“Man and Biosphere” — Studies on Sikkim Himalayas. Part 2: Acute Toxity of Mixed Copper-Zinc Solutions on Common Carp,Cyprinus carpio (LINN.)

In batch experiments for 6 to 48 h, individuals of Cyprinus carpio (2 g individual weight) were exposed to mixed solutions of copper and zinc sulphate: pH = 6.3, temperature 15 °C, 6.8 mg/l O₂, 7.1 mg/l Ca²⁺, 0.7 mg/l Mg²⁺. The LC₅₀ for the individual substances on exposures of 24 and 48 h amount to 9.04 and 7.28 mg/l, resp., of Zn and 0.11 and 0.095 mg/l, resp., of Cu. The sum of the biological activity of the two kinds of metal ions is assessed according to MARKING'S index: at low concentrations of the mixed solutions the two metals show an additive effect, at higher concentrations a synergistic effect occurs.     

The acute toxicity of silver to some freshwater fishes

In the batch experiment with daily exchange of medium the acute toxicity of Ag from AgNO₃ to Channa punctatus, Lebistes reticulatus and Puntius sophore is determined over 12 to 96 h exposure. In general, the sensitivity of species increases in the order mentioned. The LC_{50, 96h} are 18.89 μg/l Ag for Channa punctatus, 7.55 μg/l Ag for Puntius sophore and 6.44 μg/l for Lebistes reticulatus. For 12 and 48 h exposure the values in the same order of species are: 62 and 30, 44 and 14 as well as 57 and 16 μg/l Ag.     

Tidal currents and residual currents at Norderney,Elbe 1, and Aussen-Eider lightships and their variation under the influence of prevailing winds

Summary Four hourly current-and wind observations during the years 1924–1927 at the German lightvessels Norderney, Elbe 1, and Aussen-Eider were subjected to harmonic analysis with emphasis on the influence of the wind on the residual as well as on the tidal current. The tidal current is strongest at Elbe 1 and weakest at Aussen-Eider. The half-monthly inequality of the current is strongly influenced by a ₂ tidal component. Wind influences the velocity, phase and duration of ebb-and flow current in a systematic way at Norderney and Elbe 1. Deviations from the mean tidal current are caused mainly by the change in wind direction rather than by wind velocity. The mean residual current is weak at the three stations. But wind driven currents have a velocity up to 5 times as great as the mean residual current and reverse their direction with the wind. The annual variation of the mean residual current, however, is caused only to a small part by the annual wind variation.Abbreviations used in this paper Gr. M. Tr. Greenwich moon transit, i.e. Greenwich civil time of the upper or lower transit of the moon through the meridian of Greenwich - C _n computed tidal current at M1/2Hn - C _n ^m computed mean tidal current at M1/2Hn - M _n Moon-half hour mean, i.e. mean of all current velocities observed during M1/2Hn - M.A. Moon age of an observation, true Greenwich time of Gr.M.Tr. directly preceeding the time of observation, expressed in 12 integral numbers, each representing M.A. falling in 12 different hourly intervals - M1/2H Moon-half hour, 1/2 of the interval between one moon transit and the next, i.e. 1/24 of 12h25m - R _n ^o ,R _n ^' ,R _n ^" residual current computed by harmonic analysis ofn M1/2H means of the mean current, the current at weak winds, and the current at strong winds respectively - d.o.f. degrees of freedom - standard deviation ofC _n fromM _n - ^* mean standard deviation ofC _n fromM _n for analysis with weighted means - A _o Standard error of the residual currentA _o - AB standard error of the harmonic coefficientsA ₁,B ₁,A ₂,B ₂,... - S ₂ Phase of the current componentS ₂     

A Study on the Effect of Temperature upon the Toxicity of Sodium Pentachlorophenate to the Freshwater Snail Viviparus bengalensis L.

The toxicity of Na-pentachlorophenate to Viviparus bengalensis is investigated by batch tests with daily exchange of medium in the temperature range between 19 °C (February), 27 °C (April), 32 °C (June) and 30 °C (August) at times of exposure between 12 and 96 h. In the range of higher concentrations, pronounced abnormalities in behaviour by secreting mucus and discharging eggs and embryos occur. The LC₅₀ are lowest for all times of exposure at 27 °C, whereas the times of survival with a given concentration are highest at 30 °C. From the LC_{50, 96h, 27°C} = 66 μg/l results a safe concentration of only 47 μg/l Na-pentachlorophenate for Viviparus bengalensis.     

