Major Phase Research Articles

Conceptualization, development, and early dissemination of eMPACTTM: A competency-based career navigation system for translational research professionals.

Purposeful training and ongoing career support are necessary to meet the evolving and expanding roles of clinical research professionals (CRP). To address the training and employment needs of clinical research coordinators (CRCs), one of the largest sectors of the CRP workforce, we designed, developed, and implemented an online career navigation system, eMPACTTM (eMpowering Purposeful Advancement of Careers and Training). A design-based research method was employed as an overarching approach that frames iterative design, development, and implementation of educational interventions. The five major phases of this project - conceptualization, task analysis for measurement development, algorithms development, algorithms validation, and system evaluation - presented specific goals and relevant methods. The results reported how the eMPACTTM system was conceptualized, developed, and validated. The system allowed CRCs to navigate tailored training and job opportunities by completing their task competencies and career goals. The data sets could, in turn, support employees' and training coordinators' informed decisions about organizational training needs and recruitment. The early dissemination results showed steady growth in registered CRCs and diversity in users' ethnicity and job levels. The eMPACTTM service showed the possibility of supporting CRCs' individual career advancement and organizational workforce enhancement and diversity. Long-term research is needed to evaluate its impact on CRC workforce development, explore key factors influencing workforce sustainability, and expand eMPACTTM service to other CRP sectors.

Coarse-grained molecular dynamics study on submicron structuring of calcium silicate hydrate with enhanced tensile modulus and strength

Potential of cement-based materials for energy harvesting is encoded in their elusive mesoporous structure, and understanding the sub-micron structure of calcium silicate hydrate (C–S–H), a major binding phase of cement, is an important yet challenging task. Nanoscale C–S–H is ductile, while macroscopic performance is brittle, suggesting a gap in the transition of material properties from the nano-to the macro-scale, and a chance in finetuning the submicron (∼100 nm) structure to effectively deliver the atomistic properties to the bulk performance. The refined sub-micron structure of C–S–H can enhance the strength and modulus of concrete, thus providing a base material with better mechanical properties and durability. Here, two critical structural features of C–S–H, including agglomeration of globules and stacking of layers, are modeled by spherical and oblate ellipsoidal units, respectively. Coarse-grained modeling and peridynamics simulations find that the packing of ellipsoidal units is better than that of spherical units, from the perspectives of size distribution, morphology, fractality of pores and tensile properties. The analyses on the mesoporous structure shows that the ellipsoid-packing is more homogeneous than the sphere-packing model, and it yields a refined structure with enhancement in tensile modulus and strength. The submicron finetuning enhancement of C–S–H can be realized through different physical and chemical approaches, like inducing lateral growth of silicate chains by chemical additives, scaffolding materials, and conditioned hydration. This coarse-grained simulation work gives novel insights and fundamental strategies for toughening the cement matrix through delivering ductile nanoscale performance of C–S–H to macroscale cementitious materials, and provides superior performance for concrete in existing and new structures.

Magnetically separable CeO2/CoFe2O4 heterojunction photocatalysts for dye degradation: characterization and mechanism

ABSTRACTThis study developed magnetically separable CeO2/CoFe2O4 heterojunction photocatalysts for dye degradation to reduce water pollution. The CeO2/CoFe2O4 nanocomposites with different CeO2 ratios (10, 20, and 30 wt%) were prepared by a precipitation method. The nanocrystalline 20%CeO2/CoFe2O4 photocatalyst with a surface area of 117 m2.g−1, Eg 2.37 eV, and uniform distribution of quasi-spherical CeO2 minor phase (cubic fluorite structure with particle size 3 ± 1 nm) throughout the distorted spherical CoFe2O4 major phase (cubic spinel structure with particle size 9 ± 3 nm) showed the best photocatalytic performance for methylene blue (MB) degradation under UV light irradiation at the efficiency of 88.7% and the apparent rate constant (k) of 0.0138 min−1. The 20%CeO2/CoFe2O4 photocatalyst had a good magnetic response and could be easily separated from the dye solution by applying an external magnetic field. The reusability test showed lower photodegradation efficiency due to the adsorption of residual MB dye on the photocatalyst surface. The formation of heterojunction at the interfaces of CeO2/CoFe2O4 facilitated the photogenerated charge separation and increased availability of active species of holes (h+) and hydroxy radicals (∙OH), which were the key factors in improving the photocatalytic activity.

