Calculation Of Volume Research Articles

Ab Initio Investigation of the Structural, Elastic, Dynamic, Electronic, and Magnetic Properties of Cubic Perovskite CeCrO3.

We presented the results of various aspects related to structural, elastic, electronic, dynamic, and magnetic parameters of cubic perovskite CeCrO3 by means of the full-potential linearized augmented plane wave (FP-LAPW) approach. The calculation of the unit cell volume against the total energy curve confirms that CeCrO3 exhibits higher energetic stability in the ferromagnetic (FM) order. Calculated structural aspects at equilibrium demonstrate excellent similarity to present information, lending credibility to our results. Moreover, monocrystalline elastic constants have been analyzed numerically. These constants provide insights into several related properties, including elastic anisotropy, mechanical stability, and several polycrystalline elastic aspects. Furthermore, the phonon dispersion curves obtained from our calculations reveal the existence of soft modes, which suggests the potential metastability of CeCrO3. Through an analysis of the energy band dispersions, the half-metallic nature of this material is confirmed, such as Eg = 3.00 and 3.13 eV for the HM state within generalized gradient approximations Perdew-Burke-Ernzerhof (GGA-PBE) and Tran-Blaha modified Becke-Johnson (TB-mBJ) calculations, respectively, as well as the FM total magnetic moment of 4.000 μB. Partial density of states (PDOS) aided in identifying the electronic states that contribute to the energy bands. Finally, the computed total magnetic moment aligns fit the theoretical findings available in the literature.

Long-term monitoring (1953–2019) of geomorphologically active sections of Little Ice Age lateral moraines in the context of changing meteorological conditions

Abstract. We show a long-term erosion monitoring of several geomorphologically active gully systems on Little Ice Age lateral moraines in the European Central–Eastern Alps, covering a total time period from 1953 to 2019 and including several survey periods in order to identify corresponding morphodynamic trends. For the implementation, DEM (digital elevation model) of Differences (DoDs) were calculated, based on multitemporal high-resolution digital elevation models from historical aerial images (generated by structure from motion photogrammetry with multi-view stereo) and light detection and ranging from airborne platforms. Two approaches were implemented to achieve the corresponding objectives. First, by calculating linear regression models using the accumulated sediment yield and the corresponding catchment area (on a log–log scale), the range of the variability in the spatial distribution of erosion values within the sites. Second, we use volume calculations to determine the total and the mean sediment yield (as well as erosion rates) of the entire sites. Subsequently, both the sites and the different time periods of both approaches are compared. Based on the slopes of the calculated regression lines, it can be shown that the highest variability in the sediment yield at the sites occurs in the first time period (mainly 1950s to 1970s). This can be attributed to the fact that within some sites the sediment yield per square metre increases clearly more strongly (regression lines with slopes up to 1.5). In contrast, in the later time periods (1970s to mid-2000s and mid-2000s to 2017/2019), there is generally a decrease in 10 out of 12 cases (regression lines with slopes around 1). However, even at sites with an increase in the variability in the sediment yield over time, the earlier high variabilities are no longer reached. This means that the spatial pattern of erosion in the gully heads changes over time as it becomes more uniform. Furthermore, using sediment volume calculations and corresponding erosion rates, we show a generally decreasing trend in geomorphic activity (amount of sediment yield) between the different time periods in 10 out of 12 sites, while 2 sites show an opposite trend, where morphodynamics increase and remain at the same level. Finally, we summarise the results of long-term changes in the morphodynamics of geomorphologically active areas on lateral moraines by presenting the “sediment activity concept”, which, in contrast to theoretical models, is based on actually calculated erosion. The level of geomorphic activity depends strongly on the characteristics of the sites, such as size, slope length, and slope gradient, some of which are associated with deeply incised gullies. It is noticeable that especially areas with influence of dead ice over decades in the lower slope area show high geomorphic activity. Furthermore, we show that system internal factors, as well as the general paraglacial adjustment process, have a greater influence on long-term morphodynamics than changing external weather and climate conditions, which, however, had a slight impact mainly in the last, i.e. most recent, time period (mid-2000s to 2017/2019) and may have led to an increase in erosion at the sites.

Pretherapeutic PSMA PET-Derived Semiquantitative Parameters as Predictors of PSA Response in Patients with mCRPC Receiving [ 177 Lu]Lu-PSMA-617 Radioligand Therapy.

