Use of fat replacers in the production of reduced‐calorie vanilla ice cream

The purpose of this research was to determine the effects of different fat replacers on the sensory and texture attributes of vanillin‐flavored ice cream. Inulin is a fairly new fat replacer which has been proven to be a health promoter. Two vanilla ice cream formulations were produced using different ratios of inulin and Simplesse® as fat replacers to provide better flavor and textural properties. Aspartame and acesulfam‐K were used as sweeteners in the low‐calorie ice creams. Sensory and instrumental analyses were used to evaluate the texture quality of light (4.55%) (control group), low‐fat (2%) and fat‐free vanilla ice creams. The experimental mixes were significantly more viscous than the control mix due to the water binding capacity of carbohydrate‐ and protein‐based substances. The texture scores of the ice creams (sensory evaluation) paralleled the viscosity values. Ice creams manufactured with fat replacers were free of cooked‐milk flavor. The energy value of ice cream was reduced compared to full‐fat ice cream (207 kcal/100 g): by 75% for non‐fat ice cream, 71% for low‐fat ice cream and 41% for light ice cream. An increase in total solids in the mix resulted in better texture, a lower melting rate and better shape retention.     

Effect of waste matrix for the optimization of moisture content and calorific value of biodried material using Taguchi DOE

In this study, Taguchi approach was used to determine the influence of waste composition for the optimization of moisture content (MC) and calorific value (CV) of food waste via bio-drying process. The objective was to reduce MC and increase CV of the bio-dried material. The effect of three different levels of four factors including food (FW), paper (Pa), plastic (Pl) waste, and bulking agent (BA) were studied and optimized. The moisture content of the bio-dried material varied between 8.59 and 50.93%, whereas that of the calorific value was 11–25?MJ/kg. The results revealed optimum configurations for MC and CV as FW₁Pa₃Pl₃BA₃ and FW₁Pa₁Pl₃BA₁, respectively. Regression analysis revealed MC as a positive function of FW and BA with plastic positively correlated with calorific value. ANOVA analysis indicated that FW had more prominent effect on both MC and CV. The predicted and measured values were very close to each other. Additionally, the results realized in the confirmatory experiments at optimized conditions of CV was found to be higher than the test runs of Taguchi design, suggesting that Taguchi method was very successful in the optimization of bio-drying factors for MC and CV.     

Parametric identification of structural nonlinearities from measured frequency response data

Structural nonlinearity is a common phenomenon encountered in engineering structures under dynamic loading. In several cases, linear theory can suffice to analyze nonlinear systems to some extent. However, there are cases where nonlinear effects and therefore nonlinear analysis become unavoidable. In most of the engineering applications it is usually very difficult if not impossible to model nonlinearity theoretically, especially for nonlinear effects stemming from structural connections. Then it becomes necessary to detect, localize and parametrically identify nonlinear elements from measured vibration data. In this study, two different methods, one being a method suggested recently by two of the authors of this paper, and the other being again a method developed in an earlier work, are implemented on a test rig containing a nonlinear element. Both methods are capable of parametrically identifying nonlinearities from measured frequency response functions. It is aimed in this paper to asses the validity of each method by applying them to a real test structure and thus parametrically identifying the nonlinear element in the system to obtain a mathematical model, and then employing the model in harmonic response analysis of the system in order to compare predicted responses with measured ones.     

Removal of PCDD/Fs from flue gas by a fixed-bed activated carbon filter in a hazardous waste incinerator

The adsorption of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) by activated carbon (AC) was examined in a fixed-bed AC unit in a hazardous waste incinerator (IZAYDAS) in Turkey. Results showed that the removal efficiencies of PCDD/Fs decrease as the chlorination level increases, which was explained by the difference in gas/particle partitioning of the compounds. Since dioxins are tightly adsorbed by activated carbon, other flue gas constituents showed no clear effect on the dioxin removal. Adsorption kinetics indicated that the adsorption of volatile congeners and homologues fits well with Henry's law, possibly due to the higher gaseous fractions, while the correlation was lower for lowly volatile ones. PCDD/F congeners and homologues had a concentration value up to which no adsorption occurred, which could be attributed to the insufficient contact times at the low concentrations.     

