bluuebunny/crossref_metadata_2025 huggingface dataset:
Elongational flow of arrested complex fluid under the suppression of osmotic effective diffusion by surrounding flow of miscible solvent
Authors: Hussain Ashhar , Choi Gyeong Min , Kim Hyunsoo , Lee Heon Sang
Published: December 2024

Nonequilibrium interface (NI) of miscible fluids has long been of great interest; however, the acting effective interfacial tension and the deformation rate of the suspended phase in a steady immiscible state (SIS) have yet been delineated. We investigate the deformation rate and diffusion of complex fluids with a miscible surrounding fluid in a rectangular microchannel. We show here that the NI acts as a moving osmotic membrane and maintains a stable two-phase flow at a flow rate faster than the diffusion rate proportional to the osmotic pressure of the complex fluid. We report for the first time that a complex fluid suspended within a flow rate faster than the osmotic diffusion rate exhibits wet capillary thinning (WCT) behavior at the SIS. We demonstrate that either acting effective interfacial tension caused by Korteweg stress or elongational viscosity is measurable from the WCT behavior, and it was shown to be applicable to polymer solutions, animal blood, and even pure water. Our findings provide new insight into the phase behavior and managing diffusion in the flow stream of miscible fluids. The WCT technique enables precise measurement of elongational viscosity of a small amount of complex fluid, about the size of a drop without contact with the gas phase, providing a safe method for toxic, gas reactive liquid, or infected biofluids.
Operational field trialling of Felixer™ grooming traps for the control of feral cats in the Strzelecki Desert, Australia
Authors: Pedler R. D. , Read J. L. , Moseby K. E. , Hunt T. J. , Lynch C. E. , Cullen D. B. , Coulter B. , Kingsford R. T. , West R. S.
Published: December 2024

Context Feral cats (Felis catus) have an impact on native wildlife populations around the world but are difficult to control because of their neophobic behaviours and preference for live prey over scavenging poisoned baits. Felixers™ address these challenges by squirting poison-gel directly onto feral cats, exploiting their fastidious oral grooming tendencies to facilitate poison ingestion. Aims This study trialled Felixers in a landscape-scale arid-ecosystem site to assess their capacity to sustainably manage cat populations in a semi-bounded in situ predator training area and to eradicate cat incursions into a feral-free safe haven. Specifically, the aims were to determine target specificity and firing rates; optimise installation sites to exploit cat behaviour and landscape features; assess the fate of individuals following Felixer interaction; and assess the overall cost, performance and efficacy of Felixers compared with conventional cat control methods. Methods Up to nine Felixers were simultaneously deployed across three trial periods, spanning 30 months (4,642 trap nights) in Sturt National Park in the Strzelecki Desert dunefields of Australia. Felixers were deployed within and outside of feral-free safe havens, at varying cat densities, with populations monitored through camera-trap activity indices and individual behaviour monitored through satellite tracking. Key results Felixers fired at 20.3–43.9% of cats that passed in front (292 of 1,144 cats), with the remainder failing to satisfy the discriminatory algorithm’s target criteria. The devices had 99.93% target specificity from 17,425 interactions with moving animals and objects. Overall cat activity was lower in a semi-bounded 10,400 ha landscape-scale area where Felixers were intensively used, relative to an adjacent unbounded area where no cat control was occurring, over a 12-month subset of the 30-month trial. Felixers also resolved one of two incursions by cats into a 2,000 ha safe haven. Optimisation of Felixer placement and upgrading of software drove improvements in technical reliability and target identification during the trial. Shortcomings included cost and high incidence of technical faults, causing significant downtime and requiring regular investment of field staff time for monitoring and resolution. Conclusions Felixers provide a safe tool for cat management and eradication at intensively managed conservation sites. Efficacy could be improved through reductions in cost and improvements in reliability. Implications Overall Felixers appear to be an effective tool for cat management, when used in an integrated approach.
Amino acids modulate liquid–liquid phase separation in vitro and in vivo by regulating protein–protein interactions
Authors: Xu Xufeng , Rebane Aleksander A. , Roset Julia Laura , Rosowski Kathryn A. , Dufresne Eric R. , Stellacci Francesco
Published: December 2024

Liquid–liquid phase separation (LLPS) is an intracellular process widely used by cells for many key biological functions. It occurs in complex and crowded environments, where amino acids (AAs) are vital components. We have found that AAs render the net interaction between proteins more repulsive. Here, we find that some AAs efficiently suppress LLPS in test tubes (in vitro). We then screen all the proteinogenic AAs and find that three specific AAs, including proline, glutamine, and glycine, significantly suppressed the formation of stress granules (SGs) in U2OS and HeLa cell lines (in vivo) irrespective of stress types. We also observe the effect in primary fibroblast cells, a viable cell model for neurodegenerative disorders. Kinetic studies by live-cell microscopy show that the presence of AAs not only slows down the formation but also decreases the saturating number and prevents the coalescence of SGs. We finally use sedimentation-diffusion equilibrium analytical ultracentrifuge (SE-AUC) to demonstrate that the suppression effects of AAs on LLPS may be due to their modulation in protein–protein and RNA–RNA interactions. Overall, this study reveals an underappreciated role of cellular AAs, which may find biomedical applications, especially in treating SG-associated diseases.
Structural basis of the allosteric regulation of cyanobacterial glucose-6-phosphate dehydrogenase by the redox sensor OpcA
Authors: Doello Sofia , Shvarev Dmitry , Theune Marius , Sauerwein Jakob , Klon Alexander , Keskin Erva , Boehm Marko , Gutekunst Kirstin , Forchhammer Karl
Published: December 2024

