Standard Series Research Articles

Standard series of transmitting equipment for hydra-jet technology based on dimensionless geometric parameters development

Introduction. The work is devoted to the calculation of series standards for the design of high-pressure transmission devices used in various hydra jet technologies, which will provide the design of these devices based on dimensionless indicators describing the relationship between their geometric and technological parameters.Materials and methods. The methodology includes the use of mathematical models and analytical approaches to assess the influence of various parameters on heat generation processes in equipment, as well as methods for statistical processing of results.Results. A histogram of temperature distribution was constructed and the data was approximated using the distribution curve of temperature values and parametric series were generated for dimensionless parameters depending on various factors such as temperature, pressure, rotational speed and linear speed. It is possible to obtain parametric series for linear dimensions from five temperature ranges and seven standard sizes depending on the pressure and rotation speed of the drill shaft.Discussion and conclusions. The results obtained provide a better definition of the relationships between rotation speed, geometric characteristics and temperature parameters through the use of dimensionless indicators and it is possible to optimize the design of such devices taking into account operating conditions and ensuring increased efficiency.

Matrix overcompensation calibration: A new strategy to correct matrix effects of carbon origin in multielement analysis by inductively coupled plasma mass spectrometry

BackgroundElemental analysis by inductively coupled plasma mass spectrometry (ICP-MS) may suffer from matrix effects; those caused by organic matrices cannot be corrected by internal standardization. A new strategy, matrix overcompensation calibration (MOC), was developed to correct such matrix effects. ResultsClear fruit juices were diluted 1:50 in 1 % HNO3 (v/v)- 0.5 % HCl (v/v)- 5 % ethanol (v/v). A standard series was treated likewise to construct an external calibration curve. As, Se, Cd, and Pb in juices were determined by dilute-and-shoot ICP-MS based on this MOC strategy. The results agreed with those obtained by standard addition calibration and microwave-aided digestion; data accuracy was validated by spike-recovery studies. SignificanceUnlike standard addition calibration, a single external calibration curve established by MOC can be applicable to juices of diversified fruit, geographical, and manufacturer origins enhancing productivity.

Abstract PO2-01-01: Biophysical simulation using DCE-MRI to forecast response to NAT in HER2+ patients, with glucose characterization and orthogonal validation using FDG-PET

Abstract Background: Metabolic reprogramming and tumor angiogenesis are two tightly linked hallmarks of cancer. Regions of high metabolic activity within a tumor can become hypoxic or nutrient starved, eliciting a cascade of pro-angiogenic signals that can lead to increased tumor perfusion and in turn greater metabolic activity. Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) and 18Fluorodeoxyglucose (FDG) positron emission tomography (PET) are two imaging methods commonly used in the diagnosis of cancer; the former can be also used to identify the perfusion of the tumor microenvironment (TME) and the latter provides a coarse readout of glucose metabolic activity. Here, we are presented with a unique cohort of patients who underwent DCE-MRI, 18FDG-PET and 64Cu-DOTA-Traztuzumab offering potential to perform a pilot analysis. First, we characterize the performance of our perfusion model SimBioSys- Microvasculature (SBS-MV) through a stability analysis, as well as comparison with two PET modalities. Finally, we use this model in 3D simulations of individual HER2+ breast cancer patients to forecast responses to neoadjuvant chemotherapy (NAT). Methods: SBS-MV is a modified Tofts model for pharmacokinetic modeling of DCE-MRI data, utilizing a tissue segmentation model developed in-house to inform parameter fits and ensure that the derived parameters fall within acceptable values on a tissue-by-tissue level, in addition its function for standard fitting of DCE time-course data. We first evaluated the stability of the SBS-MV model by analyzing a separate cohort of 10 patients who underwent ultrafast DCE-MRI. Temporal undersampling was performed on the original high temporal resolution data to mimic low temporal resolution from standard-of-care (SoC) DCE studies. Both datasets were processed with SBS-MV model. Next, we analyzed data from a cohort of 18 patients, each of whom underwent a pre-NAT SoC DCE-MRI study, a mid-treatment FDG PET/CT study, and a mid-treatment 64Cu-DOTA-Trastuzumab/CT study during treatment. Tissue segmentation and SBS-MV fits were performed on the pre-NAT DCE MRI. Tightly cropped boxes encompassing the tumor in the 3D SBS-MV volumes as well as the PET volumes were created. Using these identified regions, all summary statistics were calculated and cross-correlated between imaging modalities. Results: SBS-MV was stable to SoC-mimicking temporally undersampled ultrafast DCE MRI series, demonstrating relatively little variability in the output parameters (a voxel wise median deviation of approximately 0.005 min-1 ). Further, we demonstrate that SBS-MV parameters (Ktrans, ve) are correlated with FDG SUVSA and 64Cu SUVSA. In addition, the glucose concentrations used in the biophysical simulations were correlated with FDG SUVSA, indicating that downstream applications of the SBS-MV models still carry this information about perfusion. Finally, using SBS-MV, our biophysical simulations of HER2-targeted therapy accurately predict patient response. In this small cohort, our biophysical simulation platform performed well, yielding predictive accuracy of 0.83, with sensitivity and specificity of 0.83 and 0.83, respectively. These performance metrics are in line with previously published reports. Conclusion: Our MV model is capable of extracting biologically meaningful perfusion parameters from standard clinical DCE MRI time series, providing the same benefits of a comprehensive kinetic analysis, without impacting current clinical workflow. This approach could be used in both the research and clinical settings, offering actionable information on what drives individual patient therapeutic response for a more personalized care. Citation Format: John Whitman, Vikram Adhikarla, Russell Rockne, Lusine Tumyan, Joanne Mortimer, Wei Huang, Joseph Peterson, Dorys Lopez-Ramos, John Cole. Biophysical simulation using DCE-MRI to forecast response to NAT in HER2+ patients, with glucose characterization and orthogonal validation using FDG-PET [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-01-01.

