Single Process Research Articles

自走式青稞收割打捆一体机的设计与试验

In view of the complex agronomic technology of highland barley production and the lack of special machinery for harvesting and bundling highland barley, the harvesting of highland barley is basically done manually. There is a seriously reduced degree of mechanization of highland barley harvesting. Therefore, this paper designs a self-propelled highland barley harvesting and bundling machine, which realizes a single operation process to complete mechanized complex operations such as harvesting, bundling and laying highland barley. By designing the highland barley harvesting method and cutting platform, the height of the cutting platform can be adjusted stepless, and the highland barley bundle knotter is designed to realize the regulation and control of the baling diameter of the highland barley. According to the design of the rope feeding mechanism, the gathering mechanism and the baling mechanism, the main parameters of the baling device are determined. The stubble cutting height of the machine is 325 mm, the average diameter of the highland barley bundles is 195 mm, the average weight per bundle is 5.08 kg, bale formation rate is 97.8%, the qualification rate of the straw bundle reaches 95.6%, drop resistance rate is 92.6%, operating efficiency is 0.82 ha/h. The harvest baler runs in low speed 1 gear, the machine has high operation efficiency, high bundling rate of highland barley, good paving effect, reduced labor intensity, provides the mechanized efficiency of highland barley harvesting. Fuel consumption per hectare is 8.05 kg.hm-2, and the three shifts are without fault, to sum up, it can meet the requirements of highland barley harvesting and baling. The above research can provide a reference basis for the design of the highland barley harvesting baler.

Double vibratory stress relief treatment of welded pipes as an alternative to heat stress relief treatment: Effects on hardness, Charpy impact energy and CTOD

This work analyzes the effects of intermittent resonant vibration treatment in pipes welded to connectors applied in the field of oil and gas wells. The vibratory stress relief (VSR) process was applied intermittently under two conditions: the first one, called Simple Vibration Treatment (TVS), which consisted of a resonant vibration treatment with the vibrational system at the mean length of the product, a second step, with the product being rotated 90°. The results obtained with this process led us to study a new resonant vibration process with the purpose of intensifying the previous one, taking care that no defects would be introduced into the product. This condition, called Double Vibration Treatment (TVD), consisted of a treatment formed of three steps: the first two steps were performed in the same way and with the same procedure used in the Single Vibration Process (TVS). The third step consisted of carrying out a second resonant vibratory treatment with the vibrator positioned on the longitudinal weld of the pipe, close to the circumferential weld of the pipe with the connector. These VSR treatments were compared with the stress relief heat treatment PWHT (Post Weld Heat Treatment) which is normally used after welding the connectors to the pipe. The resonant vibration treatments (VSR), did not introducing any damage to the product, presented reduced treatment time, and tended to positively affect the evaluated mechanical properties, exceeding or equaling the same tendency presented by the heat treatment. The resonant Doble Vibration Treatment (TVD) showed the best results, affecting the evaluated properties more positively than the TVS, which practically promoted the same trend of results produced by PWHT. The studies were characterized by Vickers hardness tests, Charpy V impact fracture tests and CTOD fracture toughness tests, and the results were analyzed using ANOVA statistical modeling.

Removing Implicit Bias From Cardiothoracic Surgery Resident Recruitment: Changing the Paradigm

IntroductionThe cardiothoracic (CT) surgery workforce continues to suffer from underrepresentation of women and minority physicians. The presence of implicit bias in the recruitment process may impair efforts to enhance the diversity of our training programs. Using a systematic approach, we aimed to investigate and optimize our candidate selection processes to minimize implicit bias. MethodsInternal review of a single center's CT fellowship program selection process was conducted. Areas of potential bias were evaluated. Specifically, we investigated how interview questions were selected, how candidates were assessed during interviews, and how they were compared after interviews. Proactive measures were implemented to remove identified sources of bias. ResultsSeveral areas of potential bias were identified, including variability in types of questions asked and disparities in how candidates were scored. We noted the presence of potentially gendered language, cultural bias, and stereotyping within traits being scored. With the goals of intentionally promoting diversity and inclusion, we selected five traits as likely predictors of success which served as the framework from which standardized interview questions were created. The interview scoresheet was modified to include all attributes felt to be important, while eliminating irrelevant confounders and language that could carry potential advantage to specific groups. ConclusionsBy implementing strategies to identify and remove sources of implicit bias in the interview and recruitment process, our training program improved its process for the recruitment of a diverse cadre of matriculants. We must aim not only to diversify the composition of our trainee classes, but also to ensure equitable support, mentorship, and sponsorship throughout training and career advancement.

