Special Issue "Lightweight Structural Materials for Automotive and Aerospace"

Modern transport represents a vital part of the global economy, but it is also a significant source of pollutants, contributing 13% of overall greenhouse gas and 25% of CO₂ emissions coming from the combustion of fossil fuels [...].

Critical Minerals for Zero-Emission Transportation

Fundamentals of critical minerals and their paramount role in the successful deployment of clean energy technologies in future transportation are assessed along with current global efforts to satisfy the needs of automotive supply chains and environmental concerns. An implementation of large quantities of minerals, in particular metals, into the manufacturing of strategic components of zero-emission vehicles will bring new challenges to energy security. As a result, a reduced dependency on conventional hydrocarbon resources may lead to new and unexpected interdependencies, including dependencies on raw materials. It is concluded that to minimize the impact of a metal-intensive transition to clean transportation, in addition to overcoming challenges with minerals mining and processing, further progress in understanding the properties of critical materials will be required to better correlate them with intended applications, to identify potential substitutions and to optimize their use through the sustainable exploration of their resources and a circular economy.

Current Trends in Automotive Lightweighting Strategies and Materials

The automotive lightweighting trends, being driven by sustainability, cost, and performance, that create the enormous demand for lightweight materials and design concepts, are assessed as a part of the circular economy solutions in modern mobility and transportation. The current strategies that aim beyond the basic weight reduction and cover also the structural efficiency as well as the economic and environmental impact are explained with an essence of guidelines for materials selection with an eco-friendly approach, substitution rules, and a paradigm of the multi-material design. Particular attention is paid to the metallic alloys sector and progress in global R&D activities that cover the “lightweight steel”, conventional aluminum, and magnesium alloys, together with well-established technologies of components manufacturing and future-oriented solutions, and with both adjusting to a transition from internal combustion engines to electric vehicles. Moreover, opportunities and challenges that the lightweighting creates are discussed with strategies of achieving its goals through structural engineering, including the metal-matrix composites, laminates, sandwich structures, and bionic-inspired archetypes. The profound role of the aerospace and car-racing industries is emphasized as the key drivers of lightweighting in mainstream automotive vehicles.

Thermal Stability of Aluminum Alloys

Thermal stability, determining the material ability of retaining its properties at required temperatures over extended service time, is becoming the next frontier for aluminum alloys. Its improvement would substantially expand their range of structural applications, especially in automotive and aerospace industries. This report explains the fundamentals of thermal stability; definitions, the properties involved; and the deterioration indicators during thermal/thermomechanical exposures, including an impact of accidental fire, and testing techniques. For individual classes of alloys, efforts aimed at identifying factors stabilizing their microstructure at service temperatures are described. Particular attention is paid to attempts of increasing the current upper service limit of high-temperature grades. In addition to alloying aluminum with a variety of elements to create the thermally stable microstructure, in particular, transition and rare-earth metals, parallel efforts are explored through applying novel routes of alloy processing, such as rapid solidification, powder metallurgy and additive manufacturing, engineering alloys in a liquid state prior to casting, and post-casting treatments. The goal is to overcome the present barriers and to develop novel aluminum alloys with superior properties that are stable across the temperature and time space, required by modern designs.

Nasal septum morphology in human fetuses in computed tomography images

Objectives

Nasal septum deformation (NSD) may cause breathing dysfunction. The reason for a septal deviation is the developmental anomaly in growth of the elastic septum or its skeleton. Such a type of deviation is called physiological. Some deviations can result from the prenatal trauma. The aim of the work was the analysis of the anatomy of the nasal cavity with a special interest focused on the nasal septum and its deviation.

Materials and methods

The nasal cavity with its bones and septum was analyzed in CT images of 105 spontaneously aborted fetuses (57 males and 48 females) aged 12 and 40 weeks of gestation. We attempted to assess the morphometric development of the nasal cavity with tomographic scanning methods and to detect anatomical variations.

Results

In 15 (14.3%) fetuses, NSD were detected on radiological sections. The angle between the virtual line from the sphenoid sinus ostium through limen nasi and the horizontal plane was 33.6 ± 2.3°, on average.

Conclusions

NSD may already be found in fetuses. The observation of the nasal cavity development enables to evaluate the growth and symmetry of the nasal septum and to foretell predispositions for dysfunction in the upper respiratory tract.

