Thermal kinetic analysis, theoretical thermodynamic calculations and antimicrobial activity of three new energetic materials

WOS: 000425965400096Three new energetic agents were synthesized using 3,5-dinitro-4-chlorobenzonitrile, sodium azide and hydrazine, which were 2,6-dinitro-4-cyano-azidobenzene (I), N-2,6-dinitro-cyanophenyl-hydrazine (II) and bis-N,N'(2,6-dinitro-4-cyanophenyl)hydrazine (III). These energetic substances were first characterized by elemental analysis, IR, mass, H-1 NMR and C-13 NMR spectroscopic methods. The energetic substances were studied by thermogravimetry, and it was understood that the mechanism of the thermal decomposition reactions consists of two successive exothermic thermal reactions. In the first thermal reaction, the energetic material was converted to furoxane compounds, and then, these furoxane compounds were decomposed by the second thermal reaction. Activation energies and Arrhenius pre-exponential factors of thermal responses were determined by using isothermal (Coats-Redfern) and nonisothermal/isoconvertional (Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall) methods with thermogravimetry and differential scanning calorimetry (DSC) data. With these calculated values, other thermodynamic parameters reaction enthalpy, entropy changes and free energy were calculated. Formation enthalpies of the elements of the energetic substances were theoretically calculated using the CBS-4M algorithm in the Gaussian 09 program for the synthesized energetic substances. In the thermal decomposition reactions, the products were estimated with the aid of literature data and the enthalpies of explosion reactions were theoretically calculated according to the Hess Law. Besides, the exothermic energies in the first and second thermal reactions of the energetic substances were measured by DSC. The results measured by DSC were compared with the calculated theoretical results and were found to be very close to each other. In the study, antimicrobial activity was estimated to be high because energetic molecules are strained molecules, and it is possible this tension can affect the medium. According to this thought, antimicrobial activity was determined by using five different bacteria and a fungus. Antimicrobial activity values were determined by "agar dilution" method, and results were found as minimum inhibition concentration. Among the three energetic substances, 2,6-dinitro-4-cyano-azidobenzene was found to have the most active compound.Scientific Research Fund of the University of Ankara [16H0430004]; Scientific Research Fund of the Ahi Evran University [FEF.A4.17.001]This work was supported by the Scientific Research Fund of the University of Ankara (project no. 16H0430004) and Scientific Research Fund of the Ahi Evran University (grant no: FEF.A4.17.001)

Strength of selection pressure is an important parameter contributing to the complexity of antibiotic resistance evolution

Revealing the genetic changes responsible for antibiotic resistance can be critical for developing novel antibiotic therapies. However, systematic studies correlating genotype to phenotype in the context of antibiotic resistance have been missing. In order to fill in this gap, we evolved 88 isogenic Escherichia coli populations against 22 antibiotics for 3 weeks. For every drug, two populations were evolved under strong selection and two populations were evolved under mild selection. By quantifying evolved populations' resistances against all 22 drugs, we constructed two separate cross-resistance networks for strongly and mildly selected populations. Subsequently, we sequenced representative colonies isolated from evolved populations for revealing the genetic basis for novel phenotypes. Bacterial populations that evolved resistance against antibiotics under strong selection acquired high levels of cross-resistance against several antibiotics, whereas other bacterial populations evolved under milder selection acquired relatively weaker cross-resistance. In addition, we found that strongly selected strains against aminoglycosides became more susceptible to five other drug classes compared with their wild-type ancestor as a result of a point mutation on TrkH, an ion transporter protein. Our findings suggest that selection strength is an important parameter contributing to the complexity of antibiotic resistance problem and use of high doses of antibiotics to clear infections has the potential to promote increase of cross-resistance in clinics

Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|$\eta$|<0.8) and transverse momentum range 0.2< $p_{\rm T}$< 5.0 GeV/$c$. The elliptic flow signal v$_2$, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 $\pm$ 0.002 (stat) $\pm$ 0.004 (syst) in the 40-50% centrality class. The differential elliptic flow v$_2(p_{\rm T})$ reaches a maximum of 0.2 near $p_{\rm T}$ = 3 GeV/$c$. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/389

K0S and Λ production in Pb-Pb collisions at sNN−−−−√=2.76 TeV

The ALICE measurement of K0S and Λ production at midrapidity in Pb-Pb collisions at sNN−−−√=2.76  TeV is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and in the pT range from 0.4  GeV/c (0.6  GeV/c for Λ) to 12  GeV/c. The pT dependence of the Λ/K0S ratios exhibits maxima in the vicinity of 3  GeV/c, and the positions of the maxima shift towards higher pT with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not observed in pp interactions at s√=0.9  TeV and at s√=7  TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured pT spectra above 2  GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of pT, models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the pT dependence of the Λ/K0S ratio

