bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic justification of the use of bicomponent beverages based on pectin substances on the example of vegetable juices
Authors: Donchenko Lyudmila V. , Belousova Anna I.
Published: July 2021

Modern food technologies are not able to preserve the healthy components of original natural raw materials in finished products. The example is the production of industrial juices. It is known that freshly squeezed juices quickly deteriorate. In order to preserve their vitamins, useful components and increase the shelf life, water is immediately removed from freshly squeezed juices in a vacuum at a temperature of 30°C. It is known that water is not only an environment favorable for the bacteria reproduction, but also a strong chemical reagent that easily decomposes all the useful components contained in food. In addition, chemical interactions occur in the water, that is, decomposition reactions, and they can only be stopped by removing water from the food system. When sterilized by heating, the chemical processes of decomposition of healthy aromatic components are accelerated. As a result, the nutritional value of such drinks is reduced. The main trend in food market is the expansion of range and volume of production of functional beverages containing the necessary nutrients.
Dynamics of mineral nitrogen in the gray forest soil under malt barley on the background of mineral fertilizers in the forest steppe of the east Prisayan
Authors: Grebenshchikov Viktor , Tyutrin Nikolay , Verkhoturov Vasily
Published: July 2021

The content of mineral nitrogen was studied when it was applied at a dose of 60 kg / ha on gray forest soil of heavy particle- size distribution at various levels of phosphorus-potassium nutrition in field experiments with barley. Fertilizer doses were determined by the normative method according to the CINAS method for a planned yield of 3 t / ha. It was shown that the dynamics of nitrate and ammonium nitrogen depended on the moisture regime during the vegetation period. With excessive moisture, nitrate nitrogen, with its initial content of 4-5 mg / kg, is not detected in the arable layer by the middle of the growing season, and with a moisture deficit, less dynamism is noted. It is found in an amount of 5-7 mg / kg by the end of vegetation. The N – NH4 + dynamics turned out to be less pronounced. With an excess of moisture, its content increased to 15.6 mg / kg, and with a deficit, it decreased more than by four times from the maximum during the vegetation. In general, the content of mineral nitrogen in gray forest soil is highly dynamic, which depends on the moisture regime and the nature of its consumption by barley.
Prospects for the use of calcium ammonium nitrate on acidic soils of the Non-Black Earth Area
Authors: Akanova N. I. , Vizirskaya M. M. , Zhdanov V. Yu.
Published: July 2021

The results of the effectiveness of the application of calcium ammonium nitrate (CAN) in winter wheat crops of the “Moskovskaya-39” variety on the dark-gray forest, heavy-loamy soil in the Ryazan region is presented. The advantage of CAN-a a universal form of nitrogen fertilizer, which has a neutral reaction and creates optimal conditions for feeding plants with nitrogen in the zone of its application, where the main mass of plant roots is located, is revealed. Along with nitrogen, fertilizer contains calcium and magnesium, which are essential for the formation of winter wheat productivity, the exchange of carbohydrates and proteins. In the field experience with winter wheat on soils not saturated with bases, the results were obtained, indicating the effectiveness of a physiologically neutral form of nitrogen fertilizer, which showed an advantage over physiologically acidic fertilizer - ammonia nitrate. Dynamics of the formation of the productivity of sowing showed that the area of leaves reached the maximum sizes by the flowering phase of 61.6-76.6 cm2/plant, the largest value of the indicator 76.6 cm2/plant was in the variant with the use of CAN feeding at a dose of 54 kg/ha of nitrogen. The use of CAN provided a reliable increase in the harvest of winter wheat grain in comparison with ammonium nitrate. The grain harvest in the experiment was 63.7 - 67.1 cents per hectare, statistically close were the values of yield in variants using CAN in doses of 68 and 54 kg/ha of nitrogen, the increase in the harvest was 3.8-5.3% respectively. The creation of optimal conditions for winter wheat during the growing season was accompanied by an improvement in the quality of the grain, in comparison with the variant with the use of ammonium nitrate.
Modern characteristics of the properties of meadow-boggy soils of rice agrocenosis in the republic of Adygeya
Authors: Chizhikov Vitaliy , Osipov A. V. , Suminsky Ilya , Belo Katinda
Published: July 2021

In this work, changes in the composition and properties of alluvial meadow-boggy soils are considered, with prolonged use in rice crop rotation and not involved in agricultural production - a virgin plot. The morphological differences of meadow-boggy soils of a rice field from a virgin area were revealed, which subsequently determine the properties of the soil cover of the Kuban River delta. The regularities of the interdependence of the granulometric composition of the soil, which lie in the mineralogical composition of alluvial soils and rocks, have been revealed. The tendency of an increase in soil density with an increase in the content of physical clay and silt, as well as an increase in the density of the solid phase of soils, has been established. No significant differences were found in the indices of the agrophysical properties of the subsurface horizons of soils and underlying sediments. The assessment of fertility indicators of meadow-boggy soil of a rice field and virgin analogue is given. Hydromorphic soil-forming processes have led to a significant change in the properties of alluvial deposits and soils involved in the rice crop rotation.
Analysis of research on soil destruction criteria during its interaction with working bodies
Authors: Konovalov Vladimir I.
Published: July 2021

