Şebnem Yezdan Pekçioğlu, C. Uraz, Selmin Yanar Ocaktan, Olcay Zunal
{"title":"MODIFICATION OF NATURAL ZEOLITE FOR ANTICORROSIVE PAINT PREPARATION","authors":"Şebnem Yezdan Pekçioğlu, C. Uraz, Selmin Yanar Ocaktan, Olcay Zunal","doi":"10.30492/IJCCE.2021.135782.4416","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.135782.4416","url":null,"abstract":"Metal surface coating occupies an important place in industry. The most important external factor on metal surfaces is corrosion. Corrosion is a natural process that occurs because of chemical reaction between the metal surfaces and the medium. It causes degradation of metals. There are three methods that used for the prevent corrosion. These methods are cathodic protection, anodic protection, and barrier coatings. In this study, it was aimed to develop environmentally friendly corrosion resistant paint for the barrier coatings, by using zeolite material which has natural characteristic of corrosion resistant. In other words, it was aimed to gain the anticorrosive effect to the production of corrosion resistant paint by adding modified natural zeolite in paint. Micro scale zeolite was modified by using lanthanum (III) nitrate, zinc acetate and magnesium chloride solutions. The best results were obtained with a zeolite size of 0.8869 μm and using a 60% zeolite / solution volume ratio. It can be said from the results of the experiments that; thin zeolite film applications are very successful for corrosion resistance paint production. Modified natural zeolite coatings show very good ability to protect surfaces from corrosion. Results of these procedures are positive and promising. The best result is obtained by zeolite with size reduction and 60% zeolite/solution by volume ratio. The amount of zinc phosphate was greatly reduced. High and low content of zinc phosphates have almost the same anticorrosive effect with zeolite modified paint formulations. As a result, cation-exchanged zeolites can be considered as a safe and efficient alternative to traditional hazardous pigments in protecting steel surfaces.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"45 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81935401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimization of Kerosene Aromatization over Ni/HY Catalysts using Response Surface Methodology","authors":"E. Saidi, M. Ziarati, N. Khandan, H. Dehghani","doi":"10.30492/IJCCE.2021.529645.4709","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.529645.4709","url":null,"abstract":"In this paper, several Ni/Y catalysts were prepared to perform kerosene aromatization. The Na+ cation of Y zeolite was exchanged with NH4+, and then Ni/HY catalysts were synthesized through the precipitation-deposition method. Properties of the samples were characterized by XRD, EDX, and BET. In addition, the Response Surface Method in combination with a three-factor Central Composite Design was employed to optimize the conditions of the reaction over Ni/HY catalysts. The three independent variables were: Ni content of the catalysts, reaction time, and temperature. Analysis of aromatic yield as the response was performed to survey the importance of these independent variables. Results of numerical optimization revealed that maximum operation conditions were 5%Ni-loading at a temperature 450oC and a reaction time of 120min, in which aromatic yield was 55.74%. This was in agreement with the predicted aromatic content (52.62%) in this condition. Acceptable value for correlation coefficient (R2= 0.989), root mean square error (RMSE = 0.77), and standard error of prediction (SEP = 1.82) was obtained. These low values confirmed the adequacy and statistical significance of the model to predict an adequate response.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"15 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74338175","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Uğurlu, Huseyn Osman, Aliİmran Vaizoğulları, A. Chaudhary
{"title":"Removal of Oxytetracycline Using Polymer Coated Magnetıc Nanopartıcular Activated Carbon: Synthesıs, Characterisation and adsorption isotherms and kinetics studies","authors":"M. Uğurlu, Huseyn Osman, Aliİmran Vaizoğulları, A. Chaudhary","doi":"10.30492/IJCCE.2021.525693.4593","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.525693.4593","url":null,"abstract":"In the presented study, the removal of oxytetracycline (OTC) from aqueous solution by adsorption was investigated onto active carbon (AC), magnetic activated carbon (MagAC), styrene-butadiene styrene magnetic activated carbon (SBS/MagAC) and poly charbon magnetic activated carbon (PC/MagAC). The process optimization was carried by investigating the effects of pH, temperature, solid-liquid ratio, adsorbent type and initial concentrations. The data