Characterization and Diffusion Kinetics of Silicon on AISI D2 Steel

This paper presents the simultaneous influence of two different activators (NH4Cl and NaF) on the kinetic evolution during siliconising of steel. The AISI D2 tool steel surface was coated by pack siliconising through the growing of silicon on the surface. Pack siliconising was accomplished by employing a mixture of powders of Si 12 wt% + NH4Cl 0.5 wt% + NaF 0.5 wt% + Al2O3 at 923, 1073 and 1223 K for 1 to 5 h, respectively. The thermodynamics of the different chemical reactions were calculated for the forecast of the coating growth mechanisms of pack siliconising. The microstructure and the precipitation evolution of the silicides were analysed by Energy Dispersive X-ray Spectroscopy line scan (EDS-line scan), X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The ranges of the silicide layers thickness resulted between 19 and 337 μm depending on the employed processing parameters. The maximum hardness related to the siliconising parameters for fabricating the different thickness of the intermetallics on the surface of the AISI D2 tool steel and the ranges of the microhardness of the substrate after siliconising is between 750 and 800 HV. The growth of the FeSi, Fe2Si and FeSi2 on the sub-layer is a function of the treatment temperature and time, their growth behavior was used for revealing the kinetics during the process. The results showed that the diffusion coefficient (k) was enhanced by increasing the treatment temperature. Activation energy (Q) resulted 138 KJmol . The crystal growth rate resistance (k) are from 1.141 × 10 - 8 to 1.078×10-6m2s .</p

OPTIMIZACIJA GALVANSKOGA IZLUŽIVANJA HALKOPIRITA UPORABOM PIRITA I SREBRA KAO KATALIZATORA TE UPORABOM METODE ODZIVNE POVRŠINE

In this research, dissolution of chalcopyrite concentrate is modelled and optimized using Response Surface Methodology (RSM). Also, effective parameters in the leaching process such as the amount of pyrite, silver ions, redox potential and initial concentration of acid are comprehensively studied. Central Composite Design (CCD) methodology is chosen as the design matrix to predict the optimum level of the parameters. In the next step, it will be proven that in the presence of silver ions, pyrite effectiveness is improved and also the chalcopyrite dissolution rate is increased considerably. Using the result of quadratic programming, a rotation speed of 1000 rpm, a pyrite/chalcopyrite mass ratio of 3:1, the amount of 150 ppm silver ion, a solution potential set point of 470 mV, at 800°C and 25 g/L initial acid concentration are the optimal level of the selected parameters wherein the maximum copper extraction with more than 95% in less than 10 hours can be accessible.U ovome istraživanju modelirano je otapanje koncentriranoga halkopirita te je proces optimiziran uporabom metode odzivne površine. Također su istražene efektivne varijable tijekom toga procesa, i to količina pirita, iona srebra, redokspotencijal i početna koncentracija kiseline. Metodom središnjega kompozitnog dizajna određena je matrica za predviđanje najboljega odnosa tih varijabli. Nakon toga je pokazano kako nazočnost iona srebra povećava efi kasnost pirita, što je rezultiralo znatno većom topivošću halkopirita. Kvadratičnim programiranjem određene su sljedeće vrijednosti kao optimalne: brzina rotacije od 1000 okretaja u minuti, zatim maseni odnos pirita i halkopirita 3 : 1, koncentracija iona srebra 150 ppm, potencijal topivosti od 470 mV na 800 ⁰C te početna koncentracija kiselina 25 g/L. Time je postignuto maksimalno izluživanje bakra (uspješnosti veće od 95 %) za vrijeme kraće od 10 sati

A Novel Sequential Risk Assessment Model for Analyzing Commercial Aviation Accidents: Soft Computing Perspective