Production and Characterization of Particle Board Laminated with Wall-paper and Wood Veneer

In this study, the lamination process on the particle board (PB) surface was carried out during the board production and the possibilities of saving wood raw material, time, labor and cost by producing the board without the need for cooling, sanding and a separate lamination process were investigated. For this purpose, ready-to-use boards were obtained by covering the board surfaces with wallpaper (WP) and beech veneer (BV) with a single hot press process. The boards were obtained by placing wallpaper and beech veneer on the surface of the chipboard draft prepared in a single layer with a thickness of 16 mm and pressing. No fine wood chips were used on the surface. 1mm thickness BV and 300 gr/m2 WP were used to cover the PB surfaces. Urea formaldehyde (UF) was treated the surface of 2 % humid wood chips (CL) according to its dry weight by 10 % and ammonium sulfate (AS) with 4 % according to solid UF. Concentration of UF and AS were 65 % and 30 % before the treated the wood chips. Particle boards were produced at 650 kg/m3, at 190°C for 10 minute, by applying 30 kg/cm2 pressure on PB. Density, water absorption (WA), thickness swelling (TS), modulus of rupture and elasticity (MOR and MOE), internal bond (IB), density profile and formaldehyde emission were determined according to the relevant TSE standards. According to the obtained results, IB strength of the coated PBs were lower than the control PB. But MOR and MOE strength were high then control samples due to BV and WP. Formaldehyde emissions of covered PBs were less than control samples. As a result, it was concluded that it is possible to produce the PB by pressing at the same time with coating materials. However, it is not currently suitable for furniture production due to its low IB strength, but it can be used as construction building material such as prefabricated house wall.

Fabrication and evaluation of a bi-layered gelatin based scaffold with arrayed micro-pits for full-thickness skin construct

There is an unmet need for a reliable and reproducible method for incorporating hair follicle derived stem cells in tissue engineered skin models to reconstitute hair follicles. This study discloses a novel method for introducing hair follicle derived stem cells in microneedle embossed micro-pits of a bilayer skin equivalent fabricated from a gelatin based scaffold. The microneedles are hard and strong enough to penetrate the upper layer of the bilayer gelatin based scaffold that corresponds to the epidermis and permeates down to lower layer that corresponds to dermal layer. This strategic location will mimic the natural niche of hair follicle stem cells for picking up signals from both the epidermis and dermis. Hair follicle stem cells are trapped in to these micro-pits by vacuum assisted cell seeding. The bilayer system consists of two distinct electrospun layers in a single processing step, representing outer epidermal layer and inner dermal layer with hair follicle stem cells in embedded pits, resulting in the formation of a closed representation of a complete skin.

Shared decision making and advance care planning: a systematic literature review and novel decision-making model

Background and AimsShared decision making (SDM) and advance care planning (ACP) are important evidence and ethics based concepts that can be translated in communication tools to aid the treatment decision-making process. Although both have been recommended in the care of patients with risks of complications, they have not yet been described as two components of one single process. In this paper we aim to (1) assess how SDM and ACP is being applied, choosing patients with aortic stenosis with high and moderate treatment complication risks such as bleeding or stroke as an example, and (2) propose a model to best combine the two concepts and integrate them in the care process.MethodsIn order to assess how SDM and ACP is applied in usual care, we have performed a systematic literature review. The included studies have been analysed by means of thematic analysis as well as abductive reasoning to determine which SDM and ACP steps are applied as well as to propose a model of combining the two concepts into one process.ResultsThe search in Medline, Cinahl, Embase, Scopus, Web of science, Psychinfo and Cochrane revealed 15 studies. Eleven describe various steps of SDM while four studies discuss the documentation of goals of care. Based on the review results and existing evidence we propose a model that combines SDM and ACP in one process for a complete patient informed choice.ConclusionTo be able to make informed choices about immediate and future care, patients should be engaged in both SDM and ACP decision-making processes. This allows for an iterative process in which each important decision-maker can share their expertise and concerns regarding the care planning and advance care planning. This would help to better structure and prioritize information while creating a trustful and respectful relationship between the participants. PROSPERO 2019. CRD42019124575

