Compositional Grading Research Articles

Study Details Strategy of Bottom-Up Water injection in a Heavy Oil Reservoir

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203783, “Challenges, Opportunities, and Threats of Deep Bottom-Up Water Injection in a Heavy Oil Reservoir: Lessons Learned From the G Field, South Oman,” by Chaitanya Behera, SPE, Sandip Mahajan, and Carlos Annia, Petroleum Development Oman, et al. The paper has not been peer reviewed. _ The complete paper presents the results of a comprehensive study aimed at improving the understanding of deep bottom-up water injection, which enabled optimizing recovery in a heavy oil field in south Oman. The work concludes that the well-reservoir-management (WRM) strategy for a heavy oil field is not the same as one for a classic light oil waterflood. Nevertheless, the reservoir heterogeneity, oil-column thickness, and saturation history also are important factors for variable water-injection response in a heavy oil field. Field Background The G field is on the eastern flank of the South Oman Salt Basin 700 km south of Muscat. The main producing reservoir, the Mahwis sand of the Haima group, culminates in two accumulations (G Main and G East). The Mahwis formation is composed of clastic sediments interlayered with several cemented zones, which often act as baffles in some areas (Fig. 1). However, all stratigraphic units are hydrodynamically connected. No major pressure shift along repeat-formation-tester (RFT) pressure profiles was observed, except at few locations across a major baffle in an oil leg in the crestal area. The reservoir quality is good, with porosity averaging 28% and permeability in the range of 200–2000 md. The maximum oil column thickness is approximately 70 m. Oil viscosity ranges from 250 to 1500 cp across the field both laterally and vertically. The viscosity in the northeast crestal area is relatively low compared with the thee southeastern part of the field. The compositional grading, multiple charging, and biodegradation of oil close to the oil/water contact (OWC) contribute to such a widespread variance in oil viscosity across the G field. The field, initially delineated by five vertical wells in 1990–91, was developed in multiple phases by horizontal producers placed at the top of the reservoir. The field produced under primary depletion until deep bottom-up water injection began in 2015. Water-Injection Development A secondary recovery scheme with infill wells and bottom-up water injection was proposed in 2009 as reservoir pressure dropped by 40%. The water-injection development consisted of injecting untreated produced water at a depth of 100 m below the original OWC under fracture conditions through 35 vertical water injectors. One hundred and thirty-three infill horizontal producers (86 single laterals and 47 dual laterals) were proposed to drill at a denser spacing. The infill campaign began in 2010, while water injection was initiated in December of 2014. The plan was to ramp up the water-injection rate to 70 000 m3/d in 3 years and double the field liquid production. After 3 years of water injection, however, only 33% of the predicted incremental rate was achieved. Approximately 40% of the incremental reserves of the redevelopment scheme was estimated to be at risk.

MP50-14 A MULTICENTER EVALUATION OF THE PROGNOSTIC UTILITY OF CHANGES IN TREATMENT-ASSOCIATED BODY COMPOSITION IN MEN WITH GERM CELL TUMORS (GCT) OF THE TESTIS: IMPLICATIONS FOR ADVERSE EVENTS AND COMPLICATIONS