Under the action of the working surface of the tillage unit, three mutually perpendicular stresses and corresponding deformations occur in the soil layer, which are characterized by different time functions. The finding of these functional relationships is the fundamental task of agricultural mechanics, with the help of which the process of soil crumbling with different physical and mechanical properties can be described in interaction with working bodies. The article presents an analysis of the results of studies of domestic and foreign scientists of the process of soil destruction in its interaction with working bodies. When considering the process of soil destruction from the point of view of stress theory, the Coulomb-Mohr theory of destruction is most often used. It is proposed to expand the consideration of the process of soil destruction by adding elements to the theory of strength that will describe the rate of change of the acting loads.
Theory on the formation of working fluid formed by an air jet and a slot sprayer
Authors: Palapin Alexey V. , Roshchupkin Stanislav I. , Storojuk Tatiana A. , Belousova Anna I.
Published: July 2021

The technology of applying the working fluid with protective and stimulating compositions to the surface of leaves of perennial plantings is an important technological operation in the production of products of orchards and vineyards. In the presented work, the formation of working fluid at a separate supply to a slot spraying tip is theoretically considered. Operating parameters of the formation of working fluid formed by an air jet and a slot sprayer after the connection of air ejecting and liquid ejecting flows are also theoretically presented. let us consider the method of calculating colliding jets are cited as well.
Justification of the requirements for an environmentally safety mobile power unit of class 1.4-2.0
Authors: Lavrov Alexander
Published: July 2021

The systematic analysis of world trends in the development of production and sale of agricultural tractors has shown that advertising and exhibition trends of overstating the power and saturation of tractors with automation elements for Russia are technologically outdated. It is proposed to consider increasing energy efficiency and ensuring their environmental safety in the full life cycle as the main indicators of the competitiveness of agricultural tractors in the world market.
Algorithm for create network diagrams for planning maintenance of agricultural machines
Authors: Popov Anton , Lukhanin Vladimir
Published: July 2021

Reducing the maintenance man-hour is one of the ways to improve of operation efficiency of agricultural machines. The total maintenance time of the agricultural machine is determined by the critical path and other network planning parameters. The network model in the form of network diagrams is used for visualization and analysis of maintenance processes. Building network diagrams be not a trivial task and it takes a long time to build. Therefore, automating the creation of network diagrams of technological maintenance of agricultural machines is an urgent task. This work aims to develop an algorithm for creating and analyzing network diagrams for planning the processes of technological maintenance and repair of various agricultural machines. When building an algorithm for creating network diagrams, the methodological apparatus of network planning and basic algorithmic structures were used. The algorithm is realized in the Matlab programming language. The article presents the flowchart and a description of the formation of an array of all and full paths. The description of identifying fictitious operations in the network diagram is given. The present algorithm calculates the maintenance man-hour of paths, determines the critical path of the network diagram and visualizes it on the graph, and also calculates the time reserves of the specified work. The logic of the algorithm is developed in accordance with the rules for building network models and excludes dead-end and tail events, closed loops. Thus, the algorithm will increase the efficiency of solving practical tasks of network planning of maintenance of agricultural machinery, shorten working hours and time for the building of the network diagram and reduce the associated possible errors.
The use of unmanned aerial vehicles in digital agriculture
Authors: Grishin Igor , Timirgaleeva Rena
Published: July 2021

The task of forming a system of remote monitoring of soil conditions based on unmanned aerial vehicles was solved by this work. The authors conducted an experimental study that showed the principal possibility of such monitoring. It was shown that the most informative channel is the red one when using a high resolution digital camera. As a result of statistical processing, the experimental regression dependences allowing to estimate the amount of humus in the soil with the error not exceeding the value of 16 percent were received. Experimental plots were laid for conducting experiments for which the soil quality was determined by laboratory methods according to Tyurin. Similar experiments with the use of hyperspectral equipment were defined as further research.
Results of using an electric drive platform for harvesting strawberries
Authors: Filippov Rostislav , Semichev Stepan , Vershinin Roman
Published: July 2021

The most common and cost-effective berry crop in the Russian Federation is strawberry garden. A feature of the cultivation of this crop is the increased labor costs, which reach up to 2000 people·h/ha, a large share of which is accounted for by manual harvesting operations. In this connection, the creation and use of an electric drive platform for the cultivation and harvesting of strawberries on an industrial plantation will significantly reduce labor costs, increase productivity and reduce the degree of labor fatigue in gardening. As a result of the conducted research, data on the effectiveness of the use of an electric drive platform for the operation of harvesting strawberries in the conditions of an industrial plantation of “ Sovhoz imeni Lenina”, so the productivity of harvesting strawberries increased by an average of 34.2%. The quality of the technological process of harvesting berries for the entire period of use of the platform was at the level of the usual manual harvesting. The completeness of the harvesting ranged from 95.8% in heavily thickened rows with a large number of weeds, to 99.5% in areas with good agricultural techniques for maintaining plantings and it is economically feasible to use an electric platform with a yield of more than 30 c / ha.
Modeling of transport and technological processes of cultivation and harvesting agricultural crops
Authors: Maystrenko Nikolay , Levshin Alexandr , Khort Dmitriy , Kutyrev Alexey
Published: July 2021

