Al Content Research Articles

Insights into the anatectic origin of granites parental to tungsten mineralization: A case study from the trans‐Aravalli terrane, NW India

AbstractPotential progenitors for W (±Sn) deposits include peraluminous granites of S‐type affinity. The anatectic origin of such granites parental to W mineralization has received little attention. This study focuses on Balda Granite (BG), a peraluminous intrusion parental to W‐rich ore bodies in the Sirohi region (NW India). We reflect upon the potential source for BG and investigate its anatectic origin through open‐system phase equilibria modeling. On the prograde path, muscovite‐ and biotite‐dehydration reactions at 675–745°C and 755–870°C yield ~10 and 13 wt.% melt, respectively. Si, K, Al, and Fe contents of the cumulative melt increased with progressive anatexis. Modeling results suggest high‐T (>800°C) stability of the peritectic garnet, which is abundantly observed in the leucosome‐dominated migmatitic patches. Cumulative melt extracted till 868°C was chosen to model the crystal fractionation along three polybaric gradients of 30, 45, and 60°C/kbar. As the modeled anatectic melt cooled, its peraluminosity and maficity decreased progressively. With the intermediate cooling gradient of 45°C/kbar, the melt achieved complete crystallization at ~7 km, the depth at which the BG had been emplaced and evolved into a W‐rich residual (fractionated) model melt. In terms of peraluminosity, and major and trace element (Lu, Sc, Dy, Y, Yb) chemistry, the fractionated (residual) model melt compares well with BG. This study also models the W concentration in the anatectic melt during its generation and fractional crystallization. We argue for the origin of BG through high‐T anatexis of Sirohi Group metapelites and cooling (and fractional crystallization) of the parent anatectic melt at the maximum gradient of 45°C/kbar. Thus, a high‐T anatectic origin of granites parental to W deposits may be more prevalent than so far inferred.

Microstructure and properties of CoCrFeNiAlxMo2-x high-entropy alloy coating by laser cladding

CoCrFeNiAlxMo2-x (x = 0, 0.5, 1, 1.5, and 2) high-entropy alloy coatings were applied to Q235 steel, and this study investigated the effect of x variations on microstructure evolution and properties. It was fount that as x increased, the crystal structure of the coatings transitioned from a face-centred cubic (FCC) + body-centred cubic (BCC) + σ + B2 phase to a BCC + σ + B2 phase, and eventually it become a BCC phase. Concurrently, the microhardness, wear resistance, corrosion resistance, and high-temperature oxidation resistance of the coatings initially increased and then decreased with the rise in x. The optimal values were achieved at x = 1. The enhancement in microhardness and wear resistance of high-entropy alloy (HEA) coatings was attributed to the change of phase type, dispersion strengthening and solid solution strengthening. Adding of the Al element generated a passivation film on the coatings’ surface, which mitigated galvanic corrosion. Furthermore, an appropriate amount of Mo increased the thickness and density of the passivation film, thereby improving its corrosion resistance. During early-stage high-temperature oxidation, the Al underwent element undergoes rapid oxidation, while Mo promoted the formation of Al2O3, leading to an excellent high-temperature oxidation resistance. Additionally, mathematical model equations were used to fit the results, adding insights into the effects of Al and Mo content changes (x value) on the wear resistance, corrosion resistance, and high-temperature oxidation resistance of the coatings.

Mineralogical and geochemical characteristics of alteration minerals related to fossil geothermal activities in the Kızıldere geothermal field, Western Turkey

