Preparation and Electrochemical Performance of a Graphene Cathode Catalyst Decorated With Pt by Prolysis

For fuel cells, to produce high-quality and low-platinum catalyst is a pressing technical problem. In this study, graphene cathode catalysts with controllable platinum content were decorated by pyrolyzing chloroplatinic acid under various process parameters to obtain a high catalytic activity and durability. The results show that platinum particles generated by pyrolyzing chloroplatinic acid are uniformly loaded on graphene without agglomeration. The average particle size of platinum particles is about 2.12 nm. The oxygen reduction reaction catalytic activity of catalyst samples first increases, then decreases with increasing platinum loading in cyclic voltammetry and LSV. Compared with the commercial Pt/C (20 wt% Pt) catalyst, the initial potential and the current density retention rate of the catalyst decorated with 8% platinum are 55 mV and 23.7% higher, respectively. From i-t curves, it was found that the stability of the catalyst prepared in this paper was improved compared with the commercial Pt/C catalyst. The catalysts prepared in the present research exhibits superior catalytic activity and stability.

Linguistic Mathematical Relationships Saved or Lost in Translating Texts: Extension of the Statistical Theory of Translation and Its Application to the New Testament

The purpose of the paper is to extend the general theory of translation to texts written in the same language and show some possible applications. The main result shows that the mutual mathematical relationships of texts in a language have been saved or lost in translating them into another language and consequently texts have been mathematically distorted. To make objective comparisons, we have defined a “likeness index”—based on probability and communication theory of noisy binary digital channels-and have shown that it can reveal similarities and differences of texts. We have applied the extended theory to the New Testament translations and have assessed how much the mutual mathematical relationships present in the original Greek texts have been saved or lost in 36 languages. To avoid the inaccuracy, due to the small sample size from which the input data (regression lines) are calculated, we have adopted a “renormalization” based on Monte Carlo simulations whose results we consider as “experimental”. In general, we have found that in many languages/translations the original linguistic relationships have been lost and texts mathematically distorted. The theory can be applied to texts translated by machines. Because the theory deals with linear regression lines, the concepts of signal-to-noise-ratio and likenss index can be applied any time a scientific/technical problem involves two or more linear regression lines, therefore it is not limited to linguistic variables but it is universal.

A blockchain-based cooperative modeling method for digital twin ontology model of the mechanical product

With the rapid increase of multi-source heterogeneous dynamic data of mechanical products, the digital twin technology is considered to be an important method to realize the deep integration of product data and intelligent manufacturing. As a digital archive of the physical entity in entire life cycle, the mechanical product digital twin model is cross-phased and multi-domain. Therefore, safe and stable cooperative modeling has become a basic technical problem that needs to be solved urgently. In this paper, we proposed a blockchain-based collaborative modeling method for the digital twin ontology model of mechanical products. First, an authorization network was constructed among stakeholders. Then modeling processes of the digital twin were mapped to ontology operations and formatted through extensible markup language. Finally, consensuses were obtained based on practical byzantine fault tolerance. And a material modification process of a helicopter damper bearing was taken as an example to verify. The proposed method enables all participants to accurately obtain the latest state of the digital twin model, and has the advantages of tamper-proof, traceability, and decentralization.

Consulting Application a Dedicated Social Media platform to get Expert Advice

In today’s fast growing world, The Information is the most powerful tool. A Doctor is an expert in medical sciences, an Engineer is an expert in Technical things similarly a fitness trainer is an expert in fitness related things. But What if a Person has some problem like a technical problem and he is not an expert in technical things ? In such situations A Person wants to have some expert advice. Now to overcome such problems a person may want to communicate with someone who is an expert in his problem domain. So Our Goal of the project is to reduce the gap between the problem seeker and the experts.

ANALYSIS OF INCREASING THE FRICTION FORCE OF THE ROBOT JAWS BY ADDING 3D PRINTED FLEXIBLE INSERTS

3D printing technology plays a key role in the production of prototypes and final functional parts. The ability to produce almost any shape using this technology in combination with lightweight materials is often used to minimise the weight of the designed components. However, for some applications, such as robot gripper jaws, conventional most commonly used materials, such as PLA, may be unsuitable due to their low coefficient of friction on the material of the manipulated object, which in some cases may cause the object to slip in the robot jaws. This article describes a technical problem from practice, where a manipulated object made of steel material slipped in the printed PLA jaws of the robot during its working cycle. This work is devoted to increasing the friction force of the robot jaws by adding 3D printed soft inserts. Two insert surface shapes made of two flexible materials TPU 30D and TPE 88 are tested. The increase in friction force is measured on a measuring device with an industrial robot and a force measuring sensor. The most suitable type of inserts and material is then tested on a collaborative robot at its required working cycle. The results of this experiment are intended to help designers as a source of information or inspiration in designing similar applications.

