Possibility of simulating natural circulation in fast neutron reactors using a light water test facility

The paper evaluates the possibility of modeling the heat transfer phenomena in a liquid-metal coolant using a light water test facility. It considers the natural circulation of the coolant in the upper plenum of the fast-neutron reactor. The sodium-cooled BN-1200 reactor was selected as the reactor installation to be modeled. The development of novel reactor designs must be based on the results of experimental studies. Some problems of modeling thermohydraulic processes in BN type reactors are studied by using sodium test facilities. Experimental studies of natural convection processes using light water test facilities can be considered as a good alternative to those using sodium test facilities. To validate the model, the similarity theory and the “black box” method were used and their principles and applicability were analyzed. Using the “black box” method makes it possible to avoid detailed modeling of such components as the reactor core and heat exchangers, replacing them by a simplified representation of these components to simulate the integral characteristics of the existing real life equipment. The paper considers the basic criteria which determine the similarity of the thermohydraulic processes under study. The governing criteria of similarity were estimated based on the fundamental differential equations of natural convection heat transfer. Based on these criteria, a set of dimensionless values was obtained which show the correlation between the model parameters and the characteristics of the reactor facility. Besides, generalized relationships were derived which can be used to estimate the scaling factors for calculating the key values of the reactor facility based on the model parameters. These relationships depend on the thermal-physics parameters of the working fluids, the geometrical scale value and the ratio of the thermal power of the model to that of the reactor facility, i.e., model-to-reactor thermal power ratio. The conditions under which it is possible to model sodium coolant by light water with adequate accuracy were analyzed. An example is given of the numerical values of the scaling factors for one of the reference light water test facilities. The paper uses the experience of a number of foreign researchers in this field, in particular, the accepted assumptions which do not result in serious loss in modeling accuracy. According to the available estimates, the assumptions used do not result in considerable losses in accuracy. Thus, the natural circulation of the sodium coolant in the upper plenum of the fast-neutron reactor can be simulated with adequate accuracy by using light water test facilities.

Comparative Study of Cleansing Action of Some Detergents Available in Nepalese Market

Detergents commercially available in the Nepalese market were studied and several parameters such as surface tension, pH, critical micelle concentration, foaming stability test, hard water test, emulsions stability test were performed. Different medium such as ground water (G.W.), tap water (T.W.), distilled water (D.W.) and 5% ethanol in distilled water were selected for this study. The decrease in surface tension and critical micelle concentration (CMC) in ground water, tap water, distilled water and 5% ethanol in distilled water, ease of cleansing action of the detergents in this medium have been found of the following order: 5% ethanol in distilled water > distilled water (D.W.) > tap water (T.W.) > ground water (G.W.). Among the four detergents, the D1 have shown the least surface tension, CMC value, foam collapsing time, the weight of scum formed when treated with hard water. And maximum emulsion stability of the detergent D1 determines good quality detergent.

RNA-Seq Based Transcriptome Analysis of Ethanol Extract of Saffron Protective Effect Against Corticosterone-Induced PC12 Cell Injury

Background Saffron is a traditional Chinese herbal medicine, which is typically used in clinical to regulate anxiety, tension, and other depression-related conditions. The study aimed to explore the neuroprotective effect of ethanol extract of saffron (EES) on corticosterone (CORT)-induced injury in PC12 cells and further explored its potential mechanism. Methods The authenticity of saffron and the active components of EES were identified by a water test and ultra-performance liquid chromatography-time of flight mass spectrometry system. The screening of cytotoxicity for PC12 cells was incubated with EES in different concentrations for 24 h, and the protective efficacy of EES on CORT (500 µM) induced PC12 cell injury, cell viability was assessed by Cell Counting Kit-8 (CCK-8) assay. The DEGs of EES-protected PC12 cells were analyzed using the RNA-seq method, and the results were analyzed for GO and KEGG enrichment. The results of RNA-seq were verified by qPCR analysis. Results The saffron was initially identified as authentic in the water test and 10 compounds were identified by UPLC-MS. The results of CCK-8 demonstrated that EES at concentrations above 640 µg/mL exerted a certain cytotoxic effect, and PC12 cells pretreated with EES (20, 40, and 80 µg/mL) significantly reversed the 500 µM CORT-induced cell death. RNA-seq analysis showed that EES regulated 246 differential genes, which were mainly enriched in the MAPK signaling pathway. Dusp5, Dusp6, Gadd45b, Gadd45G, and Pdgfc were further validated by qPCR. Experimental data showed that the results of qPCR were consistent with RNA-seq. Conclusions These findings provide an innovative understanding of the molecular mechanism of the protective effect of EES on PC12 cells at the molecular transcription level, and the above molecules may be potential novel targets for antidepressant treatment.