The productivity of technological processes in agriculture is determined by the set of transport and technological means used. The article describes the models for the unification of shift performance, taking into account a wide range of agricultural cargoes and a large number of works on their movement in the process of cultivation and harvesting of agricultural crops. A step-by-step modeling of scenarios for the use of transport and technological means was carried out on the basis of the optimality criterion and forecasting the period of agricultural work. They confirmed that the objective function is of theoretical and practical interest, as it helps to determine the optimal values of the power of technical means, depending on the combination of production conditions. The numerical value of power obtained by calculation can serve as a guide for manufacturers of agricultural machinery in the development of promising vehicles for a specific consumer, depending on the availability of resources and production and economic conditions.
Experimental Studies of Conductive Paths of Printed Circuit Boards by Using Subminiature Eddy Current Transducers
Authors: Malikov Vladimir , Ananyev Maxim , Ishkov Alexey , Nikonov Leonid
Published: July 2021

This paper describes the development and experimental study of a software and hardware complex designed for studying the conductive tracks of printed circuit boards. In the course of this development, a subminiature eddy-current transducer and a measuring system capable of performing measurements using the newly developed transducer were created. The paper contains descriptions of the main parameters of the developed measuring system, and also presents the results of experiments conducted with various printed circuit boards, both with defect-free and those with artificial model defects. These experiments made it possible to confirm the possibility of using the developed measuring system and eddy-current transducer for controlling the conductive tracks on printed circuit boards and determining their quality.
Extrusion Technologies in Ensuring Sustainable Development
Authors: Volkov Alexander R. , Chernikova Svetlana A.
Published: July 2021

The relevance of the research is environmental management is the basis for natural resources conservation, environmental protection and environmental safety. Meanwhile, it is important to use the best available technologies for neutralization and processing of production and consumption waste in addition to observance of the legal and environmental rules. Waste management of production and consumption is one of the main directions of the transition to a circular economy and the use of low-waste and non-waste production, which has recently been actively demonstrated by developed countries.

The main aim of extrusive processing of meat waste is considered. Extrusive processing of waste - an effective solution of problems of rational environmental management as allows to make in addition secondary resources products, thereby realizing the principles of economy of the closed cycle; and considerably to reduce environmental pollution due to refusal of burning and waste disposal of livestock production and the meat-processing enterprises.

Subject, tasks and methods of a research is processing of meat waste which call still biological waste and which are formed, generally in livestock production and at the meat-processing enterprises. One of perspective technologies of high-quality processing of waste is extrusive processing.

Research results confirm that In Russia outdated neutralization and recycling of agro-industrial waste technologies lead to the loss of resources. Moreover they have a significant negative impact on the environment. This article deals with the method of extrusion recycling of meat waste. Extrusion recycling of waste is an effective solution to the environmental management problems, as additionally it allows to produce products from secondary resources, thereby the principles of closed-cycle economy are implemented, and significantly reduce environmental pollution by eliminating the burning and disposal of animal waste and meat processing plants. Thus, use of extrusive technologies will allow not only to make waste products, to get additional profit, but also to prevent pollution of air, water and land resources harmful substances, providing thereby rational environmental management, and will form a basis of transition to circular economy which formation is impossible without environmental safety.
Parameters of a gas discharge with a liquid electrode in the process of gasification of hydrocarbon-containing waste
Authors: Tazmeev Bulat , Tazmeeva Ramilya , Pogosyan Vladimir
Published: July 2021

A plasma generator with a liquid cathode has been developed and investigated, which makes it possible to create a plasma flow from electrolyte vapors with a temperature of up to 1800°C with a mass flow rate of up to 3.0 g/s for the gasification of carbon-containing waste. An electrolyte in the form of a solution of Glauber salt in distilled water with a concentration of 0.5-1.0 kg/m3 by weight was used. The current-voltage characteristics of the discharge are constructed. The optimal electrical and thermal parameters of the plasma flow are determined experimentally.
Screening of Metal Chloride Anion-based Ionic Liquids for Direct Conversion of Hydrogen Sulfide by COSMO-RS
Authors: Aminuddin Muhammad Syahir , Man Zakaria , Bustam Khalil Mohamad Azmi , Abdullah Bawadi
Published: July 2021

In order to identify the best possible reaction media for performing H2S conversion, a total number of 300 different ILs from a combination of 20 cations and 15 anions were screened via COSMO-RS model simulations. By COSMO-RS method, thermodynamic and physicochemical properties of 300 ILs such as Henry’s law constants, activity coefficient, selectivity, capacity and performance index are obtained and analyzed. Thus, by comparing the performance of ILs via COSMO-RS, a series of TSILs containing cation of [P66614] with metal chloride anions such as Fe, Ga and Sn were chosen and selected for synthesis based on their performance predicted by COSMO-RS and their economic values. Consequently, the physiochemical properties such as density, viscosity, thermal properties, as well as H2S absorptive oxidation performances in those TSILs will be systematically investigated.
Synthesis and Characterization of Waste Eggshell-Based Montmorillonite Clay Catalyst for Biodiesel Production from Waste Cooking Oil
Authors: Ayoub Muhammad , Yusuf Suzana , Inayat Abrar , Ullah Sami , Uroos Maliha , Ahmad Mushtaq , Zafar Muhammad , Zulqarnain
Published: July 2021

