bluuebunny/crossref_metadata_2025 huggingface dataset:
Establishing A Three-Dimensional Geodetic Point Network Inside the University of Technology, Iraq - Baghdad
Authors: Hussein Luay Y. , Ataiwe Tariq N. , Jawad Al Sharaa Hisham M.
Published: August 2024

Geodetic networks play the most important role in the accuracy and reliability achieved for surveying and mapping applications. Since 1980, in most world countries, numerous geodetic control networks have been established for a wide range of mapping projects using Global Positioning System (GPS) technology. The main objective of this study is to create a highly accurate, multi-way control network that uses the latest Global Positioning System (GPS) devices and technologies. In this study, a network was established that consists of seven control points distributed in the University of Technology, Iraq - Baghdad, with distances ranging from 50-250 meters or more between the points. The heights above sea level for all control stations were determined using a leveling device and they were linked to the national network, allowing the creation of a geoid model. Accurate for the university in the future. This study presents the monitoring method, the results obtained, and the characteristics, standards, and specifications designed for the geodetic control network. It is expected that this network will improve the reliability of monitoring the deflections in building and the practical part of undergraduate and postgraduate studies The availability of the integrity of geodetic networks, will have a significant impact on the surveying and mapping activities of the University of Technology.
Climate Change Projections in Euphrates River Watersheds in the Middle of Iraq
Authors: Habeeb Obead Imad , Hussein Zahraa
Published: August 2024

This study investigated the climate change projections in the Euphrates River watersheds in the middle of Iraq. The LARS-WG model was used to simulate dry and wet spells during the winter and autumn seasons across a variety of local stations. The most suitable probability distribution models for the monthly rainfall and water balance data of the five stations were also identified. The SPI-12 index was used to identify and characterize drought events over a 12-month time scale. The projected SPI and SPEI values for the study stations in Iraq were also calculated under RCP4.5.

The results showed that the LARS-WG model is a reliable tool for simulating dry and wet spells during the winter and autumn seasons across a variety of local stations. The most suitable probability distribution models for the monthly rainfall and water balance data of the five stations vary. Two of the stations follow the lognormal distribution, while the remaining three stations follow the Gamma, Weibull, and logistic distributions, respectively.

Severe drought was observed during the years 2042, 2048, 2056, 2047, and 2050 in Hilla, Diwaniyah, Karbala, Najaf, and Samwa, respectively. The maximum duration of drought events is from 2050 to 2052 with a magnitude of -2.9, and 2056 to 2058 with a magnitude of -1.8 in Diwaniyah and Karbala, respectively. The findings of this study suggest that climate change is expected to have a significant impact on water resources in the Euphrates River watersheds in the middle of Iraq. Drought events are expected to become more severe and intense and are expected to last longer. This is likely to hurt different sectors in the region.
Sustainable operation of on-street parking within Hilla City by Simulation Model (VISSIM) with Surrogate Safety Assessment Model (SSAM)
Authors: Salah jasim Noor , Abdul Ameer Alwash Ali
Published: August 2024

The preservation of sustainability poses an ongoing and persistent problem. To attain sustainability, it is imperative to prioritize the preservation of road traffic safety, the prevention of crashes, the utilization of pollution-free vehicles, and the secure transportation of commodities. The research approach employed in this study involves collecting data about many factors, including air pollution, noise levels, incident frequency, and traffic volumes. The study focuses on 20 links with on-street parking facilities in Hilla City, Iraq. This study uses the VISSIM microsimulation model SSAM software. This study used PTV VISSIM (Thesis) 2024 (SP 02). This license(Thesis) of PTV VISSIM software enables one to conduct the research unlimitedly, which is good for obtaining accurate results. The simulation time used in this study is 3600 seconds. PTV ViSSIM software enables the emulation of traffic movements on selected streets that contain on-street parking. Six streets in Hilla City are divided into 20 links. The streets were monitored using video recordings to collect real traffic data, which was then used to estimate delay and emissions. Additionally, trajectory files were created for future analysis. The SSAM program can be used to determine the conflicts in each link. The simulation models were effectively calibrated and validated using actual data. This study assesses the sustainable, social, economic, and environmental aspects of roadways, including on-street parking spaces. This project intends to construct a sustainable composite index utilizing existing data collection methods. Existing data on urban transportation sustainability considers economic factors like delay, social factors like safety, and environmental factors like noise and air pollution. The composite sustainability index incorporates economic, social, and environmental data, effectively tackling the difficulties related to normalization, weighting, and aggregation. This study aims to evaluate the long-term viability of transportation in Hilla’s central business area (CBD) by considering the incorporation of on-street parking. The Composite Sustainability Transportation Index (ICST) results for links with on-street parking in Hilla City indicate that the sustainability operation is evaluated at different levels: low (8 links), moderate (7 links), and high (5 links).
Utilization of GIS to Generate a Digital Geotechnical Map of Baghdad City
Authors: Al-Mirza Hayder A. , Falih Mohammed R. , Wattan Saif , Salman Alaa D. , Karkush Mahdi
Published: August 2024

