数字化蓄热式步进梁加热炉在棒材生产中的应用与分析

简要介绍了数字化蓄热式步进梁加热炉在棒材生产上的成功应用,通过对加热炉工艺的描述,从6个方面对数字化蓄热式燃烧系统进行了详细地介绍,重点分析了数字化蓄热式燃烧系统的技术和结构特点。     

蓄热式燃烧技术在加热炉上的应用

介绍韶钢第五轧钢厂采用蓄热式燃烧技术对加热炉改造的必要性，并对几个方案进行比较和确定，重点介绍蓄热式燃烧技术在五轧厂加热炉应用的难点，以及在原加热炉上应用蓄热式燃烧技术进行改造的内容，总结了蓄热式燃烧技术的应用效果。     

蓄热式燃烧技术在中厚板轧钢厂的应用实践

介绍了高温空气蓄热式燃烧技术在中厚板轧钢厂2座加热炉上的应用情况。对采用不同蓄热体及燃烧方式的2座加热炉的实际效果进行了分析，总结了高温空气蓄热式燃烧技术的实践经验，为进行大型板坯加热炉蓄热式技术改造提供了依据。     

蓄热式加热炉的现状和前景

对蓄热燃烧技术的发展历史、技术原理及其在加热炉中的应用进行了分析，对蓄热式加热炉改造提出了方向。     

蜂窝体在蓄热式加热炉中的应用和影响分析

介绍了蜂窝状蓄热体的特点,分析了蜂窝状蓄热体在蓄热式加热炉应用中的影响因素和使用效果,提出了改进的措施,并说明了其对加热炉生产效率的影响。     

蓄热式加热炉的自动燃烧控制技术

介绍了蓄热式加热炉自动燃烧控制的关键技术及其应用，重点介绍蓄热式燃烧控制的三个特点：烟气温度测量、自动换向控制、烟空比控制．生产情况表明：自动控制系统运行稳定，排烟温度低，达到节能和环保目的.     

蓄热式燃烧技术在轧钢加热炉上的应用

介绍了蓄热式轧钢加热炉的结构形式，以南钢的实例介绍了新建和改造轧钢加热炉的所采用的两种不同炉型结构，从使用的角度对蓄热式轧钢加热炉的性能及优缺点进行了比较。     

旋转式蓄热器与换向式蓄热器在铝熔炉中的比较

简要介绍了一种用于铝熔炉的旋转式蓄热器的工作原理和蓄热体特点,并对其与在生产应用中相对传统的换向式蓄热器的技术特点和数据对比分析。在生产实际应用中,相对于传统的换向式蓄热技术,旋转式蓄热技术的熔炼速率提高了8．8％,能源利用率增加11．7％。     

蓄热式燃烧技术在非轧钢加热炉上的应用

介绍了蓄热式燃烧技术在非轧钢加热炉上的几种应用实例,例如大型台车式加热炉、敞焰加热的连续式热处理炉、蓄热式辐射管等;对在非轧钢加热炉上采用蓄热式燃烧技术时需要注意的一些问题进行了探讨。     

蓄热式燃烧技术在冶金工厂的合理应用

从蓄热式节能效果分析入手,结合冶金工厂连续化生产的实际,客观分析了目前蓄热式燃烧技术的利弊,提出了利用现有炉窑条件,继续发挥预热段和煤气换热器的作用,采用空气单预热、增加单位空气蓄热体数量的办法,保证蓄热式设备安全可靠运行.     

Apparent digestibility of minerals by lactating cows from a total mixed ration supplemented with poultry litter

Apparent digestibility of minerals by lactating cows from a multiple-component, conventional Israeli TMR (control) and from a TMR containing 10% poultry litter (DM basis) was examined. Ten cows in early lactation were divided into two groups of similar performance (39 kg of milk/d) and fed for ad libitum intake the two TMR for 28 d. Poultry litter contributed, as a percentage of total requirements, 44.4% of Ca, 41.0% of P, 32.0% of S, 22.8% of Mg, and 25.9% of K. Apparent digestibility of the macroelements was higher for cows fed the TMR supplemented with poultry litter than for those fed the control TMR. Apparent digestibility of the control TMR was 22.3% for Ca, 29.4% for Mg, 39.1% for P, and 62.2% for S; the apparent digestibility of the treatment TMR was 30.1% for Ca, 45.6% for Mg, 45.3% for P, and 65.6% for S. Poultry litter contributed the entire requirements of Zn, Mn, and Co; 56% of Cu; and 32% of Se. The apparent digestibility of the control TMR was 15.6% for Cu, 39.6% for Zn, 8.51% for Mn, 42.8% for Co, and 41.6% for Se, and the apparent digestibility of the treatment TMR was 27.9% for Cu, 54.0% for Zn, 17.8% for Mn, 37.0% for Co, and 63.9% for Se. Poultry litter is a good source of macro- and microelements for lactating cows and, at 10% of the TMR, could ensure against mineral deficiencies.     

