Range Of Content Research Articles

Analysis of phthalate esters and their novel alternatives in indoor dust using comprehensive two-dimensional gas chromatography-time of flight mass spectrometry

A comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOF-MS) method was developed to analyze 25 traditional phthalate esters (PAEs) and 19 novel alternatives in indoor dust samples. PAEs are ubiquitous in indoor environments because they are widely used as plasticizers in a variety of consumer products, and potential health concerns have prompted the need for effective monitoring methods. In this study, dust samples were collected from various indoor settings in a university campus, including classrooms, cafeterias, laboratories, and dormitories, and were subsequently ultrasonically extracted with hexane-dichloromethane (1∶1, v/v) solution for 30 min. This method was chosen to maximize PAE recovery while minimizing potential interference from other compounds present in the dust matrix. Compounds were separated on a Rix-5MS column (30 m×0.25 mm×0.25 μm) as the first dimension, with a Rix-17Sil column (1.39 m×0.25 mm×0.25 μm) serving as the second dimension. The following temperature program was used: 60 ℃ for 1 min, then increasing to 220 ℃ at 20 ℃/min, followed by a further increase to 290 ℃ at 5 ℃/min, with the final temperature held for 8 min; this program was optimized to afford maximum target-compound resolution and sensitivity. The developed method rapidly, accurately, and sensitively detected the target PAEs and their alternatives under the optimal conditions, which included a carrier-gas flow rate of 1.4 mL/min, a modulation period of 4 s, and an injection-port temperature of 250 ℃. The 44 target compounds exhibited highly linear calibration curves across a content range of 1-500 μg/g, with all correlation coefficients exceeding 0.99. The limits of detection (LODs) of the method were determined to lie between 0.57 and 13.0 ng/g, which reflects the high sensitivity of the developed approach. At spiked levels of 1, 10, and 50 μg/g, the recoveries of the analyzed compounds varied from 72.8% to 125%, with relative standard deviations ranging from 1.29% to 14.8% (n=3), which indicates that the method is highly precise and reliable. The developed method was used to analyze PAEs and their alternatives in 40 indoor dust samples, which revealed total contents of between 2.07 and 354 μg/g in dust samples. Di-2-ethylhexyl phthalate (DEHP) emerged as the most frequently detected compound, with contents ranging from "not detected" (nd) to 158 μg/g. The novel alternative, bis(2-ethylhexy) terephthalate (DEHTH), was also detected, with levels ranging from nd to 117 μg/g. Notably, significant differences in the compositions and contents of the PAEs and their alternatives were observed across various indoor environments, which suggests that diverse sources and exposure pathways exist for these compounds, highlighting the necessity for ongoing PAE monitoring and risk assessment in various indoor settings. In conclusion, the developed GC×GC-TOF-MS method provides a powerful tool for comprehensively analyzing PAEs and their alternatives in indoor dust; it is well-suited for the routine monitoring of these compounds owing to its simplicity, rapidity, and robustness. These findings provide valuable insight for future research into the sources and health implications of PAEs in indoor environments, and ultimately support risk assessment and regulatory efforts.

Eco-friendly cellulose paper based triboelectric material regulated by lignocellulose composition.

Applying cellulose paper on the triboelectric material is the trend of developing eco-friendly triboelectric nanogenerator (TENG). However, the researchers always pay attention to improve the triboelectric property of cellulose paper by the grafting of functional groups and the introduction of conductive or high dielectric property materials, while neglecting the effects of lignocellulose fiber composition including hemicellulose and lignin. In this work, the contents of hemicellulose and lignin were adjusted by sodium hydroxide and sodium chlorite, respectively; and the effects of hemicellulose and lignin on the triboelectric performance of cellulose paper were evaluated. The results showed that the open-circuit voltage (VOC) and short-circuit current (ISC) changed slightly with increasing hemicellulose contents, while the VOC and ISC values increased from 49.9±0.5V to 94.7±0.7V and 2.3±0.04μA to 4.3±0.03μA in the range of lignin contents from 0.8±0.1% to 8.9±0.2% because lignin can make the surface potential of cellulose paper more positive. The triboelectric performance was further demonstrated by driving 50 commercial LEDs and harvesting energy from human motion. This work provides a new idea for improving the triboelectric performance of cellulose paper.