The Geographic Information System (GIS) is considered one of the most prominent programs used to collect, analyze, display, process, and produce geographic information maps for a specific purpose. It is also considered one of the modern database programs. Additionally, we can perform statistical analysis within GIS on predefined data to produce quantitative results. In this study, data was collected from more than 80 engineering projects established in Baghdad City from soil investigation reports for the projects. Geographic information systems were used to produce objective maps showing the variation in the bearing capacity of shallow foundations in the soil of Baghdad Governorate. It demonstrates the importance of GIS exploration for more valuable results such as the bearing capacity of shallow foundation from the results of Standard Penetration Tests (SPT) showed in the soil of Baghdad Governorate. The total number of boreholes excavated was 150, irregularly distributed in Baghdad city. Three SPT tests were performed in each boreholes at depths of 1.5, 6 and 9 m measured from the existing ground level (EGL). The study concluded by producing objective maps that show the variation in bearing capacity of soil for all area of the Baghdad city for the aforementioned depths. These maps can be used by different local authorities to predict the bearing capacity of the soil and choose the appropriate type of foundation for each soil. We can also use it to assess the foundations of existing and irregular buildings and assess the extent of the risks of failure and collapse.
Evaluation water quality of Tigris River at the sites of Fish cages in Missan city
Authors: AlMusawi Nawar O. , Kawi Mervet A. , Adnan Jawad Adam
Published: August 2024

The current study, which extended from the beginning of November 2021 until April 2022, aimed to determine and evaluate water quality for fish farming in Missan Governorate on Tigris River, and to determine the effect of the distances between cages on fish productivity to determine the suitability of the study area to establish cages floating fish farming. In China, floating cages were found on the Qiyong River and were made of simple materials such as bamboo or reeds, tied with ropes, and fish were trapped in them and fed with leftover. In our research, five fish farms were selected on the Tigris River in Missan Governorate. The results of field measurements showed that the water temperature ranged between 13.1-23.7°C, the pH value ranged between 7.2-8.6. The water in the study area can be classified as weakly basic. The speed of the current in the study sites recorded values ranging between 0.38-0.7 m/s, the turbidity values ranged between 20.7-41.5 NTU, the electrical conductivity recorded values ranging between701-998 µSm/cm, the dissolved solids ranged between 540-618 mg/L, while the suspended solids ranged between 25.8-60.4 mg/L. The results of the laboratory examination showed that the waters of the Tigris River at the studied sites are considered to have good ventilation. The dissolved oxygen in the water was between 6.2-10.5 mg/l, while the vital oxygen requirement recorded values ranging between 0.4-2.7 mg/l, and the nutrient values that represented with nitrate and phosphate 1.58-2.48 mg/L and 0.08-0.29mg/L, respectively. The copper values were between 0.12-0.28 mg/l, the zinc were between 0.28-0.55mg/l, while the results for cadmium were between 0.0020.006mg/l, the results for lead appeared between 7.2-8.6 mg/l. Concluded from this research that the environmental load resulting from the floating cages on the Tigris River does not affect the quality of the river’s water, and that the distances between the cages do not negatively affect each other due to the speed of water currents in the area, which helps in the dispersal of pollutants and the speed of the river’s recovery.
Simulating the performance of Kerbala wastewater treatment plant using GPS-X
Authors: Galb Salman Sara , Abduredha Muhammad , Khalil Nile Basim
Published: August 2024

The treatment process in sewage plants is applied to wastewater to improve its quality for multi-purpose uses. Sewage treatment plants are designed to treat wastewater under different conditions. The Karbala Main Wastewater Treatment Plant is one of the largest wastewater treatment plants in Iraq, designed to handle a discharge of 100,000 cubic meters per day. It can serve up to two million people and accommodate the city’s population growth. The station also operates with modern treatment systems (tertiary treatment) and an electronic command and control system. The study aims to develop a simulation model for the main wastewater treatment plant in Karbala. The model includes calibration and analysis of data from the plant’s inputs and outputs, such as biological oxygen demand, chemical oxygen demand, the amount of suspended matter, phosphorus, nitrogen, and discharge value. The results showed that the model predicts the quality of treated water through the station’s output values. After entering the actual values of chemical oxygen demand with the discharge value and adjusting the practical fractional values, the output values show a clear sensitivity to the input values, especially the COD value on the station’s outputs from BOD and TSS, which helps to understand the performance and improve the system.
Impact of slaughterhouse waste on adjoining water quality
Authors: Ansari Shadab , Majid Hussein Hadeel , Hameed Ahmed Saleh , Saleem Siddiqui Yaser , Ayub Sohail
Published: August 2024

