Metal Work Research Articles

CO adsorption on MgO thin-films: formation and interaction of surface charged defects.

Two-dimensional (2D) materials formed by thin-films of metal oxides that grow on metal supports are commonly used in heterogeneous catalysis and multilayer electronic devices. Despite extensive research on these systems, the effects of charged defects at supported oxides on surface processes are still not clear. In this work, we perform spin-polarized density-functional theory (DFT) calculations to investigate formation and interaction of charged magnesium and oxygen vacancies, and Al dopants on MgO(001)/Ag(001) surface. The results show a sizable interface compressive effect that decreases the metal work function as electrons are added on the MgO surface with a magnesium vacancy. This surface displays a larger formation energy in a water environment (O-rich condition) even with additional Al-doping. Under these conditions, we found that a polar molecule such as CO is more strongly adsorbed on the low-coordination oxygen sites due to a larger contribution of the channeled electronic transport with the silver interface regardless of the surface charge. Therefore, these findings elucidate how surface intrinsic vacancies can influence or contribute to charge transfer, which allows one to explore more specific reactions at different surface topologies for more efficient catalysts for CO2 conversion.

Design of fluid flow optimized ejector drill heads for efficient metalworking fluid supply to the cutting zone

Ejector deep hole drilling is used for demanding drilling applications with high quality requirements, performed on conventional machining centers and lathes. The characteristically distributed metal working fluid flow based on the ejector effect is responsible for a stable and efficient process. The metal working fluid supply of the cutting edges as well as of the guide pads and the maintaining of a stable process are a major challenge for the optimization of ejector tools. To achieve an enhanced understanding of the fluid flow at the ejector drill head, a Smoothed Particle Hydrodynamics based simulation model was developed, which allows to simulate the challenging effects and conditions of the process. Different variants of optimized drill head concepts in favor of fluid flow are designed in this scientific paper, which lead to an enhanced metal working fluid supply to the cutting edges and guide pads at the drill head. The analysis of the fluid flow at the drill head is carried out with the results of the SPH simulation.

Combined Charcot hindfoot and midfoot reconstruction using internal fixation method-surgical technique and single surgeon series.

Isolated midfoot and hindfoot Charcot reconstruction using internal fixation is increasingly a common procedure in multidisciplinary diabetic foot units, and the surgical techniques using internal fixation have well been described. However, about a third of Charcot deformities that require surgical limb salvage present with the involvement of midfoot and hindfoot. Surgical reconstruction of a combined hindfoot and midfoot deformity is an evolving technique and technically challenging. We present the surgical technique of deformity correction and stabilisation using internal fixation, developed by the senior author (VK), and present the outcomes. All patients that had undergone combined hindfoot and midfoot reconstruction to address a limb threatening deformity due to Charcot neuroarthropathy, performed by the senior author, with a minimum follow-up of 12 months, have been included in this study. The principles of surgical reconstruction included adequate pre-operative optimisation of the patient, sequential deformity correction and stabilisation of the hindfoot followed by midfoot using the principle of long-segment rigid internal fixation with optimal bone opposition. Standard post-operative regime, including offloading, has been used in all patients. A total of 34 patients (35 feet) had undergone combined midfoot and hindfoot Charcot reconstruction between January 2009 and December 2019. Active ulcers were noted in 13 feet at the time of the procedure. Eleven reconstructions were performed as two-stage procedures due to the presence of active infection. At a mean follow-up of 53 months, 11/13 ulcer healed, and 32 patients (33 feet) were full weightbearing in surgical shoes or a brace at the latest follow-up. Bone fusion was noted in 28 feet in the hindfoot region and 32 feet in the midfoot. Metal work failure was noted in 5 feet requiring removal in 3 feet. Revision procedures were required in 4 patients. Our newly described technique of combined hindfoot and midfoot Charcot has provided functional limb salvage in majority of presentations, with an acceptable level of complications, at a medium-term follow-up of 53 months.

