Variation In Total Volume Research Articles

Characteristics of intra-annual distribution of precipitation and incoming water and the synchronization analysis of their changes in the lower reaches of the Yangtze river basin

Precipitation and incoming water are the key contributing factors to local flooding events, and analyzing the intra-annual distribution and change characteristics of precipitation and incoming water will be beneficial to the understanding of flooding contributing factors in this region. In this paper, the characteristics of intra-annual distribution of precipitation and incoming water and the synchronization of their changes in the lower reaches of the Yangtze River Basin (LYRB) from 1980 to 2020 are studied using the concentration degree and concentration period as quantitative indicators. The results are as follows: 1) the maximum precipitation occurs earlier in the year, while maximum incoming water occurs with little variation in timing but significant variation in total volume; 2) the concentration degree of both precipitation and incoming water show a slowly decreasing trend. The concentration period of precipitation is slightly advanced, and that of incoming water is significantly delayed; 3) the occurrence time and concentration period of the incoming water peak during 2010–2020 lagged behind that of precipitation, which played a role in suppressing the occurrence of floods in the LYRB. This study can provide a scientific basis for the future supply and demand of water resources in the LYRB for safe use.

Volumetric analysis on the use of customized healing abutments with or without connective tissue graft at flapless maxillary immediate implant placement: A randomized clinical trial.

To evaluate buccal volume change after using a customized healing abutment with or without connective tissue grafts (CTG) in flapless maxillary immediate implant placement (IIP). The present study was designed as a randomized clinical trial (RCT). Patients treated with flapless maxillary IIP were allocated into two groups, both receiving a customized healing abutment, and additionally, the test group received a CTG. A cone-beam computerized tomography (CBCT) allowed to access the initial buccal bone thickness (BT). Digital impressions were taken prior to extractions (T0), 1 month (T1), 4 months (T2), and 12 months (T3) after implant insertion and superimposed with computer software allowing to compute variables related to buccal volume variation (BVv) and total volume variation (TVv) (ClinicalTrials.gov: NCT05060055). Thirty-two patients (mean age 48 ± 11 years), sixteen in each group, were evaluated after a 12-month period. After 1 year of treatment, no significant differences were found between groups, although in participants with BT ≤1 mm, control and test groups showed a BVv of -14.18 ± 3.49% and -8.30 ± 3.78%, respectively (p = .033). Regarding mucosa height variation variables, the control group showed approximately the triple vertical recession in both papillae. The placement of a CTG was not capable of completely maintaining the initial peri-implant tissue architecture, although in thin-bone phenotypes, less dimensional changes are expected when a CTG was used.

Impacts of meteorological factors and crop area changes on the variations in winter wheat water requirements in the lower reaches of the Yellow River Basin

Meteorological factors and human activities (such as changes in crop area) have exerted great impacts on the agricultural water resources. A thorough understanding of the changes in crop water requirements (CWR) and irrigation water requirements (IR) is crucial for effective agricultural water management. In the present study, the unit area and total volume of winter wheat CWR and IR were estimated based on meteorological and crop area data, and spatiotemporal variations were analyzed from 2001 to 2018 in the lower reaches of the Yellow River Basin. The impacts of meteorological factors and crop area changes on the CWR and IR variations were explored using sensitivity analysis and the logarithmic mean Divisia index method along with the identification of the main driving factors. The results revealed that both the unit area CWR and IR exhibited a decreasing trend with a multi-year average value of 540 mm and 488 mm, respectively, and increased gradually from south to northwest in the spatial distribution. The significant decrease in wind speed exerted the greatest impact on the unit area CWR and IR changes with the highest sensitivity among considered meteorological factors. The total volume of CWR and IR increased by 56.5 × 108 m3 and 32.3 × 108 m3 from 2001 to 2018, respectively. The crop area change of winter wheat was a major contributor to the variations in total volume of CWR and IR rather than meteorological factors during the study period, and evident spatial and temporal differences were observed. The results of this study provide valuable insights for developing adaptive strategies considering the impacts of meteorological factors and planted crop area changes and can therefore contribute to the sustainable utilization and management of agricultural water resources.