Objective [ 177 Lu]Lu-prostate-specific membrane antigen (PSMA)-617 radioligand therapy (RLT) shows promise for metastatic castration-resistant prostate cancer (mCRPC) patients with positive PSMA positron emission tomography (PET) imaging. Identifying high-risk patients is crucial. We evaluated pretherapeutic PSMA PET-derived parameters to predict prostate-specific antigen (PSA) response in patients undergoing [ 177 Lu]Lu-PSMA-617 RLT. Materials and Methods We conducted a retrospective analysis among 27 patients (mean age: 71.0 ± 9.5 years; range: 52-85 years) who underwent PSMA PET/computed tomography (CT) and subsequent [ 177 Lu]Lu-PSMA-617 RLT between March 2019 and January 2023. After excluding patients with liver metastases, the number of patients left for analysis was 21 (14 responders and 7 nonresponders). Tumors were semiautomatically delineated with calculation of total tumor volume (PSMA-TV), lesion uptake (PSMA-TLU = PSMA-TV * standardized uptake value [SUV]mean), and lesion quotient (PSMA-TLQ = PSMA-TV/SUVmean) for each patient. Semiquantitative parameters were analyzed only in patients with mCRPC and no liver metastasis. Results In total, 17/27 patients (62.96%) had a decline in PSA levels; 15/27 patients (55.56%) experienced a decline of > 50%. Pretherapeutic PSMA PET/CT results revealed significant differences in PSMA-TV ( p = 0.003), PSMA-TLU ( p = 0.013), and PSMA-TLQ ( p = 0.011) between responders and nonresponders. SUVmax was significantly correlated to the best percentage change in PSA response after 177 Lu-PSMA-617 treatment ( r = -0.79, p = 0.006). No association was observed between PSMA-TV ( p = 0.367), PSMA-TLU ( p = 0.128), and PSMA-TLQ ( p = 0.556), with the best percentage change in PSA response after 177 Lu-PSMA-617 therapy. Conclusion Pretherapeutic PSMA PET-derived PSMA-TV, PSMA-TLU, and PSMA-TLQ were significant negative predictors of PSA response in patients with mCRPC and no liver metastasis receiving [ 177 Lu]Lu-PSMA-617 RLT.

Optical properties and luminescence behavior of Tb3+-Doped SiO2–Al2O3–BaO–BaF2 oxyfluoride glasses and glass ceramics

In this study, oxyfluoride glasses with chemical composition of 45SiO2–15Al2O3–10BaO–30BaF2-xTbF3 (x = 0.2, 0.4 and 0.6 (mole ratios)) were prepared through the conventional melt-quenching method. Raman and FTIR spectra as well as molar volume calculations proved the creation of more non-bridging oxygens (NBOs) in presence of more TbF3 content. Accordingly, absorption edge in UV–Vis spectra showed a slight red-shift to longer wavelengths. The glass with 0.4 mol ratios of TbF3, exhibited the highest photoluminescence emission and its green-to-blue intensity ratio was 0.66. Therefore, this sample was chosen and heat treated at 630, 650 and 675 °C to prepare glass ceramic samples. For the sample heat treated at 650 °C, photoluminescence intensity increased and green-to-blue intensity ratio reached 0.69. Also, lifetimes of green and blue emissions increased from 3.35 ms to 3.67 ms and from 2.95 ms to 3.10 ms, respectively, when the base glass heat treated at 650 °C. Formation of BaF2 nanocrystals in glass ceramics moved the UV–Vis absorption edge to longer wavelengths significantly. Increment of the weak and dangling bonds in crystallized samples reduced Fermi energy, indirect and direct optical band gap energies from 3.792 eV to 3.301 eV, from 3.522 eV to 3.093 eV and from 4.095 eV to 3.582 eV respectively, which led to higher semiconducting behaviors.