Nature Inspired Thermomechanical Treatment to Investigate the Mechanical Properties of AISI 1040

Strengthening of metals as a function of metal working and thermal treatment is being utilized effectively in steel structures. Effect on strength beyond thermomechanical treatment has been the focus of this research by imprinting a nature inspired pattern on one side of the sheet metal. Pangolin scale pattern overlapped on AISI 1040 sheet metal while preserving its base treatment. Microstructure, impact toughness, hardness, and tensile strength with notch opposite to worked side was investigated after forging and post forging heat-treatment. After heating at 800°C, overlapping patterned forging was done on one side of two plates and then subsequently cooled in two ways, air cooled, and water quenched. To analyze the effect of forging and heat treatment, Charpy impact, UTS, hardness tests, and metallography were carried out on the heat treated (forged + quenched), untreated (forged + air cooled) and base (as received) specimens. The Room temperature Charpy test showed that the untreated specimen has the highest impact toughness of 120 J as that of the base and heat-treated specimen, 44 J and 60 J respectively. The heat-treated specimen showed an increase in macro and micro hardness than for the base and untreated specimens. Whereas the UTS has dropped in untreated and heat-treated specimens as compared to the base specimen, because in tensile test load is applied uniformly throughout the specimen so the stress concentrations in the unforged side of the metal higher than the side which is forged with overlapping patterns.

The Implementation of Education for Sustainable Development-Oriented Problem-Based Learning in Practical Work for Making Alum

The problem-based learning (PBL) method is one method to insert the competency targets of Education for Sustainable Development (ESD). This research aims to investigate how the implementation of ESD-oriented problem-based learning to metal and non-metal chemistry practical work. The research method used in this research is a qualitative descriptive method and the research subject is the 4th-semester Chemistry Education university students. The research result shows that the ESD-oriented PBL method is applicable in metal and non-metal chemistry practical work. Practical work with the ESD-oriented PBL method can be used as an innovation for practical learning activities to achieve the ESD target competencies. Based on the questionnaires responded by the students, it can be concluded that the practical work with the ESD-oriented PBL method could increase the students’ ability for problem-solving with percentages of 33% strongly agree and 50% agree. Practical work learning with the ESD-oriented PBL affects the students to be more active in practical work activities. The stages of the PBL method help the students develop problem-solving abilities, and this is one target of ESD competencies.

Development and Designing an Adjustable Metal Cut off Machine

Nowadays metal-cutting equipment is in demand in the market because of the different construction process not only on this infrastructure but also on the training process of different schools that offer qualification under the metals and engineering sector. Cutting these metals may also affect the budgetary cost of the output. Cut off machines are commonly used for this purpose. Cut off machines that are produced in the industry seem to be more expensive not just because of the parts but also because of the use of the consumption of the disc. Cut off machines uses #14 cut off disc. After using it there is always a residual disc that is having a diameter of 12 cm. This residual disc is almost the size of the disc of an angle grinder which is having a #7 cutting discs that almost cost 80 pesos. Also, this cut off machine cannot cut at your desired angle. Upon this issue, the researcher came up with developing and designing an adjustable metal cutter that can maximize the use of the disc and can cut at a different angle, As the result of the project almost 6 cm diameter was the maximum size of the waste disc. This machine can be used in the metals and engineering sector, specifically in SMAW, welding shops, construction companies, and others related to metal workings. This has also become economical because some parts of the machine are recyclable materials. A full factorial design of the experiment is selected for experimental planning and the analysis of variance (ANOVA) has been employed. Upon the evaluation, the adjustable metal cut off machine passed the level of (1) acceptability (2) functionality and (3) safety of the product.