Takagi-Sugeno-Kang Fuzzy System Towards Label-scarce Incomplete Multi-View Data Classification

Fuzzy systems have shown a powerful ability in multi-view learning. However, most existing multi-view fuzzy systems require a large amount of labeled and complete multi-view data, which is a demanding requirement for real-world applications. To address these challenges, a novel transductive semi-supervised incomplete multi-view TSK fuzzy system (SSIMV_TSK) is proposed. First, to deal with the scarcity of labeled data, we introduce transductive learning, in which pseudo labels is assigned for unlabeled data. Then, to handle the incomplete multi-view data simultaneously, we integrate missing view imputation, pseudo label learning, and fuzzy system training as a single process to enable mutual learning. Furthermore, two new mechanisms – bidirectional structural preservation of instances and labels, and the adaptive multiple alignment collaborative learning – are proposed to further improve the robustness. Compared with the existing methods, the highlights of the proposed SSIMV_TSK are the ability to handle label scarcity and incomplete multi-view data simultaneously, the integration of missing view imputation and modeling as one process to make the imputed views more pertinent for classification; and the introduction of two new mechanisms to improve the quality of the learned pseudo labels and the imputed views. Experimental studies show that SSIMV_TSK significantly outperforms the state-of-the-art methods.

Leading Edge Technologies and Perspectives in Industrial Oilseed Extraction.

With the increase in the world's population and per capita wealth, oil producers must not only increase edible oil production but also meet the demand for a higher quality and variety of products. Recently, the focus has shifted from single processing steps to the entire vegetable oil production process, with an emphasis on introducing innovative technologies to improve quality and production efficiency. In this review, conventional methods of oilseed storage, processing and extraction are presented, as well as innovative processing and extraction techniques. Furthermore, the parameters most affecting the products' yields and quality at the industrial level are critically described. The extensive use of hexane for the extraction of most vegetable oils is undoubtedly the main concern of the whole production process in terms of health, safety and environmental issues. Therefore, special attention is paid to environmentally friendly solvents such as ethanol, supercritical CO2, 2-methyloxolane, water enzymatic extraction, etc. The state of the art in the use of green solvents is described and an objective assessment of their potential for more sustainable industrial processes is proposed.

Understanding the mechanism of performance difference when substituting Al for different transition metal ions in Li-rich Mn-based cathode materials

The Al-doped modification strategy by substituting Al for different transition metal ions (TMs, TM = Mn, Ni, Co) has achieved excellent results in improving the cyclic performance of Li-rich Mn-based cathode materials (LRMs). However, the traditional explanation known as “pegging effect” is hard to distinguish how Al works in different TM substitutions. Herein, the electrochemical performances of Li1.2Mn0.52Ni0.13Co0.13Al0.02O2 (LRM-Mn), Li1.2Mn0.54Ni0.11Co0.13Al0.02O2 (LRM-Ni) and Li1.2Mn0.54Ni0.13Co0.11Al0.02O2 (LRM-Co) are studied, and LRM-Mn shows the superior long-term cycling stability, especially at the high temperature of 55 °C. Density functional theory (DFT) reveals that LRM-Mn crystal structure has higher thermodynamic stability than any other sample, which is advantageous for inhibiting the transition of LRMs to low-energy stable phases during cycling (e.g., spinel phase and rock salt phase). Combined with density of states and Bader charge analyses, we think that the increased thermodynamic stability of LRM-Mn results from the reduction of the charge transfer of Mn and Co ions in a single delithiation process, which lowers the reactivity of TMs, alleviates the Li/TM mixing and inhibits the irreversible oxygen release. In addition, the biggest volume change during the delithiation process was observed when Al was substituted for Co, which results in the materials’ premature production of fatigue stresses and intergranular cracking. This work comprehensively explains the modification mechanism of Al-doped in LRMs. It demonstrates practical significance for both the rational design of materials and the electrode electrochemical performance prediction.

