Urea Powder Research Articles

Effect of Zeolite to Clay Ratios on the Formation of Zeolite-Clay-White Cement Composite Cylinder as an Encapsulant of Urea Fertilizer

Zeolite-clay-white cement composite cylinders have been prepared for the encapsulant of urea powder. The composites were made by mixing natural zeolite, clay, and white cement at certain ratios using a home-made cylinder mold. All processes were done at room temperature. The composites were characterized using infrared (IR) spectroscopy and X-ray diffraction (XRD). Mechanical properties of the composites were evaluated through compressive strength and water absorption capacity test. The infrared spectra showed functional groups at 3448 and 1636 cm–1, indicating the presence of calcium silicate hydrate as the main product of hydration and pozzolanic reactions in the composite. The XRD patterns also confirmed the presence of calcium silicate hydrate as tobermorite (d = 3.34, 3.22, 2.75, and 2.28 Å) and jennite (d = 4.50 Å). Increasing the natural zeolite ratio in the composite decreased the compressive strength but increased water absorption capacity. The composite cylinders are envisaged as the encapsulant of urea powder and act as a slow-release fertilizer.

Optimised curved hoppers with maximum mass discharge rate – an experimental study

This research experimentally studied the granular flow in the optimised curved hoppers obtained from our recently published optimisation method. A series of optimised hoppers were manufactured by CNC machining and an experimental apparatus was constructed to measure the MDR of various granular materials in the hoppers. Our experiment confirmed that the MDR of the optimised curved hoppers has increased more than 100% from that of those conventional conical hoppers. The critical prefill level for reaching a steady discharge rate in the curved hoppers is related to a fixed ratio to the diameter of the hopper orifice, which increases with the initial half-angle of a curved hopper. Three types of granular materials, i.e. rice, urea powders and sands, differing in shape, density and surface roughness, all gained improved MDR in the same curved hoppers, which demonstrates the flexibility of the optimised curved hoppers to maximize MDR for different granular materials.

An electrochemical evaluation of nitrogen-doped carbons as anodes for lithium ion batteries

New anode materials beyond graphite are needed to improve the performance of lithium ion batteries (LIBs). Chemical doping with nitrogen has emerged as a simple strategy for enhancing lithium storage in carbon-based anodes. While specific capacity and rate capability are improved by doping, little is known about other key electrochemical properties relevant to practical applications. This work presents a systematic evaluation of electrochemical characteristics of nitrogen-doped carbons derived from a biomass source and urea powder as anodes in LIB half- and full-cells. Results show that doped carbons suffer from a continuous loss in capacity upon cycling that is more severe for higher nitrogen contents. Nitrogen negatively impacts the voltage and energy efficiencies at low charge/discharge current densities. However, as the charge/discharge rate increases, the voltage and energy efficiencies of the doped carbons outperform the non-doped ones. We provide insights towards a fundamental understanding of the requirements needed for practical applications and reveal drawbacks to be overcome by novel doped carbon-based anode materials in LIB applications. With this work, we also want to encourage other researchers to evaluate electrochemical characteristics besides capacity and cycling stability which are mandatory to assess the practicality of novel materials.

