Stability Of Instrument Research Articles

A case of chondrosarcoma with costovertebral location in the posterior mediastinum: Resection and stabilization.

Chondrosarcoma, a primary malignant bone tumor, rarely occurs in the vertebrae. We report a 29-year-old female with a 6 × 4.2 cm chondrosarcoma in the posterior mediastinum originating from the left 9th costa vertebral junction involving vertabrea corpus. Surgical resection performed involving posterior thoracotomy, 8-9th rib resection, 8-9th thoracal vertebrae partial corpectomy, laminectomy, spinal instrumentation, and chest wall stabilization. Pathology confirmed chondrosarcoma with safe margins. The patient remained recurrence-free for 9 years. This case highlights the importance of wide-margin surgical resection and multidisciplinary approaches for long-term survival in chondrosarcoma patients.

Combined PCL and anatomic posterolateral corner reconstruction: A tibial slope under 8 degrees and a persisting dorsal instability of 4 mm or more have a negative effect on the clinical outcome

PurposeThe failure rate following posterolateral corner reconstruction (PLC) remains high. Previous research indicates that in posterior cruciate ligament (PCL) reconstruction the laxity is affected by the tibial slope (TS). However, there is currently no literature evaluating the impact of TS on surgical outcome in combined reconstruction of PLC/PCL.MethodsThis study analyzed 47 patients in a retrospective cohort study who underwent PCL and anatomical PLC reconstruction according to techniques described by Arciero or LaPrade. TS was measured, and patients were divided into two groups: Group A (n = 16) with TS < 8° and Group B (n = 31) with TS ≥ 8°. After a minimum follow-up of 12 months, the side-to-side difference (SSD) of posterior tibial translation (PTT) was assessed using instrumented stability testing (Rolimeter), and various patient-reported outcome measures (IKDC, Lysholm) were collected and compared.ResultsAt a mean follow-up of 17.7 ± 4.7 months, group A exhibited a higher SSD of PTT (A 3.9 mm ± 2.1 vs. B: 2.8 mm ± 1.5; p < 0.05). A negative correlation was observed between SSD of PTT and both TS (r = − 0.43; R2 = 0.18; p < 0.01) and the Lysholm Score (r = − 0.41; R2 = 0.17; p < 0.01) in the overall cohort. Subgroup analysis revealed a higher Lysholm Score in patients with a postoperative SSD of PTT less than 4 mm (85.7 ± 10.1 vs. 79.2 ± 6.6; p = 0.0006).ConclusionIn combined PCL and anatomic PLC reconstruction a TS < 8° results in elevated SSD of PTT. A flattened TS is linked to higher remaining SSD of PTT, while lower SSD of PTT is associated with improved clinical outcomes.Level of evidenceRetrospective Cohort Study, IV.

Error Separation Method for Geometric Distribution Error Modeling of Precision Machining Surfaces Based on K-Space Spectrum.

The geometric error distributed on components' contact surfaces is a critical factor affecting assembly accuracy and precision instrument stability. Effective error separation methods can improve model accuracy, thereby aiding in performance prediction and process optimization. Here, an error separation method for geometric distribution error modeling for precision machining surfaces based on the K-space spectrum is proposed. To determine the boundary of systematical error and random error, we used a cruciform boundary line method based on the K-space spectrum, achieving the optimal separation of the two with frequency difference. The effectiveness of the method was experimentally verified using two sets of machined surfaces. By comparing with current common random error filtering methods, the outstanding role of the proposed error separation method in separating random error and preserving processing features has been verified.

Design and validation of a self-assessment questionnaire of basic thinking skills.