You have accessJournal of UrologyCME1 Apr 2023MP50-14 A MULTICENTER EVALUATION OF THE PROGNOSTIC UTILITY OF CHANGES IN TREATMENT-ASSOCIATED BODY COMPOSITION IN MEN WITH GERM CELL TUMORS (GCT) OF THE TESTIS: IMPLICATIONS FOR ADVERSE EVENTS AND COMPLICATIONS Claire Buxton, Benjamin N. Schmeusser, Sarah K. Holt, Datta Patil, Anthea Phuong, J. Peter Marquardt, Ryan O'malley, Grace Laidlaw, George R. Schade, Daniel W. Lin, Michael T. Schweizer, Todd Yezefski, Evan Y. Yu, Bruce Montgomery, Florian J. Fintelmann, Sophia Chahine, Viraj A. Master, and Sarah P. Psutka Claire BuxtonClaire Buxton More articles by this author , Benjamin N. SchmeusserBenjamin N. Schmeusser More articles by this author , Sarah K. HoltSarah K. Holt More articles by this author , Datta PatilDatta Patil More articles by this author , Anthea PhuongAnthea Phuong More articles by this author , J. Peter MarquardtJ. Peter Marquardt More articles by this author , Ryan O'malleyRyan O'malley More articles by this author , Grace LaidlawGrace Laidlaw More articles by this author , George R. SchadeGeorge R. Schade More articles by this author , Daniel W. LinDaniel W. Lin More articles by this author , Michael T. SchweizerMichael T. Schweizer More articles by this author , Todd YezefskiTodd Yezefski More articles by this author , Evan Y. YuEvan Y. Yu More articles by this author , Bruce MontgomeryBruce Montgomery More articles by this author , Florian J. FintelmannFlorian J. Fintelmann More articles by this author , Sophia ChahineSophia Chahine More articles by this author , Viraj A. MasterViraj A. Master More articles by this author , and Sarah P. PsutkaSarah P. Psutka More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003298.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Skeletal muscle mass is associated with oncologic outcomes and treatment-associated toxicity across malignancies. However, men with GCT are younger and less likely to suffer baseline age-related muscle loss. As such, the prognostic utility of body composition metrics in GCT is undefined. We aimed to quantify changes in body composition following cytotoxic chemotherapy (CC) for GCT and evaluate associations between these changes and rates of CC-associated adverse events (AEs) and post-retroperitoneal lymphadenectomy (RPLND) complications. METHODS: This retrospective study included 216 patients with GCT (N=152 from Fred Hutchinson Cancer Center/ University of Washington; N=64 from Emory University Hospital) treated with CC and/or RPLND, with CT scans within 75 days before initiation and after completion of treatment. We analyzed L3 axial CT scans for skeletal muscle index (SMI), subcutaneous adipose index (SAI), and visceral adipose index (VAI). Logistic regression was used to evaluate associations between body composition metrics and grade 3+ AEs and Clavien 3+ post-RPLND complications. RESULTS: Median age for the cohort was 30 years (IQR 25-39) of whom, 47% of men had nonseminomatous GCT (Stage IS, II, and III in 17%, 39%, and 42%, respectively). 182 men received CC including BEP (67%), EP (19%), and VIP (7%), with a median of 3 cycles while 34 men (33%) and 69 men underwent primary and post-CC RPLND, respectively. Median time between CTs was 114 days. Median change in SMI, VAI, and SAI was -6% (Figure 1), +13%, and +11%, respectively. Overall, 79 men (43%) experienced grade 3+ AEs, and 24 men (23%) experienced Clavien 3+ post-RPLND complications. On regression analysis, higher baseline VAI (p=0.048), lower post-CC SMI (p=0.008), and decreased SMI (p=0.047) were associated with increased risk of grade 3+ AE. No baseline body composition metrics or changes therein during CC predicted risk of post-RPLND complications. CONCLUSIONS: We observed a decline in skeletal muscle and an increase in adipose tissue following CC in men with GCT. Both skeletal muscle and adipose tissue metrics were associated with the incidence of chemotherapy-associated adverse events and may have the potential for use in risk evaluation. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e690 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Claire Buxton More articles by this author Benjamin N. Schmeusser More articles by this author Sarah K. Holt More articles by this author Datta Patil More articles by this author Anthea Phuong More articles by this author J. Peter Marquardt More articles by this author Ryan O'malley More articles by this author Grace Laidlaw More articles by this author George R. Schade More articles by this author Daniel W. Lin More articles by this author Michael T. Schweizer More articles by this author Todd Yezefski More articles by this author Evan Y. Yu More articles by this author Bruce Montgomery More articles by this author Florian J. Fintelmann More articles by this author Sophia Chahine More articles by this author Viraj A. Master More articles by this author Sarah P. Psutka More articles by this author Expand All Advertisement PDF downloadLoading ...

