Light Mineral Research Articles

Mineralogy of Sand Dune Fields around Hor Al-Dalmaj Between Wasit and Al-Qadesiyah Governorates - Central Iraq

Vast percentage of the Hor Al-Dalmaj area is covered with sand dunes fields due to desertification. Therefore, it is vital to research these dunes to limit their bad action on the natural environment by defining the mineralogical composition of these sand dunes deposited around Hor Al-Dalmaj lake between Wast and Al-Qasisiyah Governorates to determine the provenance or the source of these dunes. Barchan and Nabkha dunes represent the main types that are recognized. The dimensions of barchan dunes are recognizing by a height range of about 0.5 to 3m, with lateral extension ranging from 2 to 15m and longitudinal extinction ranging from 3 to 15m. While the dimensions of nabkha dunes range from 10 cm to 2m in length and 15cm to 2m high. According to the major wind direction, these dunes are extended from North West to south-east. The mineralogical investigation reveals that the light minerals of studied dunes consist mainly of quartz, feldspars and various rock fragments such as carbonate, chert, mudstone, evaporate, igneous, and metamorphic rocks. The most frequent heavy minerals are opaque, chlorite, pyroxenes, amphiboles, muscovite, biotite, zircon, epidotes, garnet, tourmaline, rutile, kyanite, and staurolite. The source of these sediments is recent sediment that has formed in river terraces, flood plain and Quaternary deposits in the Mesopotamian Plain, and the outcrops of the ancient sedimentary formations in the north northwestern, west, and southwestern Iraq.

Evaluating surface coatings to reduce bone cement adhesion to point of care 3D printed molds in the intraoperative setting

BackgroundPolymethyl methacrylate, or “bone cement,” can be used intraoperatively to replace damaged or diseased bone and to deliver local antibiotics. 3D printed molds allow surgeons to form personalized and custom shapes with bone cement. One factor hindering the clinical utility of anatomically accurate 3D printed molds is that cured bone cement can be difficult to remove due to the strong adhesion between the mold and the bone cement. One way to reduce the adhesion between the 3D printed mold and the cured bone cement is with the use of a surface coating, such as a lubricant. This study sought to determine the optimal surface coating to prevent bone cement adhesion to 3D printed molds that could be utilized within a sterile operating room environment.MethodsHemispheric molds were 3D printed using a stereolithography printer. The molds were coated with four sterile surface coatings available in most operating theatres (light mineral oil, bacitracin ointment, lubricating jelly, and ultrasound transmission gel). Polymethyl methacrylate with tobramycin antibiotic was mixed and poured into the molds. The amount of force needed to “push out” the cured bone cement from the molds was measured to determine the efficacy of each surface coating. Tukey’s multiple comparison test was performed to compare the results of the pushout test.ResultsThe average pushout force for the surface coatings, in increasing order, were as follows (mean ± standard deviation) --- bacitracin ointment: 9.10 ± 6.68 N, mineral oil: 104.93 ± 69.92 N, lubricating jelly: 147.76 ± 63.77 N, control group: 339.31 ± 305.20 N, ultrasound transmission gel 474.11 ± 94.77 N. Only the bacitracin ointment required significantly less pushout force than the control (p = 0.0123).ConclusionsThe bacitracin ointment was the most effective surface coating, allowing the bone cement to be pushed out of the mold using the least amount of force. In addition, the low standard deviation speaks to the reliability of the bacitracin ointment to reduce mold adhesion compared to the other surface coatings. Given its efficacy as well as its ubiquitous presence in the hospital operating room setting, bacitracin ointment is an excellent choice to prevent adhesion between bone cement and 3D printed molds intraoperatively.

Characterization of costal cartilage allografts.

