bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality of life and clinical characteristics of self‐improving congenital ichthyosis within the disease spectrum of autosomal‐recessive congenital ichthyosis
Authors: Hake L. , Süßmuth K. , Komlosi K. , Kopp J. , Drerup C. , Metze D. , Traupe H. , Hausser I. , Eckl K.M. , Hennies H.C. , Fischer J. , Oji V.
Published: December 2021

Background

Autosomal‐recessive congenital ichthyosis (ARCI) is a heterogeneous group of ichthyoses presenting at birth. Self‐improving congenital ichthyosis (SICI) is a subtype of ARCI and is diagnosed when skin condition improves remarkably (within years) after birth. So far, there are sparse data on SICI and quality of life (QoL) in this ARCI subtype. This study aims to further delineate the clinical spectrum of SICI as a rather unique subtype of ARCI.

Objectives

This prospective study included 78 patients (median age: 15 years) with ARCI who were subdivided in SICI (n = 18) and non‐SICI patients (nSICI, n = 60) by their ARCI phenotype.

Methods

Quality of life (QoL) was assessed using the (Children’s) Dermatology Life Quality Index. Statistical analysis was performed with chi‐squared and t‐Tests.

Results

The genetically confirmed SICI patients presented causative mutations in the following genes: ALOXE3 (8/16; 50.0%), ALOX12B (6/16; 37.5%), PNPLA1 (1/16; 6.3%) and CYP4F22 (1/16; 6.3%). Hypo‐/anhidrosis and insufficient vitamin D levels (<30 ng/mL) were often seen in SICI patients. Brachydactyly (a shortening of the 4th and 5th fingers) was statistically more frequent in SICI (P = 0.023) than in nSICI patients. A kink of the ear’s helix was seen in half of the SICI patients and tends to occur more frequently in patients with ALOX12B mutations (P = 0.005). QoL was less impaired in patients under the age of 16, regardless of ARCI type.

Conclusions

SICI is an underestimated, milder clinical variant of ARCI including distinct features such as brachydactyly and kinking of the ears. Clinical experts should be aware of these features when seeing neonates with a collodion membrane. SICI patients should be regularly checked for clinical parameters such as hypo‐/anhidrosis or vitamin D levels and monitored for changes in quality of life.
Frequency and factors associated with foregone and delayed medical care due to COVID‐19 among nonelderly US adults from August to December 2020
Authors: Giannouchos Theodoros V. , Brooks John M. , Andreyeva Elena , Ukert Benjamin
Published: December 2021

Objectives

To estimate the frequency and factors associated with foregone and delayed medical care attributed to the COVID‐19 pandemic among nonelderly adults from August to December 2020 in the United States.

Methods

We used three survey waves from the Urban Institute's Household Pulse Survey (HPS) collected between August 19–31, October 14–26 and December 9–21. The final sample included 155,825 nonelderly (18–64) respondents representing 135,835,598 million individuals in the United States. We used two multivariable logistic regressions to estimate the association between respondents' characteristics and foregone and delayed care.

Results

The frequency of foregone and delayed medical care was 26.9% and 35.9%, respectively. Around 60% of respondents reported difficulties in paying for usual household expenses in the last 7 days. More than half reported several days of mental health issues. The regression results indicated that foregone or delayed care were significantly associated with difficulties in paying usual household expenses (p < 0.001), worse self‐reported health status (p < 0.001), increased mental health problems (p < 0.001), Veterans Affairs (p <0.001) or Medicaid (p = 0.003) coverage compared to private healthcare coverage, and older age groups. Individuals who participated in the latter two waves of the survey (October, December) were less likely to report foregone and delayed care compared to those who participated in Wave 1 (August).

Conclusion

Overall, the frequency of foregone and delayed medical care remained high from August to December 2020 among nonelderly US adults. Our findings highlight that pandemic‐induced access barriers are major drivers of reduced healthcare provision during the second half of the pandemic and highlight the need for policies to support patients in seeking timely care.
Is the frequency of dietitian support associated with greater clinical improvements in adults with Crohn's disease undertaking exclusive enteral nutrition?
Authors: Purcell Liz , Mutsekwa Rumbidzai , Angus Rebecca , Shukla Dheeraj , Palmer Michelle
Published: December 2021

Background

Exclusive enteral nutrition (EEN) is considered to be an effective, low‐risk therapy in the treatment of Crohn's disease (CD). Frequent dietetic support may assist adults to succeed. The present observational study aimed to compare whether the frequency of dietetic support during EEN therapy was associated with differences in clinical and nutritional outcomes across two gastroenterology inflammatory bowel disease services. Site A provided ≥3 visits plus more if clinically indicated and Site B provided weekly support.

Methods

Eligible patients were adults with active CD recommended to be treated with oral EEN for ≥6 weeks between February 2018 and December 2019. Demographic, anthropometric, clinical, medications, pathology and EEN treatment descriptors were sourced from the medical chart. Descriptive statistics, as well as chi‐squared and t tests, were used to compare data between sites.