The depletion of resources and increase in demand for fossil fuel raise concerns as it is natural and non-renewable. Therefore, it will cause limitation on its availability and continuous reduction. This issue has led to the search for more economic, sustainable, and environmentally friendly alternatives which is biodiesel. The major drawback that reduces the possibility of biodiesel commercialization is the high cost of oil feedstock as it covers 75% of its total production cost. The waste cooking oil is used as feedstock in continuous transesterification as it is the primary option to lower the cost of biodiesel production. Biodiesel can be prepared using waste cooking oil and catalyst through transesterification reaction. In this research, the focus is on the utilization of chicken and quail waste eggshell to synthesize highly active Calcium Oxide (CaO)-based heterogenous catalyst with montmorillonite clay to catalyze efficient conversion of waste cooking oil to biodiesel. The formation of CaO/montmorillonite catalyst was confirmed based on the outputs from X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The physio-chemically characteristics of catalysts exhibited a BET surface area from the ranging from 9.2-9.5 m2/g and presence of around 87% of elemental calcium as constituent through XRF characterization. In addition to this, high-performance liquid chromatography (HPLC) analysis is used to determine the conversion of biodiesel using conventional and microwave heating method which revealed a maximum biodiesel production yield of 98%. This optimum biodiesel yield was obtained at reaction temperature, molar ratio of waste cooking oil to methanol, and catalyst amount of 60 ºC, 2 h, 1:12, 2.5 wt.% and 5 wt.% for both eggshells, respectively.
Layered double hydroxide supported cobalt nanocluster: size control and the effect in catalytic hydrogen generation
Authors: Mahpudz Aishah , Lim Siu Ling , Inokawa Hitoshi , Kusakabe Katsuki , Tomoshige Ryuichi
Published: July 2021

Synthesizing metal nanoclusters with diameters smaller than 5nm is challenging, but desirable because of the high ratio of surface area to interior atom. However, in this report it was achieved by utilizing magnesium-aluminium layered double hydroxide (Mg/Al-LDH) as a host for cobalt citrate anion precursor, which was later reduced into cobalt nanoclusters (Co-NC). Size of the Co-NC was controlled by changing the concentration of cobalt-citrate (Co-citrate) precursor during anion exchange. XRD and FTIR showed that Co-citrate precursor was successfully intercalated on the LDH while nitrogen adsorption/desorption isotherms confirmed that mesopores in the sample were formed after chemical reduction. Furthermore, TEM/STEM observations confirmed the formation of Co-NC. It was also verified that reducing the concentration of Co-citrate from 4mM to 0.5mM resulted in a reduction in the size of Co-NC from 4.4 to 1.3 nm. However, catalytic hydrogen generation from sodium borohydride (NaBH4) hydrolysis experiment indicated that catalytic activity decreased as the size of Co-NC decreases. This is mainly attributed to the limitation in mass transport within the interlamellar space of the smaller cluster LDH compared to the bigger one. Overall, Co-NC-LDH is a promising catalyst for NaBH4 hydrolysis. However, an optimum Co-NC size is critical for enhanced catalytic activity.
Metal-Organic Frameworks: Screening M-MOF-74 (M = Co, Cr, Cu, Fe, Mg, Mn, Ni, Ti, and Zn) Based for Carbon Dioxide Adsorption
Authors: Kari N E Fatriyah , Bustam M Azmi , Ismail Marhaina
Published: July 2021

The release of carbon dioxide in the environment is increasing yearly due to human activities and it will affect greenhouse gas. To overcome this issue, adsorption technology found to be the best candidate due to its performance to capture high CO2 with lower capital cost. Much attention has focused on metal-organic framework (MOF) due to high potential of CO2 capture compared with conventional adsorbents. More research has been done on MOF-74 due to presence of the open-metal site that favors CO2 binding. The presence of metal in MOF-74 able to give higher surface area and porosity of the molecules thus result in higher adsorption of CO2. However, there is limited research related to metal in MOF-74 where most focused on the Mg-MOF-74 due to its ability to adsorb twice of CO2 compared with zeolites. Yet, Mg-MOF-74 found to lose stability in presence of water where it's only able to recover 15% from initial adsorption. Synthesizing MOF-74 requires high cost and providing not a promising result for each synthesizes. Thus, this paper introduces to screen MOF-74 for different metal centers using modeling approach by Material Studio. As result, Ni-MOF-74 shows the highest adsorption of CO2 with 12.35mmol/g compared to other metals.
A View of Artificial Neural Network Models in Different Application Areas
Authors: ArulRaj Kumaravel , Karthikeyan Muthu , Narmatha Deenadayalan
Published: July 2021

Neural network is a web of million numbers of inter-connected neurons which executes parallel processing. An Artificial neural network is a nonlinear mapping structure; an information processing pattern is stimulated by the approach as biological nervous system (brain) process the information. It is used as a powerful tool for modeling the data in the application domains where incomplete understanding of the data relationship to be solved with the readily available trained data. The basic element for this processing pattern is the structure of the data which is the collection of densely interconnected neurons to elucidate the problems. A prominent part of these network is their adaptive nature to “learn by example” just like human substitutes “programming” in resolving the problems. Through learning process, neural net is designed for data classification and prediction where statistical techniques and regression model have been employed. This report is an overview of artificial neural networks in different application areas and it also illustrate the architecture structure formed for the applications. It also provides information about the training algorithm used for certain application.
Ethylene Yield from Pyrolysis Cracking in Olefin Plant Utilizing Regression Analysis
Authors: Zakria Mohamad Hafizi , Mohd Nawawi Mohd Ghazali , Abdul Rahman Mohd Rizal
Published: July 2021

