Optimization of Aggregate Production Circuit through Modeling of Crusher Operation

The paper concerns investigation of the effect of impact crusher operation on selected qualitative characteristics of mineral aggregate products. Qualitative characteristics of crushing products in terms of size reduction ratio and fine particles contents were analyzed from the point of view of operational parameters of the impact crusher. An investigative program was carried out on a plant scale and two primary parameters of the impactor were analyzed: velocity of the crusher rotor and the width of the outlet gap. The models of the crushing device operation were built separately for each type of the tested material, as well as for general conditions.

Improved-Efficacy EM-Based Antenna Miniaturization by Multi-Fidelity Simulations and Objective Function Adaptation

The growing demand for the integration of surface mount design (SMD) antennas into miniaturized electronic devices has imposed increasing limitations on the structure dimensions. Examples include embedded antennas in applications such as on-board devices, picosatellites, 5G communications, or implantable and wearable devices. The demands for size reduction while ensuring a satisfactory level of electrical and field performance can be managed through constrained numerical optimization. The reliability of optimization-based size reduction requires utilization of full-wave electromagnetic (EM) analysis, which entails significant computational costs. This can be alleviated by incorporating surrogate modeling techniques, adjoint sensitivities, or the employment of sparse sensitivity updates. An alternative is the incorporation of multi-fidelity simulation models, normally limited to two levels, low and high resolution. This paper proposes a novel algorithm for accelerated antenna miniaturization, featuring a continuous adjustment of the simulation model fidelity in the course of the optimization process. The model resolution is determined by factors related to violation of the design constraints as well as the convergence status of the algorithm. The algorithm utilizes the lowest-fidelity model for the early stages of the optimization process; it is gradually refined towards the highest-fidelity model upon approaching convergence, and the constraint violations improve towards the preset tolerance threshold. At the same time, a penalty function approach with adaptively adjusted coefficients is applied to enable the precise control of constraints, and to increase the achievable miniaturization rates. The presented procedure has been validated using five microstrip antennas, including three broadband, and two circularly polarized structures. The obtained results corroborate the relevance of the implemented mechanisms from the point of view of improving the average computational efficiency of the optimization process by 43% as compared to the single-fidelity adaptive penalty function approach. Furthermore, the presented methodology demonstrates a performance that is equivalent or even superior to its single-fidelity counterpart in terms of an average constraint violation of 0.01 dB (compared to 0.03 dB for the reference), and an average size reduction of 25% as compared to 25.6%.

Comprehensive Statistical Exploration of Prognostic (Bio-)Markers for Responses to Immune Checkpoint Inhibitor in Patients with Non-Small Cell Lung Cancer

Metastatic non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors (ICIs) may suffer from heavy side effects and not all patients benefit from the treatment. We conducted a comprehensive statistical analysis to identify promising (bio-)markers for treatment response. We analyzed retrospective data from NSCLC patients treated with ICIs in first- or further-line therapy settings at the University Hospital Zurich. We investigated 16 possible prognostic markers with respect to overall survival, tumor size reduction, and the development of an immune-related adverse event (irAE) and assessed the robustness of our results. For the further-line patient group, the most significant result was that increased basophil counts were associated with increased odds of tumor size reduction within three months and with the development of an irAE. For the first-line patient group, the most significant results were that increased lymphocyte counts, the histology of adenocarcinoma, and the intake of non-steroidal anti-rheumatic drugs (NSAR) were associated with decreased hazards of dying. Our study yielded new hypotheses for predictive (bio-)markers for response to ICIs in NSCLC patients. The possibly beneficial role of high basophil counts is a particularly interesting finding. Our results should be tested on independent data in a prospective fashion.

