Contemporary wind generators

It is believed that wind energy is growing at a very rapid rate, especially in the last few years. When compared with other sources of renewable energy in the energy portfolio, it becomes evident that the bulk is wind energy-based. However, there are some backlogs to full manifestation of this technology ranging from initial high cost to performance and reliability issues, among others. But in spite of these bottlenecks, new research trends have been assertive in seeking out a sustainable solution for harnessing wind energy for power generation – especially in the design and construction of wind generators. In order to motivate and prime a sustainable energy mix among stakeholders, this paper is a shot at appraising the theory of these innovative wind generators towards ecological sustainability, economy, efficiency, and employment creation

Mobilisation Du Foncier Au Profit Des Investissements Immobiliers Publics Dans La Commune D’Abomey-Calavi

Pour faire face à l’évolution démographique et à l’augmentation de la demande de logement dans la ville d’Abomey-Calavi, l’Etat Béninois a initié de nombreux projets de construction de logements économiques au profit des ménages. La présente recherche vise à analyser les stratégies de mobilisation du foncier au profit de ces investissements. La méthodologie de recherche s’est basée sur les recherches documentaires, la collecte de données auprès de 113 personnes par entretien et questionnaire, le traitement de ces données et l’analyse des résultats par le biais du modèle SWOT ou FFOM (Forces, Faiblesses, Opportunités et Menaces).Les résultats obtenus montrent que deux principales stratégies sont utilisées par les autorités pour mobiliser le foncier pour la  construction de logements sociaux.  Il s’agit de la constitution de réserves administratives à l’issue des opérations de lotissement  et de l’expropriation foncière pour cause d’utilité publique.  Au total, 539 réserves administratives ont été constituées dans la Commune d’Abomey-Calavi et environ 3 457 ha de domaines ont été expropriés au profit des programmes immobiliers. Trente-deux (32) logements de type F2, soixante-quinze (75) logements de type F3 et quarante-cinq (45) logements de type F4 ont été construits sur le site de la Zopah à Abomey-Calavi en 2008. De même, il est prévu la construction de 200 logements de type F2, 500 logements de type F3 et 300 logements de type F4 sur un premier site  dans l’Arrondissement de Ouèdo.  Sur un second site du même arrondissement, 8900 logements sont en cours de construction dont 3035 sont pratiquement achevés.  Malgré ces efforts en termes d’investissements,  les ménages font évoquent  des insuffisances qui ne facilitent pas un accès équitable et juste  auxdits logements. . Pour 75% des personnes interrogées, ces logements seraient trop chers ; 20% trouvent que ces logements sont exigus, et 5% trouvent que leurs plans architecturaux ne conviennent pas aux besoins des ménages. Il paraît donc  important que les autorités publiques travaillent davantage à l’ancrage socio-économique de ces logements pour faciliter leur acquisition et leur occupation par les ménages

Ion-sculpting of Nanopores in Amorphous Metals, Semiconductors and Insulators

We report the closure of nanopores to single-digit nanometer dimensions by ion sculpting in a range of amorphous materials including insulators (SiO$_2$ and SiN), semiconductors (a-Si), and metallic glasses (Pd$_{80}$Si$_{20}$) — the building blocks of a single-digit nanometer electronic device. Ion irradiation of nanopores in crystalline materials (Pt and Ag) does not cause nanopore closure. Ion irradiation of c-Si pores below 100 °C and above 600 °C, straddling the amorphous-crystalline dynamic transition temperature, yields closure at the lower temperature but no mass transport at the higher temperature. Ion beam nanosculpting appears to be restricted to materials that either are or become amorphous during ion irradiation.Engineering and Applied SciencesPhysic

One and Two-Dimensional Pattern Formation on Ion Sputtered Silicon

ABSTRACT The evolution of surface morphology during ion beam erosion of Si(111) at glancing ion incidence (60 o from normal, 500 eV Ar + , 0.75 mA/cm 2 collimated beam current) was studied over a temperature range of 500-730 o Celsius. Keeping ion flux, incident angle, and energy fixed, it was found that one-dimensional sputter ripples with wavevector oriented perpendicular to the projected ion beam direction form during sputtering at the lower end of the temperature range. For temperatures above approximately 690 o Celsius, growth modes both parallel and perpendicular to the projected ion beam direction contribute to the surface morphological evolution. This effect leads to the formation of bumps ("dots") with nearly rectangular symmetry

