263,102 research outputs found
An analysis of drivers of seawater temperature in Kuwait Bay, Arabian Gulf
No full textKuwait Bay presents a unique ecosystem and a significant nursery ground for many fish and shrimp species. In the last three decades, the bay has been under pressure from urbanization as well as from development from the entire region of the Arabian Gulf. Seawater temperature has an important impact on the marine environment. The aim of this study is to evaluate the drivers of seawater temperature in Kuwait Bay over the last two decades. Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat satellites images were used to describe the spatial and temporal distribution of sea surface temperature (SST) in the Arabian Gulf and Kuwait Bay. Hourly temperature measurements collected during the winter, 2007 and summer, 2008 were used to define the vertical temperature gradient in the water column, sea-bed and the intertidal flats of Kuwait Bay. Advanced Very High Resolution Radiometric (AVHRR) satellite data collected between 1985 and 2007 was also used to study the trends and drivers of increasing SST in Kuwait Bay over the last two decades.Satellite imaging showed that generally SST of Kuwait Bay is higher in the south than in the north. Highest SST was recorded near local human activities especially close to power and desalination plants due to thermal discharges. The field measurements showed that the water temperature is well-mixed in the bay. Seawater temperature reached 37 ºC in summer and dropped to 15.2 ºC in winter. Measurements beneath the sea-bed and within the intertidal flats showed that the temperature increased with depth in winter and decreased in summer. In winter, the sea-bed and intertidal flats are a source of heat to the water column, during summer the opposite is true. AVHRR data showed that the seawater temperature increased in Kuwait Bay by 0.62 (± 0.01)ºC/decade in the last two decades. This trend is three times greater than the global average. The defined trends were substantiated by routine in situ monthly measurements of SST made by the EPA in the bay, and were also similar in pattern and trend to air temperature recorded at Kuwait airport. Temperature trends have been affected by drivers, conveniently sub-divided into global (which contributes 37% of the change), regional (which contributes 50% of the change) and local (which contributes 13% of the change). SST measurements showed peaks in summer temperature coincident with El Niño events in 1998 and 2003. The measurements also showed a relatively-low summertime peak during 1991 in the aftermath of Iraqi invasion of Kuwait due to atmospheric dimming brought about by dense smoke that persisted in the region for most of that year. The long term trend also showed a drop in temperature after 2004 as a result of increasing dust storm frequency in the region. Air temperature was found to be the most dominant driver of seawater temperature in Kuwait Bay and operates at a regional scale. At the local scale the seawater temperature of Kuwait Bay is influenced by intertidal flat exposure time and the thermal discharge from power and desalination plants
Dissocladella chahtorshiana Rashidi & Schlagintweit
No full text<i>Dissocladella</i> ? <i>chahtorshiana</i> n. sp. <p>Figs. 5A–D pars, 6–8</p> <p> <b>Origin of the name:</b> The name refers to the type-locality Mount Chah Torsh, Central Iran (Figs. 1–3).</p> <p> <b>Holotype:</b> Oblique section shown in Figure 8C, thin-section CT 4.</p> <p> <b>Horizon and locality:</b> Selandian carbonates from Mount Chah Torsh, lithostratigraphically not defined (= no formation name assigned).</p> <p> <b>Description:</b> A medium-sized, well calcified Dasycladale with a cylindrical to slightly clavate thallus (Fig. 7A–B, Fig. 8D). The large main axis of roughly two third of diameter is bordered by a rather smooth surface except common widenings of the proximal part of the laterals, assumed of secondary origin (Fig. 6A, F) (compare Pl. 1, Fig. 3 in Radoičic et al., 2005). The primariy laterals are numerous and regularly alternating between consecutive verticils. In shallow tangential sections they are close-set and of round outline (Fig. 7A–B, lower part). In deep tangential sections they appear of triangular outline (with rounded edges) (Fig. 7B, middle part). The primaries are