bluuebunny/crossref_metadata_2025 huggingface dataset:
Is speciation an unrelenting march to reproductive isolation?
Authors: Cannon Charles H.
Published: August 2021

Speciation is often portrayed as an “incomplete” or “incipient” process if two groups of organisms, technically distinguishable either by morphology or genetics, can exchange genes. The ultimate outcome of diversification, given this perspective, is complete reproductive isolation. But an increasing amount of evidence suggests that speciation is rarely complete and inter‐fertility between different taxonomically accepted species is consistently maintained. In this issue of Molecular Ecology, Linan et al. (2021) provide results that bridge evolutionary processes from populations to phylogenies that indicate suites of closely related tree species in the Mascarene Islands actively exchange genes, evolving as a nested set of syngameons with a hierarchical pattern of interfertility. The deep insight into diversification provided by this study is particularly powerful because of the genomic scale of the data and the complete taxonomic sampling of an island clade evolving in situ. The prevalence of syngameon dynamics in a broad range of organisms indicates that we should adopt a fluid and comprehensive approach to defining evolutionary units for conservation and research. We should move beyond focusing on single endangered species in evolutionary and ecological isolation from other species but consider the entire network of potentially interfertile species and the potential for future adaptation and innovation, particularly in a human dominated world.
Impaired brain insulin signalling in Parkinson's disease
Authors: Bassil Fares , Delamarre Anna , Canron Marie‐Hélène , Dutheil Nathalie , Vital Anne , Négrier‐Leibreich Marie‐Laure , Bezard Erwan , Fernagut Pierre‐Olivier , Meissner Wassilios G.
Published: August 2021

Aims

Brain insulin resistance (i.e., decreased insulin/insulin‐like growth factor‐1 [IGF‐1] signalling) may play a role in the pathophysiology of Parkinson's disease (PD), and several anti‐diabetic drugs have entred clinical development to evaluate their potential disease‐modifying properties in PD. A measure of insulin resistance is the amount of the downstream messenger insulin receptor substrate‐1 that is phosphorylated at serine residues 312 (IRS‐1pS312) or 616 (IRS‐1pS616). We assessed IRS‐1pS312 and IRS‐1pS616 expression in post‐mortem brain tissue of PD patients and a preclinical rat model based on viral‐mediated expression of A53T mutated human α‐synuclein (AAV2/9‐h‐α‐synA53T).

Methods

IRS‐1pS312 and IRS‐1pS616 staining intensity were determined by immunofluorescence in both neurons and glial cells in the substantia nigra pars compacta (SNc) and putamen of PD patients and controls without known brain disease. We further explored a possible relation between α‐synuclein aggregates and brain insulin resistance in PD patients. Both insulin resistance markers were also measured in the SNc and striatum of AAV2/9‐h‐α‐synA53T rats.

Results

We found higher IRS‐1pS312 staining intensity in nigral dopaminergic neurons and a trend for higher IRS‐1pS312 staining intensity in putaminal neurons of PD patients. We observed no differences for IRS‐1pS616 staining intensity in neurons or IRS‐1pS312 staining intensity in glial cells. IRS‐1pS312 showed high co‐localisation within the core of nigral Lewy bodies. Like PD patients, AAV2/9‐h‐α‐synA53T rats showed higher IRS‐1pS312 staining intensity in the SNc and striatum than controls, whereas IRS‐1pS616 was not different between groups.

Conclusions

Our results provide evidence for brain insulin resistance in PD and support the rationale for repurposing anti‐diabetic drugs for PD treatment.
The family intensive care unit syndrome: A qualitative content analysis
Authors: Saeid Yaser , Moradian Seyed Tayeb , Ebadi Abbas , Salaree Mohammad Mahdi
Published: August 2021

Background

Hospitalization of patients in an intensive care unit (ICU) is associated with a series of psychological problems for their family members called family intensive care unit syndrome (FICUS). Nonetheless, family members of patients in ICU often receive little attention from health care providers. Exploring family members' experiences of their patients' hospitalization in ICU helps health care providers focus more clearly on their problems.

Aims and objectives

This study aimed to explore FICUS‐related experiences among the family members of patients in ICU.

Design

This was a qualitative content analysis study.

Methods

This qualitative study was conducted in 2019. Participants were 14 family members of patients in ICU who were purposively selected from three hospitals in Tehran, Iran. Data were collected using semi‐structured interviews and were analyzed using qualitative content analysis.

Results

Participants' experiences of FICUS fell into four categories, that is, threat to psychological well‐being (with four subcategories), threat to physical health (with three subcategories), threat to social health (with three subcategories), and change in spiritual orientation (with two subcategories). The 12 subcategories of these categories were emotional disturbances, hopelessness, changes in sleep pattern, mood changes, physical symptoms, aggravation of the existing illnesses, negligence towards personal health, alteration in social interactions, alteration in the burden of responsibility, alternation in the life process, resort to spiritual beliefs, and spiritual conflict, respectively.

Conclusion

FICUS symptoms are not limited to psychological problems, rather they include a wide range of psychological, physical, social, and spiritual problems, which can affect the different aspects of family members' lives. Along with care delivery to patients in ICU, health care providers should provide care and support to patients' family members.

