bluuebunny/crossref_metadata_2025 huggingface dataset:
An Efficient Sensor for the Detection of Zidovudine Based on 1‐Ethyl‐3‐methylimidazolium 1,1,2,2‐tetrafluoroethanesulfonate/ZnO Nanoparticle/MWCNT Glassy Carbon Electrodes**
Authors: Xhakaza Nokukhanya Mavis , Chokkareddy Rajasekhar , Redhi Gan G
Published: December 2021

A sensitive, low cost and novel electrochemical sensor based on 1‐ethyl‐3‐methylimidazolium 1,1,2,2‐tetrafluoroethanesulfonate ionic liquid (EmimTFES) combined with multi‐walled carbon nanotubes (MWCNTs) and zinc oxide nanoparticles (ZnONPs) in order to modify the glassy carbon electrode (GCE), has been developed for the first time. It was assessed that this sensor can be used for the rapid detection of the pharmaceutically antiretroviral drug zidovudine (ZDV). The characterization of ZnONPs, MWCNTs‐ZnONPs and MWCNTs‐ZnONPs‐EmimTFES was performed using Transmission electron microscopy (TEM), Ultraviolet Visible spectrophotometer (UV‐Vis), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), and Thermogravimetric analysis (TGA). The electrochemical of behaviour of MWCNTs‐ZnONPs‐EmimTFES‐GCE was studied using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The proposed sensor shows high electrocatalytic activity towards ZDV reduction over the concentration range of 0.2 μM to 2.0 μM. In addition, the limit of detection (LOD) of 0.0029 μM and limit of quantification (LOQ) of 0.0416 μM was obtained. Under optimal conditions the ionic liquid‐based sensor showed high selectivity, stability and sensitivity for ZDV detection, making it a suitable sensor for rapid determination of ZDV.
Size and Shape Manipulation of Channel Structures Assembled Via Saddle stacking of Tetrapodal Adamantanes Containing Aryl Butadiynyl Moieties
Authors: Okayasu Misaki , Sunakawa Toshiki , Ikeda Mitsuru , Namikawa Takaya , Hagura Riho , Kikkawa Shoko , Hikawa Hidemasa , Azumaya Isao
Published: December 2021

Three tetrapodal adamantane derivatives containing aryl butadiynyl moieties were synthesized under conditions similar to those of the Hay coupling reaction, and their crystal structures were analyzed. The substituted tetrapodal adamantanes were found to pile atop each other via saddle stacking to form 1D columnar structures, and the assembly of these 1D structures gave rise to channels in the crystal. Column assembly was achieved through CH/π and π‐π interactions between the terminal aromatic rings of the adamantanes belonging to adjacent columns. The channels thus formed had different shapes and sizes depending on the terminal aryl substituents, and were occupied by a suitable number of solvent molecules. Compared to the adamantanes with phenyl butadiynyl moieties as the terminal substituents, those with naphthyl butadiynyl moieties formed wider or thicker channels owing to their greater expanse perpendicular to the direction of saddle‐stacking.
Knocking Down Barriers: Advances in siRNA Delivery
Authors: Rajeev Anjaly , Siby Aiswarya , Koottungal Merin James , George Jinu , John Franklin
Published: December 2021

RNA interference (RNAi) has been emerged as an effective method to silence a particular gene utilizing a sequence‐specific mechanism for gene regulation. It induces target mRNA degradation leading to a lower illness‐inducing gene product. RNAi represent a conserved mechanism. Novel concept of highly specific silencing of genes was revolutionized by the introduction of short interfering RNA (siRNA).This helped to overcome the drawbacks of RNAi and proved out to be a safer and efficient method than its counterpart finding its way into the pharmaceutical industry. Clinical trials enhanced the possibility of siRNA delivery and yielded promising results for the treatment of a wide range of illnesses but mainly for intractable diseases like cancer, inflammatory diseases, and genetic disorders. siRNA delivery methods were instrumental in developing it as a therapeutic, of which lipid encapsulation crept its way, to be a better in vivo delivery mechanism as it could be formulated effectively, being biodegradable, and has a lower toxicity level. However, the therapeutic potential of siRNA remains hampered due to a lack of a viable delivery method, a lower accuracy in tissue specificityand cytotoxicity. Hence the therapeutic usage of the method is in its budding stage. This review re‐examines the principle of siRNA, challenges in its delivery, and some recent advancesto overcome the obstacles in order to improve siRNA delivery.
Asymmetric and Anharmonic Electrode Kinetics: Evaluation of a Model for Electron Transfer with Concerted Rupture of Weak, Inner Shell Interactions
Authors: Lawrence Nathan S. , Schöllhorn Bernd , Wadhawan Jay D.
Published: December 2021

A surface‐integrated form of the widely used (anharmonic) Lennard‐Jones 12–6 interaction potential, the Lennard‐Jones 9–3 potential, is used to develop a quadratic activation/driving force relationship that gives rise to asymmetric Tafel plots for electron transfer occurring with simultaneous interaction rupture. The Tafel plots are shown to exhibit linearity over a wide potential range, depending on the ratio of the Gibbs interaction well to the solvent reorganisation free energy. The fit of the model to experimental data for a ferrocene‐based self‐assembled monolayer (SAM) bathed by aqueous perchloric acid suggests ion pairing between ferricenium and perchlorate ions. This crude and primitive model readily enables experimentalists to obtain a parametric understanding of the physicochemical dynamics underpinning interaction rupture in concert with electron transfer, which may empower routes to improve the efficiency of a plethora of topical electrochemical technologies.
Promising Material Based on Paraffin‐Impregnated Graphite Foil with Increased Electrochemical Stability for Bipolar Plates of Vanadium Redox Flow Battery
Authors: Loktionov Pavel , Pichugov Roman , Konev Dmitry , Abunaeva Lilia , Glazkov Artem , Petrov Mikhail , Kartashova Natalia , Antipov Anatoly
Published: December 2021

The development of effective power sources is a major challenge for global energetics. Among various power sources, the redox flow batteries (RFB) have distinctive feature due to the flexibility of adjusting the capacity and power to the needs of the customer. The vanadium RFBs are already available in the stationary storage market, but their widespread distribution requires a significant reduction in the levelized cost of storage (LCOS). Therefore, a number of works are devoted to the development of more available materials for the RFB. The utilization of affordable graphite foil (GF) for fabricating bipolar plates as well as a method for increasing its electrochemical stability by a fluoropolymer were earlier proposed. In this work, we have demonstrated an approach to significantly reduce the porosity of GF by impregnation with paraffin P‐2. Such modification significantly increases GF stability and retains the RFB performance at a high level comparable to commercial graphite.
Large‐Area Nanosphere Self‐Assembly Monolayers for Periodic Surface Nanostructures with Ultrasensitive and Spatially Uniform SERS Sensing
Authors: Song Changkun , Ye Baoyun , Xu Jianyong , Chen Junhong , Shi Wei , Yu Chunpei , An Chongwei , Zhu Junwu , Zhang Wenchao
Published: December 2021

Colloidal lithography provides a rapid and low‐cost approach to construct 2D periodic surface nanostructures. However, an impressive demonstration to prepare large‐area colloidal template is still missing. Here, a high‐efficient and flexible technique is proposed to fabricate self‐assembly monolayers consisting of orderly‐packed polystyrene spheres at air/water interface via ultrasonic spray. This “non‐contact” technique exhibits great advantages in terms of scalability and adaptability due to its renitent interface dynamic balance. More importantly, this technique is not only competent for self‐assembly of single‐sized polystyrene spheres, but also for binary polystyrene spheres, completely reversing the current hard situation of preparing large‐area self‐assembly monolayers. As a representative application, hexagonal‐packed silver‐coated silicon nanorods array (Si‐NRs@Ag) is developed as an ultrasensitive surface‐enhanced Raman scattering (SERS) substrate with very low limit‐of‐detection for selective detection of explosive 2,4,6‐trinitrotoluene down to femtomolar (10−14 m) range. The periodicity and orderliness of the array allow hot spots to be designed and constructed in a homogeneous fashion, resulting in an incomparable uniformity and reproducibility of Raman signals. All these excellent properties come from the Si‐NRs@Ag substrate based on the ordered structure, open surface, and wide‐range electric field, providing a robust, consistent, and tunable platform for molecule trapping and SERS sensing for a wide range of organic molecules.
TraceRank: Abnormal service localization with dis‐aggregated end‐to‐end tracing data in cloud native systems
Authors: Yu Guangba , Huang Zicheng , Chen Pengfei
Published: December 2021

Modern cloud native applications are generally built with a microservice architecture. To tackle various performance problems among a large number of services and machines, an end‐to‐end tracing tool is always equipped in these systems to track the execution path of every single request. However, it is nontrivial to conduct root cause analysis of anomalies with such a large volume of tracing data. This paper proposes a novel system named TraceRank to identify and locate abnormal services causing performance problems with dis‐aggregated end‐to‐end traces. TraceRank mainly includes an anomaly detection module and a root cause analysis module. The root cause analysis procedure is triggered when an anomaly is detected. To fully leverage the information provided by the tracing data, both the spectrum analysis and the PageRank‐based random walk methods are introduced to pinpoint abnormal services. The experiments in TrainTicket and Bookinfo microservice benchmarks and a real‐world system show that TraceRank can locate root causes with 90% in Precision and 86% in Recall. TraceRank has up to 10% improvement compared with several state‐of‐the‐art approaches in both Precision and Recall. Finally, TraceRank has good scalability and a low overhead to adapt to large‐scale microservice systems.
A metaheuristic‐based optimum tuning approach for tuned liquid dampers for structures
Authors: Ocak Ayla , Bekdaş Gebrail , Nigdeli Sinan Melih
Published: December 2021

This study focuses on the optimization of tuned liquid dampers (TLDs) by using metaheuristic methods using a natural phenomenon as inspiration. Unlike tuned mass dampers (TMDs), TLDs consist of two parts of bodies that contain the passive liquid that is stationary and the active part of the liquid that involves in sloshing. To optimize the amount of optimum active and passive liquids by finding the best dimensional properties of the liquid tank, a two‐degree‐of‐freedom (DOF) model was used as TLD in the dynamic analysis used in the optimization that aims to reduce the maximum displacement of the structure under earthquake excitations. For this purpose, water, oil, and glycerin liquids were selected for TLD. TLD parameters were optimized with the help of Jaya algorithm, flower pollination algorithm (FPA), harmony search (HS) algorithm, and teaching–learning‐based optimization (TLBO). Total acceleration and maximum displacement were evaluated after optimization. The performance of TLD under earthquake excitations has been also compared with TMDs. According to the results, the optimized TLD has a better performance than TMD, and Jaya algorithm has a slightly better performance than the other algorithms.
Crack Resistance of Diamond‐Like Carbon Coatings
Authors: Bobzin Kirsten , Brögelmann Tobias , Carlet Marco , Kruppe Nathan C. , Engels Martin , Arghavani Mostafa
Published: December 2021

The aim of the current paper is the study of the crack resistance of diamond‐like carbon (DCL) coatings deposited by direct current magnetron sputtering (dcMS) and high‐power pulse magnetron sputtering (HPPMS) with different process parameters. For this purpose nanoindentation with a very high force resolution of RFN ≤ 1 nN was used to analyze different a‐C coatings, which were deposited under variation of the process gases argon, helium and neon. Owing to significantly high force resolution of the indenter, a large number N = 31,872 of data points in each force‐displacement curve was recorded, which enabled the desired analyses. Based on the results, it can be stated that the nanoindentation is able to provide knowledge on the crack formation of DLC coatings. The coatings deposited with neon show a more promising behavior in point of elastic‐plastic properties. In addition, the evaluation of the force‐displacement curves indicates a higher resistance to crack formation of these coatings. Furthermore, investigations on the influence of the process gas pressure were conducted using Ne and three pressures p = 2.0 Pa, p = 1.5 Pa and p = 1.0 Pa. The results show that applying the moderate gas pressure can generate coatings with the highest toughness compared to the coatings deposited with higher and lower gas pressures.
Carboxymethyl chitosan bounded iron oxide nanoparticles and gamma‐irradiated avian influenza subtype H9N2 vaccine to development of immunity on mouse and chicken
Authors: Motamedi‐sedeh Farahnaz , Saboorizadeh Atefeh , Khalili Iraj , Sharbatdaran Massomeh , Wijewardana Viskam , Arbabi Arash
Published: December 2021

Background

Avian influenza virus (AIV) subtype H9N2 is a low pathogenic avian influenza virus (LPAIV).

Objective

This study aims to evaluate the humoral and cellular immunity in vaccinated mice and broiler chicken by irradiated AIV antigen plus carboxymethyl chitosan bounded iron oxide nanoparticles (CMC‐IO NPs) as an adjuvant.

Methods

AIV subtype H9N2 with 108.5 EID50/ml and haemagglutinin antigen assay about 10 log2 was irradiated by 30 kGy gamma radiation dose. Then, the gamma‐irradiated AIV was used as an inactivated vaccine and conjugated with CMC‐IO NPs to improve immune responses on mice. IO NPs must be applied in all activated tests using 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide (EDC) and N‐hydroxysulfosuccinimide sodium salt (sulfo‐NHS), and then functionalized by CMC as IO‐CMC. Fourier transform infrared (FTIR) spectra on functionalized IO‐CMC showed a peak of 638 cm−1 which is a band between metal and O (Fe‐O).

Results

Based on the comparison between the two X‐ray diffraction (XRD) patterns on Fe2O3‐NPs and IO‐CMC, the characteristics of IO‐NPs did not change after carboxymethylation. A CHN Analyzer was applied to measure the molecular weight of IO‐CMC that was calculated as 1045 g. IO‐CMC, irradiated AIV‐IO‐CMC and formalin AIV‐IO‐CMC were injected into 42 BALB/c mice in six groups. The fourth group was the negative control, and the fifth and sixth groups were inoculated by irradiated AIV‐ISA70 and formalin AIV‐ISA70 vaccines. An increase in haemagglutination inhibition (HI) antibody titration was observed in the irradiated AIV‐IO‐CMC and formalin AIV‐IO‐CMC groups (p < 0.05). In addition, increases in the lymphoproliferative activity of re‐stimulated splenic lymphocytes, interfron‐γ (IFN‐γ) and interleukin‐2 (IL‐2) concentration in the irradiated AIV‐IO‐CMC group demonstrated the activation of Type 1 helper cells. The concentration of IL‐4 was without any significant increases in non‐group.

Conclusions

Accordingly, Th2 activation represented no increase. Finally, the finding showed that AIV‐IO‐CMC was effective on enhancing immunogenicity as irradiated AIV antigen administered with a clinically acceptable adjuvant (i.e. IO‐CMC).
An exploration of benchtop X‐ray emission spectroscopy for precise characterization of the sulfur redox state in cementitious materials
Authors: Abramson Jared E. , Avalos Nancy M. , Bourchy Agathe L. M. , Saslow Sarah A. , Seidler Gerald T.
Published: December 2021

The evolution of sulfur chemistry in cements is best known in the bailiwick of failure mechanisms via sulfate attack, but is equally important for its contributions to the reduction capacity of cementitious materials often used for immobilizing nuclear waste streams destined for long‐term storage, for example, cementitious waste forms (CWF). The total reduction capacity of CWFs, encompassing contributions from both S and Fe reductants, and its implications toward radionuclide immobilization is most often studied by destructive wet chemistry methods requiring acid digestion in the presence of Ce(IV) and subsequent titration and colorimetric interpretation. Here, we investigate a similarly analytical but nondestructive alternative, benchtop high resolution wavelength‐dispersive X‐ray fluorescence spectroscopy, most commonly known as X‐ray emission spectroscopy (XES), for probing the bulk sulfur oxidation state distribution. We present here an initial investigation of S XES, including an improved experimental protocol for lab XES of inhomogeneous samples, both as a complement to the Ce(IV) test and for new scientific opportunities that it enables for observing changes in sulfur chemistry. We discuss future improvements and opportunities, including: (1) the practical challenges associated with coordinating XES and Ce(IV) liquid extraction for a more comprehensive perspective on reduction capacity and for a high‐precision evaluation of uncertainties in the Ce(IV) test; and (2) new opportunities, due to the nondestructive nature of XES, for controlled evolution studies aimed at elucidating specific chemical responses of CWFs exposed to invasive gas or liquid species or to accelerated aging by radiative dose or thermal treatment.
Evaluation of transmissivity in a fractured aquifer—the Nyanzari wellfield, Burundi
Authors: Vassolo Sara , Tiberghien Christian , Neukum Christoph , Baranyikwa Désiré , Ryumeko Melchior , Miburo Désiré , Nahimana Noël
Published: December 2021

Due to population growth, the city of Gitega in the central part of Burundi is lacking drinking water. Therefore, the national urban water supply company decided to expand the Nyanzari wellfield by drilling additional wells.

Two additional wells were drilled to 80 m (F7.2) and 85 m (F8bis) depths. Step tests followed by 72-hours aquifer tests were performed in each well. Results indicate bilinear flow followed by linear flow and radial flow in F7.2. No reaction was observed in observation wells. Fracture-matrix transmissivity was estimated at 3 · 10−4 m2/s. In the case of F8bis, linear flow in an infinite flow fracture followed by radial flow was visible. Reaction was measured in observation wells. Transmissivity was estimated at 3.3 · 10−3 m2/s.

Both wells lie no more than 300 m apart, but no evidence of interference between them was depicted during the tests. It appears that two independent fracture systems prevail in the wellfield.
A cross-technology benchmark for incremental graph queries
Authors: Hinkel Georg , Garcia-Dominguez Antonio , Schöne René , Boronat Artur , Tisi Massimo , Le Calvar Théo , Jouault Frederic , Marton József , Nyíri Tamás , Antal János Benjamin , Elekes Márton , Szárnyas Gábor
Published: December 2021

To cope with the increased complexity of systems, models are used to capture what is considered the essence of a system. Such models are typically represented as a graph, which is queried to gain insight into the modelled system. Often, the results of these queries need to be adjusted according to updated requirements and are therefore a subject of maintenance activities. It is thus necessary to support writing model queries with adequate languages. However, in order to stay meaningful, the analysis results need to be refreshed as soon as the underlying models change. Therefore, a good execution speed is mandatory in order to cope with frequent model changes. In this paper, we propose a benchmark to assess model query technologies in the presence of model change sequences in the domain of social media. We present solutions to this benchmark in a variety of 11 different tools and compare them with respect to explicitness of incrementalization, asymptotic complexity and performance.
The implication of BRAF mutation in advanced colorectal cancer
Authors: O’Riordan Emma , Bennett Michael William , Daly Louise , Power Derek G
Published: December 2021

Background

Advanced colorectal cancer (CRC) is frequently a lethal disease. Mutations in the BRAF gene is a key driver in CRC pathogenesis and confers a poor prognosis. To date, Irish data on this molecular subtype of CRC is lacking.

Aims

Our aim was to compare the natural history of Irish patients with BRAF (BRAFMUT) metastatic CRC with a control group of metastatic CRC patients without BRAF mutation (BRAFWT wild- type).

Method

A retrospective observational analysis of advanced CRC patients with known BRAFMUT was conducted by chart review. BRAFMUT patients were identified from the Cork University Hospital (CUH) histopathology database. Controls with known BRAFWT were randomly selected from the database. Demographic characteristics and clinicopathological data were recorded. Survival was assessed with Kaplan–Meier curve/Cox proportional hazard models.

Results

Twenty patients with BRAFMUT and 36 with BRAFWT were studied. BRAFMUT were more likely female (75% vs 33%, p = 0.007) and right-sided (65% vs 31.4%, p = 0.033). Median overall survival was lower in BRAFMUT group (17.3 months (95% CI 0–40.8)) compared to patients with BRAFWT (median survival not reached, log rank p = 0.001). On multivariate analysis, BRAFMUT was independently associated with an increased risk of mortality (HR 12.76 (95% CI 3.15–51.7), p < 0.001).

Conclusion

BRAFMUT advanced colorectal cancer was associated with significantly reduced overall survival in this Irish CRC population. Knowledge of mutation status should now be considered standard of care and should dictate management. Surgeons should be aware of this genetic signature as the natural history of the disease may mitigate against an aggressive surgical strategy. A prospective study should be conducted to further corroborate these findings.
The Jerusalem Declaration on Ageing 2020 to share in English, Arabic and Hebrew
Authors: Harper Sarah , Doron Issi
Published: December 2021

The Anglo-Israel Colloquium in November 2019, Jerusalem, was a collaboration including Jewish and Arab-Israelis, Palestinians, and British participants arranged to drive forward the agenda for addressing inequalities within our populations as they age. This Colloquium brought together scholars, policy-makers, and service providers in the field of ageing from the UK and from Israel, in order to critically examine the societal effects and implications of both individual and population ageing. The following statement on ageing is the first result. Held up in its wider dissemination by the subsequent pandemic of 2020/2021, we are now delighted that the Jerusalem Declaration is now simultaneously published in Hebrew (Harper, S., & Doron, I. (2021). The Jerusalem Declaration. Gerontology & Geriatrics, 48(1), 113–116. [Hebrew]) and here in the Journal of Population Ageing in both English and Arabic.
Systemtheoretische Überlegungen zur Unterscheidung von Sport und eSport
Authors: Borggrefe Carmen
Published: December 2021

Der vorliegende Beitrag greift die Debatte über die Anerkennung wettkampfmäßiger Video- und Computerspiele – des sogenannten eSports – als Sport auf und verfolgt das Ziel, systemtheoretische Überlegungen zur Abgrenzung von Sport und eSport zu elaborieren. Dazu wird erstens erläutert, welche erkenntnistheoretische Position dem systemtheoretischen Ansatz zugrunde liegt. Zweitens wird Sport gesellschaftstheoretisch beobachtet, um die Einheit des Sportsystems zu bestimmen und Formen der strukturellen Kopplung mit anderen gesellschaftlichen Teilsystemen zu reflektieren. Drittens erfolgt eine organisationstheoretische Beobachtung von Sport und eSport, bei der die Integration von eSport als Entscheidungsproblem von Organisationen konstruiert wird. Und viertens werden weitere Perspektiven einer wissenschaftlichen Beobachtung von Sport und eSport skizziert.
Unconventional hydrocarbon resources: geological statistics, petrophysical characterization, and field development strategies
Authors: Muther Temoor , Qureshi Haris Ahmed , Syed Fahad Iqbal , Aziz Hassan , Siyal Amaar , Dahaghi Amirmasoud Kalantari , Negahban Shahin
Published: December 2021

Hydrocarbons exist in abundant quantity beneath the earth's surface. These hydrocarbons are generally classified as conventional and unconventional hydrocarbons depending upon their nature, geology, and exploitation procedure. Since the conventional hydrocarbons are under the depletion phase, the unconventional hydrocarbons have been a major candidate for current and future hydrocarbon production. Additionally, investment and research have increased significantly for its exploitation. Having the shift toward unconventional hydrocarbons, this study reviews in depth the technical aspects of unconventional hydrocarbons. This review brings together all the important aspects of unconventional reservoirs in single literature. This review at first highlights the worldwide unconventional hydrocarbon resources, their technical concept, distribution, and future supplies. A portion of this study also discusses the resources of progressive unconventional hydrocarbon candidates. Apart from this, this review also highlights the geological aspects of different unconventional hydrocarbon resources including tight, shale, and coalbed methane. The petrophysical behavior of such assists including the response to well logs and the discussion of improved correlation for petrophysical analysis is a significant part of this detailed study. The variation in geology and petrophysics of unconventional resources with conventional resources are also presented. In addition, the latest technologies for producing unconventional hydrocarbons ranging from fractured wells to different fluid injections are discussed in this study. In the end, the latest machine learning and optimization techniques have been discussed that aids in the optimized field development planning of unconventional reservoirs.
Synthesis, characterization and evaluation of stearyl acrylate-co-behenyl acrylate copolymer as a pour point depressant of waxy crude oil
Authors: Elarbe Basem , Elganidi Ibrahim , Ridzuan Norida , Yusoh Kamal , Abdullah Norhayati , Vijayakumar Shamala
Published: December 2021

Pour point depressant (PPD) has the competitive advantage of lowering the temperature of the wax appearance (WAT) and crude oil viscosity. In this paper, a novel PPD of poly stearyl acrylate-co-behenyl acrylate (SA-co-BA) in various mass ratios (1:1, 2:1, 3:1, 1:2 and 1:3) was effectively synthesized by solution radical polymerization method, and characterized by fourier transform infrared FTIR, proton nuclear magnetic resonance NMR, x-ray diffraction XRD and scanning electron microscopy SEM. The SA-co-BA PPD was evaluated on Malaysian crude oil via the pour point, the rheological and cold finger analysis to prevent the wax deposition at low temperature and improve flowability. The findings showed that the mass ratio (1:1) at 1000 ppm has a positive effect on the pour point depression from 11 to 2 °C. It was investigated from the rheological measurement that the viscosity of crude oil increases as the temperature decreases. Whereas, the viscosity decreases as the shear rate increases and as shear rate increases, shear stress increases. The flowability performance of the crude by the mass ratio of 1:1 at 1000 of the SA-co-BA concentrations have improved by 89.76%. The highest paraffin inhibition efficiency PIE of wax deposited was obtained at 1:1 of the mass ratio by 44.14%, indicating the smallest amount of wax is formed. This finding is interestingly attributed to the acrylate groups that have a long alkyl chain. Thus, SA-co-BA copolymer was demonstrated to be an appreciable pour point depressant that can prevent the wax deposition at low temperature and increasing the flowability of Malaysian crude oil.
Inaccuracy in arc power calculation through a product of voltage and current averages
Authors: Scotti Américo , Batista Márcio Andrade , Eshagh Mehdi
Published: December 2021

Power is an indirect measurand, determined by processing voltage and current analogue signals through calculations. Using arc welding as a case study, the objective of this work was to bring up subsidies for power calculation. Based on the definitions of correlation and covariance in statistics, a mathematical demonstration was developed to point out the difference between the product of two averages (e.g. P = $$\overline{U} x \overline{I}$$

U
¯

x

I
¯

) and the average of the products (e.g. P = ($$\overline{UxI}$$

UxI

¯

). Complementarily, a brief on U and I waveform distortion sources were discussed, emphasising the difference between signal standard deviations and measurement errors. It was demonstrated that the product of two averages is not the same as the average of the products, unless in specific conditions (when the variables are fully correlated). It was concluded that the statistical correlation can easily flag the interrelation, but if assisted by covariance, these statistics quantify the inaccuracy between approaches. Finally, although the statistics' determination is easy to implement, it is proposed that power should always be calculated as the average of the instantaneous U and I products. It is also proposed that measurement error sources should be observed and mitigated, since they predictably interfere in power calculation accuracy.
Randomized Clinical Trial Comparing Dialogical Family Guidance with Ordinary Clinical Treatment for Families with a Child with Neurodevelopmental Disorders
Authors: Cavonius-Rintahaka Diana , Roos Mervi , Gillberg Christopher , Billstedt Eva , Aho Anna Liisa
Published: December 2021

Objectives

Previous studies have highlighted the need to offer targeted interventions to strengthen the wellbeing of family members in families with children with neurodevelopmental disorders (NDD). Interventions for this target group require research and development. The purpose of this study was to test a new family intervention: Dialogical Family Guidance (DFG).

Methods

Families of children with NDD were randomized into an intervention group that was delivered DFG and a comparison group provided with ordinary clinical treatment. The Family Functioning, Family Health and Social Support (FAFHES) and the DFG instrument were used to collect data at baseline and after 3 months. Repeated measure analysis of variance (ANOVA) was used as an analytical strategy.

Results

There was a significant within-subjects effect of time on family health and social support, indicating that family health and social support increased in both groups over time. There was also a significant between-subjects effect of group and interaction between time and group on social support, indicating that social support increased more in the intervention group than in the control group. Managing in daily life and the relationship between parents were associated with family functioning and family health.

Conclusion

DFG can strengthen parental experiences of social support. Managing in daily life, relationship between parents, practical guidance, psychoeducation, dialogue, and receiving positive feedback on parenting were strengthening factors during DFG. However, the results of this study must be considered as only preliminary, as they relate only to parental perceptions of the intervention effects.

Trial registration

ClinicalTrials.gov NCT04892992 (retrospectively registered).
CME-EKG 70: Thoraxschmerzen bei einem jungen Patienten – Differenzialdiagnosen neben dem akuten Koronarsyndrom
Authors: Rett Eva , Manka Robert , Brunckhorst Corinna B.
Published: December 2021

Zusammenfassung. Während bei älteren Menschen mit Thoraxschmerzen und typischen EKG-Veränderungen häufig eine kardiovaskuläre Genese zu Grunde liegt, können uns jüngere Patientinnen und Patienten mit einem vergleichbaren Beschwerdebild im klinischen Alltag vor andere Herausforderungen stellen. Anhand dieses Fallberichtes soll auf entsprechende Differenzialdiagnosen und diagnostische Schritte eingegangen werden, mit besonderem Fokus auf das EKG.
Orbital‐ and Millennial‐Scale Variability in Northwest African Dust Emissions Over the Past 67,000 years
Authors: Kinsley Christopher W. , Bradtmiller Louisa I. , McGee David , Galgay Michael , Stuut Jan‐Berend , Tjallingii Rik , Winckler Gisela , deMenocal Peter B.
Published: December 2021

Reconstructions of aeolian dust flux to West African margin sediments can be used to explore changing atmospheric circulation and hydroclimate over North Africa on millennial to orbital timescales. Here, we extend West African margin dust flux records back to 37 ka in a transect of sites from 19° to 27°N, and back to 67 ka at Ocean Drilling Program (ODP) Hole 658C, in order to explore the interplay of orbital and high‐latitude forcings on North African climate and make quantitative estimates of dust flux during the core of the Last Glacial Maximum (LGM). The ODP 658C record shows a Green Sahara interval from 60 to 50 ka during a time of high Northern Hemisphere summer insolation, with dust fluxes similar to levels during the early Holocene African Humid Period, and an abrupt peak in flux during Heinrich event 5a (H5a). Dust fluxes increase from 50 to 35 ka while the high‐latitude Northern Hemisphere cools, with peaks in dust flux associated with North Atlantic cool events. From 35 ka through the LGM dust deposition decreases in all cores, and little response is observed to low‐latitude insolation changes. Dust fluxes at sites from 21° to 27°N were near late Holocene levels during the LGM time slice, suggesting a more muted LGM response than observed from mid‐latitude dust sources. Records along the northwest African margin suggest important differences in wind responses during different stadials, with maximum dust flux anomalies centered south of 20°N during H1 and north of 20°N during the Younger Dryas.
Simulation of Unconfined Aquifer Flow Based on Parallel Adaptive Mesh Refinement
Authors: Kourakos Georgios , Harter Thomas
Published: December 2021

