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Feed spacers in reverse osmosis systems generate complex fluid flows that limit computational fluid dynamics (CFD) simulations to small length and time scales. That limits our ability to simulate mineral scaling and other membrane fouling phenomena, which occur over longer length and time scales. Thus motivated, we develop a reduced model that replaces the CFD simulation of the velocity field with an analytical model that mimics spacers. This focuses the remaining numerical effort on simulating the advection–diffusion equation governing solute transport. We motivate and validate the model with CFD simulations and bench-scale experiments of spacer filaments in three different arrangements, including cases of unsteady vortex shedding. We show that the model produces a roughly 10,000-fold speedup compared to CFD, and accurately reproduces CFD predictions of not only the average and maximum concentrations, but also the local concentration distribution along the membrane. We also demonstrate the model for simulating a feed channel with a length-to-height ratio of 200. The model provides a simple testbed for exploratory studies of multispecies transport, precipitation, and membrane fouling phenomena for which simulating spacers is often prohibitive.

The authors developed and validated the Korean version of the Experiences in Close Relationships-Short Form (K-ECRR-SF) with the goal of developing a culturally responsive scale. In study 1, a Rasch analysis was conducted on the 36 original items in the ECR-Revised (ECR-R) to select items that best represent anxiety and avoidance subscales by considering cultural equivalence. In study 2, confirmatory factor analysis (CFA) was conducted for the selected 12 items with a different sample. The factor structures of the ECR-R and K-ECRR-SF through CFA were then compared through CFA. In addition, the K-ECRR-SF items were tested for related constructs (i.e., reassurance and support seeking, loneliness, dyadic satisfaction, depression, anxiety, and fear of intimacy) to its criterion evidence. The newly developed K-ECRR-SF is confirmed to be valid and culturally responsive scale in measuring attachment in Korea.

Objective: This study examined the association among media, parental influence self-concept clarity (SCC), body image, and depression. Participants: 275 college students in South Korea participated in the survey. Methods: A structural equation model was applied to test the mediation model. Results: Results supported the hypothesized model and indicated that SCC mediated the association between media association and negative body image. Moreover, parental influence was directly associated with negative body image which, in turn, was associated with depression. Conclusions: Given that SSC mediates media's influences on college students' body image, practitioners can help students who are suffering from negative body image to have a clear sense of self by exploring other aspects of one's self, other than body image. Parental influences directly affected college students' body image in S. Korea, and these results conceptualize negative body image in terms of individual SSC with cultural consideration.

Standard method for the measurement of guar gum and other carbohydrates in produced water from the oil and gas industry. Written in compliance with USEPA protocols for the State of California agenciesANALYTE:D-Glucose, CAS#50-99-7D-Mannose, CAS# 3458-28-4D-Galactose, CAS#59-23-4D-Lactose, CAS#63-42-3Guar Gum, CAS#9000-30-0INSTRUMENTATION:PerkinElmer Lambda 35 UV/VIS Spectrophotometer1.0Scope and Application1.1This method covers the determination of mannose, guar gum and other carbohydrates in produced water samples.1.2Sugars have varying response factors by this method (Figure 1) and the carbohydrate used for calibration must be specified in the result.1.3The method is based on standard curves that are specific for mannose, one of two sugars in commercial guar gum, such that the final carbohydrate concentration is expressed as mannose, mg/L. 1.4Commercial guar gum should not be used as a calibration standard, due to variability in chemical composition and purity. 1.5Glucose is not a structural component of guar gum and is therefore not recommended as a calibration standard.1.6The method is usable in the 6 to 1000 mg/L as mannose range. Detection range may be variable according to the instrument used.2.0Summary of MethodGuar gum, a polysaccharide of galactose and mannose, is a common ingredient for hydraulic fracturing fluids [7]. Standard methods for measuring carbohydrates in flow-back and other produced water are needed, particularly in the context of reporting water quality data to regulatory agencies [6]. This method describes standard procedures for carbohydrate measurement that have been validated for use in produced water. Heating produced water with sulfuric acid hydrolyzes polysaccharides and dehydrates monosaccharides to form 2-furaldehyde from pentoses and 5-(hydroxymethyl)-2-furaldehyde from D-glucose and other hexoses [2, 8]. 2-Furaldehyde and 5-(hydroxymethyl)-2-furaldehyde reacts with anthrone to form a green colored compound [1, 2, 3, 5]. Total carbohydrate is quantified by measuring absorbance of known and unknown samples at 625 nm [2].

