Disintegration Energy Research Articles

Investigating mechanisms deteriorating the dispersibility of biodegradable and flushable wet wipes

Wet wipe dispersibility is broadly discussed since they have been detected in massive fatbergs that were found in sewer systems of big cities, e.g., London. Dispersibility describes a wet wipe’s ability to disintegrate into its fibres after being flushed in the toilet. Recently it has been found that this dispersibility of pilot-scale produced wet wipes can reduce when stored in a wet condition. This phenomenon is called dispersibility ageing. With this work we give a first approach on analysing the underlying mechanisms causing this solidification of wet wipes by measurement of the water-fibre-interactions and the mechanical strength of the wipes. Long-term swelling of the wood pulp is discussed as a possible root cause for the observed loss in dispersibility. Wet strength theory was used to find three possible mechanisms that are able to explain increased strength as a result of swelling: knot-tightening, increased friction and interdiffusion. To investigate the strength behaviour of wet wipes over wet storage time, tensile testing and a new approach to measure the disintegration energy of these fabrics were used to find a time-dependent increased mechanical characteristic. Surprisingly no increase in wet strength or disintegration energy—measured by short span, low test speed wet tensile energy absorption—over wet storage time was found. The dispersibility ageing effect of wet wipes is seemingly not measurable using mechanical testing. It seems that these test methods are not representative for the loading situation during disintegration in the sewer system and in the standard disintegration tester.Graphical abstract

SIMULASI AKTIVITAS KESTABILAN INTI PELURUHAN DERET NEPTUNIUM DENGAN PENDEKATAN ENERGI IKAT INTI MODEL TETES CAIRAN

The purpose of this study was to calculate the activity, binding energy, and disintegration energy produced by the decay of radioactive substances in the Neptunium series based on the liquid drop core model. The research steps: 1) prepare supporting data for research on activity and binding energy on nuclear stability decay; 2) review the material that has been obtained; 3) perform calculation simulations; 4) analyze and discuss the calculation results; 5) conclude the research results. The conclusion in this study is that the activity value has increased linearly with a range of values ​​from Bq to Bq. The binding energy decreased linearly with values ​​ranging from 1797.4088 MeV to 1627.7112 MeV. Meanwhile, the binding energy of the nucleons increases linearly. The disintegration energy in the Neptunium series has the largest positive value (Q>0) of 5.2712 MeV and the smallest disintegration energy of Radium-225 which is -0.4317 MeV. 
 Keyword : The activity, binding energy, liquid drop model

Prediction of half-lives of even–even superheavy nuclei

α-decay half-lives (-values) of even–even and superheavy nuclei (SHN) are determined employing interaction potential involving Coulomb and proximity potentials. The obtained results are compared with the experimental ones and to assess the precision of the present model in reproducing the experimental half-lives, a comparison is drawn with the other methods as well. We require disintegration energy (Q α -values) as an input in order to predict the (-values) of an experimentally unknown SHN. So, utilizing periodic-orbit theory within microscopic-macroscopic formalism, we have calculated the binding energies and thereafter, Q α -values of known SHN. The results are found to be in good agreement with the experimental ones. Subsequently, we predict the logarithmic values of ’s for even–even unknown SHN whose atomic numbers lie in 118 ⩽ Z ⩽ 126 regime and compare our results with those calculated employing other theoretical methods. Also, the study of spontaneous fission half-lives and branching ratios leads us to predict the SHN which can be identified through α-decay chains in the laboratories. We believe that this work can play a significant role in the experiments leading to the synthesis and identification of new superheavy elements.