Since assessment of basic thinking skills is crucial in identifying an individual's cognitive capacities and comprehending their strengths and weaknesses, developing a suitable evaluating instrument holds significant importance in scheduling the training of basic thinking skills. This study aims to develop and subsequently validate a self-assessment questionnaire of basic thinking skills for medical sciences students. The present study of designing and psychometrically testing the self-assessment questionnaire of basic thinking skills among medical sciences students was conducted between 2022 and 2023 at Isfahan University. For the validity review, exploratory factor analysis (EFA) was employed. The adequacy of sample size was checked with the KMO index and Bartlett's test of sphericity. To perform EFA, principal factor analysis with Varimax rotation was performed. To obtain evidence of reliability, the internal consistency of the questionnaire was examined using Cronbach's alpha. The instrument stability was assessed through test-retest and intra-cluster correlation coefficient (ICC) analysis. The KMO (Keyser-Meyer-Elkin) sampling index was 780, and Bartlett's sphericity test (BT) was also significant (P = .000). In analyzing the main components and checking the value, the first five components had an eigenvalue above one. The highest percentage of the total variance (67.64%) was explained by the first five factors, while the remaining variance (33.35%) was explained by the remaining 14 factors. Cronbach's alpha coefficient for 19 items of the final questionnaire was 0.83. Intra-cluster correlation index (ICC) for overall self-assessment of thinking skills (ICC = 0.77), self-assessment of basic thinking skills (ICC = 0.80), self-assessment of lateral thinking (ICC = 0.78), and the necessity of teaching thinking skills (ICC = 0.74)) were all above 0.7 (P < 0.001). This study offers the first self-assessment questionnaire for basic thinking skills of medical sciences students which can be employed as a valid and reliable instrument for self-assessment of thinking skills and gaining insight into their training experiences. While the psychometrics of this questionnaire were based on the data from medical students, this questionnaire applies to students across various academic disciplines and is not limited to medical fields.

COCCON Measurements of XCO2, XCH4 and XCO over Coal Mine Aggregation Areas in Shanxi, China, and Comparison to TROPOMI and CAMS Datasets

This study presents the first column-averaged dry-air mole fractions of carbon dioxide (XCO2), methane (XCH4) and carbon monoxide (XCO) in the coal mine aggregation area in Shanxi, China, using two portable Fourier transform infrared spectrometers (EM27/SUNs), in the framework of the Collaborative Carbon Column Observing Network (COCCON). The measurements, collected over two months, were analyzed. Significant daily variations were observed, particularly in XCH4, which highlight the impact of coal mining emissions as a major CH4 source in the region. This study also compares COCCON XCO with measurements from the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5P satellite, revealing good agreement, with a mean bias of 7.15 ± 9.49 ppb. Additionally, comparisons were made between COCCON XCO2 and XCH4 data and analytical data from the Copernicus Atmosphere Monitoring Service (CAMS). The mean biases between COCCON and CAMS were −6.43 ± 1.75 ppm for XCO2 and 15.40 ± 31.60 ppb for XCH4. The findings affirm the stability and accuracy of the COCCON instruments for validating satellite observations and detecting local greenhouse gas sources. Operating COCCON spectrometers in coal mining areas offers valuable insights into emissions from these high-impact sources.

On-orbit spectral characteristics analysis of the greenhouse gases monitoring instrument: Spectral wavelength stability and instrumental line shape stability

The Greenhouse Gases Monitoring Instrument (GMI) is a carbon satellite payload developed based on the principle of spatial heterodyne spectroscopy technology, which is specifically designed for the global analysis of greenhouse gases (CO2 and CH4) “sources” and “sinks”. Due to the low concentration and minimal gradient variations of CO2 and CH4 in the atmosphere, higher precision is required for their retrieval. Vibrations during satellite launch and harsh space environments during on-orbit operation may cause changes in the performance of various payload components, resulting in decreased quality of spectrum products and retrieval precision. This paper proposes a set of on-orbit spectral characteristic evaluation methods tailored for the GMI to monitor the quality of its spectrum. It also develops an adaptive blind pixel detection and correction algorithm specifically for the GMI and optimizes the interferogram processing flow algorithm. On-orbit spectral calibration is performed, and methods to evaluate spectral characteristic parameters have been established. The analysis focuses on the variations of the spectral characteristics in the CO2-1 bands (1.575 μm) of the GMI during one-year of on-orbit calibration spectrum. The initial spectral wavenumber offset is 0.133 cm−1 after entering orbit, and the average spectral wavenumber offset is 0.0313 cm−1 during stable operation. During the one-year period, the maximum variation in the instrumental line shape function of the GMI is 0.006 cm−1. The observed spectrum obtained in nadir observation mode, underwent to accuracy verification. The results demonstrate consistency between the spectral peak wavenumbers and the relative trend changes of the observed and theoretical spectrum, with an average relative residual of 0.987%.

