323,027 research outputs found
RECOVERY OF SILVER FROM AQUEOUS SOLUTION BY WATER HYACINTH (EICHHORNIA CRASSIPES) ROOTS
No full textRoots of water hyacinth, Eichhornia crassipes, were found to have biosorption capacity for silver. To evaluate the biosorption capacity and characteristics, the effect of solution pH, dose of biosorbent loading, contact time, temperature and initial silver concentration were investigated in a batch mode. The Langmuir and Freundlich adsorption models were used for mathematical description of the sorption equilibrium. Equilibrium data was fitted to the Langmuir model at 293 and 398 K and concentrations of 10-150 mg L-1. Based on the Langmuir isotherm plots, the maximum biosorption capacity value was calculated to be 141.54 mmol g(-1) at 293 K. Various thermodynamic parameters, such as Delta G degrees, Delta H degrees, and Delta S degrees, were evaluated with results indicating that this system was an exothermic spontaneous reaction and kinetically suited to pseudo second order model
The evelotion of lifting and moving with vacuming systems effects on public health
Get PDFBu çalışma, 04-05, Haziran 2015 tarihlerinde İstanbul[Türkiye]’de düzenlenen Global Business Research Congress (GBRC) Kongresi‘nde bildiri olarak sunulmuştur.Workers are applying momentum and power which different duration and time in their working area. There are differences between workers, cause ofsex, a ge, health s tatus, e xperience, disabling. Also s ettling of w orks effects the l imits of p ower a nd m omentum w hich applied. There are a lot of different accounting method which obtained reserch and experience to determine power and momentum applied by workers. In this study it was analaysed weight on workers who works in lift and movement job with vacuming systems. Rubber goods between 9 and 25 kg weight were moved from container to conveyor in this study. 150 pcs rubber good which is different weight and size has moved every day by a worker who employed on this job. Analaysis by REBA method and ergonomic risk evalaution has done depend on Assessment Methods of Occupational Safety and Occupational Medicine Institutions of Germany. By the studies has contributed to reducing the disease ofmusculoskeletal system in the health management
Direct Transfer Manufacturing of Flexible Silicon Carbide Nanowire-Network Prototype Device
No full textFlexible and transparent devices are expected to meet increasing consumer demands for upgrades in wearable devices, smart electronic and photonic applications. In this work, nanomanufacturing of a flexible and powerless silicon carbide nanowire network ultraviolet photodetector (SiCNW-network UVPD) prototype was investigated by a very cost-effective direct transfer method. Indeed, the powerless device exhibited a photo-to-dark current ratio (PDCR) of 15 with a responsivity of 5.92 mA/W at 254 nm wavelength exposure. The reliability and durability of the device was evaluated by bending tests. In fact, the PDCR of the device was still very good even after seventy-five bending cycles (similar to 96 % of the rest state). In brief, our flexible, powerless SiCNW-network UVPD device with cost-effectiveness, good performance, and durability can provide feasible alternatives for new generation wearable optoelectronic products
Disperse Dyeability of Polypropylene Fibres via Microwave and Ultrasonic Energy
No full textIn this study, the dyeability of polypropylene fibres with a disperse dye via microwave and ultrasonic energy was examined. A dye bath having a liquor-to-goods ratio of 20:1, and including dyestuff 2% owf was prepared and dyeing experiments using microwave and ultrasonic energy were carried out. In the case of microwave dyeing, experiments have been carried out at different energy levels (L, M-L, M, M-H and H) and different time ranges (1 to 5 min) while in the case of ultrasonic energy different temperatures (20, 40, 60 and 80 degrees C) and different time range (1 min to 30 min) were used. Additionally, effect of carrier was also investigated. Dyed samples were examined by determining their K/S values. Diffusion coefficients in all methods were calculated using Shibusawa's approximation of Hill's equation. Washing fastnesses of dyed samples were also examined. This study showed that the dyeability of polypropylene fibres was increased by both microwave and ultrasonic energy
Ergonomics risk analysis in automobile cable manufacturing
No full textBu çalışma, 04-05, Haziran 2015 tarihlerinde İstanbul[Türkiye]’de düzenlenen Global Business Research Congress (GBRC) Kongresi‘nde bildiri olarak sunulmuştur.Musculoskeletal diseases are one of the most important issues among occupationFal health illnesses because the workforce, not only developing but also developed countries are affected and burdens social security systems with high financial costs, further decreases qualified emloyees. This study analysis the musculoskeletal diseases in a cable manufacturing facility and provides new applications to eliminate physical risk factos. Based on video records, Quick Exposure Check (QEC) are made for ergonomic risk analysis and required arrangements are suggested for the related departments. Then, results are assesed in terms of efficiency. Finally, it was seen that ergonomics analysis have decreased musculoskeletal disease risks
BIOSORPTION OF CATIONIC DYES FROM AQUEOUS SOLUTION BY WATERHYACINTH ROOTS
