders and final products. This study aimed to investigate the chemical variation of turmeric finished products available in the UK and identify the quality of turmeric products obtained from specific stages of the supply chain, with a focus on quality differences in the UK. 1H-NMR spectroscopy metabolomics coupled to Principle Component Analysis (PCA) and HPTLC methods were used for the phytochemical and metabolomics investigation of 72 turmeric samples, including crude powders, intermediate products from different manufacturing stages and commercial products obtained from health food stores and the Internet. A significant variation in the chemical composition of turmeric finished products, especially in the ones containing turmeric extracts, was found. Several products were found to contain only curcumin or curcuminoids, while the other active ingredients and marker compounds of C. longa were lacking. Products obtained from different stages of the Pukka value chain presented similar chemical composition, with the intermediate products (S57-59) showing the highest amount of active ingredients. Consequently, the manufacturing practices involved in the production of turmeric food supplements are critical stages to obtain high-quality final products. Often the focus has been only on the primary material, its natural variation and forms of production. This study highlights the importance of developing well-controlled integrated systems for the quality assurance of dietary supplements throughout the supply chain from seed to final product

A Complete Solution to LTE-U and Wi-Fi Hidden Terminal Problem

With the exponential growth in mobile data traffic, mobile operators are facing the unfortunate limit on the availability of licensed spectrum which has however, led to the popularity of Long Term Evolution (LTE) in unlicensed spectrum (LTE-U). Undeniably, it is expected from LTE-U that it fairly shares the spectrum with Wi-Fi. Along with fair sharing, efficient utilization of the unlicensed spectrum is also equally important, which in some sense requires coordination between the two Radio Access Technologies (RATs) viz., LTE-U and Wi-Fi. In particular, the hidden terminal scenario between LTE-U and Wi-Fi, resulting mainly due to lack of coordination, threatens the spectrum utilization of unlicensed spectrum. Focusing on this hidden terminal problem between LTE-U and Wi-Fi, we highlight the deficiency of existing technologies from the Wi-Fi perspective, both at the user level and at the network level. We then propose a novel coexistence technique (similar to RTS-CTS mechanism in Wi-Fi) that solves the hidden terminal problem between LTE-U and Wi-Fi, and subsequently addresses the spectrum underutilization problem caused by hidden terminal collisions. The proposed mechanism achieves this by using a modified CTS frame of Wi-Fi. We have validated our proposed mechanism using a mathematical framework demonstrating its credibility

A novel coexistence scheme for IEEE 802.11 for user fairness and efficient spectrum utilization in the presence of LTE-U

A promising solution satisfying the industry’s demand to have minimum modification in LTE for its operation in unlicensed spectrum is duty cycled LTE-U scheme, which adopts discontinuous transmission to ensure fair coexistence with 802.11 (Wi-Fi) WLANs. Even though the scheme guarantees to maintain Wi-Fi network performance, the fairness among Wi-Fi users still remains arcane. In this work, we present a practical scenario where LTE-U, despite being discontinuous (by following an ON/OFF cycle), results in not only unfair throughput distribution among Wi-Fi users but also causes degradation in Wi-Fi AP’s downlink performance. This is due to the domination of few Wi-Fi users who harness channel in both ON and OFF durations of LTE-U, namely non-victim users over those who get access only in OFF duration, called victim users. In this paper, we studied the performance of victim and non-victim Wi-Fi users, and Wi-Fi AP while varying LTE-U ON fraction (i.e., duty cycle). A propitious scheme is proposed for WLANs, with regard to ease of implementation, employing Point/Hybrid Coordination Function (PCF/HCF) mode of 802.11, promising fairness among Wi-Fi users with improvement in the channel utilization of Wi-Fi network. The key idea is that the victim users, who can only be served during the LTE-U OFF period should be served in Contention Free Period (CFP)—so as to improve their throughputs and make them equally competitive with non-victim users. Also, we present an analytical model to demonstrate guaranteed improvement and to validate our simulation results

LTE-U and Wi-Fi hidden terminal problem: How serious is it for deployment consideration?

The deployment of LTE in unlicensed spectrum is a plausible solution to meet explosive traffic demand from mobile users. However, fair coexistence with the existing unlicensed technologies, mainly Wi-Fi, needs to be ensured before any such deployment. Duty cycled LTE (LTE-U) is a simple and an easily adaptable scheme which helps in fair coexistence with the Wi-Fi. Nonetheless, the immense deployment of Wi-Fi necessitates a user-oriented study to find the effects of LTE-U operation, primarily in scenarios where the LTE-U eNB remains hidden from Wi-Fi Access Point. To comprehend these effects, we perform a user-level throughput study of Wi-Fi in the presence of LTE-U using a testbed and observe a clear unfairness in throughput distribution among Wi-Fi users. Furthermore, we also notice inability among the disadvantaged users to receive the periodic Wi-Fi beacon frames successfully. The reasons and the subsequent consequences, of throughput unfairness and beacon losses, are carefully elaborated. Also, to validate the beacon loss results, we present a beacon loss analysis which provides a mathematical expression to find the beacon loss percentage. Finally, we examine the results and highlight a need for incorporating additional functionalities in either LTE-U or Wi-Fi to overcome the present challenges