Expert consensus on visualized tele-round and quality control management based on the improvement of clinical practice ability

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor's professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

A Thermodynamic and Experimental Analysis of Inclusions Modification in AH36 Liquid Steel by Calcium and Magnesium Treatment

The influence of calcium and magnesium treatment under different molten steel conditions, as well as that of the alloy proportion and addition sequence of calcium and magnesium in composite treatment, on the evolution of inclusions in AH36 liquid steel was analyzed systematically based on thermodynamic calculations. The results show that the inclusions in molten steel are mainly Al2O3, which gradually transform into a liquid phase after calcium treatment with a wide range of calcium contents, indicating that calcium treatment has a significant effect on inclusion modification. Magnesium treatment mainly converts Al2O3 into MgO·Al2O3 inclusions in molten steel; however, it is not suitable to modify inclusions with magnesium treatment alone since it does not produce a significant liquid phase. The effect of calcium and magnesium composite treatment varies with the alloy content composition and the order of alloy addition. The liquid phase range of inclusions follows the order of 80%Ca + 20%Mg composite treatment > calcium treatment > 50%Ca + 50%Mg composite treatment > 20%Ca + 80%Mg composite treatment. Combining the thermodynamic and experimental analysis results, it can be concluded that the composite treatment of magnesium followed by calcium is the best. Specifically, a small amount of magnesium should be added first as the nucleating particle to promote the fine dispersion of the inclusions, thus reducing their impact on steel performance. Then, calcium should be added to modify the surface of the inclusions into a liquid phase, which can effectively reduce nozzle clogging.

Cellulose particles filled oil-in-water emulsion: a facile strategy to prepare edible oleogels

Abstract In this work, a facile strategy of filling the O/W emulsions with cellulose particles to prepare edible oleogels was reported. Two preparation processes, particle filling in water phase of emulsion (PFWP) and one pot dispersing (OPD) are adopted. The effect of cellulose particle concentration and water content on the formation and properties of oleogels were evaluated. Results showed that both of the two processes (PFWP and OPD) could form an oleogels, within a wide range of particle concentration (20 wt% – 40 wt%) and water contents (15 wt% – 25 wt%). The formed oleogels have good centrifugal stability, thixotropic recovery properties and thermostability. The storage moduli of the oleogels increased with an increase of cellulose particle concentration, which is associated with the stronger capillary bridges network. Our results provide a fast and simple approach for oil structuring, which should have great potential application in food industry, especially in food bakery.

Organometallic-Polypeptide Block Copolymers: Synthesis and Crystallization-Driven Self-Assembly in Aqueous Solutions to Rod-like and Plate-like Micelles with Polypeptide Coronas.

The synthesis of polyferrocenyldimethylsilane-b-poly(L-glutamic acid) block copolymers was systematically explored. Rod-like and plate-like micelles were prepared from self-assembly of the block copolymers in aqueous solution with two different approaches. In a dissolution-dialysis approach, micelles were prepared by dissolving a block copolymer sample in excess aqueous base followed by the dialysis of the solution against water. The morphology of the resultant micelles showed composition dependence. The block copolymer sample with the lowest soluble block content formed rod-like micelles, while the other samples with higher soluble block content formed spherical micelles. In a THF-mediated approach, THF was added into a block copolymer solution, which was first prepared by the dissolution-dialysis approach, and then the THF was evaporated slowly. Plate-like micelles were obtained from all the block copolymer samples examined, and these had a broad range of soluble block content. The formation of these plate-like micelles was attributed to the crystallization of the PFDMS blocks in the presence of THF. A tendency of large platelet micelles evolving to thin filaments over time was observed. This change may have been driven by the increase in the corona-chain stretching energy as THF evaporated.

