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排序方式: 共有330条查询结果,搜索用时 15 毫秒
61.
Many of the large-scale biomass combustion systems for producing heat, hot water, or steam accept biomass fuels containing relatively large amounts of moisture. Dry biomass burns at higher temperatures and thermal efficiencies than wet biomass. Flame temperature is directly related to the amount of heat necessary to evaporate the moisture contained in the biomass, the lower the moisture content, the lower the amount of energy needed to remove the water and the higher the boiler efficiency. In this article, a simple predictive tool is developed to estimate boiler efficiency as a function of stack gas temperature and sugarcane bagasse moisture content. The method quantitatively illustrates the effect of moisture content on the performance of a thermochemical process, for the direct combustion of sugarcane bagasse in a conventional boiler. The results are found to be in excellent agreement with reported data in the literature with average absolute deviation being around 1%. The tool developed in this study can be of immense practical value for engineers to have a quick check on biomass moisture content on the boiler performance at various conditions without opting for any experimental trials. In particular, engineers would find the approach to be user-friendly with transparent calculations involving no complex expressions. 相似文献
62.
Sara Bazrafshan Maryam Mizani Gholamreza Pazuki Shahla Shahriari 《Journal of texture studies》2024,55(1):e12808
Enteral nutrition is a type of nutritional support that provides the necessary sources of energy and protein for patients who suffer from dysphagia, chronic disease, and loss of appetite. In this study, a gelatin-maltodextrin binary biopolymer system has been incorporated into a semi-solid formula. The I-optimal combination design approach was used to create 19 formulations, and the dynamic rheological properties, dynamic laser scattering, and zeta potential responses were evaluated over 30 days of storage at 5°C. Solid viscoelastic behavior has been approved since G′ > G″ in the frequency sweep test with no cross-over point. Maltodextrin may interfere within the gelatin network, and increasing the maltodextrin to gelatin (from 0.14 to 1) may lead to a wider linear viscoelastic (LVE) strain range (2.16%), a lower storage modulus at LVE (52%), a lower yield stress (46%), and a lower glass transition temperature (34%). The presence of maltodextrin may reduce the temperature of the sol-to-solid transformation by 48% and enhance its flexibility. In contrast, increasing the gelatin-to-maltodextrin ratio following melting at 37°C led to an increase in the cumulant mean and polydispersity index, indicating a relatively unstable system. The range of zeta potential values between −4.4 and 1.7 mV confirmed a tendency toward coagulation. Microscopic images revealed instability because of irregular or compact chains formed in the gelatin matrix by using higher amounts of maltodextrin. Finally, the best formula had the best rheological stability and was suitable for tube-feeding patients, with a gelatin-to-maltodextrin ratio of 4.35:3.64% w/w on day 17.4. 相似文献
63.
Gholamreza Karimi Roza Banitalebi Sedigheh Babaei Sedaghat 《International Journal of Electronics》2013,100(7):959-975
In this article, the small-signal equivalent circuit model of SiGe:C heterojunction bipolar transistors (HBTs) has directly been extracted from S-parameter data. Moreover, in this article, we present a new modelling approach using ANFIS (adaptive neuro-fuzzy inference system), which in general has a high degree of accuracy, simplicity and novelty (independent approach). Then measured and model-calculated data show an excellent agreement with less than 1.68?×?10?5% discrepancy in the frequency range of higher than 300 GHz over a wide range of bias points in ANFIS. The results show ANFIS model is better than ANN (artificial neural network) for redeveloping the model and increasing the input parameters. 相似文献
64.
Alireza Bahadori Sohrab Zendehboudi Gholamreza Zahedi Ahmad Jamili 《Chemical Engineering Communications》2013,200(3):287-299
To calculate the radiant intensity at a point distant from a radiator, a geometrical or configuration factor must be used. If the temperature is known, then the emissive power can be calculated using the mean equivalent beam length, but before the radiant heat flux at a distance can be estimated, a configuration factor must be calculated. In this article a simple predictive tool is developed to estimate the configuration factor for a geometry including a receiving element lying on the perpendicular to one corner of a radiant rectangle. The results are found to be in excellent agreement with reported data in the literature with average absolute deviation being around 2%. The results can be used in follow up calculations to estimate heat fluxes on surfaces exposed to radiation. The tool developed in this study can be of immense practical value for engineers as a quick check on the configuration factor for a geometry including a receiving element lying on the perpendicular to one corner of a radiant rectangle without opting for any experimental trials. In particular, engineers would find the approach to be user-friendly with transparent calculations involving no complex expressions. 相似文献
65.
Seyed Gholamreza Jalali Naini Alireza Moini Mustafa Jahangoshai Rezaee 《The International Journal of Advanced Manufacturing Technology》2013,67(1-4):475-484
Data envelopment analysis is a non-parametric technique for evaluating peer decision making units (DMUs) with using multiple inputs to produce multiple outputs. In the real world, DMUs usually have complex structures. One of these structures is a two-stage process with intermediate measures. In this structure, there are two stages and each stage uses inputs to produce outputs, separately where the outputs of the first stage are the inputs for the second stage. Cooperative model such as centralized model and non-cooperative model are game theoretic approaches to evaluate two-stage processes. Non-cooperative model supposes that one of the stages is the leader and another stage is the follower, whereas in the centralized model, both stages are evaluated simultaneously. In this paper, we propose a game theoretic model based on the Nash bargaining game to calculate weights when parallel stages with shared inputs compete to reach a high efficiency in the competitive strategy. Two data sets including the bank branches and thermal power plants in Iran are used to show the abilities of proposed model. This model can be applied in other processes such as supply chain, manufacturing and public service units. 相似文献
66.
