Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “PH VALUE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Carboplatin binding to histidine

An X-ray crystal structure showing the binding of purely carboplatin to histidine in a model protein has finally been obtained. This required extensive crystallization trials and various novel crystal structure analyses. Carboplatin is a second-generation platinum anticancer agent used for the treatment of a variety of cancers. Previous X-ray crystallographic studies of carboplatin binding to histidine (in hen egg-white lysozyme; HEWL) showed the partial conversion of carboplatin to cisplatin owing to the high NaCl concentration used in the crystallization conditions. HEWL co-crystallizations with carboplatin in NaBr conditions have now been carried out to confirm whether carboplatin converts to the bromine form and whether this takes place in a similar way to the partial conversion of carboplatin to cisplatin observed previously in NaCl conditions. Here, it is reported that a partial chemical transformation takes place but to a transplatin form. Thus, to attempt to resolve purely carboplatin binding at histidine, this study utilized co-crystallization of HEWL with carboplatin without NaCl to eliminate the partial chemical conversion of carboplatin. Tetragonal HEWL crystals co-crystallized with carboplatin were successfully obtained in four different conditions, each at a different pH value. The structural results obtained show carboplatin bound to either one or both of the N atoms of His15 of HEWL, and this particular variation was dependent on the concentration of anions in the crystallization mixture and the elapsed time, as well as the pH used. The structural details of the bound carboplatin molecule also differed between them. Overall, the most detailed crystal structure showed the majority of the carboplatin atoms bound to the platinum centre; however, the four-carbon ring structure of the cyclobutanedicarboxylate moiety (CBDC) remained elusive. The potential impact of the results for the administration of carboplatin as an anticancer agent are described.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2016

Evaluate the role of organic acids in the protection of ligands from radiolytic degradation

In the Advanced TALSPEAK process, the bis(2-ethylhexyl)phosphoric acid (HDEHP) extractant used in the traditional TALSPEAK process is replaced by the extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). In addition, the aqueous phase complexant and buffer used in traditional TALSPEAK is replaced with the combination of N-(2-hydroxyethyl)ethylenediamine-N,N’,N’-triacetic acid (HEDTA) and citric acid. In order to evaluate the possible impacts of gamma radiolysis upon the efficacy of the Advanced TALSPEAK flowsheet, aqueous and organic phases corresponding to the extraction section of the proposed flowsheet were irradiated in the INL test loop under an ambient atmosphere. The results of these studies conducted at INL, led INL researchers to conclude that the scarcity of values of rate constants for the reaction of hydroxyl radical with the components of the Advanced TALSPEAK process chemistry was severely limiting the interpretation of the results of radiolysis studies performed at the INL. In this work, the rate of reaction of hydroxyl radical with citric acid at several pH values was measured using a competitive pulse radiolysis technique. This report describes those results and is written in completion of milestone M3FT-16IN030102028, the goal of which was to evaluate the role of organic acids in the protection of ligands from radiolytic degradation. The results reported here demonstrate the importance of obtaining hydroxyl radical reaction rate data for the conditions that closely resemble actual solution conditions expected to be used in an actual solvent extraction process. This report describes those results and is written in completion of milestone M3FT-16IN030102028, the goal of which was to evaluate the role of organic acids in the protection of ligands from radiolytic degradation.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1982

Influence of corrosive solutions on microhardness and chemistry of magnesium oxide /001/ surfaces

X-ray photoelectron spectroscopy analyses and hardness experiments were conducted on cleaved magnesium oxide /001/ surfaces. The magnesium oxide bulk crystals were cleaved to specimen size along the /001/ surface, and indentations were made on the cleaved surface in corrosive solutions containing HCl, NaOH, or HNO3 and in water without exposing the specimen to any other environment. The results indicated that chloride (such as MgCl2) and sodium films are formed on the magnesium oxide surface as a result of interactions between an HCl-containing solution and a cleaved magnesium oxide surface. The chloride films soften the magnesium oxide surface. In this case microhardness is strongly influenced by the pH value of the solution. The lower the pH, the lower the microhardness. Sodium films, which are formed on the magnesium oxide surface exposed to an NaOH containing solution, do not soften the magnesium oxide surface.

