Method For Determination Of Volume Research Articles

Evaluation of Hold-Up Volume Determination Methods and Markers in Hydrophilic Interaction Liquid Chromatography.

Common methods for hold-up time and volume determination in Reversed-Phase Liquid Chromatography (RPLC) have been tested for Hydrophilic Interaction Liquid Chromatography (HILIC). A zwitterionic ZIC-HILIC column has been used for the testing. The pycnometric determination method, based on differences in column weight when filled with water or organic solvent, provides the overall volume of solvent inside the column. This includes the volume of eluent semi-sorbed on the packing of the column, which acts as the main stationary phase. The homologous series approach, based on the retention behavior of homologues in relation to their molecular volume, allows the determination of accurate hold-up volumes. However, the application of this method is time-consuming. In some cases, large neutral markers with poor dipolarity/polarizability and hydrogen bonding interactions can be used as hold-up volume markers. This is the case of dodecylbenzene and nonadecane-2-one in clearly HILIC behaving chromatographic systems, the use of decanophenone as a marker can be even extended to the boundary between HILIC and RPLC. The elution volume of the marker remains nearly unaffected by the concentration of ammonium acetate in the mobile phase up to 20 mM. The injection of pure solvents to produce minor base-line disturbance as hold-up markers is strongly discouraged, since solvent peaks are complex to interpret and depend on the ionic strength of the eluent.

Accelerated fission rate irradiation design, pre-irradiation characterization, and adaptation of conventional PIE methods for U-10Mo and U-17Mo

Metallic U alloys have high U density and thermal conductivity and thus have been explored since the beginning of nuclear power research. Alloys of U with modest amounts of Mo, such as U-10 wt % Mo (U-10Mo), are of particular interest because the γ-U crystal structure in this alloying addition shows prolonged stability in reactor service. Historically, radiation data on U-10Mo fuels were collected in Na fast reactors or lower temperature research reactor conditions, but little is known about irradiation behavior, particularly swelling and creep, at irradiation temperatures between 250 and 500°C. This work discusses the methodology and pre-irradiation characterization results from a U-Mo irradiation campaign performed in the High Flux Isotope Reactor at Oak Ridge National Laboratory. U-10Mo and U-17Mo samples irradiations are being completed at temperatures ranging from 250 to 500°C to three targeted fission densities between 2 × 1020 and 1.5 × 1021 fissions per cubic centimeter. Swelling measurement of the specimen sizes studied here required development and assessment of new methods for volume determination before and after irradiation. Laser profilometry and X-ray computation tomography (XCT) were used to provide preirradiation characterization of samples to determine the error and applicability of each to determine swelling following irradiation. These outcomes are contextualized through use of BISON simulations performed to assess the predicted expansion of U-Mo fuels subjected to the irradiation conditions of this work. Use of existing BISON fuel performance models predicted a maximum of 7% swelling under the irradiation conditions of this study. Pre-irradiation characterization revealed the as-cast U-Mo fuel samples were uniformly large-grained fully cubic U crystals with small U-C/N bearing precipitates and pores distributed throughout. Samples were found to contain a bulk porosity between .4 and 3% because of the casting process. Local porosity in areas far from large, interconnected pores was found by Slice-and-View to be under .2%. Nanometer-sized precipitates rich in C and N were identified in all samples, likely because of impurities during the fabrication process. Dendritic bands were also observed throughout the samples. These bands were characterized by variable Mo content that deviated from the overall Mo content by 2–3 wt %. No other microstructural features were correlated to these bands. Mechanical properties were found to be slightly strengthened compared to literature reports of bulk U-Mo fuels due to the nano-scale precipitates throughout the sample.

Evaluation of Hold-Up Volume Determination Methods and Markers in Hydrophilic Interaction Liquid Chromatography

Evaluation of Hold-Up Volume Determination Methods and Markers in Hydrophilic Interaction Liquid Chromatography

Use of Three-Dimensional Imaging to Assess the Effectiveness of Volume as a Critical Variable in Breast Implant Selection.

