Multistep Transformation Research Articles

Dynamic re-equilibration controlled multi-step transformations in (Mn, Fe)2(P, Si) alloys

In (Mn, Fe)2(P, Si) alloys crystallographic first-order phase transformations enable strong coupling of magnetic and entropic properties, potentially leading to high-efficiency energy generation and refrigeration applications. Although hysteresis losses that limit these applications can be reduced through careful control of alloy composition, compositional tuning can also unfavorably influence transformation temperatures and magnetocaloric coupling strength. Hence, exploration of additional processing variables enabling independent control of transformation properties is crucial. In this work, we investigate the role of thermal history as an additional processing variable, exploiting thermally-activated mechanisms to control properties of non-diffusive transformations in (Mn, Fe)2(P, Si) alloys. In so doing, we report an unusual transformation-splitting phenomenon following annealing at intermediate times, where a single well-defined magneto-structural transformation evolves towards a multi-step transformation with individual steps occurring at multiple distinct temperatures. On longer annealing at the same temperatures, single-step transformation behavior is recovered. Through additional magnetic and crystallographic characterization, we show that the thermal history-controlled multi-step behavior results from sluggish thermally-activated diffusion. The two-step transformation corresponds to non-equilibrium bimodal composition distributions in the transforming phase, and these develop through a dynamic re-equilibration process as the alloy passes relatively slowly between different thermal equilibria. Together, these results suggest that thermal history primarily controls the transformation properties of (Mn, Fe)2(P, Si) alloys indirectly through the composition of one or more transforming phases. Additional investigations are needed to develop thermal history processing for decoupling hysteresis control from other transformation properties.

A Dynamical Evolution Approach to High Placement Performance and Low Fault-Tolerant Cost for Bio-Inspired Self-Repairing Hardware

Bio-inspired self-repairing hardware is a reconfigurable system characterized by high fault-tolerant ability. To further increase the placement performance and reduce the fault-tolerant cost, a dynamical evolution approach to multi-objective dynamic placement is developed. A primary challenge for our study is computational complexity. Based on group theory, the computing task was divided on the dimensions of time and space to increase the utilization of online computing resources. By introducing the multi-step placement transformation, a discrete dynamical system model was built and the multi-objective dynamic placement was converted into a stability problem of constrained systems. In order to satisfy the dynamical requirements, an artificial particle system model was built and its evolution laws were verified by dynamic analysis. By simulating the evolution laws, a dynamical evolution algorithm was proposed, which could avoid large-scale iterative calculation used in the conventional optimization search algorithms. Experiments have shown that the dynamical evolution method could offer high placement performance with low fault-tolerant cost. Besides, it also has the advantage of high design flexibility since there is no initial placement constraint.

Defect Detection by Combination of Threshold and Multistep Watershed Techniques

In this work proposes a technique to detect some types of defects based on the radiography method. Inspection tests include two categories, destructive and nondestructive. One of the nondestructive tests is radiographic test that is used to detect internal defect. In addition, the image processing methods are used to improve defect detection in the radiographic images. The watershed technique is one of the segmentation methods that used to analyze images based on needed information. The proposed method in this paper is combination threshold and multistage watershed technique that applies to detect some of welding defects such as lack of fusion, wormholes, incomplete filled groove, and incomplete penetration. Otsu’s threshold leads to an increase in the contrast of the image and then multistep watershed transformation used to detect discontinuities and defect welding.

Magnetohydrodynamics natural convection of nanofluid flow over a vertical circular cone embedded in a porous medium and subjected to thermal radiation

In this paper, magnetohydrodynamics natural convection of nanofluid flow over a vertical circular cone immersed in a porous medium under the influence of thermal radiation is investigated using multi-step differential transformation method. The accuracies of the analytical solutions are established through the verifications of the results of the present study with the results of the numerical solutions and the past studies. The approximate analytical solutions are used to examine the impacts of cone angle, flow medium porosity, magnetic field, nanoparticles volume-fraction and shape on the flow and heat transfer behaviours of the Copper (II) Oxide-water nanofluid. It is hoped that this study will enhance better understanding of flow process for the design of flow and heat transfer equipment.

