Transmission line

Transmission lines Transmission loss Transmitters Trans-nonachlor... 

Figure 5.26 Example fibre-optic-coupled in-line transmission cell (Reproduced courtesy of Specac Limited, www.specac.co.uk).

Sollinger and Voges at Akzo Nobel (Obemburg, Germany) used off-line transmission NIR to monitor the key quality parameters in cellulose hber (viscose) spinning solutions over time. The business value lay both... 

Brearley et al" at DuPont (Wilmington, DE, USA) used in-line transmission NIR to monitor carboxyl end groups and degree of polymerization (DP) in PET oligomer and prepolymer melt streams in a new polyester process. The business value was derived from several sources. 

Transmission Line Structures and Characteristics. When interconnections exceed the critical line length, transmission lines with proper terminations are used to effectively couple the signal into the line, to minimize reflections along the line and from its ends, and to minimize crosstalk with adjacent lines. Transmission line structures provide a controlled environment... 

Microwaves are electromagnetic radiation placed between infrared radiation and radio frequencies, with wavelengths of 1 mm to 1 m, which corresponds to the frequencies of 300 GHz to 300 MHz, respectively. The extensive application of microwaves in the field of telecommunications means that only specially assigned frequencies are allowed to be allocated for industrial, scientific or medical applications (e.g., most of wavelength of the range between 1 and 25 cm is used for mobile phones, radar and radio-line transmissions). Currently, in order not to cause interference with telecommunication devices, household and industrial microwave ovens (applicators) are operated at either 12.2 cm (2.45 GHz) or 32.7 cm (915 MHz). However, some other frequencies are also available for heating [1]. Most common domestic microwave ovens utilize the frequency of 2.45 GHz, and this may be a reason that all commercially available microwave reactors for chemical use operate at the same frequency. 

J., et al. (1989) Germ-line transmission of a planned alteration made in a hypoxanthine phosphoribosyltransferase gene by homologous recombination in embryonic stem cells. Proc Natl Acad Sci USA 86, 8927-8931. 

Keeping ES cells undifferentiated is a key to success in achieving germ line transmission of the targeted allele. To prevent differentiation, ES cells must grow either on monolayers of mitotically inactivated fibroblast cells (embryonic feeder [EF] cells) or in the presence of leukemia inhibitory factor (LIF). In our experiments, we use both feeder layer cells and LIF-supplemented media for ES cell culture and maintenance. 

Thompson, S., Clarke, A. R Pow, A. M Hooper, M. L., and Melton, D. W. (1989) Germ line transmission and expression of a corrected HPRT gene produced by gene targeting in embryonic stem cells. Cell 56, 313-321. 

Guideline on the Non-Clinical Testing for Inadvertent Germ line Transmission of Gene Transfer Vectors... 

The optical properties of the wall also contribute to the emitted spectra. The usual arc tube wall material, polycrystalline alumina (PCA), has rather low "in-line" transmission and scatters most of the incident radiation. That portion which is scattered back into the discharge medium and that is also in the spectral region inside or near the peaks of the self-reversed resonance lines, is likely to be absorbed. Thus we have found greater Na reversal for PCA arc tube lamps than for sapphire lamps with the same diameters, Na-Hg alloy composition and reservoir temperatures. Indeed, various authors have reported 3-8% higher efficacies for sapphire vs PCA lamps depending upon the quality of the PCA and its surface treatment 3). 

Figure 8 Solid lines) Spectral outputs for International Conference on Harmonization (ICH) visible and ultraviolet lamps with Hg emission lines removed dotted line) absorption spectrum for the iron-citrate complex dashed line) transmission profile for the yellow light filters used in this study and common to many manufacturing areas. Note the spectral overlap of both ICH lamps with iron-citrate complex absorption.

Trials of gene therapy in hemophilia A and B, to determine safety and efficacy, are under way (2). Three patients with hemophilia B were treated in a phase I trial with a recombinant adenovirus-associated vector expressing human blood-coagulation factor IX (3). There was no evidence of formation of inhibitory antibodies against factor IX. In a phase I trial with a recombinant adenovirus-associated vector expressing human blood-coagulation factor IX, there was no evidence of germ-line transmission of vector sequences (3). 

Srivastava, S., Zou, Z., Pirollo, K., Blattner, W., and Chang, E. (1990) Germ-line transmission of a mutated p53 gene in a cancer-prone family with Li-Fraumeni syndrome. Nature 348,747-749. 

In another clinical study, patients suffering from hemophilia B, which is a bleeding disorder caused by a deficiency of coagulation factor IX, were treated with AAV vectors expressing human factor IX (13 9). These patients participated in a Phase I trial and received intramuscular injections of AAV vectors. Although only very low levels of secreted factor IX could be detected in the plasma of one patient, the treated patients showed some clinical benefits and a reduced intake of factor IX infusions. Moreover, no vector-related toxicity and germ line transmission was observed. 

Michalska, A.E. and K.H. Choo. Targeting and germ-line transmission of a null mutation at the metallothionein I and II loci in mouse. Proc. Natl Acad. Sci. USA 90 8088-8092, 1993. 

Fig. 7.21 (a) Total (solid line), specular (dashed line) and diffuse (dashed dotted line) transmission as a function of photon energy for a 150 nm thick MgH2 film capped with 12 nm Pd and loaded at 100°C... 

Besides the internal factors, there are also external factors that affect transparency of a ceramic sample, including thickness and surface finish. A rough surface means a significant diffuse scattering, so the sample should be as smooth as possible. Generally, transparency decreases with increasing thickness. Thickness-independent transparency is only possible when the material reaches its theoretical maximum of in-line transmission. 

As discussed earlier, various scattering losses are die main contribution to the decrease in in-line transmission, with respect to the theoretical maximum, of transparent ceramics, as summarized in Fig. 1.4 [7, 8]. Without the presence of these losses, the theoretical maximum of transmission is 100 % minus the reflection... 

Fig. 1.3 Thickness effect (b a) on in-line transmission of transparent of the transparent ceramics with an in-line transmission of <100 %, due to the scattering and/or absorption. Real in-line transmission is measured by using narrow measuring aperture (b). This thickness effect is absent as the transmission approaches the theoretical maximum (c). Re noduced with pmmission from [7]. Copyright 2009, Elsevier...

Besides, according to the definition of T, the transmission of transparent ceramics can never be 100 %. It is also necessary to mention that 7 in Eqs. (1.3) and (1.4) is calculated by assuming that the reflection occurs on a theoretically perfect surface. Because theoretically perfect surface is an ideal assumption, real ceramics inevitably have a certain value of roughness. Therefore, technical roughness gives rise to additional loss—another mechanism which decreases the real in-line transmission of products depending on the quality of surface preparation [7]. 

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