Gholamreza Kavoosi Asad Tafsiry Ali Asghar Ebdam Vahid Rowshan 《Journal of food science》2013,78(2):T356-T361
Carum copticum and Ferula assafoetida have several medicinal properties including antispasmodic, carminative, sedative, analgesic, and antiseptic. Reactive oxygen species (ROS), reactive nitrogen species (RNS), hydrogen peroxide (H2O2), and thiobarbituric acid reactive substances (TBARS) scavenging activities of Carum and Ferula oils along with their antibacterial and antifungal activities were examined. Thymol (40.25%), γ‐terpinene (38.7%) and p‐cymene (15.8%) were detected as the main components of Carum oil while, β‐pinene (47.1%), α‐pinene (21.36%), and 1, 2‐dithiolane (18.6%) were the main components of Ferula oil. Inhibitory concentrations (IC50) for total radical scavenging were between 40 and 60 and 130 and 160 μg/mL of Carum and Ferula oil, respectively. Minimal inhibitory concentration (MIC) for Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger, and Candida albicans were 78 ± 8, 65 ± 7, 14 ± 3, 5 ± 2, 5.6 ± 1.3, and 8.8 ± 2.2 μg/mL of Carum oil, respectively. MIC for S. typhi, E. coli, S. aureus, B. subtilis, A. niger, and C. albicans were >200, >200, 125 ± 17, 80 ± 12, 85 ± 5, and 90 ± 11 μg/mL of Ferula oil, respectively. Accordingly, Carum and Ferula oils could be used as safe and effective natural antioxidants to improve the oxidative stability of fatty foods during storage and to preserve foods against food burn pathogens. Practical Application : This study clearly demonstrates the potential of Carum and Ferula oil especially Carum oil as natural antioxidant and antimicrobial agent. The chemical composition of essential oils was identified. Thus, identification of such compounds also helps to discover of new antioxidant, antibacterial and antifungal agents for potential applications in food safety and food preservation. 相似文献
67.
68.
Polymer sintering is not only a well-established procedure for producing functional polymeric parts, but it is also the basis for the relatively new additive manufacturing technique, selective laser sintering. Although studying the impact of thermo-oxidative degradation during sintering has significant practical importance, few studies have focused on this aspect of the sintering process. In the present work, we have investigated the active thermo-oxidative degradation mechanisms during sintering of high-density polyethylene (HDPE) particles, the conditions that promote them, and their respective impact on the morphological evolution of the polyethylene particles. To perform a comprehensive study, we have complemented the rheological, thermal, chemical, and morphological analysis of the sintered HDPE particles with the study of their ensemble pore structure. We observed two distinct degradation regimes. At the beginning, the relatively low concentration of oxygen in the particles led to the dominance of branching and resulted in a pore structure evolution limited to surface relaxation. In the second regime and with the diffusion of more oxygen, chain scission became the dominant route. In this regime, the emergence of highly mobile short chains markedly accelerated the pore evolution. 相似文献
69.
Gholamreza Abdolahzadeh Seyed Mostafa Shabanian Amirsina Tavakol 《The Structural Design of Tall and Special Buildings》2019,28(6)
One of the most important connections in steel structures is column to the baseplate connection. This kind of connection has a complex nature, due to different behaviors of the constituents, including baseplate, grout, foundation, and anchor bolts. Studying the impact of this connection in general behavior of structure seems to be an essential issue, especially during earthquake, which is more likely to be associated with plastic hinge forming. The main goal of this work is to provide a hybrid modeling for describing hysteresis behavior of column to the baseplate connection. Within hybrid modeling, a mechanical model is accomplished by using neural network model components. Our findings reveal that hybrid models are able to show pinched hysteresis complex behavior of baseplate connections. Also, the proposed hybrid developed model is robust and reliable approaches for predicting behaviors of a recent designed connection. 相似文献
70.
Sunil Aryal Kai Ming Ting Takashi Washio Gholamreza Haffari 《Knowledge and Information Systems》2017,53(2):479-506
Nearest neighbor search is a core process in many data mining algorithms. Finding reliable closest matches of a test instance is still a challenging task as the effectiveness of many general-purpose distance measures such as \(\ell _p\)-norm decreases as the number of dimensions increases. Their performances vary significantly in different data distributions. This is mainly because they compute the distance between two instances solely based on their geometric positions in the feature space, and data distribution has no influence on the distance measure. This paper presents a simple data-dependent general-purpose dissimilarity measure called ‘\(m_p\)-dissimilarity’. Rather than relying on geometric distance, it measures the dissimilarity between two instances as a probability mass in a region that encloses the two instances in every dimension. It deems two instances in a sparse region to be more similar than two instances of equal inter-point geometric distance in a dense region. Our empirical results in k-NN classification and content-based multimedia information retrieval tasks show that the proposed \(m_p\)-dissimilarity measure produces better task-specific performance than existing widely used general-purpose distance measures such as \(\ell _p\)-norm and cosine distance across a wide range of moderate- to high-dimensional data sets with continuous only, discrete only, and mixed attributes. 相似文献