Effect of postharvest on the economic viability of walnut production

In this study we were studying the question whether walnut production under domestic natural and economic circumstances shall be considered a profitable activity or not. Our partial objective is to determine, what level of natural inputs and production costs are required for walnut production, what yield level, selling price and production value can be attained, what level of profitability, rentability and efficiency may production have, is the establishment of a walnut orchard profitable on the entire lifespan of the plantation, and the production of which is more efficient: the dry shelled walnut production requiring postharvest activity or the raw, shelled walnut without postharvest activities. In this study, comparison of two systems is conducted. First version: producer establishes a walnut plantation and sells walnut raw and shelled. Second version: producer also invests into a drying facility, and in this case the end product is the dry, shelled walnut. If the producer sells walnut right after harvest in a raw bulk, total production costs in productive years reaches 974,011 HUF/ha. Attainable yield is 2.63 t/ha with 396.3 HUF/kg selling price, therefore the profit is 138,258 HUF/ha with 14.19% cost-related profitability. In the case when the producer sells dried, shelled walnut, production costs are 25% higher compared to that of raw walnut due to the cost of drying. By calculating with the postharvest loss, average yield is 1.84 t/ha, however, its selling price is way higher (882.84 HUF/kg), therefore the profit per hectare reaches 475,496 HUF with 39.01% cost-related profitability. Thus it can be stated that walnut production in an average year may be profitable even without postharvest, but efficiency is improved significantly when the producer sells the products dried. Investment profitability analysis revealed that production of raw, shelled walnut is not economically viable, since the plantation does not pay off on its entire lifespan (30 years), while walnut production with postharvest is efficient and rentable, since both net present value (NPV) and internal rate of return (IRR) showed more favourable values than in the previous case, and the orchard pays off in the 21th year after establishment

Effect of Long-Term Cycling Load for Abutment Screw Fixation in Implant Prosthodontics

The aim of this in vitro study was to use rotational tests on commercially available abutment screws to evaluate their potential for preload generation and to follow changes in torque by using newer fixation geometry on the interface of the implant-abutment screw joint. Five identical implant/abutment assemblies were chosen from each of the following systems: external hex with standard abutment and Replace with TorgTite screw (Nobel Biocare), Camlog universal abutment (Altatec Biotechnologies), DenTi internal hex (Dentimplant Ltd. Szentes, Hungary), straight abutment with internal antirotational element (Uniplant, Sinalisal, Budapest). Wax patterns of the upper premolar were performed and then cast from nickel-chrome alloy and full crown castings were cemented on abutments. In a test machine the magnitude and time of chewing function was predefined by using the desired force pattern. Each specimen was stressed for cycles equivalent to an intaoral load of 5 months or longer timescale. In the static test greater loss in torques was calculated for standard Branemark and Replace screw joints. Assuming that the optimum proportion is the same when we calculate loosening versus tightening torque we obtained a decrease between 0.70-0.59 for Replace and Branemark abutments and a more moderate loss of between 0.90-0.84 for the other systems investigated. The ten month equivalent cycling test produced a loosening torque of 16-17 Ncm for Branemark and Replace abutments. Similar decrease in torque was not found for the other three systems. It was concluded that different approach in achievement of necessary mechanical integration can be seen in implant systems, although a reliable loosening torque could be measured after a longer time scale

Effect of Long-Term Cycling Load for Abutment Screw Fixation in Implant Prosthodontics

