Metallic Objects Research Articles

Green Approach for Electropolishing Surface Treatments of Additive Manufactured Parts: A Comprehensive Review

Over the years, the widespread diffusion of additive manufacturing, especially to produce metal objects, and the awareness of their poor surface quality due to the presence of a significant roughness, have highlighted the need to develop suitable post-processing surface treatments. In this regard, electropolishing techniques are ideal due to their high versatility, even on geometrically complex or small-sized objects, which are difficult to treat with techniques that require physical contact with a tool. On the other hand, the common use of strong and dangerous acid baths does not allow compliance with increasingly stringent sustainability criteria. For this reason, special attention is increasingly directed toward the identification of green electrolytes, based on deep eutectic or acid-free solvents, potentially capable of replacing conventional acid solutions. The choice of new environmentally sustainable and specifically appropriate solvents according to the metal alloys treated could allow a further expansion of the additive processing technologies, and therefore preserve their advantage, extending, among other things, the demand for the related finished products thanks to their superior aesthetic and functional quality.

Robotic Detector with Rocker Bogie Mechanism

The Rocker Bogie Mechanism (RBM) is widely used in planetary rovers for its ability to traverse challenging terrain. However, the presence of metal debris in the terrain can pose a significant threat to the rover's mobility and instrumentation. Therefore, a metal detector integrated with the RBM is necessary to avoid any potential damage. This paper presents the design and development of a metal detector for the RBM, which includes the selection of suitable components, the development of the detection algorithm, and the integration with the RBM. The detector's performance is evaluated in both simulation and experimental settings, demonstrating the successful detection of metallic objects and their location.

Expediting emergent MRI in acute ischemic stroke by extending CT scout image: a simple intervention to decrease time to treatment (P11-5.010)

<h3>Objective:</h3> We revised our acute stroke CT protocol to reduce time to MRI in acute ischemic stroke. <h3>Background:</h3> “Time is brain” in acute stroke. Patients requiring emergent MR imaging in the emergency department prior to thrombolytic treatment (e.g. wake-up strokes, iodinated contrast allergy, assessment of DWI/FLAIR mismatch) must undergo the MRI safety screen for implantable devices and foreign metallic bodies. Patient factors including neurologic deficits, language barrier, or lack of information on implantable devices make the screening process time-consuming. If patients cannot complete the safety checklist, radiographic clearance with chest and abdomen x-rays is pursued which delays time to treatment. <h3>Design/Methods:</h3> We revised our CT acute stroke radiology protocol to include scout images from the head to the femur to screen for foreign bodies, implantable devices or metallic objects. Standard CTA head and neck scout images previously only extended to the mid-chest. The new protocol obviates need for MRI screening checklist in emergent situations and allows to proceed directly from CT to MRI with the assistance of the radiologist interpreting the scout image. <h3>Results:</h3> Our multidisciplinary stroke team has implemented this change in our emergency department CT acute stroke protocol. The difference in additional radiation exposure is minimal to non-significant; the estimated total radiation dose of the topogram for the head, neck, chest, abdomen, and pelvic regions is approximately 0.24mSv (of which only the abdomen and pelvis are additional in this protocol). In comparison, the radiation dose of a standard abdomen/pelvis radiograph is 0.7mSv. Data collection is ongoing to measure impact on door to needle time. <h3>Conclusions:</h3> Revision of the CT stroke protocol to extend the CT scout from the head to the femur can expedite clearance for emergent MRI in patients who are candidates for thrombolysis or thrombectomy at no significant expense or radiation. This has potential to reduce time to acute stroke treatment. <b>Disclosure:</b> Dr. Aghajan has nothing to disclose. Dr. Gupta has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for •

Excavating the Missing Iron Age: Reinforcing Local Heritage & Identity in Sievi, Finland

In the small county in Northern Ostrobothnia, Finland, on a forest island amid fields, a few metal objects were found by metal detectorists. The finds suggested Iron Age dates and generated great interest, for both local people and researchers. As a result, an examination of the find locations was conducted by archaeologists, which was followed by excavations at one of the sites. In this article, under scrutiny is the interest excavations formulate in local contexts and how people relate to archaeological sites of their neighborhood. In addition, the role of metal-detecting in archaeology is considered. Generally, people in Finland are interested in the past of their home region. What about if there are only imperceptible remains and minor finds like fragments of ancient objects or shards of burned bone? Is material heritage important in everyday settings, and are people attracted to it? Here the aim is to relate some answers to these questions obtained by observations and discussions with the local people during the field research process.

