bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinicopathological Features of Gastric Cancer with Autoimmune Gastritis
Authors: Arai Junya , Niikura Ryota , Hayakawa Yoku , Suzuki Nobumi , Hirata Yoshihiro , Ushiku Tetsuo , Fujishiro Mitsuhiro
Published: April 2022

Most gastric cancers develop in patients with chronic gastritis. Chronic gastritis can be classified into two major subtypes: Helicobacter pylori (H. pylori)-induced gastritis and autoimmune gastritis (AIG). Whereas H. pylori-related gastric cancers are more common and have been extensively investigated, the clinicopathological features of gastric cancer with autoimmune gastritis are unclear. Patients diagnosed with gastric cancer and hospitalized in the University Tokyo Hospital from 1998 to 2017 were enrolled. Diagnosis of autoimmune gastritis was based on positivity for serum anti-parietal cell antibody (APCA). We evaluated mucin expression and immune cell infiltration by immunohistochemical staining for MUC5AC, MUC6, PD-L1, CD3, CD11, Foxp3, and PD1. We also examined the presence of bacterial taxa that are reportedly enriched in AIG. Survival analyses of recurrence and 5-year mortality were also performed. In total, 261 patients (76 APCA-positive and 185 APCA-negative) were analyzed. Immunohistochemical staining in the matched cohort showed that AIG-related gastric cancer had higher MUC5AC expression (p = 0.0007) and MUC6 expression (p = 0.0007). Greater infiltration of CD3-positive (p = 0.001), Foxp3-positive (p < 0.001), and PD1-positive cells (p = 0.001); lesser infiltration of CD11b-positive (p = 0.005) cells; and a higher prevalence of Bacillus cereus (p = 0.006) were found in AIG-related gastric cancer patients. The cumulative incidences of gastric cancer recurrence were 2.99% at 2 years, 15.68% at 6 years, and 18.81% at 10 years in APCA-positive patients; they were 12.79% at 2 years, 21.35% at 6 years, and 31.85% at 10 years in APCA-negative patients. The cumulative incidences of mortality were 0% at 3 years and 0% at 5 years in APCA-positive patients; they were 1.52% at 3 years and 2.56% at 5 years in APCA-negative patients. We identified molecular differences between AIG and non-AIG gastric cancer. Differences in T-cell populations and the gastric microbiota may contribute to the pathogenesis of gastric cancers and potentially affect the response to immunotherapy.
Ion Channels and Transporters as Therapeutic Agents: From Biomolecules to Supramolecular Medicinal Chemistry
Authors: Picci Giacomo , Marchesan Silvia , Caltagirone Claudia
Published: April 2022

Ion channels and transporters typically consist of biomolecules that play key roles in a large variety of physiological and pathological processes. Traditional therapies include many ion-channel blockers, and some activators, although the exact biochemical pathways and mechanisms that regulate ion homeostasis are yet to be fully elucidated. An emerging area of research with great innovative potential in biomedicine pertains the design and development of synthetic ion channels and transporters, which may provide unexplored therapeutic opportunities. However, most studies in this challenging and multidisciplinary area are still at a fundamental level. In this review, we discuss the progress that has been made over the last five years on ion channels and transporters, touching upon biomolecules and synthetic supramolecules that are relevant to biological use. We conclude with the identification of therapeutic opportunities for future exploration.
Novel Translational Read-through–Inducing Drugs as a Therapeutic Option for Shwachman-Diamond Syndrome
Authors: Bezzerri Valentino , Lentini Laura , Api Martina , Busilacchi Elena Marinelli , Cavalieri Vincenzo , Pomilio Antonella , Diomede Francesca , Pegoraro Anna , Cesaro Simone , Poloni Antonella , Pace Andrea , Trubiani Oriana , Lippi Giuseppe , Pibiri Ivana , Cipolli Marco
Published: April 2022

Shwachman-Diamond syndrome (SDS) is one of the most commonly inherited bone marrow failure syndromes (IBMFS). In SDS, bone marrow is hypocellular, with marked neutropenia. Moreover, SDS patients have a high risk of developing myelodysplastic syndrome (MDS), which in turn increases the risk of acute myeloid leukemia (AML) from an early age. Most SDS patients are heterozygous for the c.183-184TA>CT (K62X) SBDS nonsense mutation. Fortunately, a plethora of translational read-through inducing drugs (TRIDs) have been developed and tested for several rare inherited diseases due to nonsense mutations so far. The authors previously demonstrated that ataluren (PTC124) can restore full-length SBDS protein expression in bone marrow stem cells isolated from SDS patients carrying the nonsense mutation K62X. In this study, the authors evaluated the effect of a panel of ataluren analogues in restoring SBDS protein resynthesis and function both in hematological and non-hematological SDS cells. Besides confirming that ataluren can efficiently induce SBDS protein re-expression in SDS cells, the authors found that another analogue, namely NV848, can restore full-length SBDS protein synthesis as well, showing very low toxicity in zebrafish. Furthermore, NV848 can improve myeloid differentiation in bone marrow hematopoietic progenitors, enhancing neutrophil maturation and reducing the number of dysplastic granulocytes in vitro. Therefore, these findings broaden the possibilities of developing novel therapeutic options in terms of nonsense mutation suppression for SDS. Eventually, this study may act as a proof of concept for the development of similar approaches for other IBMFS caused by nonsense mutations.
Thrombotic and Atherogenetic Predisposition in Polyglobulic Donors
Authors: Slaninova Nikola , Bryjova Iveta , Lasota Zenon , Richterova Radmila , Kubicek Jan , Augustynek Martin , Seal Ayan , Krejcar Ondrej , Proto Antonino
Published: April 2022

