Energy intensities and greenhouse gas emission mitigation in global agriculture

Energy efficiency and greenhouse gas emissions are closely linked. This paper reviews agricultural options to reduce energy intensities and their impacts, discusses important accounting issues related to system boundaries, land scarcity, and measurement units and compares agricultural energy intensities and improvement potentials on an international level. Agricultural development in recent decades, while increasing yields, has led to lower average energy efficiencies when comparing the 1960s and the mid 1980s. In the two decades thereafter, energy intensities in developed countries increased, but with little impact on greenhouse gas emissions. Efficiency differences across countries in the year 2000 suggest a maximum improvement potential of 500 million tons of CO₂ annually. If only below average countries would increase their energy efficiency to average levels of the year 2000, the resulting emission reductions would be below 200 million tons of CO₂ annually.

A new mechanism for lengthening the lifetime of hydrogenation catalysts

Intermetallic compounds with d-transition metals have been used as catalysts. XPS and AES studies and the magnetic properties of LaNi₅ and FeTi show that surface segregation occurs and that superparamagnetic Ni and Fe precipitates are formed at the surface, catalyzing the dissociation of molecular hydrogen. The catalytic activity of many intermetallic compounds can be explained by surface segregation and the formation of d-transition metal precipitates. Contaminants often drive the segregation, hereby prolonging the lifetime of the catalyst. We predict that FeTi can replace Fe-catalysts being more resistant to contaminants.     

Wiederaufbau des Neuen Museums in Berlin – Tragwerksplanung pro Baudenkmalpflege

Reconstruction of the “Neues Museum” in Berlin – structural design pro preservation of historic buildings. “While no work can be understood without knowledge of its technology, no technology can be understood without knowledge of the work, either” [1]. The reconstruction of the “Neues Museum” in Berlin is a great challenge for all participants in Adorno's terms. Historical structures, especially arched components, usually have amazing bearing capacities. It is rarely possible to verify these only by calculation. Two examples will show how calculation and experiment complement each other in analyzing the load capacity. Thus historical structure components can be admitted to modern utilisation.     

The non-recurrent inferior laryngeal nerve. An important rarity in thyroid gland surgery

The occurrence of non-recurrent inferior laryngeal nerve is based on a rare embryologic vascular malformation of the aortic arches. Based on three recent cases, we discuss embryology, clinical presentation and operative technique.     

Hypertrophic cardiomyopathy: spontaneous course

Hypertrophic cardiomyopathy is a relatively rare (prevalence approximately 0.2%), primary myocardial disorder with an autosomal pattern of inheritance, characterized by mostly asymmetric left ventricular hypertrophy with myocyte and myofibrillar disarray. To date, about 34 mutations of the beta-cardiac myosin heavy chain gene have been described and shown to have prognostic implications. The disease has an annual mortality rate of 3%, related to both sudden cardiac death and progressive systolic dysfunction. Not only diastolic but also progressive systolic dysfunction with cavity dilatation occurs in a minority of patients with severe hypertrophy during the long-term course. Sudden death often occurs in young, asymptomatic or mildly symptomatic patients. The degree of hypertrophy and the presence of a pressure gradient are of little prognostic significance. Nonsustained ventricular tachycardia is associated with a poor prognosis in the presence of a history of syncope.