Experimental Study of the Behavior of a Lumpy Fill of Soft Clay

Land reclamation is a major civil engineering activity in Singapore. Due to depletion of suitable local fills and the cost of imported sand, dredged and excavated clay fills, in spite of their poor engineering properties, are being evaluated as a fill material. To reduce double handling, it is desirable for the clay to be used directly in a lump form, instead of the more conventional slurry fill. While the performance of a slurry fill is relatively well understood, the behavior of lumpy fill is not. This paper reports the results of a laboratory study carried out on lumpy fill made of cubical clay lumps of size ranging from 12.5?to?50?mm. The study showed that the interlump voids are substantially closed at a consolidation pressure much lower than the preconsolidation pressure of the lumps. The study also shows that at a consolidation pressure of about 100?kPa, the permeability of a lumpy fill is reduced to an order similar to that for homogeneous clay. However, the shear strength profile obtained using the cone penetration test indicates that the fill is still highly heterogeneous under a pressure of 100?kPa. When the preconsolidation pressure of the lumps is exceeded, the strength profile becomes uniform. The degree of swelling of the lumps plays a significant role. For fully swollen lumps, the consolidation pressure required to close the interlump voids is considerably less than that if the lumps were not allowed to swell. The coefficient of secondary compression of the lumpy fill is comparable to the homogeneous clay indicating that secondary compression is not a serious issue.     

"Redistribution" Effect of Lumpy Zone for Gas Flow in BF

The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping,cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called "redistribution" effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.     

富氢对块状带低钛球团矿还原的影响研究

在高炉喷吹煤造气冶炼条件下,研究在低温区块状带不同H2含量和不同温度对矿石还原情况的影响。试验结果表明:当还原温度为900℃时,还原速率随着H2含量的增加而逐渐变大,当还原气氛一定时,还原速率随着还原温度的增加而逐渐变大;还原后的球团主要物相是单质铁,并含有少量的镁钛铁矿(Mg,Fe)(Fe,Ti)O3、镁铝尖晶石(Mg Al2O4)和镁橄榄石(Mg2Si O4);随着还原温度的增加,镁钛铁矿(Mg,Fe)(Fe,Ti)O3首先开始消失,镁铝尖晶石(Mg Al2O4)和镁橄榄石(Mg2Si O4)逐渐减少,并且随着还原温度的增加,H2的还原能力显著加强,铁矿石失氧速率增加,生成的金属铁发生聚集,导致球团内部留下小细孔。     

高炉块状带矿石逐渐升温还原对料层透气性影响

 为了模拟高炉块状带内矿石还原过程对料层透气性的影响,根据实际高炉料层的运动升温及煤气成分的变化情况,设计了模拟矿石在高炉块状带行程的试验方法,建立了能够实时监测料层压差和矿石还原度的试验装置,给出了矿石逐渐升温还原对料层透气性影响的量化评价指标,并实测了某高炉烧结矿、球团矿、块矿、混合矿石在逐渐升温过程中的料层压差和还原度变化,得出逐渐升温还原后的粉化指标和料层压差增加率具有很好的一致性。与原有的低温还原粉化测试方法相比,该方法更适合用于判断高炉整个块状带内矿石还原对料层透气性的影响,更有利于评价矿石性能对高炉操作的影响。试验还研究了原始粒径、还原失重、还原温度、还原时间、加热、转鼓、泡水对矿石粉化程度的影响。     

承钢高炉块状带钒氧化物还原机理研究

对于以钒钛磁铁矿为主要原料的高炉,研究钒在高炉中的行为规律具有重大意义。通过理论分析和模拟试验研究,探索钒在高炉块状带的还原机理。热力学计算表明,钒和铁可以无限互溶;随着铁相的出现,钒氧化物还原的热力学条件将大大改善。经过对承钢钒钛烧结矿的XPS和XRD检测证实:承钢钒钛烧结矿中钒的价态表现为+5价,承钢烧结矿以钛磁铁矿、钛赤铁矿为主,V、Ti固溶于钛磁铁矿中。通过对V_2O_3纯试剂、Fe_2O_3和V_2O_3的1∶1混合试剂及承钢钒钛烧结矿的还原试验研究,结果表明,在1 000℃范围内CO不能还原V_2O_3纯试剂,在高炉块状带间接还原中钒的氧化物不能被还原出单质钒。     

“Redistribution” Effect of Lumpy Zone for Gas Flow in BF

 The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called “redistribution” effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.     

