Inhomogeneous Group Research Articles

Modeling and simulation of bubble condensation using polydisperse approach with bubble collapse model

An accurate modeling of the bubble condensation phenomena in sub-cooled water is developed in this work, using a two-fluid model with one disperse phase and one Interfacial Area Transport Equation (IATE). For this, the aspects of some models are investigated, such as the choice of population balance models, Nusselt closure model and bubble collapse model in IATE. The standard method of moments is formulated using two different bubble size distribution functions among all, namely Dirac and quadratic laws. Therefore, different models for mass and energy interfacial transfers, interfacial forces and source terms of the IATE are developed using both functions. While limited differences are noticeable for the mass and energy transfers obtained by both functions, the results are largely improved using quadratic function for the drag force term and for the IATE source terms. Moreover, the simulations results show that the widely used Ranz-Marshall correlation clearly underestimates the condensation rate. However, this work shows that Chen–Mayinger correlation is relevant to simulate this type of flow, regardless the distribution function. Afterwards, a model is introduced to take into account the effect of bubble collapse by condensation in the IATE. The numerical results obtained using the quadratic function, the collapse model in the IATE and the Chen–Mayinger correlation are comparable to those obtained by the inhomogeneous MUltiple Size Group (iMUSIG) approach, while being less time-consuming.

Factors Explaining the Willingness of Small-Scale Private Forest Owners to Engage in Forestry—A German Case Study

In Germany, 24% of the forest area is owned by small-scale private forest owners, whose property is affected by a societal demand for forest-related ecosystem services. In the inhomogeneous group of small-scale private forest owners, different living conditions and lifestyles exist, which are affecting the management of the forest ownership. To support the management activities of small-scale private forest owners, institutional instruments exist, but these are only used by a small proportion of forest owners. In order to gain insights into the accessibility and activation of small-scale private forest owners for management, and to draw conclusions for appropriate support instruments, a large number of studies have analyzed the factors influencing the management activities of forest owners. Some studies identify socio-demographic and socio-economic variables as important influencing factors, but do not take into account their complex interdependencies, which have developed as a result of the pluralization of lifestyles and individualization of forest owners. For this reason, in addition to the influencing factors identified in the literature as relevant for forest management activities of small-scale private forest owners, the lifestyle segmentation approach of Sinus milieus established in German market research was applied in this study. This approach allocates forest owners based on their complex lifestyles into ten different milieu groups. A logistic regression analysis was used to determine the parameters influencing the willingness to engage in eight different forest management activities. The results show that the willingness to engage in forest management activities in the future is higher compared to actions in the past. In addition to timber harvesting-related activities, the small-scale private forest owners show a high action potential for non-commodity-related activities. Non-commodity-related activities can primarily be explained by the Sinus milieu affiliation of the small-scale private forest owners. This result underlines the usefulness of a lifestyle segmentation approach such as the Sinus milieus to address small-scale private forest owners in a target group specific way in line with their willingness to engage in specific forest management activities. Institutional instruments such as the membership in a forest owners association or subsidies do not play a significant role for non-commodity-related activities and seem to be inappropriate for targeting small-scale private forest owners for these activities. Timber harvesting-related activities are primarily influenced by the presence of professional foresters, socio-demographic factors or institutional instruments. Based on these empirical findings, implications can be drawn for the target group-specific addressing of forest owners based on different management activities. In this way, forest owners can be motivated to engage in forest management and the provision of forest-related ecosystem services.