This article examines the condition of water in rural regions surrounding slaughterhouse industries on the Mathura bypass road in Aligarh, Uttar Pradesh, India. A total of seven villages were chosen for sample collection, with two samples from each village - one from a hand pump and the other from a submersible pump. A total of 14 samples per month were collected for analysis for their physical, chemical, and biological attributes. The study was conducted covering the dry and wet seasons so as to give the trend of water quality parameters and thereby represent a comparative analysis. Based on these findings, it can be inferred that the groundwater quality parameters have been severely impacted by effluent from slaughterhouse industries. Water samples from hand pumps showed higher concentrations of all parameters compared to those from submersible pumps, indicating better water quality from submersible pumps. Water samples from hand pumps and submersible pumps in all villages had nitrate, pH, and turbidity levels within permissible limits. Nitrates and pH were found to be within permissible limits. Some remaining parameters were found to be above and below rejection limit. As a whole it is observed that almost all water quality parameters increased during the dry season and lowered in wet seasons. However after observing the current trend of water quality parameters, it can be seen that water quality may deteriorate further due to an increase in industrialisation.
Frequency Analysis of the Loire River water Total Suspended Solid and Electrical Conductivity (Orléans, France)
Authors: Al-Juhaishi Mohammed Rashid , Fabrice Muller , Motelica-Heino Mikael
Published: August 2024

In this research, different statistical probability distributions are presented to model the total suspended solids (TSS) and electrical conductivity (EC) at two monitoring stations, Along the path of the Loire River France. These monitoring stations are Jargeau and Meung-sur-Loire. For each of these station data of the two variables are measured as a monthly series during the period 2001 to 2021. The proposed fitted statistical probability distributions are the Normal, Log-normal, Weibull, Exponential and Two parameters Gamma. The Kolmogorov-Smirnov test is used for the goodness-of-fit to select the best probability distribution from among these five tried distributions for each of the stations. The data sample is divided into two sub-samples, a fitting model sub-sample as 70 % of the data, and a validation sub-sample as the remaining 30%. The results show that the TSS at Loire a Meung-sur-Loire station has two distributions with same value of the test statistics, SIG. In these cases, the t and F tests are used to select the best-fit distribution. The Log Normal (13.71, 0.95) is found to be the best fit distribution for TSS for Jargeau station with SIG value of 0.35 while the Weibull (282.911, 8.206) with SIG value of 0.877 is the best fit for EC for the same station. For the Meung-sur-Loire station the Weibull (19.49, 1.18) and (299.40, 7.50) are the best fit distributions for the TSS and EC with test SIG values 0.75, 0.99 respectively. The best fit distribution for each station is used to generate three series of data which are tested against the 30% validation data. The Kolmogorov-Smirnov test among the three generated series with the validation confirms that these fitted models can generate data that has the same frequency of occurrence of that of the observed data.
Analytical Equation for Stress-Strain Relationship in compression for Reactive Powder Concrete
Authors: Al-Fadhli Suaad Khaleel I.
Published: August 2024

Concrete is an important construction material globally. Reactive Powder Concrete (RPC), also called Ultra-High-Performance Concrete (UHPC), represents a new type that differs significantly from traditional concrete. This new concrete was developed by Bouygues laboratory in France during the 1990s. It is characterized by its ultra-high strength and ductility composite material with advanced mechanical properties. This study conducted experimental investigations on different mixes of RPC to obtain the complete compressive stress–strain relationships. A general mathematical equation was derived to express this relationship theoretically. Two main variables were used to achieve different mixes of RPC. The variables were the type of pozzolanic materials used (metakaolin or silica fume) and the volumetric ratio of the fibers (1.25, 1, and 0.75). The results show that the increase in compressive stress for the mixtures of the first group G1, which contain metakaolin, is approximately 39% when the percentage of fiber is increased from 0.75 to 1%. The percentage becomes 50% when the fiber increases to 1.25. For the second group of mixtures with silica fume, increasing fiber percentage from 0.75% to 1% yields about a 20% rise in compressive stress, and 1.25% fiber increases it by 38%. For the compressive stress-compressive strain curve for RPC concrete, it was found that the two main variables in this research do not strongly affect the shape of the upward curve in this relationship. The downward curve is immensely affected by the quantity of fibers used. Furthermore, using steel fibers with a higher volume ratio leads to RPC concrete with higher ductility and toughness. The proposed analytical model for the stress-strain relationship of RPC mixes complies with experimental results.
Behavior of Tied Short RCA Columns Strengthened with Basalt Fiber
Authors: Alkareem Jebur Abdullah A. , Khalel Raid I. , Mohammed Dhiyaa H.
Published: August 2024

This article offers an experimental procedure to evaluate the validity of RC circular short columns with various replacement ratios of recycled coarse aggregate and strengthening with basalt fibers. In order to provide it, fifteen (15) short reinforcing concrete columns with transverse reinforcement (ties), two recycled coarse aggregate replacement ratios (50 and 100 %), and four ratios of basalt fibers (0.1, 0.2, 0.3, and 0.4%) were designed and loaded axially concentrically. The obtained experimental data is recorded and evaluated to improve the RC short column’s structural properties (first crack load, ultimate carrying load, and load-displacement curve). The results showed that for columns containing 0% recycled coarse aggregate, 0.1% basalt fibers addition increased the ultimate loading capacity by 14.1%; for columns containing 50% recycled coarse aggregate, 0.1% basalt fibers addition increased the ultimate loading capacity by 9.7%, while 0.2% basalt fibers addition had increased the ultimate loading capacity for columns that contained 100% recycled coarse aggregate by 7.9%. By utilizing basalt fibers, higher stiffness is noted in the load-displacement curve of RC columns can be seen, and Improved column ductility can be achieved. The initial cracking load was delayed and the column’s loading capacity was enhanced by the bonding forces between basalt fibers and the mixture, which offered internal confinement for the concrete that prevented the formation of initial cracks inside the concrete.
Influence of Recycled Coarse Aggregate and Steel Fiber on the Workability and Strength of Self-Compacting Concrete
Authors: Shawais Zhino A. , Abdulhaleem Khamees N. , Ahmed Saleh H. , Hamada Hussein M. , Mohammed Van R.
Published: August 2024

