Isolation of Machine Foundations by Barriers

Experimental investigation has been carried out to study the effects due to isolation of foundations subjected to vertical vibration on the displacement amplitude. Tests were conducted on an embedded footing of contact area 45 x 45cm. with different embedments and some on the surface of natural ground. Three isolation barriers viz. air gap, saw dust and sand of various depths were used. From the results of the investigation it was found that an open trench (air gap) around the foundation reduces the displacement amplitude around the footing considerably to an extent of about 75%. Saw dust as a barrier, although not as good as air gap, performs better when compared to sand. The coefficient of attenuation is not a constant for a soil medium but varies with static and dynamic loads. The resonant frequency decreases and resonant amplitude increases by providing isolating barriers

Prediction of Indoor Air Quality in a School Building Using Risk Model

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

Sens-BERT: Enabling Transferability and Re-calibration of Calibration Models for Low-cost Sensors under Reference Measurements Scarcity

Low-cost sensors measurements are noisy, which limits large-scale adaptability in airquality monitoirng. Calibration is generally used to get good estimates of air quality measurements out from LCS. In order to do this, LCS sensors are typically co-located with reference stations for some duration. A calibration model is then developed to transfer the LCS sensor measurements to the reference station measurements. Existing works implement the calibration of LCS as an optimization problem in which a model is trained with the data obtained from real-time deployments; later, the trained model is employed to estimate the air quality measurements of that location. However, this approach is sensor-specific and location-specific and needs frequent re-calibration. The re-calibration also needs massive data like initial calibration, which is a cumbersome process in practical scenarios. To overcome these limitations, in this work, we propose Sens-BERT, a BERT-inspired learning approach to calibrate LCS, and it achieves the calibration in two phases: self-supervised pre-training and supervised fine-tuning. In the pre-training phase, we train Sens-BERT with only LCS data (without reference station observations) to learn the data distributional features and produce corresponding embeddings. We then use the Sens-BERT embeddings to learn a calibration model in the fine-tuning phase. Our proposed approach has many advantages over the previous works. Since the Sens-BERT learns the behaviour of the LCS, it can be transferable to any sensor of the same sensing principle without explicitly training on that sensor. It requires only LCS measurements in pre-training to learn the characters of LCS, thus enabling calibration even with a tiny amount of paired data in fine-tuning. We have exhaustively tested our approach with the Community Air Sensor Network (CAIRSENSE) data set, an open repository for LCS.Comment: 1

Origin of Cretaceous phosphorites from the onshore of Tamil Nadu, India

Cretaceous phosphorites from the onshore of Tamil Nadu have been investigated for their origin and compared with those in the offshore. Cretaceous phosphorites occur as light brown to yellowish brown or white nodules in Karai Shale of the Uttatur Group in the onshore Cauvery basin. Nodules exhibit phosphatic nucleus encrusted by a chalky shell of carbonate. The nucleus of the nodules consists of light and dark coloured laminae, phosphate peloids/coated grains and detrital particles interspersed between the laminae. Scanning electron microscope (SEM) studies reveal trapping and binding activity of microbial filaments. A mat structure with linearly arranged microbial filaments and hollow, cell-based coccoid cyanobacterial mat are present. Nodules contain abundant carbonate fluorapatite, followed by minor calcite, quartz and feldspar. The P2O5 content of the phosphorites ranges from 18 to 26%. The CaO/P2O5, Sr and F contents are higher than that of pure carbonate fluorapatite. Concentrations of Si, Al, K, Fe, and Ti are low. We suggest that the nuclei of the nodules represent phosphate clasts related to phosphate stromatolites formed at intertidal conditions. At high energy levels the microbial mats were disintegrated into phosphate clasts, coated with carbonate and then reworked into Karai Shale. On the other hand, Quaternary phosphorites occur as irregular to rounded, grey coloured phosphate clasts at water depths between 180 and 320m on the continental shelf of Tamil Nadu. They exhibit grain-supported texture. Despite Quaternary in age, they also resemble phosphate stromatolites of intertidal origin and reworked as phosphate clasts onto the shelf margin depressions. Benthic microbial mats probably supplied high phosphorus to the sediments. Availability of excess phosphorus seems to be a pre-requisite for the formation of phosphate stromatolites

IMPACT OF ACTIVE COMPOUNDS ISOLATED FROM BANANA (MUSA SP. VAR. NANJANGUD RASABALE) FLOWER AND PSEUDOSTEM TOWARDS CYTOPROTECTIVE AND DNA PROTECTION ACTIVITIES

Objective: The present study was designed to evaluate for cytoprotective and DNA protective properties of the compounds isolated from ethanol extract of banana flower (EF) and ethanol extract of banana pseudostem (EE).Methods: The four active compounds viz., umbelliferone (C1) andlupeol (C2) from EF and stigmasterol (C3) and β-sitosterol (C4) from EE were isolated by activity-guided repeated fractionation through silica gel column chromatography. The isolated compounds were evaluated for cytoprotective on erythrocytes and pTZ57R/T plasmid DNA protection against hydroxyl radicals.Results: The study revealed that the compounds (C1-C4) at a concentration of 1 mg/ml exhibited 90% protection on erythrocytes membrane oxidation and also protect the pTZ57R/T plasmid DNA damage induced by hydroxyl radicals.Conclusion: These results endorse an insight for a strong chemical basis to the alleged beneï¬cial role of EF and EE in reducing oxidative stress conditions.Â

