bluuebunny/crossref_metadata_2025 huggingface dataset:
Harnableitung nach uro-onkologischen Eingriffen bei Frauen: was bei wem?
Authors: Lampel Alexander , Schultz-Lampel Daniela
Published: April 2021

Das Blasenkarzinom ist bei Frauen ein eher seltener Tumor. In der noch selteneren Konstellation eines invasiven Karzinoms oder in einer High-Risk-Situation mit der Indikation der Zystektomie stellt sich die Frage nach der adäquaten Harnableitung.

Die Wahl der Harnableitung wird bestimmt von den vorliegenden individuellen Gegebenheiten seitens des Tumors, der Patientin und den Erfahrungen und Präferenzen des Operateurs.

Für den Blasenersatz steht eine ganze Palette an Alternativen zur Verfügung. Die Entscheidung muss zunächst zwischen den Optionen einer inkontinenten Ableitung mit Stomaanlage wie Ureterokutaneostomie oder Ileum-Conduit und den wesentlich aufwendigeren Techniken der kontinenten Varianten des orthotopen oder heterotopen Ersatzes getroffen werden.

Dabei sind bei Frauen die vorliegenden Erfahrungen mit den kontinenten Varianten deutlich geringer als bei Männern und vor allem der orthotope Anschluß an die Harnröhre beinhaltet im Gegensatz zu den inkontinenten Formen des Blasenersatzes und der heterotopen Ableitung geschlechtsspezifische Unterschiede.

Für die verschiedenen Varianten gibt es insgesamt klare Ein- oder Ausschlußkriterien. Schwierig wird es eher in Graubereichen, für welche Form der Harnableitung man sich vor dem Eingriff entscheidet. Auf keinen Fall kann dies generell, sondern muss in jedem Fall individuell entschieden werden. Dafür bedarf es unter anderem auch umfangreicher Kenntnisse seitens des Operateurs über die verschiedenen Optionen der Operationsmethoden, deren Probleme und Komplikationsmöglichkeiten sowie insbesondere auch deren Beherrschung.
Cannabis und synthetische Cannabinoide – eine nicht nur radiologische Übersicht
Authors: Nafe Reinhold , Arendt Christophe , Hattingen Elke
Published: April 2021

Eine Übersicht zum „Drogenabusus“ mit Schwerpunkt Radiologie kann sich nicht auf rein bildmorphologisch fassbare Veränderungen beschränken. Vielmehr muss der Radiologe über Wirkungsweise und Art des Konsums der einzelnen Stoffklassen informiert sein und das Spektrum an zu erwartenden Komplikationen und Langzeitveränderungen kennen. In diesem Beitrag stehen Cannabis und synthetische Cannabinoide im Mittelpunkt.
Dermatomyositis als paraneoplastisches Syndrom bei Kopf-Hals-Malignomen: Fallserie & Literaturreview
Authors: Klukas Jana , Pudszuhn Annett , Kusch Kerstin , Obermueller Theresa , Hofmann Veit M.
Published: April 2021

Einleitung/Ziel Die Dermatomyositis (DM) ist eine seltene Erkrankung, die sich klinisch durch Schwäche und Schmerzen proximaler Muskeln sowie fliederfarbene Hautveränderungen manifestiert. In fast einem Fünftel der Fälle ist die DM mit dem Auftreten von Tumorerkrankungen assoziiert. Ziel dieser Untersuchung ist die Bewertung der Bedeutung der DM als paraneoplastisches Syndrom bei Malignomen im Kopf-Hals-Bereich unter Berücksichtigung der aktuellen Literatur.

Material/Methoden Nach retrospektiver Krankenaktenanalyse der Jahre 2008–2018 von Patienten mit Kopf-Hals-Malignomen fanden sich 8 Patienten mit einer Dermatomyositis: 4 Patienten mit Tonsillenkarzinom, 1 Patient mit Nasopharynxkarzinom, 1 Patient mit Parotiskarzinom und 2 Patienten mit Lymphomen. Es wurden die Diagnostik, Therapie und Behandlungsergebnisse der Fälle beschrieben. Zudem erfolgte eine selektive Analyse der Literatur (PubMed) zur DM bei HNO-Tumoren. Bei dieser fanden sich insgesamt 290 Fälle: Die Malignome waren in 283 Fällen im Nasopharynx, in 5 Fällen in der Tonsille und in 2 Fällen im Hypopharynx lokalisiert.

Ergebnisse/Schlussfolgerung Eine DM als paraneoplastisches Syndrom bei Kopf-Hals-Malignomen ist selten. Sie tritt häufiger in Assoziation mit Nasopharynxkarzinomen und selten bei Tonsillenkarzinomen auf.

Das gehäufte Auftreten der DM bei Kopf-Hals-Malignomen in Abhängigkeit von der ethnischen Verteilung (Nasopharynxkarzinome – asiatische Abstammung, Tonsillenkarzinom – kaukasische Abstammung) ist möglicherweise auch auf regionale Inzidenzunterschiede der genannten Tumorentitäten zurückzuführen.