Digital twin modeling and leak diagnosis of temperature and stress fields in LNG storage tanks

Temperature and stress serve as crucial indicators for monitoring the health of LNG storage tanks. To address the limitations of traditional point-based monitoring and transition to comprehensive digital monitoring, this paper introduces the application of digital twin (DT) technology. The DT model plays a pivotal role in accurately representing the state of the physical entity and serves as the foundation for monitoring services and meeting application requirements within DT systems. This article introduces a numerical simulation method guided by temperature sensor data. It utilizes a temperature and stress calculation program as a platform to create twin models for real-time assessment of the temperature and stress within the storage tank. By comparing with the Fluent simulation of physical field leakage, the DT model realizes real-time inversion of the temperature field and stress field from sensor data to the whole region. To enhance the diagnostic and predictive capabilities of the DT system, we flatten the computed temperature nephogram from the DT model and employ machine vision techniques to extract cloud map features. Machine learning methods such as support vector machine (SVM) and linear regression are utilized to achieve leakage diagnosis, leakage volume calculation, and leakage location calculation. Additionally, we introduce the sequence-to-sequence (Seq2seq) framework and combine it with convolutional neural networks (CNN) and long short-term memory (LSTM) to train the time series of nephogram, enabling spatiotemporal prediction of leakage areas.

Comparative Study of Lesions Obtained through Radiofrequency between the Irrigated Ablation Catheter with a Flexible Tip and the Non-Irrigated Catheter in Ex Vivo Porcine Hearts.

At the same conditions of delivered power and contact force, open-irrigated radiofrequency ablation catheters are believed to create deeper lesions, while non-irrigated ones produce shallower lesions. This ex vivo study aims to directly compare the lesion dimensions and characteristics of an irrigated ablation catheter with a flexible tip and a non-irrigated solid-tip catheter. Radiofrequency lesions were induced on porcine myocardial slabs using both open-tip irrigated and non-irrigated standard 4 mm catheters at three power settings (20 W, 30 W, and 40 W), maintaining a fixed contact force of 10 gr. A lesion assessment was conducted including the lesion depth, depth at the maximum diameter, and lesion surface diameters, with the subsequent calculation of the lesion volume and area being undertaken. Irrigated catheters produced lesions with significantly higher superficial widths at all power levels (3.8 vs. 4.4 mm at 20 W; 3.9 mm vs. 4.4 mm at 30 W; 3.8 mm vs. 4.5 mm at 40 W; p = 0.001, p = 0.019, p = 0.003, respectively). Non-irrigated catheters resulted in significantly higher superficial areas at all power levels (23 mm2 vs. 18 mm2 at 20 W; 25 mm2 vs. 19 mm2 at 30 W; 26 mm2 vs. 19 mm2 at 40 W; p = 0.001, p = 0.005, p = 0.001, respectively). Irrigated catheters showed significantly higher values of lesion maximum depth at 40 W (4.6 mm vs. 5.5 mm; p = 0.007), while non-irrigated catheters had a significantly higher calculated volume at 20 W (202 µL vs. 134 µL; p = 0.002). Radiofrequency ablation using an irrigated catheter with a flexible tip has the potential to generate smaller superficial lesion areas compared with those obtained using a non-irrigated catheter.

Leakage monitoring and diagnosis of LNG storage tanks with temperature sensing network integration and artificial intelligence algorithm

Temperature is the most important safety monitoring indicator for leakage diagnosis during the operation phase of liquefied natural gas (LNG) storage tanks. Timely monitoring and accurate identification of LNG leakage events are crucial for accident prevention, loss reduction, and facility safety maintenance. This study integrates artificial intelligence (AI) algorithms and temperature sensing data to achieve intelligent monitoring and diagnosis of leakage in LNG storage tanks. Firstly, a comprehensive temperature sensing network is constructed by combining numerical simulation of the temperature field and temperature sensing experiments using fiber Bragg grating sensors. Secondly, Python is used to perform linear grid interpolation and flattening on the sensing network, generating 2D temperature nephogram samples that are conducive to AI algorithm recognition. Finally, sample features are extracted using machine vision, and leakage location calculation, leakage diagnosis and leakage volume calculation are implemented with the help of machine learning algorithms, achieving satisfactory accuracy on the test set. In addition, the ConvLSTM framework is introduced for deep learning and recurrent neural network training, enabling spatiotemporal prediction of the leakage area.

