Identical Material Research Articles

The Clinical Pharmacology Sections in Drug Package Inserts: Do We Need to Reexamine the Basis?

The Clinical Pharmacology Sections in Drug Package Inserts: Do We Need to Reexamine the Basis?

Technology advancements for channel wall nozzle manufacturing in liquid rocket engines

A regeneratively-cooled or dump-cooled nozzle is a critical component for expansion of hot gases to enable high temperature and performance in liquid rocket engines systems. Regeneratively-cooled channel wall nozzles are a design solution used across the propulsion industry as a simplified method to fabricate the nozzle structure with internal coolant passages. The scale and complexity of the channel wall nozzle (CWN) design can be challenging to fabricate which results in extended lead times and higher costs. Some of these challenges include: 1) Unique and high temperature materials, 2) Tight tolerances on large parts during manufacturing and assembly to contain high pressure propellants, 3) Thin-walled features to maintain adequate wall temperatures, and 4) Unique manufacturing process operations and complex tooling. The United States (U.S.) National Aeronautics and Space Administration (NASA) and U.S. specialty manufacturing vendors are maturing modern fabrication techniques to reduce complexity and decrease costs associated with channel wall nozzle manufacturing technology. Additive Manufacturing (AM) is one of the key technology advancements under evaluation for channel wall nozzles. Much of additive manufacturing for propulsion components has focused on laser powder bed fusion (L-PBF), but the scale is not yet feasible for application to large scale nozzles. NASA is evolving directed energy deposition (DED) techniques for nozzles including arc-based deposition, blown powder deposition, and Laser Wire Direct Closeout (LWDC). There are different approaches being considered for fabrication of the nozzle, and each of these DED processes offer unique process steps for rapid fabrication. The arc-based and blown powder deposition techniques are used for the forming of the CWN liner. A variety of materials are being demonstrated including Inconel 625, Haynes 230, JBK-75, and NASA HR-1. The blown powder DED process is also being demonstrated for forming an integral channel nozzle in a single operation in similar materials. The LWDC process is a method for closing out the channels within the liner and forming the structural jacket using a localized laser wire deposition technique. Identical materials mentioned above have been used for this process in addition to bimetallic closeout (C-18150–SS347, and C-18150–Inconel 625). NASA has completed process development, material characterization, and hot-fire testing on a variety of these channel wall nozzle fabrication technique. This publication presents an overview of the various channel wall nozzle manufacturing processes and materials under evaluation including results from the hot-fire testing. Future development and technology focus areas is also discussed relative to channel wall nozzle manufacturing.

Vertical carrier transport in strain-balanced InAs/InAsSb type-II superlattice material

Anisotropic carrier transport properties of unintentionally doped InAs/InAs0.65Sb0.35 type-II strain-balanced superlattice material are evaluated using temperature- and field-dependent magnetotransport measurements performed in the vertical direction on a substrate-removed metal-semiconductor-metal device structure. To best isolate the measured transport to the superlattice, device fabrication entails flip-chip bonding and backside device processing to remove the substrate material and deposit contact metal directly to the bottom of an etched mesa. High-resolution mobility spectrum analysis is used to calculate the conductance contribution and corrected mixed vertical-lateral mobility of the two carrier species present. Combining the latter with lateral mobility results from in-plane magnetotransport measurements on identical superlattice material allows for the calculation of the true vertical majority electron and minority hole mobilities; amplitudes of 4.7 ×103 cm2/V s and 1.60 cm2/V s are determined at 77 K, respectively. The temperature-dependent results show that vertical hole mobility rapidly decreases with decreasing temperature due to trap-induced localization and then hopping transport, whereas vertical electron mobility appears phonon scattering-limited at high temperature, giving way to interface roughness scattering at low temperatures, analogous to the lateral electron mobility but with a lower overall magnitude.

Everolimus-Eluting Biodegradable Abluminal Coating Stent versus Durable Conformal Coating Stent: Termination of the Inflammatory Response Associated with Neointimal Healing in a Porcine Coronary Model.