In breast augmentation, breast base diameter has been recognized as an important variable in implant selection. However, breast implant volume also has a tremendous impact on the final result. Previous methods of preoperative volume determination have been limited to external devices in a bra. Computer-based three-dimensional simulation technology now allows the physician to effectively communicate with the patient preoperatively regarding volume. A cohort of 40 consecutive patients underwent routine breast augmentation with either anatomically shaped or round implants. Five methods of preoperative volume determination including the Crisalix three-dimensional computer imaging system (Crisalix Virtual Aesthetics, Lausanne, Switzerland), along with an associated virtual reality tool, were used to assess the preoperative desires of the patients. A postoperative questionnaire was used to assess patient satisfaction with each volume determination method. Of the 40 patients, 100 percent were satisfied with their result; however, given the opportunity, 12 percent would have chosen a larger implant. The virtual reality tool and external sizers were shown to be the most effective in choosing an implant. The virtual reality tool was judged to be very helpful (62 percent), very accurate (78 percent), and important (88 percent) in helping patients choose their desired implant size. Prioritizing volume as an implant selection variable in breast augmentation results in a very high rate of patient satisfaction. Therapeutic, IV.

A Prospective Investigation of Predictive Parameters for Preoperative Volume Assessment in Breast Reconstruction.

Preoperative breast volume estimation is very important for the success of the breast surgery. In this study four different breast volume determination methods were compared. The end-point of this prospective study was to evaluate the concordance between different modalities of breast volume assessment (MRI, BREAST-V, mastectomy specimen weight, conversion from weight to volume of mastectomy specimen) and the breast prosthetic volume implanted. The study enrolled 64 patients between 2017 and 2019, who had all been treated by the same surgeons for monolateral nipple–areola complex-sparing mastectomy and implant breast reconstruction. Only patients who had a breast reconstruction classified as “excellent” from an objective (BCCT.core software) and subjective (questionnaire) point of view at the 6-month interval after the operation were included in the study. Data analysis highlighted a strong correlation between the volumes of the chosen prostheses and the weights of mastectomy converted into volume, especially for patients with grades B and C parenchymal density. The values of the agreement between the volumes of the chosen prostheses and the assessments from MRI and BREAST -V proved to be lower than expected from the literature. None of the four studied methods presented any strong correlation with the initial breast width. Our results suggest that conversion from weight to volume of mastectomy specimen should be used to assist in determining the volume of the breast implant to be implanted. This method would help the reconstructive surgeon guide the choice of the most appropriate implant preoperatively.

Volume determination methods for hematopoietic progenitor cell products collected by apheresis

CD34+ cell count of hematopoietic progenitor cell products is often first determined using a product sample, with the final reported cell count obtained by multiplying cell count from the sample by the total product volume. Product volume may be determined by apheresis instruments used for collection or calculated based on specific gravity (SG). Here the authors sought to determine the discrepancies between these methods and the impact on patient care. A total of 262 products collected from 176 donors by apheresis were retrospectively reviewed. Volumes calculated by apheresis instruments were compared with volumes calculated based on SG. CD34+ cell/kg doses based on volumes from apheresis instruments and SG were also compared. Furthermore, among 42 patients who required multiple collections, the authors determined whether different calculation methods would have changed the number of procedures required. The volumes for 253 products (96.6%) and CD34+ cell/kg doses for 257 products (98.1%) generated from apheresis instruments and SG were similar. Products with discrepant volumes when calculated using different methods were not associated with delayed engraftment. Forty patients who underwent multiple collections (95.2%) were under their collection goals during their first collection and would have required multiple procedures regardless of which method was used to calculate product volumes. Volumes determined based on SG did not provide a clear benefit over volumes determined by apheresis instruments. Hence, variation in volume calculation methods across different laboratories is likely to lead to minimal impact on patient care.

