A comparative prospective study of platelet rich plasma versus corticosteroid injection in chronic plantar fasciitis

Background: The Plantar fasciitis is a common reason for heel pain which manifests as pain at medial process of calcaneal tuberosity. Patients are mostly diagnosed clinically on the basis of history. Conservative treatment in the form of stretching, non-steroidal anti-inflammatories, night splinting, ice packs, strapping, orthosis, and shoe modifications have been in use traditionally. Recently, the use of injectables like corticosteroids and platelet rich plasma (PRPs) has increased. This study aims at comparing the clinic-radiological outcomes of the two injectables in the treatment of chronic plantar fasciitis. Methods: This was a Prospective, Comparative, Randomized, Hospital-based clinical case study conducted in the Department of Orthopaedics, Sawai Man Singh Medical College, Jaipur, Rajasthan. 60 patients of chronic plantar fasciitis were taken and divided randomly into group A (PRP) and group B (corticosteroids) and the results were assessed based on the visual analogue scale (VAS), American Orthopaedic Foot and Ankle Society (AOFAS) score, and the plantar fascia thickness. Results: Mean VAS in Group A decreased from 8.07 before injection to 2.9 after injection and in Group B decreased from before 8.33 injection to 3.13 after injection, at the final follow-up. Mean AOFAS score improved from 54.06 to 90.60 and from 54.86 to 75.13 in the respective groups at the 6-months follow-up. Plantar fascia thickness (as measured using ultrasonography) decreased from 5.77 to 3.32 and from 5.6 to 3.73 in the respective groups. The improvements observed were statistically significant. Conclusions: Local injection of platelet rich plasma is an effective treatment option for chronic plantar fasciitis when compared with steroid injection with long lasting beneficial effects

A prospective randomized comparative study on fractures of lower third of both bones of the leg treated by interlock nailing of tibia with or without fixation of fibula

Background: In the treatment of fractures of the distal third of tibia and fibula treated by interlocking nail of tibia, the role of fixing the fibular fracture is not clearly defined. This study was conducted to assess the benefits of fixation of fibular fracture in distal third leg bones fractures.Methods: 95 patients were enrolled into study and divided randomly into two groups based on whether fibula fixed or not with interlock intramedullary nailing tibia. Patients were followed for an average period of 11 months both radiologically and clinically.Results: We observed that the average valgus angulation was significantly less (P =0.001) in the group where fibula was fixed. The outcome of the two groups for clinical ankle score, time of union and complication showed no difference (P ≥0.05). Conclusions: We concluded that fixation of fibula decrease the malalignment of tibia in distal third fractures of tibia and fibula treated with interlocking nail of tibia.

Evaluation of saliency tracking as an alternative for health monitoring in PMSM-drives under nonstationary conditions

This paper evaluates the capability of saliency tracking to assess the health condition of permanent magnet synchronous motor (PMSM) drives operating under nonstationary conditions. The evaluated scheme is based on saliency tracking methods, which are associated to the accurate sensorless control of AC drives without zero speed limitations. In this work two representative saliency tracking architectures are evaluated: High Frequency (HF) injection, and PWM transient excitation. Although a monitoring approach based on HF injection was previously reported, a comparative study to evaluate the most representative saliency tracking schemes to assess health condition in drives was still missing. The aim of this work is to fill out this gap by evaluating and comparing two saliency-based monitoring schemes (one based on HF-injection and the other based on PWM transient excitation) to evaluate their performance in the presence of inter-turn winding faults. Simulation and experimental results are presented which confirm that both schemes offer excellent detection capabilities and that are suitable for drives operating under nonstationary conditions including standstill operation. Significant differences are also found for instance, PWM transient excitation offers improved accuracy since the approach is not affected by the inverter nonlinearities and is suitable for full-speed range applications. The main drawback here is complexity and the hardware requirements. Schemes based on HF-injection proved to be very simple and provide comparable results; however a good performance is only guaranteed for the zero-to-medium speed range applications which limit their applicability

Condition monitoring approach for permanent magnet synchronous motor drives based on the INFORM method

This paper proposes a monitoring scheme based on saliency tracking to assess the health condition of PMSM drives operating under non stationary conditions. The evaluated scheme is based on the INFORM methodology, which is associated to the accurate sensorless control of PM drives without zero speed limitation. The result is a monitoring scheme that is able to detect faults that would be very difficult to evaluate under nonstationary conditions. A relevant aspect of the proposed scheme is that it remains valid for full speed range, and can be used for standstill operation. Additionally, the approach is insensitive to the inverter nonlinearities which enhance the detection capabilities further respect to similar topologies. In this work the proposed approach is evaluated numerically and experimentally in the presence of incipient winding faults and inter-turn short circuits in a PM conventional drive. The obtained results show quick response and excellent detection capabilities not only in the detection of faults, but to determine their magnitude which is vital to avoid further degradation

An oxalate cathode for lithium ion batteries with combined cationic and polyanionic redox

Authors acknowledge financial support from the National Natural Science Foundation of China (51822210), the Australian Research Council (ARC) for its support through Discover Project (DP 140100193),Shenzhen Peacock Plan (KQJSCX20170331161244761), the Program for Guangdong Innovative and Entrepreneurial Teams (No. 2017ZT07C341), and the Development and Reform Commission of Shenzhen Municipality for the development of the “Low-Dimensional Materials and Devices” discipline.The growing demand for advanced lithium-ion batteries calls for the continued development of high-performance positive electrode materials. Polyoxyanion compounds are receiving considerable interest as alternative cathodes to conventional oxides due to their advantages in cost, safety and environmental friendliness. However, polyanionic cathodes reported so far rely heavily upon transition-metal redox reactions for lithium transfer. Here we show a polyanionic insertion material, Li2Fe(C2O4)2, in which in addition to iron redox activity, the oxalate group itself also shows redox behavior enabling reversible charge/discharge and high capacity without gas evolution. The current study gives oxalate a role as a family of cathode materials and suggests a direction for the identification and design of electrode materials with polyanionic frameworks.Publisher PDFPeer reviewe

Redox anionique pour les batteries à haute énergie. Compréhension fondamentale, défis pratiques et perspectives d’avenir

Our increasing dependence on lithium-ion batteries for energy storage applications calls for continual performance improvements of their positive electrodes, which have so far relied solely on cationic redox of transition-metal ions for driving the electrochemical reactions. Great hope has recently been placed on the emergence of anionic redox – a transformational approach for designing Li-rich positive electrodes as it leads to a near-doubling of capacity – hence generating worldwide research interest. However, questions have been raised on the fundamental origins of anionic redox and whether its full potential can be realised in applications. This is exactly what this thesis aims to answer by using the knowledge from the fields of solid-state chemistry, electrochemistry, X-ray spectroscopy, and thermochemistry. We first provide a comprehensive historical account, a theoretical framework, some materials’ design rules, and a survey of characterization techniques specific to anionic redox. Then, through comprehensive experimental studies that were performed in parallel on one ‘model’ (4d metal based) and one ‘practical’ (3d metal based) material, we highlight how the fundamental interplay between cationic and anionic redox processes governs the application-wise important properties of these promising battery materials (i.e. voltage hysteresis, rate performance, voltage decay, and heat generation,). Finally, using these results, we outline possible approaches for improving such materials and for designing novel ones. We also summarize their chances for market implementation in face of the competing nickel-based layered cathodes that are prevalent today.Notre dépendance croissante vis-à-vis des batteries lithium-ion pour le stockage d’énergie exige une amélioration de leurs électrodes positives, qui fonctionnent encore grâce au redox cationique des métaux de transition. L’émergence du redox anionique – une approche transformationnelle qui double la capacité des électrodes positives « Li-riches » – a récemment suscité de grands espoirs mondialement. Toutefois, des questions subsistent sur les origines fondamentales du redox anionique et sur son potentiel dans les applications pratiques. Cette thèse vise à répondre précisément à ces questions, en utilisant les connaissances de la chimie des solides, de l’électrochimie, de la spectroscopie des rayons X, et de la thermochimie. Pour ce faire, nous fournissons d’abord un compte rendu historique, un cadre théorique, les règles de conception de nouveaux matériaux, ainsi qu’un résumé des techniques de caractérisation propres au redox anionique. Ensuite, à travers des études expérimentales menées à la fois sur un matériau « modèle » (à base de métal 4d) et sur un matériau « pratique » (à base de métal 3d), nous montrons comment l’interaction fondamentale entre les processus de redox cationique et anionique régit les propriétés pratiques de ces matériaux (c’est-à-dire hystérésis de tension, performance de vitesse, chute de tension, et production de chaleur). Enfin, en utilisant ces résultats, nous décrivons les approches possibles pour améliorer ces matériaux et en concevoir de nouveaux. Nous résumons également leurs chances d’implantation sur le marché face aux cathodes lamellaires à base de nickel qui prévalent aujourd’hui