Objectives We evaluated the effect of the different carrier systems on early vascular response through histological analysis and scanning electron microscopy using a porcine model. Background Although Synergy™ and Promus PREMIER™ share an identical stent material and drug elution (everolimus), they use different drug carrier systems: biodegradable abluminal coating polymer or durable conformal coating polymer, respectively. However, data regarding the impact of the different coating systems on vessel healing are currently limited. Methods Twelve Synergy™ and Promus PREMIER™ were implanted in 12 swine. Histopathological analysis of the stented segments was performed on the 2nd and 14th days after implantation. Morphometric analysis of the inflammation and intimal fibrin content was also performed. Results On the 2nd day, neointimal thickness, percentage of neointimal area, and inflammatory and intimal fibrin content scores were not significantly different between the two groups. On the 14th day, the inflammatory and intimal fibrin content scores were significantly lower in Synergy™ versus those observed in Promus PREMIER™. In Synergy™, smooth muscle cells were found and the neointimal layers were smooth. In contrast, inflammatory cells were observed surrounding the struts of Promus PREMIER™. Conclusions These results demonstrate that termination of reactive inflammation is accelerated after abluminal coating stent versus implantation of conformal coating stent.

Open Problem‐Based Instruction Improves Student Outcome on Short Answer Critical Thinking Physiology Questions

Classroom instruction has historically focused on teacher‐centered, lecture‐based instruction. However, evidence suggests student‐centered and team‐based approaches stimulate greater knowledge retention, student involvement, and investment in the information. Therefore, we hypothesized that students receiving problem‐based instruction would show greater performance on assessments with regards to total points as well as level of understanding compared to traditional lecture style of instruction. To test this, a quasi‐experimental study was conducted in an upper‐level (junior/senior students) animal physiology course. Students were enrolled in different course sections based on scheduling only and students had no prior knowledge of the instruction style of the course. Three sections were presented with lecture‐based instruction (LI, n=66) and two sections were presented with open problem‐based instruction (OPBI, n=40). The same professor designed and taught all sections and identical course materials were provided to students regardless of instructional group. Students were assessed with 3 exams consisting of 50% multiple choice and 50% short answer questions. Exams were scored blindly. We previously reported that students in OPBI‐based instruction performed better on short answer questions than those in the LI group (LI 47.6 ± 1.1 points vs OPBI 52.0 ± 1.8 points; out of 65 points; p<0.05 t‐test). The present study aimed to assess the short answer responses to determine whether OPBI was associated with higher level responses to critical‐thinking short‐answer questions. This was done through qualitative analysis of questions from exam 1, which covers cellular physiology, membrane potentials, and neuronal function. Responses for these questions were blindly analyzed and scored with a rubric for the following factors: accuracy (0–2 points) based on whether what was written was correct; sufficiency (0–4 points) based on the detail and level of thinking presented in the short‐answer response; and use of technical vocabulary (0–2 points) based on inclusion of physiological terminology. OPBI students scored higher in 2 out of 6 SA questions (Q3 LI 8.9 ± 0.4 points vs OPBI 10.3 ± 0.3 points; Q5: LI 10.1 ± 0.5 vs OPBI 11.8 ± 0.2; out of 12 points each; p<0.05 t‐test). Accuracy (LI 1.5 ± 0.5 vs OPBI 1.8 ± 0.3 points), sufficiency (LI 2.8 ± 1.0 vs OPBI 3.3 ± 0.8 points), and technical vocabulary usage (LI 1.4 ± 0.5 vs OPBI 1.7 ± 0.4 points) were higher for students in OPBI compared to LI for both questions (p<0.05 t‐test). Students in OPBI exhibit greater perceived understanding and technical vocabulary usage, resulting in more sufficient and accurate in‐depth responses to questions that challenge students to think critically. This strongly suggests that an open‐problem, active‐learning based instructional style not only results in retention of information, but a deeper level of understanding. Future studies include comparing additional responses and exam question wording to investigate why OPBI may have better prepared students for some questions but not all.