Empirical NOx Removal Analysis of Photocatalytic Construction Materials at Real-Scale

The NOx removal performance of photocatalytic construction materials is demonstrated using two experiments under indoor and outdoor environments: (1) A photoreactor test was conducted to assess the NO removal performance of construction materials (e.g., coatings, paints and shotcrete) using a modified ISO 22197-1 method; (2) A water washing test was conducted using two specimens enlarged to the size of actual building materials and artificially exposed to NOx in a laboratory to analyze NOx removal performance. For (1), the UV irradiation of the outdoor environment was analyzed and the experiment was conducted in an indoor laboratory under UV irradiation identical to that of the outdoor condition. Photoreactor tests were conducted on construction materials applied to actual buildings located in Seoul, South Korea. In (2), the enlarged specimen was used for a field experiment by applying a modified method from the ISO 22197-1 standard. On sunny days, the NOx removal performance (3.12–4.76 μmol/150 cm2·5 h) was twice as much as that of the ISO 22197-1 standard specification (2.03 μmol/150 cm2·5 h) in the real-world. The washing water test results indicated that general aqueous paint achieved a NOx removal of 3.88 μmol, whereas photocatalytic paint was superior to 14.13 μmol.

Three-Dimensional Nonlinear Vibration Model and Fatigue Failure Mechanism of Deep-Water Test Pipe

In deep-water test conditions, the riser-test pipe system (RTS) is subject to the vortex induced effect on riser, flow induced effect on test pipe and longitudinal/transverse coupling effect, which is prone to buckling deformation, fatigue fracture and friction perforation. To resolve this, the three-dimensional (3D) nonlinear vibration model of deep-water RTS is established using the micro-finite method, energy method and Hamilton variational principle. Based on the elastic-plastic contact collision theory, the nonlinear contact load calculation method between riser and test pipe is proposed. Compared with experimental measurement results, calculation results of the proposed vibration model in this study and the single tubing vibration model in our recent work, the correctness and effectiveness of the proposed vibration model of the deep-water RTS are verified. Meanwhile, the cumulative damage theory is used to establish the fatigue life prediction method of test pipe. Based on that, the influences of outflow velocity, internal flow velocity, significant wave height, as well as top tension coefficient on the fatigue life of test pipe are systematically analyzed. The results demonstrate that, first, with the increase of outflow velocity, the maximum alternating stress, the annual fatigue damage rate increased and the service life decreased significantly. The locations where fatigue failure of the test tube is easy to occur are mainly distributed at the upper “one third” and the bottom of test pipe. Second, with the increase of internal flow velocity, the “one third effect” of the test pipe will decrease, and is shown “the bottom damage effect”, which needs the attention of field operators. Third, during field operation, it is necessary to properly configure the top tension coefficient so that there can be a certain relaxation between the riser and the test pipe, so as to cause transverse vibration and consume some axial energy and load. The study led to the formulation of a theoretical method for safety evaluation and a practical approach for effectively improving the fatigue life of deep-water test pipe.

Preparation and Characterization of Gelatin-Based Films Cross-Linked by Two Essential Oils at Different Concentrations and Plasticized with Glycerol

Gelatin cross-linking has recently been discovered to be a very appealing method of producing gelatin-based films. The current research looks at various commercial gelatin (type B) films to improve their physical qualities. Bunium alpinum and bunium incrassatum essential oils (EOs) in two quantities (5% and 25%) were added to the films, which showed substantial biological activity (antibacterial, antioxidant, antihemolytic, and anti-inflammatory). According to electronic scanning microscopy, the basic gelatin matrix had changed and there were multiple dense spots on the cross-linked films. The particles appear to be more bonded in an isotropic form. Infrared spectroscopy cannot provide substantial accuracy on the new characteristics and chemical interactions formed due to the complex system of both gelatin and EOs. According to the UV transmission test results, adding EOs to gelatin films improves the barrier properties against UV rays and prevents UV light transmission. Finally, the swelling water test revealed that included EOs in the film composition reduce the film's swelling.