半钢炼钢加块状含碳材料补充供热试验

本文介绍马钢二炼钢厂20t转炉添加块状含碳材料补充供热的试验情况,解决了半钢炼钢热源不足问题,从而使钢质量提高,废钢比增加及显著的经济效益。     

Effect of Coke Reaction Index on Reduction and Permeability of Ore Layer in Blast Furnace Lumpy Zone Under Non-Isothermal Condition

 Reasonable control on CRI (coke reaction index) is one of the key factors for BF (blast furnace) low-carbon smelting. However, there are contrary opinions. One is increasing CRI to improve reaction efficiency in BF and the other is decreasing CRI to suppress coke degradation in furnace. Different methods are adopted to realize effective catalysis (increasing CRI) and passivation (decreasing CRI) of coke. Simulation tests of coke in BF lumpy zone under gradual temperature rising have been done. Effect of CRI on gas composition, ore reduction, burden column permeability and heat reserve zone′s temperature under non-isothermal condition are studied. Then combined with iron making calculations, a novel BF operation suggestion is proposed as coke nut with small size be catalyzed and mixed with ore while skeletal coke with large size be passivated and separately charged into BF.     

原子荧光光谱法测定土壤中的铅、铬、镉、汞、砷、锌、铜、镍等元素研究

土壤无机污染物铅、铬、镉、汞、砷、锌、铜、镍这八大重金属,是一般土壤检测中的必检项目。金属元素在土壤中积累富集后,有可能通过雨水迁移,造成地下水,地表水污染,或者通过农作物进入食物链,进而影响食品安全和人体健康,因此,对这些元素的检测显得尤为重要。本文采用原子荧光光谱法对土壤中的金属元素进行测量,同时结合微波消解技术对样品进行处理,确保测量数据的准确性。     

Analysis of mepivacaine, bupivacaine, etidocaine, lidocaine, and tetracaine

A GLC method, employing a nitrogen-phosphorus-sensitive detector, is described for the analysis of mepivacaine, bupivacaine, etidocaine, lidocaine, and tetracaine in biological fluids. The method is simple, reliable, and sensitive, with a practical limit of sensitivity of approximately 2.5 ng/ml, well below therapeutic plasma levels. Extensive start-up procedures and sample preparation are not required.     

Synthesis of sulfur-linked analogues of nigerose, laminarabiose, laminaratriose, gentiobiose, gentiotriose, and laminaran trisaccharide Y

Sulfur-linked analogues of 3-O-alpha-D-glucopyranosyl-D-glucose (nigerose), 3-O-beta-D-glucopyranosyl-D-glucose (laminarabiose), 6-O-beta-D-glucopyranosyl-D-glucose (gentiobiose), O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->3)-D-glucos e (laminaratriose), O-beta-D-glucopyranosyl)-(1-->6)-O-beta-D-glucopyranosyl-(1-->6)-D-gluco se (gentiotriose) and 3,6-di-O-beta-D-glucopyranosyl-D-glucose (laminaran trisaccharide Y), namely, respectively, 3-thionigerose (6), 3-thiolaminarabiose (11), 6-thiogentiobiose (21), 3I,3II-dithiolaminaratriose (16), 6I,6II-dithiogentiotriose (29) and 3I,6I-dithiolaminaran trisaccharide Y (37) have been conveniently prepared by SN2 reactions of the corresponding anomer of D-glucopyranose 1-thiolate with suitably activated monosaccharide derivatives in N,N-dimethylformamide (for 6 and 21) or in tetrahydrofuran in the presence of a crown ether (for 11). A sequence involving the reaction of non-anomeric thiolates with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide was alternatively used for the preparation of 11 and 21 but proved less satisfactory. The preparation of thiotrisaccharides 16, 29, and 37 involved a mixed approach.     

Thermodynamics of copper matte converting: Part III. Steady-state volatilization of Au,Ag, Pb,Zn, Ni,Se, Te,Bi, Sb,and As from slag,matte, and metallic copper

A comprehensive compilation of various thermodynamic data required for a complete analysis of copper matte converting reactions is presented. The data comprise estimated free energies of formation for such gases as SeO, SeS, TeO, TeS, BiO, BiS, SbO, SbS, AsO, and AsS, as well as activity coefficients in dilute copper alloys and vapor pressures of various elements and compounds. The volatilization of minor elements in steady-state reactors comprising gas and several condensed phases is mathematically formulated, and a parameter which governs the volatilization in such reactors is defined and named volatilization constant. The vapor pressures of various volatile species are calculated thermodynamically for the Noranda Process reactor by assuming equilibrium conditions. The volatilization constants of various minor elements are expressed explicitly as functions of oxygen and sulfur activities. Formerly Associate Professor, Department of Metal-lurgical Engineering, University of Utah, Salt Lake City, UT.     