Elucidating laser directed energy deposition based additive manufacturing of copper-stainless steel functionally graded material: Processing and material behavior

Copper (Cu)-stainless steel (SS 304L) multi-material is enduring research topic for various engineering applications such as tooling industry, aerospace, power-generation and cryogenic applications. Laser directed energy deposition (LDED) based additive manufacturing is a one of the promising technologies for fabricating Cu-SS multi-material component. However, LDED of Cu-SS is difficult due to the significant difference in thermo-physical properties and poor solubility of Cu and Fe. One of the methods to overcome this issue is adopting a functionally graded material (FGM) approach. In this pretext, the fabrication of Cu-SS FGM using the LDED process is taken up in the present study with three different Cu compositional grading approaches, such as direct (GD100Cu), 50 % (GD50Cu) and 20 % (GD20Cu). The LDED process windows for single tracks and bulk deposition of Cu-SS FGM are identified by varying the laser power, scan speed and composition of Cu and SS304L. Subsequently, the identified process window is used to deposit bulk structures of Cu-SS FGM. The LDED-built Cu-SS FGMs are characterized in terms of build quality, chemical composition, microstructural evolution and mechanical behavior. Microscopic analysis reveals, the defect-free deposition of GD100Cu and GD50Cu, at identified process parameters. For GD20Cu, the micro-crack formation in the graded region and inter-layer porosity in the Cu-rich region are two competing phenomenon, and it is observed that layer-wise increase in laser power and interlayer delay leads to minimum crack density and lower porosity. Further, increase in Cu content leads to significant change in microstructural morphology from columnar dendrites to fine cellular morphology. In Cu-SS FG structures, the chemical composition and mechanical properties are found to be changing gradually. Further, obtained ultimate tensile strength (UTS) of GD100Cu and GD50Cu is found higher than GD20Cu and the mode of failure is found to be ductile. The improved UTS in GD100Cu and GD50Cu in comparison with pure Cu arises due to formation of nano precipitate of Cu in the inter-dendritic zone of Fe rich phase. This establishes the suitability of LDED for building FG Cu-SS components at GD50Cu over GD20Cu.

Design of step-graded AlGaN buffers for GaN-on-Si heterostructures grown by MOCVD

For the growth of low-defect crack-free GaN heterostructures on large-area silicon substrates, compositional grading of AlGaN is a widely adapted buffer technique to restrict the propagation of lattice-mismatch induced defects and balance the thermal expansion mismatch-induced tensile stress. So far, a consolidation of the design strategy of such step-graded buffers has been impaired by the incomplete understanding of the effect of individual buffer design parameters on the mechanical and microstructural properties of the epilayers. Herein, we have analyzed a series of metal-organic chemical vapor deposition grown GaN/graded-AlGaN/AlN/Si heterostructures through in situ curvature measurements and post-growth x-ray diffraction (XRD). Our results reveal that in such epi structures, the GaN layer itself induces more compressive stress than the AlGaN buffer, but the underlying AlGaN layers dictate the magnitude of this stress. Furthermore, for a fixed AlGaN buffer thickness, the mean-stress accumulated during the GaN growth is found to be correlated with its structural properties. Specifically, one µm thick GaN layers that acquire 1.50 GPa or higher compressive mean-stress are seen to possess XRD ω-FWHM values less than 650 arc-sec. Also, the evolution of instantaneous stresses during the growth of the AlGaN layers is found to be a valuable indicator for buffer optimization, and composition difference between successive layers is established as a crucial criterion. The results also show that increasing the total buffer thickness (for a fixed number of steps) or increasing the number of steps (for a fixed total buffer thickness) may not always be beneficial. Irrespective of the buffer thickness, optimized high electron mobility transistor structures show similarly low sheet-resistance (∼350 Ω □)−1 and high mobility (∼2000 cm2 V−1 s −1) at room temperature.

