Complete Design Research Articles

Addressing genome scale design tradeoffs in Pseudomonas putida for bioconversion of an aromatic carbon source

Genome-scale metabolic models (GSMM) are commonly used to identify gene deletion sets that result in growth coupling and pairing product formation with substrate utilization and can improve strain performance beyond levels typically accessible using traditional strain engineering approaches. However, sustainable feedstocks pose a challenge due to incomplete high-resolution metabolic data for non-canonical carbon sources required to curate GSMM and identify implementable designs. Here we address a four-gene deletion design in the Pseudomonas putida KT2440 strain for the lignin-derived non-sugar carbon source, p-coumarate (p-CA), that proved challenging to implement. We examine the performance of the fully implemented design for p-coumarate to glutamine, a useful biomanufacturing intermediate. In this study glutamine is then converted to indigoidine, an alternative sustainable pigment and a model heterologous product that is commonly used to colorimetrically quantify glutamine concentration. Through proteomics, promoter-variation, and growth characterization of a fully implemented gene deletion design, we provide evidence that aromatic catabolism in the completed design is rate-limited by fumarase hydratase (FUM) enzyme activity in the citrate cycle and requires careful optimization of another fumarate hydratase protein (PP_0897) expression to achieve growth and production. A double sensitivity analysis also confirmed a strict requirement for fumarate hydratase activity in the strain where all genes in the growth coupling design have been implemented. Metabolic cross-feeding experiments were used to examine the impact of complete removal of the fumarase hydratase reaction and revealed an unanticipated nutrient requirement, suggesting additional functions for this enzyme. While a complete implementation of the design was achieved, this study highlights the challenge of completely inactivating metabolic reactions encoded by under-characterized proteins, especially in the context of multi-gene edits.

Determining the Effect of Different Organic Nutrient Sources on the Growth and Yield of Radish (Raphanus sativus L.)

Indiscriminate use of chemical fertilizers is a common practice which is hazardous both for soil health and environment. Chemical fertilizers have been widely used due to their immediate availability of nutrients; however, their long-term effects on soil and crop sustainability necessitate alternatives such as organic fertilizers. It has been more than three decades that global agriculture has been depicted towards organic agriculture owing to sustainability and reduced environmental effects. A field experiment was conducted at Institute of Agriculture and Animal Science (IAAS), Lamjung Campus from December 2022 to February 2023, with the objective to study the effect of various sources of organic manure on the growth and yield of radish. The experiment was conducted in Randomized Complete Design using 7 treatments (Control, Farm Yard Manure(FYM), Poultry Manure(PM), Goat Manure, FYM + Poultry Manure, FYM + Goat Manure, Poultry Manure + Goat Manure) with 3 replications of each. Tokinashi variety of radish was used in the experiment. Radish is an important root vegetable known for its nutritional value and quick growth cycle, making it a key crop for studying the impacts of organic manure. Experiment was done in field with the plot size of (2 x 1) m² and spacings of 30 cm x 20 cm with the total land area of 90 m². The growth and yield of radish were significantly affected by the different treatments. The highest total root yield (204.33) and biological yield (263.67) was found in Poultry manure. The study suggested that the application of poultry manure was more beneficial and resulted in significantly better growth and yield performance of radish.

Chemical Solution Mitigates Stuck Inflow Control Devices in Horizontal Completion