Ethylene yield is significant in showing the performance of the steam cracker furnace in the olefin plant. This study was conducted in the actual large-scale olefin plant to see the impact of various variables towards the ethylene yield. The analysis was conducted utilizing Regression Analysis in Minitab Software Version 18 to develop a reliable ethylene yield model. The model concluded that ethylene yield in the studied plant was contributed by the factor of -0.000901, 0.02649, -0.282, 0.16, -0.0834, 0.1268, and 0.0057 of Hearth Burner Flow, Integral Burner Flow, Steam Drum Pressure, Super High-Pressure Steam (SHP) Boiler Feed Water Flow, SHP Flow, Naphtha Feed Flow, and Stack NOx Emission respectively. The Response Optimizer tool also showed that the ethylene yield from naphtha liquid feed utilizing pyrolysis cracking can be maximized at 32.55% with control setting at 9,476.41 kg/hr of Hearth Burner Flow, 608.56 kg/hr of Integral Burner Flow, 112.93 Barg of Steam Drum Pressure, 109.11 t/hr of SHP Boiler Feed Water Flow, 86.42 t/hr of SHP Flow, 63.49 t/hr of Naphtha Feed Flow and 126.23 mg/m3 of Stack NOx Emission.
Steam System Load Shedding Operational Analysis Using Dynamics Simulation of a Fertilizer Plant
Authors: Norman Abdul Rahim , Mohd Khairil Hing Azleen Azna , Md Jaafar M. Azfar , Anwar Farah Syamim
Published: July 2021

Steam system operation of a fertilizer plant can be complex due to high number of equipment, unavailable redundancy of steam suppliers and inter-dependency behaviour between steam users. The plant is subjected to partial or total shutdown whenever one boiler trips as both existing boilers are operating close to design capacity. Installation of an additional boiler will provide additional capacity margin in the event of one boiler trips. iCON(Symmetry) was used as the dynamic process simulation tool to establish proper management for load shedding activity with three boilers in operation. Model was developed for the integrated steam header, fuel gas and boiler feed water network. A detailed representation of the actual plant was achieved by incorporating plant hydraulics based on actual piping configurations, high fidelity equipment modelling, process control configurations, trip sequencing and operator manual interventions. This approach gives high accuracy in replicating the plant’s transient behaviour for load shedding case studies. The case studies prove the three boiler arrangement is able to sustain the plant’s continuous operation. An operational strategy was developed to minimize the impact of equipment trips. It is recommended to expand the model to include the process side to represent the actual plant behaviour with higher accuracy.
Performance Comparison of Malaysian Air Pollution Index Prediction Using Nonlinear Autoregressive Exogenous Artificial Neural Network and Support Vector Machine
Authors: Mustakim Rosminah , Mamat Mazlina
Published: July 2021

This paper compares the performance of Nonlinear Autoregressive Exogenous (NARX) Neural Network and Support Vector Machine (SVM) regression model to predict the Air Pollutant Index (API) in Malaysia. Two models namely the NARX and SVM regression were developed using the API and air quality time series data from three monitoring stations: Pasir Gudang, TTDI Jaya and Larkin. Hourly data of API and air quality parameters collected in year 2016 and 2018 were utilized to produce one step ahead API prediction. The air quality parameters consist of the NO2, SO2, CO, O3, PM2.5, PM10 concentration as well as three meteorological parameters which are wind speed, wind direction and ambient temperature. The NARX model was realized using a series-parallel feed-forward network. For the SVM regression model, different kernel functions: Linear, Quadratic, Cubic, Fine Gaussian, Medium Gaussian and Coarse Gaussian were evaluated. The performance of NARX and SVM regression was measured using the Root Mean Square Error (RMSE) and Coefficient of Determination (R2) values. Results show that the NARX model outperformed the SVM regression model in both 2016 and 2018 data respectively.
Magnetic Hydroxyapatite for Batch Adsorption of Heavy Metals
Authors: Hui Khee Chung , Kamal Norashikin Ahmad , Sambudi Nonni Soraya , Bilad Muhammad Roil
Published: July 2021

In this work, magnetic hydroxyapatite or hydroxyapatite-iron (III) oxide (HAp-Fe3O4) composite was used as the adsorbent of heavy metals and the performance was evaluated using the batch test. The presence of heavy metals in the effluent from wastewater discharge can be toxic to many organisms and can even lead to eye burns. Therefore, hydroxyapatite synthesized from the chemical precipitation of calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions is used to remove heavy metal in aqueous media. Magnetic properties of Fe3O4 can help prevent formation of secondary pollutants caused by the loss of adsorbent. The synthesized HAp-Fe3O4 can remove cadmium, zinc and lead effectively, which is up to 90% removal. Reusability study shows that the adsorbent could retain heavy metal ions even after four cycles. The percentage removal of heavy metals maintains at around 80% after four times of usage. The composite of HAp-Fe3O4 demonstrates good performance and stability which is beneficial for heavy metal removal in the future.
Factory Tea Waste Biosorbent for Cu(II) and Zn(II) Removal from Wastewater
Authors: Tan Peng Jun Patrick , Wan Osman Wan Nur Aisyah , Samsuri Shafirah , Md Saad Juniza , Samsudin Muhamad Fadli , Hernández Yáñez Eduard
Published: July 2021