Ball-on-flat linear reciprocating tests: Critical assessment of wear volume determination methods and suggested improvements for ASTM D7755 standard

This work presents a critical assessment of wear volume determination methods for ball-on-flat linear reciprocating sliding tribological tests. It revealed that the ASTM D7755-11 standard leads to the highest relative errors (up to 106%) and deviations (up to 27%) depending on the regularity of the wear track shape. The present study suggests improvements for the ASTM D7755-11 wear computation, which can reduce errors from 106% to 17% when analysing irregularly shaped wear tracks. In addition, a five-year period review of two relevant tribology journals revealed that the most used methods for wear determination, namely three-dimensional (3D) profilometry (46%) and nonstandard profile-based methods (36%), are overall reported with incomplete procedural information for wear computation. Furthermore, as many as 8% of the papers specify no data regarding the computation method and only 3% explicitly cited and followed the existing standards (ASTM D7755-11 or G133-05). The present study highlights the importance of the correct selection, implementation, and reporting of wear volume computation method and quantifies the potential errors.

Brain atrophy patterns in patients with frontotemporal dementia: voxel-based morphometry

Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by language and behaviour deficits, which is considered the second most common cause of early-onset dementia. Detection of brain atrophy patterns is important for FTD diagnosis. However, the visual assessment of magnetic resonance imaging data may not be sensitive enough requiring the use of objective gray matter (GM) volume determination method. The study was aimed to assess the GM atrophy pattern in patients with FTD compared to control group patients using voxel-based morphometry (VBM). The study included 16 patients with FTD (12 patients with nonfluent agrammatic variant primary progressive aphasia (nfvPPA), three patients with behavioral variant of FTD, and one patient with logopenic variant PPA) and 10 healthy volunteers. VBM of patients with FTD and healthy controls revealed three significant (pFWE-corr < 0.05) atrophy areas in the left inferior frontal, left fusiform, and left supramarginal gyri. Taking into account the predominance of patients with nfvPPA in the group of FTD patients, the additional VBM of this group and control group was carried out, which revealed a distinct atrophy pattern: the reduced GM volume was detected in the left inferior frontal and left middle frontal gyri (pFWE-corr < 0.05). The results obtained indicate that regardless of the clinical variant, there is a certain atrophy pattern characteristic of FTD, which involves both frontotemporal areas and parietal lobe. The example of nfvPPA shows that each variant of the disease is associated with distinct localization of atrophy.

Verification of an Internal Close-Range Photogrammetry Approach for Volume Determination during Triaxial Testing

AbstractAccurate strain and volume measurements are critical to phase relationships and strength determination for saturated and unsaturated soils. In recent years, laboratory-based photographic techniques of monitoring soil specimens have become more common. These techniques have been used to reconstruct 3-D models and to determine strain and volumetric changes of triaxial specimens. A new technique that used digital photographs of the soil specimen, captured from within a triaxial testing cell, was utilized. Photographs were processed using photogrammetric software to reconstruct 3-D models of the soil specimens at various times during the triaxial test. By placing camera equipment within the cell, the technique eliminated the need to account for optical distortions that were due to (1) refraction at the confining fluid–cell wall–atmosphere interface, (2) the curvature of the cylindrical cell wall, and (3) the pressure-induced deformation of the cell wall. Previously unreported results from sensitivity studies and accuracy assessments for the internal photogrammetry approach are documented herein. Furthermore, through undrained triaxial compression and extension tests, the viability of determining total and local strains, volume changes, and total volume at any stage of triaxial testing was demonstrated. By comparison with other volume-determination methods that are presented herein, including digital single-lens reflex camera photogrammetry, 3-D scanning, manual measurements, and water displacement techniques, a relative error of 0.13 % was assessed for the internal photogrammetric volume determination technique.

Radiance based method for accurate determination of volume scattering parameters using GPU-accelerated Monte Carlo.

