14 research outputs found
Exergoeconomic and multi-objective optimization of a solar thermochemical hydrogen production plant with heat recovery
No full textA solar hydrogen production plant based on a four-step copper-chlorine (Cu-Cl) thermochemical cycle is presented and analyzed in this paper. The integrated system includes a pressurized solar power tower, gas turbine unit, phase change material (PCM) for thermal energy storage (TES), Cu-Cl cycle, regenerative steam Rankine cycle (SRC), and a heat recovery unit. A predictive model is developed for energy, exergy, and exergo-economic analyses of the proposed system. A parametric study is also conducted to investigate the effect of major parameters on the system performance. The system is optimized with a non-dominated sorting genetic algorithm-II (NSGA-II) considering exergy efficiency and product cost per unit exergy as the two objective functions. The results indicate that the energy and exergy efficiencies of the overall system are 48.2% and 45%, respectively, while the total product cost per unit of exergy is found to be 11.94/GJ, respectively
Enhanced mass transfer and water discharge in a proton exchange membrane fuel cell with a raccoon channel flow field
No full textThe cathode flow channel plays an important role in the water management of proton exchange membrane (PEM) fuel cells. In order to improve mass transfer and water management in traditional channels, this paper presents a new wavy flow field to increase the fuel cell performance and overall efficiency. A raccoon channel with various waviness parameters is numerically studied by a three-dimensional two-phase PEM fuel cell model. The electrochemical current-voltage performance results confirm that the PEM fuel cell's performance with the raccoon design is higher than a conventional straight channel at high current densities. The effects of uniform gas distribution, removal of the accumulated water, and sufficient water content in the membrane are crucial factors for improving cell performance. A parametric analysis is also performed by considering the amplitude and wavelength of the raccoon pattern on the fuel cell performance. The results show that the output power improves in the raccoon channel by increasing the amplitude or increasing the wavelength. The raccoon channel's output power with amplitude of 0.5 mm and a wavelength of 2 mm is enhanced by about 20%. The increase of performance in the raccoon channel is significantly higher than in the past reported studies
Heat transfer from molten salt droplets in various gases
No full textHeat recovery within the copper–chlorine cycle of hydrogen production is necessary to improve its overall thermal efficiency, and hence it is an essential part of the thermochemical cycle. A major portion of heat recovery can be achieved by cooling and solidifying the molten salt exiting the oxygen reactor of the cycle. Heat can be recovered from the molten salt by breaking the exiting molten stream into smaller dispersed droplets. This paper presents a predictive model to investigate a direct contact heat recovery process from molten copper(I) chloride (CuCl) using various gases including nitrogen, helium, and argon. The results are compared with those of air. As CuCl may react with water vapor in the presence of oxygen, inert gases are considered as the coolants for the direct contact heat recovery process. The results indicate that better heat transfer performance is observed in helium compared to other gases studied.Natural Sciences and Engineering Research Council of Canada (NSERC)Ontario Research Fund (ORF)Canadian Nuclear Laboratories (CNL
Analytical and experimental investigation of thermal efficiency improvement of thermochemical water splitting for hydrogen production
No full textThis paper examines heat recovery in a thermochemical Cu-Cl cycle for efficient hydrogen production. It is essential to recover heat within the Cu-Cl cycle to improve the overall thermal efficiency of the cycle. A major portion of heat recovery can be achieved by cooling and solidifying the molten salt exiting an oxygen reactor. Heat recovery from the molten salt is achieved by dispersing the molten stream into droplets. In this paper, an analytical study and experimental investigation of the thermal phenomena of a falling droplet quenched into water is presented, involving the droplet surface temperature during descent and resulting composition change in the quench process. The results show it is feasible to quench the molten salt droplets for an efficient heat recovery process without introducing any material imbalance for the overall cycle integration