Analytical Electron- and Atomic Force Microscopy Study of Multilayered Oxide Films Formedon Ce-DOPED Ni

Oxide films up to 200 nm thick were grown at high temperatures on Ni substrates implantedwith 2x1016 Ce ions/cm2. The surface morphology, microstructure and microchemistry were examined by AFM and TEM/STEM techniques. It has been found that the oxide films are composed of three well defined sublayers, with essentially different microstructure and Ce concentration. The outer layer is composed of NiO and CeO2 nanocrystals with a size less than 5 nm. The same two phases are also present within the middle layer, although the NiO grains are much larger in comparison to nano-sized CeO2. In addition, Ce segregation along the NiO grain boundaries is detected in this layer. The inner layer is the thickest one and is composed of pure NiO grains. Oxide films having such a complex structure are characterized by a very low diffusion rate for both metal and oxygen ions. Oxygen isotope experiments revealed that the diffusion processes within the oxide film are controlled by the Ce-rich layers.

Thermal Stability Of Electrodeposited Nanocrystalline Ni-45%Fe Alloys

Electrolytically deposited nanocrystalline Ni-45%Fe alloys, composed of γ (f.c.c.) phase, were annealed at 573 and 673 K for time periods up to 20 h in an inert atmosphere of argon. The evolutions of crystallographic texture, grain size, and microhardness were analyzed as a function of annealing parameters. The initial grains, approximately 5 nm in size increased after annealing up to 10–20 nm, however, the growth kinetics and the final grain size depended on the temperature. A correlation was found between the grain size and alloy microhardness. The phase composition was unstable and during annealing the α(b.c.c) phase was detected to precipitate from the γ matrix. The texture of γ phase, consisted of two fibre components of <111> and <200>, and evolved at high temperatures. Although the detailed changes depended on the annealing temperature, in general, the <111> component became stronger at the expense of the <200> component.

Tobacco abuse and physical activity among medical students

Objective

This lifestyle is mainly determined during childhood and connected with poor public prophylactic health policy. The aim of this study was to estimate physical activity and level of tobacco abuse, as well as knowledge about health behaviours, among medical students.

Methods

Questionnaires were completed by Polish (243) and foreign medical students (80).

Results

It was stated that about 20% of the students smoked cigarettes. Female students from Norway took up smoking significantly more often than other participants, whereas there were more smokers among those from Poland. There was a significantly larger percentage of smoking males from Norway than among male Polish students. The same students presented a low level of physical activity. The smallest level of physical activity was characteristic of the Polish women.

Conclusion

This situation requires an intensification of activities aimed at supporting pro-health lifestyles and the elimination of unfavourable effects, especially among medical students.

Deformation of the nasal septum in children, adolescents, and adults in Western Pomerania province of Poland

OBJECTIVES

Nasal septum deformation (NSD) contributes to the occurrence of upper respiratory tract diseases in around 45-55% of Poland's population. The evaluation of frequency of occurrence and type of nasal septum deformation among randomly chosen representatives of the Szczecin and surrounding area population was the aim of this study.

METHODS

NSD was assessed in 235 patients (123 male, 112 female) aged 5-60. Mladina's classification system was used for the evaluation.

RESULTS

Deformations of nasal septum were found in 43% of the examined subjects. Type 3 of NSD dominated (12.4%), while types 2 and 1 were found in 10.3% and 4.2% of the subjects, respectively. 9.2% of the patients showed type 5 of deformation, while types 6, 4, and 7 were found in 1.3%, 3.2% and 2.7% of the patients, respectively.

CONCLUSIONS

Straight nasal septum was found in females more often than in males, mostly on the left side. Associations between NSD, on one side, and age, sex, and traumas, on the other were found. NSD influenced the quality of respiration and frequency of upper respiratory tract diseases in the examined subjects.

Snoring - the role of the laryngologist in diagnosing and treating its causes

According to various data, snoring may affect about 2 billion people worldwide, with about 8 million adult people in Poland being estimated to snore. Apart from being disturbing for other people, it brings about a measurable risk for the patient, which results from transient anoxia. As a consequence, it may increase the risk of arterial hypertension, myocardial infarction, cerebral stroke and impotency, as well as mental disturbances like depression or anxiety states. The physician a snoring patient may consult in the first instance is the laryngologist. He determines whether upper airway obturation (in contrast to central sleep apnea) is dealt with, and takes a decision about treatment method, or redirects the patient to another specialist. In this paper, the position of a laryngologist in the diagnosis and treatment of snoring is presented. The material consisted of patients presenting with this problem at the otolaryngology department. The proceedings with patients in the admission office setting were described as well as qualification methods for further medical and operative treatment. A review of the applied procedures was made, in particular allowing for the most recent therapeutic methods.

Microangiographic imaging of the prostate

OBJECTIVE

To present the results of microangiography in visualizing prostatic microvascularization.