Long-Term Distributed Temperature Sensing Monitoring for Near-Wellbore Gas Migration and Gas Hydrate Formation

Summary Well integrity monitoring has always been a critical component of subsurface oil and gas operations. Distributed fiber-optic sensing is an emerging technology that shows great promise for monitoring processes, both in boreholes and in other settings. In this study, we present a case study of using distributed temperature sensing (DTS) technology to monitor a cemented and plugged well in the Alaska North Slope (ANS). The well was drilled as part of a long-term gas hydrate study, and the downhole DTS data were recorded over a period of approximately 2 years. By applying a temporal gradient and removing instrument instability noise, we reveal subtle (&amp;lt;0.001°C/h) thermal anomalies, which are characterized by brief warming periods followed by longer cooling periods at discrete depths along the borehole. The observed coherent events show an upward trajectory from deeper formations into the overlying permafrost interval, with the thermal anomalies concentrated in relatively coarse-grained sandstone layers. We also observe that the upward migration rate of the DTS anomalies varies with formation lithology and that there is a spatial and temporal correlation between the subsurface events and measured wellhead annular pressures. We interpret that the observed warming events represent the exothermic process of gas hydrate formation that is occurring in association with the upward migration of gas outside the well casing, and this interpretation is confirmed by numerical simulations. These observations demonstrate the ability of suitably processed DTS data to detect subtle processes and highlight the value of DTS technologies for wellbore integrity monitoring.

Assessing the Reliability of the Sexual Violence Questionnaire in Sport among Spanish-Speaking Athletes.

The prevalence of sexual harassment and abuse in school sport, specifically by coaches against their athletes, remains a concerning and pervasive issue. In an attempt to better understand and prevent specific coach-behaviours associated with such sexual misconduct, researchers have developed the Sexual Violence Questionnaire in Sport. While the reliability of this measurement tool has been tested in Anglo-Saxon cultural contexts, it is not known whether the questionnaire is applicable to other cultural contexts. This study aimed to analyse the internal consistency and reliability of the questionnaire on sexual harassment in sport, originally designed and developed in English. A sample of 146 (52 female, 94 male) undergraduate students from a university in the Basque Country participated in this cross-sectional study. The questionnaire was administered twice over a two-week period to assess test-retest reliability. The internal consistency of the Sexual Violence Questionnaire in Sport was high, with Cronbach's alpha values of 0.891 for perceptions and 0.813 for experiences across all participants. Gender-specific analysis showed similar reliability, with females having slightly lower alpha values for perceptions. Although significant differences were observed between the test and the retest on eight perception items and one experience item, Cohen's kappa analysis indicated agreement on all items; however, some of them were low (e.g., 0.13). In conclusion, the study highlights the questionnaire's overall reliability and suggests its effectiveness as a tool for measuring sexual violence in sport within the Spanish context. Nonetheless, the findings of this study underscore the need for further research to enhance the instrument's stability and to better understand gender differences in perceptions and experiences of sexual violence in sport contexts.

Designed bimetallic layer-encapsulated tungsten powders for reinforcing tungsten-silver matrix composite electrical contact materials

Electrical contact materials (ECMs) play a pivotal role in maintaining the stability and efficiency of electrical instruments and electronic devices by regulating the current flow. As an essential member of ECMs, W-Ag matrix composite ECMs (W-Ag-MC-ECMs) are integral, demonstrating commendable resistance to welding and arc erosion. However, the limited wettability between the two phases curtails their broader applications. Herein, Ag-Cu and Ag-Ni bimetallic layer-encapsulated tungsten powders were designed and successfully synthesized through a two-step electroless plating process. Subsequently, the W-Ag-MC-ECMs were fabricated following the powder metallurgy route, including the solution ball milling process and the spark plasma sintering technique. The results indicated that Cu-Ag solid solution and Ni with a metal binder effect could strengthen the interface bonding, which can dramatically improve the microhardness (up to 182HV), strength (up to 600 MPa), ductility (up to 24 %) and resistance to arc erosion (nearly two times longer service life). In addition, during the arc erosion, attributed to the Cu-Ag solid solution effect of W@Ag@Cu/Ag-MC-ECMs and solution-strengthening effect of W@Ag@Ni/Ag-MC-ECMs, the work function increases and the arc energy decreases, which reduces mass loss and extends the service life of the contacts.

