scholarly journals Mathematical description of ethylamine sorption from air by fibrous cation exchangers under conditions of limited sorbate permeability

2020 ◽  
Vol 56 (1) ◽  
pp. 7-14 ◽  
Author(s):  
E. G. Kosandrovich ◽  
L. N. Shachenkova ◽  
A. L. Pushkarchuk ◽  
T. V. Bez’yazychnaya ◽  
V. S. Soldatov
Keyword(s):  
Experimental Data ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Air Humidity ◽  
Acid Base ◽  
Relative Air Humidity ◽  
Cation Exchangers ◽  
Henry's Constants ◽  
Good Agreement ◽  
Base Properties

A mathematical model for description of the sorption capacity of ion exchangers on alkaline compounds protonizable in aqueous solutions (exemplified by ammonia, mono-, diand triethylamine) was proposed. The Henry’s constants for these substances were experimentally determined. The model accounts for the concentration and acid-base properties of the sorbate, relative air humidity, acid-base properties and exchange capacity of the ion exchanger, as well as spatial availability of functional groups for interaction under conditions of limited permeability of polymeric ion exchanger. The applicability of the model is illustrated by processing the experimental results on the sorption of ammonia and ethylamines by fibrous carboxylic and sulfonic cation exchangers. Good agreement between the calculated and experimental data is observed.

scholarly journals Determination of the hygroscopic equilibrium and isosteric heat of aji chili pepper

2017 ◽  
Vol 21 (12) ◽  
pp. 865-871 ◽  
Author(s):  
Ednilton T. Andrade ◽  
Vitor G. Figueira ◽  
Luciana P. Teixeira ◽  
José H. da S. Taveira ◽  
Flávio M. Borém
Keyword(s):  
Experimental Data ◽  
Moisture Content ◽  
Isosteric Heat ◽  
Chili Pepper ◽  
Sorption Behavior ◽  
Activity Levels ◽  
Air Humidity ◽  
Relative Air Humidity ◽  
Best Fit

ABSTRACT This study focuses on the determination of the hygroscopic equilibrium and isosteric heat of the aji chili pepper (Capsicum baccatum) under different controlled temperature and relative air humidity conditions. In addition, the objective was to adjust the model among the existing literature models that best represent the isothermal sorption behavior, as well as propose a new model to represent this phenomenon. Having obtained the mathematical models and experimental data, the best model and parameters that represent the hygroscopicity and the isosteric heat satisfactorily was determined. The temperatures used were 30, 55, and 70 °C, with water activity levels from 0.11 to 0.84. The model that best fit the data had a R2 value of 0.97. The integral isosteric heat of sorption for ‘Dedo-de-Moça’ chili pepper within a moisture content from 0.07 to 0.55 (dry basis) ranged from 3641.66 to 2614.38 kJ kg-1.

scholarly journals Pengambilan ion cadmium (II) dari air limbah simulasi menggunakan fly ash aktif: studi kesetimbangan

2018 ◽  
Vol 7 (2) ◽  
pp. 798
Author(s):  
I Made Bendiyasa ◽  
D Setiawan ◽  
R. Octaviany
Keyword(s):  
Experimental Data ◽  
Fly Ash ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Langmuir Model ◽  
Initial Concentration ◽  
Fixed Concentration ◽  
Experimental Rig ◽  
Langmuir And Freundlich Models ◽  
Good Agreement

The experimental study of equilibrium of Cadmium (II) adsorbed with fly ash has been performed. The experimental rig was consisted of a 0.5 L three neck flask, a stirrer, a condenser and a thermometer. The rig was immersed in a water bath that was used to control the experimental temperature. The three neck flask was filled with 0.3 L Cadmium solution of a fixed concentration and then 0.3 g of flay ash was put into the flask. Chemical composition of fly ash are as follows (weight %): SiO2 = 54,23; Al2O3 = 25,38; H2O = 2,5; MgO = 1,O; Ca0 = 4,63; Na20 = 0,32; K20 = 0,60; Mn0 = 0,014; Fe2O3 = 6,01; TiO2 = 0,007; P2O5 = 0,042 and loss of ignition (LOI) is 5,26. Cation exchange capacity is 990 meq/kg fly ash. Each run was conducted for 2 hours, and at the end of each experiment Cadmium (II) was analyzed with Atomic Absorbtion Spectrophotometer (AAS). Variables studied were temperature ranging from 303 to 323 K and initial concentration of Cadmium (II) from 7 to 10 mg Cadmium (II) L-1. Experimental data were evaluated with both Langmuir and Freundlich models. It is found that the experimental data is in a good agreement with Langmuir model. Relationships between K for Langmuir and Freundlich and temperature are, respectively, KLangmuir = 2,841066e(-35401,01/RT) and KFreundlich = 4, 75104e(-34403,20/RT) Keywords: fly ash, Langmuir, Freundlich, Cadmium, equilibrium Abstrak Pengambilan Cd(II) dari air limbah simulasi diteliti dengan menggunakan fly ash sebagai adsorben. Tujuan utama penelitian ini adalah mempelajari kesetimbangan adsorpsi Cd(II) dengan fly ash. Disamping itu juga bertujuan untuk mengetahui kapasitas maksimum adsorpsi fly ash. Setiap percobaan dilakukan dalam suatu reaktor batch yang suhunya dipertahankan tetap. Reaktor yang digunakan adalah labu leher tiga dengan volum 0, 5 L yang dilengkapi dengan pengaduk merkuri, pendingin balik, dan termometer. Fly ash dengan berat 0,3 gram dimasukkan ke dalam reaktor yang telah diisi dengan suatu larutan Cadmium dengan volume 0,3 L dan konsentrasi tertentu. Komposisi kimia fly ash adalah (% berat): %): SiO2 = 54,23; Al2O3 = 25,38; H2O = 2,5; MgO = 1,O; Ca0 = 4,63; Na20 = 0,32; K20 = 0,60; Mn0 = 0,014; Fe2O3 = 6,01; TiO2 = 0,007; P2O5 = 0,042 dan berat hilang = 5,26. Fly ash yang dipakai mempunyai nilai kapasitas pertukaran kation (KPK) yang nilainya sama dengan 990 meq/kg fly ash. Setiap percobaan dilakukan selama dua jam, dan kemudian konsentrasi Cd(II) di dalam larutan  dianalisis kadar Cd(II)-nya menggunakan Atomic Absorbtion Spectrophotometer (AAS). Variabel yang dipelajari adalah suhu (T) dan konsentrasi awal (Co) larutan. Kisaran suhu yang diteliti adalah 303 sampai 323 K dan konsentrasi awal (Co) antara 7 sampai 10 mg Cd(11) L-1. Data percobaan dievaluasi dengan model Langmuir dan Freundlich.  Hasil penelitian menunjukkan bahwa adsorpsi Cd(II) dengan fly ash lebih sesuai dengan model Langmuir. Hubungan K untuk Langmuir dan Freundlrich dengan suhu berturut adaIah KLangmuir = 2,841066e(-35401,01/RT) and KFreundlich = 4, 75104e(-34403,20/RT)Kata kunci: fly ash, Langmuir, Freundlich, Cadmium, kesetimbangan