Enjeux et amélioration de la gestion des espèces du genre Entandrophragma, arbres africains devenus vulnérables

Because of the quality of their wood and their many traditional uses, species of the Entandrophragma genus are being intensively logged, and this is likely to compromise their survival unless sustainable management is introduced. This study reviews the current status of the five main commercial Entandrophragma species: Entandrophragma angolense, E. congolense (often confused with E. angolense), E. candollei, E. cylindricum and E. utile. We suggest directions for research to improve sustainable management strategies for this genus. The study draws mainly on published scientific data, economic data (production and export statistics) and on relevant laws and regulations, but also on existing management plans and inventory reports. Although these species are reported as vulnerable on the IUCN Red List, knowledge on their management is still patchy. Industrial and artisanal logging is intensive and does not always follow a validated management plan or abide by the minimum rotation period, both of which would help to ensure the renewal of these resources. Managing them to ensure that logging is sustainable in the long term requires management measures to be developed and complied with. Sustainable use has to be based on appropriate management of natural stands and on reforestation and conservation measures. Research studies to be developed should encompass the growth rates of the species in the light of the changing climate, assessments of stocks (timber, biomass and carbon), updates of their spatial distribution, improvements to natural regeneration, reproduction processes and the anatomical and technical properties of each species. All these research topics are necessary to ensure the permanence of these Entandrophragma species

Enjeux et amélioration de la gestion des espèces du genre Entandrophragma, arbres africains devenus vulnérables

Because of the quality of their wood and their many traditional uses, species of the Entandrophragma genus are being intensively logged, and this is likely to compromise their survival unless sustainable management is introduced. This study reviews the current status of the five main commercial Entandrophragma species: Entandrophragma angolense, E. congolense (often confused with E. angolense), E. candollei, E. cylindricum and E. utile. We suggest directions for research to improve sustainable management strategies for this genus. The study draws mainly on published scientific data, economic data (production and export statistics) and on relevant laws and regulations, but also on existing management plans and inventory reports. Although these species are reported as vulnerable on the IUCN Red List, knowledge on their management is still patchy. Industrial and artisanal logging is intensive and does not always follow a validated management plan or abide by the minimum rotation period, both of which would help to ensure the renewal of these resources. Managing them to ensure that logging is sustainable in the long term requires management measures to be developed and complied with. Sustainable use has to be based on appropriate management of natural stands and on reforestation and conservation measures. Research studies to be developed should encompass the growth rates of the species in the light of the changing climate, assessments of stocks (timber, biomass and carbon), updates of their spatial distribution, improvements to natural regeneration, reproduction processes and the anatomical and technical properties of each species. All these research topics are necessary to ensure the permanence of these Entandrophragma species

Positive and negative effects of antipsychotic medication: an international online survey of 832 recipients

Background: Antipsychotic medication is currently the treatment of choice for psychosis, but few studies directly survey the first hand experience of recipients. Objectives: To ascertain the experiences and opinions of users of an international sample of antipsychotic drugs regarding positive and negative effects. Method: An online direct-to-consumer questionnaire was completed by 832 users of antipsychotics, from 30 countries – predominantly USA, UK and Australia. This is the largest such sample to date. Results: Over half (56%) thought the drugs reduced the problems they were prescribed for, but 27% thought they made them worse. Slightly less people found the drugs generally ‘Helpful’ (41%) than found them ‘Unhelpful’ (43%). While 35% reported that their ‘quality of life’ was ‘improved’, 54% reported that it was made ‘worse’. The average number of adverse effects reported was 11, with an average of five at the ‘severe’ level. Fourteen effects were reported by 57% or more participants, most commonly: ‘Drowsiness, feeling tired, sedation’ (92%), ‘Loss of motivation’ (86%), ‘Slowed thoughts’ (86%), and ‘Emotional numbing’ (85%). Suicidality was reported to be a side effect by 58%. Older people reported particularly poor outcomes and high levels of adverse effects. Duration of treatment was unrelated to positive outcomes but significantly related to negative outcomes. Most respondents (70%) had tried to stop taking the drugs. The most common reasons people wanted to stop were the side effects (64%) and worries about long-term physical health (52%). Most (70%) did not recall being told anything at all about side effects. Conclusions Clinical implications are discussed, with a particular focus on the principles of informed consent, and involving patients in decision making about their own lives