Bei Patienten mit einer DM sollte ein Tumorausschluss auch im Kopf-Hals-Bereich erfolgen, insbesondere bei Vorliegen einer zervikalen Lymphadenopathie. Der Verlauf einer tumorassoziierten DM wird durch die Tumortherapie positiv beeinflusst. Therapeutisch ist aber auch eine konsequente Behandlung der DM die Grundlage für eine erfolgreiche Tumortherapie.
Chemical Characterisation-Biological Evaluation of Greek Cultivar Cardoon Seeds (Cynara cardunculus). A By-product with Potential High Added Value
Authors: Graikou Konstantia , Kourti Panagiota-Maria , Zengin Gokhan , Gortzi Olga , Danalatos Nikolaos , Chinou Ioanna
Published: April 2021

Cynara cardunculus (artichoke) is a perennial plant of the Mediterranean basin, known since antiquity as food and for its therapeutic properties. Cynara is a relatively small genus with two cultivated species and one wild one. Recently, successful efforts have been made to cultivate wild cardoon and monetise it as a bioenergy crop. In this study, the seeds of an established Greek cultivar of C. cardunculus, cultivated in the experimental field and used as biofuel, have been researched for their chemical profile and nutritional value. According to the results, six lignans were isolated [arctigenin, arctiin, trachelogenin, tracheloside, cynarinine, and ethylate of trachelogenin (isolated for the first time from a natural source)] as well as the most characteristic metabolites of the genus (linoleic acid, trilinolein, and 3,5-dicaffeoylquinic acid). Moreover, the total phenolic content (31.18 – 54.51 mg gallic acid equivalents/g extract) and antioxidant and enzyme inhibitory activities of the seeds have been evaluated and showed strong antioxidant properties (44.42 – 516.81 mg gallic acid equivalents/g extract) as well as satisfactory bleaching (enzyme tyrosinase, 16.95 – 23.80 mg kojic acid equivalents/g extract), antidiabetic (enzymes a-amylase, a-glucosidase, 0.14 – 1.75 mmol acarbose equivalents/g extract), and protective against neurodegenerative disease (cholinesterase enzymes, 0.49 – 1.22 mg galanthamine equivalents/g extract) activities. The nutritional evaluation of the seeds confirmed them as a rich source of unsaturated fatty acids, dietary fibre (24.1%), and high protein content (19.3%). It is noteworthy that such a neglected bioactive by-product, with essentially high nutritional value, as the studied seeds could be investigated for its value-added applications towards food and food supplements areas.
Entanglement between charge qubit states and coherent states of nanomechanical resonator generated by ac Josephson effect
Authors: Bahrova O. M. , Gorelik L. Y. , Kulinich S. I.
Published: April 2021

We considered a nanoelectromechanical system consisting of a movable Cooper-pair box qubit, which is subject to an electrostatic field, and coupled to the two bulk superconductors via tunneling processes. We suggest that qubit dynamics is related to that of a quantum oscillator and demonstrate that a bias voltage applied between superconductors generates states represented by the entanglement of qubit states and coherent states of the oscillator if certain resonant conditions are fulfilled. It is shown that a structure of this entanglement may be controlled by the bias voltage in a way that gives rise to the entanglement incorporating so-called cat-states—the superposition of coherent states. We characterize the formation and development of such states analyzing the entropy of entanglement and corresponding Wigner function. The experimentally feasible detection of the effect by measuring the average current is also considered.
Beads of water hopping over hurdles
Authors: Yiu Yuen
Published: April 2021

Water droplets of different sizes, some mixed with glycerol for more viscosity, raced down a hydrophobic surface much more slowly when the surface had a few indentations.
Study on seepage and adsorption characteristics of porous media containing adsorbent based on lattice Boltzmann
Authors: Lei Jiaming , Ding Ruiyu , Zhang Jianmin
Published: April 2021

A double-distribution function Lattice Boltzmann Method (LBM) is used to simulate the seepage and adsorption process of solution flow through porous media with an adsorbent at the pore scale. The accuracy of the model is verified by simulating the interfacial adsorption and intraparticle diffusion processes. The effects of inlet and outlet density difference, inlet concentration, and adsorbent packed bed height on the permeability and adsorption process of two-dimensional porous media with adsorbent are discussed. The numerical simulation results show that the adsorption equilibrium time increases with the increase in inlet and outlet density difference and inlet concentration, and the thicker the adsorption layer, the lower the adsorption rate. The seepage rate increases with the increase in inlet and outlet density difference and the increase in adsorbent packed bed height, but the change in inlet concentration has no effect on it. The flow resistance in the adsorbent particles has a great influence on the mass transfer process, so it should be considered accurately. The LBM model proposed in this paper is an effective tool to study the remediation of seepage pollution in porous media such as soil and groundwater.
Updating the Australian digital soil texture mapping (Part 2
Authors: Malone Brendan , Searle Ross
Published: April 2021