Precise individual muscle segmentation in whole thigh CT scans for sarcopenia assessment using U-net transformer

The study aims to develop a deep learning based automatic segmentation approach using the UNETR(U-net Transformer) architecture to quantify the volume of individual thigh muscles(27 muscles in 5 groups) for Sarcopenia assessment. By automating the segmentation process, this approach improves the efficiency and accuracy of muscle volume calculation, facilitating a comprehensive understanding of muscle composition and its relationship to Sarcopenia. The study utilized a dataset of 72 whole thigh CT scans from hip fracture patients, annotated by two radiologists. The UNETR model was trained to perform precise voxel-level segmentation and various metrics such as dice score, average symmetric surface distance, volume correlation, relative absolute volume difference and Hausdorff distance were employed to evaluate the model’s performance. Additionally, the correlation between Sarcopenia and individual thigh muscle volumes was examined. The proposed model demonstrated superior segmentation performance compared to the baseline model, achieving higher dice scores (DC = 0.84) and lower average symmetric surface distances (ASSD = 1.4191 ± 0.91). The volume correlation between Sarcopenia and individual thigh muscles in the male group. Furthermore, the correlation analysis of grouped thigh muscles also showed negative associations with Sarcopenia in the male participants. This thesis presents a deep learning based automatic segmentation approach for quantifying individual thigh muscle volume in sarcopenia assessment. The results highlights the associations between Sarcopenia and specific individual muscles as well as grouped thigh muscle regions, particularly in males. The proposed method improves the efficiency and accuracy of muscle volume calculation, contributing to a comprehensive evaluation of Sarcopenia. This research enhances our understanding of muscle composition and performance, providing valuable insights for effective interventions in Sarcopenia management.

Research on the change of the storage volume of the Nordic Seas Overflows over the last 40 years

The Nordic Sea overflow, being a significant driver of the thermohaline circulation, exerts a substantial influence on environmental dynamics in the Arctic and globally. A better understanding about the trend of the storage volume of the Nordic Seas Overflows is of paramount importance to a realistic assessment of the North Atlantic circulation and variability. EN4.2.2 reanalysis data were utilized to acquire the monthly average time series of overflow water storage volume in the Nordic Sea from 1950 to 2022. The storage volume demonstrates seasonal variations, with fluctuations of approximately 10% around the average. Over the period from 1980 to 2022, the average volume per decade exhibited a consistent decrease. Linear fitting of the annual average data estimated the overall relative change trend in the last 43 years to be -7.2 ± 2.6%. However, the quality of the EN4.2.2 data brings the average error of about 12% in the calculation of the overflow storage volume, which implies that the downward trend requires further validation. From a spatial standpoint, the Norwegian Sea, particularly the Lofoten Basin, is the primary region where overflow water storage volume in the Nordic seas have decreased. This decrease corresponds to an increase in ocean temperatures within the upper layer (0-600m) of both the Lofoten Basin and the Norwegian Basin. The warming of these regions has directly impacted the overflow water storage volume, leading to its reduction. It is noteworthy that the ocean temperature rise in the upper layer is more influenced by the Atlantic inflow rather than air-sea flux, particularly in the Norwegian Basin. This is attributed to the substantial increase in SST in the North Atlantic, which aligns with the warm current regions in the Atlantic Ocean, and the lack of statistical significance in linear trend of the air-sea heat flux. Furthermore, there has been a more rapid reduction in the overflow storage volume in the Norwegian Sea from 2011 to 2022. Specifically, the annual average overflow volume from 2018 to 2022 dropped below the previous lowest value. Concurrently, the salinity of the upper Norwegian Sea and the Atlantic inflow decreased considerably, while there has been no significant change in ocean temperature. Therefore, this short-term fluctuation is predominantly attributed to the decrease in Atlantic inflow salinity. Interestingly, the decrease in overflow water volume in the Nordic Seas does not follow a linear pattern in relation to increasing ocean temperature; instead, it exhibits an accelerating trend. If the ocean temperature rises by 1°C, the overflow water volume in the Nordic Seas will decrease to 86% of the total volume. Overall, the overflow water storage in the Norwegian Sea undergoes complex interannual variations and is notably influenced by the influx from the Atlantic Ocean.