Results

Eighty‐four CD patients were eligible (44 ± 14 years, 54% female, baseline Crohn's disease activity index [CDAI] 259.5 ± 113.1, n = 51 Site A) and completed EEN for median (range) 6.1 (1–12) weeks. Most patients (82%, n = 69/84) completed ≥6 weeks of EEN treatment. CDAI score and calprotectin improved across the total sample from pre‐ to post‐EEN by −109.8 ± 92.1 (p < 0.001) and −65 µg g–1 (−65,230 to 4370) (p = 0.002), respectively. Dietitian occasions of service were more frequent at Site B (7 [4–12] occasions vs. 3 [1–8], p < 0.001). However, changes in clinical and biomarker data were similar between sites (p < 0.05).

Conclusions

EEN with regular dietetic input resulted in clinical and biochemical improvements for patients with active CD. Tailoring dietetic support based on the client's needs and preference may achieve clinical improvements similar to providing weekly dietetic support to adults on EEN.
Securitizing Communication: On the Indeterminacy of Participant Roles in Online Journalism
Authors: Cody Francis , Paz Alejandro I.
Published: December 2021

This article takes Judith T. Irvine’s insights about the indeterminacy of participant roles and interpretive frameworks to explore how the increased use of social media in journalism leads to new quandaries for political actors. The dialogics of distributing or amalgamating participant roles provide for a particularly tricky domain of maneuver for journalists in India and Israel, where rightwing leaders seek to control news that disseminates rapidly on the currents of social media. Journalists have long sought to avoid becoming the story themselves, as part of claiming liberal positions that distinguish the reported events from their representation. It considers the current attempt to clamp‐down on social media use by journalists as a securitization of communication, where the very journalistic utterance is used by ruling politicians to make the journalist, or potentially the news media more generally, into a threat to public security. However, even such policing can be too slow. This article thus also considers how outraged publics become an important aspect of policing social media.
Shadows and Mirrors: Spatial and Ideological Perspectives on Sign Language Competency
Authors: Hoffmann‐Dilloway Erika
Published: December 2021

In introducing the concept of “shadow conversations,” Judith T. Irvine (1996) sharpened our analytical understanding of instances in which conjectures about past and future moments in a chain of discourse events inform the distribution of participant roles in an unfolding interaction. Expanding upon this notion, this article considers how conversations that did or will not occur—or are imagined as having not occurred—can equally function as shadows that inform how unfolding interactions, and the participant roles entailed in their enactment, are understood. I analyze an exchange conducted in Maltese Sign Language (LSM), in which my status as a novice LSM signer led to a series of misunderstandings and repairs. In addition to illustrating the shadows cast by significant non‐occurrences, the interaction and its mix‐ups highlight the intersection of spatial and social forms of perspective taking. My analysis of the shadows that shaped interactive failure and success demonstrate the power of Irvine’s analytical tools to connect the material, embodied details of a particular interactive moment to complex interdiscursive chains and language ideological perspectives.
The politics of conviviality: On‐the‐ground experiences from Spanish‐speaking Latin Americans in Elephant and Castle, London
Authors: Márquez Reiter Rosina , Patiño‐Santos Adriana
Published: December 2021

This paper aims to contribute to studies of social relations among Spanish‐speaking Latin Americans (SsLAs) in the London‐based diaspora. In public discourse, members of this social group present themselves as an “ethnic community.” However, reported tensions among themselves suggest that this image of unity is not necessarily consonant with their on‐the‐ground experiences of one another in diaspora. The regeneration of Elephant and Castle (E&C), one of their cultural enclaves in the city, and the arrival of onward Latin Americans (OLAs) from other parts of Europe, after 2008, exacerbated some of these tensions.The data for this paper come from linguistic ethnographic fieldwork conducted over one year (2014–15) in and around the E&C area. An examination of the reflective accounts gathered in interviews with two SsLAs retailers based in E&C since the 1990s reveals that (i) the tensions are caused by the struggle to access scarce economic resources at a time of socioeconomic change, and (ii) the social hierarchies established by the history of settlement of members of the group. Together they signal the ambivalence in the way that convivial relations are experienced by different social actors and lead us to consider the situated nature of conviviality (Rampton 2015).
Spider bites in France: Epidaemiology of cases occurring in 10 years in metropolitan France
Authors: Le Roux Gaël , Richard Virginie , Larcher Gérald ,   French PCC Research Group, Sinno‐Tellier Sandra , Labadie Magali , de Haro Luc , Descatha Alexis
Published: December 2021

Spiders are often wrongly designated as responsible for cutaneous eruptions. We aim to describe spider bites and the spider species implicated in metropolitan France. A retrospective observational study was conducted for all reported cases of spider bites from 2007 to 2018 extracted from the French Poison Control Centers (PCCs) information system, after exclusion of non‐native spiders. We described identification of the spider, level of certainty of the bite, symptoms and severity of cases. 1194 cases of spider bites met the inclusion criteria. The average age of the patients was 36.9 ± 19.8 years. Identification of the species or at least that a spider was implicated was only possible in 346 cases (29.0%). Loxosceles were involved in 53 cases (4.4%), Latrodectus in 46 cases (3.9%) and Cheiracanthium in 35 cases (2.9%). In one third of cases, the involved spider was not known to be present where the bite occurred. Where most of the patients (n = 1111, 93%) reported at least one cutaneous symptom, most of the symptoms were neurological. The bite was considered proven in only 242 cases (20%). Despite the efforts of arachnologists to educate the public, the fear of spiders is still alive in France, where spider bite is rare with low severity and often unproven.
From Suriyya al‐Asad to Souriatna: Civic nationalism in the Syrian revolutionary press
Authors: Chevée Adélie
Published: December 2021

