Expert statement and assessment of medical impairment in work-related pulmonary disease

The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working group to standardise diagnostic procedures and evaluation of work-related respiratory disorders. In cases of suspected work-related diseases the physician may be asked by the National Insurance Administration or an insurance company to make a statement which will be one of the documents used to decide the patient's right to compensation benefit. We discuss the role of the physician as an independent expert. This is different from his role as clinician. The statement should include a balanced presentation of information from different sources, including health and occupational history, and the employer's information about the work environment (quantitative and qualitative exposure data). The statement must also include the results of a clinical examination and an assessment of functional status based on objective tests. The paper contains recommendations for evaluation of permanent impairment in light of the present Norwegian laws and regulations.     

Flow and Flow Decay of Refractory Castables

Installation of refractory castables depend not only on flow,but also on how soon the flow is lost because of setting.The loss of flow(flow decay)has always been one of the main problems of refractory castable manufacturers,a problem that has not been too well described in literature.The flow decay has been studied for a castable system based on alumina,pointing out some general trends.The flow decay was found very temperature sensitive,being strongly accelerated by temperature increases.To compensate for excessive flow loss,a retarder like citric acid may be used.Thus flow decay was measured as a function of citric acid(retarder) addition at 35℃.     

A dual-affinity gene fusion system to express small recombinant proteins in a soluble form: expression and characterization of protein A deletion mutants

A novel gene fusion system to express and purify small recombinantproteins in Escherichia coli has been constructed. The conceptallows for affinity purification of soluble gene products bysequential albumin- and Zn²+-affinity chromatography. The dual-affinitysystem is well suited for expression of unstable proteins asonly full-length protein is obtained after purification andproteins gain proteolytic stability in the fusion protein. Herewe show that the dual-affinity approach can be used for theexpression of various unstable derivatives of a single IgG-bindingdomain based on staphylococcal protein A. Analysis of the proteolyticstabilities and the IgG-binding properties of the differentmutant proteins suggest that the model for the structure ofan IgG-binding domain must be re-evaluated.     

Microalgae growth for nutrient recovery from sludge liquor and production of renewable bioenergy

Proof-of-concept has been demonstrated for a process that will utilize nutrients from sludge liquor, natural light, and CO2 from biogas to grow microalgae at wastewater treatment plants. This process will reduce the impact of returning side-streams to the head of the plant. The produced algae will be fed to anaerobic digesters for increased biogas production. Dewatering of anaerobically digested sludge in centrifuges produces reject water with extremely low transmittance of light. A pretreatment procedure was developed that improved light transmittance for reject water from the FREVAR, Norway, wastewater treatment plant from 0.1% T to 77% T (670 nm, 1 cm path). Chlorella sp. microalgae were found to be suitable for growth in this pre-treated reject water. Typical nitrogen removal was 80-90 g N/kg TSS of produced microalgae. The microalgae were successfully harvested by chemically assisted flocculation followed by straining through a 33 microm sieve cloth, achieving up to 99% recovery. Harvested algae were anaerobically co-digested with wastewater sludge. The specific methane gas production (mL CH4/g VS fed) for the algae varied from less than 65% to 90% of the specific methane gas production for the wastewater sludge, depending on digester temperature, retention time and pre-treatment of the algae biomass.     

高炉出铁沟用Al2O3-SiC-C浇注料流动性和流动性衰减的研究

通过调整氧化硅微粉加入量和活性氧化铝微粉的类型 ,研究了Al2 O3-SiC -C浇注料的流动性和流动性衰减以及可工作时间的变化。结果表明 :在浇注料流动性相近的情况下 ,随着氧化硅微粉加入量的增加 ,加水量显著降低 ;浇注料的流动性与所引入的活性氧化铝微粉的特性密切相关 ;氧化硅微粉加入量的增加有助于延长浇注料的可工作时间 ;浇注料流动性的衰减呈现出先缓慢后迅速降低直至凝结的特点 ,一般在可工作时间之后迅速凝结     

Melting behavior of polypropylene fibers studied by differential scanning calorimetry

Polypropylene fibers produced in a compact-spinning process were studied by differential scanning calorimetry (DSC). With unrestrained fibers, the onset of melting increases with decreasing draw ratio, increasing M_w/M_n, decreasing extrusion temperature, increasing annealing ratio, and increasing draw-down ratio. These trends are discussed in terms of restraints and reorganization. The onset of melting is shifted to lower temperatures as the heating rate increases for all combinations of material and processing parameters, indicating suppressed reorganization. At low draw ratios, the height and width of the endotherm are affected by the spinline stress, and a secondary peak or shoulder is observed on the high temperature side of the main peak. The magnitude of the secondary peak increases with decreasing M_w/M_n, increasing draw ratio, decreasing draw-down ratio, and decreasing heating rate, but its position mainly depends on the heating rate. This indicates that the secondary peak may be due to the melting of structures that have been reorganized during the heating scan. As the draw ratio increases, the melting regime broadens, especially towards lower temperatures, and several maxima emerge on the DSC curve. Reorganization and shrinkage during heating may explain these observations. © 1995 John Wiley & Sons, Inc.     

Kinetic study on the alkaline degradation of cotton hydrocellulose

The kinetics of alkaline degradation of cotton hydrocellulose were determined in 5% NaOH at various temperatures. An activation energy of 24 kcal./mole was found for the endwise degradation reaction, while that of termination to a stable m-saccharinic acid endunit is 32 kcal./mole. Consequently, the DP_n of the degradable chain length is highly dependent on the reaction temperature, being 1000 at 65°C. and 140 at 132°C. At lower temperatures, the majority of degrading chains terminate to a normal reducing endgroup at the crystalline–amorphous transition region. From the data, the D P_n of cellulose chain segments participating in the amorphous regions of the original cotton fibril was calculated to be 143. This result strongly supports the classical micellar fibril structure over the folded model proposed by Manley.