Examples Of Potential Problems Research Articles

A Versatile Strategy for Manufacturing Separator-Free Li-Ion Battery Cells: Combination of Dry Process for Electrodes and Solvent-Based Impregnation of Polymer Electrolytes

A Separator for conventional Lithium-Ion Batteries (LiBs) typically consists of functionalized Polypropylene or Polyethylene to avoid short circuiting and host the liquid electrolyte[1]. The successful removal of the separator would not only facilitate the cell assembly process, but would also reduce the process cost related to z-stacking machines, which corresponds to around 12 % of total process cost[2]. Therefore, a different strategy needs to be applied in this case to prevent short circuits while maintaining sufficient ionic conduction.An often-mentioned strategy to achieve the separator-free architecture is to impregnate and overcoat the electrodes with a polymer electrolyte dissolved in a solvent. However, a meticulous investigation of a compatible combination of binder-polymer electrolyte, conductive salt and solvent is usually necessary to avoid negative impacts of this strategy, with the delamination of the electrodes, the insufficient impregnation of the electrodes or the emergence of high interfacial resistances being only some examples of potential problems which can occur during this process.Here, we present a novel approach to overcome the above-mentioned barriers, by combining different manufacturing techniques. Firstly, in order to avoid the delamination of the electrodes, electrodes with adjustable porosity are prepared by a fully dry process using fibrillated polytetrafluorethylene (PTFE) as a binder. Due to the non-solubility of PTFE in a plethora of different solvents, the choice of solvent is much less limited and a wider range of solvents can be used to tune the viscosity during the impregnation process. Into the porous electrodes, a , dissolved in a solvent, is impregnated via a standard doctor blade-coating method. Furthermore, using dry process electrodes mitigates the impact of inhomogeneous vertical distribution, avoiding self-aggregation in electrodes and forming non-uniform pores[3]. The mentioned flexibility in the choice of solvent type and amount ensures a complete impregnation into the pores of the electrode for different mass loadings and various types of active material. A sufficient thickness of the polymer electrolyte layer during the coating step leads to an overcoating of both electrodes of around 8-10 µm, which is close to the range of commercial separators, enabling practically required high energy densities for battery applications.In our proof-of-concept study, we fabricated and tested LiB cells composed of polymer-impregnated LFP and Graphite electrodes without any separators based on the above mentioned concept. The resulting cells showed promising cyclability and high coulombic efficiencies for more than 100 cycles at intermediate C-rates. The flexibility of the concept is presented by varying the solvent, used during the impregnation step and tailoring the properties of the specialized fluoropolymer electrolyte via addition of ceramic fillers. In addition to the electrochemical performance, an efficient impregnation process of the polymer electrolyte into the porous cathodes, which can be confirmed by SEM, was successfully implemented.In summary, this study provides not only a strategy for the rational design of separator-free architecture, but also creates a novel possibility for solid-state battery applications.[1] Huang, Xiaosong “Separator technologies for lithium-ion batteries”, J Solid State Electrochem 15, 649–662 (2011).[2] Orangi, Stina, et al. “A Techno-Economic Model for Benchmarking the Production Cost of Lithium-Ion Battery Cells”, Batteries, 8, 83, (2022).[3] Kumberg, Jana, et al. "Drying of lithium‐ion battery anodes for use in high‐energy cells: influence of electrode thickness on drying time, adhesion, and crack formation." Energy Technology 7.11 (2019). Figure 1

The combination of the boundary element method and the numerical manifold method for potential problems

In this study, a boundary element method coupled with numerical manifold method is developed for solving potential problems in two dimension. This approach combines an equivalent variational form of a boundary integral equation with the finite cover approximations for generating the trial and test functions of the variational formulation. This method exploits the reduced dimensionality advantages of the BEM, and is especially suited for the problems with an unbounded domain. Since the local cover function can be chosen in the covers arbitrarily, the method provides flexibility to use different cover functions for different covers and increases the solution accuracy without any local mesh refinement, and the p-adaptive analysis can also be performed conveniently. The validity and efficiency of the present method are demonstrated by some numerical examples of potential problems.

A Perspective on the Principles of Integrity in Infectious Disease Research.