Stereological and computed tomography calculation of intracranial volume in Hamdani sheep

AbstractThe intracranial cavity contains vital organs such as the brain, cerebellum and meninges. The veterinary field employment in this region is limited. For this reason, obtaining information about the intracranial cavity, the operation to be performed on this region and information about the world will benefit our unit. It aimed to examine the width between gender differences and expectations by calculating the intracranial volume stereological and 3D models using computed tomography sections. In the study, 7 male and 6 female adult Hamdani sheep were used. The intracranial cavity was modelled in 3D using computed tomography sections. Intracranial volume was estimated using CT slices according to the Cavalieri principle. Morphometric measurements were obtained from the intracranial cavity. In the study, intracranial volume was calculated as 120.50±7.59 cm3 in females and 137.29±9.79 cm3 in males in measurements made using Computed Tomography. Intracranial volume calculation made using the Cavalieri's principle was calculated as 125.33±5.20cm3 in females and 136.89±9.13 cm3in males. In the configured CT models, a target difference was detected between the male and female volume values calculated on it (p < 0.05). There was a difference between males and females in stereologically viable intracranial volume (p < 0.05). A high level of density was observed between the results of both methods. In the mean of the data, there was no difference between the objectives (p > 0.05). Morphometric measurements determined that the maximum cranial cavity width parameter was between females and males (p < 0.005). In index1 and index2 calculated with the obtained partitions, a circulating difference between genders was observed (p < 0.05). In the resulting state, the 3‐dimensional intracranial cavity models and the intracranial volume fraction estimated by the Cavalieri principle are conserved. There are high limits between the methods. Feeding future intracranial volume and clinical care.

Comparison of Using Conventional Estimating and Sketchup Pro for Bill Quantity Takeoff Process

Departing from academic anxiety that the construction industry in Indonesia has made rapid progress with the adoption of computing technology and methods in recent years. Increasing infrastructure development encourages construction actors to effectively and efficiently improve project quality. However, the role of the quantity surveyor becomes crucial in facing challenges such as manual quantity picking which is prone to errors and cost estimation that is difficult to do based on rough schematic design. In the context of traditional construction projects, quantity lists are arranged based on 2D drawings, but the use of 3D models has diminished since the adoption of BIM. Sketchup, as a 3D modeling software, and its extension Quantifier Pro provide a solution by combining 3D models to produce accurate quantity takeoff calculations on the Bill of Quantity. This research aims to develop methods to improve the quantity accuracy of elements of an incomplete or incorrect Sketchup model, in the hope of reducing modeling time, improving quantity retrieval performance, and making Sketchup-based cost estimation more effective and efficient in the context of construction. This research method involves 3D modeling using the Sketchup Pro application, using secondary data in the form of Detailed Engineering Design (DED) working drawings. Volume calculation in the Bill of Quantity is done with the help of Sketchup Pro software. The research location is in the Mullberry Cluster residential project, Bekasi City, West Java. The house building in this project was chosen as an object of comparison between conventional calculation methods and calculation methods using Sketchup Pro software. The main focus is to overcome the challenges of manual quantity picking and cost estimation from rough schematic design, emphasizing the crucial role of quantity surveyors. The results showed that the use of 3D models in Sketchup can increase the accuracy of cost estimation and reduce modeling time. The conclusion of the study confirms that Sketchup as an effective alternative solution in increasing efficiency and accuracy in the construction process, especially in the context of taking the quantity of architectural work elements, contributes positively to the development of more sophisticated cost estimation methods in the Indonesian construction industry.

Massive sediment pulses triggered by a multi-stage 130 000 m3 alpine cliff fall (Hochvogel, DE–AT)

Abstract. Massive sediment pulses in catchments are a key alpine multi-risk component. Substantial sediment redistribution in alpine catchments frequently causes flooding, river erosion, and landsliding and affects infrastructure such as dam reservoirs as well as aquatic ecosystems and water quality. While systematic rock slope failure inventories have been collected in several countries, the subsequent cascading sediment redistribution is virtually unaccessed. For the first time, this contribution reports the massive sediment redistribution triggered by the multi-stage failure of more than 130 000 m3 from the Hochvogel dolomite peak during the summer of 2016. We applied change detection techniques to seven 3D-coregistered high-resolution true orthophotos and digital surface models (DSMs) obtained through digital aerial photogrammetry later optimized for precise volume calculation in steep terrain. The analysis of seismic information from surrounding stations revealed the temporal evolution of the cliff fall. We identified the proportional contribution of > 600 rockfall events (> 1 m3) from four rock slope catchments with different slope aspects and their volume estimates. In a sediment cascade approach, we evaluated erosion, transport, and deposition from the rock face to the upper channelized erosive debris flow channel, then to the widened dispersive debris flow channel, and finally to the outlet into the braided sediment-supercharged Jochbach river. We observe the decadal flux of more than 400 000 m3 of sediment, characterized by massive sediment waves that (i) exhibit reaction times of 0–4 years in response to a cliff fall sediment input and relaxation times beyond 10 years. The sediment waves (ii) manifest with faster response times of 0–2 years in the upper catchment and over 2 years in the lower catchments. The entire catchment (iii) undergoes a rapid shift from sedimentary (102–103 mm a−1) to massive erosive regimes (102 mm a−1) within single years, and the massive sediment redistribution (iv) shows limited dependency on rainfall frequency and intensity. This study provides generic information on spatial and temporal patterns of massive sediment pulses in highly sediment-charged alpine catchments.