In vitro propagation of Amsonia orientalis Decne (Apocynaceae)

In vitro plant regeneration was achieved from shoot explants of Amsonia orientalis Decne. The seeds were germinated aseptically in Petri dishes containing growth-regulator-free MS medium. The shoot explants of 30-day-old grown seedlings were cultured on MS medium supplemented with 1 mg/l indole-3-butryric acid (IBA) plus 0.5 mg/l kinetin (Kin) for direct regeneration and subcultured at three week intervals. While induction of adventitious buds from shoot explants was achieved approximately 33% within four weeks, a few roots (around 15%) were induced on the same medium within eight weeks. In addition, shoot explants were transferred to MS medium containing 2 mg/l benzyl aminopurine (BAP) plus 0.2 mg/l naphtalene acetic acid (NAA) for indirect regeneration and after three weeks, proliferated actively growing calli was occured

Effects of Different Milk-Tube Guidance Settings and Teat-Cup Types on the Dynamics of Teat-End Vacuum and Vacuum Fluctuations During Machine Milking

The objective of this study was to determine the effects of milk tube guidance setting and teat cup type on the dynamics of teat-end vacuum and vacuum fluctuations in quarter individual milking systems. In order to meet this objective, a series of wet tests was conducted in the laboratory. Different teat cups; AMS, BIO and RVS along with the milk tube guidance settings namely: direct tube, half-half tube and Y-piece tube system with varying tube inside diameters were tested at different water flow rates. The data obtained from the wet-test measurements were used to calculate the teat-end vacuum and vacuum fluctuation at the teat-old in b and d- phase. From the study conducted, it was found that the teat-end vacuum in BIO is always between the range of 32 and 42 kPa as recommended by DIN ISO 5707 (2010a) at any flow rate for all three types of connections. The teat-end vacuum for RVS was between 32-42 kPa range if the flow rate varies between 4 and 6 L min(-1) for both, the direct and the half-half connection. The Y-piece connection meets DIN ISO 5707 (2010a) requirements once the flow rate changes between 2 and 6 L min(-1). The findings about milk tube inside diameter indicated that the use of 14 or 16 mm milk tube diameter for BIO will provide better teat-end vacuum if the recommended value of 10 mm is used. On the other hand, the use of 16 mm milk tube diameter was found to be appropriate for AMS as recommended by the manufacturer. For the RVS, the appropriate milk tube diameter should be 14 mm when statistical differences in b and d-phase are examined from the point of teat-end vacuum and vacuum fluctuations

Effect of variety and row spacing on the performance of a cotton picker

WOS: 000288779300045Prevalence of the mechanical harvesting brought about significant changes in the conventional production processes in Turkey especially from the point of row spacing and variety. These changes in the production process increased the importance of picker performance from the point of field operation (quantitative) and effect to the lint quality (qualitative). The studies on the effect of the row spacing on the picker performance were usually concentrated on qualitative parameters. However, the amount of harvested cotton (and thus losses) and field performances of the pickers are quite important in Turkish conditions because the trading is based on seed cotton in contrast to the other countries. The objective of this study was to determine the effect of variety and row spacing on the quantitative and qualitative performances of a narrow row, self propelled cotton picker widely used in Turkey. The study was conducted in the field of 8 ha (328 m long), according to split-plot experimental design. Two varieties, Carmen and Stoneville 373 were planted at 76 and 81 cm row spacing. Defoliation was performed by ground sprayer 20 days before harvest by using mixture of 480 g/l ethephon+60 g/l cyclanilide (Finish) and 120 g/l thidiazuron+60 g/l diuron (Dropp Ultra) at application rates 2.5 and 0.4 kg.ha(-1), respectively, with volume of approximately 500 litres per ha. CASE-IH, Cotton Express 420 model, five narrow row mechanical cotton picker was used for harvesting. Ground loss and stalk loss values were within the proposed limits as indicated by the national standards. Results were influenced by variety and row spacing interactions significantly. Lower values were obtained at Carmen-76 cm and St373-81 cm plots comparing with the other plots. No significant relationships were found between harvestable boll ratio, yield and losses. No significant relationship between treatments and the other qualitative parameters was found except for micronaire. Depending on the trash content, there was a decrease in the reflectance (Rd) values of the machine picked samples in comparison to the hand picked samples, and an increase in yellowness (+b) values. In both varieties, the low defoliation ratios caused an increase in trash content and a decrease in the degree of color. The fundamental indication of the measured values was that the success of the defoliation process significantly influenced the lint quality values