Growing Pains: Positive Learning Outcomes but Evaluation Fallouts from Flipping the Embryology Curriculum in an Integrated Medical Gross Anatomy Course

Although embryology lays a strong foundation for understanding gross anatomy, variations, and congenital anomalies, its educational contact hours in the North American medical curricula have become minimal and integrated with other subjects. This poses challenges for students to learn the spatially complex developmental processes, leading many to seek external online resources or resort to rote memorization for the short‐term, neither an ideal solution.To promote effective learning and retention, embryology curriculum was offered in a flipped‐class format in the Fall of 2019 for first‐year medical students. Eleven, 8–16 minute tutorial videos were produced for each hour of embryology lecture in the integrated anatomy course. Before each embryology lecture, students were required to view the tutorial and complete a quiz. The lectures were customized based on pre‐lecture quiz outcomes and in‐class poll to review the difficult concepts, to solve clinical cases, and to complete additional assessments. Before each test in the course, students completed 2 additional hours of active learning sessions, which provided a variety of resources, including more clinical cases, assessment‐based learning, and various visual and physical embryo models. In an IRB‐exempt (#19‐1716), retrospective study, students’ embryology exam performances from the flipped class curriculum were compared with the previous year’s data (2018). The 2018 cohort received nearly identical educational materials, including the learning objectives, active learning sessions, and assessments, but lectures were provided in didactic presentations. The embryology instructor was the same individual in 2018 and 2019.Embryology exam data were analyzed using Item Response Theory, controlled for item difficulty differences. The results reveal that the 2019, flipped‐class cohort (n=184) had higher embryology exam performances in all 4 exams than the 2018, didactic cohort (n=184). T‐Tests revealed that the 2019 cohort performed significantly higher than the 2018 counterparts on embryology in the 2nd exam (p<0.01) and the comprehensive final (p<0.05). Interestingly, in student evaluations, the same embryology instructor was rated significantly lower on educational effectiveness by the 2019 cohort compared to the 2018 cohort. Thematic analysis of the evaluation comments revealed that though 2019 students found the instructor likable and appreciated the resources, efforts, and enthusiasm, the overwhelming majority disliked the flipped classroom model, citing that it did not help them learn, caused more confusion, and lectures felt disorganized.The learning outcomes of this study are consistent with the literature indicating the effectiveness of the flipped classroom in student learning and engagement; however, the negative outcomes of the educator evaluation is alarming and points to the importance of student education about evidence‐based pedagogical practices and student buy‐in.

Pensar dentro da caixa: avaliação da eficácia de embalagens em polipropileno para acondicionamento de bens culturais

In 2013 new improvements took place at the storage areas of the national palaces of Pena, Queluz and Sintra administrated by Parques de Sintra?Monte da Lua. The initial goal was to achieve a better use of the little space available by building custom made polypropylene boxes so stacking up could be done safely. We tried to develop a system that was simple and easily repeatable so that identical materials, methods and organization principles could be followed in storage areas in spite of the different characteristics of existing objects. This paper aims to share practical aspects that were developed while searching for an optimal solution to adequately cushion and box museum objects. The ongoing assessment, carried out according to the agents of deterioration, triggered significant changes to the initial methodology. Results of the evaluation of the use of boxes to block or mitigate some agents of deterioration and their contribution to preventive conservation are presented. How these improvements also reflected in collection management and lead to a better use of the collections is also discussed.

Analysis of the Maximum Heat Release Rate in Accordance with the Test Method of the Flame Retardant Performance for Pipe Insulation

In this study, the heat release rate of pipe insulation is analyzed by considering the installation status in accordance with the standards ISO 20632 and NFPA 274. The flame retardation rate was evaluated for six types of test samples: polyethylene foam covered with beaten silver (PE(S)), PE foam tapped (PE(N)), elastomeric closed cell thermal insulation (rubber), Japanese PE foam (PE(J)), Japanese polyurethane foam (PU(J)), and Japanese styro form (ST(J)) by EN 13501-1 and fire growth curve. The results show that PU(J), PE(J), and PE(N) were Class E and ultra-fast, NFPA 274 test standards for Class D and Fast, and PE(S) by ISO 20632 were Class C and Slow, and Rubber and ST(J) were Classes and Low. However, the changes in the time-averaged maximum heat release rate for each test standard (ISO 20632 and NFPA 274) to evaluate the flame retardation rate differed among identical materials. This means that the fundamental study is necessary to analyze the more accurate reasons.

