Flush Cycle Research Articles

Fast-Clearing Spray Chamber for ICP-AES

The rapid-clearing spray chamber design utilizes two critical features for a rapid-clearing system—a nebulizer wash and a high-volume gas flush. The combination of these two features with supporting design features provides a system which can clear out a signal of Fe or Zn from 500 ppm to undetectable levels (below 10 ppb) in about 20 s. A tubular injector is used in the ICP torch to minimize plasma disturbance during the gas flush cycle. Several modifications to the spray chamber were necessary to handle the nebulizer wash efficiently.

Toilet system having an air evacuating system in a water storage tank

A toilet system includes a water storage tank that stores fresh water used in the flush cycle. The water storage tank is divided into two compartments by a partition wall, and an air evacuating system is located in one of the compartments, while a flush control system and flush water are located in the other compartment. The air evacuating system includes a blower connected to an air passage way located in the toilet bowl and to the waste water disposal conduit. Air from inside the toilet bowl is moved to the waste water disposal conduit.

MEASURING THE DEBRIS

The CDM/FP/00 (Continuous Debris Monitor with Flushing Plug) is an on‐line magnetic plug designed to measure the amount of ferrous debris in oil‐lubricated and hydraulic systems. It is superior to existing self‐sealing magnetic plugs in that a continuous reading is given when the unit is plumbed into an oil line. Further, it has the advantage of being self‐flushing, thereby obviating the need for removal and inspection. The sensor consists of a patented mechanism whereby the accumulation of ferrous debris causes a flux change in a magnetic circuit. A magnetic sensor converts this flux change into an electrical signal, which is proportional to the amount of debris captured. A sensor is incorporated into the mechanism to monitor the lubricant temperature and so provide compensation for changes in temperature. As debris accumulates, the magnetic circuit would eventually saturate. The CDM/FP/00 senses this and initiates a patented flush cycle, whereby the magnetic circuit is withdrawn from the oil line enabling the flow to wash off the accumulated debris, which can then be filtered out. Withdrawal is accomplished by a linear electric actuator. Fluid integrity is maintained by a thin non‐magnetic barrier between the oil line and the magnetic circuit. The magnetic circuit is then accurately repositioned and debris accumulation recommences. The CDM/FP/00 is fully approved by the Health and Safety Executive for use in Class 1 atmospheres as defined in BS 1259:1958. This unit incorporates both Gabriel Microwave Systems Ltd, and Central Electricity Generating Board devices, each the subject of separate Patents Pending. Manufacture and sale, therefore, is under licence with respect to the CEGB device.

BIOCHEMICAL AND PHYSIOLOGICAL ASPECTS OF LEAF DEVELOPMENT IN COCOA (THEOBROMA CACAO L.)

SummaryThe export and translocation of radioactivity supplied as 14C‐auxin or as a 14C‐kinin to a donor leaf of cocoa was followed at different stages of the flush cycle to see whether there was any correlation between the pattern of movement of these growth promoters and apical bud activity. The auxin 3‐indole (1‐14C) acetic acid, (14C‐IAA), and the cytokinin, 6‐benzyI‐amino (8‐14C) purine, (14C‐BAP), were introduced into the plant by foliar feeding. Export of the radioactivity derived from the 14C‐IAA was predominantly basipetal at all stages of the flush cycle. Most of the tracer accumulated in the lower stem but there was a significantly high proportion in the older leaves. It appeared that the largest proportion of the radioactivity derived from 14C‐IAA was found in parts of the plant where growth, or possibly carbohydrate accumulation, was active. It is suggested that the movement of 14C‐IAA and its metabolites in cocoa may be largely determined by the direction of flow of the assimilate stream. The identity of the radioactive compounds exported from the donor leaf showed that some 80 % of the fed 14C‐IAA was metabolized to other indole compounds including indole aldehyde, indole aspartate and indole acetonitrile.When the 14C present in particular plant parts was expressed as a relative radioactivity ratio, this value, for the apical bud, declined throughout the flush cycle, being highest at bud break, indicating that the capacity of the bud to accumulate radioactivity derived from 14C‐IAA was greatest during the stages of leaf production.The distribution of radioactivity from 14C‐BAP indicated both acropetal and basipetal transport of cytokinin but accumulation of radioactivity occurred only in actively growing regions. Unlike 14C‐IAA, the 14C‐BAP exported from the leaf was not extensively metabolized and about 60% of the transported radioactivity was detected as 14C‐BAP and the remainder as conjugated 14C‐BAP. For this compound the relative radioactivity ratio in the bud was highest at dormancy break (F‐1), suggesting that cytokinin movement to the bud was related to the breaking of dormancy. The changes in pattern of transport of auxin and cytokinin throughout the cocoa plant were correlated with the stages of the flush cycle.