Scholarship on the Syrian conflict has too often reduced the analysis of political behaviour to the causal variable of sectarianism and therefore overlooked the role of other identities sustaining mobilization since 2011. Using the case of the revolutionary newspaper Souriatna, this article argues that a civic re‐imagining of the nation that was neither ethnic nor sectarian informed the identity claims of anti‐regime protestors throughout the conflict and well beyond the peaceful protests of 2011. Civic nationalism, a re‐imagining of the nation as a self‐determined community of equal citizens was generated through print newspaper practices and the iteration of symbols, specifically the map of Syria in its current territorial boundaries and the Independence flag. This re‐imagined nationalism from below challenged both state discourse of sectarian fragmentation since 2011 and Suriyya al‐Asad, the personification of power around the figure of the state leader.
Stable liver graft post anti‐PD1 therapy as a bridge to transplantation in an adolescent with hepatocellular carcinoma
Authors: Kang Elise , Martinez Mercedes , Moisander‐Joyce Hanna , Saenger Yvonne M. , Griesemer Adam D. , Kato Tomoaki , Yamashiro Darrell J. , Remotti Helen , Gartrell Robyn D.
Published: December 2021

Background

Immunotherapy, specifically immune checkpoint inhibitors (ICIs), including anti‐programmed cell death 1 (anti‐PD1), has recently received clinical approval for the treatment of adult hepatocellular carcinoma (HCC). However, the safety and efficacy of ICIs prior to solid organ transplant are unknown, especially in pediatrics. Safety reports are variable in adults, with some series describing subsequent allograft rejection and loss while others report successful transplants without allograft rejection.As ICIs stimulate the immune system by blocking the interaction between PD1 and the ligand‐receptor pair programmed cell death‐ligand 1 (PDL1), the downstream effects of T‐cell activation increase the risk of graft rejection.

Methods

Here, we present a case of an adolescent with moderately differentiated non‐fibrolamellar HCC treated with pembrolizumab, an anti‐PD1 therapy, who subsequently underwent successful orthotopic liver transplantation (OLT).

Results

Our patient received an OLT 138 days from the last pembrolizumab dose with graft preservation. The patient has no evidence of recurrent disease or any episode of allograft rejection 48 months post OLT. Staining of tumor and normal tissues from longitudinal specimens finds PDL1 positive Kupffer cells present in normal liver and peritumoral areas with no changes post anti‐PD1 therapy. In contrast, tumor cells were negative for PDL1.

Conclusion

This case represents a basis for optimism in potential use of anti‐PD1 therapy in liver transplant candidates and supports further investigation of immune checkpoint inhibitors use in this unique patient population.
Late renal allograft torsion in a pediatric transplant recipient
Authors: Hsiao Wendy Chiawen , Abt Peter , Amaral Sandra , Levine Matthew , LaRosa Christopher
Published: December 2021

Background

Kidney allograft torsion is a rare complication of kidney transplant that can lead to allograft loss from prolonged ischemia if not quickly corrected with detorsion and nephropexy. We report a case of late intraperitoneal renal allograft torsion in a pediatric transplant recipient.

Case Report

The patient is a 7‐year‐old male with a history of end‐stage renal disease secondary to renal dysplasia in the setting of bilateral high‐grade vesicoureteral reflux. He underwent bilateral native nephrectomies for recurrent pyelonephritis and right ureteral kink with urinary tract obstruction. Torsion occurred 3 years after transplant in the setting of one day of emesis, loose stool, severe abdominal pain, and decreased urine output. Diagnosis of transplant torsion was suspected on non‐contrast CT scan done after transplant Doppler ultrasound showed no flow to the allograft. The CT scan showed that the kidney had been medialized and renal hilum was flipped from the expected orientation. The patient required a transplant nephrectomy.

Conclusions

Renal transplant torsion is a rare event but should be suspected in any renal transplant recipient with acute onset of abdominal pain, acute kidney injury, and decreased urine output, regardless of length of time from transplantation. Patients suspected to have renal torsion should be evaluated emergently with a transplant ultrasound Doppler.
Light‐emitting‐diode‐based antimicrobial photodynamic therapies in the treatment of periodontitis
Authors: Chen Shuang , Tang Luyao , Xu Meng , Chen Tianran , Zhao Shouliang , Liu Muqing , Liu Shangfeng
Published: December 2021

The use of light‐emitting diode (LED)‐based photodynamic therapies in the treatment of periodontitis is increasing because these modalities are effective, safe, and painless. They are not subject to acquired drug resistance or environmental issues and are associated with no complications when used appropriately. These light sources have also been used in combination with pharmacological measures to synergize their effects and optimize therapeutic outcomes. This review focuses on optical devices used in treating periodontitis and delineates the current applications of various methods, including their utility and efficacy. The application of LEDs in periodontology is described.
Individualised Care Scale‐Nurse: Construct validity and internal consistency of the Spanish version
Authors: Rodríguez‐Martín Beatriz , García‐Camacha Gutiérrez Irene , Caro‐Alonso Pedro Angel , Suhonen Riitta , García‐Camacha Gutiérrez Aurora
Published: December 2021

Background

Individualising the provided care is mandatory in nursing and is essential in clinical practice. Therefore, there is a need to develop accurate instruments to evaluate the quality of care. Moreover, there is no validated instrument to assess nurses’ views of individualised care in Spanish‐speaking countries.