Stability Study of 0.5 g/mL Urea Oral Solution in InOrpha®

Abstract Background Urea is recommended in the 2nd line treatment in moderate to severe hyponatraemia induced by syndrome of inappropriate antidiuretic hormone secretion (SIADH), when water restriction is insufficient. A posology of 0.25–0.5 g/kg daily is suggested. A usual but inadequate urea oral preparation, i. e. 10 g urea powder dissolved in 100 mL water before use, was classically compounded. Therefore the pharmacy has developed a 0.5 g/mL urea oral liquid solution in InOrpha® with better organoleptic characteristics to improve treatment adherence and reduce the preparation time. The aim of this study was to determine physicochemical and microbiological stability of the urea oral liquid solution in order to establish a shelf life of the preparation. Methods The 0.5 g/mL urea solution was compounded using urea powder in a commercial suspending vehicle: Inorpha®. A validated high-performance liquid chromatographic (HPLC) method with UV detection was performed for the assay of urea. The preparations were packaged in amber glass bottles and stored at fridge (5 °C±3 °C) or at room temperature (24 °C±1 °C). The physicochemical (urea concentration, macroscopic change) and microbiological stability of the preparation was tested over 90 days. Urea concentration measurement at day 0 was considered as the reference value (100 % stability) and urea concentration in subsequent samples greater than 90 % were definite stable without macroscopic changes. Results The developed HPLC-UV method was validated in terms of linearity, specificity, accuracy and fidelity (less than 5 % for relative standard deviation and relative error). After 90 days, no microbial growth was noted and urea concentrations were always higher than 90 % of the initial concentration. Macroscopic changes were observed for the samples stored at fridge (5 °C+/− 3 °C) with massive crystallization of urea solution. Conclusions Although, all the preparations retain more than 95 % of the initial concentration after 90 days in all storage conditions, macroscopic change and pH change (more than 1 unit after 15 days at room temperature) have to be taken into account. The 0.5 g/mL urea oral liquid solution in InOrpha® remains stable for 15 days at room temperature (24 °C±1 °C) in amber glass bottles.

Stearidonic Acid Concentration by Urea Complexation from Echium Oil.

Concentration of polyunsaturated fatty acids ethyl esters (FAEE) by urea complexation from Echium oil was studied. Different variables involved in the process were investigated: amount and particle size of urea, solvent volume and ratio (hexane/ethanol), load of FAEE and reaction time. Hence, the main goal was to optimize SDA concentration (%) and yield (%) of stearidonic acid (SDA, 18:4 ω-3) and other bioactive FAEE. Similar behaviors were observed in fractionation between α-linolenic (ALA)-linoleic (LA), and γ-linolenic (GLA)-stearidonic (SDA) acids, attributed to similarities on their chemical structures, due to the position of the double bonds. At laboratory scale, the optimal conditions were 3 g urea (powder), 3.6 mL of hexane, 0.54 mL of ethanol and 800 mg of FAEE, during 20 h at 25°C. A scaling-up at pilot plant was carried out twice, obtaining more than 100 g of a final product, with ~29% SDA concentration and ~78% yield. Besides, after two washings with water, ethyl carbamates (urethanes) were not detected in the final product. Thus, a mixture of FAEE with about 85% of bioactive fatty acids with anti-inflammatory properties was obtained, which can be a high added-value product with great potential for the synthesis of functional lipids and nutraceuticals.

Modifications of Graphite and Multiwall Carbon Nanotubes in the Presence of Urea

The effect of high-energy ball milling on two carbon allotropes, graphite and multiwall carbon nanotubes (MWCNT) in the presence of urea has been studied. Samples were investigated using Raman spectroscopy, x-ray diffraction, scanning electron microscope (SEM) and x-ray photoelectron spectroscopy (XPS). Nitrogen-doped graphene has been successfully synthesized via a simple scalable mechanochemistry method using urea and graphite powder precursors. XPS results revealed the existence of the different nitrogen atoms configurations including pyridine, pyrrodic and graphitic N. SEM observations showed that the graphene nanosheets morphology become more wrinkles folded and crumbled as the milling time increased. The ID/IG ratio also increased as the milling time rose. The presence of both D′ and G + D bands at 1621 cm−1 and 2940 cm−1, respectively, demonstrated the nitrogen incorporation in the graphene lattice Two factors contribute to the used urea: first it helps to exfoliate graphite into graphene, and second it preserves the graphitic structure from damage during the milling process as well as acting as a solid-state nitrogen source. Based on the phase analysis, the d-spacing of MWCNT samples in the presence of urea decreased due to the mechanical force in the milling process as the milling time increased. On the other hand, in the graphite case, due to its open flat surface, the graphite (002) peak shifts toward lower two theta as the milling time increase. Such findings are important and could be used for large-scale production of N-doped graphene, diminishing the use of either dangerous chemicals or sophisticated equipment.

