Range Of pF Research Articles

PSII-22 Impact of stocking density and number of pigs per feeder space with wet/dry feeders: an economic analysis

Abstract The objective of this study was to evaluate the economically most profitable stocking density (SDEN) and the number of pigs per feeder space (PF) with a Crystal Springs wet/dry single-space double-sided feeder model F1-115. Data from a trial was used to model the optimal value. The initial trial included 3182 pigs from three consecutive grow-finish groups. The experimental treatments were designed as a two by three factorial (SDEN of 0.65 or 0.78 m2/pig with PF of 10, 13, or 16). Each pen was equipped with one double-sided wet/dry feeder, 37.5 cm wide, with one nipple drinker. Pigs with less floor space allowance had reduced ADG (1.00 versus 1.02 kg/d, P = 0.002) with improved G:F (0.402 versus 0.397, P = 0.039). Overall, ADG had a quadratic relationship (P = 0.005) with PF with means of 1.03, 1.01, and 1.01 kg/d for 10, 13, and 16 respectively. The G:F had a quadratic relationship (P = 0.005) with the number of pigs PF with means of 0.395, 0.404, and 0.400 for 10, 13, and 16 respectively. The G:F and ADG data were fitted to a regression equation including SDEN (linear) and PF (linear –quadratic). A pork production cost model was used to evaluate the impact of a range of SDEN (0.65 to 0.758 m2/pig) and PF (10 to 16) on annual profit of a grow-finish barn including feeder cost. Annual profit for a 1200 head grow-finisher was fitted to linear and quadratic regression of SDEN and PF (R2= 0.999). The optimal SDEN was 0.65 m2 per pig and 13 to 14 (13.26) PF. The differences between the maximum and the minimum net income year values for PF and PF were $4055 and $21667 USD respectively. Stocking density had a greater impact than the number of pigs per feeder space.

Overstrength values for light frame timber wall elements based on reliability methods

To ensure ductile behavior of light frame timber wall elements in the context of capacity design it is indispensable to design non-ductile parts and connections with considerable overstrength. The determination of overstrength values based on reliability methods enables to address different target failure probabilities. A two-step procedure is proposed. First a sensitivity analysis is carried out on 972 wall configurations. Within the configuration the nail diameter, the nail spacing, the sheathing material, the thickness of the sheathing, the arrangement of the sheathing, the length of the wall elements and the vertical load is varied to assess the influence of the varied parameters. Within the sensitivity analysis the overstrength values that ensure the target failure probability Pf=0.04 within the range of Pf=0.023 to Pf=0.067 are determined using first-order reliability methods. The sensitivity analysis shows that the determination of overstrength values for different parameter configurations seems not to be necessary. For the second step the wall configurations that lead to the greatest overstrength values according to first-order reliability methods are identified. For these wall configurations the failure probability is determined using Monte-Carlo-Methods. The failure probability is determined using overstrength values within the range of γRd=1.0 to γRd=2.6 and minimum dimensions for the main load carrying parts of a timber frame wall element. The overstrength values that leads to an exact failure probability of Pf=0.067 for the wall configurations are determined. The overstrength values determined on the selected wall configurations are used to calculate the failure probability for all 972 wall configurations using Monte-Carlo-Methods. Finally, overstrength values are proposed to achieve ductile failure for all considered wall configurations for a certain level of probability.

A generalized relationship between thermal conductivity and matric suction of soils

The soil thermal conductivity (λ) and matric suction of soil water (h, the negative of matric potential) relationship has been widely used in land surface models for estimating soil temperature and heat flux following the McCumber and Pielke (1981, MP81) λ-h model. However, few datasets are available for evaluating the accuracy and feasibility of the MP81 λ-h model under various soil and moisture conditions. In this study, we developed a new λ-h model and compared its performance with that of the MP81 model using measurements on 18 soils with a wide range of textures, water contents and bulk densities. The heat pulse technique was used to measure λ, and the suction table, micro-tensiometers, pressure plate device, and the dew point potentiometer were applied to obtain soil water retention curves at the appropriate suction ranges. In the range of pF (the common logarithm of h in cm) ≤ 3, the λ-h relationships were highly nonlinear and varied strongly with soil texture and bulk density. In the dry range (i.e., pF > 3), there existed a universal λ-h relationship for all soil textures and bulk densities, and an exponential function was established to describe the relationship. Independent evaluations using λ-h data on five intact soil samples showed that the new model produced accurate λ data from pF values with root mean square errors (RMSE) with the range of 0.03–0.18 W m−1 K−1. While, large errors (RMSEs within 0.17–0.36 W m−1 K−1) were observed with λ estimates from the MP81 model.