Analysis of genetic profiling and diversity in mango cultivar using SSR

The present study was conducted to show genetic variation and investigate inter-relationships between 30 mango genotypes. We are selected 9 SSR markers with 30 genotypes cv. Kalepad, Neelum, Swarnarekha, Alphonso Rumani, Sendura, Banganapalli, Mulgoa and Bangalora etc. The genomic DNA was extracted from mature leaf samples with cetyltrimethylammonium bromide (CTAB) method. Samples were run by Polymerase chain reaction (PCR) they produced 350 amplified products, of which 258 were polymorphic and 132 monomorphic. The sizes of the alleles detected ranged from 120 to 290 bp. SSR markers were highly polymorphic with an average of 3.04 alleles per primers. SSRs gave moderate polymorphic information content (PIC) range value of 0.147 to 0.778. The amplified products varied between 2 (MSSR 152, MSSR 155 andMSSR173) to 3 and 4 (MSSR 106, MSSR140, MSSR146, MSSR156, MSSR160 and MSSR190) bands per primer. We obtained moderate genetic diversity, with Jaccard’s similarity co-efficient values ranging from 0.065 between cluster I and II to 0.25 between clusters II and III. The dendrogram generated from the unweighted pair group arithmetic average (UPGMA) cluster analysis broadly placed 30 mango cultivars into three significant clusters at co-efficient similarity of 0.65. The cluster size varied from 1 to 27 and cluster I was the largest cluster comprising twenty-seven cultivars, followed by cluster II possessing two and clusters I possess one variety. Cluster I had the highest diverse cultivars namely, Mallika, Gundur pacharichi, Rumani, Sajahan, Dillpasanth, Senthuram, Amarapalli, Arka aruna, Banganapalli, Sundar langra, Sothuparai local etc. cluster II contain the cultivar Neelgoa, Arka puneet Cluster III contain the cultivars viz., Neelphonso. Unique fingerprints were identified in the cultivars. The tendency of clustering among mango cultivars revealed that they have a strong affinity towards further breeding programmes.

Special Education Teacher Preparation in PBIS for Students With Extensive Support Needs

ABSTRACTSchool‐wide positive behavioral interventions and supports (PBIS) is a multi‐tiered system of supports that promotes a safe and equitable school environment by supporting the social, emotional, and behavioral needs of all students, including those with extensive support needs (ESN). Research suggests not all students with ESN access and meaningfully participate in all aspects of PBIS, in part due to teachers' misconceptions and negative beliefs concerning the involvement of students with ESN in PBIS. In response to calls for research focused on teacher preparation in this area, we conducted an exploratory survey study of 34 course instructors in undergraduate and graduate teacher preparation programs that prepare special education teachers of students with ESN with a specific focus on universal, Tier 1 PBIS. Instructors at the undergraduate and graduate levels reported addressing a wide range of content focused largely on knowledge acquisition, with fewer reports of course activities involving skill development and practice‐based applications. Overall, instructors viewed the inclusion of content focused on PBIS for students with ESN as important. We present detailed findings, implications for special education teacher preparation programs, and directions for future research extending this line of inquiry.

A Hedonic Sensory Trial: Exploring the Relationship Between Sweet‐Liker Status, Demographics, and Health Measures on Acceptability in a Beverage System

ABSTRACTThere is concern that high sugar‐sweetened beverage consumption may reduce the intake of more nutritionally dense foods and lead to a higher risk of chronic diseases, particularly for vulnerable populations, including First Nations People. The current study investigates consumer acceptability of five carbonated beverages with a range of sugar contents (0%–11.5%) including novel low‐sugar formulations with bush fruits and commercial soft drink comparators. The results from 142 consumers reveal the full sugar soft drink (11.5% sugar) had the highest acceptability, closely followed by the low sugar novel formulation (5.9% sugar). The consumer cluster “full sugar soft drink likers” were more likely to be younger, of First Nations status, be a “sweet‐liker”, have a lower perceived intensity of sweetness, and a higher weekly consumption of full sugar soft drinks compared to the “full sugar soft drink disliker” group, where “sweet‐dislikers” made up > 80% of this cluster.