Towards realistic flow modelling. Creation and evaluation of two-dimensional simulated porous media: An image analysis approach

This work is part of an attempt to quantify the relationship between the permeability tensor (K) and the micro-structure of natural porous media. A brief account is first provided of popular theories used to relate the micro-structure toK. Reasons for the lack of predictive power and restricted generality of current models are discussed. An alternative is an empirically based implicit model whereinK is expressed as a consequence of a few pore-types arising from the dynamics of depositional processes. The analytical form of that implicit model arises from evidence of universal association between pore-type and throat size in sandstones and carbonates. An explicit model, relying on the local change of scale technique is then addressed. That explicit model allows, from knowledge of the three-dimensional micro-geometry to calculateK explicitly without having recourse to any constitutive assumptions. The predictive and general character of the explicit model is underlined. The relevance of the change of scale technique is recalled to be contingent on the availability of rock-like three-dimensional synthetic media. A random stationary ergodic process is developed, that allows us to generate three-dimensional synthetic media from a two-dimensional autocorrelation functionr( _x , _y ) and associated probability density function measured on a single binary image. The focus of this work is to ensure the rock-like character of those synthetic media. This is done first through a direct approach:n two-dimensional synthetic media, derived from single set ( ,r( _x , _y )) yieldn permeability tensorsK _i-1,n ⁱ (calculated by the local change of scale) of the same order. This is a necessary condition to ensure thatr( _x , _y ) and carry all structural information relevant toK. The limits of this direct approach, in terms of required Central Process Unit time and Memory is underlined, raising the need for an alternative. This is done by comparing the pore-type content of a sandstone sample andn synthetic media derived fromr( _x , _y ) and measured on that sandstone-sample. Achievement of a good match ensures that the synthetic media comprise the fundamental structural level of all natural sandstones, that is a domainal structure of well-packed clusters of grains bounded by loose-packed pores.     

Biocides in Relation to Water Pollution. Part 2: Bioassay Studies of Few Biocides to a Fresh Water Fish,Channa gachua.

The present paper deals with the determination of LT_m values of zolone, rogor, sumithion and abate for Channa gachua by conducting static bioassay experiments. The TL_m values for zolone came out to be 0.08275 mg/l, 0.08225 mg/l, 0.0815 mg/l and 0.0810 mg/l; for rogor 5.155 mg/l; 4.955 mg/l, 4.65 mg/l and 4.475 mg/l; for sumithion 12.60 mg/l, 12.50 mg/l, 12.30 mg/l and 12.20 mg/l and for abate 217.25 mg/l, 225.575 mg/l, 221.575 mg/l and 217.25 mg/l for 24, 48, 72 and 96 hours, respectively. Relative susceptibility indicates that this fish is not susceptible to zolone and less to rogor, sumithion and abate, respectively. Present studies also show that increased temperature and pH increase the toxicity of all the biocides, but increased hardness of water decreases the toxicity of biocide solutions. The safe concentrations for zolone, rogor, sumithion and abate came out to be 0.02437 mg/l, 1.3733 mg/l, 3.6907 mg/l and 66.678 mg/l, respectively.     

Biocides in Relation to Water Pollution Part I: Bioassay Studies on the Effects of a few Biocides on Fresh Water Fish,Channa gachua

• - In the present paper the toxicity of four biocides, endrin, thiodon, malathion and phosvel, has been measured by performing static bioassay experiments with Channa gachua as test fish to establish the median Tolerance Limits (TL_m and TL₅₀).
• - The results of bioassay experiments indicate that the fish is harmed even at a very low concentration of these biocides. The values of TL_m are 0.0076, 0.0073, 0.00695 and 0.0068 for endrin; 0.01120, 0.01088, 0.01069 and 0.01064 for thiodon; 9.20, 8.10, 7.90 and 7.60 for malathion and 32.90, 32.10, 31.65 and 31.15 mg/l for phosvel for the time interval of 24, 48, 76 and 96 hours, respectively.
• - As indicated by TL_m's, endrin is most toxic and phosvel least. Thiodon and malathion came in a descending order between endrin and phosvel.
• - During bioassay studies, the effect of some variables, like temerature, pH and fish-size, on TL_m's has also been observed. They gave the following results.
• a) An increase in temperature increased the toxicity of all the biocides.
• b) An increase in pH decreased the TL_m as such, making the biocides more toxic to Channa gachua.
• c) For larger fishes, the biocide solutions were less toxic, but the same solutions were more toxic to fishes of a smaller size.
• - The safe harmless concentrations of endrin, thiodon, malathion and phosvel are - 0.00289 mg/l, 0.00337 mg/l, 1.88365 mg/l and 9.16736 mg/l, respectively.