Out-of-hospital cardiac arrest volumes and characteristics during the COVID-19 pandemic.

AimThe COVID-19 pandemic has significantly impacted Emergency Medical Services (EMS) operations throughout the country. Some studies described variation in total volume of out-of-hospital cardiac arrests (OHCA) during the pandemic. We aimed to describe the changes in volume and characteristics of OHCA patients and resuscitations in one urban EMS system.MethodsWe performed a retrospective cohort analysis of all recorded atraumatic OHCA in Marion County, Indiana, from January 1, 2019 to June 30, 2019 and from January 1, 2020 to June 30, 2020. We described patient, arrest, EMS response, and survival characteristics. We performed paired and unpaired t-tests to evaluate the changes in those characteristics during COVID-19 as compared to the prior year. Data were matched by month to control for seasonal variation.ResultsThe total number of arrests increased from 884 in 2019 to 1034 in 2020 (p = 0.016). Comparing 2019 to 2020, there was little difference in age [median 62 (IQR 59–73) and 60 (IQR 47–72), p = 0.086], gender (38.5% and 39.8% female, p = 0.7466, witness to arrest (44.3% and 39.6%, p = 0.092), bystander AED use (10.1% and 11.4% p = 0.379), bystander CPR (48.7% and 51.4%, p = 0.242). Patients with a shockable initial rhythm (19.2% and 15.4%, p = 0.044) both decreased in 2020, and response time increased by 18 s [6.0 min (IQR 4.5–7.7) and 6.3 min (IQR 4.7–8.0), p = 0.008]. 47.7% and 54.8% (p = 0.001) of OHCA patients died in the field, 19.7% and 19.3% (p = 0.809) died in the Emergency Department, 21.8% and 18.5% (p = 0.044) died in the hospital, 10.8% and 7.4% (p = 0.012) were discharged from the hospital, and 9.3% and 5.9% (p = 0.005) were discharged with Cerebral Performance Category score ≤ 2.ConclusionTotal OHCA increased during the COVID-19 pandemic when compared with the prior year. Although patient characteristics were similar, initial shockable rhythm, and proportion of patients who died in the hospital decreased during the pandemic. Further investigation will explore etiologies of those findings.

Study on Particle Loss during Dissolution Based on Extreme Stress Condition

The loss process of particles in the soil contains erosion, degradation and dissolution. Either way, caused changes in the inner system of the soil. The intention of this article is to investigate the change of soil volume under particular stress condition. Sand and salt mixture were prepared in this test, which stands for small particles, as test stuff to imitate real sandy soil. The experiment was carried out in an improved consolidator. As for this test, vertical additional stress was used as the variable, as for this experiment, the stress was the maximum value 1000KPa and the minimum value 10KPa, respectively. The experiment was divided by stages: load stage and dissolve stage, the volumetric variation in the facility was recorded by a software called DS7. The results show that the variation of volume was due to total volume variation and dissolution is much more than the volume change in minimal stress. When vertical stress greatly Λ value is 0.25, and tiny Λ value is 0.14. According to the previous laboratory finding and theory of strong chain, the experimental conclusion are analyzed theoretically.

SU‐F‐T‐280: An Assessment of Deviations in Gamma Index Between PTW Octavius4D Phantom Measurements and Various Treatment Planning Systems