BackgroundHuman costal cartilage remains widely used in the reconstruction of soft tissues, particularly within the field of plastic and orthopaedic surgery. The biologic expense of using autologous human costal cartilage has become superseded by the increasingly common use of irradiated costal cartilage allografts. To date, there has been no histologic investigation of such costal cartilage allografts. This study aims to characterize the histologic variations that exist between different costal cartilage specimens, and to quantify this between specimens in spite of their common anatomical derivation.MethodsTwenty‐five specimens of cadaveric human costal cartilage were obtained from Australian Biotechnologies. Each specimen was irradiated, sectioned and stained with Haematoxylin and Eosin, Masson's trichrome and tetrachrome stains. After being analysed under light microscopy, specimen dimensions, chondrocyte counts and mineral content was quantified and measured.ResultsThe median specimen diameter was 8.20 mm, with an interquartile range (IQR) of 1.59 mm. The median measurement from the superficial to basal chondrocyte layer was 1409.91 μm (IQR = 885.59 μm), and the median measurement from superficial to calcified zone was 4146.26 μm (IQR 1441.83 μm). The median chondrocyte area was 442.74 μm2 (IQR = 2622.72 μm2) with their total chondrocyte count ranging from 289 to 591 chondrocytes per square millimetre. The median percentages of collagen and mineral content were 45.17% and 71.82%, respectively (IQR = 20.48%, 14.75%).ConclusionThese findings emphasize the histologic and biochemical degree of variation that exists between specimens of human cadaveric costal cartilage on a microscopic level. This has the potential to influence the selection of costal cartilage allografts for reconstructive purposes.

Development of the project of modular prefabricated buildings

The issues of working design with the construction of modular prefabricated buildings, with the minimization of cold bridges are revealed. Cold bridges are typical for prefabricated buildings with inadequate attention to the design of both load-bearing metal and enclosing structures, as well as their connections. Connections should not pass through its cross section both zero and negative temperatures. As a result, an original project of two modular buildings was developed from easily prefabricated metal structures and wall structures with light mineral wool filling. This project is also intended for sharply continental regional natural and climatic conditions (regardless of the geographical location on the territory of Kazakhstan – south-eastern Kazakhstan, central, eastern or western Kazakhstan. In winter, natural and climatic conditions are similar in these areas). As a result of this study, it was found that the developed project meets the requirements of thermal insulation – at the interface of the supporting and enclosing structures. The thermal insulation requirements of the above structures are important to eliminate the dew point and consequently the formation of moisture and mold in all structures. In turn, mold and other microorganisms, as studies show, adversely affect the health and normal stay of people in the premises, both during the night and during the day. Many developers do not consider these factors in prefabricated buildings. These buildings are intended for various industries. For example, in healthcare, these are mobile hospitals. In military camps – buildings of temporary residence as barracks, etc.

Injection of Xanthan Gum and Guar Gum Through Carbonate Rocks Evaluated by Two-Phase Core Flooding

Abstract Polymer flooding is widely applied to enhance oil recovery in sandstone reservoirs. However, applications in carbonate formations are challenged by the possible high adsorption of anionic polymers such as polyacrylamides and xanthan gum. Non-ionic biopolymers such as guar gum could be used to minimize retention. Many investigations using guar flooding have been conducted, but none targeted carbonate reservoirs. This work compares oil recovery improvement, water production delay, mobility control, injectivity, and polymer utilization in carbonate core flooding at reservoir conditions (salinity of 30,905 ppm and 60 °C) with xanthan (700 ppm) and guar (2500 ppm) solutions. A rheological study was performed to select target polymer concentration and solution viscosity. Indiana limestone and light mineral oil (viscosity of 6.55 ± 0.05 mPa · s at 60 °C) were used to represent the reservoir rock and oil. Guar flooding led to faster oil recovery, water production delay, and better injectivity than xanthan flooding, although the polymer utilization factor was higher. The ultimate oil recovery increased by 12.7 ± 7.0% and 9.0 ± 6.1% over waterflooding after guar and xanthan injections. The inferior performance of xanthan gum can be attributed to higher retention, especially close to the core inlet (residual resistance factor of 28 ± 4), and lower in-situ viscosity. The results suggest that guar may be a promising candidate for polymer flooding in carbonate reservoirs at moderate temperatures and salinities. In contrast, xanthan applications in these reservoirs must be carefully evaluated due to its high retention potential.