The Kızıldere geothermal field, located at the eastern part of the Büyük Menderes graben in Western Turkey, is the most important geothermal reservoir suitable for electricity generation. Fossil fumarole fields and alteration or mineralization zones are directly related to the tectonic zones influenced by N-S directional extension. Associated to fossil geothermal activities, calcite, dolomite, strontianite, quartz, gypsum, anhydrite, celestine, kaolinite, smectite, boehmite and goethite/limonite were occurred in the form of void or crack fill within the Paleozoic metamorphic and Miocene-Quaternary clastic and carbonate host rocks. The current mineralogical composition indicates temperature conditions of 100–250 °C which close to current reservoir temperatures. Some of minerals with fossil geothermal origin, i.e. calcite, anhydrite, dolomite, celestine, amorphous silica and quartz, are compatible for mineral precipitations estimated from mineral equilibrium modeling, and scale mineralogy of wells, as well. The formation order of the most common geothermal minerals is determined as calcite → gypsum → anhydrite → quartz direction indicating that alkaline conditions were followed by acidic conditions. The blade-like/prismatic rhombohedral calcites replaced by quartz occurrences in siliceous‑carbonate veins indicate the boiling was occurred in the field. The geothermal mineral zoning determined from drilling samples is anhydrite-dolomite-calcite from shallow to deeper parts. The lateral and vertical distribution of mineral zoning is related to the fact that geothermal waters are mainly affected by host rock compositions, i.e. dissolution from the host rocks and precipitation along the cracks/fractures and bedding planes. Mineralizations in the Kızıldere geothermal field mainly represent the direct precipitations from hot geothermal waters rather than transformations of minerals in the host rocks. Si, Al, Mg, K and Na concentrations in carbonate and sulfate minerals show a positive correlation relationship and are derived from metapelites. Whereas Ca is negatively related to these elements and it is derived from metacarbonate and/or carbonate host rocks. According to the current geothermal water composition, Ca enriches in the deeper parts, while Mg and B enrichment in shallow depths near the basin edge that indicates the different composition of the host rocks where minerals precipitated. The relatively high boron contents at shallow depth indicate that it is retained by the minerals precipitated this level and causes less release to the surface.

Disordered medium-pore zeolite PST-24 as an efficient low-temperature isobutanol dehydration catalyst

The disordered medium-pore zeolite PST-24 was found to be an efficient catalyst for low-temperature dehydration of bio-based isobutanol to isobutene.

Muddy sediments are an important potential source of silicon in coastal and continental margin zones

The dissolution of silicate minerals on the seafloor releases an important amount of dissolved silicon (dSi), which is necessary for maintaining high diatom production in Coastal and Continental Margin Zones (CCMZs). However, the dissolution of silicate minerals along the continental shelves is variable, which hinders our understanding of the marine Si cycle on both a regional and global scale. To understand the discrepancy of silicon (Si) released in different sediment matrices and its potential controlling factors, we investigated surface sediments of typical CCMZs of the Chinese marginal Seas using a continuous alkaline extraction technique, grain size and chemical (carbon and total nitrogen) analysis as well as a qualitative measurement of clay mineral composition by X-ray diffraction. The results showed that the amount of Si and aluminum (Al) leached from muddy sediments were 2 times greater than those released from sandy sediments. High dissolution rates (> 0.20 mg-SiO2 g−1 min−1) of silicate minerals are caused by a large sediment-specific surface area. Further, our data showed that biogenic silica (bSi) with high Al content (Si:Al < 40) has low reactivity and that the source of Al incorporated in bSi is silicate minerals undergoing dissolution. We show that although the dissolution of silicate minerals is less active than that of bSi, it still potentially releases more bio-available Si and Al to seawater due to its dominant presence on the seafloor (70.3% − 99.0%wt). This study highlights silicate minerals as an important potential marine Si source and emphasizes the need for a better understanding of the roles of silicate minerals in the Si cycle of marginal seas in future studies.

Nonionic polymer and amino acid-assisted synthesis of ZSM-5 nanocrystals and their catalytic application in the alkylation of 2-methylnaphthalene.

The synthesis of nanosized ZSM-5 zeolites with high crystallinity and suitable acidity is very significant for their great potential in various catalytic applications. Herein, a series of zeolite ZSM-5 crystals with different particle sizes and SiO2/Al2O3 ratios (10-30) were synthesized by a temperature-varying two-step crystallization method in a concentrated gel system containing L-lysine and/or polyvinylpyrrolidone (PVP) additives. By optimizing the addition amounts of the two additives, the crystal size of the ZSM-5 zeolite could be reduced to less than 100 nm. Meanwhile, relatively high crystallinity and framework Al incorporation rates could be achieved, resulting in the generation of high-quality ZSM-5 nanocrystals. The nanosized H-form ZSM-5 zeolite with a SiO2/Al2O3 ratio of 20 showed enhanced catalytic efficiency and stability for the alkylation of 2-methylnaphthalene (2-MN) with methanol to produce an important intermediate, 2,6-dimethylnaphthalene (2,6-DMN). A relatively high and steady yield of 2,6-DMN (above 7.2%) could be achieved during 20 h time-on-stream at 400 °C. The smaller crystal size, higher crystallinity and framework Al content could provide more accessible Brønsted acid sites in the 10-membered ring channel of the ZSM-5 nanocrystals, which are the main active sites responsible for the shape-selectivity of the targeted product of 2,6-DMN. As a result, the formation of other side products like 1-MN and poly-MN could be effectively inhibited, thus leading to an improved 2,6-DMN yield and coke resistance over the nanosized ZSM-5 catalyst.

