Joining wood by friction welding

At the Chair of Timber Constructions of the Swiss Federal Institute of Technology in Lausanne (EPFL) tests were carried out to join wooden work pieces by friction welding without any additional welding deposit. It could be determined that this kind of technology, which is mainly used for thermoplastics and metal, can also be applied to wood. Tests were carried out to determine the influence of the processing parameters like welding pressure, frequency and amplitude of the circular movement on the welding process and the input of energy at the interface. In addition, the resistance of the joint was examined. The development of the shear strength during solidification of the interface as well as the shear strength achievable after a complete solidification of the interface was the objective of the examinations. Furthermore, the microstructure of the welded joint was studied to reveal the manner in which the thermally decomposed wood forms the connection between the welded piece

Prevalence of Sorghum Ergot in Southeast Asia

Ergot is a serious endemic disease in most of the sorghum (Sorghum bicolor) producing countries of the wor ld, wi th most recent outbreaks being in central and South Amer ica (Reis et al . 1996). It is caused by the fungus Claviceps spp. Three species are predominant: C. africana is prevalent in southern and eastern Af r ica, South Amer ica, Southeast Asia, Aust ral ia, and India; C. sorghi in India and Southeast Asia; and C. sorghicola in Japa

Viscoelastic properties of green wood across the grain measured by harmonic tests in the range of 0\degree C to 95\degree C. Hardwood vs. softwood and normal wood vs. reaction wood

The viscoelastic properties of wood have been investigated with a dynamic mechanical analyser (DMA) specifically conceived for wooden materials, the WAVET device (environmental vibration analyser for wood). Measurements were carried out on four wood species in the temperature range of 0\degree C to 100\degree C at frequencies varying between 5 mHz and 10 Hz. Wood samples were tested in water-saturated conditions, in radial and tangential directions. As expected, the radial direction always revealed a higher storage modulus than the tangential direction. Great differences were also observed in the loss factor. The tan\delta peak and the internal friction are higher in tangential direction than in radial direction. This behaviour is attributed to the fact that anatomical elements act depending on the direction. Viscoelastic behaviour of reaction wood differs from that of normal or opposite wood. Compression wood of spruce, which has higher lignin content, is denser and stiffer in transverse directions than normal wood, and has lower softening temperature (Tg). In tension wood, the G-layer is weakly attached to the rest of the wall layers. This may explain why the storage modulus and the softening temperature of tension wood are lower than those for the opposite wood. In this work, we also point out that the time-temperature equivalence fits only around the transition region, i.e. between Tg and Tg + 30\degree C. Apart from these regions, the wood response combines the effect of all constitutive polymers, so that the equivalence is not valid anymore

Studies on Seed Colouring in Soybean and Tomato

The effects of seed colouring using 25 dyes (i.e. 20 chemical and 5 natural dyes) on the quality of soyabean (cv. JS 335) and tomato (cv. Pusa Ruby) seeds were studied in the laboratory. Data were recorded for seed germination percentage, root and shoot length, whole seedling length, dry weight of seedling, vigour index, speed of germination and electrical conductivity. Rhodamine-B, Fast green and Malachite green for soyabean and Rhodamine-B and Fast green for tomato were the best dyes for seed colouring

Studies on seed colouring in redgram, blackgram and bengalgram

The investigations on the effect of seed colouring of redgram, blackgram and bengalgram seeds encompassing 25 dyes were conducted to identify non-deleterious and deleterious dyes based on their effect on seed quality. The dyes namely Rhodamine-B, Fuchsine and Titan yellow for redgram, Rhodamine-B, Fuchsine and Phenol red and Rhodamine-B, Crystal violet, Titan yellow for bengalgram were found to be the best dyes for seen colouring at 0.75% concentration. In this paper we discuss developing colour standards for redgram, blackgram and bengalgram seeds and their resultant implications for Indian seed industry

Retrofitting of Reinforced Concrete Beams Using a Fiberglass Jacketing System

Building collapse that occurred mostly caused by structure failure in containment earthquake load. Factors that lead to the failure of the beam, among others is beam planning that does not calculate ductility or restraint, resulting decline of beams performance. One way to improve beam strength and ductility are to retrofit the beam by wrapping beams using fiberglass. Research aims to discover the increase amount of bending load capacity from concrete beam that has been retrofitted using jacketing fiberglass. Experimental testing was carried out on beam specimens with a cross section size of 150x200 mm and a length of 1400 mm. Three beam specimens were subjected to bending loads with a three point loading system, with different levels of damage, namely BL1 with collapse at level-1, BL2 at level-2, and BL0 at level-5 as a comparison. Then the BL1 and BL2 were retrofitted by being coated with 2 layers of fiberglass which were glued using epoxy resin. Beams BL-1 and BL-2 are then subjected to a bending test again until they reach level-5 collapse. The test results showed that retrofitted beams were able to increase flexural strength, BL-1 increased 115.15% from the original load and BL-2 increased 52.27% from the original load

Effects of Selective Deletion of Tyrosine Hydroxylase from Kisspeptin Cells on Puberty and Reproduction in Male and Female Mice.