Aim

To assess the construct validity and internal consistency of the Spanish version of the Individualised Care Scale‐Nurse.

Methods

A cross‐sectional study including 108 nursing professionals (40.84 ± 9.51 years old, 86.1% female) was used to validate the Spanish Individualised Care Scale‐Nurse version. A forward‐back translation method with an expert panel and a cross‐sectional study was used for transcultural adaptation and psychometric validation purposes. Psychometric properties of feasibility, reliability and validity were assessed. Construct validity was examined through a confirmatory factor analysis and fit indices of the overall model were computed. Internal consistency was explored through McDonald’s omega and Cronbach’s alpha coefficients among other correlation measures.

Results

The back‐translation concluded both Spanish and English Individualised Care Scale‐Nurse versions to be equivalent. The original structure of the Individualised Care Scale‐Nurse was verified in the Spanish version through the confirmatory factor analysis (factor loadings >0.3; acceptable fit indices: SRMR ≈ 0.08, CFI ≈ 0.9, RMSEA ≈ 0.09 after posteriori modifications). McDonald's omega exceeded 0.7 for both subscales and complete scales revealing an adequate internal consistency.

Conclusions

The Spanish version of the Individualised Care Scale‐Nurse has exhibited good properties of homogeneity and construct validity for its use in practice and research in health care systems.
Caregiver exposure to hepatitis C virus following transplantation with hepatitis C viremic donor organs: A case series
Authors: Kim Michelle , Stern Jeffrey , Robalino Ryan , Weldon Elaina P. , Ali Nicole M. , Mehta Sapna A. , Stewart Zoe A. , Lonze Bonnie E.
Published: December 2021

Direct‐acting antiviral (DAA) therapeutics have ushered in an era in which transplanting organs from donors infected with hepatitis C virus (HCV+) into recipients without (HCV–) is an increasingly common practice. Rare but potentially life‐threatening events have been reported in recipients of HCV+ organs. Since 2018 at our institution, 182 HCV– patients have received HCV+ donor organs. Here, we retrospectively reviewed cases in which recipients’ family member caregivers reported sustaining needlestick exposures at home following discharge of the transplant recipient from the hospital. Caregiver needlestick exposures were passively reported in three cases of HCV+ into HCV– transplants (1.64% of such cases at our center). In all instances, the exposed individuals were aiding in diabetic management and the exposure occurred via lancets or insulin needles. In one case, the recipient viral load was undetectable at the time of the exposure but in the other two, recipients were viremic, putting their family members at risk to contract HCV infection. Surveillance for the exposed individuals was undertaken and no transmissions occurred. For centers performing HCV+ into HCV– transplants, it is important that informed consent includes discussion of potential secondary risks to family members and caregivers. Further, protocols for postexposure surveillance and for the acquisition of DAA treatment in the event of a secondary transmission should be in place.
Ethics and consent in more‐than‐human research: Some considerations from/with/as Gumbaynggirr Country, Australia
Authors:   Yandaarra with Gumbaynggirr Country including, Smith Aunty Shaa , Marshall Uncle Bud , Smith Neeyan , Wright Sarah , Daley Lara , Hodge Paul
Published: December 2021

A considerable body of recent work within the social sciences has attempted to engage more deeply with place, place‐based knowledge, and more‐than‐human agency. Yet what this might look like in relation to ethical research practice, especially in the case of research proceeding on unceded Indigenous lands, is unclear. Taking more‐than‐human agency seriously means ethical research practice must be extended beyond a human‐centric approach. As a Gumbaynggirr and non‐Gumbaynggirr research collective researching on, with, and as Gumbaynggirr Country in so‐called Australia, we offer a contribution to discussions of research ethics and protocols that centres the consent of Country: the lands, waters, and skies of Aboriginal and Torres Strait Islander homelands, and the human and more‐than‐human beings that co‐become there. In this paper, we share some of our learnings and discuss how we have tried not just to listen to Country but also to honour its agencies, knowledges, and sovereignties. As part of this honouring, we prioritise in particular the deeply placed Gumbaynggirr knowledges of Aunty Shaa Smith and Uncle Bud Marshall to explore what being guided by Gumbaynggirr Law/Lore and sovereignty means in practice and the challenges and possibilities of gaining consent of Country in ways underpinned by Indigenous Law/Lore. We propose a more expansive understanding of consent that includes attention to more‐than‐human sovereignties and draw on our collective's learning to reframe the need for limits on research as openings rather than closures. In sharing our Gumbaynggirr‐led and Country‐led perspectives, we aim to deepen decolonising research praxis within human geography and the social sciences more broadly.
Granulocyte transfusions made with modified fluid gelatin in pediatric and adolescent patients with prolonged neutropenia
Authors: Knapp Selina , Brosig Andreas , Troeger Anja , Kleinschmidt Katharina , Offner Robert , Corbacioglu Selim , Burkhardt Ralph , Foell Juergen , Ahrens Norbert
Published: December 2021

Background

Granulocyte transfusions (GT) are used to treat progressive systemic or local infections in prolonged neutropenic patients with antibiotic or antifungal resistance. Granulocytes are most commonly collected from whole blood by apheresis using hydroxyethyl starch (HES) as the red blood cell (RBC) sedimentation agent. This is the first study on the safety and efficacy of transfusing granulocytes collected with modified fluid gelatin (MFG) instead of HES to pediatric patients.