The effect of hydrogel additives on the water retention curve of sandy soil from forest nursery in Julinek

Forest nurseries are mostly located in light and very light sandy soil sites. They are characterised by low water holding properties in the aeration zone, and their water resources depend mainly on precipitation. One of the possible ways to solve this problem is to use hydrogel additives to soils. The objective of this study was to investigate the influence of polyacrylamide SuperAbsorbent Plus on water retention curve of a sandy soil from forest nursery in Julinek. Surface soil layer (15 cm deep) was collected for experiments. It was mixed and divided into 5 parts. Each part, except control, was enriched with hydrogel additives in the amount of 0.5, 2, 4, and 6 g·dm –3 . Six samples were taken from each soil part with hydrogel treatment and from control soil (without hydrogel). Water retention was measured with the Soil Moisture Equipment Corporation (Santa Barbara, California, USA) – LAB 012 in Agrophysics Institute in Lublin. Results of soil moisture at particular water potential values were shown as pF curves, and the analyses of soil retention properties were performed for particular pF ranges adopted after WALCZAK et al. (2002). Soil treatment with hydrogel increased soil retention properties, mainly in the range of pF less then 2.0. The largest increase of retention capacity was found in the range of pF 0–2.2. It means that hydrogel accumulates the gravitation water in the soil, which under natural conditions rapidly permeates the soil profile and becomes unavailable

New fluoride-sensitive membranes prepared through an ion implantation process

A new technique used in order to realize fluoride ion-sensitive membranes is presented. This method consists of the ion implantation technique which is highly compatible with integrated circuit (i.c.) technology. This technique can be used for realizing various inorganic membranes for sensing purposes. In this paper, we studied two thin film membranes based on lanthanum and calcium fluoride compounds for fluoride detection, through the ion implantation technique. The electrical and chemical properties of the films obtained are studied on electrolyte/oxide/ semiconductor structures (EOS). The fluoride ion sensitivity is determined using capacitance voltage measurements for the EOS structures. The response obtained is 44 mV per decade in the range of pF~ 4 to 2 for LaF3 membrane, and 52 mV per decade in the range of pF~ 3 to 1 for CaF2 membranes. Finally, we present data for fluoride sensitive ISFET (ion sensitive field effect transistor) microsensors using the developed CaF2 membrane with a corresponding REFET (reference field effect transistor) in individual and differential mode.

Estimation of Soil Moisture in the Shallow Root Zone in a Humid Region

Air temperature, sunshine duration and precipitation are used to estimate the soil moisture in the shallow root zone. The model for the estimation of the soil moisture is based on the water balance of the root zone. The daily amount of evapotranspiration was estimated using the Priestley and Taylor model, modified by the ratio of total soil moisture and soil moisture at the field capacity in a given soil layer. The upward capillary flow was evaluated from the unsaturated hydraulic conductivity of soil and the gradient of water potential between the center of the root zone and at a depth 100cm from the center. This model was used to estimate the soil moisture in the 40cm deep root zone from surface in the Abashiri district in Hokkaido, Japan.Estimated soil moisture was in agreement with the measured soil moisture by tensiometer in the range of PF 1.8 to PF 2.8. The amount of upward capillary flow was higher than the expected values. Therefore, we concluded that the soil moisture could not be estimated precisely without the estimation of the upward capillary flow.

The synthesis and properties of [Fe 3(CO) 11(RCN)] derivatives, and a high-yield general route to mono- and di-substituted derivatives of [Fe 3(CO) 12]; the crystal and molecular structure of [Fe 3(CO) 11(NCC 6H 4-2-Me)

The clusters [Fe 3(CO) 11(RCN)] ( 1: R = Me, C 3H 5, C 6H 5, or C 6H 4-2-Me) have been prepared at low temperature from [Fe 3(CO) 12] and RCN in the presence of Me 3NO. Compounds 1 react essentially quantitatively with a wide range of two-electron donors, L, (viz.: CO, PPh 3, P(OMe) 3, PPh 2H, PPh 2Me, PF 3, CyNC (Cy = cyclohexyl), P(OEt) 3, SbPh 3, PBu 3, AsPh 3, or SnR 2 (R = CH(SiMe 3) 2)) to give [Fe 3(CO) 11L] ( 2). In some cases ( 2), on treatment with Me 3NO and then L′ (L′ = a second two-electron donor) yields [Fe 3(CO) 10LL′] in high yield. The crystal and molecular structures of 1 (L = NCC 6H 4Me-2) have been determined by a full single crystal structure analysis, and shown to have an axial nitrile coordinated at the unique iron atom, with two CO groups bridging the other two metal atoms.