Malone and Searle (2021) described a new approach to convert field measured soil texture categories into quantitative estimates of the proportion of clay, silt and sand fractions. Converted data can seamlessly integrate with laboratory measured data into digital soil mapping workflow. Here, we describe updating the Australian national coverages of clay, sand and silt content. The approach, based on machine learning, predicts each soil texture fraction at 90 m grid cell resolution, at depths 0–5 cm, 5–15 cm, 15–30 cm, 30–60 cm, 60–100 cm and 100–200 cm. The approach accommodates uncertainty in converting field measurements to quantitative estimates of texture fractions. Existing methods of bootstrap resampling were exploited to predict uncertainties, which are expressed as 90% prediction intervals about the mean prediction at each grid cell. The models and the prediction uncertainties were assessed by an external validation dataset. Results were compared with Version 1 Soil and Landscape Grid of Australia (v1.SLGA) (Viscarra Rossel et al. 2015). All predictive and functional accuracy diagnostics demonstrate improvements compared with v1.SLGA. Improvements were noted for the sand and clay fraction mapping with average improvement of 3% and 2%, respectively, in the RMSE estimates. Marginal improvements were made for the silt fraction mapping, which was relatively difficult to predict. We also made comparisons with recently released World Soil Grid products (v2.WSG) and made similar conclusions. This work demonstrates the need to continually revisit and if necessary, update existing versions of digital soils maps when new methods and efficiencies evolve. This agility is a key feature of digital soil mapping. However, without a companion program of new data acquisition through strategic field campaigns, continued re-modelling of existing data does have its limits and an eventual model skill ceiling will be reached which may not meet expectations for delivery of accurate national scale digital soils information.
Improved bounds on entropy production in living systems
Authors: Skinner Dominic J. , Dunkel Jörn
Published: April 2021

Significance

Thermodynamic laws fundamentally limit the efficiency and accuracy of living systems. To perform essential functions, from sensing to replication and locomotion, organisms consume energy and dissipate heat. The rate at which they consume energy can be bounded, in theory, by measuring all their internal variables. In practice, however, the entire system is rarely experimentally observable, and many internal states remain hidden. Here, we introduce a mathematical framework that yields optimal bounds on the energy consumption rate when only a small number of observables are available. Overcoming previous limitations, our approach discovers nonzero bounds even when the observed trajectories are time symmetric. We demonstrate the practical usefulness of this method in applications to a variety of recent experimental data.
Intraoperative hyperspectral label-free imaging: from system design to first-in-patient translation
Authors: Michael Ebner  , Nabavi Eli , Shapey Jonathan , Xie Yijing , Liebmann Florentin , Spirig José Miguel , Hoch Armando , Farshad Mazda , Saeed Shakeel R , Bradford Robert , Yardley Iain , Ourselin Sébastien , Edwards A David , Führnstahl Philipp , Vercauteren Tom
Published: April 2021

Despite advances in intraoperative surgical imaging, reliable discrimination of critical tissue during surgery remains challenging. As a result, decisions with potentially life-changing consequences for patients are still based on the surgeon’s subjective visual assessment. Hyperspectral imaging (HSI) provides a promising solution for objective intraoperative tissue characterisation, with the advantages of being non-contact, non-ionising and non-invasive. However, while its potential to aid surgical decision-making has been investigated for a range of applications, to date no real-time intraoperative HSI (iHSI) system has been presented that follows critical design considerations to ensure a satisfactory integration into the surgical workflow. By establishing functional and technical requirements of an intraoperative system for surgery, we present an iHSI system design that allows for real-time wide-field HSI and responsive surgical guidance in a highly constrained operating theatre. Two systems exploiting state-of-the-art industrial HSI cameras, respectively using linescan and snapshot imaging technology, were designed and investigated by performing assessments against established design criteria and ex vivo tissue experiments. Finally, we report the use of our real-time iHSI system in a clinical feasibility case study as part of a spinal fusion surgery. Our results demonstrate seamless integration into existing surgical workflows.
GaN-based complementary inverter logic gate using InGaN/GaN superlattice capped enhancement-mode field-effect-transistors
Authors: Jha Jaya , Ganguly Swaroop , Saha Dipankar
Published: April 2021

GaN-based high electron mobility transistors (HEMTs) have received much attention due to their potential usage in radio-frequency and high power applications. However, the development of logic gates has remained mostly elusive due to the still challenging reliable operation of the field-effect enhancement-mode n-transistor and nascent stage for the p-transistor. The n-transistor behavior is mainly achieved by combining the aggressive thinning down of the barrier layer, using charged oxides, and p-doping the cap layer. The p-transistor generally requires a heavily doped p-GaN layer. The realization of both transistors on the same substrate remains challenging due to the conflicting requirements for n- and p-transistors. Here, we propose a GaN-based field-effect complementary transistor device using a p-doped InGaN/GaN superlattice (SL) structure on top of the barrier layer of the HEMT heterostructure. The SL structure changes the electrostatics of the heterostructure by the formation of a two-dimensional hole gas region. An undoped SL structure is shown to be enough to lift the conduction band-edge above the Fermi level to convert the n-transistor from depletion-mode (D-mode) to enhancement-mode (E-mode). The lifting of the bands, in turn, creates a natural quantum-well for the holes in the p-transistor. An additional p-doping of the SL moves the threshold voltage of the E-mode n-transistor further into a positive direction and increases the hole density in the quantum-well E-mode p-transistor. The SL structure, which can be grown by a standard epitaxial process, facilitates the realizations of both the n- and p-transistors. The characteristics of individual devices are further analyzed. A digital inverter gate is simulated, and critical static and dynamic performance parameters are reported. The propagation delay indicates that logic operations can be done at a very high speed compared to those offered by other conventional semiconductors.
Technical considerations for evaluating clinical prediction indices: a case study for predicting code blue events with MEWS
Authors: Gadhoumi Kais , Beltran Alex , Scully Christopher G , Xiao Ran , Nahmias David O , Hu Xiao
Published: April 2021