A new method to analysis synthetic acetic acid to vinegar: Hydrogen isotope ratio at the methyl site of acetic acid in vinegar by GC-IRMS

Acetic acid is the key organic substance used to verify the authenticity of vinegar. A new method for precisely determining acetic acid δDCH3 in vinegar via gas chromatography −pyrolytic-stable isotope ratio mass spectrometry (GC-P-IRMS) was established. The δDCH3 values were obtained via calibration with a series of standards. The optimised method demonstrated a repeatability standard deviation within 3 ‰. The standard deviation of accuracy of the new method compared with that of the SNIF-NMR method was within 2.6 ‰. The synthetic acetic acid δDCH3 values was −136.7 ‰ ± 29.6 ‰, and the δDCH3 value of acetic acid in vinegar was −414.9 ‰ ± 40.5 ‰, with significant isotopic distribution characteristics. This methodology serves as a supplementary method for measuring the δDCH3 value of acetic acid in vinegar. It has advantages over other methods in terms of time, sensitivity and operability. And provides a new idea for solving the problem of analyzing substances in the presence of exchangeable groups.

Innovatory Kharkiv Mass Housing Estates in Urban Planning of the 1960s-1980s

The destructions of the Russo-Ukrainian war are leading to a rapid loss of cultural heritage in Ukraine, including contemporary 20th century monuments in Kharkiv, the cradle of Ukrainian modernism. At the greatest risk are the sites, which were complex and not well understood heritage before the war - mass housing estates of 1960s-1980s. In view of the postwar reconstruction, there is a great need to analyze mass housing estates in Kharkiv as potential objects of preservation. The purpose of this article is to reveal the architectural and historical value of the first Kharkiv mass housing estates in terms of their innovation, which might be the basis for further preservation steps. The article focuses on the three earliest areas of mass housing estates of the city - Pavlovo Pole, Novi Budynky and Saltovsky mass housing, which were designed and built during the period of the transition to rapid and large-scale pre-fabricated industry in the late 1950s - early 1960s. It is namely during the design and construction of these estates that innovatory technologies and approaches were developed and tested, which were later used in the construction of new housing estates both in Kharkiv and in other cities of Ukraine. These innovations included the system of microdistricts, the staggered system of services for the population, and the method of focusing in urban planning. The creation of a number of standard series of pioneering residential buildings for mass industrial development by the “Kharkovproject” and “Ukrmistostroyproject” design institutes. The study is based on the reconstruction of the historical chronology of design work of 1960’s - 1980’s in the history of Ukrainian city planning; a comparative analysis of the first-erected housing estates, and the definition of the unique solutions of Kharkiv city planners that were implemented in the development of the first housing estates in Kharkiv.

