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81.
Ahmet KarakayaMustafa Özilgen 《Energy》2011,36(8):5101-5110
Energy utilization and carbon dioxide emission during the production of fresh, peeled, diced, and juiced tomatoes are calculated. The energy utilization for production of raw and packaging materials, transportation, and waste management are also considered. The energy utilization to produce one-ton retail packaged fresh tomatoes is calculated to be 2412.8 MJ, whereas when the tomatoes are converted into paste, the energy utilization increases almost twofold; processing the same amount into the peeled or diced-tomatoes increases the energy utilization seven times. In case of juice production, the increase is five times. The carbon dioxide emission is determined by the source of energy used and is 189.4 kg/t of fresh tomatoes in the case of retail packaging, and did not change considerably when made into paste. The carbon dioxide emission increased twofold with peeled or diced-tomatoes, and increased threefold when juiced. Chemical fertilizers and transportation made the highest contribution to energy utilization and CO2 emission. The difference in energy utilization is determined mainly by water to dry solids ratio of the food and increases with the water content of the final product. Environmentally conscious consumers may prefer eating fresh tomatoes or alternatively tomato paste, to minimize carbon dioxide emission. 相似文献
82.
Magalie Laniel Jean-Pierre Emond Ahmet E. Altunbas 《Sensing and Instrumentation for Food Quality and Safety》2009,3(1):34-40
The performance of radio waves in open environments has been studied for years. In contrast, the behavior of Radio Frequency
Identification (RFID) inside metal enclosed areas is not yet understood. This research project focuses on the 3-D mapping
of RFID signal strength inside a 12 m refrigerated marine container instrumented with three different types of radio frequency
(RF) emitters: 915 MHz reader; 2.45 GHz reader and 433 MHz RF transmitter. The main goal is to find a frequency/configuration
that would allow real time reading of the temperature in a shipment of perishable products using RFID. Only one frequency
and one antenna were used at a time. The RF transmitter antenna was mounted at two different places inside the container;
at the top of the front wall (facing back) and on the ceiling in the middle of the container (facing down). The signal strength
was acquired by a spectrum analyzer and its antenna was mounted on a small electric cart inside the container. The cart was
programmed to move along the length of the container and stop repeatedly, allowing three automated measures per position.
All data were analyzed in terms of power level and attenuation. The maps showed that the RFID antenna positioned at the front
of the container delivered slightly better results than the one in the middle of the ceiling. The results showed a significantly
higher performance at the 433 MHz level.
This article was presented at Food Processing Automation Conference, American Society of Agricultural and Biological Engineering
(ASABE), Providence, RI, June 28–29 2008. 相似文献
83.
Yasin Varol Hakan F. Oztop Ahmet Koca Engin Avci 《Expert systems with applications》2009,36(3):5813-5821
Forecasting of entropy generation of laminar natural convection in a partially cooled square cross-sectional room has been performed using support vector machines (SVM). The two-dimensional room was modeled as floor heating story with a window. Values of temperature and velocities were obtained by solving governing equations of natural convection with finite difference technique and using these values entropy generation was calculated with its definition. Forecasting of entropy generation due to fluid friction irreversibility (FFI) and heat transfer irreversibility (HTI) were made with known values for unknown parameters using SVM. Thus, calculation time was extremely reduced and values were obtained even for non-convergence cases. It was observed that the SVM was a strong method to predict the entropy generation without computational fluid dynamic analysis for all cases. 相似文献
84.
This work is concerned with the effects of environmental factors on the adhesion and durability characteristics of epoxy-bonded concrete prisms. The results indicate that the presence of liquid water at the interfacial zone during the epoxy injection process disrupts the initial bond configurations. The freezing and thawing up to about 40 cycles do not have a significant effect on the bond stability. An adequate degree of chemical stability is maintained in the bond line by the epoxy adhesives after 120 days of exposure to corrosive environments such as MgSO4 and MgCl2. However, there is a pronounced effect of these chemical substances on the concrete strength. The load-bearing capacity of epoxy-bonded concrete prisms decreases with increasing temperature. Despite this fact, the EP3-bonded concrete prisms give relatively high joint strengths at temperatures up to 100 °C. 相似文献
85.
86.
