bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetics and mechanism of sol-gel transformation between some trivalent- and tetravalent-metal ions and Sodium alginate Anionic polyelectrolyte with formation of coordination Biopolymeric structure polymembranes Hydrogels of Capillary Structures Ex
Authors: Zaafarany Ishaq Abdullah
Published: May 2018

Abstract          The kinetics of sol-gel transformation between A13+, La 3+ and Th4+ metal ion electrolytes and sodium alginate sol have been studied complexometrically at various  temperatures. In the presence of a large excess of sodium alginate sol concentration over that of metal ion electrolyte, the pseudo first–order plots of exchange showed sigmoidal curves with two distinct stages. The initial part was relatively fast and curved significantly at early times, followed by a slow decrease in the rates of exchange over longer time periods. The rate constants of gelation showed second-order overall kinetics which was first order in the concentration of both reactants. The thermodynamic parameters have been evaluated and tentative gelation mechanisms consistent with the kinetic results of gelation are suggested. The stability of these ionotropic metal-alginate complexes has been discussed in terms of the coordination geometry and strength of chelated bonds.
Mathematical model of vacuum freeze-drying in the secondary drying
Authors: Li Hua , Li Lihua , Jiao Xingli , Qin Xueli
Published: May 2018

The freeze-drying process is a complex heat and mass transfer process virtually. The drying process of freeze-drying is not only the key stage which decides the success of freeze-drying, but also the most difficult stage to control. There are lots of papers about heat and mass transfer in vacuum freeze drying at home and abroad. The present status of research on heat and mass transfer during vacuum freeze drying in the secondary drying is summed up and analyzed, and the trend of research in this field is discussed in this paper.
Structural Study of the Compound [(C10O8H2)2 (C4N2H6)].2H2O Synthesized by Hydrothermal Condition
Authors: Halouani Manel , Abdelhedi M. , Dammak M. , Audebrand N. , Ktari L.
Published: May 2018

A new metal–organic compound [(C10O8H2)2(C4N2H6)].2H2O(I) was hydrothermally synthesized from an aqueous solution of Fe (NO3)3 9H2O, (btec) (btec= 1, 2, 4, 5-benzenetetracarboxylic acid) and piperazine. Compound I crystallizes in the triclinic system with the P1 space group. The unit cell parameters are a = 8.271 Å, b = 8.500 Å, c = 9.660 Å, α = 87.12°, β = 89.53°, γ = 70.91°, Z= 2, V= 640.96(6) Å3 and Dx= 1.602g/cm3. The refinement converged into R= 0.047 and RW = 0.059. The structure, determined by single crystal X-ray diffraction, consists of two carboxyl group, piperazine and two molecules of water.
Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline
Authors: Amereih Sameer , Barghouthi Zaher , Majjiad Lamees
Published: May 2018

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.
Chemical and Biological Leaching Methods to Remove Heavy Metals from Sewage Sludge: A Review
Authors: Ukiwe Lugard N. , J.I Allinor , A.E Ejele , C.I.C Anyadiegwu , S.I Ibeneme
Published: May 2018

The removal of heavy metals (HMs) in sewage sludge (SS) is important since sludge is often disposed or applied on farmland to enhance soil fertility. The present study reviewed two conceptual approaches (chemical and biological leaching) of removing HMs present in SS. In the chemical leaching method, traditional acid treatment together with novel methods such as aeration, complexation and sequential extraction procedure have been reviewed extensively. Certain factors influence the removal of HMs in SS. These factors include; pH, leaching agent, redox potential, and contact time. Nitric acid (HNO3), hydrochloric acid (HCl), sulphuric acid (H2SO4), phosphoric acid (H3PO4), ethylenediamine tetraacetic acid (EDTA), as well as Thiobacillus thiooxidans and Thiobacillus ferrooxidans are the most widely studied leaching agents and substrates involved in the chemical and bioleaching processes. However, the bioleaching process has been proposed as a safe, efficient, economical, environmental friendly method to remove HMs in SS due to its simplicity, high yield of metal extraction, low acid consumption, and low sludge solids concentration. Nevertheless, the present review has noted that most researchers are of the opinion that more studies are needed in the bioleaching method in order to enhance its commercial attraction.
Scope of Non-estrogenic Steroidal Congeners against Breast Cancer
Authors: Akram Sheikh M.M , Peerzadah G. M. , Banday Abid H.
Published: May 2018

Various novel non-estrogenic steroidal D-ring substituted analogs were synthesized and evaluated for their breast cancer activity against human breast cancer cell lines. The good cytotoxic results obtained against the breast cancer cell lines throws new insights into the field as the analogs are non 17β –Hydroxy estrogenic derivatives which are considered to be pivotal for the potent estrogenic activity. The synthesized steroidal analogs provide a very good platform for mechanistic studies of the interaction between non-esterogenic steroids and estrogen receptors.
Steric and Polar Factors Affecting Heteroring Opening of 2-[2-carboxy-3,4,5,6-tetrachloro]phenyl-4H-3,1-Benzoxazin-4-one by Nitrogen and Carbon Nucleophiles
Authors: Morsy Jehan Mahmoud , El-Hashash Maher Abdel Aziz
Published: May 2018

The behavior of 2-[2-carboxy-3,4,5,6-tetrachloro]phenyl-4H-3,1-Benzoxazin-4-  one towards Nitrogen nucleophiles and Carbon nucleophiles under Friedel–Crafts' reaction conditions has been investigated and steric versus polar factors affecting ring opening has been studied.
Some Polysorbate Compounds as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid
Authors: Sobhi Mohamed , Abdallah M. , Hfaez E.
Published: May 2018