Methods

Clinical data from 46 pediatric and adolescent patients receiving at least one MFG‐based granulocyte transfusion and in total 295 granulocyte concentrates from July 2013 to August 2019 at our local university medical center were evaluated retrospectively.

Results

Forty‐one patients (89%) survived at least 21 days after their last granulocyte transfusion. These survivors had lower CRP values and higher leukocyte counts after GT than non‐survivors (mean delta of −5.34 mg/dl vs. –11.99 mg/dl and + 0.62 × 103/μl vs. +0.18 × 103/μl of all GT, respectively). The neutrophil corrected count increment (CCI) was 68.72 mm2/ml in survivors versus 28.00 mm2/ml in non‐survivors. There were no major or severe adverse events.

Conclusion

This study suggests that modified fluid gelatin is a safe and effective alternative to hydroxyethyl starch for the collection of granulocytes for transfusion to prolonged neutropenic patients with progressive systemic or local infections refractory to antibiotic or antifungal therapy.
Algorithms for Improving Speed and Accuracy of Automated Three-Dimensional Reconstruction With a Depth Camera Mounted on An Industrial Robot
Authors: Malhan Rishi , Jomy Joseph Rex , Bhatt Prahar M. , Shah Brual , Gupta Satyandra K.
Published: December 2021

Three-dimensional reconstruction technology is used in a wide variety of applications. Automatically creating accurate pointclouds for large parts with complex geometries usually requires expensive metrology instruments. We are interested in using low-cost depth cameras mounted on commonly available industrial robots to create accurate pointclouds for large parts automatically. Manufacturing applications require fast cycle times. Therefore, we are interested in speeding up the 3D reconstruction process. We present algorithmic advances in 3D reconstruction that achieve a sub-millimeter accuracy using a low-cost depth camera. Our system can be used to determine a pointcloud model of large and complex parts. Advances in camera calibration, cycle time reduction for pointcloud capturing, and uncertainty estimation are made in this work. We continuously capture pointclouds at an optimal camera location with respect to part distance during robot motion execution. The redundancy in pointclouds achieved by the moving camera significantly reduces errors in measurements without increasing cycle time. Our system produces sub-millimeter accuracy.
Resistance Spot Welding of Additively Manufactured Maraging Steels—Part II: Failure Behavior
Authors: Luo Cheng , Zhang Yansong , Oelscher Michael , Shi Yandong , Pasligh Niels , Koch Raphael
Published: December 2021

Application of maraging steels via selective laser melting process in the automotive industry was unavoidably involved in the resistance spot welding with conventional steels. Due to the rapid cooling rate of welding process, selective laser melted maraging steels with unique chemical components and stack microstructure could induce the different microstructural evolution, resulting in the complicated fracture behavior in the spot welds. This paper developed a FEA model to predict the fracture mode of spot welds of DP600 to maraging steel under KSII test conditions, and the effect of test conditions and printing orientations was studied. A method was proposed to calculate the material properties of fusion zone by introducing the combined effect of melting DP600 and maraging steels via selective laser melting, resulting in the accurate prediction of fracture mode and strength of spot welds. A diffusion layer with lower strength was found around the fusion zone and the fracture path propagated in the region, resulting in the partial interfacial failure of spot welds. Meanwhile, the printing orientation had no significant effect on the fracture mode and strength of spot welds, but the different material properties of maraging steels could affect the fracture displacement of spot welds. These findings could pave a way to guide the application of maraging steels via selective laser melting process in multiple industries, especially in the automotive industry.
Design of Deployable Mechanisms Based on Wren Parallel Mechanism Units
Authors: Wang Jieyu , Kong Xianwen , Yu Jingjun
Published: December 2021

This paper presents a series of deployable mechanisms based on n-UU (universal joint) Wren parallel mechanism (PM) units, which undergo one degree-of-freedom (DOF) Borel–Bricard motion. First, the PM unit is developed into ortho-planar mechanisms by adopting an R–R joint. The link parameters of the mechanism are optimized to maximize the folding ratio while avoiding interference. Then, the optimized PM units are piled up to construct a novel 1DOF multilayer mechanism that has the largest folding ratio among similar structures in the literature. Moreover, polyhedral deployable mechanisms are obtained by connecting the PM unit using U joint or UU joint. Apart from saving space, the polyhedral mechanisms can transform among different shapes of polyhedrons. Finally, variations of the n-UU PM are investigated with different shapes of platforms, and each mechanism has its unique movement characteristics.
Flow Check and Adiabatic Effectiveness Measurements on Traditionally Versus Additively Manufactured Film-Cooling Holes
Authors: Cubeda S. , Andrei L. , Innocenti L. , Paone F. , Cocchi L. , Picchi A. , Facchini B.
Published: December 2021