Medication interruptions and associated factors among nurses working in pediatric unit at a selected referral hospital in Rwanda

Introduction: Interruptions have been proven to cause medication administration errors in pediatric settings. Therefore, this study assessed the medication interruptions and associated factors among nurses in a pediatric unit at a selected referral hospital in Rwanda. Methods: A descriptive observational study was conducted among 59 nurses using a developed observational checklist. Data were entered into SPSS, version 26. Descriptive and inferential statistics were used to analyze the data. The IRB of the University of Rwanda approved the study. Results: Among the 414 medication administrations observed, 149 (36%) had interruptions. The main source of interruption was technical problem (14.5%) with interruption from direct care (12%) as the main reason. The factors associated with interruption occurrence were shift of the day, time of medication round, duration and phase of medication administration and nurse perception (p = 0.001), age (p=0.046), educational level (p = 0.044) and professional experience (p = 0.031). Conclusion: The existence of medication interruptions is evident with associated factors predominantly being demographics and technical. Therefore, the authors recommended that an in-service training program for nurses regarding medication administration errors. The hospital leadership should address the technical problems including availing the required materials for medication administration. French title: Interruptions médicamenteuses et facteurs associés chez les infirmières travaillant dans l'unité pédiatrique d'un hôpital de référence sélectionné au Rwanda Introduction : Il a été prouvé que les interruptions provoquent des erreurs d'administration de médicaments en milieu pédiatrique. Par conséquent, cette étude a évalué les interruptions de médication et les facteurs associés chez les infirmières d'une unité de pédiatrie d'un hôpital de référence sélectionné au Rwanda. Méthode de l'étude : Une étude observationnelle descriptive a été menée auprès de 59 infirmières à l'aide d'une liste de contrôle d'observation élaborée. Les données ont été saisies dans SPSS, 26. Des statistiques descriptives et inférentielles ont été utilisées pour analyser les données. L'IRB de l'Université du Rwanda a approuvé l'étude. Résultats de l'étude : Parmi les 414 administrations de médicaments observées, 149 (36 %) ont subi des interruptions. La principale source d'interruption était un problème technique (14,5 %) avec l'interruption des soins directs (12 %) comme principale raison. Les facteurs associés à l'occurrence d'interruption étaient décalage de la journée, heure de la tournée de médicaments, durée et phase d'administration des médicaments et perception de l'infirmière (p = 0,001), âge (p=0,046), niveau d'éducation (p = 0,044) et expérience professionnelle (p = 0,031). Conclusion : L'existence d'interruptions de médication est évidente avec des facteurs associés principalement démographiques et techniques. Par conséquent, les auteurs recommandent un programme de formation continue pour les infirmières concernant les erreurs d'administration de médicaments. La direction de l'hôpital devrait résoudre les problèmes techniques, notamment en mettant à disposition les matériaux requis pour l'administration des médicaments.

Mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power

Для создания виброакустической защиты судового оборудования необходимо учитывать потоки колебательной энергии, распространяющиеся от источников как через опорные и неопорные связи, так и в виде воздушного шума. В работе представлены математические модели оценки эффективности амортизирующих креплений виброактивных механизмов морских объектов по колебательной мощности, учитываемые при обучении разрабатываемой нейросетевой системы классификации морских целей. Теоретические разработки в области виброзащиты и виброизоляции во многом имеют междисциплинарный характер и опираются на методы теории механизмов и машин, теоретической механики, теории колебаний, теории управления, используются методы инфорьт мационные технологии для оценки, поиска и выбора рациональных проектно-конструкторских решений. Создание амортизирующих устройств, способных защитить объекты от вибраций и ударов и, вместе с тем, обладающих ограниченными размерами, является сложной технической проблемой. В связи с этим первостепенное значение приобретают вопросы теории и расчета адаптивных виброзащитных систем. To create vibro-acoustic protection of ship equipment, it is necessary to take into account the flows of vibrational energy propagating from sources both through support and non-support connections, and in the form of air noise. The paper presents mathematical models for evaluating the effectiveness of shock-absorbing fasteners of vibro-active mechanisms of marine objects by vibrational power, which are taken into account when training the developed neural network system for classifying marine targets. Theoretical developments in the field of vibration protection and vibration isolation are largely interdisciplinary in nature and are based on the methods of the theory of mechanisms and machines, theoretical mechanics, vibration theory, control theory, information technology methods are used to evaluate, search and select rational design solutions. The creation of shock-absorbing devices that can protect objects from vibrations and shocks and, at the same time, have limited dimensions is a complex technical problem. In this regard, the issues of the theory and calculation of adaptive vibration protection systems are of paramount importance.