showed that adsorption reached equilibrium in as little as one hour. less adsorption at low pH values and more at approximately 5.0 values. However, all the materials performed well at room temperature when the situation is examined in terms of kinetics. It was also observed that AC, MagAC and PC/MagAC are more effective than SBS/MagAC and the initial concentration decreased from 100 ppm to 20 ppm with adsorbents. In addition, at lower concentrations, when 25ppm and 50 ppm were used , it was obsedved to 2.5 ppm and 5.0ppm values. The kinetic results presented that pseudo-second-order model (r2 ⩾ 0.99) was more effective than that of pseudo-first-order model (r2 < 0.90). Also, Intra-particle kinetic model in adsorption process exhibited two different stages with diffusion of inter-particle and external diffusion. Adsorption isotherms for all adsorbents were fitted to Langmuire models more effectively than Freundlich models (r2 ⩾ 0.99). Thermodynamics parameters were also calculated. It is seen that OTC can be removed more easily from the aqueous medium by using magnetic and polymeric material.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"20 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82031717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taiebeh Tamoradi, H. Veisi, J. Davarpanah, B. Karmakar, J. Gholami
{"title":"Synthesis of rare earth (Dy and Pr) metal impreganated asparagine functionalized CoFe2O4 nanocomposite: Two novel, efficient and magnetically-recoverable catalysts for the reduction of 4-nitrophenol","authors":"Taiebeh Tamoradi, H. Veisi, J. Davarpanah, B. Karmakar, J. Gholami","doi":"10.30492/IJCCE.2021.521945.4552","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.521945.4552","url":null,"abstract":"In recent times biomolecules engineered magnetically isolable nanoparticles have garnered significant attention in nanocatalysis arena due to their outstanding features. Doping of rare earth metals over them brings further novelty in their properties. In this current work we describe the successful synthesis of rare earth lanthanide (M = Pr, Dy) impregnated asparagine adorned CoFe2O4 as two novel magnetically isolable nanocomposite catalyst following post-functionalization approach. The as synthesized materials were characterized using physicochemical techniques like FT-IR, SEM, EDX, elemental mapping and ICP-OES analyses. Subsequently, catalytic efficiency of the materials were investigated in the reduction of 4-Nitrophenol (4-NP), a well-known carcinogenic contaminants of water. Progress of the reaction and its kinetics were monitored over UV-Vis spectroscopy. Among the two variant, Dy anchored catalyst was found to be more efficient than the Pr which led the reaction to completion in just 8 min. Kinetically also Dy catalyst exhibited higher rate constants. This is the first report of Pr and Dy anchored heterogeneous catalyst in the reduction of 4-NP. The current methodology is advantageous in terms of cleanliness, simple procedure, excellent yields in short reaction time, easy magnetic retrieval and reusability of catalysts following several runs without significant change in catalytic activity.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"10 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86122912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Removal of Phenol by Expanded Bed Airlift Loop Reactor","authors":"Ali Al-Ezzi","doi":"10.30492/IJCCE.2021.120613.3941","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.120613.3941","url":null,"abstract":"The exaggerated release of industrial wastes especially those containing phenol into the environment led to the contamination of both surface and groundwater supplies. In present work a synergistic and combined system technique between three operations, adsorption of phenol via (rice husk or granular activated carbon GAC as adsorbents) together with stripping by airflow and advance oxidation via hydrogen peroxide as the oxidation agent, to evaluate the possibility of using a proposed new design for internal airlift loop reactor for removing the phenol from wastewater. The experiments were set up in a cylindrical Perspex column consisted of a transparent outer column having a 15 cm inside diameter and 150 cm height that included an internal draught tube of 7.5 cm and extending vertically to 120 cm top contains a bed having a dimension (7.5 x 30 cm) filled with adsorbent materials (rice husk, granular activated carbon GAC) and a volume capacity 25 liters. The experiments were conducted under the influence of both of the following variables air flow rate(2-20) (L/min), treatment time(5-60 min), the molar ratio of hydrogen peroxide to phenol,(1:10, 1:15 and 1:20)). The results showed the success of the proposed design with obtaining a removal efficiency (83%),( 81%)when using GAC and the rice husk as adsorbent materials respectively, with minimum remediation time 60 minutes, airflow rate of 18 L/min, and molar ratio(20) hydrogen peroxide to phenol. This study demonstrated that the proposed synergistic system could be utilized for the remediation of contaminated aqueous systems.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"43 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84247297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Al-Dawery, W. S. A. Majeed, Hanan A. Al Riyami, Hilal A. Al Sheidi, Mohammed A. Al Badi