Relevance to clinical practice

FICUS is a major threat to health among the family members of patients in ICU. Careful assessment of these family members helps identify family members who are at risk for FICUS and identify FICUS effects on their decisions and health status.
Long‐term experience using CNI‐free immunosuppression in selected paediatric heart transplant recipients
Authors: Rosenthal Lisa‐Maria , Nordmeyer Johannes , Kramer Peter , Danne Friederike , Pfitzer Constanze , Berger Felix , Schmitt Katharina Rose Luise , Schubert Stephan
Published: August 2021

Background

CNI‐free immunosuppression with conversion to mTORi‐based immunosuppression has been demonstrated to reduce CNI‐toxicity and to exhibit anti‐proliferative properties. However, the experience of CNI‐free immunosuppression in paediatric heart transplantation is limited.

Methods

A retrospective analysis was conducted of 129 paediatric heart transplants performed between 1997 and 2015. Fifteen patients with clinically indicated conversion from CNI‐based to CNI‐free immunosuppression were identified. Survival data, rejection episodes, renal function, post‐transplantation lymphoproliferative disorder and CAV, including examination with OCT were analysed.

Results

Immunosuppression conversion was successful in all patients. Fourteen of 15 patients (93%) are currently living with good graft function. Median post‐transplant survival was 15 years (range, 5–23 years), and median follow‐up since conversion was 6 years (range, 1–11 years). Mild (grade 1R) ACR was present in three patients after discontinuation of CNIs. The recovery of renal function with a significant increase in eGFR was observed at 1 and 3 years after conversion. No patient had angiographic signs of macroscopic CAV according to the current ISHLT classification; however, OCT showed the signs of angiographically silent CAV in all patients. CAV did not progress in any patient, implying CAV was stabilised by mTORi‐based CNI‐free immunosuppression.

Conclusions

CNI‐free immunosuppression based on mTORis is a safe and appropriate strategy for maintenance therapy in selected paediatric patients, significantly improves renal function and stabilises CAV. OCT revealed early development of angiographically silent CAV.
Pathogenic and genetic diversity ofPuccinia triticinafrom triticale in Poland between 2012 and 2015
Authors: Czajowski Grzegorz , Kosman Evsey , Słowacki Piotr , Park Robert F. , Czembor Paweł
Published: August 2021

Variation amongPuccinia triticinaisolates collected from triticale in Poland between 2012 and 2015 was studied based on virulence and simple sequence repeat (SSR) markers. Two hundred and forty‐two single‐uredinial isolates from four geographically separated locations were tested for virulence against 33 near‐isogenic Thatcher lines containing knownLrresistance genes, and their molecular genotypes were characterized with 34 SSR markers. Structure and relationships of the regional and annual populations ofP.triticinawere analysed using an assignment‐based approach for both the virulence and SSR data. The molecular marker analysis was based on two different models of SSR evolution: the stepwise mutation model with a variable mutation rate (SMMv) and the infinite alleles model (IAM). A highly significant deviation from Hardy–Weinberg equilibrium among SSR genotypes, a high proportion of heterozygotes, and a moderate association of relationships between virulence phenotypes and SSR genotypes were consistent with the occurrence of clonal lineages of related races within the population. While the results suggest that genetic drift and mutation affect variation within the pathogen population, it seems that migration has the most significant role in shaping the population structure ofP.triticinaoccurring on triticale in Poland.
Foliar melatonin stimulates cotton boll distribution characteristics by modifying leaf sugar metabolism and antioxidant activities during drought conditions
Authors: Khattak Wajid Ali , He Jiaqi , Abdalmegeed Dyaaaldin , Hu Wei , Wang Youhua , Zhou Zhiguo
Published: August 2021

Drought is a severe abiotic stress affecting the plant's antioxidant system and interrupting compatible solute translocation processes, which leads to low productivity. Melatonin acts as a common growth regulator enhancing the plants defense system and regulates sugar metabolism in challenging environments. Melatonin treatments enable plants to be tolerant to abiotic stresses via enhancing their recovery potential, but its impact using various concentrations has not yet been studied in leaf physiological aspects when applied to cotton foliage during their peak flowering and boll loading stage. The overall objective of this research was to facilitate cotton boll distribution characteristics by modifying cotton leaf sugar metabolism and antioxidant activity by applying foliar melatonin (0, 25, 50, and 100 μmol l−1) under drought levels with a relative soil water content of 75%, 60%, and 45% ± 5 (FC1, FC2, and FC3, respectively). Higher rates of melatonin application (100 μmol l−1) enhanced boll distribution characteristics and controlled the boll shedding rate during drought conditions. An increase in melatonin rates proved to be more helpful in stimulating cotton sympodial leaf physiological attributes, including leaf gas exchange parameters, sugar metabolism, proline content, and antioxidants defense system as compared with less or no melatonin application during all FC conditions and showed the most significant effect at a higher melatonin concentration (M100) at 7–21 DAF. The total proline content and antioxidant activity were enhanced in the M100 treatment during all FC levels, which caused a reduction in the total malondialdehyde (MDA) contents and hydrogen peroxide (H2O2) concentrations in cotton leaves. Moreover, sugar metabolism responsible genes GhSusA and SPS2 showed an upsurge in expression levels and enhanced sucrose degradation in M100 treatments during all FC levels. Furthermore, cotton boll attributes showed also a positive relation with leaf physiological and gas exchange attributes. The results suggested that foliar melatonin application during the flowering initiation stage improved the overall performance and is helpful for cotton crops productivity against drought stress.
The Law: “Beyond the Torture Memos: How the Office of Legal Counsel Matters for Executive Branch Scholarship”
Authors: Hollis‐Brusky Amanda , Cui Isaac
Published: August 2021

