bluuebunny/crossref_metadata_2025 huggingface dataset:
Another Critical Look at Three-Phase Catalysis
Authors: Ni Xiong-Wei
Published: January 2021

Three-phase catalysis, for example, hydrogenation, is a special branch of chemical reactions involving a hydrogen reactant (gas) and a solvent (liquid) in the presence of a metal porous catalyst (solid) to produce a liquid product. Currently, many reactors are being used for three-phase catalysis from packed bed to slurry vessel; the uniqueness for this type of reaction in countless processes is the requirement of transferring gas into liquid, as yet there is not a unified system of quantifying and comparing reactor performances. This article reviews current methodologies in carrying out such heterogeneous catalysis in different reactors and focuses on how to enhance reactor performance from gas transfer perspectives. This article also suggests that the mass transfer rate over energy dissipation may represent a fairer method for comparison of reactor performance accounting for different types/designs of reactors and catalyst structures as well as operating conditions.
Cardiac MRI in this Era
Authors: Bhatia Mona , Kumar Parveen
Published: January 2021

Cardiac MRI (CMR) in this era is fast emerging as an invaluable tool in assessment of a large gamut of cardiac pathologies to not only ascertain the diagnosis but also assess severity, enable prognostication of disease process, guide management, and follow-up patients. CMR is today the gold standard for accurate and reproducible cardiac functional assessment, with excellent soft-tissue contrast, and ability to evaluate myocardial involvement even without contrast objectively via mapping techniques. CMR is thus fast emerging as the modality of choice and exponentially growing for cardiac assessment.
Endoscopic Treatment of Upper Gastrointestinal Bleeding Using Haemoseal Spray: A Retrospective, Observational Study from a Tertiary Center in North India
Authors: Bansal Rinkesh Kumar , Gupta Mahesh Kumar , Gupta Varun Kumar , Kaur Gursimran , Seth Avnish Kumar
Published: January 2021

Introduction United States Food and Drug Administration recently approved use of Hemospray for the management of gastrointestinal (GI) Bleeding. We report our experience with Haemoseal Spray (HS, Shaili Endoscopy) for the treatment of upper GI bleeding (UGIB).

Methods Records of patients who received HS for UGIB from January 2013 to June 2018 were studied retrospectively. Patients with UGIB from focal lesions refractory to conventional endotherapy or those with diffuse/multiple lesions not amenable to conventional endotherapy received 5cc HS spray. Primary end-point studied was clinical success, defined as control of bleeding over 24 hours. Secondary end-points evaluated included recurrence of bleeding within 7 days, in-hospital mortality, and complications secondary to HS.

Results Thirty-eight patients were treated with HS. The median age was 57 (range: 5–87) years with 27 males and 11 females. In 24 patients, HS was used as monotherapy, while it was combined with Injection/Clip/Argon Plasma Coagulation in 14. Etiology of bleeding was ulcers or erosions in 22, malignancy in 10, portal hypertensive gastropathy/gastric antral vascular ectasia in 4, and radiation gastropathy in 2. Clinical success was achieved in 32/38 (84%). All six nonresponders had coagulopathy related to chemotherapy/bone marrow transplant. Recurrent bleeding within 7 days was observed in four patients (gastric malignancy 2, radiation gastropathy 2). In-hospital mortality was seen in 8/38 (21%) of which 2(4.8%) were directly related to ongoing GI bleeding. There was no procedure-related complication.

Conclusion HS is an effective and safe tool in the endoscopic management of UGIB due to diffuse or multiple focal lesions or focal lesions refractory to conventional endotherapy.
Risk Factors in Young Female Patient with Polycystic Ovary Syndrome presenting with Acute Myocardial Infarction
Authors: Manade Vivek Vilas , Sridevi C
Published: January 2021

Polycystic ovary syndrome (PCOS) is known to cause weight gain, nonspecific inflammation, dyslipidemia, and coronary artery disease (CAD).

Oral contraceptives (OCs) also cause venous and arterial thromboembolism, cerebrovascular accidents (CVA), and acute coronary syndrome (ACS). Myocardial infarction (MI) is comparatively less common in patients taking newer generation OCs, particularly if risk factors for CAD are absent, but the risk for venous thromboembolism is still high.

Therefore, OCs should be considered in properly selected patients after weighing risks and benefits.
A portable laser system fills the terahertz gap
Authors: Hill Heather M.
Published: January 2021

With the right dimensions, a laser composed of a series of quantum wells emits hard-to-produce terahertz-frequency light without the usual need for cryogenic cooling.
A galactic fast radio burst finally reveals its origin
Authors: Berkowitz Rachel
Published: January 2021

Observations at multiple wavelengths provide compelling evidence that the first example of a fast radio burst detected in our galaxy came from a magnetized neutron star.
NSF launches funding schemes for medium-scale infrastructure
Authors: Feder Toni
Published: January 2021

Funding across scientific disciplines could catalyze US competitiveness.
S is for Science: The making of 3-2-1 Contact
Authors: Ockert Ingrid
Published: January 2021

The beloved after-school show of the 1980s was the product of a then revolutionary idea: asking children what they wanted in a television science series.
Overlooked mechanisms behind seismic damage
Authors: Uenishi Koji
Published: January 2021

