Condensation Research Articles

Indirect effects of latent heat of condensation on the simulation of the 2021 catastrophic Henan rainfall event in central China

AbstractCloud‐related latent heat is critical to the development and maintenance of atmospheric circulation. However, it is unclear how sensitive the key large‐scale weather systems of an extreme rainfall event could be to the variation in cloud‐related latent heat. In a companion study, by investigating the indirect effects of different microphysics schemes, we hypothesized that the latent heat of condensation (CT) would play a role in the ability to simulate the extreme rainfall event that took place in Henan Province, central China, on July 19–21, 2021. To examine the proposed hypothesis, the impacts of varying the CT and the collection of cloud water by rainwater (ACW) in the Thompson, WDM6, and Morrison microphysics schemes on the simulation of the southerly flow and its indirect effect on this extreme rainfall case were studied using the Advanced Research Weather Research and Forecasting (ARW‐WRF) model. It was found that directly changing the CT and ACW had significant effects on the southerly flow and precipitation. An increase in CT generally led to a reduced temperature gradient, a smaller pressure gradient, a stronger southerly flow, and a precipitation surge of 32%–50%. Similar outcomes resulted from increasing ACW in the WDM6 scheme, which effectively diminished the cloud mixing ratio, generated higher CT, and consequently intensified the southerly flow and precipitation by 31%. This study confirmed that the accurate simulation of microphysical processes, along with latent heating, is desirable for more realistically reproducing the key weather systems in the simulation of extreme rainfall.

Impact of desert dust on new particle formation events and the cloud condensation nuclei budget in dust-influenced areas

Abstract. Detailed knowledge on the formation of new aerosol particles in the atmosphere from precursor gases, and their subsequent growth, commonly known as new particle formation (NPF) events, is one of the largest challenges in atmospheric aerosol science. High pre-existing particle loadings are expected to suppress the formation of new atmospheric aerosol particles due to high coagulation and condensation (CS) sinks. However, NPF events are regularly observed in conditions with high concentrations of pre-existing particles and even during intense desert dust intrusions that imply discrepancies between the observations and theory. In this study, we present a multi-site analysis of the occurrence of NPF events under the presence of desert dust particles in dust-influenced areas. Characterization of NPF events at five different locations highly influenced by desert dust outbreaks was done under dusty and non-dusty conditions using continuous measurements of aerosol size distribution in both fine and coarse size fractions. Contrary to common thought, our results show that the occurrence of NPF events is highly frequent during desert dust outbreaks, showing that NPF event frequencies during dusty conditions are similar to those observed during non-dusty conditions. Furthermore, our results show that NPF events also occur during intense desert dust outbreaks at all the studied sites, even at remote sites where the amounts of precursor vapours are expected to be low. Our results show that the condensation sink associated with coarse particles (CSC) represents up to the 60 % of the total CS during dusty conditions, which highlights the importance of considering coarse-fraction particles for NPF studies in desert-dust-influenced areas. However, we did not find a clear pattern of the effect of desert dust outbreaks on the strength of NPF events, with differences from site to site. The particle growth rate (GR) did not present a clear dependence on the CS during dusty and non-dusty conditions. This result, together with the fact that desert dust has different effects on the growth and formation rates at each site, suggests different formation and growth mechanisms at each site between dusty and non-dusty conditions, probably due to differences in precursor vapours' origins and concentrations as well as changes in the oxidative capacity of pre-existing particles and their effectiveness acting as CS. Further investigation based on multiplatform measurement campaigns and chamber experiments with state-of-the-art gaseous and particulate physical and chemical properties measurements is needed to better understand the role of catalyst components present in desert dust particles in NPF. Finally, our results reveal a significant impact of NPF events on the cloud condensation nuclei (CCN) budget during desert dust outbreaks at the studied sites. Therefore, since desert dust contributes to a major fraction of the global aerosol mass load, and since there is a foreseeable increase in the frequency, duration and intensity of desert dust episodes due to climate change, it is imperative to improve our understanding of the effect of desert dust outbreaks on NPF and the CCN budget for better climate change prediction.