Classification of Flavonoid Metabolomes via Data Mining and Quantification of Hydroxyl NMR Signals.

Utilizing the distinct HMBC cross-peak patterns of lower-field range (LFR; 11.80-14.20 ppm) hydroxyl singlets, presented NMR methodology characterizes flavonoid metabolomes both qualitatively and quantitatively. It enables simultaneous classification of the structural types of 5-OH flavonoids and biogenetically related 2'-OH chalcones, as well as quantification of individual metabolites from 1H NMR spectra, even in complex mixtures. Initially, metabolite-specific LFR 1D 1H and 2D HMBC patterns were established via literature mining and experimental data interpretation, demonstrating that LFR HMBC patterns encode the different structural types of 5-OH flavonoids/2'-OH chalcones. Taking advantage of the simplistic multiplicity of the H,H-uncoupled LFR 5-/2'-OH singlets, individual metabolites could subsequently be quantified by peak fitting quantitative 1H NMR (PF-qHNMR). Metabolomic analysis of enriched fractions from three medicinal licorice (Glycyrrhiza) species established proof-of-concept for distinguishing three major structural types and eight subtypes in biomedical applications. The method identified 15 G. uralensis (GU) phenols from the six possible subtypes of 5,7-diOH (iso)flav(an)ones with 6-, 8-, and nonprenyl substitution, including the new 6-prenyl-licoisoflavanone (1) and two previously unknown compounds (4 and 7). Relative (100%) qNMR established quantitative metabolome patterns suitable for species discrimination and plant metabolite studies. Absolute qNMR with combined external and internal (solvent) calibration (ECIC) identified and quantified 158 GU metabolites. HMBC-supported qHNMR analysis of flavonoid metabolomes ("flavonomics") empowers the exploration of structure-abundance-activity relationships of designated bioactivity. Its ability to identify and quantify numerous metabolites simultaneously and without identical reference materials opens new avenues for natural product discovery and botanical quality control and can be adopted to other flavonoid- and chalcone-containing taxa.

Red Chert Quarries in the Munsungun Lake Formation: Moving beyond Norway Bluff

ABSTRACTRed chert attributed to the Munsungun Lake geologic formation located in northern Maine is common in terminal-Pleistocene, fluted-point-period lithic assemblages throughout New England. A visually identical material also appears in some later-period sites in coastal Maine. Until recently no bedrock source for this red chert showing convincing evidence of precontact use was known. Here we present the NKP site complex, a series of quarry-related stone-tool-manufacturing workshop sites associated with outcrops of high-quality red/green chert. These outcrops represent the only known source of this material with evidence of precontact human use within the Munsungun Lake formation. Although unequivocal fluted-point-period artifacts, such as fluted bifaces, are not yet documented at the NKP complex, the recurrent appearance of red Munsungun chert in fluted-point-period lithic assemblages in New England suggests the manufacture of fluted points took place in the vicinity of these outcrops.

Microstructural analysis of the effects of compaction on fatigue properties of asphalt mixtures

ABSTRACT In the current approaches to structural analysis for asphalt pavements, the entire pavement material is usually treated to identical material, which disregards the distinct heterogeneity of asphalt mixture. Asphalt mixture is actually a multi-phase heterogeneous material that is composed of air voids, aggregate and asphalt binder. In this study, asphalt specimens were drilled from a test track and the indirect tensile fatigue test was conducted to study the fatigue properties. Digital Image Processing (DIP) was used to investigate the microstructural changes of the asphalt specimens based on X-ray Computed Tomography (X-ray CT) images. The aggregate orientation and number of aggregate contact points were determined. The distribution of the air-voids content and shape index of air voids before and after the fatigue tests were comprehensively discussed. According to the results, the microscopic analysis can effectively predict the evolutions of the internal structures of asphalt mixtures during fatigue damage. The heterogeneity due to different degrees of compaction significantly affects the fatigue properties of the asphalt mixtures. This study not only provides support for the further research on the relationship between the microstructural characteristics and mechanical damages of asphalt mixture but also provides implications for conducting the structural mechanical analysis of asphalt pavement.