The medical literature is prone to overstating results, a condition not thoroughly recognized among policymakers. This article sets forth examples of potential problems with research integrity in the infectious disease literature. We describe articles that may be spun, categories lumped together in hopes of creating a significant effect (and sometimes an insignificant one), changes in metrics, and how trials may fail because of suboptimal interventions. When examined together, the examples show that the problems are widespread and illustrate the difficulty associated with interpreting medical research. The state of the current medical literature makes it of utmost importance that all sections of the manuscript are read, including associated letters to the editors and information on ClinicalTrials.gov before authors' recommendations are accepted.

AN INTERPOLATING LOCAL PETROV–GALERKIN METHOD FOR POTENTIAL PROBLEMS

In this paper, based on the moving Kriging interpolation (MKI), the meshless interpolating local Petrov–Galerkin (ILPG) method is presented to solve two- and three-dimensional potential problems. In the present method, the shape function constructed by the MKI has the property of the Kronecker δ function. Then in the ILPG method the essential boundary conditions can be implemented directly. The discrete equations are obtained using the local symmetric weak form. The Heaviside step function is used as the test function in each sub-domain to avoid some domain integral in the symmetric weak form, which will greatly improve the effectiveness of the present method. The ILPG method in this paper is a truly meshless method, which does not require a mesh either for obtaining shape function or for numerical integration in the local weak form. Several numerical examples of potential problems show that the ILPG method has higher computational efficiency and convergence rate than the MLPG method.

Flood frequency analysis using radar rainfall fields and stochastic storm transposition

Flooding is the product of complex interactions among spatially and temporally varying rainfall, heterogeneous land surface properties, and drainage network structure. Conventional approaches to flood frequency analysis rely on assumptions regarding these interactions across a range of scales. The impacts of these assumptions on flood risk estimates are poorly understood. In this study, we present an alternative flood frequency analysis framework based on stochastic storm transposition (SST). We use SST to synthesize long records of rainfall over the Charlotte, North Carolina, USA metropolitan area by “reshuffling” radar rainfall fields, within a probabilistic framework, from a 10 year (2001–2010) high-resolution (15 min, 1 km2) radar data set. We use these resampled fields to drive a physics-based distributed hydrologic model for a heavily urbanized watershed in Charlotte. The approach makes it possible to estimate discharge return periods for all points along the drainage network without the assumptions regarding rainfall structure and its interactions with watershed features that are required using conventional methods. We develop discharge estimates for return periods from 10 to 1000 years for a range of watershed scales up to 110 km2. SST reveals that flood risk in the larger subwatersheds is dominated by tropical storms, while organized thunderstorm systems dominate flood risk in the smaller subwatersheds. We contrast these analyses with examples of potential problems that can arise from conventional frequency analysis approaches. SST provides an approach for examining the spatial extent of flooding and for incorporating nonstationarities in rainfall or land use into flood risk estimates.

Translating Trial-Based Molecular Monitoring Into Clinical Practice: Importance of International Standards and Practical Considerations for Community Practitioners

The success of tyrosine kinase inhibition of the BCR-ABL fusion gene with imatinib in the treatment of chronic myeloid leukemia (CML) has resulted in the use of molecular detection techniques for routine clinical management. Current clinical guidelines recommend the use of molecular testing of BCR-ABL transcript levels by quantitative real-time transcriptase polymerase chain reaction (qRT-PCR) every 3 to 6 months. However, qRT-PCR methods have not yet been standardized, particularly in the United States, where most patients are initially treated outside of academic practices. The lack of standard methods for molecular monitoring has resulted in the failure to follow National Comprehensive Cancer Network and European LeukemiaNet guideline recommendations and in the misinterpretation of test results. Standardization of molecular monitoring methods and adherence to guideline recommendations are important for optimal patient management. In this article, we provide an update on the current clinical trial results by using the molecular technique to monitor patient response. Current problems and efforts in standardizing the qRT-PCR technique and reporting are reviewed. We provide examples of potential problems of various reference laboratory reports and present recommendations for assessing molecular test results. These recommendations seem particularly important because nilotinib and dasatinib appear to have improved the molecular response in the initial treatment of CML.

Surveys, Opinion Polls, and Focus Groups: Some Thoughts on How to Report Data

Data collected from surveys, opinion polls, and focus groups can be valuable to many groups involved in the development, marketing, promoting, and regulating of biopharma products. To be valuable, however, certain standard processes must be used and reported in a manuscript based on the work. Often data collection and analyses are not adequate, and interpretations of the findings are overextended to groups not surveyed. Examples of potential problems and solutions to problems in reporting results of surveys, polls, and focus groups provide writers with guidelines on how to strengthen their manuscripts.