Objective. There have been many efforts to develop tools predictive of health deterioration in hospitalized patients, but comprehensive evaluation of their predictive ability is often lacking to guide implementation in clinical practice. In this work, we propose new techniques and metrics for evaluating the performance of predictive alert algorithms and illustrate the advantage of capturing the timeliness and the clinical burden of alerts through the example of the modified early warning score (MEWS) applied to the prediction of in-hospital code blue events. Approach. Different implementations of MEWS were calculated from available physiological parameter measurements collected from the electronic health records of ICU adult patients. The performance of MEWS was evaluated using conventional and a set of non-conventional metrics and approaches that take into account the timeliness and practicality of alarms as well as the false alarm burden. Main results. MEWS calculated using the worst-case measurement (i.e. values scoring 3 points in the MEWS definition) over 2 h intervals significantly reduced the false alarm rate by over 50% (from 0.19/h to 0.08/h) while maintaining similar sensitivity levels as MEWS calculated from raw measurements (∼80%). By considering a prediction horizon of 12 h preceding a code blue event, a significant improvement in the specificity (∼60%), the precision (∼155%), and the work-up to detection ratio (∼50%) could be achieved, at the cost of a relatively marginal decrease in sensitivity (∼10%). Significance. Performance aspects pertaining to the timeliness and burden of alarms can aid in understanding the potential utility of a predictive alarm algorithm in clinical settings.
Cyclic behavior of an adaptive seismic isolation system combining a double friction pendulum bearing and shape memory alloy cables
Authors: Peng Zhuang , Wei Wang , Yibo Li , Miao Han
Published: April 2021

A new composite isolator named shape memory alloy cable-double friction pendulum bearing (SCDFPB), which combines a double friction pendulum bearing (DFPB) with superelastic shape memory alloy (SMA) cables, is proposed. Based on the SMA cables, the proposed isolation bearing named as SCDFPB had capability to adapt to multi-level earthquake intensities in horizontal directions, which was superior to the conventional DFPB. A series of research was performed to investigate hysteretic behavior of the SCDFPB, and a numerical simulation method for this isolation device was also developed. First, the configuration design and operation principle of the SCDFPB were described and explained in detail. Then, an analytical model of SCDFPBs was presented to understand their control and energy dissipation properties. Next, a SCDFPB specimen was designed and fabricated, and the quasi-static tests on the isolator specimen under different loading conditions were conducted to examine the isolator’s real cyclic response. The influence of displacement amplitude, vertical load and loading frequency on the hysteretic performance of SCDFPB specimen was investigated, and the behaviors of SCDFPB were compared with those of DFPB. Theoretical analyses were also performed to trace the vertical and horizontal components of the force provided by the SMA cables and their influence on the overall response of the entire isolation system during the cyclic loading process of the SCDFPB specimen. Finally, a numerical model of the SCDFPB implemented in the OpenSees program was established and validated by comparison to the experimental results.
Cooperation and dependencies in multipartite systems
Authors: Kłobus Waldemar , Miller Marek , Pandit Mahasweta , Ganardi Ray , Knips Lukas , Dziewior Jan , Meinecke Jasmin , Weinfurter Harald , Laskowski Wiesław , Paterek Tomasz
Published: April 2021

We propose an information-theoretic quantifier for the advantage gained from cooperation that captures the degree of dependency between subsystems of a global system. The quantifier is distinct from measures of multipartite correlations despite sharing many properties with them. It is directly computable for classical as well as quantum systems and reduces to comparing the respective conditional mutual information between any two subsystems. Exemplarily we show the benefits of using the new quantifier for symmetric quantum secret sharing. We also prove an inequality characterizing the lack of monotonicity of conditional mutual information under local operations and provide intuitive understanding for it. This underlines the distinction between the multipartite dependence measure introduced here and multipartite correlations.
Polarization of GRB prompt emission and its application to POLAR’s data
Authors: Lan Mi-Xiang , Wu Xue-Feng , Dai Zi-Gao
Published: April 2021

Synchrotron emission polarization is very sensitive to the magnetic field configuration. Recently, polarization of synchrotron emission with a mixed (SM) magnetic field in the gamma-ray burst (GRB) afterglow phase has been developed. Here, we apply these SM models to the GRB prompt phase and compare their polarization properties with that of synchrotron emission in purely ordered (SO) magnetic field. We find that the polarization properties in an SM model are very similar to these in a corresponding SO model (e.g., synchrotron emission in a mixed magnetic field with an aligned ordered part (SMA) and synchrotron emission with a purely ordered aligned magnetic field (SOA)), only with a lower polarization degree (PD). We also discuss the statistical properties of the models. We find PDs of the simulated bursts are concentrated around 25% for both SOA and synchrotron emission in a purely ordered toroidal magnetic field (SOT), while they can range from 0% to 25% for SMA and synchrotron emission in a mixed magnetic field with a toroidal ordered part (SMT), depending onξBvalue, i.e., the ratio of magnetic reduction of the ordered magnetic field over that of random magnetic field. From statistics, if PDs of majority GRBs are non-zero, then it favors SO and SM models. Further, if there are some bright GRBs with prominently lower PDs than that of the majority GRBs, it favors SOT (SMT) models; if all the bright GRBs have comparable PDs with the majority ones, it favors SOA (SMA) models. Finally, we apply our results to POLAR’s data and find that ∼ 10% time-integrated PDs of the observed bursts favor SMA and SMT models, and theξBparameter of these bursts is constrained to be around 1.135.
Detection of a high-confidence quasi-periodic oscillation in radio light curve of the high redshift FSRQ PKS J0805–0111
Authors: Ren Guo-Wei , Zhang Hao-Jing , Zhang Xiong , Ding Nan , Yang Xing , Li Fu-Ting , Yan Pei-Lin , Xu Xiao-Lin
Published: April 2021

