Timber composite floor beams under 2 years lon-term load

The long-term behaviour of composite beams is characterised by the response of its component parts (flanges and webs) to load, moisture content, temperature and relative humidity of the environment. This paper reports the results of a two years long-term test on two 6 m span composite floor beams made of laminated veneer lumber (LVL) under service load performed in an indoor, semi-controlled, and unheated environment. The environmental conditions were characterized by artificially induced cyclic air humidity with quasi-constant temperature. These conditions can be characterized as reasonably severe and presumably close to service class 3 according to Eurocode 5. During the test, the mid-span deflection, moisture content and air humidity were monitored. The paper recommends a creep factor for design of timber composite beams in severe environmental conditions

Type IIB Flows with N=1 Supersymmetry

We write general and explicit equations which solve the supersymmetry transformations with two arbitrary complex-proportional Weyl spinors on $\mathcal{N}=1$ supersymmetric type IIB strings backgrounds with all R-R $F_1$, $F_3$, $F_5$ and NS-NS $H_3$ fluxes turned on using SU(3) structures. The equations are generalizations of the ones found for specific relations between the two spinors by Grana, Minasian, Petrini and Tomasiello in [1] and by Butti, Grana, Minasian, Petrini and Zaffaroni in [2]. The general equations allow to study systematically generic type IIB backgrounds with $\mathcal{N}=1$ supersymmetry. We then explore some specific classes of flows with constant axion, flows with constant dilaton, flows on conformally Calabi-Yau backgrounds, flows with imaginary self-dual 3-form flux, flows with constant ratio of the two spinors, the corresponding equations are written down and some of their features and relations are discussed.Comment: 28 page

Determinants and Levels of Agricultural Development Agents Job Satisfaction: The Case of Kalu Woreda, South Wollo Zone of the Amhara National Regional State

This study was conducted with an objective of assessing the level of job satisfaction and its determinants among agricultural development agents working in different kebeles of Kalu Woreda, South Wollo Zone of the Amhara National Regional State. A total of 100 development agents were selected and interviewed using simple random sampling technique to collect data for the study through structured questionnaire. Descriptive and multiple regression methods were used to address the study objectives. Results of descriptive analysis showed that in terms of the level of job satisfaction of development agents on average development agents are 'undecided' with their job as a result of their involvement in special projects such as agriculture growth projects and donor-funded projects, in decision making, in in-service training and working relationship with farmers. The econometric results showed that there exists a statistically significant relationship between job satisfaction and recognition for best performances, rate of promotion, regular training and level of education of development agents. The study recommends that due attention needs to be given to defining career structure and provision of service training opportunities as criteria in promoting, improving and maintaining their job satisfaction.Keywords: Job satisfaction, Development agen

Construction of a polarization insensitive lens from a quasi-isotropic metamaterial slab

We propose to employ the quasiisotropic metamaterial (QIMM) slab to construct a polarization insensitive lens, in which both E- and H-polarized waves exhibit the same refocusing effect. For shallow incident angles, the QIMM slab will provide some degree of refocusing in the same manner as an isotropic negative index material. The refocusing effect allows us to introduce the ideas of paraxial beam focusing and phase compensation by the QIMM slab. On the basis of angular spectrum representation, a formalism describing paraxial beams propagating through a QIMM slab is presented. Because of the negative phase velocity in the QIMM slab, the inverse Gouy phase shift and the negative Rayleigh length of paraxial Gaussian beam are proposed. We find that the phase difference caused by the Gouy phase shift in vacuum can be compensated by that caused by the inverse Gouy phase shift in the QIMM slab. If certain matching conditions are satisfied, the intensity and phase distributions at object plane can be completely reconstructed at image plane. Our simulation results show that the superlensing effect with subwavelength image resolution could be achieved in the form of a QIMM slab.Comment: 25 pages, 8 figure

