Low Reynolds number proprotor aerodynamic performance improvement using the continuous surface curvature design approach

Low Reynolds number blade profiles of Re_C =10^5 to 2*10^5 as as based on chord length and used for small unnamed air vehicles, and near space applications are investigated for single and counter-rotating (coaxial) proprotors, i.e. acting as rotors or propellers. Such profiles are prone for early stall, significantly reducing their maximum lift to drag ratio. Two profiles previously designed by our continuous surface curvature design approach named as CIRCLE are investigated in order to improve the performance of the proprotors. The profiles are redesigns of the common symmetric NACA0012 and asymmetric E387 profiles. Using general arguments based on composite efficiency and rotor’s lift to drag ratio, the performance envelope is noticeably increased when using the redesigned profiles for high angles of attack due to stall delay. A new approach is derived to account for the distance between the rotors of a coaxial proprotor. It is coupled with a blade element method and is verified against experimental results. Single and coaxial CIRCLE-based proprotors are investigated against the corresponding non CIRCLE-based proprotors at hover and axial translation. Noticeable improvements are observed in thrust increase and power reduction at high angles of attack of the blade’s profiles, particularly for the coaxial configuration. Plots of thrust, torque, power, composite efficiency and aerodynamic efficiency distributions are given and analysed

Length-weight frequency and sex ratio of crayfish, Astacus leptodactylus, in Aras Reservoir, west Azerbaijan, Iran

The length-weight frequency and sex ratio of crayfish (Astacus leptodactylus) in Aras Reservoir, was studied seasonally from spring 2008 to winter 2009. The total mean length and weight for the crayfish were 106.43±7.94mm and 35.81±10.86g, respectively. A measured 18.99% of the caught crayfish exceeded the standard commercial size (120mm) and only 16.43% of the catch weighed higher than the standard commercial weight 50 grams. The standards have been set forth by West Azerbaijan Fishery Office. Generally, the male crayfish dominated the samples. Comparisons of growth equations confirmed that the males are heavier than females with the same size. The results showed that crayfish Astacus leptodactylus has critical condition in Aras Reservoir

Airborne Transmission of SARS-CoV-2: The Contrast between Indoors and Outdoors

COVID-19 is an airborne disease, with the vast majority of infections occurring indoors. In comparison, little transmission occurs outdoors. Here, we investigate the airborne transmission pathways that differentiate the indoors from outdoors and conclude that profound differences exist, which help to explain why SARS-CoV-2 transmission is much more prevalent indoors. Near- and far-field transmission pathways are discussed along with factors that affect infection risk, with aerosol concentration, air entrainment, thermal plumes, and occupancy duration all identified as being influential. In particular, we present the fundamental equations that underpin the Wells–Riley model and show the mathematical relationship between inhaled virus particles and quanta of infection. A simple model is also presented for assessing infection risk in spaces with incomplete air mixing. Transmission risk is assessed in terms of aerosol concentration using simple 1D equations, followed by a description of thermal plume–ceiling interactions. With respect to this, we present new experimental results using Schlieren visualisation and computational fluid dynamics (CFD) based on the Eulerian–Lagrangian approach. Pathways of airborne infection are discussed, with the key differences identified between indoors and outdoors. In particular, the contribution of thermal and exhalation plumes is evaluated, and the presence of a near-field/far-field feedback loop is postulated, which is absent outdoors

Fluctuation in density of ciliates in Bukan dam reservoir, Zarrinehrud, Iran

The abundance and species composition of ciliates were analyzed in the Bukan Dam Reservoir (West Azerbaijan, Iran) from January to December 2008. Surface water samples were collected at monthly intervals from the middle (Stations 1 and 3) and shallow (Stations 2 and 4) areas of the lake. Three samples were taken in the water column using a 5-litre sampler. Totally 30 liters water was collected, 200 ml of which was fixed immediately with 8.6 ml of a saturated HgCl2 solution and stained with 0.04% bromophenol blue. Three subsamples were counted in a 5-ml chamber and examined with a microscope (100 x) as well as Chlorophyll a and a few ecological parameters such as dissolved oxygen, pH, transperancy and water temperature were measured. Totally 50 ciliates species were found in Bukan Dam Reservoir. Regarding the density, a high-density period was detected from January to April with a mean density of 2.86 x 103 cells.l-1 Ciliata at stations 1 and 3 and 4.16 x 103 cells.l-1 at stations 2 and 4. The high density of ciliate in summer may be due to the increase in the density of bacteria and moderate metazooplankton as a result of the appearance of non-edible algae . The ciliata occurring at the highest densities were Coleps tessellates, Didinium nasutum, Paradileptus elephantinus, Stentor polymorphus, Zosterograptus labiatus, Paramecium bursaria, Cyclidium citrullus, Vorticella campanula, Halteria grandinella and Aspidisca costata. The maximum and minimum chlorophyll a values observed at the reservoir water were 10.39 µg.l-l and 1.0 µg.l-l being obtained in May and Octobor respectively

Study on effect of Rosmarinus officinalis and Zataria multiflora extracts on the stability of fatty acids in frozen silver carp minced