Simulation of displacement damage induced by protons incident on Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N materials

Gallium nitride materials, due to their excellent electrical properties and irradiation resistance, are expected to be used in future space electronics systems where electronic devices are composed of different amounts of Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N materials. However, most of their displacement damage studies currently focus on GaN materials, and less on Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N materials themselves. The mechanism of displacement damage induced by 10- keV- to-300- MeV protons incident on Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N materials with different Al content is investigated by binary collision approximation method. The results show that the non-ionization energy loss of Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N material decreases with proton energy increasing. When the proton energy is lower than 40 MeV, the non-ionization energy loss becomes larger with the increase of Al content, while the trend is reversed when the proton energy increases. Analyzing the primary knock-on atoms and non-ionizing energy deposition caused by protons, it is found that the primary knock-on atoms’ spectra of different Al&lt;sub&gt;&lt;i&gt;x&lt;/i&gt;&lt;/sub&gt;Ga&lt;sub&gt;1&lt;i&gt;–x&lt;/i&gt;&lt;/sub&gt;N materials are similar, but the higher the content of Al, the higher the proportion of the self primary knock-on atoms generated by elastic collisions is. For the non-ionizing energy deposition produced by protons at different depths, the energy deposition due to elastic collisions is largest at the end of the trajectory, while the energy deposition due to inelastic collisions is uniformly distributed in the front of the trajectory but decreases at the end of the trajectory. This study provides a good insight into the applications of GaN materials and devices in space radiation environment.

Thermal Equation of State and Structural Evolution of Al‐Bearing Bridgmanite

Abstract(Mg, Fe, Al)(Si, Al)O3 bridgmanite is the most abundant mineral of Earth′s lower mantle. Al is incorporated in the crystal structure of bridgmanite through the Fe3+AlO3 and AlAlO3 charge coupled (CC) mechanisms, and the MgAlO2.5 oxygen vacancy (OV) mechanism. Oxygen vacancies are believed to cause a substantial decrease of the bulk modulus of aluminous bridgmanite based on first‐principles calculations on the MgAlO2.5 end‐member. However, there is no conclusive experimental evidence supporting this hypothesis due to the uncertainties on the chemical composition, crystal chemistry, and/or high‐pressure behavior of samples analyzed in previous studies. Here, we synthesized high‐quality single crystals of bridgmanite in the MgO–AlO1.5–SiO2 system with different bulk Al contents and degrees of CC and OV substitutions. Suitable crystals with different compositions were loaded in resistively heated diamond anvil cells and analyzed by synchrotron X‐ray diffraction at pressures up to approximately 80 GPa at room temperature and 35 GPa at temperatures up to 1,000 K. Single‐crystal structural refinements at high pressure show that the compressibility of bridgmanite is mainly controlled by Al–Si substitution in the octahedral site and that oxygen vacancies in bridgmanite have no detectable effect on the bulk modulus in the compositional range investigated here, which is that relevant to a pyrolytic lower mantle. The proportion of oxygen vacancies in Al‐bearing bridgmanite has been calculated using a thermodynamic model constrained using experimental data at 27 GPa and 2,000 K for an Fe‐free system and extrapolated to pressures equivalent to 1,250 km depth using the thermoelastic parameters of Al‐bearing bridgmanite determined in this study.

First-principles study of the mechanical and thermodynamic properties of aluminium-doped magnesium alloys.