Applying the Bayesian Technique in Designing a Single Sampling Plan

The Bayesian sampling plans for production inspection are considered a technique of sampling inspection techniques for determining the characteristics of the sampling plan based on the assumption that the rate of defectives is a random variable that varies from one production batch to the next, resulting in a probability distribution f(p) that could be determined based on experience and the available quality information available. As part of this study, the parameters of a single Bayesian sampling plan (n,c) were derived by using the Beta-Binomial distribution and compared with those of other single sampling plans. Researchers have identified (ALA company for soft drinks), which handles product quality control. 120 production batches were selected, and the size of the batch and the number of defective items were used to determine the proportion of defective items, given that the variable varies randomly from one production batch to the next. Bayesian and decision-making models can be implemented to create a single sampling inspection process that is close to the actual quality level. The researchers discovered that when the decision-making model was used, the sample size was minimal compared to other inspection plans, leading to a low inspection cost.

Investigation of Helix-Pultruded CFRP Rebar Geometry Variants for Carbon-Reinforced Concrete Structures.

Carbon concrete is a new, promising class of materials in the construction industry. This corrosion-resistant reinforcement material leads to a reduction in the concrete cover required for medial shielding. This enables lean construction and the conservation of concrete and energy-intensive cement manufacturing. Bar-type reinforcement is essential for heavily loaded structures. The newly developed helix pultrusion is the first process capable of producing carbon fiber-reinforced polymer (CFRP) reinforcement bars with a topological surface in a single pultrusion process step, with fiber orientation tailored to the specific loads. The manufacturing feasibility and load-bearing capacity were thoroughly tested and compared with other design and process variants. Approaches to increase stiffness and strength while maintaining good concrete anchorage have been presented and fabricated. Tensile testing of the helical rebar variants with a 7.2 mm lead-bearing cross-section was conducted using adapted wedge grips with a 300 mm restraint length. The new helix geometry variants achieved, on average, 40% higher strengths and almost reached the values of the base material. Concrete pull-out tests were carried out to evaluate the bond properties. The helix contour design caused the bar to twist out of the concrete test specimen. Utilizing the Rilem beam test setup, the helical contour bars could also be tested. Compared with the original helix variant, the pull-out forces could be increased from 8.5 kN to up to 22.4 kN, i.e., by a factor of 2.5. It was thus possible to derive a preferred solution that is optimally suited for use in carbon concrete.

Next generation 3D-printed intravaginal ring for prevention of HIV and unintended pregnancy

Globally, there are 20 million adolescent girls and young women living with HIV who have limited access to long-acting, effective, women-controlled preventative methods. Additionally, although there are many contraceptive methods available, globally, half of all pregnancies remain unintended. Here we report the first 3D-printed multipurpose prevention technology (MPT) intravaginal ring (IVR) for HIV prevention and contraception. We utilized continuous liquid interface production (CLIP™) to fabricate MPT IVRs in a biocompatible silicone-based resin. Etonogestrel (ENG), ethinyl estradiol (EE), and islatravir (ISL) were loaded into the silicone poly(urethane) IVR in a controlled single step drug loading process driven by absorption. ENG/EE/ISL IVR promoted sustained release of drugs for 150 days in vitro and 14 days in sheep. There were no adverse MPT IVR-related findings of cervicovaginal toxicity or changes in vaginal biopsies or microbiome community profiles evaluated in sheep. Furthermore, ISL IVR in macaques promoted sustained release for 28 days with ISL-triphosphate levels above the established pharmacokinetic benchmark of 50–100 fmol/106 PBMCs. The ISL IVR was found to be safe and well tolerated in the macaques with no observed mucosal cytokine changes or alterations in peripheral CD4 T-cell populations. Collectively, the proposed MPT IVR has potential to expand preventative choices for young women and girls.