Distribution of assimilate during the flush cycle of growth in Theobroma cacao L.

The growth of the shoot and roots of seedling plants of cocoa (Theobroma cacao L.) under constant glasshouse conditions showed a rhythmic cycle, with the maximum growth stages of each alternating in a regular sequence. When the growth cycle of the shoot was upset by removing all new leaves immediately after unfolding, the roots showed a high constant growth rate during this period, suggesting that normally the rapidly expanding leaves exert an inhibitory influence on the roots. Conversely removal of portions of the root delayed the production of new leaves in the shoot. The level of soluble and starch carbohydrate in the mature leaves, roots and stem declined during the period of expansion of the flush leaves, but accumulated again at the end of the leaf expansion stage. It is likely that this reserve carbohydrate was remobilised and translocated to the flush leaves during their period of expansion. A large proportion of newly formed photoassimilate, as shown by the distribution of 14C radioactivity from different source leaves, was also translocated to the young leaves during expansion. The large sink created by these leaves may cause photoassimilate and reserve carbohydrate to be diverted from the roots, thereby inhibiting root growth during the stage of leaf expansion. It is suggested that the rhythmic leaf production at the apex may control the growth cycle of the roots.

BIOCHEMICAL AND PHYSIOLOGICAL ASPECTS OF LEAF DEVELOPMENT IN COCOA (THEOBROMA CACAO L.)

SummaryThe flush leaves of seedling cocoa plants were assessed at each stage of the flush cycle from leaf unfolding to maturity for differences in leaf lamina presentation angle, surface hairs, stomatal number and development and leaf cuticle thickness. Changes in these parameters were then correlated with cuticular and stomatal diffusive resistance of the leaves. It is suggested that perpendicular positioning of the young flush leaves, the presence of surface hairs, the rapid synthesis of the cuticle and the limited stomatal development during the early stages of leaf expansion, restrict water loss from the developing leaves. Maximum rate of water loss from the leaves of a new flush was only attained after leaves were fully expanded, stomata fully developed and the leaves horizontally positioned. It is suggested that the large increase in water loss from the flush leaves following these changes might lead to an internal water deficit in the plant and hence to increased synthesis of abscisic acid in the shoot which, in turn, will maintain dormancy of the shoot apex in at least part of the interflush period.

Improved determination of aluminum in serum by electrothermal atomic absorption spectrophotometry.

This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for a standard curve. We used this method on serum from 50 normal persons and from 34 patients with chronic renal failure who were on long-term intermittent hemodialysis. The mean normal serum aluminum concentration was 6.1 micrograms/L (CV 2.7%), and values for the patients ranged from 13 to 475 micrograms/L.

