Search Results (7,256)

Scaling is one of the common problems in circulating cooling water systems, which can significantly affect the cooling efficiency of equipment in severe cases. At present, the problem of scaling is usually controlled by adding water treatment agents. However, taking the external cooling system of the synchronous condenser in an ultra-high-voltage converter station as an example, due to the lack of scientific understanding of scale inhibitors, there is often a problem of excessive dosing, resulting in unsatisfactory scale inhibition effects and difficulties in wastewater treatment and discharge. In addition, the extensive use of phosphorus-containing agents has led to the enrichment of phosphorus elements in water bodies. Therefore, the optimal amount of AS-582 scale inhibitor used in the converter station with the best scale inhibition effect was determined through static calcium carbonate deposition experiments, with the scale inhibition rate of 91.4% at 90 mg/L. And the scale inhibition mechanism was explored, where the lattice distortion mechanism and threshold effect play important roles. The AS-582 scale inhibitor was mixed with two green scale inhibitors, PASP and PESA, to obtain a phosphorus reduction formula that combined excellent scale inhibition performance and low phosphorus content. When using the optimal composite scale inhibitor of n(AS-582):n(PASP):n(PESA) = 4:1:1, the scale inhibition rate is 91.8% and the phosphorus content is reduced by one-third. The effectiveness of the formula was tested using dynamic circulating water experimental equipment under practical application conditions, proving its practical value. Full article

The grand challenge of sustainable development, increased demands for resilient critical infrastructure systems, and cost efficiency calls for thinking and acting “out of the box”. We must strive to search for, identify, and utilize new and emerging technologies and new combinations of existing technologies that have the potential to improve present best practices. In integrity management of, e.g., bridge, offshore, and marine structures, relatively new technologies have shown substantial potentials for improvements that not least concern structural health monitoring (SHM), digital twin (DT)-based structural and mechanical modeling, and risk-based inspection (RBI) and maintenance planning (RBI). The motivation for the present paper is to investigate and document to what extent such technologies in isolation or jointly might have the potential to improve best practices for integrity management of offshore wind turbine structures. In this pursuit, the present paper conducts a comprehensive bibliometric analysis to explore the current landscape of advanced technologies within the offshore wind turbine industry suitable for integrity management. It examines the integration of these technologies into future best practices, taking into account normative factors like risk, resilience, and sustainability. Through this analysis, the study sheds light on current research trends and the degree to which normative considerations influence the application of RBI, SHM, and DT, either individually or in combination. This paper outlines the methodology used in the bibliometric study, including database selection and search term criteria. The results are presented through graphical representations and summarized key findings, offering valuable insights to inform and enhance industry practices. These key findings are condensed into a road map for future research and development, aimed at improving current best practices by defining a series of projects to be undertaken. Full article

Chagas disease, caused by the protozoan Trypanosoma cruzi, affects millions globally, with limited treatment options available. Current therapies, such as benznidazole and nifurtimox, present challenges, including their toxicity, side effects, and inefficacy in the chronic phase. This study explores the potential of drug repurposing as a strategy to identify new treatments for T. cruzi, focusing on compounds from the Medicines for Malaria Venture (MMV) COVID Box. An initial screening of 160 compounds identified eight with trypanocidal activity, with almitrine and bortezomib showing the highest efficacy. Both compounds demonstrated significant activity against the epimastigote and amastigote stages of the parasite and showed no cytotoxicity in murine macrophage cells. Key features of programmed cell death (PCD), such as chromatin condensation, mitochondrial membrane potential disruption, and reactive oxygen species accumulation, were observed in T. cruzi treated with these compounds. The potential to induce controlled cell death of these two compounds in T. cruzi suggests they are promising candidates for further research. This study reinforces drug repurposing as a viable approach to discovering novel treatments for neglected tropical diseases like Chagas disease. Full article

The Replicon Theory has guided the way experiments into DNA replication have been designed and interpreted for 60 years. As part of the related, explanatory package guiding experiments, it is thought that the timing of the cell cycle depends in some way on a critical mass for initiation, Mi, as licensed by a variety of macromolecules and molecules reflecting the state of the cell. To help in the re-interpretation of this data, we focus mainly on the roles of DnaA, RNA polymerase, SeqA, and ribonucleotide reductase in the context of the “nucleotypic effect”. Full article