NiS nanosheets with novel structure anchored on coal-based carbon fibers prepared by electrospinning for flexible supercapacitors

Elm seed-like NiS/coal-based carbon fibers were rationally designed and synthesized via a multistep transformation approach for flexible supercapacitors.

Genomic Analysis of Hodgkin Lymphoma

The genetic analysis of the Hodgkin and Reed/Sternberg (HRS) tumor cells in Hodgkin lymphoma (HL) is very much hampered by the rarity of these cells, typically accounting for only about 1% of cells in the lymphoma tissue. Moreover, only very few cell lines were established from HL, partly with an uncertain origin. Thus, for the identification of somatic mutations in HRS cells, methods had to be established to isolate the rare HRS cells by microdissection from tissue sections or by cell sorting from cell suspensions. Initial studies were focussed on candidate gene approaches, often inspired by results from the prior analysis of HL cell lines. These early studies revealed numerous recurrent mutations in members of the NF-κB and JAK/STAT pathways, causing or at least contributing to the constitutive activation of these signaling pathways.1 The pathobiological relevance of the constitutive activation of NF-κB and JAK/STAT factors was validated by functional studies with HL cell lines. A first whole exome sequencing analysis of flow-sorted HRS cells was published by Reichel and colleagues.2 B2M was found to be inactivated by somatic mutations in 7/10 cases, and caused loss of major histocompatibility complex 1 expression. Although later studies with larger case series identified such mutations in only about 20-30% of cases,3,4 B2M inactivation is nevertheless an important factor for immune evasion of HRS cells and a frequently mutated gene in HL. A second exome sequencing study of HRS cells used microdissected tumor cells and revealed as a major novel finding frequent somatic mutations in the STAT6 gene (ca. 30% of cases).3 The genetic lesions in STAT6 are gain-of-function mutations. Overall nearly 90% of HL cases show genetic alterations in members of the JAK/STAT pathway, further demonstrating the major role of this pathway in HL pathogenesis. Our group is currently performing studies of microdissected HRS cells by whole genome sequencing, aiming to identify further genetic lesions in HRS cells beyond those affecting exons. An alternative attractive approach to uncover mutations in HRS cells is the genetic analysis of circulating DNA in plasma, because HRS cell-derived DNA fragments can be identified in most patients at the time of diagnosis. A targeted sequencing study of circulating tumor DNA showed the feasibility of this approach and validated, for example, the frequent occurrence of STAT6 mutations in HL. In rare instances, a HL can co-occur with another lymphoma in the same patient. Such composite lymphomas frequently show a common clonal origin of both lymphomas from a mature B cell.5 Composite lymphomas are therefore elegant models to study the multi-step transformation process in lymphomagenesis. We are currently performing a whole exome sequencing analysis of composite classical HL and B-cell Non-Hodgkin lymphomas, to reveal the pattern of early shared mutations and later distinct mutations. In each of the cases under investigations, such shared and distinct mutations were indeed identified. Küppers R, Engert A, Hansmann ML. Hodgkin lymphoma. J Clin Invest. 2012; 122: 3439. Reichel J, Chadburn A, Rubinstein PG, et al. Flow sorting and exome sequencing reveal the oncogenome of primary Hodgkin and Reed-Sternberg cells. Blood. 2015; 125: 1061. Tiacci E, Ladewig E, Schiavoni G, et al. Pervasive mutations of JAK-STAT pathway genes in classical Hodgkin lymphoma. Blood. 2018; 131: 2454. Spina V, Bruscaggin A, Cuccaro A, et al. Circulating tumor DNA reveals genetics, clonal evolution, and residual disease in classical Hodgkinlymphoma. Blood. 2018; 131: 2413. Küppers R, Dührsen U, Hansmann ML. Pathogenesis, diagnosis, and treatment of composite lymphomas. Lancet Oncol. 2014; 15: e435. Disclosures No relevant conflicts of interest to declare.

Oncology practice changes during a multistep Oncology Care Model practice transformation project.