Heavy and Light Mineral Association of Late Quaternary Permafrost Deposits in Northeastern Siberia

We studied heavy and light mineral associations from two grain-size fractions (63–125 μm, 125–250 µm) from 18 permafrost sites in the northern Siberian Arctic in order to differentiate local versus regional source areas of permafrost aggradation on the late Quaternary time scale. The stratigraphic context of the studied profiles spans about 200 ka covering the Marine Isotope Stage (MIS) 7 to MIS 1. Heavy and light mineral grains are mostly angular, subangular or slightly rounded in the studied permafrost sediments. Only grains from sediments with significantly longer transport distances show higher degrees of rounding. Differences in the varying heavy and light mineral associations represent varying sediment sources, frost weathering processes, transport mechanisms, and post-sedimentary soil formation processes of the deposits of distinct cryostratigraphic units. We summarized the results of 1141 microscopic mineral analyses of 486 samples in mean values for the respective cryostratigraphic units. We compared the mineral associations of all 18 sites along the Laptev Sea coast, in the Lena Delta, and on the New Siberian Archipelago to each other and used analysis of variance and cluster analysis to characterize the differences and similarities among mineral associations. The mineral associations of distinct cryostratigraphic units within several studied profiles differ significantly, while others do not. Significant differences between sites as well as between single cryostratigraphic units at an individual site exist in mineral associations, heavy mineral contents, and mineral coefficients. Thus, each study site shows individual, location-specific mineral association. The mineral records originate from multiple locations covering a large spatial range and show that ratios of heavy and light mineral loads remained rather stable over time, including glacial and interglacial periods. This suggests mostly local sediment sources and highlights the importance of sediment reworking under periglacial regimes through time, including for example the formation of MIS 1 thermokarst and thermo-erosional deposits based on remobilized MIS 3 and 2 Yedoma Ice Complex deposits. Based on the diverse mineralogical results our study supports the viewpoint that Yedoma Ice Complex deposits are mainly results of local and polygenetic formations (including local aeolian relocation) superimposed by cryogenic weathering and varying climate conditions rather than exclusive long distance aeolian transport of loess, which would have highly homogenized the deposits across large regions.

Reinforced upconversion and charge separation via mid-gap states in WO3 nanosheet with infrared light driven tetracycline degradation

• Upconversion performance over WO 3 nanosheet was modulated by atomic doping. • Mobilized electron states increased after the atomic doping of Cu element. • NIR responsive catalytic performance was achieved over modified WO 3 . • The rate constant after modulation reached 14.4 times over that of pristine WO 3 . • Mineralization degree of TC reached 92.4% under NIR light irradiation. It is of crucial importance to fabricate near-infrared responsive (NIR) catalysts to maximize the utilization of solar energy. And achieving efficient charge separation under near-infrared light was also a great challenge. Herein, the synergy of both improved upconversion and charge separation performances of WO 3 was realized by atomic doping of Cu element. The induced mid-gap states can decrease the required excitation energy of photogenerated electrons to improve the upconversion ability, which enhanced the light absorption capacity of WO 3 nanosheet. Moreover, the introduced Cu element not only acted as the trapping sites of photogenerated charges, but also led to the charge redistribution of the crystal structure over WO 3 , which efficiently enhanced the charge separation process. As a result, excellent tetracycline photodegradation performance under NIR light (mineralization degree reaching 92.4%) was realized, where the rate constant of 1 wt% Cu-WO 3 (2.92 × 10 -3 min −1 ) reached 14.4 times over that of pristine WO 3 (2.02 × 10 -4 min −1 ).

