Individual Baths Research Articles

Balneotherapy in the treatment of subjective symptoms of lumbar syndrome

Chronic low back pain is a degenerative rheumatic disease and is characterized by various symptoms and clinical signs. Balneotherapy represents a therapy by various hot or warm baths in natural mineral waters of specific physical and chemical characteristics. When used externally, they have mechanical, chemical and thermic effects. Balneotherapy of lumbar syndrome includes: individual baths, swimming in the pool, hydrokinesitherapy, underwater massage, underwater extension, mud therapy, mud baths. The therapy should be closely monitored for optimal efficacy and it is necessary to examine: functional status of the lumbosacral region, general functional status (level of activity), lower extremities, pain measurement, use of non-steroid antirheumatic and analgesic agents. In order to follow-up the effects of therapy and establish the prognosis it is important to perform: detailed anamnesis, anthropometric measurements, socio-epidemiological research, clinical examinations. Lumbar syndrome is usually caused by a degenerative disease of the spinal column. More than 25% of people under 45 years of age are unable to work due to chronic low back pain. That is why preventive measures, prompt diagnosis and adequate therapy are of utmost importance.

Ion-chromatographic study of the possible absorption of copper and zinc by the skin of Rana pipiens

Frogs are known to obtain some of their nutrients (e.g., glucose and sodium) through their skin. However, no studies have been made of the possible absorption of transition metals, which exist in most river water at low-ppb (w/w) levels. Therefore, this research was undertaken to evaluate the use of ion chromatography for such an investigation. Solutions of copper and zinc (20 ppb in each) were chosen for use in a small-scale screening study. Ten live frogs were each placed in individual baths for approximately 50 h. Of interest were the net changes in the concentrations of the metals. These differences were the result of any absorption and/or excretion processes that took place. A Dionex IonPac CS5 column was used to analyze this simulated river water, both before and after frogs had been placed in the solution. Included in this paper are: (1) methodology and calculation formulas; (2) precautions needed to ensure sample integrity; (3) statistical analyses, which indicated that ion chromatography is an accurate, precise technique for quantifying Cu and Zn in these samples; and (4) screening-study results, which were used to test the null hypothesis that frogs do not absorb copper and zinc either onto or through their skin.

Plant-derived estrogens relax coronary arteries in vitro by a calcium antagonistic mechanism

OBJECTIVESTo investigate the potential for plant derived estrogens (phytoestrogens) genistein, phloretin, biochanin A and zearalanone to relax rabbit coronary arteries in vitro and to determine the mechanism(s) of such relaxation.BACKGROUNDEpidemiological data suggests a reduction in the incidence of coronary heart disease in humans who have a high intake of phytoestrogens.METHODSIsolated rabbit coronary artery rings were suspended in individual organ baths, precontracted with potassium chloride (30mM), and the relaxing effects and mechanisms of relaxation to genistein, phloretin, biochanin A and zearalanone were determined by measurement of isometric tension.RESULTSGenistein, phloretin and biochanin A induced significant gender-independent relaxation in rings with and without endothelium. Inhibition of nitric oxide and prostaglandin synthesis with L-NAME and indomethacin had no effect on genistein-induced relaxation. Relaxation was unaffected by the specific estrogen receptor antagonist ICI 182,780, the ATP-sensitive potassium channel inhibitor glibenclamide and the potassium channel inhibitor, barium chloride. Calcium concentration-dependent contraction curves in high potassium depolarization medium were significantly shifted to the right and downward after incubation with genistein and zearalanone. An inhibitory effect of genistein (2 μM) on L-type calcium current in guinea-pig ventricular myocytes confirmed a calcium antagonist relaxing mechanism of action. In healthy volunteers, plasma genistein levels of approximately 2 μM are achieved after ingestion of a commercially available soy protein drink (Supro) containing 37 mg genistein.CONCLUSIONSThis study demonstrates that phytoestrogens induce endothelium-independent relaxation of coronary arteries; the mechanism involves calcium antagonism. These mechanisms may contribute to the potential long-term cardiovascular protective effect of these substances.