Advantages of Robotic Surgery for Patients of Reproductive Age with Endometrial Cancer.

This review presents current knowledge on the surgical treatment of endometrial cancer in young patients. Endometrial cancer is the most common gynecological cancer in Europe. Higher morbidity is correlated with obesity, hypertension and diabetes, which are growing worldwide. However, endometrial cancer at an early age is very rare. The first line of treatment for this cancer is radical hysterectomy, which is controversial in young women. There is an alternative method of fertility-sparing treatment. However, there is a group of young patients for whom surgical treatment is recommended. According to European guidelines, minimally invasive surgery is recommended for endometrial cancer. The aim of the study was to present the advantages of robotic surgery for endometrial cancer detected at a young age. The procedure of radical treatment with robot-assisted laparoscopy is more precise. Better visualization and stabilization of instruments allow a shorter procedure time, a brief hospital stay and fewer complications. Quality of life may be at a similar level. Incisions after trocars are painless and more esthetic than a classical wound. Bilateral adnexectomy in endometrial cancer depends on age, molecular status of the cancer, stage, genetic risk factors and individual decision. Conclusions: Robotic surgery seems to be a better surgical method for endometrial cancer in younger patients.

403. ROBOTIC-ASSISTED IVOR LEWIS ESOPHAGECTOMY COMPARED TO CONVENTIONAL MINIMALLY INVASIVE ESOPHAGECTOMY: RESULTS FROM SEVEN HIGH VOLUME ITALIAN CENTERS

Abstract Background Over the past decade, minimally invasive esophagectomy has gained increasing attention, supported by numerous trials and retrospective series highlighting its advantages over the traditional open approach. In addition to the conventional minimally invasive surgery (CMIE), robotic assisted minimally invasive esophagectomy (RAMIE) has gained global popularity, due to its advantages in terms of 3D visualization and instrument stability. Methods This is a collaborative study involving seven high-volume Italian centers affiliated with the Italian Society for the Study of Esophageal Diseases (SISME). Patients who underwent Ivor Lewis esophagectomy for esophageal cancer between January 2015 and July 2022 were identified from seven institutional databases and divided in two groups according to the thoracic approach: CMIE versus RAMIE. Results We identified 316 patients in CMIE and 123 in RAMIE group. Operative time was significantly longer for RAMIE procedures (p&amp;lt;0.001). A borderline significant reduction in overall complication rate was observed (48% vs 59% in CMIE group, p=0.045), however there were no differences in severe (p=0.3) and pulmonary (p=0.13) complications rate. 90-day mortality (CMIE 3.2% vs RAMIE 0.8%, p=0.15) and readmission rate (CMIE 9.5% vs RAMIE 7.3%, p=0.47) were comparable. R0 rate was 94.9% in CMIE vs 92.7% in RAMIE (p=0.4). The most performed anastomosis was circular stapled anastomosis. Anastomotic leak rate was 13.9% for CMIE and 12.2% for RAMIE (p=0.6). Conclusion Minimally invasive Ivor Lewis esophagectomy has reached adequate surgical and oncological results with both conventional and robotic technique. Nowadays there is no clear superiority of one anastomotic technique.

Seasonal Patterns, Inter‐Annual Variability, and Long‐Term Trends of Mean Sea Level Along the Western Iberian Coast and the North Atlantic Islands

AbstractSea level rise is challenging for coastal communities and land management decision makers. Understanding the patterns of regional variations at different temporal and spatial scales is key to implement adaptation plans that mitigate the local impacts of sea level rise. In this study, in situ observations from 14 tide gauges were complemented with satellite altimetry data to assess seasonality, multidecadal variability and long‐term trends in mean sea level around the Western Iberian Coast (WIC) and the Portuguese archipelagos (Azores and Madeira). Results show varying spatial seasonal patterns between regions, with minimum (maximum) sea level observed in April (September) at the islands and minimum (maximum) observed in July (November) at the WIC. The influence of coastal upwelling on the seasonal mean sea level variations was detected over mainland. Although the influence of atmospheric patterns was observed on sea level inter‐annual variability, the Atlantic Multidecadal Oscillation (AMO) showed a greater correlation with the sea level inter‐decadal patterns. Finally, the trend analysis confirmed widespread sea level rise along the mainland and around the islands, which has intensified in recent decades. The regions of La Coruña and Cascais showed trends that were similar to the global average sea level rise since 1993, but the mainland regional average pointed to lower rates of rise (2.00 ± 0.06 mm/year). This work reinforces the need for long‐term monitoring networks of sea level, ensuring the vertical stability of instruments and platforms. The implementation of regional adaptation plans to sea level rise is deeply dependent on high quality information.