Enhanced lithium storage performance of anodes for lithium-ion batteries with biscuit-shaped LaNiO3-NiO/g-C3N4 composites

The significance of lithium-ion batteries in our daily lives cannot be overstated, and the advancement of anode materials is instrumental in achieving battery systems with remarkable energy and power density. Perovskite-type oxides with high theoretical capacity and environmental friendliness have received attention, their poor conductivity and bulk effect urgently need to be improved. With graphene-like layered structure, the rich nitrogen content of g-C3N4 can improve the wettability of the electrode and electrolyte, thus improving the lithium charge transfer process. Therefore, we demonstrated that LaNiO3 is the major phase in the LaNiO3-NiO composites with 80.57% and NiO is the sub-phase with 19.43% using Rietveld XRD refinement treatment. The theoretical capacity of the composites was calculated to be 666.8 mAh g−1 combining the respective theoretical capacities of the two phases. Subsequently, the Biscuit-shaped LaNiO3-NiO/g-C3N4 composite was prepared, which showed excellent electrochemical performance when used as an anode material for lithium-ion batteries. The LaNiO3-NiO/g-C3N4 electrodes exhibit excellent rate performance (with 154.5 mAh g−1 at 10 A g−1) and cycling stability (with 502.5 mAh g−1 for 900 cycles at 1.0 A g−1). This work is believed to provide new ideas for the design and synthesis of perovskite oxide materials in the future.

Deep Learning of Diabetic Retinopathy Classification in Fundus Images

Diabetic retinopathy is an eye disease in diabetic patients due to damage to the small blood vessels in the retina due to high and low blood sugar levels. Accurate detection and classification of Diabetic Retinopathy is an important task in computer-aided diagnosis, especially when planning for diabetic retinopathy surgery. Therefore, this study aims to design an automated model based on deep learning, which helps ophthalmologists detect and classify diabetic retinopathy severity through fundus images. In this work, a deep convolutional neural network (CNN) with transfer learning and fine tunes has been proposed by using pre-trained networks known as Residual Network-50 (ResNet-50). The overall framework of the proposed classification model is divided into three major phases, including pre-processing, training the Resnet-50 network, and classification with evaluation. In the first phase, pre-processing techniques are applied to the APTOS2019 fundus images dataset to find the best features and highlight some fine details of these images. The resnet-50 network was trained in the second phase using the training set and saved the best model obtained that gives high accuracy during the training process. Finally, this saved model has been implemented on the testing dataset for classification DR grades. The proposed model shows good and best classification performance, which was obtained with an accuracy of 98.3%, a precision of 98.4%, an F1-Score of 98.5 % and the recall of 98.4%.

Composition of olivines and spinel group minerals in aillikites from the Bushkanay dike, South Siberian Craton: Insights into alkaline melt sources and evolution