Avoidable mortality among psychiatric patients

Avoidable mortality is a selection of causes of death considered to be amenable to health care and thereby used as an indicator of the quality of health care. In this study avoidable mortality for more than 30,000 psychiatric patients discharged from any hospital of Stockholm County between 1981 and 1985 has been followed up in the Cause of Death Register for the period 1986-1990. Standardised rate ratios were calculated for different groups of psychiatric disorders compared to the general population of Stockholm County for indicators of avoidable mortality, suicide, other mortality ("unavoidable") and causes possibly related to treatment with psychotrophic drugs. As expected, the psychiatric patients had the most pronounced elevated risk for suicide. i.e. 6- to 24-fold compared to the general population, and noticeably more elevated for women. It is also noteworthy that the relative mortality risks for diagnoses amenable to medical interventions and potential side-effects of psychotrophic drugs are higher than for other causes of death ("unavoidable"). The relative risks for avoidable mortality were 4.7 for men and 3.8 for women and for diagnoses possibly related to side-effects of psychotrophic drugs, 7.2. The relative risks for "unavoidable" mortality were 3.4 for men and 3.2 for women. The excess avoidable mortality rates for psychiatric patients and the elevated suicide risk, especially for female patients, are warning signals of shortcomings in psychiatric care that warrants further investigation.     

Emerging issues in sleep-disordered breathing

An amplified capture enzyme-linked immunosorbent assay (ELISA) has been developed by the use of the biotin-avidin detection system, for the measurement of canine plasma immunoglobulins (Ig) A, G and M. Test responses of dilutions of both the Ig standards and test plasma samples were consistently linear (r > 0.987) for the three Ig classes. The within-assay variation was 3.53 per cent for IgG, 5.84 per cent for IgM and 6.34 per cent for IgA. The analytical recoveries were 95 per cent for IgA, 97 per cent for IgG and 98 per cent for IgM. The lower detection limits of the assay were 38.4 ng ml-1 for IgG, 20.3 ng ml-1 for IgM and 41.2 ng ml-1 for IgA. The results indicate that this ELISA has a much higher sensitivity than the single radial immunodiffusion assay or the non-amplified ELISA for measurements of canine Igs, but has a comparable specificity and precision.     

Detection by denaturing gradient gel electrophoresis of an Arg1689Cys mutation in a Chinese patient with mild hemophilia A

OBJECTIVE: To examine the ease of endotracheal intubation on the ground for various rescuer positions. METHODS: Six female and 18 male emergency medical technicians were asked to intubate a Laerdal Megacode Trainer placed on the ground. Rescuers assumed the following positions in random order: prone, sitting, kneeling at the mannequin's head, and straddling the chest. The authors measured times 1) for changing from mask ventilation to assuming intubation position and 2) from touching the laryngoscope to putting it down. Incidences of esophageal tube placement and clicks (possible tooth damage) were noted. The rescuers rated their satisfaction with each position on a six-point scale (1 = very good, 6 = insufficient). Total intubation times of the other three positions were compared with that for prone by rank order test for paired observations. Handling, esophageal positions, and clicks of the other three positions were compared with those for prone by sign test for paired observations. A Bonferroni correction (factor 12) was applied. RESULTS: Mean total intubation times (in seconds) were 11.8 +/- 3.3 for prone, 13.9 +/- 4.7 for sitting, 11.4 +/- 4.5 for kneeling, and 16.2 +/- 5.8 for straddling. The difference between straddling and prone was statistically significant (p < 0.005). For handling, the results were for prone 3.0 +/- 1.4, for sitting 3.1 +/- 1.1, for kneeling 2.2 +/- 0.6, and for straddling 2.8 +/- 1.4. Esophageal positions occurred for prone 1, for sitting 1, for kneeling 2, and for straddling 3. Clicks were counted for prone 2, for sitting 1, for kneeling 1, and for straddling 0. CONCLUSIONS: All tested positions provide satisfactory conditions for intubation on the ground. The straddling position requires statistically, but not clinically, significantly more time for intubation than does prone and may be an important backup position if access from behind the patient's head is impossible.     