88 Background: Treatment of lung cancer has seen a paradigm shift in recent years. While the availability of newer treatment options such as targeted therapy and immunotherapy have provided new hope for better outcomes, this has added to the cost of care. Participation in the Center for Medicare Services’ Oncology Care Model (OCM) provides opportunities for oncology practices to identify practice transformation (PT) change strategies that result in improved quality of care (QOL) and cost savings. Methods: A lung cancer PT team convened to facilitate changes that improve patient outcomes and decrease costs at an OCM organization. The year-long project included clinical treatment updates, quantitative and qualitative assessments, and data sharing. Practice changes focused on biomarker driven treatment selection, nurse navigation to better manage symptoms and decrease emergency department (ED) visits and hospitalizations, and earlier advanced care planning (ACP) discussions. Surveys were completed by oncology physicians and nurse practitioners at baseline (n = 9) and end of the project (n = 7). Results: After education, there were more correct responses in 3 of 6 knowledge questions and providers noted less concern about performance status or co-morbidities when prescribing immunotherapy. Providers noted fewer barriers with biomarker documentation; self-reported confidence in 4 questions of biomarker selection was unchanged. Providers reported increased participation of nurse navigators to impact ED visits and hospitalizations over time. Documentation of ACP discussions increased, 42% (8/19) to 56% (13/23), but did not reach statistical significance due to sample size. Although providers reported changes toward earlier ACP discussions, 1 in 3 still wait until performance status declines to initiate discussion. Conclusions: Systematic PT can improve quality of patients care and measures used in value-based care reimbursement models. Providers need ongoing education, practice feedback, and organizational support to effect positive practice changes. In addition, new strategies to increase provider ability to initiate end of life discussions need to be explored.

Application of Multi-step Differential Transformation Method (Ms-DTM) for Solving Nonlinear Problem of Heat Transfer in Solar Air Collector

Application of Multi-step Differential Transformation Method (Ms-DTM) for Solving Nonlinear Problem of Heat Transfer in Solar Air Collector

Multi-interface superstructure strategy to improve the catalytic activity and cyclic stability in enhancing the photo conversion in solar cells

The development and design of counter electrode (CE) materials using an excellent catalytic activity and cyclic stability have a significant importance for further achieving better photoelectric conversion efficiency (PCE) of dye-sensitised solar cells (DSSCs). Achieving an efficient integration of ternary active components into the CEs and understanding the interaction between the ternary components are desired. Herein, a multistep transformation approach to constructing NiS nanosheets that are fixed on the surface of N-doped hollow thin shell carbon spheres (NHCS), and then encapsulated using reduced graphene oxide (RGO) to form an NHCS/NiS/RGO nanocomposite, is demonstrated. The nanocomposite shows an excellent electrochemical property and further probes the interfacial charge distribution behaviour as a CE for DSSCs. The interfacial charge polarisation with a large surface area of RGO facilitates a charge transfer, and evenly distributed NiS nanosheets on the surfaces of the NHCS gathering electrons lead to a strong interfacial coupling and simultaneously further boost the charge transfer, as well as triiodide oxidation and reduction, with remarkable ternary functional electrode activities. A device with an NHCS/NiS/RGO nanocomposite as a CE produces a better photovoltaic conversion efficiency (PCE) of up to 9.32% more than the Pt as a CE (8.06%). This study not only offers a strategy to achieving a ternary-functional-catalyst material with a superb performance, but also unravels the role of the geometric configuration factor of the hybrid from the view of the interfacial charge distribution, offering an abundant prospective roadmap of electrode materials in energy devices.