SIMULASI ENERGI IKAT DAN ENERGI DISINTEGRASI PELURUHAN UNSUR RADIOAKTIF DERET AKTINIUM BERDASARKAN MODEL INTI TETESAN CAIRAN (TELAAH KLASIK)

The purpose of this research is to make simulation with Matlab application to calculate the binding energy and disintegration energy of Actinium series based of liquid drop model approach. This research is experimental description. The steps: 1) prepare literature studies of elements in the radioactive process; 2) reviewing some literatures; 3) do calculation simulation; 4) analyze and discuss the results of calculations; 5) conclude the research results. The calculation results show that the binding energy value of the Actinium Series based of liquid drop model approach is in accordance with the theory where the binding energy is directly proportional to the mass and the number of particles, so that the binding energy decreases in linear graph. The largest binding energy owned by 92U235 element is 1786,751 MeV. While the smallest binding energy owned by the 81Tl20 element is 1616,311 MeV. The disintegration energy found in the radioactive actinium series has a positive value, so this is in accordance with the conditions for the occurrence of decay, which is Q> 0. The largest disintegration energy produced from alpha decay by element 91Pa231 is 4.9335 MeV and the smallest binding energy generated from beta decay by the element 90Th231 is 0,0018 MeV.
 
 Key Word: Disintegration Energy, Binding Energy, Liquid Drop Model Approach.

Influence of Excess Biological Sludge Disintegration Processes on Pharmaceutical Compounds, Hormones and PAH Concentrations from Anaerobic Stabilized Sludge

This paper shows the influence of certain biological sludge disintegration processes over the concentrations of emerging pollutants, including classes of structurally different compounds such as pharmaceuticals, hormones and polycyclic aromatic hydrocarbons from anaerobic stabilized sludge. Three processes for sludge disintegration were tested: ultrasonic, ultrasonic + electrokinetic and ultrasonic + electrokinetic + microbubble generation. Activated sludge from an urban wastewater treatment plant was used in the experiments. Both pharmaceuticals from the analgesic and antipyretic classes, as well as the identified hormones (estrone) and polycyclic aromatic hydrocarbons (PAHs), were sensitive to the disintegration processes applied, the experimental results showing the decrease of their concentration correlated with the increase of the disintegration energy.

Solubilisation of fruits and vegetable dregs through surfactant mediated sonic disintegration: impact on biomethane potential and energy ratio

ABSTRACT This study investigates the symbiotic effect of cetyltrimethylammonium bromide (CTAB) coupled with sonication of fruits and vegetable dregs (FVD) on disintegration and subsequent energy efficient methane production. The liquefaction of FVD experiments was conducted by varying dosage of surfactant from 0.001to 0.01 g/g SS for 60 min in mechanical shaker. The optimised dosage of surfactant was combined with sonication. Finally, the combined pretreatment and sole pretreatment were assessed using methane potential assay. The results revealed that at optimised conditions (sonication specific energy of 5400 kJ/kg TS, CTAB dosage of 0.006 g/g SS), the maximum liquefiable organics release rate and solids reduction of CTAB mediated sonic disintegration (CSD) were found respectively to be 27% and 17% more than the ultrasonic disintegration (16% and 10%). CSD was noticed to be superior than ultrasonic disintegration (UD) based on highest volatile fatty acid yield (2000 mg/L vs. 1250 mg/L) and biochemical methane potential (203 mL/g COD vs. 144 mL/g COD). CSD achieved energy ratio of 0.9 which is greater than ultrasonic disintegration energy ratio 0.4.

Monte-Carlo simulations of electrostatic self-charging of tritiated tungsten and beryllium particles

The electrostatic self-charging rate of tokamak dust is investigated using Geant4, a toolkit for the simulation of the passage of particles through matter. To do so, the particles geometrical characteristics, the β disintegration energy spectrum and the deepness of tritium infusion are taken into account. The investigated materials are tungsten and beryllium, the plasma facing components (PFC) of ITER, considered as spherical particles from 20 nm to 200 μm in diameter, both tritiated. Two cases of tritium distribution in the particles are examined. On the one hand, tritium is homogeneously distributed over the whole sphere; on the other hand, tritium is homogeneously distributed within the external 100 nm layer of the sphere. The self-charging rate is assessed through the calculation of the particle exiting electron rate. Based on a tritium inventory of 10 GBq/g, relevant for ITER tokamak environment, our results show that, for a single tungsten or beryllium particle of 10 μm in diameter, the self-charging rate when the tritium is homogeneously distributed within the whole sphere is respectively 2.4 and 1.9 positive elementary charges per second. In the configuration where the tritium absorption is confined in the external 100 nm layer, the charge magnitude raises up to 37.1 and 8.4 respectively.