Photographs of aboveground and underground structural failures after earthquakes uncover simple but not widely recognized physics.
Science and technology of the Casimir effect
Authors: Stange Alexander , Campbell David K. , Bishop David J.
Published: January 2021

Caused by simple fluctuations in space, the Casimir effect may validate theories of the cosmological constant and allow for measurements of ultrasmall magnetic fields.
Quasi-classical approximation for magnetic monopoles
Authors: Kordyukov Yu. A. , Taimanov I. A.
Published: January 2021

A quasi-classical approximation is constructed to describe the eigenvalues of the magnetic Laplacian on a compact Riemannian manifold in the case when the magnetic field is given by a non-exact 2-form. For this, the multidimensional WKB method in the form of the Maslov canonical operator is applied. In this case, the canonical operator takes values in sections of a non-trivial line bundle. The constructed approximation is demonstrated for the example of the Dirac magnetic monopole on the two-dimensional sphere.

Bibliography: 18 titles.
Iterated Laurent series over rings and the Contou-Carrère symbol
Authors: Gorchinskiy S. O. , Osipov D. V.
Published: January 2021

This article contains a survey of a new algebro-geometric approach for working with iterated algebraic loop groups associated with iterated Laurent series over arbitrary commutative rings and its applications to the study of the higher-dimensional Contou-Carrère symbol. In addition to the survey, the article also contains new results related to this symbol.

The higher-dimensional Contou-Carrère symbol arises naturally when one considers deformation of a flag of algebraic subvarieties of an algebraic variety. The non-triviality of the problem is due to the fact that, in the case

, for the group of invertible elements of the algebra of

-iterated Laurent series over a ring, no representation is known in the form of an ind-flat scheme over this ring. Therefore, essentially new algebro-geometric constructions, notions, and methods are required. As an application of the new methods used, a description of continuous homomorphisms between algebras of iterated Laurent series over a ring is given, and an invertibility criterion for such endomorphisms is found. It is shown that the higher- dimensional Contou-Carrère symbol, restricted to algebras over the field of rational numbers, is given by a natural explicit formula, and this symbol extends uniquely to all rings. An explicit formula is also given for the higher-dimensional Contou-Carrère symbol in the case of all rings. The connection with higher-dimensional class field theory is described.

As a new result, it is shown that the higher-dimensional Contou-Carrère symbol has a universal property. Namely, if one fixes a torsion-free ring and considers a flat group scheme over this ring such that any two points of the scheme are contained in an affine open subset, then after restricting to algebras over the fixed ring, all morphisms from the

-iterated algebraic loop group of the Milnor

-group of degree

to the above group scheme factor through the higher-dimensional Contou-Carrère symbol.

Bibliography: 67 titles.
The Dickman–Goncharov distribution
Authors: Molchanov S. A. , Panov V. A.
Published: January 2021

In the 1930s and 40s, one and the same delay differential equation appeared in papers by two mathematicians, Karl Dickman and Vasily Leonidovich Goncharov, who dealt with completely different problems. Dickman investigated the limit value of the number of natural numbers free of large prime factors, while Goncharov examined the asymptotics of the maximum cycle length in decompositions of random permutations. The equation obtained in these papers defines, under a certain initial condition, the density of a probability distribution now called the Dickman–Goncharov distribution (this term was first proposed by Vershik in 1986). Recently, a number of completely new applications of the Dickman–Goncharov distribution have appeared in mathematics (random walks on solvable groups, random graph theory, and so on) and also in biology (models of growth and evolution of unicellular populations), finance (theory of extreme phenomena in finance and insurance), physics (the model of random energy levels), and other fields. Despite the extensive scope of applications of this distribution and of more general but related models, all the mathematical aspects of this topic (for example, infinite divisibility and absolute continuity) are little known even to specialists in limit theorems. The present survey is intended to fill this gap. Both known and new results are given.

Bibliography: 62 titles.
On the reasons of spatial heterogeneity of the plasma chemical composition in ablation controlled discharges
Authors: Pashchina A S
Published: January 2021

The reasons of spatial heterogeneity of the plasma chemical composition in ablation controlled discharges are analyzed. The “locking” of atoms of chemical elements with a low ionization potential in the vicinity of a negatively charged wall due to the backflow of a significant fraction of ionized atoms onto the wall is considered as one of the effective mechanisms of plasma demixing and change of its chemical composition in comparison with the initial stoichiometry of the ablating substance. The proposed approach is consistent with the results of spectroscopic studies of a capillary discharge with an ablating wall (polymethylmethacrylate), during which a significant decrease in the carbon mole fraction with a simultaneous increase in the hydrogen mole fraction in the discharge core was revealed. According to the obtained results, the physical processes leading to the spatial separation of chemical elements occur exactly in the capillary spatial domain. The observed demixing of the plasma jet is manly a consequence of the processes that take place inside the capillary.
Microwave power dissipation in a microwave plasma filament
Authors: Brovkin V G , Vedenin P V , Mashek I Ch
Published: January 2021