Waste materials pose a significant threat to both the environment and human health. On a global scale, the quantity of recyclable material is steadily growing, and its proper disposal is a significant focus of modern study. Concrete debris is a recyclable material that poses challenges for reutilization. Concrete waste refers to the fragments or remains of ready-mix concrete plants and the debris from destroyed structures, including historic buildings and those affected by earthquakes. The objective of this study is to reuse and utilize coarse aggregate formerly used in concrete constructions to create self-compacting concrete (SCC). The purpose is to assess the performance of this recycled aggregate in both its fresh and hardened states. Natural coarse aggregate (NCA) was switched out for recycled coarse aggregate (RCA) at 0, 50, and 100% volume ratios. In contrast, concrete was mixed with steel fibers (SF) at volume percentages of 0 and 0.44. Workability tests, including V-funnel, slump flow, and L-box tests, were conducted to assess the consistency of the mixes in their fresh condition. Additionally, the tensile and compressive strength of the concrete specimens were measured to evaluate their strength in the hardened state. Overall, the experimental findings showed that the fresh qualities of almost all SCC mixes fell within the required range, as outlined in the EFNARC standards. While the steel fiber harmed the fresh characteristics, it resulted in a proportionate enhancement in tensile strength. The findings indicated that including recycled aggregates into the concrete mixture enhanced its strength. The results showed that adding (0.44%) of steel fibers to concrete reduced the decline in compressive strength when the coarse aggregate was replaced entirely with recycled aggregate. In contrast, an equivalent proportion of fibers resulted in a significant improvement in tensile strength, rising from 26% to 54%, when using recycled coarse aggregate as the replacement of natural coarse aggregate. Thus, it can be concluded that using recycled aggregates and steel fibers in concrete production results in a higher quality product than regular concrete. Removing concrete waste has other benefits, such as enhanced financial return and preservation of the environment.
Evaluation of the performance of warm asphalt mixture with Sasobit
Authors: Mohammed Humam H. , Al-Ameri Mohammed A.
Published: August 2024

The highway pavement construction industry has consistently attempted to promote the use of warm-mix asphalt (WMA) to encourage the construction of environmentally friendly pavement. This study aims to investigate the mechanical characteristics of warm asphalt mixtures that are made by utilizing modified asphalt binders containing different amounts of Sasobit. The base bitumen is modified with various percentages of Sasobit (3%, 4%, 5%, and 6%) of the weight of the bitumen by shear mixing. The rheological-physical characteristics of the base and enhanced asphalt binders were assessed using various tests such as: rotational-viscosity, softening point, and penetration tests. The stiffness, susceptibility to moisture, and resistance to rutting of the hot and warm mixes, made the binders are modified by using Sasobit, were assessed through Marshall characteristics, tensile strength, and punching shear tests. The findings demonstrated a significant enhancement in the rheological-physical characteristics of the modified binders. Findings revealed that the asphalt mixtures containing 5% Sasobi-modified binders exhibited more excellent resistance to both moisture damage and rutting in comparison to the control mixture.
In-Situ EBSD Study of Austenitisation in a Wire-Arc Additively Manufactured High-Strength Steel
Authors: Taylor M , Mozumder Y H , Smith A D , Davis A E , Scenini F , Prangnell P B , Pickering E J
Published: August 2024

As-built high-strength steel wire-arc additive manufactured (WAAM) components often contain coarse columnar prior austenite grain (PAG) structures. These microstructures can result in poor mechanical properties, hence post-build re-austenitisation treatments are of interest to improve microstructures. Here, the potential for engineering austenite refinement was investigated using high-temperature in-situ EBSD with high temporal resolution. It was found that 300M first austenitised with a memory effect, reforming the columnar PAG structures in both morphology and crystallographic orientation. This was observed to occur by the coalescence of acicular austenite and happened earlier in the depleted dendritic regions. On further heating, austenite underwent recrystallisation without the application of external deformation via a discontinuous mechanism, involving the bulging of the prior high angle boundaries. Recrystallisation twins were also seen to form and grow alongside regular recrystallised grains. The predominance of discontinuous recrystallisation meant that a coarse grain structure was still retained after austenitisation, owing to the influence of a grain ‘swapping’ effect.
Understanding heterogeneous nucleation and predicting grain size in wire and arc additive manufacturing of steels with inoculation
Authors: Xu Y , Tranell G. , Li Y
Published: August 2024