Fabrication of g-C3N4/SiO2-Au composite nanofibers with enhanced visible photocatalytic activity

Abstract Graphitic carbon nitride (g-C 3 N 4 ) based ternary composite photocatalyst (g-C 3 N 4 /SiO 2 -Au NFs) was prepared using Au nanoparticles (NPs) decorated SiO 2 nanofibers (SiO 2 -Au NFs) as a support by employing a heat treatment with a mixture of urea powder and SiO 2 -Au NFs. The resulting Au NPs with the mean diameter of about 13 nm were evenly dispersed on the g-C 3 N 4 /SiO 2 -Au NFs. In addition, the thin g-C 3 N 4 nano-layers were found to be uniformly grown on the g-C 3 N 4 /SiO 2 -Au NFs as determined by electron microscopy and elemental mapping image analyses. Comparative studies revealed that the g-C 3 N 4 /SiO 2 -Au NFs showed better photocatalytic activity for the degradation of Rhodamine B (RhB) under visible light than g-C 3 N 4 /SiO 2 NFs, which was prepared by the same process. The photocurrent enhancement of the g-C 3 N 4 /SiO 2 -Au NFs also indicated an enhanced separation of photo-induced electron-hole pairs. In addition, both the g-C 3 N 4 /SiO 2 -Au and g-C 3 N 4 /SiO 2 NFs could be easily precipitated and separated, which resulted from their ultra-long one-dimensional nanostructure. Also, the g-C 3 N 4 /SiO 2 -Au NFs exhibited high stability could be reused with little loss of photocatalytic activity after three recycles.

Co Nanoparticles/Co, N, S Tri-doped Graphene Templated from In-Situ-Formed Co, S Co-doped g-C3N4 as an Active Bifunctional Electrocatalyst for Overall Water Splitting.

The development of high-performance electrocatalyst with earth-abundant elements for water-splitting is a key factor to improve its cost efficiency. Herein, a noble metal-free bifunctional electrocatalyst was synthesized by a facile pyrolysis method using sucrose, urea, Co(NO3)2 and sulfur powder as raw materials. During the fabrication process, Co, S co-doped graphitic carbon nitride (g-C3N4) was first produced, and then this in-situ-formed template further induced the generation of a Co, N, S tri-doped graphene coupled with Co nanoparticles (NPs) in the following pyrolysis process. The effect of pyrolysis temperature (700, 800, and 900 °C) on the physical properties and electrochemical performances of the final product was studied. Thanks to the increased number of graphene layer encapsulated Co NPs, higher graphitization degree of carbon matrix and the existence of hierarchical macro/meso pores, the composite electrocatalyst prepared under 900 °C presented the best activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) with outstanding long-term durability. This work presented a facile method for the fabrication of non-noble-metal-based carbon composite from in-situ-formed template and also demonstrated a potential bifunctional electrocatalyst for the future investigation and application.

A Spatially Offset Raman Spectroscopy Method for Non-Destructive Detection of Gelatin-Encapsulated Powders.

Non-destructive subsurface detection of encapsulated, coated, or seal-packaged foods and pharmaceuticals can help prevent distribution and consumption of counterfeit or hazardous products. This study used a Spatially Offset Raman Spectroscopy (SORS) method to detect and identify urea, ibuprofen, and acetaminophen powders contained within one or more (up to eight) layers of gelatin capsules to demonstrate subsurface chemical detection and identification. A 785-nm point-scan Raman spectroscopy system was used to acquire spatially offset Raman spectra for an offset range of 0 to 10 mm from the surfaces of 24 encapsulated samples, using a step size of 0.1 mm to obtain 101 spectral measurements per sample. As the offset distance was increased, the spectral contribution from the subsurface powder gradually outweighed that of the surface capsule layers, allowing for detection of the encapsulated powders. Containing mixed contributions from the powder and capsule, the SORS spectra for each sample were resolved into pure component spectra using self-modeling mixture analysis (SMA) and the corresponding components were identified using spectral information divergence values. As demonstrated here for detecting chemicals contained inside thick capsule layers, this SORS measurement technique coupled with SMA has the potential to be a reliable non-destructive method for subsurface inspection and authentication of foods, health supplements, and pharmaceutical products that are prepared or packaged with semi-transparent materials.