A plasma channel (filament) formed in the electromagnetic field of microwave (MW) radiation shows promise for its application for off-body non-electrode modification of a gas flow (plasma aerodynamics) and in the plasma assisted combustion process. In these problems, the channel is considered as an object that converts the energy of electromagnetic radiation into gas heating. To estimate the total power absorbed in the plasma from above, simple formula is obtained. Numerical calculations in air in the pressure range P = 20-100 Torr based on a simplified 2D model using a fairly complete system of plasma-chemical reactions have shown that the total absorbed power is close to its estimate from above when the plasma channel develops.
Stationary layered vector fields and their divergence functions
Authors: Burakhanov B M
Published: January 2021

A scalar – vector approach to the study of general properties of scalar functions and vector fields is formulated. This approach is based on taking into account the general properties of their scalar and vector characteristics, as well as taking into account their invariants. The scalar – vector form of writing layered vector fields and an alternative version of this form of writing are discussed. New invariant characteristics of multidimensional scalar functions are introduced. For the name of these characteristics, it is proposed to use the terms - the Hamilton derivative and the Laplace derivative. A local volume approximation of a scalar function is introduced. It is essential that the nonlinear part of this approximation consists of two qualitatively different components. For the names of these components, it is proposed to use the terms-parabolic component and harmonic component. A factorized form of writing the divergence functions of a stationary layered vector field is obtained.
Simulation of the equilibrium flow of plasma with the addition of hydrocarbons in the scope of graphene synthesis using a DC plasma torch
Authors: Shavelkina M B , Ivanov P P , Bocharov A N
Published: January 2021

Graphene synthesis in the helium and argon plasma jets generated by 40 kW DC plasma torch under the pressure 350 Torr is investigated experimentally and by means of the modeling. Propane-butane mixture and methane are used as the carbon feedstock. Scanning microscopy shows that in the case of helium the structure with lateral size up to 500 nm is being synthesized. In the case of argon the morphology of graphene flakes varies from rumpled to rectified sheets with lateral size up to 2 μm. Temperature and velocity profiles are determined for the helium and argon jets using the numerical simulation. Addition of hydrocarbons into the inert plasma jets creates an environments differing in the composition and the charge concentration.
A blended learning with social media in computer-aided drafting courses
Authors: Nuryanto A , Pardjono  , Ngadiyono Y , Nugraha Y , Rofiq Z
Published: December 2020

This study aimed to determine the effect of the blended learning model with social media on learning outcomes of computer aided drafting (CAD). The method used in this quasi-experimental study was a non-equivalent control group design. The research sample consisted of two groups, namely the control and experimental groups. The experimental group is treated by applying the blended learning model with social media in CAD courses, while the control group uses conventional learning methods. Data collection techniques used were observation, questionnaires, and documentation. The results of this study indicate that the blended learning model in CAD learning can be done face-to-face in the form of lectures, questions and answers, demonstrations and assignments, and online in the form of uploading teaching materials in the form of materials, sample videos, discussion forums, assignments, and assessment. Learning outcomes using the blended learning method with social media increased by 29.2%, and the average value was higher than conventional learning. The blended learning model with social media significantly affects CAD learning outcomes (t=7,06 and Sig. 0,000 <0,05).
Multiple intelligences in welding practice lectures
Authors: Wibowo Y E , Djatmiko R D , Marwanto A
Published: December 2020

This study aims to determine the multiple intelligences possessed by students, the level of multiple intelligences of students and to measure the relationship between multiple intelligences with the learning outcomes of welding practice lectures in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The method used is a survey. The research was carried out in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The research was conducted from April to July 2020 during the COVID-19 pandemic and was conducted online. The research subjects were students of the 2018 Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The independent variable is the student’s multiple intelligences and the dependent variable is the learning result of welding practice lectures. The result of this research shows that the highest multiple intelligences is interpersonal intelligence (78.91%) and the lowest multiple intelligences is naturalist intelligence (63.48%). Other multiple intelligences include verbal-linguistic intelligence (72.01%), logic-mathematics (72.59%), visual-spatial (71.29%), kinesthetic (72.02%), musical (68.36%), intrapersonal (73.93%) and existential (65.43%). The highest multiple intelligences that became dominant from the students of the S1 Mechanical Engineering Study Program, Faculty of Engineering, Yogyakarta State University, were interpersonal intelligence with 20 students (25.97%), intrapersonal with 17 students (22.08%), visual-spatial with 8 students (10.39%), logic-mathematics with 7 students (9.09%), musical with 7 students (9.09%), verbal-linguistics with 6 students (7.79%), kinesthetic with 5 students (6.49%), existential with 5 students (6.49%) and naturalists with 2 students (2.60%). The value (Sig.) Is 0.028 <0.05 and the t_count value is 2.246> 1.99897, it can be concluded that there is a contribution of multiple intelligences of students of the S1 Mechanical Engineering Study Program, Faculty of Engineering, Yogyakarta State University (X) to the learning outcomes of welding practice in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University (Y).
Aerodynamic Performance Analysis of Open-Wheel Vehicle: Investigation of Wings Installation Under Different Speeds
Authors: Yudianto A , Susanto H A , Suyanto A , Adiyasa I W , Yudantoko A , Fauzi N A
Published: December 2020