Chirurgie beim nichtkleinzelligen Lungenkarzinom im Stadium III N2 innerhalb multimodaler Konzepte

Stage IIIA non-small cell lung cancer comprises an inhomogeneous group of patients with both locoregional (N1) and ipsilateral mediastinal (N2) lymph node metastasis. Close collaboration between surgeons, thoracic oncologists, and radiotherapists allows selected patients to be offered multimodal treatment with curative intent despite N2 metastasis. Individual outcomes can be further improved by integration of novel multimodal treatment options into established therapeutic strategies. Targeted therapies and antibodies for checkpoint inhibition have already gained entry into standard adjuvant lung cancer treatment. Promising results of ongoing phase III trials investigating neoadjuvant chemoimmunotherapy highlight the necessity of reviewing the role of immunomodulatory drugs in the context of operable lung cancer. Approval of corresponding agents for perioperative systemic treatment of patients with nonmetastatic lung cancer is expected in the near future.

Numerical simulation of multi-size bubbly flow in a continuous casting mold using an inhomogeneous multiple size group model

Multi-size bubbly flow in a one-quarter-scale water model of a continuous casting mold was simulated using the inhomogeneous multiple size group (IMUSIG) model. The Sauter mean bubble diameter, gas volume fraction, interfacial area density, turbulence kinetic energy, and velocity field predicted by the IMUSIG and multiple size group (MUSIG) models were compared. The IMUSIG model separated the motions of the small and large bubbles on the basis of two velocity groups, and both models adopted 15 size groups. The results showed that the IMUSIG model better reflected the bubble size distribution near the nozzle. Small bubbles were further transported by the jet flow, which enlarged the bubble cluster range and decreased the gas volume fraction and interfacial area density in the upper part of the submerged entry nozzle, likely diminishing the coalescence rate in this region; consequently, the overestimation of Sauter mean bubble diameter outside the nozzle was corrected. The liquid-phase flow fields predicted by the IMUSIG and MUSIG models were very similar, and the IMUSIG-predicted magnitudes of velocity and turbulence kinetic energy were only slightly lower than the MUSIG predictions; this slight difference is attributable to the expanded bubble cluster range and higher interfacial area density, which weakened the upper recirculation in the IMUSIG model.

Establishing the mining deposit groups and the gold exploration network patterns in the Attapeu area, Lao PDR

This paper initially clarified the context of primary gold mineralization in the Attapeu area, Lao People's Democratic Republic. It proposed the priority for the exploration, using the conventional technique combined with the geological mathematic method. The research essentially summarized that the study area had a complex geological and structural setting; the mineralization zones or gold orebodies most likely formed as a lens shape and/or mineralized single vein or vein zone, extending from a few tens of meters to greater than 500 meters long, within a single dipping angle of 450÷800; the geometric of orebodies likely illustrated as small to medium size. The mineralization zone significantly extended following the geological setting, indicating consistent to the strongly inconsistent group (Vm = 8.9÷116.8%). Medium- to high-grade gold ores are commonly found in each ore body and identified as a homogeneous to strongly inhomogeneous group (Vc = 58.3÷785%). Regarding the exploration criteria, exploring primary gold mineralization in the Attapeu area fits well with the mineral exploration group III. To estimate the ore reserve in category 112 significantly requires conducting the parallel exploration grid or rectangular grid with the exploration grid interval of 40÷60 meters within the space of the exploration grid line between 20 to 30 meters. The exploration guidelines proposed in this research are efficiently applicable for exploring other primary gold mineralization elsewhere with the geological settings and mineralogical characteristics identically to the primary gold mineralization in the Attapeu area.

Experiments and fully transient coupled CFD-PBM 3D flow simulations of disperse liquid-liquid flow in a baffled stirred tank

Liquid-liquid disperse multiphase flow in a baffled tank stirred by a Rushton turbine is investigated by experiments and 3D simulations for different impeller speeds and volume fractions. Droplet size distributions are experimentally measured with an inline shadowgraphic probe and compared with fully transient coupled CFD-PBM simulations using the Eulerian multi-fluid framework, the inhomogeneous Multiple Size Group approach and a statistical turbulence model. The simulation model is assessed by a variation of size class and velocity group numbers, grid resolution and simulation domain extent. The model parameters for the breakup and coalescence kernels are fitted to match the measured droplet size distribution at a selected operation point. A subsequent application to different operation points shows that experimental droplet size trends are captured, albeit aside from the fitting point, deviations to data increase. The resulting droplet size distribution is analyzed by an assessment of the turbulent mixing, breakup and coalescence time scales.