Studies on some common adulterants in the milk sold in Kanpur City

The problem of adulteration of milk in Kanpur city is a burning problem now a days. The present study was planned for the detection of nature and extent of adulteration practiced in milk supply by the different agencies of Kanpur city. The study was conducted in the month of March - April 2010. In different agencies i.e., University dairy farm, Amul dairy, Parag dairy vendors and halwais milks. The milk samples were analysed for colours appearance, flavour, specific gravity, fat, total solid, S.N.F., pond water, starch, sodium-bicarbonate, urea and detergent powder are observed the present investigation. The maximum physical quality is observed in Amul Dairy, Maximum specific gravity was noted in Amul Dairy, highest fat and total solid, S.N.F., starch, sodium bicarbonate in Halwais milk, pond water, detergent powder, urea- Rawatpur market. It is also concluded that milk samples obtained from Amul dairy and Parag dairy were free from adulteration. It is suggested that Government should adopt all possible steps to check the fraudulent adulteration practices being used in the milk business. The milk samples collected from Rawatpur market had the maximum (50%) detergent powder positive, whereas the samples collected from Govind Nagar market had minimum (16.67%). On an average the milk supplied in Kanpur city found (33.33%) detergent powder. However, none of the samples were found to be detergent powder positive i.e., Amul dairy, Parag dairy and university dairy Kanpur.

ChemInform Abstract: Metal‐Free Efficient Photocatalyst for Stable Visible Water Splitting via a Two‐Electron Pathway.

AbstractNanocomposites of carbon nanodots embedded in a C3N4 matrix are prepared by heating a mixture of ammonia‐treated carbon nanodots and urea powder at 550 °C for 3 h in an alumina crucible.

Potential of Epoxidized Natural Rubber (ENR) as Hydrophobicity Contributor in Chitosan-Urea Fertilizer

This study is to investigate the potential of ENR to be incorporated with chitosan for slow release urea fertilizer. In this research, mixture of chitosan and epoxidized natural rubber (ENR) was used as binder to take advantage of their biodegradable and polar characteristics, respectively. The effect of mixing formulation to the properties of fertilizer was studied. Firstly, the chitosan and ENR were diluted in toluene with the presence of bentonite as filler. Then, urea powder was mixed and stirred for 20 minutes before left to dry overnight in an oven at 60°C. Water absorption and water retention analysis were carried out on compressed pellets. The increase of ENR loading was observed to contribute to the increase of hydrophobic properties of the fertilizer. The findings were supported by compositional analysis using Fourier Transform Infrared spectroscopy (FTIR).

Assessing the Significance of Rate and Time Pulse Spraying in Top Spray Granulation of Urea Fertilizer Using Taguchi Method

Studies in urea granulation process using Top Spray Fluidized Bed Granulator (TSFBG) is still limited and requires in-depth research about the effectiveness and influence of droplets to the formation of urea granule (UG). Rate and time interval of spraying technique (Pulse) significantly influence the physical properties of urea granules. Cassava starch dissolves in water was selected as the binder released at various time interval to observe impact of spray droplet on UG size formation. Using Taguchi Method, the study had identified three leading factors contributed to the formation of droplet size namely volume of binder (VOB), time pulse of spraying (TPS) and spraying rate (SR). These factors were then evaluated in terms of the influence on response as signal-to-noise analysis (S/N ratios) from Taguchi to validate UG size in range 2 mm to 4 mm from screening process with respect to the actual experimental data. These results were useful for future experiment reference to determine pressure drop and surface contact during interaction between droplet and urea powder particles using TSFBG to obtain uniform UG size and smooth surface layer with reasonable hardness.