Investigation of the resource indicators of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP

The Burshtyn TPP is separated from the unified energy system of Ukraine, operates as part of the "Burshtynskii Ostriv" in parallel with the Union for the Co-ordination of Transmission of Electricity (UCTE). Work within the "Burshtynskii Ostriv" requires the loading of up to nine power units of the station, whereas before that, no more than six power units worked at the station. On the one hand, joining the UCTE opened opportunities for increasing export supplies of electricity from Ukraine. On the other hand, the maneuvering mode of operation of the power plant in "Burshtynskii Ostriv" has an extremely negative effect on the condition of the equipment, as it leads to frequent start-stops of units. As a result of this regime, the accident rate of TPPs has increased significantly. Therefore, it is important to determine the individual resource of Burshtyn TPP power units and assess the possibility of continuing the operation. According to calculations, the total damage of the metal of the intermediate pressure rotor of the K-200-130 turbine unit of power unit No. 11 of DTEK Burshtyn TPP is 107%, with the coefficients of the safety margin for the number of cycles and for deformations at the level of 5 and 1.5, as well as at the permissible metal working time 370 thousand hours. If the total damage of the rotor metal is more than 100%, then further operation of the equipment is impossible according to regulatory documents and the resource is considered to be exhausted. According to experimental data, with the coefficients of safety margin for the number of cycles and deformations at the level of 3 and 1.25, as well as the allowable working time of the metal of 450 thousand hours, the total damage of the metal of the rotor is 83%. The residual resource of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP will be 58 908 hours. Thus, with the positive decision of the expert commission in accepting the reduced coefficients of safety margin, the allowable service life of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP can be extended by 50,000 hours. with additional number of starts of no more than 400.

Deposition of heavy metals in biological tissues of workers in metal workshops.

Welding and cutting of metals produce large amounts of particulate matter (PM), which poses a significant health risk to exposed workers. Appropriate biological markers to estimate exposure are of great interest for occupational health and safety. Here, hair and nail samples from metal workers were analyzed, which appear to be more suitable than blood or urine samples for assessing long-term exposure. Four workshops working with steel components were included in the study. The hair and nail samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentrations of 12 elements. At the workplaces, the concentrations of 15 elements in particulate matter were determined using X-ray fluorescence (XRF) and particle-induced X-ray emission (PIXE) techniques. The hair and nail samples of the workers contained significantly higher metal concentrations than the analytical results of a nonexposed control group. The most significant difference between the groups was found for Ti, Mn, Fe, and Co.

Analysis of the First Metallic Works That Represented a Geometric Innovation in Their Architectural Application: The Origin of the Architecture-Engineering Dichotomy

This research analyses the geometric modifications and improvements that the application of the technique of metallurgy meant for architecture. In the early days of engineering and without having the historical burden that architecture bore, the small variations in the classical definition of geometry meant the greatest advances at a structural and conceptual level in the world of metal structures. The use of metal as a structural element capable of containing new uses and responding to the great challenges that progress required was definitive for the development of the new architecture and paradigms of the new century. The new metallic materials and their mathematical and constructive models were the cause and effect of what would be the basis of the great change in modern architecture and engineering and would lay the foundations of today’s world. The interaction of these two new disciplines, architecture and engineering, and their relationship with metal is the basis of this research, which aims to find out where, when, and how these geometric changes took place that started to change the conception of metal structures.

Occupational safety practice among metal workers in Bangladesh: a community-level study

BackgroundThe overall information on occupational health and safety (OHS)-related knowledge and workplace practices are scarce in Bangladesh. This study aimed to (i) examine the prevalence of occupational injuries, (ii) explore the level of OHS-related knowledge and practice among workers and associated factors, and (iii) investigate the socioeconomic factors and OHS-related knowledge and practice scores as determinants of injury among metal workers at a community setting in Bangladesh.MethodsThis was a cross-sectional study conducted on all the functional metal workshops in a community of a town. The sociodemographic characteristics, history of injury and its consequences, and the state of knowledge and practice were measured using descriptive statistics. Univariate and multivariate analyses were used to measure the association between practice scores and sociodemographic factors and knowledge. Logistic regression was conducted to get the odds ratio of getting injured.ResultsA high annual rate (82.9%) of occupational injuries was documented in a one-year timeframe and the majority (81.1%) of injured workers lost more than three working days (median 20 days). Workers working in workshops with more than three workers were 3.3 times more likely to be injured [AOR = 3.33, 95% CI = 1.16, 9.58] compared to the workers in factories with one to three workers. Most of the workers had the basic knowledge related to OHS but the mean practice score was very low, 1.86 (SD 1.17). Higher education, lower monthly family income, and being an owner significantly led to higher practice scores.ConclusionsThe OHS-related knowledge was not properly translated into good workplace practices in small informal metal workshops because of the absence of implementation of OHS policies and monitoring by the relevant authority. Government should support the informal metal working sector to increase awareness and skills for the prevention and proper management of injuries and risks, and to ensure access to safety equipment and a safe environment.