Application of computer image analyzes in the investigation of refrigerants condensation in minichannels

Application of computer image analyzes in the investigation of refrigerants condensation in minichannels

SiO2-supported HClO4 catalyzed synthesis of (Z)-thiazolylhydrazonoindolin-2-ones and their electrochemical properties

In this paper, an environmentally benign silica-supported perchloric acid (HClO4–SiO2) catalyzed green FCDR strategy has been developed for the synthesis of (Z)-THIs (6) with high stereospecificity via an intramolecular hydrogen bond (IHB) directed approach, involving the reaction of methyl ketones (1), N-bromosuccinimide (NBS) (2), isatins (4) and thiosemicarbazide (5) in ethanol at reflux temperature for 45–60 min in one-pot. The reaction proceeds through the construction of C–Br (α-bromination), C–S & C–N (heterocyclization), and CN (condensation) bonds in one pot. The absolute structure of the compound (Z)-3-(2-(4-(4-bromophenyl)thiazol-2-yl)hydrazono)indolin-2-one (6e) has been confirmed by single-crystal XRD analysis. Further, the role of IHB on Z-configuration of the synthesized (Z)-THIs is proved by single-crystal XRD and 1H NMR studies. Wide substrate scope, good functional group tolerance, scalability, improved safety since the method circumvents the use of highly lachrymatric α-bromoketones as starting materials, high product yields (up to 98%), short reaction times, reusable solid Brønsted acid catalyst (HClO4–SiO2), and products that do not require column chromatography purification are all attractive features of this FCDR strategy. Electrochemical properties of THIs (6) are examined by cyclic voltammetry. The HOMO and LUMO energy level of THIs, 6a, 6c, 6d, 6j, 6o-6v, 6y, and 6aa are comparable with the reported ambipolar materials, and the HOMO levels of other THIs, 6b, 6e-6i, 6n, 6w, 6x, 6z and 6 ab-6ae are similar with the most commonly used hole transporting materials (HTMs).

Synthesis and Characterization of Benzoxazinone Derivatives

The present work reports synthesis and characterization of different benzoxazinone derivatives. 2-methyl-7-nitro-4H-3,1-benzoxazin-4-one was prepared by refluxing 4- nitroanthranilic acid with acid anhydride. Derivatives of 2-methyl-7-nitro-4H-3,1-benzoxazin-4-one were synthesized by condensation of it with different anilines. Elemental analysis and NMR spectral studies were used to confirm the formation of compounds.

Saccharochelins A-H, Cytotoxic Amphiphilic Siderophores from the Rare Marine Actinomycete Saccharothrix sp. D09.

Siderophores are secreted by microorganisms to survive in iron-depleted conditions, and they also possess tremendous therapeutic potential. Genomic-inspired isolation facilitated the identification of eight amphiphilic siderophores, saccharochelins A-H (1-8), from a rare marine-derived Saccharothrix species. Saccharochelins feature a series of fatty acyl groups appended to the same tetrapeptide skeleton. With the help of gene disruption and heterologous expression, we identified the saccharochelin biosynthetic pathway. The diversity of saccharochelins originates from the flexible specificity of the starter condensation (CS) domain at the beginning of the nonribosomal peptide synthetase (NRPS) toward various fatty acyl substrates. Saccharochelins showed cytotoxicity against several human tumor cell lines, with IC50 values ranging from 2.3 to 17 μM. Additionally, the fatty acid side chains of the saccharochelins remarkably affected the cytotoxicity, suggesting changing the N-terminal acyl groups of lipopeptides may be a promising approach to produce more potent derivatives.

Influence of Geometrical Changes in an Adiabatic Portion on the Heat Transfer Performance of a Two-Phase Closed Thermosiphon System