The neuropeptide kisspeptin, encoded by Kiss1, regulates reproduction by stimulating GnRH secretion. Kiss1-syntheizing neurons reside primarily in the hypothalamic anteroventral periventricular (AVPV/PeN) and arcuate (ARC) nuclei. AVPV/PeN Kiss1 neurons are sexually dimorphic, with females expressing more Kiss1 than males, and participate in estradiol (E2)-induced positive feedback control of GnRH secretion. In mice, most AVPV/PeN Kiss1 cells coexpress tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis (in this case, dopamine). Dopamine treatment can inhibit GnRH neurons, but the function of dopamine signaling arising specifically from AVPV/PeN Kiss1 cells is unknown. We generated a novel TH flox mouse and used Cre-Lox technology to selectively ablate TH specifically from Kiss1 cells. We then examined the effects of selective TH knock-out on puberty and reproduction in both sexes. In control mice, 90% of AVPV/PeN Kiss1 neurons coexpressed TH, whereas in mice lacking TH exclusively in Kiss1 cells (termed Kiss THKOs), TH was successfully absent from virtually all Kiss1 cells. Despite this absence of TH, both female and male Kiss THKOs displayed normal body weights, puberty onset, and basal gonadotropin levels in adulthood, although testosterone (T) was significantly elevated in adult male Kiss THKOs. The E2-induced LH surge was unaffected in Kiss THKO females, and neuronal activation status of kisspeptin and GnRH cells was also normal. Supporting this, fertility and fecundity were normal in Kiss THKOs of both sexes. Thus, despite high colocalization of TH and Kiss1 in the AVPV/PeN, dopamine produced in these cells is not required for puberty or reproduction, and its function remains unknown

Seed System Innovations in the Semi-Arid Tropics of Andhra Pradesh

The power of a seed is unlimited. As a powerful agent of change, seeds can be a means of overcoming production constraints, thereby making a difference in the lives of the poor and hungry. This requires seed demand and supply to be balanced by way of a secure seed supply system. This would give farmers access to adequate quantities of good quality seed of the desired type at the required time and at affordable cost. Seeds are key components in the conservation and ownership of biodiversity. Accordingly, sustainable seed supply and implementation of seed security are among the major activities outlined in the Global Plan of Action for the Conservation and Sustainable Utilization of Plant Genetic Resources for Food and Agriculture. Seeds therefore represent hope for the future of mankind. Throughout our history, farmers’ informal seed systems have had a great influence on the evolution of modern agriculture, by practising conservation of agrobiodiversity at the gene, farmer and ecosystem levels. Within this framework, women in particular have played a crucial role, as has been identified by a recent analysis, in sustaining the informal seed sector, and more widely, in ensuring food security. However, informal seed systems are heavily dependent on local resources and inputs, and highly vulnerable to natural disasters and sociopolitical disruptions. Therefore, investing in a range of appoaches in order to strengthen local seed systems assumes great urgency. While the formal hybrid seed industry led by the private sector has tended to focus on profit-making species and crops, the informal sector has concentrated on crops – mainly self- or open-pollinated varieties – that are crucial to local food production systems. Given such a scenario, national seed policies concludes helping to strengthen the informal sector. International support too continues to be mainly engaged with the formal sector. Perhaps matching support is required to encourage continued development of informal seed systems. In this context, the concept of ‘seed villages’, which advocates selfsufficiency in production and distribution of good quality seed, is fast gaining ground. Seed villages, or village seed banks, operate under supervision and utmost transparency, inculcating mutual trust and social responsibility among farmers, thereby reducing their dependence on external inputs. Several initiatives have been launched to revive this traditional concept, such as those initiated by the Indian Council of Agricultural Research (ICAR), the National Research Centre for Sorghum (NRCS) and state agricultural universities (SAUs). Similarly, the seed bank concept is part of ICRISAT’s projects in collaboration with the Asian Development Bank (ADB), Tata- ICRISAT project in Vidisha and Guna districts of Madhya Pradesh and the Andhra Pradesh Rural Livelihoods Project (APRLP) in Kurnool district in Andhra Pradesh and other ongoing efforts in the states of Maharashtra and Karnataka. In low-rainfall, dryland agricultural areas, cereals and legumes serve the dual purpose of providing food and income for poor farmers and fodder for their cattle. Given the critical role played by improved varieties in increasing conventional crop production, a key question arises: how do we facilitate the development of an integrated and cost-effective seed system that is capable of generating, producing and distributing improved seed varieties that meet the needs of resource-poor farmers? This book is an attempt to review and document the existing seed multiplication and delivery systems in four dryland agricultural districts of Andhra Pradesh: Anantapur, Kurnool, Mahbubnagar and Nalgonda. While analyzing the problems associated with different seed systems in these districts, the book makes a strong case for strengthening alternative seed systems and seed delivery models that address the needs of small farmers in the context of constantly changing dynamics on the national, international, political and socioeconomic fronts. I am sure this book will be a valuable reference source for those engaged in strengthening local seed systems as a step toward food security in the semiarid tropics of India

An outbreak of sorghum ergot in parts of Andhra Pradesh, India

This paper reports the incidence and severity of ergot infection (Claviceps sorghi) on sorghum (Sorghum bicolor) on 28 farms in districts of Mahbubnagar and Ranga Reddy in Andhra Pradesh during an ergot epidemic in 2000 - 2001. Cultivars sown were local Yellow Jowar, local White Jowar and ICSV 745 as dual purpose sorghums, and SSG 777 and SSG 878 for fodder. In most villages, the sorghum crop had high incidence and severity (up to 100%) of ergot infection. The source of the epidemic was suggested to be the storage of infected panicles from previous years or the movement of contaminated seed from one village to another. Pathogen development was favoured by cloudy weather and high rainfall during flowering; one village 80 km from the epidemic had no rain during flowering and no incidence of ergot