Analysis of the hazards for the molten cuprous chloride pouring operation in an industrial hydrogen production facility
No full textAn analysis is reported of a design for a local exhaust ventilation system for the molten cuprous chloride pouring station in an industrial plant. Heat recovery from molten cuprous chloride is a key process within the copper–chlorine (Cu–Cl) cycle of thermochemical water splitting for hydrogen production. Because of particulate matter, dust, and vapors emitted by the molten salt, an effective and safe design is crucial. The design process involves calculating duct diameters to provide the desired duct air velocity through the system. The static pressure is evaluated so that the fan size can be determined. An adequate supply of makeup air must be provided to replace the air exhausted through the ventilation system. The economics of the ventilation system and ways to protect employee health, as well as minimize the costs associated with exhaust ventilation, are also described
Direct contact heat transfer from molten salt droplets in a thermochemical water splitting process of hydrogen production
No full textIt is important to recover heat within the copper–chlorine cycle of hydrogen production to improve its overall efficiency. A major portion of heat recovery may be achieved by cooling and solidifying the molten salt exiting the oxygen reactor step of the cycle. Heat can be recovered from the molten salt by breaking the molten stream into smaller dispersed droplets. In this paper, a predictive model is developed to analyze heat transfer from molten salt droplets. Characteristics of a spray column, in which recovered heat from molten copper(I) chloride (CuCl) is used to produce superheated steam, are presented. Decreasing the droplet size may increase the heat transfer rate from the droplet, and hence decrease the required height of the heat recovery system. For a 1 mm droplet size, the height of the heat-recovery system is predicted to be about 7 m.Natural Sciences and Engineering Research Council of Canada (NSERC)Ontario Research Fund (ORF)Atomic Energy of Canada Limited (AECL
Thermal efficiency improvement of hydrogen production via thermochemical water splitting
No full textThis paper examines heat recovery in a thermochemical Cu-Cl cycle for efficient hydrogen production. It is essential to recover heat within the Cu-Cl cycle to improve the overall thermal efficiency of the cycle. A major portion of heat recovery can be achieved by cooling and solidifying the molten salt exiting an oxygen reactor. Heat recovery from the molten salt is achieved by dispersing the molten stream into droplets. In this paper, an analytical study and experimental investigation of the thermal phenomena of a falling droplet quenched into water is presented, involving the droplet surface temperature during descent and resulting composition change in the quench process. The results show it is feasible to quench the molten salt droplets for an efficient heat recovery process without introducing any material imbalance for the overall cycle integration
Synthesis of Zataria Multiflora extraction loaded chitosan/PEO nanofibers via electrospinning method for potential biomedical applications
No full textBackground & Objective: The nanofibers are referred to as fibers with a diameter of less than 1000 nm. There are various ways to make nanofibers, one of which is electrospinning. In this method, nanofibers are formed on aluminum sheets. The conversion of chitosan to derivatives with greater solubility, its mixing with other polymers and the use of special solvents are methods for its ease of use. In this study, antimicrobial thyme extracts were prepared for the synthesis of chitosan / polyethylenoxide and thyme nanofibers by electroporation.
Materials & methods: Using electrospinning, chitosan and polyethylenoxide were prepared Ratio of 90 to 10 and 80% tween in a 0.5 molar acetic acid solution. Thyme extract was added and after the synthesis of nanofibers, images of SEM were taken, then the diameter of the nanofibers with clemex vision software was measured.
Results: According to the scanning electron microscopy (SEM) images and the nanofibers diameter obtained from the solution with chitosan / polyethylenoxide / thyme formulation with Ratio of 90 to 10, the mean diameter of nanofibers was in the range of 100-60 nm (best fiber with the lowest node).