The new SRS/FSRT technique HyperArc for benign brain lesions: a dosimetric analysis

To evaluate the potential benefit of HyperArc (HA) fractionated stereotactic radiotherapy (FSRT) for the benign brain lesion. Sixteen patients with a single deep-seated, centrally located benign brain lesion treated by CyberKnife (CK, G4 cone-based model) were enrolled. Treatment plans for HA with two different optimization algorithms (SRS NTO and ALDO) and coplanar RapidArc (RA) were generated for each patient to meet the corresponding treatment plan criteria. These four FSRT treatment plans were divided into two groups—the homogeneous delivery group (HA-SRS NTO and coplanar RA) and the inhomogeneous delivery group (HA-ALDO and cone-based CK)—to compare for dosimetric outcomes. For homogeneous delivery, the brain V5, V12, and V24 and the mean brainstem dose were significantly lower with the HA-SRS NTO plans than with the coplanar RA plans. The conformity index, high and intermediate dose spillage, and gradient radius were significantly better with the HA-SRS NTO plans than with the coplanar RA plans. For inhomogeneous delivery, the HA-ALDO exhibited superior PTV coverage levels to the cone-based CK plans. Almost all the doses delivered to organs at risk and dose distribution metrics were significantly better with the HA-ALDO plans than with the cone-based CK plans. Good dosimetric distribution makes HA an attractive FSRT technique for the treatment of benign brain lesions.

Discrete phase space and continuous time relativistic quantum mechanics I: Planck oscillators and closed string-like circular orbits

The discrete phase space continuous time representation of relativistic quantum mechanics involving a characteristic length [Formula: see text] is investigated. Fundamental physical constants such as [Formula: see text], [Formula: see text], and [Formula: see text] are retained for most sections of the paper. The energy eigenvalue problem for the Planck oscillator is solved exactly in this framework. Discrete concircular orbits of constant energy are shown to be circles [Formula: see text] of radii [Formula: see text] within the discrete [Formula: see text]-dimensional phase plane. Moreover, the time evolution of these orbits sweep out world-sheet like geometrical entities [Formula: see text] and therefore appear as closed string-like geometrical configurations. The physical interpretation for these discrete orbits in phase space as degenerate, string-like phase cells is shown in a mathematically rigorous way. The existence of these closed concircular orbits in the arena of discrete phase space quantum mechanics, known for the non-singular nature of lower order expansion [Formula: see text] matrix terms, was known to exist but has not been fully explored until now. Finally, the discrete partial difference-differential Klein–Gordon equation is shown to be invariant under the continuous inhomogeneous orthogonal group [Formula: see text].

Influence of keratolytics on cutaneous pharmacokinetics of glucocorticoids.

Keratolytics are often used to accelerate and improve the therapeutic response of hyperkeratotic dermatoses. Keratolytics are a chemically inhomogeneous group of substances and substance mixtures that clinically lead to a decrease in symptoms of a cornification disorder, but mediate different effects. Thus, keratolytic, keratoplastic, keratoemulsifying and keratodiluting effects are distinguished. The physicochemical effects or pharmacological efficacy of the respective keratolytics result in different mechanism as well as risks with regard to local or systemic compatibility. Until now, only little attention has been paid upon selection of keratolytics to the immediate consequences regarding diffusion conditions and pharmacokinetics of sequentially applied topicals, in particular of glucocorticoids. This paper deals with the influence of keratolytics on the penetration-time profile of betamethasone dipropionate in sequential application. For this purpose, cutaneous bioavailability was investigated with the Franz chamber test using a tritium-labeled drug depending on the previous application of a keratolytic agent. Comparative data analyses were performed. It was shown that keratoplastic substances significantly promote diffusion of the glucocorticoid. Keratoemulsifying substance mixtures exert no relevant effects in this regard, while keratodiluting substance mixtures inhibit penetration. The targeted selection of a keratolytic can optimize the therapeutic effect and influence the bioavailability of sequentially applied topicals.