In this study, a modified non-uniform adiabatic section in a Two-Phase Closed Thermosiphon (TPCT) is proposed where the uniform section was replaced by convergent and divergent (C-D) sections. The heat transfer analysis was performed on the modified TPCT and their findings were compared with standard TPCT. The deionized water (DI) in the proportion of 30 vol% is filled in both the TPCTs. Further, the heat transfer performance analysis was carried out for three different orientations, such as 0°, 45° and 90°, and heat input was varied from 50 to 250 W. The effect of these geometrical changes and inclination angles on the heat transfer performance of both the TPCT were evaluated to compare the thermal resistance, wall temperature variation and heat transfer coefficient. The non-dimensional numbers such as Weber (WE), Bond (BO), Condensation (CO) and Kutateladze (KU) were investigated based on heat fluxes for both TPCTs. By introducing the convergent-divergent section nearer to the condenser, the pressure before and after the C-D section was increased and decreased. This enhances the heat transfer in the evaporator slightly up to 2% and 1.4% at horizontal and 45° orientation, respectively, in Non-Uniformed Adiabatic Section (NUAS) TPCT when compared to Uniformed Adiabatic Section (UAS) TPCT. The thermal resistance of NUAS TPCT was reduced by up to 4.5% relative to UAS TPCT in horizontal and 45°. The results of the non-dimensional number also confirmed that NUAS TPCT provided better performance by enhancing 2% more pool boiling characteristics, interaction forces and condensate returns. Several factors such as gravity assistance, fluid accumulation, pressure drop and thermal resistance exert an influence on the heat transfer performance of the proposed NUAS TPCT at various orientation angles. However, different type of cross-sectional variations subjected to orientation changes may also get influenced by several other parameters that in turn affect the heat transfer performance distinctly.

Improving Students Learning Outcomes in English Through Cooperative Learning Stad

Giving students a various method when teaching is one of the effort to achieve the goal of learning, especially in English. English is one of the subject that has very important role and also one of the national exam subject. In fact English is one of the lesson that the students do not like very much which could effect their learning outcomes. According to interviews with previous teachers learning outcomes of eleventh grade has under the KKM, it because less active of the students when learning and less creative of the teacher when teaching. Therefore, researcher need to conduct a research to improve the student’s learning outcomes. The research aimed to find out how can cooperative learning Student Teams Achievements Divisions improve students learning outcomes of Eleventh Grade Students at SMK Teluk Kepayang This study is a classroom action research using the research model of Kemmis and Taggart. This study was conducted in SMK Teluk Kepayang and the subject of this research were 27 students in eleventh grade in one cycle. The research procedure consist of planning, action, observation, and reflection. Data collection techniques used (1) observation to collect data on student activity (2) tests to assessed student achievement in the end of the study (3) a questionnaire to obtained data about the implementation of students opinion cooperative learning Students Team Achievements Division. The data obtained during the research consisted of qualitative data and quantitative data. The qualitative data were obtained from observations and interviews, while the quantitative data were gained from tests. The qualitative data were analyzed by condensing data, displaying data, and drawing conclussion. The mean scores of the tests were gained as the result of the quantitative data analysis.. The results showed that: first, students activities in the classroom was increased in every meeting. In meeting 1 53.33%, meeting 2 increased to 59.52%, meeting 3 decreased into 53.57, meeting 4 increased 62.5%, meeting 5 increased 70.63& and the last meeting 75%. Second, the learning outcomes of the students also increased with average from 68.81 to 82.22. So it means that The components of STAD contributed to students learning outcomes and students’ participation in the classroom in small group.

Scaling Design of the Pressure Response Experimental Facility for Pressure Suppression Containment

Pressure suppression containment has been adopted extensively in the BWR reactor design due to the remarkable pressure suppression capacity. In order to study the pressure response characteristics of the containment in the initial stage of the loss of coolant accident, it is necessary to build the scaling facility to simulate the prototype. The analysis of the blow down source term and the steam condensation occurred in the suppression pool are conducted respectively for the prototype PWR. The suppression pipe system resistance term is also scaled with a certain ratio. The length and the diameter of the mian pipe and the branch pipe as well as the orifice diameter are calculated. At last, the prototype and the experiment facility are modeled by MELCOR to scale the source term. The results show that the scaling method in this paper is effective to predict the pressure evolution in the prototype containment during the loss of coolant accident.

Why heat transfer coefficients are unnecessary and undesirable, and how heat transfer problems are solved without them.