Conclusion: Prepared nanofibers are widely used in the medical industry, especially in the field of tissue engineering and wound scaffolds and also are used as antibacterial candidate. In addition to being effective in wound healing, they also reduce the cost of treatment
The Development of Self and Other Forgiveness from Adolescence to Emerging Adulthood
Full text linkThe purpose of this study was to investigate the development of self, others, and situation forgiveness from adolescence to emerging adulthood. To this end, 395 individuals, aged 12 to 25 years in four age groups living in Isfahan, Iran, were selected by cluster (for the first three groups) and available sampling (for the fourth group). The study was a cross-sectional study with using the causal-comparative design and the required data were collected with the Forgiveness Scale. The results of the analysis of variance showed that forgiveness of self had a slight decreasing trend from the beginning of adolescence to adulthood. The results also revealed that forgiveness of others declined from 12 to 16 years of age, however, it increased in emerging adulthood. Moreover, the changes in situation forgiveness were not significant in four groups. Eta squared results showed a small effect of age on the forgiveness of self (2%) and forgiveness of others (4%). Finally, there was no significant gender difference in the forgiveness of self and others in different age groups.Introduction*Forgiveness can be defined as a decision to release negative feelings, cognition, and behaviors based on a sense of sympathy, respect and grievance for guilty (Lavafpour et al., 2014). Neto et al. (2014) pointed out three forms of forgiveness: other, self, and situation forgiveness. Other forgiveness manifests itself in intentionally reducing the negative feelings and thoughts against others. Furthermore, self forgiveness refers to passionately releasing the sense of agony against oneself and conversely improving compassion and love for the self (Enright, 1996). Additionally, situation forgiveness refers to rendering all the negative thoughts and feelings surrounding the inevitable hard situations (Tompson et al., 2005). Chiaramello et al. (2008), in their study of the development of forgiveness in adolescence, found that teenagers in the middle of adolescence were less forgiving and more vindictive than in the beginning. Subkowiak et al. (1995) also found that teenagers usually forgave significantly less than adults in similar situations. After adolescence, forgiveness of others increases with age in adulthood. This is because adolescence is the time of identity formation (Berk, 2007, 2014) and emerging adulthood is the period of identity consolidation (Arnett, 2000; Lotfabadi, 2009). Moreover, different ways of socialization of boys and girls (Dastranj, 2013) may cause gender differences in their forgiveness. As such, it can be concluded that the desire to forgive has a developmental trend. This research study aimed to seek this developmental trend for forgiveness from adolescence to emerging adulthood. MethodThis study employed a cross-sectional study with a causal-comparative design. Its statistical sample included 395 individuals whose aged ranged from 12 to 25 years living in Esfahan, Iran. The group classification was a 12-year-old group (55 girls and 50 boys), a 14-year-old group (49 girls and 51 boys), a 16-year-old group (51 girls and 45 boys), and an 18-23-year-old group (48 girls and 46 boys). They were selected by cluster (for the first three groups) and available sampling (for the fourth group). The data were gathered using the Hartland Forgiveness Scale (2005). Hartland Forgiveness Scale (Thompson et al., 2005) includes 18 items in three subscales (self, other, and situation forgiveness). The items are on a 5-point Likert scale ranging from 1 (the least amount of forgiveness) to 5 (the highest amount of forgiveness). The descriptive indices (mean, standard deviation), independent group t-tests, multivariate analysis of variance, and Tukey's post hoc test were used to analyze the obtained data. ResultsAccording to the multivariate analysis of variance, there was a significant difference between age groups in the forgiveness of self and others. However, the eta squares for both variables were .02 and .04, respectively, which indicates a small effect. Self-forgiveness differed significantly only between the two groups of 12 and 18-25 years old. Self-forgiveness scores decreased among 18-25-year-olds as compared to 12-year-olds (mean diff.=1.31, p = 0.02). Nonetheless, there were significant differences between the three groups in terms of other forgiveness. There was a decrease in other forgiveness between 16-years-old group and to 12-years-old (Mean diff.=1.63, p = 0.05), and there was an increase in forgiveness for the 18-25 years-old and 14 and 16-years-old groups (Mean diff.= -1.686, p=0.05 and Mean diff.