Using a handheld metal detector to detect ingested hooks and other metallic objects in freshwater turtles

AbstractTurtles can be unintentionally hooked during recreational and commercial fishing operations. While hook ingestion is not always fatal, ingested hooks can harm or kill turtles by damaging soft tissues or affecting digestion. Detecting ingested hooks and other metallic debris in the field is a challenge. As such, we tested the efficacy of a handheld metal detector in detecting ingested fish hooks and incidental metallic debris in freshwater turtles in Georgia, USA. We captured 426 individual freshwater turtles representing 4 species and radiographed 106 yellow‐bellied sliders (Trachemys scripta scripta). Of 37 turtles that tested positive with a handheld metal detector, radiographs revealed 17 (46%) had ingested at least one hook, 15 (40%) had ingested an unidentifiable metal object or objects, and 5 (14%) showed no clear signs of hooks or other metallic objects. All 69 turtles that tested negative in the field and were radiographed showed no signs of metal ingestion. Accordingly, our proportion of false positives was 14% (5 of 37), false negatives (metal not detected in field but on follow‐up radiograph) were 0% (0 of 69), and our overall accuracy at detecting ingested metal with a handheld metal detector was 95% (101 of 106 radiographed turtles). Thus, handheld metal detectors may be a useful tool for detecting ingested hooks and other metallic objects in freshwater turtles.

1600 BC: Fårdrup and Valsømagle-Type Axes and the First Evidence of Southern Alpine Metal

Abstract This article presents the results of a comprehensive investigation of Fårdrup and Valsømagle-type shafthole axes from Denmark and southern Sweden. The combination of artefact style and typology with trace element and lead isotope data in the analysis has provided new insights into the chronological relationship between these two axe types. This way, we open a new window to long-standing debates surrounding these artefact types. Did Fårdrup and Valsømagle type axes evolve parallel, or did they replace each other chronologically in evolutionary progression? The archaeometallurgical dataset presented in this article includes more than 70 axes. Four axes have been analysed for this article. This large set of data is then assessed against a background of metal analyses which trace the long and winding evolution of the use of bronze in Scandinavia c.2300–1400 BC. Combining these two datasets shows the provenance of the metals and, thus, provides insights into metallurgical developments at the onset of the Nordic Bronze Age (NBA, c.1600 BC). In particular, the shafthole axes offer new evidence of the use of a novel type of copper from the East Alpine region based on chalcopyrite ores. The first occurrences of this low-impurity copper in southern Scandinavia appeared around 1700 BC. However, it would eventually become dominant in c.1600 BC, when the local production of shafthole axes began. Significantly, a fraction of the shafthole axes – Fårdrup and Valsømagle-types alike – consist of low impurity copper most likely derived from the Italian Alps (Trentino), which was absent in earlier periods. By NBA II 1500–1300 BC, most metal objects can be related to this northern Italian copper. We interpret this in terms of chronology: Fårdrup (⁓Koszider) and Valsømagle (⁓Tumulus B1) consisted of similar types of copper, which had declined by the onset of NBA II, all indicating that Fårdrup and Valsømagle style objects flourished before the beginning of NBA II (c.1500 BC). The small influx of north Italian copper in the axes indicates that its arrival began before the breakthrough of NBA II. Therefore, while the results of the metal analyses cannot exclude chronological differences between the two shafthole axe types over the 16th century BC, it is probable that their timelines coincided. In summary, our results display correlations between societal developments and thresholds on the one hand and metal provenances and trade routes on the other.

Metal Quivers from Hasanlu

Abstract During the remarkable excavations at Hasanlu, in northwestern Iran, thousands of metal objects were discovered, but few have been systematically studied. The goal of this study is to present a catalogue of the metal quivers found by the Joint Expedition to Hasanlu (1956–1977), led by Robert H. Dyson of the University of Pennsylvania Museum. After a brief introduction concerning the site and the evidence for metal quivers in the Ancient Near East as a whole, the examples discovered at Hasanlu will be presented and analyzed within their archaeological contexts.

Топоры как товаро-деньги в контексте их ритуального и социального значения

During its history, money has undergone a complex evolution due to historical and cultural transformations in the different periods. Money as medium of account and exchange arose in the Neolithic era simultaneously with the new stage of social-economic relations, when the surplus of products takes on a commodity form and the barter exchange developed. In the Early Bronze Age (III millennium BC) the first statements arose, bronze and precious metals appeared in Western Asia including the Armenian Highland. At the same time measurement of weight was created in Mesopotamia, money expressed in metal objects became not only a price equivalent, but also medium of payment. The axe, as the most important tool and weapon, acquires the significance of money. Therefore, the Sumer/Akkadian shekel, which was the widespread unit of currency in Near East, originates from the word “axe”.