The Office of Legal Counsel (OLC) in the U.S. Department of Justice offers binding legal advice to the executive branch, including the president. Its advice touches most aspects of law, but it is especially influential for its interpretation of constitutional provisions that rarely, if ever, are subject to judicial scrutiny. While its importance is acknowledged by journalists, law professors, and legal practitioners, political science has yet to incorporate OLC systematically into studies of the presidency outside the ambit of war and emergency powers—areas where OLC achieved notoriety during the George W. Bush administration. We argue that there are unique and important reasons for political scientists to study OLC beyond its War on Terror legacy. In this essay, we construct a theory‐driven research agenda for incorporating OLC into studies of the rhetorical and administrative presidencies, Neustadtian bargaining and the unilateral presidency, and transformative bureaucracy.
Bridging the ideological gap? How fairness perceptions mediate the effect of revenue recycling on public support for carbon taxes in the United States, Canada and Germany
Authors: Jagers Sverker C. , Lachapelle Erick , Martinsson Johan , Matti Simon
Published: August 2021

Carbon taxes are frequently advocated as a means of reducing greenhouse gas (GHG) emissions, yet their political feasibility remains a challenge. To enhance their political appeal, carbon tax proponents have proposed revenue recycling as a means of alleviating public concern with this instrument's visible costs. Analyzing data from identical survey‐experiments administered in the United States, Canada, and Germany, we examine the extent to which returning revenues to the public has the potential to broaden the political acceptability of carbon taxes across ideological and national contexts. While public opinion is sensitive to the cost attributes of carbon taxes, we find that in some cases, opposition to carbon taxes can be offset by a reduction in income taxes. However, these effects tend to be modest in size, limited to some ideological groups, and varied across countries. Moreover, we demonstrate that fairness perceptions are a crucial mechanism linking revenue recycling to carbon tax support in all countries examined.
Existence, uniqueness and stability of forced waves to the Lotka‐Volterra competition system in a shifting environment
Authors: Wang Hongyong , Pan Chaohong , Ou Chunhua
Published: August 2021

We studied the existence, uniqueness, and stability of forced traveling waves for the Lotka–Volterra competition system in a shifting habitat. Based on the asymptotic behaviors of the wave profiles and by means of upper–lower solution method coupled with sliding technique, we showed that the forced wave for the system exists and is unique, when the forced speed lies in a specific interval. Explicit expressions of the two end pointsof this interval were derived and our finding indicated that they are related to the Fisher‐KPP‐type invasion speed. Furthermore, we established a squeezing theorem to show the local stability of the forced waves. Finally, with the aid of comparison principle, we established the global stability of the forced waves when the initial data were properly assigned.
Keratinocytes secrete multiple inflammatory and immune biomarkers, which are regulated by LL‐37, in a psoriasis mimicking microenvironment
Authors: Sigurgrimsdottir Hildur , Bjornsdottir Eva Osp , Eysteinsdottir Jenna Huld , Olafsson Jon Hjaltalin , Sigurgeirsson Bardur , Agnarsson Bjarni A. , Einarsdottir Helga Kristin , Freysdottir Jona , Ludviksson Bjorn Runar
Published: August 2021

Psoriasis is an autoimmune disease driven by a Th17 response linked to the antimicrobial peptide (AMP) LL‐37 that has been connected to the induction and chronicity of psoriasis. We show that keratinocytes secrete various immune biomarkers with a direct link to psoriasis immunopathogenesis. Under pro‐inflammatory microenvironmental conditions, LL‐37 was found to regulate keratinocyte secretion of various immune biomarkers (eg C‐X‐C motif chemokine ligand (CXCL)8 and interleukin (IL)‐1β) and alter extracellular signal‐regulated kinase (ERK)1/2 signalling. However, during neutral conditions LL‐37 induced a different pattern of keratinocyte immune biomarker secretion (eg vascular endothelial growth factor, CXCL8 and IL‐6). Thus, an interesting pattern emerged regarding the immunomodulatory effects of LL‐37 on keratinocytes; in general, expression of immune biomarkers that were upregulated in a Th1‐like microenvironment was downregulated in the presence of LL‐37. In contrast, LL‐37 reinforced the Th17 response. In active psoriatic skin lesions, LL‐37 expression was found to be significantly upregulated, which was also evident from the unique diffuse epidermic expression pattern not found in healthy skin. Finally, successful phototherapy of psoriasis patients converted this LL‐37 inflammatory psoriatic skin pattern into a more localized basal layer expression as found in healthy controls. Thus, these findings demonstrate that LL‐37 has a significant role in skin immune homeostasis and that its interplay with keratinocytes may have a more direct role in the immunopathogenesis of psoriasis than previously thought.
Six weeks of intensive rehearsals for the Swan Lake ballet shows ultrasound tissue characterization changes of the Achilles tendons in dancers
Authors: Anker‐Petersen Charlotte , Juul‐Kristensen Birgit , Antflick Jarrod , Aagaard Henrik , Myers Christopher , Boesen Anders Ploug , Boyle Eleanor , Hölmich Per , Thorborg Kristian
Published: August 2021