Due to the importance of the commercial aviation system and, also, the existence of countless accidents and unfortunate occurrences in this industry, there has been a need for a structured approach to deal with them in recent years. Therefore, this study presents a comprehensive and sequential model for analyzing commercial aviation accidents based on historical data and reports. The model first uses the failure mode and effects analysis (FMEA) technique to determine and score existing risks; then, the risks are prioritized using two multi-attribute decision making (MADM) methods and two novel and innovative techniques, including ranking based on intuitionistic fuzzy risk priority number and ranking based on the vague sets. These techniques are based in an intuitionistic fuzzy environment to handle uncertainties and the FMEA features. A fuzzy cognitive map is utilized to evaluate existing interactions among the risk factors, and additionally, various scenarios are implemented to analyze the role of each risk, group of risks, and behavior of the system in different conditions. Finally, the model is performed for a real case study to clarify its applicability and the two novel risk prioritization techniques. Although this model can be used for other similar complex transportation systems with adequate data, it is mainly employed to illustrate the most critical risks and for analyzing existing relationships among the concepts of the system

On the (im)possibility of receiving security beyond 2^l using an l-bit PRNG: the case of Wang et. al. protocol

Recently,Wang et al. analyzed the security of two EPC C1-G2 compliant RFID authentication protocols, called RAPLT and SRP^+, and proved that these protocols are vulnerable against de-synchronization and secret disclosure attacks. The time complexity of their attacks were O(2^{16}). In addition, they proposed an improved version of SRP^+ entitled SRP^{++}, for which they claim the security would be O(2^{32}). However, in this letter, we analyze the security of SRP^{++} and show that the complexity of retrieving all secret parameters of a given tag is $O(2^{16})$, similar to its predecessor protocol

Detection of Sea, Seb, Sec, Seq genes in staphylococcus aureus isolated from nasal carriers in Tehran province, Iran; by multiplex PCR

Staphylococcus(S.) aureus  produces different extra-cellular protein toxins and virulence factors. One of the most important extra-cellular proteins is an enterotoxin which causes staphylococcal food poisoning (SFP) due to their enterotoxins. Different methods have been used to detect this toxin, each of which has advantages and disadvantages. DNA amplification methods, however, can show the presence of enterotoxigenic strains of S. aureus before the expression of enterotoxins on the basis of specific gene sequences. In this study, 150 S. aureus strains isolated from nasal carriers were confirmed by biochemical testing. PCR was used to amplify the staphylococcal enterotoxin A, B, C and Q genes, as well as the staphylococcal nuclease gene.  Among the 150 healthy human isolates from the nasal carrier, 95 were confirmed as S. aureus.  Only 58.9% of the isolates were diagnosed as sea, b, c, q positive. There were 24 (25.3%) isolates associated with the sea gene, 15.8% isolates associated with the seb gene, 9.5% of the isolates were associated with the sec gene, and 8.4% of the isolates associated with the seq gene. Of these isolates, 41% might be possessing additional se genes but they were not see (178 bp) and sed (319 bp) genes.  The nuc gene, which encodes thermo nuclease, was used as a target DNA to identify S. aureus. Additionally, one of these enterotoxigenic isolates carried more than one toxin gene

Cloning and Expression of N-terminal Region of IpaD from Shigella dysenteriae in E. coli

Genus Shigella is one of the important members of the family enterobacteriacae. There are numerous antigens in Shigella carrying by a 220 kb plasmid. Among them, IpaD is the key virulence factor of S. flexneri. Apart from having effectors function that is essential for host cell invasion and intracellular survival, this protein also controls the secretion and translocation of other effector proteins into eukaryotic host cells. In the present study, we have cloned and expressed the ipaD in E. coli. The ipaD gene was amplified by PCR. Prokaryote expression vector pET-28a(+)- ipaD was constructed, and used to transform E. coli BL21DE3 plySs. The expression of recombinant protein induced by IPTG was examined by SDS-PAGE. Western blot were used to determine immunoreactivity of IpaD-His by a rabbit monoclonal antibodies against his-tag. SDS-PAGE demonstrated that the constructed prokaryotic expression efficiently produced IpaD at the 1 mmol/L of IPTG. IpaD protein was able to react with the rabbit monoclonal antibody against His-tag.  IpaD is essential for Shigella spp invasion. N-terminal region is most significant functional fragment of IpaD. Purification of IpaD from the wild type of Shigella is difficult furthermore profound study on a specific domain on the N-terminal of IpaD by using the wild type of purified IpaD is not feasible.