Index grade group is superior to composite grade group for prediction of biochemical recurrence following radical prostatectomy

The pathological grade of prostate cancer is the strongest predictor of recurrence. It is unclear whether the better predictor is the composite of all carcinomas within the prostate, or the highest grade lesion (index). The purpose of this study was to determine whether composite or index grade group better predicts biochemical recurrence (BCR). We undertook a retrospective analysis from a prospective institutional cohort study of men who underwent radical prostatectomy for localised prostate cancer between 2009 and 2020, in which an index and composite grade group was reported. The index grade in this study was defined as the highest grade of any tumour, usually with the highest stage, regardless of volume. Multivariate analysis and Kaplan-Meier plots were utilised. A total of 2024 men underwent radical prostatectomy during the study period; we analysed 1605 with composite grade group 2 or 3 prostate cancer. Median preoperative prostate specific antigen (PSA) was 5.9 ng/L, mean follow up was 56.8 months, 54% were pT2, 76% had multifocal disease and 16% had discordant index and composite grades. Patients with discordant index grade group had a higher risk of BCR [hazard ratio (HR) 2.22, p<0.0001]. The prevalence of BCR in the discordant group was higher at 1, 3, 5 and 7 years (4.7% vs 8.9%, 8.3% vs 18.1%, 14.5% vs 28.8% and 22.5% vs 49.5%, respectively). In cases of discordance, a higher index grade group is associated with increased rates of BCR after radical prostatectomy. Index rather than composite grade group should be used to counsel men post-operatively regarding prognosis and follow-up.

Atomic-column resolution quantitative composition analysis of AlN interlayer in MOCVD-grown AlGaN/AlN/GaN heterostructure using HAADF-STEM

Quantitative compositional analysis using high-angle annular dark-field scanning transmission electron microscopy was performed for a metal-organic chemical vapor deposition-grown AlGaN/AlN/GaN heterostructure at atomic-column resolution. In addition, the effects that different concentrations of Al in the AlN interlayer had on the electronic properties were evaluated. The maximum Al concentration in the AlN interlayer was 0.41, and the compositional grading at the upper and lower AlN interfaces resulted in an asymmetric broadening of the interface. Calculations show that increasing the Al concentration in the AlN interlayer leads to an approximately linear increase in the two-dimensional electron gas sheet density. The alloy scattering is also effectively suppressed when the Al concentration is greater than 0.4.

Optimization of Deep Ultraviolet Laser Diode with Monotonic Compositionally Graded Hole Reservoir Layer and Symmetric Compositionally Graded Hole Blocking Layer

Optimization of Deep Ultraviolet Laser Diode with Monotonic Compositionally Graded Hole Reservoir Layer and Symmetric Compositionally Graded Hole Blocking Layer

Prediction of Toxicities Induced by Sorafenib and Regorafenib

Prediction of Toxicities Induced by Sorafenib and Regorafenib

Antimicrobial properties of a multi-component alloy

High traffic touch surfaces such as doorknobs, countertops, and handrails can be transmission points for the spread of pathogens, emphasizing the need to develop materials that actively self-sanitize. Metals are frequently used for these surfaces due to their durability, but many metals also possess antimicrobial properties which function through a variety of mechanisms. This work investigates metallic alloys comprised of several metals which individually possess antimicrobial properties, with the target of achieving broad-spectrum, rapid sanitation through synergistic activity. An entropy-motivated stabilization paradigm is proposed to prepare scalable alloys of copper, silver, nickel and cobalt. Using combinatorial sputtering, thin-film alloys were prepared on 100 mm wafers with ≈50% compositional grading of each element across the wafer. The films were then annealed and investigated for alloy stability. Antimicrobial activity testing was performed on both the as-grown alloys and the annealed films using four microorganisms—Phi6, MS2, Bacillus subtilis and Escherichia coli—as surrogates for human viral and bacterial pathogens. Testing showed that after 30 s of contact with some of the test alloys, Phi6, an enveloped, single-stranded RNA bacteriophage that serves as a SARS-CoV-2 surrogate, was reduced up to 6.9 orders of magnitude (> 99.9999%). Additionally, the non-enveloped, double-stranded DNA bacteriophage MS2, and the Gram-negative E. coli and Gram-positive B. subtilis bacterial strains showed a 5.0, 6.4, and 5.7 log reduction in activity after 30, 20 and 10 min, respectively. Antimicrobial activity in the alloy samples showed a strong dependence on the composition, with the log reduction scaling directly with the Cu content. Concentration of Cu by phase separation after annealing improved activity in some of the samples. The results motivate a variety of themes which can be leveraged to design ideal antimicrobial surfaces.