Ishigaki, H.↗
DOE OSTI2017

Characterization and photocatalytic activity of Bi{sub 3}TaO{sub 7} prepared by hydrothermal method

In this paper, Bi{sub 3}TaO{sub 7} nanoparticles with visible light response have been prepared via a facile hydrothermal route and solid-state reaction. The photocatalytic performance of as-prepared samples was evaluated by the degradation of Tetracycline hydrochloride (TC). It was observed that the sample obtained by hydrothermal method showed an enhanced photocatalytic activity in contrast to the sample prepared by solid-state method. This could be ascribed to the efficient separation of photogenerated electrons and holes in the sample prepared via hydrothermal process, which is certified by the photoluminescence spectroscopy (PL) and transient photocurrent analysis. Moreover, the result of nitrogen adsorption-desorption isotherm indicated the existence of mesoporous structure in as-prepared sample with hydrothermal process, and specific surface area is significantly higher than the sample obtained by solid-state method. The optimal conditions involved in the photocatalytic reaction, such as TC concentration, catalyst concentration and pH value were investigated. - Graphical abstract: The preparation process of Bi{sub 3}TaO{sub 7} photocatalyst by hydrothermal method. Display Omitted.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2016

Effect of the electrostatic surface potential on the oligomerization of full-length human recombinant prion protein at single-molecule level

The electrostatic surface potential (ESP) of prion oligomers has critical influences on the aggregating processes of the prion molecules. The atomic force microscopy (AFM) and structural simulation were combined to investigate the molecular basis of the full-length human recombinant prion oligomerization on mica surfaces. The high resolution non-intrusive AFM images showed that the prion oligomers formed different patterns on mica surfaces at different buffer pH values. The basic binding units for the large oligomers were determined to be prion momoners (Ms), dimers (Ds), and trimers (Ts). The forming of the D and T units happened through the binding of hydrophobic β-sheets of the M units. In contrast, the α-helices of these M, D, and T units were the binding areas for the formation of large oligomers. At pH 4.5, the binding units M, D, and T showed clear polarized ESP distributions on the surface domains, while at pH 7.0, they showed more evenly distributed ESPs. Based on the conformations of oligomers observed from AFM images, the D and T units were more abundantly on mica surface at pH 4.5 because the ESP re-distribution of M units helped to stabilize these larger oligomers. The amino acid side chains involved in the binding interfaces were stabilized by hydrogen bonds and electrostatic interactions. The detailed analysis of the charged side chains at pH 4.5 indicated that the polarized ESPs induced the aggregations among M, D, and T to form larger oligomers. Therefore, the hydrogen bonds and electrostatic interactions worked together to form the stabilized prion oligomers.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Green Synthesis of Silver Nanoparticles and Study of Their Antimicrobial Properties

One of the major disadvantages of polymers when used in food-contact applications is that they are very susceptible to microbial attack. On the other hand, silver nanoparticles have received increased attention as novel antimicrobial agents. Therefore, the introduction of silver nanoparticles into conventional polymers results in new materials with improved properties. In this investigation, colloidal silver nanoparticles using an environmentally friendly procedure were synthesized. An aqueous solution of AgNO{sub 3} was used as a silver precursor with ‘green’ reducing agents either different types of honey, or β-D-glucose. In the first case, different pH values, as well as the addition of poly(ethylene glycol), PEG were studied, while in the latter, the effect of reduction time in the presence of PEG with various average molecular weights was examined. Properties of the nanoparticles were measured using X-Ray diffraction, UV–Vis and FTIR spectroscopy. Using honey it seems that spherical particles are produced with the smaller average particle size obtained at pH 8.5. Use of honey has the advantage of being a natural product, although its main drawback is that its composition varies and it cannot be predefined to result in reproducible results. Use of β-D-glucose results in stable silver nanoparticles with small average particle size after 24 h reduction. The addition of low molecular weight PEG seems to be beneficial in the production of stable nanoparticles. Finally, the antimicrobial activity of the nanoparticles produced was investigated at different concentrations on both Gram positive and negative bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli and Staphylococcus aureus.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Numb positively regulates autophagic flux via regulating lysosomal function