     

Zytotoxikologische Untersuchung von Schadstoffen und Wasserblüten mit gefrierkonserviertem Bullensperma (Spermatest)

The method is based on the determination of the number of the nonmotile sperms and/or the lethally damaged sperms with the aid of the fluorescent dye primuline. Incubation takes place at a suspension density of 10.000/mm³… 38.000/mm³, at 40°C or 46 °C for 15… 60 min. During the test with sublimate the loss of motility amounts to 55% at 4 mg/l Hg²⁺, the LC₅₀ is 7.3 mg/l Hg²⁺. Phenyl-mercuric acetate causes the total loss of motility with 20 mg/l, the LC₅₀ is above 168 mg/l (equivalent to 100 mg/l Hg²⁺). The LC₅₀ of sodiumpentadecylmonosulphonate and dodecylpyridinchloride are 11.6 and 15.8 mg/l, resp. Filtrates of blooming of cyanophyceae on Baltic, having been digested by repeated freezing and thawing, with 1.5… 6.4 g/l dry matter showed motility losses of 30… 100 % for Nodularia spumigena, whereas no significant effect was produced by a filtrate of Microcystis aeruginosa with 28.2 g/l dry matter as well as water-blooming of Nodularia spumigena from the Small Jasmund Bodden.     

Adsorption Kinetic and Equilibrium Studies on Removal of Lead(II) onto Glutamic Acid/Sepiolite

In this study, a modified method was used to increase the adsorption of lead ions from aqueous solutions by using modified clay mineral on the laboratory scale. Adsorption experiments have been carried out on the use of both thermal activated sepiolite (TAS) and their glutamate/sepiolite modification (GS) as adsorbents. The experimental data was analyzed using adsorption kinetic models (pseudo first‐ and second‐order equations). The pseudo second‐order kinetic model fitted well to the kinetic data (R² ≥ 0.99). Then, the Freundlich and Langmuir models were applied to describe the uptake of Pb(II) on GS and the Langmuir isotherm model agrees well with the equilibrium experimental data (R² ≥ 0.97). The maximum adsorption capacity was observed to be 128.205 mg/g by GS according to the Langmuir equation. Desorption efficiency of the GS was studied by the batch method using EDTA, HCl, and HNO₃ solutions. Desorption of 69.18, 74.55, and 80% of Pb(II) from GS was achieved with 0.1 M EDTA, 0.1 M HCl, and 0.1 M HNO₃ solutions, respectively. FTIR analysis suggests the importance of functional groups such as amino, hydroxyl, and carboxyl during Pb(II) removal. SEM observations demonstrated that an important interaction at the lead‐modified sepiolite interface occurred during the adsorption process. In addition, the thermodynamic constants was calculated that the values of the Gibbs free energy (ΔG*), enthalpy (ΔH*), and entropy (ΔS*) of modification were 86.79 kJ/mol, ?18.91 kJ/mol, and ?354.70 J/mol/K, respectively. The negative value of ΔH* shows exothermic nature of adsorption.     

Einsatz einer konstruierten Mischkultur zur Verwertung von Mischsubstraten mit inhibierend wirkenden Substanzen

By way of introduction the general fundamentals and kinetic setups of the competitive and non-competitive as well as substrate inhibition of cultures of microorganisms are stated. Investigated on a laboratory scale is the degradation of liquid pig slurry in a 600-1 stirring fermenter with discontinuous addition (pO₂≧=30 = saturation) of methanol as external substrate by a yeast mixed culture of Metschnikowia and Pichia membranifaceans to utilize the steam-volatile fatty acids (12 g/l) and of Acetobacter methanolicus to utilize methanol. A stable fermentation with stable residual concentrations of 235 mg/l fatty acids, 142 mg/l mH₄-N an 100 … 300 mg/l methanol for aperiod of 2400 h can be achieved.     

