Recuperative system for high and ultra-high temperature flue gases. Final report

Advanced recuperative system technology for high and ultra-high temperature flue gases was investigated. Several high temperature recuperator system and component concepts were evolved and studied for the purpose of finding the schemes and designs that attain maximum fuel savings. The most promising concepts for industrial application were pre-engineered further to devise designs for adaptation to existing steel mills. The principal effort was aimed at steel soaking pit applications. The concept which provides the highest air preheat temperatures and the largest fuel savings for soaking pit application utilizing basic state-of-the-art technology is a low air pressure ceramic recuperator operated in conjunction with a higher air pressure metallic recuperator. This concept has the additional advantage that higher air pressures can be attained at the burner than can be attained with an all ceramic recuperator. These higher air pressures are required for high momentum, high efficiency burner performance, resulting in improved productivity and additional fuel savings. The technical feasibility of applying this high temperature recuperation system to existing soaking pits was established

Faktori rizika od karcinoma larinksa u Crnoj Gori

Laryngeal cancer is the most common head and neck cancer. There might be many risk factors for laryngeal cancer. Smoking, especially cigarette smoking and alcohol are indisputable risk factors. The authors of this paper assessed the presumed risk factors in order to identify possible aetiological agents of the disease. A hospital-based case-control study was conducted. The study group consisted of 108 histologically verified laryngeal cancer patients and 108 hospital controls matched by sex, age (±3 years) and place of residence. Laryngeal cancer patients and controls were interviewed during their hospital stay using a structured questionnaire. According to multiple logistic regression analysis six variables were independently related to laryngeal cancer: hard liquor consumption (Odd Ratio /OR/=2.93, Confidence Interval /CI/ 95 % = 1.17 to 7.31), consumption more than 2 alcoholic drinks per day (OR=4.96, CI 95 % = 2.04 to12.04), cigarette smoking for more than 40 years (OR=4.32, CI 95 % = 1.69 to 11.06), smoking more than 30 cigarettes per day (OR=4.24, CI 95 % = 1.75 to 10.27), coffee consumption more than 5 cups per day (OR=4.52, CI 95 % = 1.01 to 20.12) and carbonated beverage consumption (OR=0.38, CI 95 %= 0.16 to 0.92). The great majority of laryngeal cancers could be prevented by eliminating tobacco smoking and alcohol consumption.Maligni tumori larinksa najčešći su tumori glave i vrata. Glavni faktori rizika od razvoja malignih tumora grkljana su pušenje i konzumiranje alkoholnih pića. Cilj rada bio je ispitivanje potencijalnih faktora rizika od nastanka malignih tumora larinksa. Sprovedena je studija slučaj-kontrola. Studijsku grupu činilo je 108 pacijenata s histološki verificiranim rakom larinksa i 108 kontrola individualno izjednačenih po spolu, dobi (± 3 godine) i mjestu stanovanja. Svi ispitanici su anketirani ciljanim epidemiološkim upitnikom a u analizi podataka korištena je multivarijantna logistička regresijska analiza. Koristeći se multivarijantnom logističkom regresijskom analizom, statistički značajnu povezanost s rakom larinksa dobili smo za sljedeće varijable: konzumiranje žestokih pića (omjer izgleda /OR/=2.93, interval pouzdanosti /CI/ 95 % = 1.17 do 7.31), konzumiranje više od 2 alkoholna pića na dan (OR = 4.96, CI 95 % = 2.04 do 12.04), konzumiranje cigareta duže od 40 godina (OR = 4.32, CI 95 % = 1.69 do 11.06), konzumiranje više od 30 cigareta na dan (OR = 4.24, CI 95 % = 1.75 do 10.27), konzumiranje više od 5 šalica kave na dan (OR = 4.52, CI 95 % = 1.01 do 20.12) i konzumiranje gaziranih pića (OR = 0.38, CI 95 % = 0.16 do 0.92). Obolijevanje zbog malignih tumora larinksa moglo bi se značajno smanjiti prestankom konzumiranja duhana i alkohola

Improved Combustion System for Energy Conservation in Industry

U.S. industry consumes approximately 40 percent of all fuel consumed by the nation. The majority of this fuel is used to generate heat for elevating temperatures of materials. The heat is generated by combustion of the major fuels such as natural gas, fuel oil and coal. The combustion process itself and the utilization of heat generated by combustion has been carried out rather inefficiently. In the past, combustion equipment, primarily burners, were designed and operated with very little attention to the amount of heat wasted during their operation. The burners were considered a necessity, but their full potential in improving thermal efficiency of the heating process was very rarely used. Most of the burners used a varying amount of excess air. The air-fuel ratio control was primarily left to the operator and the flame shape and momentum were rarely considered as a design factor for the heating equipment. In the last few years, heating equipment designers and suppliers have realized the importance of efficient burner operation. Midland-Ross and other burner manufacturers have, during this time, developed a large variety of special burners and associated equipment to allow the use of efficient combustion of fossil fuels. In addition to proper air-fuel ratio, the burners are capable of operating with preheated air or oxygen enriched air to recover and reduce the flue gas heat. Certain specially designed burners improve heat transfer to the work load by discharging high velocity gases into the furnace. This paper describes various types of burners, their applications, and field test results which illustrate that a properly designed and applied combustion system can reduce the energy consumption and improve the productivity by reducing the process heating time

Development of a Novel In Vitro Assay (ALS Assay) for Evaluation of Vaccine-Induced Antibody Secretion from Circulating Mucosal Lymphocytes

We describe here a novel method for measuring in vitro antibody secretion from the tissue culture of human B lymphocytes in peripheral blood mononuclear cells (PBMC) after oral vaccination with a killed cholera vaccine. Enzyme-linked immunosorbent assay (ELISA) titers of the antibody secreted in the cell supernatant were determined. The validation results demonstrated that human PBMC remained viable and continued to secrete antibodies (total immunoglobulin A [IgA] and IgG) for up to 4 days of incubation at 37°C with 5% CO(2) in cell cultures. The secreted antibody concentration correlated positively with the PBMC concentration and incubation time in the tissue culture and correlated negatively with the storage time of the whole blood at room temperature. In vitro assay of secreting antibody in the lymphocyte supernatant (i.e., the ALS assay) is capable of the detecting specific antibody response after oral vaccination with a killed whole-cell-plus-B-subunit cholera vaccine (WC-B) in healthy adults in a phase I clinical trial. Postimmunization PBMC secreted antibodies to cholera toxin in the cell supernatants. Antibody production did not require any in vitro antigen stimulation. In the ALS assay, antigen-specific antibody titers of prevaccination samples were barely detectable, whereas serum antitoxin ELISA titers in background of prevaccine samples were significantly higher than the ALS titers. We conclude that, without any in vitro antigen stimulation after vaccination, PBMC secrete antibodies into the supernatants in the ALS assay. This assay can quantitatively measure the antigen-specific antibody production from the PBMC culture in postvaccination blood samples