scholarly journals Pengaruh Waktu Milling Terhadap Sifat Desorpsi Material Penyimpan Hidrogen MgH2-Ni Melalui Teknik Mechanical Alloying

2021 ◽  
Vol 6 (3) ◽  
Author(s):  
Nirmala Sari ◽  
T. Andi Fadlly ◽  
Maulinda Maulinda
Keyword(s):  
Fossil Fuels ◽  
Milling Time ◽  
Catalytic Converter ◽  
Diffraction Peak ◽  
Ni Catalyst ◽  
X Ray Diffraction ◽  
Storage Media ◽  
Diffraction Angle ◽  
Gaseous Media ◽  
Solid Form

Hydrogen is a renewable energy source that can be used as a fuel and as an  alternative to fossil fuels. Solid  storage media in solid form are safer to use than liquid (-253 oC) or gaseous media (700 bar) media. To store hydrogen in a solid medium, it requires a metal able to  interact with hydrogen . Magnesium is one of the metals which  can form metal hybrids based on MgH2 which is capable of  absorbing hydrogen up to  (7.6wt%). However, the reaction kinetics for  magnesium are  very slow, it takes at least 60 minutes to absorb hydrogen and the operating temperature is always  very high (300 oC). Several attempts have been made to add the catalytic converter  and milling time. Hydrogen storage material based on MgH2 with a 10wt%Ni catalyst was  successfully synthesized using a mechanical alloy technique with time variations of 2 hours, 5 hours, and 10 hours. From the results of the X-ray diffraction schema  at a diffraction angle of 2θ=37.87o, it shows the presence of a MgH2 phase, Ni phase is at a diffraction angle of 61.85o, the diffraction peak also shows that there was a  widening of the diffraction peak with increasing milling time, this explains that there was  a reduction in the size of the crystal. When  calculating  with the Schereer method, the crystal size of the material reaches 10 nm. The results of the DSC test indicated  a decrease in temperature of 383 oC in 41 minutes with a milling time of 10 hours.

scholarly journals Effect of peroxide treatment on the structure and transparency of bacterial cellulose film

2018 ◽  
Vol 204 ◽  
pp. 05015 ◽  
Author(s):  
Heru Suryanto ◽  
Tito Arif Sutrisno ◽  
M. Muhajir ◽  
Neena Zakia ◽  
Uun Yanuhar
Keyword(s):  
Bacterial Cellulose ◽  
Diffraction Peak ◽  
Cellulose Film ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Pineapple Peel ◽  
Diffraction Angle ◽  
Structure Observation ◽  
Peel Extract

The cellulose extracts from plants are need of energy and have potential in damaging the environment so that an alternative cellulose source with more efficient results is by using bacteria to produce the cellulose fibers. This study aims to determine the effect of hydrogen peroxide (H2O2) treatment on the structure and transparency of biopolymer bacterial cellulose film (BCF). The method used is the making of BCF by utilizing pineapple peel extract and then cooking at 80°C for 120 min. with H2O2 concentration of 0%, 2.5%, 5%, and 7,5%. Drying is done in the electric oven and then observed the structure and morphology using X-ray diffraction and transparency test, respectively. The result of structure observation shows that the intensity of the highest diffraction peak lies at a diffraction angle of 22° achieved at 5% peroxide treatment with crystallinity and crystal index of 85.1% and 82.4%, respectively. Transparency testing shows that the higher the concentration of peroxide used, the better the transparency.