Virulence-associated genes as markers of strain diversity in Helicobacter pylori infection

To establish a marker of strain diversity of Helicobacter pylori, a genetic examination was performed based on the detection rates by PCR of cagA and vacA, which are known to be virulence-associated genes. The test strains were obtained from 70 patients suffering from gastric ulcer (GU), 82 patients with duodenal ulcer (DU) and 48 patients with gastritis (GS). Fragments located in the three different regions of vacA were amplified; V1 being the upstream portion, V2 the mid-portion and V3 the downstream portion. For cagA, the detection rates were 70% for GU, 79% for DU and 50% for GS, showing a significantly higher rate for DU than for GS (P = 0.0005). With V1, the detection rates were 90% for GU, 90% for DU and 69% for GS, giving a significantly higher rate for GU than for GS (P = 0.0036) and also giving a significantly higher rate for DU than for GS (P = 0.0019). With V2, the detection rates were 60% for GU, 70% for DU and 44% for GS, giving a significantly higher rate for DU than for GS (P = 0.0024). The differences in vacA gene polymorphism were closely related to the evidence of gastroduodenal ulcers in H. pylori infection. Furthermore, the detection rates of cagA and polymorphisms of vacA by PCR could be used as markers of strain diversity in H. pylori-induced gastroduodenal ulcer.     

Correction of partial volume effects in myocardial SPECT

BACKGROUND: Marked partial volume effects occur in myocardial single photon emission computed tomographic (SPECT) studies because of limited resolution in imaging the myocardial wall and contractile motion of the heart. Little work has been undertaken to develop correction techniques for SPECT except for efforts to improve the reconstructed resolution. Our purpose was to examine the extent of the problem and propose a correction method. METHODS AND RESULTS: A potential correction method, developed initially for positron emission tomography, involved estimation of extravascular density by means of subtracting vascular density derived in a blood pool study from total density derived from a transmission study. Provided partial volume errors are the same for transmission and emission data, activity per gram of extravascular tissue can be obtained by means of dividing the perfusion regional data by extravascular density for the same region. Simulations were designed to assess the importance of partial volume errors and the use of extravascular density to correct the errors. Recovery coefficients for the myocardium were estimated by means of simulation of the beating heart on the basis of published values for ventricular dimensions. Resolution for transmission with a scanning line source system was compared with emission resolution. The effect of spillover on measured partial volume losses was assessed, and a method for matching spillover for emission and extravascular density was demonstrated. Correction for partial volume effects was demonstrated for a phantom with variable wall thickness. Significant variation in recovery coefficient was demonstrated between posterior and septal walls for individual patients independent of heart size. Filtering was necessary to account for the difference in transmission resolution measured in the axial direction. Spillover effects had a significant influence on the measured recovery for small objects; however, for a specific reconstruction algorithm and defined region size, correction was implemented to match the spillover effects for emission and extravascular density. Use of extravascular density for correction of partial volume loss, for ordered subsets expectation maximization reconstruction with compensation for resolution, was demonstrated to be accurate to within 10%. CONCLUSIONS: The feasibility of correcting partial volume effects with extravascular density was demonstrated. Correction is effective provided care is taken to match both resolution and spillover for emission and extravascular density.     

Hip fracture incidence among elderly Asian-American populations

This study estimated national age- and sex-specific nontraumatic hip fracture incidence rates for elderly Chinese Americans, Japanese Americans, and Korean Americans. Based on a 50 percent sample of 1992 Medicare enrollees with the race/ethnicity code "Asian" and "other," cohorts of persons with distinctive Chinese (n = 24,366), Japanese (n = 28,762), and Korean (n = 5,470) names were followed passively for 2 years for a hospitalization with a diagnostic code indicating hip fracture. Cohorts of whites and blacks were followed for comparison. Year of immigration was deduced from the year of issuance of the Social Security number. Age-adjusted hip fracture incidence was lower for all three Asian-American groups than for whites. For females, the standardized fracture ratio relative to whites was 30.1 for Chinese, 73.2 for Japanese, and 52.8 for Koreans; for males, the standardized fracture ratio was 41.9 for Chinese, 58.1 for Japanese, and 90.7 for Koreans. Persons whose Social Security numbers were issued after the immigration Act of 1965 had an adjusted relative risk of 1.37 (95% confidence interval 1.05-1.78) compared with those in the US before that year, after adjustment for age, sex, and ethnic group.     