PF163 TARGETING LYSOSOMES AS A POTENTIAL THERAPEUTIC APPROACH FOR T‐CELL ACUTE LYMPHOBLASTIC LEUKAEMIA

Background:Tcell acute lymphoblastic leukaemia (T–ALL) is an immature lymphoid tumour characterized by the diffuse infiltration of the bone marrow by malignant lymphoblasts expressing immature T‐cell markers. T–ALL results from a multistep transformation process in which accumulating genetic alterations coordinately disrupt key oncogenic, tumour suppressor and developmental pathways responsible for the normal control of cell growth, proliferation, survival and differentiation during thymocyte development. T‐ALL represents about 15% of paediatric and 25% of adult cases of ALL. The actual treatment for T‐ALL typically consists of a remission‐induction phase, a consolidation phase, and continuation therapy to eliminate residual disease. Recently (Sachlos et al. 2012), dopamine receptor was identified as a possible target for cancer stem cells, validated in acute myeloid leukemia (AML) and breast cancer. We then hypothesized that based on biological similarities between AML and T‐ALL and the existence of leukemic stem cells in both neoplasms, dopamine receptors may constitute a therapeutic target also in T‐ALLAims:The main objective of the study was to validate dopamine receptors as a therapeutic target in T‐ALL.Methods:Dopamine receptor modulators were selected in concordance with the affinity for the dopamine receptor (1‐5). To study the antileukaemic effect of selected drugs, cell viability assays were performed in 3 human T‐ALL cell lines, 1 T‐ALL‐patient‐derived xenograft (PDX), 4 healthy‐donor buffy coats and 5 umbilical cord blood samples. In vivo studies were performed with conditioned adult NOD.Cg‐Prkdc scid Il2rg tm1Wjl /SzJ (NSG) mice xenotransplanted with T‐ALL PDX or cord blood cells treated with dopamine receptor antagonists for 18 h and engraftment levels were determined after 3 or 8 week respectively. The effect on lysosomes and autophagy was determined using the lysotracker and CytoID stainings by flow cytometry and fluorescence microscopy.Results:Among all subtype‐specific dopamine receptor modulators, only antagonists specific for dopamine receptor type 4 (DR4) (L741‐742, Nemonapride, RBI 257) significantly reduced cell viability in T‐ALL cells in the low microMolar range, while no effect on healthy cells was observed. In vivo studies further confirmed the differential antileukaemic effect, as the treatment with L741‐742 significantly reduced leukaemic engraftment, while sparing normal haematopoiesis.T‐ALL cell lines lacked the expression of DR4 on the surface; thus, we searched for an alternative mechanism of action. Our data demonstrated that these drugs produced an expansion of the lysosomal compartment and consequently the failure of the cell recycling system, this induced an overactivation of autophagy and the disruption of cell homestasis, eventually leading to cell death. These 3 antileukaemic DR4 antagonists shared cationic amphiphilic properties, known to induce tropism towards lysosomes, thus providing an explanation for early drug‐induced events, which could ultimately activate the autophagy‐dependent cell death program.Summary/Conclusion:A group of DR4 antagonists selectively eliminates T‐ALL cells, targeting the lysosomal compartment in a dopamine receptor‐independent manner. This organelle disruption leads to the activation of the autophagy‐dependent cell death program. Interestingly, these drugs have little effects in healthy blood cells. Therefore, our results support the further preclinical development of these drugs as potential treatments for T‐ALL.

A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts

The gas-phase oxidehydration (ODH) of 1,2-propanediol to propionic acid has been studied as an intermediate step in the multi-step transformation of bio-sourced glycerol into methylmethacrylate. The reaction involves the dehydration of 1,2-propanediol into propionaldehyde, which occurs in the presence of acid active sites, and a second step of oxidation of the aldehyde to the carboxylic acid. The two reactions were carried out using a cascade strategy and multifunctional catalysts, made of W-Nb-O, W-V-O and W-Mo-V-O hexagonal tungsten bronzes, the same systems which are also active and selective in the ODH of glycerol into acrylic acid. Despite the similarities of reactions involved, the ODH of 1,2-propanediol turned out to be less selective than glycerol ODH, with best yield to propanoic acid no higher than 13%, mainly because of the parallel reaction of oxidative cleavage, occurring on the reactant itself, which led to the formation of C1-C2 compounds.

The differing responses of various techniques in measuring the phase transformations of K2ZrF6

The compound K2ZrF6 undergoes an unusual multistep solid-solid transformation on temperature variation, whose irreversibility or reversibility depends on the target temperature: heating K2ZrF6 up to only 250 °C results in an irreversible process, while heating over this temperature results in reversible transformation. The reversibility of the back transformation indicates that α-K2ZrF6 transforms to a high-temperature phase (HTFrev) on heating above 250 °C, and on cooling reverts to the α-K2ZrF6 phase. The irreversible transformation involves transformation of α-K2ZrF6 to a high-temperature phase (HTFirrev) on heating to 250 °C, and then on cooling transforming to a mixture of meta-K2ZrF6 and K3ZrF7. With time this mixture changes to α-K2ZrF6, meta-K2ZrF6 and K3ZrF7. This transformation was monitored by DTA, DSC, 19F MAS NMR, XRD and thermal diffusivity techniques. Surprisingly, these experimental techniques showed unexpectedly differing responses.