A methodological framework for comparing fractionated and non-fractionated products in life cycle assessments: The case of milk concentrates

Fractionation is increasingly applied in the process industries and aids in diversifying the use of biomaterials. However, comparing the environmental impacts of fractionated and non-fractionated products is challenging, since multi-product processes complicate the definition of functional units, and require by-product handling by means of allocation or system expansion. This paper proposes a generic scope-definition framework for multi-product processes in attributional life cycle assessment (ALCA) and in consequential life cycle assessment (CLCA). Considering the potentials and limitations of ALCA and CLCA, this framework addresses the choice of an appropriate functional unit and by-product handling method. Three distinct categories are defined: product systems with identical products, with identical functionalities, and with exclusively identical input materials. The framework is applied to new, fractionated dairy products – micellar-casein concentrate, whey-protein concentrate, and lactose – and their non-fractionated counterpart skim-milk concentrate. The case demonstrates how appropriate functional units can be identified that capture identical specific functionalities. The results for both ALCA and CLCA show that fractionation is environmentally viable. For fractionated products with non-identical functionalities, the methodological choice is reduced to an ALCA yielding a favorable eco-efficiency perspective for fractionation. The framework presented offers a systematic procedure for how to deal with multi-product processes in life cycle assessment that is useful for a wide range of applications.

Use of a segmented cell for the combinatorial development of platinum group metal-free electrodes for polymer electrolyte fuel cells

The development of novel platinum group metal (PGM)-free catalysts is a challenging task, particularly when coupled with the integration into a cathode catalyst layer (CCL). The optimization of such PGM-free electrode structures is often non-linear and iterative, making it a demanding task due to the high number of parameters that affect performance. To accelerate both materials discovery and electrode development, this work demonstrates the application of a high-resolution segmented cell (SC) with 121 segments of 0.413 cm2 size for combinatorial high-throughput PGM-free catalyst screening and CCL optimization. The approach utilizes three flow-field strips with active areas of 4.45 cm2 each, distributed over 11 segments. Electrodes with identical catalyst material and fabrication method result in reproducible data with typically less than 10% variation between each segment and match in performance with differential single cell data. High throughput testing of combinatorial sample sets, with varied PGM-free electrocatalyst materials or electrode composition, demonstrated the ability to rapidly discern high performing outliers, and establish or confirm trends in electrode optimization. The results indicated significant performance benefits of electrodes with ionomer content of 45 wt% over lower values, and of water rich inks with 82% water content over those with 50%.

Finite element analysis of bone strength in osteogenesis imperfecta.

As a dedicated experimentalist, John Currey praised the high potential of finite element (FE) analysis but also recognized its critical limitations. The application of the FE methodology to bone tissue is reviewed in the light of his enthusiastic and colorful statements. In the past decades, FE analysis contributed substantially to the understanding of structure-function properties in the hierarchical organization of bone and to the simulation of bone adaptation. The systematic experimental validation of FE analysis of bone strength in anatomical locations at risk of fracture led to its application in clinical studies to evaluate efficacy of antiresorptive or anabolic treatment of bone fragility. Beyond the successful analyses of healthy or osteoporotic bone, FE analysis becomes increasingly involved in the investigation of other fragility-related bone diseases. The case of osteogenesis imperfecta (OI) is exposed, the multiscale alterations of the bone tissue and the effect of treatment summarized. A few FE analyses attempting to answer open questions in OI are then reported. An original study is finally presented that explored the structural properties of the Brtl/+ murine model of OI type IV subjected to sclerostin neutralizing antibody treatment using microFE analysis. The use of identical material properties in the four-point bending FE simulations of the femora reproduced not only the experimental values but also the statistical comparisons examining the effect of disease and treatment. Further efforts are needed to build upon the extraordinary legacy of John Currey and clarify the impact of different bone diseases on the hierarchical mechanical properties of bone.