Volume scattering is an important effect in different fields, ranging from biology to lighting. Models for volume scattering usually rely on parameters that are estimated with inverse methods that iteratively fit simulations to experimental data. To obtain accurate estimates for these parameters, the scattered intensity distribution can be used in such fitting methods. However, it has been shown that for samples with long optical path lengths this type of data may result in poor parameter estimates. In this work, an inverse procedure is proposed that fits to scattered radiance distributions. By taking advantage of current generation graphics processing units, the method implemented is sufficiently efficient to allow performing an in-depth simulation study on the difference between using radiance or intensity distributions to estimate the volume scattering parameters of samples. This work shows that for samples with moderate optical path lengths, the intensity distribution contains sufficient information to accurately estimate the volume scattering properties. However, for longer optical path lengths, the descriptive power of the intensity distribution is not enough and radiance distribution based methods, such as the inverse method proposed, are better suited.

Research on volume determination of mass standards with two acoustic measuring chambers

<div>The acoustic volume measuring method is a promising non-contact method for volume determination of mass weights. To improve the measuring accuracy of volume determination with the non-contact acoustic method, an acoustic measuring system with two measuring chambers is newly designed to compensate for the non-linearity measuring errors. When reducing the remaining air in the measuring chamber, the measuring accuracy can be greatly reduced. The volumes of mass standards ranging from 100 g to 5 kg are tested to evaluate the non-linearity errors of the volume measurement. The relative uncertainties of the acoustic volume determination are below 7.0 ×10<sup>-4</sup> (<em>k</em>=2).</div>

Volume determination of irregularly-shaped quasi-spherical nanoparticles.

Nanoparticles (NPs) are widely used in diverse application areas, such as medicine, engineering, and cosmetics. The size (or volume) of NPs is one of the most important parameters for their successful application. It is relatively straightforward to determine the volume of regular NPs such as spheres and cubes from a one-dimensional or two-dimensional measurement. However, due to the three-dimensional nature of NPs, it is challenging to determine the proper physical size of many types of regularly and irregularly-shaped quasi-spherical NPs at high-throughput using a single tool. Here, we present a relatively simple method that determines a better volume estimate of NPs by combining measurements from their top-down projection areas and peak heights using two tools. The proposed method is significantly faster and more economical than the electron tomography method. We demonstrate the improved accuracy of the combined method over scanning electron microscopy (SEM) or atomic force microscopy (AFM) alone by using modeling, simulations, and measurements. This study also exposes the existence of inherent measurement biases for both SEM and AFM, which usually produce larger measured diameters with SEM than with AFM. However, in some cases SEM measured diameters appear to have less error compared to AFM measured diameters, especially for widely used IS-NPs such as of gold, and silver. The method provides a much needed, proper high-throughput volumetric measurement method useful for many applications. Graphical Abstract The combined method for volume determination of irregularly-shaped quasi-spherical nanoparticles.

Gasometric method of volume determination of intercellular spaces in plant tissues

Gasometric method of volume determination of intercellular spaces in plant tissues

An innovative method for determining micro pore volume of synthetic resins

Synthetic resins are widely used in purifying pharmaceutical products, such as extracting antioxidants and antibiotics. In a fixed bed operation, the tailing behavior in the desorption process is commonly observed and this behavior might be due to the slow mass transfer within micro pore of resins. Therefore, to obtain accurate micro pore volume of resin is important to understand and overcome the tailing behavior of the desorption process. Commonly used methods on determining pore volumes for porous materials are mercury intrusion and N2 adsorption methods. However, both methods are good for determination of pore volumes of activated carbons and silica gels, but they may not be appropriate for determination of resins’ pore volumes. Two micro pore volume determination methods (adsorption/desorption technique (ADT) and carbon tetrachloride vaporization technique (CTVT)) for resins are proposed and investigated in this study. Four styrene type resins (XAD-2000, XAD-1180, XAD-2 and SYA-2) were tested via both methods. Phenolic compounds (Phenol (PHL), p-chlorophenol (PCP), p-nitrophenol (PNP), and benzoic acid (BA)) and carbon tetrachloride (CCl4) were employed in ADT and CTVT methods, respectively. In general, there is a linear relationship between micro pore volumes of resins (Vm) and adsorbate's molecular volumes (Mv). Since CCl4 has the smallest molecular volume among these adsorbents, the micro pore volume (Vc) obtained by CCL4 is the highest. For example, micro pore volume of XAD-2000 determined by BA, PNP, PCP, PHL and CCL4 are 0.02, 0.05, 0.07, 0.11 and 0.21, respectively. In addition, micro pore volume (Va) of resins determined by phenolic compounds can be predicted by the CTVT method. Therefore, CTVT has advantages of easy operation and time/chemicals saving. It is a good candidate for determination of resins’ micro pore volumes. This finding might be useful for future preparation and application of resins for organics recovery.