In this study, the effect of Rosemary and Zataria extracts on three different treatments in frozen Silver carp minced were studied in normal packaging. Therefore, a control and three treatments were defined: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced + Zataria 300mg/kg in normal packaging Treatment 3: Frozen Silver carp minced + Rosemary 200mg/kg in normal packaging Treatment 4: Frozen Silver carp minced + Rosemary compound (100mg/kg) and Zataria (100mg/kg) in normal packaging After quick freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18)°C were transferred. For six month, Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: SFA: (Saturated Fatty Acid): Meristic C14: 0/ Palmitic C16: 0 /Hepta decaenoic C17: 0 / Stearic C18: 0 / Arashidic C20: 0 B: (MUFA Mono Unsaturated Fatty Acid): Palmitoleic C16: 1-W7 / Oleic C18: 1-W9 /Gadoleic C20: 1 - W9 C: (PUFA Poly Unsaturated Fatty Acid): Linoleic C18: 2-W6 /α-Linolenic C18:3-W3 D: (HUFA High Unsaturated Fatty Acid): Arachidonic C20: 4 - W6 Eicosa panta enoic acid C20: 5- EPA/W3 Docosa hexa enoic acid C22: 6-DHA/W3. Results of this study was to determine keep frozen fish meat containing extracts of Zataria and Rosemary in freezing conditions, stability of different types of fatty acids, mono unsaturated fatty acids, poly unsaturated fatty acids, high unsaturated fatty acids, So that none of the fatty acids measured, were not observed increase or decrease Changes over time while maintaining the oxidation of fatty acids is minimized. The results obtained from the profile of fatty acids and their related indices and statistical tests show the treatment contains Rosemary extract show greater stability than thyme during storage (- 18)°C. According to studies, Frozen minced fish meat treated with extracts of Rosemary, was used until the end of the storage period

High prevalence of direct repeat unit types of 10di, 8 h and 8i among methicillin resistant Staphylococcus aureus strains with staphylococcal cassette chromosome mec type IIIA isolated in Tehran, Iran 11 Medical and Health Sciences 1103 Clinical Sciences

Background: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) is a main concern in burn care centers worldwide. The some reports of MRSA in Iran suggested that MRSA with type SCCmec III is common among burn patients. The aim of this study was to determine the prevalence, virulence genes, and antimicrobial susceptibility of the direct repeat units (dru) types of MRSA with SCCmec IIIA isolated from burn wounds in a burn care center in Tehran, Iran. Methods: In total, 165 S. aureus isolates were collected from clinical samples. In order to detect MRSA isolates, the mecA gene was amplified through the polymerase chain reaction (PCR) method. Antimicrobial susceptibility was tested using the disc agar diffusion test. Moreover, the PCR method was applied to determine SCCmec types, virulence genes, and antimicrobial resistance genes. The dru region was sequenced and thereby, dru types and dru repeats were identified. A similarity matrix was used to create minimum spanning tree (MST). Results: The prevalence of MRSA was 69 (114 out of 165 isolates). Most of MRSA isolates (61 out of 114, 53.5) were SCCmec type IIIA. All MRSA isolates were vancomycin-susceptible and more than 68 of MRSA isolates with SCCmec type IIIA were mupirocin resistant. The successful dru typing of isolates with SCCmec type IIIA revealed fourteen different dru types. There were two new dru types, namely dt10di and dt7aj. MST analysis indicated the presence of the three clusters of dt10di (cluster I), dt8i-dt8 h (cluster II), and dt11c-dt10ao-dt11dd-dt11a-dt10a (cluster III). There were significant differences between clusters I and II respecting antimicrobial resistance pattern and virulence genes. Conclusion: Three main dru clusters are prevalent in the study setting. The main dru types in the setting are dt10di, dt8i, and dt8 h. Dru typing can be used to differentiate MRSA strains with SCCmec IIIA. © 2019 The Author(s)

Conceptual Design of a UVC-LED Air Purifier to Reduce Airborne Pathogen Transmission - A Feasibility Study

Existing indoor closed ultraviolet-C (UVC) air purifiers (UVC in a box) have faced technological challenges during the COVID-19 breakout, owing to demands of low energy consumption, high flow rates, and high kill rates at the same time. A new conceptual design of a novel UVC-LED (light-emitting diode) air purifier for a low-cost solution to mitigate airborne diseases is proposed. The concept focuses on performance and robustness. It contains a dust-filter assembly, an innovative UVC chamber, and a fan. The low-cost dust filter aims to suppress dust accumulation in the UVC chamber to ensure durability and is conceptually shown to be easily replaced while mitigating any possible contamination. The chamber includes novel turbulence-generating grids and a novel LED arrangement. The turbulent generator promotes air mixing, while the LEDs inactivate the pathogens at a high flow rate and sufficient kill rate. The conceptual design is portable and can fit into ventilation ducts. Computational fluid dynamics and UVC ray methods were used for analysis. The design produces a kill rate above 97% for COVID and tuberculosis and above 92% for influenza A at a flow rate of 100 L/s and power consumption of less than 300 W. An analysis of the dust-filter performance yields the irradiation and flow fields