Invoice level forecasting with discrete survival methods for effective forecasting of account receivables in supply chain

The objective of this study is to obtain accurate and timely Account Receivables forecasts that can feed into the Cash Flow Forecasting (CFF) for a generic wholesales scenario in a supply chain company. The main components of the CFF are the Account Receivables (AR), Account Payables (AP) and Working Capital (WC). The focus of this work is on AR, in particular on how they contribute to the overall cash flow forecasting. The prediction of AR is based on the predicted payment date of each invoice, which can be obtained from the time to payment given the issue date. In this context, we propose the use of discrete survival methods for predicting the time to payment of issued invoices. To obtain more accurate predictions for time to payment, we fit a generalized linear mixed effects model with a time-varying baseline hazard function. This approach provides greater precision for subsequent account receivables predictions compared to the prediction based on simply the payment terms of each invoice, standard time series and classification models, and continuous-time survival methods. We demonstrate the approach on two financial data sets.

The current standard of the shoulder trauma series in Ireland – A national audit

Objectives/aimsThe primary aim of this study was to assess the current standard of shoulder radiographs in Ireland. The secondary aim of this study was to determine whether orthopaedic surgeons in Ireland are of the opinion that a national protocol is required, and what this protocol should consist of. MethodsA national audit of shoulder trauma series x-rays performed in emergency departments was conducted. The number and type of views performed was recorded. The anteroposterior (AP) and axillary or Velpeau views were assessed to determine if they met pre-defined audit criteria. Consultant orthopaedic surgeons working in public trauma hospitals were invited to participate in an online survey by email. ResultsThe number of shoulder trauma series included in this audit was 789. The majority of patients had two views performed (75.92%, n ​= ​599) and 21.17% (n ​= ​167) had an axillary or Velpeau view. The AP view met the audit criteria in 23.09% (n ​= ​181) of cases. The survey response rate was 70.8% (n ​= ​17). 88.2% (n ​= ​15) of surgeons agreed that three views should be performed for a shoulder trauma series and 94.12% (n ​= ​16) agreed that an axillary or Velpeau view should be included. The majority of surgeons surveyed (94%, n ​= ​16) are in favour of establishing a national protocol. ConclusionThe current standard shoulder trauma series in Irish hospitals consists of two views, most frequently a thoracic AP and a scapular Y view. We propose the introduction of a national protocol consisting of three views: Grashey AP, Scapular Y, and an axillary or Velpeau view.

The Windshield Wiper Sign, An Instability-Related Osteochondral Defect of the Anterolateral Femoral Head

PurposeTo investigate a radiographic sign believed to be indicative of hip instability and acetabular suction seal disruption in the native hip, coined the “windshield wiper” (WSW) sign. Materials and MethodsA retrospective review was performed for patients who underwent periacetabular osteotomy (PAO) with the senior author between March 2021 and September 2023. A WSW sign was identified on plain films as a concave or flat osteochondral defect on the anterolateral femoral head extending medial to the head-neck junction with resultant loss of femoral head sphericity in the native hip. Every patient underwent a standardized series of radiographs, as well as computed tomography and magnetic resonance imaging. All patients underwent arthroscopy prior to PAO to address intra-articular pathology and other indicated procedures. The osteochondral defect and resultant suction seal disruption were verified during arthroscopy. These patients were then compared with a control group of arthroscopically treated hips without hip instability. ResultsOf 250 patients reviewed, a total of 19 hips in 17 patients (prevalence of 7.6%) demonstrated radiographic evidence of the WSW sign. All patients with a WSW sign presented with symptomatic clinical hip instability requiring a PAO. The mean patient age was 31.2 years, with a mean lateral center edge angle (LCEA) of 14.3 degrees. There were 13 hips (68.4%) with dysplasia, 4 (21.1%) with borderline dysplasia, and 2 (10.5%) with a normal LCEA. All patients with a WSW sign and LCEA ≥20° displayed significant femoral antetorsion abnormalities. All arthroscopic videos and images demonstrated a compromised suction seal. Of the 50 control group hips reviewed, the WSW sign was not identified. ConclusionsThe WSW sign is an uncommon radiographic finding in patients with hip instability. When identified, it can be predictive of substantial instability, especially in cases which are otherwise considered borderline dysplasia or normal based on LCEA. Level of EvidenceIII, case-control study

A study on the hydroacoustic characterisation of a cavitating propeller by dynamic adaptive mesh refinement technique