Autophagy is a lysosome-dependent catabolic process involving in the degradation and recycling of unnecessary or damaged proteins and organelles. Emerging evidence indicates that autophagy dysfunction is closely related to various human diseases including cancer, aging, myopathies and neurodegenerative disorders. Here, using genetic knockdown, we uncover the role of Numb, an endocytic adaptor protein, in regulating the late steps of autophagy. We found that Numb depletion led to the accumulation of autophagic vacuole, as verified by RFP-LC3 staining combined with transmission electron microscopy. Further investigation indicated that Numb depletion impaired autophagic degradation through inhibiting the activities of lysosomal enzymes (Cathepsin D, β-glucuronidase and β-glucosidase). Moreover, Numb depletion induced elevation of lysosomal pH values and decrease of glycosylated lysosome-associated membrane proteins. We further observed that Rab7 activity was inhibited in Numb-depleted cells. Together, our findings revealed a novel function of Numb and its likely mechanism in regulation of autophagy events. - Highlights: • Numb depletion induces the accumulation of autophagic vacuole in MCF-7 cells. • Numb depletion impairs autophagic degradation and lysosomal enzymes activities. • Numb depletion elevates lysosomal pH but decreases glycosylated LAMPs. • Numb may regulate lysosome maturation by facilitating Rab7 activation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Chemically Modified Chitosan Bio-Sorbents for the Competitive Complexation of Heavy Metals Ions: A Potential Model for the Treatment of Wastewaters and Industrial Spills

Heavy metal pollution of water sources has become one of the most serious environmental and health problems nowadays. Chitosan (CHI) and derivatives can be used in the complexation and adsorption of heavy metals in water. Hence, this study compared the influence of CHI and carboxymethyl chitosan (CMC) ligands on the competitive complexation between toxic heavy metal ions with opposite charges Cr(VI) and Cd(II) at different pH values as an alternative and ecologically sustainable proposal for industrial spills of heavy metals into aquatic environments. The properties of the synthesized products and CHI were extensively characterized by several spectroscopy techniques, the competitive kinetics of complexation of metal ions with CHI and two type of CMC (with methanol, CMC 40-ME, and with ethanol, CMC 60-ET) was evaluated by wavelength dispersive X-ray fluorescence spectroscopy (WDXRF). The results clearly indicated the influence of the pH and ligands on the competitive complexation of the cationic or anionic ions. The results demonstrated that O-carboxymethylation of chitosan has occurred with a degree of functionalization of (1.20 ± 0.02) and (0.88 ± 0.02) for CMC 40-ME and CMC 60-ET, respectively, leading to the formation of CMC soluble in alkaline medium (pH range of 3.5 ≤ pH ≤ 6.5 and 4.0 ≤ pH ≤ 8.0 for CMC 40-ME and CMC 60-ET, respectively). In alkaline media, complexation of CMC 40-ME is approximately 10% higher (147.2 ± 0.9 mg g{sup −1}) than CMC 60-ET (99.8 ± 2.9 mg g{sup −1}) with Cd{sup 2+} ions at pH 8.5, and approximately 21% lower [(95 ± 2 mg g{sup −1}) and (96.3 ± 2.8 mg g{sup −1}) for CMC 40-ME and CMC 60-ET, respectively] than CHI (121 ± 6 mg g{sup −1}) for Cr{sub x}O{sub y}{sup z−} ions at pH 3.0. The kinetic analysis showed variations for each ion and a significant difference regarding the complexant towards the negatively charged ions. The CMC 40-ME, in any analyzed pH, the complexation occurred during the first 45 min of the process. These results showed that CMC, as polydentate functional ligand, was more efficient than CHI especially for the complexation of cations in basic media. Therefore, these systems appear to be attractive alternatives for the containment of industrial spills of heavy metals in wastewater.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2018