For 200 years, convective heat flux q has been calculated by multiplying heat transfer coefficient h times boundary layer temperature difference T. Since h times T equals q, h must be a symbol for (q/T) because (q/T) times T equals q. h (ie q/T) is generally calculated from correlations derived from experiments in which q data and T data are used to obtain (q/T){T} correlations-ie h{T} correlations. (It is not possible to obtain h data because h is not a parameter. h is the ratio of two parameters). Heat transfer coefficients are unnecessary and undesirable. It is self-evident that any problem that can be solved using q, q/T (ie h), and T can also be solved using only q and T. Therefore h (ie q/T) is unnecessary. h (ie q/T) is undesirable because, when q is a nonlinear function of T (as in free convection, condensation, and boiling), h (ie q/T) is an extraneous variable, and it greatly complicates problem solutions. When h has been abandoned, convective heat flux is determined from q{T} correlations that result from q data and T data, or from the transformation of h{T} correlations. (Transformation from h{T} correlations to q{T} correlations requires that h be replaced by q/T, and that q and T be separated.). The text includes example problems that validate the conclusion that h (ie q/T) is unnecessary and undesirable, and demonstrate that the solution of nonlinear problems is much simpler if h is abandoned.

SYNTHESIS, MOLECULAR DOCKING AND ANTICANCER ACTIVITY OF NOVEL (E)-5-((1-PHENYL-1H-1,2,3-TRIAZOL-4-YL)METHYLENE)-2-THIOXOTHIAZOLIDIN-4-ONE ANALOGUES

A novel series of (E)-5-((1-Phenyl-1H-1,2,3-triazol-4-yl)methylene)-2-thioxothiazolidin-4-one analogues have synthesized by the condensation of 1-Aryl-1H-1,2,3-triazole-4-carbaldehydes with 2-thioxothiazolidin-4-one. The compounds structure was analyzed by different spectral data such as IR, 1HNMR, 13CNMR and mass spectrometry. The compounds were screened for their in vitro anticancer activity by using four cancer cell lines viz. Lung (A549), Colon (HT-29), Breast (MCF-7) and Melanoma (A375). The screening results evident that the compounds 6g and 6j were most potent against all tested cancer cell lines. The compounds were also tested molecular docking studies, a significant dock scores observed with all the compounds and the compounds 6i and 6b have shown the highest dock scores.

“Il Villariµ, a Famous History School Textbook. The Origins (1964-1971)

This paper addresses Rosario Villari’s scientific activity in the 1960s, when he devoted himself to the writing of the famous History textbook for high schools. Villari’s correspondence with the publisher Laterza enables us to grasp not only the author’s cultural concerns, but also the existential ones. The manuscript submission was repeatedly delayed since he was simultaneously involved in other major works, and mainly in his study into the 1647 Naples revolt against the Spanish rule. Yet, for this reason too Villari managed to condense into his textbook the most recent and stimulating studies and debates of that period, and to transfer the achievements of his own research and of the main international historiography to a schoolbook.

Determinación estadística de factores para mejores prácticas de mercadeo de madera urbana y reciclada como materia prima

Esta investigación trata sobre la determinación estadística de factores catalogados como beneficios y barreras, sobre la utilización de madera urbana y reciclada en el mercado estadounidense. Mediante revisión de literatura se identificaron 14 y 8 variables catalogadas como beneficios y barreras respectivamente, para conformar un modelo inicial, el cual se sometió a consulta a 390 empresas que forman parte de este mercado para medir el nivel de importancia de cada variable basados en su experiencia. Esto se realizó por medio de una encuesta como herramienta de investigación, validada mediante triangulación metodológica (expertos en encuestas, del área académica y de la industria). Se redujo el modelo inicial en uno con 6 y 4 factores para los beneficios y barreras respectivamente, conteniendo las variables que se correlacionan entre sí.
 Para el diagnóstico de la situación actual se confirmó que este mercado es relativamente nuevo, que en su mayoría se utiliza la madera reciclada contra la urbana y que se da un bajo porcentaje de utilización de las variables en sus mensajes promocionales. Las soluciones a los problemas planteados son un modelo de gestión y una propuesta para mejores prácticas de mercadeo, el cual puede significar un aumento de ingresos que generen 60% de utilidad neta extra. Se concluye indicando que es posible resumir las variables dadas por la teoría en un modelo más simplificado, funcionando como fuente de información válida para la elaboración de planes de promoción más eficaces y el reconocimiento de las barreras para la utilización de esta materia prima.