Ethnography Of Traditional Bell Metal Craft Technology Practiced In Bankura District

Tradition of brass and bell metal work is still persisting in different parts of eastern India. Rarh Bengal is one of the most important traditional brass and bell-metal crafts region. These are non-industrial mode of technology and production, which is Practice by a number of hereditary groups. As example Kangsbanik, Karmakar, Kansari and Dhokra Kamar etc. Pukhuria (22.9351°N, 86.9662°E) is one important traditional bell metal technology center of Bankura district as well as Rarh Bengal, West Bengal, India. The artisans of Pukhuria village are specialized in making different sizes bell metal bowl and followed cast and wrought metal technique. This is locally known as Jam Bati, Ci Bati, Sada Bati etc. In this paper an attempt has been made to discuss the technological aspect of contemporary brass and bell metal work, which is practiced by artisans of Pukhuria, Bankura district. It may also highlight the sources of raw material, different tools, processing, finishing of objects etc.

The Effect of Friction Stir Welding Parameters on the Weldability of Aluminum Alloys with Similar and Dissimilar Metals: Review

The solid-state welding method known as friction stir welding (FSW) bonds two metallic work parts, whether the same or different, by plastically deforming the base metal. The frictional resistance between both metallic workpieces causes them to produce heat, which produces plastic deformation and welds them. However, the weldability and strength of FSW joints mainly depend on the FSW parameters. This review work highlights the previous research work on the FSW parameters and their effects on the weldability and quality of the aluminum alloys joined with similar and dissimilar metals through the FSW method. About 150 research studies were systematically reviewed, and the articles included data from peer-reviewed journals. It has been concluded that the key parameters, including welding speed, “rotational speed”, “plunge depth”, “spindle torque”, “shoulder design”, “base material”, “pin profile” and “tool type”, significantly affect the weldability of the aluminum joint through the FSW method. Also, the selection of these parameters is important and fundamental as they directly affect the joint. It is recommended that future work focuses on FSW for aluminum. Among these, the most essential is the application of artificial intelligence (AI) techniques to select the optimum FSW parameters for aluminum welding.

Vertical GaN/InGaN/GaN heterostructure tunnel field-effect transistor: DC and analog/RF performance

This work reports an [Formula: see text]-type GaN/InGaN/GaN heterostructure vertical double-gate tunnel field-effect transistor (VTFET) using exhaustive calibrated simulation for the first time. Investigation has been done for the proposed structure by including a polarization layer of InGaN near the source-channel junction. From the analysis, it has been observed that after the introduction of polarization layer near the source-channel interface, drain current increases due to the increase in charge concentration (2DEG) near the interface due to inter-band tunneling. Value of 2DEG concentration achieved post introducing the polarization layer is [Formula: see text] [Formula: see text]. The reported structure is optimized using parametric sweep optimization technique. Here, a detailed dc and analog/RF performance estimation has been done for the structure with heterostructure. In-depth sensitivity analysis has been done for the structure with the polarization layer. It is reported that the structure with HfO2 as the dielectric material with [Formula: see text] of 2 nm and with gate metal work function of 5.8 eV gives the optimum performance at 300 K. Further, it demonstrates high cutoff frequency ([Formula: see text] and gain bandwidth product (GBW) as 1000 GHz and 300 GHz, respectively. Hence, the reported structure is a better alternative for high-power steep switching analog and RF applications.