Some commercial non-ionic surfactants polysorbate, namely, polysorbate 80, polysorbate 40 and polysorbate 20, were tested as inhibitors for corrosion of C-steel in 2.0M HCl solution using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy techniques. It was found that all the three used compounds act as inhibitors for acid corrosion of C-steel. The inhibition efficiencies obtained by the three techniques were almost the same, and increase with increasing the hydrocarbon chain length and the surfactant concentration. The polarization studies show that these compounds act as mixed inhibitors. The inhibition action of these surfactants can be explained by their ability to adsorb on the metal surface making a barrier to mass and charge transfer.  It was found that the adsorption of these surfactants follows Langmuir adsorption isotherm. The negative values of  adsorption free energy indicating that the adsorption process is spontaneous and increases, for different surfactants, in the same direction as inhibition efficiency.
Kinetic and Conventional Spectrophotometric Determination of Bumadizone in its Tablets via Oxidative Coupling with 3-Methyl-2-Benzothiazolinone Hydrazone
Authors: Walash Mohamed , Belal Fathalla , Tolba Manar , Halawa Mohamed
Published: May 2018

Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of bumadizone in bulk drug and its tablets. Both methods based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and measuring the absorbance of the developed colors by direct or kinetic spectrophotometric method. Upon treatment of a mixture of the chromogenic reagent and drug with cerium (IV) ammonium sulfate (method I) or ferric chloride (method I), a red or violet color was developed immediately or after 30 minutes measurable at 557 nm for method I or II, respectively. The absorbance-concentration plots were rectilinear over the ranges of 1-10 μg/mL (r = 0.9999) for method I and 2-16 μg/mL (r = 0.9998) for method II. The detection limits were  0.15 and 0.27 μg/mL & the quantitation limits were 0.46 and 0.84 μg/mL for methods I and II, respectively. Different experimental parameters affecting the development and stability of the reactions products were studied and optimized. The proposed methods were applied successfully to the determination of bumadizone in its tablets, and the results obtained were in good agreement with those obtained using a comparison  method.
Defluoridation of South Tunisian Brackish Water by Alum Coagulation/Flocculation: A Preliminary Work
Authors: Missaoui Khaoula , Bouguerra Wided , Hannachi Chiraz
Published: May 2018

Fluoride removal from aqueous solution was investigated using the chemical coagulation-flocculation by alum in reason of the efficiency and the simplicity of the process. Preliminary experiments were carried out to study the effect of some operating parameters such as: pH, initial fluoride concentration, coagulant dose, adjuvant coagulation dose, flocculent dose and settling time. Obtained experimental results showed that the treatment of fluoride by alum coagulation causes acidification of the solution. The effect of the initial pH solution on fluoride removal is negligible. Experimental results proved that coagulation process is effective in waters with low or medium levels of fluoride. Defluoridation rate was seen to increase with increasing coagulant and adjuvant coagulation doses. Optimal flocculent dose and optimal settling time were found 4.2 mg L-1 of FABI and 60 min respectively. Subsequently, experimental design methodology using two-level full factorial design was applied to optimize the defluoridation by coagulation-flocculation. Therefore, four operating parameters which are supposed to affect the removal efficiency were chosen: initial fluoride concentration, coagulant dose, coagulation adjuvant dose and settling time. From the statistical analysis, it is inferred that the four studied parameters have an influence on the fluoride removal. In fact, initial fluoride concentration has a positive effect unlike coagulant dose, coagulation adjuvant dose and settling time. Experiment tests were performed to evaluate the efficiency of coagulation-flocculation process for south Tunisian brackish water with high fluoride concentration. The obtained results showed that fluoride removal reached 59%.
Synthesis and Characteristic of Precipitated Nano-Silica
Authors: Sadeghi Mohammad , Dorodian Mahboubeh , Rezaei Masoumeh
Published: May 2018

The reaction of precipitation of amorphous silicon dioxide from aqueous solution of sodium silicate and sulfuric acid has been studied. The factors affecting the precipitation process of the sodium silicate solution such as sodium silicate concentration and addition of anionic surfactant (sodium dodecyl sulfate, SDS) on particle size, size distribution and degree of agglomeration of the precipitated silica were examined. The precipitation of silica from the produced sodium silicate solution was carried out using sulfuric acid at pH 7. Scaning electron microscope (SEM), transmission electron microscope (TEM) and Dynamic light scattering (DLS) have been used for characterization of the produced nano-silica. The surface area of silica was tested by oil absorption method according to ASTM standard. Results showed that the particle size of the precipitated silica gel was decreased with increasing Na2SiO3 and SDS concentrations and Particle size of about 44nm can be achieved at 20% Na2SiO3 and 200ppm SDS. But with decreasing particle size, degree of agglomeration also increased.
Kinetic Study of the Dissolution of Tunisian Natural Phosphate or Francolite in Industrial Phosphoric Acid
Authors: CHAABOUNI Ahmed
Published: May 2018

A kinetic study of dissolution of Tunisian natural phosphate or francolite whose particles have a mesoporous texture inindustrial phosphoric acid is carried out. Therefore, We focused on the study of the influence of certain parameters thatare close to those used in plants producing phosphoric acid which are the stirring speed (300, 500 and 700 rounds perminute), concentration of phosphoric anhydride (25, 30 and 35 percent of P2O5), and the temperature (60, 70 and 80degrees Celsius); we note that the rate of dissolution of this phosphate rises by increasing the precedent parameters.Because of the complexity of the study of the dissolution of phosphate in mineral acids. Several different published kineticmodels giving different expressions of speed versus time. The shrinking core model is the appropriate model used in ourwork in a solution where there is no calcium sulfate to calculate the rate constant k and the activation energy Ea = 3.3946Kcal/mol of this phosphate.
The Kinetics of Electron Transfer Reaction of Methylene Blue and Titanium Trichloride in different Solvents
Authors: Saeed Rehana Saeed
Published: May 2018