水生高等植物马来眼子菜和金鱼藻的初级生产率(黑白瓶法)

用黑白瓶测氧法测定了水生高等植物马来眼子菜(竹叶眼子菜,Potamogeton malaianus)和金鱼藻(Ceratophyllum demersum)的初级生产。按单位鲜重或干重表示的毛生产率,马来眼子菜为0.43—1.50mg O_2/g FWt.h(3.76—13.03mg O_2/g DWt.h);金鱼藻为0.44—0.45mg O_2/g FWt.h(5.12—5.27mg O_2/g DWt.h)。净生产率则分别为0.15—1.44mg O_2/g FWt.h(1.31—12.51mg O_2/g DWt.h)和0.08—0.25mg O_2/g FWt.h(0.93—2.95mg O_2/g DWt.h)。讨论了测定时的样品重量和光照强度对生产率的影响。     

Hydraulics of runoff and loess loam deposition

On many more or less loamy soils, rill erosion is reported to start on slopes that are equal to or steeper than 2–3°; critical Froude numbers for the start of rill wash on these slopes vary between 2·0 and 3·0. This explains why colluvial deposition often occurs on slopes below 2–3°, when water spreads out at the downslope extremities of the rills. The critical hydraulic conditions for loess loam deposition were tested in the laboratory for slopes of 0·5° and 2°, applying unit-discharges (q) up to 10 cm²/s. It appeared from these experiments that for afterflow, without raindrop impact, deposition starts for critical load concentrations (c_cr) varying between several g/1 and about 60 g/l. Under rain c_cr amounts to a minimum value of 100–125 g/l and it increases when the runoff film becomes thinner. Nevertheless, deposition in pluvial runoff is also possible, as was the case during the Weichselian, according to data from quarries in Belgium and in The Netherlands. A modified Kalinske equation is proposed for c_cr prediction, with the introduction of a typical empirical coefficient C_r and considering such factors as shear stress and mean particle size. Massive sedimentation may occur when it stops raining and afterflow starts, since c_cr values are then much lower. It is shown from the Shields' diagram that loamy suspensions are more sensitive to sedimentation than sands in clear water.     

Aldrin Induced Changes in the Activities of Three Phosphatases of Macrobrachium lamarrei (H. Milne EDWARDS)

Macrobrachium lamarrei is exposed to 0.008, 0.017 and 0.021 mg/1 aldrin (0.4, 0.8 and 1.0 of the LC_50,96h) for 24… 96 h and after exposure the activities of the acid, alkaline and glucose-6-phosphatases are determined. With concentration and time of exposure the acid phosphatase shows an increasing activity up to 170 % compared with the control, which is interpreted as a part of prenecrotic changes in the cells. With concentration and time of exposure the alkaline phosphatase shows a decreasing activity down to 20 % of the control, which is indicative of considerable disturbances of the total metabolism. The glucose-6-phosphatase shows an increasing activity with the aldrin concentration up to 150 % during 72 h; then the activity drops to 60… 80 %. The initial rise in the glucose concentration of blood caused by that is the clear consequence of a stress reaction and the change of metabolism resulting from it.     

Propagation of surface waves on a nonhomogenous spherically aeolotropic shell

Summary This paper studies the propagation of Surface Waves on a spherically aeolotropic shell surrounded by vacuum. The elastic constantsc _ij and density of the material of the shell are assumed to be of the form _ij r ^l and _o r ^m respectively, where _{ij o} are constants andl, m are any integers.     

The derivatives of the lunar disturbing potential harmonics with respect to euler's angles

Summary The derivatives of the harmonicsP _n ^(k) (sin _O)cos kT_O andP _n ^(k) (sin _O)sin kT_O, occurring in the development of the lunar disturbing potential, are derived upto n=4 and for k== 0, 1, ..., n. The equatorial co-ordinates _OT_O are referred to the Moon's mass centre; the procedure for the solar disturbing potential is formally identical.     

Studies on the Germicidal Action of Ozone

Summary The germicidal action of highly dilute, aqueous ozone solutions has been investigated. Tests were performed with various bacteria and yeasts at ozone concentrations between 2 and 50 μg/l, and with fungus spores at concentrations between 50 and 350 μg/l. Survivor curves and the respective contact-time/concentration relations suggested the following sequence of test organisms with respect to increasing ozone tolerance:Escherichia coli ≤Streptococcus faecalis≤wine yeast(‘Champagne’)≤Mycobacterium tuberculosis var.avium≪Penicillium not atum (spores).     

Hydroxyl (6/2) airglow emission intensity ratios for rotational temperature determination

OH(6/2) Q1/P1 and R₁/P₁ airglow emission intensity ratios, for rotational states up to j = 4.5, are measured to be lower than implied by transition probabilities published by various authors including Mies, Langhoff et al. and Turnbull and Lowe. Experimentally determined relative values of j transitions yield OH(6/2) rotational temperatures 2 K lower than Langhoff et al., 7 K lower than Mies and 13 K lower than Turnbull and Lowe.     