On modeling and measuring viscoelasticity with dynamic Atomic Force Microscopy

The interaction between a rapidly oscillating atomic force microscope tip and a soft material surface is described using both elastic and viscous forces with a moving surface model. We derive the simplest form of this model, motivating it as a way to capture the impact dynamics of the tip and sample with an interaction consisting of two components: interfacial or surface force, and bulk or volumetric force. Analytic solutions to the piece-wise linear model identify characteristic time constants, providing a physical explanation of the hysteresis observed in the measured dynamic force quadrature curves. Numerical simulation is used to fit the model to experimental data and excellent agreement is found with a variety of different samples. The model parameters form a dimensionless impact-rheology factor, giving a quantitative physical number to characterize a viscoelastic surface that does not depend on the tip shape or cantilever frequency.Comment: 13 pages, 7 figure

Prevalence and Associated Factors of Thyroid Incidentaloma among Adult People Attending Gondar University Hospital, Northwest Ethiopia Temesgen Tadesse1

BACKGROUND: Incidentally discovered thyroid lesions have become highly common in the development and more frequent utilization of highly sensitive imaging modalities, like ultrasound. However, little is known about its prevalence and associated factors in Ethiopia. The aim of this study was to determine the prevalence of thyroid incidentalomas and associated factors through ultrasound (US) among adults attending Gondar University Hospital.METHODS: A hospital-based cross-sectional study was carried out on 290 adults aged 15 years and above. Out of the adults who visited the hospital during the study, those who neither had history of thyroid disease, thyroid surgery, nor clinically palpable thyroid nodules were involved in the investigation. The participants were examined using a high frequency linear-array transducer (7MHz). For comparing men and women, the unpaired t-test wasused. Binary logistic analysis was used to identify the associated factors, and a P-value < 0.05 was considered statistically significant.RESULT: The frequency of thyroid incidentaloma was found to be 33.4% (95% CI: 27.9, 38.9). Thyroid incidentaloma was detected in 42.4% of the females and 22.7% of the males (P<0.001). About 63% had single and 37% multiple thyroid nodules. About 25.8% had thyroid nodules greater than 1cm. In the multivariable logistic regression analysis, increasing age (AOR=5.96; 2.34, 15.15) and female sex (AOR=3.01; 1.73, 5.26) were significantly associated with thyroid incidentalomas.CONCLUSION: The frequency of thyroid incidentaloma (TI) was found to be high in this study and much higher among older women. Solitary and small sized thyroid nodules were commonly seen in the study.

Lived Experiences of Diversity Visa Lottery Immigrants in the United States

Every year approximately 50,000 people immigrate to the United States through the avenue referred to as the Diversity Visa (DV) Lottery. In this article, the authors present a literature review of immigration to the U.S. through the DV Lottery, reflect on their own immigration histories, and utilize phenomenology to investigate and describe participant feelings, expectations, and experiences as DV Lottery immigrants. Participants experienced mixed feelings, including high expectations prior to and difficulties after immigrating to the U.S. Findings presented include (a) life experienced in the U.S.; (b) access to learning and training opportunities; and (c) recommended support future DV Lottery immigrants

Immunity to Visceral Leishmaniasis

Leishmaniasis is a major vector-borne parasitic disease affecting 12 million people worldwide. With a broad range of clinical manifestations, ranging from self-healing skin ulcers to disfiguring mucosal lesions to life-threatening infections of visceral organs (liver and spleen), the disease has become a serious human health issue, particularly in developing countries. Among all of its forms, visceral leishmaniasis (VL, also known as kala-azar), caused by the Leishmania donovani complex (i.e., L. donovani and L. infantum in Old World and L. chagasi in New World), is often fatal in the absence of treatment. Although humans are the principal hosts for L. donovani, canine species are the main reservoirs of L. infantum. Canine VL affects millions of dogs and is associated with outbreaks of human VL and hence has become a major public health issue. The lack of vaccines to prevent and/or treat these infections, as well as the emergence of drug resistant parasites, is serious impediments to control leishmaniasis. Therefore, developing new prophylactic and therapeutic strategies against this disease is urgently required. However, for this to occur, a better understanding of the complex immune mechanisms generated in response to infection and defining those involved in resistance to infection is required. In this special issue on “Immunity to visceral leishmaniasis”, several selected papers will discuss these issues.Peer reviewe