Numerical simulation of gravity-driven mono- and polydisperse bubbly flows in a three-dimensional column in the framework of the Euler-Euler approach

The paper presents a comparison of the results of numerical modeling of the three-dimensional flow of mono- and polydisperse media in a rectangular bubble column reactor. The mathematical model used in the paper is based on the Euler – Euler description of a multiphase medium taking into account interphase momentum transfer, turbulence modeling of the carrier phase with bubble induced turbulence and polydispersity in the framework of the inhomogeneous multiple-size group (MUSIG) model. The comparison is carried out of the mono- and polydisperse approaches under the conditions studied for simplified and full formulations. Numerical results are compared with the available experimental data and simulations of other authors.

Reconfiguration of human evolving large-scale epileptic brain networks prior to seizures: an evaluation with node centralities

Previous research has indicated that temporal changes of centrality of specific nodes in human evolving large-scale epileptic brain networks carry information predictive of impending seizures. Centrality is a fundamental network-theoretical concept that allows one to assess the role a node plays in a network. This concept allows for various interpretations, which is reflected in a number of centrality indices. Here we aim to achieve a more general understanding of local and global network reconfigurations during the pre-seizure period as indicated by changes of different node centrality indices. To this end, we investigate—in a time-resolved manner—evolving large-scale epileptic brain networks that we derived from multi-day, multi-electrode intracranial electroencephalograpic recordings from a large but inhomogeneous group of subjects with pharmacoresistant epilepsies with different anatomical origins. We estimate multiple centrality indices to assess the various roles the nodes play while the networks transit from the seizure-free to the pre-seizure period. Our findings allow us to formulate several major scenarios for the reconfiguration of an evolving epileptic brain network prior to seizures, which indicate that there is likely not a single network mechanism underlying seizure generation. Rather, local and global aspects of the pre-seizure network reconfiguration affect virtually all network constituents, from the various brain regions to the functional connections between them.

Modular symmetry origin of texture zeros and quark-lepton unification

The even weight modular forms of level $N$ can be arranged into the common irreducible representations of the inhomogeneous finite modular group $\Gamma_N$ and the homogeneous finite modular group $\Gamma'_N$ which is the double covering of $\Gamma_N$, and the odd weight modular forms of level $N$ transform in the new representations of $\Gamma'_N$. We find that the above structure of modular forms can naturally generate texture zeros of the fermion mass matrices if we properly assign the representations and weights of the matter fields under the modular group. We perform a comprehensive analysis for the $\Gamma'_3\cong T'$ modular symmetry. The three generations of left-handed quarks are assumed to transform as a doublet and a singlet of $T'$, we find six possible texture zeros structures of quark mass matrix up to row and column permutations. We present five benchmark quark models which can produce very good fit to the experimental data. These quark models are further extended to include lepton sector, the resulting models can give a unified description of both quark and lepton masses and flavor mixing simultaneously although they contain less number of free parameters than the observables.

Perturbative BF theory

We consider a superrenormalisable gauge theory of topological type, in which the structure group is equal to the inhomogeneous group ISU(2). The generating functional of the correlation functions of the gauge fields is derived and its connection with the generating functional of the Chern-Simons theory is discussed. The complete renormalisation of this model defined in R3 is presented. The structure of the ISU(2) conjugacy classes is determined. Gauge invariant observables are defined by means of appropriately normalised traces of ISU(2) holonomies associated with oriented, framed and coloured knots. The perturbative evaluation of the Wilson lines expectation values is investigated and the up-to-third-order contributions to the perturbative expansion of the observables, which correspond to knot invariants, are produced. The general dependence of the knot observables on the framing is worked out.