Preparation and Condensation Behavior of Wear Resistant Al-based Superhydrophobic Materials

Preparation and Condensation Behavior of Wear Resistant Al-based Superhydrophobic Materials

Vibration reduction for interaction response of a maglev vehicle running on guideway girders

As a vehicle moves on multiple equal-span beams at constant speed, the running vehicle would be subjected to repetitive excitations from the beam vibrations under it. Once the exciting frequency caused by the vibrating beams coincides with any of the vehicle's frequencies, resonance would take place on the vehicle. A similar resonance phenomenon occurs on a beam subject to sequential moving loads with identical axle-intervals. To reduce both resonant phenomena of a vehicle moving on guideway girders, this study proposed an additional feedback controller based the condensed virtual dynamic absorber (C-VDA) scheme. This condensation scheme has the following advantages: (1) the feedback tuning gains required to adapt the control currents or voltages are directly obtained from the tuning forces of the VDA; (2) the condensed VDA scheme does not need additional DoFs of the absorber to control the vibration of the maglev-vehicle/guideway system. By decomposing the maglev vehicle-guideway coupling system into two sub-systems (the moving vehicle and the supporting girders), an incremental-iterative procedure associated with the Newmark method is presented to solve the two sets of sub-system equations. From the present studies, the proposed C-VDA scheme is a feasible approach to suppress the interaction response for a maglev vehicle in resonance moving on a series of guideway girders.

Total Site Utility System Structural Design Using P-graph

This paper explores the macro optimisation decisions of energy sources selection and the structural design of the utility system within the framework of Total Site Heat Integration (TSHI). Most TSHI research on utility systems focuses on optimisation of conventional Combined Heat and Power systems. To build a new Utility Systems Planner (USP) tool, P-graph has been selected as the optimisation tool. A critical element of USP is the inclusion of low-grade heat utilisation technologies within the considered superstructure. The USP outputs include the optimal structure of the utility system including the arrangement and size of each component and estimates for Greenhouse Gas and Water Footprints. The successful application of the USP to a representative industrial case study with district energy integration shows an optimal solution with a natural gas boiler, reciprocating gas engine, condensing economiser, steam turbine, thermocompressor, organic Rankine cycle, cooling tower, and electric chiller with a total cost of 14.893 M€/y. The new tool is a platform for launching further research including site-specific application, multi-period optimisation, and sensitivity analysis.

Qualitative study of early clinical experience in nursing professional degree graduates

Objective To explore nursing professional degree graduates' understanding and expetance of advanced practice nurses (APN) , reflect on the process of clinical practice teaching, and provide a reference for APN traning by interviewing nursing graduates for their experience of clinical roles. Methods Using the phenomenological method of qualitative research, a semi-structured interview was conducted among 20 individuals, including nursing professional degree graduates who were practiced in clinical for 3 months, instructors and clinical lecturers. The Colaizzi seven-step analysis method is used to repeatedly read, analyze, encode, classify, and refine the interview materials, and summarize the theme ideas. Results After encoding, analyzing and condensing the data, we obtained four themes in APN and their supervisors' training and understanding of APN roles. Theme 1: Combined development of reseatch and clinical abilities, and attention was paid to specialty abilities; theme 2: their overall quality and clinical thinking should be enhanced; theme 3: their professional quality and confidence should be improved; theme 4: a harmonious medical working environment should be built, and policy support should be enhanced. Conclusions Starting from clinical actualities, learning clinical practice experience, exploring nursing students and their supervisors' understanding and expetance of APN, and discussing the problems and causes in current clinical practice training may provide a reference for nursing educators to improve the clinical teaching practice model for APNs. Key words: Nursing professional degree; Advanced practice nurses; Clinical experience; Qualitative study

Experimental Comparison of the Evaporation and Condensation Heat Transfer Coefficients on the Outside of Enhanced Surface Tubes with Different Outer Diameters

