Application of deep learning methods in materials microscopy for the quality assessment of lithium-ion batteries and sintered NdFeB magnets

Die Qualitätskontrolle konzentriert sich auf die Erkennung von Produktfehlern und die Überwachung von Aktivitäten, um zu überprüfen, ob die Produkte den gewünschten Qualitätsstandard erfüllen. Viele Ansätze für die Qualitätskontrolle verwenden spezialisierte Bildverarbeitungssoftware, die auf manuell entwickelten Merkmalen basiert, die von Fachleuten entwickelt wurden, um Objekte zu erkennen und Bilder zu analysieren. Diese Modelle sind jedoch mühsam, kostspielig in der Entwicklung und schwer zu pflegen, während die erstellte Lösung oft spröde ist und für leicht unterschiedliche Anwendungsfälle erhebliche Anpassungen erfordert. Aus diesen Gründen wird die Qualitätskontrolle in der Industrie immer noch häufig manuell durchgeführt, was zeitaufwändig und fehleranfällig ist. Daher schlagen wir einen allgemeineren datengesteuerten Ansatz vor, der auf den jüngsten Fortschritten in der Computer-Vision-Technologie basiert und Faltungsneuronale Netze verwendet, um repräsentative Merkmale direkt aus den Daten zu lernen. Während herkömmliche Methoden handgefertigte Merkmale verwenden, um einzelne Objekte zu erkennen, lernen Deep-Learning-Ansätze verallgemeinerbare Merkmale direkt aus den Trainingsproben, um verschiedene Objekte zu erkennen. In dieser Dissertation werden Modelle und Techniken für die automatisierte Erkennung von Defekten in lichtmikroskopischen Bildern von materialografisch präparierten Schnitten entwickelt. Wir entwickeln Modelle zur Defekterkennung, die sich grob in überwachte und unüberwachte Deep-Learning-Techniken einteilen lassen. Insbesondere werden verschiedene überwachte Deep-Learning-Modelle zur Erkennung von Defekten in der Mikrostruktur von Lithium-Ionen-Batterien entwickelt, von binären Klassifizierungsmodellen, die auf einem Sliding-Window-Ansatz mit begrenzten Trainingsdaten basieren, bis hin zu komplexen Defekterkennungs- und Lokalisierungsmodellen, die auf ein- und zweistufigen Detektoren basieren. Unser endgültiges Modell kann mehrere Klassen von Defekten in großen Mikroskopiebildern mit hoher Genauigkeit und nahezu in Echtzeit erkennen und lokalisieren. Das erfolgreiche Trainieren von überwachten Deep-Learning-Modellen erfordert jedoch in der Regel eine ausreichend große Menge an markierten Trainingsbeispielen, die oft nicht ohne weiteres verfügbar sind und deren Beschaffung sehr kostspielig sein kann. Daher schlagen wir zwei Ansätze vor, die auf unbeaufsichtigtem Deep Learning zur Erkennung von Anomalien in der Mikrostruktur von gesinterten NdFeB-Magneten basieren, ohne dass markierte Trainingsdaten benötigt werden. Die Modelle sind in der Lage, Defekte zu erkennen, indem sie aus den Trainingsdaten indikative Merkmale von nur "normalen" Mikrostrukturmustern lernen. Wir zeigen experimentelle Ergebnisse der vorgeschlagenen Fehlererkennungssysteme, indem wir eine Qualitätsbewertung an kommerziellen Proben von Lithium-Ionen-Batterien und gesinterten NdFeB-Magneten durchführen

Aspirin compared with other anticoagulants for use as venous thromboembolism prophylaxis in elective orthopaedic hip and knee operations:a narrative literature review