An open-wheel vehicle with manual hybrid engine control with formula-like body shape was developed for a learning media at a vocational high school. This study aims to analyze the airflow of over the vehicle body as the effect of wing installation under various vehicle speeds. The investigations are to observe and evaluate the drag coefficient, drag force, lift coefficient, downforce, pressure distribution, streamlines, and velocity vector condition by emphasizing on the results from Computational Fluid Dynamics (CFD) simulation. The study found that installing the front and rear wings contribute to the decrement of drag coefficient 0.07 points and keeping the drag force relatively constant since the projection area changed. The benefit of having wings installed significantly increases the downforce by 334 N, which is 5.51 times higher than without wings in the speed of 150 km/h. However, the engine cover gives a significant obstacle to airflow, reducing the functionality of the rear wing. As such, the presence of the rear wing does not have a substantial effect on reducing the wake region.
Thermal Properties of Nano Tungsten - Ethylene Vinyl Acetate (EVA) Composites
Authors: Sobhy M. , Saleh Ahmed , Eid Alaa I , Khairaldien W. M.
Published: January 2021

Ethylene vinyl acetate (EVA) with different percentage of nano tungsten powder (0wt%, 30/wt %, 45/wt %, 60/wt%, and 70/wt %) composites (EVA/W nano-composites) were prepared by melt blending in a twin-screw brabender. The structural, morphological, thermal and mechanical properties of the prepared nano-composites were investigated using powder X-ray diffraction (PXRD), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). It was found that the EVA composites show a higher thermal stability at high levels of tungsten loading.
Superior spectral performance of decoy flares compositions via inclusion of graphite as a black body emitter
Authors: Elbasuney Sherif , Elmotaz Amr A. , Sadek M. A. , Yehia M. , Tantawy Hesham
Published: January 2021

Graphite particles can offer high interfacial surface area as well as high emissivity as black body; therefore it can find wide applications in advanced decoy flares. In the current study, graphite particles of 100 µm size, were employed with different reactive metal fuels including Mg, Al, and Mg-Al alloy. Different formulations based on graphite ratio up to 8 wt % were developed via granulation with subsequent pressing. Thermal signature was measured using IR spectrometer (1-6 µm) Arc-Optics. Composite flare based on Mg-Al fuel, and graphite demonstrated superior spectral intensity; this formulation offered an increase in average intensity by 83 % to reference MTV flare. In the mean time, composite flare based on Al and graphite offered the highest relative intensity value θ of 0.6. Graphite, as an allotrope of carbon, can act as an excellent source of carbonaceous materials; that can strengthen incandescence emission. Furthermore Mg-Al reactive metal alloy can offer novel synergism as Mg could vaporize at 1000 °C offering efficient combustion process. It can be concluded that tailored flare with customized thermal signature can be developed.
Ionic Liquids based on Different Chain Fatty Acids as Green Corrosion Inhibitors for C-steel in Produced Oilfield Water
Authors: Atef Y , Ghanem A
Published: January 2021

The work presents the investigation of fatty acids based ionic liquid as green corrosion inhibitors for C-steel in produced oilfield water. Different-chain length fatty acids C6, C12 and C18-1 are mixed with di-ethanol amine (DEA) to synthesize some ionic liquids and evaluated the corrosion rates on C-steel surface using weight loss method and potential time measurements. The prepared ionic solutions were shown to be effective in reducing the corrosion rates as sustainable corrosion inhibitors. The polar unit is indicated as the reaction center for the adsorption process. Generally, the inhibition efficiency increases with increase the inhibitor concentration.
Thermal and potentiometric studies for complexes of Zr and Hf with some barbituric acid derivatives
Authors: Masoud M S , Hassan A S , Desouky N M , kamel H M , El-Kholany A S
Published: January 2021

The complexes of Barbital (Bal), Thiobarbituric acid thione (TBA), Thiobarbituric acid thiol (2-TBA), 2-Thiouracil (TU) with Zr (IV) and Hf (IV) were prepared. The structures and mode of bonding were characterized by elemental analysis, IR and electronic spectroscopy. Thermal analyses of the prepared complexes were done by DTA, TG, DSC techniques. The thermodynamic parameters were evaluated. The change of entropy values, AS#, for all the complexes lie within the range -0.267,-0.299 KjK-1 mol-1. The thermal processes proceed in complicated mechanisms with ordered transition states. In general, the complexes dissociated after losing small molecules such as H2O, Cl2 and CO. The decomposition is usually ended by the metal moiety. The DSC technique explained the effect of temperature on physical properties of some complexes. The glass transition phase doesn`t appear in all the complexes, while the crystallization temperature (Tc) was 780C-322.120C. Potentiometric titration studies calculated the dissociation constants of the ligands, the stability constants of the complexes and the distribution of species at different pH values.
Radiological and environmental studies on the metamorphosed sandstones at Wadi Sikait area, southeastern desert, Egypt
Authors: El-Farrash A. H. , El-Feky M. G. , Hassan S. F. , Abu Elatta Soliman A. , Refaat M.
Published: January 2021

