A new method in data envelopment analysis to find efficient decision making units and rank both technical efficient and inefficient DMUs together

The inefficient DMUs are usually arranged after the technical efficient ones byDEA methods, however, it is possible that a technical efficient DMU neither beefficient nor be more efficient than some inefficient ones. This studydistinguishes between the terms ‘technical efficiency’ and ‘efficiency’ anddemonstrates that the technical efficiency is a necessary condition for beingefficient and it is not an enough condition to call a DMU as efficient DMU. Thestudy identifies the definitions of those terms and gives a new strong method tocharacterize efficient DMUs among the technical efficient ones. The new method,although, avoids the need for recourse to prices, weights or other assumptionsbetween inputs and outputs of DMUs, it is also able to consider the prices andweights. A numerical example is also characterized the worth and benefits of thenew proposed model in comparison with all current DEA models

The growth, survival rate and reproductive characteristics of Artemia urmiana fed by Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. as feeding microalgae

This study was performed to compare the efficiency of six microalgae namely Dunaliella tertiolecta, Tetraselmis suecica, Nannochloropsis oculata, Chaetoceros sp., Chlorella sp. and Spirolina sp. on the growth, survival rate and reproduction efficacy in Artemia urmiana in laboratory conditions. Artemia cysts were harvested from Urmia Lake and hatched according to the standard method. Live microalgae were cultured using the f/2 culture medium. Artemia survival was determined in treatments on days 8, 11, 14, 17 and 20. A highly significant difference (p<0.01) were found among three microalgae in terms of length growth, survival rates and reproduction characteristics in A. urmiana. In spite of higher length growth of A.urmiana fed on N. oculata than A. urmiana fed by T. suecica but survival and reproduction in the latter was better than the first treatment. In general, D. tertiolecta was more efficient than other microalgae examined in the present study on A. urmiana concerning not only to growth and survival but also to reproduction mode. So, it is preferred to feed A. urmiana

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

Development of luminescent photobioreactors for improved cultivation of microalgae

This study investigated the effects of light quality, culture density, and carbon dioxide aeration on the biomass production, lipid accumulation, elemental contents, and photosynthetic pigment production of microalgae. The microalgae Chlorella vulgaris and Gloeothece membranacea were cultivated either in static (flask) or aerated and mixed (photobioreactor) cultivation modes. The highest biomass productivities in the static mode for both microalgae strains were achieved using violet luminescent filters which emitted the photosynthetic active radiation ranges. In the static mode, red wavelength ranges had a major influence on pigmentation of C.vulgaris, although they were the least efficient light condition for cultivation of G.membranacea. Red light was particularly inefficient to support growth in static cultures. Luminescent bubble column photobioreactors (PBRs) were constructed and used for the aerated mode in the blue, green, yellow, orange, and red wavelength-emitting ranges. Biomass production in both strains was enhanced in the red PBR. Lipid accumulation was significantly enhanced in high culture density groups, low light intensity, and 15% CO2 aeration conditions which all represented a form of stress to the culture. The highest biomass density of 2.12 and 2.52 g L-1 were achieved at high light intensity in the red PBR for C.vulgaris and G.membranacea respectively. The blue PBR was the least efficient light condition for biopigment production, whilst it improved lipid accumulation. Chlorophyll production in C.vulgaris was promoted by the green PBR, although it was less influenced by the light condition or culture density in G.membranacea cultures. Phycobiliproteins were the dominant pigments in G.membranacea and red light favoured synthesis of these pigments. Compared to C.vulgaris, the G.membranacea cells showed higher tolerance to 15% CO2 aeration by growing in this condition over a period of two weeks. At the 15% CO2 aeration condition G.membranacea accumulated the highest lipid content of 36.6% in the blue PBR. However, due to their lower carbon content and biomass productivity, G.membranacea was less efficient than C.vulgaris in sequestrating carbon dioxide. C.vulgaris sequestrated carbon dioxide up to 363 mg L-1 day-1 in the red PBR when aerated with 15% CO2. These results have significant implications for improved photobioreactor design for cultivation of microalgae under natural light. The proposed photobioreactor design can also tailor and improve the composition of lipids and photosynthetic compounds, using variation in light

“How to publish”: the Journal of Health Policy and Economics’ first seminar

On May 4th, 2021, the Journal of Health Policy and Economics (JOHPEC) held its first seminar, “How to Publish”, coordinated and chaired by Amir Mohsenpour, an Assistant Editor of the JOHPEC. This blog shares an overview of the seminar, which welcomed guest speakers Dr. Edgar Whitley (Department of Management), Lucy Lambe (LSE Library, Houghton Street Press), and Hannah Boroudjou (LSE Library), as well as 44 attendees who tuned in from around the world. With consent from all speakers and attendees, the seminar was recorded. The link and password to the full recording can be found in the blog. If you have suggestions for future events, please fill in this form: https://forms.office.com/r/nN87zubvi

Estimating the performance evaluation of international airports of Iran using kam in data envelopment analysis

Islamic Republic of Iran has 8 international airports. This paper reports the performance evaluation of these airports in the end of forth development plan of Iran in 2009 by applying Kourosh and Arash Model (KAM) in Data Envelopment Analysis (DEA). The area of airport, apron, terminal and runway are considered as inputs and the number of flights, the number of passengers and cargo are three selected outputs for each airport. Several scenarios are considered to rank and benchmark these airports without concerning about the number of airports. In other words, the scenarios are when inputs/outputs are controllable, when some of them are non-controllable and when the number of flights and passengers are restricted to the set of integer numbers and so on while the number of inputs and outputs are approximately the same as the number of airports. The results of these scenarios not only show the robustness of KAM to assess the performance evaluation of Decision Making Units (DMUs), but they also suggest the best international airports of Iran in 2009 as well as rank and benchmark them for each scenario

Effect of organic carbon enrichment on the treatment efficiency of primary settled wastewater by Chlorella vulgaris

This work evaluated the performance of a microalgae treatment process for settled municipal wastewater in a laboratory setting under static culturing conditions, as an alternative to traditional, energy intensive secondary and tertiary wastewater treatment systems. Primary tank settled wastewater (PSW) was first enriched with small quantities of glucose (&lt; 300 mg L− 1) as an organic carbon source to facilitate the bioremediation by the mixotrophic microalga Chlorella vulgaris. Characterisation of the wastewater revealed significant reductions in NH3-N (from 28.9 to 0.1 mg L− 1) and PO4-P, (from 3.2 to 0.1 mg L− 1) in just 2 days. Additionally, the exogenous glucose appeared completely removed from the wastewater after the first day. These achieved levels of treatment in respect of both the NH3-N and PO4-P were much higher than those recorded without C. vulgaris treatment with or without glucose enrichment. This would mean that the microalgae were chiefly responsible for removing the inorganic nitrogen and phosphorus, while the naturally occurring heterotrophic organisms had consumed the carbonaceous matter. The reliability of this process was evaluated across a further three independent batches of PSW with varying compositions of these inorganics and chemical oxygen demand using alternative organic (glycerol) and inorganic (CO2) carbon sources. The efficiency of the microalgae treatment process at reducing NH3-N and PO4-P was consistent in PSW enriched with organic carbon, resulting in &gt; 90% reduction of the inorganic compounds in each batch. The results demonstrate that microalgal culturing processes to treat PSW in bioreactors without aeration are a key area to develop as an alternative biological treatment option

Reação do perfil de óleo de Camelina sativa L. à aplicação foliar de nano-ferro e nano-zinco com esterco de curral

Climate change has intensified nutrient deficiencies in soils of semi-arid regions, largely due to low organic matter, high pH levels and harsh environmental conditions. This study investigates how the combined application of nanostructured iron and zinc micronutrients with farmyard manure influences the oil quality of Camelina sativa L. The experiment was based on three levels of farmyard manure application (0, 10 and 20 t ha-1) and foliar sprays of nanostructured micronutrients at 300 ppm (water, nanostructured zinc and nanostructured iron). The oil extracted from the camelina seeds was analyzed for its fatty acids profile. The principal component analysis showed that the first two components explained 66 and 22 % of the total variance, respectively. Among the treatments, the combination of 10 t ha-1 of farmyard manure with nanostructured zinc foliar application resulted in the most notable improvement in the oil quality, significantly enhancing the levels of linolenic, oleic, docosanoic and total saturated fatty acids. It also demonstrated the strongest ability to represent and discriminate traits. Applying higher levels of manure (20 t ha-1) led to a decrease in the linolenic acid content, suggesting that the excessive organic input may negatively affect the oil’s nutritional profile. However, the combination of 20 t ha-1 of manure with nanostructured iron yielded the highest content of docosahexaenoic acid. Nanostructured zinc showed to be more effective than nanostructured iron in improving the camelina oil quality. KEYWORDS: Fatty acid profile, nanostructured micronutrients, treatment-by-trait biplot.As mudanças climáticas intensificaram as deficiências de nutrientes nos solos de regiões semiáridas, em grande parte devido à baixa matéria orgânica, altos níveis de pH e condições ambientais adversas. Objetivou-se investigar como a aplicação combinada de micronutrientes nanoestruturados de ferro e zinco com esterco de curral influencia na qualidade do óleo de Camelina sativa L. Foram utilizados três níveis de aplicação de esterco de curral (0; 10; e 20 t ha-1) e pulverizações foliares de micronutrientes nanoestruturados a 300 ppm (água, zinco nanoestruturado e ferro nanoestruturado). O óleo extraído das sementes de camelina foi analisado quanto ao perfil de ácidos graxos. A análise de componentes principais mostrou que os dois primeiros componentes explicaram 66 e 22 % da variância total, respectivamente. Entre os tratamentos, a combinação de 10 t ha-1 de esterco de curral com a aplicação foliar de zinco nanoestruturado resultou na melhoria mais notável na qualidade do óleo, aumentando significativamente os níveis de ácido linolênico, oleico, docosanoico e ácidos graxos saturados totais. Também demonstrou a maior capacidade de representar e discriminar características. A aplicação de níveis mais altos de esterco (20 t ha-1) levou a uma diminuição no teor de ácido linolênico, sugerindo que o aporte orgânico excessivo pode afetar negativamente o perfil nutricional do óleo. No entanto, a combinação de 20 t ha-1 de esterco com ferro nanoestruturado produziu o maior teor de ácido docosahexaenoico. O zinco nanoestruturado mostrou-se mais eficaz do que o ferro nanoestruturado na melhoria da qualidade do óleo de camelina. PALAVRAS-CHAVE: Perfil de ácidos graxos, micronutrientes nanoestruturados, biplot de caractere por tratamento