usually arranged perpendicular to the axis in cylindrical morphologies (Fig. 7B); in slightly claviform morphologies they are slightly inclined upwards (Fig. 8D). The shape of the primaries is variable: slightly widening outwards and without detectable secondaries (Fig. 6A–B) or with a distinct swelling (club-shaped morphology) and secondaries (Fig. 6E–F). Sometimes the swollen part of the primaries are almost touching (or do so) with neighbouring ones. The different morphologies might refer to different parts of the thallus (sterile? fertile?). In transverse or longitudinal sections, two secondaries distinctly shorter than the primaries and widening distally are detectable (Fig. 7C–D, E–G). The exact number of secondaries per primary however lateral is unknown. Often they appear as a united micritic diverging masse upon the distal surface of the primaries (Fig. 7C, E, G).</p> <p> <b>Comparisons:</b> From the Paleogene, the following species of <i>Dissocladella</i> have been described (data from Barattolo, 2002):</p> <p> <i>D. deserta</i> Elliott (Selandian-Ypresian): <i>D. deserta</i> from the Paleocene of Iraq, and lower Eocene of Egypt (Elliott, 1968) is a very small species (D = 0.39-0.47 mm), and about twelve primaries.</p> <p> <i>D. gracilis</i> Radoičić (Thanetian of Slovenia, Radoičić, 1991): as name already implies, it represents a very small alga (D: 0.16-0.290 mm, max. 0.368 mm) with four primaries.</p> <p> <i>D. longjangensis</i> Mu & Wang (Lutetian of China, Mu and Wang, 1985): medium-sized species (D up to 0.65 mm, see Kuss and Herbig, 1993, Paleogene of Egypt), and a main axis occupying about half the diameter (d/D 0.50-0.55).</p> <p> <i>D. lunata</i> Segonzac (Thanetian of France, Segonzac, 1979): small sized species (D: 0.282 -0.415 mm) with four to six primaries.</p> <p> <i>D. savitriae</i> Pia (Danian-Thanetian): large-sized and annulated representative of the genus (D: 1.5-2.0 mm) with more than 40 primaries per verticil (Rao and Pia, 1936).</p> <p> <i>D. turnsekae</i> Radoičić (Danian-Selandian of Slovenia, Radoičić, 1998): it represents a very small species (D = 0.24-0.35 mm) with about eight primaries aligned vertically between successive whorls.</p> <p> We may also note some resemblances of the lateral morphology with the poorly known <i>Jodotella volpensis</i> described by Segonzac (1976) with two sections from the Thanetian of France. The transverse section shown in plate 3, fig. 1, shows primaries that are widened proximally, displaying distinct swelling in the middle part, and two secondaries. This alga is distinctly smaller, displays a much lower d/D ratio (about 0.38), a reduced number of laterals (w = 16). <i>Jodotella</i> is different by its fertile ampullae set in clusters laterally to the primaries (Deloffre and Génot, 1982).</p> <p> <b>Dimensions (in mm):</b> The main biometric parameters are compiled in Table 1. The maximum observed length of a thallus fragment is about 17.5 mm (Fig. 5E).</p> <p> <b>Palaeoenvironment:</b> <i>Dissocladella</i> ? <i>chahtorshiana</i> occurs in bioclastic packstones with various dasycladalean algae (e.g., <i>Clypeina</i>, <i>Cymopolia</i>), among some rather large taxa such as <i>Rostroporella oviformis</i> Segonzac (Fig. 5D), halimedacean algae (Fig. 5A–B) gastropods, benthic foraminifera, and rare fragments of corals. The association generally points to an open marine, outer platform environment of moderate water energy. A similar association including <i>Rostroporella</i>, <i>Clypeina</i>, <i>Cymopolia</i> div. sp., has been reported by Deloffre and Radoičić (1978, p. 63) from the Paleocene of Slovenia and designated as "reefal environment".</p>Published as part of <i>SCHLAGINTWEIT, FELIX, RASHIDI, KOOROSH, YARAHMADZAHI, HAMED, HABIBIMOOD, SHARAM, AMIRSHAHKARMI, MAHNAZ, AHMADI, HOSSAIN & KHOKAN, HOSSAIN, 2019, Dissocladella? Chahtorshiana Rashidi & Schlagintweit N. Sp., A New Dasycladale (Green Algae) From The Paleocene Of Iran, pp. 3-13 in Acta Palaeontologica Romaniae 15 (2)</i> on pages 7-9, DOI: 10.35463/j.apr.2019.02.01, <a href="http://zenodo.org/record/10520652">http://zenodo.org/record/10520652</a>
Natural convection of Al2O3/ water nanofluid in a square cavity: effects of heterogeneous heating
No full textIn this paper, the natural convection in a square cavity filled with Al2O3/water nanofluid has been investigated.