Novel Nanocrystal Injection of Insoluble Drug Anlotinib and Its Antitumor Effects on Hepatocellular Carcinoma

The molecularly targeted agent anlotinib offers a novel therapeutic strategy against advanced hepatocellular carcinoma (HCC). With this study, we aimed to solve the technical problem of anlotinib being insoluble in injectable solutions; we also aimed to assess the antitumor activity of anlotinib on hepatocellular carcinoma cells. We prepared an anlotinib nanocrystal injection by wet grinding, and we optimized the prescription process using a transmission electron microscope (TEM) and a laser particle size analyzer (LPSA). The release of anlotinib from the injected nanocrystals was evaluated using LC-MS/MS in vitro, and the drug’s anti-tumor effects were assessed in a nude mice tumor model. The anlotinib nanocrystals had a uniform particle size distribution (the average nanoparticle size was ~200 nm). The preparation of anlotinib into nanocrystals did not change the original crystal structure. The intravenous injection of anlotinib nanocrystals achieved anti-tumor activity at very low doses compared to those required for oral administration of an anlotinib suspension: anlotinib nanocrystals at a dose of 50 μg/kg inhibited the subcutaneous growth of the HCC cell line MHCC97-H; whereas the dose of anlotinib suspension required for an equivalent effect was 1 mg/kg. Therefore, our novel anlotinib nanocrystal injection preparation provides an option for achieving a safe and effective molecularly targeted therapy against advanced HCC.

Degradation of Lithium-Ion Batteries in an Electric Transport Complex

The article provides an overview and comparative analysis of various types of batteries, including the most modern type—lithium-ion batteries. Currently, lithium-ion batteries (LIB) are widely used in electrical complexes and systems, including as a traction battery for electric vehicles. Increasing the service life of the storage devices used today is an important scientific and technical problem due to their rapid wear and tear and high cost. This article discusses the main approaches and methods for researching the LIB resource. First of all, a detailed analysis of the causes of degradation was carried out and the processes occurring in lithium-ion batteries during charging, discharging, resting and difficult operating conditions were established. Then, the main factors influencing the service life are determined: charging and discharging currents, self-discharge current, temperature, number of cycles, discharge depth, operating range of charge level, etc. when simulating a real motion process. The work considers the battery management systems (BMS) that take into account and compensate for the influence of the factors considered. In the conclusion, the positive and negative characteristics of the presented methods of scientific research of the residual life of LIB are given and recommendations are given for the choice of practical solutions to engineers and designers of batteries. The work also analyzed various operating cycles of electric transport, including heavy forced modes, extreme operating modes (when the amount of discharge and discharge of batteries is greater than the nominal value) and their effect on the degradation of lithium-ion batteries.

Neutrino Transport with the Monte Carlo Method. II. Quantum Kinetic Equations

Neutrinos have a unique quantum feature as flavor conversions. Recent studies suggested that collective neutrino oscillations play important roles in high-energy astrophysical phenomena. The quantum kinetic equation (QKE) is capable of describing the neutrino flavor conversion, transport, and matter collision self-consistently. However, we have experienced many technical difficulties in their numerical implementation. In this paper, we present a new QKE solver based on a Monte Carlo (MC) approach. This is an upgraded version of our classical MC neutrino transport solver; in essence, a flavor degree of freedom including mixing state is added into each MC particle. This extension requires updating numerical treatments of collision terms, in particular for scattering processes. We deal with the technical problem by generating a new MC particle at each scattering event. To reduce statistical noise inherent in MC methods, we develop the effective mean free path method. This suppresses a sudden change of flavor state due to collisions without increasing the number of MC particles. We present a suite of code tests to validate these new modules with comparison to the results reported in previous studies. Our QKE-MC solver is developed with fundamentally different philosophy and design from other deterministic and mesh methods, suggesting that it will be complementary to others and potentially provide new insights into physical processes of neutrino dynamics.