Distribution and characterization of heavy minerals in Meghna River sand deposits, Bangladesh

Heavy mineral (HM) concentrations in sand bar deposits of the Meghna River were evaluated using optical microscopy, X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Scanning Electron Microscopy (SEM) and Electron Probe Microanalysis (EPMA) to determine the mineralogy, geochemistry and likely source rocks of the sands, and to examine the distribution and HM potential of the valuable heavy minerals, ilmenite and garnet. The Meghna sands were dominated by the light minerals quartz and feldspar and grainsize analysis results showed that>78 wt.% of the sand population fell within the size range of fine to very fine sand (−250 + 63 μm). The HM component made up around 9 wt.% and consisted mainly of amphibole (∼17–46 wt.%), epidote (∼7–30 wt.%) and garnet (∼3–21 wt.%). Fe-Ti oxide minerals including ilmenite, rutile, and titanomagnetite were present at levels of 0.7–7 wt.% with the magnetite content at 0.9–7 wt.%. The textures (moderate sorting, sub angular) and significant feldspar (6–15 wt.%) content in the sands indicated low degrees of hydraulic sorting and low amounts of alteration/weathering. The HM assemblage indicated a likely mixed source area of varying metamorphic grade (low to high) facies and igneous rocks. EPMA results from the detrital ilmenites and garnets showed that for ilmenite, TiO2 contents were between 42.9 and 54.5 wt.% (ave. 51 wt.%), with overall low impurities, while the garnet compositions were dominated by Fe-rich, almandine types. From the chemical analysis of individual garnet and ilmenite grains, it is likely the Meghna River sands have good potential for commercial extraction of garnet and ilmenite.

Ultrapotassic Aluminosilicate Melts: Specifics of Formation by the Example of Synnyrites from the Synnyr Massif

Abstract —To reveal the formation conditions of synnyrites in the Synnyr alkaline pluton, we studied melt inclusions in the minerals of shonkinites and pseudoleucite syenites, in apatite segregations in pyroxenites, shonkinites, and synnyrites, and in the minerals of later monchiquite–camptonite dikes. Based on the obtained and earlier published data, a conclusion has been drawn that all plutonic rocks of the massif formed from the same parental alkali-basaltic magma during long-term crystallization differentiation and fractionation in a closed system excluding a release of volatile components. Similar minerals in the rocks crystallized at similar temperatures in the same sequence: clinopyroxene (1280–1150 °C) → leucite (1250–1200 °C) → K-feldspar (1200–1180 °C) → apatite (above 1180–1050 °C) → nepheline and kalsilite. The composition of the parental magma during crystallization evolved toward an increase in Si, Al, and K contents and a decrease in Fe, Mg, and Ca contents, i.e., toward melaphonolite and phonolite melts. The differentiation and fractionation processes led to the separation of minerals according to their specific gravity: Heavy minerals (clinopyroxene, ore minerals, and apatite) descended to the bottom of the magma chamber, forming the lower melanocratic series, and light minerals (leucite, K-feldspar, and foids), together with the residual melt, accumulated in the upper horizons of the chamber, forming the upper leucocratic series of rocks. During crystallization, the amount of fluids increased. At 920–830 °C, the fluids contained 3033–4051 mg/kg CO2, 397–644 mg/kg H2O, and 42.7–83.7 mg/kg CO. At the early high-temperature stage, when the amount of fluids was insignificant, the trend of magma transformation coincided with the trend of basaltoid crystallization. This fact is evidenced by the homogenization temperatures and chemical composition of inclusions in the minerals of monchiquite–camptonites and alkali basaltoids, similar to those in the plutonic rocks of the massif. Clinopyroxene crystallized in dike rocks at 4.58 kbar at a depth of 10–12 km. At the stage of crystallization of feldspars, when the amount of fluids in melts significantly increased during the formation of plutonic rocks and drastically decreased during the formation of basaltoids, the formation trends of these rocks became different. The trend of basaltoid crystallization was directed toward trachyte melts with an increase in Si contents and a decrease in Fe, Mg, Al, and alkali contents. During the formation of plutonic rocks of the massif, the high water pressure prevented the formation of plagioclase, and the melts became more enriched in Al and K and acquired a high-alumina ultrapotassic composition, forming kalsilite–nepheline–K-feldspar synnyrites at the final stages of transformation. A conclusion has been drawn that synnyrites crystallized from the residual products of differentiation and fractionation of alkali-basaltic magma in the temperature range slightly above 1050–1180 °C in a closed system excluding a release of volatiles. The occasional occurrence of synnyrites is due to the limited natural occurrence of closed magma chambers, macroanalogs of inclusions of mineral-forming media in minerals.