Effect of the Incorporation of Lysozyme on the Properties of Jackfruit Starch Films

Jackfruit starch based biodegradable films containing lysozyme were characterized for their antimicrobial activity, thickness, solubility, water vapor permeability and mechanical properties. The biodegradable films had good appearance and antimicrobial activity against Micrococcus lysodeikticus. The thickness of the biodegradable films were not affected by the variation in pH, but the addition of lysozyme increased the thickness, the thickest films being those with the highest lysozyme concentrations. The variation in pH of the filmogenic solutions affected the solubility of the biodegradable films, water solubility being greatest at pH 7.0 and with the highest lysozyme concentration. The permeability of the biodegradable films was increased by incorporating lysozyme. The lysozyme concentration and pH variation caused changes in the mechanical properties. The addition of 8% lysozyme increased the tensile strength and Young’s modulus for all the pH values studied. With respect to the release of antimicrobial activity, the diffusion of lysozyme was shown to follow Fickian transport mechanism.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Charge regulation effects on colloidal mixture nanoparticles

Changes in pH within a system containing dissociable sites affect the protonation and deprotonation of these groups, thereby influencing their physical properties. In response, the system modifies their surface charge, affecting electrostatic interactions, aggregation, stability, and structural behavior. Although the pH can be tuned in experiments, it is difficult to model this phenomenon using simulations or theoretical approaches. Here, we perform hybrid Monte Carlo-molecular dynamics simulations to model charge regulation effects in an equimolar colloidal charged system. We compare charge regulation effects with those of a system in which the charges of colloidal nanoparticles are not dissociable. The comparison between the two cases modifies the phase diagram, and it changes the volume fraction where a percolation network of nanoparticles is found. Charge regulation is found to destroy network formation, as the charge in the nanoparticles is modified because of the cooperativity dependency of the degree of charge dissociation sites among the nanoparticles favoring cluster formation. Furthermore, our work suggests that the ionic and/or electronic conductivity in functionalized nanoparticles can be modified by changing pH values. It also guides the experimental design of oppositely charged nanoparticles as inks for 3D printing processes.

Classical statistical mechanics↗
DOE OSTI2010

Free Energies for Degradation Reactions of 1,2,3-Trichloropropane from ab initio Electronic Structure Theory

Electronic structure methods were used to calculate the gas-phase and aqueous phase reaction energies for reductive dechlorination (i.e. hydrogenolysis), reductive Beta-elimination, dehydrochlorination, and nucleophilic substitution by OH- of 1,2,3-trichloropropane. The thermochemical properties Delta Hof(298.15K), So(298.15K,1 bar), and Delta GS(298.15K, 1 bar) were calculated by using ab initio electronic structure calculations, isodesmic reactions schemes, gas-phase entropy estimates, and continuum solvation models for 1,2,3-trichloropropane and several likely metabolites. On the basis of these thermochemical estimates, together with a Fe(II)/Fe(III) chemical equilibrium model for natural reducing environments, all of the reactions studied were predicted to be very favorable in the standard state and under a wide range of pH conditions. The most favorable reaction was reductive Beta-elimination (Delta Gorxn ≈ -32 kcal/mol), followed closely by reductive dechlorination (Delta Gorxn ≈ -27 kcal/mol), dehydrochlorination (Delta Gorxn ≈ -27kcal/mol), and nucleophilic substitution by OH- (Delta Gorxn ≈ -25 kcal/mol). For both reduction reactions studied, it was found that the first electron-transfer step, yielding the intermediate CH2-CHCl-CH2Cl , and CH2Cl-CH-CH2Cl species, was not favorable in the standard state (Delta Gorxn ≈ +15 kcal/mol) and was predicted to occur only at relatively high pH values. This result suggests that reduction by natural attenuation is unlikely.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2012

