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Medical implants, such as prosthetic joints, dental implants, and cardiovascular devices, have revolutionized patient care by restoring normal functionality and improving quality of life. However, to ensure optimal biocompatibility and long –term success, it is crucial to characterize the texture of these implants thoroughly. Texture characterization plays a vital role in evaluating the surface properties, roughness and topography of medical implants, enabling their enhanced design, manufacturing, and functional outcomes. This aims to explore the significance of texture characterization in medical implants especially bipolar hip joint and its implications on biocompatibility and performance.

Sundials, ancient timekeeping devices, require precise calibration for accurate time measurement. Technological advancements have significantly evolved calibration methods, now including widely available remote calibration techniques. This scientific paper delves into the uniqueness of the world’s largest gnomon sundials at Jantar Mantar, Jaipur, India. It examines the various methods and factors involved in sundial calibration and details the remote calibration technique used to assess the performance of this archaeological marvel. The paper also discusses the calibration results, offering insights that may aid researchers, horologists, and enthusiasts in enhancing the functionality and reliability of sundials in both historical and contemporary contexts.

Manufacturing industries' top priority in the current competitive environment is to increase productivity by reducing production costs. This can only be accomplished by improving Metal Removal Rate (MRR) while maintaining high tolerance and superior surface quality products. One issue that restricts the MRR in industries is tool chatter. In this paper, authors have compared two advanced computational methodology in order to predict stable machining zone during turning. Firstly, predict the stable machining zone using Local Mean Decomposition (LMD) for preprocessing of raw data and trained with Artificial Neural network. Further, compare this methodology with Wavelet Denoising and Local Mean Decomposition technique for preprocessing of data and trained with Adaptive Neuro-Fuzzy Inference System. From the analysis it has been found that, spindle speed can be raised to increase stability during machining. Nevertheless, significant chatter is seen when the depth of cut and feed rate are increased. Finally, additional experiments have been conducted to verify the validity of the suggested methodology.

Accurate estimation of Radio frequency (RF) cavity detuning is one of the important aims for controlling and monitoring of the particle accelerator used for beam acceleration. A methodological research is needed to achieve the aim of obtaining an accurate, unbiased and consistent detuning estimator. In the past, various estimation techniques for determination of RF cavity detuning have been applied. Methods like least squares, cavity parameter identification, linear and nonlinear observers have been employed for normal conducting and superconducting RF cavities. Apart from other methods, the Kalman filter has been employed by a few practitioners in the case of superconducting cavities. The Kalman filter is based on a stochastic state space framework, and it accounts for practical issues like model uncertainty and measurement noise in estimation of states and parameters. The behavioral model of a superconducting RF cavity is nonlinear due to the squared dependence of cavity detuning on the electric field inside it. Detuning being unmeasurable, is estimated from models and measured quantities. In general, a nonlinear system needs to use a nonlinear estimator for accuracy and low variability estimates. In this paper, we aim to quantify the uncertainty in detuning estimated by Kalman filter, extended Kalman filter and unscented Kalman filter for superconducting RF cavity. This aim has been achieved by characterization of noise from simulated results. Moments of the underlying probability distribution function of noise are determined as noise propagates through these filters. Tools such as quantile plots and descriptive statistics are used in this work to compare various cases quantitatively and arrive at important conclusions.

This review paper summaries the realization and updating of national standards of capacitance at CSIR-NPL. The capacitance standards maintained at CSIR-NPL are ranging from 10 pF to 1 mF with an uncertainty of 0.04 ppm to 300 ppm at 1 kHz. The capacitance measurement capabilities had been enhanced up to 30 MHz frequency with coaxial airlines and 4TP capacitance standards. The traceability links of various type of capacitance standards like fused silica, air, mica, 4TP, transformer coupled high value capacitance, coaxial airlines are discussed in brief. This paper also summaries the competency of capacitance Calibration and Measurement Capabilities (CMCs) of NPL India, with other NMIs in terms of international intercomparisons.

This manuscript presents the suitability of the compact, low-cost, dual frequency GNSS modules (CLD) for GNSS precise points positioning (PPP) by comparing the results with simultaneously operating costly geodetic receivers using two CLD modules and two geodetic receivers. Online PPP is done from NRCan, Canada, using the rapid, ultra-rapid, and final IGS products. The results show the similar performance of all the hardware with the clear advantage of cost, size, and power requirements in case of the CLD modules; 3 mm × 3 mm × 10 mm PPP position uncertainty with 95% confidence is achieved in latitude, longitude, and altitude respectively for an uBlox ZED F9P CLD module and similar performance for an NTLab 104v3 CLD module in GPS + GLONASS hybrid operation like the geodetic receivers. It is also observed that the GPS + GLONASS hybrid operation provides better performance than single-constellation operations, and the use of final IGS products marginally improves the solution quality. The results would be useful in implementing cost and power-efficient, precise GNSS PPP for relevant applications.