ACL reconstruction demonstrates better stability compared to ACL repair for patients with Schenck III and IV knee dislocations

PurposeThis study compared mid-term outcomes of two anterior cruciate ligament (ACL) restoration techniques within an early total surgical care of acute knee dislocation: repair with additional internal bracing (ACLIB) and reconstruction with autograft (ACLR). Initial results at 12 months demonstrated that ACLR offered superior stability compared to ACLIB.MethodsRetrospective clinical study of patients with acute type III or IV KD. ACLIB or ACLR procedures were performed accompanied by simultaneous suture and internal bracing of the posterior cruciate ligament (PCL) and repair with lateral augmentation of the medial and lateral complex injuries utilizing Arciero’s reconstruction technique. Patient-reported outcome measurements (PROMs), instrumental stability assessment via the Rolimeter-Test, and stress radiographs were analyzed.ResultsThe study involved 20 patients (5 IIIM, 5 IIIL, and 10 IV injuries) with an average follow-up of 35.2 ± 7.4 months. Notable differences in anterior tibial translation on stress radiography favouring ACLR persisted at 24-month follow-up in side-to-side difference (SSD) (ACLIB 2.8 ± 2.5 mm vs. ACLR 0.3 ± 2.6 mm; p = 0.0487), but Rolimeter test variance diminished (SSD ACLIB 2.5 ± 0.9 mm vs. ACLR 1.8 ± 1.7 mm). Both groups showed excellent PROMs (Lysholm Score: ACLIB 84.4 ± 15.8 vs. ACLR 89.9 ± 9.0; IKDC Score: ACLIB 77.1 ± 16.2 vs. ACLR 77.7 ± 8.6).ConclusionOur results indicate improved anterior stability at 12 months, which persisted at 24 months after ACL reconstruction compared with ACL repair by stress radiography. Both groups showed favourable patient-reported outcomes throughout the follow-up period. Notable rates of postoperative knee stiffness were observed in both groups. These were successfully managed with early, one-time arthroscopic arthrolysis within the first seven months of treatment, resulting in no major range of motion limitations at the 24-month follow-up.Level of evidenceRetrospective cohort study, III.

Vibrational stability improvement of a mirror system using active mass damping.

Addressing the demand for high stability of beamline instruments at the SHINE facility, a high stability mirror regulating mechanism has been developed for mirror adjustments. Active mass damping was adopted to attenuate pitch angle vibrations of mirrors caused by structural vibrations. An internal absolute velocity feedback was used to reduce the negative impact of spillover effects and to improve performance. The experiment was conducted on a prototype structure of a mirror regulating mechanism, and results showed that the vibration RMS of the pitch angle was effectively attenuated from 47 nrad to 27 nrad above 1 Hz.

Clinical Outcome of Posterior Instrumented Stabilization and Transpedicular Decompression in Patients Presenting with Thoracic or Lumbar Spinal Tuberculosis in a Tertiary Care Center: A Descriptive Cross-sectional Study.

Posterior instrumented stabilization is a commonly done surgery in spinal tuberculosis. This study aims to evaluate the clinical, radiological, and neurological outcomes of posterior instrumented stabilization and transpedicular decompression in thoracic and lumbar spinal tuberculosis. A descriptive cross-sectional study was conducted for one and a half years with at least six months of follow-up in a tertiary care center. The study was approved by the Institutional Review Committee (Reference number: 119 (6-11-5) 2/075-076). Total sampling was done and the study included patients over 18 years of age with spinal tuberculosis of the thoracic or lumbar regions. These patients underwent posterior instrumented stabilization and transpedicular decompression at the tertiary care center. The age, site of involvement, Visual Analog Scale score for back pain, neurological status as per Frankel Neurology grading, and local kyphotic angle in X-ray were recorded. The median, interquartile range and percentage were calculated. The data was entered in Microsoft Excel 2016 and analysis was done using Epi Info software version 7.2. Thoracic level was most commonly involved in 14 (46.68%) cases. The median back pain as assessed by the Visual Analogue Scale score improved from 8 to 2 at the 6-month follow-up. There was improvement in the neurological grading of all cases and there was no loss of correction in the local kyphotic angle till the final follow-up. The median age of cases was 48 years (interquartile range: 28-62.50). Posterior instrumented stabilization and transpedicular decompression in adult patients with thoracic or lumbar spinal tuberculosis achieves improvements in clinical, radiological, and neurological outcomes.