{"title":"An experimental investigation on drag reduction by a combination of polymer, Laurel soap and palm fiber through circulated Newtonian liquid","authors":"S. Al-Dawery, W. S. A. Majeed, Hanan A. Al Riyami, Hilal A. Al Sheidi, Mohammed A. Al Badi","doi":"10.30492/IJCCE.2021.134760.4280","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.134760.4280","url":null,"abstract":"Flowability and reduced pressure are some of the economic values in pipeline transportation. In this study, we investigated the functionality of self-made drag coefficients composed of a combination of large molecular weight polymer, Laurel soap, and date palm fiber which were induced into a circulated piping system under turbulent water flow. The proposed combination formulas are proved to be a new cost-effective drag reduction approach. The efficiency of using a mixture of polymer, palm fiber, and soap on the drag reduction was thoroughly evaluated via investigating several case studies. Using pure polyelectrolyte showed that at the highest polymer concentration (50 ppm), the percentage of drag reduction reaches 50% in 10.3 mm pipe diameter and 70% drag reduction in 13.5 mm pipe diameter at a flow of low Reynolds number counted 17166.7. Upon applying a mixture of polyelectrolyte composed of (50 ppm) and fiber in the range (30-60 ppm), a drag reduction of 63% in 10.3 mm pipe diameter and 76% in 13.5 mm pipe diameter were achieved, respectively. Upon examining a mixture composed of polyelectrolyte (50 ppm) and soap in a range (50-150 ppm), the results showed that the highest drag reduction was achieved at a low concentration of soap and a bulk flow at a low Reynolds number. The aforementioned performance results were exemplified attaining drag reductions of 70% in 10.3 mm pipe diameter and 96% in 13.5 mm pipe diameter, respectively. This is accomplished through optimizing the applied mixture formulas. The estimated drag reductions were shown higher when applying the polymer mixture compared to that of pure polymer. However, a slight decrease in the attained drag reductions when using polymer-soap was observed and attributed to the hindrance from the palm fiber, which ultimately reduces the chance for all soap particles to reach the stagnant wall layer","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73439906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. M. Nizardo, D. U. C. Rahayu, Ilma Adzani Nurandini, Vania Salsabila Veristya, R. Yunarti
{"title":"Study of the Effect of Poly(ethylene glycol) on the Nifedipine Microencapsulation and Release","authors":"N. M. Nizardo, D. U. C. Rahayu, Ilma Adzani Nurandini, Vania Salsabila Veristya, R. Yunarti","doi":"10.30492/IJCCE.2021.528708.4684","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.528708.4684","url":null,"abstract":"Nifedipine is a dihydropyridine derivate calcium channel blocker, suitable as first-line therapy for patients with hypertension. When blood pressure is high, nifedipine will prevent calcium to pass into cardiac and vascular smooth muscle cells. Nonetheless, nifedipine has a low elimination half-life that makes nifedipine needs to be consumed repeatedly to enhance its bioavailability, and thus, gives rise to nifedipine concentration in blood. Hence, a controlled drug delivery system is needed wherein the drug could be delivered at the desired time. One of the options in drug delivery is drug microencapsulation using a polymer as a coating material. In this study, nifedipine was coated with poly(D-L lactic acid) (PDLLA)/poly(ethylene glycol) (PEG) polyblend also polycaprolactone (PCL)/PEG polyblend using solvent evaporation technique. The effect of the mass composition of the polyblend and molecular weight of PEG on the encapsulation efficiency and drug release was investigated. Microcapsules with the variation of PDLLA/PEG and PCL/PEG composition and PEG molecular weight had encapsulation efficiency of about 90%-92%. Microcapsules with PDLLA/PEG600 (9/1) exhibited the highest drug release of 43.2% with an encapsulation efficiency of 91.96% whereas microcapsules with PCL/PEG400 (7/3) had the highest drug release of 44% with an encapsulation efficiency of 90.64%.