Magnesium-aluminum (Mg-Al) alloys are widely used in aerospace, automobile and medical equipment owing to their advantages of easy casting, high strength-to-mass ratio and good biocompatibility. The structural, mechanical, electronic and thermodynamic properties of MgxAly alloys (x + y = 16, x = 1, 2,…, 15) with varying Al-doping contents were studied using the first-principles method. In this work, the structures of MgxAly alloys were constructed by replacing Mg atoms in a supercell with Al atoms. The lattice parameters of the Al-doped MgxAly alloys decrease with an increasing Al content because of the smaller atomic size of Al than that of Mg. The calculated formation energies show that Mg11Al5, Mg5Al3 and Mg9Al7 have prominent structural stability. The analyses of the mechanical properties reveal that the doping of Al improves the ductility of MgxAly alloys. The elastic moduli increase with an increasing Al content, and Mg9Al7 has a notable ability to resist deformation, while Mg11Al5 and Mg5Al3 have better plasticity. The calculated results of their electronic properties reveal that Mg11Al5, Mg5Al3 and Mg9Al7 are good conductors without magnetism. Furthermore, CDD analyses show that the inner layer charges of Al atoms migrated to the outer layer, and the charges of Mg atoms accumulated significantly in the outer region of Al atoms. The Debye temperature of Mg9Al7 is higher than that of Mg11Al5 and Mg5Al3, indicating that it has better thermodynamic stability. Our findings would be helpful for the design of Mg-Al alloys with excellent mechanical and thermodynamic performances.

Explosive Nucleosynthesis in Core-collapse Type II Supernovae: Insights from New C, N, Si, and Al–Mg Isotopic Compositions of Presolar Grains

We report C, N, Si, and Al–Mg isotope data for 39 presolar X silicon carbide (SiC) and four silicon nitride grains—a group of presolar grains that condensed in the remnants of core-collapse Type II supernovae (CCSNe)—isolated from the Murchison meteorite. Energy dispersive X-ray data were used to determine the Mg and Al contents of the X SiC grains for comparison with the Mg/Al ratios determined by secondary ion mass spectroscopy (SIMS). Previous SIMS studies have used O-rich standards in the absence of alternatives. In this study, the correlated isotopic and elemental data of the X SiC grains enabled accurate determination of the initial 26Al/27Al ratios for the grains. Our new grain data suggest that (i) the literature data for X grains are affected to varying degrees by asteroidal/terrestrial contamination, and (ii) the Al/Mg ratios in SiC are a factor of 2 (with ±6% 1σ uncertainties) lower than estimated based on the SIMS analyses that used O-rich standards. The lowered Al/Mg ratios result in proportionally higher inferred initial 26Al/27Al ratios for presolar SiC grains. In addition, the suppression of asteroidal/terrestrial contamination in this study leads to the observation of negative trends for 12C/13C–30Si/28Si and 26Al/27Al–30Si/28Si among our CCSN grains. We discuss these isotope trends in the light of explosive CCSN nucleosynthesis models, based on which we provide new insights into several nontraditional CCSN nucleosynthesis processes, including explosive H burning, the existence of a C/Si zone in the outer regions of CCSNe, and neutrino–nucleus reactions in deep CCSN regions.

Aluminum-based ceramic/metal composites with tailored thermal expansion fabricated by spark plasma sintering.

We have devised a moderate temperature spark plasma sintering route for preparing aluminum matrix composites which possess tailored coefficients of thermal expansion (CTEs) in combination with tunable electrical and thermal conductivities. Due to its isotropic negative thermal expansion over a wide temperature range, cubic-phase ZrW2-xMoxO8 (x = 0.0, 1.0) is an ideal secondary phase for metal matrix composites with suitable CTEs. In this study, high-density ZrW2O8/Al and ZrWMoO8/Al composites containing 30-70 vol% Al were fabricated using spark plasma sintering. X-ray diffraction analysis indicated that the composites were composed of a thermally-stable cubic phase at temperatures as high as 873 K for ZrW2O8 and 773 K for ZrWMoO8, without any orthorhombic high-pressure phase derived from the large thermal mismatch between the ceramic and metal during sintering. The thermal expansion curves of the ZrW2-xMoxO8/Al composites were consistent with the predictions made using the Rule-of-Mixtures. The CTEs could be controlled from negative to positive and even close to zero by simply varying the volume fraction of aluminum. Similarly, the thermal and electrical conductivity of the ZrW2-xMoxO8/Al composites increases with increasing Al content, which is thought to be mainly related to the contribution of the free electron conduction path of Al in the composites.