Towards a better understanding of pathways of multiple co-occurring erosion processes on global cropland

Soil erosion is a complex process involving multiple natural and anthropic agents, causing the deterioration of multiple components comprising soil health. Here, we provide an estimate of the spatial patterns of cropland susceptibility to erosion by sheet and rill, gully, wind, tillage, and root crops harvesting and report the co-occurrence of these processes using a multi-model approach. In addition, to give a global overview of potential future changes, we identify the locations where these multiple concurrent soil erosion processes may be expected to intersect with projected dry/wet climate changes by 2070. Of a modelled 1.48 billion hectares (B ha) of global cropland, our results indicate that 0.56 B ha (∼36% of the total area) are highly susceptible (classes 4 and 5) to a single erosion process, 0.27 B ha (∼18% of the total area) to two processes and 0.02 B ha (1.4% of the total area) to three or more processes. An estimated 0.82 B ha of croplands are susceptible to possible increases in water (0.68 B ha) and wind (0.14 B ha) erosion. We contend that the presented set of estimates represents a basis for enhancing our foundational knowledge on the geography of soil erosion at the global scale. The generated insight on multiple erosion processes can be a useful starting point for decision-makers working with ex-post and ex-ante policy evaluation of the UN Sustainable Development Goal 15 (Life on Land) activities. Scientifically, this work provides the hitherto most comprehensive assessment of soil erosion risks at the global scale, based on state-of-the-art models.

A sequential aerated electrocoagulation and peroxicoagulation process for the treatment of municipal stabilized landfill leachate by iron and graphite electrodes

Electrochemical treatment has emerged as a viable technology for the treatment of leachate due to its efficient removal of ammonaical nitrogen and other recalcitrant organics. The main technical issues that prevent its practical deployment are restricted performance of a single electrochemical process and the lengthy tertiary treatment time required to achieve the disposal quality standards. This study demonstrates the performance of electrochemical treatments such as peroxicoagulation (PC) and aerated electrocoagulation (A-EC) separately and also sequentially for the treatment of stabilized leachate. In aerated electro coagulation iron is used as both anode and cathode, whereas in peroxicoagulation, iron is used as anode and graphite as cathode. The area of electrode used for treatments was fixed as 12.5 cm2. The initial concentration of NH4–N, TN, COD, and TOC of the leachate was found to be 480 mg/L, 997 mg/L, 40,200 mg/L, and 9850 mg/L respectively. Removal efficiency of aerated electrocoagulation for NH4–N, TN, COD and TOC were 25.6%, 23.67%, 25.6% and 28.7% respectively, current density of 30 mAcm−2, electrolysis time of 60 min and pH 7.3. Meanwhile for peroxicoagulation, the removal efficiency was found to be 37.2%, 43%, 37.3%, and 45.6% for NH4–N, TN, COD, and TOC respectively, at an current density of 30 mAcm−2, electrolysis time of 120 min and a pH of 3. The sequential aerated electrocoagulation – peroxicoagulation process achieves a maximum removal efficiency of 63%, 68%, 78%, and 75% for NH4–N, total nitrogen, COD, and TOC respectively for a reaction time of 180 min. Removal of NH4–N, total nitrogen, COD and TOC from stabilized landfill leachate with a BOD/COD ratio less than 0.1 was very much effective with the sequential aerated electrocoagulation – peroxicoagulaton treatment. The results also indicate that for the treatment of leachate, a significant synergistic index of 1.22 exists between aerated electrocoagulation and peroxicoagulation.

Analysis of sustainability metrics from a process design and operation perspective

As the human population grows, the strain on resources and the environment grows exponentially. Sustainable practices are therefore necessary to protect the planet as well as preserve the standard of living of those inhabiting it. The quantification of sustainability is vital to monitor and regulate industry practices. Therefore, it is necessary to understand the development of the field of sustainability quantification. Frameworks such as life cycle assessment, impact assessment, and the triple bottom line provide approaches to quantify, understand, and implement sustainability concepts. Many studies have expanded on these frameworks to provide a variety of methods to quantify sustainability in industry, with various strengths and weaknesses. Sustainability metrics to this point have lacked an inclusion of safety, time dependence, and quantification of the interrelations between sustainability pillars. To determine the validity of existing metrics, the consistency of their results must be compared. When utilizing existing sustainability indices, significant variation was found both in the final quantification of sustainability for a single process, and in the determination of a more sustainable process when comparing two processes. These inconsistencies imply the need for additional considerations within the various indices. Therefore, an interrelated, time dependent quadruple bottom line is necessary to provide a thorough assessment of the sustainability of a process.