The oxidative pentose phosphate (OPP) pathway is a fundamental carbon catabolic route for generating reducing power and metabolic intermediates for biosynthetic processes. In addition, its first two reactions form the OPP shunt, which replenishes the Calvin-Benson cycle under certain conditions. Glucose-6-phosphate dehydrogenase (G6PDH) catalyzes the first and rate-limiting reaction of this metabolic route. In photosynthetic organisms, G6PDH is redox-regulated to allow fine-tuning and to prevent futile cycles while carbon is being fixed. In cyanobacteria, regulation of G6PDH requires the redox protein OpcA, but the underlying molecular mechanisms behind this allosteric activation remain elusive. Here, we used enzymatic assays and in vivo interaction analyses to show that OpcA binds G6PDH under different environmental conditions. However, complex formation enhances G6PDH activity when OpcA is oxidized and inhibits it when OpcA is reduced. To understand the molecular basis of this regulation, we used cryogenic electron microscopy to determine the structure of
Synechocystis
G6PDH and the G6PDH–OpcA complex. OpcA binds the G6PDH tetramer and induces conformational changes in the active site of G6PDH. The redox sensitivity of OpcA is achieved by intramolecular disulfide bridge formation, which influences the allosteric regulation of G6PDH. In vitro assays reveal that the level of G6PDH activation depends on the number of bound OpcA molecules, which implies that this mechanism allows delicate fine-tuning. Our findings unveil a unique molecular mechanism governing the regulation of the OPP in
Synechocystis
.
High-temperature high-k polyolefin by rational molecular design
Authors: Hao Jing , Mutegi Irene , Mukherjee Madhubanti , Sahu Harikrishna , Khomane Ashish , Yassin Omer , Ramprasad Rampi , Sotzing Gregory A. , Cao Yang
Published: December 2024

Polymer film dielectrics are highly favored for capacitive energy storage due to the inherent advantages of high breakdown strength, low dielectric loss, and ease of processing. High-density renewables conversion and harsh-condition electrification further emphasize the need for high-temperature, high-k polymers. A unique design strategy is developed to augment high-temperature polyolefins with improved dielectric constant, via the integration of phenyl pendants hanging off the rigid bicyclic backbone. The impacts of the pendant polarizability and steric positioning on dielectric constant, bandgap, glass-transition temperature (
T
g
), and high-field, high-temperature dielectric characteristics have been investigated. The orientational polarization of the polar phenyl pendants with rotational degree of freedom imparts cyclic olefins with enhanced dielectric constants, while maintaining the large bandgap, and high glass-transition temperature (
T
g
> 170 °C). Among these synthesized polymers, m-PNB-BP stands out with a remarkable dielectric constant of 4 at a high sub-
T
g
temperature of 150 °C, and a high discharged density of 8.6 J/m
3
at 660 MV/m. This study unveils a different path for designing high-temperature polymers with enhanced dielectric constants, particularly beneficial for capacitive energy storage.
Ecosystem stability relies on diversity difference between trophic levels
Authors: Liu Yizhou , Hu Jiliang , Gore Jeff
Published: December 2024

The stability of ecological communities has a profound impact on humans, ranging from individual health influenced by the microbiome to ecosystem services provided by fisheries. A long-standing goal of ecology is the elucidation of the interplay between biodiversity and ecosystem stability, with some ecologists warning of instability due to loss of species diversity while others arguing that greater diversity will instead lead to instability. Here, by considering a minimal two-level ecosystem with multiple predator and prey species, we show that stability does not depend on absolute diversity but rather on diversity differences between levels. We found that increasing diversity in either level first destabilizes but then stabilizes the community (i.e., a reentrant stability transition). We therefore find that it is the diversity difference between levels that is the key to stability, with the least stable communities having similar diversities in different levels. An analytical stability criterion is derived, demonstrating quantitatively that the critical diversity difference is determined by the correlation between how one level affects another and how it is affected in turn. Our stability criterion also applies to consumer–resource models with other forms of interaction such as cross-feeding. Finally, we show that stability depends on diversity differences in ecosystems with three trophic levels. Our finding of a nonmonotonic dependence of stability on diversity provides a natural explanation for the variety of diversity-stability relationships reported in the literature, and emphasizes the significance of level structure in predicting complex community behaviors.
Gourmet Gardens: The Edible Flower Revolution
Authors: Kataria Priyanka
Published: December 2024

Edible flowers have an extensive past, having been utilized for both medicinal and culinary purposes in many diverse cultures for ages. Edible flower diversity offers various flavors, colors, and health advantages. Well-known edible flower varieties include marigolds and roses, while lesser-known possibilities include butterfly pea flowers and pansies. To maintain their nutritional value and attractiveness, edible flowers must undergo rigorous cultivation, meticulous handling, and adherence to safety regulations throughout the process from harvest to the consumer’s plate. They are high in bioactive compounds including flavonoids, vitamins, and antioxidants but low in calories. Health advantages may result from these functional qualities, which also may include anti-inflammatory and antioxidant activity. Even while edible flowers have many advantages, their safety profile is important. This involves correct identification, chemical-free production, and compliance with food safety regulations. Edible flowers are currently being employed in a growing variety of industries, including gourmet restaurants, health-conscious food products, and natural cosmetic formulations. The future of edible flowers includes greater environmental practices, innovative product creation, and further integration into mainstream markets. In summary, edible flowers have great promise across a range of businesses and provide a unique combination of traditional and contemporary health advantages.

Information

© The Author 2024
Advancements in Bioactive Intelligent Packaging: Enhancing Food Safety and Sustainability
Authors: Mohd Hatta Farah Ayuni
Published: December 2024

Food safety and security are vital concerns for consumers and the food industry, necessitating innovative solutions to mitigate risks associated with foodborne diseases. Bioactive intelligent packaging is at the forefront of technological advancements in food preservation, which utilizes non-toxic and environmentally friendly materials. By incorporating bioactive materials, the packaging can interact with its contents and the surrounding environment, thereby extending the shelf life of food products and supporting food safety. This case study highlights the potential of natural colourants as effective bioactive materials, showcasing their chemical, thermal, and physical sensitivity, along with their antioxidant and antimicrobial properties. Specifically, the indicators used in intelligent packaging can change colour in response to specific stimuli, such as the presence of oxygen or damage to the package, signalling potential spoilage or compromised integrity. This capability is particularly beneficial in the food industry, where it can help prevent waste and improve supply chain management by ensuring that products are consumed while still fresh. Additionally, the incorporation of bioactive materials into the packaging system allows for interaction with the food contents, further extending shelf life and preserving food integrity. Despite the promising developments, the study emphasizes the need for further research and development to facilitate the commercial application of these technologies and meet the growing demand for safe and nutritious food products.

Information

© The Author 2024
Colloidal quantum dots as solution-based nanomaterials for infrared technologies
Authors: Sevim Ünlütürk Seçil , Taşcıoğlu Didem , Özçelik Serdar
Published: December 2024

This review focuses on recent progress of wet-chemistry-based synthesis methods for infrared (IR) colloidal quantum dots (CQD), semiconductor nanocrystals with a narrow energy bandgap that absorbs and/or emits IR photos covering from 0.7 to 25 micrometers. The sections of the review are colloidal synthesis, precursor reactivity, cation exchange, doping and de-doping, surface passivation and ligand exchange, intraband transitions, quenching and purification, and future directions. The colloidal synthesis section is organized based on precursors employed: toxic substances as mercury- and lead-based metals and non-toxic substances as indium- and silver-based metal precursors. CQDs are prepared by wet-chemical methods that offer advantages such as precise spectral tunability by adjusting particle size or particle composition, easy fabrication and integration of solution-based CQDs (as inks) with complementary metal-oxide-semiconductors, reduced cost of material manufacturing, and good performances of IR CQD-made optoelectronic devices for non-military applications. These advantages may allow facile and materials’ cost-reduced device fabrications that make CQD based IR technologies accessible compared to optoelectronic devices utilizing epitaxially grown semiconductors. However, precursor libraries should be advanced to improve colloidal IR quantum dot synthesis, enabling CQD based IR technologies available to consumer electronics. As the attention of academia and industry to CQDs continue to proliferate, the progress of precursor chemistry for IR CQDs could be rapid.
In situ embedding of resistance temperature detectors with the use of laser-foil-printing additive manufacturing
Authors: Turk Tunay , Dominguez Cesar E , Sutton Austin T , Bernardin John D , Park Jonghyun , Leu Ming C
Published: December 2024

Additive manufacturing (AM) allows sensor embedding with the freedom of geometry flexibility. This research aims to experimentally determine the viability of integrating Platinum resistance temperature detectors into AM 304L stainless steel parts using laser foil printing (LFP) for real-time measurement applications. Using metal foils as a feedstock in LFP provides higher conductivity and faster cooling rate resulting in higher strength compared to powder-bed AM. However, one of the common challenges during the laser aided metal AM processes is that the heat accumulation can damage the embedded sensor. This study uses spot pattern welding processing strategy to mitigate these process-related risks by minimizing the melt pool volume during the layered fabrication process. High-temperature resistant ceramic adhesives are employed to fill the gap, and to create a conductive interface between the feedstock and the sensor. After curing the ceramic adhesives, in situ temperature measurement data are collected to investigate the success of the sensor embedding process. This work demonstrates the feasibility for LFP smart manufacturing, offering the potential for component embedding and an advanced real-time monitoring system.
Floquet dynamics of ultracold atoms in optical lattices with a parametrically modulated trapping potential
Authors: Ali Usman , Holthaus Martin , Meier Torsten
Published: December 2024

Experiments with ultracold atoms in optical lattices usually involve a weak parabolic trapping potential which merely serves to confine the atoms, but otherwise remains negligible. In contrast, we suggest a different class of experiments in which the presence of a stronger trap is an essential part of the set-up. Because the trap-modified on-site energies exhibit a slowly varying level spacing, similar to that of an anharmonic oscillator, an additional time-periodic trap modulation with judiciously chosen parameters creates nonlinear resonances which enable efficient Floquet engineering. We employ a Mathieu approximation for constructing the near-resonant Floquet states in an accurate manner and demonstrate the emergence of effective ground states from the resonant trap eigenstates. Moreover, we show that the population of the Floquet states is strongly affected by the phase of a sudden turn-on of the trap modulation, which leads to significantly modified and rich dynamics. As a guideline for further studies, we argue that the deliberate population of only the resonance-induced effective ground states will allow one to realize Floquet condensates which follow classical periodic orbits, thus providing challenging future perspectives for the investigation of the quantum–classical correspondence.
Effect of annealing temperature onto physical properties of Cu doped ZnO thin films prepared using spray pyrolysis
Authors: Aboud Ahmed A , Matar Zinab S , Mohaseb Mona , Awad Abanoub
Published: December 2024

Herein we report the effect of annealing on spray-pyrolysis-deposited Cu-doped zinc oxide thin films, with a fixed 3 wt% copper concentration and annealing temperatures of 450 and 500 °C. Various analytical techniques were employed to evaluate the effect of annealed films, which exhibited high stability in physical properties and minimal influence from the annealing process. XRD analysis confirmed that all films maintained a hexagonal ZnO structure without any additional phases, indicating the high purity of the films, with the (002) peak serving as the main diffraction peak for both as-deposited and annealed films. Crystallite size, calculated using the Halder-Wagner equation, revealing an increase from 13.96 nm for the as-deposited film to 14.26 nm for film annealed at 450 °C and 14.65 nm for film annealed at 500 °C. Microstrain values were measured at 2.3 × 10−3, 2.5 × 10−3, and 1.3 × 10−3 for the as-deposited and annealed films. Surface imaging with FE-SEM revealed average grain sizes of 57.25 nm, 68 nm, and 67.8 nm for the as-deposited film and those annealed at 450 °C and 500 °C, respectively. The estimated band gap values were 3.14 eV for the as-deposited films, 3.15 eV for those annealed at 450 °C, and 3.16 eV for films annealed at 500 °C. According to the Spitzer-Fan model, both the density of states and plasma frequency remained constant across the films, while the relaxation time and optical mobility were lowest at 450 °C, where the high-frequency dielectric constant reaches its peak.
Design of a low-power dynamic latched comparator for biomedical applications
Authors: Tyagi Mohit , Mittal Poornima , Kumar Parvin
Published: December 2024

The latched comparator is a fundamental component of all ADC topologies. Thermal noise, kickback noise, and offset voltage impact the energy efficiency of the comparator significantly. In cardiac IMD ADCs, latched comparator kickback noise may impact resolution, accuracy, and settling time. This paper describes the design and development of an a low-power dynamic latched comparator optimised for biomedical applications and running at 1V. The suggested comparator is achieved on a 45 nm CMOS technology node, having the main goal of reducing kickback noise. The main concept of the recommended comparator has been utilizing the novel resetting approach and kickback noise reduction approach to preserve the charge and kickback noise, respectively. This approach aids in minimizing delay, power consumption, and kickback noise using shared charging logic. The charging-sharing technique involves using a single-pass transistor positioned across two output nodes. The pass transistor distributes the charge evenly across two output nodes throughout the reset phase. Due to the shared charging of the load capacitances, the voltage at the output nodes would not drop under the threshold value. As a result, the input signal could be evaluated more quickly during the regenerative stage. The comparator’s delay is calculated using a rigorous statistical analysis considering the circuit’s random factors. The offset of the proposed comparator is verified using thorough Monte Carlo simulations. The comparator reduces power while preserving noise. Also, the measured simulation results of recommended comparator outperform state-of-the-art comparators regarding kickback noise, delay, power consumption, and power delay product (PDP). The input voltage inversely affects the comparator’s delay. Further, the simulation shows that the comparator consumes 9.36μW at 1 V and 1 GHz sampling frequency. The simulation results confirm that the suggested comparator effectively reduces power consumption by atleast 66.98%. The proposed comparator has less PDP value by 44.44%. Also, suggested comparator effectively reduces offset voltage by 7.6% but with a corresponding increase in the area by 5%. Additionally, the comparator successfully reduces kickback noise by 44.6%. The obtained results are not silicon proven and bound to be in the pre-silicon stage. The low-power behaviour of the suggested technique is validated using analytical derivations, PVT corner analysis, and post-layout simulation.
Chaotic time series prediction of motor system based on WOA-MFRFNN
Authors: Ma Qianran , Wei Duqu
Published: December 2024

The complexity of the operation of permanent magnet synchronous motor (PMSM) has heightened interest in its stability and reliability. Evidence suggests that chaotic oscillatory behavior can occur during PMSM operation, making the prediction of such chaotic motion crucial for maintaining stable motor performance. In this paper, a WOA-MFRFNN (Whale Optimization Algorithm-Multi Functional Recurrent Fuzzy Neural Network) model is proposed to predict chaotic time series of PMSM, where WOA is used to train the network weights and the MFRFNN contains two TSK fuzzy rules for fuzzy neural networks, which are used for the output and the state of network, respectively. The experimental results of WOA-MFRFNN are compared with those of SSA-BP, ROA-RF and iTransformer. The results imply that the WOA-MFRFNN outperforms other methods and the RMSE can reach 5.45 × 10−4. It is also shown that the WOA-MFRFNN model exhibits good predictive effect on the real-world PMSM dataset.
An efficient q-procedures to solve q-generalized quintic complex Ginzburg-Landau equations
Authors: Siddeeq Abobakkar , khan Hassan , Tchier Fairouz , Tawfiq Ferdous , Jebran Samaruddin , Nadeem Muhammad
Published: December 2024

In this work, q-Residual power series method (q-RPSM) is extended for the first time to solve q-generalized quintic complex Ginzburg-Landau (q-GCGL) equations. In 2019, Arqub (2019, Fundamenta Informaticae
166 87–110), has investigated the solutions of time fractional Schr

o

̈

dinger equations without q-derivative by using RPSM. However, in this article, the RPSM procedure is extended to non-linear q-fractional partial differential equations and thus some useful results are obtained under the definition of q-derivative, q-gamma function, q-Caputo derivative and q-factorial function. The solutions to few numerical examples under the q-Caputo operator are presented. In the current procedure, the targeted q-problems are first converted into system of two non-linear q-fractional partial differential equations and then solved by using q-RPSM and q-LADM. In particular, we considered two illustrative examples of fractional q-GCGL for analytical solutions using q-RPSM and q-LADM. The numerical simulations for the suggested numerical problems are done successfully. It is also investigated that higher terms series solution have the higher degree of accuracy. In the current q-RPSM and q-LADM simulations, the higher accuracy is achieved by taking sixth terms series solution. The fractional-order solutions are convergent toward integer-order solution as the fractional-order approaches to integer-order. The solutions curve at different q-values is also calculated and obtain the useful dynamics of the targeted problems. The q-analogy can be used effectively in the field of quantum physics and thus keep the higher norm for researchers working in the field.
Recent progress on the efficiency and stability of lead-free Cs2AgBiBr6 double halide perovskite solar cells
Authors: Jakir Hossen Md , Hamzah Hairul Mardiah , Shahinuzzaman Md , Jamal MS , Mohd Said Suhana , W M Hatta S F , Helal Miah Md , Khandaker Mayeen Uddin , Islam Mohammad Aminul
Published: December 2024

Within a decade, the power congversion efficiency (PCEs) of metal-halide perovskite solar cells (PSCs) moves upward from 3.9% to 25.7%, making them competitive with current state-of-the-art silicon-based counterparts. This steepest growth of the PCEs suggests that the commercialization of this technology might be easing the energy transition from fossil fuel to renewable energy. However, a wide range of factors restrict the commercial viability of PSCs like their toxicity and instability. A crucial and difficult task in the field of PSCs is the replacement of Pb-based perovskite with non-toxic and eco-friendly material while maintaining high-performance with improved stability. Cs2AgBiBr6 halide double perovskites (HDP) material seems to be very promising in this regard. This article reviews the recent progress in Cs2AgBiBr6 double PSC devices, especially fabrication techniques including the advancement of its efficiency and stability. Here, the evolution of Cs2AgBiBr6 towards the application and fabrication of PSCs has also been discussed. This study also analyzed the impact of numerous environmental stresses, such as mechanical, thermal, and optical stresses including the potential prospects in the case of Pb-free PSCs.
Dielectric and free volume of Poly methyl methacrylate/silver nanoparticles- polyhydroxybutyrate nanocomposites (PMMA- AgNP/PHB): positron annihilation lifetime study
Authors: Alzahrani Ali , Kaouach Houda , Al-Ahmadi Ameenah N , Al-Rasheedi Asmaa , Abdel-Hady Esam E , Awad Somia
Published: December 2024

Solution casting technique was used successfully to prepare Poly methyl methacrylate/silver nanoparticles-polyhydroxybutyrate blend with different polyhydroxybutyrate (PHB) concentrations. FTIR results assure and confirm the good compatibility between the two polymers. X-ray results of the PHB/PMMA-AgNP blend show an increase in crystallinity with increasing PHB loading. A non-destructive Positron annihilation lifetime measurements were conducted at room temperature as a function of PHB concentration. Measurements of a dielectric constant were performed in the frequency range of 50 Hz to 50 MHz at RT. It was observed that O-Ps lifetime, τ
3, O-Ps intensity, I3, free volume hole size, FV, and fractional free volume, FFV, were found to decrease with increasing PHB percentage. The dielectric constant ε
/ showed a declined behaviour with increasing PHB content. The fabricated blend shows anomalous behaviour regarding the dielectric properties and free volume properties, indicating that blending PMMA with PHB alters the blend polarization behaviour in an external electric field.
Digital slick-line monitoring technology and its application in offshore oil and gas well testing
Authors: Xin Xiaojun , Yu Weiqiang , Zhao Hongxu
Published: December 2024

Oil and gas well testing is an important means of evaluating the characteristics and production capacity of oil and gas reservoirs, providing important basis for the formulation of oil and gas field development plans. Downhole operations and testing carried out by traditional slick-line are difficult to determine the condition of downhole tools and wellbore temperature/pressure conditions, which affects the accuracy of testing data.This article explores the application of digital slick-line in downhole operations and oil and gas well testing, and provides a detailed introduction to the working principle, performance characteristics, and advantages of digital slick-line in oil and gas well testing. Through case analysis, the application of digital slick-line in underground operations under complex offshore conditions was demonstrated. Especially in oil and gas well testing and Pressure-Volume-Temperature (PVT) sampling, it can assist in determining suitable testing plans through the analysis of real-time testing data, achieving good practical application results, and providing new ideas and methods for the development of oil and gas well testing technology.
Study on offshore sandstone reservoir classification method based on cuttings digitization technology
Authors: Li Dadong , Li Chongfeng , Xu Changmin , Cui Yuliang
Published: December 2024

Reservoir classification research is of great significance for improving the accuracy of oil and gas exploration and development, reducing risks, and enhancing economic benefits. Traditional reservoir classification methods are primarily based on macroscopic geology and core analysis, lacking descriptions of reservoir pore structure characteristics and microscopic geological features, with very limited data dimensions obtained. This study uses sandstone cuttings samples from a well in an offshore sandstone reservoir as an example and employs digital core technology to conduct reservoir classification research. First, high-resolution micro-CT scanning was performed, and the microscopic lithological characteristics of different blocks were observed based on the scanned images. The diagenesis and particle contact relationships were qualitatively analyzed. Next, digital methods were used to quantitatively analyze pore structure characteristic parameters such as porosity, permeability, and connectivity. Then, the qualitative analysis results of the images were combined with the quantitative analysis results of the digital cuttings to form a set of classification evaluation standards for a certain sandstone reservoir in the eastern South China Sea. Finally, based on the characteristic parameters obtained from the digital quantitative analysis of the cuttings and the on-site pressure-flow data, a big data analysis method was used to screen out the reservoir characteristic parameters with high correlation, providing data support for the rapid evaluation of reservoir mobility. The reservoir classification evaluation standards and flow prediction models formed in this study can provide technical support for accurately formulating reservoir development plans in oil fields in the eastern South China Sea and have significant reference value for the fine evaluation of similar reservoirs. In addition, reservoir classification methods based on digital core analysis exhibit efficiency and multidimensionality, which are crucial for well placement selection, wellbore design, stability assessment of well walls during drilling, interpretation of logging data, and accurate prediction of production capacity.
Research on signal enhancement and flow rate calculation methods of multi-channel ultrasonic flowmeter
Authors: Wu Haosheng , Lan Jingjing , Hu Yitao , Ni Pengbo
Published: December 2024

In the field of drilling, accurate measurement of mud flow helps detect potential leaks or abnormal situations, thereby improving overall safety and preventing accidents from occurring. Traditional contact flow meters require breaking the pipeline before installation, making them difficult to install in underground environments. In addition, the complex composition of underground fluids and their corrosive nature can also lead to unsatisfactory measurement results. Therefore, as a non-invasive flow measurement tool, ultrasonic flowmeter is a better choice. However, the ultrasonic echo signals of current ultrasonic flow meters are susceptible to external interference in actual testing, resulting in a decrease in signal quality and making it impossible to perform accurate detection. This article focuses on the research of ultrasound echo signal processing model, designs a four channel ultrasound transceiver model, improves the wavelet denoising algorithm, designs signal reconstruction and baseline correction processing methods, and proposes a pipeline flow calculation algorithm based on Gaussian numerical integration. This method can greatly improve the quality of ultrasound echo signals and the average accuracy of flow measurement. Finally, relevant testing experiments were conducted, and the results of the final performance measurement showed that the method proposed in this paper improved the average accuracy of the measurement by 5.07%, and the relative error remained at around 2%, with a significant improvement in error rate. Therefore, the method proposed in this article has extremely high accuracy in mud flow measurement.
Rock cutting image recognition based on color and texture feature fusion
Authors: Zhang Yihao , Li Zhongbing , Han Xiong
Published: December 2024

In the realm of oil exploration, there is an increasing demand for precise lithological analysis, particularly in the rapid and accurate identification of fine rock cutting images. Therefore, a novel rock cutting image recognition method based on the fusion of color and texture features is proposed. This method utilizes the color histogram and grayscale co-occurrence matrix techniques to extract color and texture features from target images, respectively. Compared with the traditional single-feature recognition methods, this integrated feature method can greatly improve the accuracy of fragment recognition and ensure more accurate fragment classification by designing the feature fusion structure of the fragment image feature set. The model is established by using the support vector machine (SVM) classifier to realize the automatic classification and recognition of cuttings images. This not only reduces the time and labor intensity of manual operation, but also improves the efficiency and speed of cuttings analysis, which meets the needs of modern efficient drilling operations. More detailed and accurate stratigraphic data can be provided by high precision rock chip identification and lithology analysis. These data have important reference value for geologists to analyze stratigraphic structure and distribution, determine the location and distribution of underground oil and gas layers, and optimize drilling decisions and operation plans. Experimental results show that the method achieves an overall recognition accuracy of more than 90% in the task of detecting 126 rock chip images for conglomerate, 153 for mudstone, and 150 for sandstone, and up to 94% for mudstone and sandstone. It is proved that the recognition method proposed in this paper can better classify sandstone, mudstone and conglomerate in rock chips with high recognition accuracy.
Research and application of on-line testing technology for drilling fluid properties in Chuanyu deep well
Authors: Lu Qi , Xu Jianchao , Cai Xiaocong , Liu Ke
Published: December 2024

Viscosity measurement of drilling fluid while drilling is an important basis for real-time analysis of wellbore hydraulic characteristics and optimization of drilling parameters. When the current drilling fluid viscometer is used for on-line continuous detection, the drilling fluid is easy to settle and adhere to the measuring gap and stator end face, which affects the detection accuracy. This effect is particularly severe when measuring high density and high viscosity drilling fluids. Therefore, a larger measurement gap is more suitable for on-line inspection of the probe size. However, the larger measurement gap is more likely to produce eddy current and turbulence, which affects the detection accuracy. Therefore, based on Taylor Couette’s law of small gap fluid dynamics, combined with indoor evaluation experiments, and considering key influencing factors such as size requirements, laminar flow constraints, motor driving force and rotor limit speed, two different sizes of detection structures were designed. The measured gap range is 0.102 ∼ 0.146mm. Laboratory tests showed that the deposition and adhesion of drilling fluid in the measurement gap were significantly improved. A moment of inertia time-response model was established to determine the optimal reading time window: for standard fluid (GBW13607), the detection time was 33.7 seconds, and for drilling fluid (density ≤2.0g/cm³), the detection time was 67.4 seconds. The accuracy of on-line measurement of drilling fluid viscosity is ensured.
Edge detection of formation boundary based on 3D holographic azimuthal electromagnetic wave resistivity logging tool
Authors: Guo Shuyu , Wang Jie , Xing Xiangyu , Xiao Jiaqi , Liu Xiao
Published: December 2024

Geo-signals are critical in enabling the edge detection function of logging while drilling tools, with their detection depth directly reflecting the edge detection capability of the tool. To address the issue of insufficient edge detection distance in geological steering while drilling, a newly developed 3D holographic azimuthal electromagnetic wave resistivity logging tool is used to construct new geo-signals with full components to extend signal detection depth. By analyzing response characteristics in conjunction with downhole factors, it is determined that the tool can use this signal to express azimuthal information while completing formation boundary detection up to 9.6 meters in advance, with resistance to adverse effects in varying downhole environments.
Application of FLAIR technology in evaluation of complex fluids—Taking M structure of Huizhou sag as an example
Authors: Yuan Shengbin , Yang Yi , Cao Yingquan , Deng Zhuofeng
Published: December 2024

Due to the complexity of reservoir fluid types and the difficulty in identifying hydrocarbon abundance in M structure of the Huizhou sag, the conventional gas logging methods are affected by instrument accuracy, resulting in indistrument difference in gas logging response characteristics. Consequently, the traditional evaluation methoda are inadequate.To address these challenges, fluid logging & analysis in real time technology(FLAIR) is applied. This technology quantifies various gas components by detecting the ion mass, offering advantages such as precise detection and wide measurement range.In this paper,the data of FLAIR technology was analyzed. Based on the differences in hydrocarbon components of various fluids, fluid identification charts were developed using the hydrocarbon component ratio, humidity ratio (WH) and equilibrium ratio (BH) parameters, which could effectively distinguish complex fluids such as gas, condensate, oil and volatile oil formations.The oil index and gas index were selected, and the gas-oil ratio index was formulated. A relationship model between this parameter and the gas-oil ratio data, measured through cable sampling and formation testing was established, enabling the prediction of gas-oil ratio data during drilling. By correcting gas data to reduce the influence of factors such as drilling time, displacement volume and bit size through gas data correction, the evaluation chart of oil and gas abundance, based on the anomaly ratio of gas measurement can adress the evaluation challenges of buried hill reservoir. The aforementioned method provides robust technical support for reservoir fluid identification and evaluation in M structure of Huizhou sag, and has significant application value in complex reservoirs and complex fluid conditions.
Research and application of online light hydrocarbon logging technology
Authors: Du Peng , Tian Weizhi , Song Minghui , Ni Youli , Zhou Changmin , Jia Xuedong , Tao Ye
Published: December 2024