Mechanical and corrosion properties of lightweight (Ti60Cr30Nb10)100−xAlx medium-entropy alloys

Microstructure, mechanical properties and corrosion behavior of lightweight (Ti60Cr30Nb10)100−xAlx(x=0, 5, 7.5 and 10,at.%) medium-entropy alloys (MEAs) were investigated in the as-cast and homogenized states. As the Al content increases from 0 to 10 at.%, all the as-cast MEAs consist of identical phase composition, i.e., a body-centered cubic (BCC) phase and a small amount of TiCr2 Laves phase. After the homogenization, all the homogenized MEAs show a single BCC phase. The (Ti60Cr30Nb10)95Al5MEA shows the most excellent mechanical properties both in as-cast and homogenized states among the studied alloys, displaying yield strengths of ∼1048 MPa and ∼1017 MPa along with the compression strain exceeding 50%. Additionally, compared with the TC4 and the as-cast (Ti60Cr30Nb10)95Al5 alloys, the homogenized (Ti60Cr30Nb10)95Al5alloy shows superior corrosion resistance due to its uniform microstructure and chemical composition.

Effects of Al addition on the microstructure and mechanical properties of AlxCoCrFeNi2.1 high-entropy alloys

To investigate the effect of Al content on the microstructure evolution and properties of AlxCoCrFeNi2.1 high-entropy alloys, the AlxCoCrFeNi2.1 high-entropy alloys (=0.5, 0.8, 1.0, 1.2 and 1.5) were prepared by vacuum arc melting. The results show that all the designed alloys are composed of single face-centered cubic (FCC) and ordered body-centered cubic (B2) phases. With the increase of Al content, the volume fraction of FCC phase decreases while that of B2 phase increases. In addition, the increasing Al content leads to the sequential increase of the hardness and yield strength of the alloys, while both the plasticity and compressive strength decrease. And the corresponding wear rate decreases from 312.9 × 10−5 mm2 N−1 to 55.3 × 10−5 mm2 N−1. It is revealed that the wear mechanism transforms from initially dominant abrasive wear with adhesive wear as a supplement to the mechanism dominated by adhesive wear with abrasive wear as a supplement, and finally to the oxidation wear plus abrasive wear. The experimental results show that the Al1.2CoCrFeNi2.1 alloy has the most excellent comprehensive performance, with an average hardness of 441 HV, compression ratio of 36.4%, compressive strength of 2618 MPa and wear rate of 68.0 × 10−5 mm2 N−1.

Dissolution-precipitation hydration mechanism of steel slag based on ion exchange of a layered alkali-activator

This paper provided a new alkali activator for steel slag cementitious material - layered sodium disilicate (LSD), and focused on its dissolution-precipitation mechanism based on ion exchange capacity of LSD. The results showed that LSD could act as an effective activator for steel slag and the higher compressive strength of pastes (S3(14.9 MPa) and S10(22.3 MPa) increased by 222% and 332% respectively) were achieved and a matrix with much denser pore structure was formed. The pore solution analysis indicated LSD could play a role as ions transporter to facilitate the dissolution of steel slag (mainly C2S and C3S). Analysis of the hydration products showed that the addition of LSD increased the formation of C-S-H gels, CaCO3 and Mg(OH)2, but reduced the content of hydrotalcite-like phase. In addition, TEM and FTIR analysis indicated that the laminar C-S-H gel generated from LSD-activated steel slag had a higher SiO2 and Al content and a higher degree of silicate chain polymerization.