Tolga Taner Mecit Sivrioğlu Hüseyin Topal Ahmet Selim Dalkılıç Somchai Wongwises 《Sadhana》2018,43(3):42
This study presents a case study of energy management in a sugar factory in Turkey. The main idea of the study is to analyse energy consumption, the quantity of material production, and figure out a suitable energy efficiency for the case study of a sugar factory subsequently. Firstly, a material production and energy consumption audit were performed for the sugar factory. Secondly, energy efficiency was calculated from the energy data. The SPSS (Statistical Package for the Social Sciences) statistical software was used to ensure the accuracy of the data. The factory’s energy consumption was calculated as 43,590.25 toe (tons of oil equivalent) over the last year. These results were used for CUSUM (Cumulative Sum Deviation Method) graphics. This research poses the consumption of energy, cost of energy and the relationship between energy usage and material production of sugar. The unit of energy cost was 688.22 [$/toe] for the last year. This result showed that the factory decreased the unit of energy by optimisation. The results indicated that the investigated sugar factory should pay attention to the energy management issue in order to comply with the Energy Efficiency of Turkish Law and Directives. 相似文献
87.
Ahmet Ekicibil G?kmen Bulun Selda K?l?? ?etin Zafer Dikmen ?nder Orhun Tezer F?rat Kerim K?yma? 《Journal of Superconductivity and Novel Magnetism》2012,25(2):435-440
In this study the origin of ferromagnetism in ZnO-based bulk systems has been investigated using Ni-doped ZnO samples, Zn1−x
Ni
x
O with 0.25≤x≤0.50, prepared by solid-state reactions. The structural characterizations indicated that the Ni2+ ions almost uniformly distributed in all the samples, and the samples have hexagonal wurtzite structure; however, when x is increased toward 0.50, a new NiO phase is formed. A ferromagnetism (FM) has been observed for all the samples at and below
the room temperature. In other words, the room temperature results of (M–H) curves show that the FM observed is intrinsic for all the Ni-doped ZnO samples. However, the saturated magnetizations decrease
gradually with increasing Ni concentration. This indicates that, in addition to FM, the excessive doping of Ni in ZnO also
causes an antiferromagnetic (AFM) contribution which increases with increasing Ni amount. This result is also supported by
the magnetization against temperature measurements. Furthermore, the trend of the ac-susceptibility (χ) versus temperature curves, measured under an ac-magnetic field of 100 Oe, also support our conclusion about the antiferromagnetic
contribution to ferromagnetism in our samples. 相似文献
88.
The selective separation of cobalt from acidic media, containing both equimolar and nonequimolar mixtures of cobalt and nickel, was examined by supported liquid membranes using Alamine 336 as mobile carrier dissolved in various diluents. The membrane support was microporous hydrophobic polypropylene Celgard 2500 (25 μm thick, 0.209 × 0.054 μm pore size and 55% porosity). Acetic acid-Na acetate buffer was used for the adjustment of the feed pH which was critical. Various parameters were experimentally studied and the optimum conditions were determined. 相似文献
89.
Hakan Demir Ahmet Koyun Ş. Özgür Atayılmaz Özden Ağra Ahmet Selim Dalkılıç 《Journal of Mechanical Science and Technology》2013,27(8):2497-2506
Heat transfer from finned pipes buried in the soil has been investigated using experimental, analytical and numerical techniques. The experimental setup consists of a ground source heat pump system and two separate ground heat exchangers. Constant surface temperature approach based on Carslaw and Jaeger’s theory study was used for calculating the heat transfer from the pipes analytically. The problem was modeled and solved using a CFD program numerically. Effects of the fin number, fin length and simulation time on the heat transfer rate have been investigated and compared with bare tube. A modified analytical formula was also proposed for finned pipes in this study. 相似文献
90.
Mehmet Uysal Ramazan Karslioğlu Ahmet Alp Hatem Akbulut 《Ceramics International》2013,39(5):5485-5493
Core–shell nanostructured Ni-coated Al2O3 composite powders were synthesised by using the electroless plating method. The influence of the chemical components and powder concentration in the Ni coating was investigated by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction techniques. The results show that the concentration of the plating components plays an important role in the formation of core–shell Al2O3/Ni composite powders. The nickel content in the composite powders could be effectively controlled by adjusting the nickel chloride content and the concentration of NaH2PO2·H2O in the plating solution. The nanostructure of the crystalline Ni coatings was observed to be very attractive for achieving good bonding between ceramic particles and matrices for composite production. 相似文献