Although total hip and knee arthroplasty are effective methods for treating arthritis, they have an associated risk of venous thromboembolism (VTE). To reduce this risk, prophylactic agents including aspirin, low-molecular-weight Heparin, vitamin K antagonists, and direct oral anticoagulants are employed for up to 35 days after surgery. This narrative literature review utilised a systematic approach to critically assess the current evidence surrounding the use of aspirin for VTE prophylaxis compared to anticoagulants. An advanced multistage electronic search was performed in May 2021 using the OVID/Medline and Embase online libraries to identify available studies relevant to the subject from 1974. Additional studies identified during the review process were also included. The final studies meeting the inclusion criteria were then assessed using the Critical Appraisal Skills Programme tool. A total of 12 (60%) studies (two meta-analyses, three randomised trials, seven retrospective studies) favoured aspirin over anticoagulants for VTE prophylaxis. A total of 15 (75%) studies (two meta-analyses, three randomised trials, nine retrospective, one matched cohort) reported that aspirin had better bleeding profiles and complication rates, which was statistically significant in seven (46.7%) studies (one randomised trial, six retrospective studies). A total of eight studies (one randomised trial, six retrospective studies, one matched cohort) reported statistically significant results for aspirin. Five (62.5%) studies reported aspirin to be superior for VTE prophylaxis, while seven (87.5%) reported aspirin to be superior in terms of bleeding complications. The current evidence indicates that aspirin is superior to anticoagulants, in their various iterations, for VTE prophylaxis in terms of their bleeding profiles. [Abstract copyright: Copyright © 2021, Olukoya et al.

Design and Construction of a Low Cost Digital Weather Station

This work is focused on the design and construction of a low cost weather station which makes weather related data available for different purposes such as agriculture, aviation weather forecasting, etc. The design is made up of an outdoor module which measures four weather elements (temperature, atmospheric pressure, relative humidity and wind speed) through their respective sensors. This module transmits the sampled data wirelessly through radio frequency (RF) to an indoor module which receives the data and automatically logs the data to a database. A MATLAB® based graphical user interface (GUI) was also incorporated to view the logged data and perform some setup operations on the system

Modeling a Digitalized Indexing Structure for a Departmental Library Using HTML

Every existing library possesses a catalogue, which is a guiding document for every user of the library who does not intend to waste time in identifying the actual location of a resource in a section of the library. A catalogue serves as a collection of the library’s blueprints, i.e. the various sections and the system of arrangement in the library. These catalogues in most libraries have become an old pile of cards, which is of little or no help to a library user in terms of resource location. Nowadays, card catalogues are being replaced with digital catalogues. A library viewed as a network of different sections can have its catalogue modeled using a web language (HyperText Mark-up language, or HTML). The use of such a model affords the community, which the library serves, with the advantage of better awareness. This work highlights the essentials of digital cataloguing and enumerates the steps involved in the conversion of an existing card catalogue to its digital equivalence

Maximizing the penetration levels of hybrid renewable energy systems in rural areas with demand side management approaches in achieving SDGs

Access to quality healthcare services is an integral part of sustainable development goals (SDGs) and reliable electricity access is a pre-requisite for improving human lives, enhancing healthcare delivery, education as well as other developmental growth within local communities. However, many rural locations far away from the grid centres have difficulties in accessing electricity, due to distance and cost of extension of grid to such areas, and this has resulted in the inability to provide basic amenities. Rural healthcare centres located in such places are unable to deliver their intended mandate, thus hindering the realization of SDG 3. Therefore, the innovative idea of this study is increasing the penetration of renewable energy technology while minimizing the cost by integrating the users’ perspective with demand side management (DSM) approaches, techno-economic analysis, and environmental impact assessment of hybrid energy system configuration, taking a health institution as the case study. To meet the considered rural healthcare facility’s initial average load demand of 20.58kWh/day, an optimum PV-Gen-battery hybrid system was selected using HOMER with cost of energy (COE) of $0.224/kWh, net present cost (NPC) of$61,917.6 and initial capital cost of $16,046.5. After the DSM measures were applied to reduce the peak and average demand, an optimum hybrid system was obtained, producing a COE of$0.166/kWh, NPC of $18,614.7 and initial capital cost of$10,070.8. The cost saving realized for the considered rural healthcare facility is $0.057/kWh, representing a 25.8% reduction from the current COE and a 70% reduction in Total NPC. On the other hand, the optimal configurations gave around a 75% reduction in CO2 emissions compare to a diesel-alone configuration. The work provides novel insights which may be applicable worldwide. It has the potential to significantly advance the development of high-quality and timely evidence to underpin current and future developments in the rural energy sector and contribute to the implementation of SDG3 and 7