The potential sources and conditions that control the formation and evolution of alkaline melts are far from being fully understood. To address some of these fundamental questions, we have focused on the composition of olivines and spinel group minerals in aillikites from the Bushkanay dike in the Siberian Craton. These ultramafic carbonate-rich lamprophyres contain 40-50 vol% fresh olivine macrocrysts (200-600 µm) within a groundmass consisting of phlogopite (60%), magnetite (15%), perovskite (10%), apatite (5%), calcite (3%), chromite (1%), clinopyroxene (up to 1%), barite (up to 1%), serpentine and chlorite (up to 4%). Two types of compositional zoning in olivine have been recognized: (1) Mg-rich cores consisting of a relatively high #Mg (86-89) and NiO (0.25-0.4 wt%); (2) Fe-rich cores with a relatively low #Mg (82-86) and NiO (0.10-0.25 wt%). Both types of olivine cores are igneous and crystallize from an ultramafic carbonate-rich melt. The Mg#-poor (Fe-rich) cores were derived from an early and more evolved aillikitic melt and were later entrained by a more primitive melt, responsible for the formation of the Mg#-rich (Mg-rich) cores. The spinels exhibit a more complex zoning with four major growth zones: (1) an aluminum chromite core; (2) an Fe-chromite and Cr-magnetite transitional zone; and (3) a Ti-magnetite rim. The most primitive spinels of Al-chromite compositions crystallized directly from undifferentiated pulse of the melt, while further growth involved a gradual decrease in Cr due to the crystallization of Cr-rich spinels, while Al remained the same due to the absence of early phlogopite. Our results on olivines and spinels suggest that the aillikites of the Bushkanay dike were derived from a phlogopite-bearing carbonatized peridotite source. This idea is also supported by the presence of phlogopite, calcite, and amphibole as major phases in the chromite melt inclusions.

Synchrotron x‐ray diffraction for sealed Mars Sample Return sample tubes

AbstractThe joint NASA‐ESA Mars sample return campaign aims to return up to 31 sample tubes containing drilled sedimentary and igneous cores and regolith. The titanium alloy tubes will initially still be sealed when they are retrieved. Several types of measurement will be carried out on sealed samples in the pre‐basic characterization phase of scientific investigation. We show that powder x‐ray diffraction (XRD) analysis can be successfully carried out on sealed samples using an x‐ray source at the I12 beamline of Diamond Light Source synchrotron. Our experiment used an analog sample tube and a Martian regolith analog (Icelandic basaltic sand). The titanium walls of the tube analog give strong but few diffraction peaks, making identification of the major constituent mineral phases feasible. A more significant constraint on quantification of mineral phase abundances by this XRD technique is likely to be the grain size of the sample. This technique opens up the possibility of initial mineralogical analysis of samples returned from Jezero crater without opening the sample tubes and the potential changes to the sample that entails.

Zirconium stable isotope fractionation during intra-crustal magmatic differentiation in an active continental arc

Zirconium (Zr) stable isotope variations occur among co-existing Zr-rich accessory phases as well as at the bulk-rock scale, but the petrologic mechanism(s) responsible for Zr isotope fractionation during magmatic differentiation remain unclear. Juvenile magma generation and intra-crustal differentiation in convergent continental margins may play a crucial role in developing Zr isotope variations, and the Northern Volcanic Zone of the Andes is an ideal setting to test this hypothesis. To investigate the influence of these processes on Zr stable isotope compositions, we report δ94/90ZrNIST of whole rock samples from: 1) juvenile arc basalts from the Quaternary Granatifera Tuff, Colombia; 2) lower crust-derived garnet pyroxenites (i.e., arclogites), hornblendites, and gabbroic cumulates found in the same unit; and 3) felsic volcanic products from the Doña Juana Volcanic Complex, a dacitic composite volcano in close proximity to and partially covering the Granatifera Tuff. The basalts have δ94/90ZrNIST values ranging from −0.025 ± 0.018 ‰ to +0.003 ± 0.015 ‰ (n = 8), within the range of mid-ocean ridge basalts. The dacites have δ94/90ZrNIST values ranging from +0.008 ± 0.013 ‰ to +0.043 ± 0.015 ‰ (n = 14), slightly positive relative to the Granatifera and mid-ocean ridge basalts. In contrast, the (ultra)mafic cumulates have highly variable, predominantly positive δ94/90ZrNIST values, ranging from −0.134 ± 0.012 ‰ to +0.428 ± 0.012 ‰ (n = 15). Individual grains and mineral fractions of major rock-forming phases, including garnet (n = 21), amphibole (n = 9), and clinopyroxene (n = 18), were analyzed from 8 (ultra)mafic cumulates. The mineral fractions record highly variable Zr isotopic compositions, with inter-mineral fractionation (Δ94/90Zrgarnet-amphibole) up to 2.067 ‰. Recent ab initio calculations of Zr–O bond force constants in rock-forming phases predict limited inter-mineral Zr isotope fractionation in high-temperature environments, suggesting that the large fractionations we observe are not the product of vibrational equilibrium processes. Instead, we propose a scenario in which large Zr isotopic fractionations develop kinetically, induced by sub-solidus Zr diffusion between coexisting phases via changes in Zr distribution coefficients that arise from changes in temperature. Altogether, Zr isotope variability in this calc-alkaline continental arc setting exhibits no correlation with indices of magmatic differentiation (e.g., Mg#, SiO2), and is not a simple function of fractional crystallization. Furthermore, the garnet clinopyroxenite cumulates studied here represent density-unstable lower arc crust material; consequently, material with isotopically variable δ94/90Zr can be recycled into the mantle as a consequence of lower crustal foundering.