= -2.668, p=0.001). Independent t-tests were used to examine gender differences in forgiveness scores for girls and boys in each age group. Only for situation forgiveness among the12-years-old group, the gender difference was significant with an effect size of (η2=0.05, t=2.39, and p=0.01), while no difference was observed in the other groups. In the 12-year-old group, the scores of situation forgiveness were higher for boys than girls. ConclusionThe results showed that other forgiveness decreased during adolescence and reached its lowest level at the age of 16 and after that, in emerging adulthood, other forgiveness increased significantly. The research of Girard and Mallet (2012) and Chiramello et al. (2008) reported the developmental course of forgiveness of others in adolescents until the age of 15. Also, Subkowiak et al. (1995) stated that adolescents were significantly less forgiving than their same-sex parents in similar situations. As expected, the conflict of the emerging adulthood stage of intimacy versus isolation and relationships with others becomes important for the individual; therefore, the person preserves one’s valuable relationships by forgiving others' mistakes (Kaleta & Mróz, 2018). Also, the findings showed that the development of self-forgiveness has a downward slope, and the 18-25-years-old group forgave themselves significantly less than the 12-year-old group. During adolescence, when identity is formed, self-forgiveness does not change much, but with the emergence of self-esteem, self-evaluation takes place, and a person becomes more sensitive about one’s mistakes, and self-forgiveness becomes more difficult and decreases. However, this research study did not find significant changes in situation forgiveness in four groups. Unfortunately, research background focuses on the forgiveness of others, and other dimensions of forgiveness have not been carefully investigated yet. Therefore, there is little evidence to compare the findings of self-forgiveness and situation, especially during adolescence. In addition, some factors such as small effect sizes and low statistical power can limit generalization of the findings of the present study. Ethical Consideration Compliance with Ethical Guidelines: All ethical issues such as informed consent and confidentiality of participants' identity were respected. Authors’ Contributions: All authors contributed to the study. The first author wrote the first draft of the manuscript. The second and third authors edited the manuscript and the second author is corresponding author.Conflict of Interest: The authors declare no conflict of interest for this study. Funding: This study was conducted with no financial support and is part of M.A. thesis of the first author.Acknowledgment: The authors thank all participants in the study. *. Corresponding autho
PENGEMBANGAN SISTEM INFORMASI RAYONISASI WILAYAH PENJUALAN BERBASIS WEB DENGAN METODE TIME AND TERRITORY MANAGEMENT STUDI KASUS DI PT. SINAR INTERMARK CABANG YOGYAKARTA
No full textThe activity of product and service distribution is an important part in the
series of activities existing in supply chain. Product or service produced by producer
will reach the consumers in good condition if existing distribution process is
conducted appropriately. There are two important components need to be considered
by the company that operates in distribution field, i.e. sales territory and sales force.
The lack of comprehension on these two components can result the disadvantage for
the company, such as out of stock in customers, the unevenness of distribution of
product in market, the occurrence of overstock in customers, the strategy of company
is not implemented appropriately, and there are still many other emerging barriers.
In order that those barriers can be minimized then it is necessary to conduct
the harmonization between the working burden of sales territory and the working
capability of the sales force through alignment. In this thesis, the author endeavor to
develop an information system of web based sales territory alignment by purpose to
balance the working burden. The development of alignment information system is
performed on PT. Sinar Intermark of branch Yogyakarta which is the subsidiary of
PT. Konimex. The method used in alignment calculation process was Time and
Territory Management (TTM) method. In order that the calculation data can be gained
then it had been conducted some activities, i.e.: marking customers position, geocode
of customer position and analysis of time and motion study.
The implementation of system was conducted on analysis process of old
alignment and making process of new alignment. From the result of implementation it
gained conclusion that the system can find the indication of the necessity to conduct
realignment. Furthermore, the implementation of system can also increase the balance
of TTM ratio value between rayon