MATERIALS AND METHODS

A contrast medium was injected into the vessels of prostate specimens obtained during surgery, to fill small vessels; nine specimens were obtained after cystoprostatectomy and two after radical prostatectomy. Branches of prostatic or seminal vesicle arteries were used for the injection, the specimens then fixed in formalin, sectioned and X-rayed.

RESULTS

In five samples the quality of the images was sufficient to visualize small arteries; the remaining vessels were partially filled. The vascular map was compared with previous results from historadiographic studies.

CONCLUSIONS

Microangiographic imaging of prostate specimens provides a unique view of the angioarchitecture of the prostate and correlates closely with historadiographic studies. The correlation with other imaging methods, e.g. Doppler ultrasonography, needs further evaluation.

CT-guided percutaneous laser disc decompression with Ceralas D, a diode laser with 980-nm wavelength and 200-microm fiber optics

The aim of this study was to evaluate the compact, portable Ceralas-D diode laser (CeramOptec; 980 + 30 nm wavelength, 200-microm optical fiber) concerning clinical usefulness, handling, and clinical results in the CT-guided treatment of herniated lumbar discs. The positioning of the canula in intradiscal space, the placement of the laser fiber into the disc through the lying canula, and the vaporization itself were carried out under CT-guidance. Due to the thin fiber optic, it was possible to use a thin 23-gauge canula. The laser procedure was performed in 0.1- to 1-s shots with 1-s pulse pause and 4-W power output. A total of 1650-2300 J was applied on each percutaneous laser disc decompression (PLDD). Results in 26 patients were established with a visual-analogue scale (VAS). On the follow-up examinations, 46% of the patients were absolutely pain free ( > 85 % VAS) and fully active in everyday life after 4 postoperative weeks. Thirty-one percent of patients were relieved of the leg pain but had occasional back pain without sensorimotor impairment. Fifteen percent sensed a slight alleviation ( > 50% VAS) of the radiate pain. Eight percent did not experience radicular or pseudo-radicular pain alleviation (< 25% VAS). Cerales-D proves to be an efficient tool for CT-guided PLDD on non-sequestered herniated lumbar discs.

Accuracy of intravascular microcatheter pressure measurements: an experimental study

Intravascular pressure measurements are considered useful for the monitoring and assessment of endovascular treatment effects in intracranial vascular malformations. Experimental data on the accuracy of these measurements are limited. A flow phantom with defined intraluminal pressures and pulsatility flow waveforms was used in this study. Microcatheters commercially available for neuroendovascular procedures (length 140-155 cm), with different outer (0.5-0.83 mm) and inner (0.3-0.53 mm) diameters, were introduced into the phantom in the direction of flow. In a static experiment, pressure values from 0 to 75 mmHg were applied, and in the dynamic part of the experiment mean pressure values from 25 to 65 mmHg, with a pulsatile amplitude from 70 to 170 mmHg were employed. In the static experiment, there was a linear relationship between the pressure values obtained through the microcatheters and the local transducer of the flow phantom. The pulsatile experiments showed increased damping of the pressure waveforms with decreasing inner diameter of the microcatheters. However, the mean pressure values remained accurate. This experimental study has shown that mean pressure values can be accurately measured through microcatheters from 0.3-0.5 mm inner diameter and more than 140 cm in length. In vivo pressure measurements during interventional procedures are therefore reproducible and can be used for monitoring of embolization effects in patients.

Endovascular laser detachment of platinum alloy microcoils: principle and initial experimental experience

The aim of the investigation was the technical realization and approval of a new method for insertion and detachment of platinum alloy microcoils and other vascular implants via standard microcatheters. Flexible lightconducting fibers, 105 microns in diameter were connected to platinum alloy microcoils. It was examined whether an insertion wire, a lightconducting fiber and a platinum alloy microcoil could be advanced through a Tracker-18 (Target) microcatheter. The detachment of the attached coil from the lightconducting fiber was investigated. Platinum alloy microcoils can be attached to available lightconducting fibers in a reliable and reproduceable manner. Together with the fiber they can be advanced via a Tracker-18 microcatheter. Only extremely tortuous vessels may increase the friction to critical values. A Ho-YAG laser source was used. This allowed the instantaneous detachment of microcoils from laser fibers. In contrast to electrolytical detachment, no foreign substances are released to the blood stream. The detachment does not require waiting time and does not activate thrombus formation. Due to specific technical features, injuries of the vessel wall are avoided. After further miniaturization and adaption of the lightconducting fibers to the required characteristics, laster detachment may have the potential to replace current methods such as electrolytical and mechanical coil detachment.