A platform for whole-genome speed introgression from Aegilops tauschii to wheat for breeding future crops.

Breeding new and sustainable crop cultivars of high yields and desirable traits has been a major challenge for ensuring food security for the growing global human population. For polyploid crops such as wheat, introducing genetic variation from wild relatives of its subgenomes is a key strategy to improve the quality of their breeding pools. Over the past decades, considerable progress has been made in speed breeding, genome sequencing, high-throughput phenotyping and genomics-assisted breeding, which now allows us to realize whole-genome introgression from wild relatives to modern crops. Here, we present a standardized protocol to rapidly introgress the entire genome of Aegilops tauschii, the progenitor of the D subgenome of bread wheat, into elite wheat backgrounds. This protocol integrates multiple modern high-throughput technologies and includes three major phases: development of synthetic octaploid wheat, generation of hexaploid A. tauschii-wheat introgression lines (A-WIs) and homozygosis of the generated A-WIs. Our approach readily generates stable introgression lines in 2 y, thus greatly accelerating the generation of A-WIs and the introduction of desirable genes from A. tauschii to wheat cultivars. These A-WIs are valuable for wheat-breeding programs and functional gene discovery. The current protocol can be easily modified and used for introgressing the genomes of wild relatives to other polyploid crops.

Influence of Pr-ion substitution in Cu2X hexaferrites on their magnetic and dielectric properties

A series of Sr2Cu2PrxFe28-xO46 (x = 0.00 to x = 0.32 with a step of 0.08) hexagonal ferrite was synthesized by the heat treatment method, and heated at 1300 °C for 6 h. These samples were characterized using FTIR, XRD, FESEM, VSM, and low-frequency (20 Hz–2 MHz) dielectric measurements. FTIR investigation confirms the ferrite phase formation in all the samples. XRD investigation reveals that all samples possess the X-type as a major phase with a minor M-phase. FESEM images show smaller grain size ranges between 25.27 μm and 51.25 μm. EDX elemental analysis confirms the existence of constituent elements in synthesized materials. VSM analysis shows that prepared ferrites possess a soft magnetic nature, the saturation magnetization of heated samples was found in the range of 35.99 Am2/kg to 49.44 Am2/kg, and coercivity was observed in the range of 10.372 kA/m to 37.443 kA/m. Relaxation peaks have been observed in the loss tangent profile for x = 0.00, 0.08. The Nyquist plot for samples S1 and S2 represents the low-loss universal capacitance circuit, while samples S3 to S5 represent the parallel conductance-capacitance circuit.

A novel generalized multi input boosting multi-level inverter (MIB-MLI) for high-frequency AC (HFAC) power distribution