The density of a numerical mesh is a key component for the quality of the numerical solution. Common methods in groundwater simulations rely on meshes generated prior to simulation, which lead to unnecessary or insufficient degrees of freedom (dofs). In this study we use Adaptive Mesh Refinement (AMR) to substitute the subjective mesh generation process with a more rigorous approach where new dofs are iteratively added to the solution of an initial coarse mesh based on a solution error estimation. The simulation is solved on a succession of meshes through which the mesh density is increased in areas of steep gradients in the solution variable. Here, we apply the approach to unconfined aquifer flow which is a non‐linear problem commonly encountered in groundwater modeling. By taking advantage of the iterative nature of AMR we arrive at an efficient solver approach. We treat the position of the unconfined boundary as an additional unknown which is estimated iteratively. The first iterations are executed rapidly as the mesh is rather coarse, while the free boundary adapts to the computed water table position as close as the mesh density allows. In this study we demonstrate the viability of the proposed unconfined aquifer simulation method to a series of 2D hypothetical examples under several conditions and stresses as well as a 3D test case. In all cases the AMR was able to automatically resolve the solution in areas with steep hydraulic head gradient, using appropriately higher density to achieve high localized refinement and accuracy.
The Influence of Atmosphere‐Ocean Phenomenon on Water Availability Across Temperate Australia
Authors: Khaledi Jabbar , Nitschke Craig , Lane Patrick N. J. , Penman Trent , Nyman Petter
Published: December 2021

Links between climate variability modes, rainfall, and streamflow are important for understanding the trajectories of change and dynamics in water availability. In this study, we examined the influence of the El Nino Southern Oscillation, Indian Ocean Dipole, Southern Annular Mode, and Interdecadal Pacific Oscillation modes on interannual variations in rainfall and streamflow in four hydroclimate regions. We also explored the link between climate variability modes and extreme rainfall and streamflow years. Climate mode indices, rainfall, and streamflow data from 1975 to 2018 were analyzed for 92 predominately forested catchments located across temperate Australia. Climate modes had divergent influences on streamflow and rainfall between and within regions. Across temperate Australia, a higher proportion of interannual variation in rainfall was explained by climate modes than for streamflow, indicating factors other than atmosphere‐ocean phenomena are important in determining interannual streamflow variability. Extremes in rainfall and streamflow across regions were related to the co‐occurrence of climate modes, with a stronger relationship between teleconnections and low rainfall/streamflow years than high rainfall/streamflow years. The study provides new insights into the regional drivers of hydrological extremes and consolidates our understanding of the role of teleconnections on water availability in the temperate zone of Australia.
A New MEPED‐Based Precipitating Electron Data Set
Authors: Pettit Joshua M. , Randall Cora E. , Peck Ethan D. , Harvey V. Lynn
Published: December 2021

The work presented here introduces a new data set for inclusion of energetic electron precipitation (EEP) in climate model simulations. Measurements made by the medium energy proton and electron detector (MEPED) instruments onboard both the Polar Orbiting Environmental Satellites and the European Space Agency Meteorological Operational satellites are used to create global maps of precipitating electron fluxes. Unlike most previous data sets, the electron fluxes are computed using both the 0° and 90° MEPED detectors. Conversion of observed, broadband electron count rates to differential spectral fluxes uses a linear combination of analytical functions instead of a single function. Two dimensional maps of electron spectral flux are created using Delaunay triangulation to account for the relatively sparse nature of the MEPED sampling. This improves on previous studies that use a 1D interpolation over magnetic local time or L‐shell zonal averaging of the MEPED data. A Whole Atmosphere Community Climate Model (WACCM) simulation of the southern hemisphere 2003 winter using the new precipitating electron data set is shown to agree more closely with observations of odd nitrogen than WACCM simulations using other MEPED‐based electron data sets. Simulated EEP‐induced odd nitrogen increases led to ozone losses of more than 15% in the polar stratosphere near 10 hPa in September of 2003.
Field‐Aligned Current During an Interval of BY‐Dominated Interplanetary‐Field; Modeled‐to‐Observed Comparisons
Authors: Carter J. A. , Samsonov A. A. , Milan S. E. , Branduardi‐Raymont G. , Ridley A. J. , Paxton L. J. , Anderson B. J. , Waters C. L. , Edwards T.
Published: December 2021

We model an interval of remarkable interplanetary magnetic field (IMF), for which we have a comprehensive set of observational data. This interval is associated with the arrival of an interplanetary coronal mass ejection. The solar wind densities at the time are particularly high and the IMF is primarily northward over many hours. This results in strong auroral emissions within the polar cap in a cusp spot, which we associate with lobe reconnection at the high‐latitude magnetopause. We also observe areas of upwards field‐aligned current (FAC) within the summer Northern Hemisphere polar cap that exhibit large current magnitudes. The model can reproduce the spatial distribution of the FACs well, even under changing conditions in the incoming IMF. Discrepancies exist between the modeled and observed current magnitudes. Notably, the winter Southern Hemisphere exhibits much lower current magnitudes overall. We also model a sharp transition of the location of magnetopause reconnection at the beginning of the interval, before the IMF remained northward for many hours. The reconnection location changed rapidly from a subsolar location at the low‐latitude magnetopause under southward IMF conditions, to a high‐latitude lobe reconnection location when the field is northward. This occurs during a fast rotation of the IMF at the shock front of a magnetic cloud.
The Structure of the Cusp Diamagnetic Cavity and Test Particle Energization in the GAMERA Global MHD Simulation
Authors: Burkholder B. L. , Nykyri K. , Ma X. , Sorathia K. , Michael A. , Otto A. , Merkin V.
Published: December 2021

Electrons with energies ≥40 keV can be found at low density in many different regions of Earth's magnetosphere. A litany of fundamental questions in space physics have focused on the acceleration mechanism of these particles, given that the sources of plasma are the relatively cool ionosphere and solar wind (∼1–100s eV). Upgraded global solar wind‐magnetosphere simulations which can resolve mesoscale dynamics have the ability to enhance our understanding of these high energy particles. This is because the energization of particles often takes the form of a sequence of discrete steps, potentially occurring in different regions of the magnetosphere and due to both meso‐ and global‐scale processes. First, brief results are presented from the Grid Agnostic MHD for Extended Research Applications (GAMERA) global simulation on the structure of the cusp diamagnetic cavity for northward and southward IMF. Then, the Conservative Hamiltonian Integrator for Magnetospheric Particles (CHIMP) framework, with both guiding center and full Lorentz integrators, evolves necessary parameters such as the energy and pitch angle of electron test particles to investigate particle acceleration inside the cavity, as well as the ultimate fate of electrons accelerated inside the cavity. The simulation shows that particles can gain ≥ 10 keV inside the cavity and subsequently leak into the magnetosheath or onto dipolar field lines where they execute different types of bounce motion. The distribution of test particles initialized inside the cavity is compared with Magnetospheric Multi‐Scale (MMS) observations.
Magnetic Reconnection Inside Solar Wind Rotational Discontinuity During Its Interaction With the Quasi‐Perpendicular Bow Shock and Magnetosheath
Authors: Guo Zhifang , Lin Yu , Wang Xueyi , Du Aimin
Published: December 2021

Using a three‐dimensional global hybrid simulation, we investigate the formation and evolution of ion‐scale magnetic reconnection inside an interplanetary rotational discontinuity (RD) owing to its interaction with the quasi‐perpendicular (Q‐) bow shock and the magnetosphere. The interplanetary magnetic field (IMF) is initially predominantly northward, while it changes to purely southward across the RD. A significantly thinned RD current layer with a width ∼ ion skin depth and normal magnetic field is formed by a shock compression process as the RD interacts with the Q‐ shock. Magnetic reconnection thereupon takes place inside the thin RD current layer, where Hall magnetic and electric fields, reconnection electric field, and high‐speed ion outflow jets are identified. Simultaneously, flux ropes form with an extension of a few ion inertial lengths. As the RD is transmitted into the magnetosheath, multiple reconnection sites lead to the formation of longer flux ropes. Moreover, magnetosheath reconnection is also found at new reconnection sites inside the RD. No reconnection is found in the Q‐ shock alone outside the RD. The flux ropes propagate poleward and tailward in the magnetosheath. In addition, magnetopause reconnection takes place under the southward IMF on the sunward side of the RD after the RD passes through the magnetopause.
Constraints on Emission Source Locations of Methane Detected by Mars Science Laboratory
Authors: Viúdez‐Moreiras D. , Richardson M. I. , Newman C. E.
Published: December 2021

The Sample Analysis at Mars (SAM) instrument on the Mars Science Laboratory (MSL) Curiosity rover has detected both methane spikes and variable background methane abundance in recent years in Gale Crater, Mars. While methane spikes have been attributed to a hypothetical local or regional source emission, the background measurements acquired during the nighttime were postulated to represent the global methane abundance on Mars. However, recent high‐accuracy observations by instruments on the Trace Gas Orbiter (TGO) in several locations around the planet have not detected methane at all, apparently contradicting the SAM measurements. This paper analyzes the constraints that TGO and MSL impose on the hypothetical location of the emission source of methane responsible for the levels detected by SAM. The numerical simulations presented here indicate that not only the spikes but also the background measurements performed by MSL must result from localized emissions, specifically in the northwest interior of Gale Crater. Other simulated emission source locations at a greater distance from MSL, even if still within Gale Crater, are difficult to reconcile with current observations by MSL and TGO. Confirming previous studies, these results therefore point either to an improbable scenario, in which the rover has landed close to one of only a few localized emission sources on Mars, or to a problematic scenario, in which an unknown loss mechanism must be invoked that is able to destroy methane orders of magnitude faster than predicted by standard gas chemistry or to a weighted action between both scenarios.
Isotopic Composition of CO2 in the Atmosphere of Mars: Fractionation by Diffusive Separation Observed by the ExoMars Trace Gas Orbiter
Authors: Alday Juan , Wilson Colin F. , Irwin Patrick G. J. , Trokhimovskiy Alexander , Montmessin Franck , Fedorova Anna A. , Belyaev Denis A. , Olsen Kevin S. , Korablev O. , Lefèvre Franck , Braude Ashwin S. , Baggio Lucio , Patrakeev Andrey , Shakun Alexey
Published: December 2021

Isotopic ratios in atmospheric CO2 are shaped by various processes throughout Mars' history, and can help understand what the atmosphere of early Mars was like to sustain liquid water on its surface. In this study, we monitor the O and C isotopic composition of CO2 between 70 and 130 km for more than half a Martian year using solar occultation observations by the Atmospheric Chemistry Suite onboard the ExoMars Trace Gas Orbiter. We find the vertical trends of the isotopic ratios to be consistent with the expectations from diffusive separation above the homopause, with average values below this altitude being consistent with Earth‐like fractionation (δ13C = −3 ± 37‰; δ18O = −29 ± 38‰; and δ17O = −11 ± 41‰). Using these measurements, we estimate that at least 20%–40% of primordial C on Mars has escaped to space throughout history. The total amount of C lost from the atmosphere is likely to be well in excess of this lower limit, due to carbonate formation and further sink processes. In addition, we propose a photochemical transfer of light O from H2O to CO2 to explain the larger enrichment in the ratio in H2O than in CO2.