Study of central and non-central collisions in billiard games

The purpose of the billiard games is to enter the object ball into the billiard table hole. If the hole position is aligned straight with the cue ball and object ball then the player can hit it centrally, but when the cue ball and object ball positions are not straight towards the hole then the player must hit the object ball in a non-central manner so that the ball object can bounce off by forming a certain angle and into the hole. The difference in object ball direction after the collision is an application of the collision concept that is a central collision and non-central collision. There has been a study of central and non-central collision reviews on billiard games to find out the validity of the law of conservation of momentum, coefficients of restitution (e) and disintegration energy (Q). The data in this study was obtained by using an application tracker video analysis. The result of this study shows that on central collision in the billiard game the law of conservation of momentum is not applicable, e ≤ 0,510 and Q = –0,00786 Joule. In the non-central collision, the law of conservation of momentum is not applicable, e ≤ 0,537 and Q = –0,00605 Joule. The central and non-central collision in billiard games does not apply the law of conservation of momentum because it is influenced by many factors including the limited accuracy of the tracker application and the effects of external forces.

Failure mechanism and numerical simulation of zonal disintegration around a deep tunnel under high stress

The zonal disintegration phenomena in deep rock mass will appear with the increase of underground engineering depth which is widely different from shallow cavern. In order to reveal the formation mechanism of zonal disintegration, the geomechanical model test and numerical simulation of zonal disintegration are carried out respectively. Taking the deep tunnel of Dingji coal mine in China's Huainan coal mine as engineering background, a 3D geomechanical model test is carried out relying on the high stress 3D loading test system. The zonal disintegration phenomenon is observed, and the oscillation law of displacement and strain are measured. Based on the strain gradient theory and continuum damage mechanics, the zonal disintegration elastic damage-softening model is established. The relationship between rock failure and energy dissipation is analyzed. According to the strain energy density theory, the zonal disintegration energy damage failure criterion based on strain gradient is established. A numerical analysis method for zonal disintegration is proposed, the zonal disintegration calculation program is developed based on a commercial finite element code. The results of numerical simulation and the 3D geomechanical model test are basically consistent.

Atomistic molecular dynamics simulations on the interaction of TEMPO-oxidized cellulose nanofibrils in water

Atomistic molecular dynamics simulations were carried out to obtain information on the rheological, aggregation and disintegration properties of carboxylated (TEMPO-oxidized) cellulose nanofibrils with different functionalization levels. The magnitude of the inter-fibril interaction was quantified for parallel nanofibrils using the umbrella sampling method. The obtained potential of mean force was found highly sensitive to the charge configuration for intermediate functionalization levels. This feature was further studied with an electrostatic model for similar charge configurations and system periodicity as in the case of the molecular dynamics simulations. The electrostatic contribution of the charged surfaces varied from repulsive to attractive depending on the distribution of the carboxylate groups and nearby counter-ions, as well as the distance between the fibrils. The simulated deviations from average behavior for single fibrils in both models suggest heterogeneity in their aggregation and disintegration behavior. This was seen in disintegration experiments, where the differences in disintegration energy and in the structural variation qualitatively agreed with the model predictions. As to aggregation behavior, the studied case with parallel fibrils reflects the upper boundary of the repulsive interaction.