CORRELATION BETWEEN THE STRUCTURE AND FUNCTION OF THE RABBIT URINARY BLADDER FOLLOWING PARTIAL OUTLET OBSTRUCTION

To understand the relationship between contractile and structural changes in the obstructed bladder, rabbit bladder was partially obstructed for up to 70 days and alterations in tension response to field stimulation and carbachol were compared with alterations in ultrastructure and innervation of detrusor smooth muscle (SM). The effect of partial outlet obstruction on the physiological responses to field stimulation (FS) (nerve mediated contraction) and carbachol (receptor mediated contraction) were correlated with the structure and innervation of the detrusor smooth muscle (SM) of the same animal during a 70 day period. 28 rabbits were subjected to 1 to 70 days of mild partial outlet obstruction. Sham operated rabbits were euthanized at 7, 14, 28, and 70 days post-obstruction. At each time period, isolated strips of bladder body were mounted in individual baths and the contractile response to FS and carbachol determined. Three additional strips from each bladder were fixed for electron microscopy. Bladder mass increased rapidly during the first 7 days after obstruction, was constant for the next 7 days, and then continued to increase gradually. Dysfunction of the contractile response to FS was noted as early as 3 days and progressively increased over the 70-day study period. The decrease in the response to FS increased at a significantly faster rate than the decrease in the contractile response to carbachol. In ultrastructure studies, at 3 and 7 days post-obstruction the majority of SM cells displayed the characteristics of hypertrophy. At 28 days some SM cells displayed loosely packed myofilaments and an irregular distribution of sarcoplasmic dense bodies. At 70 days swollen mitochondria were present in all cell types of the bladder wall. Evidence of axonal degeneration was first observed at 7 days post-obstruction and became more extensive thereafter. No evidence of mitotic figures, nerve growth cones or regenerating SM cells was observed. Prolonged partial bladder outflow obstruction is accompanied by a progressive decrease in contractility of SM. The present study describes the structural damage that occurs in the bladder wall in response to partial outlet obstruction and correlates these observations with the contractile dysfunction with which it is associated. Furthermore, mitochondrial damage in vessels and fibroblasts is suggestive of bladder wall ischemia.

INTERMITTENT CATHETERIZATION LIMITS RABBIT BLADDER DYSFUNCTION IN RESPONSE TO PARTIAL OUTLET OBSTRUCTION

The initial response of the urinary bladder to outflow partial obstruction consists of distension, followed by a rapid increase in mass and concomitant functional adaptations. Subsequently, an indeterminate period of stabilized function and little increase in mass occurs (compensation). Finally, bladder mass again progressively increases, accompanied by deleterious changes in bladder morphology, biochemistry and pharmacology, and progressive loss of function (decompensation). The reported study was designed to determine whether limiting the level of bladder distension, using intermittent catheterization (IntCath), could protect the bladder from decompensation. Sixteen male New Zealand White rabbits were separated into 4 groups of 4 rabbits each: control, control with IntCath, obstructed, and obstructed with IntCath. IntCath was performed with the animals under inhalation anesthesia. An 8 Fr. catheter was inserted through the urethra into the bladder every 8 hours and the urine drained. After 14 days of obstruction, bladders were removed from all rabbits; longitudinal strips were cut from the bladder body and suspended in individual organ baths. Contractile responses to field stimulation (FS), KCl, ATP, and carbachol were measured. There were no significant differences between control rabbits and controls with IntCath in bladder weights, compliance, and contractile responses to all stimuli. Bladder weights of both obstructed groups increased significantly compared to those of both control groups. Bladder weights of obstructed rabbits increased to a significantly greater extent than did those of obstructed rabbits with IntCath. Bladder compliance in the obstructed group was significantly lower than compliance in both control groups and in obstructed rabbits with IntCath. Both obstructed groups exhibited significantly decreased contractile responses to FS, ATP and KCl, compared to control groups. The response of the obstructed group with IntCath to FS and carbachol was significantly greater than the responses of the obstructed group without IntCath. These findings show that limiting distension with IntCath reduces the magnitudes of the increased bladder mass, the loss of bladder wall elasticity (compliance), and the impaired contractile responses which occur secondary to outflow obstruction.

Evaluation of ureteric contraction: a comparison among ring, spiral-cut and longitudinal segments.