The objective was to investigate, first, whether six weeks of intensive ballet dance exposure is associated with structural and clinical changes in the Achilles tendon; second, the importance of demographics, self‐reported Achilles pain, and generalized joint hypermobility (GJH). Data were collected at baseline and at six weeks’ follow‐up, using Achilles tendon ultrasound tissue characteristics (UTC) as primary outcome (percentage distribution of echo‐type I–IV: type I = intact and aligned bundles, type II = discontinuous/wavy bundles, type III = fibrillar, and type IV = amorphous cells/fluid). Secondary outcomes included clinical signs of Achilles tendinopathy, Achilles tendon pain during single‐leg heel raise, self‐reported symptoms (VISA‐A questionnaire), and GJH. Sixty‐three ballet dancers (aged 18–41) participated. From baseline to follow‐up, UTC echo‐type I decreased significantly (β = −3.6, p = 0.001; 95% CI: −5.8;−1.4), whereas echo‐type II increased significantly (β = 3.2, p < 0.0001, 95% CI: 1.6;4.8). Furthermore, a significant effect of limb (left limb showed decreased echo‐type I and increased echo‐type III + IV) and sex (women showed decreased echo‐type I and increased in type II) was found. No significant changes in the remaining secondary outcomes were found. Ballet dancers showed structural changes in UTC, corresponding to a decreased echo‐type I distribution after six weeks of rehearsing for Swan Lake ballet. No changes in self‐reported symptoms, clinical signs of Achilles tendinopathy, and single‐leg heel raise test were seen from pre‐ to post‐rehearsal. Thus, UTC changes in the Achilles tendon seem to appear earlier than clinical signs of tendinopathy.
Effect of glecaprevir/pibrentasvir on weight‐adjusted tacrolimus trough/dose ratios in heart and kidney transplant recipients
Authors: Nnani Daryl U. , Campbell Alesa , Ajaimy Maria , Saeed Omar , Patel Snehal R. , Ahmed Sana , Graham Jay A. , Jorde Ulrich P.
Published: August 2021

Objective

The pharmacokinetic implications of direct‐acting antiviral (DAA) use on tacrolimus posttransplant are unknown. This study sought to investigate the effects of glecaprevir/pibrentasvir (G/P), a CYP3A4 substrate and inhibitor, on weight‐adjusted tacrolimus (FK) trough/dose ratio (T/D) following heart or kidney transplantation.

Material and methods

This was a single‐center, retrospective analysis of hepatitis C virus (HCV) viremic donors to HCV negative heart or kidney transplant recipients who received 12 weeks of G/P therapy. Weight‐adjusted T/D was assessed while patients were at steady‐state before, during, and after G/P treatment. Forty‐one HCV negative recipients (three heart, 38 kidney) were evaluated.

Results

The weight‐adjusted T/D significantly increased during G/P treatment (119.31, IQR 88–173.8) compared to before G/P treatment (67.4, IQR 53.4–115.9) (p < 0.01), but decreased after completion of treatment (90.1, IQR 52.9–122.7) (p < 0.01). There was no difference in weight‐adjusted T/D before and after G/P treatment (p = 0.42). Four patients experienced acute rejection.

Conclusion

Initiation of G/P in heart or kidney transplant recipients induces a reversible change in tacrolimus metabolism. A 33%–50% tacrolimus dose reduction may be considered at the time of G/P initiation. Regardless of tacrolimus dose adjustment, tacrolimus trough levels should be monitored 3 days after initiation of G/P. No clear relationship between HCV viremic organ transplantation and rejection risk was found. Larger studies are warranted to validate these findings
Alloimmunisation rate of patients on Daratumumab: A retrospective cohort study of patients in England
Authors: Bullock Tom , Foster Amie , Clinkard Bryony
Published: August 2021

Objective

Whilst small‐scale studies on rates of alloimmunisation of patients on Daratumumab have been undertaken, no large‐scale study has been performed to date on this cohort of patients.

Background

Patients with multiple myeloma (MM) who are relapsed or refractory to standard treatment are treated with the anti‐CD38 therapeutic monoclonal antibody, Daratumumab. Due to the complexity of pre‐transfusion compatibility testing, many MM patients in England are referred to Red Cell Immunohaematology (RCI) laboratories for investigation and provision of Red Blood Cell (RBC) components.

Methods

Over a 4‐month period, patients due to commence, or currently on anti‐CD38 therapy were identified and flagged on the RCI Laboratory Information Management System (LIMS). Data was identified and extracted for further analysis. Interrogation of data was performed independently by two subject matter experts, with discrepancies resolved through further enquiry.

Results

Of 734 English MM patients, we report an alloimmunisation rate of 0.4% whilst on an anti‐CD38 TMAb. This is in line with other smaller cohort studies.