Accuracy of the clinical diagnoses of Lewy body disease, Parkinson disease, and dementia with Lewy bodies: a clinicopathologic study

BACKGROUND: Whether Parkinson disease (PD) and dementia with Lewy bodies (DLB) represent 2 distinct nosologic entities or are diverse phenotypes of Lewy body disease is subject to debate. OBJECTIVES: To determine the accuracy of the diagnoses of Lewy body disease, PD, and DLB by validating the clinical diagnoses of 6 neurologists with the neuropathologic findings and to identify early predictors of the diagnoses. METHODS: Six raters who were unaware of the neuropathologic diagnoses analyzed 105 clinical vignettes corresponding to 29 cases of Lewy body disease (post hoc analysis of 15 patients with PD and 14 with DLB) and 76 patients without PD or DLB whose cases were confirmed through autopsy findings. MAIN OUTCOME MEASURES: Sensitivity and positive predictive value (PPV) were chosen as validity measures and the K statistic as a reliability measure. RESULTS: Interrater reliability for the diagnoses of Lewy body disease and PD was moderate for the first visit and substantial for the last, whereas agreement for diagnosis of DLB was fair for the first visit and slight for the last. Median sensitivity for diagnosis of Lewy body disease was 56.9% for the first visit and 67.2% for the last; median PPV was 60.0% and 77.4%, respectively. Median sensitivity for the diagnosis of PD was 73.3% for the first visit and 80.0% for the last; median PPV was 45.9% and 64.1%, respectively. Median sensitivity for the diagnosis of DLB was 17.8% for the first visit and 28.6% for the last; median PPV was 75.0% for the first visit and 55.8% for the last. The raters' results were similar to those of the primary neurologists. Several features differentiated PD from DLB, predicted each disorder, and could be used as clinical pointers. CONCLUSIONS: The low PPV with relatively high sensitivity for the diagnosis of PD suggests overdiagnosis. Conversely, the extremely low sensitivity for the diagnosis of DLB suggests underdiagnosis. Although the case mix included in the study may not reflect the frequency of these disorders in practice, limiting the clinical applicability of the validity measures, the raters' results were similar to those of the primary neurologists who were not exposed to such limitations. Overall, our study confirms features suggested to predict these disorders, except for the early presence of postural imbalance, which is not indicative of either disorder.     

Calculation accuracy of volumes for evaluating dose-volume histograms. Comparison of various radiation planning systems

BACKGROUND: Modern 3-dimensional treatment planning systems on the basis of sectional imaging allow the calculation of volumes for organs of interest. The aim of this study is to investigate systematically the accuracy of calculations of volumes by the use of a phantom for 4 different treatment planning systems. MATERIAL AND METHOD: The tests were done with a phantom with 5 cylindrical structures and 6 spherical shaped structures. After performing a CT-scan and reading the data into the planning systems the structures were contoured and the volumes were calculated in order to compare these values with the values calculated by mathematical equations. This was systematically done as a function of different parameters. RESULTS: Comparing different methods of contouring showed notable influence on the result. Parameters as number of calculation points or length of cylinders showed no significant differences. In summary, the mean deviations for cylinders were +7% for system A, -2% for B, -17% for C, and 0% for D. For larger spheres (radii between 5 and 2.5 cm) the mean deviations were -5% for A, +3% for B, +1% for C, and +5% for D. For smaller spheres (radii between 1.75 and 1.25 cm) the mean deviations were -14% for A, -2% for B, -10% for C, and -4% for D. CONCLUSION: Verifying results of planning systems is important for the daily routine, but it has to be taken into account, that small changes of the radius of a cylinder or sphere cause substantial volume changes. The differences are also caused by inaccuracies of the whole procedure, e.g., the CT study, the shape and dimensions of the cylinders and the spheres and the CT information and the delineariation of the structures.     

Variance component estimation and multitrait genetic evaluation for type traits of dairy goats

Covariance components for final score and 13 linear type traits of dairy goats were estimated by multitrait REML using canonical transformation with an animal model. Data were 10,932 type appraisals from 1988 through 1994 from herds with > or = 40 appraisals. Heritabilities were estimated as 0.27 for final score, 0.52 for stature, 0.29 for strength, 0.24 for dairyness, 0.38 for teat diameter, 0.21 for rear legs, 0.32 for rump angle, 0.27 rump width, 0.25 for fore udder attachment, 0.25 for rear udder height, 0.19 for rear udder arch, 0.25 for udder depth, 0.33 for suspensory ligament, and 0.36 for teat placement. Genetic correlations of linear type traits and final score were positive except for dairyness (-0.15) and teat diameter (-0.10); the largest correlations with final score were 0.66 for fore udder attachment, 0.44 for rear udder arch, 0.36 for rump width, and 0.30 for strength. The largest positive correlation among linear traits was 0.63 for stature and rump width; the largest negative correlation was -0.51 for strength and dairyness. Multitrait evaluations were calculated with data from all herds. Correlations between PTA calculated with animal and sire models ranged from 0.44 to 0.70 for bucks that had a PTA with a reliability of > or = 30%.