A Modeling Study of Electron Transport in GaN/AlGaN Superlattices Using Monte Carlo Simulation

Electron transport in superlattices (SLs) is analyzed using a single‐particle Monte Carlo (MC) method. This study includes the band structure of GaN, AlN, and their alloys, utilizing a single‐electron MC approach and a three‐band model. It explores how intervalley (IV) and electron–polar longitudinal optical phonon (PLOP) scatterings influence electron velocity. A single non‐parabolic band approximation is effectively used in SL modeling, as the miniband's energy width limits electron kinetic energy, reducing IV scattering. The energy band structure of the SL is calculated using the Schrödinger equation and a Poisson solver, incorporating a single‐band model to determine the Fermi energy and characteristics of the SL miniband. Miniband dispersion is evaluated using an effective mass approximation at low energies and a non‐parabolicity factor at higher energies. The MC method is then applied to study electron transport within the miniband, revealing that for SLs with low Al content and short periods, electron behavior resembles that in bulk GaN. It is observed that negative differential mobility can occur, attributed to electron–PLOP scattering and non‐parabolicity. This approach offers a quick and effective way to research high‐field electron transport in n‐doped SLs, aiding in device design.

Al-rich AlGaN Alloys: Unique Materials for Deep UV LEDs

Energy bandgap of AlxGa1−xN alloys can be tuned systematically from ∼ 3.4 to 6.1 eV by changing the alloy composition (x) from 0 to 1 and the direct bandgap nature is maintained in the entire range of alloy compositions which make the AlGaN alloys suitable materials for the development of light emitting diodes (LEDs) covering the ultraviolet (UV) spectral region from 210 to 400 nm. For LEDs in the deep UV regions (λ &lt; 300 nm), Al-rich AlGaN alloys of Al content higher than 50% are required. Deep UV LEDs have applications in a wide range of fields including display, disinfection, medical, sensing, and communication. With recent progress in the material growth and electrical conductivity, Al-rich AlGaN alloys have emerged as unique wideband gap materials for the development of deep UV LEDs. In this review article, how the progress of Al-rich AlGaN alloys has made in terms of the material growth and electrical conductivity leading its emergence as deep UV materials have been reviewed. Challenges and prospects of the deep UV LEDs to improve the performance of the devices will also be discussed.

Tailoring microstructures and properties in Co-free FeNiCrCuAl high entropy alloys by Al addition

In this study, a series of Co-free FeNiCrCuAlx (x = 0.1, 0.3, 0.5, 0.8 and 1.0) high entropy alloys (HEAs) were developed by vacuum arc melting and casting method in high-purity argon atmosphere. The effects of Al addition on the microstructure and properties were investigated using X-ray diffraction, scanning electron microscopy, Vickers hardness tester, tensile test, wear test and electrochemical experiment. It was found that with the increase in the large atomic-sized Al content, the closely-packed FCC structure was destabilized for a transition to the loosely-packed BCC structure at x = 0.3. As x increased up to 1.0, the structure was mainly composed of BCC phase. The hardness of HEAs was enhanced by the influence of the contiguous atomic planes in BCC structures due to the relatively lower inter-planar spacing and higher lattice friction for dislocation motion, with the potential to increase the yield strength of the HEAs by 93.5 %. The friction coefficient decreased with increasing Al content, as indicated by stable profiles of Al0.8 and Al1.0 under progressive wear in comparison to those of Al0.1, Al0.3 and Al0.5 while the associated minimal wear depth and lower capacity for debris accumulation of the higher Al content HEAs confirmed their superior wear resistance. As FeNiCrCuAl0.5 presented the most superior corrosion resistance due to high resistance to ionic transport via the steady oxide film and the indication of a comparatively wider capacitive semicircle, undue Al additions would not be beneficial to improving plasticity or enhance corrosion resistance. Thus, FeNiCrCuAlx HEAs with Al contents in the range of 0.5–1.0 were found to possess optimized comprehensive properties, and can be suitably recommended as nuclear structural materials. This study will shed light on advancing the development of cutting-edge HEAs.

Kastamonu Bölgesinden Toplanan Kestane Balının Mineral Madde ve Ağır Metal İçerikleri

