Study on Optimum IUPAC Adsorption Isotherm Models Employing Sensitivity of Parameters for Rigorous Adsorption System Performance Evaluation

Adsorption cooling technologies driven by low-grade thermal or solar power are used as an energy-efficient alternative to conventional refrigeration and air conditioning systems. Explicit understanding of the adsorption cycles requires precise determination of the performance parameters, replication of the experimental data, and the rigorous study of the adsorption heat transformation method. Hence, the optimum adsorption isotherms model must be identified. Scientists often face difficulties in selecting the suitable isotherm model as there are many models for a particular form of adsorption isotherm. The present study introduces a novel approach for choosing the optimal models for each type of International Union of Pure and Applied Chemistry (IUPAC) classified adsorption isotherm using robust statistical methods. First, the box-and-whisker plots of error identification are employed. Tóth for Type-I(a) and Type-I(b), modified BET for Type-II, GAB for Type-III, Universal for Type-IV(a), and Type-IV(b), Sun Chakrabarty for Type-V, and Yahia et al. for Type-VI were found lower than the other candidate models in box-and-whisker plot. The optimality of our selected models was further verified using analysis of variance (ANOVA), pairwise Tukey honest significant difference (HSD) test, Kruskal–Wallis rank-sum test, and pairwise Wilcoxon rank-sum test. In short, rigorous statistical analysis was performed to identify the best model for each type of isotherm by minimizing error. Moreover, specific cooling effect (SCE) of Maxsorb III/ethanol and silica gel/water pairs were determined. Results showed that Tóth is the optimal isotherm model for the studied pairs, and the SCE values obtained from the model agree well with experimental data. The optimum isotherm model is indispensable for the precise designing of the next generation adsorption cooling cycles.

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The Water Adsorption Isotherm Models on Activated Alumina

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.229-231.100 ◽

2012 ◽

Vol 229-231 ◽

pp. 100-104 ◽

Cited By ~ 1

Author(s):

Yun Fei Shi ◽

Xiang Jun Liu ◽

Hui Jiao Nie ◽

Yin Shu Liu

Keyword(s):

Experimental Data ◽

Water Vapor ◽

Adsorption Isotherm ◽

Water Adsorption ◽

Isotherm Model ◽

Isotherm Models ◽

Activated Alumina ◽

Adsorption Isotherm Models ◽

Adsorption Data

The adsorption isotherm model of water vapor on activated alumina is an essential equation in designing the performance of adsorption. In this paper, the currently existed 14 isotherm models of water adsorption are summarized. The correlations among these models are analyzed. These isotherm models are evaluated by fitting the water adsorption data on Rhone-Poulenc activated alumina. The results show that AD-Toth, AD-LRC, AD-UNILAN and DMAP can fit the experimental data well.

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Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

10.31221/osf.io/w9dj6 ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Adsorption Isotherm ◽

Adsorption Capacity ◽

Organic Solvents ◽

Competitive Adsorption ◽

Correlation Factor ◽

Isotherm Model ◽

Isotherm Models ◽

High Concentration ◽

Dual Purpose ◽

Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

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Should All Cases of High-Grade Serous Ovarian, Tubal, and Primary Peritoneal Carcinomas Be Reclassified as Tubo-Ovarian Serous Carcinoma?

International Journal of Gynecological Cancer ◽

10.1097/igc.0000000000000477 ◽

2015 ◽

Vol 25 (7) ◽

pp. 1201-1207 ◽

Cited By ~ 9

Author(s):

Esther Louise Moss ◽

Tim Evans ◽

Philippa Pearmain ◽

Sarah Askew ◽

Kavita Singh ◽

...