Inoculation has become a common practice to achieve grain refinement in metal additive manufacturing, and its application in steels has been extensively investigated in recent years. However, the nucleation behavior of equiaxed grains under high temperature gradient and fast cooling rate solidification conditions in additive manufacturing is still not well understood. And grain size prediction models for additive manufacturing of steel is lacking. In this work, a numerical microstructure simulation model is developed to simulate the growth and nucleation behaviors of grains in additive manufacturing, and to predict the grain size of inoculated steels with equiaxed grain structure. Here a wire and arc additive manufacturing (WAAM) of duplex stainless steel is selected for case study. The simulation results are in a good agreement with the experimental results.
Influence of print-chamber oxygen content on the microstructure and properties of 3D-printed 316L
Authors: Wang WY , Liu W , Godfrey A
Published: August 2024

Samples of 316L stainless steel have been prepared using laser-powder bed fusion from the same batch of powder using different print-chamber oxygen levels, ranging from 50 ppm to 1500 ppm. The oxide particle density is found to increase with oxygen content, while the cell structure is invariant with oxygen level and the grain size shows a relatively sharp transition for measured oxygen levels of above 450 ppm. Based on the microstructural observations it is suggested that the increasing oxygen levels leads to a transition in the solidification pattern. Samples printed at the higher oxygen level show higher strength and lower mechanical anisotropy than samples with a coarser grains structure printed at lower oxygen levels. The main influence of the higher oxide particle content on thermal stability is on the kinetics of recrystallization during isothermal annealing at 1000 °C.
Dislocation structure evolution during metal additive manufacturing
Authors: Upadhyay M V , Gaudez S , Pantleon W
Published: August 2024

Dislocation structures are abundantly present in any additively manufactured alloy and they play a primary role in determining the mechanical response of an alloy. Until recently, it was understood that these structures form due to rapid solidification during AM. However, there was no consensus on whether they evolve due to the subsequent solid-state thermal cycling that occurs with further addition of layers. In order to design alloy microstructures with desired mechanical responses, it is crucial to first answer this outstanding question. This question was answered in a recent work [1] involving a novel experiment employing high resolution reciprocal space mapping, a synchrotron based X-ray diffraction technique, in situ during AM of an austenitic stainless steel. The study revealed that dislocation structures formed during rapid solidification undergo significant evolution during subsequent solid-state thermal cycling, in particular during addition of the first few (up to 5) layers above the layer of interest. A summary of the findings of this study are presented in this work. A possible pathway (involving experiment and modelling synergy) to better understanding dislocation structure formation during AM is presented.
Control of crystallographic textures by metal additive manufacturing-A review
Authors: Nakano Takayoshi
Published: August 2024

Metal additive manufacturing (AM), a unique manufacturing method that stacks powder materials layer-by-layer to fabricate products with complex shapes and high precision, allows for a wide range of control over metallurgical microstructures. Metal AM defines solidification units with specific solidification directions and fast cooling, thereby enabling the control of the resulting metallurgical microstructure. However, the studies investigated texture control and utilizing textured microstructure are lacking in the literature. This review describes some of the results of our research on the control of crystallographic textures by laser powder bed fusion (LPBF), focusing on (1) the effect of powder properties on densification and crystallographic texture formation, (2) the effect of the melt pool shape and crystallographic characteristics of the starting material on the formation and orientation of single crystals, and (3) the successful application of alloy design to the preparation of highly functional single-crystalline-like textured biological high-entropy alloys considering specific solidification fields under LPBF.
Grain size assessment using EBSD on heterogeneous additively manufactured microstructures
Authors: del Gaudio J , Donoghue J , Withers P J , Garner A , Mingard K , Gee M , Gholinia A
Published: August 2024

Grain microstructures are important for a whole range of materials properties. With the widespread use of additive manufacturing (AM), current standards for grain boundary evaluation, such as ASTM E2627-13, may not be fit for purpose due to their microstructural complexity. They are notoriously anisotropic across a range of length scales due to the non-equilibrium nature of the solidification process and the tracking of the heat source. In this work we examine the grain microstructure of a nickel superalloy produced by laser powder bed AM by electron back scatter diffraction. We find that the guidelines provided by the ASTM E2627-13 are not suitable for such heterogeneous and anisotropic materials and some modified guidelines are provided on the field of view and EBSD step size that should be used to characterise such materials.
Cracking Mechanism in E-Beam 3D-Printed DZ125 Ni-based Superalloys
Authors: Wang Z , Lin Y , Zhao Y , Shangguan F , Chen K
Published: August 2024

Directionally solidified Ni-based superalloys are extensively employed to manufacture turbine blades due to their outstanding high-temperature mechanical properties. To reduce overall costs, repairing techniques are highly demanded to restored the shape and properties of damaged turbine blades. In this study, as a surrogate for the repair process, DZ125 Ni-based superalloys were grown epitaxially with the electron beam powder bed fusion 3D-printing method on a base metal with the same chemical composition. Cracks are detected within the printed part, always along the high-angle grain boundaries and roughly parallel to the building direction. The cracks are identified to be liquation cracks, and the thermal cycling effects are proved to play an important role in crack initiation and propagation. The knowledge gained from this work provides valuable insights towards 3D-printing strategy development to obtain crack-free directionally solidified superalloys.
Multiscale characterization of the additive-manufacturing-induced cell structure in 316L stainless steel: A comparative study
Authors: Wang X , Nadimpalli V K , Juul Jensen D , Yu T
Published: August 2024