To determine the optimal contractile response of isolated ureters to inflammatory mediators and neurotransmitters by evaluating four common methods of ureteric suspension. Ureters from adult domestic swine were placed immediately in Krebs buffer and cut into 4-5 mm segments. Four methods of suspension were compared: (i) an unopened ring segment suspended horizontally; (ii) a spirally cut segment (lumen cut open at a 45 degrees and suspended end-to-end); (iii) an open longitudinal segment; and (iv) a closed longitudinal segment. All segments were placed in individual water-jacketed tissue baths containing Krebs buffer, the frequency of contraction measured using a force transducer and registered on a polygraph. The sensitivity of all four segments was tested by measuring the tension and frequency in response to increasing frequencies of electric field stimulation, and by a cumulative concentration-response curve to carbachol. Ureteric segments responded with an increased frequency of contraction depending on the intensity of stimulus to both electric field stimulation and carbachol. However, there were no significant differences in spontaneous levels of contraction, sensitivity or maximal response among the methods of suspension in response to electric field stimulation or carbachol. These results indicate that all four methods of suspending the ureteric segments produce contractile responses sensitive enough to study the action of various neurotransmitters.

Local propagating Gaussians: flexible vs. frozen widths

Recently we presented a method for modeling a quantum system to a bath that explicitly correlates the system with the individual bath modes. We do this through representation of the bath by locally propagating Gaussians (LPG), which change in position and momentum but remain Gaussian in form. The explicit correlation of the system to the bath modes enters through the simultaneous use of a different Gaussian for each state (or grid point) of the system. In this work, we look at two possibilities for the LPG method. In the frozen LPG, the width of the Gaussians is kept constant. In the flexible LPG, we relax this condition and allow for the width to be both time dependent and complex. We present a comparative study of these two methods and compare them with both time-dependent self-consistent field calculations (TDSCF) and an exact quantum calculation. The two LPG methods, in comparison with TDSCF, more accurately describe the exact dynamics. The difference is especially noticeable in the case of weak coupling, where the averaging done in TDSCF is an oversimplification of the system.

A simple and accurate approximation for a coupled system-bath: locally propagating gaussians

A simple method that incorporates coupling between bath and system and between individual bath modes is proposed. In the new locally propagating gaussian (LPG) approximation, the bath is modeled by Gaussians at each system site that propagate in time. Each site couples to others by the overlap of their Gaussians. In a test case with weak but non-negligible coupling, LPG is nearly as rapid as TDSCF but more closely follows exact calculations. LPG can be extended to larger simulations. Strongly coupled system coordinates will be treated with a grid-type calculation and weakly coupled bath modes will be handled by LPG.

Digital Analysis of the Pharmacological Effects of in vitro Ischemia on Rabbit Corpus cavernosum

Purpose: Regulation of corporal smooth muscle tone is essential for the initiation of penile erection. In recent years, in vitro isometric tension studies using isolated corpus cavernosal tissue have been used extensively to investigate the mechanisms regulating corporal smooth muscle tone and tension. In the present study, we utilized digital analysis of contractile data generated from investigation of contractile and relaxation responses of isolated rabbit corpus cavenosum to various forms of stimulation. Digital analysis of the contractile and relaxation data allows quantitation of both maximal and mean rates of tension change, and time elapsed to maximal response. Rates of tension changes may provide additional important information regarding cellular events that mediate corporal tone and tension changes. Methods: Sexually mature male New Zealand White rabbits were used. Each corpus cavernosum was dissected sharply from the removed penis, then two longitudinal strips were prepared for isometric tension studies and placed in individual baths. Tension was monitored continually using an 8-channel Grass Polygraph. The Grass PolyVIEW system simultaneously converted analog signals to digital information and stored data using a 486 PC computer. Each corporal strip was prestimulated with 300 µmol/l phenylephrine to produce a maximal contraction, then field stimulation (FS), carbachol and nitroprusside were applied consecutively to determine relaxation effects. This procedure was repeated after strips were deprived of glucose and oxygen (in vitro ischemia) for 1 h. The following parameters were quantitated for all responses: maximal tension change; maximal and mean rates of tension change, and time to maximal response. Results: Effects of 1-hour in vitro ischemia on rabbit corporal tissue were as follows: (1) an 85% decrease in contractile response to phenylephrine, and (2) a marked increase in rate of contractile response to phenylephrine. Phenylephrine precontracted strips exhibited: (3) no change in relaxant response to FS; (4) increased relaxant responses to carbachol and nitroprusside; (5) no change in rates of relaxation in response to FS; (6) increased rates of relaxation in response to carbachol and nitroprusside, (7) no change in elapsed time to maximal relaxation in response to FS, and (8) decreased elapsed time to maximal relaxation in response to carbachol and nitroprusside. Conclusion: Digital analysis of the data generated facilitates recording, reviewing and analyzing of in vitro isometric tension studies on rabbit corpus cavernosum. Digital analysis allows quantification of additional parameters that have important implications for determination of mechanisms by which specific pathological processes occur.