Keyword(s):

Overall Survival ◽

Clear Cell ◽

Stage Iii ◽

Serous Carcinoma ◽

Low Grade ◽

Type I ◽

High Grade ◽

Type Ii ◽

Ovarian Serous Carcinoma ◽

Significant Difference

IntroductionThe dualistic theory of ovarian carcinogenesis proposes that epithelial “ovarian” cancer is not one entity with several histological subtypes but a collection of different diseases arising from cells of different origin, some of which may not originate in the ovarian surface epithelium.MethodsAll cases referred to the Pan-Birmingham Gynaecological Cancer Centre with an ovarian, tubal, or primary peritoneal cancer between April 2006 and April 2012 were identified from the West Midlands Cancer Registry. Tumors were classified into type I (low-grade endometrioid, clear cell, mucinous, and low-grade serous) and type II (high-grade serous, high-grade endometrioid, carcinosarcoma, and undifferentiated) cancers.ResultsOvarian (83.5%), tubal (4.3%), or primary peritoneal carcinoma (12.2%) were diagnosed in a total of 583 woman. The ovarian tumors were type I in 134 cases (27.5%), type II in 325 cases (66.7%), and contained elements of both type I and type II tumors in 28 cases (5.7%). Most tubal and primary peritoneal cases, however, were type II tumors: 24 (96.0%) and 64 (90.1%), respectively. Only 16 (5.8%) of the ovarian high-grade serous carcinomas were stage I at diagnosis, whereas 240 (86.6%) were stage III+. Overall survival varied between the subtypes when matched for stage. Stage III low-grade serous and high-grade serous carcinomas had a significantly better survival compared to clear cell and mucinous cases,P= 0.0134. There was no significant difference in overall survival between the high-grade serous ovarian, tubal, or peritoneal carcinomas when matched for stage (stage III,P= 0.3758; stage IV,P= 0.4820).ConclusionsType II tumors are more common than type I and account for most tubal and peritoneal cancers. High-grade serous carcinomas, whether classified as ovarian/tubal/peritoneal, seem to behave as one disease entity with no significant difference in survival outcomes, therefore supporting the proposition of a separate classification of “tubo-ovarian serous carcinoma”.

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A Statistical Approach to Determine Optimal Models for IUPAC-Classified Adsorption Isotherms

Energies ◽

10.3390/en12234565 ◽

2019 ◽

Vol 12 (23) ◽

pp. 4565 ◽

Cited By ~ 5

Author(s):

Rahman ◽

Muttakin ◽

Pal ◽

Shafiullah ◽

Saha

Keyword(s):

Adsorption Isotherm ◽

Adsorption Isotherms ◽

Fossil Fuels ◽

Information Criterion ◽

Single Type ◽

Average Error ◽

Type I ◽

Bootstrap Sampling ◽

Selection Probability ◽

Type Iv

Adsorption heat transformation (AHT) systems can play a major role in protecting our environment by decreasing the usage of fossil fuels and utilizing natural and alternative working fluids. The adsorption isotherm is the most important feature in characterizing an AHT system. There are eight types of International Union of Pure and Applied Chemistry (IUPAC) classified adsorption isotherms for different “adsorbent-adsorbate” pairs with numerous empirical or semi-empirical mathematical models to fit them. Researchers face difficulties in choosing the best isotherm model to describe their experimental findings as there are several models for a single type of adsorption isotherm. This study presents the optimal models for all eight types of isotherms employing several useful statistical approaches such as average error; confidence interval (CI), information criterion (ICs), and proportion tests using bootstrap sampling. Isotherm data of 13 working pairs (which include all eight types of IUPAC isotherms) for AHT applications are extracted from literature and fitted with appropriate models using two error functions. It was found that modified Brunauer–Emmet–Teller (BET) for Type-I(a) and Type-II; Tóth for Type-I(b); GAB for Type-III; Ng et al. model for Type-IV(a) and Type-IV(b); Sun and Chakraborty model for Type-V; and Yahia et al. model for Type-VI are the most appropriate as they ensure less information loss compared to other models. Moreover; the findings are affirmed using selection probability; overall; and pairwise proportion tests. The present findings are important in the rigorous analysis of isotherm data.