An Assessment of Nutritional Deficiency Symptoms in the Tea Plant (Camellia sinensis L.) Through Field Survey

The most important factor in both plant development and productivity, which mostly depends on nutrient availability in the soil and environment, is the constituents of soil nutrients. Soil is always losing its nutrients by leaching, surface runoff as well as through harvesting and cultural operations like: pruning. For maintaining the balance of agricultural ecosystem fertilizer application is necessary to improve soil condition and gain better yield. In case of tea industry for maintaining better and uniform production applying fertilizer is a widespread management technique in worldwide. Tea requires a lot of macro and micronutrients for growth because it cannot be grown without the usage of fertilizer and other nutrient supplies. The purpose of this field survey was to ascertain the nutritional condition of tea leaves as well as the signs of nutrient deficiencies in tea plants. In this study, deficiency symptoms of the essential nutrients were found out at different tea estates of Moulvibazar and Sylhet districts as well as photographs were taken. Photographs of the nutrient deficient tea plants were correlated with the established symptoms. The range of total nitrogen, phosphorus, potassium, calcium, magnesium and zinc content in the collected tea leaf samples were 2.95- 5.18%, 0.28- 0.49%, 0.56-1.88%, 0.12-0.49%, 0.07-0.08% and 0.002- 0.004%, respectively.

Measurement and optimization of estimation method for moisture diffusivity of porous building materials with different salt content

Sintered bricks, common porous building materials in architectural heritage, necessitates an accurate understanding of moisture diffusivity for effective moisture transfer analysis. Using the “ruler method” proposed by Evangelides et al., based on pure water capillary absorption experiments, we determined the moisture diffusivity ( Dl) of Chinese sintered blue brick containing sodium chloride (NaCl) crystals. Before the experiments, the samples were immersed in 0%, 1%, 5%, and 10% NaCl solutions and dried to contain salt crystals. Subsequently, based on the Dl values measured by the ruler method, a heat and moisture coupled transfer model was developed to discuss the applicability of the moisture diffusivity obtained from the ruler method by reproducing the pure water capillary absorption process of sintered bricks with different salt contents. Experimental results showed that the capillary absorption coefficient ( Acap) and capillary moisture content ( wcap) of sintered bricks both decreased with increasing NaCl content, with maximum reductions of 18% and 8.6%, respectively. The Dl increased with elevated salt content in lower moisture content range but decreased in higher moisture content range. The simulation results indicated that the choice of boundary moisture content played an important role in the determination of moisture diffusivity in porous building materials and using saturated moisture content ( θsat) over capillary moisture content ( θcap) can give more suitable moisture diffusivity and the moisture content above θcap cannot be ignored in the ruler method. This research not only extends the ruler method’s applicability for sintered bricks but also provides support data for moisture simulations and conservation initiatives related to sintered brick architectural heritage.

Experimental study on compression mechanical properties of functionally graded shape memory alloys

Functionally graded shape memory alloy (FG-SMA) hold considerable promise for diverse applications in aerospace and micro electro mechanical system (MEMS) fields, owing to their elevated ceramic hardness and distinctive phase transition characteristics. To investigate the mechanical properties and phase transition behaviors of FG-SMA, an FG-SMA specimen was fabricated for the first time using the spark plasma sintering and ball-mill mixing method. Subsequently, microstructure, phase transformation, hardness, compression fracture and shape memory effect testing experiments were carried out. The results revealed a microstructure of the FG-SMA without noticeable pores in the alumina content range of 0.1% to 0.6%. Alumina particles were effectively integrated into the NiTi matrix, enhancing the FG-SMA’s compressive strength. Varied alumina gradients in the FG-SMA cross-section led to distinct phase transitions. The addition of alumina increased the hardness of the NiTi matrix, resulting in higher fracture stress and strain in the FG-SMA. The elastic recovery strain of FG-SMA augmented with increasing alumina content, although the recoverable strain associated with the shape memory effect gradually decreased. This study provides valuable insights for the preparation, optimization, and practical applications of FG-SMAs. At the same time, the research in this article can lay an experimental foundation for the application of FG-SMA in the field of aerospace and MEMS.