Summary Horizontal open holes covering long reservoir sections can be benefitted by installing inflow control devices (ICDs) along the lateral to even the production contribution from the entire heterogeneous permeability profile. During the drilling and completion process, the well can be shut in for prolonged periods of time. Though the ICDs are designed to withstand the buildup of debris, they are still subjected to the accumulation of weighting and bridging materials existing in the drilling fluid, such as calcium carbonate (CaCO3). This debris deposits on the internal diameter of the valves or the flow control device, preventing proper shifting against the seats, or blocking the flow path of the devices. Recovering the function of the ICDs requires a chemical treatment. In high-permeability formations, it is undesirable to have acid contact the rock since this may compromise the mechanical integrity of the formation or trigger further solids buildup in the ICDs. Therefore, an acid designed to dissolve the solid deposits on ICDs but not penetrating the formation is required. In this study, a modified coreflood setup was designed and an acid-based chemical treatment was formulated to remove solid deposition on the ICD. The goal was to dissolve the CaCO3 scale on the ICD with minimal penetration into the formation to avoid formation softening. The core assembly simulates the geometry of the ICD completion system with a core matrix behind the ICD operating space. Calcite marble was used to represent the scale deposited on the ICDs, while Indiana limestone was used to represent the reservoir rock. Several acid formulations were tested using the custom-designed coreflood setup. One acid blend composed of a strong organic acid [methane sulfonic acid (MSA)] mixed with hydrochloric acid (HCl) and a second blend of HCl and mutual solvent (glycol-based solvent) showed the desirable effect of dissolving the scale deposits (calcite marble in this case) with minimum to no penetration into the formation matrix. The success of the two acid systems in dissolving CaCO3 deposits on the ICDs was confirmed by analyzing the pressure data during the coreflooding experiment, as well as from analyzing the post-treated core samples using computed tomography (CT) scan. Simulation of completion design in the laboratory is a key factor in testing and designing acid treatments to overcome scale problems in the field. Single-phase acid systems containing no gelling or emulsifying agents were tested and proved capable of dissolving the solids deposited on the ICDs with minimum to no formation contact. This will result in an economical and easier one-step treatment in the field, avoiding the complexity encountered with pulling the whole completion string out of the wellbore to be treated with acid on the surface and then reinstalling it back into the well.

The effects of poultry by-product meal and multi-strain probiotics on production performance, immune response, gut health and nutrient utilisation of broilers

This study assessed the potential of a commercial probiotic mixture on performance, gut health and nutrient utilisation of broilers-fed poultry by-product meal (PBM)-based diet. Three-hundred-and-twenty Ross-308-day-old broiler chicks were obtained from a commercial poultry hatchery. The chicks were randomly assigned to four different treatment groups, each consisting of four replicates (n = 10) in a randomised complete design. The positive control group (CON) was fed commercial poultry ration, and the negative control group (N-CON) was fed PBM partially replacing soybean meal at a 65% level. The MSP1 and MSP2 groups contained the same diet as the N-CON group but supplemented with multi-strain probiotics (MSP) at 50 mg/kg and 100 mg/kg. Overall N-CON group performed poorly, but the addition of probiotics in group MSP1 and MSP2 diets significantly improved performance. Feed efficiency and bird weight gain were improved (p < .05) by multi-strain probiotics supplementation in MSP1 and MSP2 groups compared to N-CON. The highest weight gain was observed in MSP2 and lowest in the N-CON group. Increasing levels of probiotics significantly increased villi length, width and surface area in probiotics-supplemented groups compared to non-supplemented groups. Dry matter and crude protein digestibility were improved (p < .05) in probiotics-supplemented groups compared to N-CON. In conclusion, PBM at a 6.5% level was successfully used to replace soybean meal with multi-strain probiotics supplementation without compromising broiler health.

Mechanical earth model coupled with critical drawdown pressure to mitigate sand production in the Nahr Umr Formation, Southern Iraq

Sand production is one of the major challenges in the oil and gas industry. This problem exists when sand is produced along with oil and gas causing relevant damage to production equipment, thus decreasing in the productivity of wells. Therefore, a comprehensive geomechanical analysis is necessary to mitigate sand production. This study aims to assess the potential of sand production across the Nahr Umr Formation using the 1-D Mechanical Earth Model (MEM). Tech-log software coupled with well log and core data have been employed to accurately determine the possible rock geomechanical parameters, in-situ stresses and pore pressure at which rock failure might occur. Once MEM is complete, the Poro-elastic method is used to figure out the critical drawdown pressure (CDDP) and accurately predict the sand production onset. Additionally, the effect of different well completion types on the value of the CDDP was examined, and thus it was concluded that cased hole completion is the first line of defense against sand production, and can also be considered as a strategy of sand control because it reduces the sand production potential and increases the operation drawdown. Furthermore, to demonstrate the effectiveness and applicability of our method and technique, a case study was conducted to illustrate the reliability of our method in predicting sand-producing intervals under different depletion rates and completion scenarios. The finding showed that the depth 2527.7 m is a potential location for sand production as the CDDP reads a positive value revealing a high potential for rock failure. Moreover, sensitivity analysis has been performed by considering different ranges of Unconfined Compressive Strength (USC), Poisson ratio, minimum horizontal stress (Shmin), maximum horizontal stress (SHmax), vertical stress, sand grain size, perforation diameter, perforation orientations, stress ratio, and hole deviation. These factors play an essential role in optimal decisions related to real-time sand control techniques. Through the results, it is clear that as the UCS, Shmin, and SHmax increase, the sand-free drawdown and depletion also increase, and vice versa. Also, results show that as the depletion rate increases, the CDDP decreases in both cased and open hole conditions, revealing that the onset sanding likely occurs as the depletion rate is elevated. Based on these findings, a necessary modification to the completion design has been made, ensuring sand-free production from a clastic reservoir located in the southern area of Iraq.

Feeding biotreated rumen digesta affects nutrient digestion, ruminal fermentation, and blood parameters in calves

The objective of this research was to examine the impact of feeding biologically treated rumen digesta (BTRD) to Holstein steer calves at levels of 0, 10, 20, and 30% (DM-based) on feed consumption, nutrient digestion, growth performance, rumen fermentation, and plasma metabolites. Sixteen Holstein steer calves with an initial BW of 113 ± 8 kg were randomly allocated in a randomized complete design. Dietary inclusion of BTRD in calves diet did not altered (P < 0.05) total intakes of DM, OM, and CP, when compared to those on the control diet over the experiment, but improved (P < 0.01) NDF and ADF consumption. Dietary inclusion of BTRD by 20% increased significantly DM and OM digestibility, average daily gain and feed efficiency (FE) (P < 0.05) and decreased feed conversion ratio (FCR) during 60 to 120 days. Plasma glucose, triglyceride, total protein, creatinine, or urea-N concentrations between treatments were not affected, but uric acid was reduced linearly (P = 0.02) in steers given BTRD supplements. Supplemented diets containing BTRD had the highest levels of plasma cholesterol and HDL, which increased with increasing BTRD inclusion levels. BTRD supplements were found to lower MDA levels in steers than control diets. This study found that dietary BTRD supplementation improved performance and health status of Holstein steer calves as well as their oxidative parameters.

THE EFFECT OF CONCENTRATION AND SOAKING LENGTH OF ALOE VERA GEL ON THE GROWTH OF ROBUSTA COFFEE (Coffea canephora) CUTTINGS

This study aims to determine the effect of concentration and soaking time of aloe vera gel on the growth of robusta coffee cuttings. The research was arranged in a Randomized Complete Group Design (RAKL) with a factorial experiment (4x2) consisting of two treatment factors and repeated three times as a block. The first factor is the concentration of aloe vera gel with levels of 0, 20, 40, and 60%. The second factor is the length of soaking with levels of 5 and 10 hours. The results were analyzed using variance analysis, treatments that had a significant effect were further tested with Orthogonal Polynomial for the first factor and interaction and the Least Significant Difference (LSD) test for the second factor. The results showed that 40% aloe vera gel concentration produced the highest root dry weight. The treatment of aloe vera soaking time for 5 hours produced the longest root length. The interaction between aloe vera gel concentration of 20% and soaking time for 5 hours produces the longest root length.

Game Design for a Fiverr: Precarity, Regionality, and Platform-Mediation in the Gig Economy

In this article, we investigate users who sell complete design services (i.e., ostensibly creating a full, original game for a client) on the gig economy platform Fiverr. By studying the platform’s affordances and analyzing user profiles, we construct two central arguments: First, we contend that gig economy platforms facilitate, shape, and moderate labor in ways that vary from more commonly discussed models of game design. Second, we push back against Fiverr’s claims of a boundaryless workforce by analyzing local conditions that concentrate labor in particular jurisdictions. After briefly reviewing the history of gig labor, we use the walkthrough method to analyze Fiverr: reviewing registration processes, protocols between buyers and sellers, and platform governance structures. We then survey fifty seller listings to determine what services are available, how much they cost, and how they are clustered geographically. Next, we address the prevalence of Pakistani users among our sample of sellers by scrutinizing global wage inequities and regional initiatives that may push workers toward the gig economy. To close, we reflect on Fiverr’s place in the game design ecosystem, investigate how gig economy labor is framed in educational institutions, and touch upon our research limitations. While gig economy platforms are often critiqued for labor exploitation or mocked for providing poor-quality services, these are both oversimplifications of complex economic, institutional, and policy assemblages. Ideally, this article will serve as a first step in better understanding game development on gig economy platforms and their power to reshape geographies of game development.

A Current‐Fed Switched Capacitor Inverter With Voltage Boosting, Reduced Harmonic Distortion, and Minimal Device Count

ABSTRACTDC–AC inverters are an important set of power converters when it comes to integration of the renewable energy resources in to the AC grid or to local AC loads. The multilevel inverters (MLIs) are a common and popular choice for such applications. However, MLIs require many switching devices for higher number of voltage levels, multiple isolated DC sources, need for additional charge‐balancing circuits for the DC‐link capacitor, and unequal voltage stress in the devices at higher power levels. Switched capacitor–based inverters are emerging as a popular alternative to the conventional MLIs that do provide inherent charge balancing, reduced device stress, output voltage–boosting capability, and highly compact converters. This work proposes such a current‐fed DC–AC switched capacitor converter (SCC). This converter offers advantages such as reduced count of switched capacitors and power devices, elimination of load‐side filtering elements, reduced switching ripple in output voltage due to inherent interleaving, reduced voltage and current total harmonic distortion (THD), and lower ratings of the switched capacitors. An adaptive hysteresis control scheme is used to track the voltage across the switched capacitors to a desired sinusoidal reference. The overall control architecture is straightforward to implement, and the switching architecture uses overlapping logic to prevent interrupting the input current. The work includes a complete analysis and design procedure. A 500‐W laboratory prototype of the proposed converter is built, with the control architecture implemented using the TMS320F28379D microcontroller. Simulation results are verified with experimental outcomes.

Interleaving based SCMA Codebook Design Using Arnold’s Cat Chaotic Map

Non-orthogonal multiple access (NOMA) technology is a significant topic of the present 5G investigation. A possible NOMA approach is Sparse Code Multiple Access (SCMA), increasing next-generation communication's ability to handle multiple users. In SCMA, codebook designing and optimization are crucial components that define the performance of multiple access systems. In this work, the complete design procedure of the SCMA codebook based on interleaving is explained and simulated. Furthermore, a chaotic interleaving based onArnold’sCat map is proposed to reduce the computational complexity. The performance of the SCMA codebook based on interleaving is evaluated through comparison with selected codebooks for SCMA multiplexing. The measures used for performance evaluation include Bit Error rate (BER), Peak to Average Power Ratio(PAPR), and minimum EuclidianDistance(MED). The results show that the proposed codebook with chaotic interleaving achieves comparable performance to the traditional codebook based on interleaving and less MED and higher BER compared to computer-generated and 16-star QAM codebook design methods but with reduced complexity.

Formulation and Assessment of an Optimized Glimepiride Transdermal Therapeutic System Using 32 Full Factorial Design Approach.

Currently, a large number of populations are suffering from diabetes mellitus, which significantly increases the burden on public health. Glimepiride is an antidiabetic drug with a shorter half-life (approximately 5 hours), low bioavailability, and first-pass metabolism. Due to these limitations, it is required to maintain a uniform therapeutic level, and it has been chosen as a transdermal drug delivery approach. The main objective of this investigation was to evaluate glimepiride-loaded transdermal patches on the skin to treat diabetes mellitus. To overcome the issue of oral glimepiride and provide a localized effect, a transdermal drug delivery approach was developed. The glimepiride transdermal drug delivery approach was developed by using the solvent evaporation method. To examine the impact of altering amounts of polyvinyl alcohol (X1) and polyvinyl pyrrolidone (X2) on tensile strength, % of glimepiride released in 12 hours (Q12), and % of glimepiride released in 24 hours (Q24), as reliant on variables, a 32 complete factorial design was employed. For dependent variables, regression estimation and estimation of variance were employed. In-vitro release statistics were fixed to different models for various glimepiride release kinetics. In-vitro glimepiride release was tested using the best formulation. The formulation F4 with 1300.00 milligrams of polyvinyl alcohol and 600.00 milligrams of polyvinyl pyrrolidone demonstrated a release of 96.17% for up to 24 hours and zero order release kinetics consisting of r2=0.987, which was the best batch. The optimized formulation F4 showed a controlled release of glimepiride and better permeation and deposition properties. The findings of this research work demonstrated the potential of the 32 full factorial mathematical models created to anticipate formulations with additional desirable release and permeability qualities for the treatment of diabetes mellitus.

Perceptions of a Digital Dental Technology Curriculum: A Qualitative Study of Dental Technology Students.

Integrating digital dental technology into undergraduate curricula can better prepare dental technology students for a digitally driven workplace. However, students' perspectives on this education are sparse in the literature. This qualitative study explored dental technology students' perceptions of a digital dental technology curriculum. An online questionnaire was administered to third-year and fourth-year students, as well as recent graduates from the West China School of Stomatology. It comprised three sections: (1) demographic data, (2) perceptions of learning effectiveness and its impact, and (3) suggestions for curriculum improvements. Data were analysed using descriptive statistics and a chi-squared test. Sixty-nine valid responses were collected, yielding an effective response rate of 90.79%. Over 80% of respondents thought the courses beneficial for professional learning, career selection and practical work. However, 35% of third-year students reported being unable to complete digital design independently upon finishing the courses, and 62.50% of fourth-year students also lacked confidence in this area. While 95% of third-year students and 87.5% of fourth-year students intended to pursue digital-related positions, only 33.33% of employed graduates were engaged in relevant professions, indicating that the demands for digital competence in the workplace significantly exceeded the curriculum content. This study found that most students had a positive perception of the digital dental technology curriculum. However, a gap remains between curriculum content and professional practice demands. Further research and curriculum shifts driven by skill application and work scenarios are required to support the digital transformation of dental technology education and dentistry.

Completion and Stimulation Design Evolution in Tight Chalk Formations in Offshore Norway

Summary Lower completion and acid stimulation designs for low-permeability chalk formations in a series of North Sea fields were modified from historical/legacy approaches to improve well performance for both production and injection purposes. The modifications included (1) a stimulation change from high-rate matrix acidizing to acid fracturing and (2) optimization of ball-activated sliding sleeve designs. The improvement in well performance was validated by actual productivity comparisons to offset wells. Further improvements are being developed for future extended reach wells. A ball-activated sliding sleeve completion was chosen for a new series of improved horizontal well completions. Sleeve spacing, the number of sleeves, and port sizes were subsequently optimized for targeted stimulated lateral lengths by pipe flow modeling and limited-entry design methods. Optimization of acid fracturing designs was achieved after incorporating critical findings from various laboratory tests including rotating disk tests, acid-etched fracture conductivity tests, and gel shear history simulator tests. The new acid fracturing treatment designs were generated with the help of numerical simulations that were continuously fine-tuned based on new observations made during treatments and rigorous analysis of bottomhole injection pressures during the treatment. As a result of the lower completion design optimization process, different-size nozzles were introduced into the sliding sleeves to treat up to five sleeves per stimulation stage with effective, limited-entry, fluid diversion. This allowed (1) use of available pumping weather windows effectively in the often-challenging North Sea offshore environment, (2) reducing or eliminating time-consuming wireline perforation runs, and (3) limiting acid exposure to mitigate ball/seat zonal isolation loss events (i.e., dissolvable balls were not always compatible with acid). The new and improved acid fracturing design enabled a reduction of the number of gel/acid cycles from five to three, which reduced stimulation cost without losing stimulation effectiveness. The new design also resulted in productivity enhancements depending on the well location within the structure. The largest performance improvement was observed in wells that were placed farther downflank, where stronger reservoir rock and lower permeabilities were found. These wells required a more intensive acid fracturing treatment to generate economical and sustainable production rates. Finally, wells that used the new stimulation techniques also tended to require a lower restimulation frequency. This type of analysis work has not been presented previously and it optimizes lower completion for acid fracturing stimulation on a well-by-well basis. Further improvement is expected as stimulation designs and completion technology continue to evolve.