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Biosorption potentials of acid modified Saccharum bengalense for removal of methyl violet from aqueous solutions

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq151217054d ◽

2017 ◽

Vol 23 (3) ◽

pp. 399-409 ◽

Cited By ~ 5

Author(s):

Muhammad Din ◽

Kiran Ijaz ◽

Khalida Naseem

Keyword(s):

Experimental Data ◽

Adsorption Isotherm ◽

Aqueous Medium ◽

Methyl Violet ◽

Isotherm Models ◽

Langmuir Adsorption ◽

First Order ◽

Adsorption Isotherm Models ◽

Intra Particle Diffusion ◽

Pseudo Second Order

In the present work, Saccharum bengalense (SB) was treated with sulfuric acid to enhance its efficiency. Methyl violet (MV), a cationic dye, was removed from aqueous medium using acid modified S. bengalense (A-SB). Different parameters like adsorbent dosage, stirring speed, temperature, contact time and effect of initial concentration of dye on rate of adsorption of dye from aqueous medium was studied. Experimental data obtained from adsorption of MV was analyzed by applying pseudo first order, pseudo second order and intra-particle diffusion models and it was found that the data best follows the pseudosecond order kinetics. Thermodynamic parameters indicate that adsorption reaction was spontaneous, feasible and endothermic in nature. Different adsorption isotherm models, like Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin, were used to study the mechanism of adsorption process and experimental data was well fitted by the Langmuir adsorption isotherm.

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Investigating clinical characteristics and prognostic factors in patients with chronic osteomyelitis of humerus

Burns & Trauma ◽

10.1186/s41038-019-0173-0 ◽

2019 ◽

Vol 7 ◽

Author(s):

Hongri Wu ◽

Shengpeng Yu ◽

Jingshu Fu ◽

Dong Sun ◽

Shulin Wang ◽

...

Keyword(s):

Chronic Osteomyelitis ◽

Plate Fixation ◽

Case Series ◽

Type I ◽

Cement Spacer ◽

Nerve Injuries ◽

Soft Tissue Envelope ◽

Type Iv ◽

Significant Difference

Abstract Background Chronic osteomyelitis in the humerus, which has complex neuroanatomy and a good soft tissue envelope, represents a unique clinical challenge. However, there are relatively few related studies in the literature. This article retrospectively reviewed a large case series with the aims of sharing our management experiences and further determining factors associated with the outcomes. Methods Twenty-eight consecutive adult patients with a mean age of 36 years were identified by reviewing the osteomyelitis database of our clinic centre. The database was used to prospectively identify all osteomyelitis cases between 2013 and 2017, and all data then was retrospectively analysed. Results The mean follow-up period was 35 months (range 24–60). The aetiology was trauma in 43% (12) of the patients and haematogenous in 57% (16) of the patients, and Staphylococcus aureus was a solitary agent in 50% (14) of the patients. Host-type (Cierny’s classification) was IA in 8, IIIB in 11 and IVB in 9 patients. All patients required debridement followed by the placement of a temporary antibiotic-impregnated cement spacer (rod). Seventeen patients received a cement-coated plate for internal fixation after debridement, and 13 patients needed bone grafts when the spacer was staged removed. All patients attained an infection-free bone healing state at the final follow-up. The final average DASH (disabilities of the arm, shoulder and hand) score was 18.14 ± 5.39, while 6 patients (two developed traumatic olecranarthritis, four developed radial nerve injuries) showed the lowest levels of limb function (p = 0.000) and were unemployed. Three patients (type I; significant difference between type I versus type III and type IV patients, p < 0.05) experienced recurrence after debridement and underwent a second revision, which was not related to the bone graft (p = 0.226) or plate fixation (p = 0.050). Conclusions Humeral chronic osteomyelitis can be treated with general surgery and anti-infective therapy; medullary (type I) infection presents a challenge, and the antibiotic-coated cement plate provides favourable fixation without increasing recurrence of infections. Clinicians should be aware of potential iatrogenic nerve injuries when treating these patients with complicated cases, and an experienced surgeon may improve the outcome.