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"23 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88383602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quinolinyl triazole derivatives-Dominant Inhibitors for mild steel in hydrochloric acid","authors":"P. Bhat, Nitinkumar S. Shetty","doi":"10.30492/IJCCE.2021.531825.4785","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.531825.4785","url":null,"abstract":"Abstract−Quinolinyl triazole derivatives 4-(4-chlorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-4CPCQMT), 4-(3-chlorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-3CPCQMT) and 4-(4-fluorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-4FPCQMT) are of great importance in pharmaceutical chemistry such as antifungal, antituberculosis, anticonvulsant, anticancer activities, etc. The present work highlights the synthesis of the quinolinyl triazole derivatives ((4-4CPCQMT, 4-3CPCQMTand 4-4FPCQMT). The substituents present and the compounds 4-4CPCQMT, 4-3CPCQMTand 4-4FPCQMT were confirmed by FTIR and NMR spectroscopy. These compounds having many reactive sites were used as inhibitors for mild steel in 1.0 M hydrochloric acid medium at 303 to 323K. An inhibition study was done by electrochemical measurement. The prevention efficiency is in the order 4-4FPCQMT>4-4CPCQMT>4-3CPCQMT. The surface morphology of the mild steel surface was done using SEM, AFM and, EDX.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"14 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82498127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Buldurun, N. Turan, A. Savcı, Yusuf Alan, N. Çolak
{"title":"Synthesis, characterization, X-ray diffraction analysis of a tridentate Schiff base ligand and its complexes with Co(II), Fe(II), Pd(II) and Ru(II): Bioactivity studies","authors":"K. Buldurun, N. Turan, A. Savcı, Yusuf Alan, N. Çolak","doi":"10.30492/IJCCE.2021.531629.4775","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.531629.4775","url":null,"abstract":"This study reports the synthesis of Co(II), Fe(II), Pd(II) and Ru(II) complexes with Schiff base obtained by the condensation of 2-amino-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate with salicylaldehyde. The characterization of the ligand and its complexes was arranged and studied by FT-IR, UV-Vis., 1H and 13C NMR, microanalyses (C, H, N, S), X-ray diffraction (XRD) analysis, magnetic susceptibility, mass spectra and thermogravimetry analysis (TGA) and further was screened for antimicrobial, antioxidant and antiradical activities. Antioxidant activity of the ligand and its metal complexes was examined by using different methods including the total antioxidant activity method, total reduction method and DPPH. The antimicrobial activities of Schiff base and metal complexes were investigated on bacterial and fungal strains. DNA cleavage experiments of metal complexes with supercoiled pBR322 DNA were detected by gel electrophoresis in the being of H2O2.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"52 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80955021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Moradi, Ramin Qanavati, Masumeh Mirzaei Ghaleh Ghobadi
{"title":"Reducing Nitrate from Water Using Lanthanum-modified Adsorbent: Optimization, Thermodynamics, Kinetics, and Isotherms","authors":"P. Moradi, Ramin Qanavati, Masumeh Mirzaei Ghaleh Ghobadi","doi":"10.30492/IJCCE.2021.122311.3998","DOIUrl":"https://doi.org/10.30492/IJCCE.2021.122311.3998","url":null,"abstract":"Lanthanum-modified commercial activated carbon (LMAC) adsorbent was synthesized, characterized, and then applied for reducing nitrate from aqueous solutions under various conditions. The extent of nitrate removal depended on four factors: temperature, the aqueous solution pH, initial nitrate concentration, and contact time. The Taguchi approach was used as the method of design for the experiments. Under optimal conditions ( T= 300°C, pH=3, C0=10 ppm, and t= 210 min), the removal percentages and capacity of nitrate adsorption were found to be 71.31%, and 1.43 for activated carbon (AC) and 93.31% and 1.87 for LMAC, respectively. Thermodynamic parameters, including the enthalpy, Gibbs free energy, and entropy, indicated the spontaneous and exothermic nature of the adsorption process. Various isotherms and first and second-order kinetic models were applied to investigate the adsorption process. The pseudo-second-order kinetic model and Langmuir isotherm could well describe the adsorption process.","PeriodicalId":14572,"journal":{"name":"Iranian Journal of Chemistry & Chemical Engineering-international English Edition","volume":"42 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2021-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75728047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}