The influence of soil water potential and soil temperature on the seedling emergence of wheat and barley

The time for 50 % emergence of wheat and barley increases linearly with decreasing matric potential. This increase actually begins at matric pressures above pF 2.7. The rise in temperature makes emergence faster with in the range of minimum temperature (3.1°C for wheat and 1.9°C for barley) and the temperature where growth begins to slow down(about 31°C for wheat and 27°C for barley).The optimum range for 50 % emergence was obtained at a matric pressure range of pF 1.3—2.7 or —5.0— —0.20 m (water column) at a temperature of 10°C, which quite well corresponds to the situation in Finland during the emergence period in spring. A clear increase can be observed in the required heat sum for wheat and barley when the soil water potential reaches a critical point which was pF 2.8 or—6.3m for wheat and pF 2.7 or —5.0 m for barley. The total emergence as a function of matric potential for wheat and barley was determined over a period of 30 days at 10°C. In the wet side, pF 1,0 can be considered a limit, the total emergence decreasing with lower values. In the dry side, a corresponding decrease can be noticed in total emergence at pF above 3.0. The water uptake by seeds speeded up with increasing temperature from 10 to 25°C. Radicles of wheat and barley began to appear when the water uptake by the seed was approximately 50—60 % of the initial weight of the seed. The initial water uptake caused by the moistening of the pericarp due to capillarity was about 3 % for wheat and 5 % for barley at a soil water potential of pF 1.2.

Water permeability and pathways in the proximal tubule.

The route of water transport in the proximal tubule could be either transjunctional or transcellular. A transjunctional route is supported by data showing high osmotic-to-diffusive water permeability ratios, the possible correlation of junctional leakiness to ions and nonelectrolytes with water permeability, and solvent drag of nonelectrolytes and ions. These data, however, are not convincing. A transcellular route of water transport is supported by data showing that the osmotic water permeability (Pf) for apical and/or basolateral cell membranes is sufficiently high to account for the transepithelial Pf, making a tentative conclusion for a transcellular route of water transport possible. In addition, measurements of Pf have yielded insights into the mechanism of solute-solvent coupling. Pf has been reported to be mostly between 0.1 and 0.3 cm/s. In the rabbit proximal straight and the Necturus proximal convoluted tubule, in which water transport rates are low, this range of Pf will account for volume absorption with only small osmotic gradients (less than 6 mosmol). Higher osmotic gradients are required in the rat and possibly the rabbit proximal convoluted tubule, where water transport rates are higher. Solute-solvent coupling in all species is probably due to both luminal hypotonicity and lateral intercellular space hypertonicity. These two processes are directly linked. Mass balance requires that generation of luminal hypotonicity also generates a hypertonic absorbate and, thus, some degree of lateral intercellular space hypertonicity. It is likely that, in the rabbit at least, effective osmotic pressure gradients due to differences in solute reflection coefficients play little role in solute-solvent coupling.

Status of Plastics Industry in India

Abstract The petrochemicals industry in India is just about 25 years old, the major milestone being the commencement of manufacture of the first thermoplastic, polystyrene, in 1957 with technical collaboration of Dow Chemical Co. U.S.A. The initial capacity of the plant was only 7500 tons/yr. This was followed by the manufacture of LDPE by I.C.I. and Union Carbide, HDPE in collaboration with Hoechst, and PVC in collaboration with Shell and a few other overseas companies. There is an installed capacity to manufacture 300,000 tons of the above plastics per year. Among the range of thermosets, PF, UF, MF, polyester, and epoxies are manufactured in the country.