Recent studies have shown great interest toward heavy metal removal due to its hazardous and non-biodegradable properties. Many approaches have been used for this purpose and one of them is adsorption. In this study, several experiments were carried out to investigate the feasibility of factory tea waste as a biosorbent in a fixed-bed adsorption column for heavy metal removal (zinc and copper) in wastewater. The results highlighted that zinc has better performance compared to copper in terms of the effect of initial ion concentration, pH value, and the mixed ions with respect to the removal efficiency. Zinc showed higher removal efficiency and adsorption capacity at the initial metal ion concentration of 200 mg/L, which are 99.21% and 39.68 mg/mg compared to copper. Meanwhile, for the effect of pH values and mixed ion concentration, zinc also showed slightly higher removal efficiency which are 99.91% and 98.47%, respectively compared to copper. However, both zinc and copper showed a better fit to the Langmuir isotherm. The factory tea waste was characterized using Micromeritics ASAP 2020 instrument and results showed that the factory tea waste biosorbent consists of mesopores with the diameter and width of 4.85205 and 2.546985 nm, respectively.
Purification of Anthocyanin Extract from Roselle by Progressive Freezing: Effect of coolant temperature and stirring rate
Authors: Azhar Aisyah Nur Hanis , Mohamed Anuar Muhammad Athir , Mustapha Siti Nor Adibah , Amran Nurul Aini
Published: July 2021

This study presents the process of progressive freezing as a potentially new and alternative approach for the purification of anthocyanin extract to replace the conventional methods of the aqueous two-phase system (ATPS) and adsorption. Specifically, anthocyanins extract was obtained from the roselle plant or also known as red hibiscus. It is essential to purify the anthocyanins extract before it can be used in various applications to remove the by-products of the extract i.e. free sugar, sugar alcohol, organic acids, amino acids, and proteins. Before the purification step, the anthocyanin was first extracted from the roselle flower through a maceration process. The total amount of anthocyanins in the extract was measured by a UV-VIS spectrophotometer. The extract was then concentrated via the progressive freezing process and the influence of cooling temperature and rate of stirring were analysed vis a vis the process performance, which was represented by the effective partition constant (K) and concentration efficiency. The highest concentration efficiency of 55% and the smallest K value of 0.3 were found at the coolant temperature of -14 °C and 250 rpm rate of stirring. It was also found that lower coolant temperature and higher stirring rate produced a K value that was smaller and superior efficiency.
Standard methods used for mercury analysis in the oil and gas industry
Authors: Sharizal Mohd Azam Shah Wong
Published: July 2021

Mercury is a contaminant found in a variety of hydrocarbons and non-hydrocarbon streams in the oil and gas industry. Quantification of mercury is an integral part to protect processing units especially those with aluminium components and to safeguard personnel from unwanted exposure to mercury. Although mercury is one of the many impurities in oil and gas, its impact is diverse, and this drives the need to adequately quantify the amount of mercury in the process stream as a first line of defence and to make informed decisions on mitigation. The various types of standard methods available for mercury analysis are listed and classified in this literature based on sample phase for hydrocarbon and non-hydrocarbon samples. Different types of mercury analysis such as total mercury, mercury grouping and mercury speciation are also briefly explored to determine which is best for intent of use. Measurement techniques involving different detectors and their respective detection limits are listed with specific attention provided to atomic absorption and atomic fluorescence. The diverse adoption of various mercury analysis across the hydrocarbon value chain will need to be fit for purpose and meet the analytical requirements of the test conducted.
Balanced Steady-State Free Precision and Time of Flight Noncontrast Magnetic Resonance Angiography in Peripheral Arterial Disease
Authors: Regi Soumya Susan , Irodi Aparna , Keshava Shyamkumar N. , Agarwal Sunil
Published: July 2021

Purpose To determine the diagnostic efficacy of balanced steady-state free precession (bSSFP) and time-of-flight (TOF)-based noncontrast magnetic resonance angiography (NC-MRA) in lower limb peripheral arterial disease (PAD).

Methods Ten patients with suspected PAD underwent both NC-MRA (bSSFP and 2D TOF) and contrast-enhanced MR angiography (CE-MRA)/CT angiography (CTA). A total of 170 arterial segments (17 segments in each patient) were analyzed on NC-MRA and compared with CE-MRA/CTA for quality of images and for estimating the degree of stenoses. Image quality was graded as 1—poor, 2—fair, 3—good, and 4—excellent. The degree of stenoses was graded as 0—normal, 1— < 50% narrowing, 2— > 50% narrowing, 3—near complete/100% occlusion. Sensitivity, specificity, positive predictive value, and negative predictive value of NC-MRA in identifying significant stenosis, as compared with CE-MRA/CTA, were estimated.