The kinetics of the electron transfer reaction of methylene blue and titanium trichloride was studied in water and aqueousalcoholic solvents at various temperatures by spectrophotometry. The rate of reaction was observed by taking change inabsorbance as a function of time at Î»max 660 nm. The reaction is pseudo-first order, dependent on concentration of titaniumtrichloride at fixed concentration of methylene blue.The effect of solvent was studied in the pH/Ho range from 4 to 7. It was observed that the rate of reaction increased withincrease in polarity of the reaction medium. The rate of reaction was high in acidic condition and decreased with furtherincrease in hydrogen ions activity. The increase in temperature increased the rate of electron transfer reaction of methyleneblue and titanium trichloride. Activation energy (Ea) was calculated by Arrhenius relation. The absence of any reactionintermediate was confirmed by spectroscopic and kinetic investigations. A plausible mechanism for the reaction in line withouter-sphere reaction pathway has been proposed. Thermodynamic parameters such as activation energy (Ea), enthalpychange (âˆ†H), free energy change (âˆ†G) and entropy change (âˆ†S) were also evaluated.
Growth of Ag-Nanoparticles: Shape-Directing Role of Silver Ions and Stabilizer in Aqueous Solutions
Authors: Zaheer Zoya , Rafiuddin Rafiuddin
Published: May 2018

Silver nanoparticles were synthesized using Tulsi leaves extract as reducing as well as a capping agent to reduce the steps and parameters involved in the synthesis. The morphology, stability and optical properties of Ag-nanoparticles depend on reactants and stabilizer, cetyltrimethylammonium bromide (CTAB) concentrations. The silver nanoparticles were characterized by UV-visible spectrophotometer, and transmission electron microscope (TEM). Spherical morphology of the silver nanoparticles with an average diameter of  25 nm. Morphology changed markedly from spherical aggregated to highly polydispersed in presence of CTAB.
Removal of Reactive Red 74 Dye from Textile Industrial Waste using Zinc Oxide Nanoparticle
Authors: Khoshhesab Zahra Monsef , Gonbadi Katayon , Behbehani Gholamreza Rezaei
Published: May 2018

Global population growth and industrial activities in recent decades has been caused to enter excessive amount of pollutants to water resources. Industrial textile dyes are an important class of the pollutants in the sewage system. Disposal of the dyes in precious water resources must be avoided, however, and for that various treatment technologies are in use. Considering the toxicity of the pollutants, their removal from water resources is necessary. In this research, removal of reactive red 74, RR47, from aqueous solution by zinc oxide nanoparticles was investigated and the affecting parameters such as pH, contact time and adsorbent mass on removal efficiency were determined. Langmuir and Freundlich isotherms were studied and the results indicated that the adsorption process obey the Langmuir and Freundlich isotherms. The experimental results also showed that the pseudo-second order kinetic equation could nicely describe the sorption kinetics.
A Two Step Synthesis Route of WC Nanopowders
Authors: Guan Ruqi , Hu Kailing , Wang Lihua , Chen Youjian
Published: May 2018

Here, a novel molten salt route to synthesize ceramic WC nanopowders was presented. Compared to the traditional synthesis procedures, this method is relatively low cost involving two-step synthesis route. In the argon atmosphere at 650 oC, the powders were the mixed WC and W2C phases. These synthesized powders were transferred to a small crucible (30 mL) containing molten salt, which were put into a 500 mL crucible with some carbon powder in it as reducing atmosphere, followed by maintaining the reaction temperature at 1100 °C for 1 h. The phase purity and composition were characterized by the powder X-ray diffractometer (XRD). It was found that W2C was transformed thoroughly into WC, which indicated the successful synthesis of WC powders using this method. The mechanism of the reaction process in molten salt has been discussed finally. The thermogravimetric analysis indicated that the as-prepared samples showed good thermal stability and oxidation resistance in high temperature. The methodology reported in this work was fundamentally important, which may find potential industrial applications.
Spectroscopic Study of some Schiff Bases Derived from Dibenzoylmethane
Authors: A. Saeed Bahjat , Al-Masoudi Wasfi A.
Published: May 2018

A series of Schiff bases 7-11 derived from dibenzoylmethane have been prepared. The UV, IR, 1H NMR and mass spectra revealed theses compounds were existed mainly as the keto-enamine tautomer in the solution. The absorption bands which appeared in the range λmax = 376-406 nm were assigned to the electronic transitions which arised from the central hydrogen bonded chelated unsaturated ring system in this tautomer. The appearance of the broad singlet near d  = 13 ppm due to the N-H proton and a singlet near d  = 6 ppm due to the –C=C-H proton inaddition to benzoyl fragment ion     signal m/z =105 in the mass spectra supported the above suggested products.
Green synthesis of Ag nanoparticles using aqueous extract of Kaempferia galanga Linn. (Zingiberaceae) rhizomes
Authors: Devi Asem Satyavama , Laitonjam Warjeet S
Published: May 2018

Green synthesis of noble metal nanoparticles (NPs) is a vast developing area of research. In the present study, silver nanoparticles (Ag-NPs) were rapidly synthesized by treating silver ions through a simple and green synthetic route using water extract of the rhizomes of Kaempferia galanga Linn.(KG), which acted simultaneously as a reductant and stabilizer. The reaction process was monitored using ultraviolet–visible (UV-Vis) spectroscopy. The  EPR spectra of AgKG NPs was found to be confined in a single line which showed  the presence of an unpaired electron indicating of  Ag in neutral state at room temperature. The size and morphology of AgNPs recorded by Scanning electron  microscopy (SEM) were further confirmed by transmission electron microscopy (TEM) and selected area electron diffraction (SAED). The formation of AgNPs is evidenced by the appearance of signatory brown colour of the solution. FT-IR spectrum indicates the presence of different functional groups in capping the nanoparticles with K. galanga. Average size range estimated from our studies is  2 to 4 nm. It consists of a spherical like particles.
Thermal analysis, X-ray diffraction, spectroscopy studies and magnetic properties of the new compound Tl2HAsO4.Te(OH)6
Authors: Bechibani I. , Litaiem H. , Granda S. Garcia , Dammak M. , Ktari L.
Published: May 2018

