The cost of equity capital and risk of U.S. multinational and U.S. domestic firms (1965-1978).

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Realization of a single-chip, SiGe:C-based power amplifier for multi-band WiMAX applications

A fully-integrated Multi-Band PA using 0.25 μm SiGe:C process with an output power of above 25 dBm is presented. The behaviour of the amplifier has been optimized for multi-band operation covering, 2.4 GHz, 3.6 GHz and 5.4 GHz (UWB-WiMAX) frequency bands for higher 1-dB compression point and efficiency. Multi-band operation is achieved using multi-stage topology. Parasitic components of active devices are also used as matching components, in turn decreasing the number of matching component. Measurement results of the PA provided the following performance parameters: 1-dB compression point of 20.5 dBm, gain value of 23 dB and efficiency value of %7 operation for the 2.4 GHz band; 1-dB compression point of 25.5 dBm, gain value of 31.5 dB and efficiency value of %17.5 for the 3.6 GHz band; 1-dB compression point of 22.4 dBm, gain value of 24.4 dB and efficiency value of %9.5 for the 5.4 GHz band. Measurement results show that using multi-stage topologies and implementing each parasitic as part of the matching network component has provided a wider-band operation with higher output power levels, above 25 dBm, with SiGe:C process

Phylogenetic relationships among species of the subsection Dendrophlomis Bentham

This study used randomly amplified polymorphic DNA markers to determine genetic relationships among species of the subsection Dendrophlomis. Twenty accessions of the eleven Phlomis taxa were evaluated to determine genetic variability using fourteen ten mer primers selected from a 125 random oligonucleotide set. These 14 selected primers generated 85 RAPD bands that ranged in size from 200 to 1200 base pairs. Of the total bands, 88% (75) were polymorphic among the samples. Genetic distances among accessions were computed to produce a dendrogram based on UPGMA. Genetic distances ranged from 0.133 (between P. amanica and P. monocephala) to 0.494 (between P. chimerae and P. lunariifolia). The UPGMA tree based on distances has two major groups. The first comprised 9 taxa that were clustered into two subgroups. The first subgroup consisted of P. viscosa, P. lycia, P. amanica and P. monocephala while the second comprised P. lunariifolia, P. bourgaei, P. longifolia var. longifolia, P. grandiflora var. grandiflora and P. grandiflora var. fimbrilligera. The second group comprised 2 species, P. leucophracta and P. chimerae. Species-specific bands were observed for P. lycia, P. leucophracta, P. lunariifolia, P. bourgaei, P. chimerae and P. longifolia var longifolia

The use of herbal extracts in lacquer paint coloring and determination of some mechanical resistance properties on wood-based surfaces

The aim of this study was to determine the usability of selected natural dye extracts as environmentally friendly colorants that are used in painting of MDF based furniture and evaluate their resistance to scratch resistance, adhesion resistance, and surface hardness properties. In this study, the water-based lacquer coatings were prepared with natural dyes obtained from purple cabbage (Brassica oleracea), safflower (Carthamus tinctorius L.), Red beetroot (Beta vulgaris L.) and three synthetic paints that were black, blue and light blue as a comparison. Coated MDF test panels used for evaluation of performances of dyes to abiotic factors that are determined by mechanical tests such as scratch resistance, adhesion resistance, and surface hardness. As a result of the study, it has been observed that, except for scratch resistance, natural dyes perform as well as synthetic ones as alternative colorants in the lacquer coatings. Thus, natural and aesthetic raw materials that are environmentally friendly dyes can be used safely especially in children's furniture and for wood-based products that are especially used indoors

PAVEMENTS COVERED FOR HEAT ISOLATION TO GET PEDESTRIAN THERMAL COMFORT

Civilization has been analyzed mostly with urbanization which coincides with the usage of stone and later concrete and steel in constructions. Nowadays we have been realized that construction materials used for houses, apartments, roads and pavements surrounding us create local microclimate which influences our living comfort. Local temperature increases due to asphalt roads and concrete pavements have recently been determined and they are remarkably effective in our everyday life. Usage of different types of aggregates in concrete mixtures to cast concrete pavement blocks might effective to decrease air temperature on the pavements. Therefore heat-resistant rocks were used to produce different sized aggregates where different plasters were produced from them to coat standard concrete pavement blocks. Pavement blocks plastered were then put under sun to test their surface temperatures. It was observed that heat-resistive materials used in plaster concretes influence heat distribution in the blocks and surface temperature of the concrete pavement blocks.

A review of sediment-hosted gold deposits of the world with special emphasis on recent discoveries outside the U.S.A

Most of the Great Basin sediment-hosted gold deposits are located along well defined, northwest-striking trends. Trends coincide with faults, intrusive rocks and magnetic anomalies. Sedimentary host rocks are siltstone, sandstone, conglomerate, argillic, interbedded chert and shales. Silty bedded silty dolomites, limestone and carbonaceous shales are the most favourable hosts. High, and locally, low-angle faults are very important structural features related to the formation of the ore bodies. High-angle faults are conduits of hydrothermal fluids which react, shatter and prepare the favourable host rock. Decalcification, silicification, and argillization are the most common hydrothermal alteration types. Jasperoid (intense silica replacement) is a significant characteristic; not all of these deposits are gold-bearing. Most deposits contain both oxidized and unoxidized ore. Fine grained disseminated pyrite, arsenian pyrite, and carbonaceous material are the most common hosts for gold in many deposits. These deposits are also characterized by high Au/Ag ratios, notable absence of base metal and geochemical associations of Au, As, Sb, Hg, Ba and TI. Recently numerous sediment-hosted gold deposits have been recognized in different regions of the world. They vary in their size, grades, textwe, host rock lithology, degrees of structural control and chemical characteristics. However, they have many common features which are very similar to the general characteristics of sediment-hosted gold deposits in the Great Basin, U.S.A. Besides these similarities, several unusual features are recorded in some newly discovered deposits elsewhere, such as predominant fault controlled paleokarst related mineralization and the lack of two very common trace elements (Hg, TI) in Lobongan/Alason, Indonesia; and Early Proterozoic age metamorphosed host rocks and lack of Sb in Maoling, China. The discovery of the deep ores in the Post-Betze and Rabbit Canyon, Nevada, proposed sediment-hosted Au emplacement at deeper level (4 ± 2 km; Kuehn & Rose, 1995) combined with a lack of field evidence for paleowater table and paleosurface features has ruled out a shallow epithermal origin. Recent discoveries in other parts of the world throw important new light on the ongoing genetic problems. Intrusive rocks are present in nearly all sediment-hosted gold deposits. Numerous intrusion-centred districts worldwide are characterized by tWo or more different mineralization types and consequently by metal zoning. Sediment-hosted gold deposits are proposed as a distal part of intrusion-centred magmatic hydrothermal systems (Sillitoe &Bonham, 1990)

