NOPR Community:

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

Thu, 01 Dec 2016 00:00:00 GMT

Title: Estimation of uncertainty of effective area of a pneumatic pressure reference standard using Monte Carlo method Authors: Singh, Jasveer; Kumaraswamidhas, L A; Vijay, Aditi; Kumar, Ashok; Sharma, Nita Dilawar Abstract: 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. Page(s): 755-764

Novel quadrature voltage controlled oscillator using series transistors coupling

Thu, 01 Dec 2016 00:00:00 GMT

Title: Novel quadrature voltage controlled oscillator using series transistors coupling Authors: Jin, Jie Abstract: In this paper, a novel quadrature voltage controlled oscillator (QVCO) coupled by four transistors has been presented. The proposed QVCO consists of two identical LC negative resistance voltage controlled oscillators (VCO) and four series coupling transistors. Compared with the coupling method using paralleled transistors, the series transistors coupling method has lower power consumption and phase noise. The proposed QVCO is designed and simulated with Global Foundries 0.18 μm CMOS 1P6M RF process using Cadence IC Design Tools. The simulation results demonstrate that the proposed QVCO operates from 2.388 GHz to 3.376 GHz by adjusting the control voltage, and its phase noise is –140.6 dBc/Hz at 1 MHz offset. Moreover, the power consumption of the QVCO is only 1.84 mW with 1.25 V supply voltage. Page(s): 765-770

Temperature dependence of ferroelectric mode frequency, dielectric constant and loss tangent in CsH₂PO₄ and deuterated CsH₂PO₄ crystals

Thu, 01 Dec 2016 00:00:00 GMT

Title: Temperature dependence of ferroelectric mode frequency, dielectric constant and loss tangent in CsH₂PO₄ and deuterated CsH₂PO₄ crystals Authors: Mamgain, Anubhuti; Upadhyay, Trilok Chandra Abstract: The pseudo-spin lattice coupled mode model by adding third- and fourth-order phonon anharmonic interactions and extra spin-lattice interaction term has been considered for CsH₂PO₄ (abbreviated CDP) and deuterated CsH₂PO₄ (abbreviated DCDP) crystals. Expressions for shift and width of response function, vibrational normal mode frequency, dielectric constant and loss tangent have been evaluated. Double time temperature dependent Green’s function method has been used for derivation. Fitting the values of model parameters in expressions, the temperature dependence of soft mode frequency, dielectric constant and loss tangent have been calculated. Theoretical results are in agreement with experimental results reported by Blinc et al¹⁶. Page(s): 771-776

Conjugate heat and mass transfer in square porous cavity

Thu, 01 Dec 2016 00:00:00 GMT

Title: Conjugate heat and mass transfer in square porous cavity Authors: Azeem; Badruddin, Irfan Anjum; Idris, Mohd Yamani Idna; Nik-Ghazali, N; Ahmed, Salman N J; Al-Rashed, Abdullah A A A Abstract: The present article deals with the issue of heat and mass transfer in a square porous cavity having a small solid wall or block inserted at various places at bottom surface. The main objective is to investigate the effect of size of solid wall and its location inside the porous cavity on double diffusive convention. The heat and mass transfer behavior are governed by momentum, energy and concentration equations which are converted into a set of finite element equation with the help of Galerkin method. The left surface of cavity is maintained at higher temperature and concentration, T_hand C_h as compared to that of right surface at T_cand C_c. The results are presented in terms of thermal, concentration and fluid flow profiles across the porous cavity. Page(s): 777-786

NOPR Community:

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

Novel quadrature voltage controlled oscillator using series transistors coupling

Temperature dependence of ferroelectric mode frequency, dielectric constant and loss tangent in CsH2PO4 and deuterated CsH2PO4 crystals

Conjugate heat and mass transfer in square porous cavity

Temperature dependence of ferroelectric mode frequency, dielectric constant and loss tangent in CsH₂PO₄ and deuterated CsH₂PO₄ crystals