2,194 research outputs found
The Use of Electrocoagulation as a Flocculating Aide for Deinking
The effects of electrocoagulation as a flocculating aide for deinking was evaluated using a homemade electrode unit. The unit was inserted into a laboratory-size Voith-Morden forced-air flotation cell. The process of electrocoagulation involves two steps:
1. Reducing the zeta potential of the system to 0.0 mV by pH adjustment.
2. The passing of current through the stock suspension which causes the electrolysis of the water, and thus hydrogen and oxygen gas bubbles are produced. These gas bubbles collect ink particles to form solid-gas composites which can be removed more easily using flotation.
The process was evaluated on the forced-air flotation process using brightness and microscope analysis. A relationship of deinking efficiency and shive analysis was sought, but did not prove informative. The results of the microscopic analysis and brightness measurements of the electrocoagulated stock illustrated the process has a detrimental effect on forced-air flotation system. It was determined, with further investigation, that the acid pH of the system was what was causing the detrimental effects. This suggested a more in depth look at the effects of pH on deinking; however, time was not available. The process could not be carried out under alkaline conditions due to the plating of ink on the electrodes and the degradation of the aluminum under alkaline conditions
The Use Of Marine Sponge Crude Extract To Improve The Resistance Of Tilapia Fish (Oreochromis niloticus) To Streptococcus agalactiae Infections
This study aims to examine the effect of the use of crude marine sponge extract on the resistance of streptococcus agalactiae infection in tilapia, Oreochromis niloticus, and to establish the effective dose of crude sponge extract in improving the immune system and the growth of the fish. The sponge used in the study was Cribrochalina sp. taken from Malalayang waters, Manado. The fish were taken from Freshwater Aquaculture Center, Tatelu. The fish were acclimatized for a week. After being acclimatized the fish were given feed added with sponge crude extract as a treatment with different concentrations of 20 g, 40 g and 60 g / Kg of feed for 14 days as much as 5% / body weight / day with the frequency of feeding twice a day at 10:00 am and at 5:00 p.m. After being treated, the fish was challenged with S. agalactiae. The data collected consisted of tilapia resistance, Total Leukocyte Count (TLC) as immune parameters and absolute growth. The results showed that the addition of crude extracts of Cribrochalina sp. into feed can increase TLC and growth of tilapia (p <0.05). The best results were achieved in fish fed with the addition of sponge crude extract of 40 g/kg feed. The survival rate of tilapia fed with treatment diet then challenged with pathogenic bacteria S. agalactiae showed the best results (100% survival rate) compared to controls (75%). In conclusion, feeding with a crude extract of Cribrochalina sp. has the potential to increase the immune system and growth of tilapia.Keywords: Crude Extract, Marine Sponges, Cribrochalina sp., Tilapia, Resistance, Streptococcus agalactiaeABSTRAKPenelitian ini bertujuan untuk mengkaji pengaruh penggunaan ekstrak kasar spons laut terhadap resistensi ikan nila dalam menghadapi serangan Streptococcus agalactiae, mengidentifikasi spons yang digunakan, serta mengukur pengaruh serta menetapkan dosis pemberian ekstrak kasar spons untuk meningkatkan sistem imun dan pengaruhnya terhadap pertumbuhan ikan nila. Spons yang digunakan dalam penelitian adalah spons Cribrochalina sp. yang diambil dari perairan Malalayang. Ikan uji diambil dari Balai Budidaya Air Tawar Tatelu, Provinsi Sulawesi Utara. Ikan diaklimatisasi selama seminggu. Setelah diaklimatisasi ikan diberi pakan yang ditambahkan dengan ekstrak kasar spons sebagai perlakuan dengan konsentrasi berbeda yaitu 0 g, 20 g, 40 g dan 60 g/kg pakan selama 14 hari sebanyak 5%/berat tubuh/hari dengan frekuensi pemberian pakan dua kali sehari yaitu jam 10.00 pagi dan jam 17.00 sore. Setelah diberi perlakuan, ikan diuji tantang