Adaptive sampling for accelerating neutron diffraction-based strain mapping * *This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive,paid-up, irrevocable, world-wide license to publish or reproduce the published form of

Neutron diffraction is a useful technique for mapping residual strains in dense metal objects. The technique works by placing an object in the path of a neutron beam, measuring the diffracted signals and inferring the local lattice strain values from the measurement. In order to map the strains across the entire object, the object is stepped one position at a time in the path of the neutron beam, typically in raster order, and at each position a strain value is estimated. Typical dwell times at neutron diffraction instruments result in an overall measurement that can take several hours to map an object that is several tens of centimeters in each dimension at a resolution of a few millimeters, during which the end users do not have an estimate of the global strain features and are at risk of incomplete information in case of instruments outages. In this paper, we propose an object adaptive sampling strategy to measure the significant points first. We start with a small initial uniform set of measurement points across the object to be mapped, compute the strain in those positions and use a machine learning technique to predict the next position to measure in the object. Specifically, we use a Bayesian optimization based on a Gaussian process regression method to infer the underlying strain field from a sparse set of measurements and predict the next most informative positions to measure based on estimates of the mean and variance in the strain fields estimated from the previously measured points. We demonstrate our real-time measure-infer-predict workflow on additively manufactured steel parts—demonstrating that we can get an accurate strain estimate even with 30%–40% of the typical number of measurements—leading the path to faster strain mapping with useful real-time feedback. We emphasize that the proposed method is general and can be used for fast mapping of other material properties such as phase fractions from time-consuming point-wise neutron measurements.

Object Identification With Minimal Precomputed Library Using Physical Aspect of Singularity Expansion Method

In this letter, we propose a method for estimating the circumferential length of metal objects without any <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a priori</i> information regarding object shape and dimension. Object type can also be determined using this method with a reduced precomputed library consisting of the quality factor of fundamental natural resonance frequency and the ratio of second-order to first-order damped resonance frequency for each object type. The proposed method is applied to identify different canonical objects. Natural resonance frequencies, extracted using the matrix pencil method of singularity expansion from the scattered field from different metal objects, have been validated with physical reasoning. Simple methods for predicting the resonance frequency of triangular plates and discs have been proposed.

Wearable Ungrounded Tag Antenna for UHF RFID Applications

A single-layer ungrounded tag antenna is designed for on-body radio frequency identification (RFID) applications in the ultrahigh frequency (UHF) band. The ungrounded tag antenna is designed based on a broadside radiating Huygens source. The electric dipole is generated by the center part of an original dipole, while two orthogonal magnetic dipoles are created by stacking another two metallic strips at the edge of the original dipole. The tag antenna shows good robustness of input matching and radiation efficiency with respect to the human-body effect. Furthermore, the designed tag antenna is also able to work with metallic objects and its resonant frequency is stable around 920 MHz. Finally, three tag prototypes, including the proposed tag antenna, are fabricated and tested. The measured reading range confirms the numerical simulations and demonstrates the robustness of the proposed design with respect to different distances between human-body and tag antenna. The proposed tag provides a reading range of 5.0 m (near-body), 8.0 m (free space), and 16.5 m ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$200\times200$ </tex-math></inline-formula> mm metallic plate), respectively.

A Compact UHF-RFID Tag Antenna With Embedded AMC for Metallic Objects

In this letter, a UHF-RFID tag antenna with a size of 40 × 40 × 3.2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> is proposed for metallic objects. It is composed of a modified folded dipolar antenna (MFDA) and an embedded 2 × 2 artificial magnetic conductor (AMC) array with shorting vias. Multiple slots are etched on the MFDA and AMC to increase the current path, where the slots on the MFDA is vertical to that on the AMC so that the currents on the MFDA and AMC do not affect each other. Thus, the slots can be adjusted independently without affecting the resonant feature of the MFDA. Equivalent circuit models are also presented to understand the impedance characteristics. A prototype mounted on a 20 × 20 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> metal plate has been manufactured and measured. It is demonstrated that the proposed tag antenna shows a 3.9 dB gain enhancement comparing with the MFDA without AMC and a maximum gain of −1 dBi at 919 MHz. Moreover, a maximum reading distance of about 14.2 m can be obtained.