Feasibility study on pomferet (Pampus argentus) breeding technique in Imam marine research station

This study was conducted during April to June 2007 .Pomferet brooders were captured by gill net (5 m Height, 300 m length, 7 cm size) during tidal time with 20-40 minutes interval. Khor Mermis, Khor Patil and Khor Mavi were subjected for broodstock captures. Totally 237 brooders were captured (126 male and 111 female) and were kept in 300 L. tanks. Semi dried method were used for breeding with 0.6 % fertility solution. Hatching were placed during 16-18 hoers. Fish larvae were kept in 4 T. tanks and were fed by fresh rotifer .temperature and salinity was kept 31-28 degree centigrade and 45-47 ppt. respectively .results shows successful breeding of pomferet in 2007 .egg diameter was 1.1 mm and hatching were completed during 16-18 hours at 31-29 degree centigrade. After 31 days length of larvae was 40 mm. while for 7 and 15 days length of larvae was 4.5 and 8.4 mm respectively

Health sector spending and spending on HIV/AIDS, tuberculosis, and malaria, and development assistance for health: progress towards Sustainable Development Goal 3

Sustainable Development Goal (SDG) 3 aims to “ensure healthy lives and promote well-being for all at all ages”. While a substantial effort has been made to quantify progress towards SDG3, less research has focused on tracking spending towards this goal. We used spending estimates to measure progress in financing the priority areas of SDG3, examine the association between outcomes and financing, and identify where resource gains are most needed to achieve the SDG3 indicators for which data are available. Methods We estimated domestic health spending, disaggregated by source (government, out-of-pocket, and prepaid private) from 1995 to 2017 for 195 countries and territories. For disease-specific health spending, we estimated spending for HIV/AIDS and tuberculosis for 135 low-income and middle-income countries, and malaria in 106 malaria-endemic countries, from 2000 to 2017. We also estimated development assistance for health (DAH) from 1990 to 2019, by source, disbursing development agency, recipient, and health focus area, including DAH for pandemic preparedness. Finally, we estimated future health spending for 195 countries and territories from 2018 until 2030. We report all spending estimates in inflation-adjusted 2019 US$, unless otherwise stated. Findings Since the development and implementation of the SDGs in 2015, global health spending has increased, reaching$7·9 trillion (95% uncertainty interval 7·8–8·0) in 2017 and is expected to increase to $11·0 trillion (10·7–11·2) by 2030. In 2017, in low-income and middle-income countries spending on HIV/AIDS was$20·2 billion (17·0–25·0) and on tuberculosis it was $10·9 billion (10·3–11·8), and in malaria-endemic countries spending on malaria was$5·1 billion (4·9–5·4). Development assistance for health was $40·6 billion in 2019 and HIV/AIDS has been the health focus area to receive the highest contribution since 2004. In 2019,$374 million of DAH was provided for pandemic preparedness, less than 1% of DAH. Although spending has increased across HIV/AIDS, tuberculosis, and malaria since 2015, spending has not increased in all countries, and outcomes in terms of prevalence, incidence, and per-capita spending have been mixed. The proportion of health spending from pooled sources is expected to increase from 81·6% (81·6–81·7) in 2015 to 83·1% (82·8–83·3) in 2030. Interpretation Health spending on SDG3 priority areas has increased, but not in all countries, and progress towards meeting the SDG3 targets has been mixed and has varied by country and by target. The evidence on the scale-up of spending and improvements in health outcomes suggest a nuanced relationship, such that increases in spending do not always results in improvements in outcomes. Although countries will probably need more resources to achieve SDG3, other constraints in the broader health system such as inefficient allocation of resources across interventions and populations, weak governance systems, human resource shortages, and drug shortages, will also need to be addressed

Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations