PRODUCT COMPLEMENTARITY IN PRODUCTION: THE BY-PRODUCT CASE

Production Economics,

An Examination of the Farm Level Demand for Pecans

Demand and Price Analysis,

Interface design in the process industries

Every operator runs his plant in accord with his own mental model of the process. In this sense, one characteristic of an ideal man-machine interface is that it be in harmony with that model. With this theme in mind, the paper first reviews the functions of the process operator and compares them with human operators involved in control situations previously studied outside the industrial environment (pilots, air traffic controllers, helmsmen, etc.). A brief history of the operator interface in the process industry and the traditional methodology employed in its design is then presented. Finally, a much more fundamental approach utilizing a model definition of the human operator's behavior is presented

FARM LEVEL DEMAND FOR PECANS RECONSIDERED

Previous studies have consistently indicated the anomalous result of a price inflexible demand for pecans. However, these efforts did not have an adequate measure of pecan stocks available and, as a result, stocks were either excluded from consideration or a proxy variable was introduced. A time series of pecan stocks is now available. Use of this time series in a price dependent demand function results in a flexible farm level demand for pecans. This points out the danger of excluding an appropriate variable or using a so-called "reasonable" proxy variable.Crop Production/Industries,

ECONOMIC SURPLUS AND THE DISTRIBUTIONAL CONSEQUENCES OF DEREGULATING TOBACCO PRODUCTION

Reservations on technical and theoretical grounds in the use of the consumer surplus approach to measure benefits of government programs have often appeared in the literature. Therefore, this paper uses an alternative approach in a case study to estimate the annual economic surplus created in South Carolina from deregulating tobacco production. Impacts of deregulation on cropping patterns and income on representative tobacco farms, and distribution of benefits in the economy are examined. Results of this study indicate that deregulation stimulates the economy and would increase the net value added by $5.8 million in the long run.Agricultural and Food Policy,

Response of marine ecosystems to deep-time global warming: a synthesis of biotic patterns across the Paleocene-Eocene thermal maximum (PETM)

This paper provides a synthesis of the long- and short-term response of various marine ecosystems (deep oceans, pelagic, politic shelves and carbonate platforms) to the Paleocene-Eocene thermal maximum (PETM) and its broader paleoclimatic and paleoceanographic context. Despite the severity and sudden onset of global warming the PETM is not marked by a mass extinction event. The only major extinction is among bathyal to abyssal calcareous benthic foraminifera, including some calcareous agglutinated taxa. Coexisting non-calcareous deep water agglutinated foraminifera, ostracodes and trace fossils show prominent changes in composition, population structure and biodiversity, but there is no clear evidence of global extinctions. Except for the deep-sea calcareous benthic foraminiferal record, the PETM is best classified as a migration and origination event and was instrumental in kick-starting various short- and long-term evolutionary innovations in marine microfossil lineages. In pelagic and shallow shelf ecosystems, migration and origination during and after the PETM appears to precede extinction in the aftermath of the PETM. The response of most marine invertebrates (mollusks, echinoderms, brachiopods) to paleoclimatic and associated environmental changes (e.g., acidification, deoxygenation) during the PETM is virtually unknown as continuous high-resolution data of these groups spanning the PETM are unexplored and possibly not or hardly preserved. Yet information on these groups is required in order to improve assessments of the value of biotic records to deep-time global warming in the context of current climate change. In contrast, the relatively well-established response of Tethyan reef systems to late Paleocene-early Eocene global warming may provide a potential analog to a – possibly bleak - future of present-day coral reefs

Reconstruction of a latest Paleocene shallow-marine eutrophic paleoenvironment at Sidi Nasseur (Central Tunisia) based on foraminifera, ostracoda, calcareous nannofossils and stable isotopes (d13C, d18O)

In order to unravel faunal and paleoenvironmental parameters in shallow marine settings prior to the Paleocene- Eocene thermal maximum, we investigated the Sidi Nasseur section (NAS) in Central Tunisia. This section exposes Paleocene to lower Eocene shales and marls of the El Haria Formation. The uppermost Paleocene part of the Sidi Nasseur section is marked by poor to moderately rich, but fairly diversified nannofossil associations, containing the typical latest Paleocene taxa of the top of NP9a. The ostracode record displays an almost continuous record in the uppermost Paleocene part of the section. Representatives of Aegyptiana, Paracosta, Reticulina and Reymenticosta make up the major part of the ostracode fauna. The benthic foraminiferal assemblage consists of numerous small calcareous benthic foraminifera, like Anomalinoides midwayensis and Lenticulina spp. and many large Frondicularia phosphatica, Pyramidulina spp. These, together with the non-calcareous agglutinated foraminifera and the rare planktic foraminifera, indicate an inner neritic to coastal environment with eutrophic conditions, regularly interrupted by oxygen deficiency. The dominance of non-calcareous benthic foraminifera between intervals with abundant calcareous benthic foraminifera suggests post-mortem dissolution. The foraminiferal d13C record (based upon Pyramidulina latejugata) of the latest Paleocene in the Sidi Nasseur area is very similar to these from coeval sediments at Gebel Duwi and Gebel Aweina in Egypt. Oxygen isotopic ratios indicate a marine setting with a water composition affected by evaporation. During the latest Paleocene, the highly productive shallow water environment evolved to shallower water depths with higher salinity and increasing dominance of A. midwayensis

Reconstruction of a latest Paleocene shallow-marine eutrophic paleoenvironment at Sidi Nasseur (Central Tunisia) based on foraminifera, ostracoda, calcareous nannofossils and stable isotopes (delta¹³C delta¹⁸O)

In order to unravel faunal and paleoenvironmental parameters in shallow marine settings prior to the Paleocene-Eocene thermal maximum, we investigated the Sidi Nasseur section (NAS) in Central Tunisia. This section exposes Paleocene to lower Eocene shales and marls of the El Haria Formation. The uppermost Paleocene part of the Sidi Nasseur section is marked by poor to moderately rich, but fairly diversified nannofossil associations, containing the typical latest Paleocene taxa of the top of NP9a. The ostracode record displays an almost continuous record in the uppermost Paleocene part of the section. Representatives of Aegyptiana, Paracosta, Reticulina and Reymenticosta make up the major part of the ostracode fauna. The benthic foraminiferal assemblage consists of numerous small calcareous benthic foraminifera, like Anomalinoides midwayensis and Lenticulina spp. and many large Frondicularia phosphatica, Pyramidulina spp. These, together with the non-calcareous agglutinated foraminifera and the rare planktic foraminifera, indicate an inner neritic to coastal environment with eutrophic conditions, regularly interrupted by oxygen deficiency. The dominance of non-calcareous benthic foraminifera between intervals with abundant calcareous benthic foraminifera suggests post-mortem dissolution. The foraminiferal d13C record (based upon Pyramidulina latejugata) of the latest Paleocene in the Sidi Nasseur area is very similar to these from coeval sediments at Gebel Duwi and Gebel Aweina in Egypt. Oxygen isotopic ratios indicate a marine setting with a water composition affected by evaporation. During the latest Paleocene, the highly productive shallow water environment evolved to shallower water depths with higher salinity and increasing dominance of A. midwayensis

Some Physical and Chemical Characteristics of Peanut Pods and Kernels in an Irrigation Study

Agronomy (Field Crops

Chemical Studies on the Stability of Soil Aggregates : Change in Permeability of Soil Aggregate Column Induced bu Percolating with Neutral and Alkaline Solution

既報の結果に基づいて推論した粒団生成に関与する成分が, 果して土粒子の耐水性連結にいかなる役割を演じているかを明らかにする研究の一環として, 静置状態で土壌粒団に中性ならびにアルカリ性の溶液を透過させて土壌から特定の成分の離脱を試み, その場合に起こる粒団の崩壊と土壌の持つ透液性の変移をしらべた。1. 主として水溶性と置換性の成分を土壌から溶脱する機能のある0.05N塩化ナトリウム溶液を土壌粒団に透過させると土壌粒団の崩壊ならびに透液性の低下は極めて少なかった。したがって, 置換性塩基類は粒団の安定性に対し大きな役割を果していないことが明らかになった。2. アルカリ性の腐植抽出剤である0.5%水酸化ナトリウム溶液を土壌粒団に透過させると, 粒団の崩壊が著しく, それに応じて土壌の持つ透液性も低下した。しかし, 土壌からの腐植の離脱量と透液性の低下との間に認められた相関は高くないので粒団の安定性は腐植の単独作用によって律せられるものでないことがわかった。この際同時にアルミニウムがかなり多量に離脱され, これが粒団の安定性に関与することが類推された。3. 中性の腐植抽出剤である0.1Mピロ燐酸ナトリウム溶液を土壌粒団に透過させると, 土壌の種類によってその程度はかなり異なるが概して粒団崩壊と透液比の低下は大きかった。ところが, 土壌から離脱した腐植量と透液比の低下との間には相関が見出せなかった。ピロ燐酸ナトリウム溶液は土壌から腐植と同時に鉄, アルミニウム, カルシウムなどの無機成分を溶脱し, これらの正電荷を抑えて土粒の分散を促がす機能が高いから, この場合の粒団の崩壊はとくに同時に離脱する鉄やアルミニウムによるところが大きいと考えられる。 / With the object to determine the kinds of binding materials in soil aggregates and the part played by each of them, experiments were made on the effect of percolation with neutral or alkaline solution on the aggregate stability. The results obtained are as follows : 1) Aggregates were not greatly affected by the treatment with 0.05N sodium chloride solution. Hence, the part played by exchangeable bases appeared not large in the stabilization of aggregates. 2) When 0.5% sodium hydroxide solution was passed through the column to remove humus from aggregates, the permeability was remarkably lowered. But since the amount of humus removed was not so closely related to the degree of lowering in permeability, the aggregate stability did not seem attributable to the function of humus alone. It was suggested that aluminum removed from aggregates in a large amount in addition to humus participates in their stability. 3) When treated with 0.1M sodium pyrophosphate solution, neutral reagent for humus extraction, the aggregates were markedly broken down and their permeability was greatly lowered, though not without some differences in the extent of effect among the kinds of soil. On the other hand, no distinct correlation was found between the amount of humus removed and the degree of lowering in permeability ratio (the ratio of the permeability at any given time after treatment, Pt, to the initial permeability, Pi). In this case, inorganic components such as aluminum and iron, which were removed by sodium pyrophosphate solution in addition to humus, were considered to be intimately concerned with the result. 4) From these results, it may be indicated that the part played by the combined action of humus and aluminum or iron is important for the stability of soil aggregates