The effect of sambiloto leaf (Andrographis paniculata Nees) extract inhibitor concentration on the corrosion rate of iron in the corrosive HCl medium and well water

Corrosion is a chemical reaction between metal and chemical substances in free air influenced by typographical conditions, climate, and humidity levels around the metal object. If left unchecked, it can cause damage to the metal infrastructure, material losses, and harm in terms of safety and security. Therefore, a way to inhibit corrosion is needed by creating an environmentally friendly inhibitor from natural materials. One of them is by utilizing Sambiloti leaf as a natural inhibitor. Sambiloto leaves contain tannins which can inhibit corrosion well. This study aimed to determine the efficiency of Sambiloto leaves ethanol extract in inhibiting the corrosion rate of metals in the corrosive medium of well water. HCl was soaked for seven days to determine the correlation between the corrosion rate and extract concentration in different corrosive media. Sambiloto leaves were extracted using the soxhletation method using 96% ethanol solution, then distilled to obtain a pure extract. Sambiloto leaf extract was then varied in concentration, namely 1%, 5%, 10%, and 15%. The corrosive medium is well water and HCl, and the metal material used is nails. The results showed that adding Sambiloto extract with a concentration of 15% in both corrosive mediums had the highest inhibitor efficiency values, namely 97.32% in the corrosive HCl medium and 69.3% in the corrosive well water medium. The results of the regression analysis showed that the addition of Sambiloto extract had a significant effect on the corrosion rate in well water media. In contrast, in the HCl medium, the addition of Sambiloto extract did not significantly affect the corrosion rate.

Rescue Excavation in Aggtelek-Baradla Cave in 2019

The team of the Institute of Archaeological Sciences of the Eötvös Loránd University conducted a rescue excavation in the Baradla Cave in 2019. The work concentrated in a passage leading to a less-researched branch of the cave (the so-called Róka-ág [Fox Branch]) and one of the lesser rooms named Biológiai labor (Biological Laboratory). The passage towards the low and narrow Róka-ág was used for millennia, as attested by the objects from various historical periods and the stakeholes, probably related to former wooden walkways, discovered there. We unearthed an intact Neolithic culture layer preserved by a travertine (calc-sinter) deposit in Biológiai labor, while the metal detector survey carried out in the cave simultaneously with the excavations yielded Late Bronze and Early Iron Age, as well as medieval metal objects. The most significant discovery of our metal detector specialists was a Middle Bronze Age depot of decorative bronze clothing accessories. The recovered findings and observed features confirmed that the internal spaces of the Baradla Cave served as venues for ritual activity in the Neolithic and the Bronze Age.

Hellenistic and Roman fine wares from ancient Elis, Greece: Α preliminary technological study using SEM/EDS analysis

This paper focuses on the archaeometric analysis of a pottery assemblage from the West Stoa (the so-called Stoa of the Hellanodikai) in ancient Elis, Greece. The Stoa was in use from the Archaic to the Roman times. Between the 6th and the 4th century BC, it served as the seat of the officials (the Hellanodikai) who oversaw the Olympic Games. Excavations revealed rich findings, such as fragments of glass and metal objects, murex shells, pottery fragments and a plethora of animal bones. The assemblage under examination consists of sixty-one (61) black slipped, red slipped and terra sigillata drinking pots and other forms of table wares, dated between the 3rd and the late 1st century BC. All samples were first classified based on their typological traits and then examined both macroscopically and microscopically. Based on their visual traits, five fabric groups were determined and 44 samples, representative of each fabric group, were selected for further chemical examination. SEM/EDS was used to characterize chemically and technologically the fabric groups. The combined use of LED and SEM/EDS revealed that the majority of the vessels presents a hard, non-porous, calcareous clay fabric (CaO > 10 wt%), which led to the production of high quality, durable vessels. In general, the fabrics and the chemical groups are not correlated, with the exception of the terra sigillata samples which present homogeneity, both microscopical and chemical. The examination of the microstructure showed that the pots were fired at a temperature between 850 and 1050 °C, which is typical for Hellenistic and Roman pottery production. The homogeneity and the thickness of the slip in most of the samples are indications of its high quality. Overall, the current combined typological and analytical study of a pottery assemblage from a recently excavated archaeological site significantly contributes to the acquisition of new data about western Peloponnesian pottery fabrics.

