Photocatalytic Activity of Quantum Dots

In recent years, nanoscale semiconductors have attracted great interest due to their unique structural, optical and electronic properties, which arise due to their large surface-to-volume ratio and quantum confinement effect. Quantum dots (QDs) as zero-dimensional semiconductor nanomaterials, which are confined to a size of 2–8 nm in three dimensions, are defined as particles with physical dimensions smaller than the exciton Bohr radius. One of the attractive research fields in recent years is the synthesis of various sizes and shapes of semiconductor material nanoparticles as doped with different dopants. The aim of this chapter is to focus on the photocatalytic activity of QDs as new, green and efficient nanophotocatalysts

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)

Employability of Iranian Engineering graduates: Influential factors, consequences, and strategies

Abstract University education is a significant factor in the socio-economic development of a nation and as such is expected to improve the employability capacity of the graduates. Achieving this goal, however, depends on various factors. The present study investigated the factors affecting the employability of engineering graduates of Iranian universities. To analyse this issue, a systematic grounded theory (GT) approach, drawing on in-depth interviews with academic and industry experts, was used. The participants were selected using a purposive strategy. The data analyses showed that employability is a context-oriented issue, and in addition to the university and its internal mechanisms, external factors are also involved. Based on the data, a model is presented and analysed to explain the employability of engineering graduates

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)

Theoretical study on the distribution of profit earnings and stocks returns

People make decisions in their daily life that are based on predictions made about the future. In fact, we are all trying to make a connection between two or more variables in a way that could be used for prediction. Profit and cash flow in a private profit making unit make the most fundamental part of information and are the base of most financial information users’ decision making. And judgments and profit making prediction have always been one of the interesting subjects for financial information users, because correct estimation of these figures can play an important role in making the correct decisions (Jahankhani and Saffarian, 2003). Investors buy assets hoping that their expected return over the next period is achieved efficiently. These returns can be predicted, however, it may not be the expected return. In fact, one can predict the profit-making trend of a company by analyzing the previous trend and studying some of the economic variables. However, actual happenings are different from the numbers and data achieved in predictions. The roots of most of these differences lie in the variability of criteria that are the basis for predictive models (Azad, 2004)

Comparison of expression systems for the production of human interferon-a2b.

The production of human interferon alpha2b (IFN-α2b) in two expression systems, tobacco (Nicotiana tabaccum) and Escherichia coli, was compared in various aspects such as safety, yield, quality of product and productivity. In the E. coli system, IFN-α2b was expressed under a pelB signal sequence and a T7lac promoter in a pET 26b(+) vector. The same gene was also cloned in expression plant vector (pCAMBIA1304) between cauliflower mosaic virus promoter (CaMV35S) and poly A termination region (Nos) and expressed in transgenic tobacco plants. The expression of protein in both systems was confirmed by western immunoblotting and the quantity of the protein was determined by immunoassay. The amount of periplasmic expression in E. coli was 60 µg/L of culture, while the amount of nuclear expression in the plant was 4.46 µg/kg of fresh leaves. The result of this study demonstrated that IFN-α2b was successfully expressed in periplasm of bacterial and plant systems. The limitations on the production of IFN-α2b by both systems are addressed and discussed to form the basis for the selection of the appropriate expression platform

Cloning and periplasmic expression of peptidoglycan-associated lipoprotein (PAL) protein of Legionella pneumophila in Escherichia coli

Abstract Introduction and objective: Legionella pneumophila, the etiological agent of Legionnaires’ disease, is an important cause of both community-acquired and nosocomial pneumonia; therefore, rapid diagnosis and early antibiotic treatment of pneumonia are required. Urinary antigen testing to detect Legionella antigen has proven to be the most powerful diagnostic method. Peptidoglycan-associated lipoprotein (PAL) protein of L. pneumophila, as a component of Legionella antigens, will be detected efficiently by the PAL antigen capture assay and is considered as useful diagnostic antigen to diagnose Legionella infection. Because of the transfer of protein to the periplasmic region of Escherichia coli has numerous advantages including separation from cytoplasmic proteins and the concentration of recombinant proteins in periplasm, the aim of this study was to produce periplasmic PAL protein of L. pneumophila in E. coli. Materials and methods: The pal gene of L. pneumophila serogroup 1 was amplified with specific primers, cloned and expressed under pelB signal sequence and T7 lac promoter in pET26b+ plasmid. Results: The cloning was confirmed with digestion and sequencing of recombinant pET- 26b-pal plasmid. The expression of r-PAL protein in cytoplasm and periplasmic space of E. coli was approved by SDS-PAGE and western blotting. Conclusion: The results of this study demonstrated that the r-PAL protein successfully expressed in E. coli

Characteristics of the Global Radio Frequency Interference in the Protected Portion of L-Band

The National Aeronautics and Space Administration’s (NASA’s) Soil Moisture Active–Passive (SMAP) radiometer has been providing geolocated power moments measured within a 24 MHz band in the protected portion of L-band, i.e., 1400–1424 MHz, with 1.2 ms and 1.5 MHz time and frequency resolutions, as its Level 1A data. This paper presents important spectral and temporal properties of the radio frequency interference (RFI) in the protected portion of L-band using SMAP Level 1A data. Maximum and average bandwidth and duration of RFI signals, average RFI-free spectrum availability, and variations in such properties between ascending and descending satellite orbits have been reported across the world. The average bandwidth and duration of individual RFI sources have been found to be usually less than 4.5 MHz and 4.8 ms; and the average RFI-free spectrum is larger than 20 MHz in most regions with exceptions over the Middle East and Central and Eastern Asia. It has also been shown that, the bandwidth and duration of RFI signals can vary as much as 10 MHz and 10 ms, respectively, between ascending and descending orbits over certain locations. Furthermore, to identify frequencies susceptible to RFI contamination in the protected portion of L-band, observed RFI signals have been assigned to individual 1.5 MHz SMAP channels according to their frequencies. It has been demonstrated that, contrary to common perception, the center of the protected portion can be as RFI contaminated as its edges. Finally, there have been no significant correlations noted among different RFI properties such as amplitude, bandwidth, and duration within the 1400–1424 MHz ban

Semi-analytical predictive model for natural and artificial thawing of circular ground-Ice walls

Artificial ground freezing (AGF) is a ground improvement technique enabling the construction of underground structures in challenging geological conditions. After constructing an underground structure within the ground- ice cofferdam, the soil undergoes a thawing process that can impact the structure stability and waterproofing properties of the lining. Minimizing or preventing potential damage, as well as avoiding delays in construction, can be achieved through a rational design of thawing regimes. In this paper, we present a semi-analytical model for the thermal behaviour of ice-wall during its natural or artificial thawing. The process is described by three independent one-dimensional mathematical problems: the thawing of the outer surface of the ice wall, the thawing of its inner surface, and the thawing of soils around the freeze pipes (in the case of artificial thawing). The proposed approach facilitates the calculation of natural and artificial thawing times and the power required for artificial thawing. The efficiency of the model is demonstrated by comparison with numerical simulation results. This makes the approach suitable and desirable for engineering practice. Importantly, the model allows for seamless analysis of several combinations of influencing factors to select thawing parameters aligned with the requirements of different construction projects