Molecular Diversity and Agronomic Performance of Sesame (Sesamum indicum) Cultivars in Benin: Local Cultivars and Lines Introduced From China.

Sesame cultivation was until recently restricted to the northwestern part of Benin. The yield is relatively low, as there are no improved varieties introduced and widely adopted so far. This study aimed to assess the molecular diversity, genetic differentiation, and the agronomic performance of a collection of local cultivars and introduced lines of sesame from China. The agronomic evaluation was conducted across eight environments during the 2020 cropping season using 14 descriptors on 19 accessions, including 6 introduced lines arranged in a randomized complete bloc design. Twelve simple sequence repeat markers were used to assess the molecular diversity. The analysis of variance showed significant variation among accessions for all the traits, except the number of lodges per capsule. Principal component analysis (PCA) followed by hierarchical clustering indicated that the accessions could be classified into three groups. The first group included accessions from China with the local accession SI09, characterized by early flowering and low seed yields (on average 380.13 kg ha-1). The second group included late flowering accessions and intermediate seed yield (on average 548.68 kg ha-1). The third group included higher yielding accessions (on average 715.7 kg ha-1). The PCA identified key traits such as days to 50% emergence, days to 50% flowering, collar diameter, plant height, number of branches, and seed yield as the most discriminative among accessions for agromorphological characterization. The SSR markers were polymorphic, with polymorphic information content values between 0.17 and 0.92. A total of 62 alleles were detected, with each locus exhibiting 2 to 15 alleles. The gene diversity ranged from 0.18 to 0.92, with an average value of 0.55. Cluster analysis based on the unweighted pair group method with arithmetic mean revealed that accessions were grouped in three clusters, with the coefficients of similarity/dissimilarity ranging between 0.60 and 0.92. Most of the Chinese lines were clustered together, except accession Y01. This study provided useful knowledge about local sesame cultivars in Benin and their similarities and differences with the lines introduced from China, therefore contributing to the advancement of the sesame-breeding program in the country.

Gulf of Mexico Case Study Highlights Smart-Completion Application

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 218794, “Multifaceted Smart Completion Application: A Gulf of Mexico Case Study,” by Jeffrey P. Manning, Ben J. Carter, SPE, and Leila Bannister, Occidental Petroleum, et al. The paper has not been peer reviewed. _ Reservoir heterogeneity, stacked pay systems, reservoir compartmentalization, and high temperature and pressure are common challenges seen in Gulf of Mexico (GOM) fields. The use of conventional completion design in vertical wells with commingled production from multiple zones has led to multiple operational challenges. In the complete paper, the authors explore the use of intelligent completions in deepwater GOM as a solution. Benefits of Intelligent Completions Intelligent completions allow collection, transmission, and validation of real-time, high-frequency data. This enables analysis of completion, production, and reservoir data while selected reservoir zones are controlled and monitored remotely in real time. Intelligent completions such as multiphase flowmeters, bottomhole pressure gauges, and cased-hole logging tools enable real-time data gathering and monitoring. Additionally, downhole flow-control systems, pinpoint stimulation, intelligent injection, and multizonal isolation technology are examples of intelligent completions that enable production optimization. This study concentrates on the application of downhole intelligent choke systems in wells that use radio frequency identification technology. Combining this technology with smart sensors or Global Positioning System technology enables sensor data to be transmitted wirelessly. Operations such as opening and closing of valves, indexing and release mechanisms, and a variety of other functions can be implemented using this technology. Multiple tools can be run at the same time without compromising the tool’s internal diameter. Each tool has a unique address; therefore, tags can be coded with data that identifies an individual tool to be actuated. Intelligent completions can be broadly categorized into the following: - Downhole flow-control systems: These are passive or active control systems to control flow from each zone. They are remotely controlled by hydraulic lines from the surface facility. - Permanent downhole sensors: These are discrete or distributed systems that monitor downhole parameters. - Permanent downhole chemical injection: These systems allow for treatment at different points in the wellbore and flowlines to prevent issues caused by corrosion, hydrates, asphaltenes, paraffin, and scaling. Case Study: Practical Use of Intelligent Completions in the GOM The operated field in the northern GOM has successfully used intelligent completions in multiple vertical producing wells to help significantly reduce operating costs associated with topsides water processing, mitigate the risk of sand production, and allow for better subsurface understanding using individual zone-flow tests (this synopsis concentrates on the first two of these three aspects). Intelligent completions enabled these operations without the use of an intervention vessel.