Purpose: This study aimed to gain an in-depth understanding of the meaning and nature of nursing doctoral students' lived work-life balance experiences. Methods: A qualitative descriptive study was conducted with 11 doctoral nursing students who worked and raised children. In-depth interviews were conducted to collect data, providing insight into the participants' work-life balance experiences. As proposed by van Manen, four lifeworld existential, namely lived place, lived body, lived time, and lived relations, were used for qualitative data analysis. Results: Four existential themes emerged: 1) existing in multiple spaces; 2) busy, tired, hard, and painful but must endure; 3) time to endure and grow until the end of schooling; and 4) realizing walls of togetherness. Conclusions: This study explored how the work and life of doctoral nursing students with multiple roles are balanced and how they relate to others in different contexts. We revealed the problems and difficulties they face in their daily lives and the centres and motives behind their lives. Support from families, universities, and workplaces is needed to continue the Ph.D. program, which will eventually ensure the quality of the discipline. [ABSTRACT FROM AUTHOR]

Key points The peristaltic reflex has been a central concept in gastrointestinal motility; however, evidence was published recently suggesting that post‐stimulus responses that follow inhibitory neural responses provide the main propulsive force in colonic motility. This new concept was based on experiments on proximal colon where enteric inhibitory neural inputs are mainly nitrergic. However, the nature of inhibitory neural inputs changes from proximal to distal colon where purinergic inhibitory regulation dominates. In spite of the transition from nitrergic to purinergic regulation, post‐stimulus responses and propulsive contractions were both blocked by antagonists of a conductance (ANO1) exclusive to interstitial cells of Cajal (ICC). How purinergic neurotransmission, transduced by PDGFRα+ cells, can influence ANO1 in ICC is unknown. We compared neural responses in proximal and distal colon. Post‐stimulus responses were blocked by inhibition of nitrergic neurotransmission in proximal colon, but P2Y1 receptor antagonists were more effective in distal colon. Ca2+ entry through voltage‐dependent channels (CaV3) enhances Ca2+ release in ICC. Thus, we reasoned that hyperpolarization caused by purinergic responses in PDGFRα+ cells, which are electrically coupled to ICC, might decrease inactivation of CaV3 channels and activate Ca2+ entry into ICC via anode‐break upon cessation of inhibitory responses. Post‐stimulus responses in distal colon were blocked by MRS2500 (P2Y1 receptor antagonist), apamin (SK channel antagonist) and NNC55‐0396 (CaV3 antagonist). These compounds also blocked propagating contractions in mid and distal colon. These data provide the first clear demonstration that integration of functions in the smooth muscle–ICC–PDGFRα+ cell (SIP) syncytium generates a major motility behaviour. Propagating propulsive contractions initiated by the enteric nervous system are a major motility behaviour in the colon. A major component of contractions, necessary for propulsive contractions, occurs at cessation of enteric inhibitory neurotransmission (post‐stimulus response) and is generated by interstitial cells of Cajal (ICC), which are electrically coupled to smooth muscle cells. The nature of enteric inhibitory neurotransmission shifts from proximal colon, where it is predominantly due to nitric oxide, to distal colon, where it is predominantly due to purine neurotransmitters. Different cells transduce nitric oxide and purines in the colon. ICC transduce nitric oxide, but another type of interstitial cell, PDGFRα+ cells, transduces input from purinergic neurons. However, the post‐stimulus responses in proximal and distal colon are still generated in ICC. This paper explores how integrated behaviours of ICC, PDGFRα+ cells and smooth muscle cells accomplish propulsive motility in the colon. [ABSTRACT FROM AUTHOR]

In this paper, we proposed the development of stackable 3D ferroelectric random-access memory (FeRAM), with two select transistors and n capacitors (2TnC), to address scaling limitations for bit density growth and the complicated manufacturing of 3D dynamic random-access memory (DRAM). The proposed 3D FeRAM has a 3D NAND-like architecture, with stacked metal–ferroelectric–metal (MFM) capacitors serving as memory cells in a unit string. A similar manufacturing process is used to achieve a cost-effective process and high bit density for next-generation DRAM applications. The two access transistors, string–select–line (SSL) and ground–select–line (GSL), are perfect string selections. We confirmed that the grounded back gate (GBG) of the proposed architecture can significantly improve the worst disturbance case compared to a floating back gate (FBG) like the 1TnC structure. Also, we confirmed the feasibility of performing the random-access operation during the read operation regardless of the data pattern of the selected string. [ABSTRACT FROM AUTHOR]

Although graphene has created a strong wave of enthusiasm after its discovery in 2004 and the subsequent Nobel prize awarded to the two detectors in 2010, there is no clear information how people with special interests in it feel toward the possibility of its commercial value over time. The objective of this study is to identify graphene sentiment shift and major discussion topics among the interested public on Reddit by presenting an effective tool for extracting public opinions in social media. To achieve this, we processed 11,287 comments collected from the Reddit from 2010 to 2021, and applied text mining techniques, including sentiment analysis. This study found that over half of the comments were positive toward graphene, and specific sentiment fluctuated commensurate with major events, for example, Nobel Prize, commercialisation delay and wide applications to the industry. Our research proved that public sentiments toward graphene technology follow a similar trend to the hype cycle by deriving a sentiment hype cycle for graphene. This study provides a convincing case for understanding shifts in the sentiments of the interested public regarding new technology, such as graphene, which will interest graphene technology R&D experts and policy-makers. [ABSTRACT FROM AUTHOR]