New insights into the Rhône–Simplon fault system (Swiss Alps) from a consistent earthquake catalogue covering 35 yr

SUMMARYSeismotectonic interpretations in regions characterized by low to moderate seismicity require consistent earthquake catalogues covering periods of several decades. Inevitable changes in network configuration and analysing procedures, however, introduce significant bias to the hypocentre parameters and uncertainty estimates reported in such catalogues. To overcome these limitations, we developed a procedure using coupled hypocentre-velocity inversions to compute consistent hypocentre locations covering time periods of several decades while accounting for changes in network geometry. We apply these procedures to 35 yr of instrumentally recorded seismicity along the Rhône–Simplon fault system in southwest Switzerland, which is at the transition between the Central and Western Alps. The entire catalogue is relocated using a probabilistic location algorithm in combination with the derived minimum 1-D velocity models. A combination of location parameters is used to define consistent location-quality classes allowing for reliable interpretation of epicentres and focal depths. The relocated catalogue is interpreted together with a recent 3-D P-wave tomographic model and available 2-D reflection seismic profiles. The relocated hypocentres indicate that the major band of seismicity north of the Rhône valley is associated with a 30–40 km long, steeply north-dipping shear zone, which roots in the crystalline basement of the Aar Massif and extends to the shallowest levels of the sedimentary cover of the Helvetic nappes in the Rawil Depression. Seismicity towards the southwest indicates the existence of a similar shear zone within the Aiguille Rouge Massif. This zone possibly extends to the northeast and joins the Rawil fault zone. To the south of the Rhône valley, seismicity is scattered within the Penninic nappes, but limited to the hanging wall of the Pennine Basal Thrust (PBT). The Penninic nappes are characterized by a relatively higher VP of about 5 per cent compared to the Aar Massif, indicating differences in composition or metamorphic grade across the PBT.

Crystallographic and shape preferred orientation producing anisotropy in slates from Northern Spain

Slates are common metasedimentary rocks in the Iberian Peninsula, ranging in deposition age from Proterozoic to Ordovician. Spain is currently the primary producer of high-quality slate products. The excellent cleavage is related to microstructures with very strong preferred orientation of white mica and chlorite. In this study we explore preferred orientation of eleven slates and one phyllite of different composition and metamorphic grade from Northern Spain with high energy synchrotron X-ray diffraction and study microstructures with scanning electron microscopy. While phyllosilicates display high crystallographic and shape preferred orientation, quartz, with also highly flattened grains, has in most samples a random crystallographic orientation. The microstructural and texture data are used to model anisotropic seismic properties with a self-consistent method and to explore the influence of crystal shapes on elastic anisotropy. Anisotropy for these slates is very high compared with gneiss and shale and, due to its prevalence, slate anisotropy contributes significantly to seismic anisotropy in the upper crust.

Use of Hydrogen-Rich Gas in Blast Furnace Ironmaking of V-bearing Titanomagnetite: Mass and Energy Balance Calculations.

The iron and steel industry is a major CO2 emitter and an important subject for the implementation of carbon emission reduction goals and tasks. Due to the complex ore composition and low iron grade, vanadium–bearing titanomagnetite smelting in a blast furnace consumes more coke and emits more carbon than in an ordinary blast furnace. Injecting hydrogen–rich gas into blast furnace can not only partially replace coke, but also reduce the carbon emission. Based on the whole furnace and zonal energy and mass balance of blast furnace, the operation window of the blast furnace smelting vanadium–bearing titanomagnetite is established in this study on the premise that the thermal state of the blast furnace is basically unchanged (raceway adiabatic flame temperature and top gas temperature). The effects of different injection amounts of hydrogen–rich gases (shale gas, coke oven gas, and hydrogen) on raceway adiabatic flame temperature and top gas temperature, and the influence of blast temperature and preheating temperature of hydrogen–rich gases on operation window are calculated and analyzed. This study provides a certain theoretical reference for the follow–up practice of hydrogen–rich smelting of vanadium–bearing titanomagnetite in blast furnace.