scholarly journals Immobilization of Residual Basic Dyes onto Polyamide Ion-Exchanger Materials

2005 ◽  
Vol 23 (7) ◽  
pp. 555-572 ◽  
Author(s):  
Mohamed Hassen V Baouab ◽  
Mohamed Khalfaoui ◽  
Aghleb Bartegi ◽  
Robert Gauthier
Keyword(s):  
Experimental Data ◽  
Methacrylic Acid ◽  
Exchange Capacity ◽  
Ion Exchanger ◽  
Visible Spectroscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nylon 6,6 ◽  
Basic Dyes ◽  
Langmuir And Freundlich Models

This paper reports the preparation of methacrylic acid-grafted nylon (MAA—nylon) by treating nylon-6,6 fibres with methacrylic acid (MAA) and the use of this modified polyamide as an ion-exchanger for the immobilization of pollutant basic dyes. The grafting of MAA onto nylon-6,6 was demonstrated both by weight uptake and atomic force microscopy. The exchange capacity of MAA—nylon was evaluated by potentiometric titration of the acidic groups. Five MAA—nylon fibres with different degrees of grafting (20–80%) were tested for the adsorption of two basic dyes, viz. Basic Blue 3 and Basic Red 24. Such adsorption was monitored by visible spectroscopy. The adsorption capacity was found to depend on the degree of grafting and on the temperature. The experimental data were fitted using the Langmuir and Freundlich models. However, an improved fit could be obtained by using the Jossens model.

Acid-base properties of carboxylic cation exchangers

1980 ◽  
Vol 201 ◽  
pp. 51-57 ◽  
Author(s):  
Henryk Galina ◽  
Bożena N. Kolarz
Keyword(s):  
Acid Base ◽  
Cation Exchangers ◽  
Base Properties

Visco-elastic changes of vocal fold mucosa related to high and low relative air humidity

2000 ◽  
Vol 25 (4) ◽  
pp. 329-330
Author(s):  
R.J.B. Hemler ◽  
G.H. Wieneke ◽  
P.H. Dejonckere
Keyword(s):  
Vocal Fold ◽  
Air Humidity ◽  
Relative Air Humidity

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

Clinical, epidemiological and climatic factors related to the occurrence of cutaneous leishmaniasis in an endemic area in northeastern Brazil

2020 ◽  
Author(s):  
R. S. Oliveira ◽  
K. B. A. Pimentel ◽  
M. L. Moura ◽  
C. F. Aragão ◽  
A. S. Guimarães-e-Silva ◽  
...  
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Climatic Factors ◽  
Wide Distribution ◽  
Northeastern Brazil ◽  
Public Health Issue ◽  
Air Humidity ◽  
Disease Occurrence ◽  
Relative Air Humidity ◽  
Age Range ◽  
And Control

Abstract Cutaneous leishmaniasis (CL) is a neglected tropical disease with a wide distribution in the Americas. Brazil is an endemic country and present cases in all states. This study aimed to describe the occurrence, the underlying clinical and epidemiological factors, and the correlation of climatic variables with the frequency of reported CL cases in the municipality of Caxias, state of Maranhão, Brazil. This is a retrospective and descriptive epidemiological study based on data extracted from the Brazilian Information System of Diseases Notification, from 2007 to 2017. Maximum and minimum temperature, precipitation, and relative air humidity data were provided by the Brazilian National Institute of Meteorology. A total of 201 reported autochthonous CL cases were analyzed. The predominance of cases was observed in males (70.1%). The age range between 31 and 60 years old was the most affected, with 96 cases (47.9%). Of the total number of registered cases, 38.8% of the affected individuals were engaged in agriculture-related activities. The georeferenced distribution revealed the heterogeneity of disease occurrence, with cases concentrated in the Western and Southern regions of the municipality. An association was detected between relative air humidity (monthly mean) and the number of CL cases per month (p = 0.04). CL continues to be a concerning public health issue in Caxias. In this context, there is a pressing need to strengthen measures of prevention and control of the disease through the network of health services of the municipality, considering local and regional particularities.

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