Mineralogical Variation of the Banks of Shatt Al-Arab and Shatt Al-Basrah River Sediments in Southern Iraq

The sediments on the banks of Shatt al-Arab and Shatt Al-Basrah have been studied to find out their mineralogical variation. Twenty-two samples were collected from depths of 20 cm of recent sediments Shatt Al-Arab and Shatt Al-Basrah Rivers banks, with approximately equal distances between them, the grain size analysis was conducted, and selected samples were prepared for X-ray diffraction, heavy and light minerals analysis. The result of grain size analysis showed that silt loam texture is dominated in Shatt Al-Arab River while silty clay loam texture in Shatt Al-Basrah River. quartz, calcite, dolomite, feldspar, and halite represent the light minerals in the silt fraction in the study area sediments, while the clay minerals are represented by kaolinite, palygorskite, illite, and montmorillonite-chlorite in Shatt Al-Arab River and the same clay minerals with small amount of montmorillonite in Shatt Al-Basrah River. The petrographic analysis showed that the light mineral contents in the sand fraction are composed primarily of quartz, feldspar, and rock fragment. The main rock fragments consist of carbonate, chert igneous and metamorphic rocks, mudstone, and evaporates (Gypsum). The heavy minerals contents are opaque minerals, pyroxene, hornblende, chlorite, biotite muscovite, epidote, staurolite, kyanite, garnet, tourmaline, rutile, and zircon.

Formation of the Lunar Primary Crust From a Long-Lived Slushy Magma Ocean.

Classical fractional crystallization scenarios of early lunar evolution suggest crustal formation by the flotation of light anorthite minerals from a liquid magma ocean. However, this model is challenged by the >200 Myr age range of primitive ferroan anorthosites, their concordance with Mg‐suite magmatism and by the compositional diversity observed in lunar anorthosites. Here, we propose a new model of slushy magma ocean crystallization in which crystals remain suspended in the lunar interior and crust formation only begins once a critical crystal content is reached. Thereafter crustal formation occurs by buoyant melt extraction and magmatism. The mixture viscosity strongly depends on temperature and solid fraction driving the development of a surface stagnant lid where enhanced solidification and buoyant ascent of melt lead to an anorthite‐enriched crust. This model explains lunar anorthosites heterogeneity and suggests a crustal formation timescale of 100s Ma, reconciling anorthosite ages with an early age of the Moon.

Modification of the Filler based on Kaolin and its Use in the Polymer Composites

Light mineral fillers are the natural inorganic materials of various compositions that have been used in a practical way since the beginning of the rubber industrial processing. Depending on the application, the natural kaolin is often modified by physical processes or by chemical processes (pillaring, adsorption, intercalation, functionalization, acid activation, etc.). It is important to modify kaolin due to improvement of its properties in order to adsorb the inorganic as well as organic molecules. In the introduced study, kaolin from Kaznějov deposit was modified by potassium acetate or dimethylsulphoxide and subsequently functionalized by accelerator dibenzothiazyldisulphide and its last modification was performed by silane treatment. Different techniques, such as the thermal (DTA) and spectral (FTIR) analysis were used to characterize modified kaolin samples. The main aim of the article is to observe the influence of modified kaolin forms on the physico-mechanical properties and structural changes of rubber mixtures. Combined with the carbon black, the given modified kaolin was mixed into a rubber blend in a particular ratio, which was5, 10, 24 phr. The effect of the modified kaolinite on the cure characteristics (minimum torque – ML, maximum torque – MH, optimal cure time – t90, scorch time ts2) and mechanical properties (tensile strength at break – TSb, elongation at break – Eb and hardness)in sulphur-cured rubber composites was investigated. In images from a scanning electron microscope (SEM), we observed the incorporation of modified forms of kaolin into the matrix of the rubber mixture.