In order to expand the group of chiral thiourea structures, several optically active thioureas derived from the (S)-1-(2-pyridyl)ethylamine enantiomer were prepared via its reaction with achiral or optically active isothiocyanates. To show their synthetic potential as chiral auxiliaries the isolated thioureas were tested as an optically active organocatalyst in the asymmetric version of the selected aldol condensation and addition of diethylzinc to benzaldehyde. The observation of asymmetric induction in these model reactions encourages further research on the use of this group of thioureas in asymmetric versions of multicomponent reactions and cycloadditions. The mechanistic aspects of the reactions under study are also briefly discussed. Full article

The realization of natural resource value serves as a critical entry point for advancing rural revitalization within the framework of ecological civilization construction, representing an essential approach to balancing ecological conservation and economic development in national parks. Based on clarifying the logical relationship and the driving mechanisms between the realization of natural resource value and rural revitalization, this paper employs field observation and in-depth interviews using Baishanzu National Park as a case study to analyze how general control zones in national parks can promote rural revitalization under ecological constraints through the realization of natural resource value. The results indicate the following: (1) By constructing a framework of “realistic background—pathway selection—model condensation—effectiveness analysis”, the mechanism of how natural resource value realization promotes rural revitalization can be analyzed, with a focus on its pathways and models. (2) The pathways for realizing natural resource value to promote rural revitalization include resource integration, investment development, capital production and operation, and the circulation and exchange of ecological products and services. These pathways contribute to various dimensions of rural revitalization at different stages: assetization, capitalization, productization, and monetization. (3) Within different functional zones of the general control area in national parks, including ecological restoration zones, traditional utilization zones, and recreation and exhibition zones, the value of natural resources can promote rural revitalization through three realization modes: preservation, transformation, and value-added enhancement, reflecting diverse approaches and differentiated outcomes of value realization. To comprehensively promote rural revitalization in national parks through the realization of natural resource value, it is first necessary to fully identify regional resource endowments, conservation objectives, and developmental constraints. Second, regional resources should be integrated to pursue synergistic innovation. Finally, attention must be paid to achieving comprehensive benefits for sustainable development. The research findings provide valuable references for the high-quality development of national parks and rural revitalization. Full article

The effective lifetime of ultra-cold atoms in specific quantum states plays a crucial role in studying interaction parameters within quantum systems. Measuring the effective lifetime of various quantum states within ultra-cold atoms is a fundamental task in quantum operations. In this paper, the effective lifetimes of the excited electronic states F=2,mF=−2, F=2,mF=−1, and F=2,mF=0 for a sodium atomic Bose–Einstein condensate (BEC) are investigated in both the optical dipole trap (ODT) and one-dimensional optical lattice. Through the analysis of experimental data, we demonstrate the significant advantage of lattice loading over the optical dipole trap in terms of atomic lifetimes. The results provide crucial insights into the temporal scales relevant for investigating the evolution of boson gases in optical lattices, facilitating the realization of quantum simulations pertaining to unique quantum phases, and providing an important experimental basis for the research of non-equilibrium dynamics between different spin states. Full article

The selective inhibition of key enzymes, such as carbonic anhydrases (CAs IX and XII), which are overexpressed in cancer tissues, has emerged as a promising strategy in cancer research. However, a multitarget approach is often preferred to achieve enhanced therapeutic outcomes. In this study, aryl sulfonamides were conjugated with a thiosemicarbazone moiety to enable dual functionality: the inhibition of CAs and the chelation of metal cations. Several structural factors were systematically modified, including the position of the sulfonamido group, the length of the linker, the nature of the aromatic residue, and the type of substituents. Tumor-associated CAs IX and XII inhibition was evaluated using the stopped-flow CO₂ hydrase assay, and the inhibition constants (K_i) were determined. The most promising compounds were further analyzed through molecular docking simulations. Metal chelation capabilities were evaluated using UV–Vis spectroscopy, while antiproliferative activities were measured using the sulforhodamine B (SBR) assay. Additionally, holotomographic 3D microscopy was employed to investigate the mechanisms of cell death. Sulfonamido-derived Schiff bases were synthesized through a three-step procedure that did not require column chromatography purification: (1) isothiocyanation of amino-sulfonamides, (2) nucleophilic addition of hydrazine, and (3) acid-promoted condensation with different aldehydes (benzaldehydes or pyridine-2-carboxaldehyde). The synthesized compounds exhibited inhibition of CAs in the low nanomolar to submicromolar range, with selectivity largely influenced by structural features. Notably, the m-sulfonamide derivative 5b, bearing a pyridin-2-yl residue, demonstrated potent and selective inhibition of CA IX (K_i = 4.9 nM) and XII (K_i = 5.6 nM). Additionally, it efficiently chelated Fe²⁺, Fe³⁺, and Cu²⁺ and showed promising antiproliferative activity (GI₅₀ 4.5–10 µM). Mechanistic studies revealed that apoptosis was involved in its mode of action. Therefore, the synergistic integration of sulfonamides and thiosemicarbazones represents an effective strategy for the development of multimodal anticancer agents. Full article