An experimental investigation was performed, and results are presented here for an evaporation and condensation heat transfer study that took place using enhanced heat transfer (1EHT) tubes of different outside diameters. Results were compared to the performance of a smooth surface copper tube. The equivalent outer diameter of the horizontal copper tubes considered were 12.7 mm (0.5 in) and 19.05 mm (0.75 in). The test apparatus included a straight horizontal test section with an active length heated by water. Constant heat flux was maintained and refrigerant quality varied.Experimental runs were performed using R410A and R134a as the working ?uids. Experimental condensation results are presented for a fixed inlet/outlet vapor quality and fixed saturation temperature, while mass flux varied; producing a heat transfer coef?cient increase (compared to smooth tube) in the range 54 to 64 %, with a frictional pressure drop increase for the 1EHT tubes in the range of 8 to 31 %. Unexpected evaporation results were found at higher mass flows; producing a decrease (compared to smooth tubes) of the heat transfer coef?cient for 1EHT tubes in the range of 100 – 220 %; with an increase of frictional pressure drop values for the 1EHT tubes in the range 5 to 17 %.Enhanced heat transfer tubes are important options to be considered in the design of high efficiency systems. A wide variety of industrial processes involve the transfer of heat energy during phase change and many of those processes employ old technology. These processes are ideal candidates for a redesign that could achieve improved process performance. Vipertex 1EHT enhanced tubes recover more energy and provide an opportunity to advance the design of many heat transfer products.

Effect of Supersonic Nozzle Structure on Vapor Spontaneous Condensation

To study the effect of the supersonic nozzle structure on the spontaneous condensation of water vapor, the wet steam model used to study the wet steam liquefaction of steam turbine was introduced into the numerical study of supersonic nozzle in supersonic cyclone separator, and the numerical results was in good agreement with the experimental data of the related literature. The supersonic nozzles, the contraction section with the Witozinsky curve and the bicubic curve, and the expansion section with conical curve and Foelsch curves, were designed. The influence of supersonic nozzle structure on water vapour liquefaction ability was investigated. And the following research results were obtained. When the structure of the supersonic nozzle was the same, the Witozinsky curve was selected for contraction section of the supersonic nozzle, and the nucleation rate of the droplet in the nozzle increased by 21.97 % and the number of droplets increased by 32.16 %, which was helpful to the gas liquefaction in the nozzle. When the contraction curve of the supersonic nozzle was consistent, and the expansion curve was Foelsch curve, the gas nucleation rate and the number of droplets in the nozzle were greatly improved. The distribution of nozzle humidity was related to the structure of expansion section, but not to the structure of contraction section. The maximum humidity in nozzle depended on the outlet diameter of nozzle. When the other structures of the nozzle were consistent, the cone angle of divergent section increased from 2° to 8°, the peak value of the nucleation rate increased by 493.15 %, the maximum of the droplet number increased by 246.12 %, the outlet humidity of the nozzle increased by 73.37 %, which greatly improved the gas liquefaction rate. In the case of gas liquefaction, increasing the cone angle of expansion section was conducive to liquefaction of water vapor.

Process Simulation of Syngas Purification by Gas Permeation Application

Nowadays, syngas production from renewable energy sources particularly by methanation process has taken great interest. The aim of the process is energy saving by converting surplus produced energy into a truthful chemical product. Methanation reactor outlet stream contains a gas mixture which is not feasible to be used directly in distributing grids, where a higher purity of methane is necessary to obtain the highest power density. To reach the different grades of methane (for heat, electricity and vehicle fuels applications), various purification levels should be provided for syngas. For use as a fuel, elimination of carbon dioxide and water is needed, because water affects negatively on the mechanical components within the vehicles’ engine equipment. Moreover, CO2 removal should be carried out to enhance heat quality of methane and cause less pollution in the atmosphere. In the current study, the performance of a combination of flash separator and hollow fiber membranes for syngas purification was studied. For this purpose, a flash separator model was implemented to condense water from the wet feed. Then for the elimination of CO2 from methane, a hollow fiber membrane system was considered. Therefore, a unit operation user model in FORTRAN was developed to incorporate into Aspen Plus® V8.6. Different designs and arrangements of membrane modules were compared, and the best result was to purify methane up to 98 %vol. obtained using a two-stage gas permeation system with recycle streams. The model scheme can be beneficial in the design and performance analysis of a complex methanation plant system prior to practical realization.