This work analyses the results of research regarding the predisposition of genetic hematological risks associated with secondary polyglobulia. The subjects of the study were selected based on shared laboratory markers and basic clinical symptoms. JAK2 (Janus Kinase 2) mutation negativity represented the common genetic marker of the subjects in the sample of interest. A negative JAK2 mutation hypothetically excluded the presence of an autonomous myeloproliferative disease at the time of detection. The parameters studied in this work focused mainly on thrombotic, immunological, metabolic, and cardiovascular risks. The final goal of the work was to discover the most significant key markers for the diagnosis of high-risk patients and to exclude the less important or only complementary markers, which often represent a superfluous economic burden for healthcare institutions. These research results are applicable as a clinical guideline for the effective diagnosis of selected parameters that demonstrated high sensitivity and specificity. According to the results obtained in the present research, groups with a high incidence of mutations were evaluated as being at higher risk for polycythemia vera disease. It was not possible to clearly determine which of the patients examined had a higher risk of developing the disease as different combinations of mutations could manifest different symptoms of the disease. In general, the entire study group was at risk for manifestations of polycythemia vera disease without a clear diagnosis. The group with less than 20% incidence appeared to be clinically insignificant for polycythemia vera testing and thus there is a potential for saving money in mutation testing. On the other hand, the JAK V617F (somatic mutation of JAK2) parameter from this group should be investigated as it is a clear exclusion or confirmation of polycythemia vera as the primary disease.
Sarcopenia Predicts Major Complications after Resection for Primary Hepatocellular Carcinoma in Compensated Cirrhosis
Authors: Marasco Giovanni , Dajti Elton , Serenari Matteo , Alemanni Luigina Vanessa , Ravaioli Federico , Ravaioli Matteo , Vestito Amanda , Vara Giulio , Festi Davide , Golfieri Rita , Cescon Matteo , Renzulli Matteo , Colecchia Antonio
Published: April 2022

The burden of post-operative complications of patients undergoing liver resection for hepatocellular carcinoma (HCC) is a cause of morbidity and mortality. Recently, sarcopenia has been reported to influence the outcome of patients with cirrhosis. We aimed to assess factors associated with sarcopenia and its prognostic role in liver surgery candidates. We included all patients with compensated advanced chronic liver disease (cACLD) undergoing liver resection for primary HCC consecutively referred to the University of Bologna from 2014 to 2019 with an available preoperative abdominal CT-scan performed within the previous three months. A total of 159 patients were included. The median age was 68 years, and 80.5% of the patients were male. Sarcopenia was present in 82 patients (51.6%). Age and body mass index (BMI) were associated with the presence of sarcopenia at multivariate analysis. Thirteen (8.2%) patients developed major complications and 14 (8.9%) presented PHLF grade B-C. The model for end-stage liver disease score was associated with the development of major complications, whereas cACLD presence, thrombocytopenia, portal hypertension (PH), Child-Pugh score and Albumin-Bilirubin score were found to be predictors of clinically significative PHLF. The rate of major complications was 11.8% in sarcopenic patients with cACLD compared with no complications (0%) in patients without sarcopenia and cACLD (p = 0.032). The rate of major complications was significantly higher in patients with (16.3%) vs. patients without (0%) sarcopenia (p = 0.012) in patients with PH. In conclusion, sarcopenia, which is associated with age and BMI, may improve the risk stratification of post-hepatectomy major complications in patients with cACLD and PH.
Translational Strategies to Target Metastatic Bone Disease
Authors: Pagnotti Gabriel M. , Trivedi Trupti , Mohammad Khalid S.
Published: April 2022

Metastatic bone disease is a common and devastating complication to cancer, confounding treatments and recovery efforts and presenting a significant barrier to de-escalating the adverse outcomes associated with disease progression. Despite significant advances in the field, bone metastases remain presently incurable and contribute heavily to cancer-associated morbidity and mortality. Mechanisms associated with metastatic bone disease perpetuation and paralleled disruption of bone remodeling are highlighted to convey how they provide the foundation for therapeutic targets to stem disease escalation. The focus of this review aims to describe the preclinical modeling and diagnostic evaluation of metastatic bone disease as well as discuss the range of therapeutic modalities used clinically and how they may impact skeletal tissue.
Intensification of Heat and Mass Transfer in a Diabatic Column with Vortex Trays
Authors: Voinov Nikolai A. , Bogatkova Anastasiya V. , Zemtsov Denis A.
Published: April 2022