Clinician preferences for complete-arch fixed implant-supported prostheses: A survey of the membership of the Pacific Coast Society for Prosthodontics

Statement of problemCurrent in vivo and in vitro research has difficulty keeping pace with the rapid evolution of materials, protocols, and designs of the complete-arch fixed implant-supported prosthesis. PurposeThe purpose of this survey was to determine the current prevalence of usage of various treatment modalities and materials for complete-arch fixed implant-supported prostheses. Material and methodsFrom November to December of 2018, a survey invitation was sent out to members of the Pacific Coast Society for Prosthodontics (PCSP). The survey was hosted online, and asked a series of 18 questions related to the materials, protocols, and design preferences for complete-arch fixed implant-supported prostheses. The prompt included the suggestion that answers should be based on preferences for ideal treatment of a hypothetical completely edentulous patient seeking fixed, implant-supported prostheses, assuming sufficient native bone and an opposing complete-arch fixed implant-supported prosthesis. ResultsOf 133 invitations sent via email, 45 (34%) surveys were started and 48 (36%) were completed. Pertinent results are summarized in histograms with color coding in each answer group to indicate the total number of arches the person had treated (a proxy for experience). Most respondents were in private practice (73%) and had completed more than 21 arches of fixed implant-supported prostheses (62%). Nearly half (49%) of the respondents preferred 6 implants in the maxilla, while the preferred number in the mandible was highly varied between 4 (33%), 5 (27%), and 6 (29%) implants. Three-fourths (75%) preferred bone-level implant designs, and the plurality was ambivalent on the use of a platform-switched design (48%). Two-thirds (67%) preferred to deliver a complete-arch fixed provisional prosthesis at the time of surgery. Two-thirds (67%) preferred to make the definitive impression by using rigidly splinted, open-tray copings. While most (67%) preferred to fabricate the definitive maxillary and mandibular prostheses with identical occlusal materials, the specifics of material selection between arches varied greatly. In the maxilla, a plurality preferred anatomic contour zirconia with titanium bases (33%). In the mandible, a plurality preferred laboratory-processed resin with denture teeth over a milled metal bar (32%). ConclusionsWhile a wide range of protocols, designs, and materials exist in the use of the complete-arch fixed implant-supported prosthesis, these results provide a snapshot of current clinical preferences in the Western United States.

A Stochastic Single Vehicle Routing Problem with a Predefined Sequence of Customers and Collection of Two Similar Materials

We suppose that a vehicle visits N ordered customers in order to collect from them two similar but not identical materials. The actual quantity and the actual type of material that each customer possesses become known only when the vehicle arrives at the customer’s location. It is assumed that the vehicle has two compartments. We name these compartments, Compartment 1 and Compartment 2. It is assumed that Compartment 1 is suitable for loading Material 1 and Compartment 2 is suitable for loading Material 2. However it is permitted to load items of Material 1 into Compartment 2 and items of Material 2 into Compartment 1. These actions cause extra costs that are due to extra labor. It is permissible for the vehicle to interrupt its route and go to the depot to unload the items of both materials. The costs for travelling from each customer to the next one and the costs for travelling from each customer to the depot are known. The objective is to find the routing strategy that minimizes the total expected cost among all possible strategies for servicing all customers. A dynamic programming algorithm is designed for the determination of the routing strategy that minimizes the total expected cost among all possible strategies. The structure of optimal routing strategy is characterized by a set of critical numbers for each customer.

