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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 62 (1991), S. 1054-1056 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A steady-state method for thermal conductivity measurements above 100 K on poor conductors is described. Radiation errors are made negligible using a closely fitting shield with a temperature profile matched along its length to that of the sample. Calculations show that for a typical geometry, the radiation error at room temperature is two or three orders of magnitude lower than for a shield kept at the sink temperature. The experimental setup is described and measurements on PMMA are reported. The results agree with measurements reported by other authors who use completely different methods.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of management 16 (2005), S. 0 
    ISSN: 1467-8551
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: The main objective of this study is to analyse the strategic and organizational evolution of large firms in a current time period and within a specific geographical context (Spain). In order to achieve this purpose, the paper combines the Chandlerian programme with processual analysis. We draw on documentary sources (annual reports, company histories, business directories and so on) and interviews. We have found that in the model of corporate development some characteristics of new organizational structures will coexist with some features of old ones. In line with previous studies our findings highlight the existence of the ‘multidivisional network’ but, most importantly, our findings also reflect the emergence of a new kind of organizational form that we call ‘holding network’. The ‘holding network’ is more decentralized, both strategically and operationally, than the multidivisional form. However, its level of decentralization is less than in the N-form. Furthermore, whereas the multidivisional form is a hierarchy, the ‘holding network’ emphasizes the communication among people of different levels. This multilevel communication differs from that in the N-form. Apart from the horizontal communication in the same level there is vertical and horizontal communication between different levels. We conclude by emphasizing the need to explore in future empirical studies to what extent these patterns and new organizational forms should be considered as a transitory or consolidated phenomenon.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 96 (1996), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Phosphorus-deficient Gracilaria tenuistipitata Zhang et Xia was cultured for 15 days at two different inorganic phosphate (Pi) concentrations: 3 μM (low Pi treatmenl) or 30 μM phosphate (high Pi treatment). The amount of ribulose-l,5-bisphosphate carboxy-lase/oxygenase (Rubisco), phycobiliproteins, Chl a and total soluble proteins were higher in the high Pi than in the low Pi treatment. The total N content of the low Pi plants was lower than in plants grown at high Pi concentrations whereas the amount of total C was highest in low Pi plants. The increase of Rubisco content in the high Pi treatment (3-fold) was parallel to the enhancement of the maximum photosynthetic rate which increased 5-fold. This correspondence was also found in the low Pi treatment in which Rubisco content and maximum photosynthesis did not change significantly from the initial values. The photosynthetic efficiency was also higher at high than at low Pi. The high Pi plants also showed higher dark respiration and growth rates. The data presented here suggest that marine macroalgae submitted to Pi deficiency exhibit a decrease in growth caused not only by Pi implication on energy transfer in photosynthesis and respiration, but also by the diminution of the amount of photosynthetic pigments and Rubisco.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 88 (1993), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The influence of nitrogen on ribulose-1.5-bisphosphate carboxylase/oxygenase (Rubisco. EC 4.1.1.39) content is poorly understood in macroalgae. N-deficient Gracilaria tenuistipitata Zhang et Xia var. liui was cultivated in the laboratory under constant light intensity and temperature. Biochemical and physiological variables were monitored after a high (1 mM) or low (o. 1 mM) nitrate pulse. Rubisco content in crude extracts was estimated by SDS-PAGE with the Coomassie Blue Staining procedure. Nitrate was consumed immediately in the low-N treatment, but there was always an external nitrate source in the high-N treatment. Total soluble proteins and phycobiliproteins decreased as internal nitrogen diminished in the low-N treatment, but kept fairly constant in N-sufficient conditions. However, Rubisco content increased until the 7th day and then started to decrease in both cases. Fresh weight increment showed a better correlation with Rubisco than with pigment content.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 91 (1994), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The rates of phosphate uptake and photosynthesis were simultaneously determined in order to investigate the relationship between phosphate use and photosynthesis. Porphyra umbilicalis (L.) Kützing exhibited two different phosphate uptake kinetics. The first one followed a saturation model and was observed in light (maximum phosphate uptake rate. Vmax= 94 ± 30 nmol P1 m−2 s−1: semisaturation constant. S15= 4.0 ± 3.4 μM: phosphate compensation point. PCP = 0.3 ± 0.4 μMγ: the seeraid one was linear and worked at high external phosphate concentrations in the dark. Inhibition of photosynthesis by removing the inorganic carbon from the medium produced the same effect aa darkness on phosphate uptake. Successive bicarbonate additions produced increments of photosynthesis rate and the recovering of the phosphate uptake pattern observed in light. The results showed that Porphyra umbilicalis, at the typical phosphate concentrations in its natural habitat, takes up phosphate in the light through the operation of a photosynthetically controlled active system.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Microchimica acta 98 (1989), S. 259-265 
    ISSN: 1436-5073
    Keywords: cyanide ; spectrophotometry ; indirect determination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A spectrophotometric method for cyanide based on its inhibition of the colour formation reaction between nickel(II) and 3-(4′,5′-dimethyl-2′-thiazolylazo)-2,6-dihydroxybenzoic acid has been developed, and allows the determination of down to 0.1 μg of cyanide. Most of the interferences can be avoided by displacement of the hydrogen cyanide using an arsine generator.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1436-5073
    Keywords: quinine ; derivative spectrophotometry ; soft drinks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A method is developed for the 4rd order derivative spectrophotometric determination of down to 1–6 μg/ml of quinine. This method has been applied to its determination in soft drinks. Comparison are made between this method and a spectrofluorimetric method.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2048
    Keywords: Carbonic anhydrase ; Chlorophyll ; Gracilaria ; Inorganic carbon ; Ribulose-1,5-bisphosphate carboxylase/oxygenase ; Phycobiliprotein ; Photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Gracilaria tenuistipitata Zhang et Xia was cultured for 15 d at low, normal and high inorganic carbon concentrations under constant light, temperature and nutrient conditons. Carbonic anhydrase (CA; EC 4.2.1.1.) activity, ribulose-1,5-bisphosphate carboxylase/ oxygenase (Rubisco; EC 4.1.1.39) content, pigment content and C/N ratio were measured, and also the photosynthesis and growth rates. Both Rubisco content and CA activity increased under conditions of low inorganic carbon (Ci) but decreased at high Ci with respect to the control. The amount of pigments declined considerably at high Ci and was slightly higher at low Ci. The maximum rate of photosynthesis and the photosynthetic efficiency increased in low Ci and the opposite was found at high Ci concentration. The effects of Ci concentration on maximum rate of photosynthesis and photosynthetic efficiency are discussed in relation to the variation in pigment and Rubisco contents and CA activity. The data indicate that Ci may be an important factor controlling the photosynthetic physiology of G. tenuistipitata with regard, not only to the enzymes of Ci metabolism, but also to the pigment content.
    Type of Medium: Electronic Resource
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