The flow and heat transfer characteristics of the nanofluid in the cavity are documented when
bottom wall is under heterogeneous heating, the right wall is considered cold while the top and left walls
are adiabatic. Nine different cases are considered for the non-uniform heat flux where the total heat flux
applied to the cavity is the same for all the cases in magnitude but the profile is different. For different
values of Rayleigh numbers (103–106), nanoparticle volume fractions (0–9%), and aspect ratios, the optimal
profile of heat flux is determined in which Nusselt number is maximized. It is found that the trend of
Nusselt number is different for the nine cases at Ra = 103 where the conduction is the dominant phenomenon.
The results also reveal that for high values of Rayleigh number, i.e. 106, the Nusselt number is minimized
where the heat flux in the vicinity of adiabatic wall is smallest while the heat flux near the cold
wall is biggest
Comparison between present and Rashidi et al. [43] & Dogonchi and Ganji [44] results for −<i>f</i>″(0) and −<i>θ</i>′(0).
No full textComparison between present and Rashidi et al. [43] & Dogonchi and Ganji [44] results for −f″(0) and −θ′(0).</p
Sea surface temperature trends in the coastal ocean
No full textSea surface temperature (SST) trends in the coastal zone are shown to be increasing at rates that exceed the global trends by up to an order of magnitude. This paper compiles some of the evidence of the trends published in the literature. The evidence suggests that urbanization in the coastal hinterland is having a direct effect on SST through increased temperatures of river and lake waters, as well as through heated run-off and thermal effluent discharges from coastal infrastructure. These local drivers of SST are compounded by regional drivers manifest as changing weather patterns (latent heat exchange) and direct radiative heating of shallow coastal waters (particularly in restricted embayments and seas). Thus the impact of urbanization on SST may extend well beyond the much-popularised impact of “greenhouse gasses”. The Marine Climate Change Impacts Partnership Report [37] stated that our capacity to define and predict long-term coastal changes due to anthropogenic causes is “unknown” and confidence in results is “low”. This is a major barrier to planning for inevitable changes in coastal climate that are likely to take place over the coming decades
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Geometry effects on fracture trajectory of PMMA samples under pure mode-I loading
No full textMode-I fracture strength and crack growth trajectory of polymethylmethacrylate (PMMA) samples have been investigated experimentally and theoretically for five different cracked specimens. Although all the specimens have been tested under pure mode I loading conditions, the crack growth paths and the values of apparent fracture toughness have been found to be significantly different. The crack trajectory and the fracture strength can be estimated theoretically by using a modified form of the strain energy density criterion. The observed differences in the crack trajectory and the fracture strength of different specimens have been found to be related to the magnitude and sign of the T-stress. © 2016 Elsevier Lt
Elision of /h, ?/ in the Shirazi Dialect of Persian (SHDP): An Optimality Theory Based Analysis
No full textMnogi su se znanstvenici do danas bavili proučavanjem lenicije (oslabljivanja) kao jednog od najučestalijih fonoloških procesa. Elizija (ispuštanje) grkljanika (grkljanskog frikativa /h/ i grkljanskog prekidnika /?