On the ecology of Azolla filiculoides Lam. in Damietta district, Egypt

Azolla filiculoides Lam. is a tiny aquatic fern growing as free floating mats covering the stagnant water of the irrigation and drainage canals of Damietta district, Egypt. Ecological characteristics and distribution of the fern were investigated and results were discussed.Vegetation analysis of Azolla indicate that the most common associated species with Azolla are: Phragmites australis [presence (P) = 93.3%], Echinochloa stagnina (P = 70%), Eichhornia crassipes (P = 57%), Pluchea dioscoridis (P = 56.7%), Persicaria salicifolia (P = 26.7%), Phylla nodiflora (P = 13.3%) and Ludwigia stolonifera (P = 10%). Submerged species, e.g. Ceratophyllum spp. and Potamogeton spp. are completely absent in the stands dominated with solid mats of Azolla. This could be explained by that these mats prevent light penetration and oxygen which are required to submerged plants which in turn are decayed.The pH of the water where Azolla was recorded ranged from 7.1 to 9.0 (mean = 7.8), total dissolved salts ranged from 280 to 2600 mg/l (mean = 880 mg/l). The total phosphorus showed the range from 0.01 to 0.82 mg/l (mean = 0.22 mg/l). The ammonia-N is relatively high, varying from 2 to 18 mg/l (mean = 7.0 mg/l), however, the nitrate-N varied from 2.1 to 54.1 mg/l with a mean value of 20.5 mg/l.The fresh biomass of Azolla ranged from 114 to 4280 g/m² in irrigation canals and from 506 to 2760 g/m² in drainage canals. The dry biomass varied from 16 to 23 g/m² in irrigation canals. The range from 26 to 320 g/m² was obtained for drainage canals.     

Electromagnetic scattering by a perfectly conducting half-plane in a conductive half-space

FollowingDmitriev (1960) a rigorous theoretical solution for the problem of scattering by a perfectly conducting inclined half-plane buried in a uniform conductive half-space has been obtained for plane wave excitation. The resultant integral equation for the Laplace transform of scattering current in the half-plane is solved numerically by the method of successive approximation. The scattered fields at the surface of the half-space are found by integrating the half-space Green's function over the transform of the scattering current.The effects of depth of burial and inclination, of the half-plane on the scattered fields are studied in detail. An increase in the depth of burial leads to attenuation of the fields. Inclination introduces asymmetry in the field profiles beside affecting its magnitude. Depth of exploration is greater for quadrature component. An interpretation scheme based on a phasor diagram is presented for the VLF-EM method of exploration for rich vein deposits in a conductive terrain.List of symbols x, y, z Space co-ordinates - Half-space conductivity - ₀ Free-space permeability - Excitation frequency (angular) - T Time - h Depth of the half-plane - a Inclination of the half-plane - E _x x-Directed total electric field - E _x ^p x-Directed primary electric field - E _xo ^p x-Directed primary electric field atz=0 directly over the half-plane - H _y y-Component of total magnetic field - H _y ^p y-Component of primary magnetic field - H _y0 ^p y-Component of primary magnetic field atz=0 directly over the half-plane - H _z z-Component of total magnetic field - H _z ^p z-Component of primary magnetic field - J _x Surface density ofx-directed scattering current - G Green's function - k ₀,K Wave numbers - u,u ₀,u ₁,u ₂ Functions - Space co-ordinate - s Variable in transform domain - Variable of integration - Normalized scattering current - Laplace transform of - N Normalized - , ₀, ₁, ₂ Functions - t Variable of integration - Skin depth - H Total magnetic field - H ^p Primary magnetic field - H ₀ ^p Primary magnetic field atz=0 directly over the half-plane - M,Q,R,S,U,V Functions - N ₁,N ₂ Functions     

Polarographische Bestimmung von Schwermetallen im Klärschlamm

The differential-pulse polarography (DPP) and the stripping voltametry (SV) are investigated in detail with respect to their suitability for the quantitative detection of individual traces of heavy metals in sewage sludge. The results are checked on the basis of AAS analyses and by the standard-addition method. From the hydrochloric-acid extracts of fused sludge samples down to 1 μg/l can be detected by the SV, whereas the DPP reaches a sensitivity of 100 μg/l. The following basic electrolytes are used: Zn: 2 … 3 mol/l H₃PO₄; Cu: 0.4 mol/l K₂CO₃, 0.2 mol/l Na-K-tartrate, 0.1 mol/l HCl; Ni: 1 mol/l NH₄OH, 1 mol/l NH₄Cl, 25 ml/l triethylamine; Pb and Cd: 0.1 … 0.2 mol/l HCl.