Performance optimization of thin fire blankets by varying their radiative properties

In using thin fire blankets to protect structures in wildfires, heat rejections by radiation (reflection and emission) are essential for good performance. By varying the radiative properties of the front and back surfaces of the blankets, this article offers an optimization study of several scenarios of incident heat flux including pure convection, pure radiation, and combinations of the two. Two types of blanket heat-blocking efficiencies are studied in the optimization scheme. An overall efficiency is defined as the amount of incident heat blocked to the total amount of incident heat in specified wildfire scenarios. An instantaneous heat-blocking efficiency is defined as the instantaneous heat flux blocked to the instantaneous incident total heat flux which provides good understanding of the physics of heat-blocking mechanisms of fire blanket under quasi-steady conditions. In addition to maximizing these heat-blocking efficiencies, there are other optimization objectives, including the minimization of the blanket backside temperature. A genetic algorithm is used for the multi-objective optimization schemes. For the transient heat incidence, the optimization for the entire time sequence is performed with the possibility of a change of blanket radiative properties during the fire sequence, accounting for changes to the fire-facing surface caused by the incident heat.

Sand Blocking Mechanisms and Productivity Analysis of Slant Well in Siltstone Reservoirs

The siltstone reservoir with many small layers of pay zones is usually produced by slant holes. However, severe sand blockages take place when the siltstone reservoir is developed by slant holes. Currently, the sand blocking mechanisms and the effect of sand blocking on productivity of slant well are still challenges for engineers and scholars. In this paper, based on the existing productivity model of inclined slant wells, the mechanical skin factor, which describes the effect of sand blocking on productivity, is proposed. Meanwhile, many experimental works have been done to investigate the sand blocking mechanisms in siltstone reservoirs. From the experimental work, it is concluded that with the increase of displacement PV number and displacement flow rate, the permeability of sand control system decreases by 40%. When solid particles enter the casing and block the gravel and sand control screen in the annulus, the skin factor increases sharply and the productivity decreases by more than 80%. Through the productivity calculation of multilayer sand control wells, it is considered that larger gravel packing radius can keep particles away from the well bore, which is helpful to ensure oil well productivity. Furthermore, the influence of differential filling radius on the fluid production capacity of each layer of sand control well is analyzed. It is proved that optimizing the filling radius of each layer can improve the production effect of mediate- and low-permeability layers. This method has been applied in Kendong #12 block. The daily oil production rate is increased by 9.61 t/day, and the oil recovery of this block is increased by 2.12%.

China’s Policy of Economic Sanctions: Legislation and Enforcement

This article aims at analyzing the People’s Republic of China’s sanctions policy. The authors put special emphasis on the review of the current Chinese legislation on countering foreign unilateral measures targeting China. The emergence of a legal anti-sanctions framework in China is a development of 2020–2021, driven by the growing number of sanctions against China imposed by the U.S. and its allies against the background of trade war and global strategic competition. At the official level, Beijing remains vocal in condemning unilateral and extraterritorial sanctions by certain countries as violations of international law. Despite that, even before the current large-scale confrontation with the U.S, Chinese policymakers have used restrictive measures against third countries, though they have been traditionally adopted in an informal and opaque manner. Those measures have mostly been used as retaliation for certain acts of other states viewed by China as threats to its sovereignty and territorial integrity, and they have been specifically refined to maximize the impact on the target country while minimizing the damage to the domestic economy. The growing number of anti-China sanctions by the U.S. and its allies based on special legal instruments prompted the PRC to follow suit and create its own framework for introducing countermeasures and blocking mechanisms, although their implementation procedures still largely remain intransparent. China’s first steps were to officially introduce individual restrictions, but the persisting confrontational trends in PRC’s relations with the West might bring about formal or informal broadening of Chinese restrictions to transnational corporations and sectors of economy and promote further formalization of sanctions regimes.

Assessment of removal and adsorption enhancement of high-flux hemodialyzers in convective therapies by a novel in vitro uremic matrix