Polydisperse bubble flows: a study of the bubble cloud evolution by CFD methods

The evolution of a polydisperse bubble cloud is analyzed by means of computational fluid dynamics. Gravity-driven bubble flows in a column with a circular cross-section as well as a downward flow in a long vertical pipe are numerically investigated. A method employed in the simulations is based on the Euler-Euler description of the multiphase medium. An inhomogeneous multiple-size group (MUSIG) model is used to describe the bubble size distribution. The formulated approach provides detailed description of the bubble flow structure including variation of the bubble size distribution.

Heart failure with preserved left ventricular ejection fraction

Heart failure remains the number one diagnosis among patients receiving inpatient treatment in Germany. Heart failure with preserved ejection fraction (HFpEF) needs to be verified by signs and symptoms of HF, echocardiographic parameters as well as cardiac biomarkers. Based on etiological and pathophysiological considerations, aclassification into systolic and diastolic heart failure and later heart failure with reduced ejection fraction (HFrEF) and HFpEF was proposed. The inhomogeneous group of patients with HFpEF accounts for half of all heart failure cases in the population. Effective treatment options are limited. This article discusses which verified treatments may help or may even be harmful. Aglimpse is taken into the future and those substances that are in advanced stages of clinical trials are described.

Phase space regions operators and ISp(2) maps

Region operators (generalized observable) (RO), defined as operator valued probability measures over classical phase space ensuing from quantization of phase space characteristic functions are investigated. The problem of constructing of RO is treated by means of positive trace increasing maps (pti maps). Exemplary domains of RO include: sets of points, line segments and rotated line segments, circles and disks, straight and rotated lines, canonical polygons, squeezed line segments, and lines related to Radon transform in phase space. Phase plane RO constructing pti maps, in their operator sum representation, are generated by elements of the quantum symplectic in-homogeneous group ISp(2). The group ISp(2) and its double cover metaplectic group Mp(2) are the kinematical groups for RO construction on the plane.

Suspect screening of glycoalkaloids in plant extracts using neutral loss – High resolution mass spectrometry

Alkaloids represent a very large and chemically inhomogeneous group of nitrogen compounds isolated from different natural sources. They have long been studied due to their specific toxicological characteristics, as some of them are suspected of having very dangerous properties, but there has still been little investigation of the existence of possible glycoside precursors in plant products. An analytical method based on a suspect screening approach using liquid chromatography coupled with high resolution tandem mass spectrometry in neutral loss (NL) mode was used for the tentative identification of alkaloid precursors. This NL approach applied to 15 plant extracts made it possible to tentatively identify 41 glycosidic precursors (4 monopentosides, 3 monodeoxyhexosides, 24 monohexosides, 1 pentoside-hexoside and 9 dihexosides) in 6 of them, belonging to the piperidine (21), pyrrolizidine (9), isoquinoline (7), indole (3) and tropane (1) alkaloid groups. This work confirms the promising investigative ability of a suspect screening approach in this complex field of study.

Granulocyte transfusions collected after steroid priming for severe infections during neutropenia: A single center experience.