Mechanical properties of FeAlSi powders prepared by mechanical alloying from different initial feedstock materials

2019 ◽  
Vol 107 (2) ◽  
pp. 207 ◽  
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Veronika Kadlecová ◽  
Jiří Čapek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Alloying ◽  
Young’S Modulus ◽  
Milling Time ◽  
Young's Modulus ◽  
Element Model ◽  
X Ray Diffraction ◽  
X Ray ◽  
Powder Particles ◽  
Complete Homogenization

FeAl20Si20 (wt.%) powders prepared by mechanical alloying from different initial feedstock materials (Fe, Al, Si, FeAl27) were investigated in this study. Scanning electron microscopy, X-ray diffraction and nanoindentation techniques were used to analyze microstructure, phase composition and mechanical properties (hardness and Young’s modulus). Finite element model was developed to account for the decrease in measured values of mechanical properties of powder particles with increasing penetration depth caused by surrounding soft resin used for embedding powder particles. Progressive homogenization of the powders’ microstructure and an increase of hardness and Young’s modulus with milling time were observed and the time for complete homogenization was estimated.

Problems Associated with Kα Doublet in Residual Stress Measurements

1979 ◽  
Vol 23 ◽  
pp. 333-339
Author(s):  
S. K. Gupta ◽  
B. D. Cullity
Keyword(s):  
Residual Stress ◽  
Silicon Powder ◽  
Lattice Parameter ◽  
Diffraction Peak ◽  
Parameter Determination ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
The Difference ◽  
Similar Accuracy

Since the measurement of residual stress by X-ray diffraction techniques is dependent on the difference in angle of a diffraction peak maximum when the sample is examined consecutively with its surface at two different angles to the diffracting planes, it is important that these diffraction angles be obtained precisely, preferably with an accuracy of ± 0.01 deg. 2θ. Similar accuracy is desired in precise lattice parameter determination. In such measurements, it is imperative that the diffractometer be well-aligned. It is in the context of diffractometer alignment with the aid of a silicon powder standard free of residual stress that the diffraction peak analysis techniques described here have been developed, preparatory to residual stress determinations.

Development of Biodegradable Mg-Ti Alloy Synthesized Using Mechanical Alloying

2016 ◽  
Vol 1133 ◽  
pp. 75-79 ◽  
Author(s):  
Emee Marina Salleh ◽  
Sivakumar Ramakrishnan ◽  
Zuhailawati Hussain
Keyword(s):  
Mechanical Alloying ◽  
Milling Time ◽  
Milled Powder ◽  
Milling Process ◽  
Planetary Mill ◽  
Ti Alloy ◽  
X Ray Diffraction ◽  
Argon Flow ◽  
Diffraction Patterns ◽  
Ti Powder

The aim of this work was to study the effect of milling time on binary magnesium-titanium (Mg-Ti) alloy synthesized by mechanical alloying. A powder mixture of Mg and Ti with the composition of Mg-15wt%Ti was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 400 rpm for various milling time of 2, 5, 10, 15 and 30 hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400 MPa and sintered in a tube furnace at 500 °C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Ti solid solution when Mg-Ti powder was mechanically milled for 15 hours and further. Enhancements of Mg-Ti phase formation with a reduction in Mg crystallite size were observed with the increase in milling time. A prolonged milling time has increased the density and hardness of the sintered Mg-Ti alloy.

scholarly journals Mechanochemical Preparation of Slow Release Fertilizer Based on Glauconite–Urea Complexes

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 507 ◽  
Author(s):  
Maxim Rudmin ◽  
Elshan Abdullayev ◽  
Alexey Ruban ◽  
Ales Buyakov ◽  
Bulat Soktoev
Keyword(s):  
Milling Time ◽  
Slow Release ◽  
Mechanochemical Activation ◽  
Structural Characteristics ◽  
Fluorescence Analysis ◽  
Planetary Mill ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Slow Release Fertilizers