Disintegration energy of sensitive clays

The accurate assessment or prediction of landslides in sensitive clays is not a straightforward task due to the complexity associated with understanding such material during the sliding process. There have, however, been several attempts to assess flow slide potentials by looking at certain aspects of sensitive clays, one of which is studying the energy involved in the disintegration of sensitive clays from an intact to a remoulded state. This energy is referred to as disintegration energy (DE). Here, an analytical approach is proposed to evaluate the DE of sensitive clays based on an integrated study of strength and stiffness properties of sensitive clays in intact and remoulded states. The proposed approach is illustrated by studying the DE involved in Norwegian landslides. In addition, the proposed equation is shown to be in line with an equation used for Canadian sensitive clays. Furthermore, this article attempts to illustrate that the extent of flow slides is related to the DE involved in sensitive clays using five selected Norwegian landslides. The study shows that the amount of required DE can be used to estimate the extent of landslides in soft sensitive clays.

Characterization of powder mixers based on mechanical energy using soft dye granules

Abstract In this paper, we have proposed a method to characterize various types of powder mixers based on the mechanical energy applied to the powders during the mixing operation using the soft dye granules (the agglomerates of fine Fe 2O 3 particles) as a stress-sensing material (SSM). The disintegration process of Fe 2O 3 agglomerates in the bulk CaCO 3 powder was expressed by means of a simplified comminution model and the fracture of agglomerates was dealt with as well as that of brittle materials. The energy required to disintegrate the Fe 2O 3 agglomerates was estimated in a high-speed agitating-type mixer and related to the mixing time. The disintegration energy in a bead mill agreed with the net applied energy estimated by using spherical copper particles as a SSM. It has been proved that the mechanical energy is quantitatively evaluated in various powder mixers. By using the change in the disintegration energy with the mixing time, i.e. the energy characteristic curve, the powder mixers can be characterized on the uniform scale of mechanical energy regardless of equipment structure and the principal mixing mechanism in each mixer can be clarified.

Early history of development of boron neutron capture therapy of tumors.

The stable isotope 10B has a peculiarly marked avidity to capture slow neutrons whereupon it disintegrates into a lithium and a helium atom. These give up the 2.4 MeV of disintegration energy which they share within 5 and 9 microns of the 10B atom respectively. This means that the cell closest to the 10B atom bears the brunt of its atomic explosion. The objective of the tumor therapist is to find a carrier molecule for the boron atom which will concentrate in the tumor. Although a number of investigators saw the peculiar advantage of this selective tactic to achieve destruction of a species of unwanted cells, no success in animal studies was achieved until 1950. Sweet and colleagues found that the capillary blood-brain barrier keeps many substances out of the normal brain but that the gliomas had much less of such a barrier. He, Brownell, Soloway and Hatanaka in Boston together with Farr. Godwin, Robertson, Stickley. Konikowski and others at the Brookhaven. National Laboratory worked partially in collaboration and partly independently. We irradiated at 3 nuclear reactors several series of glioma patients with no long-term remission, much less a cure being achieved. Hatanaka on his return to Japan kept BNCT alive by treating a total of 140 patients with various brain tumors. Beginning in 1972, Mishima and colleagues have achieved useful concentrations of 10B-borono-phenylalanine, an analogue of the melanin precursor tyrosine, for BNCT of melanomas.

Dependence of the disintegration (fission) energy of the ground states of isotopic nuclei with Jπ=const on the reduced mass of the daughter fragments

It is shown that the S-matrix formalism of the two-fragment problem for variable values of the reduced mass μ may be suitable for describing the disintegration of the ground states of composite isotopic systems with Jπ =const along channels which contian n (n>2) daughter fragments.

CJ90-31. Elastoplastic and shakedown analyses of a disc subjected to varying acceleration : By Pan Ligonget al. (Qinghua University, Beijing, China). Chinese J. Mech. Engng26, No. 2 (April, 1990), pp. 96–98

The zonal disintegration phenomena in deep rock mass will appear with the increase of underground engineering depth which is widely different from shallow cavern. In order to reveal the formation mechanism of zonal disintegration, the geomechanical model test and numerical simulation of zonal disintegration are carried out respectively. Taking the deep tunnel of Dingji coal mine in China's Huainan coal mine as engineering background, a 3D geomechanical model test is carried out relying on the high stress 3D loading test system. The zonal disintegration phenomenon is observed, and the oscillation law of displacement and strain are measured. Based on the strain gradient theory and continuum damage mechanics, the zonal disintegration elastic damage-softening model is established. The relationship between rock failure and energy dissipation is analyzed. According to the strain energy density theory, the zonal disintegration energy damage failure criterion based on strain gradient is established. A numerical analysis method for zonal disintegration is proposed, the zonal disintegration calculation program is developed based on a commercial finite element code. The results of numerical simulation and the 3D geomechanical model test are basically consistent.