We used vortex contact devices that we developed and investigated to make a new design of an alcohol diabatic distillation column with heat exchange pipes (as the reflux condenser) passing through concentrating section trays. In the column, ascending vapors partially condensed on the surface of vertically installed heat exchange tubes, forming a reflux. The reflux was then mixed with the draining liquid flow in the vortex contact devices placed on the trays. Heat was removed from the column through the boiling of the draining water film along the inner surface of the heat exchange pipes. We compared both diabatic and adiabatic columns fitted with the developed vortex contact devices on the trays. The proposed innovative contact system allows increasing productivity, reducing column dimensions and steam- and heat-transfer medium consumption, and increasing separation efficiency. Dependences for calculating the gas content, hydraulic resistance, and interphase surface required for designing the vortex contact devices of the proposed unit trays are presented.
Elevated Alpha-Fetoprotein in Infantile-Onset Niemann-Pick Type C Disease with Liver Involvement
Authors: Kraus Dror , Abdelrahim Huda , Waisbourd-Zinman Orith , Domin Elena , Zeharia Avraham , Staretz-Chacham Orna
Published: April 2022

Niemann-Pick disease type C (NPC) is a rare autosomal recessive neuro-visceral lipid storage disease. We describe nine cases of infantile-onset NPC with various genetic mutations in the NPC1 gene, which presented with neonatal cholestasis. Serum alpha-fetoprotein (AFP) levels were obtained as part of their workup during the first four months of life. In eight of nine (89%) patients, serum AFP demonstrated elevated levels. Seven infants displayed marked elevations, ranging from 4 to 300 times the upper limit for age-adjusted norms. In most patients, AFP levels peaked during the initial test and declined over time as cholestasis resolved. We conclude that elevated AFP levels are a common, although non-specific, marker for NPC-associated liver disease. These findings demonstrate the benefit of including AFP levels in the workup of neonatal liver disease, especially if there is accompanied cholestasis and if NPC is suspected.
Long Term Neurodevelopmental Outcomes after Sevoflurane Neonatal Exposure of Extremely Preterm Children: A Cross-Sectional Observationnal Study
Authors: Brévaut-Malaty Véronique , Resseguier Noémie , Garbi Aurélie , Tosello Barthélémy , Thomachot Laurent , Vialet Renaud , Gire Catherine
Published: April 2022

Sevoflurane, a volatile anesthetic, is used when extremely preterm neonates (EPT) undergo painful procedures. Currently, no existing studies analyze sevoflurane’s long-term effects during the EPT’s immediate neonatal period. Our primary objective was to compare the EPT’s neurocognitive development regardless of any sevoflurane exposure prior to 45 weeks corrected gestational age (GA). We analyzed those live discharges, less than 28 weeks GA, who were either exposed, unexposed, and/or multiply exposed to sevoflurane before 45 weeks GA. All data were obtained from a cross-sectional multicenter study (GPQoL study, NCT01675726). Children, both exposed and non-exposed to sevoflurane, were sampled using a propensity-guided approach. Neurological examinations (Touwen), cognitive and executive functions (WISC IV, NEPSY, Rey figure), and assessments when the children were between 7 and 10 years old, were correlated to their neonatal sevoflurane exposure. There were 139 children in the study. The mean gestational age was 26.2 weeks (±0.8) GA and the mean birth weight was 898 g (±173). The mean age of their evaluation was 8.47 years old (±0.70). Exposure to sevoflurane to the mean corrected age 27.10 (3.37) weeks GA had a significant correlation with cerebral palsy (adjusted odds ratio (aOR): 6.70 (CI 95%: 1.84–32.11)) and other major disorders (cerebral palsy and/or severe cognitive retardation) (aOR: 2.81 [95% CI: 1.13–7.35]). Our results demonstrate the possibility of long-term effects on EPT infants who had a sevoflurane exposure before 45 weeks corrected GA. However, these results will require further confirmation by randomized controlled trials.
Explain Again: Why Are We Vaccinating Young Children against COVID-19?
Authors: Iles Ray Kruse , Makhzoumi Tarek Sultani
Published: April 2022

Public trust in governmental policies concerning public health measures is often now questioned. This is an acute problem with respect to vaccinations and particularly true regarding concerns around vaccination of children. Vaccination against COVID-19 is a particularly acute issue with many conspiracy theories circulating. These can almost certainly be countered by a strong evidence base. However, what if a policy is not based on strong evidence but on a judgement call? There is a strong evidence base concerning the beneficial and lifesaving attributes of immunization of adult and particularly vulnerable elderly groups against COVID-19. But what about young children? Here the benefit of immunization is not borne out by any publicly available data and would appear to be led by opinion, not evidence. The language used and vague statements giving a public justification for childhood vaccination COVID-19 immunization could be interpreted as misleading. Given a prevailing mistrust of government public health mandates, could these policies discourage childhood immunization and cost lives of children from other diseases?
Serology-Based Model for Personalized Epithelial Ovarian Cancer Risk Evaluation
Authors: Yan Tianqing , Ma Xiaolu , Hu Haoyun , Gong Zhiyun , Zheng Hui , Xie Suhong , Guo Lin , Lu Renquan
Published: April 2022