This study evaluates the potential of various electron microscopy-based methods for the characterization of the cell structures in additive manufactured stainless steel 316L. We focus on the capability of different techniques to characterize the multiscale microstructural features of the cell structures, including cell morphology, elemental segregation, particle distribution, and dislocation arrangement. Additionally, we suggest a manual method to quantify the very small misorientation angles across cell walls and within the cells. The advantages and limitations of different methods are discussed.
Effect of solution treatment temperature on recrystallisation behaviour of Haynes 282 manufactured through laser powder bed fusion
Authors: Swaminathan K , Andersson J
Published: August 2024

Increasing layer thickness in Laser Powder Bed Fusion (PBF-LB) process of metals enable increasing productivity and facilitate industrialisation of metal additive manufacturing (AM) process. Understanding of microstructure in as-built stage and possible post-processing steps to modify the microstructure is critical for metal AM components. Haynes 282 Nickel based superalloy, typically used in aerospace and energy industries, was manufactured using PBF-LB process at 60 microns layer thickness. Two different solution treatment temperatures were studied to analyse the recrystallization behaviour of the as-built material. The as built microstructure consisted high dislocation density given the rapid cooling in PBF-LB process. Solution treatment at 1150°C resulted in reduced dislocation density but similar morphology to grains in as built condition with visible residual melt pool boundaries. Solution treatment at 1250°C resulted in recrystallised grain structure. The recrystallisation behaviour is discussed with relation to manufacturing process and kinetic behaviour of alloying elements.
Elucidating the impact of laser beam shape on the as-printed microstructure in 316L stainless steel
Authors: Alphonso W E , Ribeiro M A , Rothfelder R , Schmidt M , Hattel J H , Juul Jensen D , Bayat M
Published: August 2024

In Laser Powder Bed Fusion (L-PBF), the intrinsic inclination of the laser beam creates variability in the interaction between the laser and the melt pool, which along with thermal conditions within the pool, results in the formation of defects in the parts. To elucidate the impact of laser beam inclination on the melt pool, a deposition scale model using the finite volume method (FVM) is developed. The laser model demonstrates that as the laser beam inclines towards the periphery of the build plate, the projected laser spot size enlarges, resulting in lowered energy density. To assess how the laser beam inclination affects multi-layer printing, cubic specimens are printed at both the center and the far corner of a rectangular build plate of 280 mm x 280 mm size. X-ray computer tomography (X-CT) is used to investigate internal porosities and electron backscatter diffraction (EBSD) is used to characterize the microstructure of the printed cubes. The experimental results are discussed based on the FVM simulations.
Recrystallization kinetics in 3D printed 316L stainless steel
Authors: Zhang C , Ahmed S , Nadimpalli V K , Yu T , Juul Jensen D
Published: August 2024

During operation, many 3D printed components are likely to be exposed to external strains and/or high temperatures. However, the thermomechanical behaviours, e.g. plastic deformation and recrystallization, have not been thoroughly analysed, and are interesting to study because of the complex microstructure introduced by 3D printing. In the present work, the microstructural evolution and change in hardness during plastic deformation and recrystallization have been characterized in austenitic stainless steel 316L samples manufactured by laser powder bed fusion. The focus is on the recrystallization kinetics in both the as-printed and the plastically deformed state. It is discussed how these results compare to results for conventionally manufactured samples. The present study suggests that the inhomogeneity of 3D printed samples significantly affects the recrystallization behaviour.
Exploring the feasibility of preparing Ti/Ti6Al4V composites by laser powder bed fusion
Authors: Shen J , Pan Z , Nadimpalli V K , Yu T
Published: August 2024

Ti-based alloys and composites are advanced lightweight materials that are indispensable for many critical applications. This study presents a novel strategy of fabricating laminated plates by printing Ti6Al4V on the surface of pure Ti substrate to obtain a composite structure combining coarse equiaxial and fine acicular grains. The molten pool layer is well bonded to the substrate surface and the chemical composition is rather uniform, due to melting of the substrate surface together with the powders and subsequent solidification. These findings provide a new path for material design, which will broaden the alternatives of structural materials applied in extreme service enviroment.
The electrochemical corrosion performance of aluminum alloys grade 6082-T6 weld repair
Authors: Sareekumtorn Porntep , Chaideesungnoen Sasirat , Muangjunburee Prapas , Oo Hein Zaw
Published: August 2024

