Enhancement of alpha amylase production by Aspergillus flavus AUMC 11685 on mandarin (Citrus reticulata) peel using submerged fermentation

Mandarin peel as submerged fermentation (SmF) source was tested for the production of alpha amylase enzyme by strain of Aspergillus flavus AUMC 11685. Incubation period, concentration of substrate, temperature, pH and size of inoculum were optimized to achieve the maximum production of alpha amylase enzyme by Aspergillus flavus using mandarin peel. The maximum production of alpha amylase enzyme by Aspergillus flavus was recorded at 4-5 days of incubation, 3% substrate concentration, inoculum concentration 10%, temperature 28-40°C and pH 4-5.5. DOI: http://dx.doi.org/10.5281/zenodo.81827

Proučavanje relativističke tvorbe hadrona prema naprijed i unatrag u sudarima 3he i 4he s jezgrama u emulziji na energiji ubrzivača u dubni

The experimental results on 3He- and 4He-emulsion interactions accompanied by relativistic (shower) hadrons flying into the backward (θlab ≤ 90◦ ) hemisphere at 4.5 AGeV/c are presented and analyzed. The dependence of the probabilities of these interactions on the different target sizes, impact parameter and projectile spectator charges is studied. An investigation of average values and multiplicity distributions of these hadrons for the interactions with light and heavy emulsion nuclei has been carried out. In addition, the correlations between the multiplicities of different types of the emitted particles are studied. The data show that backward shower particles are a sensitive target parameter. The values of impact parameters can be used as good indicators for selecting events which occured with light or heavy emulsion nuclei. A comparison with the modified cascade model shows a good performance in describing the data produced in the region having less cascading (i.e. interactions with light nuclei). As for the interactions with heavy nuclei, the model overestimates the experimental data.Predstavljamo eksperimentalne rezultate i analize mjerenja međudjelovanja 3He i 4He u emulziji na 4.5 AGeV/c, u kojima se opažaju relativistički pljuskovi hadrona koji lete unatrag (θlab ≤ 90◦ ). Proučavamo ovisnost vjerojatnosti tih međudjelovanja o veličini jezgre mete, sudarnom parametru i naboju projektila-promatrača. Istražili smo prosječne vrijednosti i raspodjele višestrukosti hadrona za lake i teške jezgre u emulziji. Nadalje, proučavali smo korelacije višestrukosti različitih izlaznih čestica. Podaci pokazuju da su pljuskovi čestica unatrag osjetljiv parametar jezgri mete. Vrijednosti parametara mogu poslužiti kao dobar pokazatelj sudara s lakim odnosno teškim jezgrama. Usporedba s promijenjenim kaskadnim modelom pokazuje dobro slaganje s podacima u kojima je manje kaskada (tj. Manje sudara s lakim jezgrama). Rezultati tog modela za teške jezgre veći su od eksperimentalnih podataka

Proučavanje relativističke tvorbe hadrona prema naprijed i unatrag u sudarima 3he i 4he s jezgrama u emulziji na energiji ubrzivača u dubni

The experimental results on 3He- and 4He-emulsion interactions accompanied by relativistic (shower) hadrons flying into the backward (θlab ≤ 90◦ ) hemisphere at 4.5 AGeV/c are presented and analyzed. The dependence of the probabilities of these interactions on the different target sizes, impact parameter and projectile spectator charges is studied. An investigation of average values and multiplicity distributions of these hadrons for the interactions with light and heavy emulsion nuclei has been carried out. In addition, the correlations between the multiplicities of different types of the emitted particles are studied. The data show that backward shower particles are a sensitive target parameter. The values of impact parameters can be used as good indicators for selecting events which occured with light or heavy emulsion nuclei. A comparison with the modified cascade model shows a good performance in describing the data produced in the region having less cascading (i.e. interactions with light nuclei). As for the interactions with heavy nuclei, the model overestimates the experimental data.Predstavljamo eksperimentalne rezultate i analize mjerenja međudjelovanja 3He i 4He u emulziji na 4.5 AGeV/c, u kojima se opažaju relativistički pljuskovi hadrona koji lete unatrag (θlab ≤ 90◦ ). Proučavamo ovisnost vjerojatnosti tih međudjelovanja o veličini jezgre mete, sudarnom parametru i naboju projektila-promatrača. Istražili smo prosječne vrijednosti i raspodjele višestrukosti hadrona za lake i teške jezgre u emulziji. Nadalje, proučavali smo korelacije višestrukosti različitih izlaznih čestica. Podaci pokazuju da su pljuskovi čestica unatrag osjetljiv parametar jezgri mete. Vrijednosti parametara mogu poslužiti kao dobar pokazatelj sudara s lakim odnosno teškim jezgrama. Usporedba s promijenjenim kaskadnim modelom pokazuje dobro slaganje s podacima u kojima je manje kaskada (tj. Manje sudara s lakim jezgrama). Rezultati tog modela za teške jezgre veći su od eksperimentalnih podataka

Prospects for SIMPLE 2000: A large-mass, low-background Superheated Droplet Detector for WIMP searches

SIMPLE 2000 (Superheated Instrument for Massive ParticLE searches) will consist of an array of eight to sixteen large active mass ($\sim15$ g) Superheated Droplet Detectors(SDDs) to be installed in the new underground laboratory of Rustrel-Pays d'Apt. Several factors make of SDDs an attractive approach for the detection of Weakly Interacting Massive Particles (WIMPs), namely their intrinsic insensitivity to minimum ionizing particles, high fluorine content, low cost and operation near ambient pressure and temperature. We comment here on the fabrication, calibration and already-competitive first limits from SIMPLE prototype SDDs, as well as on the expected immediate increase in sensitivity of the program, which aims at an exposure of $>$25 kg-day during the year 2000. The ability of modest-mass fluorine-rich detectors to explore regions of neutralino parameter space beyond the reach of the most ambitious cryogenic projects is pointed out.Comment: 19 pages, 10 figures included. New Journal of Physics, in pres

First Dark Matter Limits from a Large-Mass, Low-Background Superheated Droplet Detector

We report on the fabrication aspects and calibration of the first large active mass ($\sim15$ g) modules of SIMPLE, a search for particle dark matter using Superheated Droplet Detectors (SDDs). While still limited by the statistical uncertainty of the small data sample on hand, the first weeks of operation in the new underground laboratory of Rustrel-Pays d'Apt already provide a sensitivity to axially-coupled Weakly Interacting Massive Particles (WIMPs) competitive with leading experiments, confirming SDDs as a convenient, low-cost alternative for WIMP detection.Comment: Final version, Phys. Rev. Lett. (in press

Protease-producing microorganisms inhabiting salted fish (Moloha) with special reference to protease activity of Bacillus subtilis

The investigation was designed to isolate and identify the proteolytic microorganisms inhabiting salted fish. Bacillus subtilis was chosen as the most promising protease producer. Some properties of the crude protease are presented, the effect of metal ions on protease production has been studied. It was shown that Ca2+ and Mg2+ stimulated, while Co2+ , Zn2+ and Cu2+ inhibited the enzyme production. The effect of temperature and pH and salt tolerance have also been studied. Protease activity was stable in 25% NaCl. The favourable characteristics of the enzyme might have extensive application in laundry detergents and in tanning industry

Fission of Uranium Nuclei in Flight at Relativistic Energies

The charge, mass, and energy spectra of clean binary-fission events of U238 projectiles at energies up to 1 GeV/nucleon are presented. The inelastic interaction cross section and the cross section for the production of binary fission (50% of all interactions) are found to be constant over the entire energy range. © 1984 The American Physical Society