This study aimed to establish a prognosis-prediction model based on serological indicators in patients with epithelial ovarian cancer (EOC). Patients initially diagnosed as ovarian cancer and surgically treated in Fudan University Shanghai Cancer Center from 2014 to 2018 were consecutively enrolled. Serological indicators preoperatively were collected. A risk model score (RMS) was constructed based on the levels of serological indicators determined by receiver operating characteristic curves. We correlated this RMS with EOC patients’ overall survival (OS). Finally, 635 patients were identified. Pearson’s χ2 results showed that RMS was significantly related to clinical parameters. Kaplan–Meier analysis demonstrated that an RMS less than 3 correlated with a longer OS (p < 0.0001). Specifically, significant differences were perceived in the survival curves of different subgroups. Multivariate Cox analysis revealed that age (p = 0.015), FIGO stage (p = 0.006), ascites (p = 0.015) and RMS (p = 0.005) were independent risk factors for OS. Moreover, RMS combined with age, FIGO and ascites could better evaluate for patients’ prognosis in DCA analyses. Our novel RMS-guided classification preoperatively identified the prognostic subgroups of patients with EOC and showed higher accuracy than the conventional method, meaning that it could be a useful and economical tool for tailored monitoring and/or therapy.
The Analysis of Mammalian Hearing Systems Supports the Hypothesis That Criticality Favors Neuronal Information Representation but Not Computation
Authors: Stoop Ruedi , Gomez Florian
Published: April 2022

In the neighborhood of critical states, distinct materials exhibit the same physical behavior, expressed by common simple laws among measurable observables, hence rendering a more detailed analysis of the individual systems obsolete. It is a widespread view that critical states are fundamental to neuroscience and directly favor computation. We argue here that from an evolutionary point of view, critical points seem indeed to be a natural phenomenon. Using mammalian hearing as our example, we show, however, explicitly that criticality does not describe the proper computational process and thus is only indirectly related to the computation in neural systems.
An Information Quantity in Pure State Models
Authors: Tanaka Fuyuhiko
Published: April 2022

When we consider an error model in a quantum computing system, we assume a parametric model where a prepared qubit belongs. Keeping this in mind, we focus on the evaluation of the amount of information we obtain when we know the system belongs to the model within the parameter range. Excluding classical fluctuations, uncertainty still remains in the system. We propose an information quantity called purely quantum information to evaluate this and give it an operational meaning. For the qubit case, it is relevant to the facility location problem on the unit sphere, which is well known in operations research. For general cases, we extend this to the facility location problem in complex projective spaces. Purely quantum information reflects the uncertainty of a quantum system and is related to the minimum entropy rather than the von Neumann entropy.
A Uzawa-Type Iterative Algorithm for the Stationary Natural Convection Model
Authors: Keram Aytura , Huang Pengzhan
Published: April 2022

In this study, a Uzawa-type iterative algorithm is introduced and analyzed for solving the stationary natural convection model, where physical variables are discretized by utilizing a mixed finite element method. Compared with the common Uzawa iterative algorithm, the main finding is that the proposed algorithm produces weakly divergence-free velocity approximation. In addition, the convergence results of the proposed algorithm are provided, and numerical tests supporting the theory are presented.
The Impact of Commodity Price Shocks on Banking System Stability in Developing Countries
Authors: Ngepah Nicholas , da Silva Margarida Liandra Andrade , Saba Charles Shaaba
Published: April 2022

This study examines the impact of commodity price shocks on the banking sector stability of 18 African commodity-exporting economies using an unbalanced panel dataset spanning a 16-year period from 2000–2015. The study on the impact of commodity price shocks on African commodity-exporting economies’ banking sectors was estimated using a panel fixed effects model. The empirical findings indicate that commodity price shocks increase bank credit risk (non-performing loans) and, thus, pose a risk to the banking sector stability of African commodity-exporting economies. The results for the disaggregated shocks reveal that both positive and negative shocks weaken banking sector stability. In addition, commodity price shocks are discovered to decrease credit extension to the private sector, highlighting an additional channel through which the impact of commodity price shocks may be perpetuated to the real economy.
What Myths about Green Technology Innovation and Financial Performance’s Relationship? A Bibliometric Analysis Review
Authors: Qing Lingli , Chun Dongphil , Ock Young-Seok , Dagestani Abd Alwahed , Ma Xiang
Published: April 2022

The relationship between green technology innovation and corporate financial performance has gained considerable traction in academics and businesses. However, there is limited overall bibliometric analysis on this topic. To meet the research need, this study, using Citespace (Citespace5.8r3 version, ChaomMei Chen, Philadelphia), performed the bibliometric analysis of the relationship between green technology innovation and corporate financial performance from 2007 to 2021, with 251 academic papers published in the Web of Science databases being analyzed, thus identifying the research hotspots and trends. The results showed that: (i) the number of publications has moved from slow to rapid growth and is expected to ramp up further; (ii) only a small collaboration network has been formed among the authors; (iii) institutions’ work operates relatively independently. There is still more room for inter-institutional or cross-discipline cooperation against geographical regions. However, there is a strong network of cooperation among countries. China performs best in this research area, followed by Spain and the UK; (iv) several significant co-citation relationships are also formed in the literature network. The burst literature on green innovation, product innovation, and financial performance is considered a research hotspot; and (v) “green innovation”, “corporate performance”, “legitimacy”, “environmental disclosure”, and “corporate sustainability” have become trends in research. Our results provide academics and practitioners with a robust roadmap on the relationship between green technology innovation and corporate financial performance.
Maximizing Energy Efficiency in Hybrid Overlay-Underlay Cognitive Radio Networks Based on Energy Harvesting-Cooperative Spectrum Sensing
Authors: Liu Yan , Qin Xizhong , Huang Yan , Tang Li , Fu Jinjuan
Published: April 2022