VOC and PAH characterization of petroleum coke at maximum thermal decomposition temperature

In steel industry, hard coal is proceeded in coke ovens to produce metallurgical coke. In this process, some additives such as petroleum coke (petcoke) are used for optimizing operational cost. For the determination of addition ratio of petcoke, it is important not to disrupt coke quality, especially with respect to coke reactivity index and coke strength after reaction, while another important point is emission quality. In this study, petcoke gas (PCG) emitted from the thermal decomposition of petcoke at the maximum thermal decomposition temperature is characterized for volatile organic compounds (VOCs) and polyaromatic hydrocarbons (PAHs) and the results are assessed in comparison to the coke oven gas (COG). First, the petcoke sample is heated for gasification by using thermal gravimetric analyzer-DTA device. The gas in the temperature range of 490–510°C, where the highest gasification acceleration occurs, is taken from the funnel and transferred to GC-MS device by using a headspace gas sampler unit. The total VOC concentration in PCG and COG is found to be 121.76 ppm and 5,774.76 ppm, respectively, while the total PAH concentrations are 0.625 and 0.495 ppm, respectively. The results show that using petcoke in coal blend seems to be a more environment-friendly process with respect to a significant decrease in VOC emissions.     

Penetration of oral and topical ciprofloxacin into human aqueous humor

PURPOSE: This study was planned to investigate the penetration of ciprofloxacin into aqueous humor following oral and topical application as a prophylactic antimicrobial agent. METHODS: Forty-six patients undergoing cataract surgery were randomly divided into two groups. In the first group, the patients received 500 mg oral ciprofloxacin eight hours before surgery and in the second, 5 drops of 0.3% ciprofloxacin were applied to the patients every twenty minutes, starting 100 minutes before the surgery. By paracentesis, aqueous samples were taken just before the operation so the interval between the first topical application and paracentesis was 100 minutes. RESULTS: The mean concentration of ciprofloxacin in aqueous humor was 0.63+/-0.29 microg/ml in the first group. The concentration was 0.69+/-0.30 microg/ml in the second group. Both of these mean concentrations were higher than the levels of MIC90 of S.aureus , S. epidermidis, P. aeruginosa and Gram (-) bacteriae. CONCLUSION: As a result, both topically and orally applied ciprofloxacin achieved a significant aqueous concentration. Each route studied might be suitable for surgical prophylaxis or treatment of infections.     

Vibration fatigue analysis and multi-axial effect in testing of aerospace structures

The work reported in this paper compared the fatigue damage accumulated under uni-axial loading (a procedure promoted by the vibration testing standards) to that induced by multi-axial loading. The comparison was performed for a helicopter structural element (the flare dispenser bracket of the self-defensive system's Chaff), which is exposed to the particular combination of wide-band random with sinusoidal vibrations, which is characteristic to the helicopter dynamic environment. The evaluation of the fatigue damage induced by these loads requires the calculation or measurement of the structure's dynamic response in terms of stresses or strains, and the application of the appropriate methodology to this response. In this work, dynamic response was calculated in the frequency domain based on the relations between the power spectral density matrixes of the excitations to that of the responses for a linear system. The transfer matrix that relates the excitation to the responses was evaluated numerically. The power spectral densities of the responses evaluated at different locations on the structure were used in the determination of the responses’ statistics (the counting of the loading cycles), which, combined with an appropriate physics of failure model (fatigue model), enabled the evaluation of the accumulated fatigue damage. The uni-axial-induced fatigue was evaluated from vibration tests of the kind promoted by military standards (it is assumed that axis-by-axis loading is cumulatively equal to multi-axial loading), and compared to that evaluated by analysis for the multi-axial loading. Also a numerical comparison of the effects of the two kinds of loading was performed. The results showed that the error of uni-axial testing varied for a wide range of parameters. The work led to the conclusion that simultaneous multi-axis vibration testing can improve significantly the laboratory's vibration simulation realism.