The Hanle Effect in 1D, 2D and 3D

This paper addresses the problem of scattering line polarization and the Hanle effect in one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) media for the case of a two-level model atom without lower-level polarization and assuming complete frequency redistribution. The theoretical framework chosen for its formulation is the QED theory of Landi Degl'Innocenti (1983), which specifies the excitation state of the atoms in terms of the irreducible tensor components of the atomic density matrix. The self-consistent values of these density-matrix elements is to be determined by solving jointly the kinetic and radiative transfer equations for the Stokes parameters. We show how to achieve this by generalizing to Non-LTE polarization transfer the Jacobi-based ALI method of Olson et al. (1986) and the iterative schemes based on Gauss-Seidel iteration of Trujillo Bueno and Fabiani Bendicho (1995). These methods essentially maintain the simplicity of the Lambda-iteration method, but their convergence rate is extremely high. Finally, some 1D and 2D model calculations are presented that illustrate the effect of horizontal atmospheric inhomogeneities on magnetic and non-magnetic resonance line polarization signals.Comment: 14 pages and 5 figure

Compositional fluctuations mediated by excess of tellurium in bismuth antimony telluride nanocomposite yields high thermoelectric performance

A high thermoelectric figure of merit (ZT) in state-of-the-art bismuth antimony telluride (BST) composites was attained by an excess tellurium-assisted liquid-phase compaction approach. Herein, we report a maximum ZT of approximate to 1.4 at 500 K attained for BST bulk nanocomposites fabricated by spark plasma sintering of colloidally synthesized (Bi,Sb)(2)Te-3 platelets and Te-rich rods. The Terich nanodomains and antimony precipitation during sintering result in compositional fluctuations and atomic ordering within the BST-Te eutectic microstructure, which provides additional phonon scattering and hole contributions. The electrical transport measurement and theoretical calculations corroborate the altered free carrier density via lattice defects and atomic ordering under Te-rich conditions, resulting in a higher power factor. Microstructural studies suggest that reduction in lattice thermal conductivity is due to composite interfaces and defects in the closely packed (Bi,Sb)(2)Te-3 matrix with unevenly distributed Sband Te-rich nanodomains. This work provides an unconventional chemical synthesis route with large scalability for developing high-performance chalcogenide-based bulk nanocomposites for thermoelectric applications.- We thank the members of the Nanochemistry Research Group (http://nanochemgroup.org) at INL for insightful discussions and support. This work was supported by the Portuguese national funding agency for science, research, and technology (FCT) under the UT-BORN-PT project (UTAP-EXPL/CTE/0050/2017), strategic project UID/FIS/04650/2020, Project SATRAP (POCI-01-0145-FEDER-028108) and Advanced Computing Project CPCA/A2/4513/2020 for access to MACC-BOB HPC resources. B.A.K. acknowledges funding of this work by the Robert A. Welch Foundation (grant no. F1464). N.S.C. and T.M. acknowledge SERB, India (project no. SPO/SERB/MET/2018547) for financial support

A comparative study on surgical management of distal end radius fracture with ulnar styloid fracture with and without ulnar styloid fixation

INTRODUCTION Fractures of the distal radius are the most common fractures of the upper extremity and account for 17% of all fractures treated in the emergency room. Initially thought to be simple fractures, they are now recognized as complex injuries with a high percentage of long term complications. Aims and objectives : To Observe the results and assess the Functional outcome of the management of Distal End Radius Fractures by plating, with and without ulnar styloid fixation with Tension Band Wiring (TBW) and to know the complications associated. Materials and methods : This is a prospective study from January 2015 to December 2017. Out of 40 patients of this study, radius was fixed by volar plating in all patients,where as ulnar styloid - fixed by TBW in 20pts and in remaining left without fixation at Department of orthopedics, Pratima Institute of Medical Sciences, Karimnagar. All patients were selected among admissions, operated and results were assessed clinically and radiographically. Clinical evaluation was done using modified Demerit score system of Gartland and Werely. Perioperative complications recorded. Mean followup period was 6months. Results : We had 10(50%) in ulnar styloid fixation and 9(45%) in ulnar styloid non fixation cases rated as excellent, as they had no deformity of the wrist and there was no pain. None of the patient had poor modified Demerit score system of Gartland and Werely. Complications like irritation of EPL due to K- wire(25%), loosening of K-wire(5%), stiffness (5%) seen in patients with ulnar styloid fixation. Ulnar sided wrist pain is seen in 20% of cases without ulnarstyloid fixation. Conclusion : In fixation group of ulnar styloid , excellent to good results were seen in 90% of patients, In non fixation of ulnar styloid group , excellent to good results were seen in 80% of patients suggesting that stabilizing the distal radius fracture fragments with volar plate and screws ,is only required method [in both groups] to maintain the anatomical reduction which is crucial in maintaining stability of DRUJ, till union and to prevent collapse of the fracture fragments