Spectrum demand has increased with the rapid growth of wireless devices and wireless service usage. The rapid development of 5G smart cities and the industrial Internet of Things makes the problem of spectrum resource shortage and increased energy consumption even more severe. To address the issues of high energy consumption for spectrum sensing and low user access rate in the cognitive radio networks (CRN) model powered entirely by energy harvesting, we propose a novel energy harvesting (EH)-distributed cooperative spectrum sensing (DCSS) architecture that allows SUs to acquire from the surrounding environment and radio frequency (RF) signals energy, and an improved distributed cooperative spectrum sensing scheme based on energy-correlation is proposed. First, we formulate an optimization problem to select a leader for each channel; then formulate another optimization problem to select the corresponding cooperative secondary users (SUs). Each channel has a fixed SUs cluster in each time slot to sense the main user state, which can reduce the energy consumption of SUs sensing and can reduce the sensing time, and the remaining time can be used for data transmission to improve throughput, and finally achieve the purpose of improving energy efficiency. Simulation results show that our proposed scheme significantly outperforms the centralized scheme in terms of SUs access capability and energy efficiency.
Multi-Objective RANS Aerodynamic Optimization of a Hypersonic Intake Ramp at Mach 5
Authors: De Vanna Francesco , Bof Danilo , Benini Ernesto
Published: April 2022

The work describes a systematic optimization strategy for designing hypersonic inlet intakes. A Reynolds-averaged Navier-Stokes database is mined using genetic algorithms to develop ideal designs for a priori defined targets. An intake geometry from the literature is adopted as a baseline. Thus, a steady-state numerical assessment is validated and the computational grid is tuned under nominal operating conditions. Following validation tasks, the model is used for multi-objective optimization. The latter aims at minimizing the drag coefficient while boosting the static and total pressure ratios, respectively. The Pareto optimal solutions are analyzed, emphasizing the flow patterns that result in the improvements. Although the approach is applied to a specific setup, the method is entirely general, offering a valuable flowchart for designing super/hypersonic inlets. Notably, because high-quality computational fluid dynamics strategies drive the innovation process, the latter accounts for the complex dynamics of such devices from the early design stages, including shock-wave/boundary-layer interactions and recirculating flow portions in the geometrical shaping.
Multi-Crack Dynamic Interaction Effect on Oil and Gas Pipeline Weld Joints Based on VCCT
Authors: Cui Wei , Xiao Zhongmin , Yang Jie , Tian Mi , Zhang Qiang , Feng Ziming
Published: April 2022

In pipelines for transporting oil and gas, multiple cracks often exist in weld joints. The interaction among the cracks should be considered as it directly affects the life span of the pipeline structures. In the current investigation, based on the fluid–solid magnetic coupling model, the virtual crack-closure technique (VCCT) is applied to systematically study the multi-crack dynamic interaction effect on pipeline welds during the crack propagation process. The results show that the existence of an auxiliary crack accelerates the main crack’s propagation. When the auxiliary crack is nearer to the main crack tip, the enhancement effect of the auxiliary crack on the main crack increases. Further, when the initial length of the auxiliary crack increases, the main crack becomes easier to propagate. Two important parameters, the distance between the two interacting crack tips and the initial size of the auxiliary crack, are studied in detail. Their interference effect on the main crack has been quantified, which is very user-friendly for engineers to conduct failure assessment and prevention for oil and gas pipes with multiple cracks at weld joints.
Performance Analysis of a Geothermal Radiant Cooling System Supported by Dehumidification
Authors: Pieskä Henrikki , Ploskić Adnan , Holmberg Sture , Wang Qian
Published: April 2022

Space cooling demand is increasing globally due to climate change. Cooling has also been linked to all 17 sustainable development goals of the United Nations. Adequate cooling improves productivity and thermal comfort and can also prevent health risks. Meanwhile, policy initiatives such as the European Union’s Green Deal require participants to cut greenhouse gas emissions and reduce energy use. Therefore, novel cooling systems that are capable of efficiently producing high levels of thermal comfort are needed. Radiant cooling systems provide a design capable of fulfilling these goals, but their application in hot and humid climates is limited due to the risk of condensation. In this study, we compare the performances of radiant cooling systems with and without dehumidification. The studied systems are supplied by geothermal energy. The study is conducted using building energy models of a small office building belonging to a three-building school complex located in Sant Cugat near Barcelona in Spain. The studied location has a Mediterranean climate. The simulations are conducted using IDA Indoor Climate and Energy 4.8 simulation software. The results show that the radiant cooling system with dehumidification (RCD) produces considerably improved thermal comfort conditions, with maximum predicted mean vote (PMV) reached during the cooling season being 0.4 (neutral) and the maximum PMV reached by the radiant cooling system without dehumidification (RC) being 1.2 (slightly warm). However, the improved thermal comfort comes at the cost of reduced energy and exergy efficiency. The RCD system uses 2.2 times as much energy and 5.3 times as much exergy as the RC system. A sensitivity analysis is also conducted to assess the influence of selected input parameters on the simulation output. The results suggest that maximising dehumidification temperature and minimising ventilation flow rate can improve the energy and exergy efficiency of the RCD system while having a minor effect on thermal comfort.
Research on Conductivity Damage Based on Response Surface Analysis
Authors: Pan Yuan , Yang Ze , Pan Yuting , Xu Yiwen , Liao Ruiquan
Published: April 2022