Perceived impact of mentoring programme on job satisfaction and performance among metalwork teachers

The study determined the perceived impact of mentoring on job performance and satisfaction among metal work teachers in North-West, Nigeria. A quasi-experimental design was used for the study. The sample was made up of 35 teachers drawn from four technical colleges in North West, which comprise of 16 teachers in the experimental group and 19 teachers in the control group. A questionnaire was used for data collection. Three experts validated the instrument and the reliability coefficient was 0.93. The experimental group received the mentoring programme which adapted the four stages of Krams model while the control group was trained with an unplanned and informal method. A pre-test was administered a week before the experiment to both groups followed by the treatment that lasted for 13 weeks. Similarly, post-test was administered to both groups two weeks after the treatment. ANCOVA was used to test the hypothesis. The findings revealed a significant impact of mentoring on job performance and satisfaction, but no significant influence of gender was observed. Hence, it was recommended that technical colleges in Nigeria should adopt the use of mentoring for improving metal work teachers job performance and satisfaction.

Occupational health and safety related knowledge, attitude and practice among metal workers of Bogura city

Occupational health and safety related knowledge, attitude and practice among metal workers of Bogura city

Chronic Noise Affects Middle Ear Resonance and Absorbance in Industrial Workers.

The effect of chronic noise on the middle ear is not fully known. This study aimed to evaluate the middle ear functions of metal workers exposed to chronic noise using wideband tympanometry. In this study, 62 male workers exposed to chronic noise and 30 healthy men were included. Workers exposed to chronic noise were divided into 2 groups according to their pure tone averages. Totally 30 workers (60 ears) with pure tone average less than 20 dB were included in group I, and 32 workers (64 ears) with pure tone average more than 20 dB were included in group II. All individuals were subjected to wideband tympanometry. Tympanometric peak pressure, equivalent ear canal volume, static acoustic admittance, resonance frequency, and absorbance ratios at peak pressure and ambient pressure values were analyzed. There was no difference between the groups in terms of traditional tympanometric parameters such as tympanometric peak pressure, equivalent ear canal volume, and static acoustic admittance (P >.05). Resonance frequency of workers exposed to chronic noise (group I and group II) was lower than the control group (P <.05). The absorbance ratios of workers exposed to chronic noise at approximately 4 kHz were lower in both peak pressures and ambient pressures (P <.05). Chronic noise does not only damage the inner ear but also causes changes in the middle ear structures. Wideband tympanometry can be used to detect minor auditory damage due to noise that cannot be detected by audiogram early. In this way, necessary measures can be taken in the early period before noise-induced hearing loss occurs.

Seyma-Turbino Metalworking and Microtechnics: A Game of Scale

Along with ordinary utilitarian things, Seymа-Turbinо casters made technically advanced products devoid of pragmatic functions. Miniature copies of full-size prestigious products were found in graves and shrines. Probably, communities of metalworkers treated these miniature tools as material symbols of their group identification. Numerous finds made in Petrovka, Sintashta, and Seymа-Turbino archeological sites mean that these metal miniatures were in high demand. Low-rank metal workers might have been buried with miniature samples of less technologically advanced tools. Full-size sophisticated tools, as well as their miniature copies in children's graves, could symbolize individual status. Miniature artistic castings that served as pommels on massive curved knives marked the prestigious status of this type of weapon and symbolically equated it with the Tools of the Creation. The figurines that adorned the Seyma-Turbino weapon not only emphasized its impressive size, but also gave the owners of these perfect products a higher social status. The miniature sculpture, which adorned only some of the Seyma-Turbino metal products, individualized serial samples. Thus, the microtechnics reflected not only the new possibilities of Seyma-Turbino metalworking, but also the regulatory requirements for the design of prestigious metal products. The renewal of the material ambiance was caused by the spread of serial products, the so-called quick things. It reflected the need to strengthen the connection between the owner and the possession, which was inherent to individual single-piece production

The impact of three related emission industries on regional atmospheric chlorinated paraffins pollution