Analysis of abnormal operation of condenser water chamber evacuation system in nuclear power plants

During the operation of a nuclear power plant, there was no level indication in some of the condenser outlet water chamber, the level of the vacuum control tank upstream of the water chamber evacuation pump was rising frequently and unintentionally. To find out the causes of the above phenomena, a phenomenological analysis was first carried out. The cause analysis is then carried out in conjunction with the internal pressure of the condenser, the calculation of the air volume inside the condenser water chamber, and the flow pattern of the medium inside the water chamber evacuation pipeline. The final analysis concludes that a low junction point between the inlet water chamber's evacuation pipeline and the outlet can lead to the formation of an airlock at the top of the condenser's outlet water chamber. When there is a leak in the evacuation pipeline of the condenser's outlet water chamber, the increased air intake, in conjunction with gas-liquid two-phase flow, causes the liquid level in the vacuum control tank to rise unexpectedly and frequently. Thus, the factor of higher pressure at the inlet water chamber evacuation point and the influence of gas-liquid two-phase flow pattern should be taken into account when designing the evacuation pipeline.

Development of Efficient Brain Age Estimation Method Based on Regional Brain Volume From Structural Magnetic Resonance Imaging.

We aimed to create an efficient and valid predicting model which can estimate individuals' brain age by quantifying their regional brain volumes. A total of 2,560 structural brain magnetic resonance imaging (MRI) scans, along with demographic and clinical data, were obtained. Pretrained deep-learning models were employed to automatically segment the MRI data, which enabled fast calculation of regional brain volumes. Brain age gaps for each subject were estimated using volumetric values from predefined 12 regions of interest (ROIs): bilateral frontal, parietal, occipital, and temporal lobes, as well as bilateral hippocampus and lateral ventricles. A larger weight was given to the ROIs having a larger mean volumetric difference between the cognitively unimpaired (CU) and cognitively impaired group including mild cognitive impairment (MCI), and dementia groups. The brain age was predicted by adding or subtracting the brain age gap to the chronological age according to the presence or absence of the atrophy region. The study showed significant differences in brain age gaps among CU, MCI, and dementia groups. Furthermore, the brain age gaps exhibited significant correlations with education level and measures of cognitive function, including the clinical dementia rating sum-of-boxes and the Korean version of the Mini-Mental State Examination. The brain age that we developed enabled fast and efficient brain age calculations, and it also reflected individual's cognitive function and cognitive reserve. Thus, our study suggested that the brain age might be an important marker of brain health that can be used effectively in real clinical settings.

Influence of Early Versus Delayed Hepatic Artery Perfusion Scan on 90Y Selective Internal Radiation Therapy Planning.

Purpose: This study evaluated the effect of an increase in the time interval between hepatic intra-arterial injection of 99mTc-macroaggregated albumin (MAA) and hepatic artery perfusion scintigraphy (HAPS) on the lung shunt fraction (LSF) and perfused volume (PV) calculations in the treatment planning of selective internal radiation therapy (SIRT). Methods: The authors enrolled 51 HAPS sessions from 40 patients diagnosed with primary or metastatic liver malignancy. All patients underwent scan at the first and fourth hour after hepatic arterial injection of 99mTc-MAA. Based on single-photon emission computed tomography images, LSF values were measured from each patient's first and fourth hour images. PV1 and PV4 were also calculated based on three-dimensional images using 5% and 10% cutoff threshold values and compared with each other. Results: The authors found that the median of LSF4 was statistically significantly higher than LSF1 (3.05 vs. 4.14, p ≤ 0.01). There was no statistically significant difference between PV1 and PV4 on the 10% (p = 0.72) thresholds. Conclusions: LSF values can be overestimated in case of delayed HAPS, potentially leading to treatment cancellation due to incorrectly high results in patients who could benefit from SIRT. Threshold-based PV values do not significantly change over time; nevertheless, keeping the short interval time would be safer.

