bluuebunny/crossref_metadata_2025 huggingface dataset:
Stabilisation and resuscitation with intact cord circulation is feasible using a wide variety of approaches; a scoping review
Authors: Alikhani Vesta Seyed , Thies‐Lagergren Li , Svedenkrans Jenny , Elfvin Anders , Bolk Jenny , Andersson Ola
Published: September 2023

Aim

This scoping review identified studies on approaches to intact cord resuscitation and/or stabilisation (ICR/S) for neonates delivered by Caesarean section (C‐section).

Methods

A systematic literature search was carried out using the PubMed, Web of Science, Scopus, Cochrane and CINAHL databases to identify papers published in English from inception to 14 November 2022.

Results

We assessed 2613 studies and included 18 from 10 countries, covering 1–125 C‐sections: the United States, the United Kingdom, Australia, India, Italy, China, France, The Netherlands, New Zealand and Taiwan. The papers were published from 2014 to 2023, and the majority were randomised controlled trials and observational studies. Different platforms, equipment and staff positions in relation to the operating table were described. Options for resuscitation and stabilisation included different bedding and trolley approaches, and maintaining aseptic conditions was mainly addressed by the neonatal team scrubbing in. Hypothermia was prevented by using warm surfaces, polythene bags and radiant heaters. Equipment was kept easily accessible by mounting it on a trolley or a separate mobile pole.

Conclusion

We could not reach definitive conclusions on the optimal method for performing ICR/S during a C‐section, due to study variations. However, a number of equipment and management options appeared to be feasible approaches.
Letter: Entecavir versus tenofovir on serum lipoprotein levels of hepatitis B virus‐related hepatocellular carcinoma after curative hepatectomy—Author's reply
Authors: Ogawa Eiichi
Published: September 2023

LINKED CONTENT

This article is linked to Ogawa et al papers. To view these articles, visithttps://doi.org/10.1111/apt.17107andhttps://doi.org/10.1111/apt.17668
Ash1L ameliorates psoriasis via limiting neuronal activity‐dependent release of miR‐let‐7b
Authors: Du Wan‐Jie , Yang Huan , Tong Fang , Liu Shuai , Zhang Chen , Chen Yeying , Yan Yuze , Xiang Yan‐Wei , Hua Ling‐Yang , Gong Ye , Xu Zhi‐Xiang , Liu Xiaoyan , Jiang Xingyu , Lu Mingfang , Guan Ji‐Song , Han Qingjian
Published: September 2023

Background and Purpose

Psoriasis is a common autoimmune skin disease that significantly diminishes patients' quality of life. Interactions between primary afferents of the somatosensory system and the cutaneous immune system mediate the pathogenesis of psoriasis. This study aims to elucidate the molecular mechanisms of how primary sensory neurons regulate psoriasis formation.

Experimental Approach

Skin and total RNA were extracted from wild‐type (WT) and ASH1‐like histone lysine methyltransferase (Ash1l+/−) mice in both naive and imiquimod (IMQ)‐induced psoriasis models. Immunohistochemistry, quantitative real‐time polymerase chain reaction (qRT‐PCR) and fluorescence‐activated cell sorting (FACS) were then performed. Microfluidic chamber coculture was used to investigate the interaction between somatosensory neurons and bone marrow dendritic cells (BMDCs) ex vivo. Whole‐cell patch clamp recordings were used to evaluate neuronal excitability after Ash1L haploinsufficiency in primary sensory neurons.

Key Results

The haploinsufficiency of ASH1L, a histone methyltransferase, in primary sensory neurons causes both neurite hyperinnervation and increased neuronal excitability, which promote miR‐let‐7b release from primary afferents in the skin in a neuronal activity‐dependent manner. With a ‘GUUGUGU’ core sequence, miR‐let‐7b functions as an endogenous ligand of toll‐like receptor 7 (TLR7) and stimulates the activation of dermal dendritic cells (DCs) and interleukin (IL)‐23/IL‐17 axis, ultimately exacerbating the symptoms of psoriasis. Thus, by limiting miR‐let‐7b release from primary afferents, ASH1L prevents dermal DC activation and ameliorates psoriasis.

Conclusion and Implications

Somatosensory neuron ASH1L modulates the cutaneous immune system by limiting neuronal activity‐dependent release of miR‐let‐7b, which can directly activate dermal DCs via TLR7 and ultimately lead to aggravated psoriatic lesion.
Sex‐independent timing of the onset of central puberty revealed by nocturnal luteinizing hormone concentrations
Authors: Demir And , Hero Matti , Juul Anders , Main Katharina M.
Published: September 2023

Objective

We designed a longitudinal study to investigate the association between the ages of central pubertal activation and the appearance of clinical signs of puberty and determined total luteinizing hormone (LH) immunoreactivity in daytime‐ and nocturnal sleeptime‐excreted urine samples.

Patients and Measurements

Thirty healthy volunteers (17 boys and 13 girls, aged 3.4–15.2 years and 4.3–14.3 years, respectively, at the beginning of the study) were included. Male and female subjects were followed for an average of 15 visits during 5.5 and 5.8 years on average, respectively. At each visit, subjects provided 24‐h urine samples divided into nocturnal sleeptime and waketime portions according to the participant's sleep‐and‐wake rhythm. Total urinary LH (U‐LH) concentrations were measured in duplicate by Delfia® IFMA (Wallac), which has been designed specifically to detect intact LH as well as the beta subunit and its core fragment, but not the human chorionic gonadotropin.