The Tl2HAsO4.Te(OH)6 (TlAsTe) compound crystallizes in the triclinic system P1 with unit cell parameters: a= 7.100(10) Å, b= 7.281(13) Å, c= 8.383(11) Å, α= 76.91(1)°, β= 87.16(1)°, γ= 66.96(2)°, Z= 2 and V= 388.19(1) Å3. This new structure can be described as a lamellar one with the atomic arrangement being built by planes of Te(OH)6 octahedra alterning with planes of arsenate tetrahedra. Raman and infrared spectra recorded at room temperature confirm the presence of As  and Te  groups and characterize the hydrogen bonds present in the crystal lattice. Differential scanning calorimerty shows the presence of three-phase transitions at 396 K, 408 K and 430 K present in the title compound. Typical thermal analyses, such as differential thermal analysis and thermogravimetry show that the decomposition of this material starts at about T= 445 K. Magnetization curve of Tl2HAsO4·Te(OH)6 substance have revealed a diamagnetic response overall temperature range studied.
Phase Transition and Electrical Properties in Cs2SeO4.Te(OH)6
Authors: H. Litaiem , S. Garcia-Granda , M. Dammak , T. Mhiri
Published: May 2018

Dielectric investigations in the temperature and frequency 300- 600 K and 0,1KHz–13MHz, respectively, show that cesium selenate tellurate Cs2SeO4.Te(OH)6 (CsSeTe) exhibits two phase transitions at 490 and 525 K. The a.c. complex impedance measurements performed on CsSeTe material show an important level of conductivity at high temperature, attributed to the motion of H+ proton. This behavior is in agreement with the presence of the super- protonic phase transition in CsSeTe compound at 525K. This assignment was confirmed by the analysis of the M"/M"max spectra. The temperature dependences of ε΄r and tanδ indicate that the anomaly at 490K is attributed to a ferroelectric-paraelectric phase transition. Thermal analysis at high temperature, DSC, DTA, TG,  Ms/z= 18 and Ms/z= 32 confirm the presence of the two transitions already cited, the temperature and the nature of the decomposition.
Synthesis and Crystal Structure of 3-3’-Diaminomethyldipropylammonium Hexachlorobismuthate (III)
Authors: Baklouti Yosra , Koumina Abdelaziz , Fliyou Mohamed , Zouari Fatma
Published: May 2018

Synthesis and crystal structure of 3-3’-diamino-N-methyldipropylammonuim hexachlorobismuthate (III) are reported. The compound crystallizes in the triclinic system with space group P1. The unit cell dimensions are:             a = 7.5580(5), b =7.8710(6), c = 8.3709(7) Å with Z=1. The crystal is built up of separated [BiCl6]3- octahedral anions and 3-3’-diamino-N- methyldipropylammonium cations. The organic layers are arranged in sandwich between the anionic ones. The crystal packing is governed by means of the ionic   N–H···Cl hydrogen bonds, forming a three dimensional network.
Green Synthesis of Silver Nanoparticles using Strobilanthes flaccidifolius Nees. Leaf Extract and its Antibacterial Activity
Authors: Wangkheirakpam Sujata D , Devi Wangkheirakpam Radhapiyari , Singh Chingakham Brajakishore , Laitonjam Warjeet S
Published: May 2018

The leaf extract of Strobilanthes flaccidifolius Nees. was used for the synthesis of silver nanoparticles through a green technique of synthesis. The nanoparticles was characterized by UV-VIS spectroscopy which proves the formation silver nanoparticles. FTIR (Fourier Transmission infra red spectroscopy) study was carried out to assess the biomolecule as indigo precursors, Energy dispersion X-ray analysis(EDX) data further proves it. EPR (Electron paramagnetic resonance technique) shows the free radical in silver neutral state and XRD(X-ray diffraction technique) also repots silver neutral formation.The morphology and the shape of the silver nanoparticles were determined by Scanning electron microscopy(SEM) and Tunneling electron microscopy (TEM).The nanoparticles adopted spherical morphology and the size ranging from 6nm to 54.11nm and average size was determined as 12.15± 5.3nm.The nanoparticles had antimicrobial activity
DISTRIBUTION OF IRON (II) BETWEEN BUFFERED AQUEOUS SOLUTIONS AND CHLOROFORM SOLUTION OF N,N’-ETHYLENEBIS(4-BUTANOYL-2,4-DIHYDRO-5-METHYL-2-PHENYL-3H-PYRAZOL-3-ONEIMINE)
Authors: Godwin J. , Chukwu U. J. , Gad T. D.
Published: May 2018

The distribution of Fe(II) between buffered aqueous solution and chloroform solution of N,N’-Ethylenebis(4-butanoyl-2-4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-oneimine)(H2BuEtP) was investigated. The effect of 4-butanoyl-2-4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one(HBuP) in the distribution was also studied. Fe(II) concentration in aqueous raffinate was determined colorimetrically and distribution ratios and percentage extractions calculated by difference from Fe(II) in aqueous phase before and after equilibrations. The optimal pH for Fe(II) distribution slightly lowered to 8.00 in mixed ligands(H2BuEtP/HBuP) organic phase from 8.25 in ligand (H2BuEtP) alone organic phase. The pH range at which quantitative extraction of Fe(II) from aqueous buffered solution into both type of organic phases used for the study was very narrow. The extraction parameters; pH1/2, log D from extraction plots, and log Kex calculated using extraction equations derived from slope analysis showed that the values in both type of organic phases were very close even though mixed ligands(H2BuEtP/HBuP) organic phase values were slightly higher and better. Slope analysis also indicated that the Fe(II) complexes extracted into both organic phases were Fe(BuEtP)o and Fe(HBuEtP)(BuP)o respectively.
Adsorption of Hexavalent Chromium and phenol onto Bentonite Modified With HexaDecylTriMethylAmmonium Bromide (HDTMABr)
Authors: Slimani My. S. , Ahlafi H. , Moussout H. , Boukhlifi F. , Zegaoui O.
Published: May 2018