How ADNOC Opened the UAE’s Pre-Khuff Offshore Gas Play Using Advanced Fracturing Tech

A hidden gem may lie beneath one of the world’s latest megaprojects. Next year, the Abu Dhabi National Oil Company (ADNOC) is set to launch production from its largest-ever gas development within the UAE’s shallow-water Ghasha concession. Located some 190 km northwest of Abu Dhabi, the first phase will see gas flow from the Dalma field, followed by production from the Hail and Ghasha fields, with combined output expected to boost the UAE domestic gas supply by 1.5 Bcf/D by decade’s end. Set aside for several decades due to high levels of H2S and CO2, ADNOC is now pushing to make natural gas a bigger part of its energy strategy and has thus proudly positioned this multibillion-dollar project as the world’s largest sour-gas development. As operator, ADNOC holds a 70% stake in the concession alongside partners Eni (10%), PTTEP (10%), OMV (5%), and Lukoil (5%). ADNOC has also committed to making Hail and Ghasha the first major gas fields to operate with net-zero emissions, supported by substantial investments in carbon capture technology and the use of nuclear power. Yet there may be more to Ghasha’s supply-side potential, thanks to a team of engineers and subsurface experts who weren’t ready to give up on a stubborn rock. Discovered in 1979, the Pre-Khuff formation is a gas-rich sandstone that, though free from H2S, presents other challenges that have so far kept it from reaching commercialization. “The Pre-Khuff has performed well across the region—in Saudi Arabia and Qatar—but here in the UAE, we’ve faced 4 decades of unsuccessful attempts to unlock its potential,” said Jasim Ali Alloghani, ADNOC’s subsurface manager for the Gasha concession. He explained the complexities of the Pre-Khuff formation center around its depth, temperature, and tightness. Offshore the UAE, the Pre-Khuff formation is found 16,000 ft below the mudline where temperatures are more than 350°F and reservoir pressures exceed 10,000 psi. The sandstone is also rich in clay, with estimated clay content ranging from 10 to 40%. This leaves the rock with an upper porosity of about 12%, and a permeability range of 0.01 to 1 mD. The difficulties associated with the Pre-Khuff formation intensify from there. With a Young’s modulus of around 10 million psi, the rock is more than twice as stiff as much of the prolific Wolfcamp Shale in the Permian Basin that spans Texas and New Mexico in the US. The formation is also dominated by natural fractures and varying fracture gradients. Additionally, wellbore washouts while drilling in the deep reservoir have hindered geomechanical data acquisition. ADNOC has also found that the state of stress changes both laterally and vertically, i.e., anisotropy, due to the reservoir’s structural deformation. Additionally, ADNOC has faced challenges with designing effective completion designs due to limited technology and expertise. However, ADNOC’s fortunes with the Pre-Khuff shifted in early 2023 when the company executed the first successful multistage hydraulic fracturing treatments ever performed offshore Abu Dhabi. ADNOC reported a five- to 10-fold increase in initial flow rates from Pre-Khuff wells compared with initial attempts.

Low-cost 3D vision-based triangulation system for ultrasonic probe positioning

Abstract Introduction: In ultrasonic imaging, such as echocardiography, accurately positioning the probe in relation to the patient’s body or an external coordinate system is typically done manually. However, when developing speckle-tracking methods for echocardiology, ensuring consistency in probe positioning is essential for reliable data interpretation. To address this challenge, we present a vision-based system and method for probe positioning in this study. Materials and Methods: Our system comprises two cameras, a calibration frame with eight markers of known coordinates in the frames’ local coordinate system, and a probe holder with four markers. The calibration process involves image segmentation via region growing and extraction of the camera projection matrices. Subsequently, our positioning method also utilises marker segmentation, followed by estimating the markers’ positions using triangulation. Results: To evaluate the system’s performance, we conducted tests using a validation plate with five coplanar circular markers. The distances between each pair of points were calculated, and their errors compared to the true distances were found to be within a maximum of 0.7 mm. This level of accuracy is comparable to ultrasonic imaging resolution and thus deemed sufficient for the intended purpose. Conclusion: For those interested in replicating or modifying our methods, the supplementary material includes the complete design of the calibration frame and the Matlab code.