Results

The initial increases in nocturnal sleeptime total U‐LH concentrations over the cutoff value of 0.7 IU/L occurred at around the same time (around 9–10 years of age) in both sexes, which could not be detected in waketime urine samples. The mean first age for the nocturnal sleeptime total U‐LH concentrations to reach or surpass the cutoff was 10.7 years (range: 10.2–11.6 years) in boys and 11.8 years (range: 10.7–13.4 years) in girls, showing no statistically significant difference between the sexes (p = .15). The mean time span from the age at which sleeptime total U‐LH concentration first exceeded the 0.7 IU/L level to observing pubertal stage 2 was 1.5 years in boys and 0.1 years in girls.

Conclusions

Findings in our population with a limited sample size suggest that the timing of central pubertal activation is a sex‐independent phenomenon, which can be observed by monitoring the nocturnal sleeptime total LH concentrations in urine. The lag time from central pubertal activation of gonadotropin secretion to the clinical onset of puberty is significantly longer in boys.
Novel WEE2 homozygous mutations c.1346C>T and c.949A>T identified in primary infertile women due to unexplained fertilization failure
Authors: Guo Haiyan , Wu Haibo , Yan Zheng , Yin Mingru , Wu Ling , Li Bin
Published: September 2023

The occurrence of unexplained fertilization failure can have profound psychological and financial consequences for couples struggling with infertility, and its pathogenesis remains unclear. Increasing evidence highlights genetic basis of unexplained fertilization failure occurrence. Here, we identified one novel homozygous nonsense mutation (c.949A>T), one novel homozygous missense mutation (c.1346C>T), and three reported homozygous mutations (c.585G>C, c.1006_1007insTA, c.1221G>A) in six unrelated probands, showing similar manifestations of unexplained fertilization failure. This finding expands the spectrum of WEE2 mutations, highlighting the critical role of WEE2 in fertilization process, and provides a basis for the prognostic value of testing for WEE2 mutations in primary infertile couples with unexplained fertilization failure.
Bone regeneration after maxillary sinus floor augmentation with different ratios of autogenous bone and deproteinized bovine bone mineral an in vivo experimental study
Authors: Starch‐Jensen Thomas , Schou Søren , Terheyden Hendrik , Bruun Niels Henrik , Aludden Hanna
Published: September 2023

Objective

Test the hypothesis of no difference in bone regeneration after maxillary sinus floor augmentation (MSFA) with different ratios of iliac or mandibular autogenous bone (AB) graft and deproteinized bovine bone mineral (DBBM).

Materials and Methods

Forty minipigs were randomly allocated to bilateral MSFA using: (A) 100% AB, (B) 75% AB and 25% DBBM, (C) 50% AB and 50% DBBM, (D) 25% AB and 75% DBBM, or (E) 100% DBBM. The animals were euthanized 12 weeks after surgery. Percentage of bone, non‐mineralized tissue, and residual DBBM were estimated by histomorphometric analysis in a randomly selected region of interest and summarized as mean percentage with 95% confidence interval (CI).

Results

Mean percentage of bone following MSFA with iliac or mandibular AB graft was: (A) 55.5% and 64.2%, (B) 60.3% and 61.6%, (C) 54.4% and 52.1%, (D) 51.8% and 53.1%, and (E) 47.6%, respectively. There was a significant trend toward a higher percentage of bone, with a higher ratio of AB within the graft (p < .01), regardless of the origin of AB graft (iliac or mandible).

Conclusions

The hypothesis was rejected since percentage of bone was significantly increased with larger proportions of AB within the graft. Consequently, AB or a mixture of AB and diminutive quantities of DBBM seem to be the preferred graft for MSFA based solely on histomorphometric assessment. However, it should be emphasized that newly formed bone and residual AB graft particles could not be distinguished by the applied histologic procedure.
The Hamas war against Israel as reflected in the poetry written by its leaders during the First Intifada and the early years of implementation of the Oslo Accords
Authors: Ben‐Dror Elad
Published: September 2023

This article looks at Hamas's war against Israel through the lens of the poetry written by leading members of Hamas during the period 1987–1996 (from the founding of the organization through the early stages of the implementation of the Oslo Accords). Poetry is one of the means employed by Hamas to convey its political, social, and religious messages and ideology, which links its Islamic outlook with Palestinian nationalism. During the years covered by the article, dozens of the organization's senior members expressed themselves in this genre. The article looks at ten poets who were affiliated with Hamas leadership circles and were intensively engaged in writing poetry in those years. It describes the background to this activity, extracts the main messages and motifs presented in their verse, and examines the goals served by this lyrical composition in the organization's war against Israel.
Politicized shopping in the gig economy: Retaliation and solidarity on the “other side” of the app
Authors: Maffie Michael David
Published: September 2023