Petrogenesis and Geochemistry of Upper Paleozoic Komatiites (Mashhad, NE Iran)

Abstract Upper Paleozoic, probably Permian, komatiites have been found in the Paleo Tethys suture zone in NE Iran. These rocks are divided into three groups: (i) differentiated and undifferentiated komatiite lava flows, (ii) komatiitic basalts, and (iii) ultramafic-mafic pillow lavas. The rocks have a wide range of textures including random olivine spinifex, layered olivine spinifex, random and string-beef pyroxene spinifex, micrographic intergrowths of plagioclase and clinopyroxene, and cumulate textures. MgO contents range from 7.1 wt% in basalts and gabbros in differentiated flows to 38.0 wt% in cumulates, flow margins and samples with olivine spinifex textures. The MgO content of the parental melt is estimated using the Fo content of olivine (89-91) to be between 20 and 25 wt%, and the higher MgO content in spinifex samples (30 to 36 wt%) is attributed to accumulation of olivine. The rocks have low Al2O3/TiO2 and are relatively depleted in heavy rare earth elements. They therefore are classified as Al-depleted komatiite, the first report of this magma type in a Phanerozoic locality. These characteristics are attributed to the presence of garnet in the source during mantle melting and melt extraction. The rocks also have relatively low contents of the more incompatible trace elements indicating derivation from a depleted source. Our study indicates that the parental magma formed by 10- (about) 20% partial melting in a mantle plume at pressures of about 4-5 GPa (depths of 120-150 km). Ascent of the plume into the Late Paleozoic subduction zone at the margin of the Paleo-Tethys ocean is a possible petrogenetic model for the generation of these komatiites.

Enhancing fake profile detection through supervised and hybrid machine learning: a comparative analysis

In modern times, social networks have become ubiquitous platforms facilitating widespread information dissemination, resulting in significant daily data generation. This increase in data production encompasses a wide range of user-generated content, which in turn promotes the proliferation of fraudulent users creating fake profiles and engaging in deceptive activities. This article aims to address this challenge by employing machine learning algorithms to accurately identify fake profiles. The research involves a thorough analysis of various user behaviors, engagement metrics, and content attributes within social platforms. The primary goal is to develop robust models capable of effectively detecting deceptive profiles by meticulously examining user activities and content characteristics. The study explores the application of robust methodologies such as K-means and K-medoids clustering, alongside supervised machine learning classifiers including K-nearest neighbors (KNN), support vector machine (SVM), Bernoulli Naïve Bayes (NB), logistic regression, and linear support vector classification (SVC), specifically tailored for the detection of fake profiles.

Characterization of Mulberry Biochar: Implications for Sustainable Agriculture

Mulberry, a crop generating substantial residues, presents an opportunity for sustainable biochar production. This study examined the physicochemical properties of biochar made from mulberry residues at different temperatures (250, 300, 350, and 400 °C) during the pyrolysis process. Systematic analysis was done on important physicochemical characteristics-bulk density, pH, electrical conductivity, moisture content, volatile matter, ash content, and water holding capacity. Every parameter that was examined showed a strong relationship with the pyrolysis temperature. Range of moisture content was found to be from 2.28% to 7.73%, volatile matter from 32.33% to 67.24%, ash content from 2.26% to 9.46%, fixed carbon from 24.77% to 55.93% and water-holding capacity was 68.55% to 92.46%. The 400 °C pyrolysis temperature produced the highest pH and EC values (8.38 and 0.38 dS/m, respectively) and also recorded the highest bulk density (0.67 mg m−3). The resulting biochar’s physicochemical properties proved to be well-suited for improving soil quality and supporting sustainable agricultural practices. However, further studies are necessary to improve the techniques used in the manufacture of biochar and to understand its long-term effects. Additionally, efforts should be made to raise awareness among farmers through various extension activities, such as workshops, training programs, and field demonstrations, to encourage its widespread use in agricultural practices.