Social constraints to integrating information systems, knowledge, and firm capabilities following a corporate merger

PurposeThe purpose of this paper is to contribute to a better understanding of how socially‐embedded information systems (IS), knowledge, and firm capabilities can impact the post‐merger integration efforts of a firm. In particular, this research seeks to identify, describe, and analyze how socially‐embedded resources hindered the integration of the procurement function following the merger of two telecommunications firms.Design/methodology/approachThis research was designed as a longitudinal exploratory study of a single case. The design involved multiple interviews, participant observation, and an evaluation of multiple data sources. Data were collected to develop a comprehensive and reliable understanding of events and outcomes related to the systems integration effort. Process models are used to show the development of phenomena over time.FindingsThe findings of the research are twofold. First, in line with previous findings on socially‐embedded resources, the research shows that socially‐embedded resources hindered the ability of a merged firm to integrate some resources. Previous research argued that social constraints can prevent a firm from changing the way it uses resources to establish a competitive advantage, and this research confirms those findings. Second, this research is an important contribution because it identifies two social constraints in particular – cognitive sunk costs and the reluctance to defy social traditions – that contributed to the inability of the merged firm to successfully integrate the procurement function following a merger.Research limitations/implicationsThe findings of this study provide empirical evidence to support the theoretical argument that the socially embedded resources involved in the IS, knowledge, and firm capabilities of each of the firms prior to the merger enabled them to establish a competitive advantage in their respective market environments. Further, the data provide validation for the idea that the social context in which firms compete does, in fact, contribute to the development of competitive advantages. The RBV is also extended by showing that the same social contexts can also prevent firms from integrating important resources following a corporate merger.Originality/valueOne of the main objectives of executive management following a corporate merger is to lead the organization in skillfully integrating key resources of the merged organization. However, most firms cannot successfully engage in post‐merger integration efforts unless they fully understand how resources such as IS, knowledge, and firm capabilities can help or hinder their integration efforts. By highlighting one firm's efforts to integrate resources following a merger, the paper provides concrete examples of potential problems that can arise. Potential problems and hindrances are presented in a strategic checklist for managerial consideration.

A general algorithm for the numerical evaluation of nearly singular boundary integrals in the equivalent non‐singular bies with indirect unknowns

The accurate evaluation of nearly singular boundary integrals is an important issue in boundary element analysis, and the importance of this problem is next to the singular boundary integrals. Although many ways of evaluating nearly singular integrals have been developed in recent years, and obtained varying degree of success, questions still remain. In this paper, a new efficient transformation is proposed, based on a new idea of transformation with variables. The proposed transformation can remove the near singularity efficiently by smoothing out the rapid variations of the integrand of nearly singular integrals, and improve the accuracy of numerical results of nearly singular integrals greatly without increasing the computational effort. Numerical examples of potential problems are given, with results, showing the high efficiency and the stability of the suggested approach, even when the internal point is very close to the boundary.

Planning and design of urban drainage systems in informal settlements in developing countries

Many cities in developing countries are typified by large areas of informal settlements. These often do not adhere to official planning guidelines, building regulations and construction standards and, as they are not officially recognised by local authorities, are rarely provided with adequate infrastructure and services. The provision of improved systems for drainage of wastewater and stormwater runoff is an important component of urban upgrading initiatives. This paper focuses on urban drainage as a component of urban upgrading and discusses issues related to the integration of drainage systems serving informal settlements into citywide stormwater management systems. Experiences from urban upgrading schemes in different parts of the world are used to highlight innovative approaches towards planning and design as well as illustrating examples of potential problems that may be encountered during project implementation and subsequent operation.

Clinical competencies achievement profiles - a way forward for students with disabilities?