ICP-AES法测定硅铁中锰、磷、铝、钙、铬、镍、铜

以电感耦合等离子体光谱法(ICP-AES)直接同时进行硅铁中Mn、P、Al、Ca、Cr、Ni、Cu的测定，提出了：试样溶解的方法、元素的干扰情况、元素分析谱线的最佳选择和背景校正的最佳方法。优化了仪器工作条件，综合确定了最佳试验条件。结果表明，该法准确、快速、简便，精密度、回收率、标准样品分析对照均取得了满意的结果。     

电感耦合等离子体原子发射光谱法测定镍基合金中钨、钼、钴、铝、钛、铌、铁元素

针对镍基合金的溶解方法、元素分析谱线的选择、仪器分析参数的优化、内标溶液的选用、基体元素的影响、干扰元素的校正及消除方法等进行了研究,确定了最佳试验条件;试验结果表明:检出限为0.024mg/L～0.85mg/L;加标回收率为97.1%～105.7%;方法的精密度(RSD,n=11)小于1.0%,本试验测定结果与标钢认定值和湿法分析结果做对照,都在允许偏差范围内,表明此方法精密度好,准确度高。     

Thermodynamics of copper matte converting: Part IV. A priori predictions of the behavior of Au,Ag, Pb,Zn, Ni,Se, Te,Bi, Sb,and As in the noranda process reactor

The general formulae are derived which allow calculation of the weight of each molten phase (copper, matte, slag) in the Noranda Process reactor as a function of matte grade and suspension indices. These expressions and the volatilization constants are then inserted in the steady-state volatilization equation (derived in the Part III) to calculate the overall distribution of minor elements and their concentrations in all the reactor productsi.e., copper, matte, slag, and offgas) in the Noranda Process. The overall distribution of ten minor elements can be predicted for any set of controllable process parameters such as feed composition, temperature, degree of oxygen enrichment, slag composition (or magnetite activity), and matte grade. The computer predictions are in good agreement with the commercially observed values with the exception of selenium. Formerly Associate Professor, Department of Metallurgical Engineering, University of Utah, Salt Lake City, UT.     

Relation of benzodiazepine use to the risk of selected cancers: breast, large bowel, malignant melanoma, lung, endometrium, ovary, non-Hodgkin's lymphoma, testis, Hodgkin's disease, thyroid, and liver

Some animal data have raised the possibility that benzodiazepines influence the risk of selected cancers. With data collected in 1977-1991 in a US hospital-based study, the authors assessed the relation of benzodiazepine use to the risk of 11 cancers: breast (6,056 patients), large bowel (2,203), malignant melanoma (1,457), lung (1,365), endometrium (812), ovary (767), non-Hodgkin's lymphoma (382), testis (314), Hodgkin's disease (299), thyroid (111), and liver (37). Cases were compared with cancer controls (3,777 patients with other cancers) and noncancer controls (1,919 patients admitted for acute nonmalignant disorders). Relative risks were estimated for benzodiazepine use at least 4 days a week for at least 1 month, initiated at least 2 years before admission (sustained use) by multiple logistic regression with control for confounding factors. Results derived with noncancer controls were similar to those derived with cancer controls. For sustained benzodiazepine use relative to no use, relative risk estimates for all 11 cancers were compatible with 1.0 at the 0.05 level of significance. Relative risk estimates for durations of at least 5 years were also compatible with 1.0, with the exceptions of an increased estimate, of borderline statistical significance, for endometrial cancer, and a decreased estimate for ovarian cancer. Relative risk estimates both for sustained use that continued into the 2-year period before admission and for sustained use that ended up to > or = 10 years previously were compatible with 1.0, suggesting a lack of tumor promotion and no increase in the risk after a latent interval. Results were also null for diazepam, chlordiazepoxide, and other benzodiazepines considered separately. The results suggest absence of association between benzodiazepine use and the cancers considered, with the evidence stronger for the cancers with larger numbers of subjects. The similarity of results derived with cancer and noncancer controls suggests that benzodiazepines do not influence the risk of cancer as a whole.     