Limnological of Bukan Dam Reservoir

In order to limnological study of Bukan Dam reservoir, sampling was performed monthly from determined sampling sites from April 2013 to March 2014. Sampling was conducted in reservoir lake by a PVC pipe with 2.25 m length and 5 cm diameter by columnar method. Besides, in more dipper (>5 m) sites, sampling conducted from bottom to surface with 1-m intervals (layer sampling) by a 2-liter Ruttner type sampler. In rivers due to water flow sampling was conducted by a scaled measure. Phytoplankton sampling was performed by 1-liter bottles. Zooplankton was sampled by filtering of 30 L through 55- micron plankton net. These samples were then transferred into bottles and sampling date and the name of station were attached on the bottles. Then, the samples were fixed immediately and transported to laboratory. It should be mentioned some physical parameters were determined in situ. Also, a 2-liter and another 1-liter water were collected to determine chlorophyll a and chemical factors respectively. Samples were preserved in dark and cold place for a week. The upper layers (without phytoplankton) were removed and the lower layer (with phytoplankton) was sampled into 5-ml chambers. The enumeration and identification was performed by a Nikon TS100 inverted microscope with ×400 (Phytoplankton) and ×200 (Zooplankton) magnification according to Utermohl (1958) method. About 50 fields were enumerated for each sample. The comparison of physicochemical and biological factors with standard criterion indicated that the presence of a fertile plain, agricultural growth, drought and higher water demand in recent years, as well as, higher population density, the Saghez city which is the main source of pollution in Bukan dam reservoir has caused that Bukan dam is in the transit state from mesotrophy to eutrophy. The results of the present study suggested that higher trophy in Bukan dam reservoir together with algal high density has negatively affected the Fish life and has reduced the stock in the lake. However, complementary studies should be performed prior to releasing. In this way the problems of other ecosystems should be prevented

Compare the quality fish paste production of Kilka (Clupeonella cultriventris) and Silver carp (Hypophthalmichthys molitrix)

Qualitative changes in the fish spread a mixture of minced meat, fish Kilka (Clupeonella cultiventris) and silver carp (Hypophthalmichthys molitrix) in pasteurized. Fish spread of fish products ready for consumption with soft tissue, such as butter is very good in the world market, ready to use paste of fish production due to the variety, taste good, able to use for all ages in the community a special place in the fisheries industry countries are active in the field of fisheries products. The valuable features of this product, it is possible to produce fish midget, cheap, circumstantial fished, farmed fish, waste and waste from the fish processing factories are notably food production of fish protein sources that have the flavor is very suitable for all age groups was the research goals, in order to process the cream edible fillets and minced meat (minced fish) cultured fish silver carp (Hypophthalmichthys molitrix) and fish in the Caspian Sea Kilka (Clupeonella cultriventris) are treated as a combination of four: 1. Silver carp minced meat 100% +30% filler +1% spice, thickeners, improved color, taste 2. Kilka minced meat 100% +30% filler +1% spice, thickeners, improved color, taste 3. Kilka and Silver carp minced meat 50+50 % +30% filler +1% spice, thickeners, improved color, taste 4. Silver carp and Kilka minced meat 75+25 % +30% filler +1% spice, thickeners, improved color, taste 5. Silver carp and Kilka minced meat 25+75 % +30% filler +1% spice, thickeners, improved color, taste. After the initial blanching minced meat (80oc temperature for 3 min) were processed, heat resistant glass samples processed at the full weight of 50 g were, after a hot air steam, capping has been pasteurized for 60 minutes at 80oc, after a hot air steam, capping has been pasteurized for 60 minutes at 80oc and the results show, treatment 100% Silver carp minced fish +30% filler +1% spice, thickeners, improved color, taste better than other treatments and data was significant (P<0.05)

Characterization of the Partitioning System of Myxococcus Plasmid pMF1

pMF1 is the only autonomously replicating plasmid that has been recently identified in myxobacteria. This study characterized the partitioning (par) system of this plasmid. The fragment that significantly increased the retaining stability of plasmids in Myxococcus cells in the absence of selective antibiotics contained three open reading frames (ORFs) pMF1.21-pMF1.23 (parCAB). The pMF1.22 ORF (parA) is homologous to members of the parA ATPase family, with the highest similarity (56%) to the Sphingobium japonicum ParA-like protein, while the other two ORFs had no homologs in GenBank. DNase I footprinting and electrophoretic mobility shift assays showed that the pMF1.23 (parB) product is a DNA-binding protein of iteron DNA sequences, while the product of pMF1.21 (parC) has no binding activity but is able to enhance the DNA-binding activity of ParB to iterons. The ParB protein autogenously repressed the expression of the par genes, consistent with the type Ib par pattern, while the ParC protein has less repressive activity. The ParB-binding iteron sequences are distributed not only near the partitioning gene loci but also along pMF1. These results indicate that the pMF1 par system has novel structural and functional characteristics