The efficiencies of Hexadecyltrimethylammonium bromide (HDTMABr) modified bentonite (HDTMABt) for phenol and chromium removal from aqueous solutions were studied in batch experiments at pH = 9 and pH = 2 values, respectively. FTIR, SEM, XRD and BET analyses indicated that the HDTMABr molecules were intercalated in the interlayer and at the external surface of initially Na-bentonite (NaBt). Adsorption experiments showed that the HDTMABt was more efficient than the initial NaBt for the removal of phenol and chromium, simultaneously, the extent of the enhancement differed among these pollutants depending on their affinity towards these samples. The kinetic study revealed a rapid adsorption onto HDTMABt of the pollutants during the initial stage (teq < 1h). The pseudo-second-order equation fitted well to the experimental data. Phenol adsorption on NaBt and HDTMABt could be described by a linear Freundlich equation while Langmuir and Freundlich models were the most suitable for Cr(VI) adsorption on both samples.
Spectrophotometric Assay of some Nitrogen Containing Drugs in Pharmaceutical Formulations using p-Chloranilic Acid Reagent
Authors: Al-Sabha Theia’a N. , A. Hasan Mahmood , A. Ibrahim Huda
Published: May 2018

A spectrophotometric method is developed for the determination of some drugs containing amino groups (sulfacetamide sodium, lidocaine and terbutaline sulfate) based on their reaction with p-chloranilic acid reagent in an organic medium forming colored charge transfer complexes. The complexes have maximum absorptions at 530 and 527 nm for sulfacetamide sodium and lidocaine respectively, but terbutaline sulfate gave two maximum absorptions at 529 and 319 nm. Beers law is obeyed over the concentration range of 10-60 µg.ml-1 for sulfacetamide sodium and lidocaine and 5-70 µg.ml-1 for terbutaline sulfate. The molar absorptivity values are 0.940×103, 0.913×103 L.mol-1.cm-1 for sulfacetamide sodium and lidocaine respectively while terbutaline sulfate gave 0.987×103 L.mol-1.cm-1 at 529 nm and 7.407×103 L.mol-1.cm-1 at 319 nm with accuracy range between 100.20% and 101.42% and RSD better than 3.15% for all drugs. The method is applied successfully for determination of these drugs in pharmaceutical formulations and compared favorably with British Pharmacopeia standard methods. F and t tests are less than the tabulated values at 95% confidence level.
Comparison of Adsorptive Removal of Total Nitrogen (T-N) and Total Phosphorous (T-P) in Aqueous Solution using Granular Activated Charcoal (GAC)
Authors: Ryoo Keon Sang , Choi Jong-Ha , Hong Yong Pyo
Published: May 2018

The present study is to explore the possibility of utilizing granular activated charcoal (GAC) for the removal of total phosphorous (T-P) and total nitrogen (T-N) in aqueous solution. Batch adsorption studies were carried out to determine the influences of various factors like initial concentration, contact time and temperature. The adsorption data showed that GAC has a similar adsorption capacity for both T-N and T-P. The adsorption degree of T-N and T-P on GAC was highly concentration dependent. It was found that the adsorption capacity of GAC is quite favorable at a low concentration. At concentrations of 1.0 mg L-1 of T-P and 2.0 mg L-1 of T-N, approximately 97 % of adsorption was achieved by GAC. The equilibrium data were fitted well to the Langmuir isotherm model. The pseudo-second-order kinetic model appeared to be the better-fitting model because it has higher R2 compared with the pseudo-first-order and intra-particle kinetic model. The theoretical adsorption equilibrium qe,cal from pseudo-second-order kinetic model were relatively similar to the experimental adsorption equilibrium qe,exp. To evaluate the effect of thermodynamic parameters at different temperatures, the change in free energy ΔG, the enthalpy ΔH and the entropy ΔS were estimated. Except for adsorption of T-P at 278 K, the ΔG values obtained were all negative at the investigated temperatures. It indicates that the present adsorption system occurs spontaneously. The adsorption process of T-N by GAC was exothermic in nature, whereas T-P showed endothermic behavior. In addition, the positive values of ΔS imply that there was the increase in the randomness of adsorption of T-N and T-P at GAC-solution interface.
Solubility Study and purification Of Industrial triple superphosphate in aqueous solution
Authors: Nasri Khouloud , Chtara Chaker , Chekir Hassen , EL Feki Hafed
Published: May 2018

Triple Superphosphate (TSP) is a chemical fertilizer, acknowledged by its important content of phosphorus, necessary element for plants. It’s obtained by adding phosphoric acid to phosphate ore, consisting of calcium phosphate containing many impurities. TSP was dissolved at different temperatures and in various amounts of water, filtered to remove insoluble compounds. Then the ionic conductivity was monitored for each solution as a function of the added amount of TSP. Aqueous solutions were evaporated to dryness and analyzed the P2O5. The starting materials and final products were analyzed by several methods (XRD, IR, NMR, SEM) confirming that after dissolution the product was purified.
Synthesis, crystal structure and spectroscopic characterization of a new organic bismuthate (III) [C9H28N4][Bi2Cl10].H2O
Authors: Aloui Z. , Abid S. , Jeanneau E. , Rzaigui M. , Ben Nasr C.
Published: May 2018

