A naked singularity stable under scalar field perturbations

We prove the stability of a spacetime with a naked singularity under scalar field perturbations, where the perturbations are regular at the singularity. This spacetime, found by Janis, Newman and Winicour, and independently by Wyman, is sourced by a massless scalar field and also arises as a certain limit of a class of charged dilatonic solutions in string theory. This stability result opens up specific questions for investigation related to the cosmic censorship conjecture and the mechanism by which it is implemented in nature.Comment: 19 pages, version to appear in IJMPD, references adde

ANALISA PERBEDAAN LPS (LAST PLANNER SYSTEM) DENGAN SISTEM KONVENSIONAL SERTA PENGARUH CPM DAN BAR CHART PADA LPS

Two generally method / tools which used in project construction management system in Indonesia and the name are CPM (critical part method) or network planning and Bar Chart. The system used general method called conventional management system. Nowadays, was appeared one of a new system which seldom to applied in Indonesia, it is called LPS (last planner system). This research, researcher doing analyzed the differences between LPS and conventional management system. The result which obtained in this research are LPS dominated to accentuates team collaborative in the scheduling planning, resource allocation, control and enhance of work productivity, issue solved, regularly scheduling planning. Conventional management system more rely on the way CPM and Bar Chart working in that system with project manager decision. Planning of the schedule in this system doing by scheduling team. rescheduling in this system is not routine, it’s depend by construction progress. CPM and Bar Chart methods is influence on LPS. The both of methods was appeared in master scheduling, look a head scheduling, weekly work planning, shielding production, workable back log, percent plan completed and reliable promise proces

A Systematic Review of Convolutional Neural Network-Based Structural Condition Assessment Techniques

With recent advances in non-contact sensing technology such as cameras, unmanned aerial and ground vehicles, the structural health monitoring (SHM) community has witnessed a prominent growth in deep learning-based condition assessment techniques of structural systems. These deep learning methods rely primarily on convolutional neural networks (CNNs). The CNN networks are trained using a large number of datasets for various types of damage and anomaly detection and post-disaster reconnaissance. The trained networks are then utilized to analyze newer data to detect the type and severity of the damage, enhancing the capabilities of non-contact sensors in developing autonomous SHM systems. In recent years, a broad range of CNN architectures has been developed by researchers to accommodate the extent of lighting and weather conditions, the quality of images, the amount of background and foreground noise, and multiclass damage in the structures. This paper presents a detailed literature review of existing CNN-based techniques in the context of infrastructure monitoring and maintenance. The review is categorized into multiple classes depending on the specific application and development of CNNs applied to data obtained from a wide range of structures. The challenges and limitations of the existing literature are discussed in detail at the end, followed by a brief conclusion on potential future research directions of CNN in structural condition assessment

Avian Fauna

Avian Faun

Mangrove vegetation

Mangrove vegetation includes plants ranging from herbs, shrubs to tall trees. In favourable conditions the mangrove trees can form dense forests in intertidal habitats. However; only a few species form a massive canopy. The main characteristic features of these special type of plants are the tidal amplitude, defined by the species, and their ability to tolerate high salinity and stress. The majority of the plant groups have adaptations like prop and stilt roots for fixing support and the pneumatophores otherwise called the breathing roots for exchanging gases and the viviparous germination. In addition to these, the plants have leathery, dark, ever green leaves with deeply embeded stomata and aquous tissues

Are sanitation interventions a threat to drinking water supplies in rural India? An application of tryptophan-like fluorescence.

Open defecation is practised by over 600 million people in India and there is a strong political drive to eliminate this through the provision of on-site sanitation in rural areas. However, there are concerns that the subsequent leaching of excreta from subsurface storage could be adversely impacting underlying groundwater resources upon which rural populations are almost completely dependent for domestic water supply. We investigated this link in four villages undergoing sanitary interventions in Bihar State, India. A total of 150 supplies were sampled for termotolerant (faecal) coliforms (TTC) and tryptophanlike fluorescence (TLF): an emerging real-time indicator of faecal contamination. Sanitary risk inspections were also performed at all sites, including whether a supply was located within 10 m of a toilet, the recommended minimum separation. Overall, 18% of water supplies contained TTCs, 91% of which were located within 10 m of a toilet, 58% had TLF above detection limit, and sanitary risk scores were high. Statistical analysis demonstrated TLF was an effective indicator of TTC presence-absence, with a possibility of TTCs only where TLF exceeded 0.4 mg/L dissolved tryptophan. Analysis also indicated proximity to a toilet was the only significant sanitary risk factor predicting TTC presence-absence and the most significant predictor of TLF. Faecal contamination was considered a result of individual water supply vulnerability rather than indicative of widespread leaching into the aquifer. Therefore, increasing faecal contamination of groundwater-derived potable supplies is inevitable across the country as uptake of onsite sanitation intensifies. Communities need to be aware of this link and implement suitable decentralised low-cost treatment of water prior to consumption and improve the construction and protection of new supplies

An Efficient Power Control Technique for High-Frequency Resonant Inverter in Induction Heating System

An efficacious and reliable power control technique has been developed which can be used to regulate the output power of a high-frequency full bridge series resonant inverter (HF-FBSRI) in an induction heating (IH) system. In this paper, a modified buck-boost converter is presented to control the DC link/bus voltage which maintains the IH system under resonant mode and optimizes the performance of the IH system. Controlled DC link/bus voltage has been applied to this HF- FBSRI to control the average output power in the IH system. Using this aimed control technique, a wide range of output powers has been controlled and consistent performance of the IH system has been achieved. ZVS switching technique has been used to reduce the switching losses. Varying average power has been obtained at different duty cycles ranging from 0.2 to 0.8 with variable DC link voltage and it has been corroborated using PSIM environment for an IH system rated at 5500W

Performance analysis of packed u-cell based inverter-fed fivephase induction motor drive using sinpwm technique

Induction motor is the backbone of current industrial applications. Multiphase machines can handle high power application easily. With the use of five-phase induction motor, advantage of both multi-phase and induction motor can be achieved. This paper presents analysis of five-phase seven level-based Induction motor system fed by packed U-cell based inverter. Modelling of five-phase induction motor is done with the help of mathematical equations using d-q axis transformation. Inverter voltage output comes to be approximately sinusoidal with 18.07% Total Harmonic Distortion (THD). Induction motor with specified parameters is simulated under no-load condition and attains steady state conditions after transient state..This publication was made possible by Qatar University High Impact Research grant # [QUHI-CENG-19/20-2] from the Qatar University. The statements made herein are solely the responsibility of the authors.Scopu