Allocation of carbon dioxide emissions to the by-products of combined heat and power plants: A methodological guidance

Cogeneration has higher efficiency than separate heat and power generation. Since both are generated in a single process, it is necessary to allocate the emissions to by-products for comparing their environmental performance. Numerous methods exist resulting in very different allocations. There is no consensus regarding the method choice. The main objective of this article is the development and implementation of an evaluation scheme allowing the choice of an appropriate method for specific applications. This scheme consists of nine criteria in the categories “Applicability”, “Environmental relevance”, and “Systematic approach” allowing a rating. The Finnish method performs best for a standard use case resulting in emission factors of 322 g CO2 / kWhel and 192 g CO2 / kWhth. Both are associated with less emissions per unit then the electricity and district heating mix of Germany in 2020 that were 375 g CO2 / kWhel and 270 g CO2 / kWhth. Therefore, cogeneration electricity and heat could contribute to climate protection in the short- to mid-term. The implementation of two sensitivity analyses shows that the location and country-specific emission factors can have a great influence on the results and the contribution to climate protection. Depending on use case and individual importance of certain criteria the Energy, the Exergy or the Greenhouse Gas method can be preferable. Each scored with one point less than the Finnish method. In contrast to existing publications, this study supports decision-makers in transparently selecting an appropriate allocation method when assessing the products of cogeneration by considering different criteria.

Investigating wettability and corrosion resistance of the titanium alloy surface engineered by the WEDM process

Ti-6Al-4V or the grade 5 titanium alloy, is widely used as a biomedical implant material because of its high specific strength and corrosion resistance. The formation of oxide layer over the Ti-6Al-4V alloy produced by electrical discharge machining (EDM) process was reported to act as a corrosion barrier and promote biocompatibility. In this study, surface engineering was conducted by machining micro-channels and micro-pillars over Ti-6Al-4V surface using wire-EDM (WEDM) process to investigate surface topography, corrosion resistance and wettability for improved biocompatibility. Four different samples were produced using varied micro features and varied surface topography generated by WEDM. Two of the samples were prepared by multi-pass surface finishing before fabricating micro-patterns on the surface, whereas the other two samples containing micro-patterns were first machined by single pass WEDM process. The corrosion testing was carried out on fabricated samples in simulated body fluid. Surface wettability of the engineered Ti-6Al-4V samples were carried out by measuring water contact angles of the surfaces. Surfaces with micro-channels and micro-pillars with multi-pass surface finishing provided better results in terms of corrosion resistance compared to the samples prepared by conventional WEDM process. The machined surface with micro-channels that underwent multi-pass finishing exhibited the highest corrosion resistance as well as the highest water contact angle among the four samples.

Automated classification of disease response in radiology reports using natural language processing.

108 Background: Classification of disease response is an essential task in cancer research and needs to be done at scale. Automating this process can improve efficiency in the generation of real-world evidence, potentially leading to better patient outcomes. We aim to develop and evaluate Natural Language Processing (NLP) models for this task. Methods: Using 6203 computed tomography (CT) and 1358 magnetic resonance imaging (MRI) reports from 587 patients with lung cancer of all stages seen at the National Cancer Centre Singapore (NCCS), we trained four NLP models (BioBERT, RadBERT-RoBERTA, BioClinicalBERT, GatorTron) to classify the reports into one of four categories: no evidence of disease, stable disease, partial response or disease progression. Model output was compared against human-curated ground truth and performance was evaluated by accuracy. Results: Of the 4 models, GatorTron performed the best (accuracy = 97.1%), followed by RadBERT-RoBERTA (accuracy = 96.2%), BioBERT (accuracy = 94.2%), with BioClinicalBERT being last (accuracy = 90.4%). NLP Model runtimes for the dataset were relatively short, with BioBERT and BioClinicalBERT taking 3 minutes per epoch, RadBERT-RoBERTA taking 6 minutes per epoch, and GatorTron taking 10 minutes per epoch on a single central processing unit (CPU). Conclusions: We have demonstrated the effectiveness of NLP models for classifying disease responses in radiology reports of lung cancer patients. This has the potential to help derive progression-free survival for real-world evidence generation.