The chemical preparation, crystal structure and spectroscopic characterization of [C9H28N4][Bi2Cl10].H2O have been reported. This compound crystallizes in the monoclinic system in space group P21/c and cell parameters a = 12.2385 (6), b = 17.3062 (7), c = 13.0772 (6) Å, β = 104.475 (5)°, Z = 4 and V = 2681.9 (2) Å3. Its crystal structure has been determined and refined to R = 0.049, using 5848 independent reflections. The atomic arrangement can be described by an alternation of organic and inorganic layers. The inorganic layer built up of [Bi2Cl10]4– bioctahedra arranged in sandwich between the organic layer. The organic groups are interconnected by the water molecules through N-H…O(W) hydrogen bonds to form infinite zig-zag chains spreading along the b-axis. These Chains are themselves interconnected by means of the N–H…Cl hydrogen bonds originating from [Bi2Cl10]4– anions, to form a three-dimensional network. Intermolecular Cl…Cl interactions between adjacent dimeric [Bi2Cl10]4– anions have been observed. The compound was also characterized by FT-IR and Raman spectrscopies.
PENINGKATAN KEMAMPUAN GURU DALAM MEMANFAATKAN LINGKUNGAN SEKOLAH SEBAGAI SUMBER BELAJAR MELALUI DISKUSI KELOMPOK KERJA GURU DI SDN 1 JENANGAN
Authors: Nurmiyati Nurmiyati
Published: May 2018

Penelitian ini bertujuan untuk meningkatkan kemampuan guru Kelompok Kerja Guru (KKG) terhadap peningkatan kemampuan guru dalam memanfaatkan lingkungan sekolah sebagai sumber belajar Penelitian ini dilaksanakan dalam dua siklus, Adapun subyek penelitian ini adalah guru kelas I sampai dengan kelas VI samapai dengan Idi SDN 1 Jenangan. Pada siklus I nilai rata-rata yang diperoleh dari sikap guru berdiskusi diskusi adalah 79,6 katagori”cukup, sedangkan pada siklus II nilai rata-rata yang diperoleh adalah 85,16, katagori “baik”,nilai rata-rata yang diperoleh dari penilaian skenario pembelajaran pada siklus I yaitu 78,30 katagori “cukup” sedangkan pada siklus II nilai rata-rata yang diperoleh adalah 85,0, nilai rata-rata yang diperoleh dari penilaian pelaksanaan pembelajaran pada siklus I yaitu 78,3 katagori “cukup”, sedangkan pada siklus II nilai rata-rata yang diperoleh adalah 87,20 katagori
“baik”.Melihat nilai rata-rata yang diperoleh dari hasil analisis tersebut dapat disimpulkan bahwa dari siklus I ke siklus II , terjadi peningkatan nilai rata-rata yang diperoleh dari masing-masing komponen yang di observasi maupun yang dinilai, yang berarti pembinaan dan bimbingan melalui pendekatan diskusi kelompok kerja guru dapat meningkatkan kemampuan guru dalam pemanfaatan lingkungan sekolah sebagai sumber belajar. Berdasarkan keberhasilan tersebut di atas disarankan kepada guru-guru di SDN 1 Jenangan, agar lebih mengoptimalkan pemanfaatan lingkungan sekolah sebagai sumber belajar dengan memperbanyak variasi metode pembelajaran dalam penyusunan skenario pembelajaran maupun dalam pelaksanaan pembelajaran.
MAKNA SIMBOLIK TARI PENTUL MELIKAN DI TEMPURAN PARON NGAWI
Authors: Karimah Harmin Etikasari , Hanif Muhammad
Published: May 2018

Penelitian ini bertujuan untuk menganalisis dan mendeskripsikan makna simbolik Tari Pentul Melikan di Tempuran Paron Ngawi. Penelitian ini menggunakan pendekatan kualitatif deskriptif. Sumber data yang digunakan berupa sumber data primer dan sekunder. Teknik pengumpulan datanya  menggunakan wawancara, observasi, dan dokumentasi. Validasi data menggunakan triangulasi sumber, dan dianalisis dengan kualitatif model interaktif. Hasil penelitian menggambarkan bahwa Tari Pentul Melikan memiliki makna yang dalam. Hal tersebut terlihat dari gerakannya yaitu: (1) gerakan rangkaian tangan maknanya manusia harus saling membantu satu sama lain, (2)  jari mengembang ke hidung maknya setiap perbuatan manusia  harus tetap sesuai dengan ajaran dari Tuhan, (3) gerak tangan yang menengadah ke atas sambil mengucapkan kata “ maju bung” maknanya ajakan untuk semua agar tetap bersemangat untuk maju, (4) gerak tangan siku- siku kemudian serong ke kiri sambil mengucapkan kata “selalu” maknanya kejadian di dunia ini selalu berubah, (5) gerakan jari telunjuk mengacung maknanya Tuhan itu satu, bumi itu satu dan terus berputar, (6)  jari jempol mengacung sambil mengucapkan “sudah jadi“ maknanya manusia harus dapat mengendalikan diri sendiri dari hawa nafsu, (7) gerakan tangan  terbuka ke atas sambil mengucapkan kata “aku suka” maknanya kegembiraan seseorang karena telah berhasil mencapai sesuatu yang telah menjadi tujuan. 
Suitability of forms of preparing seeds of Dalbergia miscolobium Benth for exposure to the tetrazolium test / Adequação das formas de preparação de sementes de Dalbergia miscolobium Benth para exposição ao teste de tetrazolium
Authors: Matos Juliana Martins de Mesquita , Martins Rosana De Carvalho Cristo , Bellotto Valéria Regina , Rocha Lilian Gomes da Silva , Barbosa Eloiza Aparecida , Sampaio Samara Souza
Published: May 2018