Conclusion

Given the low rate of RBC alloimmunisation, consideration should be given to revising the pre‐transfusion testing regimen in this cohort. This may improve testing costs, turn‐around times and evidence‐based patient care.
Cotrimoxazole versus sulfadoxine–pyrimethamine for intermittent preventive treatment of malaria in HIV‐infected pregnant women in Bangui, Central African Republic: A pragmatic randomised controlled trial
Authors: Manirakiza Alexandre , Tondeur Laura , Ketta Marie Yvette Batoumbou , Sepou Abdoulaye , Serdouma Eugène , Gondje Samuel , Bata Ghislain Géraud Banthas , Boulay Aude , Moyen Jean Methode , Sakanga Olga , Le‐Fouler Lenaig , Kazanji Mirdad , Briand Valerie , Lombart Jean Pierre , Vray Muriel
Published: August 2021

Objective

The main objective of the MACOMBA (Maternity and Control of Malaria‐HIV co‐infection in Bangui) trial was to show that cotrimoxazole (CTX) is more effective than sulphadoxine–pyremethamine–IPTp (IPTp‐SP) to prevent placental malaria infection (primary end point) among HIV‐positive pregnant women with a CD4+ count ≥350 cells/mm3 in Bangui, CAR.

Methods

MACOMBA is a multicentre, open‐label randomised trial conducted in four maternity hospitals in Bangui. Between 2013 and 2017, 193 women were randomised and 112 (59 and 53 in CTX and IPTp‐SP arms, respectively) were assessed for placental infection defined by microscopic parasitaemia or PCR.

Results

Thirteen women had a placental infection: five in the CTX arm (one by microscopic placental parasitaemia and four by PCR) and eight by PCR in the SP‐IPTp (8.5% vs. 15.1%, p = 0.28). The percentage of newborns with low birthweight (<2500 g) did not differ statistically between the two arms. Self‐reported compliance to CTX prophylaxis was good. There was a low overall rate of adverse events in both arms.

Conclusion

Although our results do not allow us to conclude that CTX is more effective, drug safety and good compliance among women with this treatment favour its widespread use among HIV‐infected pregnant women, as currently recommended by WHO.
Geography’s trajectories in Philippine higher education
Authors: Saguin Kristian Karlo , Lopez Yany , Cadag Jake Rom , De Guzman Mylene , Garcia Emmanuel
Published: August 2021

This piece situates the challenges and opportunities for Geography as a discipline amid the setting of Philippine higher education. By charting the discipline’s historical transformations and contemporary trajectories in the spheres of pedagogy, research, and service learning, it presents a particular picture of Geography’s place and possible futures within a global South context. Despite its disciplinal marginality rooted in institutional constraints in the country’s higher education system, Geography is at a crucial juncture in expanding its visibility and reach, and magnifying its relevance and transformative potentials in the Philippines.
Influence of preconstructed effector loop location using a barbed unidirectional suture on leakage pressures following canine enterotomy closure
Authors: Chang Yi‐Jen , Duffy Daniel J. , Moore George E.
Published: August 2021

Objective

To evaluate the influence of preconstructed effector loop location using a barbed unidirectional suture on leakage pressures following canine enterotomy closure.

Study design

Randomized, experimental, cadaveric.

Animals or sample population

Grossly normal jejunal segments from three canine cadavers.

Methods

Jejunal segments were harvested and randomly assigned based upon effector loop location from the beginning of the incisional line. Groups (n = 12/group) included 0 mm, 5 mm, 10 mm, 15 mm, and intact controls (n = 6/group), repaired using a 3–0 unidirectional barbed suture in a simple continuous pattern. Initial leakage pressure (ILP), maximum intraluminal pressure (MIP), repair time, and leakage location were recorded.

Results

Mean ILP for 0 mm group (24.42 ± 8.43 mmHg) was lower (p ≤ .001) compared to all experimental groups with ILP ~40% lower. There was no difference in MIP among experimental groups (p = .239). Repair time increased (p < .0001) as the distance of the effector loop increased ≥5 mm from the beginning of the incisional line. Leakage location differed among groups (p < .001) with leakage in the 0 mm group from the incisional line (75%), compared to leakage from predominantly from the suture holes in other groups, respectively.

Conclusion

Effector loop location influenced ILP and leakage location. Effector loops placed at the beginning of the incisional line (0 mm) decreased ILP compared to loops placed at 5, 10, and 15 mm.

Clinical significance

Effector loop location using a unidirectional barbed suture should be placed ≥5 mm from beginning of the incisional line for enterotomy closure. Further in vivo studies are necessary to determine the clinical significance of these findings.
Synchronization Via Fractal–Fractional Differential Operators on Two-Mass Torsional Vibration System Consisting of Motor and Roller
Authors: Abro Kashif Ali , Atangana Abdon
Published: August 2021

Due to increasing demand of lightweight shafts from industries, the drive systems are crucially demanded for larger inertias of motors and load machines because of control structures for the electrical equipment. The mathematical modeling of two-mass torsional vibration system consisting of motor and roller has been proposed via newly presented fractal–fractional differential operators. The dynamical model of the electromechanical coupling main drive system of rolling mill is based on total kinetic energy and potential energy on the basis of two degree-of-freedom. The fractal and fractional evolutionary differential equation containing nonlinearity have been investigated for the derivation of numerical schemes. Three types of numerical schemes say Caputo differential scheme, Caputo–Fabrizio differential scheme, and Atangana–Baleanu differential scheme have been established through Adams–Bashforth–Moulton method. In order to check the stability and effectiveness, we presented the chaotic comparison of Caputo fractal– fractional operator, Caputo–Fabrizio fractal–fractional operator, and Atangana fractal–fractional operator on the basis of dynamical embedded parameters (vibration angle, rotational speed, stiffness coefficient, load friction damping torque, and few others). Our results suggest that fractal–fractionalized model for electromechanical drive system of rolling mill has better attenuation performance and tracking behaviors in comparison with classical models.
Analysis of ESFR Decay Heat Removal Systems in Protected Station Blackout
Authors: Bodi Janos , Ponomarev Alexander , Bubelis Evaldas , Mikityuk Konstantin
Published: August 2021