Comparison of tacrine-induced cytotoxicity in primary cultures of rat, mouse, monkey, dog, rabbit, and human hepatocytes

Cisplatin (DDP) is currently one of the most effective drugs for the treatment of cancer. It causes primarily intrastrand DNA-DNA cross-links, and is highly mutagenic and carcinogenic in both in vitro and in vivo experimental models. There is, however, considerable variability between the response seen in different cellular systems, probably at least partly because of the different cellular DNA repair capacities. A number of analogues of cisplatin have been developed and one of these, carboplatin (CDDCA), is also in widespread clinical use. Although it is somewhat less toxic, there is no evidence that its mode of action differs from that of cisplatin. A limited amount of mutagenicity data suggests that it has similar mutagenic and carcinogenic consequences as the parent drug. Many further analogues of cisplatin are now in clinical trials, and some of these appear to have different DNA repair responses (and therefore possibly the development of clinical resistance). Although some (e.g., iproplatin and spiroplatin) are less mutagenic than either cisplatin or carboplatin, these appear to be the ones least likely to achieve wide use. There are insufficient data on several of the most promising clinical analogues (e.g., DWA2114R and ACDDP) to judge their relative mutagenic and carcinogenic potential. Detailed studies on the DNA repair and mutagenicity characteristics of these compounds will not only provide clinically relevant data, but may also aid in the selection of further useful antitumour agents in this series.     

Susceptibilities of non-Pseudomonas aeruginosa gram-negative nonfermentative rods to ciprofloxacin, ofloxacin, levofloxacin, D-ofloxacin, sparfloxacin, ceftazidime, piperacillin, piperacillin-tazobactam, trimethoprim-sulfamethoxazole, and imipenem

Agar dilution MICs of 10 agents against 410 non-Pseudomonas aeruginosa gram-negative nonfermentative rods were determined. MICs at which 50 and 90% of the isolates were inhibited, respectively, were as follows (in micrograms per milliliter): sparfloxacin, 0.5 and 8.0; levofloxacin, 1.0 and 8.0; ciprofloxacin, 2.0 and 32.0; ofloxacin, 2.0 and 32.0; D-ofloxacin, 32.0 and > 64.0; ceftazidime, 8.0 and 64.0; piperacillin with or without tazobactam, 16.0 and > 64.0; trimethoprim-sulfamethoxazole, 0.5 and > 64.0; imipenem, 2.0 and > 64.0. With the exception of those for Stenotrophomonas maltophilia, Burkholderia cepacia, and Alcaligenes faecalis-A. odorans, agar dilution MICs for all strains tested were within 1 dilution of inhibitory (bacteriostatic) levels as determined by time-kill methodology.     