In this work, we have searched for quasi-periodic oscillations (QPOs) in the 15 GHz light curve of the FSRQ PKS J0805--0111 monitored by the Owens Valley Radio Observatory (OVRO) 40 m telescope during the period from 2008 January 9 to 2019 May 9, using the weighted wavelet Z-transform (WWZ) and the Lomb-Scargle Periodogram (LSP) techniques. This is the first time to search for a periodic radio signal in the FSRQ PKS J0805–0111 by these two methods. Both methods consistently reveal a repeating signal with a periodicity of 3.38 ± 0.8 yr (>99.7% confidence level). In order to determine the significance of the periods, the false alarm probability method was applied, and a large number of Monte Carlo simulations were performed. As possible explanations, we discuss a number of scenarios including the thermal instability of thin disks scenario, the spiral jet scenario and the binary supermassive black hole scenario. We expect that the binary black hole scenario, where the QPO is caused by the precession of binary black holes, is the most likely explanation. FSRQ PKS J0805-0111 thus could be a good binary black hole candidate. In the binary black hole scenario, the distance between the primary black hole and the secondary black hole is about 1.71 × 1016 cm.
Measurement of Hubble constant: were differences in secondary distance indicators apparent as early as the HST Key Project?
Authors: Thakur Rahul Kumar , Gupta Shashikant , Nigam Rahul , Thiruvikraman PK
Published: April 2021

Different measurements of the Hubble constant (H
0) are not consistent, and a tension between the CMB based methods and cosmic distance ladder based methods has been observed. Measurements from various distance based methods are also inconsistent. To aggravate the problem, the same cosmological probe (Type Ia SNe for instance) calibrated through different methods also provides different values of H
0. We compare various distance ladder based methods through the already available unique data obtained from the Hubble Space Telescope (HST). Our analysis is based on parametric (t-test) as well as non-parametric statistical methods such as the Mann-Whitney U test and Kolmogorov-Smirnov test. Our results show that different methods provide different values of H
0 and the differences are statistically significant. The biases in the calibration would not account for these differences as the data have been taken from a single telescope with a common calibration scheme. The unknown physical effects or issues with the empirical relations of distance measurement from different probes could give rise to these differences.
Possible properties of TeV spectra in PKS 2155–304
Authors: Gao Quan-Gui , Lu Fang-Wu , Qin Long-Hua , Li Huai-Zhen , Ma Ju , Ren Ji-Yang , Zhao Hai-Ru , Yi Ting-Feng
Published: April 2021

We present a one-zone homogeneous lepton-hadronic model and obtain steady-state spectra by solving the time-dependent equations to study a plausible origin of hard TeV spectra in PKS 2155–304. In this model, we assume a steady electron and proton injection rate in the source and solve the non-linear time-dependent kinematic equations that self-consistently consist of proton-photon interaction, synchrotron radiation of electron/positron pairs and proton, inverse Compton scattering, and synchrotron self-absorption. We employ this model to reproduce the multi-wavelength spectrum of PKS 2155–304, then find that the possible bump located at E ∼ 1 TeV which may originate from the synchrotron radiation of secondary electrons produced by Bethe-Heitler pair production, resulting in the hard TeV spectrum.
Development of a solar energy-powered surface water pump
Authors: Agbo S , Samuel O.D. , Amosun S.T. , Oyejide O.J. , Fayomi O.S.I. , Bamisaye O.S. , Afolalu S.A.
Published: April 2021

Availability in energy and water sustainability are mounting concerns in several parts of the world where connection to the electric utility is not obtainable or irregular. There is a need to develop an alternative source of energy for pumping water. This research developed a solar energy powered 1.5 horsepower surface water pump. It comprises of the following major components: charge controller, 24 Volts DC battery, 3KVA inverter, solar panel and 1119W surface water pumping machine. The components were designed and assembled according to functions. Solar energy is used to charge the battery through solar controller. The solar charge controller used in this research was designed in such a way that it regulates the quantity of electrical energy that is stored in the battery which prevents overcharging, thereby ensuring no reduction in life span of the battery. The inverter was designed in such a way that when there is no alternative power supply from the electricity distribution company, that is, power holding company of Nigeria (PHCN), it can make use of the energy stored in the battery to power the single phase motor used to pump water into a tank. Similarly, when there is power supply from PHCN, it has an inbuilt change over switch (relay) to connect it’s output of 220 volts AC supply from PHCN used to charge a battery through a charge controller. Experiments were setup to analyze varying loads on the inverter. Average time obtained for varying loads of 0, 120, 500, 1000, 1300w are 200, 23, 9.8, 4.3 and 2.9hr. Comparisons were also made between locally built and imported inverters. It can be concluded from the results obtained that the design can best be put in use to obtain maximum efficiency of 88.2% at a load in the range of 1000–1300 watts.
Prospective of Product Development and Improved Production Processes
Authors: Fayomi O.S.I. , Akande I.G. , Oyedepo S.O. , Dunmade I. , Aikhuele D.O. , Ighravwe D.E.
Published: April 2021