As part of the European sodium fast reactor (ESFR)-safety measures assessment and research tools (SMART) project, safety assessments are being conducted on the updated ESFR design. An important part of the study is the evaluation of the reactor's behavior within hypothetical accidental conditions to assess and ensure that the accident would not lead to unexpected and disastrous events. In this paper, the analyzed accidental scenario is the so-called protected station blackout (PSBO), where the offsite power is lost for the power plant, simulated by using the TRACE and simulator-sodium fast reactor (SIM-SFR) system codes. The assessment started from the simulation of the reactor behavior without the decay heat removal systems (DHRSs). Following this, calculations of multiple DHRS arrangements have been performed to evaluate the individual and combined efficiency of the systems. Where it was possible, the results from the two system codes have been compared to show the consistency of the separate calculations. Through this study, the design of the DHRSs proposed at the beginning of the project has been investigated, and certain recommendations have been made for further improvement of the DHRS systems performance.
Toward Mechanistic Wall Heat Flux Partitioning Model for Fully Developed Nucleate Boiling
Authors: Amidu Muritala Alade
Published: August 2021

Mechanistic models developed to predict partial nucleate boiling are not adequate for fully developed nucleate boiling due to differences in the prevailing heat transfer governing mechanisms. In place of the mechanistic model, several empirical correlations and semimechanistic models have been proposed over the years for the prediction of fully developed nucleate boiling as presented in this study but they are unsuitable for use in computational fluid dynamics (CFD) code. Recently, the simulation of fully developed nucleate boiling has become much more practical because of advancement in a computational method that involves the coupling of the interface capturing method (for slug bubbles) with the Eulerian multifluid model (for dispersed spherical bubbles). Nonetheless, there is a need for a mechanistic closure law for the fully developed nucleate boiling phenomenon that would complement this advancement in CFD. Toward this end, a mechanistic wall heat flux partitioning model for fully developed nucleate boiling is proposed in this study. This model is predicated on the hypothesis that a high heat flux nucleate boiling is distinguished by the existence of a liquid macrolayer between the heated wall and the slug or elongated bubbles, and that the macrolayer is interspersed with numerous high frequency nucleate small bubbles. With this hypothesis, the heat flux generated on the heated wall is partitioned into two parts: conduction heat transfer across the macrolayer liquid film thickness and evaporation heat flux of the microlayer of the nucleating small bubbles. The proposed model is validated against experimental data.
Exploring the Effects of Piston Bowl Geometry and Injector Included Angle on Dual-Fuel and Single-Fuel RCCI
Authors: Hariharan Deivanayagam , Rahimi Boldaji Mozhgan , Yan Ziming , Gainey Brian , Lawler Benjamin
Published: August 2021

Reactivity control compression ignition (RCCI) is a low-temperature combustion technique that has been proposed to meet the current demand for high thermal efficiency and low engine-out emissions. However, its requirement of two separate fuel systems (i.e., a low-reactivity fuel system and a high-reactivity fuel system) has been one of its major challenges in the last decade. This leads to the single-fuel RCCI concept, where the secondary fuel (reformates of diesel) is generated from the primary fuel (diesel) through catalytic partial oxidation reformation. Following the in-depth analysis of the reformate fuel (reformates of diesel) and its benefit as the low-reactivity fuel with diesel, the effects of the start of injection (SOI) timing of diesel and the energy-based blend ratio were also studied in detail. In this study, the effects of piston profile and the injector included angles were experimentally examined using both conventional fuel pairs (gasoline—diesel and natural gas—diesel) and reformate RCCI. A validated computational fluid dynamics (CFD) model was also used for a better understanding of the experimental trends. Comparing a reentrant bowl piston with a shallow bowl piston at a constant compression ratio and SOI, the latter showed better thermal efficiency, regardless of the fuel combination, due to its 10% lower surface area for the heat transfer. Comparing the 150-degree included angle and 60-degree included angle on the shallow bowl piston, the latter showed better combustion efficiency, regardless of the fuel combination, due to its earlier combustion phasing (at constant SOI timing). The effect was particularly prominent on reformate RCCI because of its incredibly high diluent concentration, which retards the combustion further for the 150-deg injector. Later, using convergecfd, seven different injector included angles were studied at a constant SOI. With the change in injector included angle, the region of the cylinder targeted by the fuel spray varies significantly, and it was found to have a significant impact on the combustion efficiency and the engine-out emissions. As the injector included angle changed from 60-deg to 150-deg, the combustion efficiency increased by 15% and the CO, NOx, and HC emissions decreased by 96%, 70%, and 86%, respectively.
Fast Prediction of Thermal Data Stream for Direct Laser Deposition Processes Using Network-Based Tensor Regression
Authors: Khanzadeh Mojtaba , Dantin Matthew , Tian Wenmeng , Priddy Matthew W. , Doude Haley , Bian Linkan
Published: August 2021