Pure LiF nanophosphors for high exposures of gamma-rays

Nanocrystalline lithium fluoride (LiF) phosphors have been prepared by the chemical co-precipitation method at different pH values (7.0, 8.0, 9.0 and 10.00). The formation of nanocrystalline structure has been confirmed by X-ray diffraction and transmission electron microscope. Thermoluminescence (TL) properties of LiF phosphors irradiated with gamma rays at different doses of 10 Gy - 70 kGy have been further studied. The analysis of TL glow curve revealed the existence of three well resolved glow peaks, first low temperature peak at around 82 deg. C, second at 125 deg. C and third one at higher temperature around 303 deg. C. The LiF nano-crystallites synthesized at 8.00 pH with maximum TL sensitivity at studied gamma doses ranging from threshold to high exposures are potential candidate for dosimetry applications.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Proton Management as a Design Principle for Hydrogenase-inspired Catalysts

The properties of the hydrogenase-inspired [Ni(PNP){sub 2}]{sup 2+} (PNP = Et{sub 2}PCH{sub 2}NMeCH{sub 2}PEt{sub 2}) catalyst for homogeneous hydrogen oxidation in acetonitrile solution are explored from a theoretical perspective for hydrogen production. The defining characteristic of this catalyst is the presence of pendent bases in the second coordination sphere that function as proton relays between the solution and the metal center. DFT calculations of the possible intermediates along proposed catalytic pathways are carried out and used to construct coupled Pourbaix diagrams of the redox processes and free-energy profiles along the reaction pathways. Analysis of the coupled Pourbaix diagrams reveals insights into the intermediate species and the mechanisms favored at different pH values of the solution. Consideration of the acid-base behavior of the metal hydride and H{sub 2} adduct species imposes additional constraints on the reaction mechanism, which can involve intramolecular as well as intermolecular proton-coupled electron-transfer steps. The efficacy of the catalyst is shown to depend critically on the pK{sub a} values of these potential intermediates, as they control both the species in solution at a given pH and the free-energy profile of reaction pathways. Optimal relationships among these pK{sub a} values can be identified, and it is demonstrated that 'proton management', i.e., the manipulation of these pK{sub a} values (e.g., through choice of metal or substituents on ligands), can serve as a design principle for improved catalytic behavior.

08 HYDROGEN↗
DOE OSTI2013

The 1.6 Å resolution structure of a FRET-optimized Cerulean fluorescent protein

The high resolution X-ray structure of the cyan fluorescent protein mCerulean3 demonstrates that different combinations of correlated residue substitutions can provide near optimum quantum yield values for fluorescence. Genetically encoded cyan fluorescent proteins (CFPs) bearing a tryptophan-derived chromophore are commonly used as energy-donor probes in Förster resonance energy transfer (FRET) experiments useful in live cell-imaging applications. In recent years, significant effort has been expended on eliminating the structural and excited-state heterogeneity of these proteins, which has been linked to undesirable photophysical properties. Recently, mCerulean3, a descendant of enhanced CFP, was introduced as an optimized FRET donor protein with a superior quantum yield of 0.87. Here, the 1.6 Å resolution X-ray structure of mCerulean3 is reported. The chromophore is shown to adopt a planar trans configuration at low pH values, indicating that the acid-induced isomerization of Cerulean has been eliminated. β-Strand 7 appears to be well ordered in a single conformation, indicating a loss of conformational heterogeneity in the vicinity of the chromophore. Although the side chains of Ile146 and Leu167 appear to exist in two rotamer states, they are found to be well packed against the indole group of the chromophore. The Ser65 reversion mutation allows improved side-chain packing of Leu220. A structural comparison with mTurquoise2 is presented and additional engineering strategies are discussed.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2019

Recovery of Carbon and Valuable Components from Spent Pot Lining by Leaching with Acidic Aluminum Anodizing Wastewaters