With the advancement of exploration and development, various mud logging technologies have been gradually developed. Among these technologies, light hydrocarbon logging plays a crucial role in identifying reservoir fluid properties, guiding engineering decisions, and selecting reservoirs for oil testing due to its high resolution, accuracy, and anti-interference capabilities. However, light hydrocarbon logging technology has its limitations, for its single point analysis, lengthy analysis time, and lack of timeliness. On the other hand, gas logging technology offers good continuity and timeliness. Therefore, GW-OLS online light hydrocarbon logging technology is developed by integrating the advantages of the two logging technologies. This technology can obtain real-time reservoir data, including C1-C8, a total of 15 kinds of hydrocarbon components, with good continuity, high timeliness, resolution, accuracy, strong anti-interference, and other advantages. Through the research, the online light hydrocarbon logging gas index Lg, oil index Lo, water index Lw, and other derived parameters are established, which can realize the timely and accurate identification of fluid properties during the drilling process. Currently, online light hydrocarbon logging has been applied in many oil fields such as Liaohe, Jidong, and Changqing, and verified by oil tests, with a coincidence rate of up to 81.9%, demonstrating its extremely high application and promotion value.
On estimating the effective sensitivity of a TOF-PET system for
a particular imaging task
Authors: Nuyts J. , Zaman Pour S.A. , Noë S. , Schramm G. , Rezaei A.
Published: December 2024

Comparing positron emission tomography (PET) systems which
have different features is not straightforward. To address this, we
propose to image the same object with all considered PET systems
using a fixed scan time, and reconstruct from each scan an image at
the same predefined spatial resolution. With such resolution matched
reconstructions, the images should be identical except for their
noise. Therefore, the PET system that produces the image with the
lowest variance has the best performance. An analytical model is
described to compute this variance, assuming that the PET system is
(approximately) cylindrical, the imaged object is a uniform cylinder
centered in the field of view, and the variance is only computed at
the center of the reconstructed image. The model takes into account
the solid angle covered by the detectors, the detector stopping
power, the time-of-flight (TOF) resolution, the scatter fraction and
the spatial resolution of the system, the attenuation and diameter
of the cylinder and the desired spatial resolution of the
reconstructed image. The inverse of this variance can be considered
as the effective sensitivity of the system. This effective
sensitivity can be calibrated based on the NEMA line source
sensitivity. As a performance metric for scanning long objects, the
minimum sensitivity achieved over the object is computed, with an
optimal number of bed positions and optimal overlap between
them. The influence of the spatial and TOF resolution on the
effective sensitivity is verified with simulations.
Performance of the prototype beam drift chamber for LAMPS at RAON with proton and 12C beams
Authors: Kim H. , Bae Y. , Heo C. , Seo J. , Hwang J. , Moon D.H. , Ahn D.S. , Ahn J.K. , Bae J. , Bok J. , Cheon Y. , Choi S.W. , Do S. , Hong B. , Hong S.-W. , Huh J. , Hwang S. , Jang Y. , Kang B. , Kim A. , Kim B. , Kim C. , Kim E.-J. , Kim G. , Kim G. , Kim J. , Kim J. , Kim S.H. , Kim Y. , Kim Y.J. , Kim Y. , Kim Y.J. , Kweon M. , Lee C. , Lee H. , Lee H. , Lee H. , Lee J. , Lee J. , Lee J.-W. , Lee J.W. , Lee S.H. , Lee S. , Lee S. , Lim S. , Nam S.H. , Park J. , Shin T.
Published: December 2024

Beam Drift Chamber (BDC) is designed to reconstruct the
trajectories of incident rare isotope beams provided by RAON (Rare
isotope Accelerator complex for ON-line experiments) into the
experimental target of LAMPS (Large Acceptance Multi-Purpose
Spectrometer). To conduct the performance test of the BDC, the
prototype BDC (pBDC) is manufactured and evaluated with the high
energy ion beams from HIMAC (Heavy Ion Medical Accelerator in Chiba)
facility in Japan. Two kinds of ion beams, 100 MeV proton, and
200 MeV/u 12C, have been utilized for this evaluation, and the
track reconstruction efficiency and position resolution have been
measured as the function of applied high voltage. This paper
introduces the construction details and presents the track
reconstruction efficiency and position resolution of pBDC.
Thermodynamic simulation of a water-injected twin-screw steam compressor
Authors: Grieb M , Brümmer A
Published: December 2024

Decarbonisation of industrial heating and process steam generation is crucial for the mitigation of advancing climate change. High-temperature heat pumps can meet these demands while effectively integrating with renewable energy sources, outperforming traditional heating and boiling systems, especially when operating with natural refrigerants. Since compressor efficiency is critical for the effectiveness of heat pump systems, particular care is required in compressor design and specification. Detailed thermodynamic simulations of the compressor system are indispensable in this process. The compression of fluids with a negative saturation vapour curve leads to challenging temperature increases during compression, with substantial superheating of the working fluid. In this context, a promising approach is the injection of liquid working fluid into the compressing chambers for internal cooling. This introduces new complexity to compressor simulations for heat-pump applications. In this work, a novel two-phase approach for multi-chamber model simulations of positive displacement compressors is presented. Initially, a quasi-isentropic reference process for vapour compression with internal liquid injection is introduced and efficiency ratings are derived. Furthermore, the simulation process is described in detail, and comprehensive thermodynamic simulations of a water-injected twin-screw steam compressor are carried out.