The objective of this research is to study an effective thermal data stream prediction method for additive manufacturing (AM) processes using thermal image streams in a layer-wise manner. Reliable physics-based models have been developed to delineate the underlying thermomechanical dynamics of AM processes. However, the computational cost is extremely high. We proposed a tensor-based surrogate modeling methodology to predict the layer-wise relationship in thermal data stream of the AM parts, which is time efficient compared to available physics-based prediction models. We constructed a network tensor structure for freeform shapes based on thermal image streams obtained in metal-based AM processes. Then, we simplified the network tensor structure by concatenating images to reach a layer-wise structure. Subsequent layers were predicted based on the antecedent layer using the tensor regression model. A generalized multilinear structure, called the higher order partial least squares (HOPLS), was used to estimate the tensor regression model parameters. Through the proposed method, high-dimensional thermal histories of AM components were predicted accurately in a computationally efficient manner. Prediction performance indices (i.e., Q2=0.999 and root-mean-square errors of prediction (RMSEP) = 31.212 °C) demonstrated a significantly more efficient layer-wise prediction of thermal data stream—a larger Q2 (0 ≤ Q2 ≤ 1) and a smaller RMSEP indicated a better prediction performance. The proposed thermal data stream prediction was validated on simulated thermal images from finite element (FE) simulations.
A Coupled Two-Way Fluid–Structure Interaction Analysis for the Dynamics of a Partially Confined Cantilevered Pipe Under Simultaneous Internal and External Axial Flow in Opposite Directions
Authors: Daneshmand F. , Liaghat T. , Paidoussis M. P.
Published: August 2021

This paper presents the results of a coupled two-way fluid–structure interaction (FSI) analysis of a slender flexible vertical cantilevered pipe hanging concentrically within a shorter rigid tube forming an annulus. The pipe is subjected to internal and annular flows simultaneously. This system has applications in brine production and salt-cavern hydrocarbon storage. In this study, the fluid–structure problem is solved with a finite volume based computational fluid dynamics (CFD) code for the fluid domain coupled to a finite element based computational solid mechanics code for the structural domain. The numerical results obtained for the free-end displacement of the central pipe versus the annular/internal flow velocity ratio Uo/Ui are presented and compared with those obtained from experiment. The capability of the numerical model to predict the onset of the experimentally observed flutter instability in the system is also examined. This study provides a better insight into the dynamics of the system.
Selection of a Heat Exchanger for a Small-Scale Liquid Air Energy Storage System
Authors: Fredrickson Alexander S. , Pollman Anthony G. , Gannon Anthony J. , Smith Walter C.
Published: August 2021

This paper presents the results of a theoretical analysis of a heat exchanger design for the challenging application of a small-scale modified Linde-Hampson cycle liquid air energy storage system (LAESS). A systems engineering approach was taken to determine the best heat exchanger alternative for incorporation into an existing LAESS. Two primary heat exchanger designs were analyzed and compared: a finned tube heat exchanger (FTHE) design and a printed circuit heat exchanger (PCHE) design. These designs were chosen as alternatives due to the gas-to-gas cooling that occurs in the heat exchanger, and material selection was based on the requirement for the heat exchanger to withstand the cryogenic temperatures required for the system to produce liquid nitrogen. Thermodynamic analysis was conducted using the ε-NTU method and fin theory to determine the dimensional requirements for the finned tube heat exchanger and a trade-off study was conducted to compare the alternatives. Based on the results from the study, the PCHE was the preferred alternative due to an inherent small footprint, comparable cost to manufacture, simple integration into the LAESS and inherent safety features that are critical when working with high pressure systems. Future work will include subsystem and system integration and testing to obtain a consistently functional prototype that produces liquid nitrogen.
Performance and Complexity Trade Study of Candidate Liquid Air Generation Techniques
Authors: Torosyan Masis , Pollman Anthony , Gannon Anthony , Hernandez Alejandro
Published: August 2021

This paper presents the results of an alternatives analysis of gas-liquefaction methods used in liquid air energy storage (LAES) systems that incorporates two novel measures of performance (MOP) into the analysis: system complexity score and system density. The cryogenic methods typically considered for air, and used in this trade study, include Linde-Hampson, Claude, Heylandt, and cascade [1]. With these four options of air-liquefaction currently in use for a variety of purposes with ranging scales, there exists no standard selection process for the air-liquefaction method in LAES. This trade study provides fundamental design solutions for given stakeholder requirements, allowing for a pragmatic analysis of integration for future implementation of LAES systems. The intent of these design solutions is to be used in the earliest stage of consideration of a LAES implementation, helping stakeholders quickly narrow the focus of their design engineers to a specific liquefaction process. This will reduce the complexity of integration techniques and processes and streamline LAES into the energy-storage industry. The results of this study showed that with evenly weighted MOP the Heylandt method had the highest final weighted score (0.9), followed by Cascade (0.88), Claude (0.86), and Linde-Hampson (0.67). However, the results showed that the Cascade method was the most frequent design solution (8/11) from 11 variations of MOP weight distributions.
Renewable Energy Systems for Demand-Side Management in Industrial Facilities
Authors: Elio Joseph , Phelan Patrick , Villalobos Rene , Milcarek Ryan J.
Published: August 2021