A three-step process was employed to separate cryolite from used carbon cathodes, known as spent pot lining (SPL), and obtain valuable carbon. The process comprised leaching of NaF from the imbedded electrolyte with water, followed by leaching of Na{sub 3}AlF{sub 6}, CaF{sub 2}, and NaAl{sub 11}O{sub 17} with acidic anodizing wastewater, and then precipitating the electrolyte components from the mixed filtrate from the previous two steps. The influences of stirring rate, liquid–solid ratio, temperature, and time on the extent of leaching of cryolite and recovery of carbon were studied. Additionally, the effects of pH value, F/Al ratio, temperature, and time on the recovery of valuable components in the mixed filtrate were evaluated. The results showed that most NaF in the SPL was dissolved by water leaching. The residual electrolyte in SPL was mainly cryolite and contained approximately 0.95 pct NaF. The purity of the carbon obtained reached 95.5 pct under optimal experimental conditions (leaching temperature: 80 °C; stirring rate: 300 rpm; liquid–solid ratio: 8 mL/g; leaching time: 180 minutes). The recovery of cryolite and the purity of the sodium sulfate crystal from the mixed filtrate were 98.4 and 92.0 pct, respectively, under suitable conditions (pH 9; 75 °C; 4 hour; F/Al ratio of 6:1).

36 MATERIALS SCIENCE↗
DOE OSTI2017

Understanding the interacted mechanism between carbonation and chloride aerosol attack in ordinary Portland cement concrete

An experimental study is carried out with the aim to understand the interacted mechanism between carbonation and chloride aerosol attack in ordinary Portland cement (OPC) concrete. Effects of carbonation on the chloride profile, the chloride binding capacity and the chloride diffusion coefficient are evaluated. Besides, effect of chloride aerosol attack on the carbonation rate is investigated. Concrete specimens with three water-to-cement ratios (0.38, 0.47 and 0.53) are fabricated in this work. Tested results demonstrate that carbonation remarkably affects the chloride profile, reduces the chloride binding capacity, and also accelerates the rate of chloride ion diffusion of concrete. Besides, the presence of chloride aerosol can lead to lower the carbonation depth and increase the pH value of carbonated concrete. Microscopic properties such as morphology, porosity, and pore size distribution for the contaminated concretes are explored by scanning electron microscope and mercury intrusion porosimetry, which provide strong evidence to these research findings.

36 MATERIALS SCIENCE↗
DOE OSTI2015

In vitro fibrillization of Alzheimer’s amyloid-β peptide (1-42)

The amyloid deposition in the form of extracellular fibrillar aggregates of amyloid-β (Aβ) peptide is a critical pathological event in Alzheimer’s disease. Here, we report a systematic investigation of the effects of environmental factors on the kinetics of Aβ fibrillization in vitro. The effects of Aβ42 peptide concentration, temperature, pH, added solvents and the ratio of Aβ40 and Aβ42 on the peptide fibrillization under agitated conditions was studied. The analysis show that the rate of fibril growth by monomer addition is not limited by diffusion but by rearrangement in the monomer structure, which is enhanced by low concentrations of fluorinated alcohols and characterized by the activation energy of 12 kcal/mol. Fibrillization rate decreases at pH values below 7.0 where simultaneous protonation of His 13 and 14 inhibits fibril formation. The lag period for Aβ42 was only twofold shorter and the fibril growth rate twofold faster than those of Aβ40. Lag period was shortened and the fibrillization rate was increased only at 90% content of Aβ42.

36 MATERIALS SCIENCE↗
DOE OSTI2012

Thermoluminescence of Eu activated LiF nanophosphors

Nanocrystalline lithium fluoride (LiF) phosphors prepared by the chemical co-precipitation method at 8.00 pH value have been activated with Eu (0.01, 0.03, 0.07 and 0.1%nt;) as single dopants. The formation of nanocrystalline structure has been confirmed by X-ray diffraction. Thermolumniscence (TL) properties of LiF: Eu nano-phosphors irradiated with gamma rays at different doses of 100 Gy - 10 kGy have been further studied. There is only one main glow peak at around 122 deg. C; which shifts to higher temperature with an increase in doping concentration at all studied irradiation doses. However, the glow peak shifts to lower temperature with an increase in irradiation dose from 100 Gy to 10 kGy. The LiF nano-crystallites synthesized at 8.00 pH and activated with 0.03%nt; Eu are found to have maximum TL sensitivity at studied gamma doses.

36 MATERIALS SCIENCE↗