Wadi Sikait area lies in the southern part of the Eastern Desert of Egypt along the upper stream of Wadi.Sikait. The exposed rock units in Wadi Sikait area are ophiolitic mélange roccks, metamorphosed sandstones, and porphyritic granites, lamprophyre dykes, in addition to fluorite and quartz veins. The activity concentrations of various radionuclides are measured by NaI-Tl activated detector and the radioactive mineralization were determined by Alpha track technique using CR-39 films. Radiometric investigations indicate that 238U activity concentrations range between 37.2 and 520.4 with average 148.8 BqKg−1, 232Th activity concentrations vary between 8.08 and 366.99 BqKg−1 with 76.75 BqKg−1 as an average. The studied metamorphosed sandstones have higher values relative the world concentration levels. High uranium content of the metamorphosed sandstone is attributed to presence radioactive minerals like uranophane and autonite, in addition to accessory minerals like allanite, zircon and monazite. Other U-bearing minerals are also recorded as biotite, muscovite, iron oxides and clays. Absorbed Dose Rate (D), annual effective dose equivalent (AEDE), radium equivalent activity (Raeq), external (Hex) and internal (Hin) hazard index, in addition to activity gamma index (Iγ) caused by gamma emitting natural radionuclide are determined from the obtained values of 226Ra, 232Th and 40K. Fairly, many of the studied metamorphosed sandstone do not satisfy the universal standards.
Sub-channel thermal-hydraulic analysis for VVER- 1000 generation III PWR
Authors: Almessallmy Alsherief M , Shaat Mohamed K , Hassanien Saeed A
Published: January 2021

The sub-channel thermal-hydraulic analysis of a nuclear reactor is essential for assessing of its safety aspects. In this paper, the VVER-1000 has been selected as an example of the third generation reactors since it meets most of the international safety standards and because it has been taken as a base for designing the VVER-1200 which is belonging to the III+ generation. A steady state mathematical model has been proposed and solved to validate and assure that the hottest channel temperature limits are satisfied. The various temperature distributions, the critical heat flux and the departure from nucleate boiling ratio (DNBR) for the hottest channel were evaluated. Also, a transient state model has also been presented and solved using the finite difference method with the aid of MATLAB algorithm. An exponential loss of flow rate of the reactor core coolant was triggered from the steady state conditions. We assumed that the neutron flux and the generated power were unchanged during the postulated event. The average core coolant flow time constant was treated as a single parameter expressing the rapidity of the event. A value of 250 seconds time constant was assumed for slow transient, whereas 10 seconds was assumed for fast one. The reactor core was assumed to be protected through the reactor control system and mitigated according to the regular emergency operating procedures. The time dependent temperature distributions were calculated for the cladding of the hottest coolant channel. For each value of the temperature, the response time required for reaching unsafe conditions was evaluated, discussed and presented.
Effect of the formation parameters on the thermal properties of La2Zr2O7
Authors: Abdelkareem Ahmed
Published: January 2021

Lanthanum zirconates has been suggested as a thermal barrier coating for many high temperature applications. This study is focusing on the effect of different preparation parameters on the thermal conductivity of La2Zr2O7. We have used solid state reaction to form the zirconates powder was very good homogeneity. We have studied the effect of the intimal ZrO2/La2O3 ratio, and found the 50% to be the optimum. The effect of the sintering temperature has also been studied and 1100°c was chosen as the optimum sintering temperature. The sintering time was also studied, where 3 hours was proved to be enough to obtain a homogeneous single phase compound with affordable method.
Preparation of magnetic nanoparticle biocomposites using rice husk and sugarcane bagasse fibers as the matrix
Authors: Dewi Y S , Wijayanti H , Lestari R A , Nata I F
Published: January 2021

Fiber is one of the important components to construct a matrix structure. Biomass is a potential material as a fiber resource for matrix. Rice husk and sugarcane bagasse consist of 36.6 % and 60% cellulose, respectively. This current research focused on evaluating the production of amine functionalized magnetic nanoparticle biocomposites produced by mixture of rice husk (RH) and sugarcane bagasse (SB) fibers. First, RH and SB fibers were dried and crushed close to 60 mesh for each, followed by a delignification at 80 °C for 2 h in 1% w/v of NaOH. Through by one-step solvothermal process, it was done by adding delignified ratio of RH and SB fibers (1:1; 1:2; 1:3; 1:4) to mixture of ethylene glycol, FeCl3.6H2O, and 1.6-hexanediamine at 200 °C for 6 h. The magnetic nanoparticles appeared on the fibers surface which contained 97.97% Fe. The magnetite was formed proved by the specific peaks at 36°, 43°, and 57° by X-Ray Diffraction.(XRD). The Fourier Transformed Infrared (FT-IR) identified N–H bending vibration and Fe-O in the biocomposites at 1640 cm−1 and 582 cm−1, respectively. The restructure of matrix, iron, and amine groups on the biocomposites surface can affect the adsorption capacity of various waste water treatments.
Modified physical properties of kaolin by intercalation and exfoliation method
Authors: Prabawa I D G P , Lestari R Y , Hamdi S , Sunardi
Published: January 2021

The intercalation method and combination of the intercalation-exfoliation method were applied to modify kaolin. The intercalation process was prepared using urea 60 % as an intercalated agent and the exfoliation process was carried out by ultrasonication. The samples were characterized by X-ray diffraction (XRD), X-Ray Fluorescence (XRF), scanning electron microscope (SEM), and particle size analysis (PSA). Experimental results showed that the physical properties of kaolin significantly improved after modification. This was indicated by the increasing interlayer spacing of modified kaolin, which was confirmed by SEM and XRD analysis. Based on XRF analysis, the loss on ignition value increased after kaolin modification, suggesting that the urea had successfully intercalated into the kaolin interlayer. Kaolin modification with intercalation method produced the most significant physical properties improvement, which increased surface area from 2508.607 to 27297.990 cm2/g and decreased particle size average from 41.535 to 13.836 µm and had surface area close to illite clay.
The Effect of TiO2 additives on the antibacterial properties (Escherichia
coli and Staphylococcus aureus) of glaze on ceramic tiles
Authors: Maryani E , Nurjanah N S , Hadisantoso E P , Wijayanti R B
Published: January 2021