Hydraulic fracturing is an important means of developing unconventional oil and gas layers. The fracture conductivity of tight sandstone reservoirs after fracture is affected by many factors, such as the interaction between the fracturing fluid, water, and rocks; the fracturing materials; and the construction parameters. This paper improves the experimental process of the long-term conductivity test and provides insight into conductivity prediction and optimization based on the response surface test method. The test process is conducted in the following manner: (1) inject nitrogen to evaluate the fracture conductivity before fracturing fluid damage; (2) inject fracturing fluid to simulate shut-in; and (3) inject nitrogen again to evaluate fracture conductivity after the damage ability of the fracturing fluid. The single factor test results show that the lower the sand concentration is, the higher the fracturing fluid viscosity will be, and the longer the fracturing fluid retention time is, the greater the damage to the conductivity of the fracturing fluid will be. The response surface test results show that the order of factors affecting the retention of conductivity is fracturing fluid viscosity > sand concentration > fracturing fluid retention time. There is a certain interaction between sand concentration and fluid viscosity, and there is also a certain interaction between fluid viscosity and fluid retention time, but these interactions are not significant; when the fracturing fluid retention time is longer, there will be an interaction between the sand concentration and the fracturing fluid retention time. In addition, based on the model used to optimize the fracturing construction parameters from the perspective of proppant conductivity damage, the optimal solution is when the viscosity of the fracturing fluid is 1 mPa.s, the paved-sand content is 8.49 kg/m2, and the retention time of the fracturing fluid is 10 h. The maximum retention rate of the flow conductivity is 63.19%.
Forced Oscillation Grid Vulnerability Analysis and Mitigation Using Inverter-Based Resources: Texas Grid Case Study
Authors: Alshuaibi Khaled , Zhao Yi , Zhu Lin , Farantatos Evangelos , Ramasubramanian Deepak , Yu Wenpeng , Liu Yilu
Published: April 2022

Forced oscillation events have become a challenging problem with the increasing penetration of renewable and other inverter-based resources (IBRs), especially when the forced oscillation frequency coincides with the dominant natural oscillation frequency. A severe forced oscillation event can deteriorate power system dynamic stability, damage equipment, and limit power transfer capability. This paper proposes a two-dimension scanning forced oscillation grid vulnerability analysis method to identify areas/zones in the system that are critical to forced oscillation. These critical areas/zones can be further considered as effective actuator locations for the deployment of forced oscillation damping controllers. Additionally, active power modulation control through IBRs is also proposed to reduce the forced oscillation impact on the entire grid. The proposed methods are demonstrated through a case study on a synthetic Texas power system model. The simulation results demonstrate that the critical areas/zones of forced oscillation are related to the areas that highly participate in the natural oscillations and the proposed oscillation damping controller through IBRs can effectively reduce the forced oscillation impact in the entire system.
Decentral Hydrogen
Authors: Grunow Paul
Published: April 2022

This concept study extends the power-to-gas approach to small combined heat and power devices in buildings that alternately operate fuel cells and electrolysis. While the heat is used to replace existing fossil heaters on-site, the power is either fed into the grid or consumed via heat-coupled electrolysis to balance the grid power at the nearest grid node. In detail, the power demand of Germany is simulated as a snapshot for 2030 with 100% renewable sourcing. The standard load profile is supplemented with additional loads from 100% electric heat pumps, 100% electric cars, and a fully electrified industry. The renewable power is then scaled up to match this demand with historic hourly yield data from 2018/2019. An optimal mix of photovoltaics, wind, biomass and hydropower is calculated in respect to estimated costs in 2030. Hydrogen has recently entered a large number of national energy roadmaps worldwide. However, most of them address the demands of heavy industry and heavy transport, which are more difficult to electrify. Hydrogen is understood to be a substitute for fossil fuels, which would be continuously imported from non-industrialized countries. This paper focuses on hydrogen as a storage technology in an all-electric system. The target is to model the most cost-effective end-to-end use of local renewable energies, including excess hydrogen for the industry. The on-site heat coupling will be the principal argument for decentralisation. Essentially, it flattens the future peak from massive usage of electric heat pumps during cold periods. However, transition speed will either push the industry or the prosumer approach in front. Batteries are tried out as supplementary components for short-term storage, due to their higher round trip efficiencies. Switching the gas net to hydrogen is considered as an alternative to overcome the slow power grid expansions. Further decentral measures are examined in respect to system costs.
Multiobjective Optimization for a Li-Ion Battery and Supercapacitor Hybrid Energy Storage Electric Vehicle
Authors: Xiao Gang , Chen Qihong , Xiao Peng , Zhang Liyan , Rong Quansen
Published: April 2022