Development and Experimental Validation for Quantifying the Moisture Carryover in a Moisture Separator Using an Air/Water Test Facility

The moisture carryover (MCO) of the primary separator in a steam generator is the most important design parameter to ensure high efficiency in a steam generator. There is an inherent limitation to experimentally evaluate the MCO under the prototype conditions. In this study, the air/water test facility was constructed based on the similarity law, and a new isokinetic system was developed to quantify the MCO. Several experiments were performed for the mass quality ranging from 0.315 to 0.382. The accuracy and versatility of the experimental method was verified experimentally using a full and half scale of separators. The test results were compared with the prototype results. It was proved to be a reliable experimental method for evaluating the MCO of the moisture separator.

Sistem Mikrokontroler Untuk Menentukan Kualitas Air Yang Dapat di Gunakan Oleh Konsumen dengan Menggunakan Arduino

There are now many businesses that provide refilled drinking water in every big city, because besides that, the price that is not too expensive can save time because there is no need for difficulties in obtaining clean water. The owner of the drinking water business still does not know whether the water produced is fit for consumption. Therefore, a tool will be made to measure air quality based on the selected parameter, namely the pH value of the water by using a pH meter sensor based on Arduino Uno and displayed through an LCD screen so that you can see directly the results of the refilled water test.

Efficacy of a Ready-to-Drink Gelled Water and of a Thickening Powder in Patients with Oropharyngeal Dysphagia: a Crossover Randomized Study

Management of oropharyngeal dysphagia (OD) is mainly based on modifying liquid viscosity and solid consistency in order to preserve oral feeding while avoiding unsafe swallowing. Adding thickening powders (TP) to water is the most common practice in patients suffering from OD to liquids, but ready-to-use gelled waters (RGW) can also be proposed. The main objective of this study was to assess the efficacy of a RGW and a TP on swallowing in hospitalized patients with different OD etiologies. This open, crossover, multicenter trial recruited thirty hospitalized patients with OD to liquids, confirmed by positive 3-ounce water test or positive Practical Aspiration Screening Scheme test. The patient’s ability to swallow 120 g of a RGW (IDDSI level 4) and a drink prepared with TP (nectar viscosity; NTP, 291 cP, IDDSI level 2; or if necessary, honey; HTP, 769 cP, IDDSI level 3) was evaluated in a random order at 1- to 3-day intervals. The main criterion was the efficacy of each product, defined as the proportion of patients who successfully swallowed without immediate reflexive cough. The RGW and TP were successfully swallowed in respectively 93.3% (95% CI: 77.9–99.2) and 82.8% (95% CI: 64.2–94.2) of patients with different dysphagia etiologies (stroke, neurodegenerative diseases, or aging) and unable to swallow thin water. Taste and texture of both study products were well appreciated by patients, with a preference for the RGW over TP. Therefore, the use of these thickened products could be part of the therapeutic strategy for patients with OD to liquids.

Hindcasting Soundscapes before and during the COVID-19 Pandemic in Selected Areas of the North Sea and the Adriatic Sea

The national measures in several European countries during the COVID-19 pandemic also affected offshore human activities, including shipping. In this work, the temporal and spatial variations of shipping sound are calculated for the years before and during the pandemic in selected shallow water test areas from the Southern North Sea and the Adriatic Sea. First, the monthly sound pressure level maps of ships and wind between 2017 and 2020 are calculated for frequencies between 100 Hz to 10 kHz. Next, the monthly changes in these maps are compared. The asymptotic approximation of the hybrid flux-mode propagation model reduces the computational requirements for sound mapping simulations and facilitates the production of a large number of sound maps for different months, depths, frequencies, and ship categories. After the strictest COVID-19 measures were applied in April 2020, the largest decline was observed for the fishing, passenger and recreational ships. Although the changes in the number of fishing vessels are large, their contribution to the soundscape is minor due to their low source level. In both test areas, the spatial exceedance levels and acoustic energies were decreased in 2020 compared to the average of the previous three years.