Purpose:There is a variety of treatment planning systems (TPS) available for clinical use all with highly variable settings to calculate patient dose. Patient specific IMRT QA is often a daily procedure at most clinics and each clinic devises their own policy on the TPS settings for testing the quality of the patient plan against a measured dose on IMRT QA phantoms. With this in mind, it is the aim of this study to evaluate the effect of dose calculation parameters on IMRT QA.Methods:Six patient plans were optimized and calculated using Pinnacle3 (v9.10). Patient QAs were calculated using the PTW Octavius4D phantom with a dose grid resolution of 3mm and a phantom density of 1.045g/cc. Using PTW's VeriSoft, the calculated dose distribution of Pinnacle3, Monaco, and Eclipse were compared to the delivered plan (the control) on the Octavius4D. For each TPS, the dose grid was varied from 2–4mm, and the phantom density varied ±10% in increments of 2%. Additionally, statistical uncertainties ranging from 0.7%–3% were calculated for Monaco. Using the evaluation metric of 3% and 3mm with a threshold of 10% of the max dose, the average and standard deviation of the 3D γ‐index were calculated for each plan. The γ‐index from axial, sagittal, and coronal slices at isocenter and the overall 3D γ‐index were used for the comparisons.Results:The disparity in γ‐index was small between most plan modifications. An extreme example is one case in which a 3D slice yielded a γ‐index that differed up to 12.9% whereas the maximum variation in total volume for any case was merely 2.3%. The average standard deviation of all slices was ±1.49% and the average standard deviation for total volume was only ±0.55%.Conclusion:Dose calculation resolution and algorithm does not significantly affect the patient QA measurements.

Interobserver variability in clinical target volume delineation for primary mediastinal B-cell lymphoma

PurposeThe purpose of this study was to evaluate interobserver variability among radiation oncologists with experience in the field of lymphoma radiation therapy in the delineation of clinical target volume (CTV) in a challenging case of primary mediastinal B-cell lymphoma. Methods and materialsTen experienced radiation oncologists were invited to a 1-day contouring session. The case of a 56-year-old man with primary mediastinal B-cell lymphoma with complete metabolic response after chemotherapy was chosen as the sample for the study. A brief presentation of his clinical history was given, together with guidelines for contouring. The 10 CTVs obtained were then compared in terms of variation in total volume and in craniocaudal, laterolateral, and anteroposterior diameters. The CTV with the best Dice similarity coefficient (DSC) between the union of all 10 CTVs and the individual CTV was considered the reference CTV, and the DSC and the Hausdorff distance (HD) for each volume compared with the reference CTV were then calculated. ResultsA significant variability was found in total volume (mean, 498.3 cm3; range, 181.8-1003 cm3) and craniocaudal (median, 144.7 mm; range, 80.6-159 mm), laterolateral (median, 133.5 mm; range, 83.7-149.5 mm), and anteroposterior diameters (median, 136.2 mm; range, 84-150.5 mm). Analysis of the DSC and the HD showed a mean DSC of 0.53 (range, 0.31-0.74) and a mean HD of 6.4 cm (range, 1.8-14.8 cm). ConclusionsResults of this study strongly indicate the need to develop and share appropriate contouring guidelines among experts and suggest the promotion of specific educational activities to improve radiation therapy quality in both clinical trials and routine clinical practice.

Effect of lithiation potential and cycling on chemical and morphological evolution of Si thin film electrode studied by ToF-SIMS.

Si thin films obtained by plasma enhanced chemical vapor deposition (PECVD) were used to investigate chemical and morphological modifications induced by lithiation potential and cycling. These modifications were thoughtfully analyzed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) depth profiling, which allows to distinguish the surface and bulk processes related to the formation of the solid electrolyte interphase (SEI) layer, and Li-Si alloying, respectively. The main results are a volume expansion/shrinkage and a dynamic behavior of the SEI layer during the single lithiation/delithiation process and multicycling. Trapping of lithium and other ions corresponding to products of electrolyte decomposition are the major reasons of electrode modifications. It is shown that the SEI layer contributes to 60% of the total volume variation of Si electrodes (100 nm). The apparent diffusion coefficient of lithium (DLi) calculated from the Fick's second law directly from Li-ion ToF-SIMS profiles is of the order of ∼5.9 × 10(-15) cm(2).s(-1). This quite low value can be explained by Li trapping in the bulk of electrode material, at the interfaces, continuous growth of the SEI layer and increase of SiO2 quantity. These modifications can result in limitation the ionic transport of Li.