Cervical cancer presents considerable public health issues, particularly in its advanced stages, which require the implementation of effective management strategies. The role of radiation therapy in treatment is vital, highlighting the necessity for enhanced delivery techniques. We retrospectiveselected 15 patients with cervical cancer in FIGO stages IIB to IVA. 3DCRT, IMRT and Rapid Arc plans were compared in terms of target, organs at risk (OARs), conformity index (CI), uniformity index (UI), homogeneity index (HI), grandient index (GI), uniformity dosimetry index (UDI), conformation number (CN) and also recorded eclipse gradient index (GM), the high dose spillage index (outside the PTV) and the dose spillage index (R50%), the number of monitor units (MUs). Both IMRT and Rapid Arc demonstrated significantly better conformity (CN: 0.91 ± 0.012, 0.92 ± 0.002) compared to 3D-CRT (CN: 0.62 ± 0.037; p < 0.001). Rapid Arc not only minimized dose spillage (R50%: 2.91 ± 0.18) but also required fewer monitor units (MU: 578.15 ± 40.27) than IMRT (MU: 1595.7 ± 119.41). Both techniques provided enhanced organ-at-risk (OAR) sparing relative to 3D-CRT, particularly in reducing doses to the bladder and rectum (p < 0.001). Rapid Arc further decreased doses to the femoral head and bowel, highlighting its effectiveness in controlling spillage, improving dose gradient, and achieving overall dose conformity. Both Rapid Arc and IMRT improved dose conformity and provided better protection of organs at risk compared to 3D-CRT. Rapid Arc offered the most effective control over dose spillage, required fewer monitor units, and is an effective option for ensuring optimal target coverage while reducing doses to the OARs.

The radiance temperature, determined using a radiation thermometer, depends on the spectral emissivity of the measured surface. If the surface is opaque, to determine its temperature from the signal measured by the thermometer, it is common to use the approximation of an average effective emissivity, weighted over the spectral range of operation of the thermometer, and to consider the average effective reflectivity as its complement, such that the sum of their values is one. We found that, when the spectral emissivity of the surface has relevant variations, such consideration can induce noticeable deviations in the calculated radiance temperature, so besides the average effective emissivity, a true effective reflectivity should be calculated as well. By using the real spectral emissivity values of two different surfaces, we performed numerical calculations of the deviations on the estimated radiance temperature, due to the approximation described above, for different common wavelengths and thermometer spectral responses. We found that for a ceramic sample of known spectral emissivity, the above approximation led to deviations in the estimated radiance temperature of 1.4 K at 348.15 K and 2 K at 723.15 K.

The metrological comparison of reference materials at the multiple levels of quantity value is a relatively complex mode of metrological comparison. To study the determination of comparative reference equations and the calculation method of degree of equivalence, taking the data from CCQM-K80 “Comparison of value-assigned CRMs and PT materials: Creatinine in human serum” comparison project of the Consultative Committee for Amount of Substance (CCQM) as an example, while considering both the uncertainty of reference materials and the uncertainty of comparison measurements, a generalized distance regression method is used to determine the comparison reference equation and obtain the comparison reference values and uncertainties of reference materials at different levels of quantity value. Based on the certified values and uncertainties of reference materials, comparison measurement values and uncertainties, and corresponding comparison reference values and uncertainties, combined with comparison reference equations, the Monte Carlo method is used to the calculate degree of equivalence and uncertainty. Compared to ζ, using generalized distance regression to determine the reference equation and then calculate the degree of equivalence and uncertainty, the calculation results are more comprehensive, integrating information such as reference material quantity values, comparison measurement results, and comparison reference values.

GNSS receivers provide direct and easy access to the UTC through its hardware 1PPS output. Despite the widespread use of geodetic GNSS receivers, more studies are needed on their timing performance. A campaign mode exercise was conducted with a geodetic GNSS receiver in GPS-only mode to address this gap. The experiment was performed in two modes- without and with an external standard frequency fed to the receiver to study its impact on the performance. The impact of a stable oscillator has been observed by the appreciable improvement in frequency stability of the GNSS time with respect to UTC(NLPI). Though notable improvement in standard deviation is observed with the external reference frequency, the performance in the other mode was within a limit of 10 ns; such results are not reported earlier. Further, this paper proposes a novel method of evaluating the delay of the hardware 1PPS during its derivation from the internal time solution from the measured pseudo ranges. The delay is 30.6 ns for this receiver, though depending on its internal circuit arrangement, it may vary across receivers. Understanding this delay would be crucial for specific timing applications. The importance of finding the delay is explained through a notional application.