In the recent years Additive Manufacturing (AM) methods, such as the Direct Metal Laser Melting (DMLM) technology, are getting more and more attractive and feasible for the realization of components and subcomponents of gas turbines. In particular, they are receiving much attention since, on the one hand, the manufacturing of complex 3D geometries is allowed and, on the other, manufacturing and delivery times can be cut down. Lately, Baker Hughes is studying the possibility to manufacture film-cooling holes via the DMLM technology in order to exploit the flexibility of such innovative manufacturing method and hence eliminate additional processes and lead time. From the open literature, it is known that additively manufactured holes can have a more irregular shape and higher roughness than traditional ones, which may lead not only to a reduction in coolant flow but more importantly to decay of the film-cooling adiabatic effectiveness. For this reason, a test campaign has been conducted in collaboration with the University of Florence (Italy) with the objective of characterizing the performance (minimum passage diameter, flow check, and adiabatic effectiveness) of AM versus traditional cylindrical holes on simple-geometry coupons built upon different construction angles. Ultimately, the dependency of AM holes performance on print angles is sought with the purpose of characterizing the impact of such manufacturing technology on film-cooling holes design.
Inverse Design of Airfoils Using Convolutional Neural Network and Deep Neural Network
Authors: Kumar Amit , Vadlamani Nagabhushana Rao
Published: December 2021

In this paper, we compare the efficacy of two neural network based models: Convolutional Neural Network (CNN) and Deep Neural Networks (DNN) to inverse design the airfoil shapes. Given the pressure distribution over the airfoil in pictorial (for CNN) or numerical form (for DNN), the trained neural networks predict the airfoil shapes. During the training phase, the critical hyper-parameters of both the models, namely — learning rate, number of epochs and batch size, are tuned to reduce the mean squared error (MSE) and increase the prediction accuracy. The training parameters in DNN are an order of magnitude lower than that of CNN and hence the DNN model is found to be ≈ 7× faster than the CNN. In addition, the accuracy of DNN is also observed to be superior to that of CNN. After processing the raw airfoil shapes, the smoothed airfoils are shown to yield the target pressure distribution thereby validating the framework.
A Numerical Study of Flow Around Different Hydrofoil Systems In Presence of the Free Surface
Authors: Kumari Nutan , Chakraborty Arnab
Published: December 2021

The hydrofoils are essential element in tidal current turbine and in high speed marine crafts. Hence, the study of hydrodynamic characteristics of hydrofoils are important as they play a vital role in improving the performance of these propulsion devices (hydro-kinetic turbine, marine craft). In the present study, the dynamics of unsteady and viscous flow around a two hydrofoil system is investigated for two different configuration: (a) tandem, and in (b) stagger arrangement. The incompressible Navier-Stokes equations were solved using Finite Volume Solver in STAR-CCM+ commercial software package. k-ε turbulence model is incorporated in the present simulation in order to explain the turbulence flow physics while the free surface is captured using Volume of Fluid (VOF) technique. Further, the obtained numerical simulation results were compared with experimental data available in the literature as a validation purpose. The objective of the present study is to investigate the effects of spacing distance on the lift and drag coefficient generated by two foil system in tandem and stagger arrangements which is one of the important design parameter for a tidal turbine blades in presence of free sea surface. It could be observed that the hydrofoils are arranged in tandem configuration, the lift coefficients of the upstream and downstream hydrofoils are higher in comparison to single hydrofoil. Interference effect didn’t die out even at large spacing for 2-D hydrofoil.
Numerical Investigation on the Cavity Implementation Methods in Trapped Vortex Combustor
Authors: M S Nisanth , Panda Pratikash P. , R V Ravikrishna
Published: December 2021

Well-stabilized vortices inside a physical cavity using direct injection of reactants can be used to provide stable combustion with performance benefits. The adaptation of the Trapped Vortex Combustion (TVC) concept involves the placement of the cavity-based flame stabilization device in the main duct of the combustor using annular or planar geometric configurations. In this work, we compare the performance of inner annular, outer annular and planar arrangements of the cavity with dual-vortex structure configuration enabled by a single injection port on the upstream wall of the cavity. The comparison is done using Reynolds Averaged Navier-Stokes (RANS) simulations. The effect of cavity implementation methods on the flame stabilization, temperature distribution at the exit of the combustor and pollutant emissions are analyzed with three combustor operating conditions based on the flow parameters. Significant differences in the flame stabilization are observed in the combustors due to the dissimilarity of the velocity and fuel distribution. The parameter, jet momentum flux ratio, denoted by J, is defined based on the inlet conditions and the estimate of actual cavity flow velocity from numerical results. This parameter is used to correlate the combustor performance among the various configurations studied. The inner annular combustor can be scaled to higher power by increasing the combustor radius (R) with same cavity size, flow parameters and chemical parameters, however, the flame stabilization and performance are affected by the geometric parameters, combustor radius (R) and cavity depth (D). Strategies to scale-up the combustor to obtain the required performance are discussed along with the challenges faced in comparing results of the various configurations studied.
Influence of Texture Portion and Dimple Area Density on the Tribological Characteristics of Dimple Textured Hydrodynamic Journal Bearing
Authors: Syed Nayab Rasool , Kakoty Sashindra Kumar
Published: December 2021

