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Studies of gene expression following fear conditioning have demonstrated that the inducible transcription factor, egr-1, is increased in the lateral nucleus of the amygdala shortly following fear conditioning. These studies suggest that egr-1 and its protein product Egr-1 in the amygdala are important for learning and memory of fear. To directly test this hypothesis, an egr-1 antisense oligodeoxynucleotide (antisense-ODN) was injected bilaterally into the amygdala prior to contextual fear conditioning. The antisense-ODN reduced Egr-1 protein in the amygdala and interfered with fear conditioning. A 250-pmole dose produced an 11% decrease in Egr-1 protein and reduced long-term memory of fear as measured by freezing in a retention test 24 h after conditioning, but left shock-induced freezing intact. A larger 500-pmole dose produced a 25% reduction in Egr-1 protein and significantly decreased both freezing immediately following conditioning and freezing in the retention test. A nonsense-ODN had no effect on postshock or retention test freezing. In addition, 500 pmole of antisense-ODN infused prior to the retention test in previously trained rats did not reduce freezing, indicating that antisense-ODN did not suppress conditioned fear behavior. Finally, rats infused with 500 pmole of antisense-ODN displayed unconditioned fear to a predator odor, demonstrating that unconditioned freezing was unaffected by the antisense-ODN. The data indicate that the egr-1 antisense-ODN interferes with learning and memory processes of fear without affecting freezing behavior and suggests that the inducible transcription factor Egr-1 within the amygdala plays important functions in long-term learning and memory of fear.

Rabbits were given reinforced training of the nictitating membrane (NM) response using separate conditioned stimuli (CSs), which were a tone, light, and/or tactile vibration. Then, two CSs were compounded and given further pairings with the unconditioned stimulus (US). Evidence of both overexpectation and summation effects appeared. That is, responding to the individual CSs declined despite their continued pairing with the US on compound trials (overexpectation), and responding on the compound trials was greater than responding to the individual CSs (summation). The response loss appeared regardless of the testing regime, that is, whether the test presentations of the individual CSs were themselves reinforced (Experiment 2), not reinforced (Experiment 1), or deferred until the end of compound training (Experiment 2). The results are discussed with respect to the roles of excitatory versus inhibitory processes, elemental versus configural processes, and the possible roles of cerebellar and hippocampal pathways.

Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in Aplysia are helping to narrow the gap in the level of understanding between operant and classical conditioning, and have raised the possibility of studying the neuronal processes underlying the interaction of operant and classical components in a relatively complex learning task. In the present study, we describe a first step toward realizing this goal, by developing a single in vitro preparation in which both operant and classical conditioning can be studied concurrently. The new paradigm reproduced previously published results, even under more conservative and homogenous selection criteria and tonic stimulation regime. Moreover, the observed learning was resistant to delay, shortening, and signaling of reinforcement.

Rats were trained by shocking them in a closed compartment. When subsequently tested in the same closed compartment with no shock, normal rats showed an increased tendency to freeze. They also showed an increased tendency to actively avoid the compartment when given access to an adjacent neutral compartment for the first time. Amygdala inactivation with bilateral muscimol injections before training attenuated freezing and eliminated avoidance during the test. Rats trained in a normal state and given intra-amygdala muscimol injections before the test did not freeze or avoid the shock-paired compartment. This pattern of effects suggests that amygdala inactivation during training impaired acquisition of a conditioned response (CR) due either to inactivation of a neural substrate essential for its storage or to elimination of a memory modulation effect that facilitates its storage in some other brain region(s). The elimination of both freezing and active avoidance by amygdala inactivation during testing suggests that neither of these behaviors is the CR. The possibility that the CR is a set of internal responses that produces both freezing and avoidance as well as other behavioral effects is discussed.

Pavlovian conditioning inHermissendaconsists of pairing light, the conditioned stimulus (CS) with activation of statocyst hair cells, the unconditioned stimulus (US). Conditioning produces CS-elicited foot shortening and inhibition of light-elicited locomotion, the two conditioned responses (CRs). Conditioning correlates have been identified in the primary sensory neurons (photoreceptors) of the CS pathway, interneurons that receive monosynaptic input from identified photoreceptors, and putative pedal motor neurons. While cellular mechanisms of acquisition produced by the synaptic interaction between the CS and US pathways are well-documented, little is known about the mechanisms responsible for the generation or expression of the CR. Here we show that in conditioned animals light reduced tonic firing of ciliary activating pedal neurons (VP1) below their pre-CS baseline levels. In contrast, pseudorandom controls expressed a significant increase in CS-elicited tonic firing of VP1 as compared to pre-CS baseline activity. Identified interneurons in the visual pathway that have established polysynaptic connections with VP1 were examined in conditioned animals and pseudorandom controls. Depolarization of identified type Ieinterneurons with extrinsic current elicited a significant increase in IPSPs recorded in VP1 pedal neurons of conditioned animals as compared with pseudorandom controls. Conditioning also enhanced intrinsic excitability of type Ieinterneurons of conditioned animals as compared to pseudorandom controls. Light evoked a modest increase in IPSP frequency in VP1 of conditioned preparations and a significant decrease in IPSP frequency in VP1 of pseudorandom controls. Our results show that a combination of synaptic facilitation and intrinsic enhanced excitability in identified components of the CS pathway may explain light-elicited inhibition of locomotion in conditioned animals.

In his classical studies, Pavlov (1927) demonstrated that when a neutral stimulus is frequently paired with an event (unconditioned stimulus: US), which always produces innate or unconditioned responses, it becomes capable (conditioned stimulus: CS) of eliciting learned or conditioned responses. Conditioned responses typically have adaptive functions. However, conditioning of certain states, such as fear, can also be nonproductive. Fortunately, both animals and humans can exhibit opposing central mechanisms that weaken the strength of conditioned responses in certain conditions. For example, if after conditioning (CS–US pairing), the CS is repeatedly presented without the US, the strength of the conditioned response diminishes progressively over time. According to Pavlov (1927), this process, which he termed extinction, occurs as the result of the activation of a central inhibitory state that prevents the expression of conditioned responses. He also demonstrated that the engagement of this inhibitory state declines with the passage of time, a phenomenon known as spontaneous recovery (Pavlov 1927). This observation is not only true in appetitive conditioning (Pavlov’s studies; Bouton 1993; Brooks and Bouton 1993), but has also been validated in aversive conditioning (Brooks et al. 1999). In this issue of Learning & Memory, Quirk (2002) investigates several questions pertaining to the persistence of extinction memory and the development of spontaneous recovery and presents results indicating that conditioning and extinction of cued fear conditioning are mediated by independent systems. Studies on postextinction effects of CS, particularly the phenomenon of spontaneous recovery, have fundamentally contributed to the understanding of certain aspects of the nature of extinction. For example, these studies indicate that extinction does not erase memory of conditioning (see Fig. 1). Thus, conditioning and extinction result from the formation of distinct CS-related memories that are separately accessible after the extinction period (Falls et al. 1992; Bouton 1993; Rescorla 2001; Santini et al. 2001). However, it remains unclear whether the extinction memory trace progressively fades with the passage of time or whether this memory persists despite spontaneous recovery. To examine these issues, Quirk (2002) measured spontaneous recovery at various time points up to 14 d. Rats were previously conditioned to express freezing response toward a tone following tone–footshock (CS–US) pairings and then exposed to the CS-alone presentations for extinction of the conditioned fear, which was characterized by a progressive reduction of conditioned freezing to negligible levels. Remarkably, when rats were reexposed to the CSalone, they started displaying, from days 1–2, low levels of fear return (spontaneous recovery), which increased as a function of retention interval reaching 100% of preextinction values by day 10. Data from control rats, submitted to conditioning but not to extinction, showed that the passage of time alone did not increase the expression of conditioned freezing. Thus, the observed progressive spontaneous recovery was likely due to reduced activation of extinction memory rather than to increased activation of conditioning memory. The finding opens up the possibility that extinction memory is a short-lasting phenomenon that fades completely when long delays elapse between extinction and testing. Quirk also examined this possibility by resubmitting rats to extinction at day 14. Although all rats exhibit a full return of conditioned fear on day 14, they significantly reextinguished this fear faster than they did during the initial extinction, suggesting savings from the initial learning training (initial postconditioning CS-alone presentations). If, following extinction, both forms of memory (extinction and conditioning memories) are simultaneously accessible, which factors preferentially activate one or the other type of memory during further exposure to the CS? Environmental cues have been suggested to play a key role. Bouton (1993) has suggested that the passage of time may produce temporal context changes, which may, in turn, incur a failure to retrieve the extinction memory. In this condition the perception of the CS automatically activates the CS–US memory (signaling a possible occurrence of the US); the outcome being stronger conditioned responses. In Quirk’s study, because conditioning and extinction took place in the same context, it may be possible that with longer retention intervals the CS preferentially activated the CS–US memory rather than the CS–no-US memory. However, if such conditioning (i.e., tone–footshock pairings) E-MAIL rene.garcia@unice.fr; FAX (33)-4-9207-6162. Article and publication are at http://www.learnmem.org/cgi/doi/ 10.1101/lm.56402.

One of the hallmarks of the pathology in Alzheimer's disease is the deposition of amyloid plaques throughout the brain, especially within the hippocampus and amygdala. Transgenic mice that overexpress the Swedish mutation of human amyloid precursor protein (hAPPswe;Tg2576) show age-dependent memory deficits in hippocampus-dependent learning tasks. However, the performance of aged Tg2576 mice in amygdala-dependent learning tasks has not been thoroughly assessed. We trained young (2–4 mo) and old (16–18 mo) Tg2576 and wild-type mice in a T-maze alternation task (hippocampus-dependent) and a Pavlovian fear-conditioning task (amygdala- and hippocampus-dependent). As previously reported, old Tg2576 mice showed impaired acquisition of rewarded alternation; none of these mice reached the criterion of at least five out of six correct responses over three consecutive days. In contrast, old Tg2576 mice showed normal levels of conditional freezing to an auditory conditional stimulus (CS) and acquired a contextual discrimination normally. However, when the salience of the fear-conditioning context was decreased, old (12–14 mo) Tg2576 mice were impaired at acquiring fear to the conditioning context, but not to the tone CS. Histological examination of a subset of the mice verified the existence of amyloid plaques in the cortex, hippocampus, and amygdala of old, but not young, Tg2576 mice. Hence, learning and memory deficits in old Tg2576 mice are limited to hippocampus-dependent tasks, despite widespread amyloid deposition in cortex, hippocampus, and amygdala.

Aerial respiratory behavior in Lymnaea was operantly conditioned so that the animals perform aerial respiration significantly less often. Using the standard training procedure (pond water made hypoxic by bubbling N2 through it) both food-deprived and fed animals learned and exhibited long-term memory (LTM). However, food-deprived animals exhibited neither learning nor memory when trained under a condition in which the hypoxic pond water also contained a food odorant (carrot, the food-odorant procedure). Fed animals, however, learned and exhibited LTM with the food-odorant procedure. Thus, the presence of the food odorant per se did not prevent learning or the establishment of LTM. Further experimentation, however, revealed that the ability of the snails to have recall (i.e., memory) for the learned behavior was dependent on the context in which memory was tested. That is, if animals were trained with the food-odorant procedure they could only exhibit recall if tested in the food-odorant context and vice versa with the standard training procedure. Thus, although fed animals could learn and show LTM with either training and testing procedure, LTM could only be seen when they were tested in the context in which they were trained.

Seed as it comes from the field is almost never pure. It usually arrives at the cleaning plant containing large quantities of trash, leaves, weed segments, other crop seeds, and insects. If it contains such materials as green leaves and other high-moisture materials, it cannot be safely stored, efficiently handled, nor accurately cleaned until most of the foreign material has been removed. The process of removing these unwanted materials from a seed lot, along with overall improvement of seed quality, is known as seed conditioning.

Trace eyeblink conditioning (with a trace interval ≥500 msec) depends on the integrity of the hippocampus and requires that participants develop awareness of the stimulus contingencies (i.e., awareness that the conditioned stimulus [CS] predicts the unconditioned stimulus [US]). Previous investigations of the relationship between trace eyeblink conditioning and awareness of the stimulus contingencies have manipulated awareness or have assessed awareness at fixed intervals during and after the conditioning session. In this study, we tracked the development of knowledge about the stimulus contingencies trial by trial by asking participants to try to predict either the onset of the US or the onset of their eyeblinks during differential trace eyeblink conditioning. Asking participants to predict their eyeblinks inhibited both the acquisition of awareness and eyeblink conditioning. In contrast, asking participants to predict the onset of the US promoted awareness and facilitated conditioning. Acquisition of knowledge about the stimulus contingencies and acquisition of differential trace eyeblink conditioning developed approximately in parallel (i.e., concurrently).

We have studied the effect of training conditions on hippocampal protein synthesis-dependent processes in consolidation of the inhibitory avoidance task. Adult male Wistar rats were trained and tested in a step-down inhibitory avoidance task (0.4 mA foot shock, 24 hr training–test interval). Fifteen minutes before or 0, 3, or 6 hr after training, animals received a 0.8-μl intrahippocampal infusion of the protein-synthesis inhibitor anisomycin (80 μg) or vehicle (PBS, pH 7.4). The infusion of anisomycin impaired retention test performance in animals injected 15 min before and 3 hr after the training session, but not at 0 or 6 h post-training. Pretraining with a low foot shock intensity (0.2 mA) 24 hr before training, prevented the amnestic effect of anisomycin injected at 15 min before or 3 hr after training. However, simple pre-exposure to the inhibitory avoidance apparatus did not alter the amestic effects of anisomycin. The results suggest that hippocampal protein synthesis is critical in two periods, around the time of, and 3 hr after training. A prior weak training session, however, which does not itself alter step-down latencies, is sufficient to prevent the amnestic effect of anisomycin, suggesting that even if not behaviorally detectable, weak training must be sufficient to produce some lasting cellular expression of the experience.

We studied lambs' preferences for nonnutritive flavors that were paired with a glucose solution. On the 1st d of the experiment, lambs were offered a saccharin solution flavored with either orange or grape. The following day lambs received a glucose solution containing either orange or grape flavor. Lambs that had received grape and saccharin on d 1 received orange and glucose on d 2, and the reverse was true for the remaining lambs. Conditioning lasted 10 d; odd days were like the first and even days like the second. After conditioning, when lambs were offered a choice between orange- or grape-flavored water without sweeteners, lambs chose the flavor that had been paired with glucose. We also tested the initial hedonic response of naive lambs to the flavor of glucose and saccharin solutions. Lambs exhibited no initial preference. Our results indicate that lambs preferred the flavor that was paired with glucose (calories). Furthermore, results of this study suggest that ruminants may not innately recognize specific chemical constituents in foods or select diets based on initial hedonic value. Rather, learning plays a key role in the formation of dietary preference.

During the past year (1933-1934), much difficulty has been experienced in securing a good water supply for aquaria and for experimental purposes in laboratories of the department of zoology at the University of Illinois. Due to the excessive chlorine and ammonia treatment of the University water supply, fish and some invertebrates have died in large numbers. It is well known that hardy adult fishes are sensitive to over five-tenths of a part per million of chlorine. Our results show that some delicate species are even sensitive to a residual chlorine or chloramine as low as 0.05 of a part per million. Several experimental attempts to remove the chloramine were made, and it is the purpose of this paper to sketch briefly the results of these experiments.

Freeze/thaw conditioning of sludges has been shown to be an effective and economical method of sludge dewatering especially for areas where natural freezing is possible. Freeze treatment dehydrates the sludge particles by freezing the water associated to the floc and upon thawing an easily drainable granular type of material is obtained. The solid content of the freeze/thawed sludge from specially designed freezing beds ranges from 30% to as high as 60%. Pathogen reduction capacity of freeze/thaw conditioning has not been evaluated. The purpose of this study is to determine the variables affecting the pathogen reduction in freeze/thaw sludge conditioning. Previous research has shown that freezing rate, time in the frozen state, and temperature all influence the condition of the freeze/thawed sludge, and these are chosen to be the independent variables of the research. The three microorganisms- salmonella, fecal coliforms and plaque forming units for viruses-are chosen to be the dependent variables, since they best represent the other pathogenic microorganisms. Three different rates, four different temperatures and three different times of freezing are tested for their effects on the reduction of the three selected microorganisms. Results indicate that all of the parameters, time, rate and temperature of freezing have significant effects on the reduction of the indicator microorganisms.

This study investigated the relationship between sludge loading rate, COD-to-nitrogen ratio of influent waste, and maximum difference in specific resistance as a result of chemical conditioning (DeltaZ). It also related DeltaZ to sludge carbohydrate content, protein content, and surface charge. This research also explored the necessity of chemical conditioning when an activated sludge exhibits excellent bioflocculation characteristics.

FOUR conditioning treatments of alfalfa (Medicago sativa) were compared which included: (a) no conditioning, (b) mechanical conditioning using intermeshing rubber rolls, (c) chemical conditioning using aqueous potassium carbonate and (d) mechanical and chemical conditioning combined. Mechanical conditioning increased drying rate during first cutting by about 80% with a small effect on second cutting and no effect on later cuttings. Chemical conditioning improved drying of all cuttings when drying conditions were good. During first cutting, chemical conditioning provided only a 40% increase in drying rate due to the heavier swath structure, but up to a 175% increase was measured on later cuttings. A combination of mechanical and chemical conditioning provided only a small increase in drying rate over mechanical conditioning alone during first cutting. During later cuttings where mechanical conditioning was less effective, the combination provided similar increases in drying rate as obtained with chemical conditioning alone. Dry matter losses and quality changes during field curing were not affected by conditioning treatment. Loss and quality degradation in storage was higher for unconditional hay because it was often baled at 25 to 30% moisture due to slow drying.

Tests at a commercial plant showed that a new in-line steam process was better than the existing process in conditioning inshell pecans for cracking, as determined on the basis of shelling efficiency, or yield of unbroken nutmeat halves. Steam conditioning was more effective than commercial conditioning in reducing total plate count and yeast and mold count on the product. Peroxide and free fatty acid values of oils, Hunter color values of nutmeat halves and sensory taste analyses indicated that the quality of the nutmeats conditioned by the two methods was essentially the same immediately after conditioning. Commercial test results agreed with results of previous pilot-scale studies.

chemical reagents to raw sludge resulted in increased rates of sludge dewatering, decreased sludge volumes, and reduced equipment costs.13 Initially, most of the chemical-conditioning reagents used were inorganic salts, but more recently high molecular weight organic polyelectrolytes have been used either independently or in conjunction with the inorganic materials. The use of organic polyelectrolytes as coagulants and sludge-conditioning agents led to a considerable increase in the consumption and demand for commercial polyelectrolytes. There are hundreds of these polymers available on the commercial market, but most of the information pertaining to commercial polyelectrolyte characteristics is regarded as proprietary and not obtainable through product bulletins nor directly from the manufacturer. While a number of studies have shown

A poultry layer-diet was used in experiments to determine the effects of steam-conditioning level on pelleting variables. Dry pelleting was compared with steam conditioning (to 65 and 80° C) before pelleting, at both constant and maximum production rates. Samples were obtained before and after conditioning, and after pelleting. Electrical energy used by the pellet mill was measured with a watt-hour meter, and the amount of steam used for conditioning was calculated using steam tables. Temperature rise of the meal being extruded through the die and electrical energy required to pellet showed that steam decreased mechanical friction during pelleting. Pellet durability and percentage of fines from the scalper showed that steam improved pellet quality. Pressing the mash through the pellet die caused more starch damage during dry pelleting than during steam pelleting. Starch was not damaged during the steam-conditioning process. Total energy required for pelleting (electrical plus steam) was highest for the 80° C treatment. However, steam conditioning allows increased production rates and improved pellet durability during handling and transportation of finished feeds.

A novel process that can reject as much as 90% of the pyrite from finely divided coal is described. Cells of Thiobacillus ferrooxidans are mixed with an aqueous slurry of the coal and the mixture is vigorously agitated for as little as 15 min. Pyrite is apparently rendered hydrophilic and is rejected with the tailings when the hydrophobic coal is recovered by oil agglomeration. The process is superior to bacteriological oxidation which requires several days to remove comparable amounts of pyrite from coal through conversion to sulphate. It is shown that the bacterial cells can be recovered after agglomeration and used to treat at least six successive batches of coal. The minimum contact time, the minimum inoculum size and the ultimate number of times that the bacteria can be recycled are related variables that could not be defined under the laboratory conditions used. It was found, however, that Thiobacillus ferrooxidans grown on rejected tailings supplemented with inexpensive mineral salts are at least as effective in the process as cells grown in synthetic medium.

Canadian and UK wheats have been conditioned separately to different moisture levels, then blended and held for varying periods before milling. A progressive and substantial moisture migration between the components of the blend was observed, but the extent of such migration had a negligible effect on milling performance. This is interpreted with reference to earlier work on the conditioning of the individual wheat types.

Summary With suitable storage conditions, diets manufactured with certain modifications to conventional processes will remain in a satisfactory usable condition for periods considerably longer than those normally accepted. Diets for laboratory animals are manufactured using essentially the same processes as those used in the manufacture of feeds for farm animals. Some of these processes, which include weighing, grinding, mixing, steam conditioning, extruding (pelleting), cooling, screening and packing are frequently blamed for poor quality, instability and unsatisfactory performance. The more obvious conditions giving rise to criticism include rancidity, with the attendant off-odours and flavours, mould growth, vitamin loss and poor physical quality, this last usually being associated with wastage. Rancidity can, to some extent, be controlled by the inclusionof antioxidants.Mouldgrowth can be retarded with other chemical additives. However, since the introduction of the American Good Laboratory Practice Regulations (FDA 1978), the use of non-nutritive additives is not recommended, because their presence in diets could affect data from experiments in which these diets were fed. Unless otherwise stated, the data presented here relate to diets which did not contain any such additives. Materials and methods 4 different modifications of the manufacturing processes are considered for several types of conventional formula laboratory animal diets. I. Unprocessed meal diets. 3 different formulae in which the ingredients were simply weighed, ground and mixed.

A method has been developed using a laboratory 2 roll mill for reproducibly milling malt produced from European Barley (two-row). The procedure can be readily adapted to give grists of similar particle size distribution to those produced by either commercial four or six roll mills. Factors which were considered likely to affect the milling of malt were studied with particular attention to moisture level, the degree of modification, extent of kilning, influence of storage, differences in grain size and extent of steam conditioning. Most of these factors did exert an effect on milling. However, in the majority of cases the values needed to be outside normal commercial limits before substantial changes in milling performance were observed. Studies employing a laboratory mashing system have shown that by using malts containing c.a. 6% moisture it is possible to reduce wort separation times without affecting extract recovery. Steam conditioning can have a marked beneficial effect on the milling performance of malt providing the extent of moisture pick-up is carefully controlled.

1. Moisture content of uncured GR-S compounds must be reckoned with because of its effect on curing rate and the serious consequence of overcure. 2. Excessively dry polymer (below about 0.15 per cent water) will, in general, be slow curing (Figure 2). 3. Mixed stock with less than 0.5 per cent water will, in general, be slow curing and erratic in curing rate (Figure 5). 4. The normal moisture range of carbon black does not affect the curing rate of GR-S (Figure 4). 5. The normal moisture content of carbon black is not available to the polymer for stabilizing its curing rate. 6. Mixed stock which is dry and slow curing may be conditioned to stable curing rate by storage under humid conditions. A moisture content of 0.5 to 1.0 per cent is indicated. This moisture content seems also to iron out differences in curing rate between polymers. 7. Since conditioning of mixed stocks is not always feasible on the factory scale, the stabilization of cure by direct water addition during mixing should be given consideration. 8. Laboratory-scale tests on a GR-S tread compound indicate that an addition of about 2.5 to 5 per cent water (on the polymer) during mixing will result in a mixed-stock moisture content giving minimal cure variation for normal-curing and slow-curing (very dry) polymers for periods of stock layover up to about 3 weeks. 9. Any additions of water as suggested above will, on the factory scale, require adjustment, since moisture retention is a function of the compounding ingredients, mixing cycle and temperature, storage time, and humidity conditions actually obtaining.

This paper presents the effects of chemical sludge, produced by coagulation processes, on the settleability and dewaterability of biological sludge, produced by the activated sludge processes. It was demonstrated that the settleability of the mixed biological and chemical sludges was significantly better compared with that of the unblended biological sludge. The average settling velocity and density of the discrete particles of the mixed sludges were much higher than those of the biological sludge. The improvement of the mixed sludges’ settleability was influenced by both mixing and ALT ratios of the chemical sludge. It was also determined that the dewaterability of the mixed sludges was improved and the specific resistance was lowered by one order of magnitude compared with the biological sludge.

Still pitch remaining after the commercial distillation of soy and cottonseed oil fatty acids may be an effective agent for improving the tilth of certain agricultural soils. It greatly increases the water-holding capacity. Up to 98% of Boston blue clay was converted to water-stable aggregates by 4% of pitch. One per cent of pitch ($0.02/1b.) gave 10.8% aggregation while 0.1% of Krilium ($1.47/1b.) gave 8.5%.

Traditional air conditioning systems run on the vapor compression cycle, which utilizes electricity generated from fossil fuels, the reserves of which are fast depleting. Moreover, the refrigerants used in such systems have exacerbated ozone layer depletion and climate change. Liquid desiccant air conditioning (LDAC) systems appear as a favorable option in light of these drawbacks. This paper has developed the numerical model of an LDAC system using a dehumidifier that is internally cooled and has a finned coil. The study of this particular model has been limited in the past. The model has been validated against a reference study available in the literature. Moreover, the commonly used desiccant materials tend to be corrosive and detrimental to the air quality. Therefore, the feasibility of an ionic liquid (65% [Emim]OAc) and an organic salt solution (73% HCOOK) as desiccant materials has also been investigated in this paper. With the proposed scheme for room air conditioning, the air temperature and humidity levels within the range of comfort (21∘C, 53% R.H.) could be supplied to the conditioned space. Performance analysis revealed that the eco-friendly desiccants could achieve dehumidifier and regeneration effectiveness similar to that of the traditionally used corrosive salt solution of calcium chloride (CaCl2). Furthermore, the estimated dehumidifier efficiency of about 76% is found to be higher than that available in the previous studies. Economic analysis provides a comparison of total cost between the conventional and the novel desiccant air conditioning systems and also reveals HCOOK to be a more economical choice as desiccant material.

When formulating history matching within the Bayesian framework, we may quantify the uncertainty of model parameters and production forecasts using conditional realizations sampled from the posterior probability density function (PDF). It is quite challenging to sample such a posterior PDF. Some methods e.g., Markov chain Monte Carlo (MCMC), are very expensive (e.g., MCMC) while others are cheaper but may generate biased samples. In this paper, we propose an unconstrained Gaussian Mixture Model (GMM) fitting method to approximate the posterior PDF and investigate new strategies to further enhance its performance. To reduce the CPU time of handling bound constraints, we reformulate the GMM fitting formulation such that an unconstrained optimization algorithm can be applied to find the optimal solution of unknown GMM parameters. To obtain a sufficiently accurate GMM approximation with the lowest number of Gaussian components, we generate random initial guesses, remove components with very small or very large mixture weights after each GMM fitting iteration and prevent their reappearance using a dedicated filter. To prevent overfitting, we only add a new Gaussian component if the quality of the GMM approximation on a (large) set of blind-test data sufficiently improves. The unconstrained GMM fitting method with the new strategies proposed in this paper is validated using nonlinear toy problems and then applied to a synthetic history matching example. It can construct a GMM approximation of the posterior PDF that is comparable to the MCMC method, and it is significantly more efficient than the constrained GMM fitting formulation, e.g., reducing the CPU time by a factor of 800 to 7300 for problems we tested, which makes it quite attractive for large scale history matching problems.

The use of recycled asphalt shingles (RAS) in pavement construction has received significant attention due to its economic and environmental advantages. However, asphalt binder in RAS is significantly aged and requires modification before application to ensure it does not compromise pavement performance. The paper introduces a novel approach to modify RAS to facilitate its application in new construction while examining the feasibility of rejuvenating RAS via bio-modification. In addition, this study investigates the durability of the modified RAS, referred to as bio-modified shingles (BMS), by exposing BMS to both severe oxidation aging and sub-zero extended conditioning followed by a comprehensive thermo-mechanical characterization. Study results showed the performance of RAS was significantly improved after bio-modification. The performance improvement was reflected in BMS having lower viscosities, stiffnesses, shear susceptibilities, crossover temperatures, while having higher m-values and failure strains compared to RAS asphalt. It was further observed that the enhancement lasted even after BMS was exposed to severe oxidation aging and 72 hr conditioning at −18 °C indicating an enhanced durability of BMS. The latter can be attributed to molecular interactions between the bio-modifier and aged asphalt disturbing the molecular packing of asphaltene and wax molecules. Such molecular packing is known as a dominant mechanism for hardening at sub-zero temperatures. This paper contributes to the body of knowledge and practice by providing insights on the merits of revitalizing recycled asphalt shingles to enhance its durability and facilitate its application in construction to promote sustainable construction practices.

Objectives/Scope In today's Oil and Gas Industry, as we evolve more towards smart fields and integrated operations, the term digital oilfield is being used more often. Many companies implement smart fields where transmitters and gauges are installed in the field along with a Supervisory Control and Data Acquisition (SCADA) system. One common threat faced in a digital oilfield setup is the failure of accurate data transmission. This includes no data transmitted, erroneous/wrong data transmitted, error in the calibration of the field devices, network interruptions, failure of SCADA system etc. Methods, Procedures, Process This paper describes the development of a methodology used to overcome the issues of bad data from the field with the usage of data conditioning and also the suitable data tolerance which can be accepted before the system fails. This method uses smart rules and automated data conditioning which involves historical data, data from nearby wells and results from well modeling workflows. When applied in the field, it ensures that the system runs even when not all the required data from the field is acquired for successful workflow execution. Results, Observations, Conclusions Implementing data conditioning rules described in the paper improved the accuracy of the workflow from 71% to 98% which represents a huge improvement. The solution was applied in an offshore field. The automated workflows involved in this solution was well status identification, real time production surveillance, real time gas lift optimization, theoretical production rates from well models, well test validation and platform monitoring. As more data becomes unreliable and missing, the confidence level of the results of the workflow also decreases to a certain point where too many required data points are missing or not available and the system would send an alarm and flag the results of the workflow due to unreliable data transmission. This scenario will be seen if there is a complete failure of the SCADA system or severe network interruptions for an extended period of time. The solution and data conditioning methods applied managed to increase production by reducing the amount of time needed to identify wells which quit offshore which reduces deferred production. Novel/Additive Information The paper provides a quantitative assessment of the benefits realized by applying the data conditioning and using suitable data tolerance when running workflows used for production surveillance and optimization in a digital oilfield. As we try to achieve higher production rates and greater recovery from the field, more high frequency data is required and the methods described in this paper can be applied to other fields to solve the missing and erroneous data transmission problems.

This paper investigates the effect of preconditioning on the variability of the results when measuring the Repetitive Partial Discharges Inception Voltage (RPDIV) of electrical insulation systems subjected to impulsive voltage stresses. The reference International Standard considered in the following (IEC 60034-18-41 [1]) defines the RPDIV as the minimum voltage at which at least five Partial Discharges (PD) occurs in ten voltage impulses applied. Many testing devices have been designed according to such definition: they inject ten voltage impulses and, if five of them trigger PD events, the voltage is recorded as the RPDIV. Otherwise, the voltage is increased until the RPDIV condition is met. On the other hand, other systems focus their analysis on the time behavior of the PD probability in the course of the tests. They do not simply record the RPDIV at the ratio where the number of PDs is greater than 0.5 times the voltage surges, but when it is persistently larger than such threshold. It has been noted that the PD probability (i.e. the number of PD per number of voltage pulses) shows a non-monotone behavior during the RPDIV measurements and consistent variations above and below the 50% threshold occur. Therefore, results coming from the types of equipment having the two different approaches are often noticeably different and, as a consequence, the RPDIV results using different measurement systems might vary depending on how this parameter is calculated. This paper proposes the electrical conditioning as a possible procedure to reduce this variation, and thus to have results independent from the measuring apparatus.

A new machine learning (ML)/statistical-based methodology for conditioning and predicting production data for a well pad has been developed. Typically, data conditioning involves outlier detection, missing data, data imputation, and smoothing. Time-series production data prediction can be challenging because the target (wellbore oil production) depends on large-scale, high-dimensional data sets with unknown distributions and is influenced by missing data and outliers. Hence, data conditioning is key for accurate predictions. The current work is the first attempt at using ensemble ML and statistical techniques, such as multilayer perceptron (MLP), principal component analysis (PCA), and support vector regression (SVR), for well pad data conditioning using recently disclosed subsurface and production data from a field in the southern area of the Norwegian North Sea. The time-series forecasting based on large-scale, high-dimensional conditioned and cleaned data sets is also presented. The data with an oil production rate greater than 10 Sm3 have been retained for data cleansing, which reduced the size of the production well data set by 14.9%. Outliers are detected using the z-score method. The missing values are predicted using a trained ML model on all available nonmissing data. The procedure first predicts the downhole missing values from all the wells, including the available neighboring wells, and then uses these features to predict other missing values for the well pad. In this paper, the two approaches implemented and compared for prediction of missing data are MLP and SVR, and PCA is performed to extract the most important data features. Production data with 12 related variables (i.e., dates, hours, temperature, pressure, etc.) are used to explore the complex nonlinearity of features and estimate wellbore oil production with ML and deep-learning models. Conventional SVR and MLP methods are implemented as the benchmark. During this work, more than 60% of the missing and abnormal data from the field data set are detected and imputed using advanced ML methods, such as MLP and SVR with radial basis function kernel. More than 6% of data are outliers and are removed using the z-score method. The modified SVR with time-series data structure and long short-term memory (LSTM) algorithms are used for the comparisons. An R-squared (R2) of 98% is achieved for both the algorithms; however, LSTM has the lowest root mean square error (RMSE) results compared to SVR. Data conditioning is conventionally performed using statistical techniques, but here, an ensemble of ML techniques is used depending on the available data. This paper presents a new methodology to perform data conditioning and production prediction for a well pad using ML and neighboring well data. The ML algorithms used are highly efficient, as demonstrated by the results.