Identifying the contributions of various chlorinated paraffins (CPs) sources in the environment plays an important practical role in the prevention and control of the CPs contamination. However, little is known about how main CP-related emission industries affect the regional atmospheric characteristics of CPs, including CP products industry, metal working industry, and polyvinyl chloride (PVC) industry. In this study, 60 passive air samples were collected from five typical cities in Henan Province, China, which had serious CP pollution and different structures of CP-related emission industry. Short chain CPs (SCCPs) and medium chain CPs (MCCPs) were detected in all samples in concentrations ranging of 2.6–7.7 × 102 and 2.1–4.3 × 102 ng m−3, respectively, which were higher than those in most reports. Moreover, Luoyang (LY) is different from other cities, showing a relatively severe MCCP contaminations. The CP pollution characteristics between different cities are obviously affected by the proportion of local CP-related industries. According to the results of cluster heatmaps, the local CP-related emission industrial structure had a greater impact on MCCPs pollution than SCCPs. Additionally, the contribution of metal working industry was beyond that of PVC production industry and CP products industry.

HVAC-AHU System Evaluation using WPM method

In this paper, we are going to analyze the smart sensor networks based on the four parameters using WPM (Weighted Product Model) methodology. Real-time profession of HVAC zones to keep energy without compromising occupier comfort / Various strategies to comprehend the vacancy had been explored. The air coping with unit or AHU is the air conditioning A self-assembly of components (fanatics, cooling coils, filters, humidifiers and dampers) Integrated inside the construction package deal and established as a separate unit, with metallic pipe work device Connected. Distributes conditional air. Weighted Product Model (WPM) is a popular number Criterion choice evaluation (MCDA) / Multi Scale decision making (MCDM) method. This is much like the weighted sum version (WSM). The main distinction is, in the main mathematical function there is now multiplication rather than addition. MCDM is multi, contradictory, preferred and/or a technique for integrating alternative overall performance into quantitative standards and developing an answer that calls for consensus.In this paper we used WPM for ranking the WPM method is the most ideal solution Short-distance and Alternative The solution with the longest distance from the solution Determines, but the comparison of these distances Does not consider importance. Bluetooth low energy, Wifi, Long Range radio. Evaluation Parameters in Depression Loneliness Life Satisfaction Sensor networks, Packet length (kb), TX/RX bandwidth (kbps), RS (sample/s), NS (pkt/sample). Use Attention deficit from the result it is seen that genetic engineering (A2) is got the first rank whereas is the Biotechnology (A5) is having the lowest rank.

Ocular health among industrial workers: a prevalence study of foreign body injury, refractive error, dry eye, pterygium and pingueculae.

Workplaces play a critical role in developing ocular diseases, owing to the risk of accidents. This study aimed to evaluate the ocular health of industrial workers by determining the prevalence of foreign body injury, refractive error, dry eye, and pterygium/pingueculae, as well as the factors influencing these diseases. This study involved on-site examinations of workers from an industrial area hosting marble processing factories and metal sectors. Data such as refractive error, foreign body injury-related corneal nephelium, pterygium/pingueculae presence, and Schirmer test-assisted dry eye evaluation were all collected. The average age of workers was 35.78±10.05 years, with a female-to-male ratio of 20:220. The majority of workers had completed primary school (56.3%), smoked >1 cigarette/day (57.6%), and did not use any assistive devices for bodily functions (88.3%). On average, working hours/week were 55.07±8.79, and working years were 5.99±7.00. Dry eyes were found in 31 (22%), and 35 (34%) marble and metal workers, respectively (p=0.042). 11 (7.9%) marble workers and 29 (28%) metal workers had foreign body ocular injury-related corneal nephelium (p=0.0001). Furthermore, pterygium/pingueculae were revealed in 17 marble workers (12.3%) and three metal workers (3%) (p=0.009). Ocular health is essential, and routine ocular health screening in industrial workers, as well as workplace safety measures, should be implemented to prevent potential occupational accidents.