There is a growing interest towards the textured bearings. The normal surface texture has the shape of micro-dimples with preselected diameter, area density and depth. The use of different amount of texturing and dimple area density, can be an effective way to improve tribological properties of textured bearing. In the present study, the tribological properties, of the dimple textured journal bearing of L/D = 2, such as attitude angle, load carrying capacity, friction variable and flow coefficient are estimated for different texture portion and dimple area density. The computationally efficient Progressive mesh densification method is implemented for the numerical solution. The governing Reynolds equation is discretized with the finite difference scheme and then solved using Gauss Seidel method coupled with Successive over relaxation scheme. The numerical results show that the flow coefficient and attitude angle has been improved significantly with texture portion variation. Similarly, when the dimple area density is varied, there is significant improvement in flow coefficient and attitude angle resulting in the maximum flow coefficient at the dimple area density of 0.25 and minimum attitude angle, at the eccentricity ratios from 0.5 to 0.7, for the dimple area density of 0.20. However, the texture portion and dimple area density have no positive influence on the load carrying capacity and friction variable.
Life Prediction of Thermal Barrier Coated C3X Gas Turbine Blade of CMSX-4 Material
Authors: Kumar Ajmit , Kumar Sanket , Pandey K. N.
Published: December 2021

The drive to higher efficient gas turbine engines and improved performance is attained by increasing turbine inlet temperature. This lead to the use of advanced material, multi-layered thermal barrier coatings (TBCs) and effective cooling technique in a gas turbine blade system. The main objective is to predict and compare the life between an uncoated blade developed by NASA named C3X and a tri-layered thermal barrier coated C3X blade working under four different high temperature operating conditions. The geometry of the uncoated blade was modelled using Catia software. Three layers of coatings i.e., top coat, bond coat and thermally grown oxide with suitable thickness were generated by the mesh offset technique which was applied to an uncoated blade to model the coated blade. Thereafter steady-state 3D conjugate heat transfer analysis (CFD) with k-ε turbulence model by Ansys Cfx was performed to obtain temperature, pressure and heat transfer coefficient distribution on the surface of the blade. Firstly, this CFD analysis was performed using stainless steel as substrate material, then validated with experimental values and lastly, the same simulation model was applied to Nickel based super-alloy CMSX-4 material. The next step was carrying out transient uncoupled heat transfer, thermal stress, mechanical stress and sequentially coupled thermo-mechanical stress analyses using Abaqus for a flight length of 5000 seconds. At last, the creep-fatigue interaction life of the blade was computed by ductility exhaustion concept with morrow mean stress correction method using Fesafe/Turbolife software. After carrying out above mentioned processes for both uncoated and coated blade, an effective comparison was made. A significant decrease in Temperature (up to 127 K) and Thermo-Mechanical Stress (up to 263 MPa) and a significant increase in Fatigue-Creep Life (up to 16.5 times) was observed when TBCs were applied. The result shows that the thermal load was more severe than the mechanical load. The maximum thermo-mechanical stress was found at the trailing edge and fixed portion of the blade.
Numerical Investigations on Aerodynamic Design Criteria for Low Speed Mixed Flow Compressor
Authors: Kumar Hemant , S. Mistry Chetan
Published: December 2021

A surge in the small jet engine market due to aero-propulsion purposes generates a requirement to develop compact and robust high-performance compressors. Mixed flow compressors can provide a comparatively higher pressure ratio compared to axial compressors and have less frontal area than centrifugal compressors. Rapid progress in manufacturing and computational capabilities has resulted in the successful design of mixed flow compressors in recent decades.

In the present study, the mixed flow compressor was designed to operate at 3,000 rpm with a small total-to-total pressure ratio of 1.03 and a mass flow rate = 1.98 kg/s to carry at low-speed testing for university-level research. Meanline design for the compressor with air as working fluid was done. The blade geometry was developed using commercial Ansys® Bladegen module. The flow domain mesh was generated by the TurboGrid module. Ansys CFX was used as a solver and post-processing tool for the present numerical study.

The present work describes the detailed design procedure, overall performance, and flow field features of a low-speed mixed-flow compressor with the special requirement of axial flow exit. The parametric analysis was carried out on splitter blade placement, wrap angle (10°, 20°, 30°, and 50°), and exit cone angle (30°, 40°, 50°, 60°, and 65°), at constant tip clearance and keeping the other parameters constant to observe their effect on performance and flow structure. The use of splitter blades smoothen the flow structure along both stream-wise and span-wise direction, which minimizes flow the separation issue and thereby helping in extending the overall operating range. Comparing the flow field characteristic and performance of each parametric variable, the optimum range of design values is exhibited. The numerical observation and analysis done on parametric variations in this paper can be used for the design of such a future low-speed mixed flow compressor for different performance expectations and installation requirements.
Experimental Investigation of Performance Characteristics for Savonius-Style VAWTs: A Comparative Study
Authors: Paul Diplina , Banerjee Abhisek
Published: December 2021