MOF-derived Fe based catalysts for efficiently Advanced Oxidation Processes: From single atoms to diatomic and nanoparticles

Sub-nanometer catalysts have drawn great attention based on their superior catalytic activity and extensive application in advanced oxidation processes (AOPs). Nonetheless, the precise regulation of the coordination environment and exploration of the peroxymonosulfate (PMS) activation mechanism remain the focus of research. Herein, we report the preparation of Fe catalysts with diverse sizes, including single atoms (SAs), double atoms (DAs), and nanoparticles (NPs) via adjusting the precursor. Sub-nanometric Fe catalysts exhibit a higher catalytic activity for Bisphenol A (BPA) degradation. It is confirmed that the catalytic activity of the Fe diatomic catalysts (Fe2–N/C) is 2.5 times that of the Fe single-atom catalysts (Fe1–N/C) and 8.3 times that of the Fe-nanoparticle-loaded catalysts (FeNP–N/C). Broad pH adaptation ranges and reusability have also been proved. Based on experimental verification and density functional theory, non-free radical pathways dominate the degradation process of BPA, while free radical pathways are in an auxiliary position, accompanied by electron transfer process. It is found that the synergistic effect of Fe2–N6 sites and pyridinic N adsorption centers contribute to the ultra-high catalytic activity of Fe2–N/C. This work opens up an efficient way for single atom catalysts-based advanced oxidation processes for the efficient removal of refractory organic pollutants.

Single fathers' experiences of using egg donation and surrogacy to start a family.

What are the experiences of single men using egg donation and surrogacy as a route to parenthood? The fathers mainly had a positive relationship with the surrogate and simultaneously exercised agency, and experienced challenges, during the process of surrogacy. Little is known about single men's experiences of egg donation and surrogacy arrangements. Studies have focused on single men's decision-making processes about the use of surrogacy and family functioning once these families are formed. Questions remain about how fathers experience and navigate the process of surrogacy as a single man. The study is an international, in-depth qualitative study of fathers who chose to begin a family and parent alone. Data were collected between 2018 and 2021 as part of a larger study of solo fathers with different routes to parenthood. The present study reports on 21 fathers who used surrogacy and egg donation to begin their family. The average age of the fathers was 44 years, the fathers had young children aged 6 years or younger, and lived in countries across Australia, Europe, and North America. Purposive sampling was used to recruit participants. In-depth semi-structured interviews were conducted. Interview topics included fathers' experiences of the process of using egg donation and surrogacy, and navigating the relationship with the surrogate. The audio-recorded interviews lasted around 2 hours and were subsequently transcribed verbatim. Data were analysed using reflexive thematic analysis and qualitative content analysis. Most of the fathers chose an identifiable egg donor. Regarding the relationship with the surrogate, many fathers had remained in contact with her, but to differing degrees, and they generally reported positive relationships. Thematic analysis led to the identification of three themes relating to the fathers' experiences of choosing surrogacy as a single man: the ability to make choices; challenges and constraints; and special relationship. Due to the variation between different countries regarding laws on surrogacy, contextual factors may have impacted on the experiences of single fathers, and the sample size was small. However, the research provides new insights into an area with little academic literature. Given the growing trend of single men having children through surrogacy, the findings suggest that this new path to parenthood can be both rewarding and challenging. Single men may benefit from tailored support and counselling to help them navigate the surrogacy journey. This study was funded by the Wellcome Trust (grant number 208013/Z/17/Z). The authors have no conflicts of interest to declare. n/a.