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The Value of Contrast-Enhanced Ultrasound Classification in Diagnosis of Pancreatic Cystic Lesions

BioMed Research International ◽

10.1155/2019/5698140 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Yixi Wang ◽

Yanjie Wang ◽

Zhihui Fan ◽

Jun Shan ◽

Kun Yan

Keyword(s):

Diagnostic Accuracy ◽

Diagnostic Value ◽

Type I ◽

Cystic Lesions ◽

Type Ii ◽

Contrast Enhanced Ultrasound ◽

Type Iii ◽

Type Iv ◽

Contrast Enhanced ◽

Significant Difference

Objective. To compare the consistency of contrast-enhanced ultrasound (CEUS) classification results with magnetic resonance imaging (MRI) and to investigate the diagnostic value of CEUS classification in pancreatic cystic lesions. Methods. 84 cases of pancreatic cystic lesions were enrolled in this study. According to the CEUS classification methods of previous study in our center, all the lesions were classified into four types: type I, unilocular cysts; type II, microcystic lesions; type III, macrocystic lesions; and type IV, cystic lesions with enhanced solid components. The consistency of CEUS and MRI typing results was analysed. Among the 84 cases, 45 cases had pathological results. The CEUS results were compared with the pathological results, and the diagnostic value of CEUS classification in diagnosing pancreatic cystic lesions was explored. Results. Among the 84 cases, CEUS diagnosed 8 cases of type I, 24 of type II, 8 of type III, and 45 of type IV. MRI diagnosed 10 cases of type I, 25 of type II, 7 of type III, and 43 of type IV. The classification typing results of CEUS were highly consistent with that of enhanced MRI (kappa value: 0.852). Among the 45 cases with pathological results, the diagnostic accuracy of each type was 91.1%, 95.6%, 93.3%, and 88.9%. The accuracy of CEUS and MRI in diagnosing pancreatic cystic lesions was 75.56% (34/45) and 80% (36/45), respectively. The diagnostic accuracy of CEUS had no significant difference from that of MRI (P=0.687). Conclusion. The classification results by CEUS and MRI are in excellent agreement. The classification of pancreatic cystic lesions by CEUS is significantly helpful for clinical diagnosis.

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Alternative Composite Nanosorbents Based on Turkish Perlite for the Removal of Cr(VI) from Aqueous Solution

Journal of Nanomaterials ◽

10.1155/2015/697026 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 7

Author(s):

Serpil Edebali

Keyword(s):

Electron Microscopy ◽

Experimental Data ◽

Aqueous Solution ◽

Scanning Electron Microscopy ◽

Contact Time ◽

Isotherm Model ◽

Isotherm Models ◽

Chromium Removal ◽

Ph Dependent ◽

Scanning Electron

New nanocomposite sorbents were synthesized and used for Cr(VI) removal from aqueous solution by modifying Turkish perlite withα-MnO2(PAM) andγ-Fe2O3(PGI) nanoparticles. Nanocomposite sorbents were characterized using scanning electron microscopy (SEM) and FTIR. The effects of several parameters such as contact time, amount of sorbent, pH, and concentration were investigated and it was found that the sorption capacity for Cr(VI) was found to be highly pH dependent. Also the experimental data were evaluated in terms of different isotherm models. The data of PGI were well fit to DR isotherm model whereas PAM data were well described with Temkin isotherm model. The sorption capacities were found to be 8.64 and 7.6 mg g−1for PGI and PAM, respectively. This confirms that these nanocomposites retain the constituent nanoparticle properties while being macroscopic particles suitable for chromium removal in water treatment.

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Adsorption of Toluene Using Low Cost Adsorbent

Jurnal Teknologi ◽

10.11113/jt.v40.420 ◽

2012 ◽

Author(s):

Bassim H. Hameed ◽

Abdul Rahman Mohamed ◽

Hui Ying Chong

Keyword(s):