Dalbergia miscolobium or Jacarandá do Cerrado is a species of legume in the Fabaceae family. It occurs in the sensu stricto Cerrado and in the dystrophic cerradão. It shows potential for landscaping and for recovering damaged areas. It is an endangered species and therefore is protected by the law that prevents cut in areas of the Federal District (Decree No. 14.783/93). The purpose of this study was to determine the best procedure to prepare seeds of Dalbergia miscolobium to assess viability in the tetrazolium test. We carried out the following treatments: i) hydration on filter paper at 25 ° C, ii) hydration on filter paper at 25 ° C followed by a cut in the tegument and iii) hydration on filter paper at 25 ° C followed bya complete removal of the tegument. The results were analyzed using analysis of variance and the Tukey range test. The analyzes showed that the best procedure to prepare seeds of Dalbergia miscolobium is the treatment in which there is a hydration followed by the complete removal of the integument. Where 78% of the seeds showed uniform staining, indicating that the seeds analyzed are of good quality. The other treatments, hydration and hydration followed by cutting, showed respectively 35% and 41% of viable seeds.

RESUMO

A Dalbergia miscolobium ou Jacarandá do Cerrado é uma espécie de leguminosa da família Fabaceae. Ocorre no sentido stricto Cerrado e no cerradão distrófico. Possui potencial para paisagismo e para recuperar áreas degradadas. É uma espécie ameaçada de extinção e, portanto, está protegida pela lei que previne o corte em áreas do Distrito Federal (Decreto 14.783 / 93). O objetivo deste estudo foi determinar o melhor procedimento de prepararação das sementes de Dalbergia miscolobium para serem submetidas à análise de viabilidade pelo teste de tetrazólio. Foram realizados os seguintes tratamentos: i) hidratação em papel de filtro a 25 ° C, ii) hidratação em papel de filtro a 25 ° C seguida de um corte no tegumento e iii) hidratação em papel de filtro a 25 ° C seguido de remoção completa do tegumento. Os resultados foram analisados utilizando-se a análise de variância e o teste de médias de Tukey. As análises mostraram que o melhor procedimento para preparar sementes de Dalbergia miscolobium é o tratamento em que há uma hidratação seguida pela remoção completa do tegumento, onde 78% das sementes apresentaram coloração uniforme, indicando que as sementes analisadas são de boa qualidade. Os demais tratamentos, hidratação e hidratação seguida de corte, mostraram respectivamente 35% e 41% de sementes viáveis.
The academic migration between Spain and Ecuador during the period of economic recession: a survival strategy of Spanish teachers and researchers?
Authors: Pérez-Gañán Rocío , Moreno Gorka
Published: May 2018

Within the flows of migrants with professional skills or education, Spanish academic migration has traditionally followed a North-North direction in its search for spaces of insertion. Nonetheless, during the economic crisis of the past few years, there has been a significant change and increase, directing migrants to counties in the global South. This change of direction is not a coincidence; it is in response to a geographic strategy which is articulated around two fundamental axes: securing teaching and research experience, which, in today’s Spain, is difficult to find yet key to enter or continue in Academia, and enjoying a quality of life which is not possible in Spain. By way of qualitative methodology, this paper attempts to highlight the principal elements and dynamics which make up this «new» geostrategic migration.
The emigration of Spanish abroad (2002-2011): geodemographic dimensions and characteristics
Authors: Romero-Valiente Juan Manuel
Published: May 2018

The aim of this work is extended the knowledge of the geo-demographic dimensions and characteristics of the emigration of Spanish abroad that takes place between 2002 and 2011. The principal sources used are the statistics of Spanish emigration that publishes the National Institute of Statistics of Spain, the statistics of Spanish immigration of the countries recipients and a survey about the situation of the Spanish abroad realized in 2012. The principal findings and conclusions of this work are: the magnitude of the flow is very superior to the one that the Spanish statistics indicate, concerning the double; the women, the young persons and born abroad have a singular leadership in this process; the principal areas of origin of emigres are both big urban Spanish agglomerations (Madrid and Barcelona); western Europe and Latin America are the principal areas of destination, emphasizing as area recipient the United Kingdom.
The imperative of mobility and the processes of precarity in Higher Education. Spanish professors and researchers between Ecuador and Spain
Authors: Gómez Carmen , Vega Cristina
Published: May 2018

The new mobilities of the Spanish are inextricably linked to the crisis and the way it impacts on Higher Education. In the last decade, Latin America has been a leading destination for qualified young people who have been inserted into university systems in the region attracted by educational reforms and demand for graduate degrees. In the article the keys to such insertion within the framework of an unequal knowledge economy on a global scale, questioning the implications of the imperative of mobility that today has been elevated to a requirement of the academic career, are analysed. The latter only conceals a form of precariousness that is prolonged over time, subject to the social, economic and political swings chained in the countries of origin, destination and transit. This is the case of Ecuador, which has gone from being a receiving country for university graduates to presenting a scenario of incorporation and uncertain permanence. This gives rise to different responses, among them, the return to Spain, the displacement to new destinations and the insertion in other labour or training activities in Ecuador. Based on a survey and in-depth interviews with Spaniards at Ecuadorian universities, as well as data from the Ecuadorian higher education system, the inequalities that arise in these mobilities, the role played by university policies and the dynamics of crisis, are analysed in the article. That condition the displacements.
Outcome of the public consultation on the draft guidance on the assessment of the efficacy of feed additives
Authors:   European Food Safety Authority (EFSA)
Published: May 2018