/) jedna je od najčešćih fonoloških alternacija u perzijskom Shirazi dijalektu (SHDP) koja je do danas, koliko je znanstvenicima poznato, neistražena. U radu se nastoje opisati činjenice o toj čestoj fonološkoj alternaciji u spomentom perzijskom regionalnom dijalektu te se naglašavaju osnovne razlike u nastupanju tih procesa u Shirazi dijalektu i standardnom perzijskom jeziku (SP). Analiza je rađena prema okviru optimalne teorije (Optimality theory) (McCarthy and Prince 1995., 2001.) prema kojoj su jezični oblici rezultat međudjelovanja prekršivih općih ograničenja. Istraživanjem se pokazalo da su spomenuti procesi brisanja suglasnika u Shirazi dijalektu ograničeni položajem u slogu te su uvjetovani položajem u kodi, između dvaju vokala ili u suglasničkom skupu. Uglavnom se ne ostvaruju u pristupu, iako postoje primjeri u kojima je gubljenje dopušteno i u pristupu naglašenog sloga. Stoga ovo istraživanje Shirazi dijalekt svrstava među jezike koji dopuštaju oslabljivanje u pristupu naglašenog sloga. Spomenuti procesi ispuštanja ne događaju se na početku riječi, a nakon ispuštanja grkljanika uvijek slijedi kompenzacijsko produljivanje (Compensatory lengthening – CL), čak i nakon ispuštanja u pristupu naglašenog sloga.Until recently, many researchers have shown interest in studying lenitions, which are examples of the most common universal types of phonological processes. Elision of laryngeals (glottal fricative /h/ and glottal stop /?/) is one of the most common phonological alternations exhibited in the Shirazi dialect of Persian (SHDP) which to the knowledge of the researchers, has not been studied to date. This paper seeks to provide a description of the facts about this common phonological alternation in the addressed regional dialect of Persian and points out some main differences between the behavior of these processes in SHDP and Standard Persian (SP). The analysis is cast in an Optimal Theoretic (OT) framework (McCarthy and Prince 1995, 2001), which holds that linguistic forms are the outcome of interaction among violable universal constraints. The present study shows that the addressed processes of consonant deletion in SHDP are restricted by syllabic position and are conditioned by coda position, intervocalic position or consonant clusters. They are usually blocked in the onset, but there are cases where reduction is allowed in the onset of the stressed syllable. Thus, the study adds SHDP to the list of languages which permit lenition in the onset of the stressed syllable. The addressed processes of elision are always blocked in word-initial position and laryngeal elision is always followed by Compensatory lengthening (CL), even after deletion from the onset of the stressed syllable
Nanostructured mixed transition metal oxides for high performance asymmetric supercapacitors: Facile synthetic strategy
No full textAbstract not availableSanaz Tajik, Deepak P. Dubal, Pedro Gomez-Romero, Amir Yadegari, Alimorad Rashidi, Bahram Nasernejad, Inamuddin, Abdullah M. Asir
Meta-analysis of association between c.963A<i>></i>G single-nucleotide polymorphism on <i>BMP15</i> gene and litter size in goats
No full textAbstract. Litter size is an important economic trait in the goat industry. Previous
studies on the bone morphogenetic protein 15 (BMP15) gene detected some single-nucleotide polymorphisms (SNPs) such as c.963A>G that
were associated with an increase in ovulation rate and litter size. The aim
of this study was to conduct a meta-analysis on the effect of this
polymorphism on litter size. We gathered and pooled data from five eligible
published studies. To investigate the effect of c.963A>G on
litter size, we utilized four different genetic models assuming dominant
(GG + GA vs. AA), recessive (GG vs. GA + AA), additive (GG vs. AA) and
co-dominant (GG + AA vs. GA) model of inheritance. Data were analyzed under
random-effects models based on the I2 value. Furthermore, sensitivity
analysis was carried out to validate the stability of results. The results
showed that the c.963A>G polymorphism is associated with litter
size when applying a dominant model (standardized mean difference (SMD) is 0.815, 95 % CI [0.170,
1.461], P value = 0.013) and also with an additive model (SMD = 0.755, 95 % CI [0.111, 1.400], P value = 0.022). However, the effect of c.963A>G
polymorphism was not significant under recessive (SMD = 0.186, 95 % CI [−0.195, 4.259], P value = 0.339) and co-dominant (SMD = −0.119, 95 % CI [−0.525, 0.288], P value = 0.568) models. Sensitivity analysis demonstrated
that dropping studies with wide confidence intervals affects overall results
under the assumption of an additive model. The meta-analysis results revealed
that the AA genotype could be positively connected with litter size in goats.
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