Experimental Data ◽

Low Cost ◽

Freundlich Isotherm ◽

Langmuir Model ◽

Isotherm Model ◽

Isotherm Models ◽

Batch System ◽

Key Words Toluene ◽

Langmuir Isotherm Model ◽

Langmuir And Freundlich Models

Kertas kerja ini membincangkan tentang kecekapan penjerap yang lebih murah, iaitu tayar getah terbuang (DRT), dalam menyingkirkan toluena daripada fasa akuas. Penjerapan toluena pada tayar getah terbuang dikaji menggunakan sistem berkelompok pada suhu 25°C dan 30°C. Daripada kajian ini, didapati toluena dapat disingkirkan sehingga 70% dengan menggunakan julat kepekatan awalan antara 50 mg/l hingga 300 mg/l. Dengan menggunakan model keseimbangan terlelurus, iaitu model Langmuir dan Freundlich, keupayaan penjerapan maksimum dapat ditentukan. Daripada data eksperimen, terbukti bahawa walaupun kedua–dua model isoterma Langmuir dan Freundlich boleh menjelaskan data isoterma, tetapi penjerapan toluena pada DRT dapat ditunjukkan dengan lebih baik oleh isoterma Freudlich. Bagi nilai K Freundlich, keupayaan penjerapan ialah 6.6374 mg/l dan 7.7535 mg/l, pada suhu 25°C dan 30°C. Nilai eksponen n Freudlich adalah lebih daripada satu untuk kedua–dua suhu. Kata kunci: Toluena, penjerapan, isoterma, tayar getah terbuang, model isoterma Langmuir, model isoterma Freundlich This paper discusses the effectiveness of a less expensive adsorbent, a discarded rubber tyre (DRT) in removing toluene from aqueuos phase. Adsorption of toluene on a DRT has been studied by using batch system at 25 and 30°C. It was found that up to 70% of toluene was removed for the range of toluene initial concentrations studied between 50–300 mg/l. Using linearized forms of equilibrium models, namely Langmuir and Freundlich models, the maximum adsorptive capacities were determined. It was evident from the experimental data that, although both Langmuir and Freundlich isotherm models could describe the isotherm data, the adsorption of toluene on a DRT was described well by the Freundlich isotherm. For Freundlich K values, sorption capacities were 6.6374 and 7.7535 mg/l at 25 and 30°C, respectively. The values of Freundlich exponent n were greater than one for both temperatures. Key words: Toluene, adsoprtion, isotherms, discarded rubber tyre, Langmuir isotherm model, Freundlich isotherm model

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C-O-H-N fluid inclusions associated with gold-stibnite mineralization in low-grade metamorphic rocks, Mari Rosa mine, Caceres, Spain

Mineralogical Magazine ◽

10.1180/minmag.1991.055.379.12 ◽

1991 ◽

Vol 55 (379) ◽

pp. 235-247 ◽

Cited By ~ 10

Author(s):

L. Ortega ◽

E. Vindel ◽

C. Beny

Keyword(s):

Black Shales ◽

Low Grade ◽

Type I ◽

Homogeneous Fluid ◽

Quartz Veins ◽

Type Iv ◽

Two Generations ◽

Deformation Event ◽

Rich Mixtures ◽

Main Deformation

AbstractThe Mari Rosa mine lies within a low-grade Precambrian alternating series of black shales and metagreywackes in the Spanish Hercynian massif. There are two generations of mineralized veins: V2, gold-(stibnite)-bearing quartz veins, parallel to the main cleavage, and V3, stibnite-bearing quartz veins which postdate the main deformation event.Four main types of inclusions have been identified. Type I, II and IV are aqueous-carbonaceous inclusions, with variable degrees of filling, while type III are non-aqueous and typically single-phase at room temperature. Except for type I (absent in V3), similar inclusions have been observed in both V2 and V3 veins. Gas compositions are always characterised by CH4-N2-CO2 assemblages, ranging from CO2-rich mixtures in the earliest inclusions (type I), to N2-rich mixtures in the latest inclusions (type IV).Gold precipitation in V2 veins can be related to type I inclusions at T > 380°C (TH = 300–380°C). A subsequent drop in XCO2 and cooling are recorded in type II and III inclusions, interpreted to be the result of unmixing of a previously homogeneous fluid derived from type I. This boiling would provoke the precipitation of stibnite at 300°C and 1 kbar. The type IV inclusions, which are the richest in H2O, represent a late fluid circulation at lower temperatures (TH = 190–280°C).

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