Underwater radiated noise (URN) of a marine propeller has received significant interest in recent decades due to its implications on marine fauna. Therefore, an accurate prediction of URN at an early stage of the propeller design is becoming imperative. This study presents a numerical investigation into the noise prediction of a marine propeller, including cavitation and a comparison with experimental test results obtained from the URN database from the King's College D (KCD) standard propeller series. Amongst the propellers tested in the series, the member KCD-193 was chosen to scrutinise in this study due to the significant variance of the cavitation types experienced by this propeller member and consequent characteristic variations observed in its URN spectral response. Numerical URN predictions of different flow conditions, represented by the advance coefficient and cavitation number, were conducted to investigate their effects on the noise spectrum. These predictions were compared with the experimental results to enable interpretation of the impact of various aspects of the simulation on URN prediction accuracy. In this investigation, one of the most prominent noise sources, tip-vortex cavitation (TVC), was identified as a critical aspect that needs to be captured by the numerical simulations for accurate URN predictions using CFD simulations. The influence of TVC on the spectrum was observed to be significant. The inception and stable presence of TVC dominated the frequency response of the broadband hump. In order to address this, a systematic adaptive mesh refinement strategy was implemented based on the vortex criterion to solve the flow characteristics in the propeller slipstream accurately. To further complement this task, a correlation between the cavitation bubble growth and collapse phenomenon by the sensitivity of the broadband hump on the spectrum was established based on the experimental results. The central frequency of the broadband hump was observed to vary with the advance coefficient and cavitation number. The reduction in the cavitation number resulted in a shift of this hump towards lower frequencies. The URN level of the hump decreased slightly in the high frequency by the reduction in the advance coefficient and the developing cavitation, demonstrating the cushioning effect on the spectrum. An accurate assessment of the noise spectrum, as far as numerical predictions are concerned, particularly on the broadband hump frequency bandwidth, was directly associated with the resolution of the TVC.

ENERGY MANAGEMENT: NEW PRIORITIES OF THE 21ST CENTURY

The development of management methodology and the concept of energy management in modern conditions of transforming the energy sector by the requirements of the carbon-free economy are considered. New qualitative features and new areas of application of energy management and energy management systems (EMS) in the implementation of the energy transition and implementation of the Smart Grid concept have been revealed. It has been established that modern energy management is a proactive, organized, and systematic coordination of the purchase, transformation, distribution, and use of energy to meet requirements, taking into account environmental and economic goals. In contrast to the formation of the EMS according to the ISO 50000 series of standards, today the construction of the EMS is becoming more relevant, which provides systemic (complex) optimization of the parameters, structure, and modes of various technical objects according to a set of technical, economic and environmental criteria. It is shown that EMS is much more than a simple technical solution for monitoring the parameters and state of energy systems. With comprehensive forecasts of energy demand and supply, this system takes energy management to a completely new level, allowing operators of facilities (enterprises, buildings, and smart networks and systems) to determine the strategic direction of energy management, implement it, and achieve both energy efficiency and energy availability and environmental (social) acceptability. The components of EMS for Smart Grid are characterized, in particular: monitoring (actual energy production, actual energy demand, state of charge of energy storage, price uncertainty); forecast (energy production, energy demand, mobile data storage, uncertainty); power quality management (loss minimization, power quality indicators, and reliability/comfort); planning/dispatch/cost (operating costs, reduction of GHG emissions, profit maximization). It is proposed that a promising direction is to consider the SEM as a system of information and communication technologies, which at the system level is combined with power energy processes used by operators of electric power systems and networks to monitor, control, and optimize the productivity of production, transmission, and consumption of energy resources in systems of various hierarchical levels. level (as UES of Ukraine, regional and local systems, on specific energy facilities or individual energy technologies, etc.). Based on the analysis of prospective areas of application of EMS at energy sector facilities, modern areas of scientific and technical research in the construction of energy management systems for energy, electric power, and electrotechnical systems, which are practical to carry out in Ukraine, have been determined.