Retention behaviour of natural clayey materials at different temperatures

The water retention capacity of geomaterials, and especially clayey soils, is sensitive to temperature changes as the physical mechanisms of retention, such as capillarity or adsorption, are affected by it. It is therefore a major issue to be able to define temperature-dependent behaviour of materials, especially for geo-energy and geo-environmental applications involving non-isothermal conditions. This paper presents results of experiments conducted on two representative materials: a hard clay (Opalinus clay) and a plastic clay (Boom clay), both of which have been considered as buffer materials for underground radioactive waste disposal, in Switzerland and Belgium, respectively. Two new devices were developed for this purpose to permit the analysis of water retention behaviour at different temperatures. The behaviour of these two materials at ambient (20 °C) and high temperature (80 °C) was observed and described through the evolution of the degree of saturation, the water content and the void ratio with respect to suction. It appears that the retention capability of the clays reduces significantly with an increase in temperature; on the other hand, the change in temperature had less of an effect on the total volume variation.

Shape evolution of patterned amorphous and polycrystalline silicon microarray thin film electrodes caused by lithium insertion and extraction

Silicon is the most promising high capacity anode material to replace graphite for developing next generation high energy density Li-ion batteries. In this approach, patterned amorphous and microcrystalline Si thin film electrodes (a-Si and μc-Si) have been prepared by rf-sputtering and etched further by a reactive ion etching (RIE) system to form square-shape microcolumn electrodes with controllable size (5 × 5 μm width, 500 nm height, aspect ratio of width/height is 10:1) and array distance (5 μm). It has been found that the volume expansion and contraction of a-Si and μc-Si are anisotropic, about 180% along vertical direction and 40% along lateral direction. The total volume variation changes linearly with the increase of lithium insertion content up to ∼310% for a-Si and ∼300% for μc-Si. It occurs nearly reversibly. In addition, it is observed that the original square-shape Si column transforms into the dome-like appearance after lithium insertion and changes into bowl shape after lithium extraction gradually. Radial-like curved cracks are formed after 5−10 cycles and the neighboring Si columns tend to merge together when the distance of the columns is less than 1 μm.

Optimization of single SOFC structural design for maximum power

This paper improves previously published models by the authors for a single solid oxide fuel cell (SOFC), and introduces a procedure to optimize its external configuration and operating conditions, so that the net power is maximized. The previous models are hereby improved to include: i) a constant offset overpotential in total potential drop; ii) heat generation associated with all the potential losses; iii) temperature-dependent thermo-physical properties of fuel and air, and iv) pumping power to maximize fuel cell performance. The thermodynamic model is derived from physical laws (e.g., the first law of thermodynamics, Fick's law, Fourier's law) to obtain the temperature and pressure spatial distribution in the SOFC. The electrochemical model is validated by direct comparison with experimental data from the Pacific Northwest National Laboratory (PNNL), and allows for the computation of the SOFC voltage, current, and power output. Based on the simulation results, the structural design, the active three phase boundaries regions at the electrodes and the fuel utilization factor, and their impact on the SOFC performance are discussed. Subjected to fixed total volume, the optimal geometric and operating parameters are pursued so that the net power of the SOFC is maximized through a 4-way-optimization procedure. The method used is general and the numerically obtained maxima are sharp, taking into account that up to a 631% single SOFC performance variation was observed within the studied parameters' range. The fixed volume constraint was then relaxed, and the effect of total volume variation on performance was investigated, delivering the general optimal parameters for the 4-way maximized SOFC net power output within the studied total dimensionless fuel cell volume range. These findings show the potential to use the model as a tool for future SOFC design, simulation and optimization.