The acceptance of hybrid energy storage system (HESS) Electric vehicles (EVs) is increasing rapidly because they produce zero emissions and have a higher energy efficiency. Due to the nonlinear and strong coupling relationships between the sizing parameters of the HESS components and the control strategy parameters and EV’s performances, energy consumption rate, running range and HESS cost, how to design the HESS EVs for different preferences is a key problem. How to get the real time performances from the HESS EV is a difficulty. The multiobjective optimization for the HESS EV considering the real time performances and the HESS cost is a solution. A Li-ion battery (BT) semi-active HESS and optimal energy control strategy were proposed for an EV. The multiobjectives include energy consumption over 100 km, acceleration time from 0–100 km per hour, maximum speed, running range and HESS cost of the EV. According to the degrees of impact on the multiobjectives, the scaled factors of BT capacity, the series number of Li-ion BTs, the series number of super-capacitors (SCs), the parallel number of SCs, and charge power of the SCs were chosen as the optimization variables. Two sets of different weights were used to simulate the multiobjective optimization problem in the ADVISOR software linked with MATLAB software. The simulation results show that some of the multiobjectives are sensitive to their weights. HESS EVs meeting different preferences can be designed through the weights of different objectives. Compared with the direct optimization algorithm, the genetic algorithm (GA) has a stronger optimization ability, and the single objective is more sensitive to its corresponding weight. The proposed optimization method is practical for a Li-ion BT and SC HESS EV design.
The Casual Nexus between Income and Energy Poverty in EU Member States
Authors: Carfora Alfonso , Passaro Renato , Scandurra Giuseppe , Thomas Antonio
Published: April 2022

This paper investigates the presence of a causal relationship between energy poverty and income poverty in the EU Member States through a Panel Vector Autoregressive specification, and controlled with a set of explanatory variables collected from the Eurostat energy database and the OECD environment database for 2007–2018. Deepening the nexus between energy poverty and income poverty is a relevant issue for tailoring policies to tackle poverty and improve the well-being of citizens, supporting the policy makers in the allocation of planned funds provided by the Recovery plan, “Next Generation EU”. The results of the panel VAR model estimation and Dumitrescu and Hurlin test suggest that there will be no change in the long-run equilibrium when income poverty remains constant. Moreover, the reduction in energy poverty is expected to have a positive effect in terms of overall economic poverty reduction. Finally, there is evidence that substituting fossil fuels with renewables helps to reduce energy poverty and widespread poverty due to the leverage effect on economic development as well as to support the achievement of some of the 17 Sustainable Development Goals addressed by United Nations.
Experimental Performance Analysis of Adsorption Modules with Sintered Aluminium Fiber Heat Exchangers and SAPO-34-Water Working Pair for Gas-Driven Heat Pumps: Influence of Evaporator Size, Temperatures, and Half Cycle Times
Authors: Velte Andreas , Joos Lukas , Füldner Gerrit
Published: April 2022

A major challenge for gas-driven adsorption heat pumps is the production of compact, efficient, and cost-effective adsorption modules. We present the experimental data of a design based on sintered aluminum fiber heat exchangers, a technology currently under development. The adsorption module presented here is the result of the downsizing of a larger module. The downsized module has an adsorption heat exchanger that is 60% of the size of the larger-scale component, and an evaporator-condenser that is only 30% of the size of the larger-scale component. It is designed to fit the heating requirements of a wall-hung heat pump for a single-family home. For the first time, a comprehensive experimental study of the influence of half-cycle time, evaporator and adsorption temperature, and driving temperature on the efficiency and power of the module is presented. At temperature conditions relevant for the application of a gas-driven adsorption heat pump, i.e., evaporator temperature < 10 °C and adsorption temperature > 30 °C, we found that the downsizing has its price in terms of a higher thermal capacity of the components in relation to the adsorbent mass (9.6 kJ/(kg∙K) for ‘Size S’) vs. 5.6 kJ/(kg∙K) for ‘Size L’). We carried out an evaluation of heat and mass transfer resistances to compare the ‘Size L’ module directly with the ‘Size S’ module. Both modules have nearly the same volume-scaled heat and mass transfer resistances of 0.012 dm3 K/W (adsorption heat exchanger during adsorption) and 0.005 dm3 K/W (evaporator–condenser during evaporation), and consequently a very similar volumetric power density. This evaluation proves the applicability and the consistency of the concept of heat and mass transfer resistances, and the scalability of this adsorption module technology.
Influence of the Canopy Drip Effect on the Accumulation of Atmospheric Metal and Nitrogen Deposition in Mosses
Authors: Nickel Stefan , Schröder Winfried , Völksen Barbara , Dreyer Annekatrin
Published: April 2022