The simplified topology for the high-frequency ac (HFAC) power distribution method with a multi-level inverter (MLI) hybrid switched capacitor (SC) is introduced. Capacitors, switches, diodes, and DC sources are among the components that are reduced in the designed MIB-MLI (Multi Input Boosting Multi-level Inverter). Where asymmetric dc voltage sources are available, such as in renewable energy farm-based ac microgrids and current electric vehicle, this architecture is advantageous. The proposed inverter has the feature of self-balancing the capacitor voltages and voltage boosting by using the series-parallel conversion scheme. The quality of output power is increased when a dc source array is connected with the unidirectional switched converter. Moreover, if a major phase variation betwixt the output current along with the voltage is no more mandatory, multiple alive switches may be recouped with diodes. In the switched capacitor group ripple volatge is reciprocal to the output frequency, so the MIB-MLI is favorable for HFAC implementations. Also, this paper clarifies the operating theory of the complete network and switching condition covered by the sinusoidal pulse width modulation (SPWM) technique. Mathematical equation related to power loss and capacitor voltages are provided. The modeling and simulation results of the proposed seventeen-level (17-L) inverter are depicted in this paper. The findings have shown that the proposed inverter is superior at HFAC along with the power efficiency of the inverter is adequate with SPWM technique.

Nurses’ job preferences for working in deprived areas in Tehran: a discrete choice experiment

BackgroundIn Iran, the issue of the nursing shortage and unequal distribution exist simultaneously. The shortage of healthcare workers is one of the most important concerns of the health systems. In addition, the disparity in the distribution of healthcare workers between large metropolises and remote or non-capital areas has become a serious concern and a top priority to address. We conducted this study to identify and create a sufficient understanding of the different financial and non-financial preferences of nurses for working in deprived areas.MethodsThis research was carried out in June and April 2022. It was carried out in three major phases. The factors influencing the nurses' job preferences were first discovered using qualitative methods. The second phase was conducting a pilot study and determining the best design for discrete choice experiment scenarios. The last phase involved publishing the questionnaire to gather information. Data were analyzed (discrete choice analysis) using JMP Pro 16 software.ResultsA desirable job for the participants (nurses) in this study would have a higher salary, work in a city, the Rasmi employment contract, a low workload, adequate workplace facilities, an appropriate work schedule, and 1 to 3 years spent on the assigned job to promote to a higher position. Willingness to pay (WTP) and the probability of selecting different attribute levels were also calculated and reported. For example, the highest amount of money that a nurse expected to be paid was for changing the geographical location of the workplace from a city to a deprived area. In this case, a nurse tends to receive 91.87 million IRR more to move from a city to a deprived area to work. This amount of money was by far the most among other WTPs.ConclusionThe results of this study indicated that nurses are willing to forego net income in exchange for other favorable characteristics of their working environment and conditions. This shows that a variety of actions are accessible to policymakers that can greatly enhance the working conditions for nurses. The WTP and the probability of selecting various attributes may help policymakers plan more effectively.

Fabrication, microstructure and mechanical properties of multi-phase tantalum carbide based (TaCz-Ta5Si3) ceramics

Three multi-phase tantalum carbide composites (TaCz-Ta5Si3) were fabricated by Spark plasma Sintering (SPS) using Ta, TaC and SiC powders. SiC was added to control the C:Ta ratio (z = 0.6, 0.74, 1.0), regulating the phase composition and grain morphology while also serving as a deoxidizer. Composite TaC0.6-Ta5Si3 had Ta2C as the major phase and contained Ta4C3−x, TaC and Ta5Si3. It exhibited an excellent combination of high flexure strength (714 ± 21 MPa) and toughness (13.9 ± 0.2 MPa·m1/2), despite a low Ta4C3−x fraction, a phase known to have very high toughness. The outstanding performance was attributed to the elongated Ta2C grain morphology, highly laminated intra-granular Ta4C3−x laths, and the refined Ta2C grain size. Composite TaC0.74-Ta5Si3, characterised by equiaxed grain morphology, exhibited good flexure strength (571 ± 36 Mpa) and toughness (7.6 ± 1.1 MPa·m1/2) due to the presence of Ta4C3−x laths in the c-TaC. Lastly, composite TaC1.0-Ta5Si3, composed of c-TaC and Ta5Si3, exhibited moderate strength (545 ± 25 MPa) and toughness (5.3 ± 0.1 MPa·m1/2).