Results a) Mean grade of the image quality of NC-MRA was 3.10 and the CE-MRA/CTA was 3.64. b) The agreement in the estimation of the degree of stenosis on NC-MRA as compared with CE-MRA/CTA was substantial in aortoiliac segments (weighted kappa 0.646 [95% CI] [0.361–0.931] [p < 0.001]), almost perfect in femoropopliteal segments (weighted kappa 0.911 [95% CI] [0.79–1.032] [p < 0.001]), and poor in infrapopliteal segments (weighted kappa 0.052 [95% CI] [0.189–0.293] [p < 0.33587]).

Conclusion TOF and bSSFP-based NC-MRA was found to be comparable to the CE-MRA/CTA in the evaluation of PAD in lower limbs in the aortoiliac and femoropopliteal regions. NC-MRA was especially helpful in assessing the aortoiliac vessels and femoropopliteal vessels, with the imaging of infrapopliteal arteries being suboptimal.
Venous Thromboembolism in Hospitalized Critical and Noncritical COVID-19 Patients: A Systematic Review and Meta-analysis
Authors: Mansory Eman M. , Srigunapalan Suthan , Lazo-Langner Alejandro
Published: July 2021

Introduction Venous thromboembolism (VTE) has been observed as a frequent complication in patients with severe novel coronavirus disease 2019 (COVID-19) infection requiring hospital admission.

Aim This study was aimed to evaluate the epidemiology of VTE in hospitalized intensive care unit (ICU) and non-ICU patients.

Materials and Methods PubMed was searched up to November 13, 2020, and updated in December 12, 2020. We included studies that evaluated the epidemiology of VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), in patients with COVID-19.

Results A total of 91 studies reporting on 35,017 patients with COVID-19 was included. The overall frequency of VTE in all patients, ICU and non-ICU, was 12.8% (95% confidence interval [CI]: 11.103–14.605), 24.1% (95% CI: 20.070–28.280), and 7.7% (95% CI: 5.956–9.700), respectively. PE occurred in 8.5% (95% CI: 6.911–10.208), and proximal DVT occurred in 8.2% (95% CI: 6.675–9.874) of all hospitalized patients. The relative risk for VTE associated with ICU admission was 2.99 (95% CI: 2.301–3.887, p <0.001). DVT and PE estimated in studies that adopted some form of systematic screening were higher compared with studies with symptom-triggered screening. Analysis restricted to studies in the 5th quintile of sample size reported significantly lower VTE estimates.

Conclusion This study confirmed a high risk of VTE in hospitalized COVID-19 patients, especially those admitted to the ICU. Nevertheless, sensitivity analysis suggests that previously reported frequencies of VTE in COVID-19 might have been overestimated.
Noncomplicated Surgical Removal of Fractured Maxillary Central Incisor from Lower Lip and Its Reattachment: A Case Report
Authors: Narayan Megha , Singh Rajat Kumar , Singh Aparna , Anand Siddharth , Sulekha Sulekha
Published: July 2021

Traumatic injuries to maxillary anterior teeth while playing are common in children and adolescents. Sequelae of such trauma include broken, lost, aspirated, and swallowed tooth. At times, the broken tooth fragments get embedded in the adjoining soft tissue and frequently get neglected during diagnosis. The present case report discusses the case of a 13-year-old adolescent who had broken tooth fragment emerged in the lower lip and its surgical excision to prevent detrimental reactions and scarring.
Infant COVID-19 Infection: An Experience from Pediatric Intensive Care Unit of a Tertiary Care Dedicated Pediatric COVID Hospital
Authors: Sarkar Mihir , Mahapatra Manas Kumar , Ghosh Sanajit , Chowdhoury Satyabrata Roy , Kazi Maha Ashraf , Datta Kalpana
Published: July 2021

This study aimed to assess different clinical, disease severity, laboratory, treatment, and outcome-related factors of COVID-19 positive infants admitted to a pediatric intensive care unit (PICU) and to compare these parameters with COVID-19 positive noninfants (1–12 years of age) who also required intensive care admission. This retrospective observational study was conducted in a PICU of a tertiary care, dedicated pediatric COVID facility. The clinical, epidemiological, laboratory parameters, and treatment outcomes of COVID-19 infected infants admitted to the PICU were recorded and analyzed. During comparison with the noninfant group, malignancy and coinfection with dengue and scrub typhus were excluded from both groups. A total 313 COVID-19 positive children aged from 1 month to 12 years old were admitted, of which 115 (36.7%) children required PICU admission. Infants constituted 37.4% of total PICU admissions. Most common symptoms were respiratory (83.7%) followed by fever (60.5%). Fifteen (34.9%) infants presented with shock. Ten infants (23.3%) had myocardial dysfunction. C-reactive protein (CRP) and ferritin were high in 60.5 and 16.7% infants, respectively. Fourteen infants needed invasive mechanical ventilation. Nine patients had acute respiratory distress syndrome (ARDS) and five had MIS-C. However, 53.5% infants had different comorbidities. Four infants died and all of them had severe comorbidities. Respiratory distress (p = 0.009), pediatric sequential organ failure assessment score (p = 0.032) and number of ARDS cases (p = 0.044) were significantly higher in infants than noninfants. Infants are one of the most vulnerable groups of children suffering from serious illness from COVID-19 infection requiring PICU admission due to predominantly respiratory involvement. Overall outcome was good among infants without significant comorbidity.
Role of Increased Lipoprotein (a) in Retinal Vein Occlusion: A Systematic Review and Meta-analysis
Authors: Paciullo Francesco , Giannandrea David , Virgili Gianni , Cagini Carlo , Gresele Paolo
Published: July 2021

Background Increased lipoprotein (a) [Lp(a)] has been associated with enhanced risk of cardiovascular events and more recently with venous thromboembolism. However, there is inconclusive data on the association between enhanced Lp(a) and retinal vein occlusion (RVO). We aimed to assess the role of Lp(a) in RVO.