Economic evaluation of hybrid energy systems for rural electrification in six geo-political zones of Nigeria

Rural electrification improves the quality of life of rural dwellers having limited or non-access to electricity through decentralized electricity coverage. Since the price of oil is unstable and fluctuating day by day and grid expansion is not also a cost effective solution, integrating renewable energy sources thus become an important alternative for rural electrification. The present study investigated the feasibility of different power generation configurations comprising solar array, wind turbine and diesel generator in different locations within the geo-political zones of Nigeria. Six rural communities were randomly chosen from each of the six geo-political zones in Nigeria with the intention that the results of the study could be replicated in other remote locations of the selected zones with similar terrains. HOMER (Hybrid Optimization Model for Electric Renewable) simulation software was used to determine the economic feasibility of the systems. The simulations concentrated on the net present costs, cost of energy and renewable fraction of the given hybrid configurations for all the climatic zones. The analysis indicates that the PV/diesel/battery hybrid renewable system configuration is found as optimum architecture for both sensitivity cases of 1.1 and $1.3/l of diesel. It also displayed better performance in fuel consumption and CO2 reductio

Demand side management strategies for solar-PV penetration in powering rural healthcare centre in Africa

This paper explored the possibility of applying Demand Side Management (DSM) strategies in meeting the energy demands of rural healthcare centres in Africa. Using an energy management system, it is possible to increase renewable energy penetration, optimize energy costs and reduces carbon emissions. DSM is a process of managing energy consumption to optimize available and planned resources for power generation. The DSM strategies employed in this study incorporates all activities that influence the rural healthcare facilities use of electricity, hence leading to manageable demand. The main focus of this study is on feasibility of increasing penetration of off-grid hybrid renewable energy in delivering basic healthcare services in rural areas with limited or no electricity access. Renewable energy resources (RES) such as solar is considered abundant in many rural places, it is also environmental friendly, hence suitable for providing electricity in rural healthcare facilities where there is no electricity access or limited supply. To meet the facility’s energy need, an optimum PV-Gen-battery hybrid system was designed using HOMER (Hybrid Optimization of Multiple Electric Renewables), with COE of $0.224/kWh, Net Present Cost (NPC) of$61,917.6 and initial capital cost of $16,046.5. DSM measures were applied to reduce the peak and average demand. With this new load profile, an optimum hybrid system was obtained, producing a COE of$0.166/kWh, NPC of $18,614.7 and initial capital cost of$10,070.8 after the DSM. The cost saving realized for the considered rural healthcare center is $0.057/kWh, representing 25.8% reduction from the current COE and 70% reduction in Total NPC. The research provides novel insights which may be applicable worldwide. It has the potential to significantly advance the development of high-quality and timely evidence to underpin current and future developments in the rural energy sector and contribute to the implementation of SDG7.

Activation of Rat Intestinal Alkaline Phosphatase by Taurine May be an Alternative Mechanism of Endotoxemic Injury Protection