On the conduction mechanism in compositionally graded AlGaN

A two-band transport model is proposed to explain electrical conduction in graded aluminum gallium nitride layers, where the free hole conduction in the valence band is favored at high temperatures and hopping conduction in the impurity band dominates at low temperatures. The model simultaneously explains the significantly lowered activation energy for p-type conduction (∼10 meV), a nearly constant sheet conductivity at lower temperatures (200–330 K), and the anomalous reversal of the Hall coefficient caused by the negative sign of the Hall scattering factor in the hopping conduction process. A comparison between the uniform and graded samples suggests that compositional grading significantly enhances the probability of phonon-assisted hopping transitions between the Mg atoms.

Occurrence and Preservation of Gastropod Shells in Recent Riverine and Estuarine Sediments of Chennai, SE-India

Objectives: The distribution of aquatic gastropod shells was investigated in riverine and coastal sediments of Chennai, India. Next to taxonomic identification, the shell preservation was characterized and quantified with a taphonomic grade. Methods: Sediments of the Adyar and Cooum rivers as well as of coastal backwaters of the metropolitan area were taken down to a maximum depth of 81 cm using a handheld geoslicer and inspected by optical and electron microscopy. Taphonomic features (i.e. exfoliation, external luster, cracking, fragmentation, edge preservation, bioerosion, encrustation) reflecting different destructive post-mortem processes were observed, individually ranked and averaged in a composite taphonomic grade for each specimen. Results: Shells and shell fragments of various families occur with markedly different abundances between 63.7 and < 1% (in decreasing order Potamididae, Bithyniidae, Stenothyridae, Planorbidae, Thiaridae, Bullinidae, Nassariidae, Neritidae, Paludomidae). Their distribution invokes salinity as a major factor controlling occurrence in a habitat. The lack of larger and globose shells in freshwater river sediments may reflect the preference of stagnant water habitats and limited preservation in sedimentary transport. The predominance of Pirenella cingulata among the shells found in sediments of brackish environments probably reflects mechanical robustness and its extreme abundance in tidal flats. Due to post-mortem destruction most shells are incomplete. Roughly 25% of all specimens are almost complete shells not only showing spire and body whorl but at least in part also apex and/or aperture and outer lip. More than 50% represent spires or combinations of apex and spire. Composite taphonomic grades for gastropod families show a large range and reach high values. The lowest grades, indicative of best preservation, are observed for Stenothyra blanfordiana and Bithynia sp. Novelty: The distribution of gastropods in riverine and coastal environments represents a valuable ecosystem characteristic. Shell preservation shown here for sediments of Chennai is the basis for retrospective environmental characterization. Keywords: Gastropods; shells; river sediments; taphonomy; Chennai

Study on impact factors of small- and medium-span bridges under the special-purpose vehicle load

To promote the infrastructure-construction and economic development, special-purpose vehicles (SPVs) to transport large indivisible loads are increasingly appearing on highway bridges, of which most are oversized and overweight. Dynamic impact of moving vehicles on bridges is an important and long-standing issue in the design and evaluation of bridges. The dynamic impact factor (IM) of SPVs on highway bridges is usually ignored or overestimated for the response of internal forces and safety assessments, which has been a barrier to the permit checking of SPVs. So, this paper studied the dynamic impact factors of small- and medium-span bridges under the special-purpose vehicle load. First, the characteristics of overweight SPVs load larger than 80T in one province of China is analyzed and five typical SPVs based on wheelbase distribution and market surveys were summarized. Then, an SPV-bridge coupled system was introduced. Dynamic model of SPVs and the spatial roughness models of bridge deck based on the wheel track correlation principle were established. Finally, effects of bridge type, span composition, vehicle speed, vehicle type, and road grade on the IMs are examined. The recommended IMs of average road condition (class C) are proposed for different bridge types and internal forces based on mathematical statistics and extreme value analysis. The results of this study can be used to scientifically evaluate bridges under SPVs loads and revise specifications.