The variation in the response of solar full-disc magnetographs

Context.The utility of full solar disc magnetograms as a long-term record of the photospheric magnetic field requires an understanding of how stable these observations are with time and the systematic differences between the various instruments.Aims.We compared magnetograms from the KPVT/SPM, SoHO/MDI, SOLIS/VSM, and SDO/HMI with the aim of probing the effect on measured solar magnetism of the variation in instrument response with time, magnetogram signal level, and position on the solar disc.Methods.Taking near-simultaneous observations from the various instruments, we examined the surface coverage by magnetic activity and the effect of cross-calibrating the various instruments under different assumptions.Results.By comparing the surface coverage by magnetic activity in the observations from the various instruments, we traced the effect of the time variation in instrument response on the longitudinal magnetogram signal and disc-integrated unsigned magnetic flux. This yielded evidence of acute changes in the response of MDI and VSM with certain events such as the SoHO vacation in 1998 and the upgrade of the VSM CCD camera in 2009. Excluding these changes, the effect of instrument instability on the magnetogram signal and disc-integrated magnetic flux appears to be rather benign, with an associated uncertainty of less than 2%. We determined the magnetogram signal ratio between each instrument pairing as a function of magnetogram signal level and distance from disc centre and with it cross-calibrated the various instruments. We compared the result with that from repeating the cross-calibration with the overall magnetogram signal ratio. This allowed us to estimate the uncertainty in the magnetogram signal associated with the variation in instrument response with magnetogram signal level and distance from disc centre to be about 8%–14%. The corresponding uncertainty in the disc-integrated magnetic flux is about 7%–23%.Conclusions.To the best of our knowledge, this is the first study of its kind to quantify the uncertainty in measured magnetism from the variation in instrument response with time, magnetogram signal level, and disc position. The results here will be useful to the interpretation of SPM, MDI, VSM, and HMI magnetograms. As examples, we applied our findings to selected results from earlier studies based on such data.

Cross-Cultural Adaptation of The Indonesian Version Functional Assessment of Denture Instrument as a Measuring Tool for Complete Denture Functional Quality.

Making good quality dentures is necessary to avoid patients' discomfort when adapting to new dentures. Several studies regarding the assessment of the quality of dentures have been carried out in many other countries, such as using the Functional Assessment of Dentures (FAD) by Anastassiadou. However, studies have yet to be conducted in Indonesia. This study aims to obtain a valid and reliable instrument to measure the quality of complete dentures (CDs). This study also aims to find out whether the functional quality of a CD measured with the Indonesian version of the FAD Instrument (PFGT) can affect patient satisfaction in receiving CD treatment (measured with Indonesian version of Patient's Denture Assessment [PDA-Id]) and to find contributing factors to the functional quality of a CD. The study was conducted in two stages. The first stage was a qualitative study using cross-cultural adaptation methods and focus group discussions with experts. The second stage was a quantitative test with a total of 40 subjects for statistical analysis in the form of a kappa test, test-retest, Kuder-Richardson (KR) 20, and a correlation test between PDA-Id and PFG. Multivariate analysis was done to analyze contributing factors to the functional quality of CD. The final instrument was obtained from the qualitative test, which was tested for content and face validation. The interrater kappa test result of 0.828 shows an almost perfect agreement. The results of the intrarater test-retest (0.564; p > 0.05; intraclass correlation coefficient 0.889) showed excellent instrument stability. The results of the internal consistency test with Kuder-Richardson 20 (1.08; KR > 1) showed good internal consistency. The correlation test results between PFGT and PDA-Id (0.044; p < 0.05) showed a positive correlation. Multivariate analysis showed a relationship between the quality of the CD, the length of time the CD was used, and the patient's satisfaction with CD treatment. The PFGT instrument is considered a valid and reliable tool to measure the functional quality of a denture that can distinguish between good and bad quality.