dengan bakteri S. agalactiae. Data yang dikumpulkan terdiri dari kelangsunganhidup ikan nila. Total leukosit sebagai parameter imun dan pertumbuhan mutlak. Hasil penelitian mendapatkan bahwa penambahan ekstrak kasar spons Cribrochalina sp. ke dalam pakan mampu meningkatkan total leukosit dan pertumbuhan ikan nila (p<0.05). Dimana hasil terbaik dicapai pada ikan yang diberi pakan dengan penambahan ekstrak kasar spons sebanyak 40 g/kg pakan. Kelangsungan hidup ikan nila yang diberi pakan perlakuan yang diuji tantang dengan bakteri patogen menunjukkan hasil yang paling baik (tingkat kelangsungan hidup 100%) dibandingkan dengan kontrol (75%). Sebagai kesimpulan bahwa pemberian pakan dengan ekstrak kasar spons Cribrochalina sp. berpotensi untuk meningkatkan sistem kekebalan tubuh dan pertumbuhan pada ikan nila.Kata Kunci: Ekstrak kasar, Spons laut, Cribrochalina sp., Tilapia, Resistensi, Streptococcus agalactia
Plasma flow in an argon cascade arc
A model is described for the plasma flow in an Ar cascade arc which takes into account the heating and pressure effects. As the pressure increases the elec. field increases and the arc temp. decreases. The results agree with exptl. detns. [on SciFinder (R)
On anomalous diffusion in a plasma in velocity space
The problem of anomalous diffusion in momentum space is considered for
plasma-like systems on the basis of a new collision integral, which is
appropriate for consideration of the probability transition function (PTF) with
long tails in momentum space. The generalized Fokker-Planck equation for
description of diffusion (in momentum space) of particles (ions, grains etc.)
in a stochastic system of light particles (electrons, or electrons and ions,
respectively) is applied to the evolution of the momentum particle distribution
in a plasma. In a plasma the developed approach is also applicable to the
diffusion of particles with an arbitrary mass relation, due to the small
characteristic momentum transfer. The cases of an exponentially decreasing in
momentum space (including the Boltzmann-like) kernel in the PT-function, as
well as the more general kernels, which create the anomalous diffusion in
velocity space due to the long tail in the PT-function, are considered.
Effective friction and diffusion coefficients for plasma-like systems are
found.Comment: 18 pages, no figure
Inhomogeneity of dusty crystals and plasma diagnostics
Real dusty crystals are inhomogeneous due to the presence of external forces. We suggest approximations for calculations of different types of inhomogeneous DC (chain and DC with a few slabs) in the equilibrium state. The results are in a good agreement with experimental results and can be used as an effective diagnostic method for many dusty systems
Effectiveness of physical conditioning practices for female military personnel
Aim: to investigate the most effective physical conditioning practices for female military personnel.Design: Systematic review.Method: Following the PRISMA guidelines and protocol registered with OSF, PubMed, Embase, CINAHL, SPORTDiscus, and reference lists of included studies were searched using the themes ‘female’, ‘military’ and ‘conditioning’. Dedicated inclusion and exclusion criteria were applied. Critical appraisal and data extraction were performed independently by two authors.Results: Seven of 6,317 citations were included in the study. The mean quality score of the studies was considered ‘good’ (64.4±16.4%). All included studies incorporated strength and aerobic endurance training as a training paradigm; 71% included power specific training; and 43% included occupational specific task training. Improvements in fitness included 50% increase of 1-RM strength, 18.4% increase in VO2max and 14.1% decrease in pack march time.Conclusion: The volume of evidence suggests that several training modalities, including strength, power, and aerobic endurance, can optimise both training adaptations and occupational performance for female soldiers. This review provides summary evidence to assist in informing optimal training practices and guide future direction of research
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