Relationship between Root Dostribution of Upland Crops and their Yield : III. Influence of soil moisture levels on root distribution and root dry matter of upland-cultured paddy rice, crossbred rice of paddy rice and upland rice, and upland rice

This experiment was conducted to clarify the effects of different soil moisture levels on the root distribution and root dry matter of upland-cultured paddy rice (cv. Myojoo, Kochihibiki), crossbred rice of paddy rice and upland rice (cv. Ishioka glutinous No.10, Mizuhatamochi), and upland rice (cv. Norin No. 12, Norin No. 21). In the first experiment (1977), the root distribution and dry matter was investigated on the six cultivars which were cultivated under irrigation and nonirrigation. The irrigation treatments were begun at July 18. The soil moisture tension of the two irrigation plots were at pF 2.5 and pF 2.0 at l0 cm depth, respectively. During July 24 to August 8, the soil moisture tension of nonirrigation plot was over pF 2.9 and in the range of pF 2.5 to 2.9, at 10 cm and 30 cm depths, respectively. Therefore, the soil moisture of nonirrigation plots reached to first permanent wilting point at l0 A.M., August 4. Top dry matter, root dry matter and root distribution were investigated at maturity. The investigation of the root distribution was practiced by excavating soil masses, which were sectioned by 7 cm increments up to 35 cm depth. The second experiment (1978) was set up in cylindrical plastic pots of 30 cm height and 25 cm inner diameter using four cultivars (Myojoo, Mizuhatamochi, Norin No. 12, Norin No. 21). Soil moisture treatments composed by two levels of high and low were begun at July 10. That is, high soil moisture plot was irrigated by each pots every day. While, low soil moisture plot was irrigated when every time the soil moisture became to first permanent wilting point. The treatments were continued for 58 days. The results showed that root distribution of the rice plants was effectively influenced by different soil moisture levels. The roots of rice plants distributed in the shallow layer under irrigation, while the roots distributed in the deeper layer under nonirrigation. Root distribution of upland-cultured paddy rice and crossbred rice of paddy rice and upland rice distributed in the shallow layer than that of upland rice. Also, root dry matter was influenced by different soil moisture levels. The root dry matter was increased in drier soil condition, where rice plants proliferated numerous branches to gather a small amount of soil water. The root dry matter of upland rice cultivar 'Norin No. 12' was increased conspicuously in surface layer under nonirrigation. It is suggested that high growth rate of root weights in water stressed rice plants was correlated with drought resistance, because high growth rate of root weight was obtained by upland rice which has drought tore-lance. R-T ratio was increased in drier treatments, because root dry matter was increased and top dry matter was decreased by water stress.

The behaviour of the adult ofAphodius tasmaniaeHope (Col., Scarabaeidae) in South Australia.

In the lower South-East of South Australia, adults of Aphodius tasmaniae Hope, which is an economic pest of improved pastures, emerge from the soil 2–3 days after rain has fallen in summer. The females may lay two batches of eggs. The first batch (about 35 eggs) is developed at the expense of the fat-body and is laid 3–6 days after emergence; a second batch (about 20 eggs) can be developed and laid after the female has fed on dung.The beetles are crepuscular and fly after sunset if the weather is suitable for flight. The first batch of eggs may or may not be laid before flight, depending on the weather. Until the fat-body is largely depleted, beetles fly with the wind and are attracted to lights, but after that stage has been reached they fly upwind to dung and are not attracted to lights. After feeding on dung for a few days the females become gravid again, and apparently change their responses to light and wind once more. The distribution of larvae in the field suggested that adults aggregated and laid eggs in specific places. The factors which promote aggregations of adults were therefore studied.The survival-rate of the females and the number of eggs they laid in two soils, a sand and a clay loam, were related to the ‘available water’ in soil as measured by the pF scale. Females survived in largest numbers and laid most eggs in the range of pF 2·8–3·2 in both soils. Similarly, when given a choice of a number of water contents in soil, beetles aggregated in largest numbers within the range 2·8–3·2 in one soil and pF 2·8–3·5 in another. In the latter soil, however, the pF values that were tested were more widely spaced, and it is suggested that the combined data are only intelligible if there was an optimum range of pF within the vicinity of 2·8–3·2 in both soils. These and other experiments indicated that moisture in soil was the major factor capable of' promoting aggregations of adults.When water was not limiting, aggregations of beetles occurred on loose as opposed to compact surfaces. However, ‘shelter’ (dry grass stems broken off the parent plant, dung, etc.) was capable of promoting aggregations even if the soil underneath ordinarily inhibited burrowing. Aggregations of beetles also occurred on surfaces into which other beetles had previously burrowed; this was probably due not to any attraction of beetles to other beetles, but to loosening of the surface soil by the original beetles, which permitted later arrivals to burrow rapidly.It is probable that the patchy distribution of larvae in the field is due to the aggregation of the adults in the field mainly in relation to moisture in soil, type of surface and shelter. It is also suggested that aggregations of larvae that occur around conspicuous objects, such as trees, result from beetles colliding with these objects by chance when they are flying after dark, dropping to the ground and burrowing into the soil to lay eggs there.