Recent progress in food processing applications of air impingement technology: A review.

Air impingement method has been widely used in a variety of industrial applications, such as textile and paper drying, turbine cooling, and glass quenching, because it is an efficient technology with high heat and mass transfer rates. This technology has received increasing interest in the field of food processing over the last two decades, such as drying, baking, blanching, freezing, and thawing. In a food processing equipment using air impingement, jets of high-velocity air (with speeds of 10-50 m/s) are directed at a food product. The performance of the system is influenced by several critical elements, including jet velocity, nozzle array diameter and layout, jet distance, and boundary layer characteristics. The use of computational fluid dynamics, an emerging tool, has been shown to be valuable in the analysis of fluid flow and heat and mass transfer in jet impingement systems. The physical properties of impinging jets, such as turbulent mixing in the free jet zone, stagnation, boundary layer formation, recirculation, and their interactions with food products in terms of heat and mass transfer, have been discussed in this article. The benefits and disadvantages of air jet impingement technology in different food processing applications together with potential trends for improving impingement technology performance were identified and discussed. This review not only contributes to a better understanding of the research status of impingement technology on food processing but also triggers new research opportunities in this field in order to provide more healthy and nutritious food in a more sustainable way to the world's growing population.

Fourteen-year trend of tuberculosis dynamics in the northwest of Turkey.

BACKGROUND: The incidence of tuberculosis (TB) in different countries as estimated by the World Health Organization (WHO) vary from 23/100,000 and less in industrialized countries, 191/100,000 in Africa and 237/100,000 in South East Asia. OBJECTIVES: The aim of this study was to analyze the dynamics of TB in the northwest of Turkey, between 1988 and 2001. METHODS: All pulmonary TB cases reported to the National Tuberculosis Center by local TB dispensaries during 1988-2001 were analyzed. The number of new and relapsed TB cases were documented and classified according to age and type of TB (standard classification of TB patients according to disease type: pulmonary, new, smear positive; pulmonary, smear negative; relapse, and extrapulmonary). We recorded information about the prevalence of TB in different patient groups (patients with a contact history, patients who were detected in active community screening or passive case finding), TB trends in different age groups, type of TB, patients who had relapses, percentage of patients who were lost to follow-up. RESULTS: A total number of 288,996 patients were examined at Zonguldak Tuberculosis Dispensary between 1988 and 2001. Case notification rates of TB decreased over the study period. Respiratory TB was the most commonly encountered form of disease (>90%). The percentage of TB decreased in the 0- to 14-, 15- to 24-year-olds and increased in the 25- to 44- and 45- to 64-year-olds. CONCLUSION: Properly designed disease surveillance systems are critical for monitoring the TB trends so that each country can identify its own high-risk groups and target interventions to prevent, diagnose, and treat the disease.

Antituberculosis drug resistance patterns in two regions of Turkey: a retrospective analysis.

BACKGROUND: The emergence of Mycobacterium tuberculosis strains resistant to antituberculosis agents has recently received increased attention owing largely to the dramatic outbreaks of multi drug resistance tuberculosis (MDR-TB). METHODS: Patients residing in Zonguldak and Kayseri provinces of Turkey with, pulmonary tuberculosis diagnosed between 1972 and 1999 were retrospectively identified. Drug susceptibility tests had been performed for isoniazid (INH), rifampin (RIF), streptomycin (SM), ethambutol (EMB) and thiacetasone (TH) after isolation by using the resistance proportion method. RESULTS: Total 3718 patients were retrospectively studied. In 1972-1981, resistance rates for to SM and INH were found to be 14.8% and 9.8% respectively (n: 2172). In 1982-1991 period, resistance rates for INH, SM, RIF, EMB and TH were 14.2%, 14.4%, 10.5%, 2.7% and 2.9% (n: 683), while in 1992-1999 period 14.4%, 21.1%, 10.6%, 2.4% and 3.7% respectively (n: 863). Resistance rates were highest for SM and INH in three periods. MDR-TB patients constituted 7.3% and 6.6% of 1982-1991 and 1992-1999 periods (p > 0.05). CONCLUSION: This study demonstrates the importance of resistance rates for TB. Continued surveillance and immediate therapeutic decisions should be undertaken in order to prevent the dissemination of such resistant strains.