Fundamentals of Green Steel Production: On the Role of Gas Pressure During Hydrogen Reduction of Iron Ores.

Out of the multitude of researched processing routes for sustainable ironmaking, hydrogen-based direct reduction and hydrogen plasma smelting reduction (HyPSR) are currently the most promising candidates for a successful industrial application. Both processes operate under gaseous atmospheres, which turn the partial and absolute pressure of hydrogen into a relevant process parameter. Here, we present first insights into the influence of total pressure and concentration of hydrogen on the reduction of hematite, focusing on the more pressure-sensitive route (HyPSR). The effect of pressure on the dissociation of H2 molecules into metastable H atoms or H+ ions,- and the overall hydrogen utilization is discussed using a thermodynamic approach. Validation experiments were conducted to testify the practical feasibility of adjusting these parameters. A decrease in the total pressure of the system from 900 mbar to 450 mbar resulted in an improved hydrogen utilization, thus suggesting that a larger population of H atoms can exist in the plasma arcs ignited under 450 mbar. An increase in the hydrogen concentration to 20 vol.% lead to undesired evaporation, likely because of a parallel increase in plasma temperature. Possibilities and challenges for exploiting these pressure-related phenomena for the industrial production of green steel are outlined and discussed. Supplementary Information: The online version contains supplementary material available at 10.1007/s11837-023-05829-z.

Properties of particle phases for metal-matrix-composite design.

Successful metallurgical design of metal-matrix-composites relies on the knowledge of the intrinsic property profiles of the metal matrix and especially the compounds employed for particles, whiskers or fibres. In this work we compiled the key properties melting point, bulk modulus, shear modulus, Young׳s modulus, density, hardness, Poisson׳s ratio and structure/space group from the widespread literature data for the most relevant compound types, i.e. borides, carbo-borides, carbides, oxides, nitrides and intermetallic phases.

Stiff, light, strong and ductile: nano-structured High Modulus Steel.

Structural material development for lightweight applications aims at improving the key parameters strength, stiffness and ductility at low density, but these properties are typically mutually exclusive. Here we present how we overcome this trade-off with a new class of nano-structured steel - TiB2 composites synthesised in-situ via bulk metallurgical spray-forming. Owing to the nano-sized dispersion of the TiB2 particles of extreme stiffness and low density - obtained by the in-situ formation with rapid solidification kinetics - the new material has the mechanical performance of advanced high strength steels, and a 25% higher stiffness/density ratio than any of the currently used high strength steels, aluminium, magnesium and titanium alloys. This renders this High Modulus Steel the first density-reduced, high stiffness, high strength and yet ductile material which can be produced on an industrial scale. Also ideally suited for 3D printing technology, this material addresses all key requirements for high performance and cost effective lightweight design.

Comparison of Holstein and Jersey innate immune responses to Escherichia coli intramammary infection.

Mastitis is one of the most prevalent diseases in cattle and remains among the most costly diseases to the dairy industry. Various surveys have indicated a greater prevalence of and risk for mastitis in Holstein cows than in Jersey cows. The innate immune system comprises the immediate host defense mechanisms that respond to infection, and differences in the magnitude and rapidity of this response are known to influence susceptibility to and clearance of infectious pathogens. The reported differences in the prevalence of mastitis between Holstein and Jersey cows may suggest the occurrence of breed-dependent differences in the innate immune response to intramammary infection. The objective of the current study was to compare the acute phase and cytokine responses of Holstein and Jersey cows following intramammary infection by the bacterial pathogen Escherichia coli, a leading cause of clinical mastitis. All cows in the study were in similar stages of lactation, of the same parity, subjected to the same housing and management conditions, and experimentally infected on the same day with the same inoculum preparation. Before and after infection, the following innate immune parameters were monitored: bacterial clearance; febrile response; induction of the acute phase proteins serum amyloid A and lipopolysaccharide-binding protein; alterations in total and differential white blood cell counts; changes in milk somatic cell counts and mammary vascular permeability; and induction of the cytokines IFN-gamma, IL-1beta, IL-8, IL-12, and tumor necrosis factor-alpha. Overall innate immune responses were similar between the 2 breeds; however, temporal differences in the onset, cessation, and duration of several responses were detected. Despite these differences, intramammary clearance of E. coli was comparable between the breeds. Together, these data demonstrate a highly conserved innate immune response of Holstein and Jersey cows to E. coli intramammary infection.

Nasal potential difference measurements in patients with atypical cystic fibrosis.