The aim of this in vitro study was to use rotational tests on commercially available abutment screws to evaluate their potential for preload generation and to follow changes in torque by using newer fixation geometry on the interface of the implant-abutment screw joint. Five identical implant/abutment assemblies were chosen from each of the following systems: external hex with standard abutment and Replace with TorgTite screw (Nobel Biocare), Camlog universal abutment (Altatec Biotechnologies), DenTi internal hex (Dentimplant Ltd. Szentes, Hungary), straight abutment with internal antirotational element (Uniplant, Sinalisal, Budapest). Wax patterns of the upper premolar were performed and then cast from nickel-chrome alloy and full crown castings were cemented on abutments. In a test machine the magnitude and time of chewing function was predefined by using the desired force pattern. Each specimen was stressed for cycles equivalent to an intaoral load of 5 months or longer timescale. In the static test greater loss in torques was calculated for standard Branemark and Replace screw joints. Assuming that the optimum proportion is the same when we calculate loosening versus tightening torque we obtained a decrease between 0.70-0.59 for Replace and Branemark abutments and a more moderate loss of between 0.90-0.84 for the other systems investigated. The ten month equivalent cycling test produced a loosening torque of 16-17 Ncm for Branemark and Replace abutments. Similar decrease in torque was not found for the other three systems. It was concluded that different approach in achievement of necessary mechanical integration can be seen in implant systems, although a reliable loosening torque could be measured after a longer time scale

Rainforests at the beginning of the 21st century

Rainforests are situated at low latitude where forests enjoy steady and strong radiation. Biodiversity in rainforests has been very high, for historical and climatic reasons. The number of species is very high and tends to increase with precipitation and decrease with seasonality. Disturbance, soil fertility and forest stature also influence the species richness and high turnover of species contribute to diversity. Field observation and studies revealed that large scale deforestation could alter the regional and global climate significantly. Deforestation alters the surface albedo which leads to climate change. Regional land use contributes to climate change through surface-energy budget, as well as the carbon cycle. Forest fragmentation, logging, overhunting, fire and the expanding agriculture threaten the biodiversity. Rainforest covered area has significantly shrunk in the last decades. It is hard to protect the forests because of the growing demand for agricultural area and forest-derived products. Most measures proved ineffective to slow down the destruction. Hence, more forest will be lost in the future. Conservationists should take into consideration the secondary forests because biodiversity can be high enough and it is worth protecting them

Groene groei: hoe bereiken we dat?

Het regeerakkoord van het kabinet Rutte II belooft veel aandacht voor economische groei en duurzaamheid. Dit artikel bespreekt op welke wijze inhoud kan worden gegeven aan de wens van het kabinet om economische groei en zorg voor het milieu met elkaar te combineren. Vanuit het perspectief van de economische welvaartsanalyse gaat het daarbij om de afweging tussen de materiele welvaart en de milieukwaliteit. Vanuit de economische groeitheorie wordt geschetst welke mogelijkheden er zijn voor een dergelijke groene groei. De verschillende manieren om de productiviteit te beïnvloeden en te bevorderen vormen daarbij het aangrijpingspunt voor het beleid. Een verhoging van de milieu efficiëntie, bijvoorbeeld door een milieubesparende technologie kan tot groei met minder milieugebruik leiden, maar dat hoeft niet altijd het geval te zijn

LISA as a dark energy probe

Recently it was shown that the inclusion of higher signal harmonics in the inspiral signals of binary supermassive black holes (SMBH) leads to dramatic improvements in parameter estimation with the Laser Interferometer Space Antenna (LISA). In particular, the angular resolution becomes good enough to identify the host galaxy or galaxy cluster, in which case the redshift can be determined by electromagnetic means. The gravitational wave signal also provides the luminosity distance with high accuracy, and the relationship between this and the redshift depends sensitively on the cosmological parameters, such as the equation-of-state parameter $w=p_{\rm DE}/\rho_{\rm DE}$ of dark energy. With a single binary SMBH event at $z < 1$ having appropriate masses and orientation, one would be able to constrain $w$ to within a few percent. We show that, if the measured sky location is folded into the error analysis, the uncertainty on $w$ goes down by an additional factor of 2-3, leaving weak lensing as the only limiting factor in using LISA as a dark energy probe.Comment: 11pages, 1 Table, minor changes in text, accepted for publication in Classical and Quantum Gravity (special issue for proceedings of 7th LISA symposium