Application of oil and dye flow visualization in incompressible turbomachinery flows

Flow visualization is one of many available tools in experimental fluid mechanics and is used from the primary stages of fluid mechanics research in order to identify the physical sizes and locations of the flow features under consideration. Most of the fluids used in engineering applications are transparent (water, air, etc) and flow visualization techniques are used in order to make their flow patterns visible. Simple flow visualization experiments are relatively inexpensive and they can be easily implemented providing with a first feeling of the characteristics of the flow domain. Subsequently, flow visualization techniques are of great applicability in complex flow fields and especially in turbomachinery applications where the flow is characterized by three dimensional and secondary flow patterns. In general, fluid motion can be visualized by surface flow visualization, by particle tracer methods or by optical methods. The former flow visualization technique reveals the streamlines of fluid flows around a solid surface. In this paper flow visualization techniques applied in two different cases of experimental testing (fans in crossflow and cascade experiment) are presented. In both cases, the mixture of paint was prepared using a highly volatile light mineral or heavy machine oil of viscosities of approximately100cPand200cP, respectively, together with very fine pigments of Titanium Dioxide (TiO2) or fluorescein sodium in various colors. After the preparation of the mixture, a homogenous thin film was applied onto the whole plate surface by painting it with a soft brush. The air stream which flows over the surface of the plate, modifies the concentration and the homogeneity of the oil film, according to the flow conditions very close to the wall. The film was dried by the airflow and photographed for further consideration while the time taken for drying depended on the wind tunnel velocity as well as, on the pigmentation of the mixture. Successful and un-successful flow visualization tests are herein presented while each case is respectively commented as far as the mixtures, the proportions used and the application onto the rigs are concerned.

Aeolian transportation mechanics and mass movement of surficial beach sands – a case study on Bendi-BaruvaMineral Sand Deposit, Srikakulam District, Andhra Pradesh

Surficial sediment transportation studies carried out in the beach zone of Bendi-Baruva mineral sand deposit show that sand grains are transported by wind (saltation and suspension) beyond the high water line. The sand population of the study area contains heavy mineral sands (~20%) like ilmenite, garnet and sillimanite which covers 95% of the heavy mineral distribution with subordinate amounts of monazite, rutile, and zircon whereas light mineral sands (~80%) contain mostly quartz. Due to the sorted nature of these beach and dune sands the whole spectra falls within a specific range of grain size which shows a bi-modal distribution, primary mode at 0.025cm and secondary at 0.015cm. Due to this variation in density and grain size, mass of these sand particles vary resulting in differential transportation in any energy regime. In the study area, on the beach near the frontal dunes, surficial concentration of garnet grains are observed in patches having an average thickness 0.2cm i.e. around ten times of the dominant grain diameter. This surficial enrichment of garnet grains resting on a semi-uniform sand surface is the result of differential transportation of the dominant mineral grains. As more than 80% of the grain size population show a dominant grain size of 0.025cm, the wind flow parameters for the whole population is standardized with mean grain diameter (D) of 0.025cm. Mass of dominant individual minerals arrived from the grain counting technique was tallied with the theoretical mass considering spherical shape of the grains indicates a difference of mass to be within 5%. For ease of calculation and generalization the grains were considered to be spherical and their theoretical masses were taken into consideration in calculations. Considering the whole spectra of mineralogical distribution, a theoretical mass group distribution for dominant different minerals of different dominant grain sizes were formulated and total six mass groups were identified. Because quartz (~80%), ilmenite, sillimanite and garnet (together ~20%) are the most abundant, their positions were identified specifically in the theoretical mass groups and only these are considered for further discussion. To analyse wind velocity and pressure at different heights from the surface, a sediment trap was fabricated using piezo-electric sensors. A tail was attached to orient the device parallel to the wind flow so that the piezo surfaces always face the wind flow at 900 angle. The device records pressure data and converts those into voltage. Using the velocity data, macroscopic physical quantities of aeolian transportation were calculated for the study area, which empirically show the effect of mass in differential transportation of the dominant minerals that gives rise to these surficial garnet patches.