Silver, cobalt and nickel mineralogy and geochemistry of shale ore in the sediment-hosted stratiform Nowa Sól copper–silver deposit, SW Poland

The Nowa Sól deposit is a part of the newly discovered Northern Copper Belt and is situated some 30 km NW of the Lubin–Sieroszowice mining district (the so-called New Copper District) in SW Poland. The ore horizon spans across the upper part of the Lower Permian (Rotliegend) terrestrial redbeds and the lower part of the Upper Permian (Zechstein) marine rocks. It comprises three lithotypes: sandstone, shale and carbonate. The high-grade shale ore has polymetallic characteristics and is a crucial host for by-product metals such as Ag, Co and Ni (studied in this paper), but also Mo, V and Re. The results of bulk-rock and electron microprobe as well as mineralogical (optical and scanning electron microscope) data of the mineralized, organic-rich shale ore from the Nowa Sól deposit are presented. This thin stratigraphic horizon, ranging from 0.06 to 0.59 m, shows notable concentrations of critical metals, including on average 15.9 wt% Cu, 715 grams per tonne (g t -1 ) Ag, 318 g t -1 Co and 345 g t -1 Ni. It constitutes less than 10% of the total ore mass, but accounts for 36% of the Ag, 40% of the Ni and 42% of the Co found within the deposit. The ore sulfides in the mineralized shale in the Nowa Sól deposit include chalcocite, djurleite and bornite, accompanied by digenite, covellite, tennantite, galena, sphalerite and pyrite. The Ag content within the Cu sulfides exhibits a linear decrease: chalcocite > djurleite > bornite. Three primary Ag minerals are identified within the shale ore, namely native Ag, Ag amalgam and stromeyerite. Two types of Ag amalgam are observed: Hg-rich and Hg-poor. Cobaltite and gersdorffite represent the primary Co and Ni minerals, occurring as micrometre-sized inclusions within chalcocite and djurleite. Textural observations suggest that the Ag, Co and Ni mineralization postdates the major phase of Cu sulfide precipitation. It is shown that in the Nowa Sól deposit, the Kupferschiefer horizon has acted as a geochemical barrier for the above-mentioned metals during protracted time, from early syndepositional to late epigenetic stage of basin evolution. Supplementary material: The supplementary material contains the results of the electron microprobe analyses and the specific experimental conditions employed for these analyses – available at https://doi.org/10.6084/m9.figshare.c.6873631

Pleistocene valley incision, landscape evolution and inferred tectonic uplift in the central parts of the Balkan Peninsula – Insights from the geochronology of cave deposits in the lower part of Crna Reka basin (N. Macedonia)

Although the general geomorphology is reasonably well understood, not much information is available on the incision rates of rivers and related tectonic uplift in the central parts of the Balkan Peninsula. Caves in the lower part of Crna Reka drainage (N. Macedonia) provide the possibility to reconstruct the Neogene-Quaternary evolution of this area, as previous research has identified two major cave development phases: one related to Pliocene-Early Pleistocene basin infilling and establishment of lacustrine environments, and a subsequent cave development phase related to valley incision due to draining of the lacustrine systems and tectonic uplift.Here, we present new geochronological data obtained by U-Th dating on speleothems and cosmogenic nuclide burial age determination of clastic cave sediments, that provide time constraints on the Pleistocene karst and valley evolution, and an insight into the related tectonic uplift. The obtained cosmogenic nuclide burial age (2.1 ± 0.5 Ma) of the clastic cave sediments from Temna Peštera – Dragožel, further supports previous results on placing the onset of the draining of the Pliocene lakes in Macedonia in the Early Pleistocene. The similar timing obtained for the downstream and upstream parts of Crna Reka drainage suggests that the draining was more likely initiated by regional uplift, rather than headward erosion related to subsidence in the Aegean Sea. The Middle to Late Pleistocene age of the dated speleothems agrees well with the existing conceptual model for karst and landscape evolution in the area. The cumulative valley incision rates based on these radiometric data show an increase towards the present, with values of <0.1 m/ka in Early Pleistocene, increasing to ∼0.2–0.5 m/ka in Middle Pleistocene, and up to 1 m/ka in Late Pleistocene. They are lower than the measured uplift rates in the area (1.1–1.2 m/ka), and mostly overlap with the range of GPS-based vertical deformation rates in the Hellenides. Higher Middle to Late Pleistocene uplift rate is inferred in the downstream part of Crna Reka, an area in the Vardar zone bounded by seismogenic faults, than in the upstream part, at the easternmost edge of the Pelagonian massif.