Study of Extraction of Rare Earth Elements from Hard Coal Fly Ash

Rare earth elements (REEs) extraction from wastes and/or by-products is alternative possibility of their winning. The occurrence ofREEs, namely 50.1 ppm of La, 100.1 ppm of Ce and 44.3 ppm of Nd was confirmed in solid fly ash samples from the coal fired heatingplant (TEKO, Inc. Košice, eastern Slovakia). The submitted contribution presents laboratory results of REEs leaching from coal fly ashusing 3M HCl, HNO3, H2SO4 and H3PO4 at 80°C during 120 min.It was found, that recoveries 65.5% of La, 64.4% Ce and 64.3% of Nd into liquor may be attained after grain size reduction to below5 μm.

Workload, Work Engagement and Job Size – How Physicians’ Decision to Work Less Is Influenced by the Work-Related State of Mind.

Background: According to new estimates, the health care sector will suffer a shortage of physicians in primary and specialty care. In this context, work engagement and burnout are two constructs that have gained attention recently. The aim of this study was to investigate how these constructs are related to job size preference.Method: The present study is based on the baseline survey of the long-term study of physicians with different specialties, in which 1,001 physicians took part (response rate: 33.4%). Workload was measured using the Copenhagen Burnout Inventory adapted for health care professionals; work engagement was assessed using the Utrecht Work Engagement scale. Data analyses includes regression and mediation models.Results: Overall, 297 out of 725 physicians plan to reduce their job size. Several reasons - such as workload - are discussed. Multiple regression analyses show that job size reduction is significantly linked to all three dimensions of workload (p<0.001) as well as work engagement (p=0.001). In addition, work engagement significantly mediates the relationship between workload on job size reduction (patient-related: b= −0.135, p<0.001; work-related: b= −0.190, p<0.001; personal: b= −0.133, p<0.001 ).Discussion: Physicians that tend to reduce working hours exhibit different levels of work engagement as well as workload (personal, patient- and work-related). Moreover, work engagement is acting as a mediator, influencing the relationship between workload and job size reduction. Therefore, interventions that increase work engagement may buffer negative effects of workload on job size changes.

Preparation and Characterization of Fenofibrate Microparticles with Surface-Active Additives: Application of a Supercritical Fluid-Assisted Spray-Drying Process

In this study, supercritical fluid-assisted spray-drying (SA-SD) was applied to achieve the micronization of fenofibrate particles possessing surface-active additives, such as d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), sucrose mono palmitate (Sucroester 15), and polyoxyethylene 52 stearate (Myrj 52), to improve the pharmacokinetic and pharmacodynamic properties of fenofibrate. For comparison, the same formulation was prepared using a spray-drying (SD) process, and then both methods were compared. The SA-SD process resulted in a significantly smaller mean particle size (approximately 2 μm) compared to that of unprocessed fenofibrate (approximately 20 μm) and SD-processed particles (approximately 40 μm). There was no significant difference in the effect on the particle size reduction among the selected surface-active additives. The microcomposite particles prepared with surface-active additives using SA-SD exhibited remarkable enhancement in their dissolution rate due to the synergistic effect of comparably moderate wettability improvement and significant particle size reduction. In contrast, the SD samples with the surface-active additives exhibited a decrease in dissolution rate compared to that of the unprocessed fenofibrate due to the absence of particle size reduction, although wettability was greatly improved. The results of zeta potential and XPS analyses indicated that the surface-active additive coverage on the surface layer of the SD-processed particles with a better wettability was higher than that of the SA-SD-processed composite particles. Additionally, after rapid depletion of hydrophilic additives that were excessively distributed on the surfaces of SD-processed particles, the creation of a surface layer rich in poorly water-soluble fenofibrate resulted in a decrease in the dissolution rate. In contrast, the surface-active molecules were dispersed homogeneously throughout the particle matrix in the SA-SD-processed microparticles. Furthermore, improved pharmacokinetic and pharmacodynamic characteristics were observed for the SA-SD-processed fenofibrate microparticles compared to those for the SD-processed fenofibrate particles. Therefore, the SA-SD process incorporating surface-active additives can efficiently micronize poorly water-soluble drugs and optimize their physicochemical and biopharmaceutical characteristics.