The Radiobiology of Targeted Radiotherapy

Targeted radiotherapy consists of biologically selective irradiation of malignant cells by means of radionuclides attached to tumour-seeking molecules. A variety of clinical strategies for targeted radiotherapy may be used, for which different normal tissues will be critical. A large number of radionuclides exist, emitting nuclear particles with a range of path lengths from nanometres to millimetres. An important feature of normal-tissue radiobiology is the dose-rate effect, which is especially marked for late-responding tissues. Radiobiological calculations imply that tolerance dose for targeted radiotherapy using low-LET emitters will depend strongly on the effective half-life of the radionuclide, which will be affected by pharmacokinetics and may vary between patients. Some strategies designed to improve the therapeutic radio (e.g. accelerated clearance of radionuclide) may have modulating effects on the tolerance dose. Tumour response will be governed by the 'four Rs' (repair, repopulation, reoxygenation, redistribution) as well as by mechanisms peculiar to targeted radiotherapy. Analysis based on the extended linear quadratic model predicts that dose-rate effects will be of major importance for only a minority of tumours. Most of the radiation dose to tumour will usually be delivered over a time-scale of a few days. This might give insufficient time for tumour reoxygenation, making the use of hypoxic sensitizers appropriate. A special feature of targeted radiotherapy is the complex relationship between tumour curability and tumour size for different radionuclides. For long-range beta-emitters, microscopic tumours may be operationally resistant because of inefficient absorption of radionuclide disintegration energy in small volumes. Short-range emitters will be more efficient in sterilization of micrometastases but sterilization of larger tumours may require an unattainable degree of homogeneity of radionuclide distribution. Optimal use of targeted radiotherapy may require it to be combined with external-beam irradiation or chemotherapy. Experimental studies will be necessary to investigate those features of targeted radiotherapy which differ from external-beam irradiation. Future directions may include targeted radiotherapy of minimal numbers of tumour cells detected by use of molecular probes. Such applications call for use of short-range alpha-emitters and Auger emitters whose radiobiology will become increasingly important.

Disintegration Energy of Ferrocene Crystal in Triclinic Phase and Kinetic Study on Monotropic Transition from Monoclinic to Orthorhombic Phase

Abstract Cooling of single crystals of ferrocene below the λ-type phase transition at 163.9 K leads to crystal disintegration with explosive violence independently of the λ-type transition. The strain energy evolved at the disintegration (“the disintegration energy” for short) was determined to be (1.10 ± 0.11) kJ mol–1 by a drop calorimetry system using a low-temperature Calvet microcalorimeter. The disintegration energy was independent of the crystal size with four sieve fractions in the range 2.5–0.25 mm. The violent disintegration is interpreted here in terms of an energy transfer from the strain energy accumulated in the domain boundaries in a form of elastic energy to the kinetic energy of disintegrated crystallites. The speed of a crystallite with the grain size of 60–70 pm was estimated to be 110 m s 1. On the other hand, kinetic aspect of a monotropic transition from the undercooled monoclinic to the stable orthorhombic phase at around 190 K. has been investigated with the same drop calorimetry s...