The total synthesis of biologically and pharmacologically important phenolic isoprenoids, grifolin and neogrifolin, was developed through simple allylation and cyclization procedures using only ethyl acetoacetate, ethyl crotonate, and farnesyl bromide as substrates. The regioisomeric terpenophenols, which consist solely of orcinol and farnesyl moieties, cannot be synthesized purely by direct coupling between the units. The regioselectivity issue was solved by controlling the timing of the allylation of β-ketoester with farnesyl bromide and the cyclization with ethyl crotonate. 2-Farnesyl-5-methyl-cyclohexane-1,3-dione and 6-farnesyl-5-methyl-cyclohexane-1,3-dione were prepared in a highly regioselective manner from ethyl acetoacetate in overall yields of 43% and 40%, respectively. The oxidative aromatization of the regioisomeric cyclohexane-1,3-diones produced grifolin and neogrifolin, respectively. Full article

Triple negative breast cancer, TNBC, is a difficult disease to treat due to relapse and resistance to known therapies. Epidermal growth factor receptor (EGFR), a tyrosine kinase responsible for downstream signaling leading to cell growth and survival, is typically overexpressed in TNBC. Our previous work has detailed the synthesis of triazole-estradiol derivatives as inhibitors of EGFR and downstream receptors, and this work continues that discussion by evaluating them in EGFR-dependent TNBC cell models MDA-MB-231 and MDA-MB-468. Compound Fz25 was cytotoxic against both MDA-MB-231 and MDA-MB-468 cell lines, yielding IC₅₀ values of 8.12 ± 0.85 and 25.43 ± 3.68 µM, respectively. However, compounds Fz57 and Fz200 were potent against only MDA-MB-231 cells, generating IC₅₀ values of 21.18 ± 0.23 and 10.86 ± 0.69 µM, respectively. Pathway analyses revealed that Fz25, Fz57 and Fz200 arrested the G₀/G₁ phase of the cell cycle and concomitantly suppressed cell cycle regulators, cyclin D₁, cyclin E and Dyrk1B in MDA-MB-231 cells. Additionally, all compounds inhibited EGFR and its downstream signaling pathways—extracellular receptor kinase (ERK) and the mammalian target of rapamycin (mTOR)—in a dose-dependent manner. Furthermore, Fz25, Fz57 and Fz200 induced apoptosis in MDA-MB-231 cells by modulating morphological changes, including chromatin condensation, and attenuating the levels of cytochrome c, APAF1, caspases-3 and -9 as well as cleaved PARP. Of these compounds, only Fz25 showed overall satisfactory ADMET properties in silico. Similarly, Fz25 showed suitable binding parameters explored using molecular dynamic simulations in silico. These findings suggest that Fz25 warrants further preclinical and clinical investigations as a new generation of triazole congeners with significant potency in EFGR-dependent TNBC. Full article