Hybrid Rocket Engine Burnback Simulations Using Implicit Geometry Descriptions

The performance of hybrid rocket engines is significantly influenced by the fuel geometry. Burnback simulations, to determine the fuel surface and fluid volume, are therefore an important tool for preliminary design. This work presents a method for the simulation of spatially constant burn-ups on arbitrary geometries. An implicit surface definition by means of a signed distance function is used to represent the fluid volume and the fuel block on tetrahedral meshes. Two methods each are used to determine the fluid volume and the burning surface. The first method is based on a direct integration of the signed distance function with the Heaviside function or the Dirac delta distribution, respectively. The second method linearly interpolates the position of an isosurface and thus reconstructs the fuel surface. Both methods are compared and validated with analytical results of four example geometries. Both calculations of the fluid volume and the calculation of the surface content with the interpolation method are characterized as first-order methods. With practicable mesh resolutions of one million computational cells, errors below two percent can be achieved. With the interpolation method, numerical meshes can also be exported for any time points of the burn. Finally, the application of the program to the fuel geometry of the Viserion hybrid rocket engine is demonstrated.

Clinical Impact of the Volumetric Quantification of Ventricular Secondary Mitral Regurgitation by Three-Dimensional Echocardiography

The assessment of ventricular secondary mitral regurgitation (v-SMR) severity through effective regurgitant orifice area (EROA) and regurgitant volume (RegVol) calculations using the proximal isovelocity surface area (PISA) method and the two-dimensional echocardiography volumetric method (2DEVM) is prone to underestimation. Accordingly, we sought to investigate the accuracy of the three-dimensional echocardiography volumetric method (3DEVM) and its association with outcomes in v-SMR patients. We included 229 patients (70±13years, 74% men) with v-SMR. We compared EROA and RegVol calculated by the 3DEVM, 2DEVM, and PISA methods. The end point was a composite of heart failure hospitalization and death for any cause. After a mean follow-up of 20±11months, 98 patients (43%) reached the end point. Regurgitant volume and EROA calculated by 3DEVM were larger than those calculated by 2DEVM and PISA. Using receiver operating characteristic curve analysis, both EROA (area under the curve, 0.75; 95% CI, 0.68-0.81; P=.008) and RegVol (AUC, 0.75; 95% CI, 0.68-0.82; P=.02) measured by 3DEVM showed the highest association with the outcome at 2years compared to PISA and 2DEVM (P<.05 for all). Kaplan-Meier analysis demonstrated a significantly higher rate of events in patients with EROA ≥ 0.3cm2 (cumulative survival at 2years: 28%±7% vs 32%±10% vs 30%±11%) and RegVol ≥ 45mL (cumulative survival at 2years: 21%±7% vs 24%±13% vs 22%±10%) by 3DEVM compared to those by PISA and 2DEVM, respectively. In Cox multivariable analysis, 3DEVM EROA remained independently associated with the end point (hazard ratio, 1.02, 95% CI, 1.00-1.05; P=.02). The model including EROA by 3DEVM provided significant incremental value to predict the combined end point compared to those using 2DEVM (net reclassification index=0.51, P=.003; integrated discrimination index=0.04, P=.014) and PISA (net reclassification index=0.80, P<.001; integrated discrimination index=0.06, P<.001). Effective regurgitant orifice area and RegVol calculated by 3DEVM were independently associated with the end point, improving the risk stratification of patients with v-SMR compared to the 2DEVM and PISA methods.

Switching Sudan’s Power Generation Units’ Fuel to Natural Gas Enhances the Efficiency, Durability and Lower the Cost

Sudan ranks among the top 20 Sub-Saharan countries facing electricity shortages, affecting approximately 20 million people as of 2020. Political and economic instability led to an increase in the electricity deficit, reaching over 62% in 2021, an 8% rise from 2019. Thermal power stations in Sudan, which contribute 37% of the electricity supply, encounter operational, maintenance, and fuel procurement challenges. They rely on various fuels, including liquefied petroleum gas (LPG), light diesel oil (LDO), and heavy fuel oil (HFO), with fuel procurement difficulties amid declining oil production. This study explores the potential of using natural gas instead of the conventional crude oil-based fuels listed above. Natural gas is known for its cost-effectiveness and lower greenhouse gas emissions, offering a cleaner alternative. The study involves the calculation of total gas volumes, flared gas, and operational costs for diesel and natural gas, with an evaluation of their compatibility with the operational requirements of thermal power generation units. The study reveals that upgrading existing thermal stations to a combined cycle system and transitioning to natural gas can reduce costs by 52% compared to diesel operations. The study also demonstrates that the annual gas requirement for operations is approximately 245 billion cubic feet, which is higher than the local production, indicating the need for importing liquified natural gas (LNG).