Product development is an integral part of an organization that plans to stay relevant and competitive in today’s world. Several companies have research and development sections, which are most times responsible for developing new products. Still, there are other processes such as technology development, technology acquisition, capacity acquisition, and project management in which product development can be achieved. Improved product development processes such as lean manufacturing, six sigma, and a hybrid of the two known as lean six sigma (LSS) are platforms that enhance product development, which helps organizations remain relevant.
Reinforcement of AA1237 with Al2O3 to form Metal Matrix Composite
Authors: Babalola P.O. , Kilanko O. , Banjo S.O. , Ogulu J.O. , Makinde A. , Jolayemi J.K. , Ayara W.A.
Published: April 2021

The fabrication of advanced materials which possess an array of desired properties is a significant accomplishment of humanity. Composites are described as enhanced materials as they possess various advantages over conventional materials, which is why these composite materials are seen as viable alternatives in diverse engineering fields such as the aerospace, electronics and automobile industries. This work involved the fabrication of a metallic composite with the use of aluminium (AA1237) and crushed Al2O3 ceramic particles of 150nm and 600nm sizes as the reinforcement. The manufacturing of these composite samples was accomplished using the liquid phase process of stir casting, and they were subjected to various mechanical and electrical tests. For both hardness and tensile tests, the specimen Al/Al2O3/10p/150nm ( 10 per cent) had the highest values with 14.9 HBS and 124.41 MPa respectively. The electrical conductivity test affirmed the presence of non-conductive ceramic particles in the composite samples as the control (AA1237) had the highest conductivity value.
Fractal Dimension Analysis of Ternary Blends Structure: Polypropylene/Chitosan/Sisal Fiber Membranes
Authors: Mokrani T. , Agboola O. , Fayomi O.S.I. , Ayeni A.O. , Ayoola A.
Published: April 2021

Generally, the microstructures of thin and dense skin membranes have a disorderly nature. Due to their extremely complex nature, it is necessary to study the relationship between surface morphology and fractal dimension of microfiltration membrane. The fractal dimension analysis of the polymer composite was study to provide information about the primary pore size and their associations with flux in porous media. The fractal dimensions of membranes were obtained by the box-counting method. The membranes with increased amount of sisal fiber have inter-twined fibrous network with larger pores. The fractal dimension values of the membranes were also high with increasing amount of sisal fiber, with 86%PP/10% SF/4% C having the highest value of 1.9951.
A Review of the Impact of Construction Automation and Robotics on Project Delivery
Authors: Akinradewo O I , Aigbavboa C O , Okafor C C , Oke A E , Thwala D W
Published: April 2021

The use of construction technologies is to improve working conditions, improve health and safety, scheduling and improving quality of the construction products. Construction automation redefines construction with machines and advanced technology to mitigate the problems faced in construction, such as labour-related issues among others. To adequately understand the impact of automation and robotics in the construction industry, this study is aimed at reviewing extant literature on how automation and robotics can be put into use in the construction industry as it is being used in the manufacturing industry. The study employed a systematic literature review approach and sourced for published journal and conference articles from Web of Science and Scopus databases. The review revealed that construction automation and robotics increase accuracy of components’ dimension through the use of lasers for dimension analysis, promote design specifications through the use of computer aided designs, increase quality of construction products by ensuring standards are met, brings cost effectiveness as value for money spent is achieved, eliminate material wastage due to accurate and precise estimate of materials needed, reduce construction accidents due to the usage of machines for dangerous construction activities, improve working condition as workers’ are more secure and safety is guaranteed, and reduce labour cost given the fact that machines are deployed for construction activities.
Effect of Fibre Glass Addition on the Mechanical Properties of Glass Fibre Reinforced Polymer (GFRP) Composite
Authors: Udo Mfon , Babalola Philip , Ongbali Samson , Banjo Solomon , Obasa Victoria , Adelore Jesutoni
Published: April 2021

A fibre glass reinforced polymer was developed, using epoxy resin as the matrix material and E-glass fibre as the reinforcement, by hand laying method. Different set of the composite were produced by varying the weight percentage (wt%) addition of the reinforcement to the epoxy resin as follows 10%, 20%, 30%, 40% and 50%. The polymeric composite so produced were subjected to various mechanical property tests as hardness, tensile, impact, tests. The hardness test was conducted using TQ SM1000 Universal Testing Machine, the tensile strength test was carried out on Hounsfield Tensiometer model while the impact test was carried out on Izod Impact Testing Machine. It was observed that the mechanical properties of hardness, tensile strength and impact strength were of higher values in the composites with different weight fractions of glass fibre than in unreinforced epoxy resin. It was also found out that the values of those mechanical properties increased directly proportional to the amount of weight percentage of the reinforcement in the composites with the highest of the values residing in the composite with 50 wt% of the reinforcement. The hardness value for GFRP composite with 50 wt% glass fibre reinforcement stood at 57 BHN, tensile strength at 332.7 MPa and impact energy value of 17.5 J/m2.
Corrosion and Protection of Facilities and Infrastructures in Telecommunications Industry - A Review
Authors: Loto Roland T. , Loto Cleophas A.
Published: April 2021