The diagnosis of cystic fibrosis (CF) is based on characteristic clinical and laboratory findings. However, a subgroup of patients present with an atypical phenotype that comprises partial CF phenotype, borderline sweat tests and one or even no common cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The aim of this study was to evaluate the role of nasal potential difference (PD) measurements in the diagnosis of CF patients with an atypical presentation and in a population of patients suspected to have CF. Nasal PD was measured in 162 patients from four different groups: patients with classical CF (n = 31), atypical phenotype (n = 11), controls (n = 50), and patients with questionable CF (n = 70). The parameter, or combination of nasal PD parameters was calculated in order to best discriminate all CF patients (including atypical CF) from the non-CF group. The patients with atypical CF disease had intermediate values of PD measurements between the CF and non-CF groups. The best discriminate model that assigned all atypical CF patients as CF used: e(response to chloride-free and isoproterenol/response to amiloride) with a cut-off >0.70 to predict a CF diagnosis. When this model was applied to the group of 70 patients with questionable CF, 24 patients had abnormal PD similar to the atypical CF group. These patients had higher levels of sweat chloride concentration and increased rate of CFTR mutations. Nasal potential difference is useful in diagnosis of patients with atypical cystic fibrosis. Taking into account both the sodium and chloride transport elements of the potential difference allows for better differentiation between atypical cystic fibrosis and noncystic fibrosis patients. This calculation may assist in the diagnostic work-up of patients whose diagnosis is questionable.

Re-implantation of autoclaved bone segments in musculoskeletal tumor surgery. Clinical experience in 9 patients followed for 1.1-8.4 years and review of the literature.

Nine patients who had malignant bone tumors of the lower extremity were managed with wide en bloc resection and re-implantation of the extracorporeally autoclaved specimens. The segments were fixed by plate osteosynthesis, knee arthrodesis rod, or intramedullary nails. In one patient the complete femur was re-implanted. After a mean follow-up of 66 months (range 13-101 months), 8 out of 9 patients were still free of disease. One patient with Ewing's sarcoma and re-implantation of the complete femur died of systemic recurrence. No local recurrence was seen. One patient with Ewing's sarcoma of the tibia who had undergone postoperative irradiation developed a local infection 18 months postoperatively which finally had to be treated by knee disarticulation. After an average duration of 13 months, all graft-host junctions had healed. The functional result of the patient with the knee disarticulation was poor. In all other patients, the functional outcome was good or excellent. The evaluation of 115 patients (106 from the literature, 9 from our study) with a mean follow-up of 63 months showed 8 local recurrences. There were 4 secondary infections and only 1 primary infection. In tumors of the extremities and the pelvis, the functional outcome was excellent or good in about 80%. Limb salvage using re-implantation of autoclaved tumor-bearing bone segments for reconstruction has a low complication rate and good functional results in appropriately selected patients compared with other options of management.

Computer mediated learning experiences spanning the globe: a pilot study between schools of nursing in the United States and the Netherlands.

The use of telecommunications in health care, education, and our daily lives has become a popular topic in both the professional and lay literature. The promise of the "Information Superhighway" and the expanded use of the Internet by other professionals have precipitated the examination of computer mediated communication as an instructional tool that transcends geographic boundaries and time barriers. This paper will discuss the development and implementation of a pilot project to foster collaborative learning experiences for nursing students between two schools of nursing in two different countries. The pilot is framed within the context of a Global Collaborative Learning Project in Nursing Informatics. A pilot project was initiated between the Schools of Nursing at the University of Colorado Health Sciences Center and the Hogeschool Holland during the 1994-95 academic year. Each school taught a nursing informatics course and assignments were designed to allow students from each school to participate in a collaborative learning experience. The presentation will highlight the outcomes of this pilot project and project future plans.

Ear involvement in human brucellosis.

A case report of mixed-type hearing loss following brucella infection is presented. Damage to the ear in brucellosis is well documented in the Polish literature whereas, surprisingly, it is not mentioned in the otolaryngologic and microbiologic English literature. Otolaryngologists should be aware of possible ear damage in brucellosis, in order to be helpful in the diagnostic process, with the aim of starting antibiotic treatment as soon as possible, in order to prevent irreversible ear damage.

[Somatosensory evoked potentials in surgery of the spine]. / Somatosensorisch evozierte Potentiale bei Eingriffen an der Wirbelsäule.

The authors report on their experience using cortical somatosensorially evoked potentials in 23 studies on 21 patients. The method is used intraoperatively when the spinal cord is at risk, for early identification of functional damage to the cord. The potentials found are classified according type of manifestation and compared with the results obtained by other authors.

Microcomputer-based measurement of beat-to-beat intervals and analysis of heart rate variability.

This paper presents detailed information about a small, low-cost computerized system for on-line data processing which may easily be adapted to various problems. In the application described, the system operates as a heart detector and analyzer providing ECG signal filtering, measurement of beat-to-beat intervals (resolution: 1 ms), elimination of both artifacts and extrasystoles, and statistical analysis. All data and results are stored on magnetic tape and printed. This device proved to be a valuable tool in the investigation of heart rate abnormalities, which seem to indicate the presence of autonomic dysfunction observed in long-term diabetes mellitus. Preliminary results show that the decrease of normal beat-to-beat variation in diabetics is highly correlated with diabetic neuropathy and microangiopathy of the eye.