Beneficial effects of Tadenan therapy after two weeks of partial obstruction in the rabbit.

Tadenan (Debat Laboratories, France) is a plant extract used in Europe for the treatment of micturition disorders associated with benign prostatic hypertrophy (BPH). Prior studies demonstrated that pretreatment of rabbits with Tadenan significantly reduced the contractile dysfunction observed after 2 weeks of partial outlet obstruction. The specific aim of the present study was to determine the effect of Tadenan therapy following the creation of partial outlet obstruction. Two sets of experiments were performed: one with mild and the other with severe outlet obstruction. For both sets of experiments, male New Zealand rabbits (3-5 kg) were separated into 3 groups of 5 rabbits each. Each rabbit in groups 1 and 2 was obstructed using standard methodology. Rabbits in group 3 served as controls and did not receive any surgery. After 2 weeks, each rabbit in group 1 received Tadenan orally at 100 mg/kg/day for 3 weeks; each rabbit in group 2 received vehicle (peanut oil). After 3 weeks of treatment (5 weeks after partial outlet obstruction), rabbits were anesthetized and cystometries were performed. Immediately after cystometry, the rabbits were euthanized, the bladder rapidly removed, and 4 longitudinal strips prepared and mounted in individual baths for contractile studies. The contractile responses to field stimulation, carbachol, adenosine-5'-triphosphate (ATP), and potassium chloride (KCl) were determined, as follows: (1) Bladder mass approximately doubled in the mildly obstructed groups. Bladder mass increased significantly (3-5-fold) in the severely obstructed groups. (2) Cystometrograms from the mildly obstructed rabbits treated with peanut oil showed low compliance, whereas those of the mildly obstructed rabbits treated with Tadenan showed normal compliance. The cystometrograms of all severely obstructed rabbits showed low compliance. (3) Mild obstruction caused small but significant decreases in the contractile response to field stimulation that were reversed by Tadenan treatment. No changes were noted in response to bethanechol, ATP, and KCl stimulation. (4) Severe obstruction caused significant decreases in the response of bladder strips to field stimulation and bethanechol. Following Tadenan therapy, there was a significant improvement in the response to high-frequency field stimulation and a substantial improvement in the response to bethanechol (response equal to control). No changes were noted in response to ATP and KCl stimulation. In conclusion, Tadenan treatment reversed the bladder dysfunctions induced by mild partial outlet obstruction, and resulted in improved bladder function in the severe model of outlet obstruction. These studies are consistent with previous studies showing that Tadenan pretreatment protects the bladder against the development of contractile dysfunctions.

Elution characteristics of vancomycin and tobramycin combined in acrylic bone—cement

Combining two antibiotics in antibiotic-loaded bone-cement is common in clinical practice. As the effect this has on elution characteristics is unknown, an in vivo quantitative elution study was carried out. Three groups of five antibiotic-loaded cement disks were prepared and placed in individual saline baths for 5 weeks. The elution of tobramycin from the disks in the study group (containing 2.4 g tobramycin and 1.0 g vancomycin per 40-g packet of Palacos-R cement powder [Smith & Nephew Orthopaedics, Memphis, TN]) was increased by 68% over that of the tobramycin control disks (2.4 g tobramycin only) ( P = .024). The release of vancomycin from the study group disks was increased by 103% over the vancomycin control disks (1.0 g vancomycin only) ( P = .007). Combining two antibiotics in bone—cement improves elution of both antibiotics in vitro and may translate into enhanced elution in vivo.

Effects of Tadenan Pretreatment on Bladder Physiology and Biochemistry Following Partial Outlet Obstruction