Facial design and synthesis of CoSx/Ni-Co LDH nanocages with rhombic dodecahedral structure for high-performance asymmetric supercapacitors

In this paper, two-component nanocages containing CoSx and nickel-cobalt layered double hydroxides (Ni-Co LDH) were facilely synthesized via a multistep transformation approach. The zeolitic imidazolate framework-67 (ZIF-67) nanocrystals were firstly synthesized, and then after partial sulfuration, the CoSx/Ni-Co LDH nanocages were achieved by adding nickel ions for etching and precipitation. The prepared CoSx/Ni-Co LDH nanocages consisted of the hollow rhombic dodecahedral morphology with many nanosheets arrays on the shell. When used as electrode materials for electrochemical capacitors, this CoSx/Ni-Co LDH nanocages deliver a specific capacitance of 1562 F g−1 at a current density of 1 A g−1. In addition, an asymmetric supercapacitor assembled with CoSx/Ni-Co LDH as cathode and active carbon (AC) as anode shows a high energy density of 35.8 Wh kg−1 at a power density of 800 W kg−1 and has an excellent cycling performance with the retention rate of 94.56% after 10,000 cycles, suggesting their potential application in high-performance electrochemical capacitors. These exceptional electrochemical properties can be attributed to the unique structure and synergistic effects between the metal sulfide and the bimetallic hydroxide, which also indicate the potential application of CoSx/Ni-Co LDH nanocages in high-performance supercapacitors.

Modelling the stress-induced multi-step martensite transformation of single crystal NiMnGa ferromagnetic shape memory alloys

Existing experimental results have shown that multi-step martensite transformation can be induced by the applied stress in single crystal NiMnGa ferromagnetic shape memory alloys (FSMAs) and the transformation property depends on the ambient temperature strongly. In this work, a crystal-plasticity based constitutive model is established to quantify such a phenomenon. Based on the crystallographic symmetry, the lattice structures and eigenstrains of austenite (A) and three different martensite phases, i.e., the modulated martensite phases with a periodicity of 5 lattice cells (5M) and a periodicity of 7 lattice cells (7M), and a non-modulated (NM) martensite phase are analyzed. A three-dimensional (3D) single crystal constitutive model is constructed in the framework of finite strain by considering five different martensite transformation processes, i.e., the transformations between A and 5M, A and 7M, A and NM, 5M and 7M, and 7M and NM phases. Thermodynamically consistent kinetic equations for the five different martensite transformation processes are proposed based on the constructed Helmholtz free energy and Clausius's dissipative inequality. The capability of the proposed model to describe the tensile stress-induced multi-step martensite transformation of single crystal NiMnGa FSMA in [100] crystallographic orientation is verified by comparing the predictions with corresponding experimental results. Further, the proposed model is used to predict the deformations of the single crystal under the tension and compression in various crystallographic orientations.

Risk assessment for long-distance gas pipelines in coal mine gobs based on structure entropy weight method and multi-step backward cloud transformation algorithm based on sampling with replacement

Destruction of pipelines because of coal mine gob disasters may result in enormous financial loss and significantly affect public safety. Hence, risk assessment of gob pipelines is of immense significance for field personnel. Given the lack of statistical data and the limitations of expert experience, a prior single risk value is often insufficient to reflect the actual situation and cannot meet the needs of the site. The backward cloud transformation (BCT) algorithm is a method that can fully mine the local information contained in expert experience to restore the overall information. However, the existing BCT algorithm has no solution under certain conditions, which considerably limits its application. This study proposes a comprehensive risk assessment method by combining the structural entropy method with a multi-step backward cloud transformation algorithm based on sampling with replacement (MBCT-SR). First, a simplified model for rapid identification is used to determine whether it is worth calculating risk values. Second, a fault tree that fits the actual situation is established, and the weights of the indexes are determined by the structural entropy weight method. Third, the interval scores of the indexes are transformed into numerical features of the cloud model, which are then logically operated using virtual cloud algorithms. Finally, the risk values of the pipeline can be obtained, the cloud droplet diagram of the risk values is clearly shown by the forward cloud transformation (FCT) algorithm, and the risk level can be obtained by the probability that the cloud droplet falls into each risk level interval. To validate the utility of the proposed method, a case study of a coal mine gob around a long-distance gas pipeline was investigated.