Effect of Particle Size on Direct Compaction of Urea Fertilizer

The effect of particle size on compaction properties and characteristics of urea tablets manufactured from available urea granules (TG tablets) and ground urea powders (TP tablets) was investigated. The compaction properties, namely, plastic work, elastic work, friction work, and maximum ejection pressure were analyzed from the force-displacement profile of the compaction process. Five applied pressures ranging between 37.67 MPa and 188.35 MPa were used to compact the materials using a universal testing machine. Characteristics of the tablets tested were mechanical strength and the release of ammonium ion through dissolution test. The results demonstrated that TG tablets underwent high plastic work and elastic work but low friction work compared to the TP tablets. TG tablets released lower amount of ammonium ion compared to the TP tablets at almost all applied pressures, except at 75.34 MPa. This study provides a valuable data for evaluating the behavior of urea in the form of granules and powders during the compaction process as well as the suitability in choosing the form of raw material for the production of urea tablets.

Cost-effective therapeutic hypothermia treatment device for hypoxic ischemic encephalopathy

Despite recent advances in neonatal care and monitoring, asphyxia globally accounts for 23% of the 4 million annual deaths of newborns, and leads to hypoxic-ischemic encephalopathy (HIE). Occurring in five of 1000 live-born infants globally and even more in developing countries, HIE is a serious problem that causes death in 25%–50% of affected neonates and neurological disability to at least 25% of survivors. In order to prevent the damage caused by HIE, our invention provides an effective whole-body cooling of the neonates by utilizing evaporation and an endothermic reaction. Our device is composed of basic electronics, clay pots, sand, and urea-based instant cold pack powder. A larger clay pot, lined with nearly 5 cm of sand, contains a smaller pot, where the neonate will be placed for therapeutic treatment. When the sand is mixed with instant cold pack urea powder and wetted with water, the device can extract heat from inside to outside and maintain the inner pot at 17°C for more than 24 hours with monitoring by LED lights and thermistors. Using a piglet model, we confirmed that our device fits the specific parameters of therapeutic hypothermia, lowering the body temperature to 33.5°C with a 1°C margin of error. After the therapeutic hypothermia treatment, warming is regulated by adjusting the amount of water added and the location of baby inside the device. Our invention uniquely limits the amount of electricity required to power and operate the device compared with current expensive and high-tech devices available in the United States. Our device costs a maximum of 40 dollars and is simple enough to be used in neonatal intensive care units in developing countries.

Improving rumen fermentation and feed digestibility in cattle by mangosteen peel and garlic pellet supplementation

This experiment was conducted to investigate the effect of mangosteen peel and garlic powder supplementation on intake, digestibility, ruminal fermentation and methane production in beef cattle steers fed on rice straw based diets. Four, 2 year old rumen fistulated crossbred beef cattle were randomly assigned in a 4×4 Latin square design to receive four dietary treatments; mangosteen peel pellet (Mago-pel), mangosteen peel with garlic powder pellet (Maga-lic), mangosteen peel pellet with urea and garlic powder (Maga-ulic) supplemented at 200g/h/d and non-supplemented group (control). All animals were fed with rice straw ad-libitum while concentrate was fed at 0.5% body weight (BW). It was found that supplementation of mangosteen peel and garlic with or without urea had no effect on daily feed intake (FI), digestibility of dry matter (DM), organic matter (OM) and crude protein (CP). Supplementation resulted in significantly lower overall NDF and ADF digestibility when compared with the control. Ruminal pH, concentration of ruminal NH3N and blood urea nitrogen (BUN) concentrations were not significantly different among treatments. The proportion of C2 and methane were decreased, while C3 proportion was increased by the supplementation. It was found that all supplemented treatments had no effects on Ruminococcus albus, Fibrobacter succinogenes and Ruminococcus flavefaciens populations (P>0.05), whereas total bacteria and total methanogens populations were affected by supplementation (P<0.05). Total bacteria were the highest in control group and lowest when supplemented with Mago-pel and Maga-lic. The total methanogen populations were the highest in control group and was similar with Mago-pel supplementation. Supplementation of Maga-lic and Maga-ulic resulted in lower population when compared to the control group and also with Mago-pel's supplemented groups.