This research investigated the corrosion behavior of standard current metal inert gas weld repair for 6082-T6 aluminum alloy using ER5356 filler metal. The new and repaired (NW and RW) welds were studied. The welds comprised the weld metal (WM), the heat affected zone (HAZ) (solid solution and softened zones), and the base metal (BM). The study focused on investigating electrochemical corrosion using polarization and electrochemical impedance spectroscopy (EIS) methods in 3.5% NaCl solutions, especially in HAZ, including metallurgical and mechanical examinations. The BM containing an α-Al matrix with Al(Fe,Mn)Si and Mg2Si phases exhibited the maximum hardness (70–104 HV0.1). The WM hardness decreased (67–76 HV0.1) with the α-Al, β-Mg3Al2, and Mg2Si phases. Despite having comparable phases to BM, HAZs showed lower hardness (Solid HAZ: 70–82 HV0.1) due to more intermetallic phases. The RW’s softened HAZ revealed the minimum hardness (52–63 HV0.1) compared to that of the NW (55–70 HV0.1). Besides, the tensile strength of the RW (179.7 MPa) was also lower than that of the NW (174.4 MPa) because of the reheating effect. The electrochemical corrosion results indicated that the BM exhibited the maximum corrosion resistance (the lowest corrosion current density (icorr), the highest corrosion potential (Ecorr), and the charge transfer resistance (Rct)), followed by the HAZ and the WM, respectively. The softened HAZ demonstrated better corrosion resistance than the solid solution HAZ. Conversely, the over-aging effect reduced the softened zone’s pitting corrosion resistance (Ep) compared to the solid solution zone. The RW exhibited inferior corrosion resistance compared to the NW due to increased intermetallic phases, which was consistent with the mechanical results. However, the RW’s softened HAZ corrosion characteristics were inconsistent with its mechanical properties; its hardness and tensile strength were the lowest, but its corrosion resistance was not. Pitting corrosion was observed on the weld surfaces using the SEM.
Soluble ST2 Is a Biomarker Associated With Left Ventricular Hypertrophy and Concentric Hypertrophy in Patients With Essential Hypertension
Authors: Wang Xia , Han Shu-Jie , Wang Xiao-Li , Xu Yun-Feng , Wang Hui-Cheng , Peng Jiang-Yang , Pan Guang-Ming , Chen Ya-Hui , Wang Chuangchang
Published: August 2024

BACKGROUND

Elevated soluble stimulating factor 2 (sST2) level is observed in cardiovascular diseases, such as heart failure and acute coronary syndrome, which reflects myocardial fibrosis and hypertrophy, indicating adverse clinical outcomes. However, the association between sST2 and hypertensive heart disease are less understood. This study aimed to determine the relationship of sST2 with left ventricular hypertrophy (LVH) and geometric remodeling in essential hypertension (EH).

METHODS

We enrolled 483 patients (aged 18–80 years; 51.35% female). sST2 measurements and echocardiographic analyses were performed.

RESULTS

Stepwise multiple linear regression analysis showed significant associations among sST2, left ventricular (LV) mass, and LV mass index. The prevalence of LVH and concentric hypertrophy (CH) increased with higher sST2 grade levels (P for trend < 0.05). Logistic regression analysis suggested that the highest tertile of sST2 was significantly associated with increased LVH risk, compared with the lowest tertile (multivariate-adjusted odds ratio [OR] of highest group: 6.61; P < 0.001). Similar results were observed in the left ventricular geometric remodeling; the highest tertile of sST2 was significantly associated with increased CH risk (multivariate-adjusted OR of highest group: 5.80; P < 0.001). The receiver operating characteristic analysis results revealed that sST2 had potential predictive value for LVH (area under the curve [AUC]: 0.752, 95% confidence interval [CI]: 0.704–0.800) and CH (AUC: 0.750, 95% CI: 0.699–0.802) in patients with EH.

CONCLUSIONS

High sST2 level is strongly related to LVH and CH in patients with EH and can be used as a biomarker for the diagnosis and risk assessment of hypertensive heart disease.

CLINICAL TRIALS REGISTRATION

Trial Number ChiCTR2400082764
A qualitative analysis of opportunities to strengthen pharmacy technician career pathways across practice settings
Authors: Bacci Jennifer L , Oster Natalia , Pollack Samantha W , Skillman Susan M
Published: August 2024

Purpose

To identify pharmacy technician career pathways across pharmacy practice settings and opportunities to strengthen and expand these pathways.

Methods

Interviews were conducted with 17 participants from national pharmacy organizations, community pharmacies, health systems, and academia from March to May 2023. Interview questions were designed to elicit participants’ perceptions of factors influencing entry into, recruitment and retention of, and advancement of the pharmacy technician workforce. Interview notes were analyzed using a rapid thematic analysis approach.

Results

Seven themes were identified, including 3 themes related to entry: (1) healthcare interest and prior exposure facilitate pharmacy technician career discovery; (2) variation in and quantity of entry-level requirements can impede entry into pharmacy technician careers; and (3) proactive promotion of pharmacy technician careers needed. Two themes were related to recruitment and retention: (4) pharmacy technician compensation not aligned with job demands and (5) career ladders or lattices create advancement opportunities. Two themes were related to professional advancement: (6) pharmacy technician advancement limited by weak professional identity and (7) scope-of-practice policies can facilitate pharmacy technician advancement.