In this mixed‐methods article, the author investigates how gig workers behave when they become consumers of these products. The author finds that workers engage in politicized shopping – where they order from platform companies with comparably better labor standards – both to retaliate against companies with substandard labor practices and support their fellow gig workers. By examining worker behavior on the “other side” of the platform, this article expands our understanding politicized shopping in this emerging area of work.
Carbon‐neutral pathways to 2050 for Japan's aviation industry in the absence of a mass supply of sustainable aviation fuels
Authors: Kito Minami , Takayabu Hirotaka , Nansai Keisuke
Published: September 2023

The global aviation sector must reduce its carbon dioxide (CO2) emissions to achieve its 2050 net‐zero emissions target. Although the current pathway to the target considers an increase in aviation demand following the COVID‐19 pandemic, emissions can be offset by the introduction of future technologies such as electric and hydrogen aircraft and sustainable aviation fuels (SAF). However, the commercialization of these future technologies is uncertain. In this study, we explore the feasible pathways for achieving the 2050 target in Japan. Specifically, we compare non‐future technology pathways, such as improving fuel efficiency and controlling flight distance and aircraft lifespan, with future technology pathways, such as introducing SAF. The results showed that the non‐future technology pathway would require up to 27% suppression of cumulative flight distances by 2050 relative to the predicted flight distance if only improving fuel efficiency and controlling flight distance and aircraft lifetimes. Minimizing the cumulative cost of the target achievement is contingent upon maximizing fuel efficiency and aircraft life extension. Additionally, the target achievement requires switching domestic flights to railway transport and limiting international flights for leisure, as well as increasing fares by up to 48% to compensate for sale declines. If future technologies are not fully implemented, substantial social change will be required to achieve the target.
Science in the Trading Zone: Interdisciplinarity and the ‘Environment’
Authors: Honeybun‐Arnolda Elliot
Published: September 2023

Interdisciplinarity continues to be a focus and method for complex social and environmental challenges. This paper explores how the School of Environmental Sciences (ENV) at the University of East Anglia (UEA) which was founded through the idea of scientific interdisciplinarity operated in practice to create new knowledge about a new object of concern, the ‘environment’. Using the ‘trading zone’ concept, the social and epistemic processes behind making scientific interdisciplinarity a material and institutional reality are uncovered, and to what extent interdisciplinary knowledge was actually produced. This paper concludes that interdisciplinary processes can be effective in dealing with complex challenges but often rely on the institutional and social dynamics of the researchers involved. Historicising interdisciplinarity in knowledge‐making settings can go some way in supporting new interdisciplinary endeavours associated with environmental and climate research.
A SYNTHESIS OF THE GEOLOGY AND PETROLEUM GEOLOGY OF THE IRANIAN PORTION OF THE SOUTH CASPIAN BASIN AND SURROUNDING AREAS
Authors: Ghassemi Mohammad R. , Allen Mark B. , Motamedi Hossein
Published: September 2023

The South Caspian Basin, the northern Alborz Mountains, the Gorgan plain and the Moghan plain constitute the northernmost and youngest petroleum system in Iran. This region was part of the Paratethys realm from Oligocene to Pliocene time. The Oligocene – Miocene Maikop/Diatom Total Petroleum System of the South Caspian Basin produces major volumes of hydrocarbons in Azerbaijan and Turkmenistan, and the Iranian sector of the basin has consequently undergone exploration due to its generally similar geology. The 20 km thick, dominantly Cenozoic sedimentary cover in the basin is reduced to less than 3 km in the northern foothills of the Alborz Mountains, and scattered surface oil seepages in the latter region are believed to be generated by Cretaceous and Miocene source rocks. In the Moghan plain to the southwest of the South Caspian Basin, anticlinal folds of Oligo‐Miocene Zivar Formation sandstones may be prospective for hydrocarbon exploration. Mud volcanoes in the Gorgan plain and in adjacent offshore regions at the SE margin of the South Caspian Basin are associated with hydrocarbon seepages, and appear to be sourced by Cretaceous and Cenozoic shales and mudstones. Major structural features in the southern part of the South Caspian Basin include Cenozoic mud diapirs, folds and gravity structures.
Italy's Antitrust Chief: The Case For Regulating Fake News Online
Authors: Pitruzzella Giovanni
Published: September 2023

Because of the unlimited amount of information on the internet, there is a less pluralistic exchange of different opinions than in traditional media.
Effect of an action‐research nutrition intervention on the Global Diet Quality Score of Colombian adolescents
Authors: Restrepo‐Mesa Sandra L. , Correa Guzmán Nathalia , Calvo Víctor , Giraldo Quijano María Cristina , Hernández Álvarez Carolina , Bergeron Gilles
Published: September 2023