Contaminant Trends in Urban Groundwater: Case Study from Ljubljana (Central Slovenia)

Urban areas can significantly alter the quality status of aquifers if appropriate strategies to prevent and detect groundwater contamination are not implemented in time. The prevention of groundwater contamination should be a priority due to its potential long-term impact on the environment and the high cost of remediation. For effective and sustainable groundwater management, it is crucial to proactively monitor a wide range of compounds to prevent their spread, progression and increasing concentrations. This study is one of the few to analyse the trends of various urban groundwater contaminants (nitrate, sulphate, hexavalent chromium, pesticides, PCE and TCE) from a groundwater management perspective. Characteristic trends are assessed using linear regression and the Mann–Kendall method, while significant changes in trends are determined using the Darken and Pettitt tests. The time span of the analysed trends covers the transition period before and after the implementation of the Water Framework Directive (2000/60/EC) and the Groundwater Directive (2000/60/EC). This study confirms the effectiveness of enforcement measures to protect groundwater quality, as evidenced by several statistically significant decreasing trends. On the other hand, this study emphasises the importance of intervention-targeted sampling campaigns and the reporting of raw analytical values according to the ISO 11843 series of standards. This approach is essential to detect upward trends in emerging contaminants at an early stage and prevent them from reaching levels that could negatively impact the economy or even jeopardise the safety of drinking water supplies.

Comparison of patch test positivity after 24 and 48 hours of occlusion time in patients of allergic contact dermatitis: A prospective study.

Patch test is the gold standard for diagnosing allergic contact dermatitis. Conventionally, the patches are applied for 48 h, which in tropical weather conditions causes excessive sweating, leading to irritation, and sometimes the patches come off, making the test inconclusive. To compare the patch test positivity after 24 and 48 h of occlusion time in patients of allergic contact dermatitis, using standard allergen concentration. Clinically suspected patients of allergic contact dermatitis were enrolled and patch tested using the Indian Standard Series, parthenium acetone extracts (1:50, 1:100 and 1:200 dilutions) and patient material. Patches were applied in duplicate on either side of the back, using a random number table. One set of patches was removed after 24-h of occlusion, while the other set after 48-h. Readings were performed at 48- and 96-h by two independent dermatologists, blinded to the duration of occlusion. The study had 97 adult patients (58 males and 39 females; mean age: 48.12 ± 13.07 years). A total of 133 and 142 positive reactions were observed after 48 h occlusion at 48 and 96 h reading, respectively. Of these 117 (87.9%) and 132 (92.9%) patches were positive and concordant and noted at 24 h occlusion time. The Cohen's kappa coefficient were 0.94 for 48 h and 0.97 for 96 h reading, hence showing an almost complete agreement (ⱪ > 0.81) between patches occluded for 24 and 48 h. Though there is no significant difference in patch test positivity among ISS allergens after either occlusion time, 48 h occlusion performs significantly better compared with 24 h, when reactions of all allergens (ISS, patient material and parthenium acetone extract) are analysed together.

Evaluation of the applicability of GARDskin to predict skin sensitizers in extracts from medical device materials.

Biocompatibility testing of medical devices is governed by the ISO 10993 series of standards and includes evaluation of skin sensitization potential of the final product. A majority of all medical devices are tested using in vivo methods, largely due to the lack of in vitro methods validated within the applicability domain of solid materials. The GARDskin method for assessment of chemical skin sensitizers is a validated method included in the OECD Test Guideline 442E, based on evaluation of transcriptional patterns of an endpoint-specific genomic biomarker signature in a dendritic cell-like cell, following test chemical exposure. The current study aimed to evaluate the applicability of GARDskin for the purpose of testing solid materials by incorporation of extraction procedures described in ISO 10993-12:2021, as well as to demonstrate the functionality of the proposed protocols, by testing of custom-made materials spiked with sensitizing agents. It was shown that GARDskin is compatible with both polar and non-polar extraction vehicles frequently used for the purpose of medical device biological testing. Further, exploring three different material types spiked with up to four different sensitizing agents, as well as three unspiked control materials and commercial reference products, it was shown that the method correctly classified all evaluated test materials. Taken together, the data presented suggest that GARDskin may constitute a valid alternative to in vivo experimentation for the purpose of skin sensitization assessment of medical devices.