Phase composition and liquidus temperatures of the CaO–SiO2–MgO-13 wt%Al2O3–TiO2 system in reduction conditions

Effects of TiO2, binary basicity and MgO content on the liquidus temperatures of TiO2–CaO–SiO2–MgO–Al2O3 slags were experimentally studied in equilibrium with carbon. The experimental techniques include high temperature equilibration, quenching and Electron Probe X-ray Microanalysis (EPMA). It was found that the major primary phase in the composition range investigated is M3O5 (M = Ti, Mg, Al). The liquidus temperatures increase with increasing TiO2 and MgO contents, whereas decrease with increasing CaO/SiO2 mass ratio. The experimentally determined liquidus temperatures are much higher than the predicted ones by FactSage and the primary phases between the experiment results and predictions are also different. The mole fractions of Al2TiO5 and Ti3O5 in the M3O5 phase decrease, but MgTi2O5 increases with increasing MgO content and CaO/SiO2 in the samples. Moreover, the proportions of Al2TiO5 and MgTi2O5 in the M3O5 phase decrease, while Ti3O5 proportion in the M3O5 phase increases with increasing the reaction time. The mole ratio of Ti3+/Ti4+ in the M3O5 phase decreases with MgO content and CaO/SiO2 mass ratio in the samples but increases with increasing reaction time.

The Crystallization, Microstructure, and Dielectric Characteristics of MgO–Al2O3–SiO2–TiO2–CeO2 Materials for Microwave Applications

In this article, the impacts of varying CeO2 contents and heat‐treatment procedures on the crystallization, microstructure, and dielectric characteristics of MgO–Al2O3–SiO2–TiO2–CeO2 (MASTC) materials are investigated. In this research, it is indicated that perrierite, rutile, and α‐cordierite are the major crystalline phases in the materials. An increased CeO2 content promotes the formation of perrierite and inhibits the precipitation of α‐cordierite and rutile in the glass ceramics. An appropriate amount of CeO2 content contributes to a dense microstructure and improves the dielectric characteristics of the samples. However, an excessive amount of CeO2 deteriorates the densification and dielectric characteristics of the MASTC materials. Furthermore, heat‐treatment temperature and duration also have a significant impact on the crystallization, microstructure, and dielectric performance of the materials. The MASTC material with 20.2 wt% CeO2, heat‐treated at 1100 °C for a duration of 3 h, possesses superior characteristics with a density of 3.14 g cm−3, a permittivity of 11.1, and a Q × f factor of 17 357 (14 GHz).

Synthesis, crystal structure and properties of chlorido-tetra-kis-(pyridine-3-carbo-nitrile)-thio-cyanato-iron(II).