Investigation of the effect of taurine on the hydrolysis of para-nitrophenylphosphate (p-NPP) by rat intestinal alkaline phosphatase (ALP), L-phenylalanine inhibition of ALP and the mechanism of ALP activation by taurine as well as its role in endotoxemic injury protection was carried out. Rat intestinal ALP was exposed to taurine, and L-phenylalanine at varying concentrations and periods of time. Substrate concentration-dependent kinetic analysis was carried out at 10 mM concentration of taurine and 5.17mM of p-NPP. The concentration dependent kinetic analysis of L-phenylalanine was also investigated at 60 mM. The partially purified rat intestinal alkaline phosphatase activity was also investigated in the presence of taurine. Their interactive effect on L-phenylalanine inhibition was also analyzed. Investigation of the effect of taurine on rat intestinal ALP hydrolysis of p-NPP revealed that taurine is an activator of intestinal ALP. At 10 mM taurine and 60 mM L-phenylalanine, taurine relieved L-phenylalanine inhibition of rat intestinal ALP. The effect of lipopolysaccharide in the absence and presence of taurine on ALP activity was also carried out in vivo. The kinetic analysis of the data from the in vivo study revealed that rat intestinal ALP activity is higher (12x10-3nmol -1min-1mg protein) in the presence of taurine and LPS when compared with the activity in the presence of LPS (9x10-3nmol-1min-1mg protein) or taurine (8.8x10-3nmol-1min-1mg protein) alone. From this study, it may be concluded that the activation of rat intestinal ALP by taurine may be one of the mechanisms of endotoxemic injury protection.Keywords: Intestinal Alkaline Phosphatase, Taurine, Endotoxemic , Lipopolysaccharid

Hybrid renewable energy supply for rural healthcare facilities: An approach to quality healthcare delivery

The lack of modern electricity supply has been a major impediment to proper functioning of the healthcare centers in the rural areas, contributing to high maternal and child mortality rates in a country. Therefore, this study focuses on how to address the identified problem so that the healthcare centers or clinics in the remote areas can provide timely delivery of medical services for the concerned people. This paper, then, presents the analysis of stand-alone hybrid renewable energy systems for basic healthcare services in the rural areas, where there is no grid energy supply or the supply from the existing grid is erratic and unreliable. One major factor that informs the selection of the hybrid energy system in this study is that it promises high reliability compared to a single energy system. The research presents a statistical analysis of the potential of wind and solar energies for a selected rural locations in Nigeria based on the available long-term hourly and daily meteorological data. It employs an optimal technical and economic design and sizing of hybrid electrical power systems’ components such as the wind, PV, battery and inverter systems, using the hybrid optimisation software (HOMER). Results show that Sokoto and Jos sites exist in the high wind potential regions, while the remaining sites are only suitable for small wind applications. Values obtained for global radiation show that all the sites enjoy considerable solar energy potential suitable for varying degree of solar energy applications. PV/wind/diesel/battery hybrid system configuration is considered optimum for rural health center at Iseyin, Sokoto, Maiduguri, Jos and Enugu, while hybrid systems involving PV/diesel/battery is considered ideal for Port-Harcourt, due to the quality of renewable energy potential. Hence, it was concluded that, the abundance of wind and solar resources in the country create an ideal environment for inclusion of renewable energy systems in the design and implementation of standalone power supply systems to improve rural healthcare delivery

Indoor air quality assessment of Federal University Dutse Library North West, Nigeria

The present study was aimed at evaluating the number of bacteria and fungi in the indoor environment of Federal University Dutse Library. The sampling site was located in the University main reading room. Forty (40) air samples were collected in the month of June 2018. Air samples comprising of twenty (20) for bacteria and twenty (20) for fungi were taken twice a day; in the morning and afternoon. All the samples were analyzed for the concentration of bacteria and fungi using plate count method. The average bacterial and fungal counts in the library were found to be 240.10 CFU/m3 and 280.60 CFU/m3 respectively and ranged from 132-345 CFU/m3 for bacteria and 180-416 CFU/m3 for fungi respectively. Having subjected the generated results to statistical analysis (T-test at 95% confidence limit), there was no significant difference between microbial loads recorded for bacteria and fungi (p-value=0.000). However, the mean microbial concentration of the library indoor air was within a range which indicates intermediate level of contamination according to the guidelines established in 1993 by the European Community Commission. It is therefore recommended that the surfaces of the library should be kept clean and dry, as the wet condition in the library can cause growth of pathogenic microorganisms. Again, a follow up study is required with a view to detecting seasonal variations of the indoor microbial counts of the library.Keywords: Indoor air quality, pollution, bacterial counts, fungal count