Long-term Monitoring of Low-cost Seismometers: Consistency Analysis of The Instrument

Instruments have become an essential part of conducting a study or research. With the aid of instruments, the measurement process can be faster, more efficient, and more accurate. However, an instrument also has a limited service life. Over time, the performance of the instrument will degrade. Therefore, the equipment must be regularly maintained and calibrated periodically. This research aims to test the measurement consistency of a low-cost seismometer (RS-3D). The approach involves long-term measurements to assess the instrument's stability in taking measurements. The measurement data is then processed and presented as frequencies using spectrum analysis. The research findings indicate that the instrument's consistency is generally good, with an average standard deviation of 0.18 and a coefficient of variation of 5%. Additionally, 95% confidence interval calculations yielded values of 2.52±0.02 for measurements at RKD, 3.04±0.05 for measurements at GLT-USK, and 3.3±0.04 for measurements at GFT-USK. Data validation was performed using the equations from building codes, showing that the difference between the measured microtremor frequency and the empirical equation was less than 1, indicating good measurement results. The conclusion drawn from this study is that a higher standard deviation value indicates a more distributed data spread, signifying less consistent research data. Conversely, a lower standard deviation indicates that the data is more concentrated around the mean value, indicating more consistent measurement results. Moreover, with previous studies having conducted validation and consistency testing, it is hoped that both tests will be routinely performed during instrument maintenance.

Advances in Atom Interferometry and their Impacts on the Performance of Quantum Accelerometers On-board Future Satellite Gravity Missions

Recent advances in cold atom interferometry have cleared the path for space applications of quantum inertial sensors, whose level of stability is expected to increase dramatically with the longer interrogation times accessible in space. In this study, an in-orbit model is developed for a Mach–Zehnder-type cold-atom accelerometer. Performance tests are realized under different assumptions about the positioning and rotation compensation method, and the impact of various sources of errors on instrument stability is evaluated. Current and future advances for space-based atom interferometry are discussed, and their impact on the performance of quantum sensors on-board satellite gravity missions is investigated in three different scenarios: state-of-the-art scenario (expected to be ready to launch in 5 years), near-future (expected to be launched in the next 10 to 15 years) and far-future scenarios (expected for the next 20 to 25 years). Our results indicate that the highest sensitivity is achievable by positioning the electrostatic accelerometer at the center of mass of the satellite and the quantum accelerometer aside, on the cross-track axis of the satellite. We show that one can achieve a sensitivity level close to 5 × 10−10 m/s2/Hz with the current state-of-the-art technology. We also estimate that in the near and far-future, atom interferometry in space is expected to achieve sensitivity levels of 1 × 10−11 m/s2/Hz and 1 × 10−12 m/s2/Hz, respectively. A roadmap for improvements in atom interferometry is provided that would maximize the performance of future quantum accelerometers, considering their technical capabilities. Finally, the possibility and challenges of having ultra-sensitive atom interferometry in space for future space missions are discussed.

Cross polarization stability in multidimensional NMR spectroscopy of biological solids

Magic-angle spinning (MAS) solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a powerful and versatile technique for probing structure and dynamics in large, insoluble biological systems at atomic resolution. With many recent advances in instrumentation and polarization methods, technology development in SSNMR remains an active area of research and presents opportunities to further improve data collection, processing, and analysis of samples with low sensitivity and complex tertiary and quaternary structures. SSNMR spectra are often collected as multidimensional data, requiring stable experimental conditions to minimize signal fluctuations (t1 noise). In this work, we examine the factors adversely affecting signal stability as well as strategies used to mitigate them, considering laboratory environmental requirements, configuration of amplifiers, and pulse sequence parameter selection. We show that Thermopad® temperature variable attenuators (TVAs) can partially compensate for the changes in amplifier output power as a function of temperature and thereby ameliorate one significant source of instability for some spectrometers and pulse sequences. We also consider the selection of tangent ramped cross polarization (CP) waveform shapes, to balance the requirements of sensitivity and instrumental stability. These findings collectively enable improved stability and overall performance for CP-based multidimensional spectra of microcrystalline, membrane, and fibrous proteins performed at multiple magnetic field strengths.