To investigate the high-accuracy roundness metrology of a needle roller 1.5 mm in diameter and 5.8 mm in length using the stitching linear scan method, a ruby ball stylus with a tip radius of 150 μm ...and a diamond stylus with a tip radius of 2 μm were employed to perform experiments under the same conditions. The precision coordinate data, derived from the needle roller’s cross-sectional circumference, were segmented into uniform eighths, each scanned with the stylus of a roughness measuring machine. The roundness profile of the needle roller was obtained by stitching the arc profiles, which were characterized according to the precision coordinate data of the arcs. The cross-correlation function, Euclidean distance, residual sum of squares, position error, and curvature of the measured arcs were used to evaluate the results, which can reflect the performance of the stylus. A comparison of the results obtained using the ruby ball stylus versus the diamond stylus demonstrates the ruby ball stylus’ greater suitability for use in the roundness metrology of the needle roller bearing examined in this paper.
Most existing multi-channel spectrometers are constructed by physically stacking single-channel spectrometers, resulting in their large size, high weight, and limited number of channels. Therefore, ...their miniaturization is urgently needed. In this paper, a microlens array grating is designed for miniature multi-channel spectrometers. A transmissive element integrating microlens arrays and gratings, the MLAG, enables simultaneous focusing and dispersion. Using soft lithography, the MLAG was fabricated with a deviation of less than 2.2%. The dimensions are 10 mm × 10 mm × 4 mm with over 2000 available units. The MLAG spectrometer operates in the 400–700 nm wavelength range with a resolution of 6 nm. Additionally, the designed MLAG multi-channel spectrometer is experimentally verified to have independently valid cells that can be used in multichannel spectrometers. The wavelength position repeatability deviation of each cell is about 0.5 nm, and the repeatability of displacement measurements by the chromatic confocal sensor with the designed MLAG multi-channel spectrometer is less than 0.5 μm.
A stitching linear scan method is proposed for roundness and diameter measurement of small cylindrical workpieces instead of the conventional rotary scan method due to the crucial alignments of ...eccentricity and inclination. To verify the reliability of the proposed method, by which the coordinates of the cross-sectional circle of a small cylinder is divided into several equal parts to be obtained and reconstructed, the diameter and roundness measurement uncertainties of the small cylinders with a diameter 1.5 mm are evaluated to be 0.047 μm and 0.095 μm, respectively, which can meet the uncertainty target of 0.1 μm. To investigate the measurable dimension by the proposed method, measurement uncertainty analysis of the small cylinders with various dimensions has been conducted according to the previous evaluation, since all the procedures are the same except for the uncertainty of X coordinates, which changes with the measured dimension’s change. The results show that the small cylinders with a diameter range from 0.01 mm to 50 mm can be measured by the proposed method when the position error θZ is reduced to the corresponding value. There is no measuring limitation set by the proposed model theoretically in the case of θX = θZ = 0.1°, while the machine has a measuring limitation.
A through-transmission ultrasonic method is proposed to address limitations in conventional ultrasonic reflection methods for non-destructive testing of ferrite tiles. The method utilizes a ...dual-probe configuration on both sides of the test piece to measure ultrasonic transmission signals, overcoming issues related to blind zones and orientation limitations in pulse-echo reflection methods. This method demonstrates excellent capabilities for full inspection of internal and external defects in ferrite tiles. Physical field finite element simulations were conducted to analyze detection capabilities and a transmissive testing system is developed based on the simulation results. Experimental validation was performed on artificially manufactured quantified defect samples in aluminum alloy, and the same testing system was applied to evaluate ferrite tile samples. The results confirmed the effectiveness of the system in distinguishing defective (NG) signals from normal defect-free (OK) signals, with a recall rate of at least 95% on samples of various sizes up to 0.1 mm. This research provides insights for quality control and defect detection technology in ferrite tiles.