Strategies to address the nutritional needs of adolescent girls and young women often focus on supplementation. In this study, an action‐research approach involving a nutrition education and entrepreneurship intervention was carried out among adolescent girls and young women in poor neighborhoods of Medellín, Colombia. The intervention group significantly increased its intake of several nutrients, including energy, protein, total fat, saturated fat, monounsaturated fat, polyunsaturated fat, cholesterol, dietary fiber, calcium, zinc, and vitamins A, B2, B3, B9, and C. A significant increase was observed in the intake of the Global Diet Quality Score (GDQS) healthy food groups (other fruits, other vegetables, legumes, high‐fat dairy products), accompanied by a decrease in the consumption of some unhealthy food groups (sweets and ice creams). A multivariate regression controlling for age, socioeconomic status, occupation, Household Hunger Scale, mean probability of adequacy, physical activity, and body self‐perception showed that the nutrition intervention improved the total GDQS by 33% in the intervention group—a substantial improvement notwithstanding the study group's precarious social and economic conditions. We conclude that nutrition education and entrepreneurship models based on this approach may improve the dietary profile of this population and reduce future pressures from nutrition‐related chronic diseases.
Oral microbial biomap in the drought environment: Sjogren's syndrome
Authors: Bustos‐Lobato Laura , Rus Maria J. , Saúco Carlos , Simon‐Soro Aurea
Published: September 2023

Sjogren's syndrome (SS) is an autoimmune disease that affects primarily the salivary glands, making perturbations in the oral ecosystem and potential factors of salivary flow that influence the onset and development of the disease. The oral cavity contains diverse microorganisms that inhabit various niches such as the oral microbial “biomap.” It does not seem specific enough to establish a characteristic microbiome, given the diversity of clinical manifestations, variable rates of salivary secretion, and influential risk factors in patients with SS. This review discusses the biogeography of the oral microbiome in patients with SS such as saliva, tongue, tooth, mucosa, and gum. The microorganisms that were more abundant in the different oral niches were Gram‐positive species, suggesting a higher survival of cell wall bacteria in this arid oral environment. Reduced salivary flow appears not to be linked to the cause of dysbiosis alone but influences host‐associated risk factors. However, much work remains to be done to establish the role of the microbiome in the etiopathogenesis of autoimmune diseases such as SS. Future studies of the microbiome in autoimmunity will shed light on the role of specific microorganisms that have never been linked before with SS.
A Novel Technology for 3D‐Printing Artificial Vertebral Bodies for Treating Lumbar Spine Adrenal Pheochromocytoma Metastases: A Case Report and Review of the Literature
Authors: Zhang Yadong , Li Houkun , Wang Wentao , Shan Lequn , Hao Dingjun
Published: September 2023

Background

Pheochromocytoma is an adrenal medullary neuroendocrine tumor that rarely metastasizes to the spine. Currently, its specific treatment methods still present challenges.

Case Description

A 41‐year‐old male patient who underwent left total adrenalectomy due to pheochromocytoma 3 years ago presented with lower back pain, accompanied by numbness and decreased muscle strength in both legs, as well as decreased sensation. Abnormal transmittance of the L3 vertebral body could be seen on anterior–posterior and lateral lumbar X‐rays, irregular bone destruction of the L3 vertebral body was found on CT, and an MRI scan showed that the tumor was located within the L3 vertebral body, protruding into the spinal canal and compressing the epidural sac. No recurrence was found in the abdomen. Preoperatively, perform local embolization of the blood vessels supplying the tumor. First, the L2‐3 intervertebral disc, L3‐4 intervertebral disc and L3 vertebral body were removed using an anterior approach, the whole tumor was removed, and some of the vertebrae were taken for pathological examination and replaced with a 3D‐printed prosthesis. Then, four pedicle screws were placed in the bilateral pedicles of L2 and L4 using the posterior approach, pre‐bent connecting rods were installed to replace the bone cortex of the lamina and articular process followed by bone graft fusion of the interlaminar and facet joints. The postoperative results were satisfactory, and there were no perioperative complications.

Conclusion

Lumbar pheochromocytoma metastasis is rare, difficult to treat, and should be considered in spinal metastases' differential diagnoses so early diagnosis can be made based on medical history and imaging. Preoperative local vascular imaging and embolization of the blood supply vessels were performed. After total en‐bloc spondylectomy of the tumor during surgery, a prosthesis was implanted and combined with pedicle screw fixation to reconstruct spinal biomechanical stability, achieving satisfactory results. Therefore, 3D printed artificial vertebral bodies are a good choice for treating adrenal pheochromocytoma lumbar metastasis. The key to successful treatment is close interdisciplinary collaboration in formulating rigorous comprehensive perioperative plans.
Impact of soil moisture stress during the silk emergence and grain‐filling in maize
Authors: Vennam Ranadheer Reddy , Poudel Sadikshya , Ramamoorthy Purushothaman , Samiappan Sathishkumar , Reddy K. Raja , Bheemanahalli Raju
Published: September 2023