Reaction of FeCl2·4H2O with KSCN and 3-cyano-pyridine (pyridine-3-carbo-nitrile) in ethanol accidentally leads to the formation of single crystals of Fe(NCS)(Cl)(3-cyano-pyridine)4 or [FeCl(NCS)(C6H4N2)4]. The asymmetric unit of this compound consists of one FeII cation, one chloride and one thio-cyanate anion that are located on a fourfold rotation axis as well as of one 3-cyano-pyridine coligand in a general position. The FeII cations are sixfold coordinated by one chloride anion and one terminally N-bonding thio-cyanate anion in trans-positions and four 3-cyano-pyridine coligands that coordinate via the pyridine N atom to the FeII cations. The complexes are arranged in columns with the chloride anions, with the thio-cyanate anions always oriented in the same direction, which shows the non-centrosymmetry of this structure. No pronounced inter-molecular inter-actions are observed between the complexes. Initially, FeCl2 and KSCN were reacted in a 1:2 ratio, which lead to a sample that contains the title compound as the major phase together with a small amount of an unknown crystalline phase, as proven by powder X-ray diffraction (PXRD). If FeCl2 and KSCN is reacted in a 1:1 ratio, the title compound is obtained as a nearly pure phase. IR investigations reveal that the CN stretching vibration for the thio-cyanate anion is observed at 2074 cm-1, and that of the cyano group at 2238 cm-1, which also proves that the anionic ligands are only terminally bonded and that the cyano group is not involved in the metal coordination. Measurements with thermogravimetry and differential thermoanalysis reveal that the title compound decomposes at 169°C when heated at a rate of 4°C min-1 and that the 3-cyano-pyridine ligands are emitted in two separate poorly resolved steps. After the first step, an inter-mediate compound with the composition Fe(NCS)(Cl)(3-cyano-pyridine)2 of unknown structure is formed, for which the CN stretching vibration of the thio-cyanate anion is observed at 2025 cm-1, whereas the CN stretching vibration of the cyano group remain constant. This strongly indicates that the FeII cations are linked by μ-1,3-bridg-ing thio-cyanate anions into chains or layers.

Supporting Preparedness and Response to Cyclone Freddy In Madagascar- A Contribution from the Social and Behaviour Change Communication

Social and Behaviour Change Communication (SBC) is one of the vital strategic programs that aim to empower people to be resilient in preparation and response to emergencies. This paper outlines steps undertaken by SBC partners in Madagascar as a contribution towards preparation and response initiatives to cyclone Freddy, and discusses observations and lessons learnt to inform future programming in the country and other cyclone-affected regions. It bases its conceptual framework around the emergency prevention, preparedness, response and recovery (PPRR), the Emergency Risk Management Framework (ERM) as well as the UNICEF Framework on Accountability to Affected Population (AAP) to define the interventions based on three major phases of the intervention i.e., before, during and after. An SMS-based survey was used as a feedback mechanism and as a tool to assess SBC interventions 3 days after the passage of cyclone Freddy. The survey used a structured questionnaire where 450 respondents participated from 13 regions of the country. Scouts (youth mobilisers) and other NGO partners in the emergency network conducted phone calls, entered data into a Kobo-Collect template and analysed the data using simple percentiles in excel sheets. Analysis of the processes and results of the survey indicated that there was adequate utilisation of systematic steps in emergency preparedness. These included strategic planning and prepositioning of communication materials in all the 23 regions of the country, coordination and partnership at national, regional and district levels, implementation of a mixture communication and engagement methods and efforts to collect and respond to feedback. Three days from the onset of Freddy, the affected people were highly exposed to life saving messages (86%) but needed more exposure to life improving messages i.e., health (29.6%), child stimulation (29.3%), WASH (29.3%), nutrition (18%), Gender-based Violence (10.2%) and Violence against Children (4%). SBC interventions showed positive results in the use of bed nets to prevent malaria (85.7%), hand washing with soap to prevent diarrheal diseases and COVID-19 (95.6%) and reporting of cases on gender-based violence and violence against children (31.6%). 50.9% of the interviewed individuals acknowledged having been well informed about humanitarian interventions.

ANALYSIS OF ADDITIVELY MANUFACTURED AlSi10Mg ALLOY USING X-RAY DIFFRACTION

This research deals with the study of additively manufactured AlSi10Mg alloy samples by X-ray diffraction. The effect of sample orientation during 3D printing by Selective Laser Melting on the values of macroscopic residual stresses and microstructural parameters and their possible inhomogeneities of the cylindrical sample was investigated. Phase analysis identified the intermetallic phase Mg2Si in addition to the major phases (solid solutions of Al and Si). Tensile residual stresses weredetected in the surface layer for all samples. Inhomogeneities of the investigated parameters of all samples were observed along the circumference of the shank. These effects may be related to the direction of the layers relative to the axis of the sample. These inhomogeneities form so-called microstructural notches or weak spots that are prone to the formation of fatigue cracks, which have a major influence on the fatigue life.