Purpose Tadenan is a pharmaceutical agent used in the treatment of BPH. Prior studies demonstrated that pretreatment of rabbits with Tadenan significantly reduced the contractile dysfunction following two weeks of partial outlet obstruction. The specific aim of the present study was to determine the effect of Tadenan pretreatment on the time course of the response to partial outlet obstruction and correlate the effect of Tadenan on the contractile responses to field stimulation, bethanechol, and KCl with both mitochondrial enzyme activity (citrate synthase) and sarcoplasmic reticular function (calcium-ATP'ase activity). Materials and Methods Sixty male New Zealands white rabbit (3 to 5 kg.) were separated into 12 groups of 5 rabbits each. Each rabbit in groups 1-6 received Tadenan orally at 100 mg./kg./day for three weeks; each rabbit in groups 7-12 received vehicle (peanut oil). Each rabbit in groups 2-6 and 8-12 received a partial outlet obstruction as described below. One group of Tadenan treated and one group of vehicle-treated rabbits were euthanized at 1, 3, 5, 7, and 14 days following partial outlet obstruction. The non-obstructed groups were studied after 4 weeks of drug or vehicle treatment. Each bladder was rapidly removed and weighed, and 3 longitudinal strips prepared and mounted in individual baths for contractile studies. The remainder of the bladder was frozen for biochemical analysis. The contractile response to field stimulation, bethanechol, and KCl were determined; and the enzyme activities of citrate synthase (marker for mitochondrial function) and calcium-ATP'ase (marker for sarcoplasmic reticulum) were determined. Results 1) Tadenan did not reduce the effect of partial outlet obstruction on bladder mass. 2) Although the contractile responses to all forms of stimulation were reduced at 1 day following partial outlet obstruction, Tadenan pretreatment resulted in a significant protective effect on the contractile responses to field stimulation, bethanechol, and KCl at 3, 5, 7, and 14 days of obstruction. 3) The activities of both citrate synthase and calcium ATP'ase were reduced significantly at 1 day following obstruction for both Tadenan treated and vehicle treated groups. The activities of both enzymes returned to near normal levels at 7 and 14 days for the Tadenan groups whereas the activities of both enzyme remained significantly reduced in the vehicle treated groups. Conclusions These results clearly demonstrate that Tadenan pretreatment protected the bladder from both the contractile and metabolic dysfunctions induced by partial outlet obstruction.

Physiological effects of a novel bioactive agent.

Urinary bladder smooth muscle contraction can be evaluated using field stimulation (neurohumoral transmission), carbachol (muscarinic stimulation), and KCl (direct membrane depolarization). We recently evaluated the activity of a novel organic chemical, macrocycle-1, on the contractile responses of the bladder to field stimulation, carbachol, and KCl. Isolated strips of rabbit bladder were mounted in individual baths containing 7.5 ml Tyrode's solution. The response to FS (1-32 Hz), carbachol (1 mumol/l), and KCl (120 mmol/l) were determined in the presence and absence of 3 different concentrations of macrocycle-1. Maximal tension, the rate of tension generation, the time to maximal tension, and the rate of decay following maximal tension were determined. The results can be summarized as follows: (1) In the absence of macrocycle-1, maximal tension and the maximal and mean rate of tension generation increased with frequency, whereas the time to maximal tension was constant. The rate of decay of tension following maximum tension was greater for 8, 16 and 32 Hz as compared to 1 or 2 Hz. (2) The maximal response to KCl was lower than either FS or carbachol. The maximal rates of tension generation for carbachol and KCl were lower than that of FS; and the rate of tension generation for KCl was lower than that of carbachol. The time to maximal stimulation for KCl was greater than that of either carbachol or FS. (3) Macrocycle-1 had a greater inhibitory effect on KCl stimulation than on carbachol stimulation; and a greater inhibitory effect on KCl and carbachol stimulation than on FS. (4) The rate of tension generation was more sensitive to macrocycle-1 inhibition than was the maximal tension responses to all methods of stimulation. Our current hypothesis is that macrocycle-1 is acting as an intracellular calcium buffer whose affinity constant and association rate does not interfere with rapid intracellular release mechanisms (FS) while it inhibits slow intracellular calcium release mechanisms (carbachol and KCl).

Pulmonary Hypertension in Acute Lung Injury Is Due to Impaired Vasodilation with Intact Vascular Contractility