Adsorption properties of hemodialyzers are traditionally retrieved from diffusive treatments and mainly focused on inflammatory markers and plasma proteins. The possible depurative enhancement of middle and high molecular weight solutes, as well as protein-bound uremic toxins by adsorption in convective treatments, is not yet reported. We used discarded plasma exchanges from uremic patients and out-of-date erythrocytes as a novel in vitro uremic precursor matrix to assess removal and adsorption patterns of distinct material and structure but similar surface hemodialyzers in hemodialysis and on-line hemodiafiltration treatments. We further related the obtained results to the possible underlying membrane pore blocking mechanisms. Convection improved removal but slightly enhanced adsorption in the cellulosic and synthetic dialyzers tested. The polymethylmethacrylate hemodialyzer obtained the highest extracted ($$M_{ext}$$ M ext ) and adsorbed ($$M_{ads}$$ M ads ) mass values when submitted to hemodiafiltration for all molecules analyzed including albumin ($$M_{ext}=15.8\pm 3.9$$ M ext = 15.8 ± 3.9 g, $$M_{ads}=44.3\pm 11.5$$ M ads = 44.3 ± 11.5 mg), whereas the polyamide membrane obtained substantial lower results even for this molecule ($$M_{ext}=2.2\pm 1.2$$ M ext = 2.2 ± 1.2 g, $$M_{ads}=4.2\pm 0.7$$ M ads = 4.2 ± 0.7 mg) under the same treatment parameters. Hemodiafiltration in symmetric and enlarged pore hemodialyzers enhances removal and adsorption by internal pore deposition (intermediate pore-blocking) for middle and high molecular weight toxins but leads to substantial and deleterious albumin depuration.

Potential of Mesenchymal Stem Cells in Anti-Cancer Therapies

Mesenchymal stem/stromal cells (MSCs) are localized throughout the adult body as a small population in the stroma of the tissue concerned. In injury, tissue damage, or tumor formation, they are activated and leave their niche to migrate to the site of injury, where they release a plethora of growth factors, cytokines, and other bioactive molecules. With the accumulation of data about the interaction between MSCs and tumor cells, the dualistic role of MSCs remains unclear. However, a large number of studies have demonstrated the natural anti-tumor properties inherent in MSCs, so this is the basis for intensive research for new methods using MSCs as a tool to suppress cancer cell development. This review focuses specifically on advanced approaches in modifying MSCs to become a powerful, precision- targeted tool for killing cancer cells, but not normal healthy cells. Suppression of tumor growth by MSCs can be accomplished by inducing apoptosis or cell cycle arrest, suppressing tumor angiogenesis, or blocking mechanisms mediating metastasis. In addition, the chemosensitivity of cancer cells may be increased so that the dose of the chemotherapeutic agent used could be significantly reduced.

Micellar-Enhanced Ultrafiltration Using a Plant-Derived Surfactant for Dye Separation in Wastewater Treatment

Micellar-enhanced ultrafiltration (MEUF) is one of several membrane methods used for the removal of trace organic pollutants from aqueous streams. In this process, a surfactant is added to a polluted aqueous solution at a concentration higher than its critical micelle concentration (CMC). Unlike synthetic surfactants, natural surfactants, from plants such as the saponin, while ecologically adaptable as surfactants in MEUF systems, are also biodegradable, renewable, and environmentally safe. This study applied Sapindus rarak extract as the natural surfactant in MEUF for Remazol dye separation. It was found that the presence of Sapindus rarak extract increased separation of Remazol red and blue dyes by up to 97.02% and 99.42%, respectively. However, the addition of surfactant decreased permeate fluxes due to membrane fouling and concentration polarization. In addition, loading micelle (Lm), representing the performance of the surfactant micelle for dye separation, as well as the blocking mechanism, was investigated. Lm was found to be in the range of 0.002–0.068 mM dyes/mM saponin. Ultrafiltration blocking mechanisms, as confirmed by the Hermia model, were: standard blocking, for cases without the addition of surfactant; cake formation, for cases with surfactant below the CMC; and complete blocking, for cases with surfactant above the CMC.

New Aspects of Pathogenesis and Treatment of Membranous Glomerulopathy After the MENTOR Study

Membranous nephropathy (MN) is the major cause of nephrotic syndrome in adults, accounting for 20% of cases with an annual incidence of 1 per 100,000 population. In the past 10 years, the role of podocytes has been identified. Environmental triggers in genetically predisposed patients can activate podocytes to exhibit antigenic epitopes, including PLA2R, THBS1, and NELL1, which become targets of specific autoantibodies with subsequent complement activation. The discovery of these mechanisms has opened a new horizon in the treatment of MN, and novel drugs are available with more specific mechanisms of action. Rituximab, a monoclonal antibody directed against CD20 expressed on B lymphocytes, has been used in several trials and appears to induce remission of nephrotic syndrome in 60% of patients (GEMRITUX trial). The recently published results of the MENTOR trial documented the superior efficacy of rituximab in patients observed for up to 24 months. In MN, the concept of targeting disease control has introduced novel therapies with specific blocking mechanisms, such as belimumab; nonspecific blocking mechanisms, such as those against adrenocorticotropic hormone; and new therapeutic options, such as ofatumumab, bortezomib, and eculizumab, which have recognised the pathological processes involved in the glomerular diseases.