Walrus Pipes and Waving Panpipes

Musical instruments play a fundamental role in speculative music creations. Standing at the intersection of various fields, they embody concepts, meanings, symbols and musical consonances that are specific to each and every culture. In the present age, mass-produced Western instruments are primarily made for musical geniuses in service of virtuosity, while they all sound the consonances of a single standardized tuning system. In contrast, the 3D printed wind instrument project presented here aims to be a counterpoint to these instruments. They are simple, custom-made new instruments that work together as an ensemble, in service of communal playing. For this reason, they can be used for diverse musical purposes: they are open, nonauthoritative, and as embodiments of new meanings and uncommon consonances, they might as well be agents and representatives of speculative music worlds. This article reveals the complete design process of two 3D printed wind instrument ensembles developed throughout the project: the Walrus Pipes and the Waving Panpipes.

Stress shadow effects in multistage horizontal hydrofracturing of tight reservoirs: a numerical analysis considering perforation cluster spacings and fracturing sequences

AbstractMultistage horizontal fracturing technology of reservoirs has been widely used to enhance tight hydrocarbon resource recovery. Determining the proper perforation cluster spacing is crucial to developing a complex fracture network that connects natural rock fractures and facilitates gas flow in reservoirs. The stress shadow effect that occurs between multiple clusters has a significant effect on the development of the fracture network in reservoirs. The quantification of the stress shadow effect and its influences on the development of fracture networks has not been resolved satisfactorily due to experimental and numerical difficulties with detecting and identifying crack propagation and intersection in deep reservoirs. In this study, we used an adaptive finite element-discrete element method to analyze crack propagation and intersection in tight shale reservoirs by altering perforation spacings and fracture sequences. The effects of five perforation cluster spacings using sequential, simultaneous and parallel fracturing techniques were compared. The non-linear properties of shales, hydromechanical coupling and fluid leak-off effects, proppant transport, dual-rupture criteria of strength and energy, and intersection of hydraulic fractures were taken into account in the simulation. The areas affected by the stress shadow and the optimum perforation cluster spacing in terms of hydraulic fracture propagation lengths, volumes, and microseismic magnitudes were evaluated when adopting different fracturing methods. This study extends the understanding of the impact of the different independent factors that contribute to the stress shadow effect and, therefore, provides new information to help guide wellbore completion design in horizontal fracturing wells.

Influence of different lead concentrations on the growth parameters of French marigold (Tagetes patula L.)

This study was carried out to investigate the effect of different lead (Pb) concentrations on some growth characteristics of French marigold (Tagetes patula L.). The research was carried out at Siirt University (Turkey) Faculty of Agriculture, Agricultural Biotechnology Laboratory. In the study, French marigold (T. patula L.) seeds were used as plant material. Five different concentrations of lead (0, 200, 400, 600, and 800 ppm) were considered as research subjects. 7 pots were used for each concentration, and the laboratory experiment was set up in a randomized complete plots design with 7 replications. In the experiment, a 2:2:1 ratio peat:sand: soil mixture was used as the plant growing medium. Plant height (cm), stem thickness (mm), the number of branches per plant, the number of flowers per plant, single flower weight, and plant fresh and dry weights (g) were evaluated. According to the results, the difference between Pb concentrations was found to be significant in terms of all parameters except for the number of branches, and fresh and dry plant weights. In the study, according to Pb concentrations, plant height values were between 46.25-52.50 cm, stem thickness was between 4.13-5.77 mm, the number of branches was between 4.25-5.75 per plant, the number of flowers was between 3.25-6.25 per plant, single flower weight was between 0.84-1.49 g, plant fresh weight was between 11.66-14.32 g and plant dry weight varied between 1.10-1.29 g. In the study, promising results were obtained that the French marigold can be used for phytoremediation in Pb-contaminated areas.