We introduce a modular reduction method that is optimized for hardware and outperforms conventional approaches. By leveraging calculated reduction cycles and combinatorial logic, we achieve a remarkable 30% reduction in power usage, 27% reduction in Configurable Logic Blocks (CLBs), and 42% fewer look-up tables (LUTs) than the conventional implementation. Our Hardware-Optimized Modular Reduction (HOM-R) system can condense a 256-bit input to a four-bit base within a single 250 MHz clock cycle. Further, our method stands out from prevalent techniques, such as Barrett and Montgomery reduction, by eliminating the need for multipliers or dividers, and relying solely on addition and customizable LUTs. This innovative method frees up FPGA resources typically consumed by power-intensive DSPs, offering a compelling low-power, low-latency alternative for diverse design needs. Full article

This paper establishes a simulation model for the performance of an R290 variable frequency compressor in automotive air conditioning and sets up a compressor performance testing system. It investigates the effects of different evaporation temperatures, condensation temperatures, compressor speeds, and pressure ratios on the oil circulation rate (OCR), as well as the impact of various oil circulation rates on the performance of the R290 compressor. As the comparison between simulation and experimental data shows, compressor performance predictions from the simulation model align with experimental results when the OCR is not taken into consideration. Experimental results indicate that the OCR increases with a rising evaporation temperature, decreases with a lowering condensation temperature, and increases with higher compressor speeds. The simulation model shows a minor deviation when predicting volumetric efficiency, while errors are larger when predicting isentropic efficiency and the discharge temperature. Isentropic efficiency and the discharge temperature show a notable impact from the OCR. Additionally, for system cooling capacity, power, and COP predictions, when the OCR is within the range of 2~10%, the accuracy of the simulation model proves satisfactory, with deviations within 5%. Full article

ETICS is a popular external wall insulation system, which is not without possible defects and damages. A frequent cause, direct or indirect, of damage to buildings is the impact of water (moisture). This article presents, among others, the results of tests of the moisture content of ETICS layers, the water absorption and capillary absorption of the render by means of the Karsten tube method, numerical thermo-moisture simulations, and tests of interlayer adhesion, in sample residential buildings. Mass moisture content testing of the wall substrate showed acceptable moisture levels (1–4%m) within masonry walls made of silicate blocks, as well as locally elevated moisture levels (4–8%m) in the case of reinforced concrete walls. Moisture testing of the insulation samples showed a predominantly dry condition, and testing of the reinforcement layer showed an acceptable level of moisture. Severe moisture was found in the sample taken in the ground-floor zone at the interface between mineral wool and EPS-P insulation underneath the reinforced layer. Capillary water absorption tests helped classify silicone render as an impermeable and surface hydrophobic coating. Tests of the water absorption of the facade plaster showed that the value declared by the manufacturer (<0.5 kg/m²) was mostly met (not in the ground-floor zone). The simulation calculations gave information that there was no continuous increase in condensation during the assumed analysis time (the influence of interstitial condensation on the observed anomalies was excluded). The tests carried out indicated the occurrence of numerous errors in the implementation of insulation works affecting the moisture content and durability of external partitions. Full article

The relation between the pressure and molar concentration (in mol/L) of real gases in a low- to medium-pressure range is precisely described by a logarithmic two-parameter equation. Increasing the concentration caused an increase in pressure and also the weakening of the effect due to intermolecular interactions, forming the basis for an equation with an adjusted parameter. Exceeding a critical concentration by a further increase caused a switch to another set of parameters in the same equation. At high pressure, a second switch to an exponential term was observed. This equation of state, defined segment by segment, was attributed to three different structures of the medium. The validity of the equations found was verified with experimental data reported in the literature for helium, neon, argon, krypton, and xenon and is discussed in more detail for argon. The temperature dependence of the parameters of the equations is reported and the formation of a liquid phase is discussed. Full article

This paper presents a method for purifying molybdenum concentrate through vacuum distillation and examines the phase evolution of MoS₂ during the process. First, the forms in which impurities exist in molybdenum concentrate and the feasibility of their volatilization are analyzed, while the structural changes of MoS₂ in a vacuum environment are discussed and verified through theoretical calculations. Next, experiments are conducted to study the effects of holding temperature, holding time, and other influencing factors on the transformation process of the molybdenum concentrate. The feasibility of impurity volatilization and the structural evolution of MoS₂ are further evaluated through experimental analysis of the condensates and residues in the temperature interval of 1273 K–1623 K. The results demonstrate that impurities can be effectively removed without compromising the natural structure of MoS₂. Full article