Methods We performed a systematic review and meta-analysis of the studies addressing the role of Lp(a) in RVO. A systematic literature search was performed to identify all published papers reporting Lp(a) levels. Main outcome measures consisted of Lp(a) levels in patients with (cases) or without (controls) RVO.

Results We included 13 studies for a total of 1,040 cases and 16,648 controls. Lp(a) levels above normal limits were associated with RVO (OR 2.38, 95% CI 1.7–3.34) and patients with RVO had higher Lp(a) levels than controls (weighted mean difference: 13.4 mg/dL, 95% CI 8.2–18.6).

Conclusion Increased Lp(a) levels associate with RVO and should be included among diagnostic and prognostic indexes for this unusual-site vein thrombosis. Therapeutic interventions aimed to lower Lp(a) should be tested in RVO patients.
Asymmetric temperature application boosts water electrolysis for clean energy solutions
Authors: Bandari Anashe
Published: July 2021

Hydrogen production by water electrolysis is a promising pathway to sustainable energy and can be enhanced by applying a temperature gradient to an electrolyzer’s cathodes.
Probing the role of quantum confinement in radiative heat transfer
Authors: Lim Alane
Published: July 2021

Researchers model how the sizes of quantum dots can change their radiative-heat-transfer properties.
Optoelectronic properties of ultra-wide-bandgap semiconductor NaYO2: A first-principles study
Authors: Muhammad Nisar , Muzaffar M. U. , Li Hui-min , Ding Ze-jun
Published: July 2021

Ultra-wide-bandgap semiconductors have tremendous potential to advance electronic devices, as device performance improves nonlinearly with increasing gap. In this work we employ density-functional theory with the accurate screened-hybrid functional to evaluate the electronic and optical properties of NaYO2 in two different phases. The electronic structure calculation results show that both monoclinic and trigonal phases of NaYO2 exhibit direct bandgaps of 5.6 eV and 5.4 eV, respectively, offering a physically realistic material platform to derive the semiconductor industry beyond the well-established diamond and GaN semiconducting materials. Next, we investigate the optical properties and reveal that both phases of NaYO2 are transparent in the infrared and visible regions, thereby, these materials can be used as infrared window materials.
Photocatalytic N2 fixation by plasmonic Mo-doped
TiO2 semiconductor
Authors: Niu Xiao-you , Jiang Shen-long , Zhang Qun
Published: July 2021

Photocatalytic N2 fixation has attracted substantial attention in recent years, as it represents a green and sustainable development route toward efficiently converting N2 to NH3 for industrial applications. How to rationally design catalysts in this regard remains a challenge. Here we propose a strategy that uses plasmonic hot electrons in the highly doped TiO2 to activate the inert N2 molecules. The synthesized semiconductor catalyst Mo-doped TiO2 shows a NH3 production efficiency as high as 134 µmol·g−1·h−1 under ambient conditions, which is comparable to that achieved by the conventional plasmonic gold metal. By means of ultra-fast spectroscopy we reveal that the plasmonic hot electrons in the system are responsible for the activation of N2 molecules, enabling improvement the catalytic activity of TiO2. This work opens a new avenue toward semiconductor plasmon-based photocatalytic N2 fixation.
Investigating the potential of ZTO as an efficient and cheap SERS substrate for the identification of bacteria
Authors: Zohaib A. , Mateen A. , Mahmood K. , Ali A. , Amin N.
Published: July 2021

In recent years, Surface Enhanced Raman Spectroscopy (SERS) has been considered the best tool for the detection and identification of the least concentration of analytes and micro-organisms, such as bacteria. In this article, we have successfully obtained the SERS signal of Escherichia coli and Methylene Blue (MB) using Zinc Tin Oxide (ZTO) nanostructures as the SERS substrate. The ZTO SERS substrates were grown by a simple thermal evaporation method and annealed at various temperatures ranging from 600 to 800 °C before using them for bacteria identification. After the structural verification and morphological analysis using XRD and SEM, ZTO samples were used as SERS substrates for the detection of E. coli and MB by placing a drop of each solution on the ZTO. SERS data strongly identified the presence of MB and E. coli Raman peaks. Furthermore, it was found that intensity of signals (for both E. coli and MB) was found to be improved from SERS substrates that are pre-annealed at higher temperature. The intensity of Raman peaks for E. coli and MB was increased by 60 000 and 120 000 counts as the annealing temperature increased to 600 and 800 °C, respectively. An enhancement factor of 1.44 × 104 was observed for MB. Results obtained in this study indicate that zinc oxide based nanostructured SERS chips are potential candidates for rapid identification of many pathogens.