We investigated the mechanochemical synthesis of complex slow release fertilizers (SRF) derived from glauconite. We studied the effectiveness of the mechanical intercalation of urea into glauconite using planetary and ring mills. The potassium-nitric complex SRFs were synthesized via a mechanochemical method mixing glauconite with urea in a 3:1 ratio. The obtained composites were analyzed using X-ray diffraction analysis, scanning electron microscopy, X-ray fluorescence analysis, and infrared spectroscopy. The results show that as duration of mechanochemical activation increases, the mineralogical, chemical, and structural characteristics of composites change. Essential modifications associated with a decrease in absorbed urea and the formation of microcrystallites were observed when the planetary milling time increased from 5 to 10 min and the ring milling from 15 to 30 min. Complete intercalation of urea into glauconite was achieved by 20 min grinding in a planetary mill or 60 min in a ring mill. Urea intercalation in glauconite occurs much faster when using a planetary mill compared to a ring mill.

scholarly journals Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev
Keyword(s):  
Hydrogen Bonds ◽  
Dissolution Rate ◽  
Aqueous Medium ◽  
Acid Amide ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Reference Drug ◽  
X Ray ◽  
Time Period ◽  
Solid Form

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.

scholarly journals Novel solid forms of the analgesic drug ethenzamide

2014 ◽  
Vol 70 (a1) ◽  
pp. C995-C995
Author(s):  
Duane Choquesillo-Lazarte ◽  
Cristóbal Verdugo-Escamilla ◽  
Juan Manuel García-Ruiz
Keyword(s):  
Polycrystalline Material ◽  
X Ray Diffraction ◽  
Analgesic Drug ◽  
X Ray ◽  
Solution Methods ◽  
Additional Stability ◽  
Ft Ir ◽  
Model Drug ◽  
Solid Form ◽  
Ir And Raman

The interest in multicomponent solid forms has increased in the last years within the pharmaceutical industry and also the solid-state community due to the possibility of obtaining materials with new properties [1]. Crystallization strategies, supported by solvent- and solid-based techniques, have also received attention in the search and development of methodologies for the screening of multicomponent crystals. In this work, ethenzamide, an anti-inflammatory and analgesic drug, was selected as a model drug to develop cocrystals on the basis of the synthon types using a series of phenolic coformers. Ethenzamide cocrystals and cocrystal solvates have been reported recently [2,3]. Liquid Assisted Grinding (LAG) and solution methods were used as synthetic tools. Attempts to produce cocrystals by LAG and Reaction Crystallization led to the formation of polycrystalline material. The solids obtained were then characterized by powder X-ray diffraction (PXRD), FT-IR and Raman spectroscopy. Recrystallization by slow solvent evaporation was carried out when the above-referred techniques strongly suggest the formation of a new solid form. The structure of five new multicomponent solids has been determined by single crystal X-ray diffraction. Additional stability studies have been performed at controlled relative humidity conditions and followed by PXRD.

On the Mechanical Milling of the AlCuFe Icosahedral Phase with Water

2014 ◽  
Vol 793 ◽  
pp. 23-27
Author(s):  
C. Patiño-Carachure ◽  
J. Luis López-Miranda ◽  
F. de la Rosa ◽  
M. Abatal ◽  
R. Pérez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Milling Time ◽  
Induction Furnace ◽  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Cast Sample ◽  
X Ray ◽  
Transmission Electron ◽  
Icosahedral Quasicrystalline

In this investigation the Al64Cu24Fe12 alloy was melted in an induction furnace and solidified under normal casting conditions. The as-cast sample was subject to a heat treatment at 700 oC under argon atmosphere in order to obtain the icosahedral quasicrystalline phase in a monophase region. Subsequently, the icosahedral phase was milled for different times and water added conditions. The pre-alloyed and milled powders were characterized using scanning electron microscopy, X-Ray diffraction, and transmission electron microscopy. The experimental results showed that the icosahedral phase is sensitive to the reaction between water and aluminum of the quasicrystalline alloy to generate hydrogen. As the milling time and the amount of water are increased, the embrittlement reaction of the alloy is accentuated releasing more hydrogen.

Microstructure Evolution of a Fine Grain Al-50wt%Si Alloy Fabricated by High Energy Milling

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Method ◽  
X Ray ◽  
Fine Grain

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.

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