Antibacterial glaze coating on ceramic tiles with TiO2 additive was conducted to meet environmental sanitation needs. Raw materials used were commercial glaze 107, silica sand, and 0-5% weight of TiO2 powder. The glaze mixture was added with distilled water and ground in an alumina pot mill for 24 hours. The glaze mass was coated on the green body, dried and then burned at a temperature of 1200°C with a holding time of 2 hours. On the glazed tiles, there was a layer of glass with an amorphous structure based on the X-Ray Diffraction results. The addition of TiO2 caused an increase in opacity but decreased visual white color. Glaze antibacterial properties were tested for Escherichia coli and Staphylococcus aureus bacteria using the disc diffusion method. The addition of TiO2 caused resistance to two types of bacteria, both for raw and burned glaze. The TiO2 inhibition was similar to amoxicillin as a positive control. It had a greater resistance to S. aureus than E. coli bacteria. The largest inhibitory diameter value of 7.7 mm obtained by 5% TiO2 glaze powder burnt against S. aureus bacteria. Glaze coating on the tile caused a greater inhibition diameter of 24.75 mm for 1% TiO2 burned glazed.
Sodium alginate-chitosan nanocomposite as a novel carrier agent for cinnamaldehyde: characterisation and release studies
Authors: Wong S T S , Kamari A , Jumadi J
Published: January 2021

The ultimate aim of this study was to synthesize sodium alginate-chitosan (SA-Chi) nanocomposites for the first time in larvicide formulation. The physicochemical properties of the nanocomposites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The feasibility of SA-Chi nanocomposites to encapsulate and load cinnamaldehyde, a common essential oil used against mosquitoes larvae, was evaluated in terms of encapsulation efficiency (EE) and loading capacity (LC). There were three mass ratios of SA-Chi nanocomposites to cinnamaldehyde, namely 50:1,100:1 and 125:1. Research findings suggested that the mass ratio of nanocomposites to drugs, significantly affected the functional groups availability, crystallinity property and thermal stability of nanocomposites. The EE and LC of cinnamaldehyde-loaded nanocomposites at 125:1 were determined as 91.33% and 75.25%, respectively. The release profile data of the nanocomposite were well fitted to Korsmeyer-Peppas kinetic model with correlation coefficient (R2) of 0.9231 for the mass ratio of cinnamaldehyde-loaded nanocomposites at 125:1. The cinnamaldehyde-loaded nanocomposites at 125:1 had prolonged the drug release for 24 hours. Overall, results from this study highlight the potential of SA-Chi nanocomposites as novel nanocarriers to deliver cinnamaldehyde in mosquito larvicide formulations.
Co (II) desorption from silica gel and mercapto-silica hybrid
Authors: Mujiyanti D R , Irawati U , Akhir N M
Published: January 2021

This paper aims to study Co (II) desorption from silica gel (SG) and mercapto-silica hybrids (MSH) by many desorbing agents. SG was prepared from sodium silicate from rice husk ash, whereas MSH was SG modified by organic compounds 3-(trimethoxysilyl) - 1-propanthiol. The characterization of adsorbents covered by an X-ray diffractometer and an FTIR spectrophotometer. Optimization of contact time for adsorption of Co (II) on HMS and the procedure of desorption agents (H2O, HCl, Na2EDTA.2H2O) at different contact times and concentrations via batch methods. The results showed that the optimum contact time for Co (II) adsorption on MSH was 120 minutes. The most appropriate desorbing agents for SG and MSH were HCl and Na2EDTA.2H2O. The optimum contact times for Co (II) desorption on SG and MSH were 90 and 120 minutes, respectively. The optimum concentration of HCl for desorbing Co (II) on SG was 0.025 M. While, the optimum concentration of Na2EDTA.2H2O for Co (II) desorption on MSH was 0.1 M.
Application of cocoa pod husk (Theobroma cocoa Spp) for natural dyes powder on silk batik cloth
Authors: Masiswo  , Haerudin A , Isnaini  , Lestari D W , Mandegani G B , Satria Y , Arta T K , Atika V
Published: January 2021

The chocolate industry (Theobroma cocoa) in Indonesia reaches a total production of approximately 500 thousand tons. It has the potential to be used as natural dyes for the batik industry. This study aims to utilize cocoa pod husk powder on silk batik. The method was carried out by varying the concentration of maltodextrin as filler powder by 5%, 10%, and 15%, the final mordant variations (alum, calcium oxide, and ferrous sulfate) on silk cloth, and the natural dye solution of cocoa pod husk. The natural dye solution for cocoa pod skin was tested for phytochemistry to see the tannin and flavonoid content, the results of dyeing application on silk batik cloth were tested for the quality of its color resistance to washing, color strength, and color differences. The colorfastness test result showed a good category with an average value of 4-5 and the result of the color strength test showed that the best maltodextrin was 5% with a natural dye concentration of 15g / L. The results of alum mordant, calcium oxide, and ferrous sulfate (tunjung) produced colors that led to light and dark with a predominance of brown, red, and blackish brown.
The ulitization of durian wood (Durio zibethinus) and corn cob (Zea mays) biochar on corn yields in acid sulphate soil
Authors: Setiawati E , Yusuf W A
Published: January 2021