Identification of factors affecting competitive tension in the domestic air transport market in Turkey

Competitive tension refers to pressure that is considered to exist among firms operating in a competitive market and that forces them to take competitive action against each other. An imaginary upper limit of competitive tension symbolizes the difference between whether to take competitive action or not. The antecedents of competitive tension are examined in this study. Within this scope, market commonality and resource similarity are the variables studied as components of competitor analysis; market concentration that provides clues for the competitive structure of competed markets; and finally, competitive asymmetry, presuming that the competition among the companies is not equal and rivals do not consider each other at the same level as competing firms, were taken as primary variables of competitive tension. In order to test whether these variables have an effect on competitive tension among airlines, airlines operating in the domestic air transport market in Turkey were examined in this study. The perceived competitive tension that was detected as a result of regression analyses was studied on three different dimensions, namely, internal tension, external tension, and total tension, and each dimension was analyzed as a different model. The findings of the study revealed that market commonality and market concentration have a significant effect on competitive tension. These effects were found to be positive for market commonality and negative for market concentration. Resource similarity and competitive asymmetry were found to have no significant effect. Document type: Articl

A fully integrated low-power SiGe power amplifier for biomedical applications

In this work, a full-integrated very-low power SiGe Power Amplifier (PA) is realized using the IHP (Innovations for High Performance), 0.25μm-SiGe process. The behaviour of the amplifiers has been optimized for the 2.1-2.4 GHz frequency band for a higher 1-dB compression point and high efficiency at a lower supply voltage. The PA delivers an output power of 3.75 mW and 1.25 mW for 2V and 1V, respectively. The PA measurements yielded the following parameters; gain of 13 dB, 1-dB compression point of 5.7 dBm, and Power-Added-Efficiency of 30% for 2V supply voltage. The PA circuit can go down to 1V of supply voltage with a gain of 10 dB, 1-dB compression point of 1 dBm, and Power-Added-Efficiency of 20%. For both supply voltages, the input and the output of the circuit give good reflection performance. With this performance, the PA circuit may be used for low-power biomedical implanted transceiver systems

A Case of Viral Myocarditis Presenting With Acute Asthma Attack

Acute viral myocarditis is one of the causes of heart failure. Cardiac asthma is commonly observed in elderly patients with left heart failure. If the pulmonary manifestations are prominent it can mask the involvement of heart. We report a young case of viral myocarditis mimicking acute asthma attack. Case Presentation: A 27-year-old young man with a history of asthma presented to the pulmonary department of our hospital with dyspnea, left sided chest pain, cough, wheezing. Asthma was diagnosed and treated, however his respiratory complaints have persisted. Laboratory evaluations revealed that elevated cardiac enzymes, Echocardiogram showed global hypokinesia in the left ventricle and a decrease of ejection fraction. We concluded that viral myocarditis can present itself like an acute asthma attack

Efficacy of c-arm scopy-guided erector spinae plane block (ESPB) in postoperative pain control and reduction of opioid side effects in spinal instrumentation surgery

Background: Spinal instrumentation surgery causes significant pain in patients. As a result, patients are exposed to excessive opioid use and the associated side effects, as well as prolonged hospital stay, resulting in economic burden. Local anaesthetics can help both reduce postoperative pain and minimize the side effects associated with systemically administered opioid analgesics. Objective: The aim of this retrospective study was to investigate the effect of erector spinae plane block on analgesia in spinal instrumentation surgery and to reduce the side effects of excessive opioid use. Materials and Methods: We reported a retrospective study. Thirty patients, who underwent spinal instrumentation surgery from 2017 to 2018, were chosen from the hospital records. We performed spinal instrumentation and decompression by laminectomy to all patients under general anaesthesia. While 15 of these patients underwent erector spinae plane block, these patients received patient-controlled analgesia postoperative period. The other 15 patients received only patient-controlled analgesia postoperative period. We analyzed patients' data for differences in preoperative and postoperative visual analogue scores, nausea vomiting scores, constipation life quality scale, patient-controlled analgesia shot count and mean opioid consumption of patients. Results: The data of 30 patients undergoing lumbar spinal instrumentation surgery were retrospectively analyzed. There was no significant difference in the age, preoperative VAS, preoperative ODI and sex between the two groups (p?0,05). In addition, there were statistically significant differences in postoperative VAS, postoperative ODI, Nausea Vomiting Score, Constipation Life Quality Score (CLQS), petidin consumption and PCA shot count (p <0.05). In all variables with significant differences, the values ??in the block group were lower than the non-block group. Conclusion: ESPB provides effective analgesia and reduces side effects due to excessive opioid usage