PurposeThis paper aims to illuminate mechanisms through which memorable experiences with brands create lasting preferences. It is based on the proposition that intense positive (negative) affective consumption in the consumer’s youth creates powerful imprints, which influence brand preference (distaste) throughout life.Design/methodology/approachAutobiographical memories with Nutella are retrieved from three different user groups, i.e. heavy-, light- and non-users. The retrieved memory narratives are analysed using conditioning theory, i.e. operant, classical or no conditioning are identified and compared across groups.FindingsThe research’s central proposition is affirmed, yet the dominant form of conditioning mechanism differs per group. Operant conditioning outperforms classical conditioning in creating strong and lasting preferences. Heavy- and non-users predominantly exhibit in-tensely positive and negative operant conditioning, respectively. Light-users on the other hand recall less affectively intense consumption experiences, mainly featuring classical conditioning. The light-users’ recollections suggest a mere exposure effect to be more appropriate in describing the preference formation in this user group.Research limitations/implicationsUsers not having experienced affectively intense consumption, i.e. light-users, are likely to be influenced in their preference over time through other factors, which this paper does not focus on.Practical implicationsMemory elicitation and exploration provides valuable insights to shape both promotional as well as advertising strategies.Originality/valueThe study extends existing theory on conditioning in marketing by first using a novel qualitative approach to analyse conditioning procedures in real-life settings, and second, it highlights operant conditioning’s superior ability in creating lasting preferences.

Dempster–Shafer evidence theory (DST) is an important tool for uncertainty modeling and reasoning, where the uncertainty reasoning includes both the evidence combination and conditioning. New conditioning rules for evidence updating in DST are proposed in this paper. First, two new definitions, namely the weak conditional basic belief assignment (BBA) and strong conditional BBA, are proposed in the spirit of conditional probability in the probabilistic framework. Then, the corresponding Jeffrey-like conditioning rules are proposed to update evidence. The proposed methods have some desirable properties for the evidence updating. Some numerical examples are provided, where existing conditioning rules in DST are compared with newly proposed methods. Experimental results and related analyses show that the conditional BBAs and Jeffrey-like rules proposed in this paper are rational and effective.

A sleeping person is naturally immobile in a relatively small space. Hence, task\ambient air conditioning (TAC) can be best applied to a sleeping environment because of its proven performances in energy saving. However, when using previously developed the TAC systems for sleeping environment applications, cold draft was a serious issue and could hardly be avoided due to a high air velocity and a low air temperature inside an occupied zone. Therefore, in the experimental study reported in this paper, a radiation-based TAC (R-TAC) system has been developed, and its performances experimentally evaluated. In this paper, firstly, an experimental setup for a prototype R-TAC system, and experimental conditions and methods are reported. This is followed by presenting experimental results on the thermal comfort and ventilation performance. Finally, the issues of condensation risk when using the proposed R-TAC system are discussed. The study results presented in this paper have shown that the use of the R-TAC system could not only result in better thermal comfort and ventilation performances, but also effectively resolve the cold draft problem. In addition, the potential problem of potential condensation on a surface may be resolved by raising the panel surface temperature, or using a lower fresh air supply humidity.

In this paper single-phase AC to DC cuk converter is presented. It improves the power quality at AC mains input source and also the power factor. The AC-DC converters convert to regulate supply process which injects harmonics distortion and waveform at input AC source. These AC-DC cuk converter are used with PFC based technique. This technique reduces the input current harmonics and improves power quality. In this paper it is desire to obtained unity power factor (PF) and continuous DC link voltage. Here, a source conditioning-based design of these converters is demonstrated and a comparison of with and without source conditioning-based converter is shown. The operation and simulated results of proposed source conditioning scheme is presented.

Recently, generalized credal sets have been introduced for modeling contradiction (incoherence) in the information. In previous papers, we did not discuss how such information could be updated if some events occur. In this paper, we show that it can be done by the conjunctive rule based on generalized credal sets. We show that the application of generalized credal sets results in several types of conditioning for imprecise probabilities.