The major hemodynamic feature of acute lung injury (ALI) is pulmonary hypertension. Both endothelial-dependent and -independent pulmonary vasorelaxation is impaired in ALI due to endotoxemia. We hypothesized that endotoxemia selectively impairs relaxation of the pulmonary artery but does not impair contractility of pulmonary vascular smooth muscle (VSM). Our purpose was to determine the effect of endotoxemia (ETX) on the contractile response of pulmonary VSM to (1) cellular depolarization (KCI), (2) α 1-adrenoreceptor stimulation (phenylephrine, PE), (3) 5HT 2 receptor stimulation (serotonin, 5HT), and (4) prostaglandin F 2α receptor stimulation. Pulmonary artery rings were isolated from rats 6 hr after injection of ETX, 20 mg/kg ip ( n ⩾ 6), or saline ( n ⩾ 6) and suspended on tensiometers in individual organ baths. Endothelial-dependent cGMP-mediated relaxation was determined using the receptor agonist acetylcholine (ACh) in rings preconstricted with PE. Dose-response curves were generated to each contractile agonist. Statistical comparison was performed using one-way ANOVA with post hoc Bonferonni-Dunn, P < 0.05 accepted as significant. Relaxation to ACh was 96.4 ± 1.3% in controls vs 21.4 ± 3.1% ( P ± 0.05) in endotoxin-treated rats. Endotoxin did not affect the maximal tension in response to the contractile agonists nor did it change the concentration required to produce 50% contraction (EC 50). From these data we conclude that endotoxemia causes a decrease in vasorelaxation to the endothelial-dependent receptor agonist acetylcholine but does not impair agonist-induced contractility of pulmonary VSM. This suggests that pulmonary hypertension in ALI is mediated by impairment of pulmonary vasodilation with preservation of VSM contractility.

Optical bistability and nonclassical photon counting statistics with few atoms

The behavior of a collection of atoms that are strongly coupled to a resonant cavity is numerically studied. Atoms and mode are coupled to individual heat baths. The mode is coupled to a classical driving field. The system exhibits interesting properties like optical bistability and nonclassical photon counting statistics.

Electrodeposition of Cu-Zn alloys from glucoheptonate baths

Cu-Zn alloy deposition processes from glucoheptonate baths have been studied by analysing the composition of deposits, measuring the current density-potential curves and measuring the absorption spectra of the bath. Alloying interactions during codeposition were discussed on the basis of partial current density-potential curves of each component and absorption spectra of the bath. Baths adjusted to pH 4.5 and 10.0 were studied. From the pH 4.5 bath, only copper was deposited at current densities below 0.5 A dm −2. At current densities above 0.5 A dm −2, however, the zinc content of deposits increased rapidly with increasing current density. The current density-potential curve of the pH 4.5 alloy bath was almost an algebraic sum of those of the individual baths and did not exhibit any alloying interactions. In contrast, the compositions of deposits from the pH 10.0 bath were almost constant over a wide range of current density from 0.5 to 2.0 A dm −2, and zinc was codeposited even at low current densities below 0.2 A dm −2. The partial current density-potential curve of copper exhibited a less noble (negative) shift with an addition of Zn 2+. This less noble shift is attributed to the formation of a more stable Cu 2+ complex species, on the basis of the change in the absorption spectra. However, the partial current density-potential curve of zinc was essentially unchanged in the presence of Cu 2+ except that the limiting current was increased. The difference in the limiting current was ascribed to the difference in the rate of mass transfer due to H 2 evolution.

Membrane Processing in the Metal Finishing Industry

Two important applications of membrane processing in the metal-finishing field are the use of reverse osmosis for electroplating waste treatment, and ultrafiltration for concentration of oily wastes prior to disposal. Waste waters from electroplating contain contaminants of high toxicity, but also of substantial potential value. Reverse osmosis has been used to close the loop on treatment of individual plating bath rinse waters, returning concentrates to the baths, and reusing purified water for rinsing. A discussion of advantages and limitations is presented for treatment of various plating baths. Reverse osmosis has also been used to concentrate electroplating shop mixed effluents, with up to 95 percent water recovery for reuse. The low-volume concentrate is dried for ultimate solids removal, and waste-water treatment becomes closed loop. Data are presented for this application. Spent oil-containing coolants present the metal-finishing industry with a difficult waste-treatment problem. Conventional disposal of the 1–5 percent emulsions by chemical destruction, incineration or contract hauling is expensive. Ultrafiltration has been employed to concentrate emulsions to over 50 percent oil. These are readily incinerated with no fuel addition required, and work has been done which shows that reuse of the oil either upgraded to a fuel or a lubricant is the best answer for the concentrate. Data are presented for concentration of several wastes.

The B.N.F. Jet-Test on Organic Bright Nickel Deposits

SynopsisThe rate of penetration of organic bright nickel deposits in the B.N.F. jet-test is shown to vary with the thickness of the deposit. Therefore, to determine thickness by this method it is necessary to use a calibration curve relating apparent and true thickness. Although minor variations in plating conditions have little effect, separate calibration curves are required for deposits from different proprietary solutions and there is some evidence that differences can arise between individual baths of nominally the same type. Unless the calibration can be checked on deposits from a given bath, it is therefore recommended that the jet test on organic bright nickel deposits be used primarily as an acceptance test of the “limit” type.