RAPID QUANTITATIVE ANALYSIS OF METHAMPHETAMINE BY PORTABLE NEAR-INFRARED SPECTROSCOPY AND PLS MODELING

To rapidly detect different types of methamphetamine in the field, a portable near infrared spectroscopy (NIR) method was used to model and analyze the collected samples. Transmission spectra of 359 methamphetamine crystal samples (content range of 7.5-99.4%) and 187 methamphetamine tablet samples (content range of 2.43-23.91%) were collected, first-order derivatives and the Savitaki-Golay smoothing method were applied for spectral preprocessing. The drug concentrations in the calibration and validation sample sets were analyzed using high-performance liquid chromatography. The partial least squares quantitative analysis models were built, and the quantitative models for methamphetamine crystals were 2.10, 2.12 and 2.19% for root mean square error of cross-validation (RMSECV), root mean square error of validation (RMSEV) and root mean square error of prediction (RMSEP), respectively; in contrast, RMSECV, RMSEV, and RMSEP of methamphetamine tablets were 0.78, 0.80, and 0.82%, respectively. The results of the internal cross-validation and the methodology review show that the measurements of the modeled results are consistent with the true values, and that the model has good stability and can be used for accurate field measurements. Therefore, real time sample analysis can be performed using NIR technology combined with chemometric models, which helps the police to determine the quality of drugs in a timely manner for case analysis.

ONTOGENESIS OF CLEAR IMAGE: CONTEMPORARY TELEVISION AND FILM PROGRAMMING ON RADIO TELEVISION OF SERBIA IN THE DIGITAL AGE FROM AN EDITORIAL PERSPECTIVE

This paper examines the transformation of television production, specifically focusing on film programming within the digital environment from an editorial perspective at Radio Television of Serbia (RTS). The study delves into the transition from traditional analog broadcasting, where a single film was aired once a week, often a western, to the complexities of modern digital television production, which incorporates advanced organizational and technical skills, as well as the integration of contemporary technologies in program realization.The research highlights the increasing importance of editorial work in creating diverse and engaging content that caters to various demographic groups, with a special focus on the responsibilities of editors in shaping program quality and audience engagement. As television production has evolved into a leading creative sector, it now encompasses a wide range of genres, multimedia content, and interactive media, reflecting significant changes in both cultural and organizational strategies within the media landscape.The paper also explores the impact of globalization, technological advancements, and changing cultural policies on the development of national public service broadcasters like RTS. It discusses how these institutions have adapted to the challenges posed by a rapidly changing media environment, such as the increasing demand for efficiency, the expansion of content, and the inclusion of marginalized social groups in the programming.Through the examination of editorial practices in contemporary film programming, this work aims to offer insights into the evolving role of editorial decisions in shaping television content, as well as their contribution to the broader cultural and educational objectives of public broadcasting in the digital age.Top of Form

Nutritional status of some selected indigenous leafy vegetables of Assam, india

The study aimed to assess the nutritional status of 14 types of indigenous leafy vegetables, namely Houttuynia cordata, Paederia foetida, Alternanthera sessilis, Amaranthus viridis, Eryngium foetidum, Bacopa monnieri, Polygonum chinense, Hydrocotyl rotundifolia, Talinum triangularae, Tetrastigma leucostaphylum, Pogostemon heyneanus, Celosia argentea, Glebionis coronaria and Peperomia pellucia. All the indigenous leafy vegetables contained high amount of moisture, which ranged from 79.38 to 92.80%. The vitamin C content range from 41.86 to 537.24 mg/100g, vitamin A from 35.87 to 8685 IU and protein content was found in between 1.25 to 8.63 g/100g. Among the species total phenol content ranged from 32.30 to 259.10 mg/100g, total flavonoid from 138.20 to 288.90 mg/100g, IC50 value for scavenging DPPH radicals from 24.06 to 214.56 µg/ml and alkaloid content 0.16 to 3.18%. Leafy vegetable also possess good amount of minerals which range from 173.17 to 2109 mg/100g of calcium, 27.48 to 396.17 mg/100g of iron, 141.62 to 4037.00 mg/100g of magnesium and total chlorophyll from 1.02 to 2.49 mg/100g FW. The result of the study revealed that the indigenous leafy vegetables such as Amaranthus viridis, Paederia foetida, Tetrastigma leucostaphylum and Alternanthera sessilis were found to be superior in terms of nutritional attributes with good antioxidant properties. Bangladesh J. Bot. 53(4): 865-870, 2024 (December)