Construction of Intelligent Evaluation Model of English Composition Based on Machine Learning

To automatically grade compositions, automatic composition grading primarily employs statistics, mathematical analysis, machine learning, natural language processing, and other technologies. This paper presents a machine learning-based intelligent evaluation model for English composition. As a result, this paper proposes a word vector grouping-based text content representation method and a vector space model-based text content representation method. The Word2Vec model is first trained with words, then used to generate a test model of word vectors, with the statistical information of the corresponding words in each category serving as content text features. The results show that when features based on word vector clustering are added to the content text, the effect of each model improves significantly, especially the maximum entropy model, which improves by 0.048. The XGBoost model has also seen a significant improvement, going from 0.771 to 0.803. The test corpus is made up of 100 articles chosen at random from the corpus, and the test set is checked for errors. The rate of accuracy is 68 percent. The conclusion demonstrates that the model presented in this paper can help promote English teaching reform and quality-oriented higher education while also easing the burden on teachers and students.

Analysis of Grain Morphology, Mineral Composition, and Ore Grade on Gold Placer Deposits in Bantimurung, Pangkep Regency, South Sulawesi, Indonesia

The information through social media shows that there is quite an intense placer mining activity by local residents in the Bantimurung area, Tondong Tallasa District, Pangkep Regency. This study as a preliminary research aims to determine the grain morphology characteristics of mineral composition and metal grade in gold placer deposits in the study area. The data collected were eight samples. The collected samples were prepared into thin section, polished and observed using a microscope to identify the mineral composition and grain morphology. The grades of Au metal and its associated metals consisting of Ag, Zn, Pb, and Cu in the placer samples were analyzed by the AAS method. Petrography shows abundant of quartz, plagioclase, biotite and pyroxene minerals it might be indication of mineralization of epithermal. Ore petrography shows pyrite present along the river, silver is also found quite a lot along the river. Meanwhile, covellite, magnetite, sphalerite, and garnet were found only slightly at the sampling station this mineral composition indicates that the source of the placer deposits was epithermal. The grain morphology of the thin-section observation shows that quartz dominant has a high sphericity with character of roundness tends to be very angular to sub-rounded from upstream to downstream of the river. Plagioclase tends to have sub rounded roundness and high sphericity. Biotite tends to have a high sphericity with roundness from upstream to downstream is very angular, then angular, then sub-rounded. Pyroxenes tend to have high sphericity with very angular and angular roundness. Au content is directly proportional to Cu and inversely proportional to Zn, Pb, and Ag. Statistically Au affects the content of Cu by 50.97%. It can be concluded that Au is genetically associated with Cu, however Au grains that were still attached to the mineral and had not been separated from other minerals so that it could not be seen visually. This can also indicate that the source of this placer deposit is not far from the study site. Au grade corelated with stream sediment types it is 97,86 ppm for channel bar and 94,16 ppm for point bar, based on this we conclude the downstream has higher grade of Au compare to the upstream.

Study of simulations of double graded InGaN solar cell structures

The performances of various configurations of InGaN solar cells are compared using nextnano semiconductor simulation software. Here, we compare a flat base-graded wall GaN/InGaN structure, with an InxGa1−xN well with sharp GaN contact layers, and an InxGa1−xN structure with InxGa1−xN contact layers, i.e., a homojunction. The doping in the graded structures is the result of polarization doping at each edge (10 nm from each side) due to the compositional grading, while the well structures and homojunctions are impurities doped at each edge (10 nm from each side) at levels equal to the polarization doping density in the graded structure with similar maximum indium concentration. The solar cells are characterized by their open-circuit voltage, Voc, short circuit current, Isc, solar efficiency, η, and energy band diagram. The results indicate that an increase in Isc and η results from increasing both the fixed and maximum indium compositions, while the Voc decreases. The maximum efficiency is obtained for the InGaN well with 60% In.