Authentication of Transylvanian Spirits Based on Isotope and Elemental Signatures in Conjunction with Statistical Methods.

The potential association between stable isotope ratios of light elements and mineral content, in conjunction with unsupervised and supervised statistical methods, for differentiation of spirits, with respect to some previously defined criteria, is reviewed in this work. Thus, based on linear discriminant analysis (LDA), it was possible to differentiate the geographical origin of distillates in a percentage of 96.2% for the initial validation, and the cross-validation step of the method returned 84.6% of correctly classified samples. An excellent separation was also obtained for the differentiation of spirits producers, 100% in initial classification, and 95.7% in cross-validation, respectively. For the varietal recognition, the best differentiation was achieved for apricot and pear distillates, a 100% discrimination being obtained in both classifications (initial and cross-validation). Good classification percentages were also obtained for plum and apple distillates, where models with 88.2% and 82.4% in initial and cross-validation, respectively, were achieved for plum differentiation. A similar value in the cross-validation procedure was reached for the apple spirits. The lowest classification percent was obtained for quince distillates (76.5% in initial classification followed by 70.4% in cross-validation). Our results have high practical importance, especially for trademark recognition, taking into account that fruit distillates are high-value commodities; therefore, the temptation of “fraud”, i.e., by passing regular distillates as branded ones, could occur.

Effects of Petroleum-Based Oils as Dispersing Aids on Physicochemical Characteristics of Magnetorheological Elastomers.

This paper investigated the effects of petroleum-based oils (PBOs) as a dispersing aid on the physicochemical characteristics of natural rubber (NR)-based magnetorheological elastomers (MREs). The addition of PBOs was expected to overcome the low performance of magnetorheological (MR) elastomers due to their inhomogeneous dispersion and the mobility of magnetic particles within the elastomer matrix. The NR-based MREs were firstly fabricated by mixing the NR compounds homogeneously with different ratios of naphthenic oil (NO), light mineral oil (LMO), and paraffin oil (PO) to aromatic oil (AO), with weight percentage ratios of 100:0, 70:30, 50:50, and 30:70, respectively. From the obtained results, the ratios of NO mixed with low amounts of AO improved the material physicochemical characteristics, such as thermal properties. Meanwhile, LMO mixed the AO led to the best results for curing characteristics, microstructure observation, and magnetic properties of the MREs. We found that the LMO mixed with a high content of AO could provide good compatibility between the rubber molecular and magnetic particles due to similar chemical structures, which apparently enhance the physicochemical characteristics of MREs. In conclusion, the 30:70 ratio of LMO:AO is considered the preferable dispersing aid for MREs due to structural compounds present in the oil that enhance the physicochemical characteristics of the NR-based MREs.

A study of triangular membership function and multiple regressions to calculate the MSW compost index

The municipal solid waste compost consists of elements with a varied composition, including light and heavy metal elements. For MSW compost to act as a soil conditioner, and to ensure agricultural stakeholders to believe in its use for crops production, validation of elements is obligatory. The triangular membership function evaluates each element of a fuzzy set for both discrete and continuous values, and regression analysis estimates the relationship between values. In this paper, a triangular membership function (μf) is studied and used to characterize the effect of individual elements available in the compost sample. The characterization determines the variation in the composition of elements in the compost sample and accordingly calculates its scorei. Furthermore, a reinvestigation is done by applying multiple regression analysis, especially on heavy metals, to compare their composition with light mineral nutrients and other supplementary elements. A relationship between R=4.12 and R2=0.067498635 is derived to determine the predicted value and defines the composition of heavy metals as attributed to another mineral nutrients. Furthermore, a correlation (Co) is derived to find the performance of the compost sample todecide whether both light and supplementary mineral nutrients are capable of minimizing the effect of heavy metals. A gratuity score (Gsi) is added to each heavy metal depending on the correlation value to form a composti. The scorei=88.11 and composti = 9.12 obtained, was summated to derive Ci=97.23, stating that the increase in score value declares that the compost sample is mature enough to be used for agriculture and enhance crops productivity.