VARIATIONS IN ENZYME ACTIVITY DURING PERIODIC FRUITING OF AGARICUS BISPORUS

SummaryGlucose‐6‐phosphate dehydrogenase (G6PD), glucosephosphate isomerase (GPI) and mannitol dehydrogenase (MD) were assayed in sporophores harvested at stages 1 (pin) and 2 (button) of development throughout several fruiting cycles. Higher G6PD specific activity was consistently found in stage 1 and 2 sporophores harvested between periods of maximum stage 2 production (flushes). There was minimum G6PD activity during the flushes. At stage 1 the range of variation was greater and the timing of the peaks in the flush cycle more uniform than in stage 2 sporophores. GPI and MD activities also varied with flushing, but showed a less consistent pattern than G6PD. MD normally exhibited greatest activity in stage 1 and 2 sporophores between flushes. GPI activity was higher between flushes in stage 1 sporophores, and during flushes at stage 2.Mannitol and trehalose were highest in stage 1 sporophores harvested between flushes. The results are discussed in relation to the mechanism of flushing.

BIOCHEMICAL AND PHYSIOLOGICAL ASPECTS OF LEAF DEVELOPMENT IN COCOA (THEOBROMA CACAO)

SummaryThe dormant phase of the flush cycle of leaf growth in cocoa is known to be correlated with high abscisic acid (ABA) levels in the mature leaves of the new flush (NF) and previous flush (PF) leaves. Defoliation of either the NF leaves or PF leaves of cocoa seedlings reduced the length of the dormant phase of the flush cycle, thus showing that the mature leaves were a source of growth inhibitors which could affect shoot apical activity. The application of ABA to the NF and PF leaves led to an extension of the dormant phase, whereas application of zeatin or gibberellic acid decreased it. The distribution of [14C]ABA following its application to NF and PF leaves at different stages throughout the growth cycle showed that [14C] ABA was accumulated by the bud in relatively larger amounts during the final stages of bud dormancy (I‐1 and I‐2) than in the earlier stage (F‐2). The results suggest that internal competition for nutrients may be responsible for the inhibition of growth at the F‐2 stage but that ABA translocated from the mature leaves causes the buds to remain dormant during the subsequent stages of I‐1 and I‐2.

Biochemical and physiological aspects of leaf development in cocoa ( Theobroma cacao). IV. Changes in growth inhibitors

Cocoa seedlings were grown under greenhouse conditions in the absence of any environmental stress. During a flush cycle of shoot growth, leaves of the current flush and of the previous flush were sampled at intervals and ABA levels determined by bioassay. In young expanding flush leaves (stages F-1 to F-2) amounts of both free and bound abscisic acid (ABA) were low. At full expansion (end of F-2 stage) both forms increased, particularly the bound ABA, then declined again during the dormant period (I-1 to I-2) to reach a low level at the start of the new cycle. In the leaves of the previous flush, the early stage of the cycle (F-2) was marked by a high level of free ABA which thereafter declined rapidly and remained low throughout the rest of the cycle, whereas the bound form increased at the end of F-2 and only declined at the end of the cycle. It is suggested that both the mature leaves of the current flush and the leaves of the previous flush act as sources of ABA which maintain the bud in a state of dormancy during the latter half of the growth cycle.

Culture of Shoot Apices of Theobroma cacao

AbstractSurface sterilized buds of young cocoa plants (Theobroma cacao L.) taken at particular stages of the flush cycle were placed in Linsmaier and Skoog agar medium supplemented with a range of growth regulators. Only buds taken at the 1–2 (dormant) stage of the flush cycle and treated with gibberellic acid (GA3) alone and GA3plus kinetin (KN) supplement showed bud opening. In liquid Linsmaier and Skoog medium buds isolated at the 1–2 stage also responded to GA3 and KN. In this case addition of KN caused bud opening, while GA3 either initiated bud opening only or opening followed by leaf expansion depending on the concentration of GA3 supplied. Bud development was inhibited when ABA was included in the medium hut this was overcome by the presence of GA3 but not KN. Since a hormonal supplement was required for any response from the excised buds, it is suggested that the intermittent growth of the shoot apex in the intact plant may be determined by hormonal stimuli derived from other parts of the plant. The findings also indicate that the bud apices could be maintained in culture for long periods which may provide a basis for the development of a micropropagation procedure for cocoa.