Impact of DC-DC Converters on the Energy Performance of a Dense Concentrator PV Array under Nonuniform Irradiance and Temperature Profiles

Efficiency losses resulting from electrical mismatching in densely packed photovoltaic arrays present a significant challenge, particularly exacerbated in nonuniformly illuminated receivers and under varying temperatures. Serial configurations are particularly susceptible to radiation nonuniformities, while parallel systems are negatively affected by temperature variations. Various authors have recommended the incorporation of electrical voltage and current sources to mitigate these losses. This study explores different electrical connection configurations utilizing concentrated photovoltaic (CPV) cells and DC-DC electrical current converters. A self-adaptive microfluidic cell matrix cooling system is employed to mitigate thermal dispersion caused by the highly nonuniform illumination profile. The obtained results for each configuration are compared with the total electrical power produced by individual cells, operating under identical radiation and temperature conditions to those of the entire array. The results reveal a noteworthy increase in production across all studied configurations, with the parallel–series arrangement demonstrating the most promising practical utility. This configuration exhibited a remarkable 50.75% increase in power production compared with the standard series connection.

Radionuclides distribution and radiation hazards assessment of black sand separation plant’s minerals: a case study

This study assessed the radioactivity levels and associated risks in the black sand-separated products obtained from the black sand separation plant in Delta, Egypt. A total of sixteen samples were taken from hot spots during and after the separation process. These include water samples and other samples that represent monazite, rutile, zircon, granite, ilmenite, and silica products. The hot spots included the area where the ore was stored. The activity concentrations of 232Th\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{232}Th$$\\end{document}, 226Ra\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{226}Ra$$\\end{document}, and 40K\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{40}K$$\\end{document} were determined in these samples using a p-type HPGe detector. Based on gamma spectrometric analysis, samples of rutile, zircon, and monazite had the highest amounts of radioactivity because they contained the highest NORM’s activity concentrations. In addition, it indicated that the radiological hazard indices of the collected samples were higher than the average world limits for sand texture. These findings suggest that the black sand separation process reveals potential risks to human health and the environment, and therefore, appropriate measures need to be taken to mitigate these risks, especially for the safety of the workers on-site. Reducing the risk associated with those sites should be controlled by implementing the recommendations declared for the series of International Basic Safety Standards of the International Atomic Energy Agency (GSR) Part 3, as affirmed in Document No. 103 of 2007 by the International Commission on Radiological Protection (ICRP) as will be presented in the paper body.

Phase transformation sequence of pre-oxidized roast-leach ferrovanadium residue

The depletion of the primary metal sources has prompted the exploration of alternative avenues for metal recovery. In the case of titanium and iron, the ferrovanadium residue produced through roast-leach processing of titanomagnetite presents a viable option for accessing these metals. Titanomagnetite resources, which contain valuable elements, such as iron, vanadium, and titanium, possess significant valuable potential. Titanomagnetite deposits are normally treated via smelting for vanadium or vanadium and iron recovery; titanium is not commercially recoverable. Titanomagnetites have recently been processed through the roast-leach method for vanadium primary production, and iron and titanium are typically part of the waste stream in this process. This study proposes a novel approach to determine the characteristic mineralogy and to study the phase transformation sequence of the roasted-leached ferrovanadium residue during the pre-oxidation process. Leaching was also done to evaluate the extraction potential of Fe, V and Ti on the pre-oxidized residue in comparison to the raw residue The roasted-leached ferrovanadium residue was sampled using the cone and quartering method and then, dried in an oven at temperatures of between 30 and 40 °C, for an hour after which, the remaining moisture content was determined. The bond milling method was employed to reduce the sample size, while the particle size distribution (PSD) was verified by using the standard laboratory Tyler series. Thereafter, the roasted-leached ferrovanadium residue was characterized with XRD, SEM, ICP-OES, and XRF. The samples were pre-oxidized at temperatures ranging from 300 °C to 1000 °C with an aim of improving the grades of iron, vanadium, and titanium-bearing minerals prior leaching. The results revealed the moisture content to be ∼5.07%. The bond work index of typical slags was estimated to be 10.2 kwh/t, with a determined d80 value of 200 μm. According to the XRF analysis, the predominant compounds present are hematite, Fe2O3 (75.55%), titanium dioxide, TiO₂ (12.79%), silicon dioxide, SiO2 (3.03%), and alumina, Aℓ2O3 (2.62%), along with minor compounds. XRD patterns exhibited the presence of FeTiO3 and VO2 in the as-received samples, while pre-oxidation induced the evolution of new phases such as hematite, rutile, anatase, and pseudobrookite.

The U-shaped impact of export quality on firms' innovation output: Empirical evidence from China.