Determining rational complex modifying and alloying additives to improve the mechanical characteristics of gray cast iron

The object of this study is the mechanical properties and parameters of the cast iron microstructure. The task to solve was to ensure high mechanical properties of cast iron for mechanical engineering part. To this end, a working hypothesis was put forward, which assumed the possibility of increasing mechanical properties by selecting complex additives based on modifiers and alloying ferroalloys. The effect of 4 groups of additives was investigated: group 1 – ferrochrome (FeCr025) and silicocalcium (SiCa-30), group 2 – ferrotitanium (FТі35) and ferroboral (FEB6), group 3 – ferrotitanium (FТі35) and ferrochrome (FeCr025), group 4 – ferroboral (FEB6) and silicocalcium (SiCa-30). They were introduced into the liquid metal in different percentages in the amount of 3 % of the mass of liquid cast iron. The following mechanical characteristics were selected: flexural strength (σ, MPa), tensile strength (UTS, MPa), deflection arrow (f, mm), hardness (HB), and whitening. It was determined that the strength characteristics of cast iron treated with ferroalloys of group 1 reach a maximum at about 40 % silicocalcium in the composition of the additive. The tensile strength of cast iron reaches about 320 MPa, the bending strength is about 710 MPa, the deflection arrow is 4.5 mm, and the hardness corresponds to the HB250 level. The fact of competition of hardness and other mechanical properties was established in the range of silicocalcium content in the modifier composition up to 40 %. Thus, it was established that it is the combination FeCr025+SiCa-30 with the ratio of components of 40:60, respectively, that is rational. The revealed regularities of changes in the amount of carbides, the size of graphite, and the amount of ferrite when using different additives allow us to explain patterns in the formation of mechanical properties of cast irons. Owing to this, it becomes possible to identify the mechanism of formation of properties, ensuring purposeful regulation of the quality of cast iron

Diagenesis and Reservoir Evolution of Low Permeability Sandstones: A Case Study of the Second Member of the Jurassic Sangonghe Formation, Central Junggar Basin, China

ABSTRACTThe low‐permeability oil‐bearing tuffaceous sandstones of the second member of the lower Jurassic Sangonghe Formation (J1s2) in the Well Pen‐1 west sag of the central Junggar Basin occur in a deep burial setting (> 4000 m). They contain abundant oil and gas shows and hold promising exploration prospects. However, the reservoir heterogeneity is strong due to complex lithofacies and diagenesis, leading to significant productivity differences between adjacent wells. Therefore, identifying the lithofacies and diagenesis of the J1s2 sandstones and elucidating their influence on the evolution of relatively high‐quality reservoirs is of utmost importance for oil and gas exploration and development in this area. Samples from the Well Pen‐1 west sag, representing the J1s2 sandstones, were investigated utilising core and thin section observations, scanning electron microscopy, X‐ray diffraction, fluid inclusions and carbon and oxygen isotope analyses. The J1s2 sandstones are mainly medium‐ to fine‐grained and moderate‐ to‐well‐sorted feldspathic litharenites and litharenites. The tuffaceous contents range from 2.6% to 25% and the authigenic clay contents, produced by diagenesis, range from 0.6% to 12%, although carbonate cements are not abundant (av. 3.1%). Four sandstone lithofacies have been identified based on mineral compositions, leading to variations in diagenetic evolution and reservoir quality. Early diagenetic events included compaction, alteration of tuffaceous matrix and feldspar, and development of smectite, chlorite, kaolinite and early calcite. Mesogenic alteration included feldspar and tuffaceous matrix dissolution, alteration of kaolinite, chlorite and illite, and precipitation of quartz, anhydrite, late calcite and ferrocalcite. The alteration of the tuffaceous matrix resulted in a complex pore‐throat structure in the J1s2 sandstones. The pebbly sandstone and conglomerate (SC) and fine‐grained sandstone (Sm) lithofacies are generally characterised by high compaction resistance, low tuffaceous matrix and cement contents, and abundant secondary dissolution pores, and they exhibit better reservoir quality and great potential for oil and gas enrichment.