Solid cancers like pancreatic ductal adenocarcinoma (PDAC), a type of pancreatic cancer, frequently exploit nerves for rapid dissemination. This neural invasion (NI) is an independent prognostic ...factor in PDAC, but insufficiently modeled in genetically engineered mouse models (GEMM) of PDAC. Here, we systematically screened for human-like NI in Europe's largest repository of GEMM of PDAC, comprising 295 different genotypes. This phenotype screen uncovered 2 GEMMs of PDAC with human-like NI, which are both characterized by pancreas-specific overexpression of transforming growth factor α (TGF-α) and conditional depletion of p53. Mechanistically, cancer-cell-derived TGF-α upregulated CCL2 secretion from sensory neurons, which induced hyperphosphorylation of the cytoskeletal protein paxillin via CCR4 on cancer cells. This activated the cancer migration machinery and filopodia formation toward neurons. Disrupting CCR4 or paxillin activity limited NI and dampened tumor size and tumor innervation. In human PDAC, phospho-paxillin and TGF-α-expression constituted strong prognostic factors. Therefore, we believe that the TGF-α-CCL2-CCR4-p-paxillin axis is a clinically actionable target for constraining NI and tumor progression in PDAC.
Influences of angular misalignments of a small cylinder on its roundness measurement by the method referred to as the stitching linear scan method are theoretically investigated. To compensate for ...the influences, a technique for measuring angular misalignments of a small cylinder by utilizing the linear-scan surface form stylus profilometer, which is employed for roundness measurement, is newly proposed. In addition, for roundness measurement, a holder unit capable of compensating for the angular misalignments of a small cylinder is developed, and the feasibility of the proposed technique is verified in experiments. Furthermore, a measurement uncertainty analysis of the stitching linear-scan method is carried out through numerical calculations based on a Monte Carlo method.
Attempts are made in this paper to improve the quality of the stitching between adjacent arc-profiles in the stitching linear-scan method for the roundness measurement of a cylinder in a small ...dimension. The data in the edge region of an arc-profile, which could be influenced by the pressure angle of the measurement probe of a linear-scan stylus profiler, are eliminated in the stitching process to improve the quality of stitching. The effectiveness of the elimination of the edge region of an arc-profile is evaluated by employing the cross-correlation coefficient of two adjacent arc-profiles as an evaluation index. Furthermore, a modification is made to the experimental setup to reduce the misalignment of a workpiece along its axial direction with respect to the scanning probe. Experiments are carried out by using the modified setup to demonstrate the feasibility of the stitching linear-scan method for the roundness measurement of a small cylinder, which is difficult to measure by the conventional rotary-scan method.
...selective blocking of these receptors can change the immune cell distribution towards CD8+ immune-competent cell lines. ...we interbred compound KC mouse mutants with IL-6 knockout allele ...(Il-6−/−) or the conditional Cxcl12lox/+ allele and analyzed the distribution of immune cells in the pancreas (Supplementary Figure S8A-C). ...the CD8+:CD11b+ ratio was significantly higher in mice with cytokine depletion (KC vs. ...the treated animals showed a higher mean 13-week survival rate (Control vs. ...we showed that autochthonous, oncogenic Kras-based mouse models of PDAC have a specific immune cell distribution in the primary tumor, comparable to human PDAC at only few time points of tumor development.
•Contact measurement is not proper for the superfine cylindrical parts.•Non-contact measurement is firstly developed for the superfine cylindrical parts.•The surface form of a superfine cylindrical ...part is modelled by coordinates.•The roundness profile is reconstructed according to the obtained coordinates.•The measurement uncertainty is evaluated to be 0.1 μm which meets the requirements.
To address the issue of measuring force of a stylus that can move and/or hook up the measured workpiece with a small dimension in the contact measurement, a spectral confocal displacement sensor and an ultra-precision linear stage are employed to develop a two-dimensional coordinate measuring machine instead of the conventional stylus contact measurement to avoid the measuring force problem, by which the non-contact ultra-precision metrology can be achieved. A coordinate modeling-dividing method is proposed for the diameter and roundness measurement of the small cylindrical workpieces with a diameter of 0.5 mm and length of 50 mm, whose cross-sectional circle is divided into several equal arcs to be scanned by the developed two-dimensional coordinate measuring machine. Thus, a set of arcs, each of which consists of large numbers of coordinate points, can be obtained. The radius of each arc can be fitted by the least square method, and the arc profile can be characterized by a series of data processing. The diameter and roundness of the measured workpiece can be obtained by averaging these fitted arcs’ radii and stitching these arc profiles together, respectively. A preliminary measurement uncertainty analysis is carried out to verify the developed device and proposed method.
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