Ensuring product quality plays a pivotal role in the successful execution of new product development and serves as a cornerstone for fostering innovation within enterprises. In this study, we investigate the impact of export quality at the firm level on innovation outcomes, utilizing data from Chinese publicly listed companies and customs data spanning the period from 2010 to 2015. Our analysis uncovers a notable U-shaped relationship between export quality and innovation output in Chinese manufacturing enterprises, particularly with respect to invention patents and utility model patents. Subsequent exploration of heterogeneity reveals that this U-shaped relationship is consistent for non-state-owned enterprises, firms operating in high-technology sectors, young firms, firms exporting to high-income countries, firms situated in the eastern region, and firms engaged in processing trade. Additionally, we find a positively significant effect of Chinese manufacturing export quality on the innovation output of firms exclusively involved in general trade. This paper's key contribution lies in identifying the U-shaped influence of export quality on firms' innovation output and its applicability. The findings suggest that Chinese manufacturing enterprises need to improve the quality of their export products on a long-term and sustained basis. A series of quality standards for the dynamic development of different industries should be formulated, and actively safeguard the innovation needs of these enterprises, thereby enhancing the value chain position of Chinese manufacturing enterprises.

TCDformer: A transformer framework for non-stationary time series forecasting based on trend and change-point detection

Although time series prediction models based on Transformer architecture have achieved significant advances, concerns have arisen regarding their performance with non-stationary real-world data. Traditional methods often use stabilization techniques to boost predictability, but this often results in the loss of non-stationarity, notably underperforming when tackling major events in practical applications. To address this challenge, this research introduces an innovative method named TCDformer (Trend and Change-point Detection Transformer). TCDformer employs a unique strategy, initially encoding abrupt changes in non-stationary time series using the local linear scaling approximation (LLSA) module. The reconstructed contextual time series is then decomposed into trend and seasonal components. The final prediction results are derived from the additive combination of a multilayer perceptron (MLP) for predicting trend components and wavelet attention mechanisms for seasonal components. Comprehensive experimental results show that on standard time series prediction datasets, TCDformer significantly surpasses existing benchmark models in terms of performance, reducing MSE by 47.36% and MAE by 31.12%. This approach offers an effective framework for managing non-stationary time series, achieving a balance between performance and interpretability, making it especially suitable for addressing non-stationarity challenges in real-world scenarios.

Clinical relevance of doubtful reactions in patch testing: A single-centre retrospective study.

Doubtful reactions in patch testing are infrequently reported in the literature; however, recent reports have suggested they be assessed with the same scrutiny as stronger reactions. Assess the clinical relevance of doubtful reactions in patch testing. Retrospective study of 1514 patients comprehensively patch tested via the NACDG standard series and additional allergens based on history. The clinical relevance of each reaction was graded based on the NACDG scale: definite, probable, possible, past, unknown and irritant. Reactions were considered 'unique' if an additional mild-to-strong reaction to the same chemical at a different concentration was not observed. 68.9% (1043) of patients demonstrated at least 1 doubtful reaction. Of 4453 total doubtful reactions, 92.2% (4106) were unique. Only 3.3% (137) and 12.2% (500) of these were determined to be of definite or probable clinical relevance respectively. 'Fragrance' was the most common allergen family present among the unique definite doubtful reactions (37). However, 24 (64.9%) of these also had a stronger reaction to another fragrance. Cocamidopropyl betaine was the second most frequent allergen demonstrating definite doubtful reactions (27) and unique in 85.2% (23) of cases. Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) was most prevalent (36) but less frequently unique (58.3%, 21). Doubtful reactions may not be as impactful to clinical decision making as theorised in the literature. Few demonstrate definite clinical significance, and many have related stronger reactions that capture them for clinical purposes. Identification of doubtful reactions to cocamidopropyl betaine and MCI/MI may be of greatest significance as they most frequently were not supported by stronger reactions.

Exploring socioeconomic similarity-inequality: a regional perspective

AbstractSocioeconomic variables have been studied in many different contexts. Considering several socioeconomic variables as well as using the standard series clustering technique and the Ward’s algorithm, we rank the countries in the world and evaluate the similarity and inequality between geographic areas. Various relationships between variables are also identified. Additionally, since the Gini coefficient is one of the most frequently used metrics to measure economic inequality, with a global scope, we model this coefficient utilising machine learning techniques. 16 exploratory variables are utilised, which pertain to the health (9), economic (2), social labour protection (4) and gender (1) fields. International repositories that include time series of variables referred to these domains as well as education and labour market fields are used.