A review of corrosion and protection of telecommunications facilities and infrastructures is reported here. The article gives a brief insight into the broad aspects of basic corrosion and telecommunications engineering and technology. These areas of discussion include all telecommunications metallic materials and equipment, buildings, and masts/towers. The review also discussed various corrosion protection methods such as organic/inorganic coatings, hot dip galvanizing, electroplating and electroless plating, cathodic protection, materials selection and systems design. The protection level for different components of the tower to which cathodic protection is used includes tower base, foundation of telecommunication shelters, buried portion of waveguide bridges, anchor shafts, and grounding system which were briefly discussed.
Experimental Investigation of Welding Parameters and Simulation of Heat and Fluid Flow in Weldments
Authors: Egole C.P. , Nzebuka G.C. , Anaele J.U. , Ukonu D.C.
Published: April 2021

Welding is one of the most versatile processes for joining components in the industrial and manufacturing sectors. Hence, the critical study of welding parameters and the heat and fluid flow behaviour is deemed necessary. In the current work, an experimental investigation of the effect of welding parameters on the mechanical properties of the welded joints and simulation of heat and fluid flow within the weldments were presented. Low carbon steel was welded using a shielded metal arc welding process (SMAW) and a single V-grooved butt joint was produced. Welding currents of 100 amperes and 115 amperes were varied for different electrode types of E 6013 (ENL), E 6013 (AWS) and E 7018 for the welding process. Tensile and hardness tests were carried out on the welded joints. X-ray diffraction analysis was carried out to ascertain the phases present within the weld area. Additionally, the heat and fluid flow patterns within the weld pool were studied using ANSYS Fluent. The results show that there are significant effects of welding current and electrode type on the tensile strength and hardness of the weldment. For all the samples analysed, electrode type rather increase in current improved the mechanical properties significantly. The optimum tensile strength for the SMAW process was produced by the welding electrode E 7018 at 115 A with a strength of 652 MPa. The lowest value of tensile strength was 491 MPa for E 6013 (AWS). The highest hardness was produced by E 7018 electrode at 115 A with a value of 177 HV while the lowest was 122 HV for E 6013 (AWS) electrode. Heat transfer analysis showed that the maximum temperature value of 1867 K was obtained close to the arc region. Due to the narrow area of weld pool occasioned by large thermal gradient and rapid solidification, the fluid flow region reported was small and the supposed recirculating flow cells and loops were not well developed.
Review of metal protection techniques and application of drugs as corrosion inhibitors on metals
Authors: Nduma R.C. , Fayomi O.S.I. , Nkiko M.O. , Inegbenebor A.O. , Udoye N. E. , Onyisi O. , Sanni O. , Fayomi J.
Published: April 2021

The inability of metals to resist degradation as a result of corrosion remains a unique global problem that depend on different metals for daily operations. Therefore, knowing the appropriate method to use is a key to ameliorate corrosion effect on metals. Green inhibitors serve as a modern, cheaper and environmentally favorable method to retard the effects of corrosion. Drugs are corrosion inhibitors which can reduce the action of corrosion without being hazardous to the environment as they are synthesized from natural products. The review studies the metal protection techniques and the use of drug as corrosion inhibitors. The importance of copper as a useful metal as good corrosion resistance due to inherent properties alongside its malleability was also discussed.
Corrosion behavior of Electro-deposited Ni-Cr2O3/SnO2 coatings on mild steel
Authors: Raswiswi P.B , Kanyane L.R , Fayomi J. , Popoola A.P.I , Fayomi O.S.I
Published: April 2021

The increasing use of mild steel in diverse environments and under different conditions requires the increased interest in research into these groups of specific steels with attention to their moderate corrosion rate and performance. The electrochemical study of Ni-Cr2O3/SnO2 coating was studied using potentiodynamic techniques. The microhardness properties of the deposits were studied using Emco microhardness tester. The effect of Cr2O3/SnO2 on nickel-based coatings was investigated to analyze the corrosion resistance of the coating by using the polarization method. The result indicates a reduction in corrosion rate with the addition of Cr2O3/SnO2 and the hardness of the coated sample also reduced drastically with the addition of SnO2 to the bath.
Mechanical and Microstructural Properties of MIG Welded Aluminium Alloy
Authors: Abima C.S. , Akinlabi S.A. , Madushele N. , Fatoba O.S. , Akinlabi E.T.
Published: April 2021