Phase Transformation Behavior and Stability of LiNiO2 Cathode Material for Li-Ion Batteries Obtained from In Situ Gas Analysis and Operando X-Ray Diffraction.

Ni-rich layered oxide cathode materials, in particular the end member LiNiO2 , suffer from drawbacks such as high surface reactivity and severe structural changes during de-/lithiation, leading to accelerated degradation and limiting practical implementation of these otherwise highly promising electrode materials in Li-ion batteries. Among all known phase transformations occurring in LiNiO2 , the one from the H2 phase to the H3 phase at high state of charge is believed to have the most detrimental impact on the material's stability. In this work, the multistep phase transformation process and associated effects are analyzed by galvanostatic cycling, operando X-ray diffraction, and in situ pressure and gas analysis. The combined results provide thorough insights into the structural changes and how they affect the stability of LiNiO2 . During the H2-H3 transformation, the most significant change occurs in the c-lattice parameter, resulting in large mechanical stress in LiNiO2 . As for electrochemical stability, it suffers strongly in the H3 region. Oxygen evolution is observed not only during charge but also during discharge and found to be correlated with the presence of the H2 and H3 phases. Taken together, the experimental data improve the understanding of the degradation processes and the inherent instability of LiNiO2 in Li-ion cells when operated above around 75 % state of charge.

Properties of NiTi Shape Memory Alloy Micro-Foils Obtained by Pulsed-Current Sintering of Ni/Ti Foils

Successful one-step manufacturing of micro-foils of NiTi shape memory compound by pulsed-current sintering of nickel and titanium is reported. Sandwich-like starting configurations of Ni/Ti/Ni (ST1, ST4), Ti/Ni/Ti (ST3), and a simple Ni/Ti (ST2) one, were used. XRD and differential scanning calorimetry (DSC) measurements revealed multistep martensitic transformation, much more pronounced for ST1 than for ST2 and ST3. SEM/energy dispersive X-ray spectrometer (EDS) measurements showed the predominant NiTi phase in ST1, ST4, and other intermetallic compounds in addition to it, for ST2 and ST3. The temperature dependence of the electrical resistance for ST4 shows a peak corresponding to the R-phase and a high residual resistivity. The shape memory effect of 100% was obtained for ST1 and ST4, with the temperature range of its recovery dependent on the initial strain. The ST2 and ST3 materials revealed brittleness and a lack of plasticity due to the dominancy of the austenite phase and/or the intermetallic compound content.

One-Pot Sequential Multistep Transformation of α,β-Unsaturated Trifluoromethyl Ketones: Facile Synthesis of Trifluoromethylated 2-Pyridones

A one-pot transformation of α,β-unsaturated trifluoromethyl ketones with 2-(phenylsulfinyl)acetamide to give trifluoromethylated 2-pyridones is realized. The reaction proceeds under mild conditions and involves multiple steps in an expeditious and controlled sequence to provide efficient access to a broad range of trifluoromethylated 2-pyridones in moderate to high yields. Moreover, further synthetic manipulations permit the routine synthesis of a diverse array of trifluoromethylated pyridines with good efficiency.

Laboratory of the future: a modular flow platform with multiple integrated PAT tools for multistep reactions

The coupling of a modular microreactor platform, real-time inline analysis by IR and NMR, and online UPLC, leads to efficient optimization of a multistep organolithium transformation to a given product without the need for human intervention.

Design of multiple electrode structures based on nano Ni3S2 and carbon nanotubes for high performance supercapacitors

3D-networked CNT–Ni3S2–CNT-A supported by Ni foam was rationally designed and synthesized via a multistep transformation approach.