Savonius-style wind turbines are mainly gauged by two types of coefficients namely: (i) coefficient of power (CP) and (ii) coefficient of torques (CT). Coefficient of power is defined as the ratio of power generated by the turbine to the total power available to the turbine from the free-flowing wind. This is synonymous to the operational efficiency of the wind turbine. Coefficient of torque reflects the torque generating ability of the turbine. In this manuscript, experiments have been performed using three different types of rotor profiles for Savonius-style wind turbines (SSWTs) namely, classical SSWT, Benesh type SSWT and elliptical shaped SSWT using oriented jets. Using deflector plates the orientation of jets have been varied from 20° to 70°. Addition of deflector plates to the wind turbines, assists in maximizing the utilization of wind energy. Experiments have been performed in the laminar air flow. Mechanical loads have been used to study Coefficient of performance (CP) and coefficient of torque (CT) as a function of tip speed ratio (TSRs). The velocity of the wind is adjusted by varying the rheostat that controls the AC motor for the wind tunnel systems. Experimental results indicated that optimum performance could be achieved from all three types of SSWT variants at TSR ∼ 0.70. Out of the three designs studied in this manuscript, elliptic shaped SWT yielded best coefficient of performance equal to 0.39 at TSR = 0.70.
Sleep Deprivation Training to Reduce the Negative Effects of Sleep Loss on Endurance Performance: A Single Case Study
Authors: Gattoni Chiara , Girardi Michele , O’Neill Barry Vincent , Maria Marcora Samuele
Published: December 2021

Purpose: Sleep deprivation (SD) is very common during ultraendurance competitions. At present, stimulants such as caffeine and naps are the main strategies used to reduce the negative effects of SD on ultraendurance performance. In this case study, the authors describe the application of a novel strategy consisting of the intermittent repetition of SD (SD training [SDT]) during the weeks preceding an ultraendurance competition. Methods: A male ultraendurance runner underwent a 6-week SDT program (consisting of 1 night SD every Sunday) in addition to his regular physical training program before taking part in a 6-day race. Before and after SDT, the participant performed 5 consecutive days of daily 2-hour constant-pace running with SD on the first and third night. Psychological and physiological responses were measured during this multiday test. Results: SDT was well tolerated by the athlete. A visual analysis of the data suggests that including SDT in the weeks preceding an ultraendurance competition may have beneficial effects on sleepiness and perceived mental effort in the context of 5 consecutive days of prolonged running and 2 nights of SD. This multiday test seems a feasible way for assessing ultraendurance athletes in the laboratory. Conclusions: The results provided some encouraging initial information about SDT that needs to be confirmed in a randomized controlled trial in a group of ultraendurance athletes. If confirmed to be effective and well tolerated, SDT might be used in the future to help ultraendurance athletes and other populations that have to perform in conditions of SD.
The Effect of Dry Needling on Pain, Range of Motion of Ankle Joint, and Ultrasonographic Changes of Plantar Fascia in Patients With Plantar Fasciitis
Authors: Moosaei Saein Afsaneh , Safavi-Farokhi Ziaeddin , Aminianfar Atefeh , Mortezanejad Marzieh
Published: December 2021

Context: Plantar fasciitis (PF) is a common and devastating disease. Despite different treatments, there is no clear evidence for the effect of these treatments on PF. One of the therapy methods used in physiotherapy is dry needling (DN). So the purpose of this study is to investigate the effect of DN on the pain and range of motion of the ankle joint and plantar fascia thickness in subjects with PF who are suffering from the trigger points of the gastrocnemius and soleus muscles. Methods: In this study, 20 volunteer females with PF were randomly assigned into DN treatment and control groups. Measurements were range of motion in dorsiflexion and plantar flexion, plantar fascia thickness, and visual analog scale measured before, immediately, and 1 month after the end of the intervention in both groups. Results: There were significant differences in the plantar fascia thickness and visual analog scale between the 2 groups. Plantar fascia thickness (P = .016) and visual analog scale (P = .03) significantly decreased in the treatment group. However, there was no significant difference in plantar flexion (P = .582) and dorsiflexion range of motion (P = .173) between groups. Conclusion: The result of this study showed that DN can reduce pain and plantar fascia thickness in women with PF who are suffering from trigger points of the gastrocnemius and soleus muscles. Level of evidence: Level 1, randomized controlled trial.
Feasibility of the Mothers and Daughters Moving Together Physical Activity Intervention
Authors: Dlugonski Deirdre , Schwab Lacey , DuBose Katrina D.
Published: December 2021

Purpose: Preschool-aged children, especially girls, have low levels of physical activity that may be influenced through parent role modeling. Evidence for mother–daughter interventions that include preschool-aged children is sparse. The primary purpose of this study was to examine the feasibility of recruitment procedures, protocol compliance, and participant retention for the Mothers and Daughters Moving Together intervention. The secondary aim was to provide initial estimates of the intervention effect on mother–daughter and family physical activity co-participation, moderate to vigorous physical activity, and maternal physical activity enjoyment and support. Method: This nonrandomized feasibility study included mother–daughter (2–5 y) dyads who self-selected into the intervention (n = 21 dyads) or comparison (n = 10 dyads) group. Results: The recruitment rate was 41.9% (31 enrolled/74 interested). Intervention group mother–daughter dyads attended 57% of intervention sessions. Among the whole sample, 70% to 80% of participants (mothers and daughters) had at least 4 valid days of accelerometer data at preintervention and postintervention. The retention rate was 90% (28/31 dyads completed the study). Initial estimates of intervention effect indicated small, positive changes for mother–daughter physical activity co-participation, and maternal physical activity support and enjoyment. Conclusions: This study provides valuable information that should be confirmed using an adequately powered and randomized study design.