Breast volume estimation from systematic series of CT scans using the Cavalieri principle and 3D reconstruction

Objectives: Preoperative breast volume estimation is very important for the success of the breast surgery. In the present study, two different breast volume determination methods, Cavalieri principle and 3D reconstruction were compared. Material and methods: Consecutive sections were taken in slice thickness of 5 mm. Every 2nd breast section in a set of consecutive sections was selected. We marked breast tissue with blue line on each selected section, and so prepared CT scans used for breast volume estimation. The volumes of the 60 breasts were estimated using the Cavalieri principle and 3D reconstruction. Results: The mean breast volume value was established to be 467.79 ± 188.90 cm3 with Cavalieri method and 465.91 ± 191.41 cm3 with 3D reconstruction. The mean CE for the estimates in this study was calculated as 0.25%. Skin-sparing volume was about 91.64% of the whole breast volume. Both methods are very accurate and have a strong linear association. Conclusion: Our results suggest that the calculation of breast volume or its part in vivo from systematic series of CT scans using the Cavalieri principle or 3D breast reconstruction is accurate enough to have a significant clinical benefit in planning reconstructive breast surgery. These methods can help the surgeon guide the choice of the most appropriate implant or/and flap preoperatively.

Guinea pig ciliary muscle development.

The purpose of this study was to develop a method for quantifying guinea pig ciliary muscle volume (CMV) and to determine its relationship to age and ocular biometric measurements. Six albino guinea pigs' eyes were collected at each of five ages (n = 30 eyes). Retinoscopy and photography were used to document refractive error, eye size, and eye shape. Serial sections through the excised eyes were made and then labeled with an α-smooth muscle actin antibody. The ciliary muscle was then visualized with an Olympus BX51 microscope, reconstructed with Stereo Investigator (MBF Bioscience), and analyzed using Neurolucida Explorer (MBF Bioscience). Full (using all sections) and partial (using a subset of sections) reconstruction methods were used to determine CMV. There was no significant difference between the full and partial volume determination methods (p = 0.86). The mean (±SD) CMV of the 1-, 10-, 20-, 30-, and 90-day-old eyes was 0.40 (±0.16) mm, 0.48 (±0.13) mm, 0.67 (±0.15) mm, 0.86 (±0.35) mm, and 1.09 (±0.63) mm, respectively. Ciliary muscle volume was significantly correlated with log age (p = 0.001), ocular length (p = 0.003), limbal circumference (p = 0.01), and equatorial diameter (p = 0.003). It was not correlated with refractive error (p = 0.73) or eye shape (p = 0.60). Multivariate regression determined that biometric variables were not significantly associated with CMV after adjustment for age. Three-dimensional reconstruction was an effective means of determining CMV. These data provide evidence that ciliary muscle growth occurs with age in tandem with eye size in normal albino guinea pigs. Additional work is needed to determine the relationship between CMV and abnormal ocular growth.

Growth Pattern Analysis of Murine Lung Neoplasms by Advanced Semi-Automated Quantification of Micro-CT Images