No full textWater hyacinth Eichhomia crassipes was found to have biosorption capacity for cationic dyes, malachite green and methylene blue from aqueous solutions. To evaluate the biosorption capacity and characteristics, the effect of solution pH, initial dye concentration, temperature, dose of biosorbent loading, contact time and shaking rate were investigated in a batch mode. Biosorption was increased with the increasing temperature for both studied dyes. The Langmuir and Freundlich adsorption models were used for mathematical description of the sorption equilibrium. Equilibrium data was fitted well to the Langmuir model in the studied concentrations (1-200 mg L-1) at 293 and 313 K. Based on the Langmuir isotherm plots the maximum biosorption capacity values were calculated to be 44.64 mg g(-1) for malachite green and 42.55 mg g(-1) for methylene blue at 313 K. Various thermodynamic parameters such as Delta G degrees, Delta H degrees, and Delta S degrees were evaluated with results indicating that this system was an endothermic spontaneous reaction and kinetically suited to pseudo-second-order model
ADSORPTION OF SOME TEXTILE DYES ON ACTIVATED CARBON PREPARED FROM RICE HULLS
No full textThe removal of textile dyes (CI acid blue 40 and CI basic blue 41) from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH), have been investigated depending on pH, activated carbon dosage, contact time and initial concentration. The optimum values of pH, contact time and activated carbon dosage at 75 mg/L initial concentration and 100 mL volume of the dyes solutions have been determined as 2-9, 20 min and 0.25 for CI basic blue 41 and 2-6, 40 min. and 0.50 g for CI acid blue 40, respectively. Freundlich and Langmuir equations were applied for the adsorption of both dyes and their adsorption followed both isotherms. Adsorption capacity has been found as 130.87 and 53.55 mg/g for CI basic blue 41 and CI acid blue 40 from Langmuir isotherms, respectively
Ergonomic analysis of working postures that cause strain on workers that work in hand placement business of transporting containers
No full textBu çalışma, 04-05, Hazziran 2015 tarihlerinde Istanbul[Türkiye]’de düzenlenen Global Business Research Congress (GBRC) Kongresi‘nde bildiri olarak sunulmuştur.Due to increased competition in the globalized world, technological innovations and higher production rates have become very important for businesses. Despite advances and innovations in technology, the employees who work in countries which have developed industry resulting musculoskeletal disorders causes serious economic losses, it has been shown to affect the entire community rather than individuals in it. Reducing the fatigue and stress consists physical overloading on human provides significant contributions on productivity and labor costs. To be understanding of this situation emerges the i mportance of working stance. Today has started to benefit from t he ergonomic analysis for the elimination of all actions and activities that do not contribute to production. Poor posture is observed during the some works such as hand placement business of transporting containers. For study of analysis, these works are selected and the methods of REBA and BAUA are benefited to investigate the posture of employees during work. BAUA analysis method cares about all body posture, carried load and time of carrying but REBA analysis method considers also the score of stance of upper limb. In this study, REBA and BAUA ergonomic analysis methods are evaluated by comparing to learn what the results are in a predetermined proces
Adsorption of cobalt by activated carbon from the rice hulls
No full textThe removal of cobalt (II) ion from aqueous solutions, by adsorption on activated carbon prepared from the rice hulls (ACRH), has been investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time have been determined as 6-7, 1.5 g ACRH/50 mt solution and 40 minutes respectively. Freundlich and Langmuir isotherm constants have been calculated at two different temperatures of 293 K and 313 K. Furthermore the other thermodynamic data for Delta G degrees and Delta S degrees, have been also calculated at two temperatures of 293 K and 313 K. The adsorption of Co (II) ion from aqueous solutions has been found to be exothermic (Delta H degrees=-1.543 KJ/mol)
Adsorption of copper and cadmium ions by activated carbon from rice hulls
No full textThe removal of copper (II) and cadmium (II) ions from aqueous solutions, by adsorption on activated carbon prepared from rice hulls (ACRH); was investigated depending on pH, activated carbon dosage, contact time, initial metal concentration and solution temperature. The optimum values of pH, ACRH dosage and contact time were determined to be 5-8, 0.5 g ACRH/25 mt solution an 60 minutes respectively for the adsorption of Cu (II) ions and 5-8, 1.5 g ACRH/25 mt solution and 60 minutes for the adsorption of Cd (II) ions. From the initial concentrations, the constants for the Freundlich and Langmuir isotherm were calculated at 293 K and 313 K. The adsorption of Cu (II) and Cd (II) ions from aqueous solutions was found to be exothermic [Delta H degrees=-13.474 KJ/mol for Cu (II) and Delta H degrees=-2.302 KJ/mol for Cd (II)]. Furthermore, the other thermodynamic data for Delta G degrees and Delta S degrees, were also calculated at 293 K and 313 K
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