Investigations on River Sediments in Chak Sedimentary Basin, Wardak Province, Afghanistan

This sedimentary is from a largest basin of Afghanistan, which covers an area of 9772 km2. It is located about 80 km, at west side of Kabul. In this research, we studied different types of heavy and light minerals, gravel analysis in river sediments. Logar River is core stream flowing over basin,it carries diverse masses of sediments from dissimilar parts of surroding montians. Further, in the months of summer while snowmelting is started,transfer diverse materials and cause different traces to be made. Area of basin is enclosed by mountain range and separated into two sections,majore part is Khawat Olya and second one is Khawat Sufla. The main aim of study is to characterize different sizes and types of minerals in river load for the previous geological periods. This research is therefore essential to explain different sizes and type of minerals in river sediments, which is no any study has been conducted in the study area. This study found out that the category of sediments is related to the parental materials that are placed in the close mountains such as; gneiss, limestone, and granite, dissimilar varities of conglomerate, slate, schist, reefs, conglomerate and sandston.

A probabilistic approach towards source level inquiries for forensic soil examination based on mineral counts

Forensic soil examination has a well-established foundation in forensic science, this is in part due to the widely varied and complex nature of soil. Within this domain, mineral suite studies are a commonly utilized tool in soil examination. However, statistical or probabilistic approaches towards the interpretation of results from such analysis are lacking and this study aims to fill that gap. Soil samples from four different locations in the city of Lausanne, Switzerland were sampled and their mineral fractions, light and heavy of size between 90 and 180 µm, were studied utilizing microscopical methods. First, the light minerals were identified and counted by employing scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS). Second, the heavy minerals were identified and counted manually under a polarized light microscope (PLM). The resulting count data were subjected to various multivariate statistical treatments such as principal components analysis (PCA), hierarchical clustering analysis (HCA), and linear discriminant analysis (LDA). These methods assist in identifying pertinent variables and subsequently in building various classification models. The validities of these models were then tested and evaluated using blind tests. Finally, these methods demonstrate how a probabilistic approach can be taken in the interpretation of the results to answer source level questions.

Sedimentological and Heavy Metals Characteristics of Streets Dust in some Areas East of Baghdad for 2020

Road-side dust samples were collected during August in 2020 from selected areas of, Al-Rusafa, Baghdad, Iraq. A sedimentological and mineralogical analysis of street dust was conducted. Three areas were selected to study street dusts which are Al-Baladitat, Al-Obaidi and Ziona. The laboratory analyses were done in the Department of Geology, College of Science, University of Baghdad. The heavy metal contents were determined in the roadside dust using XRF Method. It was found that the dust is of muddy texture, and is believed to be transmitted with the various storms blowing on Baghdad or by the wheels of Cars. The results of mineralogical investigation revealed that the dust samples composed of quartz, feldspar, calcite, gypsum and sedimentary rocks fragments, as light minerals and the heavy minerals were found as garnet, epidote, chlorites, pyroxene, biotite, zircon, muscovite, hornblende, tourmaline. The heavy metals (Fe, Co, Ni, Cu, Zn and Pb) in these streets dust samples were studied and used as indicator for pollution. two o main indices are applied: contamination factor, and pollution load index. The contamination factor for Co, Zn, Pb, and Ni is classified as class 2, which indicate moderately contamination, while the contamination factor for Fe and Cu is classified as class 1, which indicate low contamination. The pollution load index values in the all of studied sites are classified as class 2 (Deterioration on site quality) indicating local pollution, as well as denote perfection with class 0 of no pollution.