Development perspectives of relational capital in women-led firms

The purpose of the paper is to analyze the strategic role of relational capital for the achievement of sustainable development in Italian micro and small tourist businesses run by women. The paper focuses on the tourism enterprises because that sector constitute 10 % of the Italian GDP. The qualitative research methodology that has been used is that of case study research (Yin, 2009). Such process consisted in a survey with an ad-hoc questionnaire developed to analyze the distinctive features of a woman-owned micro and small enterprise that can be identified with the CAOS model (Paoloni, 2011). The paper applies the CAOS model examining the personal characteristics of the female entrepreneur (C); the environment in which the in SMEs operates (A); organizational and managerial aspects (O); and the motivations for manage a new business (S). This model is able to link these factors and classify different types of connections, it is possible to identify the kind of existing relations. The paper intends to help address a gap in the existing literature regarding the management and governance of tourism firms run by women. The paper can contribute to improving the competitiveness Italian enterprises studying how women entrepreneurs manage her business

Immigrant women’s entrepreneurship: is there a development model in Italy?

The aim of this paper is to verify if there is a typical enterprise model for the development of immigrant female entrepreneurship in Italy. Based on the literature on the subject, however, it is useful to ask the following research question: “can membership in a national and international network facilitate the development of immigrant female entrepreneurship operating in Italy”? The survey was carried out by submitting a questionnaire to a sample of immigrant women entrepreneurs in the textile and clothing sector based in Italy. The choice fell on this specific economic segment because it represents the third largest sector for the number of female immigrant entrepreneurs (2.271 units) which amounts to 16% of the total number of entrepreneurs operating in the same sector. The percentage of respondents was 35%, with 795 completed questionnaires. The structure of the questionnaire reflects the need to examine the personal features of female entrepreneurs, the organizational aspects and the style of leadership, the task environment in which the enterprise works and the main possible benefits, or obstacles, they might obtain, or face. In addition to the objective of enlarging the literature regarding the management and governance of businesses run by women entrepreneurs, that is quite limited to date, this paper is a contribution to the analysis of a possible development model of women entrepreneurs

Sub-THz traveling wave amplifiers based on the double corrugated waveguide

Email Print Request Permissions Summary form only given. The importance of the sub-THz (0.1-1 THz) portion of the spectrum is recognized fundamental for many applications. In particular, the region around 0.22 THz is suitable for high data rate communications1 and imaging due the low atmospheric attenuation window. However, high power is needed in this frequency range to provide a reasonable length of the transmission path. Vacuum electron devices represent so far the only viable solution for relatively output power at those frequencies. Wideband Traveling Wave Tube Amplifiers (TWTAs) operating in the 0.22 THz range were demonstrated with relevant performance2. The high cost of TWTAs still prevents their wide market diffusion. The double corrugated waveguide (DCW) is a slow wave structure of easy fabrication and assembly. A TWT based on the DCW is presented as possible affordable approach3. A relative high output power (3.7W) over a wide bandwidth (20 GHz) centered at 0.23THz was demonstrated, with 13kV beam voltage and 30mA beam current. The wideband performance is related to the superposition of the beam line with the dispersion curve over a wide frequency region. The optimization of the DCW dimensions is then a crucial step to assure wideband amplification. A study on the definition of the widest synchronism region is proposed. The aim is to extend the region included between the lower and upper cutoff frequencies of the dispersion curve and to control the its slope, maintaining a low beam voltage and suitable values of interaction impedance and losses

Photonic band gap corrugated slow wave structure for THz sheet-beam vacuum electron devices

The use of photonic band gap (PBG) technology is investigated to alleviate some of the typical issues of vacuum electron devices at terahertz and is shown as particularly suitable for the use of large sheet beams. A full interaction structure including the slow wave structure and the coupler based on a tapered PBG corrugated waveguide is proposed for sheet beam backward wave oscillators (BWO). The case of a 346 GHz BWO is considered

Photonic crystal-coupler for sheet beam THz vacuum electron tubes

Photonic Crystal (PhC) technology was recently proposed as a compact and effective solution to improve the performance and ease the fabrication of terahertz vacuum electron devices. In particular, the introduction of defects in a bi-dimensional, all metallic PhC provides very effective transmission of the useful signal in a compact input/output coupler where a novel tunnel for sheet-beam injection/collection is realized. Simulation results are here experimentally validated via measurements on a Ku-band scaled model of the PhC-coupler which confirm the validity of the concept

Double corrugated waveguide for Ka-Band traveling wave tube

The double corrugated waveguide (DCW), incorpo- rating a row of metallic pillars on each side of the electron beam, is demonstrated as a promising slow-wave structure for millimeter wave, Ka-band, traveling wave tubes (TWTs). Different configurations, including novel bent couplers with tapered pillars, have been designed, realized, and validated by S-parameter measurements. The design and simulation of a DCW TWT demonstrated very good performance in the frequency band 32–37 GHz. The ease of fabrication and assembly make the DCW a suitable basis for a new generation of millimeter wave TWTs

Design and fabrication of double corrugated waveguide for a Ka-band traveling wave tube

The double corrugated waveguide is demonstrated to be a slow wave structure which is straightforward to manufacture and assemble. The design and fabrication of a Ka-band prototype is presented. The ability of the double corrugated waveguide to be bent through 90o has permitted the build of a compact slow wave structure with very good electrical behavior which is suitable for millimeter wave travelling wave tubes

Clinical characteristics and outcome of patients with autoimmune hemolytic anemia (AIHA) uniformly defined as primary by a diagnostic work-up

Primary autoimmune hemolytic anemia (P-AIHA) is a relatively uncommon and hetereogeneous disease characterized by the destruction of red blood cells due to anti-erythrocyte autoantibodies (AeAbs) in the absence of an associated disease [1–3]. Secondary AHIA is frequently associated with lymphoproliferative diseases (LD) in particular, chronic lymphocytic leukemia, aggressive or indolent lymphomas, autoimmune disorders, malignancies other than lymphoid, and infections [1,2,4]. On the hypothetical assumption that in a significant proportion of cases defined as P-AIHA the clinical heterogeneity could be due to an ignored associated disease, we retrospectively analyzed the clinical characteristics and outcome of patients with a diagnosis of P-AIHA based on a diagnostic work-up aimed at excluding or identifying an associated disease. ..

Microwave coupler for W-band micro re-entrant square cavities

Klystrons are vacuum electronic devices widely used for microwave amplification up to the millimetre-wave region. The opportunity to push the operating frequency of conventional klystrons above 30–40 GHz is limited by the 20 fabrication difficulties of the cavities that have very small dimensions. A high order mode micro re-entrant square cavity was purposely devised to be compatible with the available micro fabrication processes and represents a viable solution for the design of millimetre-wave klystrons. In this study, a coupler to correctly excite the higher order mode of the square re-entrant cavities for W-band operation is proposed. The design of the proposed novel coupler structure has been validated by realisation and measurement of a scaled X-band prototype. The post-realisation tuning methods 25 adopted to improve the matching of the high order mode are also presented

Dispersion characteristics of double-corrugated rectangular waveguide for terahertz vacuum devices

An analytical study on the dispersion of the double-corrugated waveguide for THz vacuum devices is presented. The boundary element method (BEM) is introduced to improve the accuracy of the dispersion. The results are compared with the 3D electromagnetic simulations