P-35 An observational study of health-related quality of life (HRQoL) with electronic patient-reported outcome (ePRO) monitoring during nivolumab therapy for advanced gastric cancer as the 3rd or later line treatment: NIVO-G QoL study

Nivolumab is the first immune checkpoint inhibitor that proves efficacy in advanced gastric or gastroesophageal junction cancer and is approved as the 3rd or later line treatment. However, the patients (pts)'s HRQoL has not been evaluated in this setting. We thus investigated how adverse events (AEs) affect HRQoL decline during nivolumab treatment and assessed the feasibility of symptom monitoring at home using the patient’s own smartphone. Eligible pts were aged ≧20 years with ECOG-PS of 0-2, diagnosed as advanced gastric cancer, and were scheduled to receive nivolumab every two weeks as the 3rd or later line treatment. Pts assessed symptomatic AEs by themselves with PRO-CTCAE and HRQoL with FACT-Ga weekly through ePRO system using pts’ own smartphones or rental devices. Objective AEs were evaluated with NCI-CTCAE v5 at the time of consultation. The observation period was 12 weeks. The primary endpoint was the association between each AE and HRQoL decline. The impact of AE deterioration on HRQoL decline was determined by the longitudinal data analysis using a general linear model. The response variable was FACT-Ga total score changes from baseline for each time point. Explanatory variables were FACT-Ga total score at baseline, time point, and composite grade of each AE based on PRO-CTCAE. After ePRO monitoring, the pts completed the questionnaire about its usability. Between April 2019 and April 2020, 30 pts were enrolled, out of which 29 were evaluable. Twenty pts had completed ePRO monitoring by the end of the observation period, of which 10 pts had still continued nivolumab. The median age of pts was 71 years, and 58% were male. 97% of the pts were PS 0-1 and treated after the third line of treatment. 37.9% of pts do not use their smartphones on a regular basis, and 52.4% were aware of the difficulty of using them. As a result, only 0.95% of the total timepoints were missing data due to no ePRO input, indicating good compliance. The median time until the definitive deterioration of the FACT-Ga total score was nine weeks (95%CI: 3-NA). AEs such as stomatitis (p<0.0001), dysgeusia (p<0.0001), pain (p<0.0001, malaise (p<0.0001, nausea (p=0.0006, depression (p=0.0011, insomnia (p=0.0035), loss of appetite (p=0.0047, shortness of breath (p=0.0052, and vomiting (p=0.0123) were associated with worsening HRQoL, but peripheral neuropathy, diarrhea, and constipation were not. For the questionnaire about the usability of ePRO, no pts answered “not satisfied”, but only 33.4% of pts were answered “satisfied”. While 33.4% of pts wanted to continue using ePRO, 22.2% did not. Symptom monitoring with ePRO revealed that certain AEs may be responsible for the decrease in HRQoL in pts with advanced gastric cancer during the 3rd or later line nivolumab treatment. Although compliance in the ePRO input was sufficient, there are still challenges in implementing it in daily practice to meet pts expectations.

SRH suppressed P-G-I design for very long-wavelength infrared HgCdTe photodiodes.

The very long wavelength infrared (VLWIR, >14 µm) spectral band is an indispensable part of new-generation infrared remote sensing. Mercury cadmium telluride (HgCdTe or MCT) has shown excellent potential across the entire infrared band. However, the dark current, which is extremely sensitive to the technological level and small Cd composition, severely limits the performance of VLWIR HgCdTe photodiodes. In this study, cut-off wavelengths of up to 15 µm for HgCdTe devices with novel P-G-I (including wide bandgap p-type cap layer, grading layer and intrinsic absorption layer) designs have been reported. Compared with a device with a double-layer heterojunction (DLHJ) structure, the designed P-G-I structure successfully reduced dark current by suppressing the Shockley-Read-Hall process. Considering the balance of quantum efficiency and dark current, with the introduction of an approximately 0.8 µm thickness Cd composition grading layer, the device can achieve a high detectivity of up to 2.5×1011 cm Hz1/2 W-1. Experiments show that the P-G-I-T device has a lower dark current and a better SRH process suppressing ability than DLHJ devices, the measured detectivity achieved 8.7×1010 cm Hz1/2 W-1. According to additional research, the trap-assisted tunneling current is the primary component of the dark current. Controlling the trap concentration to as low as 1×1013 cm-3 will be continuous and meaningful work. The proposed study provides guidance for VLWIR HgCdTe photodetectors.