Dusts,scale, slags,sludges... Not wastes,but sources of profits

Historically, the steel industry has focused on the need for and the many benefits of recycling steel that is discarded either in its own or in its customers’ manufacturing processes, as well as in recovery and reuse of steel scrap that arises after the product has served its intended purpose. In fact, modern steelmaking relies on the use of recycled iron units for at least half of its production. The other side of the story is the fate of the non-steel by-products (e.g., oxide dusts, sludges, scales, slags, spent refractories and the contained “low grade” energy units that are generated as natural adjuncts to iron and steelmaking processes). These valuable by-products often are classified as “wastes” and are discarded to landfills, at significant cost, although in reality they offer significant potential for cost savings or profit if reintroduced into the industrial arena via well planned programs. Examples of such instances will be presented, including energy credit issues, in the hope of pointing the way for future expansion of benefits from these opportunities. Preparing for a challenge and honor such as the Howe Memorial Lecture, one has to stand in awe of the accomplishments of the predecessor we honor in this forum. He worked in the early days of our industry without the benefits of the many technological improvements he and his successors brought to play as the years went by. John Stubbles, in his Howe Memorial Lecture in 1997,_[1] presented a masterful and entertaining biography of Howe and his very active and prolific life. Perhaps the most telling quotation he attributed to Howe is very pertinent to the topic we will address presently: “Metallurgy lives by profit, not logic,” to which I would like to add a comment that bears on the topic of this lecture from the 1991 Howe lecturer, my friend and mentor Bill Dennis, “Where there is muck, there is money.” There are numerous examples of “one hand washes the other” in this business; that is, of the synergism between needs and capabilities. We will address some of these situations, such as in a new process under development for dezincing of post consumer scrap, and in the use of iron units in by-product oxides and recycling of ladle slags and of spent refractories. Peter J. Koros, the Iron and Steel Society’s 77th Howe Memorial Lecturer (2001), is Principal of Koros Associates, Inc. (Pittsburgh, PA), a consultancy he founded following retirement from the former LTV Steel Company where he worked for nearly 41 years, retiring as Senior Research Consultant. He earned the Bachelor of Science degree in Metallurgical Engineering from Drexel University, and his master’s and doctoral degrees in Metallurgy from the Massachusetts Institute of Technology (MIT). In 1958, he joined Jones and Laughlin Steel (which became LTV Steel Company), where he held positions in research (Director, Process Metallurgy), Technical Services and Quality Control, with most activities focused on steelmaking and related areas. He was responsible for J&L’s development work in injection technology for desulfurization of hot metal and steel, was the inventor of the patented co-injection concept now in use worldwide, and had the lead role in LTV Steel’s programs for degalvanizing scrap and for recovery and utilization of by-product oxides. He led the AISI Opt-In program for degalvanizing scrap and the LTV-USS pilot program for processing “by-product” oxides. Koros has authored more than 75 publications and presentations, and holds eight U.S. patents, the latest issued in 2000. Dr. Koros was elected a Distinguished Member and Fellow of the ISS in 1984 and a Fellow of ASM International in 1988. Other honors include the ISS Distinguished Service Award (1998), ISS Electric Furnace Honorable Mention Citation (1987), International Magnesium Association Design and Applications Award (1978), AISI Gold (1977) and Silver (1969) Medals, ISS Herty (1963), McKune (1963), and Toy (1962) Awards. Koros served on the Technical Advisory Committee of the AISI-DOE Direct Steelmaking Program and its follow-on Waste Oxide Recycling Program. He was chairman of the AISI Task Force on Degalvanizing Steel Scrap and of the Industrial Advisory Panel to the Argonne Lab-MRI Program on Dezincing Steel Scrap. The 2001 Howe Memorial Lecture, titled “Dusts, Scale, Slags, Sludges ... Not Wastes But Sources of Profits,” as well as an invited Keynote Lecture for an International Recycling Conference in Sweden (June 2002, “Iron Units in Search of a Home: New Steel”) were based on the experience from these programs. Koros has been an active member of the ISS Advanced Technology Committee for which he participated in and chaired several symposia, including New Melting Technologies II (October 2002) and the first New Melting Technologies Symposium (1997). He was Director of the ISS 2000 Short Course on Injection Technology, a lecturer in the 2000 ISS/AISI Course on BOF Steelmaking, lead Co-chairman for the Elliott Symposium (1990), and Chairman of the Program Committee for the Fifth International Iron and Steel Congress (1986). Dr. Koros served on the Industrial Advisory Board of MIT’s Materials Processing Center (1995–98) and the AISI’s Iron and Steel Research Subcommittee (1976–86.) He was chairman of the ISS National Science Foundation Advisory Committee, the Advisory Council of the U.S. Bureau of Mines Generic Minerals Technology Center for Pyrometallurgy Research (1983–85), and of the Advisory Board for Carnegie Mellon University’s Center for Iron and Steel Research, for which he served as chairman (1991–1992). Service included participation in the NRC-NAS Alternative Energy and Development Strategy Study (1989–90.) Koros was very active in the creation of the ISS, having served as Chairman of the predecessor TMS Iron and Steel Division in 1972–73 and on the AIME Board of Directors (1974). Professional Society memberships: ISS (elected Distinguished Member and Fellow, Life Member), TMS (Senior or Life Member), ASM International (elected Fellow, Life Member), and AISE.     

Proceedings of the American Psychological Association, Incorporated, for the year 1993: Minutes of the Annual Meeting of the Council of Representatives August 19 and 22, 1993, Toronto, Ontario, Canada, and February 25-27, 1994, Washington, DC.

Presents the minutes representing the official record of the actions of the American Psychological Association (APA) taken during 1993 by both the Board of Directors and the Council of Representatives. The report addresses action taken in the areas of elections, appointments, awards, membership, and human resources. Membership information includes lists of persons elected to initial membership in the APA in 1993, members who died in 1993, members who resigned in 1993, members who were reinstated during 1993, and members elected to initial APA fellowship status effective as of January 1, 1994. The report also discusses action in the areas of ethics, Board of Directors, divisions and state and provincial associations, organization of the APA, convention affairs, educational affairs, professional affairs, scientific affairs, public interest, Central Office, financial affairs, and communications concerning outside organizations. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)