Estimation of uncertainty of effective area of a pneumatic pressure reference standard using Monte Carlo method

The current paper presents a comparative investigation of the experimental as well as simulated evaluation of effective area and the associated uncertainties, of a pneumatic pressure reference standard (NPLI-4) of CSIR-National Physical Laboratory, India, (NPLI). The experimental evaluation has been compared to the simulated estimation of the effective area obtained through Monte Carlo method (MCM). The Monte Carlo method has been applied by taking fixed number of trials (FMCM) and also by trials chosen adaptively (AMCM). The measurement uncertainties have been calculated using the conventional method, i.e., law of propagation of uncertainty (LPU) as well as MCM. Experimentally, the NPLI-4 has cross-floated against our newly established pneumatic primary pressure standard (NPLI-P10), which is a large diameter piston gauge. An excellent agreement in effective area and measurement uncertainty has been observed between these approaches

BioSimulators: a central registry of simulation engines and services for recommending specific tools

Computational models have great potential to accelerate bioscience, bioengineering, and medicine. However, it remains challenging to reproduce and reuse simulations, in part, because the numerous formats and methods for simulating various subsystems and scales remain siloed by different software tools. For example, each tool must be executed through a distinct interface. To help investigators find and use simulation tools, we developed BioSimulators (https://biosimulators.org), a central registry of the capabilities of simulation tools and consistent Python, command-line and containerized interfaces to each version of each tool. The foundation of BioSimulators is standards, such as CellML, SBML, SED-ML and the COMBINE archive format, and validation tools for simulation projects and simulation tools that ensure these standards are used consistently. To help modelers find tools for particular projects, we have also used the registry to develop recommendation services. We anticipate that BioSimulators will help modelers exchange, reproduce, and combine simulations

Experimental Investigation on Filament Extrusion using recycled materials.

Plastics have become an essential part of our lives whether it is a food container or a high-tech medical instrument or just ordinary household item. Various advantages and disadvantages of plastics co-exist and hence it is difficult to eliminate the usage of plastic materials in everyday life. It is favorable because of its low weight, durability, flexibility, ease of processing etc. At the same time, it is not recommended due to health and safety hazards related to it.  Plastics made from renewable resources are high in demand for recycling application and one such thermoplastic is PLA.  Polylactic Acid (PLA) is biodegradable, transparent polymer derived from 100% renewable resources, such as corn and sugar beets. Its application ranges from simple packaging of food to biomedical applications. It has also become an essential part of 3D printing due to its ease of use compared to other thermoplastics. 3D printing is an additive manufacturing tool that uses layer by layer deposition phenomenon to print a 3D object. Using CAD software, the object is designed as per dimensional requirements and then the printer converts it into an object by deposition of material.   This study is an initiative to reuse discarded plastic products into something useful. Thus, failed prints of PLA material are used as the raw material and processed to get filaments of desired thickness in order to be used for 3D printing again. The 3D printed objects with dimensional irregularities or functional failures were crushed using a shredder and the shredded pieces were then sieved in order to eliminate the bigger pieces of material. The shredded material was then fed into the extruder and processed with high temperature and variation of speed of the extruder to get filaments of desired dimensions. The tests were performed in different settings that included variation of speed and temperature of heater. It is seen that both the parameter; speed and temperature, have a strong effect on the filament thickness

Temperature dependent Raman investigation of multiwall carbon nanotubes

We report anomalous observations in our investigations of the temperature dependent Raman spectroscopic measurement of multiwall carbon nanotubes. The Micro-Raman spectra were recorded with the laser source having 514.5 nm wavelength and within the temperature range of 80-440 K. The major Raman bands, the G and D band, are observed at 1584 and 1348 cm(-1), respectively, at ambient. The absence of the radial breathing mode confirms the multiwall nature of carbon nanotubes. It has been observed that with an increase in the temperature above 120 K, there is a shift in Raman bands towards the higher wave-number region. However, a drop in the G and D bands is observed from 80 to 120 K which was not observed for the second order band. Thereafter, all Raman modes exhibited mode hardening up to about 320 K followed by mild softening of the phonon modes. Linear temperature coefficients were found to have higher contribution to mode hardening as compared to higher order terms. Total anharmonicity estimation shows a predominant effect of the quasi-harmonic term as compared to the true anharmonic term

Raman scattering of rare earth sesquioxide Ho2O3: A pressure and temperature dependent study

Pressure and temperature dependent Raman scattering studies on Ho2O3 have been carried out to investigate the structural transition and the anharmonic behavior of the phonons. Ho2O3 undergoes a transition from cubic to monoclinic phase above 15.5 GPa, which is partially reversible on decompression. The anharmonic behavior of the phonon modes of Ho2O3 from 80K to 440K has been investigated. We find an anomalous line-width change with temperature. The mode Gruneisen parameter of bulk Ho2O3 was estimated from high pressure Raman investigation up to 29 GPa. Furthermore, the anharmonic components were calculated from the temperature dependent Raman scattering

Temperature dependent Raman investigation of multiwall carbon nanotubes

We report anomalous observations in our investigations of the temperature dependent Raman spectroscopic measurement of multiwall carbon nanotubes. The Micro-Raman spectra were recorded with the laser source having 514.5 nm wavelength and within the temperature range of 80-440 K. The major Raman bands, the G and D band, are observed at 1584 and 1348 cm(-1), respectively, at ambient. The absence of the radial breathing mode confirms the multiwall nature of carbon nanotubes. It has been observed that with an increase in the temperature above 120 K, there is a shift in Raman bands towards the higher wave-number region. However, a drop in the G and D bands is observed from 80 to 120 K which was not observed for the second order band. Thereafter, all Raman modes exhibited mode hardening up to about 320 K followed by mild softening of the phonon modes. Linear temperature coefficients were found to have higher contribution to mode hardening as compared to higher order terms. Total anharmonicity estimation shows a predominant effect of the quasi-harmonic term as compared to the true anharmonic term

A comparative investigation of pressure distortion coefficient of a pneumatic piston gauge and its associated uncertainty using varied approaches

This paper reports the evaluation of the measurement uncertainty of the pressure distortion coefficient () of a piston gauge using the Monte Carlo method (MCM) and its comparison with results obtained from the GUM (Guide to the expression of Uncertainty in Measurement) approach using the law of propagation of uncertainty. A reference pressure standard NPLI-4 was cross-floated against our pneumatic primary pressure standard NPLI-10, which is a large diameter piston gauge. The MCM was used for the simulated estimation. A good agreement is observed between the two methodologies, and the results are discussed in detail