Wet, dry, and occult atmospheric deposition may be modified by vegetation canopies. The aim of this study was to verify canopy drip effect studies conducted in 2012, in 2013, and in 2015/2016. For this purpose, 26 moss samples were taken at each of eight monitoring sites of the European Moss Survey 2020/2021 in Germany from a corresponding number of subplots, each representing the site categories “under tree canopy” and adjacent “open land”. The sampling, as well as the chemical analyses, of 12 metals (Al, As, Cd, Cr, Cu, Fe, Hg, Pb, Ni, Sb, V, Zn) and nitrogen (N) and the recording of sample- and site-describing metadata were conducted according to the ICP Vegetation experimental protocol. The results demonstrate an overall higher metal and nitrogen accumulation in moss samples of “canopy” sites compared to neighboring “open land sites” (grassland, heath). The ratios between the “canopy” and “open land” sites of 1.18 to 1.69 and significant correlations of r > 0.8 in case of five elements agree well with corresponding values from samplings in 2012, 2013, and 2015/2016. These results should be used for modeling atmospheric deposition aiming at more realistic results. With regard to the question of whether, and to what extent, moss samples should preferably be taken from “open land” or “canopy” sites, the following can be concluded: The recommendations of ICP Vegetation with regard to the minimum distance to be maintained from trees and shrubs should not be interpreted to mean that “open” sites are fundamentally more suitable for moss sampling in Germany than, for example, clearings in forests. The mostly higher variability of the measured values compared to the “canopy” sites rather suggests that in the open country a much higher number of influencing factors could be significant for the element accumulation in mosses in addition to the background pollution through atmospheric deposition. This is also supported by the fact that the metal contents in the moss samples of the “open” sites can clearly exceed those of the neighboring “canopy” sites in individual cases. With regard to “open” land, grassland sites seem to be less suitable for moss sampling than bog and heathland sites. In grassland, moss occurrences are often sparser and/or cut short by meadow mowing, so that the removal of three-year shoots on grassland, as recommended by ICP Vegetation, must be replaced in places by one-year shoots. The comparatively higher state dynamics of grassland sites also make the resampling of moss at previously sampled sites more difficult.
Juvenile Hake Merluccius gayi Spatiotemporal Expansion and Adult-Juvenile Relationships in Chile
Authors: Yepsen Daniela V. , Cubillos Luis A. , Arancibia Hugo
Published: April 2022

The abundance of juvenile fish changes due to endogenous processes, and determining the functional relationships among conspecifics is essential for fisheries’ management. The hake (Merluccius gayi) is an overexploited demersal fish widely distributed in Chile, from 23°39′ S to 47°00′ S in shallow and deep water over the continental shelf and shelf break. We studied the spatiotemporal distribution of hake juveniles (from ages 0 and 1), emphasizing endogenous relationships among juveniles and adults. The abundance per age data were obtained from bottom trawl cruises carried out in the austral winter between 1997 and 2018. Generalized additive models showed a similar spatiotemporal pattern for ages between 0 and 1, and negative effects of adult hake aged seven and older on the abundance of the young generation. Regarding the changes in juvenile abundance, the residual deviance of selected models explained 75.9% (for the age 0) and 95.3% (for the age 1) of the null deviance, revealing a significant increase in juvenile abundance from 2002 to 2007 and subsequent abundance stability at higher levels. Furthermore, the expansion in the abundance of juveniles after 2002 was favored by the low abundance of older adult hake, most which are able to cannibalize young hake. Our results highlight the importance of endogenous factors in the spatial distribution of Chilean hake juveniles to identify nurseries or juvenile areas free of potential cannibal adults.
Mathematical Modeling and Pilot Test Validation of Nanoparticles Injection in Heavy Hydrocarbon Reservoirs
Authors: Valencia Juan D. , Mejía Juan M. , Icardi Matteo , Zabala Richard
Published: April 2022

Heavy-oil mobility in reservoir rocks can be improved, using nanotechnology, by reducing the viscosity of the oil and improving the rock wettability to a water-wet condition. Previous pilot studies in Colombian heavy oil fields reported that nanoparticles dispersed in an oleic carrier fluid (diesel) increased oil production rates between 120–150% higher than before the interventions. However, to optimally deploy a massive nanofluid intervention campaign in heavy oil fields, it is valuable to implement simulation tools that can help to understand the role of operational parameters, to design the operations and to monitor the performance. The simulator must account for nanoparticle transport, transfer, and retention dynamics, as well as their impact on viscosity reduction and wettability restoration. In this paper, we developed and solved, numerically, a 3D mathematical model describing the multiphase flow and interaction of the nanoparticles with oil, brine, and rock surface, leading to viscosity reduction and wettability restoration. The model is based on a multiphase pseudo-compositional formulation, coupled with mass balance equations, of nanoparticles dispersed in water, nanoparticles dispersed in oil, and nanoparticles retained on the rock surface. We simulated a pilot test study of a nanofluid stimulation done in a Colombian heavy oil field. The injection, soaking, and production stages were simulated using a 3D single-well formulation of the mathematical model. The comparison of simulation results with the pilot test results shows that the model reproduced the field observations before and after the stimulation. Simulations showed that viscosity reduction during the post-stimulation period is strongly related to the detachment rate of nanoparticles. Simulation indicates that the recovery mechanism of the nanofluid stimulation is initially governed by viscosity reduction and wettability alteration. At latter times, wettability alteration is the main recovery mechanism. The nanoparticles transferred to the residual water promote the wettability alteration to a water wet condition. The model can be used to design field deployments of nanofluid interventions in heavy oil reservoirs.