Polymorphs of lithium transition-metal phosphates : synthesis and characterization

textLithium transition-metal phosphates, LiMPO₄ (M = Mn, Fe, Co, and Ni) have gained significant research interest over the past two decades as an important class of lithium-ion battery cathode materials. However, almost all of the investigations thus far have focused on the olivine polymorph which exists in orthorhombic Pnma space group. In this report, a distinct orthorhombic but non-olivine polymorph of LiMPO₄, described by a Cmcm space group symmetry, has been synthesized with M = Mn, Fe, Co, and Ni. Of these, LiMPO₄ in the Cmcm space group had never been reported before. A rapid microwave-assisted solvothermal (MW-ST) heating process with tetraethylene glycol (TEG) as the solvent and transition-metal oxalates as precursors facilitate the synthesis of these materials. The peak reaction temperatures and pressures, respectively, were below 300 °C and 30 bar, which is several orders of magnitude lower than the previously reported high pressure (GPa) method. The physiochemical and electrochemical properties of the synthesized materials are characterized with several techniques. X-ray diffraction (XRD) confirms the crystal structure with Cmcm space group and scanning electron micrographs (SEM) indicate a sub-micron thin platelet like morphology. The synthesis process conditions have been optimized to obtain impurity-free samples with correct stoichiometry, as characterized with XRD and inductively coupled plasma - optical emissions spectroscopy (ICP-OES). Upon heat treatment to higher temperatures, the transformation of the Cmcm polymorphs into olivine is observed with XRD and Fourier transform infrared spectroscopy (FTIR). Although the electrochemical activity of these polymorphs as lithium-ion cathodes turns out to be poor, the facile synthesis under mild conditions has enabled easy access to these materials, some of which were not even possible before.Mechanical Engineerin

Rapid Microwave-Assisted Solvothermal Synthesis of Non-Olivine <i>Cmcm</i> Polymorphs of LiMPO₄ (M = Mn, Fe, Co, and Ni) at Low Temperature and Pressure

Lithium transition-metal phosphates, LiMPO₄ (M = Mn, Fe, Co, and Ni), have attracted significant research interest over the past two decades as an important class of lithium ion battery cathode materials. However, almost all of the investigations thus far have focused on the olivine polymorph that exists in the orthorhombic <i>Pnma</i> space group. In this study, a distinct orthorhombic but non-olivine polymorph of LiMPO₄, described by a <i>Cmcm</i> space group symmetry, has been synthesized with M = Mn, Fe, Co, and Ni. Of these, LiMnPO₄ in the <i>Cmcm</i> space group is reported for the first time. A rapid microwave-assisted solvothermal (MW-ST) heating process with tetraethylene glycol (TEG) as the solvent and transition-metal oxalates as precursors facilitates the synthesis of these materials. The peak reaction temperatures and pressures were below 300 °C and 30 bar, respectively, which are several orders of magnitude lower than those of the previously reported high-pressure (gigapascals) method. X-ray diffraction (XRD) confirms the crystal structure with the <i>Cmcm</i> space group, and scanning electron micrographs indicate a submicrometer thin platelet-like morphology. The synthesis process conditions have been optimized to obtain impurity-free samples with the correct stoichiometry, as characterized by XRD and inductively coupled plasma-optical emission spectroscopy (ICP-OES). Upon heat treatment to higher temperatures, an irreversible transformation of the metastable <i>Cmcm</i> polymorphs into olivine is observed by XRD and Fourier transform infrared spectroscopy. Although the electrochemical activity of these polymorphs as lithium ion cathodes turns out to be poor, the facile synthesis under mild conditions has permitted easy access to these materials in a nanomorphology, some of which were not even possible before

Probing the thermal effects of voltage hysteresis in anionic redox-based lithium-rich cathodes using isothermal calorimetry