Approaching virtual osteoid volume estimation and in-depth tissue characterization in patients with tumor-induced osteomalacia.

Tumor-induced osteomalacia (TIO) poses a significant diagnostic challenge, leading to increased disease duration and patient burden also by missing clinical suspicion. Today, diagnosis of osteomalacia relies on invasive iliac crest biopsy, if needed. Therefore, a noninvasive method would be beneficial for patients with severe osteomalacia, such as TIO, to inform their clinical management and address specific needs, like estimating the regeneration capacity at high osteoid volumes (OVs) or the potential of a hungry bone syndrome after tumor removal. Furthermore, given the lack of comprehensive histological characterization of TIO, there is a need for additional tissue characterization. Therefore, our assessment encompassed iliac crest biopsies that were examined using quantitative electron backscattered microscopy, Raman spectroscopy, micro-computed tomography, and histology to analyze the biopsy tissue. Our clinical assessment encompassed DXA and high-resolution peripheral quantitative computed tomography (HR-pQCT) alongside with biochemical analyses and clinical evaluations. Combining imaging and clinical data, we established a model to predict the OV. We compared 9 TIO patients with 10 osteoporosis (OPO) patients and 10 healthy controls. Histological analyses confirmed a pronounced OV in TIO patients (OPO: 1.20% ± 1.23% vs TIO: 23.55% ± 12.23%, P < .0005), and spectroscopy revealed lower phosphate levels in TIO biopsies. By combining HR-pQCT and laboratory diagnostics, we developed a linear regression model to noninvasively predict the OV revealing significantly higher modeled OV/BVmodel values of 24.46% ± 14.22% for TIO compared to the control group (5.952% ± 3.44%, P ≤ .001). By combining laboratory diagnostics, namely, ALP and Tt.BMDRadius measured by HR-pQCT, we achieved the calculation of the virtual osteoid volume to bone volume ratio (OV/BVmodel) with a significant correlation to histology as well as reliable identification of TIO patients compared to OPO and control. This novel approach is potentially helpful for predicting OV by noninvasive techniques in diagnostic procedures and improving the clinical management of TIO.

Terrestrial laser scanning vs. manual methods for assessing complex forest stand structure: a comparative analysis on plenter forests

In continuous cover forestry, plenter silviculture is regarded as an elaborated system for optimizing the sustainable production of high-quality timber maintaining a constant but heterogeneous canopy. Its complexity necessitates high silvicultural expertise and a detailed assessment of forest stand structural variables. Terrestrial laser scanning (TLS) can offer reliable techniques for long-term tree mapping, volume calculation, and stand variables assessment in complex forest structures. We conducted surveys using both automated TLS and conventional manual methods (CMM) on two plots with contrasting silvicultural regimes within the Black Forest, Germany. Variations in automated tree detection and stand variables were greater between different TLS surveys than with CMM. TLS detected an average of 523 tree stems per hectare, while CMM counted 516. Approximately 9.6% of trees identified with TLS were commission errors, with 6.5% of CMM trees being omitted using TLS. Basal area per hectare was slightly higher in TLS (38.9 m3) than in CMM (38.2 m3). However, CMM recorded a greater standing volume (492.7 m3) than TLS (440.5 m3). The discrepancy in stand volume between methods was primarily due to TLS underestimating tree height, especially for taller trees. DBH bias was minor at 1 cm between methods. Repeated TLS inventories successfully matched an average of 424 tree positions per hectare. While TLS adequately characterizes complex plenter forest structures, we propose enhancing this methodology with personal laser scanning to optimize crown coverage and efficiency and direct volume measurements for increased accuracy of wood volume estimations. Additionally, utilizing 3D point cloud data-derived metrics, such as structural complexity indices, can further enhance plenter forest management.