Biochar addition can be used to overcome the problem of acid sulphate soil. This study was aimed to analyze the effect of biochar dose on plant height and corn yield in acid sulphate soils. Durian wood waste and corn cob biochar used in this study was pyrolyzed for 2 hours at 550 °C temperature and grinded until around 0.4-1.0 mm. The experiment was conducted in a screen house at the Indonesian Swampland Agriculture Research Institute. The experimental design used was a Completely Randomized Design consisting of six doses of biochar treatment of with 3 replications. The total of 18 experimental pots was obtained with the following details: B1 0 t/ha, B2 4 t/ha, B3 8 t/ha, B4 12 t/ha, B5 16 t/ha and B6 20 t ha. Biochar treatment significantly affect plant height age of 2nd, 4th, 6th, 8th, 10th and 12th weeks. The longer the age, the higher the corn plant height. The corn cob length, corn cob diameter, dry weight of seed, and the dry water content significantly different in all treatments. The biochar dose significantly affected the corn yields. The best treatment of biochar in acid sulphate soil was obtained in 12 t ha-1.
The utilization of activated carbon from cassava stems on the glucose and cholesterol adsorption
Authors: Mutiaradini S , Efiyanti L , Pari G , Soebrata B M
Published: January 2021

The utilization of cassava stems from waste as an activated carbon raw material for glucose and cholesterol adsorption has been investigated. This study aims to know about the application of activated carbon from cassava stems waste on glucose and cholesterol adsorption with the variations of adsorbent weight and reaction contact time. The process of carbon acquiring was done by the pyrolysis method at a temperature of 400°C for 4 hours. After that, the process was followed by the chemical activation process using KOH as an activator. The carbon obtained was washed in KOH solution with a ratio of 1:2 w/w for ±24 hours, then filtered, washed again, and heated with an activation reactor at a temperature of 800°C. The application of activated carbon was carried out on glucose and cholesterol adsorption to produce glucose and cholesterol adsorption of 3.33 mg/g and 6.84 mg/g respectively. The optimum contact time for glucose and cholesterol adsorption was 45 minutes with the use of 0.1 g adsorbent.
Nixtamalization application to shelf life of corn flour
Authors: Musita N
Published: January 2021

Corn is very potential to be developed as a source of flour and starch for the raw material of the food industry and others, but the functional properties of corn flour are less favored in its application to processed products because the lack of texture and the durability of flour is lack due to the fat content of corn. One way to improve it is by the process of nixtamalization. The purpose of this study was to evaluate the effect of nixtamalization on aflatoxin content and shelf life of corn flour. The treatments used were long immersion in water or without nixtamalization (W1), and soaking time in a solution of Ca(OH)2 consisting of 8 hours (W2), 16 hours (W3), 24 hours (W4), and 32 hours (W5), washed. and ground to form a smooth dough (mass). The experiments were arranged with a single treatment, with variation in the duration of immersion in lime solution (control, 8, 16, 24, and 32 hours). This treatment was repeated 3 times. The results showed a decrease in level of type B1 aflatoxin with increasing immersion time, namely 85 µg/kg (0 hours), 69 µg/kg (8 hours), 62 µg/kg (16 hours), 55 µg/kg (24 hours), and 52 µg/kg (32 hours). The shelf life of corn flour through observation of critical moisture content is 426 days (0 hours), 430 days (8 hours), 489 days (16 hours), 408 days ( 24) hours, and 462 days (32 hours).
Structural characterization and antioxidant activity of liquid sugar from Alabio potato using enzymatic hydrolysis processes
Authors: Angkasawati VS , Kamaliyah I , Putra MD , Nata IF , Irawan C
Published: January 2021

This study aims to produce functional antioxidant liquid sugar from Alabio potato (Dioscorea alata L.). This study focuses on the effect of the percentage of Alabio potato starch in the liquefaction process, the concentration of β-glucosidase enzymes, and the determination of the optimum concentration of cinnamon extract in its activity as an antioxidant liquid sugar. The amount of glucose/reduced sugar was analyzed by the DNS method. The optimum percentage of glucose was obtained from the liquefaction results with 10% starch and saccharification with a concentration of β-glucosidase enzyme of 1.2 mL/kg of starch with a liquid sugar concentration of 59.16 mg/mL. FTIR analysis showed that antioxidant liquid sugar had hydroxyl functional groups of C-O, C-H and O-H at wavelengths of 1560.11 cm-1, 1720.22 cm-1, and 3520 cm-1. Antioxidant liquid sugar activity showed the optimum performance at cinnamon extract concentration was 5 grams. DPPH free radicals of 56.72% were consumed for 5 minutes and reached 57.60% for 10 minutes. Liquid glucose produced could be a substitute for glucose sources with antioxidant content from the cinnamon extract.
The sustainability of the iron industry based on local wisdom in the Barito watershed
Authors: Hartatik  , Soffian H O , Sunarningsih  , Susanto N N , Sulistiyo R B
Published: January 2021