Analysis of electrical grounding design of substation and lines

This work analyzed the electrical grounding design of substation and lines. Substations are a crucial component of the electrical power system, so it is important to have properly designed grounding systems to protect people working nearby earthed facilities from electric shock risk, protect equipment from breakdowns, and ensure steady operation of the entire electrical system. There is frequently a concern that earth faults can produce hazardous voltage gradients in the earth at the site of the fault when energy is produced remotely and there are no other return channels for earth faults except the earth itself (called ground potential rises). In other words, someone standing close to the fault runs the risk of getting an electrical shock due to two factors: first, a potentially dangerous potential difference between the earth and any metallic objects they may be touching; and second, a potentially dangerous voltage gradient between their feet and the ground. The goal of constructing a safe grounding system is to give fault currents the simplest and shortest path without going above equipment and operating restrictions and negatively compromising service continuity. This work proposes a suitable grounding system design for alternating current (A.C.) substations based on the relevant IEEE Standards and International best practices. The study outlines the detailed calculations required to arrive at the mesh, touch, and step potential values appropriate for a good grounding system model for the A.C. Electrical substation. The suggested design provides for the safe functioning of all substation facilities, the safety of substation staff, and greater system dependability.

Money or ingots? Metrological research on pre-contact Ecuadorian “axe-monies”

The so-called “axe-monies”, trapezoidal sheet metal objects made of arsenical copper alloy, are associated with graves and hoards of the Manteño-Huancavilca (AD 600–1532) and Milagro-Quevedo (AD 400–1532) cultures, both located on the southern coast of Ecuador. Historically, scholars identified these artifacts as money, relating them to a currency system. This paper aims to test this hypothesis by investigating the degree of standardization (if any) through analyzing an important sample of these objects. Metrological analysis of their dimensions (length, width) and weight show that the currency hypothesis is flawed because neither clustering of dimensions nor a tendency towards a single (range of) weight value(s) is found. We suggest that the axe-monies may have been used as ingots, for arsenical copper alloys were a key commodity in the framework of exchange involving different cultures across America’s Pacific coast.

A metal object detection system for electric vehicle wireless charging with quadrupole detection coils

In the practical application of magnetic coupling wireless charging technology, the absence of direct contact between the receiver and transmitter usually leads to metal objects (MOs) entering the charging area. The strong magnetic field between the receiver and transmitter causes eddy current effects and generates large amounts of heat in MOs, which may lead to serious hazards such as fires, so it is necessary to detect accidental entry of MOs. In this paper, a novel detection coil layout suitable for wireless charging of electric vehicles (EVs) has been proposed, which consists of multiple quadrupole coils arranged to achieve decoupling from the receiver and the transmitter to minimize the effect on the system efficiency. The influence of the presence of MOs on the equivalent inductance and equivalent resistance of the quadrupole detection coil has been deduced. The simulation results show that the maximum self-inductance change rate of the proposed detection coil reaches 28.11%, and a high self-inductance variation rate is also achieved at the edge of the detection coil.

Indigesible foreign bodies in feedfor livestock and preventive measures in farm conditions

In the modern conditions of dairy farming, the presence of indigestible foreign bodies in the stomachs of cattle is common, which is due to many factors. In 15 cows of the farm (6 % of the total number of animals in the herd), culled due to the pathology of the digestive organs, damage to the mesh and adjacent organs was diagnosed. The largest number of indigestible foreign bodies was metal objects, which were found in 8 cows; nylon ropes, kapron nets, polyethylene bags – for 4 cows; rags and leather items – from 2 cows; gravel and pieces of concrete were found in one animal. Consumption of indigestible foreign bodies is a common occurrence in farmed cattle, which can be a significant cause of loss of productivity, premature culling, and even animal death. Proper handling of indigestible foreign objects, plastic waste on the farm should be an integral part of preventive measures for animal disease, reduction of culling and improvement of animal welfare. Comprehensive dispensation must be carried out in the following areas: determination of herd syndromes, clinical studies of animals, laboratory studies of blood, milk, urine, analysis of feeding and keeping of animals. One of the main preventive measures is the regular probing of cows for metal-carrying objects with magnetic probes, the introduction of metal object catchers. Among the workers serving the livestock industry, carry out explanatory work on the danger of spreading various indigestible objects on the territory of fodder lands and livestock farms.

Comparative study of real-time terahertz imaging of concealed metallic objects, drug, wood and TNT explosive in transmission/reflection modes using uncooled microbolometer and ultrafast pulsed terahertz imaging systems

Comparative study of real-time terahertz imaging of concealed metallic objects, drug, wood and TNT explosive in transmission/reflection modes using uncooled microbolometer and ultrafast pulsed terahertz imaging systems