Physical Activity, Sedentary Behavior, and Adiposity in English Children

The importance of variation in total volume of physical activity or moderate- to vigorous-intensity physical activity (MVPA) to development of body fatness in childhood is unclear, and it is unclear if physical activity has a greater influence on adiposity in boys than girls. To assess relationships between 2-year changes in objectively measured physical activity, sedentary behavior, and adiposity in English children. Prospective cohort study, set in Northeast England, of a socioeconomically representative sample of 403 children. Measures were change in accelerometer-determined physical activity and sedentary behavior from age 7 to 9 years (data collected 2006/2007 and 2008/2009; analyzed in 2010) and concurrent change in adiposity (fat mass index derived from bioelectric impedance) and change in BMI Z-score. Decline in MVPA was associated with a greater increase in fat mass index in boys but not girls. Declining MVPA was associated with increased BMI Z-score in boys but not girls. Increased sedentary behavior was not associated with increased BMI Z-score in either gender. Avoiding mid-late childhood reductions in MVPA may reduce excessive fat gain, although such strategies may have greater impact on boys than girls.

PH reduction and vegetable tissue structure changes of zucchini slices during pulsed vacuum acidification

A pulsed vacuum acidification treatment (PVA) applied to zucchini slices and the related response of vegetable tissues, were studied. Results showed that in comparison with a traditional acidifying–dipping at atmospheric pressure, PVA may improve the pH reduction as a consequence of the increase of acid solution-vegetable tissues contact area. Nevertheless, the low porosity fraction of fresh zucchini, the variability of the vegetable tissue structure and its mechanical properties did not allow to increase the acidification rate by increasing the vacuum level of 200 mbar. In particular, the study of structural changes showed that the liquid volume changes occurred without significant total volume variation due to the rigidity of vegetable tissues. Probably, this aspect reduced the deformation–relaxation phenomena which have great effect on liquid impregnation at both 200 mbar and 400 mbar. In addition, due to the low viscosity of acid solution it was hypothesize a great filling also at 400 mbar reducing the effect of the increase of vacuum pressure.

Synthesis by ATRP and effects of molecular weight on photomechanical properties of liquid crystalline polymers containing side-chain azobenzene chromophores

The synthesis of a series of azobenzene containing liquid crystalline methacrylic homopolymers, poly(4-ω-methacryloyloxy-hexyloxy-4′-ethoxyazobenzene) [Poly( M6A)], with distinct average chain lengths and low polydispersity has been achieved by Atom Transfer Radical Polymerization (ATRP) in THF solution using allyl 2-bromoisobutyrate as initiator and Cu(I)Br as catalyst. Under the adopted conditions the living centers concentration is found to be constant throughout the polymerization process and well defined chain end-groups are obtained. All the obtained polymeric samples, having average molecular mass ( M ¯ n ) ranging from 3300 to 14000 g/mol, exhibit smectic and nematic liquid-crystalline phases on heating, with transition temperatures strongly dependent on polymerization degree, as characterized by differential scanning calorimetry and polarized optical microscopy. The photomechanical effects (i.e. the dependence of volume and density) exhibited upon trans-to- cis and cis-to- trans photoisomerization of the azobenzene mesogenic groups have been investigated by ellipsometry and related to molecular weight, with particular attention to important parameters for potential applications such as the relative variation of total volume, response time, stability and reproducibility.

Time-dependent cell disintegration kinetics in lung tumors after irradiation

We study the time-dependent disintegration kinetics of tumor cells that did not survive radiotherapy treatment. To evaluate the cell disintegration rate after irradiation, we studied the volume changes of solitary lung tumors after stereotactic radiotherapy. The analysis is performed using two approximations: (1) tumor volume is a linear function of the total cell number in the tumor and (2) the cell disintegration rate is governed by the exponential decay with constant risk, which is defined by the initial cell number and a half-life T1/2. The half-life T1/2 is determined using the least-squares fit to the clinical data on lung tumor size variation with time after stereotactic radiotherapy. We show that the tumor volume variation after stereotactic radiotherapy of solitary lung tumors can be approximated by an exponential function. A small constant component in the volume variation does not change with time; however, this component may be the residual irregular density due to radiation fibrosis and was, therefore, subtracted from the total volume variation in our computations. Using computerized fitting of the exponent function to the clinical data for selected patients, we have determined that the average half-life T1/2 of cell disintegration is 28.2 days for squamous cell carcinoma and 72.4 days for adenocarcinoma. This model is needed for simulating the tumor volume variation during radiotherapy, which may be important for time-dependent treatment planning of proton therapy that is sensitive to density variations.