The need for sustainable materials in engineering applications cannot be overemphasized. Engineering innovation and material manufacturing and processing are now geared towards longevity and safety. Aluminium is one of the few materials that meets the ever-increasing demand for lightweight and high strength materials for various industries, including; aircraft industries, marine, solar panels, automobile, construction companies and many other applications to mention but just a few. Aluminium is known to possess excellent mechanical properties which makes them very useful and desirable. However, the final metallurgical and mechanical properties which characterise the final quality and strength of every weld depends on: (i) the technique employed in the welding of the component together and (ii) the selected process parameters for the welding operation. This work focuses on analysing the effect of heat input as a function of welding current, welding voltage and welding speed on the mechanical and microstructural behaviour of 150 × 100 × 3 mm3 aluminium sheets produced by metal inert gas welding. The parameters were set to represent the low, medium and high heat input values. It is imperative to determine the mechanical properties as a function of the structural integrity of welds to ascertain their functionality and durability for typical applications. Tensile testing, vickers hardness and microstructural examination were performed. The result revealed finer grain structures at lower heat input and more grain deformation and elongation occurring as heat input increases. The hardness property reduces (from 43.57 HV to 39.48 HV in the fusion zone as heat input increases. The width of the weld bead increases (from 328 μm to 496 μm) as heat input increases. However, the selected welding parameters did not greatly influence the tensile properties of the welded joints.
A Review on Waste-wood Reinforced Polymer Matrix Composites for Sustainable Development
Authors: Babatunde Fadare Olugbenga , Omotayo Adewuyi Benjamin , Oluwole Oladele Isiaka , Ukoba Kingsley
Published: April 2021

This study reviews the various techniques used in the preparation and processing of waste-wood fibre/particle reinforced polymer matrix composite with special interests on mechanical and structural applications. Polymer composite materials are being used in a wide range of structural applications such as construction, safety wears, aerospace and automotive industries owing to their lightweight, high specific stiffness and strength. A number of materials are being used ranging from lower performance of glass fibre/polyester used in small sail boats and domestic products to high performance of carbon fibre/epoxy systems used in military aircraft and spacecraft. In recent years, many studies have been dedicated to utilize organic fillers such as coconut shell, coir, wood, pineapple leaf, cow bone, palm kernel shell, rice husk. As fillers in order to replace synthetic fillers through utilization of natural fillers or reinforcement in thermoplastic and thermoset polymer composites in an attempt to minimize the cost, manage waste-wood, increase productivity and enhance mechanical properties of composites. Waste-wood as reinforcing fillers in plastics, in place of the previously used inorganic substances and synthetic fibres, offer a major benefit in terms of environmental protection. The benefits offered by waste-wood over synthetic fibres are low densities, non-abrasive, non-toxic, high stiffness and specific properties.
Solar powered cars - a review
Authors: Babalola P.O. , Atiba O.E.
Published: April 2021

The world population is increasing and so is the demand for transportation. The commonest of the means of transportation has been the automobile. And while the automobile industry is growing proportionally with population increase, there are still many problems with managing the causes of the pollution by automobiles. Hence, to cater for the needs of the society and still protect our environment, researchers have been seeking alternative sources to power transportation with little or no harmful emission. Suggested forms of energy for automobiles would be ones that are sustainable over the years. There are various available options of solar-powered vehicles which produces electricity through photovoltaic cells without any form of harmful waste to the atmosphere. In developing solar cars in particular, some discovery has been made in the aspect of effectively capturing, converting, and storing the solar energy to make it competitive with the conventional fossil fuel drive vehicles. This review covers the advancement and gaps in existing literature in the modulus operand of solar cars.
Short review on nanocomposite coating advances in the industry
Authors: Emmanuel O.A. , Fayomi O.S.I. , Agboola O. , Ayoola A.A , Oloke O.C. , Amusan L.M.
Published: April 2021

Study on the nanocomposite coating is on increase due to their multifunctional characteristics in industries. Nanocomposite coatings are made up of two or more immiscible nanomaterials which can also be detached with the purpose of providing mechanical properties that make them strong. It has also been of great importance in minimizing deterioration and biofouling impact. This coating has a great aplication in automotive, aerospace, seawater condensers and tubes, electronic industries, water electrolysis, energy generation. Furthermore, it has also enhanced the growth of paints and its properties in industrial production. Due to its properties, they are utilized in contruction firm, medical area, etc. Despite the aforementioned, nanocomposite coatings has increase in recent years as a result of advancements of nanoparticle manufacturing processes. This paper provides a brief review on nanocomposite coating in industry with focus on the effect, role, types and its application.
Ameliorating Urban Traffic Congestion for Sustainable Transportation
Authors: Busari A.A , Loto R.T. , Ajayi S.O , Odunlami O. , Folake Akintayo , Kehinde Oyesomi , Olawuyi O.
Published: April 2021

Population, ownership of vehicles and economic growth are increasing at a geometric rate. Invariably, this will lead to an increase in traffic volume and the demand for limited road infrastructures. These has generated a lot of constraint on the few available road infrastructures in most developed and developing nations of the world. One of the consequences of this, is traffic congestion. This arises when the road system approaches vehicle capacity. Although governments and policy makers may never be able to eliminate road congestion, there are several ways cities and states can move to curb it. Hence, this review of literature assessed the myriad effect of traffic congestion, with focus on the economic and environmental impact. Additionally, long and short term measures to reduce the menace in 2030 were evaluated. This was done by assessing the relevant literature on the topic. The outcome of the review revealed that increase in income and living standard favours the ownership of automobiles thereby increasing traffic congestion. Households that reside in areas with compact, mixed land use own fewer vehicles, make fewer vehicle trips, therefore mixed land use should be encouraged in urban development. Additionally, level of Service (LOS) is another factor that affects traffic congestion and traffic crashes. The outcome of this review will aid the government and policy makers on the appropriate tool to adopt and the draw backs in a bid to reduce this menace now and in the foreseeable future.