Chestnut honey, which is known for its apitherapic properties besides its nutritional attributes, is one of the main groups of monofloral honey types. Kastamonu is the most important province because where constitutes two-thirds of the chestnut forest flora of the Black Sea region. Kastamonu Chestnut Honey, produced in apiaries within the chestnut forests, has been registered as a geographical indication and designation of origin. The nutritional value of honey is related to its nutritional and chemical content. Kastamonu chestnut forests have a different distribution with their scattered structure from the coastline to 1000-1200 meters altitude. Therefore, this study was planned with the prediction that chestnut honey produced in different districts has a different composition. The aim of the study is to contribute to official regulations regarding the product, product standardization, and national branding studies by determining mineral and heavy metal contents based on the region where the chestnut honey is produced. As a result of the study, the main concentrations of the elements in the chestnut honey samples were affected by the geographical location, because the apiaries where honey samples were collected in chestnut forests in Kastamonu districts had different altitudes, climates and soil properties, and different secondary flora. The most abundant elements in the samples were potassium (1410.0-6581.5 ppm) sodium (0-204.4 ppm), calcium (125.3-287.5 ppm), and magnesium (24.73-61.88 ppm). Iron (1.32-9.54 ppm), zinc (1.34-20.84 ppm), and manganese (1.39-18.69 ppm) were also found in moderate and others in trace levels. Because manganese is found at moderate levels in all chestnut honey samples and it is found at higher levels than other honey types, it can be recommended that Mn, as fingerprints to detect imitation and adulteration of chestnut honey. While Cd, a heavy metal, was found in only one sample, Ni was not detected in any sample. Whereas Pb concentration varied between 1.84 ppm and 3.38 ppm for the samples, the contents of Al concentrations were quite high (2.94-13.94 ppm). Because there wasn't a maximum limit for heavy metal contents of honey types in the Turkish Food Codex Contaminants Regulation, no evaluation could have been made regarding the suitability of these heavy metal contents. It is thought that heavy metal contamination limits in honey types should be included in the regulations and especially secondary sources such as metallic containers used for storage during handling processes and harvesting of honey for heavy metal contamination should be reviewed.

A functionally graded material from stainless steel 304 to Fe–40Al fabricated by dual wire arc additive manufacturing

In this study, gas tungsten arc welding (GTAW) based dual wire additive manufacturing (D-WAAM) is adopted to fabricate the functionally graded material (FGM) from stainless steel (SS) 304 to Fe–40Al, using SS 304 and aluminum alloy (AA) 1070 wires. The Al/Fe atomic ratio varies from 0 to 40 % by varying the ratio of the wire feed speeds of the SS and AA wires. The chemical composition, phases, microstructure, and mechanical properties of the FGM are investigated. The results showed that with the increase of Al content, microstructures evolve as follows: γ-Fe → γ-Fe + α-Fe → α-Fe → Fe3Al → FeAl. Cracks occur in FeAl region, caused by the high stress and the low plasticity. Dislocation walls prevent the large grains from slipping, leading to the loss of plasticity. The microhardness of SS 304 to Fe–40Al FGM ranges from 188HV0.5 to 558HV0.5. As Al content increases, the ultimate compressive strength decreases from 1820 MPa to 1061 MPa. The results on microstructure and mechanical properties provide guidance for the preparation of steel - aluminum alloy FGMs.

Al-Maslahat and Development of Islamic Law

The Topic of this article/research is “Al-Maslahat And Development of Islamic Law”. There are three main problems which is attractive to elaborate in this article, namely; First, How are the essence and existence of al-Maslahat? Second, How is the al-Maslahat become a basic for development of Islamic law? And the third, How is the function and position of al-Maslahat for Islamic law product? Talking about Al-Maslahat is one object and very attractive in study of Islamic law theory. And it is important part that related with the Maqashid al-Syari’ah. The method that used in this writing/research is “The al-Tasyri’-methode by using “Istishlahiy approach”. Many of Muslims Scholars or the Experts of Regulation of Islamic jurisprudence-wheather at classic era or nowadays—are talking about the existence and position al-Maslahat in Islamic law regulation by using Istishlahiy approach. According to the experts of Islamic Jurisprudence, al-Maslahat can be used as the cause or ratio legis (al-‘Illat) in determining Islamic law regulation. And sometimes, al-Maslahat often called by al-Istidlal, namely logic argumentation or logical reasoning. Through this article/research, we found that al-Maslahat, beside it is functioned as part of method In Islamic law theory but it is also used to develop Islamic law it self. And al-Maslahat is used very widest in determining and development of Islamic law, especially concerning with the contemporary issues. So Imam Malik ever said that where ever you get advantageous and it is not contrary with the content of al-Quran wa al---Sunnah, that is al-Syari’ah (Islamic law).