Outpatient preoperative evaluation clinic can lead to a rapid shift from inpatient to outpatient surgery: a retrospective review of perioperative setting and outcome

Study Objective: To report the rapid shift from inpatient to outpatient surgery that occurred after opening an outpatient preoperative evaluation clinic and the perioperative complications and mortality rates before and after this intervention. Design: Monthly variations of total volume of procedures and percentages of outpatient procedures were analyzed retrospectively using control charts over two consecutive 10-month periods before and after the intervention. For each type of procedure (inpatient vs. outpatient), the perioperative complications and 30-day mortality rates were compared between periods. Setting: The Veterans Affairs Palo Alto Health Care System, Palo Alto, California Patients: Patients who underwent 3,159 inpatient or outpatient procedures in the main operating room suite during the control period were compared with patients who underwent 3,190 procedures in the same operating room suite during the intervention period. Intervention: The establishment of an outpatient preoperative evaluation clinic. Measurements and Main Results: For each period, the total monthly surgical volume (inpatient and outpatient), perioperative complications, deaths within 30 days of surgery, and the number of procedures performed on patients classified as ASA physical status III, IV, or V were analyzed. The monthly total number of procedures was stable over both periods, but the monthly percentage of outpatient procedures departed from its baseline immediately after establishing the clinic (control period: 24.7%; study period: 45.4%; p << 0.0001). Finally, the perioperative complication rate did not change for outpatient procedures but increased for inpatient procedures (control period: 2.31%; study period: 3.50%; p < 0.05). The 30-day mortality rate remained unchanged for inpatient and outpatient procedures. Conclusions: Establishing an outpatient preoperative evaluation clinic can lead to a rapid shift from inpatient to outpatient surgery at a government funded hospital without a concomitant increase in perioperative morbidity or mortality.

Predicting Site Productivity of Mixed Conifer Stands in Northern Idaho from Soil and Topographic Variables

AbstractCharacteristics of 32 soils, consisting of an upper sequum influenced by volcanic ash over a buried sequum, and topographic variables were used to develop prediction equations for site index, height, and total volume of mixed coniferous stands in northern Idaho. Soil and topographic variables explained 70% of the variation in site index. Ninety‐four percent of the variation in height of the site trees, and 86% of the variation in total volume of the stand were explained by soil and topographic properties and age. Depth of volcanic ash influence, bulk density, P content, and elevation were important soil and topographic variables.Site index was negatively correlated with elevation, and positively correlated with extractable Ca, exchange acidity, cation exchange capacity, organic matter, total N, soil to rock ratio of the buried soils, and clay of the ash derived soils.

Particle size distributions in a region of coastal upwelling analyzed by characteristic vectors1

Particle size distributions (8–105‐µm diameter), chlorophyll a, and particulate carbon were measured off the Oregon coast during July 1973. The particle counts were transformed to volume concentration and then subjected to characteristic vector analysis. Ninety‐two percent of the variance was accounted for by linear combinations of the first two characteristic vectors. Two weighting factors define the proportions of the two characteristic vectors which will, when added to the mean volume concentration curve, approximate the actual data for each sample. Variations in the first weighting factor correspond well with variations in total volume. Changes in the second weighting factor indicate which segment of the size range contains the largest proportion of the particulate volume. Comparison with temperature and salinity data indicated that the near surface water with proportionately large volumes of particles less than 20 µm was warmer and less saline than the surface waters with large volumes between 20 and 50 µm. High correlation with particulate carbon and chlorophyll suggests that in both cases a large proportion of the particles is phytoplankton.