GITT Analysis of Lithium Insertion Cathodes for Determining the Lithium Diffusion Coefficient at Low Temperature: Challenges and Pitfalls

Understanding the diffusion of lithium ions in electrode materials for lithium ion batteries is of great importance for their knowledge-based optimization and development of novel materials and cell designs. The galvanostatic intermittent titration technique (GITT) is widely applied in battery research to study the diffusion of lithium in anode and cathode materials depending on the degree of lithiation. While transport properties of electrode materials at high and ambient temperatures are largely available, low temperature diffusion and rate coefficients are hardly reported in the literature and vary by orders of magnitude for identical active materials. Herein, we demonstrate and discuss several challenges and pitfalls in the application and evaluation of GITT measurements for determining the effective chemical lithium ion diffusion coefficient in lithium insertion electrodes, which become especially important at low temperature. This includes theoretical considerations and an experimental analysis of the promising cathode material LiNi0.5Co0.2Mn0.3O2 (NCM523) in the wide temperature range of −40 °C to 40 °C. We show how the choice of experimental conditions for the GITT measurements and of the subsequent mathematical evaluation significantly influence the derived diffusion coefficient. The results suggest that the large scattering of reported values of the diffusion coefficient could be caused by the use of different evaluation procedures. Simple calculation methods appear to be less suited the lower the temperature is. It is shown that the complementary use of GITT and EIS supplemented by detailed knowledge of the microstructure of the electrode significantly improves the accuracy of determining the diffusion coefficient.

On-machine angle measurement of a precision V-groove on a ceramic workpiece

The included angle of a V-groove on a large ceramic workpiece with a length of 500 mm is measured on an ultra-precision surface grinding machine. A pair of electronic dial gauges is mounted on the grinding wheel head to detect the ground flank surfaces of the groove. A calibrated artefact with identical material and nominal geometry but a shorter length of 100 mm is aligned side-by-side with the workpiece. The influences of machine scanning motion errors and thermal errors on the angle measurement are compensated through measuring the angular deviations of the V-grooves on the workpiece and on the artefact.

Linking structure to performance of Li1.2Mn0.54Ni0.13Co0.13O2 (Li and Mn rich NMC) cathode materials synthesized by different methods.

Li and Mn-rich Li1+xNiyCozMnwO2 (LMR-NMC, 0 < x < 0.2; w > 0.5) materials remain commercially relevant owing to their high specific capacity. Due to this stoichiometry, their synthesis forms always at least two phases: monoclinic Li2MnO3 and rhombohedral LiNiaCobMncO2 (a = b = c = 1) layered moieties. However, a complete understanding of their complex crystal structure has not yet been fully realized. The monoclinic phase may become electrochemically active only at high potentials (>4.6 V vs. Li). To complicate matters even more, it has been shown that the electrochemical performance of these materials, having formally the same stoichiometry, can vary with the chosen method of material synthesis. Identification of the chemical and/or structural reasons for these variations in performance is crucial to ensure the promotion of these important cathode materials towards a practical use. Yet most methods of analysis cannot distinguish the subtle, localized variations that account for such differences. Here, solid state 6,7Li NMR was found to be successful in identifying several distinctions between compounds with identical chemical formulae. Many distinctions can be made, and even suggested to account for some of the differences in the electrochemical behaviors noted for the differently prepared materials.

Media-Tight Polymer-Polymer Assemblies By Means of Sintered Powder Layer in Assembly Injection Moulding

The demand for media-tight assemblies has increased continuously in recent years. The explanation for this is the increasing automation, which not only is the reason for more electronics and sensors, but also for the application in increasingly exposed areas. Components must be efficiently protected from these new stresses, such as those caused by contact with aggressive and corrosive media. Assembly injection moulding is a process suitable for large series production that can be used to achieve a protective effect by overmoulding. The focus in this article is a novel and innovative approach that exploits local additive structuring to generate increased media-tightness due to a labyrinth sealing effect. Using an IR spot, the surface of the insert made of polyamide 12 (PA12) is melted and a powder layer made of PA12 is applied, thus creating a structure made of identical material. The inserts prepared in this way are overmolded with polypropylene (PP). The properties of this adhesion-incompatible polymer combination were then examined with regard to their bond quality in the pull-out test and their media-tightness by differential pressure method. It was shown that the additive structuring clearly increased both the bond quality and the media-tightness. This showed the functionality of the pre-treatment. In addition to the feasibility, various application variants were investigated in order to be able to define an initial process window. Overall, it was shown that, depending on the powder application, very good local tightness increases can be achieved.