There is no universally accepted opinion on the use of granulocyte transfusions collected using apheresis (GTA) in neutropenic patients and severe infection. The efficacy and safety of GTAs transfused at a single center over 10 years were analyzed retrospectively. GTAs were harvested from voluntary unrelated donors after priming with methylprednisolone using continuous apheresis and hydroxyethylstarch as sedimentation agent. 41 patients with neutropenia and hematologic malignancy (15 females and 26 males aged 22-69 (median 45.5)) were given a median 3.5 GTAs per patient (range: 1-17) containing a median 1.39×1010 granulocyte/GTA (range: 0.65-2.81). The indications for GTA use were soft tissue inflammation, sepsis, and pneumonia in 30, 22, and 14 cases, respectively. After GTA complete(30 patients: 73.2%) or partial (6 patients: 14.6%) healing of the infection was achieved. The success rate was 91.7% in soft tissue infections, 66.7% in invasive fungal infections, and 68% in sepsis. Septic shock (documented in 12 cases) was associated with a poor response (P<0.03; Chi-square test). Clinical worsening was observed in six cases (14.6%); four patients died. No significant short-term side effects of GTA treatment were recorded. In our study GTAs collected after steroid priming and used for the treatment of infection during severe neutropenia have shown comparable efficacy with several previously reported trials. However retrospective fashion of our study and inhomogeneous group of patients do not allow any firm conclusions. Prospective studies (including patients' registries) are needed for the better clarification of the role and the dose of GTAs necessary for the successful infection management during neutropenia.

Abdominal pain and fever in a patient with familial periodic fever: an extremely rare mutation of the TNF receptor superfamily member 1A gene

Periodic fever syndromes (PFSs) are a clinically inhomogeneous group of diseases based on peculiar genetic mutations. PFSs have to be suspected in young patients presenting with recurrent attacks of abdominal pain, skin rashes, arthritis, myalgia and fever as soon as more prevalent diseases have been excluded. An unconsidered hypothesis of PFSs may lead in delaying the diagnosis and unnecessary medical and surgical treatments. In this article, we described the case of a young man presented to our attention due to recurrent abdominal pain and fever caused by TNF-receptor-associated periodic syndrome (TRAPS) sustained by the TNFRSF1A gene mutation.

Tectal gliomas: assessment of malignant progression, clinical management, and quality of life in a supposedly benign neoplasm.

OBJECTIVE Tectal gliomas constitute a rare and inhomogeneous group of lesions with an uncertain clinical course. Because these supposedly benign tumors are frequently followed up by observation over many years, the authors undertook this analysis of their own case series in an effort to demonstrate that the clinical course is highly variable and that there is a potential for a progressive biology. METHODS Clinical data analysis of 23 cases of tectal glioma (involving 9 children and 14 adults) was performed retrospectively. Radiographic data were analyzed longitudinally and MR images were evaluated for tumor volume, contrast enhancement, and growth progression. Quality of life was assessed using the EORTC BN20 and C30 questionnaires during follow-up in a subgroup of patients. RESULTS The patients' mean age at diagnosis was 29.2 years. The main presenting symptom at diagnosis was hydrocephalus (80%). Six patients were treated by primary tumor resection (26.1%), 3 patients underwent biopsy followed by resection (13.1%), and 3 patients underwent biopsy only (13.1%). For additional treatment of hydrocephalus, 14 patients (60.9%) received shunts and/or endoscopic third ventriculostomy. Radiographic tumor progression was observed in 47.9% of the 23 cases. The mean time between diagnosis and growth progression was 51.5 months, and the mean time to contrast enhancement was 69.7 months. Histopathological analysis was obtained in 12 cases (52.2%), resulting in 5 cases of high-grade glioma (3 cases of glioblastoma multiforme [GBM], grade IV, and 2 of anaplastic astrocytoma, grade III), 5 cases of pilocytic astrocytoma, 1 diffuse astrocytoma, and 1 ganglioglioma. Malignant progression was observed in 2 cases, with 1 case progressing from a diffuse astrocytoma (grade II) to a GBM (grade IV) within a period of 13 years. Quality-of-life measurements demonstrated distinct functional deficits compared to a healthy sample as well as glioma control cohorts. CONCLUSIONS Analysis of this case series shows that a major subpopulation of tectal gliomas show progression and malignant transformation in children as well as in adolescents. These tumors therefore cannot be considered inert lesions and require histological confirmation and close follow-up. Quality-of-life questionnaires show that tectal glioma patients might benefit from special psychological support in emotional, social, and cognitive functionality.