Le genre Entandrophragma (Meliaceae) : taxonomie et écologie d'arbres africains d'intérêt économique (synthèse bibliographique)

Introduction. Les espèces d'arbres du genre Entandrophragma font l'objet d'une attention toute particulière de la part des exploitants forestiers et des scientifiques depuis plusieurs décennies. Établir un bilan exhaustif actualisé des connaissances acquises sur leur taxonomie et leur écologie afin d'en dégager des pistes de nouvelles recherches est le but de cette synthèse bibliographique. Littérature. Le genre Entandrophragma compte des espèces (10 à 12) exclusivement africaines et qui sont exploitées pour la qualité de leur bois. Ces espèces sont répandues dans la région guinéo-congolaise (6 espèces) et dans les régions zambézienne et afromontagnarde (5 espèces). Le genre est caractérisé par une évolution taxonomique qui s'est traduite par une importante synonymie des noms d'espèces (36 à 37). Des études écologiques un peu larges ont été réalisées sur quelques principales espèces commerciales (Entandrophragma angolense, Entandrophragma congoense, Entandrophragma candollei, Entandrophragma cylindricum, Entandrophragma palustre et Entandrophragma utile) dans leurs zones phytogéographiques comprises principalement dans la région guinéo-congolaise. Conclusions. Les informations sur la taxonomie et l'écologie des espèces d'arbres d'Entandrophragma des forêts claires et des savanes sont insuffisantes comparativement à celles des forêts denses humides. Des travaux de recherches devraient être développés pour l'amélioration des connaissances taxonomiques, génétiques et la maitrise de leur écologie en vue de formuler des recommandations adéquates en matière de préservation et de gestion durable de ces espèces. (Résumé d'auteur

EGFR in enterocytes & endothelium and HIF1α in enterocytes are dispensable for massive small bowel resection induced angiogenesis

Background: Short bowel syndrome (SBS) results from significant loss of small intestinal length. In response to this loss, adaptation occurs, with Epidermal Growth Factor Receptor (EGFR) being a key driver. Besides enhanced enterocyte proliferation, we have revealed that adaptation is associated with angiogenesis. Further, we have found that small bowel resection (SBR) is associated with diminished oxygen delivery and elevated levels of hypoxia-inducible factor 1-alpha (HIF1α). Methods: We ablated EGFR in the epithelium and endothelium as well as HIF1α in the epithelium, ostensibly the most hypoxic element. Using these mice, we determined the effects of these genetic manipulations on intestinal blood flow after SBR using photoacoustic microscopy (PAM), intestinal adaptation and angiogenic responses. Then, given that endothelial cells require a stromal support cell for efficient vascularization, we ablated EGFR expression in intestinal subepithelial myofibroblasts (ISEMFs) to determine its effects on angiogenesis in a microfluidic model of human small intestine. Results: Despite immediate increased demand in oxygen extraction fraction measured by PAM in all mouse lines, were no differences in enterocyte and endothelial cell EGFR knockouts or enterocyte HIF1α knockouts by POD3. Submucosal capillary density was also unchanged by POD7 in all mouse lines. Additionally, EGFR silencing in ISEMFs did not impact vascular network development in a microfluidic device of human small intestine. Conclusions: Overall, despite the importance of EGFR in facilitating intestinal adaptation after SBR, it had no impact on angiogenesis in three cell types–enterocytes, endothelial cells, and ISEMFs. Epithelial ablation of HIF1α also had no impact on angiogenesis in the setting of SBS