International audienceI ncreasing the energy density of lithium-ion batteries requires denser positive electrodes with higher voltage and/or capacity. Li-rich nickel-manganese-cobalt layered oxides (Li-rich NMCs), such as Li[Li 0.2 Ni 0.13 Mn 0.54 Co 0.13 ]O 2 , can deliver specific capacities above 270 mAh g-1 to reach 1,000 Wh kg-1 of specific energy at the material level. Despite their slightly lower crystalline density than today's Li-stoichiometric Ni-based layered oxides (Li NMCs and Li nickel-cobalt-aluminium oxides), Li-rich cathodes remain very promising for the long term, as we will need to move away from Ni-based towards Mn-based materials (Mn is inexpensive and environmentally benign) without compromising the energy density 1-3. The high capacity of Li-rich NMCs stems from cumulative anionic and cationic bulk redox processes 4-6. However, these electrodes currently fall short in other performance metrics 7 because of large voltage hysteresis 5,8 , sluggish kinetics 5,9,10 and gradual voltage fade 11. These issues are concomitant with anionic redox activity 7-the very same feature that enhances capacity. Therefore, further investigations are needed to fundamentally understand the overall anionic redox process, which constitutes not just electron removal from oxygen-based electronic states, but also the ensuing (local) struc-tural/bonding rearrangements 7. The undesirable issue of voltage hysteresis in rechargeable batteries leads to energy inefficiency, presumably dissipated as heat, consequently imposing an additional energy cost on the end users 12. Voltage hysteresis would also complicate the state of charge (SOC) and thermal management of such batteries. Li-rich NMCs show a relatively large difference between charge/discharge voltages (~400-500 mV after the first cycle and ~87% energy efficiency; Fig. 1). This gap persists over cycling, even at extremely low rates (C/300) 10 , at high temperatures (55 or 85 °C) 13 and after long relaxation periods (100 h) 10. Such behaviour therefore cannot be described by simple electro-chemical kinetics that fails to explain the observed path dependence and quasi-static hysteresis. Interestingly, and similar to Li-rich NMCs, many other newly discovered Li-and Na-based materials with reversible anionic redox also suffer from voltage hysteresis 7. These include layered Li 2 Ru 1-y Sn y O 3 9 (Fig. 1), Na 2/3 [Mn 1-y Mg y ]O 2 14 and Na 2 RuO 3 15 , as well as disordered Li 1.2 Mn 0.4 Ti 0.4 O 2 16 and Li 2 MnO 2 F 17. Only a few studies have attempted to understand the origin of voltage hysteresis in this class of cathodes. These include electro-chemical measurements in different voltage windows to identify correlated differential capacity (dQ/dV) peaks 5,8,11,18,19 , 6 Li nuclear magnetic resonance to observe path dependence in Li site occupation 20 , X-ray diffraction to claim back-and-forth (partially reversible) transition metal migration 21 , and bulk X-ray spectrosco-pies 5,22,23 to show the absence of hysteresis in the potentials at which transition metals show redox activity, unlike for the hysteretic oxygen redox process. A couple of phenomenological models assuming either an Li-driven phase change 10 or an asymmetry in transition metal migration 24 were also conceived. Despite such widespread efforts, the general thermodynamic mechanism behind voltage hys-teresis and its thermal effects remains unclear. Two questions need answering: (1) how exactly is the lost energy dissipated as heat so that it can be better managed/predicted? and (2) what is the underlying mechanism along with the corresponding thermochemical conditions that lead to hysteresis? In light of this, we adopt a different approach herein and perform isothermal calorimetry measurements during the cycling of a 'model' Li-rich layered cathode-Li 2 Ru 0.75 Sn 0.25 O 3 (LRSO) or Li[Li 0.33 Ru 0.5 Sn 0.17 ]O 2. This high-capacity (~250 mAh g-1 reversibly) material, although only suitable for niche applications without cost barriers (for example, space), shows remarkable structural and elec-trochemical similarities to the practically important Li-rich NMCs (Fig. 1) 9,25. Overall, it serves as a simplified 'model' compound for understanding the general properties of Li-rich layered electrodes. The commercialization of high-energy batteries with lithium-rich cathode materials exhibiting combined cationic/anionic redox processes awaits the elimination of certain practical bottlenecks. Among these, large voltage hysteresis remains the most obscure from a fundamental thermochemical perspective. Here, we study this issue by directly measuring, via isothermal calo-rimetry, the heat generated by Li/Li 2 Ru 0.75 Sn 0.25 O 3 (Li/LRSO) cells during various cycling conditions, with LRSO being a 'model' Li-rich layered cathode. We show how this heat thermodynamically relates to the lost electrical work that is crucial for practical applications. We further reveal that anionic redox on charging and discharging adopts different metastable paths having non-identical enthalpy potentials, such that the overall Li content no longer remains the unique reaction coordinate, unlike in fully path-reversible cationic redox. We elucidate how quasi-static voltage hysteresis is related to heat dissipated due to non-equilibrium entropy production. Overall, this study establishes the great benefits of isothermal calorimetry for enabling energy-efficient electrode materials in next-generation batteries