Computed tomography (CT) is a non-invasive imaging modality used to monitor human lung cancers. Typically, tumor volumes are calculated using manual or semi-automated methods that require substantial user input, and an exponential growth model is used to predict tumor growth. However, these measurement methodologies are time-consuming and can lack consistency. In addition, the availability of datasets with sequential images of the same tumor that are needed to characterize in vivo growth patterns for human lung cancers is limited due to treatment interventions and radiation exposure associated with multiple scans. In this paper, we performed micro-CT imaging of mouse lung cancers induced by overexpression of ribonucleotide reductase, a key enzyme in nucleotide biosynthesis, and developed an advanced semi-automated algorithm for efficient and accurate tumor volume measurement. Tumor volumes determined by the algorithm were first validated by comparison with results from manual methods for volume determination as well as direct physical measurements. A longitudinal study was then performed to investigate in vivo murine lung tumor growth patterns. Individual mice were imaged at least three times, with at least three weeks between scans. The tumors analyzed exhibited an exponential growth pattern, with an average doubling time of 57.08 days. The accuracy of the algorithm in the longitudinal study was also confirmed by comparing its output with manual measurements. These results suggest an exponential growth model for lung neoplasms and establish a new advanced semi-automated algorithm to measure lung tumor volume in mice that can aid efforts to improve lung cancer diagnosis and the evaluation of therapeutic responses.

Volumetry of Fetal Hearts using 3D Real-Time Matrix Echocardiography – In Vitro Validation Experiments and 3D Echocardiographic Studies in Fetuses

The aim of this study was to assess the feasibility, accuracy and reliability of 3D real-time echocardiography for fetal heart volumetry. Fifty unselected and consecutive fetuses, including 14 with cardiac malformations, were scanned prospectively using real-time 3D matrix technology and 2D echocardiography to determine ventricular volumes. Small phantoms as well as modified balloons (0.5 - 20 ml) were used to assess the validity of 2D and 3D distance, area and volume calculations and to study potential sources of error during data acquisition and analysis. The data was evaluated by two blinded observers. In vitro, real-time 3D and 2D underestimated the actual volumes by -5.49 % (3D) and -6.86 % (2D). The intraobserver and interobserver variability were excellent. In vivo, real-time 3D was superior to 2D with regard to intraobserver and interobserver variability (mean coefficient of variation 8.28 % (3D) versus 13.96 % (2D), and mean intraclass correlation coefficient 0.997 (3D) versus 0.885 (2D) for left ventricular volumes). Similar to in vitro, in vivo 2D volumes were calculated smaller than 3D volumes (mean difference -0.39 to -0.94 ml). The ventricular volumes and stroke volumes increased exponentially with gestation. Secondary to poor imaging windows in advanced gestation or inadequate delineation of endocardial borders in small hearts at less than 19 weeks, 3D data could not be analyzed sufficiently in 6 / 50 fetuses. Real-time 3D using a matrix transducer is a feasible, reliable and valid method for volume determination in the fetus beyond 19 weeks of gestation. If compared to 2D, real-time 3D echocardiography provides improved accuracy of cardiac volumetry, decreases intraobserver and interobserver variability and is a promising tool for the accurate assessment of cardiac size and function.

Lung lesion doubling times: values and variability based on method of volume determination

To determine doubling times (DTs) of lung lesions based on volumetric measurements from thin-section CT imaging. Previously untreated patients with > or = two thin-section CT scans showing a focal lung lesion were identified. Lesion volumes were derived using direct volume measurements and volume calculations based on lesion area and diameter. Growth rates (GRs) were compared by tissue diagnosis and measurement technique. 54 lesions were evaluated including 8 benign lesions, 10 metastases, 3 lymphomas, 15 adenocarcinomas, 11 squamous carcinomas, and 7 miscellaneous lung cancers. Using direct volume measurements, median DTs were 453, 111, 15, 181, 139 and 137 days, respectively. Lung cancer DTs ranged from 23-2239 days. There were no significant differences in GRs among the different lesion types. There was considerable variability among GRs using different volume determination methods. Lung cancer doubling times showed a substantial range, and different volume determination methods gave considerably different DTs.

Analysis of Complex Transverse Susceptibility Method for Determination of Volume and Anisotropy Field Distributions in Recording Media

This paper is dedicated to the analysis of determination of volume and anisotropy field distributions using the complex transverse susceptibility (TS). We consider in our study two-dimensional arrays of particles as magnetic patterned media. It is shown that the amplitude of excitatory ac field and the interactions between particles play an important role