Due to high energy usage and power demand in industrial facilities, demand-side management (DSM) can simultaneously yield substantial energy cost savings for the facility and reduce the load on the power grid. There are many means of DSM, the most common being peak clipping, which is easily done with renewable energy systems and other power-generating devices. In this work, renewable energy systems (RESs) are critically reviewed and compared based on their application to industrial demand-side management (IDSM). Specifically, the RESs reviewed herein include photovoltaics, wind turbines, geothermal, and hybrid renewable energy systems. These devices are introduced, followed by a discussion of their advantages, disadvantages, and feasibility for use in IDSM. Most importantly, the reduction in the carbon footprint of power generation plants resulting from the use of RESs for IDSM is investigated. Comparisons are made based upon rated power, capital costs, O&M costs, levelized cost of energy, and the feasibility for use in industrial facilities. Using the values in the cost comparisons, the levelized cost of energy (LCOE) is derived for each device and used in a techno-economic analysis comparing the cost savings for the different RESs for a hypothetical plant.
Predicting Peak Energy Demand for an Office Building Using Artificial Intelligence (AI) Approaches
Authors: Chen Yuxuan , Phelan Patrick
Published: August 2021

Due to the technological advancement in smart buildings and the smart grid, there is increasing desire of managing energy demand in buildings to achieve energy efficiency. In this context, building energy prediction has become an essential approach for measuring building energy performance, assessing energy system efficiency, and developing energy management strategies. In this study, two artificial intelligence techniques (i.e., ANN = artificial neural networks and SVR = support vector regression) are examined and used to predict the peak energy demand to estimate the energy usage for an office building on a university campus based on meteorological and historical energy data. Two-year energy and meteorological data are used, with one year for training and the following year for testing. To investigate the seasonal load trend and the prediction capabilities of the two approaches, two experiments are conducted relying on different scales of training data. In total, 10 prediction models are built, with 8 models implemented on seasonal training datasets and 2 models employed using year-round training data. It is observed that a backpropagation neural network (BPNN) performs better than SVR when dealing with more data, leading to stable generalization and low prediction error. When dealing with less data, it is found that there is no dominance of one approach over another.
Analysis of a Multigeneration Energy System for Wastewater Treatment
Authors: Erguvan Mustafa , MacPhee David W.
Published: August 2021

The United Nations World Water Development Report claims that more than 6 billion people will suffer from clean water shortage by 2050. This is a result of climate change, demand increase for water, increase of water pollution, increasing population, and reduction of water resources [1]. In order to delay / prevent water scarcity, humans must take action using less water or perhaps recovering wastewater. Aerobic digestion is one of the best common methods to treat wastewater; however, this technology requires heavily on the use of electric motors and is estimated to consume 2–3% of US electricity. In this paper, a multigeneration energy system is developed to treat wastewater using a net-zero energy building model. This system consists of four major sub-systems: an aerobic digester, an anaerobic digester, a Brayton cycle, and a Rankine cycle. Using anaerobic digestion to produce bio-fuels, which can then be used on-site to power aeration systems, may offer significant advantages to reduce electricity usage. This study shows that the required energy for a sample aeration case study process can be supplied by a multigeneration system. Parametric analyses are performed to show how system efficiency may be increased as well as to investigate the required oxygen and power for an activated sludge process in a wastewater treatment plant. It is found here that the proposed CHP system can produce 6 times more energy than the required energy for the aeration in the activated sludge process.
First Numerical Evaluation of the Thermal Performance of a Tubular Receiver Equipped With Raschig Rings for CSP Applications
Authors: Ebadi Hossein , Allio Andrea , Cammi Antonio , Savoldi Laura
Published: August 2021

Porous media are typically capable to enhance heat transfer, at the cost of an increase of the pressure drop, mainly in view of the huge increase in the surface wetted by the fluid. In this work, a tubular receiver for CSP applications, partly filled with a porous medium constituted by a packed bed of copper Raschig Rings is investigated for the first time. The analysis, carried out numerically, aims at studying in detail the mechanisms of the heat transfer from the wall to the gaseous heat transfer fluid (air) through the porous metal matrix in symmetric and asymmetric heating conditions. The computed results are compared to what occurs in a smooth tube subjected to the same heating, to check the increase in the heat transfer. The investigation carried out in this work represents the first step in the optimization of the porous medium structure inside the tubular receiver.
Adjoint Optimization of Heat Transfer Within a Stirling Engine
Authors: DiCarlo Anthony A. , Caldwell Rickey A.
Published: August 2021

This work aims to determine the optimal heat sink fin shape to promote the efficient rise of hot air away from the heat sink. The heat transfer and convective flow dynamics external to a commercial Stirling engine are investigated. In particular, this study employs an adjoint optimization approach based on CFD simulations to determine the sensitivity of the objective function to the shape of the heat sink and influence on the natural convection heat flow away from the external heat sink. This deterministic optimization approach increases the heat transfer rate of the heat sink by nearly 20% in this study when performing a small number of design iterations.