Iron has been important in human civilization since the abandonment of stone tools. The traditional technology of iron ore smelting in Indonesia has been known for hundreds of years, but research on the local traditional iron industry is still very minimal. This study aims to explain the iron industry in the southeast Kalimantan before modern times until the present using ethnohistory and experimental archaeological approaches. The research conducted in 2017-2019 at the upstream of Barito watershed, North Barito Regency, Central Kalimantan, has found 19 sites with the findings were furnaces, air pipes, iron ore fragments, charcoal, and slag. The traditional iron-making began with the process of mining, followed by iron ore smelting and forging. The archaeological experiments by smelting furnace produced the raw iron by a percentage of 40-60% from ore. The experiments produced the ingots with Fe content of about 80% (XRF analysis) and showed good ore quality. However, since the early 20th century the iron-making industry has been abandoned because of the arrivals of cheaper iron from China. Recently, the remaining iron industry consists of only the blacksmiths who produce agricultural equipment from scrap iron, some only gild to sharpen machetes and ‘mandau’.
Improving the stability of catechin from gambier in β-cyclodextrin and nanoemulsion-based inclusion complexes
Authors: Yeni G , Syamsu K , Suparno O , Mardliyati E , Silfia  , Syafri E , Nazir N , Fudholi A
Published: January 2021

The application of catechin is limited due to low stability, however nanoencapsulation technology can improve catechin stability. This study aimed to determine the effect of the types and concentrations surfactants in the catechin encapsulation process on β-CD. Concentrations of surfactants used were Poloxamer 188 (NKP, 0.5%-1.5%), Tween 80 (NKT, 2,5% and 3%) without surfactants was used to control (NKB). The catechin nanoemulsion complex formed was inclusion them into β-CD (ratio 1:1), and dried by spray drying. The stability test showed a sample of NKP 1% was more stable with the lower turbidity and viscosity values, namely 175 NTU and 0.93 cP, NKT 2.5% (118 NTU and 0.94 cP), NKB (461 NTU and 4.0 cP). The size of the sample particle decreased according to an increase in the surfactant concentration, where the NKP 1% (37 nm) produced smaller particles, the appearance of clear and yellowish suspension. NKP 1% had the highest EE value, followed by that NKT 2.5%, and NKB, i.e. 91.9%, 89.5%, 77.4%, respectively. Sample NKP 1% had a morphology shape with compact structures and the highest crystallinity degree (92.4%). This research showed the use of surfactants could improve the stability of catechins compared to that without surfactants.
The initial study on the synthesis and characterization of NaZr2(PO4)3 from West-Borneo ZrSiO4
Authors: Septawendar R , Arifiadi F , Taufik D , Wahyudi K , Suhanda
Published: January 2021

Due to its excellent electrical properties, NaZr2(PO4)3-type sodium superionic conductor is a preferred material for the application in energy storages such as sodium ion batteries. Here, the initial study on the synthesis of NaZr2(PO4)3 from Indonesian West-Borneo Zircon is reported. The synthesis was conducted using our facile technique of a sodium carbonate sintering method. Zircon and the carbonate were mixed at a stoichiometry ratio approach and sintered at 1000°C. The sintered product was leached with water to dissolve the silica compound and continued by filtration and washing to obtain the zirconia compound, followed with phosphoric acid blending until pH 5 to get a precipitate. It was calcined at 800°C. The mineralogy, chemical composition, and particle sizes of the calcined product were evaluated. The synthesized sodium superionic conductor consists of NaZr2(PO4)3 with a trigonal structure as the main phase and SiO2 as the minor phase. The SiO2 content is accounting 6% of the total. Particle size analysis measured 90% of the total particle size distribution of the calcined NZP is less than 18.283 µm in sizes, while the average particle size is about 5.633 µm. The present study unveils a facile technique in the synthesis of NaZr2(PO4)3 from Indonesian West-Borneo ZrSiO4.
Optimisation and characterisation studies of biodiesel production from black soldier fly larvae fed by soya residue
Authors: Kamari A , Ishak S , Hussin M I A M , Wong S T S , Jumadi J , Yahaya N M
Published: January 2021

In this study, a two-step transesterification process was applied to convert crude BSF larval oil into biodiesel. The effects of methanol:oil (molar ratio), catalyst amount (weight %), reaction time (minutes) and temperature (°C) on biodiesel production were investigated. Central Composite Design (CCD) of Response Surface Methodology (RSM) was used to optimise experimental data obtained from these four variables. The prediction of biodiesel yield was made by employing a quadratic model, whereby the R2 values were greater than 0.99. Based on optimisation studies, a combination of an application of petroleum ether and reaction time of 6 hours was the best to extract crude larval oil with 47% of lipid yield. Meanwhile, methanol:oil molar ratio of 12:1, catalyst (NaOH) concentration of 1.0 weight %, a reaction time of 32 minutes and temperature of 60°C were required to obtain biodiesel with 96% of production yield from BSF crude larval oil. Both BSF crude larval oil and biodiesel were characterised using several analytical instruments such as Fourier Transform Infrared (FTIR) spectrometer and Gas Chromatography – Flame Ionisation Detector (GC-FID). Overall, findings from this study highlight the potential to produce eco-friendly biodiesel from BSF larvae reared on soya residue.