Development of higher-order modal methods for transient thermal and structural analysis

A force-derivative method which produces higher-order modal solutions to transient problems is evaluated. These higher-order solutions converge to an accurate response using fewer degrees-of-freedom (eigenmodes) than lower-order methods such as the mode-displacement or mode-acceleration methods. Results are presented for non-proportionally damped structural problems as well as thermal problems modeled by finite elements

Allons compter les vers de terre

Avant l’hiver, il vaut la peine d’évaluer l’état de santé de ses parcelles. L’un des indicateurs du sol les plus sympathiques est probablement le ver de terre (VDT)

Digital Skills and Self-employment among Graduates of Technical Higher Education Institutions in Tanzania

Digital skills are the driving forces for innovative, inclusive and sustainable growth through innovations and digitalization which in turn stimulate job creation, alleviate poverty, reducing inequality, facilitating the delivery of goods and services. However, large number of graduates is shown to be weak in digital skills in the industry hence affect their employability including self-employment. Recently, the Technical Higher Education Institutions (THEIs) took some initiatives to instill the digital skills to their respective students. This study therefore assessed the level of competence of digital skills among graduates following the initiatives taken by the THEIs and their influence on self-employment. It specifically identified the digital skills and ranking the digital skills acquired by the graduates when in the THEIs. It likewise established relationship between digital skills and self-employment among the graduates. The data were collected using a questionnaire from 500 graduates sampled through a stratified random sampling technique. The collected data were analyzed using Descriptive Statistics and Chi-square. The findings show that, the surveyed graduates acquired basic digital skills (i.e. creating professional online profiles, word processing, using keyboards and touch-screens, managing privacy settings, emails) to the large extent (53%); intermediate digital skills (i.e. desktop publishing, digital graphic design, digital marketing) to the small extent (52%) and advanced digital skills (i.e. big data, artificial intelligence, digital entrepreneurship, cybersecurity, internet of things, virtual reality) to the very small extent (54%) when in the college/university. Furthermore, intermediate and advanced digital skills were ranked higher as digital skills for self-employment by the graduates. All three digital skills were found positive and significant for self-employment among the graduates in Tanzania. The study recommends that, the colleges, institutes and universities should emphatically inculcate all the digital skills to the students as they are both significant for self-employment of their respective graduates

Implementation of Digital Transformation in the Technical Higher Education Institutions in Tanzania

Digital transformation has been prioritized recently in this era of fourth industrial revolution by various organizations for maintaining strong competitive advantage, especially in the fourth industrial revolution. The higher education institutions must likewise adopt and implement digital transformation to enrich their students with the knowledge, experience and the skills they need for a very different future. Technical higher education institutions are inevitable in the given transformation. However, very little is known regarding adoption of digital transformation in the given institutions. This study therefore examined the level of adoption of digital services in the technical higher education institutions in Tanzania. It determined the level of awareness of students on digital transformation, opportunity of students to experience digital technologies in teaching-learning process and determining satisfaction level of students on digital teaching-learning environment. This study applied quantitative approach through the cross-sectional survey design. The data were collected using questionnaire from 500 third year (2019/2020) students of two public technical higher education institutions (i.e., Dar es Salaam Institute of Technology and Arusha Technical College). The collected data were analysed using descriptive statistics and t-test. The results indicate that, students from those two institutions had different levels of awareness on digital transformation. Furthermore, the students from both institutions have low opportunity to experience digital technologies in teaching-learning process. Moreover, the students were partly satisfied on the digital teaching-learning environment in the surveyed institutions. The findings of this study advocate the public technical higher education institutions to fully adopt digital transformation for maximally harnessing the opportunities of fourth industrial revolution through their product students

Cover Crop Productivity in Contrasting Growing Conditions and Influence on the Subsequent Crop

In arable systems, cover crops provide multiple ecosystem services involved in soil protection and fertility. They can efficiently compete against weeds, control erosion or recycle nutrients. The supply of these services is however largely dependent on cover crop growth as most of the services are related to biomass production. The choice of a cover crop adapted to the growing conditions is thus essential. Growing mixtures instead of sole crops is expected to be a way to overcome variable growing conditions and to insure high biomass production.Different field trials have been conducted from 2013 to 2016 in Nyon, Switzerland to assess cover crop biomass production and stability, and their influence on the following crop. Indian mustard, field pea, black oat and phacelia were sown as sole crops and in mixtures with different diversity levels (2, 3 and 4 species). A mixture of 11 species (50% of legumes and 50% of other species) was also tested. Biomass production was assessed about three months after seeding, just before the seeding of the next main crop, in two 0.5 m × 0.5 m quadrats. For each cover crop, a risk of failure, e.g. the probability of producing less than 3 t/ha (minimal biomass allowing to provide the services expected from cover crops), was estimated. Weed pressure was appraised by weed biomass in quadrats. The yield of the following main crop, here winter wheat, was determined after harvesting with a combine harvester, at wheat maturity, in summer. Sole crops showed very contrasting performance according to the growing conditions. Pea was the most productive in low yielding conditions with 2 t/ha while other sole crops produced only 0.5 t/ha. Pea was barely more productive in high yielding conditions, reaching only 3 t/ha when cover crop average was 6 t/ha. By contrast, mustard and oat showed high production potential in these conditions, exceeding 7 t/ha. Pea should thus be favoured when the growing conditions are clearly identified as limiting (low N availability), while oat or mustard should be chosen in favourable conditions. However, in general, conditions are hardly predictable. Our results showed that mixtures should be preferred as they were adapted to a wider range of environments than sole crops, performing well regardless of the conditions and resulting in a lower risk of failure than sole crops. The 11-specie mixture revealed that generally 4 to 5 species are sufficient to insure a good performance regardless of the conditions. Regarding cover crop effect on the following crop, we evidenced the importance of high biomass production for efficient weed control and positive influence on crop yield in no till treatments.Our results showed that cover crop mixtures rather than sole crops should be chosen as they insure high biomass production and thus a good supply of ecosystem services. In addition, cover crop cultivation, even for a short period, proved to be paramount to the maintenance of grain yield and soil fertility on the long term, especially in reduced tillage systems