Conclusion

This study highlights the challenges pharmacy technicians face in their careers. Key findings stress cultivating a professional identity for pharmacy technicians, establishing career ladders or lattices, and advocating for policies that facilitate pharmacy technician professional advancement. These efforts are vital for sustaining the pharmacy technician workforce and ensuring quality patient care amidst the changing landscape of the pharmacy profession.
ncStem: a comprehensive resource of curated and predicted ncRNAs in cancer stemness
Authors: Liu Hui , Zhang Nan , Jia Yijie , Wang Jun , Ye Aokun , Yang Siru , Zhou Honghan , Lv Yingli , Xu Chaohan , Wang Shuyuan
Published: August 2024

Cancer stemness plays an important role in cancer initiation and progression, and is the major cause of tumor invasion, metastasis, recurrence, and poor prognosis. Non-coding RNAs (ncRNAs) are a class of RNA transcripts that generally cannot encode proteins and have been demonstrated to play a critical role in regulating cancer stemness. Here, we developed the ncStem database to record manually curated and predicted ncRNAs associated with cancer stemness. In total, ncStem contains 645 experimentally verified entries, including 159 long non-coding RNAs (lncRNAs), 254 microRNAs (miRNAs), 39 circular RNAs (circRNAs), and 5 other ncRNAs. The detailed information of each entry includes the ncRNA name, ncRNA identifier, disease, reference, expression direction, tissue, species, and so on. In addition, ncStem also provides computationally predicted cancer stemness-associated ncRNAs for 33 TCGA cancers, which were prioritized using the random walk with restart (RWR) algorithm based on regulatory and co-expression networks. The total predicted cancer stemness-associated ncRNAs included 11 132 lncRNAs and 972 miRNAs. Moreover, ncStem provides tools for functional enrichment analysis, survival analysis, and cell location interrogation for cancer stemness-associated ncRNAs. In summary, ncStem provides a platform to retrieve cancer stemness-associated ncRNAs, which may facilitate research on cancer stemness and offer potential targets for cancer treatment.

Database URL: http://www.nidmarker-db.cn/ncStem/index.html.
Diagnosis, treatment and prognosis of Fournier’s gangrene in Africa: a scoping review protocol
Authors: Nedjim Saleh Abdelkerim , Biyouma Marcella D C , Mahamat Mahamat Ali , Kalli Moussa , Kouldjim Adoumadji , Remadji Hervé Yanhdet , Salissou Kaka A , Seid Younouss , Owon'abessolo Philip Fernandez , Mah Sarah Diaby , Ndiath Abdoulaye , Fouda Jean Cedrick , Jacquet Djamal , Ndoye Médina , Ouchemi Choua , Aboutaieb Rachid
Published: August 2024

Fournier’s gangrene is a rare necrotizing soft-tissue infection affecting the perineal, perianal and genital regions. It constitutes a genuine medical, surgical and urological emergency. Despite a better understanding of the etiology and pathophysiology of Fournier’s gangrene, mortality rates reported in the literature remain high. Still very common in Africa, it seems to occur mainly during hot, dry months and particularly affects people of low socio-economic status. This explains why the diagnosis is often made at a late stage. To our knowledge, there is no literature evaluating the epidemiology, clinical presentation, management and prognosis of Fournier’s gangrene in Africa, necessitating a review of the scope. This literature review protocol describes how the authors intend to study the available data on the presentation, management and prognosis of Fournier’s gangrene in Africa. Databases such as PubMed/Medline, Embase, Google Scholar and African Journal Online will be searched for articles published on Fournier’s gangrene in Africa and covering clinical, therapeutic and prognostic outcomes. The sociodemographic profile of all included studies will be examined. Results will include epidemiological, clinico-biological, severity score, management and prognostic data. Based on the analyzed results, the various parameters linked to the specific objectives of the African and non-African studies will be discussed and compared. This discussion will focus on clinical presentation, management and prognosis. This scoping review will be the first to address this research question, which has yet to be reported serially by African authors.
Evaluation of polypropylene CSF low-bind collection tubes for trace metal contamination
Authors: Bitzer Anna C , Jannetto Paul J , Bornhorst Joshua A
Published: August 2024

Background

Due to the ability of metal ions to cross the blood–brain barrier, there has been interest in analyzing cerebrospinal fluid (CSF) for trace element concentrations to investigate possible correlations with neurodegenerative diseases. In this study, Sarstedt polypropylene CSF collection tubes were analyzed to determine the contamination levels of aluminum, titanium, chromium, manganese, cobalt, nickel, molybdenum, gadolinium, vanadium, arsenic, cadmium, mercury, lead, thallium, selenium, copper, zinc, and iron.

Methods

Sarstedt polypropylene CSF collection tubes from 2 separate lots (n = 10 per lot) were filled with a 2 mL aliquot of a CSF pool with known element concentrations. After 24 hours of leaching at room temperature, all 18 elements were analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Results were subtracted from the initial pool concentration to determine contamination levels.

Results

No detectable contamination above the assay limit of detection was found in 11 analytes. Molybdenum and selenium contamination was measured in all tubes, and aluminum, titanium, manganese, thallium, and zinc had minimal levels of sporadic detectable contamination in 25% or fewer of the tubes tested.

Conclusions

Sarstedt polypropylene CSF tubes are an acceptable collection tube for the analysis of most assessed metals in CSF.