Levels in 206Po populated in the EC-β+ decay of 206At

Levels of 84206Po122 excited in the positon decay of 85206At121 have been studied. Measured were γ-rays, conversion electrons, positons and γ-γ coincidences. Energies and relative intensities of 60 γ-rays following the decay of 206At have been measured. The positon spectrum was found to contain two branches. The total disintegration energy is 5 687±150 keV. Conversion coefficients and multipolarities of the strongest transitions have been determined. The existence of levels with the following energies in keV (spin-parities in parentheses) was deduced: 700.66(2+); 1 177.76(4+); 1 434.34(4+); 1 573.30(6+); 1 915.81; 2 100.73(4,5-); 2 138.85(4,5,6+); 2 302.57; 2 500.50; 2 581.69; 2 916.97(5,6+); 3 361.83; 3 396.45; 3 595.45(5,6+); 3 872.11; 4 038.80; 4 409.92; 4 419.53 and 4 697.84. The half-life of 206At was measured to be 29.3±0.4 m. The spin-parity of the 206At ground-state is found to be 5+.

Half-life ofPu242from precise low-temperature heat capacity measurements

Heat capacity measurements on three pure compounds, PuF/sub 3/, PuF/sub 4/, and PuO/sub 2/, made from 99.91 at.% /sup 242/Pu, have been used to evaluate the power produced by radioactive decay. The mean specific power was found to be (0.12099 +- 0.00024) mW per gram of plutonium in the samples. The contribution of nuclides other than /sup 242/Pu to the power was calculated to be (5.15 +- 0.11) ..mu..W per gram of plutonium, and so the specific power of pure /sup 242/Pu is (0.115 94 +- 0.000 26) mW g/sup -1/. A correction for the (5.50 x 10/sup -4/) % spontaneous fission branching reduces the specific power due to ..cap alpha.. decay to (0.11591 +- 0.00026) mW g/sup -1/. Combining this value of the specific power with the total disintegration energy of (4.9823 +- 0.0012) MeV, we obtain (3.763 +- 0.009) x 10/sup 5/ years as the ..cap alpha.. half-life of pure /sup 242/Pu. (AIP)

Future Regard to the Atomic Waste Disposal Problem

AbstractThe waste disposal in an ice sheet need not rely on storage periods longer than some hundreds of years. Three hundred years after dumping, the radioactive power of the fission products has decreased to about 10-4 times the value of two-year-old waste. Six hundred years after dumping, it has decreased to about 10-6 times the two-year value. There are only four radioactive fission.isotopes with half-lives between six years and 60000 years: 85Kr (10 years) has practically disintegrated after 300 years. 90Sr (with its daughter 90Y) and 137Cs (both 30 years) are reduced to 10-3 after 300 years and to 10-6 after 600 years. 151Sm (85 years) has an extremely low disintegration energy; the waste contains only a very small percentage of this isotope.Radiation and thermal power of all fission products with long half-lives (more than 60 000 years) are many orders of magnitude smaller than those of all other fission products in waste that has been stored for several years. Furthermore, long-lived fission products have almost no radiation other than β-radiation. Future research is necessary as to whether and to what extent such long-lived isotopes, and possibly other isotopes (c.g. 239Pu or 14C), have to be separated and as to how it could be done in the safest and most economical way. The technology of separating and recycling 239Pu, an extremely valuable fissionable fuel, is being developed in view of the increasing importance of breeder reactors. The separate disposal of long-lived isotopes would not raise serious thermal or handling problems; for example, they could be deposited in a highly concentrated form into a deep geological formationShould the waste be retrievable or not? That is ultimately a philosophical question. Which is more reliable, man or Nature? Should we trust that our descendants will have sufficient knowledge and goodwill to keep the waste safe and not misuse it—or should we rely more on Nature not to bring the waste into the biosphere by unexpected catastrophic events ?The proposed ice-sheet disposal—be it in deep ice layers or near the surface—avoids the main dangers of both aspects. Under normal glaciological conditions the waste containers are practically irretrievable from the beginning (deep-layer deposit) or after some centuries (near-surface deposit). If, however, a catastrophic climatic change should melt away the ice sheets very quickly, the ablation melts off one after the other of the upper layers while the deep layers still remain cold. Under these circumstances the containers are “self-retrieving”: they come to the surface of (the ice or of the ice-freed bedrock and can easily be picked up. Further research on such a melt-out process and on the durability of the waste containers and their solidified contents should be carried out.