Suboptimal soil moisture during the growing season often limits maize growth and yield. However, the growth stage‐specific responses of maize to soil moisture regimes have not been thoroughly investigated. This study investigated the response of maize to five different soil moisture regimes, that are, 0.25, 0.20, 0.15, 0.10, and 0.05 m3 m−3 volumetric water content (VWC), during flowering and grain‐filling stages. Sub‐optimal soil moisture at the flowering and grain‐filling stages reduced ear leaf stomatal conductance by 73 and 64%, respectively. An increase in stress severity caused significant reductions in ear leaf chlorophyll content and greenness‐associated vegetation indices across growth stages. Fourteen days of soil moisture stress during flowering delayed silk emergence, reduced silk length (19%), and silk fresh weight (34%). Furthermore, sub‐optimal soil moisture caused a significant reduction in both kernel number (53%) and weight (54%). Soil moisture stress at the flowering had a direct impact on kernel number and an indirect effect on kernel weight. During grain‐filling, disruption of ear leaf physiology resulted in a 34% decrease in kernel weight and a 43% decrease in kernel number. Unlike grain‐filling, treatments at the flowering significantly reduced kernel starch (3%) and increased protein by 29%. These findings suggest that developing reproductive stage stress‐tolerant hybrids with improved resilience to soil moisture stress could help reduce the yield gap between irrigated and rainfed maize.
Untangling the relationship between childhood risk factors and obstructive sleep apnoea in adulthood
Authors: Nixon Gillian M. , Horne Rosemary S. C.
Published: September 2023

See related article
‘Whispered in corridors’: Intra‐national politics and practices of knowledge production in South African Human Geography
Authors: Hammett Daniel , Hoogendoorn Gijsbert , Masutha Mukovhe
Published: September 2023

Reflections on the state of Geography around the globe have noted multiple challenges and opportunities—including a call for the reconfiguring of the discipline as a critical space of care and praxis (Daya, Transactions of the Institute of British Geographers, 47, 9, 2022). Such a call is indelibly connected to broader conversations on the politics of knowledge production and critical engagements with cultures of knowledge production. In order to realise the reconfiguring of the discipline, it is imperative to engage with the multi‐scalar politics and practices of knowledge production, to look beyond global inequalities and critically examine the intra‐national inequities and structural biases of knowledge production. Through a focus on South African Human Geography and detailed analysis of publication data and interviews with staff at universities across the country, we critically examine how the ‘haunting’ of apartheid legacies contributes to a double‐peripheralisation of staff at historically disadvantaged institutions while critical conversations remain ‘whispered in corridors’. This more granular engagement with the politics and practices of knowledge production highlights the entwining of intra‐ and inter‐national privilege which produces a mosaic of ‘cores’ and ‘peripheries’ in the uneven landscape of knowledge production that requires critical scholars to engage with on multiple scales in order to realise a more just and equitable knowledge economy.
Clinical performance of a new multiplex assay for the detection of HIV‐1, HIV‐2, HCV, HBV, and HEV in blood donations in Catalonia (Spain)
Authors: Sauleda Silvia , Bes Marta , Piron Maria , Ong Edgar , Coco Sonia Bakkour , Carrió Jaume , Linnen Jeffrey M.
Published: September 2023

Background

Commercial multiplex nucleic acid tests (NATs) for HIV‐1/HIV‐2/HCV/HBV are widely used in developed countries to screen blood donations. HEV NAT screening has been implemented in some blood banks but is tested with a different assay.

Study Design and Methods

This study describes the clinical sensitivity and specificity of the Procleix® UltrioPlex E (UPxE) assay on the automated Procleix Panther® system for the simultaneous detection of HIV‐1/HIV‐2/HCV/HBV/HEV. To evaluate routine performance, 10,138 donations were tested in parallel with UPxE (in ID‐NAT) and current assays (Procleix Ultrio Elite [UE] assay in ID‐NAT and Procleix HEV assay in pool of 16). To assess clinical sensitivity, archived donations positive for HCV, HIV‐1, HBV, HEV, or occult HBV infection (OBI) were tested (n = 104–186).

Results

Five donations were initially reactive (IR) with UPxE; none of them were reactive with current assays. Two of the three samples IR for HIV‐1/HIV‐2/HCV/HBV were confirmed positive for HBV (HBV NAT and/or anti‐HBV core positive) and classified as OBI. The two samples IR for HEV were confirmed positive (Procleix HEV assay in ID‐NAT and in‐house RT‐PCR HEV assay). One sample IR for HIV‐1/HIV‐2/HCV/HBV with UPxE and another with UE were not confirmed. UPxE showed a specificity of 99.99% for HIV‐1/HIV‐2/HCV/HBV and 100% for HEV. Comparable sensitivities were observed for HIV‐1, HCV, HBV, OBI, and HEV samples tested in the UPxE, UE, and Procleix HEV assays.

Discussion

UPxE may provide an efficient solution for the simultaneous detection of HIV‐1, HIV‐2, HCV, HBV, and HEV in blood donations in a single test.
Evaluation of Nox Emissions Associated to Non-Premixed Combustion of H2/Natural Gas Blends in a 40 MW Heavy-Duty Gas Turbine
Authors: Carusotto Salvatore , Labrini Giovanni , Salvadori Simone , Baratta Mirko , Cardile Francesco , Toppino Marco , Valsania Massimo , Misul Daniela
Published: September 2023

The tightening in the international regulations is leading the energy production sector toward the usage of hydrogen, which is a zero-carbon energy carrier. In the field of gas turbine lifetime extension, a nonpremixed approach including hydrogen blending with conventional fuels is the most promising. However, high-temperature spots might occur, thus increasing thermo-mechanical stresses and NOx emissions. Therefore, a reliable evaluation of the impact of hydrogen blends in combustors characterized by nonpremixed flames is necessary. In the present work, a 40 MW heavy-duty multican combustor belonging to EthosEnergy is investigated by means of steady, reactive simulations by using the ANSYS® FLUENT® solver. The combustor geometry is simplified by removing the casing volume, being the flow split among the holes already available. Such simplification allows for paying major attention to the chemical kinetics thanks to the use of the extended reaction mechanism for natural gas developed by National University of Ireland Galway. Simulations include the assessment of the natural gas base load configuration together with hydrogen blends up to 50% in volume, while maintaining unaltered the turbine inlet temperature (TIT). The obtained data provide some retrofitting guidelines in the field of hydrogen usage in nonpremixed combustion and prove for a modified temperature field in the combustor core and close to the basket. A linear increase in NOx emission is also associated with hydrogen addition, thus suggesting the need for NOx abatement technologies (e.g., water injection).
Caputo and Conformable Fractional Order Guava Model for Biological Pest Control: Discretization, Stability and Bifurcation
Authors: Kartal Senol
Published: September 2023

Two predator-prey model describing the guava borers and natural enemies are studied in this paper. Positivity, existence, and uniqueness of the solution, global and local stability analysis of the fixed points of the first model based on the Caputo fractional operator are studied. By adding piecewise constant functions to the second model including conformable fractional operator allows us to transition discrete dynamical system via discretization process. Applying Schur-Cohn criterion to the discrete system, we hold some regions where the equilibrium points in the discretized model are local asymptotically stable. We prove that discretized model displays supercritical Neimark–Sacker bifurcation at the equilibrium point. Theoretical and numerical results show that the discretized system demonstrates richer dynamic properties such as quasi-periodic solutions, bifurcation, and chaotic dynamics than the fractional order model with Caputo operator. All theoretical results are interpreted biologically and the optimum time interval for the harvesting of the guava fruit is given.
Toward Design Guidelines for Multidirectional Patient Transfer on a Bed Surface Using Traveling Waves
Authors: Mansouri Mahshid , Hsiao-Wecksler Elizabeth T. , Krishnan Girish
Published: September 2023

Patients who have limited body movement ability need assistance with frequent repositioning and transfers from their caregivers. These common manual tasks are physically strenuous for caregivers. To minimize caregiver physical effort, several assistive devices have been proposed. However, most devices have complex designs, are expensive, can only move the patient in one direction, or still need the caregiver’s intervention. Inspired by natural waves such as water waves that can carry objects, this study presents actuator-agnostic design guidelines for moving a body on a bed surface using traveling waves as an alternative solution. Specifically, this study explores how transportation speed and movement smoothness are affected by wave parameters such as the wavelength, wave amplitude, number of the actuators used to create the wave profile, and their movement pattern. Additional requirements for moving an elastic object, such as a human body, were also established to minimize the stiffness of the interface layer between the body and wave particles. Results suggest that transportation speed is linearly proportional to wave frequency and horizontal displacement of the wave actuators. Maximizing the number of actuators while minimizing wave amplitude and wavelength will increase the smoothness. Meanwhile, the wavelength must be at least half of the object length to ensure motion stability while also exceeding a critical value to guarantee that feasible waves are achieved in practice. Additionally, the wavelength, wave amplitude, and number of actuators will determine the minimum required stiffness of the interface layer.
Capital and Operational Cost Estimations for a Net-Zero Carbon Emissions Microgrid Application
Authors: Karg Bulnes Fernando , Schmitt Joshua M. , Smith Natalie R. , Khawly George N. , Allison Timothy C. , McClung Aaron
Published: September 2023

The current global perspective in energy production strongly favors the development, implementation, and transition to low carbon emission sources. As more companies and governments make carbon reduction and sustainability goals, the financial reality and viability of this transition becomes a major factor. One of the biggest challenges when it comes to emerging clean energy production systems is scaling and pricing them accurately. Several of these potential technologies have relatively low technology readiness levels (TRL), which further adds to the challenges of creating accurate cost estimates. Sources in literature cite different capital costs available for these energy systems. This paper discusses the methods used to calculate the capital cost associated with a variety of system types, including six energy storage technologies, renewable electricity production using a photovoltaic field, and fossil fuel with carbon capture. The analysis includes a brief assessment of the implementation of these technologies, discusses available literature, and gives a high-level overview of the model and methods used for the design and cost calculations of these facilities. The findings are used in the design of a net-zero carbon emission microgrid based on historic operational data of a 25 MW peak load, with a baseload of 10MW in the winter and 15 MW in the summer. Costs of technologies discussed in this paper and their implementation can be applied for future designs and initial feed studies for similar small-scale grid applications. Findings showed operating scenarios favoring a photovoltaic field with storage over fossil fuel sources with carbon capture.
Synergies and Trade-Offs in Hybrid Propulsion Systems Through Physics-Based Electrical Component Modelling
Authors: Bermperis Dimitrios , Ntouvelos Elissaios , Kavvalos Mavroudis D. , Vouros Stavros , Kyprianidis Konstantinos G. , Kalfas Anestis I.
Published: September 2023

Hybrid-electric propulsion is recognized as one of the enabling technologies for reducing aviation’s environmental impact. In this work a serial/parallel hybrid configuration of a 19-passenger commuter aircraft is investigated. Two underwing-mounted turboprop engines are connected to electrical branches via generators. One rear fuselage-mounted electrically driven ducted fan is coupled with an electric motor and respective electrical branch. A battery system completes the selected architecture. Consistency in modelling accuracy of propulsion systems is aimed for by development of an integrated framework. A multi-point synthesis scheme for the gas turbine and electric fan is combined with physics-based analytical modelling for electrical components. Influence of turbomachinery and electrical power system design points on the integrated power system is examined. An opposing trend between electrical and conventional powertrain mass is driven by electric fan design power. Power system efficiency improvements in the order of 2% favor high-power electric fan designs. A trade-off in electrical power system mass and performance arises from oversizing of electrical components for load manipulation. Branch efficiency improvements of up to 3% imply potential to achieve battery mass reduction due to fewer transmission losses in mission-significant segments. A threshold system voltage of 1kV, yielding 32% mass reduction of electrical branches and performance improvements of 1–2%, is defined. Above the indicated threshold, benefits are limited, and system design complexity increases unfavorably. This work sets the foundation for interpreting mission-level electrification outcomes that are driven by interactions on the integrated power system. Areas of conflicting interests and synergistic opportunities are highlighted for optimal conceptual design of hybrid powertrains.
Energy Management System for Smart Grids Including Renewable Sources and Industrial Symbiosis
Authors: Ferrari Mario L. , Gini Lorenzo , Maccarini Simone
Published: September 2023

The aim of this work regards the development of an energy management system (EMS) for smart grids with a high integration level of renewable sources. Special attention is devoted to waste recycling due to a large industrial symbiosis involving the production of alternative fuels (syngas and biogas). In details, the paper focuses attention on the Eigerøy island (Norway) that will be the demonstration site of the ongoing EU ROBINSON project. The main purpose of this activity is the development of technology integration solutions for decarbonization path, starting from industrialized districts in islands and considering high flexibility for replication issues.

The mentioned technology integration is obtained with an EMS able to operate in real-time mode for minimization of energy costs (fuels and electricity). So, this tool includes a minimization subroutine for calculating the optimal operative condition (on/off status for generators and the related set-points) connected with a Model Predictive Control (MPC) software for the real-time calculation of the generator set-points. An innovative approach is the integration of the electrolyzer management scheduling two different pressure levels for the connected hydrogen storage vessel. Simulation results assess the EMS performance and robustness for the innovative integrated layout including the industrial symbiosis. Special attention is devoted to the performance improvement in terms of cost decrease, CO2 emission decrease, and system efficiency increase.
Sensitivity Analysis of Performance Parameters of a Compressor Blade With Correlated Profile Parameters
Authors: Prots Andriy , Schlüter Lukas , Voigt Matthias , Meyer Marcus , Mailach Ronald
Published: September 2023

Sensitivity analysis is a commonly used method in engineering applications to identify the input variables whose variance has the largest impact on the variance of a model output. Two major difficulties are often encountered. First, many computationally intensive model evaluations are required to obtain sensitivity indices with high statistical confidence. Second, input variables are often correlated, which cannot be handled unambiguously by most sensitivity analysis methods.

Shapley values are a promising sensitivity measure for problems with correlations between input variables, as interaction effects are distributed evenly among the respective input parameters. However, Shapley values are affected by spurious correlations with input variables that have no functional influence. In this case, the Shapley value is dispersed and its significance is reduced. Therefore, a sensitivity measure that detects input variables without functional influence is desirable.

This paper analyzes the behavior of different sensitivity measures with respect to correlated input variables. It is shown that first-order and total-effect Sobol sensitivity indices, and Shapley values alone do not fully detect input variables without functional influence. Therefore, the modified coefficient of importance is introduced to detect such input variables.

In the final part of this paper, a sensitivity analysis for a compressor blade subject to manufacturing variability and wear is performed using the aforementioned sensitivity measures. The blade variation is described by profile parameters. First, the sensitivity analysis is performed, which allows to identify profile parameters that have no functional influence on the isentropic efficiency. Then, the sensitivity analysis is repeated with appropriately grouped profile parameters. It is found that the profile parameters describing the blade thickness have the greatest influence on the variance of the efficiency. With the proposed approach, it is therefore possible to identify the most important profile parameters, even if they are correlated.
Direct Numerical Simulation of Transitional and Turbulent Flows Over Multi-Scale Surface Roughness - Part II: The Effect of Roughness on the Performance of a High-Pressure Turbine Blade
Authors: Nardini Massimiliano , Jelly Thomas O. , Kozul Melissa , Sandberg Richard D. , Vitt Paul , Sluyter Greg
Published: September 2023

Turbine blades generally present surface roughness introduced in the manufacturing process or caused by in-service degradation, which can have a significant impact on aero-thermal performance. A better understanding of the fundamental physical mechanisms arising from the interaction between the roughness and the turbine flow at engine-relevant conditions can provide insights for the design of blades with improved efficiency and longer operational life. To this end, a high-fidelity numerical framework combining a well-validated solver for Direct Numerical Simulation and a second-order accurate immersed boundary method is employed to predict roughness-induced aero-thermal effects on an LS89 high-pressure turbine (HPT) blade at engine-relevant conditions. Different amplitudes and distributions of surface roughness are investigated and a reference smooth-blade simulation under the same flow conditions is conducted for comparison. Roughness of increasing amplitude progressively shifts the blade suction side boundary layer transition upstream, producing larger values of the turbulent kinetic energy and higher total wake losses. The on-surface data-capturing capabilities of the numerical framework provide direct measurements of the heat flux and the skin friction coefficient, hence offering quantitative information between the surface topology and engineering-relevant performance parameters. This work may provide a benchmark for future numerical studies of turbomachinery flows with roughness.
Flame Transfer Function and Emissions of a Piloted Single Jet Burner: Influence of Hydrogen Content
Authors: zur Nedden Philipp Maximilian , Eck Mattias Ettore Giulio , Lückoff Finn , Panek Lukasz , Orchini Alessandro , Paschereit Christian Oliver
Published: September 2023

The next generation of gas turbines must enable partial or pure hydrogen combustion to decarbonize electricity production. In this respect, jet burners have received increased attention in research and industry as a viable solution for combustors functioning over a wide operational range, as they are well-suited for stabilizing flames with high propagation speeds. In this work, a generic piloted single-jet hydrogen burner is developed and characterized experimentally. The jet burner is operated under lean and dry conditions to keep NOx emissions low. These operating conditions are generally prone to thermoacoustic instabilities. The flame shape, NOx emissions, and the acoustic response of the flame are characterized while varying the hydrogen concentration and the strength of a pilot injection stage. The measurements of the emissions demonstrate that the jet burner is well suited for the combustion of natural gas blends and pure hydrogen with low NOx. The mean flame OH* chemiluminescence images display a decreasing flame length with increasing hydrogen share and a strong dependence on the pilot strength. Last, the heat release rate response is assessed based on measured flame transfer functions for different fuel blends. We demonstrate that the injector used in this study is non-stiff. To assess the stiffness of the injector, a full flame transfer matrix is measured for selected cases, and a comparison of the two methods is provided.
Compressible Large Eddy Simulation of Thermoacoustic Instabilities in the PRECCINSTA Combustor Using Flamelet Generated Manifolds With Dynamic Thickened Flame Model
Authors: Gövert Simon , Lipkowicz Jonathan Timo , Janus Bertram
Published: September 2023

The fully compressible, density-based CFD-solver TRACE has been extended for simulations of turbulent reacting flows in aero engine gas turbine combustors. The flamelet generated manifolds combustion model is utilized to account for detailed chemical kinetics and combined with the dynamically thickened flame model to resolve the flame front on the large eddy simulation (LES) mesh. The chemistry tabulation is coupled with the LES solver by inversion of the transported energy equation using tabulated mixture averaged NASA polynomial coefficients. LES of the PRECCINSTA test case, a lean, partially-premixed swirl combustor are performed and the two distinctive regimes are correctly predicted: a stable regime with a ‘quite’ stable flame and an unstable regime with an oscillating flame driven by self-excited thermoacoustic instabilities. Statistics collected from the simulations, mean and root-mean-square values, are in good agreement with the experimental reference data for both operating conditions. The dominant frequency of the unstable flame deviates from the measurement by about 100 Hz and requires further investigation. The results demonstrate the general suitability of the simulation framework for reacting flow simulations in gas turbine combustion systems and the prediction of self-excited thermoacoustic oscillations.
Transonic Compressor Darmstadt Open Test Case: Experimental Investigation of Stator Secondary Flows and Hub Leakage
Authors: Klausmann Fabian , Kilian Nicklas , He Xiao , Franke Daniel , Schmidt Benedikt , Schiffer Heinz-Peter
Published: September 2023

The future trend of clean sky aviation has led to a smaller core engine, resulting in highly loaded stages with increased relative tip gaps and leakage flows, which causes a reinforced influence of secondary flow phenomena. This paper experimentally investigates the secondary flow effects in the 3D-optimized shrouded stator of the TUDa-GLR-OpenStage, representative of a transonic high-pressure compressor front stage, and its susceptibility to typical hub leakage flows. The impact of stator hub leakage on efficiency and total pressure ratio is investigated for several operating speeds, from subsonic to nominal transonic operating conditions. Steady five-hole probe and time-resolved virtual multi-hole probe measurements at different operating conditions at nominal speed are conducted to investigate the underlying loss mechanisms. The leakage mass flow is determined using the measured pressure difference within the fin seal. Steady results show that the optimized 3D stator effectively suppresses the hub corner separation compared to the predecessor 2D stator, but its performance is further limited by a near-tip separation. With the increased stator hub leakage (at a leakage-to-main flow ratio of about 0.4%), the compressor isentropic efficiency generally drops (by about −0.5%) at the full operating range due to an enhanced hub corner separation effect. However, the increased leakage also helps alleviate the tip-corner separation when operating near stall, leading to a smaller efficiency penalty under these conditions. Unsteady results reveal the sensitivity of transient compressor performance to the passing rotor wake, but limited interaction between this phenomenon and the increased leakage is observed. These findings provide insight into the stator hub leakage-related penalties on the compressor aerodynamics efficiency.