The UK Veterinary Medicine Disability Project (DIVERSE) has recently produced a report (‘Time to Take Stock: Disability and Professional Competence’)1 on issues of disability relating to veterinary undergraduate education and practice. Although this is placed in the veterinary context, much of the material is relevant to medicine, dentistry and the allied health professions. Particularly useful are a variety of practical examples of potential problems and how they might be resolved. Despite its focus on UK legislation, it contains a great deal of value for the world community. In the United Kingdom, the General Medical Council (GMC) has statutory obligations with regard to medical education. It has indicated that it will leave it to individual medical schools to determine whether particular candidates should be admitted. The GMC outlines, but does not specify in detail, the outcomes required for graduation, and can withdraw accreditation from a medical programme as a whole. On qualification from a UK medical school, students are registered automatically for practice without further intervention by the GMC. Admission policies for medical schools in the United Kingdom are therefore more significant than in some other countries. The GMC has stated that: for the GMC the issue is not the health or disability status of the medical student but the ability to achieve all the outcomes in Tomorrow's Doctors… when a medical school awards a primary medical qualification it is confirming to us that the graduate has completed in full a curriculum that meets our guidance and the requirements of the Medical Act.2 Here the key phrases are ‘completed in full’ and ‘achieved all the outcomes’. This suggests clearly that there is little leeway for individual medical schools to accommodate disability. Since the entry into UK law of the Disability Discrimination Acts of 1995 and 2005, and the Special Educational Needs and Disability Act 2001, discrimination against the disabled is illegal. There is therefore an unresolved tension between GMC guidance and the law, which is likely to be explored through the courts rather than by professional decision-making at a national level. This situation is not to anyone's advantage. Individual medical schools are exposed to the possibility of expensive legal action and there is a lack of detailed guidance as to what the GMC considers the essential components of a medical course. There is no question that qualified doctors who become disabled remain fit to practise in areas unaffected by their disability; but the GMC's requirement that students achieve all the outcomes in full means that it regards a complete course as an essential part of medical training. Such a view would close the profession to many people with disabilities. It is also believed widely that the presence of students with disabilities would be beneficial to classmates in enriching their experience of disability, and that doctors with disabilities may be particularly valuable in certain areas of practice after graduation.3 These dilemmas might be resolved by ‘limited licensing’, which limits the practice of graduating medical students with disabilities to certain disciplines. However, this would not take adequate account of technological advances which might extend the capabilities of doctors currently regarded as disabled. An alternative way forward might be the concept of a ‘clinical competencies achievement profile’ (assuming that ‘knowledge’ and ‘attitudes’ should be developed equally in all medical graduates). If the GMC defined ‘day 1 essential competencies’, as does the Royal College of Veterinary Surgeons, it would be possible for medical schools to certify which competencies had been achieved by each medical graduate. Normally, students should achieve all the defined competencies. However, a student with a registered disability could be permitted to graduate by recording those competencies she or he has achieved to date. A potential employer would be able to specify the required clinical competencies for each post, and select for interview in a way in accord with current legislation. This would send a strongly inclusive message to the community as a whole. It would allow, for instance, a severely visually impaired student to explore which competencies they could achieve. It might possibly require the Medical Act to be amended, but the GMC should lead this process rather than allowing individual medical schools to be caught between the Scylla of disability legislation and the Charybdis of a requirement to deliver a ‘full’ course.

Path integrals for potential problems with δ-function perturbation

The author presents several examples of potential problems with a δ-function perturbation by means of path integrals. The idea is to sum a perturbation series expansion resulting in an energy-dependent Green function G(E). The energy levels En of the perturbed problem are determined by the equation (one-dimensional case) iG(V)(a, a; En)=/ gamma where G(V) is the Green function of the unperturbed problem, gamma is the strength of the δ potential and a its location in R. In D-dimensional radial problems with a spherically shaped delta function located at r=a this equation changes into iG(V)l(a, a; En)=/aD-1 γ , where l denotes the angular momentum number.

Product liability aspects of bioengineering

The introduction of the Consumer Protection Act 1987 brought the problems of product liability directly into hospital bioengineering and medical physics departments. This law makes great demands upon manufacturers, but also on suppliers and maintainers of medical equipment. Departments which manage medical equipment carry a responsibility for ensuring the requirements of product liability are known by all those whose actions may affect the potential of a piece of equipment to injure or damage a patient. This paper addresses these problems from a bioengineering, rather than a legal, viewpoint. The problems of design, manufacture, modification, maintenance and use are discussed and examples of potential problems are identified. The paper concludes that as long as good standards of quality control and professionalism are applied in bioengineering and medical physics departments then there is little to be feared from this piece of legislation.