The European Food Safety Authority (EFSA) carried out a public consultation to receive input from the scientific community and all interested parties on the draft guidance on the assessment of the efficacy of feed additives prepared by the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) and endorsed by the Panel for public consultation at its Plenary meeting on 28 November 2017. The written public consultation for this document was open from 04 December 2017 to 28 January 2018. EFSA received a total of 175 comments from twelve interested parties. EFSA and its FEEDAP Panel wish to thank all stakeholders for their contributions. The current report summarises the outcome of the public consultation, and includes the comments received and how the comments were addressed. The FEEDAP Panel prepared an updated version of the guidance on the assessment of the efficacy of feed additives taking into account the questions/comments received. This guidance was discussed and adopted at the FEEDAP Plenary meeting on 17 April 2018, and is published in the EFSA Journal.
PENGARUH JARAK DAN POLA PREFABRICATED VERTICAL DRAIN (PVD) PADA PERBAIKAN TANAH LEMPUNG LUNAK = EFFECT OF DISTANCE AND PATTERN OF PREFABRICATED VERTICAL DRAIN FOR IMPROVEMENT OF SOFT CLAY SOIL
Authors: Aspar Wimpie Agoeng Noegroho , Fitriani Eka Nur
Published: May 2018

Abstract

If a structure for reasons of technical, economic, social, or startegic is to be builtÂ on a soft ground, then there are usually two problems to be solved, namely theÂ low geotechnical bearing capacity and large soil deformation with sometimesÂ differential settlement. Pre-compression is a foundation soil compression processÂ with the provision of temporary loading (preloading) before actually constructing aÂ building. Pre-fabricated vertical drain is a synthetic drainage system installedÂ vertically inside soft soil layers. Soil condition at the project activity is a relativelyÂ very soft clay soil with relatively high coefficient of consolidation resulting in veryÂ long period of consolidation process. Therefore, it is needed advance soilÂ improvement by prealoding of pre-fabricated vertical drain. Spacings of installedÂ PVD vary, those are 50 cm, 100 cm, 150 cm, and 200 cm with a pattern ofÂ triangles and rectangles. Based on the analytical calculation, it is resulted thatÂ optimum PVD distance to achieve 90% consolidation is 150 cm with a triangularÂ pattern. The time of consolidation was achieved within four months.

Â 

Abstrak

Ketika suatu struktur karena alasan-alasan teknis, ekonomi, sosial, atau strategisÂ terpaksa didirikan di atas tanah lunak, maka biasanya ada dua masalah geoteknikÂ yang harus dipecahkan yaitu daya dukung yang rendah dan penurunan sertaÂ beda penurunan yang besar. Prakompresi adalah suatu proses pemampatanÂ tanah pondasi dengan jalan pemberian pembebanan sementaraÂ (prabeban/preloading) sebelum konstruksi yang sesungguhnya didirikan. PrefabricatedÂ vertical drain (PVD) adalah sistem drainase buatan yang dipasangÂ vertikal di dalam lapisan tanah lunak. Kondisi tanah di lokasi kegiatan relatifÂ sangat lunak dengan koefisien konsolidasi relatif sangat tinggi mengakibatkanÂ proses konsolidasi berjalan relatif sangat lama. Untuk itu diperlukan perbaikanÂ tanah terlebih dahulu dengan prealoading menggunakan PVD. Jarak spasi antarÂ PVD yang dipasang bervaiasi yaitu 50 cm, 100 cm, 150 cm, dan 200 cm denganÂ pola konfigurasi segitiga dan segiempat. Berdasarkan hasil perhitungan secaraÂ analitis didapatkan jarak optimum PVD untuk mencapai konsolidasi 90% adalahÂ 150 cm dengan pola segitiga dengan proses konsolidasi dicapai selama waktuÂ penurunan 4 bulan.
PENGEMBANGAN PENGECORAN BERBAHAN BAKU PADUAN MANGANESE BRONZE UNTUK PROPELLER KAPAL YANG BERBASIS BAHAN SCRAP = CASTING DEVELOPMENT OF MANGANESE BRONZE ALLOY FOR SHIP PROPELLER BASED ON SCRAP MATERIAL
Authors: Iwan Setyadi
Published: May 2018

Many attempts were made to improve the quality of ship components, in particular the ship's propeller made through little-midle industries of casting (IKM) in order to reduce dependence on imports and in order to increase local content for the national ship industries. One of the efforts is to design the material balance of manganese bronze alloy to be applied on a ship's propeller foundry by using scrap materials. In this research, the variable is the percentage level of manganese in the alloy. Achievement of optimal research results occurred in 3.27% Mn content, which obtained an increase in hardness into BHN 180.4, up 11.9% from the initial conditions with Mn content of 0.42%. While the grain size reached 130.78 Î¼m, or 30.6% less than the current content of 0.42% Mn.

Â 

ABSTRAK

Banyak upaya dilakukan untuk meningkatkan kualitas komponen kapal, khususnya baling-baling kapal yang dibuat melalui IKM pengecoran guna mengurangi ketergantungan impor dan dalam upaya peningkatan TKDN untuk industri kapal nasional. Salah satu upaya yang dilakukan adalah merancangneraca bahan paduan manganese bronze untuk diaplikasikan pada pengecoran baling-baling kapal dengan memanfaatkan bahan scrap. Dalam penelitian ini yang diatur adalah kadar prosentasi mangan dalam paduan. Pencapaian hasil penelitian yang optimal terjadi pada kandungan 3,27% Mn, dimana diperoleh peningkatan kekerasan menjadi 180,4 BHN atau naik 11,9 % dari kondisi awal dengan kandungan Mn 0,42%. Sedangkan ukuran butirnya mencapai 130,78 Î¼m, atau lebih kecil 30,6 % dibanding saat kandungan 0,42% Mn.