Ammonia Production From Solid Urea Using Nonthermal Plasma

Among various NOx reduction technologies, selective catalytic reduction (SCR) methods have been studied for cleaning of diesel engine exhaust. Urea SCR system, in which ammonia is used as reducing agent is thought to be one of the most promising methods. However, further improvement of the performance is required at low temperatures for example below 400 K. The purpose of this study is to enhance ammonia generation from urea at low temperatures. In this study, a dielectric barrier discharge (DBD) plasma reactor in which dielectric pellets and urea powder were packed was investigated experimentally. The reactor was fed with humid gas and driven by pulsed high voltage at 400 K or lower. The effect of the pellet material, gas humidity, and gas flow rate on ammonia generation was experimentally examined. Application of discharge plasma enhanced the ammonia generation significantly at low temperatures in which ammonia generation was negligible without plasma. Material of the catalyst pellets packed in the reactor significantly affected the ammonia generation. Air plasma showed nearly the same ammonia generation as that of nitrogen plasma. These results suggest that our method can provide a compact and low temperature on-board ammonia production system.

The Power Consumption Performance of an Orbiting Screw Solid-Solid Mixer

In this work we have investigated mixing in a modified orbiting screw mixer (MOSM) designed for solid-solid mixing. Mixing was carried out using urea powder and natural zeolite powder (UZ) of three varying particle sizes (50- 60, 60-80 and 80 mesh). Power consumption was calculated from the measured torque of orbit and screw, obtained from computerized records. It was found that the mixing process in the modified orbiting screw mixer with air injection required a lower power consumption for each particle-size group when compared to mixing without air injection. With UZ mixing in MOSM with air injection, the lowest E was obtained for the 60-80 mesh particle-size group (4,297 Joule/kg -1 ), whereas when mixing without air injection, the value was 10,296 J/kg. The best mixing operation in this experiment was achieved at NFr = 1.18x10 -3 and in the range of values NRe ≈ 8.77x10 7 to 2.63x10 8 . Moreover, in this study, we have developed an equation to estimate the power consumption required for mixing and determined its correlation with dimensionless numbers.

Microwave synthesis and characterization of Zn-doped nickel ferrite nanoparticles

Microwave assisted combustion method was used to synthesize nanocrystalline Zn x Ni 1− x Fe 2O 4 from a stoichiometric mixture of corresponding metal nitrates and urea powders. The structural, chemical and magnetic properties of Ni–Zn ferrite was determined by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM) and DC conductivity measurements. Results showed that the material was spinel structure with a high purity with an estimated crystallite size of ∼20 nm by X-ray line profile fitting. TEM analysis showed necked near-spherical particles with an average size of ∼20 nm, reflecting highly crystalline nature of these nanoparticles. Magnetic properties showed anomalities as the Zn doping level increased. This has been explained and attributed to the relative positions of Ni, Zn, and Fe ions in the crystal lattice.

Cyanobacterial biomass as N-supplement to agro-waste for hyper-production of laccase from Pleurotus ostreatus in solid state fermentation

The potential application of dry biomass of a cyanobacterium Anacystis nidulans as a supplement in SSF for the production of laccase from Pleurotus ostreatus was evaluated. Experiments were carried out in solid culture using groundnut shell as a basic substrate supplemented with four independent nitrogen sources (ammonium sulphate, urea, yeast extract and dry powder of cyanobacteria). All the four supplements enhanced the enzyme yield, and yeast extract showed precedence over inorganic nitrogenous sources. However, when dry biomass of A. nidulans was used as an additive to groundnut shell (agricultural residues), it supported maximum cell growth (56.83 ± 5.56 mg/g dry substrate) and laccase production (49.21 ± 4.89 U/g dry substrate). Addition of 1 mM copper salt in the medium containing groundnut shell supplemented with yeast extract gave laccase activity of 32.64 ± 3.4 U/g dry substrate. When dry powder of cyanobacterial biomass was used as N-supplement, laccase production enhanced to 65.42 ± 6.48 U/g dry substrate. In addition to the enhancement to enzyme production inhibitory effects of high concentrations of copper was also diminished in the medium having dry cyanobacterial biomass. This study, forms the first report on the potential application of cyanobacterial biomass as an additive for production of laccase by Pleurotus ostraetus MTCC 1804 in solid state fermentation and has relevance in scale-up production of this fungal enzyme of commercial significance.